Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation

NASA Astrophysics Data System (ADS)

Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

2016-02-01

We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice ( Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m-2 day-1) and elevated UV-B radiation (E, a 20 % higher dose of UV-B than the reference, 14.4 kJ m-2 day-1), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha-1), Si1 (sodium silicate, 100 kg SiO2 ha-1), Si2 (sodium silicate, 200 kg SiO2 ha-1), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha-1). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate ( Pn), intercellular carbon dioxide (CO2) concentration ( Ci), transpiration rate ( Tr), stomatal conductivity ( Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3 %, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9 %, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2 %, respectively, but decreased Tr by 1.9-10.8 %, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the application of slag silicon fertilizer mitigates the negative effects of elevated UV-B radiation on photosynthesis and transpiration in rice.

Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation.

PubMed

Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

2016-02-01

We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice (Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m(-2) day(-1)) and elevated UV-B radiation (E, a 20% higher dose of UV-B than the reference, 14.4 kJ m(-2) day(-1)), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha(-1)), Si1 (sodium silicate, 100 kg SiO2 ha(-1)), Si2 (sodium silicate, 200 kg SiO2 ha(-1)), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha(-1)). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate (Pn), intercellular carbon dioxide (CO2) concentration (Ci), transpiration rate (Tr), stomatal conductivity (Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3%, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9%, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2%, respectively, but decreased Tr by 1.9-10.8%, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the application of slag silicon fertilizer mitigates the negative effects of elevated UV-B radiation on photosynthesis and transpiration in rice.

Influence of UV radiation on chlorophyll, and antioxidant enzymes of wetland plants in different types of constructed wetland.

PubMed

Xu, Defu; Wu, Yinjuan; Li, Yingxue; Howard, Alan; Jiang, Xiaodong; Guan, Yidong; Gao, Yongxia

2014-09-01

A surface- and vertical subsurface-flow-constructed wetland were designed to study the response of chlorophyll and antioxidant enzymes to elevated UV radiation in three types of wetland plants (Canna indica, Phragmites austrail, and Typha augustifolia). Results showed that (1) chlorophyll content of C. indica, P. austrail, and T. augustifolia in the constructed wetland was significantly lower where UV radiation was increased by 10 and 20 % above ambient solar level than in treatment with ambient solar UV radiation (p < 0.05). (2) The malondialdehyde (MDA) content, guaiacol peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities of wetland plants increased with elevated UV radiation intensity. (3) The increased rate of MDA, SOD, POD, and CAT activities of C. indica, P. australis, and T. angustifolia by elevated UV radiation of 10 % was higher in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland. The sensitivity of MDA, SOD, POD, and CAT activities of C. indica, P. austrail, and T. augustifolia to the elevated UV radiation was lower in surface-flow-constructed wetland than in the vertical subsurface-flow-constructed wetland, which was related to a reduction in UV radiation intensity through the dissolved organic carbon and suspended matter in the water. C. indica had the highest SOD and POD activities, which implied it is more sensitive to enhanced UV radiation. Therefore, different wetland plants had different antioxidant enzymes by elevated UV radiation, which were more sensitive in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland.

Ionizing radiation from Chernobyl affects development of wild carrot plants.

PubMed

Boratyński, Zbyszek; Arias, Javi Miranda; Garcia, Cristina; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P; Pajares, Antonio Jesús Muñoz; Piwczyński, Marcin; Tukalenko, Eugene

2016-12-16

Radioactivity released from disasters like Chernobyl and Fukushima is a global hazard and a threat to exposed biota. To minimize the deleterious effects of stressors organisms adopt various strategies. Plants, for example, may delay germination or stay dormant during stressful periods. However, an intense stress may halt germination or heavily affect various developmental stages and select for life history changes. Here, we test for the consequence of exposure to ionizing radiation on plant development. We conducted a common garden experiment in an uncontaminated greenhouse using 660 seeds originating from 33 wild carrots (Daucus carota) collected near the Chernobyl nuclear power plant. These maternal plants had been exposed to radiation levels that varied by three orders of magnitude. We found strong negative effects of elevated radiation on the timing and rates of seed germination. In addition, later stages of development and the timing of emergence of consecutive leaves were delayed by exposure to radiation. We hypothesize that low quality of resources stored in seeds, damaged DNA, or both, delayed development and halted germination of seeds from plants exposed to elevated levels of ionizing radiation. We propose that high levels of spatial heterogeneity in background radiation may hamper adaptive life history responses.

Ionizing radiation from Chernobyl affects development of wild carrot plants

NASA Astrophysics Data System (ADS)

Boratyński, Zbyszek; Arias, Javi Miranda; Garcia, Cristina; Mappes, Tapio; Mousseau, Timothy A.; Møller, Anders P.; Pajares, Antonio Jesús Muñoz; Piwczyński, Marcin; Tukalenko, Eugene

2016-12-01

Radioactivity released from disasters like Chernobyl and Fukushima is a global hazard and a threat to exposed biota. To minimize the deleterious effects of stressors organisms adopt various strategies. Plants, for example, may delay germination or stay dormant during stressful periods. However, an intense stress may halt germination or heavily affect various developmental stages and select for life history changes. Here, we test for the consequence of exposure to ionizing radiation on plant development. We conducted a common garden experiment in an uncontaminated greenhouse using 660 seeds originating from 33 wild carrots (Daucus carota) collected near the Chernobyl nuclear power plant. These maternal plants had been exposed to radiation levels that varied by three orders of magnitude. We found strong negative effects of elevated radiation on the timing and rates of seed germination. In addition, later stages of development and the timing of emergence of consecutive leaves were delayed by exposure to radiation. We hypothesize that low quality of resources stored in seeds, damaged DNA, or both, delayed development and halted germination of seeds from plants exposed to elevated levels of ionizing radiation. We propose that high levels of spatial heterogeneity in background radiation may hamper adaptive life history responses.

Lightning electromagnetics

NASA Technical Reports Server (NTRS)

Wahid, Parveen

1995-01-01

This project involved the determination of the effective radiated power of lightning sources and the polarization of the radiating source. This requires the computation of the antenna patterns at all the LDAR site receiving antennas. The known radiation patterns and RF signal levels measured at the antennas will be used to determine the effective radiated power of the lightning source. The azimuth and elevation patterns of the antennas in the LDAR system were computed using flight test data that was gathered specifically for this purpose. The results presented in this report deal with the azimuth patterns for all the antennas and the elevation patterns for three of the seven sites.

Radiation measurements over a snowfield at an elevated site

NASA Technical Reports Server (NTRS)

Korff, H. C.; Gailiun, J. J.; Vonderhaar, T. H.

1974-01-01

The components of short wave radiation were measured over a snowfield in a valley of the Rocky Mountains at a height of 2700 m above sea level. Global and reflected radiation were obtained by a set of Eppley pyranometers. In addition, the direct solar radiation and the turbidity of the atmosphere were derived from pyrheliometric data on cloud-free days. Emphasis was given to the reflectance of the snowfield in relation to the position of the sun, especially at low elevation angles. These reflectance values were measured for cloudless as well as for cloudy days and compared with already published values for arctic and antarctic conditions.

Background radiation in the Albuquerque, New Mexico, U.S.A., area

NASA Astrophysics Data System (ADS)

Brookins, Douglas G.

1992-01-01

Background radiation levels in the Albuquerque, New Mexico, area are elevated when compared to much of the United States. Soil K, U, and Th are somewhat elevated compared to average values in this country and generate roughly 60 mrem per year to the average resident. Cosmic ray contribution, due to the mean elevation of 5,200 ft above sea level, is 80 mrem/yr—well over the average for the United States. Thirty percent of the homes in Albuquerque contain indoor radon levels over the EPA action level of 4 pCi/ℓ compared to 10 12 percent of homes for the entire United States. Indoor radon contributes about 100 300 mrem/yr. Food, beverages, and x-ray doses are assumed at an average-equivalent for the United States and locally yield 96 mrem/yr. Total contributions from other minor sources (color TV, coal, weapons fallout, etc.) are under 10 mrem/yr. Thus total background radiation received by Albuquerque residents is about 330 530 mrem/yr, well in excess of the rest of the United States. The spread in mrem values is due to variations in the contribution from indoor radon.

Combined effects of gamma radiation doses and sodium nitrite content on the lipid oxidation and color of mortadella.

PubMed

Dutra, Monalisa Pereira; Cardoso, Giselle Pereira; Fontes, Paulo Rogério; Silva, Douglas Roberto Guimarães; Pereira, Marcio Tadeu; Ramos, Alcinéia de Lemos Souza; Ramos, Eduardo Mendes

2017-12-15

The effects of different doses of gamma radiation (0-20kGy) on the color and lipid oxidation of mortadella prepared with increasing nitrite levels (0-300ppm) were evaluated using a central composite rotatable design. Higher radiation doses increased the redox potential, promoted the lipid oxidation and elevating the hue color of the mortadellas. Nevertheless, higher addition of sodium nitrite elevated the residual nitrite content, reduced the lipid oxidation and promoted the increase of redness and the reduce of hue color of the mortadellas, regardless of the radiation dose applied. Nitrite addition had a greater effect than irradiation on the quality parameters evaluated, and even at low levels (∼75ppm), its use decreased the deleterious effects of irradiation at doses as high as 20kGy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic Materials Suitable for Fission Power Conversion in Space Missions

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.

2012-01-01

Terrestrial fission reactors use combinations of shielding and distance to protect power conversion components from elevated temperature and radiation. Space mission systems are necessarily compact and must minimize shielding and distance to enhance system level efficiencies. Technology development efforts to support fission power generation scenarios for future space missions include studying the radiation tolerance of component materials. The fundamental principles of material magnetism are reviewed and used to interpret existing material radiation effects data for expected fission power conversion components for target space missions. Suitable materials for the Fission Power System (FPS) Project are available and guidelines are presented for bounding the elevated temperature/radiation tolerance envelope for candidate magnetic materials.

The influence of aminotransferase levels on liver stiffness assessed by Acoustic Radiation Force Impulse Elastography: a retrospective multicentre study.

PubMed

Bota, Simona; Sporea, Ioan; Peck-Radosavljevic, Markus; Sirli, Roxana; Tanaka, Hironori; Iijima, Hiroko; Saito, Hidetsugu; Ebinuma, Hirotoshi; Lupsor, Monica; Badea, Radu; Fierbinteanu-Braticevici, Carmen; Petrisor, Ana; Friedrich-Rust, Mireen; Sarrazin, Christoph; Takahashi, Hirokazu; Ono, Naofumi; Piscaglia, Fabio; Marinelli, Sara; D'Onofrio, Mirko; Gallotti, Anna; Salzl, Petra; Popescu, Alina; Danila, Mirela

2013-09-01

Acoustic Radiation Force Impulse Elastography is a new method for non-invasive evaluation of liver fibrosis. To evaluate the impact of elevated alanine aminotransferase levels on liver stiffness assessment by Acoustic Radiation Force Impulse Elastography. A multicentre retrospective study including 1242 patients with chronic liver disease, who underwent liver biopsy and Acoustic Radiation Force Impulse. Transient Elastography was also performed in 512 patients. The best Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis was 1.29 m/s in cases with normal alanine aminotransferase levels and 1.44 m/s in patients with alanine aminotransferase levels>5 × the upper limit of normal. The best cut-off for predicting liver cirrhosis were 1.59 and 1.75 m/s, respectively. Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis and cirrhosis were relatively similar in patients with normal alanine aminotransferase and in those with alanine aminotransferase levels between 1.1 and 5 × the upper limit of normal: 1.29 m/s vs. 1.36 m/s and 1.59 m/s vs. 1.57 m/s, respectively. For predicting cirrhosis, the Transient Elastography cut-offs were significantly higher in patients with alanine aminotransferase levels between 1.1 and 5 × the upper limit of normal compared to those with normal alanine aminotransferase: 12.3 kPa vs. 9.1 kPa. Liver stiffness values assessed by Acoustic Radiation Force Impulse and Transient Elastography are influenced by high aminotransferase levels. Transient Elastography was also influenced by moderately elevated aminotransferase levels. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Radiation-induced cyclooxygenase 2 up-regulation is dependent on redox status in prostate cancer cells.

PubMed

Li, Lingyun; Steinauer, Kirsten K; Dirks, Amie J; Husbeck, Bryan; Gibbs, Iris; Knox, Susan J

2003-12-01

Cyclooxygenase 2 (COX2) is the inducible isozyme of COX, a key enzyme in arachidonate metabolism and the conversion of arachidonic acid (AA) to prostaglandins (PGs) and other eicosanoids. Previous studies have demonstrated that the COX2 protein is up-regulated in prostate cancer cells after irradiation and that this results in elevated levels of PGE(2). In the present study, we further investigated whether radiation-induced COX2 up-regulation is dependent on the redox status of cells from the prostate cancer cell line PC-3. l-Buthionine sulfoximine (BSO), which inhibits gamma glutamyl cysteine synthetase (gammaGCS), and the antioxidants alpha-lipoic acid and N-acetyl-l-cysteine (NAC) were used to modulate the cellular redox status. BSO decreased the cellular GSH level and increased cellular reactive oxygen species (ROS) in PC-3 cells, whereas alpha-lipoic acid and NAC increased the GSH level and decreased cellular ROS. Both radiation and the oxidant H(2)O(2) had similar effects on COX2 up-regulation and PGE(2) production in PC-3 cells, suggesting that radiation-induced COX2 up-regulation is secondary to the production of ROS. The relative increases in COX2 expression and PGE(2) production induced by radiation and H(2)O(2) were even greater when PC-3 cells were pretreated with BSO. When the cells were pretreated with alpha-lipoic acid or NAC for 24 h, both radiation- and H(2)O(2)-induced COX2 up-regulation and PGE(2) production were markedly inhibited. These results demonstrate that radiation-induced COX2 up-regulation in prostate cancer cells is modulated by the cellular redox status. Radiation-induced increases in ROS levels contribute to the adaptive response of PC-3 cells, resulting in elevated levels of COX2.

Effects of lanthanum(III) on nitrogen metabolism of soybean seedlings under elevated UV-B radiation.

PubMed

Cao, Rui; Huang, Xiao-hua; Zhou, Qing; Cheng, Xiao-ying

2007-01-01

The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m2 and high level 0.45 W/m2 significantly affected the whole nitrogen metabolism in soybean seedlings (p < 0.05). It restricted uptake and transport of NO3(-), inhibited activity of some key nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.

Will Global Change Effect Primary Productivity in Coastal Ecosystems?

NASA Technical Reports Server (NTRS)

Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

1997-01-01

Algae are the base of coastal food webs because they provide the source of organic carbon for the remaining members of the community. Thus, the rate that they produce organic carbon to a large extent controls the productivity of the entire ecosystem. Factors that control algal productivity range from the physical (e.g., temperature, light), chemical (e.g., nutrient levels) to the biological (e.g., grazing). Currently, levels of atmospheric carbon dioxide surficial fluxes of ultraviolet radiation are rising. Both of these environmental variables can have a profound effect on algal productivity. Atmospheric carbon dioxide may increase surficial levels of dissolved inorganic carbon. Our laboratory and field studies of algal mats and phytoplankton cultures under ambient and elevated levels of pCO2 show that elevated levels of inorganic carbon can cause an increase in photosynthetic rates. In some cases, this increase will cause an increase in phytoplankton numbers. There may be an increase in the excretion of fixed carbon, which in turn may enhance bacterial productivity. Alternatively, in analogy with studies on the effect of elevated pCO2 on plants, the phytoplankton could change their carbon to nitrogen ratios, which will effect the feeding of the planktonic grazers. The seasonal depletion of stratospheric ozone has resulted in elevated fluxes of UVB radiation superimposed on the normal seasonal variation. Present surface UV fluxes have a significant impact on phytoplankton physiology, including the inhibition of the light and dark reactions of photosynthesis, inhibition of nitrogenase activity, inhibition of heterocyst formation, reduction in motility, increased synthesis of the UV-screening pigment scytonemin, and mutation. After reviewing these issues, recent work in our lab on measuring the effect of UV radiation on phytoplankton in the San Francisco Bay Estuary will be presented.

60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges.

PubMed

Chang, W P; Chan, C C; Wang, J D

1997-09-01

Since late 1992, more than 100 building complexes containing public and private schools and nearly 1,000 apartments have been identified in Taiwan with elevated levels of gamma-radiation from construction steel contaminated with 60Co. Due to improper handling of 60Co contaminated scrap steel in late 1982 and 1983, contaminated construction materials have been widely distributed throughout the country. These contaminated construction materials have generated elevated radiation exposures to members of the public in Taiwan. As of early 1996, more than 4,000 people, including young students, have been identified as receiving more than 1 mSv y(-1) above the local background for up to 12 y. This report provides a detailed discussion of the sources of the 60Co contamination in construction steel, its discovery in the building complexes, and preliminary evaluation and remediation activities.

Opposite Roles for p38MAPK-Driven Responses and Reactive Oxygen Species in the Persistence and Resolution of Radiation-Induced Genomic Instability

PubMed Central

Werner, Erica; Wang, Huichen; Doetsch, Paul W.

2014-01-01

We report the functional and temporal relationship between cellular phenotypes such as oxidative stress, p38MAPK-dependent responses and genomic instability persisting in the progeny of cells exposed to sparsely ionizing low-Linear Energy Transfer (LET) radiation such as X-rays or high-charge and high-energy (HZE) particle high-LET radiation such as 56Fe ions. We found that exposure to low and high-LET radiation increased reactive oxygen species (ROS) levels as a threshold-like response induced independently of radiation quality and dose. This response was sustained for two weeks, which is the period of time when genomic instability is evidenced by increased micronucleus formation frequency and DNA damage associated foci. Indicators for another persisting response sharing phenotypes with stress-induced senescence, including beta galactosidase induction, increased nuclear size, p38MAPK activation and IL-8 production, were induced in the absence of cell proliferation arrest during the first, but not the second week following exposure to high-LET radiation. This response was driven by a p38MAPK-dependent mechanism and was affected by radiation quality and dose. This stress response and elevation of ROS affected genomic instability by distinct pathways. Through interference with p38MAPK activity, we show that radiation-induced stress phenotypes promote genomic instability. In contrast, exposure to physiologically relevant doses of hydrogen peroxide or increasing endogenous ROS levels with a catalase inhibitor reduced the level of genomic instability. Our results implicate persistently elevated ROS following exposure to radiation as a factor contributing to genome stabilization. PMID:25271419

Elevated blood lead levels from exposure via a radiator workshop.

PubMed

Treble, R G; Thompson, T S; Morton, D N

1998-04-01

Elevated lead levels were discovered in blood samples collected from family members where both the father and the mother worked in a radiator repair workshop. The father and mother were found to have blood lead levels of 2.0 and 0.5 mumol/L (41.7 and 10.4 micrograms/dL), respectively. The father's blood lead level was just below the Canadian occupational health and safety intervention level (2.5 mumol/L or 52.1 micrograms/dL). The two children had blood lead levels of 1.0 and 0.8 mumol/L (20.8 and 16.7 micrograms/dL), both of which are in excess of the recommended guideline for intervention in the case of children (0.5 mumol/L or 10.4 micrograms/dL). The exposure of the two children was possibly due to a combination of pathways including exposure at the workshop itself during visits and also the transportation of lead-containing dust to the home environment.

Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact.

PubMed

Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

2015-10-01

The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14-19% and the ambient radiation by 9-16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems.

Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact

PubMed Central

Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

2015-01-01

The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14–19% and the ambient radiation by 9–16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems. PMID:26423726

Insolation-sunshine relation with site elevation and latitude

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raja, I.A.

1994-07-01

Data from six meteorological stations dispersed widely over Pakistan have been used to produce a correlation between the monthly means of easily measured sunshine duration and the less frequently recorded global solar radiation, taking into account the site elevation above sea level and the latitude. The relation is shown to be valuable for other regions too.

Protective role of Vernonia cinerea L. against gamma radiation--induced immunosupression and oxidative stress in mice.

PubMed

Pratheeshkumar, P; Kuttan, Girija

2011-08-01

The radioprotective effect of Vernonia cinerea extract was studied in balb/c mice. Whole-body irradiation of γ-rays (6 Gy) given to animals reduced the white blood cell count, bone marrow cellularity and α-esterase positive cells in control animals, which were elevated by the administration of V. cinerea extract (20 mg/kg body weight [b.wt.], intraperitoneally [i.p.]). The elevated levels of serum enzymes alkaline phosphatase (ALP), glutamate pyruvate transferases (GPT) and lipid peroxidation (LPO) after irradiation were also reduced with V. cineria extract administration. V. cinerea treatment also significantly enhanced the animal's antioxidant status by enhancing the activities superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH) level in irradiated animals. Histopathological analysis of liver and small intestine also suggests that V. cinerea could reduce the tissue damages induced by radiation. The level of pro-inflammatory cytokines such as interleukin 1β (IL-1β), tumour necrosis factor α (TNF-α) and C-reactive protein (CRP) elevated after irradiation, which were significantly reduced by V. cinerea extract administration. On the other hand, the extract stimulated the production of other cytokines such as granulocyte monocyte-colony stimulating factor (GM-CSF) and interferon-γ (IFN-γ) in animals exposed to radiation. Agarose gel electrophoresis of DNA isolated from bone marrow of control animals showed heavy DNA damage, but a reduced DNA damage was seen in animals treated with V. cinerea extract. Administration of V. cinerea did not compromise the anti-neoplastic efficiency of radiation. In fact, there was a synergistic action of radiation and V. cinerea in reducing the solid tumours in mice. Methanolic extract of V. cinerea given i.p. showed a significant radioprotective activity without compromising the radiotherapeutic efficacy of radiation, indicating its possible use as an adjuvant during radiotherapy.

Radiation dose to the global flying population.

PubMed

Alvarez, Luis E; Eastham, Sebastian D; Barrett, Steven R H

2016-03-01

Civil airliner passengers and crew are exposed to elevated levels of radiation relative to being at sea level. Previous studies have assessed the radiation dose received in particular cases or for cohort studies. Here we present the first estimate of the total radiation dose received by the worldwide civilian flying population. We simulated flights globally from 2000 to 2013 using schedule data, applying a radiation propagation code to estimate the dose associated with each flight. Passengers flying in Europe and North America exceed the International Commission on Radiological Protection annual dose limits at an annual average of 510 or 420 flight hours per year, respectively. However, this falls to 160 or 120 h on specific routes under maximum exposure conditions.

Radiation from wireless technology elevates blood glucose and body temperature in 40-year-old type 1 diabetic male.

PubMed

Kleiber, Catherine E

2017-01-01

A type 1 diabetic male reports multiple instances when his blood glucose was dramatically elevated by the presence of microwave radiation from wireless technology and plummeted when the radiation exposure ended. In one instance, his body temperature elevated in addition to his blood glucose. Both remained elevated for nearly 48 h after exposure with the effect gradually decreasing. Possible mechanisms for microwave radiation elevating blood glucose include effects on glucose transport proteins and ion channels, insulin conformational changes and oxidative stress. Temperature elevation may be caused by microwave radiation-triggered Ca 2+ efflux, a mechanism similar to malignant hyperthermia. The potential for radiation from wireless technology to cause serious biological effects has important implications and necessitates a reevaluation of its near-ubiquitous presence, especially in hospitals and medical facilities.

Estimated Radiation on Mars, Hits per Cell Nucleus

NASA Technical Reports Server (NTRS)

2002-01-01

This global map of Mars shows estimates for amounts of high-energy-particle cosmic radiation reaching the surface, a serious health concern for any future human exploration of the planet.

The estimates are based on cosmic-radiation measurements made on the way to Mars by the Mars radiation environment experiment, an instrument on NASA's 2001 Mars Odyssey spacecraft, plus information about Mars' surface elevations from the laser altimeter instrument on NASA's Mars Global Surveyor. The areas of Mars expected to have least radiation are where elevation is lowest, because those areas have more atmosphere above them to block out some of the radiation. Earth's thick atmosphere shields us from most cosmic radiation, but Mars has a much thinner atmosphere than Earth does.

Colors in the map refer to the estimated average number of times per year each cell nucleus in a human there would be hit by a high-energy cosmic ray particle. The range is generally from two hits (color-coded green), a moderate risk level, to eight hits (coded red), a high risk level.

NASA's Jet Propulsion Laboratory, Pasadena, Calif. manages the 2001 Mars Odyssey and Mars Global Surveyor missions for NASA's Office of Space Science, Washington D.C. The Mars radiation environment experiment was developed by NASA's Johnson Space Center. Lockheed Martin Astronautics, Denver, is the prime contractor for Odyssey, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Lead exposure in radiator repair workers: a survey of Washington State radiator repair shops and review of occupational lead exposure registry data.

PubMed

Whittaker, Stephen G

2003-07-01

Radiator repair workers in Washington State have the greatest number of very elevated (> or =60 microg/dL) blood lead levels of any other worker population. The goals of this study were to determine the number of radiator repair workers potentially exposed to lead; estimate the extent of blood lead data underreporting to the Occupational Lead Exposure Registry; describe current safety and health practices in radiator repair shops; and determine appropriate intervention strategies to reduce exposure and increase employer and worker awareness. Lead exposure in Washington State's radiator repair workers was assessed by reviewing Registry data and conducting a statewide survey of radiator repair businesses. This study revealed that a total of 226 workers in Washington State (including owner-operators and all employees) conduct repair activities that could potentially result in excessive exposures to lead. Approximately 26% of radiator repair workers with elevated blood lead levels (> or =25 microg/dL) were determined to report to Washington State's Registry. This study also revealed a lack of awareness of lead's health effects, appropriate industrial hygiene controls, and the requirements of the Lead Standard. Survey respondents requested information on a variety of workplace health and safety issues and waste management; 80% requested a confidential, free-of-charge consultation. Combining data derived from an occupational health surveillance system and a statewide mail survey proved effective at characterizing lead exposures and directing public health intervention in Washington State.

Interactive effects of elevated ozone and UV-B radiation on soil nematode diversity.

PubMed

Bao, Xuelian; Li, Qi; Hua, Jianfeng; Zhao, Tianhong; Liang, Wenju

2014-01-01

Ultraviolet-B (UV-B) radiation and elevated tropospheric ozone may cause reductions in the productivity and quality of important agricultural crops. However, research regarding their interactive effect is still scarce, especially on the belowground processes. Using the open top chambers experimental setup, we monitored the response of soil nematodes to the elevated O3 and UV-B radiation individually as well as in combination. Our results indicated that elevated O3 and UV-B radiation have impact not only on the belowground biomass of plants, but also on the community structure and functional diversity of soil nematodes. The canonical correspondence analysis suggested that soil pH, shoot biomass and microbial biomass C and N were relevant parameters that influencing soil nematode distribution. The interactive effects of elevated O3 and UV-B radiation was only observed on the abundance of bacterivores. UV-B radiation significantly increased the abundance of total nematodes and bacterivores in comparison with the control at pod-filling stage of soybean. Following elevated O3, nematode diversity index decreased and dominance index increased relative to the control at pod-filling stage of soybean. Nematode functional diversity showed response to the effects of elevated O3 and UV-B radiation at pod-bearing stage. Higher enrichment index and lower structure index in the treatment with both elevated O3 and UV-B radiation indicated a stressed soil condition and degraded soil food web. However, the ratios of nematode trophic groups suggested that the negative effects of elevated O3 on soil food web may be weakened by the UV-B radiations.

Solar UV irradiances modulate effects of ocean acidification on the coccolithophorid Emiliania huxleyi.

PubMed

Xu, Kai; Gao, Kunshan

2015-01-01

Emiliania huxleyi, the most abundant coccolithophorid in the oceans, is naturally exposed to solar UV radiation (UVR, 280-400 nm) in addition to photosynthetically active radiation (PAR). We investigated the physiological responses of E. huxleyi to the present day and elevated CO2 (390 vs 1000 μatm; with pH(NBS) 8.20 vs 7.86) under indoor constant PAR and fluctuating solar radiation with or without UVR. Enrichment of CO2 stimulated the production rate of particulate organic carbon (POC) under constant PAR, but led to unchanged POC production under incident fluctuating solar radiation. The production rates of particulate inorganic carbon (PIC) as well as PIC/POC ratios were reduced under the elevated CO2, ocean acidification (OA) condition, regardless of PAR levels, and the presence of UVR. However, moderate levels of UVR increased PIC production rates and PIC/POC ratios. OA treatment interacted with UVR to influence the alga's physiological performance, leading to reduced specific growth rate in the presence of UVA (315-400 nm) and decreased quantum yield, along with enhanced nonphotochemical quenching, with addition of UVB (280-315 nm). The results clearly indicate that UV radiation needs to be invoked as a key stressor when considering the impacts of ocean acidification on E. huxleyi. © 2014 The American Society of Photobiology.

Toric focusing for radiation force applications using a toric lens coupled to a spherically focused transducer.

PubMed

Arnal, Bastien; Nguyen, Thu-Mai; O'Donnell, Matthew

2014-12-01

Dynamic elastography using radiation force requires that an ultrasound field be focused during hundreds of microseconds at a pressure of several megapascals. Here, we address the importance of the focal geometry. Although there is usually no control of the elevational focal width in generating a tissue mechanical response, we propose a tunable approach to adapt the focus geometry that can significantly improve radiation force efficiency. Several thin, in-house-made polydimethylsiloxane lenses were designed to modify the focal spot of a spherical transducer. They exhibited low absorption and the focal spot widths were extended up to 8-fold in the elevation direction. Radiation force experiments demonstrated an 8-fold increase in tissue displacements using the same pressure level in a tissue-mimicking phantom with a similar shear wave spectrum, meaning it does not affect elastography resolution. Our results demonstrate that larger tissue responses can be obtained for a given pressure level, or that similar response can be reached at a much lower mechanical index (MI). We envision that this work will impact 3-D elastography using 2-D phased arrays, where such shaping can be achieved electronically with the potential for adaptive optimization.

Novel biomarker identification using metabolomic profiling to differentiate radiation necrosis and recurrent tumor following Gamma Knife radiosurgery.

PubMed

Lu, Alex Y; Turban, Jack L; Damisah, Eyiyemisi C; Li, Jie; Alomari, Ahmed K; Eid, Tore; Vortmeyer, Alexander O; Chiang, Veronica L

2017-08-01

OBJECTIVE Following an initial response of brain metastases to Gamma Knife radiosurgery, regrowth of the enhancing lesion as detected on MRI may represent either radiation necrosis (a treatment-related inflammatory change) or recurrent tumor. Differentiation of radiation necrosis from tumor is vital for management decision making but remains difficult by imaging alone. In this study, gas chromatography with time-of-flight mass spectrometry (GC-TOF) was used to identify differential metabolite profiles of the 2 tissue types obtained by surgical biopsy to find potential targets for noninvasive imaging. METHODS Specimens of pure radiation necrosis and pure tumor obtained from patient brain biopsies were flash-frozen and validated histologically. These formalin-free tissue samples were then analyzed using GC-TOF. The metabolite profiles of radiation necrosis and tumor samples were compared using multivariate and univariate statistical analysis. Statistical significance was defined as p ≤ 0.05. RESULTS For the metabolic profiling, GC-TOF was performed on 7 samples of radiation necrosis and 7 samples of tumor. Of the 141 metabolites identified, 17 (12.1%) were found to be statistically significantly different between comparison groups. Of these metabolites, 6 were increased in tumor, and 11 were increased in radiation necrosis. An unsupervised hierarchical clustering analysis found that tumor had elevated levels of metabolites associated with energy metabolism, whereas radiation necrosis had elevated levels of metabolites that were fatty acids and antioxidants/cofactors. CONCLUSIONS To the authors' knowledge, this is the first tissue-based metabolomics study of radiation necrosis and tumor. Radiation necrosis and recurrent tumor following Gamma Knife radiosurgery for brain metastases have unique metabolite profiles that may be targeted in the future to develop noninvasive metabolic imaging techniques.

Elevated blood histamine levels and mast cell degranulation in solar urticaria.

PubMed Central

Hawk, J L; Eady, R A; Challoner, A V; Kobza-Black, A; Keahey, T M; Greaves, M W

1980-01-01

1 Ultraviolet radiation (UVR)-induced wealing was studied in four patients with solar urticaria, whose measured action spectra were within the range 300 to 700 nm. 2 Elevated histamine levels were found in blood draining wealed skin in all four patients. 3 Histological and electron microscopial studies of the irradiated skin showed evidence of mast cell degranulation. 4 These findings demonstrate an association between histamine release from mast cells and wealing in solar urticaria, and should encourage evaluation of drugs which suppress histamine release in this disorder. Images Figure 2 PMID:7356907

Outdoor 220Rn, 222Rn and terrestrial gamma radiation levels: investigation study in the thorium rich Fen Complex, Norway.

PubMed

Mrdakovic Popic, Jelena; Bhatt, Chhavi Raj; Salbu, Brit; Skipperud, Lindis

2012-01-01

The present study was done in the Fen Complex, a Norwegian area rich in naturally occurring radionuclides, especially in thorium ((232)Th). Measurement of radioactivity levels was conducted at the decommissioned iron (Fe) and niobium (Nb) mining sites (TENORM) as well as at the undisturbed wooded sites (NORM), all open for free public access. The soil activity concentrations of (232)Th (3280-8395 Bq kg(-1)) were significantly higher than the world and the Norwegian average values and exceeded the Norwegian screening level (1000 Bq kg(-1)) for radioactive waste, while radium ((226)Ra) was present at slightly elevated levels (89-171 Bq kg(-1)). Terrestrial gamma dose rates were also elevated, ranging 2.6-4.4 μGy h(-1). Based on long-term surveys, the air concentrations of thoron ((220)Rn) and radon ((222)Rn) reached 1786 and 82 Bq m(-3), respectively. Seasonal variation in the outdoor gamma dose rates and Rn concentrations was confirmed. Correlation analyses showed a linear relationship between air radiation levels and the abundance of (232)Th in soil. The annual outdoor effective radiation doses for humans (occupancy 5 h day(-1)) were estimated to be in the range of 3.0-7.7 mSv, comparable or higher than the total average (summarized indoor and outdoor) exposure dose for the Norwegian population (2.9 mSv year(-1)). On the basis of all obtained results, this Norwegian area should be considered as enhanced natural radiation area (ENRA).

Air pollution effects field research facility: 3. UV-B exposure and monitoring system

DOE Office of Scientific and Technical Information (OSTI.GOV)

McEvers, J.A.; Hileman, M.S.; Edwards, N.T.

1993-03-01

The Oak Ridge National Laboratory Outdoor UltraViolet-B (UV-B) Exposure and Monitoring Facility was developed in 1980 to provide well-controlled and -monitored exposure of specific terrestrial plant. species to elevated levels of ultraviolet (UV) radiation. The introduction of various anthropogenic agents into the earth`s stratosphere has resulted in a decrease in the volume of ozone (O{sub 3}) present here. The decrease in O{sub 3} has resulted in an increase in the level of UV radiation reaching thee earth`s surface. Of particular interest is the level of UV-B, because it has the most detrimental effect on living tissue. A thorough understanding ofmore » the effects of elevated levels of UV-B on living tissue is critical to the formulation of economic policy regarding production of such agents and alternative strategies. The UV region of interest is referred to as UV-B and corresponds to radiation with a wavelength of 290 to 320 nm. Design, operation, and performance of the automated generation, exposure, and monitoring system are described. The system has proved to be reliable and easy to maintain and operate, and it provides significant flexibility in exposure programs. The system software is described, and detailed listings are provided. The ability to expose plants to controlled set point percentages of UV-B above the ambient level was developed.« less

ABC transporter activity linked to radiation resistance and molecular subtype in pediatric medulloblastoma

PubMed Central

2013-01-01

Background Resistance to radiation treatment remains a major clinical problem for patients with brain cancer. Medulloblastoma is the most common malignant brain tumor of childhood, and occurs in the cerebellum. Though radiation treatment has been critical in increasing survival rates in recent decades, the presence of resistant cells in a substantial number of medulloblastoma patients leads to relapse and death. Methods Using the established medulloblastoma cell lines UW228 and Daoy, we developed a novel model system to enrich for and study radiation tolerant cells early after radiation exposure. Using fluorescence-activated cell sorting, dead cells and cells that had initiated apoptosis were removed, allowing surviving cells to be investigated before extensive proliferation took place. Results Isolated surviving cells were tumorigenic in vivo and displayed elevated levels of ABCG2, an ABC transporter linked to stem cell behavior and drug resistance. Further investigation showed another family member, ABCA1, was also elevated in surviving cells in these lines, as well as in early passage cultures from pediatric medulloblastoma patients. We discovered that the multi-ABC transporter inhibitors verapamil and reserpine sensitized cells from particular patients to radiation, suggesting that ABC transporters have a functional role in cellular radiation protection. Additionally, verapamil had an intrinsic anti-proliferative effect, with transient exposure in vitro slowing subsequent in vivo tumor formation. When expression of key ABC transporter genes was assessed in medulloblastoma tissue from 34 patients, levels were frequently elevated compared with normal cerebellum. Analysis of microarray data from independent cohorts (n = 428 patients) showed expression of a number of ABC transporters to be strongly correlated with certain medulloblastoma subtypes, which in turn are associated with clinical outcome. Conclusions ABC transporter inhibitors are already being trialed clinically, with the aim of decreasing chemotherapy resistance. Our findings suggest that the inhibition of ABC transporters could also increase the efficacy of radiation treatment for medulloblastoma patients. Additionally, the finding that certain family members are associated with particular molecular subtypes (most notably high ABCA8 and ABCB4 expression in Sonic Hedgehog pathway driven tumors), along with cell membrane location, suggests ABC transporters are worthy of consideration for the diagnostic classification of medulloblastoma. PMID:24219920

Ellagic and ferulic acids alleviate gamma radiation and aluminium chloride-induced oxidative damage.

PubMed

Salem, Ahmed M; Mohammaden, Tarek F; Ali, Mohamed A M; Mohamed, Enas A; Hasan, Hesham F

2016-09-01

Ionizing radiation interacts with biological systems through the generation of free radicals, which induce oxidative stress. Aluminium (Al) can negatively impact human health by direct interaction with antioxidant enzymes. Ellagic acid (EA) and Ferulic acid (FA) are plant polyphenolic compounds, have gained attention due to their multiple biological activities. To date, no studies investigating the antioxidant effect of EA/FA in a model involving both γ radiation and aluminium chloride (AlCl3) have been reported. Herein, we investigated the protective effect of EA and FA against oxidative stress induced by γ radiation and AlCl3 in rats. Rats were divided into thirteen groups: a negative control group, 3 positive control groups (γ-irradiated, AlCl3-treated and γ-irradiated+AlCl3-treated) and 9 groups (3 γ-irradiated, 3 AlCl3-treated and 3 γ-irradiated+AlCl3-treated) treated with EA and/or FA. Liver function and lipid profile were assessed. Levels of lipid peroxidation, protein oxidation and endogenous antioxidants as well as the concentrations of copper, iron and zinc were estimated in liver tissue homogenate. Furthermore, liver tissue sections were histologically examined. Oral administration of EA and/or FA resulted in 1) amelioration of AlCl3 and/or γ-radiation-induced hepatic function impairment, dyslipidemia and hepatic histological alterations; 2) reduction in liver MDA and PCC levels; 3) elevation of liver CAT, GPx and SOD activity as well as GSH level; 4) elevation in liver Cu concentrations which was accompanied by a reduction in Fe and Zn concentrations. Oral administration of EA and/or FA may be useful for ameliorating γ radiation and/or AlCl3-induced oxidative damage. Copyright © 2016 Elsevier Inc. All rights reserved.

Lead exposure in Mexican radiator repair workers.

PubMed

Dykeman, Ronald; Aguilar-Madrid, Guadalupe; Smith, Tom; Juárez-Pérez, Cuauhtemoc Arturo; Piacitelli, Gregory M; Hu, Howard; Hernandez-Avila, Mauricio

2002-03-01

Lead exposure was investigated among 73 Mexican radiator repair workers (RRWs), 12 members of their family (4 children and 8 wives), and 36 working controls. RRWs were employed at 4 radiator repair shops in Mexico City and 27 shops in Cuernavaca and surrounding areas. Exposure was assessed directly through the use of personal air sampling and hand wipe samples. In addition, industrial hygiene inspections were performed and detailed questionnaires were administered. Blood lead levels were measured by graphite furnace atomic absorption spectroscopy (AAS). The mean (SD) values for blood lead of the RRWs, 35.5 (13.5) microg/dl, was significantly greater than the same values for the working controls, 13.6 (8.7) microg/dl; P < 001. After excluding a single outlier (247 microg/m(3)), air lead levels ranged from 0 to 99 microg/m(3) with a mean (SD) value of 19 (23) microg/m(3) (median = 7.9 microg/m(3)). In a final multivariate regression model of elevated blood lead levels, the strongest predictors were smoking (vs. non-smoking), the number of radiators repaired per day on average, and the use (vs. non-use) of a uniform while at work, which were associated with blood lead elevations of 11.4 microg/dl, 1.95 microg/dl/radiator/day, and 16.4 microg/dl, respectively (all P <.05). Uniform use was probably a risk factor because they were not laundered regularly and consequently served as reservoir of contamination on which RRWs frequently wiped their hands. Lead exposure is a significant problem of radiator repair work, a small industry that is abundant in Mexico and other developing countries. Copyright 2002 Wiley-Liss, Inc.

Final Tactical Decision Aid (FTDA) for Infrared (8-12 Micrometers) Systems - Manual Version. Appendix B. Insolation and Sky Radiation Tables,

DTIC Science & Technology

1982-09-15

for use in determining solar irradiance as a function of terrain elevation is also presented. Errors in computed sea level values of sky radiation as a...Renobserved if the Ground Were at Sea Level .. ..................... 365 5. Sky Radiation (W SK).. .. ....... ....... ....... 366 SKYY and Dewpoint SKY...WS -M 00 OiLn 00 00 00 .0 .. q . m1’ C14 IN’ .- *- * .0 *0 *0 0 .0 0 Y -’ CD N inC 0 M W N L- 04c 1- Wq an’ U) 14 N- 00 00 Mcq N N r- (’IC’I) (’ - M -0

REGIONAL MONITORING OF CORAL CONDITION IN THE FLORIDA KEYS

EPA Science Inventory

Tropical reef corals have experienced unprecedented levels of bleaching and disease during the last three decades. Declining health has been attributed to several stressors, including exposures to elevated water temperature, increased solar radiation, and degraded water quality. ...

Effects of nuclear radiation and elevated temperature storage on electroexplosive devices

NASA Technical Reports Server (NTRS)

Menichelli, V. J.

1976-01-01

Aerospace type electroexplosive devices (EEDs) were subjected to nuclear radiation. Components and chemicals used in the EEDs were also included. The kind of radiation and total dosage administered were those which may be experienced in a space flight of 10 years duration, based on information available at this time. After irradiation, the items were stored in elevated constant-temperature ovens to accelerate early effects of the exposure to radiation. Periodically, samples were withdrawn for visual observation and testing. Significant changes occurred which were attributed to elevated-temperature storage and not radiation.

Case-control study of lung cancer in civilian employees at the Portsmouth Naval Shipyard, Kittery, Maine.

PubMed

Rinsky, R A; Melius, J M; Hornung, R W; Zumwalde, R D; Waxweiler, R J; Landrigan, P J; Bierbaum, P J; Murray, W E

1988-01-01

Case-control analysis of deaths due to lung cancer (International Classification of Diseases, Eighth Revision, code 162) among persons who worked at the Portsmouth Naval Shipyard, Kittery, Maine, between 1952 and 1977 found elevated odds ratios for exposures to ionizing radiation, asbestos, and welding byproducts. The radiation-related excess was statistically significant in persons with cumulative lifetime exposures of 1.0-4.999 rem. When asbestos and welding histories were combined into a single risk factor, odds ratios for the combined exposure were significantly elevated for two of three duration-of-exposure categories examined. Further analysis of data on radiation exposure, controlling for exposures to asbestos and welding, found reductions in initial estimates of radiation risk at all levels of radiation exposure. This reduction suggests that radiation workers were more heavily exposed to asbestos and/or welding fumes than were other workers and that those exposures confounded the observed association between radiation and lung cancer. Analysis of mortality by time since first exposure to radiation revealed no pattern of progressive increase as latency increased. By contrast, odds ratios for asbestos/welding increased with latency. Data on cigarette smoking and socioeconomic status were not available. The results of this study do not preclude a possible association between radiation exposure at the Portsmouth Naval Shipyard and excess mortality from lung cancer. However, they provide no evidence in support of such a relation.

Effect of Americium-241 Content on Plutonium Radiation Source Terms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rainisch, R.

1998-12-28

The management of excess plutonium by the US Department of Energy includes a number of storage and disposition alternatives. Savannah River Site (SRS) is supporting DOE with plutonium disposition efforts, including the immobilization of certain plutonium materials in a borosilicate glass matrix. Surplus plutonium inventories slated for vitrification include materials with elevated levels of Americium-241. The Am-241 content of plutonium materials generally reflects in-growth of the isotope due to decay of plutonium and is age-dependent. However, select plutonium inventories have Am-241 levels considerably above the age-based levels. Elevated levels of americium significantly impact radiation source terms of plutonium materials andmore » will make handling of the materials more difficult. Plutonium materials are normally handled in shielded glove boxes, and the work entails both extremity and whole body exposures. This paper reports results of an SRS analysis of plutonium materials source terms vs. the Americium-241 content of the materials. Data with respect to dependence and magnitude of source terms on/vs. Am-241 levels are presented and discussed. The investigation encompasses both vitrified and un-vitrified plutonium oxide (PuO2) batches.« less

Synergistic effect of Ebselen and gamma radiation on breast cancer cells.

PubMed

Thabet, Noura M; Moustafa, Enas M

2017-08-01

To explore the synergistic effect of a seleno-organic compound Ebselen (Ebs) and/or γ-radiation to exert antitumor effects on human breast cancer (MCF-7) cell line in vitro. Ebs cytotoxicity at various concentrations (10, 25, 50 and 75 μg), cell proliferation and clonogenic assay of Ebs and/or γ-radiation (at 1, 3 and 6 Gy), expression of p-IκBα and NF-κB, inflammatory cytokines levels (TNF-α, IL-2, INF-γ, IL-10 and TGF-β), apoptotic factors (Caspase-3, Granzyme-B and TRAIL) and angiogenic factor (VEGF) were investigated. The results showed that the effective dosage of this combination was observed at 25 μg/ml of Ebs with γ-radiation at 6 Gy. Data displayed a significant reduction in NF-κB mRNA along with an elevation in granzyme-B mRNA and TRAIL mRNA expression. Furthermore, protein expression of caspase-3 was elevated, whereas p-IκBα and p-NF-κB(p65) protein expression was reduced significantly. Also, a significant decline in TNF-α, IL-2, INF-γ, TGF-β with a significant increase in IL-10 levels were revealed. Meanwhile, a significant decrease in VEGF level and proliferation capacity were observed. We conclude that a combination of Ebs with radiotherapy has a major antitumor efficiency in inducing apoptosis and inhibiting cancer cell progression, due to the synergistic effect in regulating gene and protein expression, and in a modulating response of pro-and anti-inflammatory cytokines.

Oxidative Lung Damage Resulting from Repeated Exposure to Radiation and Hyperoxia Associated with Space Exploration.

PubMed

Pietrofesa, Ralph A; Turowski, Jason B; Arguiri, Evguenia; Milovanova, Tatyana N; Solomides, Charalambos C; Thom, Stephen R; Christofidou-Solomidou, Melpo

2013-09-30

Spaceflight missions may require crewmembers to conduct Extravehicular Activities (EVA) for repair, maintenance or scientific purposes. Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours (5-8 hours), and may be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health and therefore, pose a threat to the success of the mission. We have developed a murine model of combined, hyperoxia and radiation exposure (double-hit) in the context of evaluating countermeasures to oxidative lung damage associated with space flight. In the current study, our objective was to characterize the early and chronic effects of repeated single and double-hit challenge on lung tissue using a novel murine model of repeated exposure to low-level total body radiation and hyperoxia. This is the first study of its kind evaluating lung damage relevant to space exploration in a rodent model. Mouse cohorts (n=5-15/group) were exposed to repeated: a) normoxia; b) >95% O 2 (O 2 ); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O 2 and IR (O 2 +IR) given 3 times per week for 4 weeks. Lungs were evaluated for oxidative damage, active TGFβ1 levels, cell apoptosis, inflammation, injury, and fibrosis at 1, 2, 4, 8, 12, 16, and 20 weeks post-initiation of exposure. Mouse cohorts exposed to all challenge conditions displayed decreased bodyweight compared to untreated controls at 4 and 8 weeks post-challenge initiation. Chronic oxidative lung damage to lipids (malondialdehyde levels), DNA (TUNEL, cleaved Caspase 3, cleaved PARP positivity) leading to apoptotic cell death and to proteins (nitrotyrosine levels) was elevated all treatment groups. Importantly, significant systemic oxidative stress was also noted at the late phase in mouse plasma, BAL fluid, and urine. Importantly, however, late oxidative damage across all parameters that we measured was significantly higher than controls in all cohorts but was exacerbated by the combined exposure to O 2 and IR. Additionally, impaired levels of arterial blood oxygenation were noted in all exposure cohorts. Significant but transient elevation of lung tissue fibrosis ( p <0.05), determined by lung hydroxyproline content, was detected as early as 2 week in mice exposed to challenge conditions and persisted for 4-8 weeks only. Interestingly, active TGFβ1 levels in +BAL fluid was also transiently elevated during the exposure time only (1-4 weeks). Inflammation and lung edema/lung injury was also significantly elevated in all groups at both early and late time points, especially the double-hit group. We have characterized significant, early and chronic lung changes consistent with oxidative tissue damage in our murine model of repeated radiation and hyperoxia exposure relevant to space travel. Lung tissue changes, detectable several months after the original exposure, include significant oxidative lung damage (lipid peroxidation, DNA damage and protein nitrosative stress) and increased pulmonary fibrosis. These findings, along with increased oxidative stress in diverse body fluids and the observed decreases in blood oxygenation levels in all challenge conditions (whether single or in combination), lead us to conclude that in our model of repeated exposure to oxidative stressors, chronic tissue changes are detected that persist even months after the exposure to the stressor has ended. This data will provide useful information in the design of countermeasures to tissue oxidative damage associated with space exploration.

Oxidative Lung Damage Resulting from Repeated Exposure to Radiation and Hyperoxia Associated with Space Exploration

PubMed Central

Pietrofesa, Ralph A; Turowski, Jason B; Arguiri, Evguenia; Milovanova, Tatyana N; Solomides, Charalambos C; Thom, Stephen R; Christofidou-Solomidou, Melpo

2013-01-01

Background Spaceflight missions may require crewmembers to conduct Extravehicular Activities (EVA) for repair, maintenance or scientific purposes. Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours (5-8 hours), and may be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health and therefore, pose a threat to the success of the mission. We have developed a murine model of combined, hyperoxia and radiation exposure (double-hit) in the context of evaluating countermeasures to oxidative lung damage associated with space flight. In the current study, our objective was to characterize the early and chronic effects of repeated single and double-hit challenge on lung tissue using a novel murine model of repeated exposure to low-level total body radiation and hyperoxia. This is the first study of its kind evaluating lung damage relevant to space exploration in a rodent model. Methods Mouse cohorts (n=5-15/group) were exposed to repeated: a) normoxia; b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) given 3 times per week for 4 weeks. Lungs were evaluated for oxidative damage, active TGFβ1 levels, cell apoptosis, inflammation, injury, and fibrosis at 1, 2, 4, 8, 12, 16, and 20 weeks post-initiation of exposure. Results Mouse cohorts exposed to all challenge conditions displayed decreased bodyweight compared to untreated controls at 4 and 8 weeks post-challenge initiation. Chronic oxidative lung damage to lipids (malondialdehyde levels), DNA (TUNEL, cleaved Caspase 3, cleaved PARP positivity) leading to apoptotic cell death and to proteins (nitrotyrosine levels) was elevated all treatment groups. Importantly, significant systemic oxidative stress was also noted at the late phase in mouse plasma, BAL fluid, and urine. Importantly, however, late oxidative damage across all parameters that we measured was significantly higher than controls in all cohorts but was exacerbated by the combined exposure to O2 and IR. Additionally, impaired levels of arterial blood oxygenation were noted in all exposure cohorts. Significant but transient elevation of lung tissue fibrosis (p<0.05), determined by lung hydroxyproline content, was detected as early as 2 week in mice exposed to challenge conditions and persisted for 4-8 weeks only. Interestingly, active TGFβ1 levels in +BAL fluid was also transiently elevated during the exposure time only (1-4 weeks). Inflammation and lung edema/lung injury was also significantly elevated in all groups at both early and late time points, especially the double-hit group. Conclusion We have characterized significant, early and chronic lung changes consistent with oxidative tissue damage in our murine model of repeated radiation and hyperoxia exposure relevant to space travel. Lung tissue changes, detectable several months after the original exposure, include significant oxidative lung damage (lipid peroxidation, DNA damage and protein nitrosative stress) and increased pulmonary fibrosis. These findings, along with increased oxidative stress in diverse body fluids and the observed decreases in blood oxygenation levels in all challenge conditions (whether single or in combination), lead us to conclude that in our model of repeated exposure to oxidative stressors, chronic tissue changes are detected that persist even months after the exposure to the stressor has ended. This data will provide useful information in the design of countermeasures to tissue oxidative damage associated with space exploration. PMID:24358450

Combined effects of lanthanum(III) and elevated ultraviolet-B radiation on root growth and ion absorption in soybean seedlings.

PubMed

Huang, Guang Rong; Wang, Li Hong; Zhou, Qing

2014-03-01

Rare earth element accumulation in the soil and elevated ultraviolet (UV)-B radiation (280-315 nm) are important environmental issues worldwide. To date, there have been no reports concerning the combined effects of lanthanum (La)(III) and elevated UV-B radiation on plant roots in regions where the two issues occur simultaneously. Here, the combined effects of La(III) and elevated UV-B radiation on the growth, biomass, ion absorption, activities, and membrane permeability of roots in soybean (Glycine max L.) seedlings were investigated. A 0.08 mmol L(-1) La(III) treatment improved the root growth and biomass of soybean seedlings, while ion absorption, activities, and membrane permeability were obviously unchanged; a combined treatment with 0.08 mmol L(-1) La(III) and elevated UV-B radiation (2.63/6.17 kJ m(-2) day(-1)) exerted deleterious effects on the investigated indices. The deleterious effects were aggravated in the other combined treatments and were stronger than those of treatments with La(III) or elevated UV-B radiation alone. The combined treatment with 0.24/1.20 mmol L(-1) La(III) and elevated UV-B radiation exerted synergistically deleterious effects on the growth, biomass, ion absorption, activities, and membrane permeability of roots in soybean seedlings. In addition, the deleterious effects of the combined treatment on the root growth were due to the inhibition of ion absorption induced by the changes in the root activity and membrane permeability.

Transient elevation of glycolysis confers radio-resistance by facilitating DNA repair in cells.

PubMed

Bhatt, Anant Narayan; Chauhan, Ankit; Khanna, Suchit; Rai, Yogesh; Singh, Saurabh; Soni, Ravi; Kalra, Namita; Dwarakanath, Bilikere S

2015-05-01

Cancer cells exhibit increased glycolysis for ATP production (the Warburg effect) and macromolecular biosynthesis; it is also linked with therapeutic resistance that is generally associated with compromised respiratory metabolism. Molecular mechanisms underlying radio-resistance linked to elevated glycolysis remain incompletely understood. We stimulated glycolysis using mitochondrial respiratory modifiers (MRMs viz. di-nitro phenol, DNP; Photosan-3, PS3; Methylene blue, MB) in established human cell lines (HEK293, BMG-1 and OCT-1). Glucose utilization and lactate production, levels of glucose transporters and glycolytic enzymes were investigated as indices of glycolysis. Clonogenic survival, DNA repair and cytogenetic damage were studied as parameters of radiation response. MRMs induced the glycolysis by enhancing the levels of two important regulators of glucose metabolism GLUT-1 and HK-II and resulted in 2 fold increase in glucose consumption and lactate production. This increase in glycolysis resulted in resistance against radiation-induced cell death (clonogenic survival) in different cell lines at an absorbed dose of 5 Gy. Inhibition of glucose uptake and glycolysis (using fasentin, 2-deoxy-D-glucose and 3-bromopyruvate) in DNP treated cells failed to increase the clonogenic survival of irradiated cells, suggesting that radio-resistance linked to inhibition of mitochondrial respiration is glycolysis dependent. Elevated glycolysis also facilitated rejoining of radiation-induced DNA strand breaks by activating both non-homologous end joining (NHEJ) and homologous recombination (HR) pathways of DNA double strand break repair leading to a reduction in radiation-induced cytogenetic damage (micronuclei formation) in these cells. These findings suggest that enhanced glycolysis generally observed in cancer cells may be responsible for the radio-resistance, partly by enhancing the repair of DNA damage.

Effects of gamma-Radiation on Select Lipids and Antioxidants

NASA Technical Reports Server (NTRS)

Gandolph, Jacob; Mauer, Lisa; Perchonok, Michele

2006-01-01

Radiation encountered on an extended duration space mission (estimates of 3 Sieverts for a mission to Mars) poses a threat not only to human health, but also to the quality, nutritional value, and palatability of the food system. Free radicals generated by radiation interaction with foods may initiate many unwanted reactions including: 1) autoxidation in lipids that alters flavor, odor, and concentrations of essential fatty acids, and 2) depletion of antioxidants food products and dietary supplements. Studies have shown that antioxidants may provide long term health protection from oxidative stress caused by radiation exposure; therefore, consumption of antioxidants will be important. Stability of essential fatty acids is also important for astronauts long-term health status. The objectives of this study were to characterize the effects of low dose gamma-radiation on lipids and antioxidants by monitoring oxidation and reducing power, respectively, in model systems. Select oils and antioxidants were exposed to levels of gamma-radiation ranging from 0 to 1000 Gy (1 Gy = 1 Sv) using a Gammacell 220 and stored at ambient or elevated temperatures (65 C) for up to 3 months prior to analysis. A Fricke dosimeter was used to verify differences between the radiation doses administered. Primary and secondary products of lipid oxidation in soybean and peanut oils were monitored using conjugated diene and 2-thiobarbituric acid (TBARs) assays. Changes in fatty acid composition and formation and vitamin E levels were also measured. The reducing power of antioxidant compounds, including vitamins C and E and beta-carotene, was determined using the ferric reducing antioxidant power (FRAP) assay. Significant differences (alpha =0.05) were present between all radiation doses tested using the Fricke dosimeter. Increasing radiation doses above 3 Sv resulted in significantly (alpha =0.05) elevated levels of oxidation and free fatty acids in soybean and peanut oils. Decreases in concentrations of essential fatty acids upon increasing radiation doses were also observed. Increasing radiation doses caused significant (alpha =0.05) decreases in reducing power and hence the effectiveness of vitamins C and E as well as beta-carotene. This work establishes a need for quantifying the effects of space relevant radiation doses in the development of a food system for an extended duration mission and for identifying threshold radiation levels that will impact the useful shelf-life of the variety of foods that will be sent. Eventual rancidity of lipids and the loss of antioxidant bioprotective effects are major concerns for the acceptability and nutritional profile of a food system.

Radiated noise characteristics of a modern cargo ship

PubMed

Arveson; Vendittis

2000-01-01

Extensive measurements were made of the radiated noise of M/V OVERSEAS HARRIETTE, a bulk cargo ship (length 173 m, displacement 25 515 tons) powered by a direct-drive low-speed diesel engine-a design representative of many modern merchant ships. The radiated noise data show high-level tonal frequencies from the ship's service diesel generator, main engine firing rate, and blade rate harmonics due to propeller cavitation. Radiated noise directionality measurements indicate that the radiation is generally dipole in form at lower frequencies, as expected. There are some departures from this pattern that may indicate hull interactions. Blade rate source level (174 dB re 1 microPa/m at 9 Hz, 16 knots) agrees reasonably well with a model of fundamental blade rate radiation previously reported by Gray and Greeley, but agreement for blade rate harmonics is not as good. Noise from merchant ships elevates the natural ambient by 20-30 dB in many areas; the effects of this noise on the biological environment have not been widely investigated.

Design Issues for Using Magnetic Materials in Radiation Environments at Elevated Temperature

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.

2013-01-01

One of the challenges of designing motors and alternators for use in nuclear powered space missions is accounting for the effects of radiation. Terrestrial reactor power plants use distance and shielding to minimize radiation damage but space missions must economize volume and mass. Past studies have shown that sufficiently high radiation levels can affect the magnetic response of hard and soft magnetic materials. Theoretical models explaining the radiation-induced degradation have been proposed but not verified. This paper reviews the literature and explains the cumulative effects of temperature, magnetic-load, and radiation-level on the magnetic properties of component materials. Magnetic property degradation is very specific to alloy choice and processing history, since magnetic properties are very much entwined with specific chemistry and microstructural features. However, there is basic theoretical as well as supportive experimental evidence that the negative impact to magnetic properties will be minimal if the bulk temperature of the material is less than fifty percent of the Curie temperature, the radiation flux is low, and the demagnetization field is small. Keywords: Magnets, Permanent Magnets, Power Converters, Nuclear Electric Power Generation, Radiation Tolerance.

Sustained Radiosensitization of Hypoxic Glioma Cells after Oxygen Pretreatment in an Animal Model of Glioblastoma and In Vitro Models of Tumor Hypoxia

PubMed Central

Clarke, Ryon H.; Moosa, Shayan; Anzivino, Matthew; Wang, Yi; Floyd, Desiree Hunt; Purow, Benjamin W.; Lee, Kevin S.

2014-01-01

Glioblastoma multiforme (GBM) is the most common and lethal form of brain cancer and these tumors are highly resistant to chemo- and radiotherapy. Radioresistance is thought to result from a paucity of molecular oxygen in hypoxic tumor regions, resulting in reduced DNA damage and enhanced cellular defense mechanisms. Efforts to counteract tumor hypoxia during radiotherapy are limited by an attendant increase in the sensitivity of healthy brain tissue to radiation. However, the presence of heightened levels of molecular oxygen during radiotherapy, while conventionally deemed critical for adjuvant oxygen therapy to sensitize hypoxic tumor tissue, might not actually be necessary. We evaluated the concept that pre-treating tumor tissue by transiently elevating tissue oxygenation prior to radiation exposure could increase the efficacy of radiotherapy, even when radiotherapy is administered after the return of tumor tissue oxygen to hypoxic baseline levels. Using nude mice bearing intracranial U87-luciferase xenografts, and in vitro models of tumor hypoxia, the efficacy of oxygen pretreatment for producing radiosensitization was tested. Oxygen-induced radiosensitization of tumor tissue was observed in GBM xenografts, as seen by suppression of tumor growth and increased survival. Additionally, rodent and human glioma cells, and human glioma stem cells, exhibited prolonged enhanced vulnerability to radiation after oxygen pretreatment in vitro, even when radiation was delivered under hypoxic conditions. Over-expression of HIF-1α reduced this radiosensitization, indicating that this effect is mediated, in part, via a change in HIF-1-dependent mechanisms. Importantly, an identical duration of transient hyperoxic exposure does not sensitize normal human astrocytes to radiation in vitro. Taken together, these results indicate that briefly pre-treating tumors with elevated levels of oxygen prior to radiotherapy may represent a means for selectively targeting radiation-resistant hypoxic cancer cells, and could serve as a safe and effective adjuvant to radiation therapy for patients with GBM. PMID:25350400

Elevation-Dependence of the Summer Climate Over the South Slope of Mt. Everest, Central Himalaya

NASA Astrophysics Data System (ADS)

Yang, K.; Salerno, F.; Ouyang, L.; Guyennon, N.; Tian, L.; Tartari, G.

2016-12-01

Exploring the climate over high elevations is crucial for understanding hydro-meteorological processes in the Himalayan Range. Using data from stations deployed at 2660 to 7986 m a.s.l. (above sea level) along the south slope of Mt. Everest, central Himalaya, we confirmed the nocturnal precipitation peak and the asymmetric diurnal cycle of wind speed (a strong upslope in the daytime and a weak downslope at night) over the lower-high elevations (LHE, i.e. <4500 m a.s.l.) in summer. Further, we found some unique features over the slopes, particularly a distinct summer climate over upper-high elevations (UHE, i.e. >4500 m a.s.l.). First, the upslope wind in the daytime accelerated along the LHE slope but slowed along the UHE slope, a phenomenon that causes surface air convergence and a precipitation peak in the afternoon over the UHE. Satellite cloud data and precipitation-event-based analysis also demonstrated an earlier precipitation peak for UHE. Second, the diurnal cycle of wind was evident at 5600 m a.s.l., but it disappeared at 6700 m a.s.l., implying water vapor conveyed by valley winds could reach high elevations but could barely cross the highest mountains. Third, solar radiation had distinct spatiotemporal variations. It reached its lowest intensity in summer at stations below 6000 m a.s.l., and high elevations often had weaker radiation due to the afternoon precipitation peak over the UHE. Moreover, the summer monsoon caused a rapid increase of downward longwave radiation. Last, both lapse rates of air temperature and relative humidity were generally greater over the UHE than over the LHE. Because of these complex elevation-dependences of the individual variables, caution must be exercised in estimating UHE climate from observed data at lower elevations in the mountainous region.

Elevated Urine Levels of Macrophage Migration Inhibitory Factor in Inflammatory Bladder Conditions: A Potential Biomarker for a Subgroup of Interstitial Cystitis/Bladder Pain Syndrome Patients.

PubMed

Vera, Pedro L; Preston, David M; Moldwin, Robert M; Erickson, Deborah R; Mowlazadeh, Behzad; Ma, Fei; Kouzoukas, Dimitrios E; Meyer-Siegler, Katherine L; Fall, Magnus

2018-06-01

To investigate whether urinary levels of macrophage migration inhibitory factor (MIF) are elevated in interstitial cystitis/bladder pain syndrome (IC/BPS) patients with Hunner lesions and also whether urine MIF is elevated in other forms of inflammatory cystitis. Urine samples were assayed for MIF by enzyme-linked immunosorbent assay. Urine samples from 3 female groups were examined: IC/BPS patients without (N = 55) and with Hunner lesions (N = 43), and non-IC/BPS patients (N = 100; control group; no history of IC/BPS; cancer or recent bacterial cystitis). Urine samples from 3 male groups were examined: patients with bacterial cystitis (N = 50), radiation cystitis (N = 18) and noncystitis patients (N = 119; control group; negative for bacterial cystitis). Urine MIF (mean MIF pg/mL ±  standard error of the mean) was increased in female IC/BPS patients with Hunner lesions (2159 ± 435.3) compared with IC/BPS patients without Hunner lesions (460 ± 114.5) or non-IC/BPS patients (414 ± 47.6). Receiver operating curve analyses showed that urine MIF levels discriminated between the 2 IC groups (area under the curve = 72%; confidence interval 61%-82%). Male patients with bacterial and radiation cystitis had elevated urine MIF levels (2839 ± 757.1 and 4404 ± 1548.1, respectively) compared with noncystitis patients (681 ± 75.2). Urine MIF is elevated in IC/BPS patients with Hunner lesions and also in patients with other bladder inflammatory and painful conditions. MIF may also serve as a noninvasive biomarker to select IC/BPS patients more accurately for endoscopic evaluation and possible anti-inflammatory treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Climate change conditions (elevated CO2 and temperature) and UV-B radiation affect grapevine (Vitis vinifera cv. Tempranillo) leaf carbon assimilation, altering fruit ripening rates.

PubMed

Martínez-Lüscher, J; Morales, F; Sánchez-Díaz, M; Delrot, S; Aguirreolea, J; Gomès, E; Pascual, I

2015-07-01

The increase in grape berry ripening rates associated to climate change is a growing concern for wine makers as it rises the alcohol content of the wine. The present work studied the combined effects of elevated CO2, temperature and UV-B radiation on leaf physiology and berry ripening rates. Three doses of UV-B: 0, 5.98, 9.66 kJm(-2)d(-1), and two CO2-temperature regimes: ambient CO2-24/14 °C (day/night) (current situation) and 700 ppm CO2-28/18 °C (climate change) were imposed to grapevine fruit-bearing cuttings from fruit set to maturity under greenhouse-controlled conditions. Photosynthetic performance was always higher under climate change conditions. High levels of UV-B radiation down regulated carbon fixation rates. A transient recovery took place at veraison, through the accumulation of flavonols and the increase of antioxidant enzyme activities. Interacting effects between UV-B and CO2-temperature regimes were observed for the lipid peroxidation, which suggests that UV-B may contribute to palliate the signs of oxidative damage induced under elevated CO2-temperature. Photosynthetic and ripening rates were correlated. Thereby, the hastening effect of climate change conditions on ripening, associated to higher rates of carbon fixation, was attenuated by UV-B radiation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Control of excessive lead exposure in radiator repair workers.

PubMed

1991-03-01

In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

Comparison of transient measurements of infrared radiation and stress waves for practical ablation monitoring during photorefractive keratectomy

NASA Astrophysics Data System (ADS)

Ishihara, Miya; Arai, Tsunenori; Kikuchi, Makoto; Nakano, Hironori; Kawauchi, Satoko; Obara, Minoru

1998-05-01

We compared infrared radiation measurement with stress wave measurement for real-time ablation monitoring during photorefractive keratectomy (PRK). We estimated temperature elevation which may be one of the most effective parameter for PRK monitoring, because the ablation mechanism is mainly attributed to thermal kinetics. The temperature elevation of ablated cornea was evaluated by the infrared radiation and the stress wave. The thermal radiation from irradiated cornea was detected by a MCT detector. The measured signal increased sharply just after the laser irradiation and decreased quasi- exponentially. We could calculate the temperature elevation by observed signal using Stefan-Boltzmann radiation law. In the case of the gelatin gel (15% wt) ablation in vitro, the temperature elevation was 97 deg. at 208 mJ/cm2 in the laser fluence. We also measured transient stress wave by the acoustic transducer which was made by polyvinylidene fluoride (PVDF) film. The temperature elevation could be calculated from the peak stress amplitude based on the short pulsed laser ablation theory. The good agreement on the temperature elevation was obtained between the infrared and the stress based estimations. Due to non-contact and non-invasive method, our infrared measurements for temperature elevation monitoring may be available to accomplish the feedback control on the PRK.

Radiation protection aspects of the cosmic radiation exposure of aircraft crew.

PubMed

Bartlett, D T

2004-01-01

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe.

Transforming growth factor-beta-1 is a serum biomarker of radiation-induced pneumonitis in esophageal cancer patients treated with thoracic radiotherapy: preliminary results of a prospective study.

PubMed

Li, Jingxia; Mu, Shuangfeng; Mu, Lixiang; Zhang, Xiaohui; Pang, Ranran; Gao, Shegan

2015-01-01

To examine the relationship between cytokine levels of transforming growth factor-beta-1 (TGF-β1), interleukin-1 beta (IL-1β), and angiotensin-converting enzyme (ACE) in the plasma of esophageal carcinoma patients and radiation-induced pneumonitis (RP). Sixty-three patients with esophageal carcinoma were treated with three-dimensional conformal radiotherapy (RT) using the Elekta Precise treatment planning system with a prescribed dose of 50-70 Gy. Dose-volume histograms were collected from three-dimensional conformal RT to determine the volume percentage of the lung received V5, V10, V20, and the normal tissue complication probability. RP was diagnosed based on computed tomography imaging, respiratory symptoms, and signs. The severity of radiation-induced lung toxicity was determined using the Lent-Soma scale defined by the Radiation Therapy Oncology Group. Plasma samples obtained before RT, during RT (at 40 Gy), and at 1 day, 1 month, and 3 months after RT were assayed for TGF-β1, IL-1β, and ACE levels by enzyme-linked immunosorbent assay. From the 63 patients, 17 (27%) developed RP, and 13 (21%) had RP of grade I and four (6%) had grade II or higher. We found plasma TGF-β1 levels were elevated in the patients that had RP when compared with the other 46 patients who did not have RP. The plasma IL-1β levels were not changed. The ACE levels were significantly lower in the 17 patients with RP compared to the 46 patients without RP throughout the RT. As expected, RP is associated with a higher dose of irradiation (>60 Gy); no other factors, including dose-volume histogram, age, sex, smoking status, location of tumor, and methods of treatment, are associated with RP. Elevated plasma TGF-β1 levels can be used as a marker for RP.

TopoSCALE v.1.0: downscaling gridded climate data in complex terrain

NASA Astrophysics Data System (ADS)

Fiddes, J.; Gruber, S.

2014-02-01

Simulation of land surface processes is problematic in heterogeneous terrain due to the the high resolution required of model grids to capture strong lateral variability caused by, for example, topography, and the lack of accurate meteorological forcing data at the site or scale it is required. Gridded data products produced by atmospheric models can fill this gap, however, often not at an appropriate spatial resolution to drive land-surface simulations. In this study we describe a method that uses the well-resolved description of the atmospheric column provided by climate models, together with high-resolution digital elevation models (DEMs), to downscale coarse-grid climate variables to a fine-scale subgrid. The main aim of this approach is to provide high-resolution driving data for a land-surface model (LSM). The method makes use of an interpolation of pressure-level data according to topographic height of the subgrid. An elevation and topography correction is used to downscale short-wave radiation. Long-wave radiation is downscaled by deriving a cloud-component of all-sky emissivity at grid level and using downscaled temperature and relative humidity fields to describe variability with elevation. Precipitation is downscaled with a simple non-linear lapse and optionally disaggregated using a climatology approach. We test the method in comparison with unscaled grid-level data and a set of reference methods, against a large evaluation dataset (up to 210 stations per variable) in the Swiss Alps. We demonstrate that the method can be used to derive meteorological inputs in complex terrain, with most significant improvements (with respect to reference methods) seen in variables derived from pressure levels: air temperature, relative humidity, wind speed and incoming long-wave radiation. This method may be of use in improving inputs to numerical simulations in heterogeneous and/or remote terrain, especially when statistical methods are not possible, due to lack of observations (i.e. remote areas or future periods).

2011 investigation of internal contamination with radioactive strontium following rubidium Rb 82 cardiac PET scan.

PubMed

Pillai, Satish K; Chang, Arthur; Murphy, Matthew W; Buzzell, Jennifer; Ansari, Armin; Whitcomb, Robert C; Miller, Charles; Jones, Robert; Saunders, David P; Cavicchia, Philip; Watkins, Sharon M; Blackmore, Carina; Williamson, John A; Stephens, Michael; Morrison, Melissa; McNees, James; Murphree, Rendi; Buchanan, Martha; Hogan, Anthony; Lando, James; Nambiar, Atmaram; Torso, Lauren; Melnic, Joseph M; Yang, Lucie; Lewis, Lauren

2014-01-01

During routine screening in 2011, US Customs and Border Protection (CBP) identified 2 persons with elevated radioactivity. CBP, in collaboration with Los Alamos National Laboratory, informed the Food and Drug Administration (FDA) that these people could have increased radiation exposure as a result of undergoing cardiac Positron Emission Tomography (PET) scans several months earlier with rubidium Rb 82 chloride injection from CardioGen-82. We conducted a multistate investigation to assess the potential extent and magnitude of radioactive strontium overexposure among patients who had undergone Rb 82 PET scans. We selected a convenience sample of clinical sites in 4 states and reviewed records to identify eligible study participants, defined as people who had had an Rb 82 PET scan between February and July 2011. All participants received direct radiation screening using a radioisotope identifier able to detect the gamma energy specific for strontium-85 (514 keV) and urine bioassay for excreted radioactive strontium. We referred a subset of participants with direct radiation screening counts above background readings for whole body counting (WBC) using a rank ordering of direct radiation screening. The rank order list, from highest to lowest, was used to contact and offer voluntary enrollment for WBC. Of 308 participants, 292 (95%) had direct radiation screening results indistinguishable from background radiation measurements; 261 of 265 (98%) participants with sufficient urine for analysis had radioactive strontium results below minimum detectable activity. None of the 23 participants who underwent WBC demonstrated elevated strontium activity above levels associated with routine use of the rubidium Rb 82 generator. Among investigation participants, we did not identify evidence of strontium internal contamination above permissible levels. This investigation might serve as a model for future investigations of radioactive internal contamination incidents.

Thyroid Cancer Induction: Nitrates as Independent Risk Factors or Risk Modulators after Radiation Exposure, with a Focus on the Chernobyl Accident.

PubMed

Drozd, Valentina M; Branovan, Igor; Shiglik, Nikolay; Biko, Johannes; Reiners, Christoph

2018-03-01

In recent decades, differentiated thyroid cancer (DTC) incidence has been increasing worldwide. The important contributions to this phenomenon of "overdiagnosis" driven by wider use of improved ultrasound systems are amply documented, notwithstanding the "real" carcinogenic effects of ionizing radiation, e.g., from the Chernobyl accident or health care interventions. Less well understood is the role of nitrates - as environmental pollutants, in diet, and in medication - in thyroid carcinogenesis. Increasing exposure to nitrates is associated with rising incidence of esophageal, stomach, bladder, and colon cancers. Recent data suggest that in agricultural areas with higher mean nitrate levels in groundwater, DTC risk is also elevated. Our work in Belarus after Chernobyl has shown that children in districts with high nitrate concentrations in drinking water had significantly higher thyroid cancer incidence after irradiation than did their counterparts in areas with lower nitrate concentrations. Notwithstanding thyroid shielding, increasing use of computed tomography and dental X-rays heightens radiation exposure of the salivary glands in the general population, especially in children and adolescents. When nitrate intake is increased, salivary gland irradiation may potentially result in carcinogenic elevations in plasma nitric oxide concentrations. In conclusion, excess nitrate intake seems to be an independent risk factor for DTC. Additionally, we hypothesize from our data that high nitrate levels modulate the carcinogenic effect of radiation on the thyroid. Cohort studies, case-control studies, or both, are needed to quantify the effects of nitrates on DTC risk in the presence or absence of radiation exposure, e.g., that associated with diagnostic or therapeutic health care interventions.

Integrated molecular analysis indicates undetectable change in DNA damage in mice after continuous irradiation at ~ 400-fold natural background radiation.

PubMed

Olipitz, Werner; Wiktor-Brown, Dominika; Shuga, Joe; Pang, Bo; McFaline, Jose; Lonkar, Pallavi; Thomas, Aline; Mutamba, James T; Greenberger, Joel S; Samson, Leona D; Dedon, Peter C; Yanch, Jacquelyn C; Engelward, Bevin P

2012-08-01

In the event of a nuclear accident, people are exposed to elevated levels of continuous low dose-rate radiation. Nevertheless, most of the literature describes the biological effects of acute radiation. DNA damage and mutations are well established for their carcinogenic effects. We assessed several key markers of DNA damage and DNA damage responses in mice exposed to low dose-rate radiation to reveal potential genotoxic effects associated with low dose-rate radiation. We studied low dose-rate radiation using a variable low dose-rate irradiator consisting of flood phantoms filled with 125Iodine-containing buffer. Mice were exposed to 0.0002 cGy/min (~ 400-fold background radiation) continuously over 5 weeks. We assessed base lesions, micronuclei, homologous recombination (HR; using fluorescent yellow direct repeat mice), and transcript levels for several radiation-sensitive genes. We did not observe any changes in the levels of the DNA nucleobase damage products hypoxanthine, 8-oxo-7,8-dihydroguanine, 1,N6-ethenoadenine, or 3,N4-ethenocytosine above background levels under low dose-rate conditions. The micronucleus assay revealed no evidence that low dose-rate radiation induced DNA fragmentation, and there was no evidence of double strand break-induced HR. Furthermore, low dose-rate radiation did not induce Cdkn1a, Gadd45a, Mdm2, Atm, or Dbd2. Importantly, the same total dose, when delivered acutely, induced micronuclei and transcriptional responses. These results demonstrate in an in vivo animal model that lowering the dose-rate suppresses the potentially deleterious impact of radiation and calls attention to the need for a deeper understanding of the biological impact of low dose-rate radiation.

Regional Monitoring of Coral Condition in the Florida Keys

Treesearch

William S. Fisher; Deborah L. Santavy; William P. Davis; Lee A. Courtney

2006-01-01

Tropical reef corals have experienced unprecedented levels of bleaching and disease during the last three decades. Declining health has been attributed to several stressors, including exposures to elevated water temperature, increased solar radiation, and degraded water quality. Consequences of coral bleaching and disease vary; some recover, while others lose tissue,...

Public exposure due to external gamma background radiation in boundary areas of Iran.

PubMed

Pooya, S M Hosseini; Dashtipour, M R; Enferadi, A; Orouji, T

2015-09-01

A monitoring program in boundary areas of a country is an appropriate way to indicate the level of public exposure. In this research, gamma background radiation was measured using TL dosimeters at 12 boundary areas as well as in the capital city of Iran during the period 2010 to 2011. The measurements were carried out in semi-annual time intervals from January to June and July to December in each year. The maximum average dose equivalent value measured was approximately 70 μSv/month for Tehran city. Also, the average dose values obtained were less than 40 μSv/month for all the cities located at the sea level except that of high level natural radiation area of Ramsar, and more than 55 μSv/month for the higher elevation cities. The public exposure due to ambient gamma dose equivalent in Iran is within the levels reported by UNSCEAR. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cytokine production in BALB/c mice immunized with radiation attenuated third stage larvae of the filarial nematode, Brugia pahangi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bancroft, A.J.; Devaney, E.; Grencis, R.K.

1993-02-15

BALB/c mice immunized with radiation-attenuated third stage larvae of the filarial nematode Brugia pahangi are strongly immune to challenge infection. Investigation of the profile of cytokines secreted by spleen cells from immune mice stimulated in vitro with either parasite Ag or with Con A revealed high levels of IL-5 and IL-9 and moderate levels of IL-4. In contrast, secretion of IFN-[gamma] by spleen cells from immune animals was negligible. Spleen cells from control mice secreted low levels of all cytokines assayed. Levels of parasite-specific IgE were significantly elevated in immune animals and a peripheral blood eosinophilia was observed, which exhibitedmore » a biphasic distribution. Our results are consistent with the preferential expansion of Th2 cells in immune animals and provide the basis for dissecting the means by which radiation-attenuated larvae of filarial nematodes stimulate immunity. 5l refs., 3 figs., 3 tabs.« less

Effect of elevated CO2, O3, and UV radiation on soils.

PubMed

Formánek, Pavel; Rejšek, Klement; Vranová, Valerie

2014-01-01

In this work, we have attempted to review the current knowledge on the impact of elevated CO2, O3, and UV on soils. Elevated CO2 increases labile and stabile soil C pool as well as efficiency of organic pollutants rhizoremediation and phytoextraction of heavy metals. Conversely, both elevated O3 and UV radiation decrease inputs of assimilates to the rhizosphere being accompanied by inhibitory effects on decomposition processes, rhizoremediation, and heavy metals phytoextraction efficiency. Contrary to elevated CO2, O3, or UV-B decreases soil microbial biomass, metabolisable C, and soil N t content leading to higher C/N of soil organic matter. Elevated UV-B radiation shifts soil microbial community and decreases populations of soil meso- and macrofauna via direct effect rather than by induced changes of litter quality and root exudation as in case of elevated CO2 or O3. CO2 enrichment or increased UV-B is hypothesised to stimulate or inhibit both plant and microbial competitiveness for soluble soil N, respectively, whereas O3 favours only microbial competitive efficiency. Understanding the consequences of elevated CO2, O3, and UV radiation for soils, especially those related to fertility, phytotoxins inputs, elements cycling, plant-microbe interactions, and decontamination of polluted sites, presents a knowledge gap for future research.

Effect of Elevated CO2, O3, and UV Radiation on Soils

PubMed Central

Rejšek, Klement; Vranová, Valerie

2014-01-01

In this work, we have attempted to review the current knowledge on the impact of elevated CO2, O3, and UV on soils. Elevated CO2 increases labile and stabile soil C pool as well as efficiency of organic pollutants rhizoremediation and phytoextraction of heavy metals. Conversely, both elevated O3 and UV radiation decrease inputs of assimilates to the rhizosphere being accompanied by inhibitory effects on decomposition processes, rhizoremediation, and heavy metals phytoextraction efficiency. Contrary to elevated CO2, O3, or UV-B decreases soil microbial biomass, metabolisable C, and soil Nt content leading to higher C/N of soil organic matter. Elevated UV-B radiation shifts soil microbial community and decreases populations of soil meso- and macrofauna via direct effect rather than by induced changes of litter quality and root exudation as in case of elevated CO2 or O3. CO2 enrichment or increased UV-B is hypothesised to stimulate or inhibit both plant and microbial competitiveness for soluble soil N, respectively, whereas O3 favours only microbial competitive efficiency. Understanding the consequences of elevated CO2, O3, and UV radiation for soils, especially those related to fertility, phytotoxins inputs, elements cycling, plant-microbe interactions, and decontamination of polluted sites, presents a knowledge gap for future research. PMID:24688424

Action levels for airborne uranium in the workplace: chemical and radiological assessments.

PubMed

Leggett, R W; Meck, R A

2018-06-01

A method is described for deriving two levels of action-an investigation level (IL) and an immediate action level (IAL)-for different forms and mixtures of the natural uranium (U) isotopes 234 U, 235 U, and 238 U in air in the workplace. An IL indicates the need to confirm the validity of moderately elevated measurements of airborne U and adequacy of confinement controls and determine whether work limitations are appropriate. An IAL indicates that safeguards should be put into place immediately, including removal of workers from further exposure until conditions are acceptable. Derivations of ILs and IALs are based on latest radiation protection guidance, information on chemical toxicity of U, and biokinetic models for U. An action level (IL or IAL) is the more restrictive of two derived values, the action level based on U as a chemical hazard and the action level based on U as a radiation hazard.

Thyroid Cancer after Childhood Exposure to External Radiation: An Updated Pooled Analysis of 12 Studies.

PubMed

Veiga, Lene H S; Holmberg, Erik; Anderson, Harald; Pottern, Linda; Sadetzki, Siegal; Adams, M Jacob; Sakata, Ritsu; Schneider, Arthur B; Inskip, Peter; Bhatti, Parveen; Johansson, Robert; Neta, Gila; Shore, Roy; de Vathaire, Florent; Damber, Lena; Kleinerman, Ruth; Hawkins, Michael M; Tucker, Margaret; Lundell, Marie; Lubin, Jay H

2016-05-01

Studies have causally linked external thyroid radiation exposure in childhood with thyroid cancer. In 1995, investigators conducted relative risk analyses of pooled data from seven epidemiologic studies. Doses were mostly <10 Gy, although childhood cancer therapies can result in thyroid doses >50 Gy. We pooled data from 12 studies of thyroid cancer patients who were exposed to radiation in childhood (ages <20 years), more than doubling the data, including 1,070 (927 exposed) thyroid cancers and 5.3 million (3.4 million exposed) person-years. Relative risks increased supralinearly through 2-4 Gy, leveled off between 10-30 Gy and declined thereafter, remaining significantly elevated above 50 Gy. There was a significant relative risk trend for doses <0.10 Gy (P < 0.01), with no departure from linearity (P = 0.36). We observed radiogenic effects for both papillary and nonpapillary tumors. Estimates of excess relative risk per Gy (ERR/Gy) were homogeneous by sex (P = 0.35) and number of radiation treatments (P = 0.84) and increased with decreasing age at the time of exposure. The ERR/Gy estimate was significant within ten years of radiation exposure, 2.76 (95% CI, 0.94-4.98), based on 42 exposed cases, and remained elevated 50 years and more after exposure. Finally, exposure to chemotherapy was significantly associated with thyroid cancer, with results supporting a nonsynergistic (additive) association with radiation.

Radiation detection method and system using the sequential probability ratio test

DOEpatents

Nelson, Karl E [Livermore, CA; Valentine, John D [Redwood City, CA; Beauchamp, Brock R [San Ramon, CA

2007-07-17

A method and system using the Sequential Probability Ratio Test to enhance the detection of an elevated level of radiation, by determining whether a set of observations are consistent with a specified model within a given bounds of statistical significance. In particular, the SPRT is used in the present invention to maximize the range of detection, by providing processing mechanisms for estimating the dynamic background radiation, adjusting the models to reflect the amount of background knowledge at the current point in time, analyzing the current sample using the models to determine statistical significance, and determining when the sample has returned to the expected background conditions.

Difference in the action mechanism of radon inhalation and radon hot spring water drinking in suppression of hyperuricemia in mice.

PubMed

Etani, Reo; Kataoka, Takahiro; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro; Yamaoka, Kiyonori

2016-06-01

Although radon therapy is indicated for hyperuricemia, the underlying mechanisms of action have not yet been elucidated in detail. Therefore, we herein examined the inhibitory effects of radon inhalation and hot spring water drinking on potassium oxonate (PO)-induced hyperuricemia in mice. Mice inhaled radon at a concentration of 2000 Bq/m(3) for 24 h or were given hot spring water for 2 weeks. Mice were then administrated PO at a dose of 500 mg/kg. The results obtained showed that serum uric acid levels were significantly increased by the administration of PO. Radon inhalation or hot spring water drinking significantly inhibited elevations in serum uric acid levels through the suppression of xanthine oxidase activity in the liver. Radon inhalation activated anti-oxidative functions in the liver and kidney. These results suggest that radon inhalation inhibits PO-induced hyperuricemia by activating anti-oxidative functions, while hot spring water drinking may suppress PO-induced elevations in serum uric acid levels through the pharmacological effects of the chemical compositions dissolved in it. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Radon in Soil Gas Above Bedrock Fracture Sets at the Shepley’s Hill Superfund Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.R. Giles; T.L. McLing; M.V. Carpenter

2012-12-01

The Idaho National Laboratory (INL) recently provided technical support for ongoing environmental remediation activities at the Shepley’s Hill remediation site near Devens, MA (Figure 1). The technical support was requested as follow-on work to an initial screening level radiation survey conducted in 2008. The purpose of the original study was to assess the efficacy of the INL-developed Backpack Sodium Iodide System (BaSIS) for detecting elevated areas of natural radioactivity due to the decay of radon-222 gases emanating from the underlying fracture sets. Although the results from the initial study were mixed, the BaSIS radiation surveys did confirm that exposed bedrockmore » outcrops have higher natural radioactivity than the surficial soils, thus a high potential for detecting elevated levels of radon and/or radon daughter products. (INL 2009) The short count times associated with the BaSIS measurements limited the ability of the system to respond to elevated levels of radioactivity from a subsurface source, in this instance radon gas emanating from fracture sets. Thus, it was postulated that a different methodology be employed to directly detect the radon in the soil gases. The CR-39 particle track detectors were investigated through an extensive literature and technology search. The relatively long deployment or “detection” time of several days, as well as the sensitivity of the measurement and robustness of the detectors made the CR-39 technology promising for deployment at the Shepley’s Hill site.« less

European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer.

PubMed

McColl, Neil; Auvinen, Anssi; Kesminiene, Ausrele; Espina, Carolina; Erdmann, Friederike; de Vries, Esther; Greinert, Rüdiger; Harrison, John; Schüz, Joachim

2015-12-01

Ionising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other epidemiological studies of groups that have been exposed to radiation from medical, occupational or environmental sources; experimental animal studies; and studies of cellular responses to radiation. Considering exposure to environmental ionising radiation, inhalation of naturally occurring radon is the major source of radiation in the population - in doses orders of magnitude higher than those from nuclear power production or nuclear fallout. Indoor exposure to radon and its decay products is an important cause of lung cancer; radon may cause approximately one in ten lung cancers in Europe. Exposures to radon in buildings can be reduced via a three-step process of identifying those with potentially elevated radon levels, measuring radon levels, and reducing exposure by installation of remediation systems. In the 4th Edition of the European Code against Cancer it is therefore recommended to: "Find out if you are exposed to radiation from naturally high radon levels in your home. Take action to reduce high radon levels". Non-ionising types of radiation (those with insufficient energy to ionise molecules) - including extremely low-frequency electric and magnetic fields as well as radiofrequency electromagnetic fields - are not an established cause of cancer and are therefore not addressed in the recommendations to reduce cancer risk. Copyright © 2015 International Agency for Research on Cancer. Published by Elsevier Ltd. All rights reserved.

Excitotoxic and Radiation Stress Increase TERT Levels in the Mitochondria and Cytosol of Cerebellar Purkinje Neurons.

PubMed

Eitan, Erez; Braverman, Carmel; Tichon, Ailone; Gitler, Daniel; Hutchison, Emmette R; Mattson, Mark P; Priel, Esther

2016-08-01

Telomerase reverse transcriptase (TERT) is the catalytic subunit of telomerase, an enzyme that elongates telomeres at the ends of chromosomes during DNA replication. Recently, it was shown that TERT has additional roles in cell survival, mitochondrial function, DNA repair, and Wnt signaling, all of which are unrelated to telomeres. Here, we demonstrate that TERT is enriched in Purkinje neurons, but not in the granule cells of the adult mouse cerebellum. TERT immunoreactivity in Purkinje neurons is present in the nucleus, mitochondria, and cytoplasm. Furthermore, TERT co-localizes with mitochondrial markers, and immunoblot analysis of protein extracts from isolated mitochondria and synaptosomes confirmed TERT localization in mitochondria. TERT expression in Purkinje neurons increased significantly in response to two stressors: a sub-lethal dose of X-ray radiation and exposure to a high glutamate concentration. While X-ray radiation increased TERT levels in the nucleus, glutamate exposure elevated TERT levels in mitochondria. Our findings suggest that in mature Purkinje neurons, TERT is present both in the nucleus and in mitochondria, where it may participate in adaptive responses of the neurons to excitotoxic and radiation stress.

Observations of Surfzone Albedo

NASA Astrophysics Data System (ADS)

Sinnett, G.; Feddersen, F.

2014-12-01

The surfzone environment (where waves break) contains several unique and previously unconsidered processes that affect the heat budget. Entering short-wave radiation is a dominant term in both shelf and surfzone heat budgets. In contrast to the shelf, however, depth limited wave breaking in the surfzone generates spray, whitewater and suspended sediments, elevating the surface albedo (ratio of reflected to incident short-wave radiation). Elevated albedo reduces the level of solar short-wave radiation entering the water, potentially resulting in less heating. Additionally, surfzone water quality is often impacted by fecal bacteria contamination. As bacteria mortality is related to short-wave solar radiation, elevated surfzone albedo could reduce pathogen mortality, impacting human health. Albedo in the open ocean has been frequently studied and parameterizations often consider solar zenith angle, wind speed and ocean chlorophyll concentration, producing albedo values typically near 0.06. However, surfzone albedo observations have been extremely sparse, yet show depth limited wave breaking may increase the albedo by nearly a factor of 10 up to 0.5. Here, we present findings from a field study at the Scripps Institution of Oceanography pier to observe the affect of waves on surfzone albedo. Concurrent measurements were taken with a four-way radiometer (to measure both downwelling and upwelling short-wave and long wave radiation) mounted above the surfzone. A co-located GoPro camera was used to relate visual aspects of the surfzone to measured reflectance, and wave height and period were observed with a bottom mounted pressure sensor in 5 m water depth just outside the surfzone. Wind speed and direction were observed on the pier 10 m above the water surface. Here, we will examine the surfzone albedo dependence on surfzone parameters, such as wave height.

Influence of altitude and enhanced ultraviolet-B radiation on tuber production, seed viability, leaf pigments and morphology in the wild potato species Solanum kurtzianum Bitter & Wittm collected from an elevational gradient.

PubMed

Ibañez, V N; Berli, F J; Masuelli, R W; Bottini, R A; Marfil, C F

2017-08-01

Climate change could lead to an upward shift in plant distribution, exposing populations to higher levels of ultraviolet (UV)-B radiation. In the framework of an in situ strategy for conserving potato wild relatives, we evaluated the effect of high UV-B levels on natural population of Solanum kurtzianum. The hypothesis is that plants from naturally higher altitudes are more adapted to increased UV-B radiation. Two populations from low and high altitudes were field supplemented using UV-B-lamps (+UV-B) or excluded from it with plastic filters. Additionally, to assess in which extent the plant responses to these artificial experimental conditions are reproducible in natural conditions, three genotypes were cultivated in two mountain experimental gardens (EG) at different elevations. +UV-B treatment induced changes in leaf morphology and increases in phenolic compounds in both populations, indicating plant adaptation, since chlorophylls and reproductive structures were not negatively affected. These results indicate that this environmental factor may not limit the displacement of populations towards sites with higher UV-B levels. Meanwhile, in higher-altitude EG a tubers yield reduction, mainly through a decreased tuber number and a bigger accumulation of phenolic compounds than in +UV-B treatment were observed, suggesting that UV-B is not the only factor involved in plants adaptation to high altitude environments. Copyright © 2017. Published by Elsevier B.V.

Ultraviolet radiation-induced cataract in mice: the effect of age and the potential biochemical mechanism.

PubMed

Zhang, Jie; Yan, Hong; Löfgren, Stefan; Tian, Xiaoli; Lou, Marjorie F

2012-10-19

To study the effect of age on the morphologic and biochemical alterations induced by in vivo exposure of ultraviolet radiation (UV). Young and old C57BL/6 mice were exposed to broadband UVB+UVA and euthanized after 2 days. Another batch of UV-exposed young mice was monitored for changes after 1, 2, 4, and 8 days. Age-matched nonexposed mice served as controls. Lens changes were documented in vivo by slit-lamp biomicroscopy and dark field microscopy photographs ex vivo. Lens homogenates were analyzed for glutathione (GSH) level, and the activities of thioredoxin (Trx), thioltransferase (TTase), and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Glutathionylated lens proteins (PSSGs) were detected by immunoblotting using GSH antibody. Western blot analysis was also done for the expression levels of TTase and Trx. Both age groups developed epithelial and superficial anterior subcapsular cataract at 2 days postexposure. The lens GSH level and G3PD activity were decreased, and PSSGs were elevated in both age groups, but more prominent in the older mice. TTase and Trx activity and protein expression were elevated only in the young mice. Interestingly, lens TTase and Trx in the young mice showed a transient increase, peaking at 2 days after UV exposure and returning to baseline at day 8, corroborated by lens transparency. The lenses of old mice were more susceptible to UV radiation-induced cataract. The upregulated TTase and Trx likely provided oxidation damage repair in the young mice.

Spectroscopy of X-ray Photoionized Plasmas in the Laboratory

NASA Astrophysics Data System (ADS)

Liedahl, Duane A.; Loisel, Guillaume; Bailey, James E.; Nagayama, Taisuke; Hansen, Stephanie B.; Rochau, Gregory; Fontes, Christopher J.; Mancini, Roberto; Kallman, Timothy R.

2018-06-01

The physical processes operating in astrophysical plasmas --- heating, cooling, ionization, recombination, level population kinetics, and radiation transport --- are all accessible to observation in the laboratory. What distinguishes X-ray photoionized plasmas from the more common case of high-temperature collisionally-ionized plasmas is the elevated level of importance of the radiation/matter interaction. The advent of laboratory facilities with the capability to generate high-powered X-ray sources has provided the means by which to study this interaction, which is also fundamental to active galactic nuclei and other accretion-powered objects. We discuss recent and ongoing experiments, with an emphasis on X-ray spectroscopic measurements of silicon plasmas obtained at the Sandia Z Pulsed Power Facility.

Effects of HZE irradiation on chemical neurotransmission in rodent hippocampus

NASA Astrophysics Data System (ADS)

Machida, Mayumi

Space radiation represents a significant risk to the CNS (central nervous system) during space missions. Most harmful are the HZE (high mass, highly charged (Z), high energy) particles, e.g. 56Fe, which possess high ionizing ability, dense energy deposition pattern, and high penetrance. Accumulating evidence suggests that radiation has significant impact on cognitive functions. In ground-base experiments, HZE radiation induces pronounced deficits in hippocampus dependent learning and memory in rodents. However, the mechanisms underlying these impairments are mostly unknown. Exposure to HZE radiation elevates the level of oxidation, resulting in cell loss, tissue damage and functional deficits through direct ionization and generation of reactive oxygen species (ROS). When hippocampal slices were exposed to ROS, neuronal excitability was reduced. My preliminary results showed enhanced radio-vulnerability of the hippocampus and reduction in basal and depolarization-evoked [3H]-norepinephrine release after HZE exposure. These results raised the possibility that HZE radiation deteriorates cognitive function through radiation-induced impairments in hippocampal chemical neurotransmission, the hypothesis of this dissertation. In Aim 1 I have focused on the effects of HZE radiation on release of major neurotransmitter systems in the hippocampus. I have further extended my research on the levels of receptors of these systems in Aim 2. In Aim 3, I have studied the level of oxidation in membranes of my samples. My research reveals that HZE radiation significantly reduces hyperosmotic sucrose evoked [3H]-glutamate and [14C]-GABA release both three and six months post irradiation. The same radiation regimen also significantly enhances oxidative stress as indicated by increased levels of lipid peroxidation in the hippocampus, suggesting that increased levels of lipid peroxidation may play a role in reduction of neurotransmitter release. HZE radiation also significantly reduces levels of neurotransmitter receptors critical to synaptic plasticity; glutamatergic NMDA (N-methyl D-aspartate) receptors and beta1 adrenergic receptors, three months post irradiation. By six months post irradiation, the levels of these receptors are returned to normal, implying that partial repair may take place. My findings demonstrate that a single dose of HZE radiation alters the neurochemical environment in the hippocampus, which may underlie radiation-induced cognitive dysfunction.

The effect of topography on arctic-alpine aboveground biomass and NDVI patterns

NASA Astrophysics Data System (ADS)

Riihimäki, Henri; Heiskanen, Janne; Luoto, Miska

2017-04-01

Topography is a key factor affecting numerous environmental phenomena, including Arctic and alpine aboveground biomass (AGB) distribution. Digital Elevation Model (DEM) is a source of topographic information which can be linked to local growing conditions. Here, we investigated the effect of DEM derived variables, namely elevation, topographic position, radiation and wetness on AGB and Normalized Difference Vegetation Index (NDVI) in a Fennoscandian forest-alpine tundra ecotone. Boosted regression trees were used to derive non-parametric response curves and relative influences of the explanatory variables. Elevation and potential incoming solar radiation were the most important explanatory variables for both AGB and NDVI. In the NDVI models, the response curves were smooth compared with AGB models. This might be caused by large contribution of field and shrub layer to NDVI, especially at the treeline. Furthermore, radiation and elevation had a significant interaction, showing that the highest NDVI and biomass values are found from low-elevation, high-radiation sites, typically on the south-southwest facing valley slopes. Topographic wetness had minor influence on AGB and NDVI. Topographic position had generally weak effects on AGB and NDVI, although protected topographic position seemed to be more favorable below the treeline. The explanatory power of the topographic variables, particularly elevation and radiation demonstrates that DEM-derived land surface parameters can be used for exploring biomass distribution resulting from landform control on local growing conditions.

Growth habit and leaf economics determine gas exchange responses to high elevation in an evergreen tree, a deciduous shrub and a herbaceous annual

PubMed Central

Shi, Zuomin; Haworth, Matthew; Feng, Qiuhong; Cheng, Ruimei; Centritto, Mauro

2015-01-01

Plant growth at high elevations necessitates physiological and morphological plasticity to enable photosynthesis (A) under conditions of reduced temperature, increased radiation and the lower partial pressure of atmospheric gases, in particular carbon dioxide (pCO2). Previous studies have observed a wide range of responses to elevation in plant species depending on their adaptation to temperature, elevational range and growth habit. Here, we investigated the effect of an increase in elevation from 2500 to 3500 m above sea level (a.s.l.) on three montane species with contrasting growth habits and leaf economic strategies. While all of the species showed identical increases in foliar δ13C, dark respiration and nitrogen concentration with elevation, contrasting leaf gas exchange and photosynthetic responses were observed between species with different leaf economic strategies. The deciduous shrub Salix atopantha and annual herb Rumex dentatus exhibited increased stomatal (Gs) and mesophyll (Gm) conductance and enhanced photosynthetic capacity at the higher elevation. However, evergreen Quercus spinosa displayed reduced conductance to CO2 that coincided with lower levels of photosynthetic carbon fixation at 3500 m a.s.l. The lower Gs and Gm values of evergreen species at higher elevations currently constrains their rates of A. Future rises in the atmospheric concentration of CO2 ([CO2]) will likely predominantly affect evergreen species with lower specific leaf areas (SLAs) and levels of Gm rather than deciduous species with higher SLA and Gm values. We argue that climate change may affect plant species that compose high-elevation ecosystems differently depending on phenotypic plasticity and adaptive traits affecting leaf economics, as rising [CO2] is likely to benefit evergreen species with thick sclerophyllous leaves. PMID:26433706

Thoron (220Rn) in the indoor environment and work places

NASA Astrophysics Data System (ADS)

Ramachandran, T. V.; Sahoo, B. K.

2009-08-01

Ever since studies on uranium miners established the presence of a positive risk coefficient for the occurrence of lung cancer in miners exposed to elevated levels of 222Rn and its progeny, there was a great upsurge of interest in the measurement of 222Rn in the environment. Subsequently, considerable data is being generated on the levels of 222Rn in the environment across the worlds and is being periodically reported by UNSCEAR reports. In contrast to this, data pertaining to 220Rn in indoors and workplace environment is scaree due to the genral perception that its levels are negligible due to its shorter half life, and subsequently its contribution to the total inhalation dose is ignored, in the presence of other significant sources of natural radiation. This may not be true. Globally many locations have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon (222Rn), and thoron (220Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It is estimated that inhalation of 222Rn, 220Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. 220Rn problem exists in industries which use thorium nitrate. Including India, lamps using thoriated gas mantles are still being used for indoor and outdoor lighting and by hawkers in rural as well as urban areas. Considering the fact that large amount of thorium nitrate is being handled by these industries, contribution to the inhalation dose of workers from 220Rn gas emanated and build up of the progeny in ambient air may also be quite significant. In this paper current status of 220Rn levels in the indoor environment and workplaces as well as in other industries where large amount of 232Th is being handled is being summarized. Methods of measurement and reported levels are also summarized.

Relationship between white matter integrity and serum cortisol levels in drug-naive patients with major depressive disorder: diffusion tensor imaging study using tract-based spatial statistics.

PubMed

Liu, Xiaodan; Watanabe, Keita; Kakeda, Shingo; Yoshimura, Reiji; Abe, Osamu; Ide, Satoru; Hayashi, Kenji; Katsuki, Asuka; Umene-Nakano, Wakako; Watanabe, Rieko; Ueda, Issei; Nakamura, Jun; Korogi, Yukunori

2016-06-01

Higher daytime cortisol levels because of a hyperactive hypothalamic-pituitary-adrenal axis have been reported in patients with major depressive disorder (MDD). The elevated glucocorticoids inhibit the proliferation of the oligodendrocytes that are responsible for myelinating the axons of white matter fibre tracts. To evaluate the relationship between white matter integrity and serum cortisol levels during a first depressive episode in drug-naive patients with MDD (MDD group) using a tract-based spatial statistics (TBSS) method. The MDD group (n = 29) and a healthy control group (n = 47) underwent diffusion tensor imaging (DTI) scans and an analysis was conducted using TBSS. Morning blood samples were obtained from both groups for cortisol measurement. Compared with the controls, the MDD group had significantly reduced fractional anisotropy values (P<0.05, family-wise error (FWE)-corrected) in the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation. The fractional anisotropy values of the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation had significantly negative correlations with the serum cortisol levels in the MDD group (P<0.05, FWE-corrected). Our findings indicate that the elevated cortisol levels in the MDD group may injure the white matter integrity in the frontal-subcortical and frontal-limbic circuits. © The Royal College of Psychiatrists 2016.

Perfluorocarbon emulsions radiosensitise brain tumors in carbogen breathing mice with orthotopic GL261 gliomas

PubMed Central

Feldman, Lisa A.; Fabre, Marie-Sophie; Grasso, Carole; Reid, Dana; Broaddus, William C.; Lanza, Gregory M.; Spiess, Bruce D.; Garbow, Joel R.; McConnell, Melanie J.

2017-01-01

Background Tumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO2 in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy. Aim To investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O2 and 5%CO2). Results PFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone. Conclusion IV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors. PMID:28873460

Terahertz NDE of Stressed Composite Overwrapped Pressure Vessels - Initial Testing

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Seebo, Jeffrey P.; Anatasi, Robert F.

2009-01-01

Terahertz radiation nondestructive evaluation was applied to a set of Kevlar composite overwrapped pressure vessel bottles that had undergone a series of thermal and pressure tests to simulate stress rupture effects. The bottles in these nondestructive evaluation tests were bottles that had not ruptured but had survived various times at the elevated load and temperature levels. Some of the bottles showed evidence of minor composite failures. The terahertz radiation did detect visible surface flaws, but did not detect any internal chemical or material degradation of the thin overwraps.

Thyroid Cancer Induction: Nitrates as Independent Risk Factors or Risk Modulators after Radiation Exposure, with a Focus on the Chernobyl Accident

PubMed Central

Drozd, Valentina M.; Branovan, Igor; Shiglik, Nikolay; Biko, Johannes; Reiners, Christoph

2018-01-01

In recent decades, differentiated thyroid cancer (DTC) incidence has been increasing worldwide. The important contributions to this phenomenon of “overdiagnosis” driven by wider use of improved ultrasound systems are amply documented, notwithstanding the “real” carcinogenic effects of ionizing radiation, e.g., from the Chernobyl accident or health care interventions. Less well understood is the role of nitrates – as environmental pollutants, in diet, and in medication – in thyroid carcinogenesis. Increasing exposure to nitrates is associated with rising incidence of esophageal, stomach, bladder, and colon cancers. Recent data suggest that in agricultural areas with higher mean nitrate levels in groundwater, DTC risk is also elevated. Our work in Belarus after Chernobyl has shown that children in districts with high nitrate concentrations in drinking water had significantly higher thyroid cancer incidence after irradiation than did their counterparts in areas with lower nitrate concentrations. Notwithstanding thyroid shielding, increasing use of computed tomography and dental X-rays heightens radiation exposure of the salivary glands in the general population, especially in children and adolescents. When nitrate intake is increased, salivary gland irradiation may potentially result in carcinogenic elevations in plasma nitric oxide concentrations. In conclusion, excess nitrate intake seems to be an independent risk factor for DTC. Additionally, we hypothesize from our data that high nitrate levels modulate the carcinogenic effect of radiation on the thyroid. Cohort studies, case-control studies, or both, are needed to quantify the effects of nitrates on DTC risk in the presence or absence of radiation exposure, e.g., that associated with diagnostic or therapeutic health care interventions. PMID:29594057

Interactions between the impacts of ultraviolet radiation, elevated CO2, and nutrient limitation on marine primary producers.

PubMed

Beardall, John; Sobrino, Cristina; Stojkovic, Slobodanka

2009-09-01

It is well known that UV radiation can cause deleterious effects to the physiological performance, growth and species assemblages of marine primary producers. In this review we describe the range of interactions observed between these impacts of ultraviolet radiation (UVR, 280-400 nm) with other environmental factors such as the availability of photosynthetically active radiation (PAR), nutrient status and levels of dissolved CO2, all of which can, in turn, be influenced by global climate change. Thus, increases in CO2 levels can affect the sensitivity of some species to UV-B radiation (UV-B), while others show no such impact on UV-B susceptibility. Both nitrogen- and phosphorus-limitation can have direct interactive effects on the susceptibility of algal cells and communities to UVR, though such effects are somewhat variable. Nutrient depletion can also potentially lead to a dominance of smaller celled species, which may be less able to screen out and are thus likely to be more susceptible to UVR-induced damage. The variability of responses to such interactions can lead to alterations in the species composition of algal assemblages.

Measured Thermal and Fast Neutron Fluence Rates for ATF-1 Holders During ATR Cycle 157D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Larry Don; Miller, David Torbet

This report contains the thermal (2200 m/s) and fast (E>1MeV) neutron fluence rate data for the ATF-1 holders located in core for ATR Cycle 157D which were measured by the Radiation Measurements Laboratory (RML) as requested by the Power Reactor Programs (ATR Experiments) Radiation Measurements Work Order. This report contains measurements of the fluence rates corresponding to the particular elevations relative to the 80-ft. core elevation. The data in this report consist of (1) a table of the ATR power history and distribution, (2) a hard copy listing of all thermal and fast neutron fluence rates, and (3) plots ofmore » both the thermal and fast neutron fluence rates. The fluence rates reported are for the average power levels given in the table of power history and distribution.« less

Cell line specific modulation of connexin43 expression after exposure to ionizing radiation.

PubMed

Banaz-Yaşar, Ferya; Tischka, Rabea; Iliakis, George; Winterhager, Elke; Gellhaus, Alexandra

2005-01-01

Gap junctional intercellular communication plays a significant role in mediating radiation-induced bystander effects. However, the level of Cx43 itself is influenced by ionizing radiation, which could modify the bystander effect. Here we have investigated several cell lines for the modulation of Cx43 expression 24 h after irradiation with 5 Gy X-rays. The mouse endothelial cell line bEnd3 revealed a significantly elevated level of Cx43 already 15 min after exposure to X-rays, whereas human hybrid endothelial cells (EA.hy926) exhibited a transient downregulation of Cx43 mRNA. No obvious changes in the communication properties of the different cell lines could be observed after irradiation. The communication-deficient malignant human trophoblast cell line Jeg3 stably transfected with Cx43 did not reveal any induction of endogenous nor alteration in the exogenous Cx43 transcript level upon exposure to 5 Gy. Taken together, our data show a cell line specific modulation of Cx43 expression after exposure to X-rays.

Effects of low-dose ionizing radiation and menadione, an inducer of oxidative stress, alone and in combination in a vertebrate embryo model.

PubMed

Bladen, Catherine L; Kozlowski, David J; Dynan, William S

2012-11-01

Prior work has established the zebrafish embryo as an in vivo model for studying the biological effects of exposure to low doses of ionizing radiation. One of the known effects of radiation is to elevate the levels of reactive oxygen species (ROS) in tissue. However, ROS are also produced as by-products of normal metabolism and, regardless of origin, ROS produce similar chemical damage to DNA. Here we use the zebrafish embryo model to investigate whether the effects of low-dose (0-1.5 Gy) radiation and endogenous ROS are mechanistically distinct. We increased levels of endogenous ROS by exposure to low concentrations of the quinone drug, menadione. Imaging studies in live embryos showed that exposure to 3 μM or higher concentrations of menadione dramatically increased ROS levels. This treatment was associated with a growth delay and morphologic abnormalities, which were partially or fully reversible. By contrast, exposure to low doses of ionizing radiation had no discernable effects on overall growth or morphology, although, there was an increase in TUNEL-positive apoptotic cells, consistent with the results of prior studies. Further studies showed that the combined effect of radiation and menadione exposure are greater than with either agent alone, and that attenuation of the expression of Ku80, a gene important for repair of radiation-induced DNA damage, had only a slight effect on menadione sensitivity. Together, results suggest that ionizing radiation and menadione affect the embryo by distinct mechanisms.

Thyroid Cancer after Childhood Exposure to External Radiation: An Updated Pooled Analysis of 12 Studies

PubMed Central

Veiga, Lene H. S.; Holmberg, Erik; Anderson, Harald; Pottern, Linda; Sadetzki, Siegal; Adams, M. Jacob; Sakata, Ritsu; Schneider, Arthur B.; Inskip, Peter; Bhatti, Parveen; Johansson, Robert; Neta, Gila; Shore, Roy; de Vathaire, Florent; Damber, Lena; Kleinerman, Ruth; Hawkins, Michael M.; Tucker, Margaret; Lundell, Marie; Lubin, Jay H.

2016-01-01

Studies have causally linked external thyroid radiation exposure in childhood with thyroid cancer. In 1995, investigators conducted relative risk analyses of pooled data from seven epidemiologic studies. Doses were mostly <10 Gy, although childhood cancer therapies can result in thyroid doses >50 Gy. We pooled data from 12 studies of thyroid cancer patients who were exposed to radiation in childhood (ages <20 years), more than doubling the data, including 1,070 (927 exposed) thyroid cancers and 5.3 million (3.4 million exposed) person-years. Relative risks increased supralinearly through 2–4 Gy, leveled off between 10–30 Gy and declined thereafter, remaining significantly elevated above 50 Gy. There was a significant relative risk trend for doses <0.10 Gy (P < 0.01), with no departure from linearity (P = 0.36). We observed radiogenic effects for both papillary and nonpapillary tumors. Estimates of excess relative risk per Gy (ERR/Gy) were homogeneous by sex (P = 0.35) and number of radiation treatments (P = 0.84) and increased with decreasing age at the time of exposure. The ERR/Gy estimate was significant within ten years of radiation exposure, 2.76 (95% CI, 0.94–4.98), based on 42 exposed cases, and remained elevated 50 years and more after exposure. Finally, exposure to chemotherapy was significantly associated with thyroid cancer, with results supporting a nonsynergistic (additive) association with radiation. PMID:27128740

Characteristics of chromosome instability in the human lymphoblast cell line WTK1

NASA Technical Reports Server (NTRS)

Schwartz, J. L.; Jordan, R.; Evans, H. H.

2001-01-01

The characteristics of spontaneous and radiation-induced chromosome instability were determined in each of 50 individual clones isolated from control populations of human lymphoblasts (WTK1), as well as from populations of these cells previously exposed to two different types of ionizing radiation, Fe-56 and Cs-137. The types of chromosome instability did not appear to change in clones surviving radiation exposure. Aneuploidy, polyploidy, chromosome dicentrics and translocations, and chromatid breaks and gaps were found in both control and irradiated clones. The primary effect of radiation exposure was to increase the number of cells within any one clone that had chromosome alterations. Chromosome instability was associated with telomere shortening and elevated levels of apoptosis. The results suggest that the proximal cause of chromosome instability is telomere shortening.

High dietary iron increases oxidative stress and radiosensitivity in the rat retina and vasculature after exposure to fractionated gamma radiation

PubMed Central

Theriot, Corey A; Westby, Christian M; Morgan, Jennifer L L; Zwart, Sara R; Zanello, Susana B

2016-01-01

Radiation exposure in combination with other space environmental factors including microgravity, nutritional status, and deconditioning is a concern for long-duration space exploration missions. Astronauts experience altered iron homeostasis due to adaptations to microgravity and an iron-rich food system. Iron intake reaches three to six times the recommended daily allowance due to the use of fortified foods on the International Space Station. Iron is associated with certain optic neuropathies and can potentiate oxidative stress. This study examined the response of eye and vascular tissue to gamma radiation exposure (3 Gy fractionated at 37.5 cGy per day every other day for 8 fractions) in rats fed an adequate-iron diet or a high-iron diet. Twelve-week-old Sprague-Dawley rats were assigned to one of four experimental groups: adequate-iron diet/no radiation (CON), high-iron diet/no radiation (IRON), adequate-iron diet/radiation (RAD), and high-iron diet/radiation (IRON+RAD). Animals were maintained on the corresponding iron diet for 2 weeks before radiation exposure. As previously published, the high-iron diet resulted in elevated blood and liver iron levels. Dietary iron overload altered the radiation response observed in serum analytes, as evidenced by a significant increase in catalase levels and smaller decrease in glutathione peroxidase and total antioxidant capacity levels. 8-OHdG immunostaining, showed increased intensity in the retina after radiation exposure. Gene expression profiles of retinal and aortic vascular samples suggested an interaction between the response to radiation and high dietary iron. This study suggests that the combination of gamma radiation and high dietary iron has deleterious effects on retinal and vascular health and physiology. PMID:28725729

The impact of solar radiation on the use of dissolved organic matter in two Ozark Streams: Possible role of photo-enhanced humification

NASA Astrophysics Data System (ADS)

Townsend, S. L.; Ziegler, S. E.

2005-05-01

The effect of solar radiation on dissolved organic matter (DOM) utilization was studied in two contrasting streams from June 2002 through October 2004. Moores Creek is an agricultural stream with elevated nutrient and dissolved organic carbon (DOC) concentrations. Huey Hollow is a forested stream with low nutrient and DOC concentrations. A series of experiments were conducted seasonally to assess how solar radiation influenced DOM utilization. Exposure of DOM to solar radiation significantly decreased its utilization during most seasons in both streams. Each stream experienced one seasonal period when exposure of DOM significantly increased bacterial production; during these periods, DOM appeared to be the least bioavailable and most photochemically reactive. Interestingly, in spring when bioavailability of DOM was lowest in Moores Creek solar radiation exposure further reduced DOM bioavailability. Elevated ammonium concentrations during this spring experiment suggest photochemically-enhanced humification may have been an important mechanism influencing DOM cycling. Bioassays using 15N-labeled ammonium indicated no significant effect of elevated ammonium on the utilization of DOM in either stream in fall 2004. Detection of elevated 15N in the DOM fractions, however, would reveal light stimulated humification under elevated ammonium concentrations not detected with the bioassay.

[Five cases of severe radiation pneumonitis after chemoradiotherapy for esophageal cancer].

PubMed

Sakurai, Katsunobu; Kubo, Naoshi; Shibutani, Masatsune; Yamazoe, Sadaaki; Kimura, Kenjiro; Nagahara, Hisashi; Toyokawa, Takahiro; Amano, Ryosuke; Tanaka, Hiroaki; Muguruma, Kazuya; Ohtani, Hiroshi; Yashiro, Masakazu; Maeda, Kiyoshi; Ohira, Masaichi; Hirakawa, Kosei

2013-11-01

Chemoradiotherapy( CRT) for esophageal cancer is a useful modality for both locally advanced and resectable cases. Among adverse events related to CRT, radiation pneumonitis( RP) requires special attention because it has been shown to be occasionally associated with a worse acute prognosis. We report 5 cases of severe RP after CRT. All patients were male, and their mean age was 72 years (range: 66-76 years). The clinical stage of esophageal cancer was I in 1 case, II in 2 cases, and IVa in 2 cases. The mean total radiation dose was 51.8 Gy (range: 43.4-61.4). Initial symptoms and first abnormal findings were a high fever in 4 cases and elevated serum C-reactive protein( CRP) levels in 1 case. No patients presented with respiratory symptoms, including dyspnea and coughing, as initial symptoms. All cases were diagnosed as RP by chest computed tomography examination, an average of 6.8 days after the completion of RT. Four patients required intensive care and were put on ventilator support. All patients received steroid pulse therapy. Two patients recovered from RP; however, 3 died( 1 attributable to multi-organ failure and 2 to respiratory failure). It is important to consider RP caused by CRT when patients present with high fever or elevated CRP levels after the completion of RT for esophageal cancer.

76 FR 47612 - AAR Manufacturing, Inc.; Completion of Radiological Survey Activities at CSX Transportation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-05

... Plan list in August 1994. In May 1997, NRC inspectors performed a limited radiation survey of the CSXT..., 1997, letter; the report identified three locations with elevated levels of thorium in the soil (ADAMS... CSXT property. Based on the survey and sampling results, as well as an all- pathways analysis of the...

The Effect of Topographic Shadowing by Ice on Irradiance in the Greenland Ice Sheet Ablation Zone

NASA Astrophysics Data System (ADS)

Leidman, S. Z.; Rennermalm, A. K.; Ryan, J.; Cooper, M. G.; Smith, L. C.

2017-12-01

Accurately predicting runoff contributions to global sea level rise requires more refined surface mass balance (SMB) models of the Greenland Ice Sheet (GrIS). Topographic shadowing has shown to be important in the SMB of snow-covered regions, yet SMB models for the GrIS generally ignore how surface topography affects spatial variability of incoming solar radiation on a surface. In the ablation zone of Southwest Greenland, deeply incised supraglacial drainage features, fracturing, and large-scale bed deformation result in extensive areas of rough surface topography. This topography blocks direct radiation such that shadowed areas receive less energy for melting while other topographic features such as peaks recieve more energy. In this study, we quantify how shadowing from local topography features changes incoming solar radiation. We apply the ArcGIS Pro Solar Radiation Toolset to calculate the direct and diffuse irradiance in sunlit and shadowed areas by determining the sun's movement for every half hour increment of 2016. Multiple digital elevation models (DEMs) with spatial resolutions ranging from 0.06 to 5m were derived from fixed wing and quadcopter UAV imagery collected in summer 2016 and the ArcticDEM dataset. Our findings show that shadowing significantly decreases irradiance compared to smoothed surfaces where local topography is removed. This decrease is exponentially proportional to the DEM pixel sized with 5m DEMs only able to capture a small percentage of the effect. Applying these calculations to the ArcticDEM to cover a larger study area indicates that decreases in irradiance are nonlinearly proportional to elevation with highly crevassed areas showing a larger effect from shadowing. Even so, shading at higher elevations reduces irradiance enough to result in several centimeters snow water equivalence (SWE) per year of over-prediction of runoff in SMB models. Furthermore, analysis of solar radiation products shows that shadowing predicts albedo variability far better than a range of variables derived from UAV imagery mosaics including slope, aspect, elevation, or the distance to dark surface features. In summary, implementation of the effect of shadowing on irradiance should therefore be considered for accurate surface mass balance calculations for the Greenland ice sheet.

The Effects of Ambient Conditions on Helicopter Harmonic Noise Radiation: Theory and Experiment

NASA Technical Reports Server (NTRS)

Greenwood, Eric; Sim, Ben W.; Boyd, D. Douglas, Jr.

2016-01-01

The effects of ambient atmospheric conditions, air temperature and density, on rotor harmonic noise radiation are characterized using theoretical models and experimental measurements of helicopter noise collected at three different test sites at elevations ranging from sea level to 7000 ft above sea level. Significant changes in the thickness, loading, and blade-vortex interaction noise levels and radiation directions are observed across the different test sites for an AS350 helicopter flying at the same indicated airspeed and gross weight. However, the radiated noise is shown to scale with ambient pressure when the flight condition of the helicopter is defined in nondimensional terms. Although the effective tip Mach number is identified as the primary governing parameter for thickness noise, the nondimensional weight coefficient also impacts lower harmonic loading noise levels, which contribute strongly to low frequency harmonic noise radiation both in and out of the plane of the horizon. Strategies for maintaining the same nondimensional rotor operating condition under different ambient conditions are developed using an analytical model of single main rotor helicopter trim and confirmed using a CAMRAD II model of the AS350 helicopter. The ability of the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique to generalize noise measurements made under one set of ambient conditions to make accurate noise predictions under other ambient conditions is also validated.

Dried fruit extract from Xylopia aethiopica (Annonaceae) protects Wistar albino rats from adverse effects of whole body radiation.

PubMed

Adaramoye, Oluwatosin A; Okiti, Osume O; Farombi, E Olatunde

2011-11-01

The effect of dried fruit extract from Xylopia aethiopica (Annonaceae) (XA) and vitamin C (VC) against γ-radiation-induced liver and kidney damage was studied in male Wistar rats. XA and VC were given orally at a dose of 250 mg/kg, orally for 6 weeks prior to and 8 weeks after radiation (5 Gy). The rats were sacrificed after 1 and 8 weeks of single exposure to radiation. Results showed that all animals in un-irradiated group survived (100%), while 83.3% and 66.7% survived in XA- and VC-treated groups, respectively, and 50% survived in irradiated group. The levels of serum, liver and kidney lipid peroxidation (LPO) were elevated by 88%, 102% and 73% after 1 week of exposure, and by 152%, 221% and 178%, after 8 weeks of exposure, respectively. Treatment with XA and VC significantly (p<0.05) decreased the levels of LPO in the irradiated animals. Also, γ-radiation caused significant decreases (p<0.05) in the levels of liver glutathione (GSH), glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), kidney GSH and SOD by 41%, 60%, 81%, 79%, 72% and 58% after 1 week of exposure. Similarly, γ-radiation caused significant increases (p<0.05) in the levels of serum alanine (ALT) and aspartate aminotransferases (AST) after 8 weeks of exposure. Precisely, ALT and AST levels were increased by 69% and 82%, respectively. These changes were significantly (p<0.05) attenuated in irradiated animals treated with XA and VC. These results suggest that XA and VC could increase the antioxidant defence systems in the liver and kidney of irradiated animals, and may protect from adverse effects of whole body radiation. Copyright © 2010 Elsevier GmbH. All rights reserved.

Trichostatin A inhibits radiation-induced epithelial-to-mesenchymal transition in the alveolar epithelial cells

PubMed Central

Nagarajan, Devipriya; Wang, Lei; Zhao, Weiling; Han, Xiaochen

2017-01-01

Radiation-induced pneumonitis and fibrosis are major complications following thoracic radiotherapy. Epithelial-to-mesenchymal transition (EMT) plays an important role in tissue injury leading to organ fibrosis, including lung. Our previous studies have reported that radiation can induce EMT in the type II alveolar epithelial cells in both in vitro and in vivo. HDAC inhibitors are a new family of anti-cancer agents currently being used in several clinical trials. In addition to their intrinsic anti-tumor properties, HDAC inhibition is also important in other human diseases, including fibrosis and radiation-induced damage. In this study, we evaluated the effect of Trichostatin A (TSA), a HDAC inhibitor, on radiation-induced EMT in type II alveolar epithelial cells (RLE-6TN). Pre-treatment of RLE-6TN cells with TSA inhibited radiation-induced EMT-like morphological alterations including elevated protein level of α-SMA and Snail, reduction of E-cadherin expression, enhanced phosphorylation of GSK3β and ERK1/2, increased generation of ROS. Radiation enhanced the protein level of TGF-β1, which was blocked by N-acetylcysteine, an antioxidant. Treating cells with SB-431542, TGF-β1 type I receptor inhibitor, diminished radiation-induced alterations in the protein levels of p-GSK-3β, Snail-1 and α-SMA, suggesting a regulatory role of TGF-β1 in EMT. Pre-incubation of cells with TSA showed significant decrease in the level of TGF-β1 compared to radiation control. Collectively, these results demonstrate that i] radiation-induced EMT in RLE-6TN cells is mediated by ROS/MEK/ERK and ROS/TGF-β1 signaling pathways and ii] the inhibitory role of TSA in radiation-induced EMT appears to be due, at least in part, to its action of blocking ROS and TGF-β1 signaling. PMID:29254201

Estimating net solar radiation using Landsat Thematic Mapper and digital elevation data

NASA Technical Reports Server (NTRS)

Dubayah, R.

1992-01-01

A radiative transfer algorithm is combined with digital elevation and satellite reflectance data to model spatial variability in net solar radiation at fine spatial resolution. The method is applied to the tall-grass prairie of the 16 x 16 sq km FIFE site (First ISLSCP Field Experiment) of the International Satellite Land Surface Climatology Project. Spectral reflectances as measured by the Landsat Thematic Mapper (TM) are corrected for atmospheric and topographic effects using field measurements and accurate 30-m digital elevation data in a detailed model of atmosphere-surface interaction. The spectral reflectances are then integrated to produce estimates of surface albedo in the range 0.3-3.0 microns. This map of albedo is used in an atmospheric and topographic radiative transfer model to produce a map of net solar radiation. A map of apparent net solar radiation is also derived using only the TM reflectance data, uncorrected for topography, and the average field-measured downwelling solar irradiance. Comparison with field measurements at 10 sites on the prairie shows that the topographically derived radiation map accurately captures the spatial variability in net solar radiation, but the apparent map does not.

The Semipalatinsk nuclear test site: a first assessment of the radiological situation and the test-related radiation doses in the surrounding territories.

PubMed

Gusev, B I; Abylkassimova, Z N; Apsalikov, K N

1997-09-01

As a result of atmospheric nuclear tests at the Semipalatinsk test site 'Polygon', adjacent territories were contaminated by radionuclide fallout. The population of some districts in the Semipalatinsk oblast were exposed to elevated levels of radiation. Contamination and exposure mostly resulted from early atmospheric tests. The radiological situation of the Semipalatinsk oblast is described. Effective dose estimates due to external and internal exposure attributable to the 1949 and 1953 tests in villages near the Polygon range from 70 mSv to 4470 mSv.

Blood lead levels in NASCAR Nextel Cup teams.

PubMed

O'Neil, Joseph; Steele, Gregory; McNair, C Scott; Matusiak, Matthew M; Madlem, Jyl

2006-02-01

This pilot study determines whether NASCAR racing teams demonstrate exposure to lead from exhaust by evaluation of blood lead levels (BLL). Participants were stratified by proximity to fuel exhaust or whether they worked on an engine. Each participant completed a self-reported survey recording demographics, lead exposure (occupational or in-home environment), and any physical symptoms of lead toxicity. Blood lead levels were then measured. BLL of 47 individuals ranged from 1-22 microg/dL with a median of 9.4 microg/dL. Nineteen of 47 (40.4%) had BLL > or = 10 microg/dL. Participants exposed to exhaust gas had the highest relative risks (RR) for elevated lead, followed by working on brakes and radiator repair. The RR of having an elevated BLL and self-reported adverse health outcomes or symptoms was increased. This study of NASCAR racing teams demonstrates lead exposure.

Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis ofmore » testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.« less

Effects of Low-Dose Ionizing Radiation and Menadione, an Inducer of Oxidative Stress, Alone and in Combination in a Vertebrate Embryo Model

PubMed Central

Bladen, Catherine L.; Kozlowski, David J.; Dynan, William S.

2014-01-01

Prior work has established the zebrafish embryo as an in vivo model for studying the biological effects of exposure to low doses of ionizing radiation. One of the known effects of radiation is to elevate the levels of reactive oxygen species (ROS) in tissue. However, ROS are also produced as byproducts of normal metabolism and, regardless of origin, ROS produce similar chemical damage to DNA. Here we use the zebrafish embryo model to investigate whether the effects of low-dose (0–1.5 Gy) radiation and endogenous ROS are mechanistically distinct. We increased levels of endogenous ROS by exposure to low concentrations of the quinone drug, menadione. Imaging studies in live embryos showed that exposure to 3 μM or higher concentrations of menadione dramatically increased ROS levels. This treatment was associated with a growth delay and morphologic abnormalities, which were partially or fully reversible. By contrast, exposure to low doses of ionizing radiation had no discernable effects on overall growth or morphology, although, there was an increase in TUNEL-positive apoptotic cells, consistent with the results of prior studies. Further studies showed that the combined effect of radiation and menadione exposure are greater than with either agent alone, and that attenuation of the expression of Ku80, a gene important for repair of radiation-induced DNA damage, had only a slight effect on menadione sensitivity. Together, results suggest that ionizing radiation and menadione affect the embryo by distinct mechanisms. PMID:23092554

Epstein-Barr virus myocarditis as the first symptom of infectious mononucleosis.

PubMed

Zabala López, Sergio; Vicario, Juana M; Lerín, Francisco J; Fernández, Amalia; Pérez, Gloria; Fonseca, Cherpentier

2010-01-01

This case report describes a 20-year-old immunocompetent man with an episode of chest pain radiating into both arms, an increase in the level of myocardial enzymes, electrocardiogram abnormalities (widespread ST-segment elevation and q waves in leads V(4)-V(6)) and serological evidence for acute Epstein-Barr Virus infection preceding typical signs and symptoms of infectious mononucleosis.

UV-B radiation-induced oxidative stress and p38 signaling pathway involvement in the benthic copepod Tigriopus japonicus.

PubMed

Kim, Bo-Mi; Rhee, Jae-Sung; Lee, Kyun-Woo; Kim, Min-Jung; Shin, Kyung-Hoon; Lee, Su-Jae; Lee, Young-Mi; Lee, Jae-Seong

2015-01-01

Ultraviolet B (UV-B) radiation presents an environmental hazard to aquatic organisms. To understand the molecular responses of the intertidal copepod Tigriopus japonicus to UV-B radiation, we measured the acute toxicity response to 96 h of UV-B radiation, and we also assessed the intracellular reactive oxygen species (ROS) levels, glutathione (GSH) content, and antioxidant enzyme (GST, GR, GPx, and SOD) activities after 24 h of exposure to UV-B with LD50 and half LD50 values. Also, expression patterns of p53 and hsp gene families with phosphorylation of p38 MAPK were investigated in UV-B-exposed copepods. We found that the ROS level, GSH content, and antioxidant enzyme activity levels were increased with the transcriptional upregulation of antioxidant-related genes, indicating that UV-B induces oxidative stress by generating ROS and stimulating antioxidant enzymatic activity as a defense mechanism. Additionally, we found that p53 expression was significantly increased after UV-B irradiation due to increases in the phosphorylation of the stress-responsive p38 MAPK, indicating that UV-B may be responsible for inducing DNA damage in T. japonicus. Of the hsp family genes, transcriptional levels of hsp20, hsp20.7, hsp70, and hsp90 were elevated in response to a low dose of UV-B radiation (9 kJ m(-2)), suggesting that these hsp genes may be involved in cellular protection against UV-B radiation. In this paper, we performed a pathway-oriented mechanistic analysis in response to UV-B radiation, and this analysis provides a better understanding of the effects of UV-B in the intertidal benthic copepod T. japonicus. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of low-level chronic irradiation on the radiosensitivity of mammals: Modeling studies

NASA Astrophysics Data System (ADS)

Smirnova, O. A.

Mathematical models of the major hematopoietic lines are used to study the modifying effects of low-level chronic preirradiation on radiosensitivity of mammals which resulted in their reduced radiosensitivity (acquired radioresistance) and elevated radiosensitivity (hypersensitivity) to the subsequent radiation exposure. These effects of preirradiation manifest themselves, respectively, in decreased and increased mortality of preirradiated experimental animals (mice) after challenge acute exposure in comparison with that for previously nonirradiated ones. Analysis of the modeling results reveals the biological mechanisms of these radioprotection and radiosensitization effects, and enables one to estimate the ranges of dose rate and duration of chronic preirradiation where these effects are realized. Juxtapositions of the modeling predictions with the relevant experimental data show their qualitative agreement. All this testifies to the importance of accounting the nonlinear effect of low-level chronic irradiation on radiosensitivity of the hematopoiesis system and organism as a whole, when the radiation risk for astronauts on long-term space missions is estimated. The developed models of hematopoiesis can be used, after appropriate identification, as a component of the mathematical tools for radiation risk assessment.

Increased expression of connective tissue growth factor (CTGF) in multiple organs after exposure of non-human primates (NHP) to lethal doses of radiation

PubMed Central

Zhang, Pei; Cui, Wanchang; Hankey, Kim G.; Gibbs, Allison M.; Smith, Cassandra P.; Taylor-Howell, Cheryl; Kearney, Sean R.; MacVittie, Thomas J.

2015-01-01

Exposure to sufficiently high doses of ionizing radiation is known to cause fibrosis in many different organs and tissues. Connective tissue growth factor (CTGF/CCN2), a member of the CCN family of matricellular proteins, plays an important role in the development of fibrosis in multiple organs. The aim of the present study was to quantify the gene and protein expression of CTGF in a variety of organs from non-human primates (NHP) that were previously exposed to potentially lethal doses of radiation. Tissues from non-irradiated NHP, and NHP exposed to whole thoracic lung irradiation (WTLI) or partial-body irradiation with 5% bone marrow sparing (PBI/BM5) were examined by real-time quantitative reverse transcription PCR, western blot, and immunohistochemistry. Expression of CTGF was elevated in the lung tissues of NHP exposed to WTLI relative to the lung tissues of the non-irradiated NHP. Increased expression of CTGF was also observed in multiple organs from NHP exposed to PBI/BM5 compared to non-irradiated NHP; these included the lung, kidney, spleen, thymus and liver. These irradiated organs also exhibited histological evidence of increased collagen deposition compared to the control tissues. There was significant correlation of CTGF expression with collagen deposition in the lung and spleen of NHP exposed to PBI/BM5. Significant correlations were observed between spleen and multiple organs on CTGF expression and collagen deposition respectively, suggesting possible crosstalk between spleen and other organs. Our data suggest that CTGF levels are increased in multiple organs after radiation exposure and that inflammatory cell infiltration may contribute to the elevated levels of CTGF in multiple organs. PMID:26425899

Bystander effects in radiation-induced genomic instability

NASA Technical Reports Server (NTRS)

Morgan, William F.; Hartmann, Andreas; Limoli, Charles L.; Nagar, Shruti; Ponnaiya, Brian

2002-01-01

Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and radiation-induced chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that radiation induces conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability.

Effect of Low Level Subchronic Microwave Radiation on Rat Brain.

PubMed

Deshmukh, Pravin Suryakantrao; Megha, Kanu; Nasare, Namita; Banerjee, Basu Dev; Ahmed, Rafat Sultana; Abegaonkar, Mahesh Pandurang; Tripathi, Ashok Kumar; Mediratta, Pramod Kumari

2016-12-01

The present study was designed to investigate the effects of subchronic low level microwave radiation (MWR) on cognitive function, heat shock protein 70 (HSP70) level and DNA damage in brain of Fischer rats. Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies: 900, 1800, and 2450 MHz. Animals were divided into 4 groups: Group I: Sham exposed, Group II: animals exposed to microwave radiation at 900 MHz and specific absorption rate (SAR) 5.953 × 10-4 W/kg, Group III: animals exposed to 1800 MHz at SAR 5.835 × 10-4 W/kg and Group IV: animals exposed to 2450 MHz at SAR 6.672 × 10-4 W/kg. All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues. HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay. Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function, increase in HSP70 level and DNA damage in brain. The results of the present study suggest that low level microwave exposure at frequencies 900, 1800, and 2450 MHz may lead to hazardous effects on brain. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Leaf movement in Calathea lutea (Marantaceae).

PubMed

Herbert, Thomas J; Larsen, Parry B

1985-09-01

Calathea lutea is a broad-leaved, secondary successional plant which shows complex leaf movements involving both elevation and folding of the leaf surface about the pulvinus. In the plants studied, mean leaf elevation increased from approximately 34 degrees in the early morning to 70 degrees at noon while the angle of leaf folding increased from 13 degrees to 50 degrees over the same time period. During the period from early morning to noon, these movements resulted in a significant decrease in the cosine of the angle of incidence, a measure of the direct solar radiation intercepted. The observed changes in elevational angle significantly reduce the cosine of angle of incidence while folding does not significantly reduce the fraction of direct solar radiation intercepted during the period of direct exposure of the leaf surface to the solar beam. Since elevational changes seem to account for the reduction in exposure to direct solar radiation, the role of folding remains unclear.

Climate change and agricultural workers' health in Ecuador: occupational exposure to UV radiation and hot environments.

PubMed

Harari Arjona, Raul; Piñeiros, Jessika; Ayabaca, Marcelo; Harari Freire, Florencia

2016-01-01

Climate change is a global concern but little is known about its potential health effects in workers from non-industrialized countries. Ecuadorian workers from the coast (hot environments) and Andean region (elevated UV radiation) might be at particular risk of such effects. In the Andean region, measurements of UV index show maximum levels exceeding 11, a level considered being extreme according to the WHO. Also, an increased incidence of skin cancer was reported the last decennium, this being the second most common cancer type in men and women. In the coast, a high reported prevalence of kidney disease in agricultural workers is suggested to be related to exposure to hot temperatures. The scarce data available on occupational health in Ecuadorian agricultural workers raise the need for further investigation. Data worldwide shows an increasing prevalence of UV radiation- and heat stress-related illnesses in agricultural workers and urges the adoption of preventive measures.

Overexpression of SKP2 promotes the radiation resistance of esophageal squamous cell carcinoma.

PubMed

Wang, Xiao-Chun; Tian, Li-Li; Tian, Jing; Jiang, Xiao-Yan

2012-01-01

SKP2 is the substrate recognition subunit of the SCF(SKP2) ubiquitin ligase complex. It is implicated in ubiquitin-mediated degradation of the cyclin-dependent kinase (CDK) inhibitor p27(KIP1) and positively regulates the G(1)/S transition. Overexpression of SKP2 has been found in many kinds of tumors. In the present study, we found that SKP2 expression levels increased in esophageal squamous cell carcinoma tissues. Elevated expression of SKP2 correlated significantly with tumor stage and positive lymph node metastasis (P < 0.05). Moreover, a significantly negative correlation was found between SKP2 expression and the survival of patients who received radiotherapy (P < 0.05). At the molecular level, induced expression of SKP2 promoted the radioresistance of EC9706 cells. Knockdown of SKP2 expression sensitized cancer cells to radiation, and a wobble mutant of SKP2 that was resistant to SKP2 siRNA was able to rescue this effect. Increased or decreased expression levels of SKP2 had effects on Rad51 expression after irradiation. These results demonstrate for the first time that overexpression of SKP2 was correlated with the increased radioresistance of esophageal squamous cell carcinoma. Elevated expression of SKP2 promoted the radioresistance of cancer cells, and this effect was mediated at least in part by the Rad51 pathway.

Why Does Rhinopithecus bieti Prefer the Highest Elevation Range in Winter? A Test of the Sunshine Hypothesis

PubMed Central

Behm, Jocelyn E.; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo

2011-01-01

Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100–4400 m in winter although the yearly home range spanned from 3500–4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. PMID:21915329

Mortality among the residents of the Three Mile Island accident area: 1979-1992.

PubMed

Talbott, E O; Youk, A O; McHugh, K P; Shire, J D; Zhang, A; Murphy, B P; Engberg, R A

2000-06-01

The largest U.S. population exposed to low-level radioactivity released by an accident at a nuclear power plant is composed of residents near the Three Mile Island (TMI) Plant on 28 March 1979. This paper (a collaboration of The University of Pittsburgh and the Pennsylvania Department of Health) reports on the mortality experience of the 32,135 members in this cohort for 1979-1992. We analyzed standardized mortality ratios (SMRs) using a local comparison population and performed relative risk regression modeling to assess overall mortality and specific cancer risks by confounding factors and radiation-related exposure variables. Total mortality was significantly elevated for both men and women (SMRs = 109 and 118, respectively). All heart disease accounted for 43.3% of total deaths and demonstrated elevated SMRs for heart disease of 113 and 130 for men and women, respectively; however, when controlling for confounders and natural background radiation, these elevations in heart disease were no longer evident. Overall cancer mortality was similar in this cohort as compared to the local population (male SMR = 100; female SMR = 101). In the relative risk modeling, there was a significant effect for all lymphatic and hematopoietic tissue in males in relation to natural background exposure (p = 0.04). However, no trend was noted. We found a significant linear trend for female breast cancer risk in relation to increasing levels of TMI-related likely [gamma]-exposure (p = 0.02). Although such a relationship has been noted in other investigations, emissions from the TMI incident were significantly lower than in other documented studies. Therefore, it is unlikely that this observed increase is related to radiation exposure on the day of the accident. The mortality surveillance of this cohort does not provide consistent evidence that radioactivity released during the TMI accident has a significant impact on the mortality experience of this cohort to date. However, continued follow-up of these individuals will provide a more comprehensive description of the morbidity and mortality experience of the cohort.

Succinylcholine-induced hyperkalemia in the rat following radiation injury to muscle. [60Co

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cairoli, V.J.; Ivankovich, A.D.; Vucicevic, D.

1982-02-01

During anesthetic preparation of a patient who had received routine radiation therapy of sarcoma of the leg, cardiac collapse occurred following succinylcholine (SCh) administration. Experiments were designed to test the hypothesis that radiation injury to muscle might cause increased sensitivity to SCh similar to that reported in patients with muscle trauma, severe burns, and lesions causing muscle denervation. Venous plasma potassium levels and arterial blood gas tensions were measured in rats after they were given SCh (3 mg/kg) at various times following 60Co irradiation of the hind legs. Nonirradiated rats responded to SCh with a slight but statistically significant increasemore » in plasma K+. Rats subjected to high levels of radiation (10,000 to 20,000 R) and given SCh 4 to 7 days later responded in the same way as the control rats. Plasma K+ levels in rats exposed to a fractionated irradiated dosage (25000 R given twice with a 1-week interval) followed by SCh 1 week later were similar to those in the control group, but when SCh was given 2 weeks later (3 weeks after initial irradiation) there was a marked elevation of plasma K+, from 3.6 to 7.7 meq/L, a statistically significant increase.« less

Succinylcholine-induced hyperkalemia in the rat following radiation injury to muscle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cairoli, V.J.; Ivankovich, A.D.; Vucicevic, D.

1982-02-01

During anesthetic preparation of a patient who had received routine radiation therapy for sarcoma of the leg, cardiac collapse occurred following succinylcholine (SCh) administration. Experiments were designed to test the hypothesis that radiation injury to muscle might cause increased sensitivity to SCh similar to that reported in patients with muscle trauma, severe burns, and lesions causing muscle denervation. Venous plasma potassium levels and arterial blood gas tensions were measured in rats after they were given SCh (3 mg/kg) at various times following /sup 60/Co irradiation of the hind legs. Nonirradiated rats responded to SCh with a slight but statistically significantmore » increase in plasma K+. Rats subjected to high levels of radiation (10,000 to 20,000 R) and given SCh 4 to 7 days later responded in the same way as the control rats. Plasma K+ levels in rats exposed to a fractionated irradiated dosage (2500 R given twice with a 1-week interval) followed by SCh 1 week later were similar to those in the control group, but when SCh was given 2 weeks later (3 weeks after initial irradiation) there was a marked elevation of plasma K+, from 3.6 to 7.7 meq/L, a statistically significant increase.« less

Polymer materials and component evaluation in acidic-radiation environments

NASA Astrophysics Data System (ADS)

Celina, M.; Gillen, K. T.; Malone, G. M.; Clough, R. L.; Nelson, W. H.

2001-07-01

Polymeric materials used for cable/wire insulation, electrical connectors, O-rings, seals, and in critical components such as motors, level switches and resistive thermo-devices were evaluated under accelerated degradation conditions in combined radiation-oxidative elevated-temperature acidic-vapor (nitric/oxalic) environments relevant to conditions in isotope processing facilities. Experiments included the assessment of individual materials such as PEEK, polyimides, polyolefin based cable insulation, EPDM rubbers, various epoxy systems, commercial caulking materials as well as some functional testing of components. We discuss how to conduct laboratory experiments to simulate such complex hostile environments, describe some degradation effects encountered, and evaluate the impact on appropriate material and component selection.

Consequences of irradiation on bone and marrow phenotypes, and its relation to disruption of hematopoietic precursors

PubMed Central

Green, Danielle E.; Rubin, Clinton T.

2014-01-01

The rising levels of radiation exposure, specifically for medical treatments and accidental exposures, have added great concern for the long term risks of bone fractures. Both the bone marrow and bone architecture are devastated following radiation exposure. Even sub-lethal doses cause a deficit to the bone marrow microenvironment, including a decline in hematopoietic cells, and this deficit occurs in a dose dependent fashion. Certain cell phenotypes though are more susceptible to radiation damage, with mesenchymal stem cells being more resilient than the hematopoietic stem cells. The decline in total bone marrow hematopoietic cells is accompanied with elevated adipocytes into the marrow cavity, thereby inhibiting hematopoiesis and recovery of the bone marrow microenvironment. Poor bone marrow is also associated with a decline in bone architectural quality. Therefore, the ability to maintain the bone marrow microenvironment would hinder much of the trabecular bone loss caused by radiation exposure, ultimately decreasing some comorbidities in patients exposed to radiation. PMID:24607941

Hypothermia modulates the DNA damage response to ionizing radiation in human peripheral blood lymphocytes.

PubMed

Lisowska, Halina; Cheng, Lei; Sollazzo, Alice; Lundholm, Lovisa; Wegierek-Ciuk, Aneta; Sommer, Sylwester; Lankoff, Anna; Wojcik, Andrzej

2018-06-01

Low temperature at exposure has been shown to act in a radioprotective manner at the level of cytogenetic damage. It was suggested to be due to an effective transformation of DNA damage to chromosomal damage at low temperature. The purpose of the study was to analyze the kinetics of aberration formation during the first hours after exposing human peripheral blood lymphocytes to ionizing radiation at 0.8 °C and 37 °C. To this end, we applied the technique of premature chromosome condensation. In addition, DNA damage response was analyzed by measuring the levels of phosphorylated DNA damage responsive proteins ATM, DNA-PK and p53 and mRNA levels of the radiation-responsive genes BBC3, FDXR, GADD45A, XPC, MDM2 and CDKN1A. A consistently lower frequency of chromosomal breaks was observed in cells exposed at 0.8 °C as compared to 37 °C already after 30 minutes postexposure. This effect was accompanied by elevated levels of phosphorylated ATM and DNA-PK proteins and a reduced immediate level of phosphorylated p53 and of the responsive genes. Low temperature at exposure appears to promote DNA repair leading to reduced transformation of DNA damage to chromosomal aberrations.

Protective effects of seabuckthorn pulp and seed oils against radiation-induced acute intestinal injury.

PubMed

Shi, Jing; Wang, Lan; Lu, Yan; Ji, Yue; Wang, Yaqing; Dong, Ke; Kong, Xiangqing; Sun, Wei

2017-01-01

Radiation-induced gastrointestinal syndrome, including nausea, diarrhea and dehydration, contributes to morbidity and mortality after medical or industrial radiation exposure. No safe and effective radiation countermeasure has been approved for clinical therapy. In this study, we aimed to investigate the potential protective effects of seabuckthorn pulp and seed oils against radiation-induced acute intestinal injury. C57/BL6 mice were orally administered seabuckthorn pulp oil, seed oil and control olive oil once per day for 7 days before exposure to total-body X-ray irradiation of 7.5 Gy. Terminal deoxynucleotidyl transferase dUTP nick end labeling, quantitative real-time polymerase chain reaction and western blotting were used for the measurement of apoptotic cells and proteins, inflammation factors and mitogen-activated protein (MAP) kinases. Seabuckthorn oil pretreatment increased the post-radiation survival rate and reduced the damage area of the small intestine villi. Both the pulp and seed oil treatment significantly decreased the apoptotic cell numbers and cleaved caspase 3 expression. Seabuckthorn oil downregulated the mRNA level of inflammatory factors, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-8. Both the pulp and seed oils elevated the level of phosphorylated extracellular-signal-regulated kinase and reduced the levels of phosphorylated c-Jun N-terminal kinase and p38. Palmitoleic acid (PLA) and alpha linolenic acid (ALA) are the predominant components of pulp oil and seed oil, respectively. Pretreatment with PLA and ALA increased the post-radiation survival time. In conclusion, seabuckthorn pulp and seed oils protect against mouse intestinal injury from high-dose radiation by reducing cell apoptosis and inflammation. ALA and PLA are promising natural radiation countermeasure candidates. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Indirect effects of radiation induce apoptosis and neuroinflammation in neuronal SH-SY5Y cells.

PubMed

Saeed, Yasmeen; Xie, Bingjie; Xu, Jin; Wang, Hailong; Hassan, Murtaza; Wang, Rui; Hong, Ma; Hong, Qing; Deng, Yulin

2014-12-01

Recent studies have evaluated the role of direct radiation exposure in neurodegenerative disorders; however, association among indirect effects of radiation and neurodegenerative diseases remains rarely discussed. The objective of this study was to estimate the relative risk of neurodegeneration due to direct and indirect effects of radiation. (60)Co gamma ray was used as source of direct radiation whereas irradiated cell conditioned medium (ICCM) was used to mimic the indirect effect of radiation. To determine the potency of ICCM to inhibit neuronal cells survival colony forming assay was performed. The role of ICCM to induce apoptosis in neuronal SH-SY5Y cells was estimated by TUNEL assay and Annexin V/PI assay. Level of oxidative stress and the concentration of inflammatory cytokines after exposing to direct radiation and ICCM were evaluated by ELISA method. Expression of key apoptotic protein following direct and indirect radiation exposure was investigated by western blot technique. Experimental data manifest that ICCM account loss of cell survival and increase apoptotic induction in neuronal SH-SY5Y cells that was dependent on time and dose. Moreover, ICCM stimulate significant release of inflammatory cytokines i.e., tumor necrosis factor TNF-alpha (P < 0.01), Interleukin-1 (IL-1, P < 0.001), and Interleukin-6 (IL-6, P < 0.001) in neuronal SH-SY5Y cells and elevate the level of oxidative stress (MDA, P < 0.01). Up-regulation of key apoptotic protein expression i.e., Bax, Bid, cytochrome C, caspase-8 and caspase-3 confirms the toxicity of ICCM to neuronal cells. This study provides the evidence that indirect effect of radiation can be as much damaging to neuronal cells as direct radiation exposure can be. Hence, more focused research on estimation risks of indirect effect of radiation to CNS at molecular level may help to reduce the uncertainty about cure and cause of several neurodegenerative disorders.

Inclusion of Solar Elevation Angle in Land Surface Albedo Parameterization Over Bare Soil Surface.

PubMed

Zheng, Zhiyuan; Wei, Zhigang; Wen, Zhiping; Dong, Wenjie; Li, Zhenchao; Wen, Xiaohang; Zhu, Xian; Ji, Dong; Chen, Chen; Yan, Dongdong

2017-12-01

Land surface albedo is a significant parameter for maintaining a balance in surface energy. It is also an important parameter of bare soil surface albedo for developing land surface process models that accurately reflect diurnal variation characteristics and the mechanism behind the solar spectral radiation albedo on bare soil surfaces and for understanding the relationships between climate factors and spectral radiation albedo. Using a data set of field observations, we conducted experiments to analyze the variation characteristics of land surface solar spectral radiation and the corresponding albedo over a typical Gobi bare soil underlying surface and to investigate the relationships between the land surface solar spectral radiation albedo, solar elevation angle, and soil moisture. Based on both solar elevation angle and soil moisture measurements simultaneously, we propose a new two-factor parameterization scheme for spectral radiation albedo over bare soil underlying surfaces. The results of numerical simulation experiments show that the new parameterization scheme can more accurately depict the diurnal variation characteristics of bare soil surface albedo than the previous schemes. Solar elevation angle is one of the most important factors for parameterizing bare soil surface albedo and must be considered in the parameterization scheme, especially in arid and semiarid areas with low soil moisture content. This study reveals the characteristics and mechanism of the diurnal variation of bare soil surface solar spectral radiation albedo and is helpful in developing land surface process models, weather models, and climate models.

A combination of He-Ne laser irradiation and exogenous NO application efficiently protect wheat seedling from oxidative stress caused by elevated UV-B stress.

PubMed

Li, Yongfeng; Gao, Limei; Han, Rong

2016-12-01

The elevated ultraviolet-B (UV-B) stress induces the accumulation of a variety of intracellular reactive oxygen species (ROS), which seems to cause oxidative stress for plants. To date, very little work has been done to evaluate the biological effects of a combined treatment with He-Ne laser irradiation and exogenous nitric oxide (NO) application on oxidative stress resulting from UV-B radiation. Thus, our study investigated the effects of a combination with He-Ne laser irradiation and exogenous NO treatment on oxidative damages in wheat seedlings under elevated UV-B stress. Our data showed that the reductions in ROS levels, membrane damage parameters, while the increments in antioxidant contents and antioxidant enzyme activity caused by a combination with He-Ne laser and exogenous NO treatment were greater than those of each individual treatment. Furthermore, these treatments had a similar effect on transcriptional activities of plant antioxidant enzymes. This implied that the protective effects of a combination with He-Ne laser irradiation and exogenous NO treatment on oxidative stress resulting from UV-B radiation was more efficient than each individual treatment with He-Ne laser or NO molecule. Our findings might provide beneficial theoretical references for identifying some effective new pathways for plant UV-B protection.

Developing Present-day Proxy Cases Based on NARVAL Data for Investigating Low Level Cloud Responses to Future Climate Change.

NASA Astrophysics Data System (ADS)

Reilly, Stephanie

2017-04-01

The energy budget of the entire global climate is significantly influenced by the presence of boundary layer clouds. The main aim of the High Definition Clouds and Precipitation for Advancing Climate Prediction (HD(CP)2) project is to improve climate model predictions by means of process studies of clouds and precipitation. This study makes use of observed elevated moisture layers as a proxy of future changes in tropospheric humidity. The associated impact on radiative transfer triggers fast responses in boundary layer clouds, providing a framework for investigating this phenomenon. The investigation will be carried out using data gathered during the Next-generation Aircraft Remote-sensing for VALidation (NARVAL) South campaigns. Observational data will be combined with ECMWF reanalysis data to derive the large scale forcings for the Large Eddy Simulations (LES). Simulations will be generated for a range of elevated moisture layers, spanning a multi-dimensional phase space in depth, amplitude, elevation, and cloudiness. The NARVAL locations will function as anchor-points. The results of the large eddy simulations and the observations will be studied and compared in an attempt to determine how simulated boundary layer clouds react to changes in radiative transfer from the free troposphere. Preliminary LES results will be presented and discussed.

Persistent nature of alterations in cognition and neuronal circuit excitability after exposure to simulated cosmic radiation in mice.

PubMed

Parihar, Vipan K; Maroso, Mattia; Syage, Amber; Allen, Barrett D; Angulo, Maria C; Soltesz, Ivan; Limoli, Charles L

2018-07-01

Of the many perils associated with deep space travel to Mars, neurocognitive complications associated with cosmic radiation exposure are of particular concern. Despite these realizations, whether and how realistic doses of cosmic radiation cause cognitive deficits and neuronal circuitry alterations several months after exposure remains unclear. In addition, even less is known about the temporal progression of cosmic radiation-induced changes transpiring over the duration of a time period commensurate with a flight to Mars. Here we show that rodents exposed to the second most prevalent radiation type in space (i.e. helium ions) at low, realistic doses, exhibit significant hippocampal and cortical based cognitive decrements lasting 1 year after exposure. Cosmic-radiation-induced impairments in spatial, episodic and recognition memory were temporally coincident with deficits in cognitive flexibility and reduced rates of fear extinction, elevated anxiety and depression like behavior. At the circuit level, irradiation caused significant changes in the intrinsic properties (resting membrane potential, input resistance) of principal cells in the perirhinal cortex, a region of the brain implicated by our cognitive studies. Irradiation also resulted in persistent decreases in the frequency and amplitude of the spontaneous excitatory postsynaptic currents in principal cells of the perirhinal cortex, as well as a reduction in the functional connectivity between the CA1 of the hippocampus and the perirhinal cortex. Finally, increased numbers of activated microglia revealed significant elevations in neuroinflammation in the perirhinal cortex, in agreement with the persistent nature of the perturbations in key neuronal networks after cosmic radiation exposure. These data provide new insights into cosmic radiation exposure, and reveal that even sparsely ionizing particles can disrupt the neural circuitry of the brain to compromise cognitive function over surprisingly protracted post-irradiation intervals. Copyright © 2018 Elsevier Inc. All rights reserved.

Mutational influences of low-dose and high let ionizing radiation in drosophila melanogaster

NASA Astrophysics Data System (ADS)

Lei, Huang; Fanjun, Kong; Sun, Yeqing

For cosmic environment consists of a varying kinds of radiation particles including high Z and energy ions which was charactered with low-dose and high RBE, it is important to determine the possible biofuctions of high LET radiation on human beings. To analyse the possible effectes of mutational influences of low-dose and high-LET ionizing radiation, wild fruit flies drosophila melanogaster were irradiated by 12C6+ ions in two LET levels (63.3 and 30 keV/µum) with different low doses from 2mGy to 2000mGy (2, 20, 200, 2000mGy) in HIRFL (Heavy ion radiation facility laboratory, lanzhou, China).In the same LET value group, the average polymorphic frequency was elevated along with adding doses of irradation, the frequency in 2000 mGy dose samples was significantly higher than other samples (p<0.01).These results suggest that genomic DNA sequence could be effected by low-dose and high-LET ionizing radiation, the irradiation dose is an important element in genomic mutation frequency origination.

Effects of sunlight exposure on grapevine powdery mildew development.

PubMed

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.

Radiation effects and mitigation strategies for modern FPGAs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stettler, M. W.; Caffrey, M. P.; Graham, P. S.

2004-01-01

Field Programmable Gate Array devices have become the technology of choice in small volume modern instrumentation and control systems. These devices have always offered significant advantages in flexibility, and recent advances in fabrication have greatly increased logic capacity, substantially increasing the number of applications for this technology. Unfortunately, the increased density (and corresponding shrinkage of process geometry), has made these devices more susceptible to failure due to external radiation. This has been an issue for space based systems for some time, but is now becoming an issue for terrestrial systems in elevated radiation environments and commercial avionics as well. Characterizingmore » the failure modes of Xilinx FPGAs, and developing mitigation strategies is the subject of ongoing research by a consortium of academic, industrial, and governmental laboratories. This paper presents background information of radiation effects and failure modes, as well as current and future mitigation techniques. In particular, the availability of very large FPGA devices, complete with generous amounts of RAM and embedded processor(s), has led to the implementation of complete digital systems on a single device, bringing issues of system reliability and redundancy management to the chip level. Radiation effects on a single FPGA are increasingly likely to have system level consequences, and will need to be addressed in current and future designs.« less

Draft Genome Sequence of the Polyextremophilic Exiguobacterium sp. Strain S17, Isolated from Hyperarsenic Lakes in the Argentinian Puna.

PubMed

Ordoñez, Omar F; Lanzarotti, Esteban; Kurth, Daniel; Gorriti, Marta F; Revale, Santiago; Cortez, Néstor; Vazquez, Martin P; Farías, María E; Turjanski, Adrian G

2013-07-25

Exiguobacterium sp. strain S17 is a moderately halotolerant, arsenic-resistant bacterium that was isolated from Laguna Socompa stromatolites in the Argentinian Puna. The draft genome sequence suggests potent enzyme candidates that are essential for survival under multiple environmental extreme conditions, such as high levels of UV radiation, elevated salinity, and the presence of critical arsenic concentrations.

Opportunities for nutritional amelioration of radiation-induced cellular damage

NASA Technical Reports Server (NTRS)

Turner, Nancy D.; Braby, Leslie A.; Ford, John; Lupton, Joanne R.

2002-01-01

The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

Atmospheric Radiation Modeling of Galactic Cosmic Rays Using LRO/CRaTER and the EMMREM Model with Comparisons to Balloon and Airline Based Measurements

NASA Astrophysics Data System (ADS)

Joyce, C. J.

2016-12-01

The current state of the Sun and solar wind, with uncommonly low densities and weak magnetic fields, has resulted in galactic cosmic ray fluxes that are elevated to levels higher than have ever before been observed in the space age. Given the continuing trend of declining solar activity, it is clear that accurate modeling of GCR radiation is becoming increasingly important in the field of space weather. Such modelling is essential not only in the planning of future manned space missions, but is also important for assessing the radiation risks to airline passengers, particularly given NASA's plans to develop supersonic aircraft that will fly at much higher altitudes than commercial aircraft and thus be more vulnerable to radiation from GCRs. We provide an analysis of the galactic cosmic ray radiation environment of Earth's atmosphere using measurements from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) aboard the Lunar Reconnaissance Orbiter (LRO) together with the Badhwar-O'Neil model and dose lookup tables generated by the Earth-Moon-Mars Radiation Environment Module (EMMREM). Newly available measurements of atmospheric dose rates from instruments aboard commercial and research aircraft enable evaluation of the accuracy of the model in computing atmospheric dose rates. Additionally, a newly available dataset of balloon-based measurements, including simultaneous balloon launches from California and New Hampshire, provide an additional means of comparison to the model. When compared to the available observations of atmospheric radiation levels, the computed dose rates seem to be sufficiently accurate, falling within recommended radiation uncertainty limits.

DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behne, Patrick Alan

The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulationmore » potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.« less

Microgravity Droplet Combustion in CO2 Enriched Environments at Elevated Pressures

NASA Technical Reports Server (NTRS)

Hicks, Michael C.; Nayagam, V.; Williams, F. A.

2007-01-01

Microgravity droplet combustion experiments were performed in elevated concentrations of CO2 at pressures of 1.0 atm, 3.0 atm, and 5.0 atm to examine the effects of a radiatively participating suppression agent in space applications. Methanol and n-heptane droplets, with an initial diameter of 2.0 mm supported on a quartz fiber, were used in these experiments. The ambient O2 concentration was held constant at 21% and the CO2 concentrations ranged from 0% to a maximum of 70%, by volume with the balance consisting of N2 . Results from the methanol tests showed slight decreases in burning rates with increased CO2 concentrations at all ambient pressures. The n-heptane tests show slight increases in burning rates with increasing CO2 concentrations at each pressure level. Instantaneous radiative heat flux was also measured using both a broadband radiometer (i.e., wavelengths from 0.6 microns to 40.0 microns) and a narrowband radiometer (i.e., centered at 5.6 microns with a filter width at half maximum of 1.5 microns). Radiative exchanges between the droplet and surrounding gases as well as the soot field produce departures from the classical quasisteady theory which would predict a decrease in burning rates with increasing CO2 concentrations in microgravity.

On the role of radiation and dimensionality in predicting flow opposed flame spread over thin fuels

NASA Astrophysics Data System (ADS)

Kumar, Chenthil; Kumar, Amit

2012-06-01

In this work a flame-spread model is formulated in three dimensions to simulate opposed flow flame spread over thin solid fuels. The flame-spread model is coupled to a three-dimensional gas radiation model. The experiments [1] on downward spread and zero gravity quiescent spread over finite width thin fuel are simulated by flame-spread models in both two and three dimensions to assess the role of radiation and effect of dimensionality on the prediction of the flame-spread phenomena. It is observed that while radiation plays only a minor role in normal gravity downward spread, in zero gravity quiescent spread surface radiation loss holds the key to correct prediction of low oxygen flame spread rate and quenching limit. The present three-dimensional simulations show that even in zero gravity gas radiation affects flame spread rate only moderately (as much as 20% at 100% oxygen) as the heat feedback effect exceeds the radiation loss effect only moderately. However, the two-dimensional model with the gas radiation model badly over-predicts the zero gravity flame spread rate due to under estimation of gas radiation loss to the ambient surrounding. The two-dimensional model was also found to be inadequate for predicting the zero gravity flame attributes, like the flame length and the flame width, correctly. The need for a three-dimensional model was found to be indispensable for consistently describing the zero gravity flame-spread experiments [1] (including flame spread rate and flame size) especially at high oxygen levels (>30%). On the other hand it was observed that for the normal gravity downward flame spread for oxygen levels up to 60%, the two-dimensional model was sufficient to predict flame spread rate and flame size reasonably well. Gas radiation is seen to increase the three-dimensional effect especially at elevated oxygen levels (>30% for zero gravity and >60% for normal gravity flames).

Investigation of Radiation and Chemical Resistance of Flexible HLW Transfer Hose

DOE Office of Scientific and Technical Information (OSTI.GOV)

E. Skidmore; Billings, K.; Hubbard, M.

A chemical transfer hose constructed of an EPDM (ethylene-propylene diene monomer) outer covering with a modified cross-linked polyethylene (XLPE) lining was evaluated for use in high level radioactive waste transfer applications. Laboratory analysis involved characterization of the hose liner after irradiation to doses of 50 to 300 Mrad and subsequent exposure to 25% NaOH solution at 93 C for 30 days, simulating 6 months intermittent service. The XLPE liner mechanical and structural properties were characterized at varying dose levels. Burst testing of irradiated hose assemblies was also performed. Literature review and test results suggest that radiation effects below doses ofmore » 100 kGy are minimal, with acceptable property changes to 500 kGy. Higher doses may be feasible. At a bounding dose of 2.5 MGy, the burst pressure is reduced to the working pressure (1.38 MPa) at room temperature. Radiation exposure slightly reduces liner tensile strength, with more significant decrease in liner elongation. Subsequent exposure to caustic solutions at elevated temperature slightly increases elongation, suggesting an immersion/hydrolytic effect or possible thermal annealing of radiation damage. This paper summarizes the laboratory results and recommendations for field deployment.« less

A Systematic Review of the Association between Immunogenomic Markers and Cancer-Related Fatigue

PubMed Central

Saligan, LN; Kim, HS

2012-01-01

Fatigue, which is one of the most commonly reported symptoms in cancer, can negatively impact the functional status and the health-related quality of life of individuals. This paper systematically reviews 34 studies to determine patterns of associations between immunogenomic markers and levels of cancer-related fatigue (CRF). Findings from the longitudinal studies revealed that elevated fatigue symptoms especially of women with early stages of breast cancer were associated with high levels of neutrophil/monocyte, IL-1ra, and IL-6 during radiation therapy; high levels of CD4+, IL-1β, and IL-6 with stressing stimuli; high levels of IL-1β during chemotherapy; low NK cell levels after chemotherapy; and presence of homozygous IL-6 and TNF alleles. In the cross-sectional studies, associations between levels of fatigue and immune/inflammatory markers were not consistently found, especially when covariates such as BMI, ethnicity, menopausal status, and educational level were controlled in the statistical analyses. However, a number of genomic markers were observed to be elevated mostly in fatigued breast cancer survivors in the cross-sectional studies. Gaps in knowledge and recommendations for future research are discussed. PMID:22595751

A systematic review of the association between immunogenomic markers and cancer-related fatigue.

PubMed

Saligan, L N; Kim, H S

2012-08-01

Fatigue, which is one of the most commonly reported symptoms in cancer, can negatively impact the functional status and the health-related quality of life of individuals. This paper systematically reviews 34 studies to determine patterns of associations between immunogenomic markers and levels of cancer-related fatigue (CRF). Findings from the longitudinal studies revealed that elevated fatigue symptoms especially of women with early stages of breast cancer were associated with high levels of neutrophil/monocyte, IL-1ra, and IL-6 during radiation therapy; high levels of CD4+, IL-1β, and IL-6 with stressing stimuli; high levels of IL-1β during chemotherapy; low NK cell levels after chemotherapy; and presence of homozygous IL-6 and TNF alleles. In the cross-sectional studies, associations between levels of fatigue and immune/inflammatory markers were not consistently found, especially when covariates such as BMI, ethnicity, menopausal status, and educational level were controlled in the statistical analyses. However, a number of genomic markers were observed to be elevated mostly in fatigued breast cancer survivors in the cross-sectional studies. Gaps in knowledge and recommendations for future research are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Determination of cytokine protein levels in oral secretions in patients undergoing radiotherapy for head and neck malignancies

PubMed Central

2012-01-01

Background Cytokines may be elevated in tumor and normal tissues following irradiation. Cytokine expression in these tissues may predict for toxicity or tumor control. The purpose of this pilot study was to determine the feasibility of measuring local salivary cytokine levels using buccal sponges in patients receiving chemo-radiation for head and neck malignancies. Patients and methods 11 patients with epithelial malignancies of the head and neck were recruiting to this study. All patients received radiotherapy to the head and neck region with doses ranging between 60 – 67.5 Gy. Chemotherapy was delivered concurrently with radiation in all patients. Salivary samples were obtained from high dose and low dose regions prior to treatment and at three intervals during treatment for assessment of cytokine levels (IL-4, IL-6, IL-8, IL-10, EGF, MCP-1, TNF-α, and VEGF). Results Cytokine levels were detectable in the salivary samples. Salivary cytokine levels of IL-4, IL-6, IL-8, EGF, MCP-1, TNF- α , and VEGF were higher in the high dose region compared to the low dose region at all time points (p < 0.05). A trend toward an increase in cytokine levels as radiation dose increased was observed for IL-6, IL-8, MCP-1, and TNF-α. Conclusion Assessment of salivary cytokine levels may provide a novel method to follow local cytokine levels during radiotherapy and may provide a mechanism to study cytokine levels in a regional manner. PMID:22537315

The effects of radiofrequency electromagnetic radiation on sperm function.

PubMed

Houston, B J; Nixon, B; King, B V; De Iuliis, G N; Aitken, R J

2016-12-01

Mobile phone usage has become an integral part of our lives. However, the effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted by these devices on biological systems and specifically the reproductive systems are currently under active debate. A fundamental hindrance to the current debate is that there is no clear mechanism of how such non-ionising radiation influences biological systems. Therefore, we explored the documented impacts of RF-EMR on the male reproductive system and considered any common observations that could provide insights on a potential mechanism. Among a total of 27 studies investigating the effects of RF-EMR on the male reproductive system, negative consequences of exposure were reported in 21. Within these 21 studies, 11 of the 15 that investigated sperm motility reported significant declines, 7 of 7 that measured the production of reactive oxygen species (ROS) documented elevated levels and 4 of 5 studies that probed for DNA damage highlighted increased damage due to RF-EMR exposure. Associated with this, RF-EMR treatment reduced the antioxidant levels in 6 of 6 studies that discussed this phenomenon, whereas consequences of RF-EMR were successfully ameliorated with the supplementation of antioxidants in all 3 studies that carried out these experiments. In light of this, we envisage a two-step mechanism whereby RF-EMR is able to induce mitochondrial dysfunction leading to elevated ROS production. A continued focus on research, which aims to shed light on the biological effects of RF-EMR will allow us to test and assess this proposed mechanism in a variety of cell types. © 2016 Society for Reproduction and Fertility.

4-(4-Hydroxy-3-methoxyphenyl)-2-butanone modulates redox signal in gamma-irradiation-induced nephrotoxicity in rats.

PubMed

Abozaid, Omayma A R; Moawed, Fatma S M; Farrag, Mostafa A; Abdel Aziz, Abdel Aziz A

2017-12-01

Cellular exposure to ionising radiation leads to oxidative stress events, which refer to elevated intracellular levels of reactive oxygen species (ROS). The elevated levels of ROS significantly contributed to γ-radiation (IR) induced cytotoxicity. In an attempt to minimise these cytotoxic effects, antioxidant compounds have been identified to counteract radiation- associated toxicities. We mainly aimed to study the protective effect of 4-(4-hydroxy-3-methoxyphenyl)-2-butanone (HMB) on IR-induced nephrotoxicity, whereas it was previously shown to have anti-inflammatory effects in different inflammation models. Animals were treated orally with HMB (25 mg/kg b.wt daily) then performed by whole-body gamma-irradiation of animals with 6 Gy; a single dose applied on the 15th day and animals were sacrificed at the end of the 23rd day. It was found that IR exposure significantly induced renal oxidative injury that accompanied by inflammatory disturbance. Also, NADPH oxidase and iNOS gene expressions were significantly up-regulated, while the mitochondrial enzymes (complex I & II) were significantly down-regulated in IR exposed animals. Additionally, Western immunoblotting analysis of signalling growth factor protein; p38 MAPK was significantly overexpressed. Interestingly, HMB treatment showed statistically significant amelioration in parameters with an improved histological structure upon the IR-induced nephrotoxicity. It can be concluded that modulation of NADPH-oxidase, iNOS and mitochondrial enzymes by HMB might be responsible for the amendment of the antioxidant status and impairment of p38 MAPK signal, thus attenuate the nephrotoxicity induced post IR exposure.

Formerly Utilized Sites Remedial Action Program (FUSRAP) Hazelwood Interim Storage Site annual site environmental report. Calendar year 1985. [FUSRAP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-04-01

The Hazelwood Interim Storage Site (HISS) is presently used for the storage of low-level radioactively contaminated soils. Monitoring results show that the HISS is in compliance with DOE concentration guides and radiation protection standards. Derived Concentration Guides (DCGs) represent the concentrations of radionuclides in air or water that would limit the radiation dose to 100 mrem/y. The applicable limits have been revised since the 1984 environmental monitoring report was published. The limits applied in 1984 were based on a radiation protection standard of 500 mrem/y; the limits applied for 1985 are based on a standard of 100 mrem/y. The HISSmore » is part of the Formerly Utilized Sites Remedial Action Program (FUSRAP), a DOE program to decontaminate or otherwise control sites where low-level radioactive contamination remains from the early years of the nation's atomic energy program. To determine whether the site is in compliance with DOE standards, environmental measurements are expressed as percentages of the applicable DCG, while the calculated doses to the public are expressed as percentages of the applicable radiation protection standard. The monitoring program at the HISS measures uranium, radium, and thorium concentrations in surface water, groundwater, and sediment; radon gas concentrations in air; and external gamma radiation exposure rates. Potential radiation doses to the public are also calculated. The HISS was designated for remedial action under FUSRAP because radioactivity above applicable limits was found to exist at the site and its vicinity. Elevated levels of radiation still exist in areas where remedial action has not yet been completed.« less

A WRF simulation of the impact of 3-D radiative transfer on surface hydrology over the Rocky Mountains and Sierra Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, K. N.; Gu, Y.; Leung, L. R.

2013-01-01

We investigate 3-D mountains/snow effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and Sierra Nevada. The Weather Research and Forecasting (WRF) model, applied at a 30 km grid resolution, is used in conjunction with a 3-D radiative transfer parameterization covering a time period from 1 November 2007 to 31 May 2008, during which abundant snowfall occurred. A comparison of the 3-D WRF simulation with the observed snow water equivalent (SWE) and precipitation from Snowpack Telemetry (SNOTEL) sites shows reasonable agreement in terms of spatial patterns and daily andmore » seasonal variability, although the simulation generally has a positive precipitation bias. We show that 3-D mountain features have a profound impact on the diurnal and monthly variation of surface radiative and heat fluxes, and on the consequent elevation-dependence of snowmelt and precipitation distributions. In particular, during the winter months, large deviations (3-D-PP, in which PP denotes the plane-parallel approach) of the monthly mean surface solar flux are found in the morning and afternoon hours due to shading effects for elevations below 2.5 km. During spring, positive deviations shift to the earlier morning. Over mountaintops higher than 3 km, positive deviations are found throughout the day, with the largest values of 40–60 W m -2 occurring at noon during the snowmelt season of April to May. The monthly SWE deviations averaged over the entire domain show an increase in lower elevations due to reduced snowmelt, which leads to a reduction in cumulative runoff. Over higher elevation areas, positive SWE deviations are found because of increased solar radiation available at the surface. Overall, this study shows that deviations of SWE due to 3-D radiation effects range from an increase of 18% at the lowest elevation range (1.5–2 km) to a decrease of 8% at the highest elevation range (above 3 km). Since lower elevation areas occupy larger fractions of the land surface, the net effect of 3-D radiative transfer is to extend snowmelt and snowmelt-driven runoff into the warm season.Finally, because 60–90% of water resources originate from mountains worldwide, the aforementioned differences in simulated hydrology due solely to 3-D interactions between solar radiation and mountains/snow merit further investigation in order to understand the implications of modeling mountain water resources, and these resources' vulnerability to climate change and air pollution.« less

Synchrotron radiation analysis of possible correlations between metal status in human cementum and periodontal disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, R.R.; Naftel, S.J.; Nelson, A.J.

2010-03-16

Periodontitis is a serious disease that affects up to 50% of an adult population. It is a chronic condition involving inflammation of the periodontal ligament and associated tissues leading to eventual tooth loss. Some evidence suggests that trace metals, especially zinc and copper, may be involved in the onset and severity of periodontitis. Thus we have used synchrotron X-ray fluorescence imaging on cross sections of diseased and healthy teeth using a microbeam to explore the distribution of trace metals in cementum and adhering plaque. The comparison between diseased and healthy teeth indicates that there are elevated levels of zinc, coppermore » and nickel in diseased teeth as opposed to healthy teeth. This preliminary correlation between elevated levels of trace metals in the cementum and plaque of diseased teeth suggests that metals may play a role in the progress of periodontitis.« less

Mortality Among a Cohort of U.S. Commercial Airline Cockpit Crew

PubMed Central

Yong, Lee C.; Pinkerton, Lynne E.; Yiin, James H.; Anderson, Jeri L.; Deddens, James A.

2015-01-01

Background We evaluated mortality among 5,964 former U.S. commercial cockpit crew (pilots and flight engineers). The outcomes of a priori interest were non-chronic lymphocytic leukemia, central nervous system (CNS) cancer (including brain), and malignant melanoma. Methods Vital status was ascertained through 2008. Life table and Cox regression analyses were conducted. Cumulative exposure to cosmic radiation was estimated from work history data. Results Compared to the U.S. general population, mortality from all causes, all cancer, and cardiovascular diseases was decreased, but mortality from aircraft accidents was highly elevated. Mortality was elevated for malignant melanoma but not for non-chronic lymphocytic leukemia. CNS cancer mortality increased with an increase in cumulative radiation dose. Conclusions Cockpit crew had a low all-cause, all-cancer, and cardiovascular disease mortality but elevated aircraft accident mortality. Further studies are needed to clarify the risk of CNS and other radiation-associated cancers in relation to cosmic radiation and other workplace exposures. PMID:24700478

Ectotherm thermal stress and specialization across altitude and latitude.

PubMed

Buckley, Lauren B; Miller, Ethan F; Kingsolver, Joel G

2013-10-01

Gradients of air temperature, radiation, and other climatic factors change systematically but differently with altitude and latitude. We explore how these factors combine to produce altitudinal and latitudinal patterns of body temperature, thermal stress, and seasonal overlap that differ markedly from patterns based solely on air temperature. We use biophysical models to estimate body temperature as a function of an organism's phenotype and environmental conditions (air and surface temperatures and radiation). Using grasshoppers as a case study, we compare mean body temperatures and the incidence of thermal extremes along altitudinal gradients both under past and current climates. Organisms at high elevation can experience frequent thermal stress despite generally cooler air temperatures due to high levels of solar radiation. Incidences of thermal stress have increased more rapidly than have increases in mean conditions due to recent climate change. Increases in air temperature have coincided with shifts in cloudiness and solar radiation, which can exacerbate shifts in body temperature. We compare altitudinal thermal gradients and their seasonality between tropical and temperate mountains to ask whether mountain passes pose a greater physiological barrier in the tropics (Janzen's hypothesis). We find that considering body temperature rather than air temperature generally increases the amount of overlap in thermal conditions along gradients in elevation and thus decreases the physiological barrier posed by tropical mountains. Our analysis highlights the limitations of predicting thermal stress based solely on air temperatures, and the importance of considering how phenotypes influence body temperatures.

Noise Prediction Models for Elevated Rail Transit Structures

DOT National Transportation Integrated Search

1975-08-01

The report presents the theoretical development of a model for the prediction of noise radiated by elevated structures on rail transit lines. In particular it deals with noise and vibration control for urban rail transit track and elevated noise and ...

A prospective cohort study on radiation-induced hypothyroidism: development of an NTCP model.

PubMed

Boomsma, Marjolein J; Bijl, Hendrik P; Christianen, Miranda E M C; Beetz, Ivo; Chouvalova, Olga; Steenbakkers, Roel J H M; van der Laan, Bernard F A M; Wolffenbuttel, Bruce H R; Oosting, Sjoukje F; Schilstra, Cornelis; Langendijk, Johannes A

2012-11-01

To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm(3)). Model performance was good with an area under the curve (AUC) of 0.85. This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume. Copyright © 2012 Elsevier Inc. All rights reserved.

Acetone photophysics at 282 nm excitation at elevated pressure and temperature. II: Fluorescence modeling

NASA Astrophysics Data System (ADS)

Hartwig, Jason; Raju, Mandhapati; Sung, Chih-Jen

2017-07-01

This is the second in a series of two papers that presents an updated fluorescence model and compares with the new experimental data reported in the first paper, as well as the available literature data, to extend the range of acetone photophysics to elevated pressure and temperature conditions. This work elucidates the complete acetone photophysical model in terms of each and every competing radiative and non-radiative rate. The acetone fluorescence model is then thoroughly examined and optimized based on disparity with recently conducted elevated pressure and temperature photophysical calibration experiments. The current work offers insight into the competition between non-radiative and vibrational energy decay rates at elevated temperature and pressure and proposes a global optimization of model parameters from the photophysical model developed by Thurber (Acetone Laser-Induced Fluorescence for Temperature and Multiparameter Imaging in Gaseous Flows. PhD thesis, Stanford University Mechanical Engineering Department, 1999). The collisional constants of proportionality, which govern vibrational relaxation, are shown to be temperature dependent at elevated pressures. A new oxygen quenching rate is proposed which takes into account collisions with oxygen as well as the oxygen-assisted intersystem crossing component. Additionally, global trends in ketone photophysics are presented and discussed.

Disaster waste characteristics and radiation distribution as a result of the Great East Japan Earthquake.

PubMed

Shibata, Tomoyuki; Solo-Gabriele, Helena; Hata, Toshimitsu

2012-04-03

The compounded impacts of the catastrophes that resulted from the Great East Japan Earthquake have emphasized the need to develop strategies to respond to multiple types and sources of contamination. In Japan, earthquake and tsunami-generated waste were found to have elevated levels of metals/metalloids (e.g., mercury, arsenic, and lead) with separation and sorting more difficult for tsunami-generated waste as opposed to earthquake-generated waste. Radiation contamination superimposed on these disaster wastes has made it particularly difficult to manage the ultimate disposal resulting in delays in waste management. Work is needed to develop policies a priori for handling wastes from combined catastrophes such as those recently observed in Japan.

Thyrotropin-secreting pituitary adenoma in an 11-year-old boy with type 1 autoimmune polyglandular syndrome.

PubMed

Mazerkina, Nadia; Trunin, Yuri; Gorelyshev, Sergey; Golanov, Andrey; Kadashev, Boris; Shishkina, Liudmila; Rotin, Daniil; Karmanov, Maxim; Orlova, Elizabet

2016-02-01

Thyrotropinomas (TSHomas) are rare pituitary adenomas, particularly in childhood. We present here the case of an 11-year-old boy with type 1 autoimmune polyglandular syndrome (APS1) and TSHoma which was diagnosed by elevated thyroid - stimulating hormone and thyroid hormones levels without evident clinical signs of hyperthyroidism. He was underwent partial resection of the tumor via transsphenoidal approach and subsequently radiation therapy. Consequently, 1 year after radiotherapy, the patient developed growth hormone deficiency, three and half years after radiation became euthyroid, and five and half years after treatment - hypothyroid. This is the first case of the coexistence of these two rare endocrine diseases in one patient.

Analysis of beam loss induced abort kicker instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang W.; Sandberg, J.; Ahrens, L.

2012-05-20

Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems andmore » improved stability of the RHIC operation.« less

Seasonal and Elevational Variations of Black Carbon and Dust in Snow and Ice in the Solu-Khumbu, Nepal and Estimated Radiative Forcings

NASA Astrophysics Data System (ADS)

Kaspari, S.; Painter, T. H.; Gysel, M.; Skiles, M.; Schwikowski, M.

2014-12-01

Black carbon (BC) and dust deposited on snow and glacier surfaces can reduce the surface albedo, accelerate melt, and trigger albedo feedback. Assessing BC and dust concentrations in snow and ice in the Himalaya is of interest because this region borders large BC and dust sources, and seasonal snow and glacier ice in this region are an important source of water resources. Snow and ice samples were collected from crevasse profiles and snowpits at elevations between 5400 and 6400 m asl from Mera glacier located in the Solu-Khumbu region of Nepal. The samples were measured for Fe concentrations (used as a dust proxy) via ICP-MS, total impurity content gravimetrically, and BC concentrations using a Single Particle Soot Photometer (SP2). BC and Fe concentrations are substantially higher at elevations < 6000 m due to post-depositional processes including melt and sublimation and greater loading in the lower troposphere. Because the largest areal extent of snow and ice resides at elevations < 6000 m, the higher BC and dust concentrations at these elevations can reduce the snow and glacier albedo over large areas, accelerating melt, affecting glacier mass-balance and water resources, and contributing to a positive climate forcing. Radiative transfer modeling constrained by measurements at 5400 m at Mera La indicates that BC concentrations in the winter-spring snow/ice horizons are sufficient to reduce albedo by 6-10% relative to clean snow, corresponding to localized instantaneous radiative forcings of 75-120 W m-2. The other bulk impurity concentrations, when treated separately as dust, reduce albedo by 40-42% relative to clean snow and give localized instantaneous radiative forcings of 488 to 525 W m-2. Adding the BC absorption to the other impurities results in additional radiative forcings of 3 W m-2. While these results suggest that the snow albedo and radiative forcing effect of dust is considerably greater than BC, there are several sources of uncertainty.

Modeling of microclimatic characteristics of highland area

NASA Astrophysics Data System (ADS)

Sitdikova, Iuliia; Rusin, Igor

2013-04-01

Microclimatic characteristics of highlands may vary considerably over distances of a few meters depending on slope and aspect. There is a problem of estimation of components of surface energy balance based on observation of single stations for description of microclimate highlands. The aim of this paper is to develop a method that would restore microclimatic characteristics of terrain, based on observations of the single station, by physical extrapolation. The input parameters to obtain the microclimatic characteristics are as follows: air temperature, relative humidity, and wind speed on two vertical levels, air pressure, surface temperature, direct and diffused solar radiation and surface albedo. The recent version of the Meteorological Radiation Model (MRM) has been used to calculate a solar radiation over the area and to estimate an influence of cloudiness amounts. The height, slope and aspect were accounted at each point with using a digital elevation model. Have been supposed that air temperature and specific humidity vary with altitude only. Net radiation was calculated at all points of the area. Supposed that the difference between the surface temperature and the air temperature is a linear function of net radiation. The empirical coefficient, which depends on wind speed with adjustment of given area. Latent and sensible fluxes are calculated by using the modified Bowen ratio, which varies on the area. Method was tested on field research in Krasnodar region (RF). The meteorological observations were made every three hour on actinometric and gradient sites. The editional gradient site with different orientation of the slope was organized from 400 meters of the main site. Topographic survey of area was made 1x1,3 km in size for a digital elevation model constructing. At all points of the area of radiation and heat balance were calculated. The results of researches are the maps of surface temperature, net radiation, latent and sensible fluxes. The calculations showed that the average value of components of heat balance by area differ significantly from the data observed on meteorological station.

Radiation-induced transgenerational instability.

PubMed

Dubrova, Yuri E

2003-10-13

To date, the analysis of mutation induction has provided an irrefutable evidence for an elevated germline mutation rate in the parents directly exposed to ionizing radiation and a number of chemical mutagens. However, the results of numerous publications suggest that radiation may also have an indirect effect on genome stability, which is transmitted through the germ line of irradiated parents to their offspring. This review describes the phenomenon of transgenerational instability and focuses on the data showing increased cancer incidence and elevated mutation rates in the germ line and somatic tissues of the offspring of irradiated parents. The possible mechanisms of transgenerational instability are also discussed.

Neutron Monitors as a Tool for Specifying Solar Energetic Particle Effects on Earth and in Near-Earth Space

NASA Astrophysics Data System (ADS)

Bieber, J. W.; Clem, J.; Evenson, P.; Kuwabara, T.; Pyle, R.; Ruffolo, D.; Saiz, A.

2007-12-01

Neutron monitors are ground-based instruments that record the byproducts of collisions between cosmic rays and molecules in Earth's atmosphere. When linked together in real-time coordinated arrays, these instruments can make valuable contributions to the specification of major solar energetic particle events. Neutron monitors can provide the earliest alert of elevated radiation levels in Earth's atmosphere caused by the arrival of relativistic solar particles (Ground Level Enhancement or GLE). Early detection of GLE is of interest to the aviation industry because of the associated radiation hazard for pilots and air crews, especially for those flying polar routes. Network observations can also be used to map, in principle in real time, the distribution of radiation in Earth's atmosphere, taking into account the particle anisotropy which can be very large in early phases of the event. Observations from the large GLE of January 20, 2005 and December 13, 2006 will be used to illustrate these applications of neutron monitors. Supported by NSF grant ATM-0527878, the Thailand Research Fund, and the Mahidol University Postdoctoral Fellowship Program.

Effects of electromagnetic radiation (bright light, extremely low-frequency magnetic fields, infrared radiation) on the circadian rhythm of melatonin synthesis, rectal temperature, and heart rate.

PubMed

Griefahn, Barbara; Künemund, Christa; Blaszkewicz, Meinolf; Lerchl, Alexander; Degen, Gisela H

2002-10-01

Electromagnetic spectra reduce melatonin production and delay the nadirs of rectal temperature and heart rate. Seven healthy men (16-22 yrs) completed 4 permuted sessions. The control session consisted of a 24-hours bedrest at < 30 lux, 18 degrees C, and < 50 dBA. In the experimental sessions, either light (1500 lux), magnetic field (16.7 Hz, 0.2 mT), or infrared radiation (65 degrees C) was applied from 5 pm to 1 am. Salivary melatonin level was determined hourly, rectal temperature and heart rate were continuously recorded. Melatonin synthesis was completely suppressed by light but resumed thereafter. The nadirs of rectal temperature and heart rate were delayed. The magnetic field had no effect. Infrared radiation elevated rectal temperature and heart rate. Only bright light affected the circadian rhythms of melatonin synthesis, rectal temperature, and heart rate, however, differently thus causing a dissociation, which might enhance the adverse effects of shiftwork in the long run.

Wayside Noise of Elevated Rail Transit Structures : Analysis of Published Data and Supplementary Measurements

DOT National Transportation Integrated Search

1980-12-01

Elevated structures that carry rail traffic are classified in terms of their noise-radiating components and are compared to similar trains operating at grade, according to how much more noise results from trains running on elevated structures. : The ...

Antioxidant capacity reduced in scallions grown under elevated CO 2 independent of assayed light intensity

NASA Astrophysics Data System (ADS)

Levine, Lanfang H.; Paré, Paul W.

2009-10-01

Long-duration manned space missions mandate the development of a sustainable life support system and effective countermeasures against damaging space radiation. To mitigate the risk of inevitable exposure to space radiation, cultivation of fresh fruits and vegetables rich in antioxidants is an attractive alternative to pharmacological agents. However it has yet to be established whether antioxidant properties of crops can be preserved or enhanced in a space environment where environmental conditions differ from that which plants have acclimated to on earth. Scallion ( Allium fistulosum) rich in antioxidant vitamins C and A, and flavonoids was used as a model plant to study the impact of a range of CO 2 concentrations and light intensities that are likely encountered in a space habitat on food quality traits. Scallions were hydroponically grown in controlled environmental chambers under a combination of 3 CO 2 concentrations of 400, 1200 and 4000 μmol mol -1 and 3 light intensity levels of 150, 300, 450 μmol m -2 s -1. Total antioxidant activity (TAA) of scallion extracts was determined using a radical cation scavenging assay. Both elevated CO 2 and increasing light intensity enhanced biomass accumulation, but effects on TAA (based on dry weight) differed. TAA was reduced for plants grown under elevated CO 2, but remained unchanged with increases in light intensity. Elevated CO 2 stimulated greater biomass production than antioxidants, while an increase in photosynthetic photo flux promoted the synthesis of antioxidant compounds at a rate similar to that of biomass. Consequently light is a more effective stimulus than CO 2 for antioxidant production.

Systemic Tolerance Mediated by Melanoma Brain Tumors is Reversible by Radiotherapy and Vaccination

PubMed Central

Jackson, Christopher M.; Kochel, Christina M.; Nirschl, Christopher J.; Durham, Nicholas M.; Ruzevick, Jacob; Alme, Angela; Francica, Brian J.; Elias, Jimmy; Daniels, Andrew; Dubensky, Thomas W.; Lauer, Peter; Brockstedt, Dirk G.; Baxi, Emily G.; Calabresi, Peter A.; Taube, Janis M.; Pardo, Carlos A.; Brem, Henry; Pardoll, Drew M.; Lim, Michael; Drake, Charles G.

2016-01-01

Purpose Immune responses to antigens originating in the CNS are generally attenuated, since collateral damage can have devastating consequences. The significance of this finding for the efficacy of tumor-targeted immunotherapies is largely unknown. Experimental Design The B16 murine melanoma model was used to compare cytotoxic responses against established tumors in the CNS and in the periphery. Cytokine analysis of tissues from brain tumor-bearing mice detected elevated TGF-β secretion from microglia and in the serum and TGF-β signaling blockade reversed tolerance of tumor antigen-directed CD8 T cells. Additionally, a treatment regimen using focal radiation therapy and recombinant Listeria monocytogenes was evaluated for immunologic activity and efficacy in this model. Results CNS melanomas were more tolerogenic than equivalently progressed tumors outside the CNS as antigen-specific CD8 T cells were deleted and exhibited impaired cytotoxicity. Tumor-bearing mice had elevated serum levels of TGF-β; however, blocking TGF-β signaling with a small molecule inhibitor or a monoclonal antibody did not improve survival. Conversely, tumor antigen-specific vaccination in combination with focal radiation therapy reversed tolerance and improved survival. This treatment regimen was associated with increased polyfunctionality of CD8 T cells, elevated T effector to T regulatory cell ratios and decreased TGF-β secretion from microglia. Conclusions These data suggest that CNS tumors may impair systemic antitumor immunity and consequently accelerate cancer progression locally as well as outside the CNS while antitumor immunity may be restored by combining vaccination with radiation therapy. These findings are hypothesis-generating and warrant further study in more contemporary melanoma models as well as human trials. PMID:26490306

Adaptive response studies may help choose astronauts for long-term space travel.

PubMed

Mortazavi, S M; Cameron, J R; Niroomand-rad, A

2003-01-01

Long-term manned exploratory missions are planned for the future. Exposure to high-energy neutrons, protons and high charge and energy particles during a deep space mission, needs protection against the detrimental effects of space radiation. It has been suggested that exposure to unpredictable extremely large solar particle events would kill the astronauts without massive shielding. To reduce this risk to astronauts and to minimize the need for shielding, astronauts with highest significant adaptive responses should be chosen. It has been demonstrated that some humans living in very high natural radiation areas have acquired high adaptive responses to external radiation. Therefore, we suggest that for a deep space mission the adaptive response of all potential crew members be measured and only those with high adaptive response be chosen. We also proclaim that chronic exposure to elevated levels of radiation can considerably decrease radiation susceptibility and better protect astronauts against the unpredictable exposure to sudden and dramatic increase in flux due to solar flares and coronal mass ejections. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Cancer Risk Map for the Surface of Mars

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Cucinotta, Francis A.

2011-01-01

We discuss calculations of the median and 95th percentile cancer risks on the surface of Mars for different solar conditions. The NASA Space Radiation Cancer Risk 2010 model is used to estimate gender and age specific cancer incidence and mortality risks for astronauts exploring Mars. Organ specific fluence spectra and doses for large solar particle events (SPE) and galactic cosmic rays (GCR) at various levels of solar activity are simulated using the HZETRN/QMSFRG computer code, and the 2010 version of the Badhwar and O Neill GCR model. The NASA JSC propensity model of SPE fluence and occurrence is used to consider upper bounds on SPE fluence for increasing mission lengths. In the transport of particles through the Mars atmosphere, a vertical distribution of Mars atmospheric thickness is calculated from the temperature and pressure data of Mars Global Surveyor, and the directional cosine distribution is implemented to describe the spherically distributed atmospheric distance along the slant path at each elevation on Mars. The resultant directional shielding by Mars atmosphere at each elevation is coupled with vehicle and body shielding for organ dose estimates. Astronaut cancer risks are mapped on the global topography of Mars, which was measured by the Mars Orbiter Laser Altimeter. Variation of cancer risk on the surface of Mars is due to a 16-km elevation range, and the large difference is obtained between the Tharsis Montes (Ascraeus, Pavonis, and Arsia) and the Hellas impact basin. Cancer incidence risks are found to be about 2-fold higher than mortality risks with a disproportionate increase in skin and thyroid cancers for all astronauts and breast cancer risk for female astronauts. The number of safe days on Mars to be below radiation limits at the 95th percent confidence level is reported for several Mission design scenarios.

Organ Dose Assessment and Evaluation of Cancer Risk on Mars Surface

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee; Cucinotta, Francis A.

2011-01-01

Organ specific fluence spectra and doses for large solar particle events (SPE) and galactic cosmic rays (GCR) at various levels of solar activity are simulated on the surface of Mars using the HZETRN/QMSFRG computer code and the 2010 version of the Badhwar and O Neill GCR model. The NASA JSC propensity model of SPE fluence and occurrence is used to consider upper bounds on SPE fluence for increasing mission lengths. To account for the radiation transmission through the Mars atmosphere, a vertical distribution of Mars atmospheric thickness is calculated from the temperature and pressure data of Mars Global Surveyor. To describe the spherically distributed atmospheric distance on the Mars surface at each elevation, the directional cosine distribution is implemented. The resultant directional shielding by Mars atmosphere at each elevation is then coupled with vehicle and body shielding for organ dose estimates. Finally, cancer risks for astronauts exploring Mars can be assessed by applying the NASA Space Radiation Cancer Risk 2010 model with the resultant organ dose estimates. Variations of organ doses and cancer risk quantities on the surface of Mars, which are due to a 16-km elevation range between the Tharsis Montes and the Hellas impact basin, are visualized on the global topography of Mars measured by the Mars Orbiter Laser Altimeter. It is found that cancer incidence risks are about 2-fold higher than mortality risks with a disproportionate increase in skin and thyroid cancers for male and female astronauts and in breast cancer for female astronauts. The number of safe days, defined by the upper 95% percent confidence level to be below cancer limits, on Mars is analyzed for several Mars mission design scenarios.

Cholinergic mechanisms of analgesia produced by physostigmine, morphine and cold water swimming.

PubMed

Romano, J A; Shih, T M

1983-07-01

This study concerns the cholinergic involvement in three experimental procedures which produce analgesia. Rats were given one of seven treatments: saline (1.0 ml/kg, i.p.); morphine sulfate (3.5, 6.0 or 9.0 mg/kg, i.p.); physostigmine salicylate (0.65 mg/kg, i.p.); warm water swim (3.5 min at 28 degrees C); and cold water swim (3.5 min at 2 degrees C). Each rat was tested on a hot plate (59.1 degrees C) once prior to and 30 min after treatment. Immediately after the last test the rats were killed with focussed microwave radiation. Levels of acetylcholine (ACh) and choline (Ch) in six brain areas (brain stem, cerebral cortex, hippocampus, midbrain, cerebellum and striatum) were analyzed by gas chromatograph-mass spectrometer. Morphine (9.0 mg/kg), physostigmine and cold water swimming caused significant analgesia. Morphine elevated the levels of ACh in the cerebellum and striatum, cold water swimming--in the cerebellum, striatum and cortex, and physostigmine--in the striatum and hippocampus. Levels of choline were elevated by morphine in the cerebellum, cortex and hippocampus, while cold water swimming elevated levels of choline in the cerebellum, cortex, striatum and hippocampus. Physostigmine did not change levels of choline in any of the brain areas studied. These data suggest that the analgetic effects of morphine or cold water swimming may be mediated by components of the cholinergic system that differ from those involved in the analgetic effects of physostigmine.

The influence of proteasome inhibitor MG132, external radiation and unlabeled antibody on the tumor uptake and biodistribution of 188Re-labeled anti-E6 C1P5 antibody in cervical cancer in mice

PubMed Central

Phaeton, Rébécca; Wang, Xing Guo; Einstein, Mark H.; Goldberg, Gary L.; Casadevall, Arturo; Dadachova, Ekaterina

2009-01-01

Background Human Papillomavirus (HPV) infection is considered a necessary step for the development of cervical cancer and >95% of all cervical cancers have detectable HPV sequences. We have recently demonstrated the efficacy of radioimmunotherapy (RIT) which targeted viral oncoprotein E6 in treatment of experimental cervical cancer We hypothesized that pre-treatment of tumor cells with various agents which cause cell death and/or elevation of E6 levels would increase the accumulation of radiolabeled antibodies to E6 in cervical tumors. Methods HPV-16 positive CasKi cells were treated in vitro with up to 6 Gy of external radiation, or proteasome inhibitor MG-132 or unlabeled anti-E6 antibody C1P5 and cell death was assessed. Biodistribution of 188Rhenium (188Re)-labeled C1P5 antibody was performed in both control and radiation MG-132 treated CasKi tumor-bearing nude mice. Results . 188Re-C1P5 antibody demonstrated tumor specificity and very low uptake and fast clearance from the major organs. The amount of tumor uptake was enhanced by MG-132 but was unaffected by pre-treatment with radiation. In addition, in vitro studies demonstrated an unanticipated effect of unlabeled antibody on the amount of cell death, a finding that was suggested by our previous in vivo studies in CasKi tumor model. Conclusion We demonstrated that pre-treatment of cervical tumors with proteasome inhibitor MG-132 and with unlabeled antibody to E6 can serve as a means to generate non-viable cancer cells and to elevate the levels of target oncoproteins in the cells for increasing the accumulation of targeted radiolabeled antibodies in tumors. These results favor further development of RIT of cervical cancers targeting viral antigens. PMID:20127955

Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration.

PubMed

Pietrofesa, Ralph A; Solomides, Charalambos C; Christofidou-Solomidou, Melpo

Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O 2 (O 2 ); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O 2 and IR (O 2 +IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early tissue oxidative damage associated with space exploration.

Flaxseed Mitigates Acute Oxidative Lung Damage in a Mouse Model of Repeated Radiation and Hyperoxia Exposure Associated with Space Exploration

PubMed Central

Pietrofesa, Ralph A.; Solomides, Charalambos C.; Christofidou-Solomidou, Melpo

2015-01-01

Background Spaceflight missions may require crewmembers to conduct extravehicular activities (EVA). Pre-breathe protocols in preparation for an EVA entail 100% hyperoxia exposure that may last for a few hours and be repeated 2-3 times weekly. Each EVA is associated with additional challenges such as low levels of total body cosmic/galactic radiation exposure that may present a threat to crewmember health. We have developed a mouse model of total body radiation and hyperoxia exposure and identified acute damage of lung tissues. In the current study we evaluated the usefulness of dietary flaxseed (FS) as a countermeasure agent for such double-hit exposures. Methods We evaluated lung tissue changes 2 weeks post-initiation of exposure challenges. Mouse cohorts (n=5/group) were pre-fed diets containing either 0% FS or 10% FS for 3 weeks and exposed to: a) normoxia (Untreated); b) >95% O2 (O2); c) 0.25Gy single fraction gamma radiation (IR); or d) a combination of O2 and IR (O2+IR) 3 times per week for 2 consecutive weeks, where 8-hour hyperoxia treatments were spanned by normoxic intervals. Results At 2 weeks post challenge, while control-diet fed mice developed significant lung injury and inflammation across all challenges, FS protected lung tissues by decreasing bronchoalveolar lavage fluid (BALF) neutrophils (p<0.003) and protein levels, oxidative tissue damage, as determined by levels of malondialdehyde (MDA) (p<0.008) and nitrosative stress as determined by nitrite levels. Lung hydroxyproline levels, a measure of lung fibrosis, were significantly elevated in mice fed 0% FS (p<0.01) and exposed to hyperoxia/radiation or the combination treatment, but not in FS-fed mice. FS also decreased levels of a pro-inflammatory, pro-fibrogenic cytokine (TGF-β1) gene expression levels in lung. Conclusion Flaxseed mitigated adverse effects in lung of repeat exposures to radiation/hyperoxia. This data will provide useful information in the design of countermeasures to early tissue oxidative damage associated with space exploration. PMID:25705570

Rats exposed to 2.45GHz of non-ionizing radiation exhibit behavioral changes with increased brain expression of apoptotic caspase 3.

PubMed

Varghese, Rini; Majumdar, Anuradha; Kumar, Girish; Shukla, Amit

2018-03-01

In recent years there has been a tremendous increase in use of Wi-Fi devices along with mobile phones, globally. Wi-Fi devices make use of 2.4GHz frequency. The present study evaluated the impact of 2.45GHz radiation exposure for 4h/day for 45days on behavioral and oxidative stress parameters in female Sprague Dawley rats. Behavioral tests of anxiety, learning and memory were started from day 38. Oxidative stress parameters were estimated in brain homogenates after sacrificing the rats on day 45. In morris water maze, elevated plus maze and light dark box test, the 2.45GHz radiation exposed rats elicited memory decline and anxiety behavior. Exposure decreased activities of super oxide dismutase, catalase and reduced glutathione levels whereas increased levels of brain lipid peroxidation was encountered in the radiation exposed rats, showing compromised anti-oxidant defense. Expression of caspase 3 gene in brain samples were quantified which unraveled notable increase in the apoptotic marker caspase 3 in 2.45GHz radiation exposed group as compared to sham exposed group. No significant changes were observed in histopathological examinations and brain levels of TNF-α. Analysis of dendritic arborization of neurons showcased reduction in number of dendritic branching and intersections which corresponds to alteration in dendritic structure of neurons, affecting neuronal signaling. The study clearly indicates that exposure of rats to microwave radiation of 2.45GHz leads to detrimental changes in brain leading to lowering of learning and memory and expression of anxiety behavior in rats along with fall in brain antioxidant enzyme systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of ionizing radiation upon natural populations and ecosystems. Final report. [Ecological perspectives in land use planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCormick, J.F.

Accomplishments throughout a 10-year period summarized include: a study of the effects of radiation from a ..gamma.. source on the ecology of the El Verde rain forest in Puerto Rico, with emphasis on the role of secondary succession in the recovery of forest ecosystems following irradiation; the effects of light and temperature on gaseous exchange in trees using /sup 14/CO/sub 2/ as a tracer in Palcourea; the nature of the sensitivity of pine trees to ionizing radiation and the possible synergistic effects of elevated ozone levels on radiosensitivity; the combined effects of radioactive and thermal effluents on plant communities ofmore » a swamp hardwood forest; and the development of a new conceptual approach to the evaluation of environmental quality, with emphasis on ecological perspectives in land use planning. (CH)« less

Induction of metallothionein synthesis in transplanted murine tumors by X irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiyoshi, Shibuya; Masahiko Satoh; Yuzo, Watanabe

1995-07-01

Although recent studies have shown that radiation can induce metallothionein (MT) synthesis in normal tissues, the induction of tumor MT synthesis by irradiation has not been reported. We examined the accumulation of MT in the Meth-A tumor (mouse fibrosarcoma cells) transplanted into mice exposed to whole-body X irradiation. In the present study, the MT content in the tumor cells was increased by X irradiation in a dose-dependent manner. The MT level induced in the tumor cells by X irradiation was elevated not only after a single exposure but also after repeated exposures. Several studies have shown that MT is onemore » of the important cellular factors in resistance to various anti-cancer drugs and ionizing radiation. Thus our results suggest that the radiation-induced MT in the tumor cells may have to be taken into consideration when designing protocols for radio-and chemotherapy. 29 refs., 3 figs.« less

Effects of High Dietary HEME Iron and Radiation on Cardiovascular Function

NASA Technical Reports Server (NTRS)

Westby, Christian M.; Brown, A. K.; Platts, S. H.

2012-01-01

The radiation related health risks to astronauts is of particular concern to NASA. Data support that exposure to radiation is associated with a number of disorders including a heightened risk for cardiovascular diseases. Independent of radiation, altered nutrient status (e.g. high dietary iron) also increases ones risk for cardiovascular disease. However, it is unknown whether exposure to radiation in combination with high dietary iron further increases ones cardiovascular risk. The intent of our proposal is to generate compulsory data examining the combined effect of radiation exposure and iron overload on sensitivity to radiation injury to address HRP risks: 1) Risk Factor of Inadequate Nutrition; 2) Risk of Cardiac Rhythm Problems; and 3) Risk of Degenerative Tissue or other Health Effects from Space Radiation. Towards our goal we propose two distinct pilot studies using the following specific aims: Vascular Aim 1: To determine the short-term consequences of the independent and combined effects of exposure to gamma radiation and elevated body iron stores on measures of endothelial function and cell viability and integrity. We hypothesize that animals that have high body iron stores and are exposed to gamma radiation will show a greater reduction in endothelial dependent nitric oxid production and larger pathological changes in endothelial integrity than animals that have only 1 of those treatments (either high iron stores or exposure to gamma radiation). Vascular Aim 2: Identify and compare the effects of gamma radiation and elevated body iron stores on the genetic and epigenetic regulation of proteins associated with endothelial cell function. We hypothesize that modifications of epigenetic control and posttranslational expression of proteins associated with endothelial cell function will be differentially altered in rats with high body iron stores and exposed to gamma radiation compared to rats with only 1 type of treatment. Cardiac Aim 1: To determine the short-term consequences of the independent and combined effects of gamma radiation and elevated body iron stores on measures of cardiac structure. We hypothesize that modifications to cardiac structure and function will be greater in rats with high body iron stores and exposed to gamma radiation than in rats that have only 1 of those treatments. Cardiac Aim 2: Identify and compare the effects of gamma radiation and elevated body iron stores on the genetic and epigenetic regulation of proteins associated with cardiac structure and function. We hypothesize that modifications of epigenetic control and posttranslational expression of proteins associated with cardiac contractile function will be differentially altered in rats with high body iron stores and exposed to gamma radiation compared to rats with only 1 type of treatment.

Specific interactions between lectins and red blood cells of Chornobyl cleanup workers as indicator of some late radiation effects.

PubMed

Karpova, I S

2016-12-01

Growing interest in lectins is based on their diagnostic and pharmacological potential, especially the ability to inhibit proliferation and initiate apoptosis of cancer cells. In our research microplate lectinoassay able to detect carbohydrate containing structures (receptors) on erythrocyte surface have been proposed for Chornobyl cleanup workers (1986) monitoring. It was expected to reveal specific abnormalities associated with pathological condition arising as a result of late radiation effects. Red blood cell (RBC) specimens were taken from 171 persons distributed into the six cohorts: nonexposed donors (1); chronically exposed to the doses below (2) and over 50 cGy (3); exposed to acute radiation without (4) and with manifestation of acute radiation syndrome (5 and 6). Lectins from 24 species of medicinal plants were purified by ethanol fractionation and electrofocusing. Intensity of lectin-receptor interactions was determined in reaction of hemagglutination. Method of flow cytofluorometry was used to study B-cell counts. Hormone levels in blood serum were determined by radioimmunoassay. An elevated ability of RBC to interact with the panel of lectins was found in all cohorts of exposed persons versus nonexposed donors, moreover, changes in the intensity of lectin-receptor binding depended on the dose of irradiation. Diagnostic value of specific RBC reactions with some individual lectins has been elucidated. Elevated intensity of RBC reaction with Zea mays lectin was accompanied by a decrease in serum content of thyroid hormones T4 and T3, as well as reduction of B-cell counts. In the case of Rubus caesius lectin the more intensive reaction with RBC, the higher level of hormone cortisol was observed. Deviations from donor's norm in intensity of lectin - RBC interactions in radiation exposed men are supposed to carry information about negative changes in their health status following Chornobyl catastrophe and show the diagnostic potential. The most sensitive reactions have been associated primarily with shifts in endocrine and immune systems. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

The long non-coding RNA PARTICLE is associated with WWOX and the absence of FRA16D breakage in osteosarcoma patients.

PubMed

O'Leary, Valerie Bríd; Maugg, Doris; Smida, Jan; Baumhoer, Daniel; Nathrath, Michaela; Ovsepian, Saak Victor; Atkinson, Michael John

2017-10-20

Breakage of the fragile site FRA16D disrupts the WWOX (WW Domain Containing Oxidoreductase) tumor suppressor gene in osteosarcoma. However, the frequency of breakage is not sufficient to explain the rate of WWOX loss in pathogenesis. The involvement of non-coding RNA transcripts is proposed due to their accumulation at fragile sites, where they are advocated to influence specific chromosomal regions associated with malignancy. The long ncRNA PARTICLE (promoter of MAT2A antisense radiation-induced circulating long non-coding RNA) is transiently elevated in response to irradiation and influences epigenetic silencing modification within WWOX . It now emerges that elevated PARTICLE levels are significantly associated with FRA16D non-breakage in OS patients. Although not associated with overall survival, high PARTICLE levels were found to be significantly linked to metastasis free outcome. The transcription of both PARTICLE and WWOX are transiently responsive to exposure to low doses of radiation in osteosarcoma cell lines. Herein, a relationship between WWOX and PARTICLE transcription is suggested in human osteosarcoma cell lines representing alternative genetic backgrounds. PARTICLE over-expression ameliorated WWOX promoter activity in U2OS harboring FRA16D non-breakage. It can be concluded that the lncRNA PARTICLE influences the WWOX tumor suppressor and in the absence of WWOX FRA16D breakage, it is associated with OS metastasis-free survival.

Mass elevation and lee effects markedly lift the elevational distribution of ground beetles in the Himalaya-Tibet orogen

PubMed Central

Schmidt, Joachim; Böhner, Jürgen; Brandl, Roland; Opgenoorth, Lars

2017-01-01

Mass elevation and lee effects markedly influence snow lines and tree lines in high mountain systems. However, their impact on other phenomena or groups of organisms has not yet been quantified. Here we quantitatively studied their influence in the Himalaya–Tibet orogen on the distribution of ground beetles as model organisms, specifically whether the ground beetle distribution increases from the outer to the inner parts of the orogen, against latitudinal effects. We also tested whether July temperature and solar radiation are predictors of the beetle’s elevational distribution ranges. Finally, we discussed the general importance of these effects for the distributional and evolutionary history of the biota of High Asia. We modelled spatially explicit estimates of variables characterizing temperature and solar radiation and correlated the variables with the respective lower elevational range of 118 species of ground beetles from 76 high-alpine locations. Both July temperature and solar radiation significantly positively correlated with the elevational ranges of high-alpine beetles. Against the latitudinal trend, the median elevation of the respective species distributions increased by 800 m from the Himalayan south face north to the Transhimalaya. Our results indicate that an increase in seasonal temperature due to mass elevation and lee effects substantially impact the regional distribution patterns of alpine ground beetles of the Himalaya–Tibet orogen and are likely to affect also other soil biota there and in mountain ranges worldwide. Since these effects must have changed during orogenesis, their potential impact must be considered when biogeographic scenarios based on geological models are derived. As this has not been the practice, we believe that large biases likely exist in many paleoecological and evolutionary studies dealing with the biota from the Himalaya-Tibet orogen and mountain ranges worldwide. PMID:28339461

A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, W. -L.; Gu, Y.; Liou, K. N.

2015-05-19

We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance atmore » the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.« less

Confirmatory radiological survey of the BORAX-V turbine building Idaho National Engineering Laboratory, Idaho Falls, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, G.H.; Coleman, R.L.; Jensen, M.K.

1993-07-01

An independent assessment of the remediation of the BORAX-V (Boiling Water Reactor Experiment) turbine building at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho, was accomplished by the Oak Ridge National Laboratory Pollutant Assessments Group (ORNL/PAG). The purpose of the assessment was to confirm the site`s compliance with applicable Department of Energy guidelines. The assessment included reviews of both the decontamination and decommissioning Plan and data provided from the pre- and post-remedial action surveys and an independent verification survey of the facility. The independent verification survey included determination of background exposure rates and soil concentrations, beta-gamma and gamma radiationmore » scans, smears for detection of removable contamination, and direct measurements for alpha and beta-gamma radiation activity on the basement and mezzanine floors and the building`s interior and exterior walls. Soil samples were taken, and beta-gamma and gamma radiation exposure rates were measured on areas adjacent to the building. Results of measurements on building surfaces at this facility were within established contamination guidelines except for elevated beta-gamma radiation levels located on three isolated areas of the basement floor. Following remediation of these areas, ORNL/PAG reviewed the remedial action contractor`s report and agreed that remediation was effective in removing the source of the elevated direct radiation. Results of all independent soil analyses for {sup 60}Co were below the detection limit. The highest {sup 137}Cs analysis result was 4.6 pCi/g; this value is below the INEL site-specific guideline of 10 pCi/g.« less

Educational Activity for the Radiation Emergency System in the Northern Part of Japan: Meeting Report on "The 3rd Educational Symposium on Radiation and Health (ESRAH) by Young Scientists in 2016".

PubMed

Matsuya, Yusuke; Tsujiguchi, Takakiyo; Yamaguchi, Masaru; Kimura, Takaaki; Mori, Ryosuke; Yamada, Ryota; Saga, Ryo; Fujishima, Yohei; Date, Hiroyuki

2017-06-01

In the northern part of Japan, close cooperation is essential in preparing for any possible emergency response to radiation accidents because several facilities, such as the Low-Level Radioactive Waste Disposal Facility, the MOX Fuel Fabrication Plant and the Vitrified Waste Storage Center, exist in Rokkasho Village (Aomori Prefecture). After the accident at Fukushima Daiichi Nuclear Power Plant in 2011, special attention should be given to the relationship between radiation and human health, as well as establishing a system for managing with a radiation emergency. In the area of Hokkaido and Aomori prefectures in Japan, since 2008 an exchange meeting between Hokkaido University and Hirosaki University has been held every year to have opportunities to discuss radiation effects on human health and to collect the latest news on monitoring environmental radiation. This meeting was elevated to an international meeting in 2014 titled "Educational Symposium on Radiation and Health (ESRAH) by Young Scientists". The 3rd ESRAH meeting took place in 2016, with the theme "Investigating Radiation Impact on the Environmental and Health". Here we report the meeting findings on the continuing educational efforts after the Fukushima incident, what was accomplished in terms of building a community educational approaches, and future goals.

An Empirical Method for deriving RBE values associated with Electrons, Photons and Radionuclides

DOE PAGES

Bellamy, Michael B; Puskin, J.; Eckerman, Keith F.; ...

2015-01-01

There is substantial evidence to justify using relative biological effectiveness (RBE) values greater than one for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer (LET) has been assigned a radiation weighting factor w R of one. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for othermore » similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few keV. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.« less

Gene expression analyses of the small intestine of pigs in the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant.

PubMed

Morimoto, Motoko; Kato, Ayaka; Kobayashi, Jin; Okuda, Kei; Kuwahara, Yoshikazu; Kino, Yasushi; Abe, Yasuyuki; Sekine, Tsutomu; Fukuda, Tomokazu; Isogai, Emiko; Fukumoto, Manabu

2017-11-15

After the accident at the Fukushima Daiichi Nuclear Power Plant, radioactive contaminants were released over a widespread area. Monitoring the biological effects of radiation exposure in animals in the ex-evacuation zone should be continued to understand the health effects of radiation exposure in humans. The present study aimed to clarify the effects of radiation by investigating whether there is any alteration in the morphology and gene expressions of immune molecules in the intestine of pigs and inobuta (wild boar and domestic pig hybrid) in the ex-evacuation zone in 2012. Gene expression analysis was performed in small intestine samples from pigs, which were collected from January to February 2012, in the ex-evacuation zone. Pigs lived freely in this zone, and their small intestine was considered to be affected by the dietary intake of radioactive contaminants. Several genes were selected by microarray analysis for further investigation using real-time polymerase chain reaction. IFN-γ, which is an important inflammatory cytokine, and TLR3, which is a pattern recognize receptor for innate immune system genes, were highly elevated in these pigs. The expressions of the genes of these proteins were associated with the radiation level in the muscles. We also examined the alteration of gene expressions in wild boars 5 years after the disaster. The expression of IFN-γ and TLR3 remained high, and that of Cyclin G1, which is important in the cell cycle, was elevated. We demonstrated that some changes in gene expression occurred in the small intestine of animals in the ex-evacuation zone after radiation. It is difficult to conclude that these alterations are caused by only artificial radionuclides from the Fukushima Daiichi Nuclear Power Plant. However, the animals in the ex-evacuation zone might have experienced some changes owing to radioactive materials, including contaminated soil, small animals, and insects. We need to continue monitoring the effects of long-term radiation exposure in living things.

A Prospective Cohort Study on Radiation-induced Hypothyroidism: Development of an NTCP Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boomsma, Marjolein J.; Bijl, Hendrik P.; Christianen, Miranda E.M.C.

Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. Methods and Materials: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. Results: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroidmore » gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm{sup 3}). Model performance was good with an area under the curve (AUC) of 0.85. Conclusions: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.« less

Radioactivity levels in the mostly local foodstuff consumed by residents of the high level natural radiation areas of Ramsar, Iran.

PubMed

Fathabadi, Nasrin; Salehi, Ali Akbar; Naddafi, Kazem; Kardan, Mohammad Reza; Yunesian, Masud; Nodehi, Ramin Nabizadeh; Deevband, Mohammad Reza; Shooshtari, Molood Gooniband; Hosseini, Saeedeh Sadat; Karimi, Mahtab

2017-04-01

Among High Level Natural Radiation Areas (HLNRAs) all over the world, the northern coastal city of Ramsar has been considered enormously important. Many studies have measured environmental radioactivity in Ramsar, however, no survey has been undertaken to measure concentrations in the diets of residents. This study determined the 226 Ra activity concentration in the daily diet of people of Ramsar. The samples were chosen from both normal and high level natural radiation areas and based on the daily consumption patterns of residents. About 150 different samples, which all are local and have the highest consumption, were collected during the four seasons. In these samples, after washing and drying and pretreatment, the radionuclide was determined by α-spectrometry. The mean radioactivity concentration of 226 Ra ranged between 5 ± 1 mBq kg -1 wet weight (chino and meat) to 725 ± 480 mBq kg -1 for tea dry leaves. The 226 Ra activity concentrations compared with the reference values of UNSCEAR appear to be higher in leafy vegetables, milk and meat product. Of the total daily dietary 226 Ra exposure for adults in Ramsar, the largest percentage was from eggs. The residents consuming eggs from household chickens may receive an elevated dose in the diet. Copyright © 2016. Published by Elsevier Ltd.

14 CFR 171.319 - Approach elevation monitor system requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... an error in the time division multiplex synchronization of a particular elevation function such that... within the time allowed, radiation shall cease. After shutdown, no attempt must be made to restore...

14 CFR 171.319 - Approach elevation monitor system requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... an error in the time division multiplex synchronization of a particular elevation function such that... within the time allowed, radiation shall cease. After shutdown, no attempt must be made to restore...

14 CFR 171.319 - Approach elevation monitor system requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... an error in the time division multiplex synchronization of a particular elevation function such that... within the time allowed, radiation shall cease. After shutdown, no attempt must be made to restore...

14 CFR 171.319 - Approach elevation monitor system requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... an error in the time division multiplex synchronization of a particular elevation function such that... within the time allowed, radiation shall cease. After shutdown, no attempt must be made to restore...

14 CFR 171.319 - Approach elevation monitor system requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... an error in the time division multiplex synchronization of a particular elevation function such that... within the time allowed, radiation shall cease. After shutdown, no attempt must be made to restore...

Inactivation of Mirk/Dyrk1b Kinase Targets Quiescent Pancreatic Cancer Cells *

PubMed Central

Ewton, Daina Z.; Hu, Jing; Vilenchik, Maria; Deng, Xiaobing; Luk, Kin-chun; Polonskaia, Ann; Hoffman, Ann F.; Zipf, Karen; Boylan, John F.; Friedman, Eileen A.

2011-01-01

A major problem in the treatment of cancer arises from quiescent cancer cells that are relatively insensitive to most chemotherapeutic drugs and radiation. Such residual cancer cells can cause tumor regrowth or recurrence when they re-enter the cell cycle. Earlier studies demonstrated that levels of the serine/theronine kinase Mirk/dyrk1B are elevated up to 10-fold in quiescent G0 tumor cells, that Mirk uses several mechanisms to block cell cycling, and that Mirk increases expression of antioxidant genes which lower ROS levels and increase quiescent cell viability. We now show that a novel small molecule Mirk kinase inhibitor blocked tumor cells from undergoing reversible arrest in a quiescent G0 state and enabled some cells to exit quiescence. The inhibitor increased cycling in Panc1, AsPc1 and SW620 cells that expressed Mirk, but not in HCT116 cells that did not. Mirk kinase inhibition elevated ROS levels and DNA damage detected by increased phosphorylation of the histone protein H2AX and by S phase checkpoints. The Mirk kinase inhibitor increased cleavage of the apoptotic proteins PARP and caspase 3, and increased tumor cell kill several-fold by gemcitabine and cisplatin. A phenocopy of these effects occurred following Mirk depletion, showing drug specificity. In prior studies Mirk knockout or depletion had no detectable effect on normal tissue, suggesting that the Mirk kinase inhibitor could have a selective effect on cancer cells expressing elevated levels of Mirk kinase. PMID:21878655

Compact antenna arrays with wide bandwidth and low sidelobe levels

DOEpatents

Strassner, II, Bernd H.

2014-09-09

Highly efficient, low cost, easily manufactured SAR antenna arrays with lightweight low profiles, large instantaneous bandwidths and low SLL are disclosed. The array topology provides all necessary circuitry within the available antenna aperture space and between the layers of material that comprise the aperture. Bandwidths of 15.2 GHz to 18.2 GHz, with 30 dB SLLs azimuthally and elevationally, and radiation efficiencies above 40% may be achieved. Operation over much larger bandwidths is possible as well.

Cancer in Children and Adolescents

MedlinePlus

... to radiation from the World War II atomic bomb blasts had an elevated risk of leukemia ( 12 ), ... of leukemia, lymphoma and multiple myeloma among atomic bomb survivors: 1950-2001. Radiation Research 2013; 179(3): ...

Evaluation of background radiation dose contributions in the United Arab Emirates.

PubMed

Goddard, Braden; Bosc, Emmanuel; Al Hasani, Sarra; Lloyd, Cody

2018-09-01

The natural background radiation consists of three main components; cosmic, terrestrial, and skyshine. Although there are currently methods available to measure the total dose rate from background radiation, no established methods exist that allow for the measurement of each component the background radiation. This analysis consists of a unique methodology in which the dose rate contribution from each component of the natural background radiation is measured and calculated. This project evaluates the natural background dose rate in the Abu Dhabi City region from all three of these components using the developed methodology. Evaluating and understanding the different components of background radiation provides a baseline allowing for the detection, and possibly attribution, of elevated radiation levels. Measurements using a high-pressure ion chamber with different shielding configurations and two offshore measurements provided dose rate information that were attributed to the different components of the background radiation. Additional spectral information was obtained using an HPGe detector to verify and quantify the presence of terrestrial radionuclides. By evaluating the dose rates of the different shielding configurations the comic, terrestrial, and skyshine contribution in the Abu Dhabi City region were determined to be 33.0 ± 1.7, 15.7 ± 2.5, and 2.4 ± 2.1 nSv/h, respectively. Copyright © 2018. Published by Elsevier Ltd.

Metabolomic applications in radiation biodosimetry: exploring radiation effects through small molecules.

PubMed

Pannkuk, Evan L; Fornace, Albert J; Laiakis, Evagelia C

2017-10-01

Exposure of the general population to ionizing radiation has increased in the past decades, primarily due to long distance travel and medical procedures. On the other hand, accidental exposures, nuclear accidents, and elevated threats of terrorism with the potential detonation of a radiological dispersal device or improvised nuclear device in a major city, all have led to increased needs for rapid biodosimetry and assessment of exposure to different radiation qualities and scenarios. Metabolomics, the qualitative and quantitative assessment of small molecules in a given biological specimen, has emerged as a promising technology to allow for rapid determination of an individual's exposure level and metabolic phenotype. Advancements in mass spectrometry techniques have led to untargeted (discovery phase, global assessment) and targeted (quantitative phase) methods not only to identify biomarkers of radiation exposure, but also to assess general perturbations of metabolism with potential long-term consequences, such as cancer, cardiovascular, and pulmonary disease. Metabolomics of radiation exposure has provided a highly informative snapshot of metabolic dysregulation. Biomarkers in easily accessible biofluids and biospecimens (urine, blood, saliva, sebum, fecal material) from mouse, rat, and minipig models, to non-human primates and humans have provided the basis for determination of a radiation signature to assess the need for medical intervention. Here we provide a comprehensive description of the current status of radiation metabolomic studies for the purpose of rapid high-throughput radiation biodosimetry in easily accessible biofluids and discuss future directions of radiation metabolomics research.

Therapeutic effects of C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO-Me; bardoxolone methyl) on radiation-induced lung inflammation and fibrosis in mice.

PubMed

Wang, Yan-Yang; Zhang, Cui-Ying; Ma, Ya-Qiong; He, Zhi-Xu; Zhe, Hong; Zhou, Shu-Feng

2015-01-01

The C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO-Me), one of the synthetic triterpenoids, has been found to have potent anti-inflammatory and anticancer properties in vitro and in vivo. However, its usefulness in mitigating radiation-induced lung injury (RILI), including radiation-induced lung inflammation and fibrosis, has not been tested. The aim of this study was to explore the therapeutic effect of CDDO-Me on RILI in mice and the underlying mechanisms. Herein, we found that administration of CDDO-Me improved the histopathological score, reduced the number of inflammatory cells and concentrations of total protein in bronchoalveolar lavage fluid, suppressed secretion and expression of proinflammatory cytokines, including transforming growth factor-β and interleukin-6, elevated expression of the anti-inflammatory cytokine interleukin-10, and downregulated the mRNA level of profibrotic genes, including for fibronectin, α-smooth muscle actin, and collagen I. CDDO-Me attenuated radiation-induced lung inflammation. CDDO-Me also decreased the Masson's trichrome stain score, hydroxyproline content, and mRNA level of profibrotic genes, and blocked radiation-induced collagen accumulation and fibrosis. Collectively, these findings suggest that CDDO-Me ameliorates radiation-induced lung inflammation and fibrosis, and this synthetic triterpenoid is a promising novel therapeutic agent for RILI. Further mechanistic, efficacy, and safety studies are warranted to elucidate the role of CDDO-Me in the management of RILI.

1999-2003 Shortwave Characterizations of Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) Broadband Active Cavity Radiometer Sensors

NASA Technical Reports Server (NTRS)

Lee, Robert B., III; Smith, George L.; Wong, Takmeng

2008-01-01

From October 1984 through May 2005, the NASA Earth Radiation Budget Satellite (ERBS/ )/Earth Radiation Budget Experiment (ERBE)ERBE nonscanning active cavity radiometers (ACR) were used to monitor long-term changes in the earth radiation budget components of the incoming total solar irradiance (TSI), earth-reflected TSI, and earth-emitted outgoing longwave radiation (OLR). From September1984 through September 1999, using on-board calibration systems, the ERBS/ERBE ACR sensor response changes, in gains and offsets, were determined from on-orbit calibration sources and from direct observations of the incoming TSI through calibration solar ports at measurement precision levels approaching 0.5 W/sq m , at satellite altitudes. On October 6, 1999, the onboard radiometer calibration system elevation drive failed. Thereafter, special spacecraft maneuvers were performed to observe cold space and the sun in order to define the post-September 1999 geometry of the radiometer measurements, and to determine the October 1999-September 2003 ERBS sensor response changes. Analyses of these special solar and cold space observations indicate that the radiometers were pointing approximately 16 degrees away from the spacecraft nadir and on the anti-solar side of the spacecraft. The special observations indicated that the radiometers responses were stable at precision levels approaching 0.5 W/sq m . In this paper, the measurement geometry determinations and the determinations of the radiometers gain and offset are presented, which will permit the accurate processing of the October 1999 through September 2003 ERBE data products at satellite and top-of-the-atmosphere altitudes.

Rangeland -- Plant responses to elevated CO sub 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owensby, C.E.; Coyne, P.I.; Ham, J.M.

1992-01-01

Several broad conclusions which can be drawn from the work that was accomplished during the first 3-year phase of the study is described. In prairie ecosystems dominated by C{sub 4} grasses, it is likely that elevated atmospheric CO{sub 2} will increase ecosystem level productivity, with a greater increase in belowground productivity. The increased productivity will primarily result from increased water use efficiency due to the anti-transpirant action of CO{sub 2}. Fumigation chambers are directly confounded with elevated CO{sub 2} effects, in that both reduce evapotranspiration. The reduced evapotranspiration of the fumigation chamber is primarily through reduced wind speeds and reducedmore » radiation. In very dry years, fumigation chamber effects are negligible, but in years with normal precipitation, chamber effects and elevated CO{sub 2} effects are essentially equal with respect to reduced evapotranspiration effects. Increased production under elevated CO{sub 2} results in reduced nitrogen concentration in the herbage and increased fiber concentrations. Consequently, digestibility of the herbage is reduced, and microbial degradation of surface litter and soil organic matter is slowed. On the negative side, ruminant productivity will likely be reduced substantially, but increased carbon storage in the soil may buffer against future rise in atmospheric CO{sub 2}. Tallgrass prairie will not likely change greatly in botanical composition, since the C{sub 4} dominants responded to elevated CO{sub 2} more than the C{sub 3} subdominants.« less

NIOSH comments to DOL on MSHA's advance notice of proposed rulemaking (ANPR) metal and nonmetal mine safety and health, radiation standards by J. D. Millar, March 18, 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-03-18

The testimony presents the views of NIOSH with regard to specific issues raised by MSHA in a proposed rulemaking affecting metal and nonmetal mine safety and health, radiation standards. Results are included from epidemiological studies in which the relationship between lung cancer and exposure to radon daughters was examined. A quantitative risk assessment is also noted which will be considered in the development of a NIOSH recommended exposure limit for radon daughters. Specific issues addressed include risk assessment, particularly the relationship and the associated uncertainty between cumulative lifetime radon daughters exposure at or below 120 working level months and themore » lifetime risk of lung cancer or other biological response, and themethodology used to arrive at the risk relationship. The use of a nonthreshold model extrapolating from elevated exposure levels is considered along with modification of the risk relationship to account for cell repair or other factors. Questions concerning the latency period, cigarette smoking, exposure to thoron daughters, exposure to gamma radiation, and exposure to ore dusts are also addressed.« less

Increased expression of EMMPRIN and VEGF in the rat brain after gamma irradiation.

PubMed

Wei, Ming; Li, Hong; Huang, Huiling; Xu, Desheng; Zhi, Dashi; Liu, Dong; Zhang, Yipei

2012-03-01

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.

Martian particle size based on thermal inertia corrected for elevation-dependent atmospheric properties

NASA Technical Reports Server (NTRS)

Bridges, N. T.

1993-01-01

Thermal inertia is commonly used to derive physical properties of the Martian surface. If the surface is composed of loosely consolidated grains, then the thermal conductivity derived from the inertia can theoretically be used to compute the particle size. However, one persistent difficulty associated with the interpretation of thermal inertia and the derivation of particle size from it has been the degree to which atmospheric properties affect both the radiation balance at the surface and the gas conductivity. These factors vary with atmospheric pressure so that derived thermal inertias and particle sizes are a function of elevation. By utilizing currently available thermal models and laboratory information, a fine component thermal inertia map was convolved with digital topography to produce particle size maps of the Martian surface corrected for these elevation-dependent effects. Such an approach is especially applicable for the highest elevations on Mars, where atmospheric back radiation and gas conductivity are low.

Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion.

PubMed

Iimoto, T; Nunokawa, J; Fujii, H; Takashima, R; Hashimoto, M; Fukuhara, T; Yajima, T; Matsuzawa, H; Kurosawa, K; Yanagawa, Y; Someya, S

2015-11-01

Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quasi-analytical treatment of spatially averaged radiation transfer in complex terrain

NASA Astrophysics Data System (ADS)

Löwe, H.; Helbig, N.

2012-04-01

We provide a new quasi-analytical method to compute the topographic influence on the effective albedo of complex topography as required for meteorological, land-surface or climate models. We investigate radiative transfer in complex terrain via the radiosity equation on isotropic Gaussian random fields. Under controlled approximations we derive expressions for domain averages of direct, diffuse and terrain radiation and the sky view factor. Domain averaged quantities are related to a type of level-crossing probability of the random field which is approximated by longstanding results developed for acoustic scattering at ocean boundaries. This allows us to express all non-local horizon effects in terms of a local terrain parameter, namely the mean squared slope. Emerging integrals are computed numerically and fit formulas are given for practical purposes. As an implication of our approach we provide an expression for the effective albedo of complex terrain in terms of the sun elevation angle, mean squared slope, the area averaged surface albedo, and the direct-to-diffuse ratio of solar radiation. As an application, we compute the effective albedo for the Swiss Alps and discuss possible generalizations of the method.

Elevated Rate of Genome Rearrangements in Radiation-Resistant Bacteria.

PubMed

Repar, Jelena; Supek, Fran; Klanjscek, Tin; Warnecke, Tobias; Zahradka, Ksenija; Zahradka, Davor

2017-04-01

A number of bacterial, archaeal, and eukaryotic species are known for their resistance to ionizing radiation. One of the challenges these species face is a potent environmental source of DNA double-strand breaks, potential drivers of genome structure evolution. Efficient and accurate DNA double-strand break repair systems have been demonstrated in several unrelated radiation-resistant species and are putative adaptations to the DNA damaging environment. Such adaptations are expected to compensate for the genome-destabilizing effect of environmental DNA damage and may be expected to result in a more conserved gene order in radiation-resistant species. However, here we show that rates of genome rearrangements, measured as loss of gene order conservation with time, are higher in radiation-resistant species in multiple, phylogenetically independent groups of bacteria. Comparison of indicators of selection for genome organization between radiation-resistant and phylogenetically matched, nonresistant species argues against tolerance to disruption of genome structure as a strategy for radiation resistance. Interestingly, an important mechanism affecting genome rearrangements in prokaryotes, the symmetrical inversions around the origin of DNA replication, shapes genome structure of both radiation-resistant and nonresistant species. In conclusion, the opposing effects of environmental DNA damage and DNA repair result in elevated rates of genome rearrangements in radiation-resistant bacteria. Copyright © 2017 Repar et al.

Solar radiation alert system : final report.

DOT National Transportation Integrated Search

2009-03-01

The Solar Radiation Alert (SRA) system continuously evaluates measurements of high-energy protons made by instruments on GOES satellites. If the measurements indicate a substantial elevation of effective dose rates at aircraft flight altitudes, the C...

Portable nuclear material detector and process

DOEpatents

Hofstetter, Kenneth J [Aiken, SC; Fulghum, Charles K [Aiken, SC; Harpring, Lawrence J [North Augusta, SC; Huffman, Russell K [Augusta, GA; Varble, Donald L [Evans, GA

2008-04-01

A portable, hand held, multi-sensor radiation detector is disclosed. The detection apparatus has a plurality of spaced sensor locations which are contained within a flexible housing. The detection apparatus, when suspended from an elevation, will readily assume a substantially straight, vertical orientation and may be used to monitor radiation levels from shipping containers. The flexible detection array can also assume a variety of other orientations to facilitate any unique container shapes or to conform to various physical requirements with respect to deployment of the detection array. The output of each sensor within the array is processed by at least one CPU which provides information in a usable form to a user interface. The user interface is used to provide the power requirements and operating instructions to the operational components within the detection array.

Effects of mobile phone radiation on reproduction and development in Drosophila melanogaster.

PubMed

Weisbrot, David; Lin, Hana; Ye, Lin; Blank, Martin; Goodman, Reba

2003-05-01

In this report we examined the effects of a discontinuous radio frequency (RF) signal produced by a GSM multiband mobile phone (900/1,900 MHz; SAR approximately 1.4 W/kg) on Drosophila melanogaster, during the 10-day developmental period from egg laying through pupation. As found earlier with low frequency exposures, the non-thermal radiation from the GSM mobile phone increased numbers of offspring, elevated hsp70 levels, increased serum response element (SRE) DNA-binding and induced the phosphorylation of the nuclear transcription factor, ELK-1. The rapid induction of hsp70 within minutes, by a non-thermal stress, together with identified components of signal transduction pathways, provide sensitive and reliable biomarkers that could serve as the basis for realistic mobile phone safety guidelines. Copyright 2003 Wiley-Liss, Inc.

Relapse surveillance in AFP-positive hepatoblastoma: re-evaluating the role of imaging.

PubMed

Rojas, Yesenia; Guillerman, R Paul; Zhang, Wei; Vasudevan, Sanjeev A; Nuchtern, Jed G; Thompson, Patrick A

2014-10-01

Children with hepatoblastoma routinely undergo repetitive surveillance imaging, with CT scans for several years after therapy, increasing the risk of radiation-induced cancer. The purpose of this study was to determine the utility of surveillance CT scans compared to serum alpha-fetoprotein (AFP) levels for the detection of hepatoblastoma relapse. This was a retrospective study of all children diagnosed with AFP-positive hepatoblastoma from 2001 to 2011 at a single institution. Twenty-six children with hepatoblastoma were identified, with a mean age at diagnosis of 2 years 4 months (range 3 months to 11 years). Mean AFP level at diagnosis was 132,732 ng/ml (range 172.8-572,613 ng/ml). Five of the 26 children had hepatoblastoma relapse. A total of 105 imaging exams were performed following completion of therapy; 88 (84%) CT, 8 (8%) MRI, 5 (5%) US and 4 (4%) FDG PET/CT exams. A total of 288 alpha-fetoprotein levels were drawn, with a mean of 11 per child. The AFP level was elevated in all recurrences and no relapses were detected by imaging before AFP elevation. Two false-positive AFP levels and 15 false-positive imaging exams were detected. AFP elevation was found to be significantly more specific than PET/CT and CT imaging at detecting relapse. We recommend using serial serum AFP levels as the preferred method of surveillance in children with AFP-positive hepatoblastoma, reserving imaging for the early postoperative period, for children at high risk of relapse, and for determination of the anatomical site of clinically suspected recurrence. Given the small size of this preliminary study, validation in a larger patient population is warranted.

Sucrose modulation of radiofrequency-induced heating rates and cell death.

PubMed

Pulikkathara, Merlyn; Mark, Colette; Kumar, Natasha; Zaske, Ana Maria; Serda, Rita E

2017-09-01

Applied radiofrequency (RF) energy induces hyperthermia in tissues, facilitating vascular perfusion This study explores the impact of RF radiation on the integrity of the luminal endothelium, and then predominately explores the impact of altering the conductivity of biologically-relevant solutions on RF-induced heating rates and cell death. The ability of cells to survive high sucrose (i.e. hyperosmotic conditions) to achieve lower conductivity as a mechanism for directing hyperthermia is evaluated. RF radiation was generated using a capacitively-coupled radiofrequency system operating at 13.56 MHz. Temperatures were recorded using a FLIR SC 6000 infrared camera. RF radiation reduced cell-to-cell connections among endothelial cells and altered cell morphology towards a more rounded appearance at temperatures reported to cause in vivo vessel deformation. Isotonic solutions containing high sucrose and low levels of NaCl displayed low conductivity and faster heating rates compared to high salt solutions. Heating rates were positively correlated with cell death. Addition of sucrose to serum similarly reduced conductivity and increased heating rates in a dose-dependent manner. Cellular proliferation was normal for cells grown in media supplemented with 125 mM sucrose for 24 hours or for cells grown in 750 mM sucrose for 10 minutes followed by a 24 h recovery period. Sucrose is known to form weak hydrogen bonds in fluids as opposed to ions, freeing water molecules to rotate in an oscillating field of electromagnetic radiation and contributing to heat induction. The ability of cells to survive temporal exposures to hyperosmotic (i.e. elevated sucrose) conditions creates an opportunity to use sucrose or other saccharides to selectively elevate heating in specific tissues upon exposure to a radiofrequency field.

Characterizing low dose and dose rate effects in rodent and human neural stem cells exposed to proton and gamma irradiation.

PubMed

Tseng, Bertrand P; Lan, Mary L; Tran, Katherine K; Acharya, Munjal M; Giedzinski, Erich; Limoli, Charles L

2013-01-01

Past work has shown that exposure to gamma rays and protons elicit a persistent oxidative stress in rodent and human neural stem cells (hNSCs). We have now adapted these studies to more realistic exposure scenarios in space, using lower doses and dose rates of these radiation modalities, to further elucidate the role of radiation-induced oxidative stress in these cells. Rodent neural stem and precursor cells grown as neurospheres and human neural stem cells grown as monolayers were subjected to acute and multi-dosing paradigms at differing dose rates and analyzed for changes in reactive oxygen species (ROS), reactive nitrogen species (RNS), nitric oxide and superoxide for 2 days after irradiation. While acute exposures led to significant changes in both cell types, hNSCs in particular, exhibited marked and significant elevations in radiation-induced oxidative stress. Elevated oxidative stress was more significant in hNSCs as opposed to their rodent counterparts, and hNSCs were significantly more sensitive to low dose exposures in terms of survival. Combinations of protons and γ-rays delivered as lower priming or higher challenge doses elicited radioadaptive changes that were associated with improved survival, but in general, only under conditions where the levels of reactive species were suppressed compared to cells irradiated acutely. Protective radioadaptive effects on survival were eliminated in the presence of the antioxidant N-acetylcysteine, suggesting further that radiation-induced oxidative stress could activate pro-survival signaling pathways that were sensitive to redox state. Data corroborates much of our past work and shows that low dose and dose rate exposures elicit significant changes in oxidative stress that have functional consequences on survival.

An empirical method for deriving RBE values associated with electrons, photons and radionuclides.

PubMed

Bellamy, M; Puskin, J; Hertel, N; Eckerman, K

2015-12-01

There is substantial evidence to justify using relative biological effectiveness (RBE) values of >1 for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer has been assigned a radiation weighting factor wR of 1. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few kiloelectron volts. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions. Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Lap Shear Testing of Candidate Radiator Panel Adhesives

NASA Technical Reports Server (NTRS)

Ellis, David; Briggs, Maxwell; McGowan, Randy

2013-01-01

During testing of a subscale radiator section used to develop manufacturing techniques for a full-scale radiator panel, the adhesive bonds between the titanium heat pipes and the aluminum face sheets failed during installation and operation. Analysis revealed that the thermal expansion mismatch between the two metals resulted in relatively large shear stresses being developed even when operating the radiator at moderate temperatures. Lap shear testing of the adhesive used in the original joints demonstrated that the two-part epoxy adhesive fell far short of the strength required. A literature review resulted in several candidate adhesives being selected for lap shear joint testing at room temperature and 398 K, the nominal radiator operating temperature. The results showed that two-part epoxies cured at room and elevated temperatures generally did not perform well. Epoxy film adhesives cured at elevated temperatures, on the other hand, did very well with most being sufficiently strong to cause yielding in the titanium sheet used for the joints. The use of an epoxy primer generally improved the strength of the joint. Based upon these results, a new adhesive was selected for the second subscale radiator section.

Three-Dimensional Conformal Radiotherapy in Prostate Cancer Patients: Rise in Interleukin 6 (IL-6) but not IL-2, IL-4, IL-5, Tumor Necrosis Factor-{alpha}, MIP-1-{alpha}, and LIF Levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira Lopes, Carlos; Callera, Fernando, E-mail: fcallera@gmail.com

Purpose: To investigate the effect of radiotherapy (RT) on serum levels of interleukin-2 (IL-2), IL-4, IL-5, IL-6, tumor necrosis factor alpha (TNF-{alpha}), macrophage inflammatory protein-1-alpha (MIP-1-{alpha}) and leukemia inhibitory factor (LIF) in patients with prostate cancer. Methods and Materials: Forty eight patients with prostate cancer received three-dimensional conformal blocking radiation therapy with a linear accelerator. IL-2, IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were measured by the related immunoassay kit 1 day before the beginning of RT and during RT at days 15 and 30. Results: The mean IL-2 values were elevated before and during the RT in contrastmore » with those of IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF, which were within the normal range under the same conditions. Regarding markers IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF, comparisons among the three groups (before treatment and 15 and 30 days during RT) did not show significant differences. Although values were within the normal range, there was a significant rise in IL-6 levels at day 15 of RT (p = 0.0049) and a decline at day 30 to levels that were similar to those observed before RT. Conclusions: IL-6 appeared to peak after 15 days of RT before returning to pre-RT levels. In contrast, IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were not sensitive to irradiation. The increased levels of IL-6 following RT without the concurrent elevation of other cytokines involved in the acute phase reaction did not suggest a classical inflammatory response to radiation exposure. Further studies should be designed to elucidate the role of IL-6 levels in patients with prostate cancer treated with RT.« less

PAR modulation of the UV-dependent levels of flavonoid metabolites in Arabidopsis thaliana (L.) Heynh. leaf rosettes: cumulative effects after a whole vegetative growth period.

PubMed

Götz, Michael; Albert, Andreas; Stich, Susanne; Heller, Werner; Scherb, Hagen; Krins, Andreas; Langebartels, Christian; Seidlitz, Harald K; Ernst, Dieter

2010-07-01

Long-term effects of ultraviolet (UV) radiation on flavonoid biosynthesis were investigated in Arabidopsis thaliana using the sun simulators of the Helmholtz Zentrum München. The plants, which are widely used as a model system, were grown (1) at high photosynthetically active radiation (PAR; 1,310 micromol m(-2) s(-1)) and high biologically effective UV irradiation (UV-B(BE) 180 mW m(-2)) during a whole vegetative growth period. Under this irradiation regime, the levels of quercetin products were distinctively elevated with increasing UV-B irradiance. (2) Cultivation at high PAR (1,270 micromol m(-2) s(-1)) and low UV-B (UV-B(BE) 25 mW m(-2)) resulted in somewhat lower levels of quercetin products compared to the high-UV-B(BE) conditions, and only a slight increase with increasing UV-B irradiance was observed. On the other hand, when the plants were grown (3) at low PAR (540 micromol m(-2) s(-1)) and high UV-B (UV-B(BE) 180 mW m(-2)), the accumulation of quercetin products strongly increased from very low levels with increasing amounts of UV-B but the accumulation of kaempferol derivatives and sinapoyl glucose was less pronounced. We conclude (4) that the accumulation of quercetin products triggered by PAR leads to a basic UV protection that is further increased by UV-B radiation. Based on our data, (5) a combined effect of PAR and different spectral sections of UV radiation is satisfactorily described by a biological weighting function, which again emphasizes the additional role of UV-A (315-400 nm) in UV action on A. thaliana.

Intercomparison of shortwave radiative transfer schemes in global aerosol modeling: results from the AeroCom Radiative Transfer Experiment

NASA Astrophysics Data System (ADS)

Randles, C. A.; Kinne, S.; Myhre, G.; Schulz, M.; Stier, P.; Fischer, J.; Doppler, L.; Highwood, E.; Ryder, C.; Harris, B.; Huttunen, J.; Ma, Y.; Pinker, R. T.; Mayer, B.; Neubauer, D.; Hitzenberger, R.; Oreopoulos, L.; Lee, D.; Pitari, G.; Di Genova, G.; Quaas, J.; Rose, Fred G.; Kato, S.; Rumbold, S. T.; Vardavas, I.; Hatzianastassiou, N.; Matsoukas, C.; Yu, H.; Zhang, F.; Zhang, H.; Lu, P.

2012-12-01

In this study we examine the performance of 31 global model radiative transfer schemes in cloud-free conditions with prescribed gaseous absorbers and no aerosols (Rayleigh atmosphere), with prescribed scattering-only aerosols, and with more absorbing aerosols. Results are compared to benchmark results from high-resolution, multi-angular line-by-line radiation models. For purely scattering aerosols, model bias relative to the line-by-line models in the top-of-the atmosphere aerosol radiative forcing ranges from roughly -10 to 20%, with over- and underestimates of radiative cooling at higher and lower sun elevation, respectively. Inter-model diversity (relative standard deviation) increases from ~10 to 15% as sun elevation increases. Inter-model diversity in atmospheric and surface forcing decreases with increased aerosol absorption, indicating that the treatment of multiple-scattering is more variable than aerosol absorption in the models considered. Aerosol radiative forcing results from multi-stream models are generally in better agreement with the line-by-line results than the simpler two-stream schemes. Considering radiative fluxes, model performance is generally the same or slightly better than results from previous radiation scheme intercomparisons. However, the inter-model diversity in aerosol radiative forcing remains large, primarily as a result of the treatment of multiple-scattering. Results indicate that global models that estimate aerosol radiative forcing with two-stream radiation schemes may be subject to persistent biases introduced by these schemes, particularly for regional aerosol forcing.

Prediction of Clinical Outcomes by Chemokine and Cytokine Profiling In CSF from Radiation Treated Breast Cancer Primary with Brain Metastases

NASA Astrophysics Data System (ADS)

Lok, Edwin

Whole brain radiation is the standard treatment for patients with brain metastasis but unfortunately tumors can recover from radiation-induced damage with the help of the immune system. The hypothesis that differences in immunokines in the cerebrospinal fluid (CSF) pre- and post-irradiation could reveal tumor biology and correlate with outcome of patients with metastatic breast cancer to the brain is tested. Collected CSF samples were analyzed using Luminex's multiplexing assays to survey global immunokine levels while Enzyme-Linked Immunosorbent Assays were used to quantify each individual immunokines. Cluster analysis was performed to segregate patients based on their common immunokine profile and each cluster was correlated with survival and other clinical parameters. Breast cancer brain metastasis was found to have altered immunokine profiles in the CSF, and that Interleukin-1α expression was elevated after irradiation. Therefore, immunokine profiling in the CSF could enable cancer physicians to monitor the status of brain metastases.

Noise Rating Criteria for Elevated Rapid Transit Structures

DOT National Transportation Integrated Search

1980-05-01

The purpose of this report is to recommend criteria for rating the noise radiated from elevated rapid transit structures during train passages, so that different types of structures can be inter-compared with respect to their noise impact on the imme...

System Re-set: High LET Radiation or Transient Musculoskeletal Disuse Cause Lasting Changes in Oxidative Defense Pathways Within Bone

NASA Technical Reports Server (NTRS)

Kumar, Akhilesh; Chatterjee, A.; Alwood, Joshua S.; Dvorochkin, Natalya; Almeida, Eduardo A. C.

2011-01-01

Six months post-IR, there were no notable changes in skeletal expression of 84 principal genes in the p53 signaling pathway due to low dose IR (0.5Gy), HU, or both. In contrast, numerous genes relevant to oxidative stress were regulated by the treatments, typically in a direction indicative of increased oxidative stress and impaired defense. IR and HU independently reduced (between 0.46 to 0.88 fold) expression levels of Noxa1, Gpx3, Prdx2, Prdx3, and Zmynd17. Surprisingly, transient HU alone (sham-irradiated) decreased expression of several redox-related genes (Gpx1,Gstk1, Prdx1, Txnrd2), which were not affected significantly by IR alone. Irradiation increased (1.13 fold) expression of a gene responsible for production of superoxides by neutrophils (NCF2). Of interest, only combined treatment with HU and IR led to increased expression levels of Ercc2, (1.19 fold), a DNA excision repair enzyme. Differences in gene expression levels may reflect a change in gene expression on a per cell basis, a shift in the repertoire of specific cell types within the tissue, or both. Serum nitrite/nitrate levels were elevated to comparable levels (1.6-fold) due to IR, HU or both, indicative of elevated systemic nitrosyl stress. CONCLUSIONS The magnitude of changes in skeletal expression of oxidative stress-related genes six months after irradiation and/or transient unloading tended to be relatively modest (0.46-1.15 fold), whereas the p53 pathway was not affected. The finding that many different oxidative stress-related genes differed from controls at this late time point implicates a generalized impairment of oxidative defense within skeletal tissue, which coincides with both profound radiation damage to osteoprogenitors/stem cells in bone marrow and impaired remodeling of mineralized tissue.

Influence of dermal exposure to ultraviolet radiation and coal tar (polycyclic aromatic hydrocarbons) on the skin aging process.

PubMed

Borska, Lenka; Andrys, Ctirad; Krejsek, Jan; Palicka, Vladimir; Vorisek, Viktor; Hamakova, Kvetoslava; Kremlacek, Jan; Borsky, Pavel; Fiala, Zdenek

2016-03-01

Ultraviolet radiation (UVR) and crude coal tar (CCT) containing PAHs can accelerate the skin-aging process (SAP). However, UVR induces the formation of an important protective factor in SAP (vitamin D). To determine the relation of SAP to selected risks and benefits of combined dermal exposure to UVR and coal tar (PAHs). The study group consisted of patients with chronic stable plaque psoriasis and treated by Goeckerman therapy (GT; daily dermal application of UVR and 5% CCT ointment). The levels of urinary 1-hydroxypyrene (1-OHP), oxidative stress (DNA and RNA damage), genotoxic damage (chromosomal aberration in peripheral lymphocytes; ABC), 25-hydroxy-vitamin D [25(OH)D] and the PASI score were evaluated before and after GT. Intensive dermal absorption of PAHs was confirmed by increased levels of 1-OHP (p<0.01). After the therapy, we found an increased level of oxidative stress (p<0.05), an increased level of genotoxic damage (ABC; p<0.001), a high efficiency of the treatment (p<0.001) and an elevated production of 25(OH)D (p<0.01). We also found a relationship between the duration of UVR and the genotoxic damage (p<0.01), vitD (p<0.05) and the PASI score (p<0.05). Furthermore, we found a relationship between oxidative stress and 25(OH)D (p<0.05) and between genotoxic damage and the PASI score (p<0.05). Dermal exposure to UVR and coal tar (PAHs) enhances the level of oxidative stress and genotoxic damage and thus contributes to SAP. However, the exposure is very effective as a treatment and elevates the production of 25(OH)D, the protective factor in SAP. According to our results, UVR is probably a more hazardous factor in SAP. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Magnet Architectures and Active Radiation Shielding Study - SR2S Workshop

NASA Technical Reports Server (NTRS)

Westover, Shane; Meinke, Rainer; Burger, William; Ilin, Andrew; Nerolich, Shaun; Washburn, Scott

2014-01-01

Analyze new coil configurations with maturing superconductor technology -Develop vehicle-level concept solutions and identify engineering challenges and risks -Shielding performance analysis Recent advances in superconducting magnet technology and manufacturing have opened the door for re-evaluating active shielding solutions as an alternative to mass prohibitive passive shielding.Publications on static magnetic field environments and its bio-effects were reviewed. Short-term exposure information is available suggesting long term exposure may be okay. Further research likely needed. center dotMagnetic field safety requirements exist for controlled work environments. The following effects have been noted with little noted adverse effects -Magnetohydrodynamic (MHD) effects on ionized fluids (e.g. blood) creating an aortic voltage change -MHD interaction elevates blood pressure (BP) center dot5 Tesla equates to 5% BP elevation -Prosthetic devises and pacemakers are an issue (access limit of 5 gauss).

UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations.

PubMed

Barnes, Paul W; Ryel, Ronald J; Flint, Stephan D

2017-01-01

Ongoing changes in Earth's climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280-315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (T UV A ) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which T UV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial T UV A , measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on T UV A , though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600-3800 m, T UV A was variable (mean range = 6.0-11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus ; however, T UV A was consistently low (3%) and did not vary with elevation in the native V. reticulatum . Results indicate that high levels of UV protection occur in both native and non-native species in this high UV-B tropical alpine environment, and that flexibility in UV screening is a mechanism employed by some, but not all species to cope with varying solar UV-B exposures along elevation gradients.

UV Screening in Native and Non-native Plant Species in the Tropical Alpine: Implications for Climate Change-Driven Migration of Species to Higher Elevations

PubMed Central

Barnes, Paul W.; Ryel, Ronald J.; Flint, Stephan D.

2017-01-01

Ongoing changes in Earth’s climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280–315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUV A) in a diversity of plant species representing different growth forms to test whether native and non-native species growing above 2800 m elevation on Mauna Kea, Hawaii differed in their UV screening capabilities. We further compared the degree to which TUV A varied along an elevation gradient in the native shrub Vaccinium reticulatum and the introduced forb Verbascum thapsus to evaluate whether these species differed in their abilities to adjust their levels of UV screening in response to elevation changes in UV-B. For plants growing in the Mauna Kea alpine/upper subalpine, we found that adaxial TUV A, measured with a UVA-PAM fluorometer, varied significantly among species but did not differ between native (mean = 6.0%; n = 8) and non-native (mean = 5.8%; n = 11) species. When data were pooled across native and non-native taxa, we also found no significant effect of growth form on TUV A, though woody plants (shrubs and trees) were represented solely by native species whereas herbaceous growth forms (grasses and forbs) were dominated by non-native species. Along an elevation gradient spanning 2600–3800 m, TUV A was variable (mean range = 6.0–11.2%) and strongly correlated with elevation and relative biologically effective UV-B in the exotic V. thapsus; however, TUV A was consistently low (3%) and did not vary with elevation in the native V. reticulatum. Results indicate that high levels of UV protection occur in both native and non-native species in this high UV-B tropical alpine environment, and that flexibility in UV screening is a mechanism employed by some, but not all species to cope with varying solar UV-B exposures along elevation gradients. PMID:28878792

Under-canopy snow accumulation and ablation measured with airborne scanning LiDAR altimetry and in-situ instrumental measurements, southern Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Kirchner, P. B.; Bales, R. C.; Musselman, K. N.; Molotch, N. P.

2012-12-01

We investigated the influence of canopy on snow accumulation and melt in a mountain forest using paired snow on and snow off scanning LiDAR altimetry, synoptic measurement campaigns and in-situ time series data of snow depth, SWE, and radiation collected from the Kaweah River watershed, Sierra Nevada, California. Our analysis of forest cover classified by dominant species and 1 m2 grided mean under canopy snow accumulation calculated from airborne scanning LiDAR, demonstrate distinct relationships between forest class and under-canopy snow depth. The five forest types were selected from carefully prepared 1 m vegetation classifications and named for their dominant tree species, Giant Sequoia, Jeffrey Pine, White Fir, Red Fir, Sierra Lodgepole, Western White Pine, and Foxtail Pine. Sufficient LiDAR returns for calculating mean snow depth per m2 were available for 31 - 44% of the canopy covered area and demonstrate a reduction in snow depth of 12 - 24% from adjacent open areas. The coefficient of variation in snow depth under canopies ranged from 0.2 - 0.42 and generally decreased as elevation increased. Our analysis of snow density snows no statistical significance between snow under canopies and in the open at higher elevations with a weak significance for snow under canopies at lower elevations. Incident radiation measurements made at 15 minute intervals under forest canopies show an input of up to 150 w/m2 of thermal radiation from vegetation to the snow surface on forest plots. Snow accumulated on the mid to high elevation forested slopes of the Sierra Nevada represents the majority of winter snow storage. However snow estimates in forested environments demonstrate a high level of uncertainty due to the limited number of in-situ observations and the inability of most remote sensing platforms to retrieve reflectance under dense vegetation. Snow under forest canopies is strongly mediated by forest cover and decoupled from the processes that dictate accumulation and ablation of snow in open locations, where almost all precipitation and meteorlogic measurements concerning snow are made. Snow accumulation is intercepted by vegetation until it accumulates to a depth equal to or greater than the height of the vegetation, is reduced by the amount of sublimation or evaporation occurring while on the canopy and is redistributed beneath the canopy at a different density or as liquid water. Ablation processes are dictated by the energy environment surrounding vegetation where sensible heat is mediated by shading of short wave radiation.

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

NASA Astrophysics Data System (ADS)

Stevens, Bjorn; Brogniez, Hélène; Kiemle, Christoph; Lacour, Jean-Lionel; Crevoisier, Cyril; Kiliani, Johannes

In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere—below the height, z *, of the triple-point isotherm, T *. The measurements are evaluated in light of understanding of how lowertropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between T * and the temperature at which primary ice forms gives a `first-mover advantage' to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near T * implies relative humidity reversals below z * which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors.

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

NASA Astrophysics Data System (ADS)

Stevens, Bjorn; Brogniez, Hélène; Kiemle, Christoph; Lacour, Jean-Lionel; Crevoisier, Cyril; Kiliani, Johannes

2017-11-01

In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere—below the height, z_*, of the triple-point isotherm, T_*. The measurements are evaluated in light of understanding of how lower-tropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between T_* and the temperature at which primary ice forms gives a `first-mover advantage' to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near T_* implies relative humidity reversals below z* which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors.

Influence of electron radiation and temperature on the cyclic, matrix dominated response of graphite-epoxy

NASA Technical Reports Server (NTRS)

Reed, Susan M.; Herakovich, Carl T.; Sykes, George F., Jr.

1987-01-01

The effects of electron radiation and elevated temperature on the matrix-dominated cyclic response of standard T300/934 and a chemically modified T300/934 graphite-epoxy are characterized. Both materials were subjected to 1.0 x 10 to the 10th rads of 1.0 MeV electron irradiation, under vacuum, to simulate 30 years in geosynchronous orbit. Cyclic tests were performed at room temperature and elevated temperature (121 C) on 4-ply unidirectional laminates to characterize the effects associated with irradiation and elevated temperature. Both materials exhibited energy dissipation in their response at elevated temperature. The irradiated modified material also exhibited energy dissipation at room temperature. The combination of elevated temperature and irradiation resulted in the most severe effects in the form of lower proportional limits, and greater energy dissipation. Dynamic-mechanical analysis demonstrated that the glass transition temperature, T(g), of the standard material was lowered 39 C by irradiation, wereas the T(g) of the modified material was lowered 28 C by irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated materials.

Minimally toxic approach for treatment of cutaneous breast cancer metastases: capecitabine-enhanced photodynamic therapy

NASA Astrophysics Data System (ADS)

Anand, Sanjay; Bullock, Taylor; Maytin, Edward V.

2017-02-01

Cutaneous metastasis (CM) occurs in 20% of patients with breast carcinoma (BCA), and is extremely difficult to treat. These CM are relatively resistant to chemotherapy, generally responding only to ionizing radiation (IR). Multiple rounds of IR, however, lead to debilitating fibrosis and radiation dermatitis. An alternative to IR is needed for better management of BCA/CM. In our laboratory, we have developed differentiation-enhanced combination PDT (cPDT), a concept in which a pro-differentiating agent (methotrexate; vitamin D; or 5-fluorouracil, 5FU) is used as a neoadjuvant prior to PDT. After using these neoadjuvants, levels of protoporphyrin IX (PpIX) were elevated in animal tumor models of skin, prostate, and BCA, leading to better PDT efficacy. However, all the agents have toxicity issues. Here, we use a nontoxic 5FU precursor called Capecitabine (CPBN) for cPDT. CBPN is a standard chemotherapeutic for metastatic BCA, and is metabolized to 5FU specifically within tumor tissue. Murine (4T1) and human (MCF-7) BCA cell lines were injected into breast fat pads of nude mice. After tumor nodules appeared, CPBN (400-600 mg/kg/day) was administered by oral gavage for five days followed by intraperitoneal ALA administration on day 6. Mice were sacrificed and tumors harvested. CPBN pretreatment led to a 4-fold elevation of PpIX levels in tumors, relative to vehicle control. Not only did PpIX levels increase, but also PpIX distribution became more homogeneous after CPBN pretreatment. In summary, the use of non-toxic CPBN as a neoadjuvant prior to PDT is a combination approach with significant potential for translation into the clinic.

Evaluating Ultraviolet Radiation Exposures Determined from TOMS Satellite Data at Sites of Amphibian Declines in Central and South America

NASA Technical Reports Server (NTRS)

Middleton, Elizabeth M.; Smith, David E. (Technical Monitor)

2000-01-01

Many amphibian species have experienced substantial population declines, or have disappeared altogether, during the last several decades at a number of amphibian census sites in Central and South America. This study addresses the use of satellite-derived trends in solar ultraviolet-B (UV-B; 280-320 nm) radiation exposures at these sites over the last two decades, and is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. UV-B radiation levels at the Earth's surface were derived from the Total Ozone Mapping Spectrometer (TOMS) satellite data, typically acquired daily since 1979. These data were used to calculate the daily erythemal (sunburning) UV-B, or UV-B(sub ery), exposures at the latitude, longitude, and elevation of each of 20 census sites. The annually averaged UV-B(sub ery) dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels received at the Central American sites. The annually averaged UV-B(sub ery) exposures increased significantly from 1979-1998 at all 11 Central American sites examined (r(exp 2) = 0.60 - 0.79; P<=0.015), with smaller but significant increases at five of the nine South American sites (r(exp 2) = 0.24-0.42; P<=0.05). The contribution of the highest UV-B(sub ery) exposure levels (>= 6750 J/sq m*d) to the annual UV-B(sub ery) total has increased from approx. 5% to approx. 15% in Central America over the 19 year period, but actual daily exposures for each species are unknown. Synergy among UV-B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats is discussed. These findings justify further research concerning whether UV-B(sub ery) radiation plays a role in amphibian population declines and extinctions.

Planetary Sources for Reducing Sulfur Compounds for Cyanosulfidic Origins of Life Chemistry

NASA Astrophysics Data System (ADS)

Ranjan, S.; Todd, Z. R.; Sutherland, J.; Sasselov, D. D.

2017-12-01

A key challenge in origin-of-life studies is understanding the chemistry that lead to the origin of the key biomolecules of life, such as the components of nucleic acids, sugars, lipids, and proteins. Prebiotic reaction networks based upon reductive homologation of nitriles (e.g., Patel et al. 2015), are building a tantalizing picture of sustained abiotic synthesis of activated ribonucleotides, amino acids and lipid precursors under environmental conditions thought to have been available on early Earth. Sulfidic anions in aqueous solution (e.g., HS-, HSO3-) under near-UV irradiation play important roles in these chemical pathways. However, the sources and availability of these anions on early Earth have not yet been quantitatively constrained. Here, we evaluate the potential for the atmosphere to serve as a source of sulfidic anions, via dissolution of volcanically-outgassed SO2 and H2S into water reservoirs. We combine photochemical modeling from the literature (Hu et al. 2013) with equilibrium chemistry calculations to place constraints on the partial pressures of SO2 and H2S required to reach the elevated concentrations of sulfidic anions (≥1 μM) thought to be necessary for prebiotic chemistry. We find that micromolar levels of SO2-derived anions (HSO3-, SO3(2-)) are possible through simple exposure of aqueous reservoirs like shallow lakes to the atmosphere, assuming total sulfur emission flux comparable to today. Millimolar levels of these compounds are available during the epochs of elevated volcanism, due to elevated sulfur emission flux. Radiative transfer modeling suggests the atmospheric sulfur will not block the near-UV radiation also required for the cyanosulfidic chemistry. However, H2S-derived anions (e.g., HS-) reach only sub-micromolar levels from atmospheric sources, meaning that prebiotic chemistry invoking such molecules must invoke specialized, local sources. Prebiotic chemistry invoking SO2-derived anions may be considered more robust than chemistry invoking H2S-derived anions. In general, epochs of moderately high volcanism may have been especially conducive to cyanosulfidic prebiotic chemistry.

Elevated Frequency of Cataracts in Birds from Chernobyl

PubMed Central

Mousseau, Timothy Alexander; Møller, Anders Pape

2013-01-01

Background Radiation cataracts develop as a consequence of the effects of ionizing radiation on the development of the lens of the eye with an opaque lens reducing or eliminating the ability to see. Therefore, we would expect cataracts to be associated with reduced fitness in free-living animals. Methodology/Principal Findings We investigated the incidence of lens opacities typical of cataracts in more than 1100 free-living birds in the Chernobyl region in relation to background radiation. The incidence of cataracts increased with level of background radiation both in analyses based on a dichotomous score and in analyses of continuous scores of intensity of cataracts. The odds ratio per unit change in the regressor was 0.722 (95% CI 0.648, 0.804), which was less than odds ratios from investigations of radiation cataracts in humans. The relatively small odds ratio may be due to increased mortality in birds with cataracts. We found a stronger negative relationship between bird abundance and background radiation when the frequency of cataracts was higher, but also a direct effect of radiation on abundance, suggesting that radiation indirectly affects abundance negatively through an increase in the frequency of cataracts in bird populations, but also through direct effects of radiation on other diseases, food abundance and interactions with other species. There was no increase in incidence of cataracts with increasing age, suggesting that yearlings and older individuals were similarly affected as is typical of radiation cataract. Conclusions/Significance These findings suggest that cataracts are an under-estimated cause of morbidity in free-living birds and, by inference, other vertebrates in areas contaminated with radioactive materials. PMID:23935827

Estimating risks of heat strain by age and sex: a population-level simulation model.

PubMed

Glass, Kathryn; Tait, Peter W; Hanna, Elizabeth G; Dear, Keith

2015-05-18

Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan's man model "MANMO") to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions.

Effects of X-ray radiation on complex visual discrimination learning and social recognition memory in rats.

PubMed

Davis, Catherine M; Roma, Peter G; Armour, Elwood; Gooden, Virginia L; Brady, Joseph V; Weed, Michael R; Hienz, Robert D

2014-01-01

The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation.

Effects of X-Ray Radiation on Complex Visual Discrimination Learning and Social Recognition Memory in Rats

PubMed Central

Davis, Catherine M.; Roma, Peter G.; Armour, Elwood; Gooden, Virginia L.; Brady, Joseph V.; Weed, Michael R.; Hienz, Robert D.

2014-01-01

The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation. PMID:25099152

Physiological acclimation to elevated temperature in a reef-building coral from an upwelling environment

NASA Astrophysics Data System (ADS)

Mayfield, A. B.; Fan, T.-Y.; Chen, C.-S.

2013-12-01

Recent work has found that pocilloporid corals from regions characterized by unstable temperatures, such as those exposed to periodic upwelling, display a remarkable degree of phenotypic plasticity. In order to understand whether important reef builders from these upwelling reefs remain physiologically uncompromised at temperatures they will experience in the coming decades as a result of global climate change, a long-term elevated temperature experiment was conducted with Pocillopora damicornis specimens collected from Houbihu, a small embayment within Nanwan Bay, southern Taiwan that is characterized by 8-9 °C temperature changes during upwelling events. Upon nine months of exposure to nearly 30 °C, all colony (mortality and surface area), polyp ( Symbiodinium density and chlorophyll a content), tissue (total thickness), and molecular (gene expression and molecular composition)-level parameters were documented at similar levels between experimental corals and controls incubated at 26.5 °C, suggesting that this species can readily acclimate to elevated temperatures that cause significant degrees of stress, or even bleaching and mortality, in conspecifics of other regions of the Indo-Pacific. However, the gastrodermal tissue layer was relatively thicker in corals of the high temperature treatment sampled after nine months, possibly as an adaptive response to shade Symbiodinium from the higher photosynthetically active radiation levels that they were experiencing at that sampling time. Such shading may have prevented high light and high temperature-induced photoinhibition, and consequent bleaching, in these samples.

Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149.

PubMed

Tkavc, Rok; Matrosova, Vera Y; Grichenko, Olga E; Gostinčar, Cene; Volpe, Robert P; Klimenkova, Polina; Gaidamakova, Elena K; Zhou, Carol E; Stewart, Benjamin J; Lyman, Mathew G; Malfatti, Stephanie A; Rubinfeld, Bonnee; Courtot, Melanie; Singh, Jatinder; Dalgard, Clifton L; Hamilton, Theron; Frey, Kenneth G; Gunde-Cimerman, Nina; Dugan, Lawrence; Daly, Michael J

2017-01-01

Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans . However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.

Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149

PubMed Central

Tkavc, Rok; Matrosova, Vera Y.; Grichenko, Olga E.; Gostinčar, Cene; Volpe, Robert P.; Klimenkova, Polina; Gaidamakova, Elena K.; Zhou, Carol E.; Stewart, Benjamin J.; Lyman, Mathew G.; Malfatti, Stephanie A.; Rubinfeld, Bonnee; Courtot, Melanie; Singh, Jatinder; Dalgard, Clifton L.; Hamilton, Theron; Frey, Kenneth G.; Gunde-Cimerman, Nina; Dugan, Lawrence; Daly, Michael J.

2018-01-01

Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans. However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites. PMID:29375494

The global topography mission gains momentum

USGS Publications Warehouse

Farr, Tom; Evans, Diane; Zebker, Howard; Harding, David; Bufton, Jack; Dixon, Timothy; Vetrella, S.; Gesch, Dean B.

1995-01-01

An accurate description of the surface elevation of the Earth is of fundamental importance to many branches of Earth science. Continental topographic data are required for studies of hydrology, ecology, glaciology, geomorphology, and atmospheric circulation. For example, in hydrologic and terrestrial ecosystem studies, topography exerts significant control on intercepted solar radiation, water runoff and subsurface water inventory, microclimate, vegetation type and distribution, and soil development. The topography of the polar ice caps and mountain glaciers directly reflects ice-flow dynamics and is closely linked to global climate and sea level change.

Detection of regional air pollution episodes utilizing satellite data in the visual range

NASA Technical Reports Server (NTRS)

Bowley, C. J.; Burke, H. K.; Barnes, J. C.

1981-01-01

A comparative analysis of satellite-observed haze patterns and ground-based aerosol measurements is carried out for July 20-23, 1978. During this period, a significant regional air pollution episode existed across the northeastern United States, accompanied by widespread haze, reduced surface visibility, and elevated sulfate levels measured by the Sulfate Regional Experiment (SURE) network. The results show that the satellite-observed haze patterns correlate closely with the area of reported low surface visibility (less than 4 mi) and high sulfate levels. Quantitative information on total aerosol loading derived from the satellite-digitized data, using an atmospheric radiative transfer model, agrees well with the results obtained from the ground-based measurements.

Rangeland -- Plant responses to elevated CO{sub 2}. Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owensby, C.E.; Coyne, P.I.; Ham, J.M.

1992-10-01

Several broad conclusions which can be drawn from the work that was accomplished during the first 3-year phase of the study is described. In prairie ecosystems dominated by C{sub 4} grasses, it is likely that elevated atmospheric CO{sub 2} will increase ecosystem level productivity, with a greater increase in belowground productivity. The increased productivity will primarily result from increased water use efficiency due to the anti-transpirant action of CO{sub 2}. Fumigation chambers are directly confounded with elevated CO{sub 2} effects, in that both reduce evapotranspiration. The reduced evapotranspiration of the fumigation chamber is primarily through reduced wind speeds and reducedmore » radiation. In very dry years, fumigation chamber effects are negligible, but in years with normal precipitation, chamber effects and elevated CO{sub 2} effects are essentially equal with respect to reduced evapotranspiration effects. Increased production under elevated CO{sub 2} results in reduced nitrogen concentration in the herbage and increased fiber concentrations. Consequently, digestibility of the herbage is reduced, and microbial degradation of surface litter and soil organic matter is slowed. On the negative side, ruminant productivity will likely be reduced substantially, but increased carbon storage in the soil may buffer against future rise in atmospheric CO{sub 2}. Tallgrass prairie will not likely change greatly in botanical composition, since the C{sub 4} dominants responded to elevated CO{sub 2} more than the C{sub 3} subdominants.« less

Impurity seeding for tokamak power exhaust: from present devices via ITER to DEMO

NASA Astrophysics Data System (ADS)

Kallenbach, A.; Bernert, M.; Dux, R.; Casali, L.; Eich, T.; Giannone, L.; Herrmann, A.; McDermott, R.; Mlynek, A.; Müller, H. W.; Reimold, F.; Schweinzer, J.; Sertoli, M.; Tardini, G.; Treutterer, W.; Viezzer, E.; Wenninger, R.; Wischmeier, M.; the ASDEX Upgrade Team

2013-12-01

A future fusion reactor is expected to have all-metal plasma facing materials (PFMs) to ensure low erosion rates, low tritium retention and stability against high neutron fluences. As a consequence, intrinsic radiation losses in the plasma edge and divertor are low in comparison to devices with carbon PFMs. To avoid localized overheating in the divertor, intrinsic low-Z and medium-Z impurities have to be inserted into the plasma to convert a major part of the power flux into radiation and to facilitate partial divertor detachment. For burning plasma conditions in ITER, which operates not far above the L-H threshold power, a high divertor radiation level will be mandatory to avoid thermal overload of divertor components. Moreover, in a prototype reactor, DEMO, a high main plasma radiation level will be required in addition for dissipation of the much higher alpha heating power. For divertor plasma conditions in present day tokamaks and in ITER, nitrogen appears most suitable regarding its radiative characteristics. If elevated main chamber radiation is desired as well, argon is the best candidate for the simultaneous enhancement of core and divertor radiation, provided sufficient divertor compression can be obtained. The parameter Psep/R, the power flux through the separatrix normalized by the major radius, is suggested as a suitable scaling (for a given electron density) for the extrapolation of present day divertor conditions to larger devices. The scaling for main chamber radiation from small to large devices has a higher, more favourable dependence of about Prad,main/R2. Krypton provides the smallest fuel dilution for DEMO conditions, but has a more centrally peaked radiation profile compared to argon. For investigation of the different effects of main chamber and divertor radiation and for optimization of their distribution, a double radiative feedback system has been implemented in ASDEX Upgrade (AUG). About half the ITER/DEMO values of Psep/R have been achieved so far, and close to DEMO values of Prad,main/R2, albeit at lower Psep/R. Further increase of this parameter may be achieved by increasing the neutral pressure or improving the divertor geometry.

Impact of ionizing radiation exposure on in vitro differentiation of preosteoblastic cell lines

NASA Astrophysics Data System (ADS)

Hu, Yueyuan; Lau, Patrick; Hellweg, Christine; Baumstark-Khan, Christa; Reitz, Guenther

Bone demineralization of astronauts during residence in microgravity is a well known phe-nomenon during space travel. Besides altered gravity conditions, radiation risk is considered to be one of the major health hazards for astronauts in both orbital and interplanetary space. Un-til know, little is known about the effects of space radiation on the skeletal system especially on the bone forming osteoblasts. Accelerator facilities are used to simulate parts of the radiation environment in space. We examined the effects of heavy ion exposure on osteoblastic differ-entiation of murine preosteoblastic cell lines to gain insight into potential cellular mechanisms involved in bone cellular response after exposure to heavy ions. Therefore, we examined gene expression modulation of bone specific transcription factors, osteoblast specific marker genes as well as genes function as coupling factors that link bone resorption to bone formation. mRNA levels were determined using quantitative real time reverse transcriptase PCR (qRT-PCR). Expression of a target gene was standardized to unregulated reference genes. We investigated the transcriptional regulation of Osteocalcin (OCN) as well as TGF-β1, p21(CDKN1A) and the bone specific transcription factor Runx2 (cbfa1). We investigated gene expression modula-tions after exposure to energetic carbon ions (35 MeV/u, 73 keV/µm), iron ions (1000 MeV/u, 150 keV/µm) and lead ions (29 MeV/u, 9600 keV/µm) versus low LET X-rays. X-irradiation dose-dependently increased the mRNA levels of p21(CDKN1A) and Runx2 (cbfa1) whereas expression of OCN and TGF-β1 were elevated at later time points. Exposure to heavy ions provoked a more pronounced effect on osteoblastic specific gene expression within the dif-ferentiation process. Collectively, our results indicate that heavy ions facilitate osteoblastic differentiation more effectively than X-ray. Using the proposed in vitro model we confirmed that exposure to ionizing radiation significantly modulates gene expression levels of marker genes involved in the differentiation of osteoblasts. The data presented allow us to suggest that exposure to ionizing radiation interferes with bone formation at the level of cell differentiation.

Solar radiation and functional traits explain the decline of forest primary productivity along a tropical elevation gradient.

PubMed

Fyllas, Nikolaos M; Bentley, Lisa Patrick; Shenkin, Alexander; Asner, Gregory P; Atkin, Owen K; Díaz, Sandra; Enquist, Brian J; Farfan-Rios, William; Gloor, Emanuel; Guerrieri, Rossella; Huasco, Walter Huaraca; Ishida, Yoko; Martin, Roberta E; Meir, Patrick; Phillips, Oliver; Salinas, Norma; Silman, Miles; Weerasinghe, Lasantha K; Zaragoza-Castells, Joana; Malhi, Yadvinder

2017-06-01

One of the major challenges in ecology is to understand how ecosystems respond to changes in environmental conditions, and how taxonomic and functional diversity mediate these changes. In this study, we use a trait-spectra and individual-based model, to analyse variation in forest primary productivity along a 3.3 km elevation gradient in the Amazon-Andes. The model accurately predicted the magnitude and trends in forest productivity with elevation, with solar radiation and plant functional traits (leaf dry mass per area, leaf nitrogen and phosphorus concentration, and wood density) collectively accounting for productivity variation. Remarkably, explicit representation of temperature variation with elevation was not required to achieve accurate predictions of forest productivity, as trait variation driven by species turnover appears to capture the effect of temperature. Our semi-mechanistic model suggests that spatial variation in traits can potentially be used to estimate spatial variation in productivity at the landscape scale. © 2017 John Wiley & Sons Ltd/CNRS.

Changes in Liver Metabolic Gene Expression from Radiation Exposure

NASA Technical Reports Server (NTRS)

Peters, C. P.; Wotring, V. E.

2012-01-01

Increased exposure to radiation is one physiological stressor associated with spaceflight. While known to alter normal physiological function, how radiation affects metabolism of administered medications is unclear. Crew health could be affected if the actions of medications used in spaceflight deviated from expectations formed during terrestrial medication use. Three different doses of gamma radiation (50 mGy - 6.05 Gy) and a sham were administered to groups of 6 mice each, and after various intervals of recovery time, liver gene expression was measured with RT-qPCR arrays for drug metabolism and DNA repair enzymes. Results indicated approx.65 genes of the 190 tested were significantly affected by at least one of the radiation doses. Many of the affected genes are involved in the metabolism of drugs with hydrophobic or steroid-like structures, maintenance of redox homeostasis and repair of DNA damage. Most affected genes returned to near control expression levels by 7 days post-treatment. With 6 Gy exposure, metallothionein expression was 132-fold more than control at the 4 hr time point, and fell at each later time point (11-fold at 24 hrs, and 8-fold at 7 days). In contrast, Cyp17a1 showed a 4-fold elevation at 4 hrs after exposure and remained constant for 7 days.

Estimating soot emissions from an elevated flare

NASA Astrophysics Data System (ADS)

Almanza, Victor; Sosa, Gustavo

2009-11-01

Combustion aerosols are one of the major concerns in flaring operations, due to both health and environmental hazards. Preliminary results are presented for a 2D transient simulation of soot formation in a reacting jet with exit velocity of 130 m/s under a 5 m/s crossflow released from a 50 m high elevated flare and a 50 cm nozzle. Combustion dynamics was simulated with OpenFOAM. Gas-phase non-premixed combustion was modeled with the Chalmers PaSR approach and a κ-ɛ turbulence model. For soot formation, Moss model was used and the ISAT algorithm for solving the chemistry. Sulfur chemistry was considered to account for the sourness of the fuel. Gas composition is 10 % H2S and 90 % C2H4. A simplified Glassman reaction mechanism was used for this purpose. Results show that soot levels are sensitive to the sulfur present in the fuel, since it was observed a slight decrease in the soot volume fraction. NSC is the current oxidation model for soot formation. Predicted temperature is high (about 2390 K), perhaps due to soot-radiation interaction is not considered yet, but a radiation model implementation is on progress, as well as an oxidation mechanism that accounts for OH radical. Flame length is about 50 m.

Effects of elevated ultraviolet radiation on primary metabolites in selected alpine algae and cyanobacteria

PubMed Central

Hartmann, Anja; Albert, Andreas; Ganzera, Markus

2015-01-01

Extremophilic green algae and cyanobacteria are the most abundant species in high mountain habitats, where rough climate conditions such as temperature differences, limited water retention and high ultraviolet (UV) radiation are the cause for a restricted biological diversity in favor of a few specialized autotrophic microorganisms. In this study, we investigated four algal species from alpine habitat in a sun simulator for their defense strategies in response to UV-A radiation (315–400 nm) up to 13.4 W/m2 and UV-B radiation (280–315 nm) up to 2.8 W/m2. Besides changes in pigment composition we discovered that primary polar metabolites like aromatic amino acids, nucleic bases and nucleosides are increasingly produced when the organisms are exposed to elevated UV radiation. Respective compounds were isolated and identified, and in order to quantify them an HPLC-DAD method was developed and validated. Our results show that especially tyrosine and guanosine were found to be generally two to three times upregulated in the UV-B exposed samples compared to the non-treated control. PMID:26065817

Aerosol Absorption Effects in the TOMS UV Algorithm

NASA Technical Reports Server (NTRS)

Torres, O.; Krotkov, N.; Bhartia, P. K.

2004-01-01

The availability of global long-term estimates of surface UV radiation is very important, not only for preventive medicine considerations, but also as an important tool to monitor the effects of the stratospheric ozone recovery expected to occur in the next few decades as a result of the decline of the stratospheric chlorine levels. In addition to the modulating effects of ozone and clouds, aerosols also affect the levels of UV-A and W-B radiation reaching the surface. Oscillations in surface W associated with the effects of aerosol absorption may be comparable in magnitude to variations associated with the stratospheric ozone recovery. Thus, the accurate calculation of surface W radiation requires that both the scattering and absorption effects of tropospheric aerosols be taken into account. Although absorption effects of dust and elevated carbonaceous aerosols are already accounted for using Aerosol Index technique, this approach does not work for urban/industrial aerosols in the planetary boundary layer. The use of the new TOMS long-term global data record on UV aerosol absorption optical depth, can improve the accuracy of TOMS spectral UV products, by properly including the spectral attenuation effects of carbonaceous, urban/industrial and mineral aerosols. The TOMS data set on aerosol properties will be discussed, and results of its use in the TOMS surface W algorithm will be presented.

Inversion climatology at San Jose, California

NASA Technical Reports Server (NTRS)

Morgan, T.; Bornstein, R. D.

1977-01-01

Month-to-month variations in the early morning surface-based and near-noon elevated inversions at San Jose, Calif., were determined from slow rise radiosondes launched during a four-year period. A high frequency of shallow, radiative, surface-based inversions were found in winter during the early morning hours, while during the same period in summer, a low frequency of deeper based inversions arose from a combination of radiative and subsidence processes. The frequency of elevated inversions in the hours near noon was lowest during fall and spring, while inversion bases were highest and thicknesses least during these periods.

PROBABILISTIC RISK ASSESSMENT FOR THE EFFECTS OF SOLAR ULTRAVIOLET RADIATION ON AMPHIBIANS

EPA Science Inventory

Several studies have demonstrated that exposure to solar ultraviolet (UV) radiation can cause elevated mortality and an increased prevalence of eye and limb malformations in developing amphibian larvae. From these observations scientists have hypothesized that recent increases in...

Exposure to Heavy Ion Radiation Induces Persistent Oxidative Stress in Mouse Intestine

PubMed Central

Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V. S.; Fornace, Albert J.

2012-01-01

Ionizing radiation-induced oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after radiation exposure and is implicated in the late effects of radiation. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on radiation quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of γ-rays, a low-linear energy transfer (LET) radiation, and intestinal tissues and IEC were collected 1 year after radiation exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of γ radiation were compared to 56Fe radiation (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/µm), we used as representative of high-LET radiation, since it's one of the important sources of high Z and high energy (HZE) radiation in cosmic rays. Radiation quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET 56Fe radiation compared to unirradiated controls and γ radiation. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in 56Fe-irradiated mice. Compared to γ radiation oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after 56Fe radiation. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion radiation-induced persistent oxidative stress in IEC with potential for neoplastic transformation. PMID:22936983

Continuous Exposure to Low-Dose-Rate Gamma Irradiation Reduces Airway Inflammation in Ovalbumin-Induced Asthma.

PubMed

Kim, Joong Sun; Son, Yeonghoon; Bae, Min Ji; Lee, Seung Sook; Park, Sun Hoo; Lee, Hae June; Lee, Soong In; Lee, Chang Geun; Kim, Sung Dae; Jo, Wol Soon; Kim, Sung Ho; Shin, In Sik

2015-01-01

Although safe doses of radiation have been determined, concerns about the harmful effects of low-dose radiation persist. In particular, to date, few studies have investigated the correlation between low-dose radiation and disease development. Asthma is a common chronic inflammatory airway disease that is recognized as a major public health problem. In this study, we evaluated the effects of low-dose-rate chronic irradiation on allergic asthma in a murine model. Mice were sensitized and airway-challenged with ovalbumin (OVA) and were exposed to continuous low-dose-rate irradiation (0.554 or 1.818 mGy/h) for 24 days after initial sensitization. The effects of chronic radiation on proinflammatory cytokines and the activity of matrix metalloproteinase-9 (MMP-9) were investigated. Exposure to low-dose-rate chronic irradiation significantly decreased the number of inflammatory cells, methylcholine responsiveness (PenH value), and the levels of OVA-specific immunoglobulin E, interleukin (IL)-4, and IL-5. Furthermore, airway inflammation and the mucus production in lung tissue were attenuated and elevated MMP-9 expression and activity induced by OVA challenge were significantly suppressed. These results indicate that low-dose-rate chronic irradiation suppresses allergic asthma induced by OVA challenge and does not exert any adverse effects on asthma development. Our findings can potentially provide toxicological guidance for the safe use of radiation and relieve the general anxiety about exposure to low-dose radiation.

Status of FeCrAl ODS Irradiations in the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Howard, Richard H.

2016-08-19

FeCrAl oxide-dispersion strengthened (ODS) alloys are an attractive sub-set alloy class of the more global FeCrAl material class for nuclear applications due to their high-temperature steam oxidation resistance and hypothesized enhanced radiation tolerance. A need currently exists to determine the radiation tolerance of these newly developed alloys. To address this need, a preliminary study was conducted using the High Flux Isotope Reactor (HFIR) to irradiate an early generation FeCrAl ODS alloy, 125YF. Preliminary post-irradiation examination (PIE) on these irradiated specimens have shown good radiation tolerance at elevated temperatures (≥330°C) but possible radiation-induced hardening and embrittlement at irradiations of 200°C tomore » a damage level of 1.9 displacement per atom (dpa). Building on this experience, a new series of irradiations are currently being conceptualized. This irradiation series called the FCAD irradiation program will irradiate the latest generation FeCrAl ODS and FeCr ODS alloys to significantly higher doses. These experiments will provide the necessary information to determine the mechanical performance of irradiated FeCrAl ODS alloys at light water reactor and fast reactor conditions.« less

Long-term prediction test procedure for most ICs, based on linear response theory

NASA Technical Reports Server (NTRS)

Litovchenko, V.; Ivakhnenko, I.

1991-01-01

Experimentally, thermal annealing is known to be a factor which enables a number of different integrated circuits (IC's) to recover their operating characteristics after suffering radiation damage in the space radiation environment; thus, decreasing and limiting long term cumulative total-dose effects. This annealing is also known to be accelerated at elevated temperatures both during and after irradiation. Linear response theory (LRT) was applied, and a linear response function (LRF) to predict the radiation/annealing response of sensitive parameters of IC's for long term (several months or years) exposure to the space radiation environment were constructed. Compressing the annealing process from several years in orbit to just a few hours or days in the laboratory is achieved by subjecting the IC to elevated temperatures or by increasing the typical spaceflight dose rate by several orders of magnitude for simultaneous radiation/annealing only. The accomplishments are as follows: (1) the test procedure to make predictions of the radiation response was developed; (2) the calculation of the shift in the threshold potential due to the charge distribution in the oxide was written; (3) electron tunneling processes from the bulk Si to the oxide region in an MOS IC were estimated; (4) in order to connect the experimental annealing data to the theoretical model, constants of the model of the basic annealing process were established; (5) experimental data obtained at elevated temperatures were analyzed; (6) time compression and reliability of predictions for the long term region were shown; (7) a method to compress test time and to make predictions of response for the nonlinear region was proposed; and (8) nonlinearity of the LRF with respect to log(t) was calculated theoretically from a model.

Assessment of Satellite Surface Radiation Products in Highland Regions with Tibet Instrumental Data

NASA Technical Reports Server (NTRS)

Yang, Kun; Koike, Toshio; Stackhouse, Paul; Mikovitz, Colleen

2006-01-01

This study presents results of comparisons between instrumental radiation data in the elevated Tibetan Plateau and two global satellite products: the Global Energy and Water Cycle Experiment - Surface Radiation Budget (GEWEX-SRB) and International Satellite Cloud Climatology Project - Flux Data (ISCCP-FD). In general, shortwave radiation (SW) is estimated better by ISCCP-FD while longwave radiation (LW) is estimated better by GEWEX-SRB, but all the radiation components in both products are under-estimated. Severe and systematic errors were found in monthly-mean SRB SW (on plateau-average, -48 W/sq m for downward SW and -18 W/sq m for upward SW) and FD LW (on plateau-average, -37 W/sq m for downward LW and -62 W/sq m for upward LW) for radiation. Errors in monthly-mean diurnal variations are even larger than the monthly mean errors. Though the LW errors can be reduced about 10 W/sq m after a correction for altitude difference between the site and SRB and FD grids, these errors are still higher than that for other regions. The large errors in SRB SW was mainly due to a processing mistake for elevation effect, but the errors in SRB LW was mainly due to significant errors in input data. We suggest reprocessing satellite surface radiation budget data, at least for highland areas like Tibet.

Estimating Catchment-Scale Snowpack Variability in Complex Forested Terrain, Valles Caldera National Preserve, NM

NASA Astrophysics Data System (ADS)

Harpold, A. A.; Brooks, P. D.; Biederman, J. A.; Swetnam, T.

2011-12-01

Difficulty estimating snowpack variability across complex forested terrain currently hinders the prediction of water resources in the semi-arid Southwestern U.S. Catchment-scale estimates of snowpack variability are necessary for addressing ecological, hydrological, and water resources issues, but are often interpolated from a small number of point-scale observations. In this study, we used LiDAR-derived distributed datasets to investigate how elevation, aspect, topography, and vegetation interact to control catchment-scale snowpack variability. The study area is the Redondo massif in the Valles Caldera National Preserve, NM, a resurgent dome that varies from 2500 to 3430 m and drains from all aspects. Mean LiDAR-derived snow depths from four catchments (2.2 to 3.4 km^2) draining different aspects of the Redondo massif varied by 30%, despite similar mean elevations and mixed conifer forest cover. To better quantify this variability in snow depths we performed a multiple linear regression (MLR) at a 7.3 by 7.3 km study area (5 x 106 snow depth measurements) comprising the four catchments. The MLR showed that elevation explained 45% of the variability in snow depths across the study area, aspect explained 18% (dominated by N-S aspect), and vegetation 2% (canopy density and height). This linear relationship was not transferable to the catchment-scale however, where additional MLR analyses showed the influence of aspect and elevation differed between the catchments. The strong influence of North-South aspect in most catchments indicated that the solar radiation is an important control on snow depth variability. To explore the role of solar radiation, a model was used to generate winter solar forcing index (SFI) values based on the local and remote topography. The SFI was able to explain a large amount of snow depth variability in areas with similar elevation and aspect. Finally, the SFI was modified to include the effects of shading from vegetation (in and out of canopy), which further explained snow depth variability. The importance of SFI for explaining catchment-scale snow depth variability demonstrates that aspect is not a sufficient metric for direct radiation in complex terrain where slope and remote topographic shading are significant. Surprisingly, the net effects of interception and shading by vegetation on snow depths were minimal compared to elevation and aspect in these catchments. These results suggest that snowpack losses from interception may be balanced by increased shading to reduce the overall impacts from vegetation compared to topographic factors in this high radiation environment. Our analysis indicated that elevation and solar radiation are likely to control snow variability in larger catchments, with interception and shading from vegetation becoming more important at smaller scales.

Measures against increased environmental radiation dose by the TEPCO Fukushima Dai-ichi NPP accident in some local governments in the Tokyo metropolitan area: focusing on examples of both Kashiwa and Nagareyama cities in Chiba prefecture.

PubMed

Iimoto, T; Fujii, H; Oda, S; Nakamura, T; Hayashi, R; Kuroda, R; Furusawa, M; Umekage, T; Ohkubo, Y

2012-11-01

The accident of the Fukushima Dai-ichi nuclear power plant of Tokyo Electric Power Cooperation (TEPCO) after the great east Japan earthquake (11 March 2011) elevated the background level of environmental radiation in Eastern Japan. Around the Tokyo metropolitan area, especially around Kashiwa and Nagareyama cities, the ambient dose equivalent rate has been significantly increased after the accident. Responding to strong requests from citizens, the local governments started to monitor the ambient dose equivalent rate precisely and officially, about 3 months after the accident had occurred. The two cities in cooperation with each other also organised a local forum supported by three radiation specialists. In this article, the activities of the local governments are introduced, with main focus on radiation monitoring and measurements. Topics are standardisation of environmental radiation measurements for ambient dose rate, dose mapping activity, investigation of foodstuff and drinking water, lending survey meters to citizens, etc. Based on the data and facts mainly gained by radiation monitoring, risk management and relating activity have been organised. 'Small consultation meetings in kindergartens', 'health consultation service for citizens', 'education meeting on radiation protection for teachers, medical staffs, local government staffs, and leaders of active volunteer parties' and 'decontamination activity', etc. are present key activities of the risk management and restoration around the Tokyo metropolitan area.

Early exposure to ultraviolet-B radiation decreases immune function later in life

PubMed Central

Ceccato, Emma; Cramp, Rebecca L.; Seebacher, Frank; Franklin, Craig E.

2016-01-01

Amphibians have declined dramatically worldwide. Many of these declines are occurring in areas where no obvious anthropogenic stressors are present. It is proposed that in these areas, environmental factors such as elevated solar ultraviolet-B (UV-B) radiation could be responsible. Ultraviolet-B levels have increased in many parts of the world as a consequence of the anthropogenic destruction of the ozone layer. Amphibian tadpoles are particularly sensitive to the damaging effects of UV-B radiation, with exposure disrupting growth and fitness in many species. Given that UV-B can disrupt immune function in other animals, we tested the hypothesis that early UV-B exposure suppresses the immune responses of amphibian tadpoles and subsequent juvenile frogs. We exposed Limnodynastes peronii tadpoles to sublethal levels of UV-B radiation for 6 weeks after hatching, then examined indices of immune function in both the tadpoles and the subsequent metamorphs. There was no significant effect of UV-B on tadpole leucocyte counts or on their response to an acute antigen (phytohaemagglutinin) challenge. However, early UV-B exposure resulted in a significant reduction in both metamorph leucocyte abundance and their response to an acute phytohaemagglutinin challenge. These data demonstrate that early UV-B exposure can have carry-over effects on later life-history traits even if the applied stressor has no immediately discernible effect. These findings have important implications for our understanding of the effects of UV-B exposure on amphibian health and susceptibility to diseases such as chytridiomycosis. PMID:27668081

Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment

PubMed Central

Menezes, Riya C.; Jayarajan, Aditi; Shanker, Kartik

2016-01-01

The historical processes underlying high diversity in tropical biodiversity hotspots like the Western Ghats of Peninsular India remain poorly understood. We sampled bush frogs on 13 massifs across the Western Ghats Escarpment and examined the relative influence of Quaternary glaciations, ecological gradients and geological processes on the spatial patterns of lineage and clade diversification. The results reveal a large in situ radiation (more than 60 lineages), exhibiting geographical structure and clade-level endemism, with two deeply divergent sister clades, North and South, highlighting the biogeographic significance of an ancient valley, the Palghat Gap. A majority of the bush frog sister lineages were isolated on adjacent massifs, and signatures of range stasis provide support for the dominance of geological processes in allopatric speciation. In situ diversification events within the montane zones (more than 1800 m) of the two highest massifs suggest a role for climate-mediated forest-grassland persistence. Independent transitions along elevational gradients among sub-clades during the Miocene point to diversification along the elevational gradient. The study highlights the evolutionary significance of massifs in the Western Ghats with the high elevations acting as centres of lineage diversification and the low- and mid-elevations of the southern regions, with deeply divergent lineages, serving as museums. PMID:27534957

Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment.

PubMed

Vijayakumar, S P; Menezes, Riya C; Jayarajan, Aditi; Shanker, Kartik

2016-08-17

The historical processes underlying high diversity in tropical biodiversity hotspots like the Western Ghats of Peninsular India remain poorly understood. We sampled bush frogs on 13 massifs across the Western Ghats Escarpment and examined the relative influence of Quaternary glaciations, ecological gradients and geological processes on the spatial patterns of lineage and clade diversification. The results reveal a large in situ radiation (more than 60 lineages), exhibiting geographical structure and clade-level endemism, with two deeply divergent sister clades, North and South, highlighting the biogeographic significance of an ancient valley, the Palghat Gap. A majority of the bush frog sister lineages were isolated on adjacent massifs, and signatures of range stasis provide support for the dominance of geological processes in allopatric speciation. In situ diversification events within the montane zones (more than 1800 m) of the two highest massifs suggest a role for climate-mediated forest-grassland persistence. Independent transitions along elevational gradients among sub-clades during the Miocene point to diversification along the elevational gradient. The study highlights the evolutionary significance of massifs in the Western Ghats with the high elevations acting as centres of lineage diversification and the low- and mid-elevations of the southern regions, with deeply divergent lineages, serving as museums. © 2016 The Author(s).

Ion mobility-enhanced MS(E)-based label-free analysis reveals effects of low-dose radiation post contextual fear conditioning training on the mouse hippocampal proteome.

PubMed

Huang, Lin; Wickramasekara, Samanthi I; Akinyeke, Tunde; Stewart, Blair S; Jiang, Yuan; Raber, Jacob; Maier, Claudia S

2016-05-17

Recent advances in the field of biodosimetry have shown that the response of biological systems to ionizing radiation is complex and depends on the type and dose of radiation, the tissue(s) exposed, and the time lapsed after exposure. The biological effects of low dose radiation on learning and memory are not well understood. An ion mobility-enhanced data-independent acquisition (MS(E)) approach in conjunction with the ISOQuant software tool was utilized for label-free quantification of hippocampal proteins with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-rays, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. Global proteome analysis revealed deregulation of 73 proteins (out of 399 proteins). Deregulated proteins indicated adverse effects of irradiation on myelination and perturbation of energy metabolism pathways involving a shift from the TCA cycle to glutamate oxidation. Our findings also indicate that proteins associated with synaptic activity, including vesicle recycling and neurotransmission, were altered in the irradiated mice. The elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which would be consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. This study is significant because the biological consequences of low dose radiation on learning and memory are complex and not yet well understood. We conducted a IMS-enhanced MS(E)-based label-free quantitative proteomic analysis of hippocampal tissue with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-ray, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. The IMS-enhanced MS(E) approach in conjunction with ISOQuant software was robust and accurate with low median CV values of 0.99% for the technical replicates of samples from both the sham and irradiated group. The biological variance was as low as 1.61% for the sham group and 1.31% for the irradiated group. The applied data generation and processing workflow allowed the quantitative evaluation of 399 proteins. The current proteomic analysis indicates that myelination is sensitive to low dose radiation. The observed protein level changes imply modulation of energy metabolism pathways in the radiation exposed group, specifically changes in protein abundance levels suggest a shift from TCA cycle to glutamate oxidation to satisfy energy demands. Most significantly, our study reveals deregulation of proteins involved in processes that govern synaptic activity including enhanced synaptic vesicle cycling, and altered long-term potentiation (LTP) and depression (LTD). An elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which is consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. Overall, our results underscore the importance of low dose radiation experiments for illuminating the sensitivity of biochemical pathways to radiation, and the modulation of potential repair and compensatory response mechanisms. This kind of studies and associated findings may ultimately lead to the design of strategies for ameliorating hippocampal and CNS injury following radiation exposure as part of medical therapies or as a consequence of occupational hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

A classification of forest environments in the south Umpqua Basin.

Treesearch

Don Minore

1972-01-01

Forest environments are classified by elevation, temperature, moisture, potential solar radiation, and soil type. Broad elevation classes are derived from topographic maps or altimeter measurements, measured temperature and moisture conditions are related to vegetation by using plant indicator species (illustrated), and tabular values are employed in estimating...

Noise Impact Inventory of Elevated Structures in U.S. Urban Rail Rapid Transit Systems

DOT National Transportation Integrated Search

1980-09-01

This report presents the results of the third task of a five-task program dealing with the reduction of noise from elevated structures in use in U.S. rail rapid transit systems. This report is an inventory and impact assessment of the noise radiated ...

Radiosensitization of HT-29 cells and xenografts by the nitric oxide donor DETANONOate.

PubMed

Gao, Xiaohuan; Saha, Debabrata; Kapur, Payal; Anthony, Thomas; Livingston, Edward H; Huerta, Sergio

2009-08-01

Mechanisms of radioresistance in rectal cancer remain unclear. To determine mechanisms of radioresistance in rectal cancer cells and to assess the role of the nitric oxide donor DETANONOate as a radiosensitizing agent. Survival was determined by clonogenic assays, apoptosis by PARP-1 cleavage, and phenotypic differences by Western blot analysis. SCID mice bearing HT-29 xenografts were treated with ionizing radiation (IR) [2.0 Gy x 5], DETANONOate [0.4 mg/kg i.p.], or combination treatment. Colorectal cancer HT-29-p53-null cells were resistant and HCT-116-p53 wild-type cells sensitive to IR, which correlated with cleaved PARP-1. Increased levels of p21 occurred in HCT-116 cells, while Bcl-2 and survivin were elevated in HT-29 cells. Radiosensitization was achieved with a substantial elevation of cleaved PARP-1 in DETANONOate-HT-29-treated versus control cells, which was accompanied by elevation of p21, p27, and BAX, and a concomitant decrease in Bcl-2. SCID mice bearing HT-29 xenografts demonstrated a 37.6%, 51.1%, and 70.1% inhibition in tumor growth in mice receiving IR, DETANONOate, and combination treatment versus control, respectively. Radioresistant HT-29 cells are p53-null and have substantially decreased levels of p21. DETANONOate radiosensitized HT-29 cells in vitro and in vivo by an additive effect in apoptosis.

The Hiroshima/Nagasaki Survivor Studies: Discrepancies Between Results and General Perception

PubMed Central

2016-01-01

The explosion of atom bombs over the cities of Hiroshima and Nagasaki in August 1945 resulted in very high casualties, both immediate and delayed but also left a large number of survivors who had been exposed to radiation, at levels that could be fairly precisely ascertained. Extensive follow-up of a large cohort of survivors (120,000) and of their offspring (77,000) was initiated in 1947 and continues to this day. In essence, survivors having received 1 Gy irradiation (∼1000 mSV) have a significantly elevated rate of cancer (42% increase) but a limited decrease of longevity (∼1 year), while their offspring show no increased frequency of abnormalities and, so far, no detectable elevation of the mutation rate. Current acceptable exposure levels for the general population and for workers in the nuclear industry have largely been derived from these studies, which have been reported in more than 100 publications. Yet the general public, and indeed most scientists, are unaware of these data: it is widely believed that irradiated survivors suffered a very high cancer burden and dramatically shortened life span, and that their progeny were affected by elevated mutation rates and frequent abnormalities. In this article, I summarize the results and discuss possible reasons for this very striking discrepancy between the facts and general beliefs about this situation. PMID:27516613

Dust Propagation and Radiation In the Presence of a Low-level Jet in Central China on March 17, 2010

NASA Astrophysics Data System (ADS)

McDowell, B. K.; Chen, S. H.

2014-12-01

Suspended dust in the air can directly change the energy budget in the atmosphere and at the surface through scattering and absorption of radiation. Thus, dust can potentially modify the development of weather systems. To explore the dust-radiation effects on weather systems, a dust model was developed based on the Weather Research and Forecasting (WRF) model. The calculations of dust processes in the WRF dust model include emission, advection, boundary layer mixing, cumulus mixing, dust-radiation interaction, wet scavenging, and sedimentation. Due to a high vertical spatial resolution near the surface a time splitting method was applied to the calculation of dust sedimentation to relax the numerical time step. The "Hexi Corridor" is the historical name given to a string of oases along the northern slope of the Tibetan Plateau that formed a relatively easy transportation route between eastern China and central Asia. As trade developed over the centuries, this route became known as the Silk Road. This corridor also marks the transition from the relatively flat Gobi desert area in northern China to the elevated mountains of the Tibetan Plateau. These mountains present a southern barrier to the paths of dust storms that develop during spring outbreaks of the Mongolian Cyclone. In March of 2010, a series of dust storms developed in the Gobi Desert north of the Hexi Corridor that transported massive amounts of dust eastward to central and northeastern China, Korea and Japan. On March 17 during this event, a low-level jet developed along the northern perimeter of the Plateau, in alignment with upper level winds and the Hexi Corridor. Over the course of the day, a well-defined short-duration dust plume was emitted in the southern Gobi desert area and was transported over 1300 km in a southeast direction, over the Loess Plateau and into the Gansu Province. In this study, the interactions of synoptic conditions with regional topography that led to the development of the low-level jet are evaluated. A dust model based on the Weather Research and Forecasting Model V3.2.1 is used to investigate the interaction of dust and radiation on air temperatures in and around the plume, dust emission and transport, and the resulting regional radiative forcing in the presence of the low-level jet.

Andrographolide Sensitizes Ras-Transformed Cells to Radiation in vitro and in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hung, Shih-Kai; Department of Radiation Oncology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan; Tzu Chi University School of Medicine, Hualian, Taiwan

2010-07-15

Purpose: Increasing the sensitivity of tumor cells to radiation is a major goal of radiotherapy. The present study investigated the radiosensitizing effects of andrographolide and examined the molecular mechanisms of andrographolide-mediated radiosensitization. Methods and Materials: An H-ras-transformed rat kidney epithelial (RK3E) cell line was used to measure the radiosensitizing effects of andrographolide in clonogenic assays, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide assays, and a xenograft tumor growth model. The mechanism of andrographolide-sensitized cell death was analyzed using annexin V staining, caspase 3 activity assays, and terminal transferase uridyl nick end labeling assays. The roles of nuclear factor kappa B (NF-{kappa}B) and Akt inmore » andrographolide-mediated sensitization were examined using reporter assays, electrophoretic mobility shift assays, and Western blotting. Results: Concurrent andrographolide treatment (10 {mu}M, 3 h) sensitized Ras-transformed cells to radiation in vitro (sensitizer enhancement ratio, 1.73). Andrographolide plus radiation (one dose of 300 mg/kg peritumor andrographolide and one dose of 6 Gy radiation) resulted in significant tumor growth delay (27 {+-} 2.5 days) compared with radiation alone (22 {+-} 1.5 days; p <.05). Radiation induced apoptotic markers (e.g., caspase-3, membrane reversion, DNA fragmentation), and andrographolide treatment did not promote radiation-induced apoptosis. However, the protein level of activated Akt was significantly reduced by andrographolide. NF-{kappa}B activity was elevated in irradiated Ras-transformed cells, and andrographolide treatment significantly reduced radiation-induced NF-{kappa}B activity. Conclusion: Andrographolide sensitized Ras-transformed cells to radiation both in vitro and in vivo. Andrographolide-mediated radiosensitization was associated with downregulation of Akt and NF-{kappa}B activity. These observations indicate that andrographolide is a novel radiosensitizing agent with potential application in cancer radiotherapy.« less

Fibrinogen deficiency suppresses the development of early and delayed radiation enteropathy

PubMed Central

Wang, Junru; Pathak, Rupak; Garg, Sarita; Hauer-Jensen, Martin

2017-01-01

AIM To determine the mechanistic role of fibrinogen, a key regulator of inflammation and fibrosis, in early and delayed radiation enteropathy. METHODS Fibrinogen wild-type (Fib+/+), fibrinogen heterozygous (Fib+/-), and fibrinogen knockout (Fib-/-) mice were exposed to localized intestinal irradiation and assessed for early and delayed structural changes in the intestinal tissue. A 5-cm segment of ileum of mice was exteriorized and exposed to 18.5 Gy of x-irradiation. Intestinal tissue injury was assessed by quantitative histology, morphometry, and immunohistochemistry at 2 wk and 26 wk after radiation. Plasma fibrinogen level was measured by enzyme-linked immunosorbent assay. RESULTS There was no difference between sham-irradiated Fib+/+ and Fib+/- mice in terms of fibrinogen concentration in plasma and intestinal tissue, intestinal histology, morphometry, intestinal smooth muscle cell proliferation, and neutrophil infiltration. Therefore, Fib+/- mice were used as littermate controls. Unlike sham-irradiated Fib+/+ and Fib+/- mice, no fibrinogen was detected in the plasma and intestinal tissue of sham-irradiated Fib-/- mice. Moreover, fibrinogen level was not elevated after irradiation in the intestinal tissue of Fib-/- mice, while significant increase in intestinal fibrinogen level was noticed in irradiated Fib+/+ and Fib+/- mice. Importantly, irradiated Fib-/- mice exhibited substantially less overall intestinal structural injury (RIS, P = 0.000002), intestinal wall thickness (P = 0.003), intestinal serosal thickness (P = 0.009), collagen deposition (P = 0.01), TGF-β immunoreactivity (P = 0.03), intestinal smooth muscle proliferation (P = 0.046), neutrophil infiltration (P = 0.01), and intestinal mucosal injury (P = 0.0003), compared to irradiated Fib+/+ and Fib+/- mice at both 2 wk and 26 wk. CONCLUSION These data demonstrate that fibrinogen deficiency directly attenuates development of early and delayed radiation enteropathy. Fibrinogen could be a novel target in treating intestinal damage. PMID:28765691

Expression of Cyclin d1 protein and CCND1 та PNKP genes in peripheral blood mononuclear cells in clean up worker of Chornobyl accident with different state of immune system.

PubMed

Bazyka, D A; Kubashko, A V; Ilyenko, I M; Belyaev, O A; Pleskach, O J

2015-12-01

to investigate the Cyclin D1+ cells levels changes, associated CCND1 and PNKP genes in peripheral blood mononuclear cells in clean up workers of Chornobyl accident with different state of immune system in depends on the dose irradiation. Relative level of Cyclin D1+cells in peripheral blood mononuclears of 39 clean up workers, men, irradiated in dose range (0,01-2,00) Gy have been analyzed. Immunological status of examinee' subjects was determined by CD3/19, CD4/8, CD3/HLA DR, СD3/16/56 testing using flow cytometry method and Ig A,M,G testing by immunoenzymatic assay in blood. CCND1 та PNKP gene expression, which associated with Cyclin D1 metabolism, was conducted using PCR real time method. The obtained results were compared in relation to data from 18 healthy men, who had no contact with ionizing radiation over then nature background. Аnalyzed data of the nuclear controller of cell cycle - Cyclin D1 protein expression changes and related CCND1 та PNKP genes in peripheral blood mononuclear cells in clean up workers Chornobyl accident with different status of immune system in remote period after exposure is represented. It is shown, that in examinees' subjects exposed in dose > 0,1 Gy percentage of Суclin D1+ cells is elevated against normal range and correlates with dose of radiation (rs = 0,417, p = 0,048). Normal range deflation of relative amount of Cyclin D1+cells connects with changes in cellular and humoral immunity. Decline of relative amount of Cyclin D1+ cells below the control level following CD3+ lymphocytes decrease and CD3 16+56+ elevation in clean up workers exposed in dose < 0,35 Gy. Increase of relative amount of Cyclin D1+ cells above the control range associates with CD3+ fall together with tendency of CD3+16+56+ lymphocytes fall that attends the IgG elevation in examinees' subjects with dose > 0,35 Gy. Percentage of Cyclin D1+ cells correlates with CD3 16+56+ (rs = 0,872, p = 0,049), CD8+ and IgG (rs = 0,683, p = 0,042; rs = 0,809, p = 0,014), CD4+ (rs = 0,602, p = 0,029), CD19+ and IgM (rs = 0,604, p = 0,017; rs = 0,538, p = 0,038) under condition of increased level CD4+, CD19+, Іreg. and IgG accordantly. Reviled decrease the CCND1 and PNKP gene expression in clean up workers exposed in dose > 0,1 Gy following appearance of correlation between (relative quantification) RQ PNKP and irradiation dose (rs = 0,638, p = 0,035) and also with RQ PNKP and percentage of Cyclin D1+ cells (rs = 0,792, p = 0,034).Concusions. Reveled changes in expression of Cyclin D1+ cells and regulation of related genes may point on possi ble radiation associated firm molecular disturbances occurred during elimination of consequences of Chornobyl accident, that could be a potential basis for cell and humoral communicative links breach in immune system result ing in elevation of stochastic effects like oncopathology in clean up workers of Chornobyl accident in remote peri od after exposure. D. A. Bazyka, A. V. Kubashko, I. M. Ilyenko, O. A. Belyaev, O. J. Pleskach.

Process for crosslinking methylene-containing aromatic polymers with ionizing radiation

NASA Technical Reports Server (NTRS)

Bell, Vernon L. (Inventor); Havens, Stephen J. (Inventor)

1990-01-01

A process for crosslinking aromatic polymers containing radiation-sensitive methylene groups (-CH2-) by exposing the polymers to ionizing radiation thereby causing crosslinking of the polymers through the methylene groups is described. Crosslinked polymers are resistant to most organic solvents such as acetone, alcohols, hydrocarbons, methylene, chloride, chloroform, and other halogenated hydrocarbons, to common fuels and to hydraulic fluids in contrast to readily soluble uncrosslinked polymers. In addition, the degree of crosslinking of the polymers depends upon the percentage of the connecting groups which are methylene which ranges from 5 to 50 pct and preferably from 25 to 50 pct of the connecting groups, and is also controlled by the level of irradiation which ranges from 25 to 1000 Mrads and preferably from 25 to 250 Mrads. The temperature of the reaction conditions ranges from 25 to 200 C and preferably at or slightly above the glass transition temperature of the polymer. The crosslinked polymers are generally more resistant to degradation at elevated temperatures such as greater than 150 C, have a reduced tendency to creep under load, and show no significant embrittlement of parts fabricated from the polymers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shourbaji, AA

Oak Ridge National Laboratory conducted field radiological measurements at two port locations at the request of the Environmental Protection Agency (EPA). The radiological measurements were performed on five radiation detection systems at the port of Darrow, Louisiana and three systems at the port of Charleston, South Carolina. Darrow was visited on January 20-23, 2004 and Charleston on May 25, 2004. All tested systems are designed to detect radioactive material that might be present in scrap metals as the scrap is being unloaded from ships. All eight systems are commercially known as the Cricket and manufactured by RAD/COMM Systems. Each radiationmore » detection system consists of a detector with two channels and a wireless transmitter, both mounted on the grapple, and a controller located in the crane cab. The cranes at both locations are operated by the Cooper T. Smith Company. The purpose of the radiological measurements was to evaluate the performance of the radiation detection systems in terms of their ability to detect elevated radiation levels, and to develop a routine testing method for all EPA Cricket systems.« less

A laser scanning system for metrology and viewing in ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spampinato, P.T.; Barry, R.E.; Menon, M.M.

1996-05-01

The construction and operation of a next-generation fusion reactor will require metrology to achieve and verify precise alignment of plasma-facing components and inspection in the reactor vessel. The system must be compatible with the vessel environment of high gamma radiation (10{sup 4} Gy/h), ultra-high-vacuum (10{sup {minus}8} torr), and elevated temperature (200 C). The high radiation requires that the system be remotely deployed. A coherent frequency modulated laser radar-based system will be integrated with a remotely operated deployment mechanism to meet these requirements. The metrology/viewing system consists of a compact laser transceiver optics module which is linked through fiber optics tomore » the laser source and imaging units that are located outside of a biological shield. The deployment mechanism will be a mast-like positioning system. Radiation-damage tests will be conducted on critical sensor components at Oak Ridge National Laboratory to determine threshold damage levels and effects on data transmission. This paper identifies the requirements for International Thermonuclear Experimental Reactor metrology and viewing and describes a remotely operated precision ranging and surface mapping system.« less

Hawaiian birds

USGS Publications Warehouse

Scott, J. Michael; Sincock, John L.; Di Silvestro, Roger L.

1985-01-01

Hawaii's 132 islands, reefs, and shoals extend 1,523 miles from the southernmost island of Hawaii to the northernmost islands at Kure Atoll. The northernmost islands, now eroded almost to sea level, are about 27 million years old, whereas the still-forming island of Hawaii is only about 750,000 years old. The Hawaiian Islands are the most isolated in the world and, as such, have developed many species and subspecies of plants and animals found nowhere else. the arrival of few ancestral species and the isolation of the islands, with their varying ages, elevations, climates, and microhabitats, were ideal for creating this great endemic biota through adaptive radiation.

Inhibition of EphB4-ephrin-B2 signaling enhances response to Cetuximab-radiation therapy in head and neck cancers.

PubMed

Bhatia, Shilpa; Sharma, Jaspreet; Bukkapatnam, Sanjana; Oweida, Ayman; Lennon, Shelby; Phan, Andy V; Milner, Dallin; Uyanga, Nomin; Jimeno, Antonio; Raben, David; Somerset, Hilary; Heasley, Lynn; Karam, Sana D

2018-05-30

The clinical success of targeted therapies such as cetuximab and radiation (RT) is hampered by the low response rates and development of therapeutic resistance. In the current study, we investigated the involvement of EphB4-ephrin-B2 pro-tumorigenic signaling in mediating resistance to EGFR inhibition and radiation therapy in head and neck cancers. We used patient-derived xenograft (PDX) models of head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines to test our hypothesis. Tumor tissues were subjected to PhosphoRTK array, and western blotting to detect changes in EphB4-ephrin-B2 targets. mRNA sequencing and microarray data analysis was performed on PDX tumors and HNSCC cell lines respectively to determine differences in gene expression of molecules involved in tumor cell growth, proliferation, and survival pathways. Effects on cell growth were determined by MTT assay on HNSCC cells downregulated for EphB4/ephrin-B2 expression, with and without EGFR inhibitor and radiation. Our data from locally-advanced HNSCC patients treated with standard of care definitive chemo-RT show elevated EphB4 and ephrin-B2 levels after failure of treatment. We observed significant response towards cetuximab and radiation therapy following EphB4-ephrin-B2 inhibition resulting in improved survival in tumor-bearing mice. Tumor growth inhibition was accompanied by decrease in the levels of proliferation and pro-survival molecules and increased apoptosis. Our findings underscore the importance of adopting rational drug combinations to enhance therapeutic effect. Our study documenting enhanced response of HNSCC to cetuximab-RT therapy with EphB4-ephrin-B2 blockade has the potential to translate into clinic to benefit this patient population. Copyright ©2018, American Association for Cancer Research.

UV ATTENUATION NEAR CORAL REEFS IN THE FLORIDA KEYS: LIGHT ABSORPTION BY CDOM AND PARTICLES

EPA Science Inventory

We have investigated the roles of chromophoric dissolved organic matter (CDOM) and suspended particles in the attenuation of UV radiation in the middle and lower regions of the Florida Keys. Extended exposure to UV radiation, along with elevated sea surface temperatures, impairs...

Dust-on-snow and the timing of peak streamflow in the upper Rio Grande

USDA-ARS?s Scientific Manuscript database

Dust radiative forcing on high elevation snowpack is well-documented in the southern Rockies. Various field studies show that dust deposits decrease snow albedo and increase absorption of solar radiation, leading to earlier snowmelt and peak stream flows. These findings have implications for the use...

INDICATORS OF UV EXPOSURE IN CORALS: RELEVANCE TO GLOBAL CLIMATE CHANGE AND CORAL BLEACHING

EPA Science Inventory

Increased exposure to solar UV radiation and elevated water temperatures are believed to play a role in the bleaching of corals. To provide additional tools for evaluating the role of UV radiation, we have examined UV-specific effects in coral and have characterized factors that ...

The rising greenhouse effect: experiments and observations in and around the Alps

NASA Astrophysics Data System (ADS)

Philipona, R.

2010-09-01

The rapid temperature increase of more than 1°C in central Europe over the last three decades is larger than expected from anthropogenic greenhouse warming. Surface radiation flux measurements in and around the Alps in fact confirm that not only thermal longwave radiation but also solar shortwave radiation increased since the 1980s. Surface energy budget analyses reveal the rising surface temperature to be well correlated with the radiative forcing, and also show an increase of the kinetic energy fluxes explaining the rise of atmospheric water vapor. Solar radiation mainly increased due to a strong decline of anthropogenic aerosols since mid of the 1980s. While anthropogenic aerosols were mainly accumulated in the boundary layer, this reduction let solar radiation to recover (solar brightening after several decades of solar dimming) mainly at low altitudes around the Alps. At high elevations in the Alps, solar forcing is much smaller and the respective temperature rise is also found to be smaller than in the lowlands. The fact that temperature increases less in the Alps than at low elevations is unexpected in the concept of greenhouse warming, but the radiation budget analyses clearly shows that in the plains solar forcing due to declining aerosols additionally increased surface temperature, whereas in the Alps temperature increased primarily due to greenhouse warming that is particularly manifested by a strong water vapor feedback.

Biomechanical properties of crystalline lens as a function of intraocular pressure assessed noninvasively by optical coherence elastography

NASA Astrophysics Data System (ADS)

Wu, Chen; Aglyamov, Salavat R.; Liu, Chih-Hao; Han, Zhaolong; Singh, Manmohan; Larin, Kirill V.

2017-02-01

Many ocular diseases such as glaucoma and uveitis can lead to the elevation of intraocular pressure (IOP). Previous research implies a link between elevated IOP and lens disease. However, the relationship between IOP elevation and biomechanical properties of the crystalline lens has not been directly studied yet. In this work, we investigated the biomechanical properties of porcine lens as a function of IOP by acoustic radiation force optical coherence elastography.

Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to <10 Gy Total Body Irradiation.

PubMed

Unthank, Joseph L; Miller, Steven J; Quickery, Ariel K; Ferguson, Ethan L; Wang, Meijing; Sampson, Carol H; Chua, Hui Lin; DiStasi, Matthew R; Feng, Hailin; Fisher, Alexa; Katz, Barry P; Plett, P Artur; Sandusky, George E; Sellamuthu, Rajendran; Vemula, Sasidhar; Cohen, Eric P; MacVittie, Thomas J; Orschell, Christie M

2015-11-01

The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p < 0.01 vs. non-irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p < 0.01 vs. non-irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs.

HZE ⁵⁶Fe-ion irradiation induces endothelial dysfunction in rat aorta: role of xanthine oxidase.

PubMed

Soucy, Kevin G; Lim, Hyun Kyo; Kim, Jae Hyung; Oh, Young; Attarzadeh, David O; Sevinc, Baris; Kuo, Maggie M; Shoukas, Artin A; Vazquez, Marcelo E; Berkowitz, Dan E

2011-10-01

Ionizing radiation has been implicated in the development of significant cardiovascular complications. Since radiation exposure is associated with space exploration, astronauts are potentially at increased risk of accelerated cardiovascular disease. This study investigated the effect of high atomic number, high-energy (HZE) iron-ion radiation on vascular and endothelial function as a model of space radiation. Rats were exposed to a single whole-body dose of iron-ion radiation at doses of 0, 0.5 or 1 Gy. In vivo aortic stiffness and ex vivo aortic tension responses were measured 6 and 8 months after exposure as indicators of chronic vascular injury. Rats exposed to 1 Gy iron ions demonstrated significantly increased aortic stiffness, as measured by pulse wave velocity. Aortic rings from irradiated rats exhibited impaired endothelial-dependent relaxation consistent with endothelial dysfunction. Acute xanthine oxidase (XO) inhibition or reactive oxygen species (ROS) scavenging restored endothelial-dependent responses to normal. In addition, XO activity was significantly elevated in rat aorta 4 months after whole-body irradiation. Furthermore, XO inhibition, initiated immediately after radiation exposure and continued until euthanasia, completely inhibited radiation-dependent XO activation. ROS production was elevated after 1 Gy irradiation while production of nitric oxide (NO) was significantly impaired. XO inhibition restored NO and ROS production. Finally, dietary XO inhibition preserved normal endothelial function and vascular stiffness after radiation exposure. These results demonstrate that radiation induced XO-dependent ROS production and nitroso-redox imbalance, leading to chronic vascular dysfunction. As a result, XO is a potential target for radioprotection. Enhancing the understanding of vascular radiation injury could lead to the development of effective methods to ameliorate radiation-induced vascular damage.

Analyses of Radiation and Mesothelioma in the US Transuranium and Uranium Registries

PubMed Central

Fulcher, Keri; Nagarajan, Sumitha; McCord, Stacey; Fallahian, Naz Afarin; Hoffman, Heather J.; Haver, Cary; Tolmachev, Sergei

2013-01-01

Objectives. We examined the relationship between radiation and excess deaths from mesothelioma among deceased nuclear workers who were part of the US Transuranium and Uranium Registries. Methods. We performed univariate analysis with SAS Version 9.1 software. We conducted proportionate mortality ratio (PMR) and proportionate cancer mortality ratio (PCMR) analyses using the National Institute for Occupational Safety and Health Life Table Analysis System with the referent group being all deaths in the United States. Results. We found a PMR of 62.40 (P < .05) and a PCMR of 46.92 (P < .05) for mesothelioma. PMRs for the 4 cumulative external radiation dose quartiles were 61.83, 57.43, 74.46, and 83.31. PCMRs were 36.16, 47.07, 51.35, and 67.73. The PMR and PCMR for trachea, bronchus, and lung cancer were not significantly elevated. Conclusions. The relationship between cumulative external radiation dose and the PMR and PCMR for mesothelioma suggests that external radiation at nuclear facilities is associated with an increased risk of mesothelioma. The lack of a significantly elevated PMR and PCMR for trachea, bronchus, and lung cancer suggests that asbestos did not confound this relationship. PMID:23409888

Optical and morpho-functional traits of the leaves of tree species growing in a mountain cloud forest

NASA Astrophysics Data System (ADS)

Velázquez-Rosas, Noé; Barradas, Víctor L.; Vázquez-Santana, Sonia; Cruz-Ortega, Rocio; García-Jiménez, Federico; Toledo-Alvarado, Edith; Orozco-Segovia, Alma

2010-11-01

The physiological, anatomical and optical leaf properties relative to photosynthetically active (PAR) and ultraviolet (UV-B) radiation were assessed in Ticodendron incognitum, Drimys granadensis, Podocarpus matudae var. macrocarpus and Vaccinium consanguineum, growing along an elevation gradient (1520-2550 m asl) in a montane cloud forest in México. PAR and UV-B absorptance, transmittance and reflectance, UV-B absorptance by foliar compounds, chlorophylls, carotenoids, leaf nitrogen, leaf mass per area, leaf blades, cuticles, epidermis and parenchymas thickness were measured. PAR absorptance efficiencies were calculated. Among the evaluated morpho-functional traits, the studied species displayed different patterns of variation with elevation. Leaf traits could be explained in part by changes in elevation or the distribution of PAR and UV-B in the elevation gradient. Ticodendron and Drimys leaf traits were likely determined by two cloud banks located at 1940 and 2380 m. In Vaccinium, eight traits were related to elevation and PAR or UV-B. Contrary to this, in Podocarpus, most of the nine leaf traits could be explained by only one of these factors. The morphological traits of the studied species were similar to those of species growing in other oligotrophic ecosystems. Significant differences between sun exposed and shade leaves were limited to particular elevations or to particular traits of each species. Vaccinium showed more significant differences between sun and shade leaves than did the other species growing along the gradient. The morpho-functional traits measured in Podocarpus and Vaccinium showed that, some leaf traits did not change linearly with elevation or PAR. At elevation levels where species co-occur, the species ranking with respect to evaluated traits varied from trait to trait. This indicate that each species copes with light and other environmental factors, that vary with elevation, according to its morpho-functional plasticity and susceptibility to these factors; which may determine the distribution of these species along the gradient.

A longitudinal study on the radiation-induced thyroid gland changes after external beam radiotherapy of nasopharyngeal carcinoma.

PubMed

Lin, Zhixiong; Wu, Vincent Wing-Cheung; Lin, Jing; Feng, Huiting; Chen, Longhua

2011-01-01

Radiation-induced thyroid disorders have been reported in radiotherapy of head and neck cancers. This study evaluated the radiation-induced damages to thyroid gland in patients with nasopharyngeal carcinoma (NPC). Forty-five patients with NPC treated by radiotherapy underwent baseline thyroid hormones (free triiodothyronine, free thyroxine [fT4], and thyrotropin [TSH]) examination and CT scan before radiotherapy. The volume of the thyroid gland was calculated by delineating the structure in the corresponding CT slices using the radiotherapy treatment planning system. The thyroid doses were estimated using the treatment planning system. Subsequent CT scans were conducted at 6, 12, and 18 months after radiotherapy, whereas the hormone levels were assessed at 3, 6, 12, and 18 months after radiotherapy. Trend lines of the volume and hormone level changes against time were plotted. The relationship between the dose and the change of thyroid volume and hormone levels were evaluated using the Pearson correlation test. An average of 20% thyroid volume reduction in the first 6 months and a further 8% shrinkage at 12 months after radiotherapy were observed. The volume reduction was dependent on the mean thyroid doses at 6, 12, and 18 months after radiotherapy (r = -0.399, -0.472, and -0.417, respectively). Serum free triiodothyronine and fT4 levels showed mild changes of <2.5% at 6 months, started to drop by 8.8% and 11.3%, respectively, at 12 months, and became stable at 18 months. The mean serum TSH level increased mildly at 6 months after radiotherapy and more steeply after 18 months. At 18 months after radiotherapy, 12 patients had primary hypothyroidism with an elevated serum TSH, in which 4 of them also presented with low serum fT4. There was a significant difference (p = 0.014) in the mean thyroid doses between patients with hypothyroidism and normal thyroid function. Radiotherapy for patients with NPC caused radiation-induced changes of the thyroid gland. The shrinkage of the gland was greatest in the first 6 months after radiotherapy, whereas the serum fT4 and TSH levels changed at 12 months. Radiation-induced changes were dependent on the mean dose to the gland. Therefore, measures to reduce the thyroid dose in radiotherapy should be considered.

A novel interaction of PAK4 with PPARγ to regulate Nox1 and radiation-induced epithelial-to-mesenchymal transition in glioma.

PubMed

Kesanakurti, D; Maddirela, D; Banasavadi-Siddegowda, Y K; Lai, T-H; Qamri, Z; Jacob, N K; Sampath, D; Mohanam, S; Kaur, B; Puduvalli, V K

2017-09-14

Tumor recurrence in glioblastoma (GBM) is, in part, attributed to increased epithelial-to-mesenchymal transition (EMT) and enhanced tumor cell dissemination in adjacent brain parenchyma after ionizing radiation (IR). EMT is associated with aggressive behavior, increased stem-like characteristics and treatment resistance in malignancies; however, the underlying signaling mechanisms that regulate EMT are poorly understood. We identified grade-dependent p21-activated kinases 4 (PAK4) upregulation in gliomas and further determined its role in mesenchymal transition and radioresistance. IR treatment significantly elevated expression and nuclear localization of PAK4 in correlation with induction of reactive oxygen species (ROS) and mesenchymal transition in GBM cells. Stable PAK4 overexpression promoted mesenchymal transition by elevating EMT marker expression in these cells. Of note, transcription factor-DNA-binding arrays and chromatin immunoprecipitation experiments identified the formation of a novel nuclear PAK4/PPARγ complex which was recruited to the promoter of Nox1, a peroxisome proliferator-activated receptor gamma (PPARγ) target gene. In addition, IR further elevated PAK4/PPARγ complex co-recruitment to Nox1 promoter, and increased Nox1 expression and ROS levels associated with mesenchymal transition in these cells. Conversely, specific PAK4 downregulation decreased PPARγ-mediated Nox1 expression and suppressed EMT in IR-treated cells. In vivo orthotopic tumor experiments showed inhibition of growth and suppression of IR-induced PPARγ and Nox1 expression by PAK4 downregulation in tumors. Our results provide the first evidence of a novel role for PAK4 in IR-induced EMT and suggest potential therapeutic efficacy of targeting PAK4 to overcome radioresistance in gliomas.

Multiple continental radiations and correlates of diversification in Lupinus (Leguminosae): testing for key innovation with incomplete taxon sampling.

PubMed

Drummond, Christopher S; Eastwood, Ruth J; Miotto, Silvia T S; Hughes, Colin E

2012-05-01

Replicate radiations provide powerful comparative systems to address questions about the interplay between opportunity and innovation in driving episodes of diversification and the factors limiting their subsequent progression. However, such systems have been rarely documented at intercontinental scales. Here, we evaluate the hypothesis of multiple radiations in the genus Lupinus (Leguminosae), which exhibits some of the highest known rates of net diversification in plants. Given that incomplete taxon sampling, background extinction, and lineage-specific variation in diversification rates can confound macroevolutionary inferences regarding the timing and mechanisms of cladogenesis, we used Bayesian relaxed clock phylogenetic analyses as well as MEDUSA and BiSSE birth-death likelihood models of diversification, to evaluate the evolutionary patterns of lineage accumulation in Lupinus. We identified 3 significant shifts to increased rates of net diversification (r) relative to background levels in the genus (r = 0.18-0.48 lineages/myr). The primary shift occurred approximately 4.6 Ma (r = 0.48-1.76) in the montane regions of western North America, followed by a secondary shift approximately 2.7 Ma (r = 0.89-3.33) associated with range expansion and diversification of allopatrically distributed sister clades in the Mexican highlands and Andes. We also recovered evidence for a third independent shift approximately 6.5 Ma at the base of a lower elevation eastern South American grassland and campo rupestre clade (r = 0.36-1.33). Bayesian ancestral state reconstructions and BiSSE likelihood analyses of correlated diversification indicated that increased rates of speciation are strongly associated with the derived evolution of perennial life history and invasion of montane ecosystems. Although we currently lack hard evidence for "replicate adaptive radiations" in the sense of convergent morphological and ecological trajectories among species in different clades, these results are consistent with the hypothesis that iteroparity functioned as an adaptive key innovation, providing a mechanism for range expansion and rapid divergence in upper elevation regions across much of the New World.

Marine CDOM accumulation during a coastal Arctic mesocosm experiment: No response to elevated pCO2 levels

NASA Astrophysics Data System (ADS)

Pavlov, Alexey K.; Silyakova, Anna; Granskog, Mats A.; Bellerby, Richard G. J.; Engel, Anja; Schulz, Kai G.; Brussaard, Corina P. D.

2014-06-01

A large-scale multidisciplinary mesocosm experiment in an Arctic fjord (Kongsfjorden, Svalbard; 78°56.2'N) was used to study Arctic marine food webs and biogeochemical elements cycling at natural and elevated future carbon dioxide (CO2) levels. At the start of the experiment, marine-derived chromophoric dissolved organic matter (CDOM) dominated the CDOM pool. Thus, this experiment constituted a convenient case to study production of autochthonous CDOM, which is typically masked by high levels of CDOM of terrestrial origin in the Arctic Ocean proper. CDOM accumulated during the experiment in line with an increase in bacterial abundance; however, no response was observed to increased pCO2 levels. Changes in CDOM absorption spectral slopes indicate that bacteria were most likely responsible for the observed CDOM dynamics. Distinct absorption peaks (at 330 and 360 nm) were likely associated with mycosporine-like amino acids (MAAs). Due to the experimental setup, MAAs were produced in absence of ultraviolet exposure providing evidence for MAAs to be considered as multipurpose metabolites rather than simple photoprotective compounds. We showed that a small increase in CDOM during the experiment made it a major contributor to total absorption in a range of photosynthetically active radiation (PAR, 400-700 nm) and, therefore, is important for spectral light availability and may be important for photosynthesis and phytoplankton groups composition in a rapidly changing Arctic marine ecosystem.

Disturbance of DKK1 level is partly involved in survival of lung cancer cells via regulation of ROMO1 and γ-radiation sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, In Gyu, E-mail: igkim@kaeri.re.kr; Department of Radiation Biotechnology and Applied Radioisotope, University of Science and Technology; Kim, Seo Yoen

2014-01-03

Highlights: •DKK1 was expressed differently among non-small-cell lung cancer cell lines. •DKK1 negatively regulated ROMO1 gene expression. •Disturbance of DKK1 level induced the imbalance of cellular ROS. •DKK1/ROMO1-induced ROS imbalance is involved in cell survival in NSCLC. -- Abstract: Dickkopf1 (DKK1), a secreted protein involved in embryonic development, is a potent inhibitor of the Wnt signaling pathway and has been postulated to be a tumor suppressor or tumor promoter depending on the tumor type. In this study, we showed that DKK1 was expressed differently among non-small-cell lung cancer cell lines. The DKK1 expression level was much higher in A549 cellsmore » than in H460 cells. We revealed that blockage of DKK1 expression by silencing RNA in A549 cells caused up-regulation of intracellular reactive oxygen species (ROS) modulator (ROMO1) protein, followed by partial cell death, cell growth inhibition, and loss of epithelial–mesenchymal transition property caused by ROS, and it also increased γ-radiation sensitivity. DKK1 overexpression in H460 significantly inhibited cell survival with the decrease of ROMO1 level, which induced the decrease of cellular ROS. Thereafter, exogenous N-acetylcysteine, an antioxidant, or hydrogen peroxide, a pro-oxidant, partially rescued cells from death and growth inhibition. In each cell line, both overexpression and blockage of DKK1 not only elevated p-RB activation, which led to cell growth arrest, but also inactivated AKT/NF-kB, which increased radiation sensitivity and inhibited cell growth. This study is the first to demonstrate that strict modulation of DKK1 expression in different cell types partially maintains cell survival via tight regulation of the ROS-producing ROMO1 and radiation resistance.« less

Ionizing Radiation Induces Morphological Changes and Immunological Modulation of Jurkat Cells

PubMed Central

Voos, Patrick; Fuck, Sebastian; Weipert, Fabian; Babel, Laura; Tandl, Dominique; Meckel, Tobias; Hehlgans, Stephanie; Fournier, Claudia; Moroni, Anna; Rödel, Franz; Thiel, Gerhard

2018-01-01

Impairment or stimulation of the immune system by ionizing radiation (IR) impacts on immune surveillance of tumor cells and non-malignant cells and can either foster therapy response or side effects/toxicities of radiation therapy. For a better understanding of the mechanisms by which IR modulates T-cell activation and alters functional properties of these immune cells, we exposed human immortalized Jurkat cells and peripheral blood lymphocytes (PBL) to X-ray doses between 0.1 and 5 Gy. This resulted in cellular responses, which are typically observed also in naïve T-lymphocytes in response of T-cell receptor immune stimulation or mitogens. These responses include oscillations of cytosolic Ca2+, an upregulation of CD25 surface expression, interleukin-2 and interferon-γ synthesis, elevated expression of Ca2+ sensitive K+ channels and an increase in cell diameter. The latter was sensitive to inhibition by the immunosuppressant cyclosporine A, Ca2+ buffer BAPTA-AM, and the CDK1-inhibitor RO3306, indicating the involvement of Ca2+-dependent immune activation and radiation-induced cell cycle arrest. Furthermore, on a functional level, Jurkat and PBL cell adhesion to endothelial cells was increased upon radiation exposure and was highly dependent on an upregulation of integrin beta-1 expression and clustering. In conclusion, we here report that IR impacts on immune activation and functional properties of T-lymphocytes that may have implications in both toxic effects and treatment response to combined radiation and immune therapy in cancer patients. PMID:29760710

Ionizing Radiation Induces Morphological Changes and Immunological Modulation of Jurkat Cells.

PubMed

Voos, Patrick; Fuck, Sebastian; Weipert, Fabian; Babel, Laura; Tandl, Dominique; Meckel, Tobias; Hehlgans, Stephanie; Fournier, Claudia; Moroni, Anna; Rödel, Franz; Thiel, Gerhard

2018-01-01

Impairment or stimulation of the immune system by ionizing radiation (IR) impacts on immune surveillance of tumor cells and non-malignant cells and can either foster therapy response or side effects/toxicities of radiation therapy. For a better understanding of the mechanisms by which IR modulates T-cell activation and alters functional properties of these immune cells, we exposed human immortalized Jurkat cells and peripheral blood lymphocytes (PBL) to X-ray doses between 0.1 and 5 Gy. This resulted in cellular responses, which are typically observed also in naïve T-lymphocytes in response of T-cell receptor immune stimulation or mitogens. These responses include oscillations of cytosolic Ca 2+ , an upregulation of CD25 surface expression, interleukin-2 and interferon-γ synthesis, elevated expression of Ca 2+ sensitive K + channels and an increase in cell diameter. The latter was sensitive to inhibition by the immunosuppressant cyclosporine A, Ca 2+ buffer BAPTA-AM, and the CDK1-inhibitor RO3306, indicating the involvement of Ca 2+ -dependent immune activation and radiation-induced cell cycle arrest. Furthermore, on a functional level, Jurkat and PBL cell adhesion to endothelial cells was increased upon radiation exposure and was highly dependent on an upregulation of integrin beta-1 expression and clustering. In conclusion, we here report that IR impacts on immune activation and functional properties of T-lymphocytes that may have implications in both toxic effects and treatment response to combined radiation and immune therapy in cancer patients.

The Efficacy of Nardostachys Jatamansi Against The Radiation Induced Haematological Damage In Rats

PubMed Central

Gowda, Damodara K M; Shetty, Lathika; A P, Krishna; Kumari, Suchetha N; Sanjeev, Ganesh; P, Naveen

2013-01-01

Introduction: Radiation is increasingly being used for medical purposes and it is an established weapon in the diagnosis and the therapy of cancer. An exposure to 1-2 Gys causes the NVD (Nausea, vomiting, diarrhoea) syndrome, whereas an exposure to 2-6 Gys causes the haematopoietic syndrome. The aim of the present study was to investigate the protective effect of the Nardostachys jatamansi root extract (NJE) on the radiation induced haematological damage in rats. Materials and Methods: EBR was performed at the Microtron Centre, Mangalore University, India. Rats were treated with NJE once daily for 15 days before and after the irradiation. After the irradiation, blood was collected for determining the peripheral blood counts (RBC and WBC), haemoglobin, the platelet count and the packed cell volume (PCV) at 6 hours, 12 hours, 24 hours, 48 hours and 5, 10 and 15 days post irradiation. The data was analyzed by one way ANOVA, followed by the Tukey’s test for multiple comparisons. Result: NJE provided protection against the radiation induced haematological disorders. The rats treated with NJE exhibited a time dependent significant elevation in all the haematological parameters which were studied and its modulation upto the near normal level was recorded. Conclusion: From this study, we concluded that, NJE provides protection by modulating the radiation induced damage on the haematopoietic system. PMID:23905085

Design of a phased array for the generation of adaptive radiation force along a path surrounding a breast lesion for dynamic ultrasound elastography imaging.

PubMed

Ekeom, Didace; Hadj Henni, Anis; Cloutier, Guy

2013-03-01

This work demonstrates, with numerical simulations, the potential of an octagonal probe for the generation of radiation forces in a set of points following a path surrounding a breast lesion in the context of dynamic ultrasound elastography imaging. Because of the in-going wave adaptive focusing strategy, the proposed method is adapted to induce shear wave fronts to interact optimally with complex lesions. Transducer elements were based on 1-3 piezocomposite material. Three-dimensional simulations combining the finite element method and boundary element method with periodic boundary conditions in the elevation direction were used to predict acoustic wave radiation in a targeted region of interest. The coupling factor of the piezocomposite material and the radiated power of the transducer were optimized. The transducer's electrical impedance was targeted to 50 Ω. The probe was simulated by assembling the designed transducer elements to build an octagonal phased-array with 256 elements on each edge (for a total of 2048 elements). The central frequency is 4.54 MHz; simulated transducer elements are able to deliver enough power and can generate the radiation force with a relatively low level of voltage excitation. Using dynamic transmitter beamforming techniques, the radiation force along a path and resulting acoustic pattern in the breast were simulated assuming a linear isotropic medium. Magnitude and orientation of the acoustic intensity (radiation force) at any point of a generation path could be controlled for the case of an example representing a heterogeneous medium with an embedded soft mechanical inclusion.

Environmental Sciences: YIP: Combining Remotely Sensed Vegetation Data and Ecohydrologic Process Models to Improve Estimation of Root Zone Moisture at Spatial Scales Relevant to the Army

DTIC Science & Technology

2016-04-01

vegetation arising due to contrasts in incoming solar radiation that is associated with hillslope aspects. At lower elevations, shrubs can be present on North...whereas shrubs are more prevalent on South-facing aspects. At watershed scales, the transition from grasses at lower elevations to coniferous evergreens...Mountain sage communities, adapted to cooler temperatures, are also found at higher elevations in RCEW, with ceanothus shrubs common   Mean annual

Response of the Water Cycle of West Africa and Atlantic to Radiative Forcing by Saharan Dust

NASA Technical Reports Server (NTRS)

Lau, K. M.; Kim, Kyu-Myong; Sud, Yogesh C.; Walker, Gregory L.

2010-01-01

The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence in support of the "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summer, as a result of large-scale atmospheric feed back triggered by absorbing dust aerosols, rainfall and cloudiness are enhanced over the West Africa/Easter Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean. region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while long wave has the opposite response. The elevated dust layer warms the air over Nest Africa and the eastern Atlantic. The condensation heating associated with the induced deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in northward shift of the West Africa precipitation over land, increased low-level westerlies flow over West Africa at the southern edge of the dust layer, and a near surface energy fluxes, resulting in cooling of the Nest African land and the eastern Atlantic, and a warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at 0.95 or higher.

Handbook of the Radiation Regime of the Arctic Basin: Results from the Drift Stations

NASA Technical Reports Server (NTRS)

Mishin, A. A.; Marshunova, M. S.; Radionov, V. F. (Editor); Colony, R. (Editor)

1994-01-01

This Handbook summarizes the radiation data from the Soviet 'North Pole' drifting research stations operated in the Arctic from 1950 to 1991. The Handbook contains reduced mean monthly values of the fluxes of solar radiation for solar elevations up to 35 deg at 5 deg intervals, monthly totals of the net radiation and its constituents, and mean monthly values of the albedo of the sea-ice surfaces. The Handbook presents information of interest to specialists studying the physics of the atmosphere, climatology, geography, and related disciplines.

Moderating night radiative cooling reduces frost damage to Metrosideros polymorpha seedlings used for forest restoration in Hawaii

Treesearch

Paul G. Scowcroft; Frederick C. Meinzer; Guillermo Goldstein; Peter J. Melcher; Jack Jeffrey

2000-01-01

Winter frosts caused by radiative cooling were hypothesized to limit successful reintroduction of Hawaiian plants other than Acacia koa to alien-dominated grasslands above 1700 m elevation. We determined, in the laboratory, the temperature at which irreversible tissue damage occurred to Metrosideros polymorpha leaves. We also...

RESPONSE OF OXIDATIVE STRESS DEFENSE SYSTEMS IN RICE (ORYZA SATIVA) LEAVES WITH SUPPLEMENTAL UV-B RADIATION

EPA Science Inventory

The impact of elevated ultraviolet-B radiation (UV-B, 280-320 nm) on membrane systems and lipid peroxidation, and possible involvement of active oxygen radicals was investigated in leaves of two UV-B susceptible rice cultivars (Oryza sativa L. cvs IR74 and Dular). Rice seedlings ...

Langley program of GaAs solar cells. [emphasizing energy conversion efficiency and radiation resistance

NASA Technical Reports Server (NTRS)

Conway, E. J.

1979-01-01

A brief overview of the development of GaAs solar cell technology is provided. An 18 to 20 percent AMO efficiency, stability under radiation and elevated-temperature operation, and high power-to-weight ratio are among the factors studied. Cell cost and availability are also examined.

Adenosine Kinase Inhibition Protects against Cranial Radiation-Induced Cognitive Dysfunction

PubMed Central

Acharya, Munjal M.; Baulch, Janet E.; Lusardi, Theresa A.; Allen, Barrett. D.; Chmielewski, Nicole N.; Baddour, Al Anoud D.; Limoli, Charles L.; Boison, Detlev

2016-01-01

Clinical radiation therapy for the treatment of CNS cancers leads to unintended and debilitating impairments in cognition. Radiation-induced cognitive dysfunction is long lasting; however, the underlying molecular and cellular mechanisms are still not well established. Since ionizing radiation causes microglial and astroglial activation, we hypothesized that maladaptive changes in astrocyte function might be implicated in radiation-induced cognitive dysfunction. Among other gliotransmitters, astrocytes control the availability of adenosine, an endogenous neuroprotectant and modulator of cognition, via metabolic clearance through adenosine kinase (ADK). Adult rats exposed to cranial irradiation (10 Gy) showed significant declines in performance of hippocampal-dependent cognitive function tasks [novel place recognition, novel object recognition (NOR), and contextual fear conditioning (FC)] 1 month after exposure to ionizing radiation using a clinically relevant regimen. Irradiated rats spent less time exploring a novel place or object. Cranial irradiation also led to reduction in freezing behavior compared to controls in the FC task. Importantly, immunohistochemical analyses of irradiated brains showed significant elevation of ADK immunoreactivity in the hippocampus that was related to astrogliosis and increased expression of glial fibrillary acidic protein (GFAP). Conversely, rats treated with the ADK inhibitor 5-iodotubercidin (5-ITU, 3.1 mg/kg, i.p., for 6 days) prior to cranial irradiation showed significantly improved behavioral performance in all cognitive tasks 1 month post exposure. Treatment with 5-ITU attenuated radiation-induced astrogliosis and elevated ADK immunoreactivity in the hippocampus. These results confirm an astrocyte-mediated mechanism where preservation of extracellular adenosine can exert neuroprotection against radiation-induced pathology. These innovative findings link radiation-induced changes in cognition and CNS functionality to altered purine metabolism and astrogliosis, thereby linking the importance of adenosine homeostasis in the brain to radiation injury. PMID:27375429

Contamination and radiation exposure in central Europe after the Chernobyl accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayer, A.; Mueck, K.; Loosli, H.H.

1996-06-01

Ten years ago, on 26 April 1986, as a consequence of an accident in Unit 4 of the Chernobyl-NPP, a large quantity of radioactive material was released into the atmosphere for some days. This material was spread over wide areas of Europe. Due to variable weather conditions the activity concentrations in air varied considerably in different regions. Also as a consequence of large variations in precipitation intensity-particularly in the regions of Southeastern Germany, Austria and Southern Switzerland-up to 100 kBq m{sup -2} {sup 137}Cs were deposited on the soil. Due to fallout, washout, and/or rainout, a range of foodstuffs weremore » contaminated, and foodstuffs directly exposed to the fallout [vegetables and green fodder (grass)] showed the highest contamination levels. Consequently, milk also showed a significantly increased activity concentration, in particular of {sup 131}I. In the following years contamination in all kinds of foodstuffs decreased, but elevated contamination levels in special pathways like venison and mushrooms are still observed to date. This contamination resulted in additional exposure, mainly due to external radiation from ground and from consumption of contaminated food. The radiation exposure in the most contaminated areas was calculated on the basis of model assumptions and was found to be about 1 mSv during the first year after the accident. Using this model, the ingestion pathway was overestimated by at least a factor of two. This additional exposure decreased and is now less than 1 % on average; in the most contaminated areas, this is a few percent of the average natural radiation exposure.« less

CIELO-A GIS integrated model for climatic and water balance simulation in islands environments

NASA Astrophysics Data System (ADS)

Azevedo, E. B.; Pereira, L. S.

2003-04-01

The model CIELO (acronym for "Clima Insular à Escala Local") is a physically based model that simulates the climatic variables in an island using data from a single synoptic reference meteorological station. The reference station "knows" its position in the orographic and dynamic regime context. The domain of computation is a GIS raster grid parameterised with a digital elevation model (DEM). The grid is oriented following the direction of the air masses circulation through a specific algorithm named rotational terrain model (RTM). The model consists of two main sub-models. One, relative to the advective component simulation, assumes the Foehn effect to reproduce the dynamic and thermodynamic processes occurring when an air mass moves through the island orographic obstacle. This makes possible to simulate the air temperature, air humidity, cloudiness and precipitation as influenced by the orography along the air displacement. The second concerns the radiative component as affected by the clouds of orographic origin and by the shadow produced by the relief. The initial state parameters are computed starting from the reference meteorological station across the DEM transept until the sea level at the windward side. Then, starting from the sea level, the model computes the local scale meteorological parameters according to the direction of the air displacement, which is adjusted with the RTM. The air pressure, temperature and humidity are directly calculated for each cell in the computational grid, while several algorithms are used to compute the cloudiness, net radiation, evapotranspiration, and precipitation. The model presented in this paper has been calibrated and validated using data from some meteorological stations and a larger number of rainfall stations located at various elevations in the Azores Islands.

Thyroid hypofunction after exposure to fallout from a hydrogen bomb explosion.

PubMed

Larsen, P R; Conard, R A; Knudsen, K D; Robbins, J; Wolff, J; Rall, J E; Nicoloff, J T; Dobyns, B M

1982-03-19

Thyroid function was evaluated in the Marshallese who were accidentally exposed to fallout-containing radioiodine isotopes in 1954. Measurements of thyrotrophin (TSH, thyroid-stimulating hormone) levels and free thyroxine (T4) index (FT4I) have revealed that, among 86 persons exposed on Rongelap and Ailingnae atolls, 14 have shown evidence of thyroid hypofunction. This was first noted in some individuals about ten years after exposure. Only two of these showed clinical evidence of hypothyroidism. The most marked TSH elevations were noted in nine persons exposed when younger than 6 years, with estimated doses to the thyroid from 390 to 2,100 rad. Most of this group subsequently had surgery for removal of thyroid nodules. The remaining five cases have been noted more recently among 36 surviving adults exposed at an older age who showed no other detectable thyroid abnormalities. This group had received estimated thyroid doses ranging from 135 to 335 rad and showed modest elevation of serum TSH levels (6 to 9 microU/mL) and a slightly subnormal FT4I. No abnormalities were found in persons on Utirik who received substantially less radiation, and hypothyroidism was present in less than 1% of the control, unexposed Marshallese. The high prevalence of a thyroid hypofunction in these persons indicates that this condition, as well as thyroid nodularity, can be a delayed complication of exposure to early fallout from a nuclear explosion. The fact that a significant fraction of the radiation to the thyroid was from short-lived radioiodine isotopes (132I, 133I, 135I), as opposed to 131I, may account for the severity of the thyroid damage.

Life at extreme elevations on Atacama volcanoes: the closest thing to Mars on Earth?

PubMed

Schmidt, S K; Gendron, E M S; Vincent, K; Solon, A J; Sommers, P; Schubert, Z R; Vimercati, L; Porazinska, D L; Darcy, J L; Sowell, P

2018-03-20

Here we describe recent breakthroughs in our understanding of microbial life in dry volcanic tephra ("soil") that covers much of the surface area of the highest elevation volcanoes on Earth. Dry tephra above 6000 m.a.s.l. is perhaps the best Earth analog for the surface of Mars because these "soils" are acidic, extremely oligotrophic, exposed to a thin atmosphere, high UV fluxes, and extreme temperature fluctuations across the freezing point. The simple microbial communities found in these extreme sites have among the lowest alpha diversity of any known earthly ecosystem and contain bacteria and eukaryotes that are uniquely adapted to these extreme conditions. The most abundant eukaryotic organism across the highest elevation sites is a Naganishia species that is metabolically versatile, can withstand high levels of UV radiation and can grow at sub-zero temperatures, and during extreme diurnal freeze-thaw cycles (e.g. - 10 to + 30 °C). The most abundant bacterial phylotype at the highest dry sites sampled (6330 m.a.s.l. on Volcán Llullaillaco) belongs to the enigmatic B12-WMSP1 clade which is related to the Ktedonobacter/Thermosporothrix clade that includes versatile organisms with the largest known bacterial genomes. Close relatives of B12-WMSP1 are also found in fumarolic soils on Volcán Socompa and in oligotrophic, fumarolic caves on Mt. Erebus in Antarctica. In contrast to the extremely low diversity of dry tephra, fumaroles found at over 6000 m.a.s.l. on Volcán Socompa support very diverse microbial communities with alpha diversity levels rivalling those of low elevation temperate soils. Overall, the high-elevation biome of the Atacama region provides perhaps the best "natural experiment" in which to study microbial life in both its most extreme setting (dry tephra) and in one of its least extreme settings (fumarolic soils).

Deciphering the evolution of birdwing butterflies 150 years after Alfred Russel Wallace.

PubMed

Condamine, Fabien L; Toussaint, Emmanuel F A; Clamens, Anne-Laure; Genson, Gwenaelle; Sperling, Felix A H; Kergoat, Gael J

2015-07-02

One hundred and fifty years after Alfred Wallace studied the geographical variation and species diversity of butterflies in the Indomalayan-Australasian Archipelago, the processes responsible for their biogeographical pattern remain equivocal. We analysed the macroevolutionary mechanisms accounting for the temporal and geographical diversification of the charismatic birdwing butterflies (Papilionidae), a major focus of Wallace's pioneering work. Bayesian phylogenetics and dating analyses of the birdwings were conducted using mitochondrial and nuclear genes. The combination of maximum likelihood analyses to estimate biogeographical history and diversification rates reveals that diversity-dependence processes drove the radiation of birdwings, and that speciation was often associated with founder-events colonizing new islands, especially in Wallacea. Palaeo-environment diversification models also suggest that high extinction rates occurred during periods of elevated sea level and global warming. We demonstrated a pattern of spatio-temporal habitat dynamics that continuously created or erased habitats suitable for birdwing biodiversity. Since birdwings were extinction-prone during the Miocene (warmer temperatures and elevated sea levels), the cooling period after the mid-Miocene climatic optimum fostered birdwing diversification due to the release of extinction. This also suggests that current global changes may represent a serious conservation threat to this flagship group.

Metabolic changes in serum steroids induced by total-body irradiation of female C57B/6 mice.

PubMed

Moon, Ju-Yeon; Shin, Hee-June; Son, Hyun-Hwa; Lee, Jeongae; Jung, Uhee; Jo, Sung-Kee; Kim, Hyun Sik; Kwon, Kyung-Hoon; Park, Kyu Hwan; Chung, Bong Chul; Choi, Man Ho

2014-05-01

The short- and long-term effects of a single exposure to gamma radiation on steroid metabolism were investigated in mice. Gas chromatography-mass spectrometry was used to generate quantitative profiles of serum steroid levels in mice that had undergone total-body irradiation (TBI) at doses of 0Gy, 1Gy, and 4Gy. Following TBI, serum samples were collected at the pre-dose time point and 1, 3, 6, and 9 months after TBI. Serum levels of progestins, progesterone, 5β-DHP, 5α-DHP, and 20α-DHP showed a significant down-regulation following short-term exposure to 4Gy, with the exception of 20α-DHP, which was significantly decreased at each of the time points measured. The corticosteroids 5α-THDOC and 5α-DHB were significantly elevated at each of the time points measured after exposure to either 1 or 4Gy. Among the sterols, 24S-OH-cholestoerol showed a dose-related elevation after irradiation that reached significance in the high dose group at the 6- and 9-month time points. Copyright © 2014 Elsevier Ltd. All rights reserved.

Deciphering the evolution of birdwing butterflies 150 years after Alfred Russel Wallace

PubMed Central

Condamine, Fabien L.; Toussaint, Emmanuel F. A.; Clamens, Anne-Laure; Genson, Gwenaelle; Sperling, Felix A. H.; Kergoat, Gael J.

2015-01-01

One hundred and fifty years after Alfred Wallace studied the geographical variation and species diversity of butterflies in the Indomalayan-Australasian Archipelago, the processes responsible for their biogeographical pattern remain equivocal. We analysed the macroevolutionary mechanisms accounting for the temporal and geographical diversification of the charismatic birdwing butterflies (Papilionidae), a major focus of Wallace’s pioneering work. Bayesian phylogenetics and dating analyses of the birdwings were conducted using mitochondrial and nuclear genes. The combination of maximum likelihood analyses to estimate biogeographical history and diversification rates reveals that diversity-dependence processes drove the radiation of birdwings, and that speciation was often associated with founder-events colonizing new islands, especially in Wallacea. Palaeo-environment diversification models also suggest that high extinction rates occurred during periods of elevated sea level and global warming. We demonstrated a pattern of spatio-temporal habitat dynamics that continuously created or erased habitats suitable for birdwing biodiversity. Since birdwings were extinction-prone during the Miocene (warmer temperatures and elevated sea levels), the cooling period after the mid-Miocene climatic optimum fostered birdwing diversification due to the release of extinction. This also suggests that current global changes may represent a serious conservation threat to this flagship group. PMID:26133078

The Risk of Cataract among Survivors of Childhood and Adolescent Cancer: A Report from the Childhood Cancer Survivor Study

PubMed Central

Chodick, Gabriel; Sigurdson, Alice J.; Kleinerman, Ruth A.; Sklar, Charles A.; Leisenring, Wendy; Mertens, Ann C.; Stovall, Marilyn; Smith, Susan A.; Weathers, Rita E.; Veiga, Lene H. S.; Robison, Leslie L.; Inskip, Peter D.

2016-01-01

With therapeutic successes and improved survival after a cancer diagnosis in childhood, increasing numbers of cancer survivors are at risk of subsequent treatment-related morbidities, including cataracts. While it is well known that the lens of the eye is one of the most radiosensitive tissues in the human body, the risks associated with radiation doses less than 2 Gy are less understood, as are the long- and short-term cataract risks from exposure to ionizing radiation at a young age. In this study, we followed 13,902 five-year survivors of childhood cancer in the Childhood Cancer Survivor Study cohort an average of 21.4 years from the date of first cancer diagnosis. For patients receiving radiotherapy, lens dose (mean: 2.2 Gy; range: 0–66 Gy) was estimated based on radiotherapy records. We used unconditional multivariable logistic regression models to evaluate prevalence of self-reported cataract in relationship to cumulative radiation dose both at five years after the initial cancer diagnosis and at the end of follow-up. We modeled the radiation effect in terms of the excess odds ratio (EOR) per Gy. We also analyzed cataract incidence starting from five years after initial cancer diagnosis to the end of follow-up using Cox regression. A total of 483 (3.5%) cataract cases were identified, including 200 (1.4%) diagnosed during the first five years of follow-up. In a multivariable logistic regression model, cataract prevalence at the end of follow-up was positively associated with lens dose in a manner consistent with a linear dose-response relationship (EOR per Gy = 0.92; 95% CI: 0.65–1.20). The odds ratio for doses between 0.5 and 1.5 Gy was elevated significantly relative to doses <0.5 Gy (OR = 2.2; 95% CI: 1.3–3.7). The results from this study indicate a strong association between ocular exposure to ionizing radiation and long-term risk of pre-senile cataract. The risk of cataract increased with increasing exposure, beginning at lens doses as low as 0.5 Gy. Our findings are in agreement with a growing body of evidence of an elevated risk for lens opacities in populations exposed to doses of ionizing radiation below the previously suggested threshold level of 2 Gy. PMID:27023263

Non-solar ultraviolet radiation and the risk of basal and squamous cell skin cancer.

PubMed Central

Bajdik, C. D.; Gallagher, R. P.; Astrakianakis, G.; Hill, G. B.; Fincham, S.; McLean, D. I.

1996-01-01

A case-control study of non-melanocytic skin cancer was conducted among men in the province of Alberta, Canada. Two hundred and twenty-six cases of basal cell carcinoma (BCC), 180 cases of squamous cell carcinoma (SCC) and 406 age-matched controls provided information concerning skin pigmentation, occupational history, recreational activity, exposure to sunlight and sources of non-solar ultraviolet radiation (NSUVR) and other potential risk factors. Our analyses show no evidence of elevated risk for BCC or SCC among subjects exposed to various types of NSUVR. This is in opposition to studies of melanoma that have shown elevated risks for exposure to fluorescent lighting, sunlamps and sunbeds. PMID:8664139

A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

PubMed

Shakeri, Mahsa; Zakeri, Farideh; Changizi, Vahid; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

2017-06-15

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The State of the Thermosphere in 2017 as Observed by SABER

NASA Astrophysics Data System (ADS)

Hunt, L. A.; Mlynczak, M. G.; Marshall, B. T.; Russell, J. M., III

2017-12-01

Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 μm) and by nitric oxide (NO, 5.3 μm) has been observed for nearly 16 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. SABER has documented dramatic variability in the radiative cooling on timescales ranging from days to the nominal 11-year solar cycle, providing important information about the radiation budget in the upper atmosphere. The effects of Solar Cycle 24 are clearly evident in the infrared radiative cooling of the thermosphere as observed by SABER. The peak NO cooling in SC24 is about one-third less than the maximum seen in SC23 since the beginning of the SABER record in January 2002, while the SC24 CO2 peak is nearly 95% of that in SC23. SC24 has been weakening throughout all of 2017 as measured by the F10.7 index and the sunspot number. Despite this, the radiative cooling by NO and CO2 has not yet reached the low levels of the prior minimum in 2008-2009. This is due to continuing elevated levels of geomagnetic activity as clearly shown by the Ap index. During the years preceding the prior solar minimum, harmonics of the solar rotation period were evident in time series of the NO and CO2 power, and were associated with high speed solar wind streams emanating from coronal holes roughly evenly spaced in solar longitude. Despite a number of large, Earth-facing coronal holes in 2017, periodic features have not yet been observed in spectral/Fourier analysis of the SABER radiative cooling time series. Additional comparisons between solar cycles and with other solar and geomagnetic indicators will also be shown.

Activation of Hif1α by the Prolylhydroxylase Inhibitor Dimethyoxalyglycine Decreases Radiosensitivity

PubMed Central

Ayrapetov, Marina K.; Zhu, Kaya; Parmar, Kalindi; D'Andrea, Alan D.; Price, Brendan D.

2011-01-01

Hypoxia inducible factor 1α (Hif1α) is a stress responsive transcription factor, which regulates the expression of genes required for adaption to hypoxia. Hif1α is normally hydroxylated by an oxygen-dependent prolylhydroxylase, leading to degradation and clearance of Hif1α from the cell. Under hypoxic conditions, the activity of the prolylhydroxylase is reduced and Hif1α accumulates. Hif1α is also constitutively expressed in tumor cells, where it is associated with resistance to ionizing radiation. Activation of the Hif1α transcriptional regulatory pathway may therefore function to protect normal cells from DNA damage caused by ionizing radiation. Here, we utilized the prolylhydroxylase inhibitor dimethyloxalylglycine (DMOG) to elevate Hif1α levels in mouse embryonic fibroblasts (MEFs) to determine if DMOG could function as a radioprotector. The results demonstrate that DMOG increased Hif1α protein levels and decreased the sensitivity of MEFs to ionizing radiation. Further, the ability of DMOG to function as a radioprotector required Hif1α, indicating a key role for Hif1α's transcriptional activity. DMOG also induced the Hif1α -dependent accumulation of several DNA damage response proteins, including CHD4 and MTA3 (sub-units of the NuRD deacetylase complex) and the Suv39h1 histone H3 methyltransferase. Depletion of Suv39h1, but not CHD4 or MTA3, reduced the ability of DMOG to protect cells from radiation damage, implicating increased histone H3 methylation in the radioprotection of cells. Finally, treatment of mice with DMOG prior to total body irradiation resulted in significant radioprotection of the mice, demonstrating the utility of DMOG and related prolylhydroxylase inhibitors to protect whole organisms from ionizing radiation. Activation of Hif1α through prolylhydroxylase inhibition therefore identifies a new pathway for the development of novel radiation protectors. PMID:22016813

Intercellular communications-redox interactions in radiation toxicity; potential targets for radiation mitigation.

PubMed

Farhood, Bagher; Goradel, Nasser Hashemi; Mortezaee, Keywan; Khanlarkhani, Neda; Salehi, Ensieh; Nashtaei, Maryam Shabani; Shabeeb, Dheyauldeen; Musa, Ahmed Eleojo; Fallah, Hengameh; Najafi, Masoud

2018-06-17

Nowadays, using ionizing radiation (IR) is necessary for clinical, agricultural, nuclear energy or industrial applications. Accidental exposure to IR after a radiation terror or disaster poses a threat to human. In contrast to the old dogma of radiation toxicity, several experiments during the last two recent decades have revealed that intercellular signaling and communications play a key role in this procedure. Elevated level of cytokines and other intercellular signals increase oxidative damage and inflammatory responses via reduction/oxidation interactions (redox system). Intercellular signals induce production of free radicals and inflammatory mediators by some intermediate enzymes such as cyclooxygenase-2 (COX-2), nitric oxide synthase (NOS), NADPH oxidase, and also via triggering mitochondrial ROS. Furthermore, these signals facilitate cell to cell contact and increasing cell toxicity via cohort effect. Nitric oxide is a free radical with ability to act as an intercellular signal that induce DNA damage and changes in some signaling pathways in irradiated as well as non-irradiated adjacent cells. Targeting of these mediators by some anti-inflammatory agents or via antioxidants such as mitochondrial ROS scavengers opens a window to mitigate radiation toxicity after an accidental exposure. Experiments which have been done so far suggests that some cytokines such as IL-1β, TNF-α, TGF-β, IL-4 and IL-13 are some interesting targets that depend on irradiated organs and may help mitigate radiation toxicity. Moreover, animal experiments in recent years indicated that targeting of toll like receptors (TLRs) may be more useful for radioprotection and mitigation. In this review, we aimed to describe the role of intercellular interactions in oxidative injury, inflammation, cell death and killing effects of IR. Moreover, we described evidence on potential mitigation of radiation injury via targeting of these mediators.

Methodology to estimate variations in solar radiation reaching densely forested slopes in mountainous terrain.

PubMed

Sypka, Przemysław; Starzak, Rafał; Owsiak, Krzysztof

2016-12-01

Solar radiation reaching densely forested slopes is one of the main factors influencing the water balance between the atmosphere, tree stands and the soil. It also has a major impact on site productivity, spatial arrangement of vegetation structure as well as forest succession. This paper presents a methodology to estimate variations in solar radiation reaching tree stands in a small mountain valley. Measurements taken in three inter-forest meadows unambiguously showed the relationship between the amount of solar insolation and the shading effect caused mainly by the contour of surrounding tree stands. Therefore, appropriate knowledge of elevation, aspect and tilt angles of the analysed planes had to be taken into consideration during modelling. At critical times, especially in winter, the diffuse and reflected components of solar radiation only reached some of the sites studied as the beam component of solar radiation was totally blocked by the densely forested mountain slopes in the neighbourhood. The cross-section contours and elevation angles of all obstructions are estimated from a digital surface model including both digital elevation model and the height of tree stands. All the parameters in a simplified, empirical model of the solar insolation reaching a given horizontal surface within the research valley are dependent on the sky view factor (SVF). The presented simplified, empirical model and its parameterisation scheme should be easily adaptable to different complex terrains or mountain valleys characterised by diverse geometry or spatial orientation. The model was developed and validated (R 2  = 0.92 , σ = 0.54) based on measurements taken at research sites located in the Silesian Beskid Mountain Range. A thorough understanding of the factors determining the amount of solar radiation reaching woodlands ought to considerably expand the knowledge of the water exchange balance within forest complexes as well as the estimation of site productivity.

Pediatric FAST and elevated liver transaminases: An effective screening tool in blunt abdominal trauma.

PubMed

Sola, Juan E; Cheung, Michael C; Yang, Relin; Koslow, Starr; Lanuti, Emma; Seaver, Chris; Neville, Holly L; Schulman, Carl I

2009-11-01

The current standard for the evaluation of children with blunt abdominal trauma (BAT) consists of physical examination, screening lab values, and computed tomography (CT) scan. We sought to determine if the focused assessment with sonography for trauma (FAST) combined with elevated liver transaminases (AST/ALT) could be used as a screening tool for intra-abdominal injury (IAI) in pediatric patients with BAT. Registry data at a level 1 trauma center was retrospectively reviewed from 1991-2007. Data collected on BAT patients under the age of 16 y included demographics, injury mechanism, ISS, GCS, imaging studies, serum ALT and AST levels, and disposition. AST and ALT were considered positive if either one was >100 IU/L. Overall, 3171 cases were identified. A total of 1008 (31.8%) patients received CT scan, 1148 (36.2%) had FAST, and 497 (15.7%) patients received both. Of the 497 patients, 400 (87.1%) also had AST and ALT measured. FAST was 50% sensitive, 91% specific, with a positive predictive value (PPV) of 68%, negative predictive value (NPV) of 83%, and accuracy of 80%. Combining FAST with elevated AST or ALT resulted in a statistically significant increase in all measures (sensitivity 88%, specificity 98%, PPV 94%, NPV 96%, accuracy 96%). FAST combined with AST or ALT > 100 IU/L is an effective screening tool for IAI in children following BAT. Pediatric patients with a negative FAST and liver transaminases < 100 IU/L should be observed rather than subjected to the radiation risk of CT.

A fast calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations

NASA Astrophysics Data System (ADS)

Fiorino, Steven T.; Elmore, Brannon; Schmidt, Jaclyn; Matchefts, Elizabeth; Burley, Jarred L.

2016-05-01

Properly accounting for multiple scattering effects can have important implications for remote sensing and possibly directed energy applications. For example, increasing path radiance can affect signal noise. This study describes the implementation of a fast-calculating two-stream-like multiple scattering algorithm that captures azimuthal and elevation variations into the Laser Environmental Effects Definition and Reference (LEEDR) atmospheric characterization and radiative transfer code. The multiple scattering algorithm fully solves for molecular, aerosol, cloud, and precipitation single-scatter layer effects with a Mie algorithm at every calculation point/layer rather than an interpolated value from a pre-calculated look-up-table. This top-down cumulative diffusivity method first considers the incident solar radiance contribution to a given layer accounting for solid angle and elevation, and it then measures the contribution of diffused energy from previous layers based on the transmission of the current level to produce a cumulative radiance that is reflected from a surface and measured at the aperture at the observer. Then a unique set of asymmetry and backscattering phase function parameter calculations are made which account for the radiance loss due to the molecular and aerosol constituent reflectivity within a level and allows for a more accurate characterization of diffuse layers that contribute to multiple scattered radiances in inhomogeneous atmospheres. The code logic is valid for spectral bands between 200 nm and radio wavelengths, and the accuracy is demonstrated by comparing the results from LEEDR to observed sky radiance data.

Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats

PubMed Central

Gultekin, Fatma Ayca; Bakkal, Bekir Hakan; Guven, Berrak; Tasdoven, Ilhan; Bektas, Sibel; Can, Murat; Comert, Mustafa

2013-01-01

Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-α levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity. PMID:22915786

Radiant heat loss, an unexploited path for heat stress reduction in shaded cattle.

PubMed

Berman, A; Horovitz, T

2012-06-01

Reducing thermal radiation on shaded animals reduces heat stress independently of other means of stress relief. Radiant heat exchange was estimated as a function of climate, shade structure, and animal density. Body surface portion exposed to radiant sources in shaded environments was determined by geometrical relations to determine angles of view of radiation sources (roof underside, sky, sun-exposed ground, shaded ground) on the animal's surface. The relative representation of environment radiation sources on the body surface was determined. Animal thermal radiation balance was derived from radiant heat gained from radiation sources (including surrounding animals) and that lost from the animal surface. The animal environment was assumed to have different shade dimensions and temperatures. These were summed to the radiant heat balance of the cow. The data formed served to estimate the effect of changes in intensity of radiation sources, roof and shaded surface dimensions, and animal density on radiant heat balance (Rbal) of cattle. Roof height effect was expressed by effect of roof temperature on Rbal. Roof underside temperature (35 to 75°C) effect on Rbal was reduced by roof height. If roof height were 4m, an increase in its underside temperature from 35 to 75°C would increase mean Rbal from -63 to -2 W·m⁻², whereas if roof height were 10 m, Rbal would only increase from -99 to -88 W·m⁻². A hot ground temperature increase from 35 to 65°C reduced mean Rbal heat loss from -45 to 3 W·m⁻². Increasing the surface of the shaded area had only a minor effect on Rbal and on the effect of hot ground on Rbal. Increasing shade roof height reduced the effect of roof temperature on Rbal to minor levels when height was > 8m. Increasing the roof height from 4 to 10 m decreased Rbal from -32 to -94 W·m⁻². Increasing indirect radiation from 100 to 500 W·m⁻² was associated with an increase in Rbal from -135 to +23 W·m⁻². Their combined effects were lower Rbal with increasing roof height and a reduction in rate of decrease with increasing level of indirect radiation. Roof height as an Rbal attenuator declined with increasing indirect radiation level. The latter factor might be reduced by lowering roof surface radiation absorption and through roof heat transfer, as well as by use of shade structure elements to reduce indirect radiation in the shaded area. Radiant heat from the cow body surface may be reduced by lower cow density. Radiant heat attenuation may thus further elevate animal productivity in warm climates, with no associated operation costs. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Minimal Internal Radiation Exposure in Residents Living South of the Fukushima Daiichi Nuclear Power Plant Disaster.

PubMed

Akiyama, Junichi; Kato, Shigeaki; Tsubokura, Masaharu; Mori, Jinichi; Tanimoto, Tetsuya; Abe, Koichiro; Sakai, Shuji; Hayano, Ryugo; Tokiwa, Michio; Shimmura, Hiroaki

2015-01-01

Following the Fukushima nuclear power plant disaster, assessment of internal radiation exposure was indispensable to predict radiation-related health threats to residents of neighboring areas. Although many evaluations of internal radiation in residents living north and west of the crippled Fukushima nuclear power plant are available, there is little information on residents living in areas south of the plant, which were similarly affected by radio-contamination from the disaster. To assess the internal radio-contamination in residents living in affected areas to the south of the plant or who were evacuated into Iwaki city, a whole body counter (WBC) screening program of internal radio-contamination was performed on visitors to the Jyoban hospital in Iwaki city, which experienced less contamination than southern areas adjacent to the nuclear plant. The study included 9,206 volunteer subjects, of whom 6,446 were schoolchildren aged 4-15 years. Measurements began one year after the incident and were carried out over the course of two years. Early in the screening period only two schoolchildren showed Cs-137 levels that were over the detection limit (250 Bq/body), although their Cs-134 levels were below the detection limit (220 Bq/body). Among the 2,760 adults tested, 35 (1.3%) had detectable internal radio-contamination, but only for Cs-137 (range: 250 Bq/body to 859 Bq/body), and not Cs-134. Of these 35 subjects, nearly all (34/35) showed elevated Cs-137 levels only during the first year of the screening. With the exception of potassium 40, no other radionuclides were detected during the screening period. The maximum annual effective dose calculated from the detected Cs-137 levels was 0.029 and 0.028 mSv/year for the schoolchildren and adults, respectively, which is far below the 1 mSv/year limit set by the government of Japan. Although the data for radiation exposure during the most critical first year after the incident are unavailable due to a lack of systemic measurements, the present results suggest that internal radio-contamination levels more than one year after the incident were minimal for residents living south of the crippled Fukushima nuclear plant, and that the annual additional effective doses derived from internal Cs contamination were negligible. Thus, internal radio-contamination of residents living in southern radio-contaminated areas appears to be generally well controlled.

Adaptation to high CO2 concentration in an optimal environment: radiation capture, canopy quantum yield and carbon use efficiency

NASA Technical Reports Server (NTRS)

Monje, O.; Bugbee, B.

1998-01-01

The effect of elevated [CO2] on wheat (Triticum aestivum L. Veery 10) productivity was examined by analysing radiation capture, canopy quantum yield, canopy carbon use efficiency, harvest index and daily C gain. Canopies were grown at either 330 or 1200 micromoles mol-1 [CO2] in controlled environments, where root and shoot C fluxes were monitored continuously from emergence to harvest. A rapidly circulating hydroponic solution supplied nutrients, water and root zone oxygen. At harvest, dry mass predicted from gas exchange data was 102.8 +/- 4.7% of the observed dry mass in six trials. Neither radiation capture efficiency nor carbon use efficiency were affected by elevated [CO2], but yield increased by 13% due to a sustained increase in canopy quantum yield. CO2 enrichment increased root mass, tiller number and seed mass. Harvest index and chlorophyll concentration were unchanged, but CO2 enrichment increased average life cycle net photosynthesis (13%, P < 0.05) and root respiration (24%, P < 0.05). These data indicate that plant communities adapt to CO2 enrichment through changes in C allocation. Elevated [CO2] increases sink strength in optimal environments, resulting in sustained increases in photosynthetic capacity, canopy quantum yield and daily C gain throughout the life cycle.

Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

PubMed Central

Pearson, William G.; Hindson, David F.; Langmore, Susan E.; Zumwalt, Ann C.

2012-01-01

Summary Elevation of the larynx is critical to swallowing function, an observation supported by the fact that radiation therapy-induced dysphagia is associated with reduced laryngeal elevation. We investigated muscles underlying hyolaryngeal elevation by using muscle functional MRI. We acquired scans from 11 healthy subjects to determine whole-muscle T2 signal profiles pre-swallowing, post-swallowing, and after performing swallowing exercises. Results demonstrate muscles essential to laryngeal elevation and exercises that target them. Purpose Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions Muscles of both the suprahyoid and the longitudinal pharyngeal muscle groups are active in swallowing, and both swallowing exercises effectively target muscles elevating the hyolaryngeal complex. mfMRI is useful in testing swallowing muscle function. PMID:22995662

Geometrical Model of Solar Radiation Pressure Based on High-Performing Galileo Clocks - First Geometrical Mapping of the Yarkowsky effect

NASA Astrophysics Data System (ADS)

Svehla, Drazen; Rothacher, Markus; Hugentobler, Urs; Steigenberger, Peter; Ziebart, Marek

2014-05-01

Solar radiation pressure is the main source of errors in the precise orbit determination of GNSS satellites. All deficiencies in the modeling of Solar radiation pressure map into estimated terrestrial reference frame parameters as well as into derived gravity field coefficients and altimetry results when LEO orbits are determined using GPS. Here we introduce a new approach to geometrically map radial orbit perturbations of GNSS satellites using highly-performing clocks on board the first Galileo satellites. Only a linear model (time bias and time drift) needs to be removed from the estimated clock parameters and the remaining clock residuals map all radial orbit perturbations along the orbit. With the independent SLR measurements, we show that a Galileo clock is stable enough to map radial orbit perturbations continuously along the orbit with a negative sign in comparison to SLR residuals. Agreement between the SLR residuals and the clock residuals is at the 1 cm RMS for an orbit arc of 24 h. Looking at the clock parameters determined along one orbit revolution over a period of one year, we show that the so-called SLR bias in Galileo and GPS orbits can be explained by the translation of the determined orbit in the orbital plane towards the Sun. This orbit translation is due to thermal re-radiation and not accounting for the Sun elevation in the parameterization of the estimated Solar radiation pressure parameters. SLR ranging to GNSS satellites takes place typically at night, e.g. between 6 pm and 6 am local time when the Sun is in opposition to the satellite. Therefore, SLR observes only one part of the GNSS orbit with a negative radial orbit error that is mapped as an artificial bias in SLR observables. The Galileo clocks clearly show orbit translation for all Sun elevations: the radial orbit error is positive when the Sun is in conjuction (orbit noon) and negative when the Sun is in opposition (orbit midnight). The magnitude of this artificial negative SLR bias depends on the orbit quality and should rather be called GNSS orbit bias instead of SLR bias. When LEO satellite orbits are estimated using GPS, this GPS orbit bias is mapped into the antenna phase center. All LEO satellites, such as CHAMP, GRACE and JASON-1/2, need an adjustment of the radial antenna phase center offset. GNSS orbit translations towards the Sun in the orbital plane do not only propagate into the estimated LEO orbits, but also into derived gravity field and altimetry products. Geometrical mapping of orbit perturbations using an on board GNSS clock is a new technique to monitor orbit perturbations along the orbit and was successfully applied in the modeling of Solar radiation pressure. We show that CODE Solar radiation pressure parameterization lacks dependency with the Sun's elevation, i.e. elongation angle (rotation of Solar arrays), especially at low Sun elevations (eclipses). Parameterisation with the Sun elongation angle is used in the so-called T30 model (ROCK-model) that includes thermal re-radiation. A preliminary version of Solar radiation pressure for the first five Galileo and the GPS-36 satellite is based on 2×180 days of the MGEX Campaign. We show that Galileo clocks map the Yarkowsky effect along the orbit, i.e. the lag between the Sun's illumination and thermal re-radiation. We present the first geometrical mapping of anisotropic thermal emission of absorbed sunlight of an illuminated satellite. In this way, the effects of Solar radiation pressure can be modelled with only two paramaters for all Sun elevations.

Illustrating harvest effects on site microclimate in a high-elevation forest stand.

Treesearch

W.B. Fowler; T.D. Anderson

1987-01-01

Three-dimensional contour surfaces were drawn for physiologically active radiation (PAR) and air and soil temperatures from measurements taken at a high-elevation site (1450 m) near the crest of the Cascade Range in central Washington. Measurements in a clearcut were compared with measurements from an adjacent uncut stand. Data for 31 days in July and August 1985...

Persistently Elevated Somatic Mutation as a Biomarker for Clinically Relevant Exposures in GWI

DTIC Science & Technology

2017-10-01

radiation and/or chemicals. However, since some, but not...microarray data in breast cancer and acute myelogenous leukemia, for this analysis. Figure 1. Expression of NER genes in 10 GWI patients (red...undergoing genotoxic radio- and/or chemotherapy and victims of radiation accidents and A-bomb survivors. Perhaps because the published

Numerical analysis of quantitative measurement of hydroxyl radical concentration using laser-induced fluorescence in flame

NASA Astrophysics Data System (ADS)

Shuang, Chen; Tie, Su; Yao-Bang, Zheng; Li, Chen; Ting-Xu, Liu; Ren-Bing, Li; Fu-Rong, Yang

2016-06-01

The aim of the present work is to quantitatively measure the hydroxyl radical concentration by using LIF (laser-induced fluorescence) in flame. The detailed physical models of spectral absorption lineshape broadening, collisional transition and quenching at elevated pressure are built. The fine energy level structure of the OH molecule is illustrated to understand the process with laser-induced fluorescence emission and others in the case without radiation, which include collisional quenching, rotational energy transfer (RET), and vibrational energy transfer (VET). Based on these, some numerical results are achieved by simulations in order to evaluate the fluorescence yield at elevated pressure. These results are useful for understanding the real physical processes in OH-LIF technique and finding a way to calibrate the signal for quantitative measurement of OH concentration in a practical combustor. Project supported by the National Natural Science Foundation of China (Grant No. 11272338) and the Fund from the Science and Technology on Scramjet Key Laboratory, China (Grant No. STSKFKT2013004).

The role of climatic and geological events in generating diversity in Ethiopian grass frogs (genus Ptychadena).

PubMed

Smith, Megan L; Noonan, Brice P; Colston, Timothy J

2017-08-01

Ethiopia is a world biodiversity hotspot and harbours levels of biotic endemism unmatched in the Horn of Africa, largely due to topographic-and thus habitat-complexity, which results from a very active geological and climatic history. Among Ethiopian vertebrate fauna, amphibians harbour the highest levels of endemism, making amphibians a compelling system for the exploration of the impacts of Ethiopia's complex abiotic history on biotic diversification. Grass frogs of the genus Ptychadena are notably diverse in Ethiopia, where they have undergone an evolutionary radiation. We used molecular data and expanded taxon sampling to test for cryptic diversity and to explore diversification patterns in both the highland radiation and two widespread lowland Ptychadena . Species delimitation results support the presence of nine highland species and four lowland species in our dataset, and divergence dating suggests that both geologic events and climatic fluctuations played a complex and confounded role in the diversification of Ptychadena in Ethiopia. We rectify the taxonomy of the endemic P. neumanni species complex, elevating one formally synonymized name and describing three novel taxa. Finally, we describe two novel lowland Ptychadena species that occur in Ethiopia and may be more broadly distributed.

Cancer mortality risk among military participants of a 1958 atmospheric nuclear weapons test.

PubMed Central

Watanabe, K K; Kang, H K; Dalager, N A

1995-01-01

OBJECTIVES. This study was undertaken to determine if Navy veterans who participated in an atmospheric nuclear test in 1958 were at increased risk of death from certain cancers. METHODS. Cancer mortality risk of 8554 Navy veterans who participated in an atmospheric nuclear test in the Pacific was compared with that of 14,625 Navy veterans who did not participate in any test. Radiation dosage information was obtained from film badges for 88% of the test participants. RESULTS. The median radiation dose for the test participants was 388 mrem (3.88 millisieverts [mSv]). Among participants who received the highest radiation dose (> 1000 mrem, or 10 mSv), an increased mortality risk for all causes (relative risk [RR] = 1.23; 95% confidence interval [CI] = 1.04, 1.45), all cancers (RR = 1.42; 95% CI = 1.03, 1.96), and liver cancer (RR = 6.42; 95% CI = 1.17, 35.3) was observed. The risk for cancer of the digestive organs was elevated among test participants (rate ratio = 1.47; 95% CI = 1.06, 2.04) but with no significant dose-response trend. Many of the cancers of a priori interest were not significantly elevated in the overall test participant group or in the group that received the highest radiation dose. CONCLUSIONS. Most of the cancers suspected of being radiogenic were not significantly elevated among the test participants. Nevertheless, increased risks for certain cancers cannot be ruled out at this time. Veterans who participated in the nuclear weapons tests should continue to be monitored. PMID:7702116

Spectral measurements of direct and scattered gamma radiation at a boiling-water reactor site

NASA Astrophysics Data System (ADS)

Block, R. C.; Preiss, I. L.; Ryan, R. M.; Vargo, G. J.

1990-12-01

Quantitative surveys of direct and scattered gamma radiation emitted from the steam-power conversion systems of a boiling-water reactor and other on-site radiation sources were made using a directionally shielded HPGe gamma spectrometry system. The purpose of this study was to obtain data on the relative contributions and energy distributions of direct and scattered gamma radiation in the site environs. The principal radionuclide of concern in this study is 16N produced by the 16O(n,p) 16N reaction in the reactor coolant. Due to changes in facility operation resulting from the implementation of hydrogen water chemistry (HWC), the amount of 16N transported from the reactor to the main steam system under full power operation is excepted to increase by a factor of 1.2 to 5.0. This increase in the 16N source term in the nuclear steam must be considered in the design of new facilities to be constructed on site as well as the evaluation of existing facilities with repect to ALARA (As Low As Reasonably Achievable) dose limits in unrestricted areas. This study consisted of base-line measurements taken under normal BWR chemistry conditions in October, 1987 and a corresponding set taken under HWC conditions in July, 1988. Ground-level and elevated measurements, corresponding to second-story building height, were obtained. The primary conclusion of this study is that direct radiation from the steam-power conversion system is the predominant source of radiation in the site environs of this reactor and that air scattering (i.e. skyshine) does not appear to be significant.

A Generalized Approach to Model the Spectra and Radiation Dose Rate of Solar Particle Events on the Surface of Mars

NASA Astrophysics Data System (ADS)

Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F.; McDole, Thoren; Kühl, Patrick; Appel, Jan C.; Matthiä, Daniel; Krauss, Johannes; Köhler, Jan

2018-01-01

For future human missions to Mars, it is important to study the surface radiation environment during extreme and elevated conditions. In the long term, it is mainly galactic cosmic rays (GCRs) modulated by solar activity that contribute to the radiation on the surface of Mars, but intense solar energetic particle (SEP) events may induce acute health effects. Such events may enhance the radiation level significantly and should be detected as immediately as possible to prevent severe damage to humans and equipment. However, the energetic particle environment on the Martian surface is significantly different from that in deep space due to the influence of the Martian atmosphere. Depending on the intensity and shape of the original solar particle spectra, as well as particle types, the surface spectra may induce entirely different radiation effects. In order to give immediate and accurate alerts while avoiding unnecessary ones, it is important to model and well understand the atmospheric effect on the incoming SEPs, including both protons and helium ions. In this paper, we have developed a generalized approach to quickly model the surface response of any given incoming proton/helium ion spectra and have applied it to a set of historical large solar events, thus providing insights into the possible variety of surface radiation environments that may be induced during SEP events. Based on the statistical study of more than 30 significant solar events, we have obtained an empirical model for estimating the surface dose rate directly from the intensities of a power-law SEP spectra.

Modeling photosynthetically active radiation in water of Tampa Bay, Florida, with emphasis on the geometry of incident irradiance

USGS Publications Warehouse

Miller, R.L.; McPherson, B.F.

1995-01-01

A model is developed that uses a simplified geometric description of incident direct solar beam and diffuse skylight. The model incorporates effects of solar elevation angle and cloudiness on the amount of in-air photosynthetically active radiation (PAR) that passes through the air-water interface and on K0 in waters of relatively low turbidity. The value of K0 was estimated to vary as much as 41% on a clear summer day due to changes in solar elevation angle. The model was used to make estimates of the depth to which sea-grasses might receive adequate light for survival for a range of values of K0. -from Authors

Did a Gamma-Ray Burst Initiate the Late Ordovician Mass Extinction?

NASA Technical Reports Server (NTRS)

Melott, A. L.; Lieberman, B. S.; Laird, C. M.; Martin, L. D.; Medvedov, M. V.; Thomas, B. C.; Cannizzo, J. K.; Gehrels, N.; Jackman, C. H.

2004-01-01

Gamma-ray bursts (hereafter GRB) produce a flux of radiation detectable across the observable Universe. A GRB within our own galaxy could do considerable damage to the Earth's biosphere; rate estimates suggest that a dangerously near GRB should occur on average several times per billion years. At leastfive times in the history of lfe, the Earth experienced mass extinctions that eliminated a large percentage of the biota. Many possible causes have been documented, and GRB may also have contributed. The late Ordovician mass extinction approximately 440 million years ago may be at least partly the result of a GRB. Due to severe depletion of the ozone layer, intense solar ultraviolet radiation is expected to result from a nearby GRB, and some of the patterns of extinction and survivorship at this time may be attributable to elevated levels of UV radiation reaching the Earth. In addition a GRB could trigger the global cooling which occurs at the end of the Ordovician period that follows an interval of relatively warm climate. Intense rapid cooling and glaciation at that time, previously identijied as the probable cause of this mass extinction, may have resultedfiom a GRB.

An ethanol extract derived from Bonnemaisonia hamifera scavenges ultraviolet B (UVB) radiation-induced reactive oxygen species and attenuates UVB-induced cell damage in human keratinocytes.

PubMed

Piao, Mei Jing; Hyun, Yu Jae; Cho, Suk Ju; Kang, Hee Kyoung; Yoo, Eun Sook; Koh, Young Sang; Lee, Nam Ho; Ko, Mi Hee; Hyun, Jin Won

2012-12-14

The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB)-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE) scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO₄ + H₂O₂), both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280-320 nm). These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.

Elevated mutation rates in the germ line of first- and second-generation offspring of irradiated male mice

PubMed Central

Barber, Ruth; Plumb, Mark A.; Boulton, Emma; Roux, Isabelle; Dubrova, Yuri E.

2002-01-01

Mutation rates at two expanded simple tandem repeat loci were studied in the germ line of first- and second-generation offspring of inbred male CBA/H, C57BL/6, and BALB/c mice exposed to either high linear energy transfer fission neutrons or low linear energy transfer x-rays. Paternal CBA/H exposure to either x-rays or fission neutrons resulted in increased mutation rates in the germ line of two subsequent generations. Comparable transgenerational effects were observed also in neutron-irradiated C57BL/6 and x-irradiated BALB/c mice. The levels of spontaneous mutation rates and radiation-induced transgenerational instability varied between strains (BALB/c>CBA/H>C57BL/6). Pre- and postmeiotic paternal exposure resulted in similar increases in mutation rate in the germ line of both generations of CBA/H mice, which together with our previous results suggests that radiation-induced expanded simple tandem repeat instability is manifested in diploid cells after fertilization. The remarkable finding that radiation-induced germ-line instability persists for at least two generations raises important issues of risk evaluation in humans. PMID:11997464

Effect of space relevant radiation exposure on differentiation and mineralization of murine osteoprogenitor cells

NASA Astrophysics Data System (ADS)

Lau, Patrick; Hu, Yueyuan; Hellweg, Christine; Baumstark-Khan, Christa; Reitz, Guenther

Extended exposure to altered gravity conditions like during long-term space flight results in significant bone loss. Exposure to ionizing radiation for cancer therapy causes bone damage and may increase the risk of fractures. Similarly, besides altered gravity conditions, astronauts on exploratory missions beyond low-Earth orbit will be exposed to high-energy heavy ions in addition to proton and photon radiation, although for prolonged periods and at lower doses and dose rates compared with therapy. Space conditions may place astronauts at a greater risk for mission-critical fractures. Until now, little is known about the effects of space radiation on the skeletal system especially on osteoprogenitor cells. Accelerator facilities are used to simulate parts of the radiation environment in space. Heavy ion accelerators therefore could be used to assess radiation risks for astronauts who will be exposed to higher radiation doses e.g. on a Mars mission. The aim of the present study was to determine the biological effects of spaceflight-relevant radiation exposure on the cellular level using murine osteoprogenitor cell lines compared to nonirradiated controls. To gain a deeper understanding of bone cell differenti-ation and mineralization after exposure to heavy ions, we examined gene expression modulation of bone specific transcription factors, osteoblast specific marker genes as well as genes function as coupling factors that link bone resorption to bone formation. We investigated the transcrip-tional modulation of type I collagen (Col I), osteocalcin (Ocn), Transforming growth factor-β1 (TGF-β1), interleukin-6 (IL-6) and the bone specific transcription factor Runx2 (Cbfa1). To gain deeper insight into potential cellular mechanisms involved in cellular response after ex-posure to heavy ions, we investigated gene expression modulations after exposure to energetic carbon ions (35 MeV/u, 73.2 keV/µm), iron ions (1000 MeV/u, 150 keV/µm) and lead ions (29 MeV/u, 9600 keV/µm) versus low LET X-rays. Exposure to X-irradiation dose-dependently increased the mRNA levels of Runx2 (cbfa1) whereas expression values of OCN and TGF-β1 were elevated at later time points. Exposure to heavy ions provoked a more marked effect on bone specific gene expression within the differentiation process. Collectively, our results indi-cate that heavy ions facilitate differentiation more effectively than X-rays as a major response in the progeny of irradiated osteoprogenitor cells. The data presented allow us to suggest that exposure to ionizing radiation interferes with bone formation at the level of cellular differenti-ation. In this regard, further experiments are needed to investigate gene expression patterns in mammalian cells that respond to differentiation after exposure to ionizing radiation.

Model of radiation transmittance by inorganic fouling on UV reactor lamp sleeves.

PubMed

Wait, Isaac W; Blatchley, Ernest R

2010-11-01

The efficacy of UV disinfection of water depends on the ability of radiation to pass from UV lamps through the quartz sleeves that encase them; the accumulation of metal-containing foulants on sleeve surfaces inhibits disinfection by absorbing radiation that would otherwise be available for inactivation. In a series of experiments, the composition and quantity of sleeve foulants were studied relative to water chemistry and sleeve transmittance. Findings indicate that iron and calcium dominate fouling, with elevated fouling activity by iron, aluminum, manganese, and zinc. A regression-based modeling approach was used to characterize and quantify the effects of foulant metals on UV absorbance. The molar extinction coefficient for iron was found to be more than 3 times greater than that of calcium. Iron's relatively high activity in fouling reactions, elevated capacity to absorb UV, and reduced solubility under oxidizing conditions makes it a fouling precursor of particular concern, with respect to potential for sleeve fouling in UV reactors.

Using ACIS on the Chandra X-ray Observatory as a Particle Radiation Monitor II

NASA Technical Reports Server (NTRS)

Grant, C. E.; Ford, P. G.; Bautz, M. W.; ODell, S. L.

2012-01-01

The Advanced CCD Imaging Spectrometer is an instrument on the Chandra X-ray Observatory. CCDs are vulnerable to radiation damage, particularly by soft protons in the radiation belts and solar storms. The Chandra team has implemented procedures to protect ACIS during high-radiation events including autonomous protection triggered by an on-board radiation monitor. Elevated temperatures have reduced the effectiveness of the on-board monitor. The ACIS team has developed an algorithm which uses data from the CCDs themselves to detect periods of high radiation and a flight software patch to apply this algorithm is currently active on-board the instrument. In this paper, we explore the ACIS response to particle radiation through comparisons to a number of external measures of the radiation environment. We hope to better understand the efficiency of the algorithm as a function of the flux and spectrum of the particles and the time-profile of the radiation event.

Quasi-analytical treatment of spatially averaged radiation transfer in complex terrain

NASA Astrophysics Data System (ADS)

LöWe, H.; Helbig, N.

2012-10-01

We provide a new quasi-analytical method to compute the subgrid topographic influences on the shortwave radiation fluxes and the effective albedo in complex terrain as required for large-scale meteorological, land surface, or climate models. We investigate radiative transfer in complex terrain via the radiosity equation on isotropic Gaussian random fields. Under controlled approximations we derive expressions for domain-averaged fluxes of direct, diffuse, and terrain radiation and the sky view factor. Domain-averaged quantities can be related to a type of level-crossing probability of the random field, which is approximated by long-standing results developed for acoustic scattering at ocean boundaries. This allows us to express all nonlocal horizon effects in terms of a local terrain parameter, namely, the mean-square slope. Emerging integrals are computed numerically, and fit formulas are given for practical purposes. As an implication of our approach, we provide an expression for the effective albedo of complex terrain in terms of the Sun elevation angle, mean-square slope, the area-averaged surface albedo, and the ratio of atmospheric direct beam to diffuse radiation. For demonstration we compute the decrease of the effective albedo relative to the area-averaged albedo in Switzerland for idealized snow-covered and clear-sky conditions at noon in winter. We find an average decrease of 5.8% and spatial patterns which originate from characteristics of the underlying relief. Limitations and possible generalizations of the method are discussed.

Acclimation to UV-B radiation and visible light in Lactuca sativa involves up-regulation of photosynthetic performance and orchestration of metabolome-wide responses.

PubMed

Wargent, J J; Nelson, B C W; McGhie, T K; Barnes, P W

2015-05-01

UV-B radiation is often viewed as a source of stress for higher plants. In particular, photosynthetic function has been described as a common target for UV-B impairment; yet as our understanding of UV-B photomorphogenesis increases, there are opportunities to expand the emerging paradigm of regulatory UV response. Lactuca sativa is an important dietary crop species and is often subjected to rapid sunlight exposure at field transfer. Acclimation to UV-B and visible light conditions in L. sativa was dissected using gas exchange and chlorophyll fluorescence measurements, in addition to non-destructive assessments of UV epidermal shielding (SUV ). After UV-B treatment, seedlings were subjected to wide-range metabolomic analysis using liquid chromatography hybrid quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS). During the acclimation period, net photosynthetic rate increased in UV-treated plants, epidermal UV shielding increased in both subsets of plants transferred to the acclimatory conditions (UV+/UV- plants) and Fv /Fm declined slightly in UV+/UV- plants. Metabolomic analysis revealed that a key group of secondary compounds was up-regulated by higher light conditions, yet several of these compounds were elevated further by UV-B radiation. In conclusion, acclimation to UV-B radiation involves co-protection from the effects of visible light, and responses to UV-B radiation at a photosynthetic level may not be consistently viewed as damaging to plant development. © 2014 John Wiley & Sons Ltd.

Cytogenetic analysis in 16-year follow-up study of a mother and fetus exposed in a radiation accident in Xinzhou, China.

PubMed

Liu, Qing-Jie; Lu, Xue; Zhao, Hua; Chen, Sen; Wang, Ming-Ming; Bai, Yushu; Zhang, Shu-Lan; Feng, Jiang-Bin; Zhang, Zhao-Hui; Chen, De-Qing; Ma, Li-Wen; Jia, Ting-Zhen; Liang, Li

2013-07-04

In November 1992, a radiation accident occurred in Xinzhou, due to the collection by a farmer of an unused (60)Co source; 37 individuals were exposed to ionizing radiation. Three individuals died and the farmer's 19-weeks-pregnant wife suffered acute radiation symptoms. Conventional chromosome analysis, cytokinesis-block micronuclei (CBMN) assay and fluorescence in situ hybridization (FISH) painting with three pairs of whole chromosome probes were used to analyze chromosomal aberrations for the pregnant female and her baby during the 16 years following the accident. The yields of dicentrics and rings (dic+r) continually declined between 41 days and 16 years after the accident. The frequency of binucleated MN also decreased over time for both mother and daughter. Sixteen years after exposure, the yields of dic+r and binucleated MN decreased to normal levels, but the reciprocal translocation frequencies remained elevated, for both mother and daughter. FISH results showed a decreasing yield of translocations with time. Based on the changes in maternal translocation frequency, the daughter's dose at the time of exposure was estimated as 1.82 (1.35-2.54)Gy. This was consistent with the clinical manifestations of severe mental retardation and low IQ score. FISH-based translocation analysis can be used for follow-up studies on accidental exposure and, after correction, for retrospective dose estimation for individuals prenatally exposed to radiation. Copyright © 2013 Elsevier B.V. All rights reserved.

Factors determining extreme brain natriuretic peptide elevation.

PubMed

Guglin, Maya; Hourani, Rayan; Pitta, Sridevi

2007-01-01

Brain natriuretic peptide (BNP) level is elevated in heart failure and reflects its severity. It is unknown why some patients have extremely high BNP levels. The authors retrospectively reviewed data on 179 consecutive patients whose BNP levels fell within one of several predetermined ranges: mild elevation, 500 to 1000 pg/mL (n=82); moderate elevation, 2000 to 3000 pg/mL (n=48); and high elevation, 4000 to 20,000 pg/mL (n=49). The statistical analysis was conducted with the unpaired t test and Pearson's correlation coefficient. Adjustments were made for age, sex, and serum creatinine level. Patients with moderate BNP elevation were more symptomatic and had more advanced structural and hemodynamic changes than did patients with lower BNP elevation. Characteristics of the high BNP level group did not differ from those of the moderate BNP level group. Serum creatinine level correlated with BNP level, but neither age nor sex did. High BNP level (4000-20,000 pg/mL) is determined more by renal dysfunction than by the severity of heart failure.

Factors driving mortality and growth at treeline: a 30-year experiment of 92 000 conifers.

PubMed

Barbeito, Ignacio; Dawes, Melissa A; Rixen, Christian; Senn, Josef; Bebi, Peter

2012-02-01

Understanding the interplay between environmental factors contributing to treeline formation and how these factors influence different life stages remains a major research challenge. We used an afforestation experiment including 92 000 trees to investigate the spatial and temporal dynamics of tree mortality and growth at treeline in the Swiss Alps. Seedlings of three high-elevation conifer species (Larix decidua, Pinus mugo ssp. uncinata, and Pinus cembra) were systematically planted along an altitudinal gradient at and above the current treeline (2075 to 2230 m above sea level [a.s.l.]) in 1975 and closely monitored during the following 30 years. We used decision-tree models and generalized additive models to identify patterns in mortality and growth along gradients in elevation, snow duration, wind speed, and solar radiation, and to quantify interactions between the different variables. For all three species, snowmelt date was always the most important environmental factor influencing mortality, and elevation was always the most important factor for growth over the entire period studied. Individuals of all species survived at the highest point of the afforestation for more than 30 years, although mortality was greater above 2160 m a.s.l., 50-100 m above the current treeline. Optimal conditions for height growth differed from those for survival in all three species: early snowmelt (ca. day of year 125-140 [where day 1 is 1 January]) yielded lowest mortality rates, but relatively later snowmelt (ca. day 145-150) yielded highest growth rates. Although snowmelt and elevation were important throughout all life stages of the trees, the importance of radiation decreased over time and that of wind speed increased. Our findings provide experimental evidence that tree survival and height growth require different environmental conditions and that even small changes in the duration of snow cover, in addition to changes in temperature, can strongly impact tree survival and growth patterns at treeline. Further, our results show that the relative importance of different environmental variables for tree seedlings changes during the juvenile phase as they grow taller.

Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in the Life Span Study cohort of atomic bomb survivors.

PubMed

Semmens, Erin O; Kopecky, Kenneth J; Grant, Eric; Mathes, Robert W; Nishi, Nobuo; Sugiyama, Hiromi; Moriwaki, Hiroko; Sakata, Ritsu; Soda, Midori; Kasagi, Fumiyoshi; Yamada, Michiko; Fujiwara, Saeko; Akahoshi, Masazumi; Davis, Scott; Kodama, Kazunori; Li, Christopher I

2013-01-01

We examined colon cancer risk in atomic bomb survivors to investigate whether excess body weight after the bombings alters sensitivity to radiation effects. Of the 56,064 Japanese atomic bomb survivors with follow-up through 2002 with self-reported anthropometric data obtained from periodic mail surveys, 1,142 were diagnosed with colon cancer. We evaluated the influence of body mass index (BMI) and height on radiation-associated colon cancer risk using Poisson regression. We observed a similar linear dose-response relationship for the 56,064 subjects included in our analysis and the entire cohort of Japanese atomic bomb survivors [excess relative risk (ERR) per Gray (Gy) = 0.53, 95 % confidence interval (CI) 0.25-0.86]. Elevation in earliest reported BMI, BMI reported closest to colon cancer diagnosis, and time-varying BMI were associated with an elevated risk of colon cancer [relative risk (RR) per 5 kg/m(2) increase in BMI = 1.14, 95 % CI 1.03-1.26; RR = 1.16, 95 % CI 1.05-1.27; and RR = 1.15, 95 % CI 1.04-1.27, respectively]. Height was not significantly related to colon cancer risk. Inclusion of anthropometric variables in models had little impact on radiation risk estimates, and there was no evidence that sensitivity to the effect of radiation on colon cancer risk depended on BMI. Radiation exposure and BMI are both risk factors for colon cancer. BMI at various times after exposure to the atomic bombings does not significantly influence the relationship between radiation dose and colon cancer risk, suggesting that BMI and radiation impact colon cancer risk independently of each other.

Trends of Training Courses Conducted in the Human Resources Development Center of the National Institute for Quantum and Radiological Science and Technology After the Fukushima Dai-Ichi Nuclear Power Plant Accident.

PubMed

Shimizu, Yuko; Iida, Haruzo; Nenoi, Mitsuru

2017-07-01

Environmental contamination with radioactive materials caused by the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident in 2011 raised a serious health concern among residents in Japan, and the demand for radiation experts who can handle the radiation-associated problems has increased. The Human Resources Development Center (HRDC) of the National Institute of for Quantum and Radiological Science and Technology in Japan has offered a variety of training programs covering a wide range of technologies associated with radiation since 1959. In this study, the time-course change in the number and age of the applicants for training programs regularly scheduled at HRDC were analyzed to characterize the demand after the NPP accident. The results suggested that the demand for the training of industrial radiation experts elevated sharply after the NPP accident followed by a prompt decrease, and that young people were likely stimulated to learn the basics of radiation. The demand for the training of medical radiation experts was kept high regardless of the NPP accident. The demand for the training of radiation emergency experts fluctuated apparently with three components: a terminating demand after the criticality accident that occurred in 1999, an urgent demand for handling of the NPP accident, and a sustained demand from local governments that undertook reinforcement of their nuclear disaster prevention program. The demand for the training of school students appeared to be increasing after the NPP accident. It could be foreseen that the demand for training programs targeting young people and medical radiation experts would be elevated in future.

Diversity and disparity through time in the adaptive radiation of Antarctic notothenioid fishes.

PubMed

Colombo, M; Damerau, M; Hanel, R; Salzburger, W; Matschiner, M

2015-02-01

According to theory, adaptive radiation is triggered by ecological opportunity that can arise through the colonization of new habitats, the extinction of antagonists or the origin of key innovations. In the course of an adaptive radiation, diversification and morphological evolution are expected to slow down after an initial phase of rapid adaptation to vacant ecological niches, followed by speciation. Such 'early bursts' of diversification are thought to occur because niche space becomes increasingly filled over time. The diversification of Antarctic notothenioid fishes into over 120 species has become one of the prime examples of adaptive radiation in the marine realm and has likely been triggered by an evolutionary key innovation in the form of the emergence of antifreeze glycoproteins. Here, we test, using a novel time-calibrated phylogeny of 49 species and five traits that characterize notothenioid body size and shape as well as buoyancy adaptations and habitat preferences, whether the notothenioid adaptive radiation is compatible with an early burst scenario. Extensive Bayesian model comparison shows that phylogenetic age estimates are highly dependent on model choice and that models with unlinked gene trees are generally better supported and result in younger age estimates. We find strong evidence for elevated diversification rates in Antarctic notothenioids compared to outgroups, yet no sign of rate heterogeneity in the course of the radiation, except that the notothenioid family Artedidraconidae appears to show secondarily elevated diversification rates. We further observe an early burst in trophic morphology, suggesting that the notothenioid radiation proceeds in stages similar to other prominent examples of adaptive radiation. © 2014 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

Association of CA 15-3 and CEA with clinicopathological parameters in patients with metastatic breast cancer.

PubMed

Geng, Biao; Liang, Man-Man; Ye, Xiao-Bing; Zhao, Wen-Ying

2015-01-01

The objective of this study was to investigate the association of serum cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) levels with clinicopathological parameters in patients diagnosed with metastatic breast cancer (MBC). We retrospectively evaluated the medical records of 284 patients diagnosed with MBC between January, 2007 and December, 2012 who fulfilled the specified criteria and the association between the levels of the two tumor marker and clinicopathological parameters was analyzed. Of the 284 patients, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were identified in 163 (57.4%) and 97 (34.2%) patients, respectively. Elevated CA 15-3 and CEA levels were significantly associated with breast cancer molecular subtypes (P<0.001 and P=0.032, respectively). Cases with luminal subtypes exhibited a higher percentage of elevated CA 15-3 and CEA levels compared to non-luminal subtypes. Elevated CA 15-3 level was correlated with bone metastasis (P=0.017). However, elevation of CEA was observed regardless of the site of metastasis. Elevation of CA 15-3 was significantly more common in MBC with multiple metastatic sites compared to MBC with a single metastasis (P=0.001). However, the incidence of elevated CEA levels did not differ between patients with a single and those with multiple metastatic sites. In conclusion, elevated CA 15-3 and CEA levels at initial diagnosis of recurrence were found to be associated with breast cancer molecular subtypes, whereas an elevated CA 15-3 level was significantly correlated with bone metastasis and an elevated CEA level was observed regardless of metastatic site. The proportion of MBC cases with elevated CA 15-3 levels differed according to the number of metastatic sites.

Thermoregulation of foraging honeybees on flowering plants: seasonal variability and influence of radiative heat gain

PubMed Central

Kovac, Helmut; Stabentheiner, Anton

2011-01-01

1. During nectar and pollen foraging in a temperate climate, honeybees are exposed to a broad range of ambient temperatures, challenging their thermoregulatory ability. The body temperature that the bees exhibit results from endothermic heat production, exogenous heat gain from solar radiation, and heat loss. In addition to profitability of foraging, season was suggested to have a considerable influence on thermoregulation. To assess the relative importance of these factors, the thermoregulatory behaviour of foragers on 33 flowering plants in dependence on season and environmental factors was investigated. 2. The bees (Apis mellifera carnica Pollman) were always endothermic. On average, the thorax surface temperature (Tth) was regulated at a high and rather constant level over a broad range of ambient temperatures (Tth = 33.7–35.7°C, Ta = 10–27°C). However, at a certain Ta, Tth showed a strong variation, depending on the plants from which the bees were foraging. At warmer conditions (Ta = 27–32°C) the Tth increased nearly linearly with Ta to a maximal average level of 42.6 °C. The thorax temperature excess decreased strongly with increasing Ta (Tth−Ta = 21.6 − 3.6°C). 3. The bees used the heat gain from solar radiation to elevate the temperature excess of thorax, head, and abdomen. Seasonal dependance was reflected in a 2.7 °C higher mean Tth in the spring than in the summer. An anova revealed that season had the greatest effect on Tth, followed by Ta and radiation. 4. It was presumed the foragers' motivational status to be the main factor responsible for the variation of Tth between seasons and different plants. PMID:22419834

Neurochemical Evidence of Potential Neurotoxicity After Prophylactic Cranial Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalm, Marie, E-mail: marie.kalm@neuro.gu.se; Abel, Edvard; Wasling, Pontus

2014-07-01

Purpose: To examine whether cerebrospinal fluid biomarkers for neuroaxonal damage, neuroglial activation, and amyloid β–related processes could characterize the neurochemical response to cranial radiation. Methods and Materials: Before prophylactic cranial irradiation (PCI) of patients with small cell lung cancer, each patient underwent magnetic resonance imaging of the brain, lumbar puncture, and Mini-Mental State Examination of cognitive function. These examinations were repeated at approximately 3 and 12 months after radiation. Results: The major findings were as follows. (1) Cerebrospinal fluid markers for neuronal and neuroglial injury were elevated during the subacute phase after PCI. Neurofilament and T-tau increased 120% and 50%, respectively, aftermore » PCI (P<.05). The same was seen for the neuroglial markers YKL-40 and glial fibrillary acidic protein, which increased 144% and 106%, respectively, after PCI (P<.05). (2) The levels of secreted amyloid precursor protein-α and -β were reduced 44% and 46%, respectively, 3 months after PCI, and the levels continued to decrease as long as 1 year after treatment (P<.05). (3) Mini-Mental State Examination did not reveal any cognitive decline, indicating that a more sensitive test should be used in future studies. Conclusion: In conclusion, we were able to detect radiation therapy–induced changes in several markers reflecting neuronal injury, inflammatory/astroglial activation, and altered amyloid precursor protein/amyloid β metabolism, despite the low number of patients and quite moderate radiation doses (20-30 Gy). These changes are hypothesis generating and could potentially be used to assess the individual risk of developing long-term symptoms of chronic encephalopathy after PCI. This has to be evaluated in large studies with extended clinical follow-up and more detailed neurocognitive assessments.« less

Cardioprotective effect of zingerone against oxidative stress, inflammation, and apoptosis induced by cisplatin or gamma radiation in rats.

PubMed

Soliman, Ahmed F; Anees, Lobna M; Ibrahim, Doaa M

2018-05-07

Despite their clinical benefits in cancer treatment, the deleterious effects on heart following chemo/radiotherapy are of increasing importance. Zingerone, a natural polyphenol, possesses multiple biological activities, such as antioxidant and anti-inflammatory. Thus, the current study was designed to assess the potential cardioprotective effects of zingerone against cisplatin or γ-radiation. Zingerone was given by intragastric intubation (25 mg/kg) daily for three successive weeks prior to the induction of cardiotoxicity using a single dose of cisplatin (20 mg/kg, i.p.) or a whole body γ-irradiation at a single dose of 6 Gy. Zingerone pre-treatment significantly reduced the abnormalities in heart histology and the increase in the cardiotoxicity indices, serum lactate dehydrogenase, and creatine kinase-MB activities, as well as plasma cardiac troponin T and B-natriuretic peptide, induced by cisplatin or γ-radiation. Further, zingerone, except for superoxide dismutase, notably ameliorated the state of oxidative stress as evidenced by a significant decrease in malondialdehyde level accompanied with a significant increase in the reduced glutathione content and catalase activity. Additionally, zingerone mitigated the increase in the inflammatory markers including serum level of tumor necrosis factor-alpha, cardiac myeloperoxidase activity, and cyclooxygenase-2 protein expression. Moreover, zingerone alleviated the elevation of caspase-3 gene expression and the prominent nuclear DNA fragmentation and attenuated the decrease in mitochondrial complexes' activities. This study sheds the light on a probable protective role of zingerone as an antioxidant, anti-inflammatory, and antiapoptotic agent against cisplatin- or γ-radiation-induced cardiotoxicity and holds a potential in regard to therapeutic intervention for chemo/radiotherapy mediated cardiac damage.

Summary of oceanographic and water-quality measurements in Rachel Carson National Wildlife Refuge, Wells, Maine, in 2013

USGS Publications Warehouse

Montgomery, Ellyn T.; Ganju, Neil K.; Dickhudt, Patrick J.; Borden, Jonathan; Martini, Marinna A.; Brosnahan, Sandra M.

2015-01-01

Suspended-sediment transport is a critical element controlling the geomorphology of tidal wetland complexes. Wetlands rely on organic material and inorganic sediment deposition to maintain their elevation relative to sea level. The U.S. Geological Survey performed observational deployments to measure suspended-sediment concentration and water flow rates in the tidal channels of the wetlands in the Rachel Carson National Wildlife Refuge in Wells, Maine. The objective was to characterize the sediment-transport mechanisms that contribute to the net sediment budget of the wetland complex. We deployed a meteorological tower, optical turbidity sensors, and acoustic velocity meters at sites on Stephens Brook and the Ogunquit River between March 27 and December 9, 2013. This report presents the time-series oceanographic and atmospheric data collected during those field studies. The oceanographic parameters include water velocity, depth, turbidity, salinity, temperature, and pH. The atmospheric parameters include wind direction, speed, and gust; air temperature; air pressure; relative humidity; short wave radiation; and photosynthetically active radiation.

Change in the immunophenotype of a somatotroph adenoma resulting in gigantism.

PubMed

Thawani, Jayesh P; Bailey, Robert L; Burns, Carrie M; Lee, John Y K

2014-01-01

Examining the pathologic progression of a pituitary adenoma from the point of a prepubescent child to an adult with gigantism affords us an opportunity to consider why patients may develop secretory or functioning tumors and raises questions about whether therapeutic interventions and surveillance strategies could be made to avoid irreversible phenotypic changes. A patient underwent a sublabial transsphenoidal resection for a clinically non-functioning macroadenoma in 1999. He underwent radiation treatment and was transiently given growth hormone (GH) supplementation as an adolescent. His growth rapidly traversed several percentiles and he was found to have elevated GH levels. The patient became symptomatic and was taken for a second neurosurgical procedure. Pathology and immunohistochemical staining demonstrated a significantly higher proportion of somatotroph cells and dense granularity; he was diagnosed with a functional somatotroph adenoma. While it is likely that the described observations reflect the manifestations of a functional somatotroph adenoma in development, it is possible that pubertal growth, GH supplementation, its removal, or radiation therapy contributed to the described endocrine and pathologic changes.

A 'crytic' microbial mat: A new model ecosystem for extant life on Mars

NASA Technical Reports Server (NTRS)

Rothschild, L. J.

1995-01-01

If life were present on Mars today, it would face potentially lethal environmental conditions such as a lack of water, frigid temperatures, ultraviolet radiation, and soil oxidants. In addition, the Viking missions did not detect near-surface organic carbon available for assimilation. Autotrophic organisms that lived under a protective layer of sand or gravel would be able to circumvent the ultraviolet radiation and lack of fixed carbon. Two terrestrial photosynthetic near-surface microbial communities have been identified, one in the inter- and supertidal of Laguna Ojo de Liebere (Baja California Sur, Mexico) and one in the acidic gravel near several small geysers in Yellowstone National Park (Wyoming, U.S.A.). Both communities have been studied with respect to their ability to fix carbon under different conditions, including elevated levels of inorganic carbon. Although these sand communities have not been exposed to the entire suite of Martian environmental conditions simultaneously, such communities can provide a useful model ecosystem for a potential extant Martian biota.

Superfund record of decision (EPA Region 5): Feed Materials Production Center, (USDOE), Operable Unit 4, Fernald, Hamilton County, OH, December 7, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This decision document presents the selected remedial action for Operable Unit 4 of the Fernald Site in Fernald, Ohio. The materials within Operable Unit 4 exhibit a wide range of properties. Most notable would be the elevated direct radiation associated with the K-65 residues versus the much lower direct radiation associated with cold metal oxides in Silo 3. Even more significant would be the much lower levels of contamination associated with the soils and building materials, like concrete, within the Operable Unit 4 Study Area. On the basis of the evaluation of final alternatives, the selected remedy addressing Operable Unitmore » 4 at the FEMP is a combination of Alternatives 3A.1/Vit - Removal, Vitrification, and Off-site Disposal - Nevada Test Site (NTS); 3B.1/Vit - Removal, Vitrification, and Off-site Disposal - NTS; and 2C - Demolition, Removal and On-Property Disposal.« less

Sensitivity of Downward Longwave Surface Radiation to Moisture and Cloud Changes in a High-elevation Region

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Chen, Yonghua; Rangwala, Imtiaz; Miller, James R.

2013-01-01

Several studies have suggested enhanced rates of warming in high-elevation regions since the latter half of the twentieth century. One of the potential reasons why enhanced rates of warming might occur at high elevations is the nonlinear relationship between downward longwave radiation (DLR) and specific humidity (q). Using ground-based observations at a high-elevation site in southwestern Colorado and coincident satellite-borne cloud retrievals, the sensitivity of DLR to changes in q and cloud properties is examined and quantified using a neural network method. It is also used to explore how the sensitivity of DLR to q (dDLR/dq) is affected by cloud properties. When binned by season, dDLR/dq is maximum in winter and minimum in summer for both clear and cloudy skies. However, the cloudy-sky sensitivities are smaller, primarily because (1) for both clear and cloudy skies dDLR/dq is proportional to 1/q, for q>0.5 g/kg, and (2) the seasonal values of q are on average larger in the cloudy-sky cases than in clear-sky cases. For a given value of q, dDLR/dq is slightly reduced in the presence of clouds and this reduction increases as q increases. In addition, DLR is found to be more sensitive to changes in cloud fraction when cloud fraction is large. In the limit of overcast skies, DLR sensitivity to optical thickness decreases as clouds become more opaque. These results are based on only one high-elevation site, so the conclusions here need to be tested at other high-elevation locations.

Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay.

PubMed

Seidel, Clemens; Lautenschläger, Christine; Dunst, Jürgen; Müller, Arndt-Christian

2012-04-20

To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III) and twice (IV) irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V) and mean variance (Mvar), mutual comparisons were done by one-way analysis of variance (ANOVA). Heterogeneity of initial DNA-damage (I, 0 min repair) increased without histones (II). Absence of histones was balanced by addition of antioxidants (III). Repair reduced heterogeneity of all samples (with and without irradiation). However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88). Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity.

Seasonal and long-term effects of CO2 and O3 on water loss in ponderosa pine and their interaction with climate and soil moisture.

PubMed

Lee, E Henry; Tingey, David T; Waschmann, Ronald S; Phillips, Donald L; Olszyk, David M; Johnson, Mark G; Hogsett, William E

2009-11-01

Evapotranspiration (ET) is driven by evaporative demand, available solar energy and soil moisture (SM) as well as by plant physiological activity which may be substantially affected by elevated CO2 and O3. A multi-year study was conducted in outdoor sunlit-controlled environment mesocosm containing ponderosa pine seedlings growing in a reconstructed soil-litter system. The study used a 2 x 2 factorial design with two concentrations of CO2 (ambient and elevated), two levels of O3 (low and high) and three replicates of each treatment. The objective of this study was to assess the effects of chronic exposure to elevated CO2 and O3, alone and in combination, on daily ET. This study evaluated three hypotheses: (i) because elevated CO2 stimulates stomatal closure, O3 effects on ET will be less under elevated CO2 than under ambient CO2; (ii) elevated CO2 will ameliorate the long-term effects of O3 on ET; and (iii) because conductance (g) decreases with decreasing SM, the impacts of elevated CO2 and O3, alone and in combination, on water loss via g will be greater in early summer when SM is not limiting than to other times of the year. A mixed-model covariance analysis was used to adjust the daily ET for seasonality and the effects of SM and photosynthetically active radiation when testing for the effects of CO2 and O3 on ET via the vapor pressure deficit gradient. The empirical results indicated that the interactive stresses of elevated CO2 and O3 resulted in a lesser reduction in ET via reduced canopy conductance than the sum of the individual effects of each gas. CO2-induced reductions in ET were more pronounced when trees were physiologically most active. O3-induced reductions in ET under ambient CO2 were likely transpirational changes via reduced conductance because needle area and root biomass were not affected by exposures to elevated O3 in this study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprawls, P

Purpose: To enhance the understanding of medical physics concepts and develop higher levels of learning relating to invisible physics phenomena such as radiation. To provide medical physics educators in all countries of the world with understanding of knowledge structures in the human brain, the different levels of learning, and the types of knowledge required for higher level functions such as problem solving, creative innovations, and applied clinical applications. To provide medical physics educators with an open access resource (tool) that they can use in their teaching activities to enrich and elevate the level of learning for their students, residents, etc.more » with respect to the invisible realm of medical physics. Methods: An experienced clinical medical physicist and educator has created and provided with open access three complementary web-based resources to achieve the purposes described above. One is a module focusing on the medical physics learning process with respect to mental knowledge structures, how they relate to outcomes and applications, and learning activities that are required to develop the required knowledge structures. The second is an extensive set of visuals that educators can use in their activities (classes, small group discussions, etc.) to visualize the invisible. The third is an interactive online simulation where learners can adjust factors and visually observe changes in x-radiation.These resources are available online at www.BLINDED FOR REVIEW . Results: Medical physics education, especially for non-physicists, is becoming much more interesting and useful especially with respect to invisible radiation. The global impact is that medical imaging professionals can be more effective in optimizing x-ray imaging procedures and risk management when they have knowledge levels that enhance problem solving, innovation, and creativity. Conclusion: Medical physics educators in all institutions can be much more effective and efficient in the sharing of their knowledge and experience when enhanced with high-quality visuals.« less

CNS germinoma with elevated serum human chorionic gonadotropin level: Clinical characteristics and treatment outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogino, Hiroyuki; Shibamoto, Yuta; Takanaka, Tsuyoshi

2005-07-01

Purpose: The prognostic significance of human chorionic gonadotropin (HCG) level in central nervous system germinoma remains controversial. The purpose of this study was to compare clinical characteristics and prognosis of germinoma patients with normal and high HCG titers in the serum. Methods and Materials: We undertook a multi-institutional retrospective analysis of 103 patients with central nervous system germinoma whose serum HCG and/or {beta}-HCG level had been measured before treatment between 1984 and 2002. All patients had been treated with radiation therapy either alone (n = 66) or in combination with chemotherapy (n = 37) with a median dose of 47.8more » Gy. Results: HCG and/or {beta}-HCG level in the serum was high in 39% of all patients. The proportion of HCG-producing tumors was higher in the lesions at the basal ganglia than in the lesions at the other sites. No correlation was found between tumor size and HCG level, but there seemed to be a weak correlation between size and {beta}-HCG. The 5- and 10-year survival rates were 96% and 94%, respectively, in both patient groups with normal and high HCG (p = 0.99). The 5- and 10-year relapse-free survival rates were 87% and 82%, respectively, in patients with normal HCG level and were both 87% in patients with high HCG (p = 0.74). Also, no other patient-, tumor-, or treatment-related factors seemed to influence the prognosis of the patients. Conclusion: Serum HCG level does not seem to influence patient prognosis when treated with sufficient doses of radiation. Relationship between tumor size and site and HCG level should be investigated further.« less

Distribution of boreal toad populations in relation to estimated UV-B dose in Glacier National Park, Montana, USA

USGS Publications Warehouse

Hossack, B.R.; Diamond, S.A.; Corn, P.S.

2006-01-01

A recent increase in ultraviolet B radiation is one hypothesis advanced to explain suspected or documented declines of the boreal toad (Bufo boreas Baird and Girard, 1852) across much of the western USA, where some experiments have shown ambient UV-B can reduce embryo survival. We examined B. boreas occupancy relative to daily UV-B dose at 172 potential breeding sites in Glacier National Park, Montana, to assess whether UV-B limits the distribution of toads. Dose estimates were based on ground-level UV-B data and the effects of elevation, local topographic and vegetative features, and attenuation in the water column. We also examined temporal trends in surface UV-B and spring snowpack to determine whether populations are likely to have experienced increased UV-B exposure in recent decades. We found no support for the hypothesis that UV-B limits the distribution of populations in the park, even when we analyzed high-elevation ponds separately. Instead, toads were more likely to breed in water bodies with higher estimated UV-B doses. The lack of a detectable trend in surface UV-B since 1979, combined with earlier snow melt in the region and increasing forest density at high elevations, suggests B. boreas embryos and larvae likely have not experienced increased UV-B.

Silencing of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase gene enhances glioma radiosensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sung Youl; Yoo, Young Hyun; Park, Jeen-Woo, E-mail: parkjw@knu.ac.kr

Highlights: •Silencing of the IDPm gene enhances IR-induced autophagy in glioma cells. •Autophagy inhibition augmented apoptosis of irradiated glioma cells. •Results offer a redox-active therapeutic strategy for the treatment of cancer. -- Abstract: Reactive oxygen species (ROS) levels are elevated in organisms that have been exposed to ionizing radiation and are protagonists in the induction of cell death. Recently, we demonstrated that the control of mitochondrial redox balance and the cellular defense against oxidative damage are primary functions of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDPm) via the supply of NADPH for antioxidant systems. In the present study, we report anmore » autophagic response to ionizing radiation in A172 glioma cells transfected with small interfering RNA (siRNA) targeting the IDPm gene. Autophagy in A172 transfectant cells was associated with enhanced autophagolysosome formation and GFP–LC3 punctuation/aggregation. Furthermore, we found that the inhibition of autophagy by chloroquine augmented apoptotic cell death of irradiated A172 cells transfected with IDPm siRNA. Taken together, our data suggest that autophagy functions as a survival mechanism in A172 cells against ionizing radiation-induced apoptosis and the sensitizing effect of IDPm siRNA and autophagy inhibitor on the ionizing radiation-induced apoptotic cell death of glioma cells offers a novel redox-active therapeutic strategy for the treatment of cancer.« less

A case-control study of leukemia at a naval nuclear shipyard.

PubMed

Stern, F B; Waxweiler, R A; Beaumont, J J; Lee, S T; Rinsky, R A; Zumwalde, R D; Halperin, W E; Bierbaum, P J; Landrigan, P J; Murray, W E

1986-06-01

A matched case-control study was conducted of 53 leukemia deaths and of 212 controls within a previously studied cohort of 24,545 on-shore workers employed between January 1, 1952 and August 15, 1977 at the Portsmouth (New Hampshire) Naval Shipyard. The study sought to ascertain a priori whether there was an association between leukemia deaths and occupational exposure to either ionizing radiation or organic solvents. To obtain information on individual exposures, radiation dose histories and detailed work histories by job and shop were evaluated for each subject. No statistically significant associations were found either between ionizing radiation or presumed solvent exposure and myelogenous or lymphatic leukemia. However, when specific job categories and shops were examined without benefit of a priori hypotheses, two occupations, electrician and welder, were found to be associated with leukemia. For electricians, the Mantel-Haenszel odds ratio (ORMH) was significantly elevated for all leukemias (ORMH = 3.00, 95% confidence interval (CI) = 1.29-6.98), particularly for lymphatic leukemia (ORMH = 6.00, 95% CI = 1.47-24.45). For welders, the odds ratio was not significantly elevated for all leukemias (ORMH = 2.25, 95% CI = 0.92-5.53), but was significantly elevated for myeloid leukemia (ORMH = 3.83, 95% CI = 1.28-11.46). These findings persisted when potential confounders were adjusted by means of a conditional logistic regression model.

Evaluation of the Protective Role of Vitamin C on the Metabolic and Enzymatic Activities of the Liver in the Male Rats After Exposure to 2.45 GHz Of Wi-Fi Routers.

PubMed

Shekoohi-Shooli, F; Mortazavi, S M J; Shojaei-Fard, M B; Nematollahi, S; Tayebi, M

2016-09-01

The use of devices emitted microwave radiation such as mobile phones, wireless fidelity (Wi-Fi) routers, etc. is increased rapidly. It has caused a great concern; the researchers should identify its effects on people's health. We evaluated the protective role of Vitamin C on the metabolic and enzymatic activities of the liver after exposure to Wi-Fi routers. 70 male Wistar rats weighing 200-250 g were randomly divided into 7 groups (10 rats in each group).The first stage one -day test: Group A (received vitamin C 250 mg/kg/day orally together with 8- hour/day Wi-Fi exposure).Group B (exposed to Wi-Fi radiation). Group C (received vitamin C). Group D or Control (was neither exposed to radiation of Wi-Fi modem nor did receive vitamin C). The second phase of experiment had done for five consecutive days. It involved Group E (received vitamin C), Group F (exposed to Wi-Fi radiation), Group G (received vitamin C together with Wi-Fi radiation). The distance between animals' restrainers was 20 cm away from the router antenna. Finally, blood samples were collected and assayed the level of hepatic enzymes including alkaline phosphatase(ALP), alanine amino transferase(ALT) aspartate amino transferase (ASL), gamma glutamyl transferase (GGT) and the concentration of Blood Glucose, Cholesterol , Triglyceride(TG),High density lipoprotein (HDL)and low density lipoprotein (LDL). Data obtained from the One day test showed an increase in concentration of blood glucose, decrease in Triglyceride level and GGT factor (P<0.05), however no observed significant difference on the Cholesterol , HDL , LDL level and hepatic enzymes activities in compare to control group. Groups of the five-day test showed reduction in the amount of blood glucose, elevation of cholesterol level and LDL relative to control group(P<0.05). WiFi exposure may exert alternations on the metabolic parameters and hepatic enzymes activities through stress oxidative and increasing of free radicals, but the use of vitamin C protects them from changing induced. Also taking optimum dose of vitamin C is essential for radioprotective effect and maintaining optimum health.

Evaluation of the Protective Role of Vitamin C on the Metabolic and Enzymatic Activities of the Liver in the Male Rats After Exposure to 2.45 GHz Of Wi-Fi Routers

PubMed Central

Shekoohi-Shooli, F.; Mortazavi, S.M.J.; Shojaei-fard, M.B.; Nematollahi, S.; Tayebi, M.

2016-01-01

Background: The use of devices emitted microwave radiation such as mobile phones, wireless fidelity (Wi-Fi) routers, etc. is increased rapidly. It has caused a great concern; the researchers should identify its effects on people’s health. We evaluated the protective role of Vitamin C on the metabolic and enzymatic activities of the liver after exposure to Wi-Fi routers. Material and Methods: 70 male Wistar rats weighing 200-250 g were randomly divided into 7 groups (10 rats in each group).The first stage one -day test: Group A (received vitamin C 250 mg/kg/day orally together with 8- hour/day Wi-Fi exposure).Group B (exposed to Wi-Fi radiation). Group C (received vitamin C). Group D or Control (was neither exposed to radiation of Wi-Fi modem nor did receive vitamin C). The second phase of experiment had done for five consecutive days. It involved Group E (received vitamin C), Group F (exposed to Wi-Fi radiation), Group G (received vitamin C together with Wi-Fi radiation). The distance between animals’ restrainers was 20 cm away from the router antenna. Finally, blood samples were collected and assayed the level of hepatic enzymes including alkaline phosphatase(ALP), alanine amino transferase(ALT) aspartate amino transferase (ASL), gamma glutamyl transferase (GGT) and the concentration of Blood Glucose, Cholesterol , Triglyceride(TG),High density lipoprotein (HDL)and low density lipoprotein (LDL). Results: Data obtained from the One day test showed an increase in concentration of blood glucose, decrease in Triglyceride level and GGT factor (P<0.05), however no observed significant difference on the Cholesterol , HDL , LDL level and hepatic enzymes activities in compare to control group. Groups of the five-day test showed reduction in the amount of blood glucose, elevation of cholesterol level and LDL relative to control group(P<0.05). Conclusion: WiFi exposure may exert alternations on the metabolic parameters and hepatic enzymes activities through stress oxidative and increasing of free radicals, but the use of vitamin C protects them from changing induced. Also taking optimum dose of vitamin C is essential for radioprotective effect and maintaining optimum health. PMID:27853723

CONTINUOUSLY SENSITIVE BUBBLE CHAMBER

DOEpatents

Good, R.H.

1959-08-18

A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

Host conservatism, geography, and elevation in the evolution of a Neotropical moth radiation.

PubMed

Jahner, Joshua P; Forister, Matthew L; Parchman, Thomas L; Smilanich, Angela M; Miller, James S; Wilson, Joseph S; Walla, Thomas R; Tepe, Eric J; Richards, Lora A; Quijano-Abril, Mario Alberto; Glassmire, Andrea E; Dyer, Lee A

2017-12-01

The origins of evolutionary radiations are often traced to the colonization of novel adaptive zones, including unoccupied habitats or unutilized resources. For herbivorous insects, the predominant mechanism of diversification is typically assumed to be a shift onto a novel lineage of host plants. However, other drivers of diversification are important in shaping evolutionary history, especially for groups residing in regions with complex geological histories. We evaluated the contributions of shifts in host plant clade, bioregion, and elevation to diversification in Eois (Lepidoptera: Geometridae), a hyper-diverse genus of moths found throughout the Neotropics. Relationships among 107 taxa were reconstructed using one mitochondrial and two nuclear genes. In addition, we used a genotyping-by-sequencing approach to generate 4641 SNPs for 137 taxa. Both datasets yielded similar phylogenetic histories, with relationships structured by host plant clade, bioregion, and elevation. While diversification of basal lineages often coincided with host clade shifts, more recent speciation events were more typically associated with shifts across bioregions or elevational gradients. Overall, patterns of diversification in Eois are consistent with the perspective that shifts across multiple adaptive zones synergistically drive diversification in hyper-diverse lineages. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Ionizing radiation stimulates expression of pro-osteoclastogenic genes in marrow and skeletal tissue

DOE PAGES

Alwood, Joshua S.; Shahnazari, Mohammad; Chicana, Betsabel; ...

2015-03-03

Exposure to ionizing radiation can cause rapid mineral loss and increase bone-resorbing osteoclasts within metabolically active, cancellous bone tissue leading to structural deficits. To better understand mechanisms involved in rapid, radiation-induced bone loss, we determined the influence of total body irradiation on expression of select cytokines known both to stimulate osteoclastogenesis and contribute to inflammatory bone disease. Adult (16 week), male C57BL/6J mice were exposed to either 2 Gy gamma rays ( 137Cs, 0.8 Gy/min) or heavy ions ( 56Fe, 600MeV, 0.50–1.1 Gy/min); this dose corresponds to either a single fraction of radiotherapy (typical total dose is ≥10 Gy) ormore » accumulates over long-duration interplanetary missions. Serum, marrow, and mineralized tissue were harvested 4 h—7 days later. Gamma irradiation caused a prompt (2.6-fold within 4 h) and persistent (peaking at 4.1-fold within 1 day) rise in the expression of the obligate osteoclastogenic cytokine, receptor activator of nuclear factor kappa-B ligand ( Rankl), within marrow cells over controls. Similarly, Rankl expression peaked in marrow cells within 3 days of iron exposure (9.2-fold). Changes in Rankl expression induced by gamma irradiation preceded and overlapped with a rise in expression of other pro-osteoclastic cytokines in marrow (eg, monocyte chemotactic protein-1 increased by 11.9-fold, and tumor necrosis factor-alpha increased by 1.7-fold over controls). The ratio, Rankl/ Opg, in marrow increased by 1.8-fold, a net pro-resorption balance. In the marrow, expression of the antioxidant transcription factor, Nfe2l2, strongly correlated with expression levels of Nfatc1, Csf1, Tnf, and Rankl. Radiation exposure increased a serum marker of bone resorption (tartrate-resistant acid phosphatase) and led to cancellous bone loss (16% decrement after 1 week). Finally, we conclude that total body irradiation (gamma or heavy-ion) caused temporal elevations in the concentrations of specific genes expressed within marrow and mineralized tissue related to bone resorption, including select cytokines that lead to osteoclastogenesis and elevated resorption; this is likely to account for rapid and progressive deterioration of cancellous microarchitecture following exposure to ionizing radiation.« less

Ionizing radiation stimulates expression of pro-osteoclastogenic genes in marrow and skeletal tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alwood, Joshua S.; Shahnazari, Mohammad; Chicana, Betsabel

Exposure to ionizing radiation can cause rapid mineral loss and increase bone-resorbing osteoclasts within metabolically active, cancellous bone tissue leading to structural deficits. To better understand mechanisms involved in rapid, radiation-induced bone loss, we determined the influence of total body irradiation on expression of select cytokines known both to stimulate osteoclastogenesis and contribute to inflammatory bone disease. Adult (16 week), male C57BL/6J mice were exposed to either 2 Gy gamma rays ( 137Cs, 0.8 Gy/min) or heavy ions ( 56Fe, 600MeV, 0.50–1.1 Gy/min); this dose corresponds to either a single fraction of radiotherapy (typical total dose is ≥10 Gy) ormore » accumulates over long-duration interplanetary missions. Serum, marrow, and mineralized tissue were harvested 4 h—7 days later. Gamma irradiation caused a prompt (2.6-fold within 4 h) and persistent (peaking at 4.1-fold within 1 day) rise in the expression of the obligate osteoclastogenic cytokine, receptor activator of nuclear factor kappa-B ligand ( Rankl), within marrow cells over controls. Similarly, Rankl expression peaked in marrow cells within 3 days of iron exposure (9.2-fold). Changes in Rankl expression induced by gamma irradiation preceded and overlapped with a rise in expression of other pro-osteoclastic cytokines in marrow (eg, monocyte chemotactic protein-1 increased by 11.9-fold, and tumor necrosis factor-alpha increased by 1.7-fold over controls). The ratio, Rankl/ Opg, in marrow increased by 1.8-fold, a net pro-resorption balance. In the marrow, expression of the antioxidant transcription factor, Nfe2l2, strongly correlated with expression levels of Nfatc1, Csf1, Tnf, and Rankl. Radiation exposure increased a serum marker of bone resorption (tartrate-resistant acid phosphatase) and led to cancellous bone loss (16% decrement after 1 week). Finally, we conclude that total body irradiation (gamma or heavy-ion) caused temporal elevations in the concentrations of specific genes expressed within marrow and mineralized tissue related to bone resorption, including select cytokines that lead to osteoclastogenesis and elevated resorption; this is likely to account for rapid and progressive deterioration of cancellous microarchitecture following exposure to ionizing radiation.« less

The Austrian UV monitoring network

NASA Astrophysics Data System (ADS)

Blumthaler, Mario; Klotz, Barbara; Schwarzmann, Michael; Schreder, Josef

2017-02-01

The Austrian UV Monitoring network is operational since 1998 providing a large data set of erythemally weighted UV irradiance recorded with broadband UV biometer at 12 stations distributed all over Austria. In order to obtain high quality data all biometer are recalibrated once a year, the detectors are checked regularly for humidity and quality control is done routinely. The collected data are processed and then published on the website http://www.uv-index.at where the UV-Index of all measurement sites is presented in near real time together with a map of the distribution of the UV-Index over Austria. These UV-Index data together with measurements of global radiation and ozone levels from OMI are used to study long term trends for the stations of the monitoring network. Neither for all weather conditions nor for clear sky conditions is a statistically significant trend found for the UV-Index (with one exception) and for ozone. Furthermore, the radiation amplification factor (RAF) is determined experimentally from the power law correlation between UV-Index and ozone level for the site Innsbruck (577 m above sea level, 47.26°N, 11.38°E) for 19°solar elevation. A value of 0.91 ± 0.05 is found for the RAF for clear sky days with low ground albedo and a value of 1.03 ± 0.08 for days with high ground albedo (snow cover).

Overview of the atmospheric ionizing radiation environment monitoring by Bulgarian build instruments

NASA Astrophysics Data System (ADS)

Dachev, Tsvetan; Tomov, Borislav; Matviichuk, Yury; Dimitrov, Plamen; Spurny, Frantisek; Ploc, Ondrej; Uchihori, Yukio; Flueckiger, Erwin; Kudela, Karel; Benton, Eric

2012-10-01

Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating risks for their health. Spacecraft and aircraft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and to secondary radiation produced in the atmosphere, the vehicle structure and its contents. The aircraft crew monitoring is required by the following recommendations of the International Commission on Radiological Protection (ICRP) (ICRP 1990), the European Union (EU) introduced a revised Basic Safety Standards Directive (EC 1997) which, inter alia, included the exposure to cosmic radiation. This approach has been also adopted in other official documents (NCRP 2002). In this overview we present the results of ground based, mountain peaks, aircraft, balloon and rocket radiation environment monitoring by means of a Si-diode energy deposition spectrometer Liulin type developed first in Bulgarian Academy of Sciences (BAS) for the purposes of the space radiation monitoring at MIR and International Space Station (ISS). These spectrometers-dosemeters are further developed, calibrated and used by scientific groups in different countries. Calibration procedures of them are performed at different accelerators including runs in the CERN high-energy reference field, simulating the radiation field at 10 km altitude in the atmosphere and with heavy ions in Chiba, Japan HIMAC accelerator were performed also. The long term aircraft data base were accumulated using specially developed battery operated instrument in 2001-2009 years onboard of A310-300 aircrafts of Czech Air Lines, during 24 about 2 months runs with more than 2000 flights and 13500 flight hours on routes over the Atlantic Ocean mainly. The obtained experimental data are compared with computational models like CARI and EPCARD. The mountain peak measurements are performed with Liulin-6S, Liulin-6MB and Liulin-6M internet based instruments. They use internet module to generate WEB page, which is posted online. The obtained deposited energy spectra, dose and flux data are transmitted via LAN interface by HTTP and FTP protocols. They work online for different periods between 2005 and 2011 at Jungfrau (3453 meters Above Mean Sea Level (AMSL) http://130.92.231.184/); at Lomnicky stit (2633 meters AMSL http://147.213.218.13/) and Moussala (2925 meters AMSL http://beo-db.inrne.bas.bg/moussala/) peaks in Switzerland, Slovakia and Bulgaria. 4 small size battery operated instruments were flown on balloon over south France in June 2000 and NASA balloon over New Mexico, USA on 11th of June 2005. 1 instrument was used in rocket experiment January 2008.

A GCM Study of Responses of the Atmospheric Water Cycle of West Africa and the Atlantic to Saharan Dust Radiative Forcing

NASA Technical Reports Server (NTRS)

Lau, K. M.; Kim, K. M.; Sud, Y. C.; Walker, G. K.

2009-01-01

The responses of the atmospheric water cycle and climate of West Africa and the Atlantic to radiative forcing of Saharan dust are studied using the NASA finite volume general circulation model (fvGCM), coupled to a mixed layer ocean. We find evidence of an "elevated heat pump" (EHP) mechanism that underlines the responses of the atmospheric water cycle to dust forcing as follow. During the boreal summerr, as a result of large-scale atmospheric feedback triggered by absorbing dust aerosols, rainfall and cloudiness are ehanIed over the West Africa/Eastern Atlantic ITCZ, and suppressed over the West Atlantic and Caribbean region. Shortwave radiation absorption by dust warms the atmosphere and cools the surface, while longwave has the opposite response. The elevated dust layer warms the air over West Africa and the eastern Atlantic. As the warm air rises, it spawns a large-scale onshore flow carrying the moist air from the eastern Atlantic and the Gulf of Guinea. The onshore flow in turn enhances the deep convection over West Africa land, and the eastern Atlantic. The condensation heating associated with the ensuing deep convection drives and maintains an anomalous large-scale east-west overturning circulation with rising motion over West Africa/eastern Atlantic, and sinking motion over the Caribbean region. The response also includes a strengthening of the West African monsoon, manifested in a northward shift of the West Africa precipitation over land, increased low-level westerlies flow over West Africa at the southern edge of the dust layer, and a near surface westerly jet underneath the dust layer overr the Sahara. The dust radiative forcing also leads to significant changes in surface energy fluxes, resulting in cooling of the West African land and the eastern Atlantic, and warming in the West Atlantic and Caribbean. The EHP effect is most effective for moderate to highly absorbing dusts, and becomes minimized for reflecting dust with single scattering albedo at0.95 or higher.

Sleep-enhancing effects of far-infrared radiation in rats

NASA Astrophysics Data System (ADS)

Honda, K.; Inoué, S.

1988-06-01

Unrestrained male rats continuously exposed to far-infrared radiation exhibited a significant increase in slow wave sleep (SWS) during the light period but not in the dark period. The change was largely due to the elevated occurrence of SWS episodes but not to the prolongation of their duration. Paradoxical sleep was not affected throughout the observation period except for a significant decrease at the end of the dark period. Thus the far-infrared radiation exerted a sleep modulatory effect closely related to the circadian activity-rest cycle.

Radiation with or without Antiandrogen Therapy in Recurrent Prostate Cancer

PubMed Central

Shipley, W.U.; Seiferheld, W.; Lukka, H.R.; Major, P.P.; Heney, N.M.; Grignon, D.J.; Sartor, O.; Patel, M.P.; Bahary, J.-P.; Zietman, A.L.; Pisansky, T.M.; Zeitzer, K.L.; Lawton, C.A.F.; Feng, F.Y.; Lovett, R.D.; Balogh, A.G.; Souhami, L.; Rosenthal, S.A.; Kerlin, K.J.; Dignam, J.J.; Pugh, S.L.; Sandler, H.M.

2017-01-01

BACKGROUND Salvage radiation therapy is often necessary in men who have undergone radical pros-tatectomy and have evidence of prostate-cancer recurrence signaled by a persistently or recurrently elevated prostate-specific antigen (PSA) level. Whether antiandrogen therapy with radiation therapy will further improve cancer control and prolong overall survival is unknown. METHODS In a double-blind, placebo-controlled trial conducted from 1998 through 2003, we assigned 760 eligible patients who had undergone prostatectomy with a lymphadenectomy and had disease, as assessed on pathological testing, with a tumor stage of T2 (confined to the prostate but with a positive surgical margin) or T3 (with histologic extension beyond the prostatic capsule), no nodal involvement, and a detectable PSA level of 0.2 to 4.0 ng per milliliter to undergo radiation therapy and receive either antiandrogen therapy (24 months of bicalutamide at a dose of 150 mg daily) or daily placebo tablets during and after radiation therapy. The primary end point was the rate of overall survival. RESULTS The median follow-up among the surviving patients was 13 years. The actuarial rate of overall survival at 12 years was 76.3% in the bicalutamide group, as compared with 71.3% in the placebo group (hazard ratio for death, 0.77; 95% confidence interval, 0.59 to 0.99; P=0.04). The 12-year incidence of death from prostate cancer, as assessed by means of central review, was 5.8% in the bicalutamide group, as compared with 13.4% in the placebo group (P<0.001). The cumulative incidence of metastatic prostate cancer at 12 years was 14.5% in the bicalutamide group, as compared with 23.0% in the placebo group (P=0.005). The incidence of late adverse events associated with radiation therapy was similar in the two groups. Gynecomastia was recorded in 69.7% of the patients in the bicalutamide group, as compared with 10.9% of those in the placebo group (P<0.001). CONCLUSIONS The addition of 24 months of antiandrogen therapy with daily bicalutamide to salvage radiation therapy resulted in significantly higher rates of long-term overall survival and lower incidences of metastatic prostate cancer and death from prostate cancer than radiation therapy plus placebo. (Funded by the National Cancer Institute and AstraZeneca; RTOG 9601 ClinicalTrials.gov number, NCT00002874.) PMID:28146658

International Radiation Monitoring and Information System (IRMIS)

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Sanjoy; Baciu, Florian; Stowisek, Jan; Saluja, Gurdeep; Kenny, Patrick; Albinet, Franck

2017-09-01

This article describes the International Radiation Monitoring Information System (IRMIS) which was developed by the International Atomic Energy Agency (IAEA) with the goal to provide Competent Authorities, the IAEA and other international organizations with a client server based web application to share and visualize large quantities of radiation monitoring data. The data maps the areas of potential impact that can assist countries to take appropriate protective actions in an emergency. Ever since the Chernobyl nuclear power plant accident in April of 19861 European Community (EC) has worked towards collecting routine environmental radiological monitoring data from national networked monitoring systems. European Radiological Data Exchange Platform (EURDEP) was created in 19952 to that end - to provide radiation monitoring data from most European countries reported in nearly real-time. During the response operations for the Fukushima Dai-ichi nuclear power plant accident (March 2011) the IAEA Incident and Emergency Centre (IEC) managed, harmonized and shared the large amount of data that was being generated from different organizations. This task underscored the need for a system which allows sharing large volumes of radiation monitoring data in an emergency. In 2014 EURDEP started the submission of the European radiological data to the International Radiation Monitoring Information System (IRMIS) as a European Regional HUB for IRMIS. IRMIS supports the implementation of the Convention on Early Notification of a Nuclear Accident by providing a web application for the reporting, sharing, visualizing and analysing of large quantities of environmental radiation monitoring data during nuclear or radiological emergencies. IRMIS is not an early warning system that automatically reports when there are significant deviations in radiation levels or when values are detected above certain levels. However, the configuration of the visualization features offered by IRMIS may help Member States to determine where elevated gamma dose rate measurements during a radiological or nuclear emergency indicate that actions to protect the public are necessary. The data can be used to assist emergency responders determine where and when to take necessary actions to protect the public. This new web online tool supports the IAEA's Unified System for Information Exchange in Incidents and Emergencies (USIE)3, an online tool where competent authorities can access information about all emergency situations, ranging from a lost radioactive source to a full-scale nuclear emergency.

Pre-Radiation Therapy Fluorine 18 Fluorodeoxyglucose PET Helps Identify Patients with Esophageal Cancer at High Risk for Radiation Pneumonitis.

PubMed

Castillo, Richard; Pham, Ngoc; Castillo, Edward; Aso-Gonzalez, Samantha; Ansari, Sobiya; Hobbs, Brian; Palacio, Diana; Skinner, Heath; Guerrero, Thomas M

2015-06-01

To examine the association between pre-radiation therapy (RT) fluorine 18 fluorodeoxyglucose (FDG) uptake and post-RT symptomatic radiation pneumonitis (RP). In accordance with the retrospective study protocol approved by the institutional review board, 228 esophageal cancer patients who underwent FDG PET/CT before chemotherapy and RT were examined. RP symptoms were evaluated by using the Common Terminology Criteria for Adverse Events, version 4.0, from the consensus of five clinicians. By using the cumulative distribution of standardized uptake values (SUVs) within the lungs, those values greater than 80%-95% of the total lung voxels were determined for each patient. The effect of pre-chemotherapy and RT FDG uptake, dose, and patient or treatment characteristics on RP toxicity was studied by using logistic regression. The study subjects were treated with three-dimensional conformal RT (n = 36), intensity-modulated RT (n = 135), or proton therapy (n = 57). Logistic regression analysis demonstrated elevated FDG uptake at pre-chemotherapy and RT was related to expression of RP symptoms. Study subjects with elevated 95% percentile of the SUV (SUV95) were more likely to develop symptomatic RP (P < .000012); each 0.1 unit increase in SUV95 was associated with a 1.36-fold increase in the odds of symptomatic RP. Receiver operating characteristic (ROC) curve analysis resulted in area under the ROC curve of 0.676 (95% confidence interval: 0.58, 0.77), sensitivity of 60%, and specificity of 71% at the 1.17 SUV95 threshold. CT imaging and dosimetric parameters were found to be poor predictors of RP symptoms. The SUV95, a biomarker of pretreatment pulmonary metabolic activity, was shown to be prognostic of symptomatic RP. Elevation in this pretreatment biomarker identifies patients at high risk for posttreatment symptomatic RP. RSNA, 2015

On the Angular Variation of Solar Reflectance of Snow

NASA Technical Reports Server (NTRS)

Chang, A. T. C.; Choudhury, B. J.

1979-01-01

Spectral and integrated solar reflectance of nonhomogeneous snowpacks were derived assuming surface reflection of direct radiation and subsurface multiple scattering. For surface reflection, a bidirectional reflectance distribution function derived for an isotropic Gaussian faceted surface was considered and for subsurface multiple scattering, an approximate solution of the radiative transfer equation was studied. Solar radiation incident on the snowpack was decomposed into direct and atmospherically scattered radiation. Spectral attenuation coefficients of ozone, carbon dioxide, water vapor, aerosol and molecular scattering were included in the calculation of incident solar radiation. Illustrative numerical results were given for a case of North American winter atmospheric conditions. The calculated dependence of spectrally integrated directional reflectance (or albedo) on solar elevation was in qualitative agreement with available observations.

Rattlesnake Mountain Observatory (46.4° N, 119.6° W) Multispectral Optical Depth Measurements: 1979-1994 (NDP-053)

DOE Data Explorer

Larson, Nels R. [Pacific Northwest Laboratory (PNNL), Richland, WA (USA); Michalsky, Joseph J. [Atmospheric Sciences Research Center, Albany, NY (USA); LeBaron, Brock A. [Utah Bureau of Air Quality, Salt Lake City, Utah (USA)

2012-01-01

Surface measurements of solar irradiance of the atmosphere were made by a multipurpose computer-controlled scanning photometer at the Rattlesnake Mountain Observatory in eastern Washington. The observatory is located at 46.4° N, 119.6° W at an elevation of 1088 m above mean sea level. The photometer measures the attenuation of direct solar radiation for different wavelengths using 12 filters. Five of these filters (i.e., at 428 nm, 486 nm, 535 nm, 785 nm, and 1010 nm, with respective half-power widths of 2, 2, 3, 18, and 28 nm) are suitable for monitoring variations in the total optical depth of the atmosphere.

The Correlation of Radon Concentration with Various Building Attributes at U.S. Air Force Bases

DTIC Science & Technology

1992-08-01

these daughter products that continue to decay giving off radiation which can then lead to the development of lung cancer . The United States Air Force...USAF) is concerned about the increased risk of developing lung cancer by persons exposed to elevated levels of radon in their domiciles and in their...CONOM 0 S * 0 0 a N&NO.)C Nowfum - a w em C mec0- C Mama - 00 4.4 .Q0 0 40 VO O 02ýCt > a MW 0 5 O 0 500 0 ’-ONM > Co S- -W N 00l 0 N 0 O--0 CPe go - Na Wm

A method to generate surface UV radiation maps over Europe using GOME, Meteosat, and ancillary geophysical data

NASA Astrophysics Data System (ADS)

Verdebout, Jean

2000-02-01

This paper presents a method for generating surface ultraviolet (UV) radiation maps over Europe, with a spatial resolution of 0.05°, and potentially on a half-hour basis. The UV irradiance is obtained by interpolation in a look-up table (LUT), the entries of which are solar zenith angle, total column ozone amount, cloud liquid water thickness, near-surface horizontal visibility, surface elevation, and UV albedo. Both satellite (Meteosat, GOME) and nonsatellite (synoptic observations, meteorological model results, digital elevation model) data are exploited to assign values to the influencing factors. With the help of another LUT simulating the visible signal, Meteosat data are processed to retrieve the cloud liquid water thickness. The radiative transfer calculations are performed with the UVspec code. A preliminary step consists in generating an effective surface Meteosat albedo map from a series of 10 consecutive days. In this process the well-known difficulty of distinguishing clouds from snow-covered surfaces is encountered. An attempt is made to partially resolve the ambiguity by using the Meteosat infrared channel and modeled snow cover data. After additional empirical cloud filtering, the effective albedo map is used as a baseline to estimate the cloud liquid water thickness. The UV surface albedo is assigned uniform values for land and sea/ocean, except in the presence of snow. In this case it is given a value proportional to the Meteosat effective albedo. The total column ozone is extracted from the level 3 GOME products. The aerosol optical thickness is mapped by gridding the daily measurements performed by ˜1000 ground stations. The digital elevation model is the GTOPO30 data set from the U.S. Geological Survey. European wide UV dose rate maps are presented for one day in April 1997, and the influence of the various factors is illustrated. A daily integrated dose map was also generated using 27 Meteosat acquisitions at half-hour intervals on the same day. The dose map produced in this way takes into account the evolution of the cloud field and is thought to be more accurate than if it were estimated from one data take, in particular at the relatively high spatial resolution of the product. Finally, a preliminary comparison of modeled dose rate and daily dose with measurements performed with a ground instrument is discussed.

TH-A-BRF-09: Integration of High-Resolution MRSI Into Glioblastoma Treatment Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreibmann, E; Cordova, J; Shu, H

2014-06-15

Purpose: Identification of a metabolite signature that shows significant tumor cell infiltration into normal brain in regions that do not appear abnormal on standard MRI scans would be extremely useful for radiation oncologists to choose optimal regions of brain to treat, and to quantify response beyond the MacDonald criteria. We report on integration of high-resolution magnetic resonance spectroscopic imaging (HR-MRSI) with radiation dose escalation treatment planning to define and target regions at high risk for recurrence. Methods: We propose to supplement standard MRI with a special technique performed on an MRI scanner to measure the metabolite levels within defined volumes.more » Metabolite imaging was acquired using an advanced MRSI technique combining 3D echo-planar spectroscopic imaging (EPSI) with parallel acquisition (GRAPPA) using a multichannel head coil that allows acquisition of whole brain metabolite maps with 108 μl resolution in 12 minutes implemented on a 3T MR scanner. Elevation in the ratio of two metabolites, choline (Cho, elevated in proliferating high-grade gliomas) and N-acetyl aspartate (NAA, a normal neuronal metabolite), was used to image infiltrating high-grade glioma cells in vivo. Results: The metabolite images were co-registered with standard contrast-enhanced T1-weighted MR images using in-house registration software and imported into the treatment-planning system. Regions with tumor infiltration are identified on the metabolic images and used to create adaptive IMRT plans that deliver a standard dose of 60 Gy to the standard target volume and an escalated dose of 75 Gy (or higher) to the most suspicious regions, identified as areas with elevated Cho/NAA ratio. Conclusion: We have implemented a state-of-the-art HR-MRSI technology that can generate metabolite maps of the entire brain in a clinically acceptable scan time, coupled with introduction of an imaging co-registration/ analysis program that combines MRSI data with standard imaging studies in a clinically useful fashion.« less

Development of an Assessment Method for Building Materials Under Euratom Scope.

PubMed

de With, Govert

2017-11-01

In 2013, the European Commission published its basic safety standards for protection against the dangers arising from exposure to ionizing radiation (Council Directive 2013/59/Euratom)-also known as EU-BSS. As a result, the use of raw materials with potentially elevated activity concentrations such as fly ash, phosphogypsum, and slags will now fall under EU-BSS scope when applied in building materials. In light of this new policy, a variety of tools are available to assess compliance with the 1-mSv y reference level for building materials. At the heart of these tools is a gamma-spectrometric determination of the naturally occurring radionuclides Ra, Th, and K in the material of concern. As a large number of construction products contain a certain amount of the raw material that falls under the scope of the EU regulation, this policy will lead to substantial measurement of building materials that pose little radiation risk. For this reason, a method is developed to enable assessment against the 1-mSv value not on the basis of gamma-spectrometric analysis but rather based on the product's material composition. The proposed method prescribes a maximum permitted content of raw materials with potentially elevated activity concentrations in terms of a weight percentage of the end product, where the raw materials of concern are defined as those listed in Annex XIII of the EU-BSS. The permitted content is a function of the product's surface density. Therefore, a product with a low surface density of up to 25 kg m can consist of nearly 100% raw materials with potentially elevated activity concentrations, and this percentage drops to around 15% for products with a surface density of around 500 kg m. Building materials that comply with these requirements on product composition are exempt from testing, while products that do not comply must perform regular gamma-spectrometric analysis. A full validation and testing of the method is provided. In addition, the paper discusses issues relevant for regulatory implementation.

Effects of elevated CO2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress*

PubMed Central

Jia, Yan; Tang, Shi-rong; Ju, Xue-hai; Shu, Li-na; Tu, Shu-xing; Feng, Ren-wei; Giusti, Lorenzino

2011-01-01

This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam. and Lolium perenne L. exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0, 4, and 16 mg/L) under hydroponic conditions. The results show that elevated levels of CO2 increased shoot biomass more, compared to root biomass, but decreased Cd concentrations in all plant tissues. Cd exposure caused toxicity to both Lolium species, as shown by the restrictions of the root morphological parameters including root length, surface area, volume, and tip numbers. These parameters were significantly higher under elevated levels of CO2 than under ambient CO2, especially for the number of fine roots. The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress, suggesting an ameliorated Cd stress under elevated levels of CO2. The total Cd uptake per pot, calculated on the basis of biomass, was significantly greater under elevated levels of CO2 than under ambient CO2. Ameliorated Cd toxicity, decreased Cd concentration, and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation. PMID:21462388

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumann, Brian C.; Bosch, Walter R.; Bahl, Amit

Purpose: To develop multi-institutional consensus clinical target volumes (CTVs) and organs at risk (OARs) for male and female bladder cancer patients undergoing adjuvant radiation therapy (RT) in clinical trials. Methods and Materials: We convened a multidisciplinary group of bladder cancer specialists from 15 centers and 5 countries. Six radiation oncologists and 7 urologists participated in the development of the initial contours. The group proposed initial language for the CTVs and OARs, and each radiation oncologist contoured them on computed tomography scans of a male and female cystectomy patient with input from ≥1 urologist. On the basis of the initial contouring, themore » group updated its CTV and OAR descriptions. The cystectomy bed, the area of greatest controversy, was contoured by another 6 radiation oncologists, and the cystectomy bed contouring language was again updated. To determine whether the revised language produced consistent contours, CTVs and OARs were redrawn by 6 additional radiation oncologists. We evaluated their contours for level of agreement using the Landis-Koch interpretation of the κ statistic. Results: The group proposed that patients at elevated risk for local-regional failure with negative margins should be treated to the pelvic nodes alone (internal/external iliac, distal common iliac, obturator, and presacral), whereas patients with positive margins should be treated to the pelvic nodes and cystectomy bed. Proposed OARs included the rectum, bowel space, bone marrow, and urinary diversion. Consensus language describing the CTVs and OARs was developed and externally validated. The revised instructions were found to produce consistent contours. Conclusions: Consensus descriptions of CTVs and OARs were successfully developed and can be used in clinical trials of adjuvant radiation therapy for bladder cancer.« less

Possible protective effect of the algae spirulina against nephrotoxicity induced by cyclosporine A and/or gamma radiation in rats.

PubMed

Aziz, Maha M; Eid, Nihad I; Nada, Ahmed S; Amin, Nour El-Din; Ain-Shoka, Afaf A

2018-03-01

The present study was conducted to evaluate the possible protective role of the algae spirulina (Sp) against nephrotoxicity and oxidative stress which are the main secondary effects induced by the immunosuppressant drug CSA and/or ionizing radiation. In this study, male rats were given Sp (1 g/kg) either for 15 days before irradiation (6.5 Gy) or 5 days before and 10 days concomitant with CSA (25 mg/kg). Markers used to assess renal injury included serum creatinine, urea, glucose, albumin, protein, and lipid profile as well as kidney content of reduced glutathione (GSH); lipid peroxidation (thiobarbituric acid reactive substances (TBARS)); nitrite and superoxide dismutase (SOD) activity. In addition, some trace elements (Zn and Mg) were estimated in kidney. Apoptosis was assessed by immunohistochemical estimation of caspase-3 expression in addition to histopathological examination. Results revealed that gamma radiation and/or CSA induced elevation in urea, creatinine, lipids, and glucose while decreasing albumin and protein levels. There was a noticeable increase in kidney content of GSH, TBARS, and nitrite. Meanwhile, profound decrease in kidney SOD activity was observed. Treatment with Sp significantly reversed the changes induced by CSA and/or gamma radiation in renal function tests. Spirulina also ameliorated kidney oxidative stress through decreasing GSH, TBARS, and nitrite kidney content while increasing SOD activity. Histopathological examination further confirmed Sp protective efficacy. Moreover, kidney caspase-3 expression that was triggered by CSA and/or gamma radiation was decreased. In conclusion, spirulina can be regarded as a promising renoprotective natural agent against renal injury induced by CSA and/or gamma radiation.

Targeting the cMET pathway augments radiation response without adverse effect on hearing in NF2 schwannoma models.

PubMed

Zhao, Yingchao; Liu, Pinan; Zhang, Na; Chen, Jie; Landegger, Lukas D; Wu, Limeng; Zhao, Fu; Zhao, Yanxia; Zhang, Yanling; Zhang, Jing; Fujita, Takeshi; Stemmer-Rachamimov, Anat; Ferraro, Gino B; Liu, Hao; Muzikansky, Alona; Plotkin, Scott R; Stankovic, Konstantina M; Jain, Rakesh K; Xu, Lei

2018-02-27

Neurofibromatosis type II (NF2) is a disease that needs new solutions. Vestibular schwannoma (VS) growth causes progressive hearing loss, and the standard treatment, including surgery and radiotherapy, can further damage the nerve. There is an urgent need to identify an adjunct therapy that, by enhancing the efficacy of radiation, can help lower the radiation dose and preserve hearing. The mechanisms underlying deafness in NF2 are still unclear. One of the major limitations in studying tumor-induced hearing loss is the lack of mouse models that allow hearing testing. Here, we developed a cerebellopontine angle (CPA) schwannoma model that faithfully recapitulates the tumor-induced hearing loss. Using this model, we discovered that cMET blockade by crizotinib (CRZ) enhanced schwannoma radiosensitivity by enhancing DNA damage, and CRZ treatment combined with low-dose radiation was as effective as high-dose radiation. CRZ treatment had no adverse effect on hearing; however, it did not affect tumor-induced hearing loss, presumably because cMET blockade did not change tumor hepatocyte growth factor (HGF) levels. This cMET gene knockdown study independently confirmed the role of the cMET pathway in mediating the effect of CRZ. Furthermore, we evaluated the translational potential of cMET blockade in human schwannomas. We found that human NF2-associated and sporadic VSs showed significantly elevated HGF expression and cMET activation compared with normal nerves, which correlated with tumor growth and cyst formation. Using organoid brain slice culture, cMET blockade inhibited the growth of patient-derived schwannomas. Our findings provide the rationale and necessary data for the clinical translation of combined cMET blockade with radiation therapy in patients with NF2.

Stomach Cancer Risk After Treatment for Hodgkin Lymphoma

PubMed Central

Morton, Lindsay M.; Dores, Graça M.; Curtis, Rochelle E.; Lynch, Charles F.; Stovall, Marilyn; Hall, Per; Gilbert, Ethel S.; Hodgson, David C.; Storm, Hans H.; Johannesen, Tom Børge; Smith, Susan A.; Weathers, Rita E.; Andersson, Michael; Fossa, Sophie D.; Hauptmann, Michael; Holowaty, Eric J.; Joensuu, Heikki; Kaijser, Magnus; Kleinerman, Ruth A.; Langmark, Frøydis; Pukkala, Eero; Vaalavirta, Leila; van den Belt-Dusebout, Alexandra W.; Fraumeni, Joseph F.; Travis, Lois B.; Aleman, Berthe M.; van Leeuwen, Flora E.

2013-01-01

Purpose Treatment-related stomach cancer is an important cause of morbidity and mortality among the growing number of Hodgkin lymphoma (HL) survivors, but risks associated with specific HL treatments are unclear. Patients and Methods We conducted an international case-control study of stomach cancer nested in a cohort of 19,882 HL survivors diagnosed from 1953 to 2003, including 89 cases and 190 matched controls. For each patient, we quantified cumulative doses of specific alkylating agents (AAs) and reconstructed radiation dose to the stomach tumor location. Results Stomach cancer risk increased with increasing radiation dose to the stomach (Ptrend < .001) and with increasing number of AA-containing chemotherapy cycles (Ptrend = .02). Patients who received both radiation to the stomach ≥ 25 Gy and high-dose procarbazine (≥ 5,600 mg/m2) had strikingly elevated stomach cancer risk (25 cases, two controls; odds ratio [OR], 77.5; 95% CI, 14.7 to 1452) compared with those who received radiation < 25 Gy and procarbazine < 5,600 mg/m2 (Pinteraction < .001). Risk was also elevated (OR, 2.8; 95% CI, 1.3 to 6.4) among patients who received radiation to the stomach ≥ 25 Gy but procarbazine < 5,600 mg/m2; however, no procarbazine-related risk was evident with radiation < 25 Gy. Treatment with dacarbazine also increased stomach cancer risk (12 cases, nine controls; OR, 8.8; 95% CI, 2.1 to 46.6), after adjustment for radiation and procarbazine doses. Conclusion Patients with HL who received subdiaphragmatic radiotherapy had dose-dependent increased risk of stomach cancer, with marked risks for patients who also received chemotherapy containing high-dose procarbazine. For current patients, risks and benefits of exposure to both procarbazine and subdiaphragmatic radiotherapy should be weighed carefully. For patients treated previously, GI symptoms should be evaluated promptly. PMID:23980092

Oxidative Stress and Autophagy Responses of Osteocytes Exposed to Spaceflight-like Radiation.

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Rael, Victoria E.; Globus, Ruth K.

2015-01-01

Weightlessness and radiation, two of the unique elements of the space environment, causes a profound decrement in bone mass that mimics aging. This bone loss is thought to result from increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. Our current understanding of the signaling factors and mechanisms underlying bone loss is incomplete. However, it is known that oxidative stress, characterized by the excess production of free radicals, is elevated during radiation exposure. The goals of this study is to examine the response of osteocytes to spaceflight-like radiation and to identify signaling processes that may be targeted to mitigate bone loss in scenarios of space exploration, earth-based radiotherapy and accidental radiation exposure. We hypothesize that (1) oxidative stress, as induced by radiation, decreases osteocyte survival and increases pro-osteoclastogenic signals and that (2) autophagy is one of the key cellular defenses against oxidative stress. Autophagy is the process by which cellular components including organelles and proteins are broken down and recycled. To test our hypothesis, we exposed the osteocyte-like cell line, MLO-Y4, to 0.5, 1, and 2 Gy of simulated space radiation (Iron-56 radiation at 600 MeV/n) and assessed cell numbers, cell growth-associated molecules as well as markers of autophagy and oxidative stress at various time points post-irradiation. We observed a reduction in cell numbers in the groups exposed to 1 and 2 Gy of Iron-56 radiation. Collectively, flow cytometry and gene expression analysis revealed that radiation caused a shift in cell cycle distribution consistent with growth arrest. Compared to sham-treatment, 2 Gy of Iron-56 increased FoxO3, SOD1, and RANKL gene expression yet unexpectedly decreased LC3B-II protein levels at 4 and 24 hours post-IR. Taken together, these findings suggest that simulated space radiation invoke antioxidant, pro-osteoclastogenic, and growth arrest responses in osteocytes. The implications of reduced autophagy flux at the time points examined remain to be elucidated.

Pathology effects at radiation doses below those causing increased mortality

NASA Technical Reports Server (NTRS)

Carnes, Bruce A.; Gavrilova, Natalia; Grahn, Douglas

2002-01-01

Mortality data from experiments conducted at the Argonne National Laboratory (ANL) on the long-term effects of external whole-body irradiation on B6CF(1) mice were used to investigate radiation-induced effects at intermediate doses of (60)Co gamma rays or fission-spectrum neutrons either delivered as a single exposure or protracted over 60 once-weekly exposures. Kaplan-Meier analyses were used to identify the lowest dose in the ANL data (within radiation quality, pattern of exposure, and sex) at which radiation-induced mortality caused by primary tumors could be detected (approximately 1-2 Gy for gamma rays and 10-15 cGy for neutrons). Doses at and below these levels were then examined for radiation-induced shifts in the spectrum of pathology detected at death. To do this, specific pathology events were pooled into larger assemblages based on whether they were cancer, cardiovascular disease or non-neoplastic diseases detected within the lungs and pleura, liver and biliary tract, reproductive organs, or urinary tract. Cancer and cardiovascular disease were further subdivided into categories based on whether they caused death, contributed to death, or were simply observed at death. Counts of how often events falling within each of these combined pathology categories occurred within a mouse were then used as predictor variables in logistic regression to determine whether irradiated mice could be distinguished from control mice. Increased pathology burdens were detected in irradiated mice at doses lower than those causing detectable shifts in mortality-22 cGy for gamma rays and 2 cGy for neutrons. These findings suggest that (1) models based on mortality data alone may underestimate radiation effects, (2) radiation may have adverse health consequences (i.e. elevated health risks) even when mortality risks are not detected, and (3) radiation-induced pathologies other than cancer do occur, and they involve multiple organ systems.

Turbulent Radiation Effects in HSCT Combustor Rich Zone

NASA Technical Reports Server (NTRS)

Hall, Robert J.; Vranos, Alexander; Yu, Weiduo

1998-01-01

A joint UTRC-University of Connecticut theoretical program was based on describing coupled soot formation and radiation in turbulent flows using stretched flamelet theory. This effort was involved with using the model jet fuel kinetics mechanism to predict soot growth in flamelets at elevated pressure, to incorporate an efficient model for turbulent thermal radiation into a discrete transfer radiation code, and to couple die soot growth, flowfield, and radiation algorithm. The soot calculations used a recently developed opposed jet code which couples the dynamical equations of size-class dependent particle growth with complex chemistry. Several of the tasks represent technical firsts; among these are the prediction of soot from a detailed jet fuel kinetics mechanism, the inclusion of pressure effects in the soot particle growth equations, and the inclusion of the efficient turbulent radiation algorithm in a combustor code.

Collimator of multiple plates with axially aligned identical random arrays of apertures

NASA Technical Reports Server (NTRS)

Hoover, R. B.; Underwood, J. H. (Inventor)

1973-01-01

A collimator is disclosed for examining the spatial location of distant sources of radiation and for imaging by projection, small, near sources of radiation. The collimator consists of a plurality of plates, all of which are pierced with an identical random array of apertures. The plates are mounted perpendicular to a common axis, with like apertures on consecutive plates axially aligned so as to form radiation channels parallel to the common axis. For near sources, the collimator is interposed between the source and a radiation detector and is translated perpendicular to the common axis so as to project radiation traveling parallel to the common axis incident to the detector. For far sources the collimator is scanned by rotating it in elevation and azimuth with a detector to determine the angular distribution of the radiation from the source.

Experiences of radiological examinations of buildings in Hungary.

PubMed

Homoki, Zsolt; Rell, Péter; Déri, Zsolt; Kocsy, Gábor

2017-05-01

Natural radioisotopes occur everywhere in the environment, being a source of exposure to the general population. Everyone is continuously exposed to terrestrial and cosmic radiations both indoors and outdoors, which are the main contributors to external exposure of individuals. There were made many ambient dose rate and indoor gamma radiation and radon concentration measurements in Hungarian by different laboratories. The main goal of the present work is the summarisation and evaluation of the latest results of the Laboratory of National Public Health Center National Research Directorate for Radiobiology and Radiohygiene. The reviewed examinations were made between 1995 and 2016. The average ambient dose rate was 103 ± 17 nSv/h and the average indoor gamma dose rate was 155 ± 47 nSv/h based on the data of 382 and 581 sampling points, respectively. The average indoor radon concentration was 108 Bq/m 3 with the median value of 75 Bq/m 3 based on the data of 415 sampling points. We performed an additional analysis of the results of 233 personal surveyed buildings where sophisticated gamma radiation and/or indoor radon concentration measurements were made. We were also interested in has got any affect the presence of slag to the radiation levels of the buildings? We found that usually elevated radiation can be detected in houses which contain slag compared to buildings without slag. In addition we conclude that the recommended minimum duration of short-term radon measurement shall be at least three days even if it does by closed conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microwave off-gas treatment apparatus and process

DOEpatents

Schulz, Rebecca L.; Clark, David E.; Wicks, George G.

2003-01-01

The invention discloses a microwave off-gas system in which microwave energy is used to treat gaseous waste. A treatment chamber is used to remediate off-gases from an emission source by passing the off-gases through a susceptor matrix, the matrix being exposed to microwave radiation. The microwave radiation and elevated temperatures within the combustion chamber provide for significant reductions in the qualitative and quantitative emissions of the gas waste stream.

Hyperthermia apparatus

DOEpatents

Larsen, Lawrence E.

2000-01-01

A hyperthermia apparatus, suitable for transurethral application, has an energy radiating element comprising a leaky-wave antenna. The leaky wave antenna radiation pattern is characterized by a surface wave which propagates along an aperture formed by openings (small in comparison to a wavelength) in the outer conductor of a transmission line. Appropriate design of the leaky wave antenna produces a uniform, broadside pattern of temperature elevation that uniformly heats all or part of the periurethral tissues.

Lead poisoning in United States-bound refugee children: Thailand-Burma border, 2009.

PubMed

Mitchell, Tarissa; Jentes, Emily; Ortega, Luis; Scalia Sucosky, Marissa; Jefferies, Taran; Bajcevic, Predrag; Parr, Valentina; Jones, Warren; Brown, Mary Jean; Painter, John

2012-02-01

Elevated blood lead levels lead to permanent neurocognitive sequelae in children. Resettled refugee children in the United States are considered at high risk for elevated blood lead levels, but the prevalence of and risk factors for elevated blood lead levels before resettlement have not been described. Blood samples from children aged 6 months to 14 years from refugee camps in Thailand were tested for lead and hemoglobin. Sixty-seven children with elevated blood lead levels (venous ≥10 µg/dL) or undetectable (capillary <3.3 µg/dL) blood lead levels participated in a case-control study. Of 642 children, 33 (5.1%) had elevated blood lead levels. Children aged <2 years had the highest prevalence (14.5%). Among children aged <2 years included in a case-control study, elevated blood lead levels risk factors included hemoglobin <10 g/dL, exposure to car batteries, and taking traditional medicines. The prevalence of elevated blood lead levels among tested US-bound Burmese refugee children was higher than the current US prevalence, and was especially high among children <2 years old. Refugee children may arrive in the United States with elevated blood lead levels. A population-specific understanding of preexisting lead exposures can enhance postarrival lead-poisoning prevention efforts, based on Centers for Disease Control and Prevention recommendations for resettled refugee children, and can lead to remediation efforts overseas.

Accuracy assessment of a net radiation and temperature index snowmelt model using ground observations of snow water equivalent in an alpine basin

NASA Astrophysics Data System (ADS)

Molotch, N. P.; Painter, T. H.; Bales, R. C.; Dozier, J.

2003-04-01

In this study, an accumulated net radiation / accumulated degree-day index snowmelt model was coupled with remotely sensed snow covered area (SCA) data to simulate snow cover depletion and reconstruct maximum snow water equivalent (SWE) in the 19.1-km2 Tokopah Basin of the Sierra Nevada, California. Simple net radiation snowmelt models are attractive for operational snowmelt runoff forecasts as they are computationally inexpensive and have low input requirements relative to physically based energy balance models. The objective of this research was to assess the accuracy of a simple net radiation snowmelt model in a topographically heterogeneous alpine environment. Previous applications of net radiation / temperature index snowmelt models have not been evaluated in alpine terrain with intensive field observations of SWE. Solar radiation data from two meteorological stations were distributed using the topographic radiation model TOPORAD. Relative humidity and temperature data were distributed based on the lapse rate calculated between three meteorological stations within the basin. Fractional SCA data from the Landsat Enhanced Thematic Mapper (5 acquisitions) and the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) (2 acquisitions) were used to derive daily SCA using a linear regression between acquisition dates. Grain size data from AVIRIS (4 acquisitions) were used to infer snow surface albedo and interpolated linearly with time to derive daily albedo values. Modeled daily snowmelt rates for each 30-m pixel were scaled by the SCA and integrated over the snowmelt season to obtain estimates of maximum SWE accumulation. Snow surveys consisting of an average of 335 depth measurements and 53 density measurements during April, May and June, 1997 were interpolated using a regression tree / co-krig model, with independent variables of average incoming solar radiation, elevation, slope and maximum upwind slope. The basin was clustered into 7 elevation / average-solar-radiation zones for SWE accuracy assessment. Model simulations did a poor job at estimating the spatial distribution of SWE. Basin clusters where the solar radiative flux dominated the melt flux were simulated more accurately than those dominated by the turbulent fluxes or the longwave radiative flux.

The Effect of Topography on the Exposure of Airless Bodies to Space Radiation: Phobos Case Study

NASA Astrophysics Data System (ADS)

Stubbs, T. J.; Wang, Y.; Guo, J.; Schwadron, N.; Cooper, J. F.; Wimmer-Schweingruber, R. F.; Spence, H. E.; Jordan, A.; Sturner, S. J.; Glenar, D. A.; Wilson, J. K.

2017-12-01

The surfaces of airless bodies, such as the Moon and Phobos (innermost Martian moon), are directly exposed to the surrounding space environment, including energetic particle radiation from both the ever-present flux of galactic cosmic rays (GCRs) and episodic bursts of solar energetic particles (SEPs). Characterizing this radiation exposure is critical to our understanding of the evolution of these bodies from space weathering processes, such as radiation damage of regolith, radiolysis of organics and volatiles, and dielectric breakdown. Similarly, this also has important implications for the long-term radiation exposure of future astronauts and equipment on the surface. In this study, the focus is the influence of Phobian topography on the direct exposure of Phobos to space radiation. For a given point on its surface, this exposure depends on: (i) the solid angle subtended by the sky, (ii) the solid angle of the sky blocked by Mars, and (iii) the energy and angular distributions of ambient energetic particle populations. The sky solid angle, determined using the elevation of the local horizon calculated from a digital elevation model (DEM), can be significantly reduced around topographic lows, such as crater floors, or increased near highs like crater rims. The DEM used in this study was produced using images from the Mars Express High Resolution Stereo Camera (HRSC), and has the highest available spatial resolution ( 100m). The proximity of Phobos to Mars means the Martian disk appears large in the Phobian sky, but this only effects the moon's near side due its tidally locked orbit. Only isotropic distributions of energetic particles are initially considered, which is typically a reasonable assumption for GCRs and sometimes for SEPs. Observations of the radiation environments on Mars by Curiosity's Radiation Assessment Detector (RAD), and the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) onboard the Lunar Reconnaissance Orbiter (LRO) at the Moon, will be used to estimate the average, annual radiation dose at the orbit of Phobos. These three elements will be combined to produce a map of radiation exposure on the surface of Phobos, which will be used to assess the implications for space weathering and future human exploration.

Radiological characterization survey of the former Diamond Magnesium Company Company site, 720 Fairport-Nursery Road, Painesville, Ohio (DMP001, DMP002)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foley, R.D.; Carrier, R.F.

1991-12-01

At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory performed an investigative radiological survey at the former Diamond Magnesium Company (DMC) site at 720 Fairport-Nursery Road, Painesville, Ohio, in September 1990. The purpose of the survey was to determine if the site is contaminated with radioactive residues as a result of federal government operation in the development of nuclear energy for defense-related projects. The survey of the site, separate parcels of which are currently owned by the Uniroyal Chemical Company (DMP001) and the Lonza Chemical Company (DMP002), included a gamma scan overmore » the ground surface, determination of gamma exposure rates at the surface and at 1 m above the surface at grid points, collection and radionuclide analysis of soil samples, and directly measured radiation levels inside three buildings used during original DMC processing. Results of the survey revealed widespread radiological contamination outdoors on the Uniroyal property and several isolated spots of elevated radiation levels on the Lonza property. The contaminants consisted of radium, uranium, and thorium in surface and subsurface soil in concentrations exceeding DOE guidelines for the release of property for unrestricted use.« less

Radiological characterization survey of the former Diamond Magnesium Company Company site, 720 Fairport-Nursery Road, Painesville, Ohio (DMP001, DMP002)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foley, R.D.; Carrier, R.F.

At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory performed an investigative radiological survey at the former Diamond Magnesium Company (DMC) site at 720 Fairport-Nursery Road, Painesville, Ohio, in September 1990. The purpose of the survey was to determine if the site is contaminated with radioactive residues as a result of federal government operation in the development of nuclear energy for defense-related projects. The survey of the site, separate parcels of which are currently owned by the Uniroyal Chemical Company (DMP001) and the Lonza Chemical Company (DMP002), included a gamma scan overmore » the ground surface, determination of gamma exposure rates at the surface and at 1 m above the surface at grid points, collection and radionuclide analysis of soil samples, and directly measured radiation levels inside three buildings used during original DMC processing. Results of the survey revealed widespread radiological contamination outdoors on the Uniroyal property and several isolated spots of elevated radiation levels on the Lonza property. The contaminants consisted of radium, uranium, and thorium in surface and subsurface soil in concentrations exceeding DOE guidelines for the release of property for unrestricted use.« less

Immortalisation of a human diploid fibroblast cell strain: a DT-diaphorase paradox.

PubMed Central

Kuehl, B. L.; Brezden, C. B.; Traver, R. D.; Siegel, D.; Ross, D.; Renzing, J.; Rauth, A. M.

1996-01-01

Transfection of a normal human diploid fibroblast cell strain, GM38, with a simian virus 40 (SV40) large T antigen containing plasmid, yielded an immortal cell line, G38-8X, which had a similar sensitivity as the parental cell strain to the quinone-containing chemotherapeutic agent mitomycin C (MMC), under both aerobic and hypoxic exposure conditions. The activity level of DT-diaphorase was similar in both the parental GM38 and G38-8X cells. Although DT-diaphorase could be detected by Western blot analysis, using two mouse anti-human monoclonal antibodies, in GM38 cells, it was not detected in the G38-8X cells. G38-8X cells have a slightly increased P450R activity (2-fold), and have elevated P-glycoprotein levels compared with the parental GM38 cell strain. The immortal G38-8X cell line is 2-fold more resistant to ionising radiation than the parental GM38 cell strain (D10 approximately 5 Gy). Although these SV40 large T antigen immortalised human diploid fibroblasts behaved similarly to their parental cell strain in terms of MMC sensitivity and DT-diaphorase activity, careful characterisation revealed that these cells had enhanced P-glycoprotein activity and had a decreased sensitivity to ionising radiation. Images Figure 3 PMID:8763839

Altitudinal variation of secondary metabolite profiles in flowering heads of Arnica montana cv. ARBO.

PubMed

Spitaler, Renate; Schlorhaufer, P Daniel; Ellmerer, Ernst P; Merfort, Irmgard; Bortenschlager, Sigmar; Stuppner, Hermann; Zidorn, Christian

2006-02-01

The altitudinal variation on the contents of secondary metabolites in flowering heads of Arnica montana was assessed. Plants of A. montana cultivar ARBO were grown in nine experimental plots at altitudes between 590 and 2230m at Mount Patscherkofel near Innsbruck/Austria. The total contents of sesquiterpene lactones and flavonoids were not positively correlated with the altitude of the growing site. However, the proportion of flavonoids with vicinal free hydroxy groups in ring B to flavonoids lacking this feature significantly increased with elevation. Additionally, the level of caffeic acid derivatives also positively correlated with the altitude of the growing site. In particular amounts of 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid significantly increased in higher sites and samples from the summit region contained 85% more of this compound than samples from valley sites. These results are discussed with regards to chemosystematic studies comparing samples collected in different altitudes as well as in the light of a UV-B protective and radical scavenging function of phenolics and their significance for plant life in environments with elevated UV-B radiation.

Outreach Plans for Storm Peak Laboratory

NASA Astrophysics Data System (ADS)

Hallar, A. G.; McCubbin, I. B.

2006-12-01

The Desert Research Institute (DRI) operates a high elevation facility, Storm Peak Laboratory (SPL), located on the west summit of Mt. Werner in the Park Range near Steamboat Springs, Colorado at an elevation 10,500 ft. SPL provides an ideal location for long-term research on the interactions of atmospheric aerosol and gas- phase chemistry with cloud and natural radiation environments. SPL includes an office-type laboratory room for computer and instrumentation setup with outside air ports and cable access to the roof deck, a full kitchen and two bunk rooms with sleeping space for nine persons. We plan to create a unique summer undergraduate education experiences for students of diversity at Storm Peak Laboratory. As stressed by the College Pathways to Science Education Standards [Siebert and McIntosh, 2001], to support changes in K-12 science education transformations must first be made at the college level, including inquiry-oriented opportunities to engage in meaningful research. These workshops will be designed to allow students to experience the excitement of science, increasing their likelihood of pursing careers within the fields of scientific education or research.

Elevated levels of CXC chemokine connective tissue activating peptide (CTAP)-III in lung cancer patients.

PubMed

Lee, Gina; Gardner, Brian K; Elashoff, David A; Purcell, Colleen M; Sandha, Harpavan S; Mao, Jenny T; Krysan, Kostyantyn; Lee, Jay M; Dubinett, Steven M

2011-05-15

Despite advances in treatments, lung cancer has been the leading cause of cancer-related deaths in the United States for the past several decades. Recent findings from the National Lung Screening Trial reveal that low-dose helical computed tomography (CT) scan screening of high-risk individuals reduces lung cancer mortality. This suggests that early detection is of key importance to improving patient outcome. However, of those screened with CT scans, 25% had positive scans that require further follow-up studies which often involve more radiation exposure and invasive tests to reduce false positive results. The purpose of this study was to identify candidate plasma biomarkers to aid in diagnosis of lung cancer in at-risk individuals. We found increased expression of the CXC chemokine connective tissue-activating peptide (CTAP)-III from plasma specimens of lung cancer patients compared to at-risk control subjects. Identification of the peptide was confirmed by the addition of an anti-NAP-2 antibody that recognizes CTAP-III and NAP-2. We also quantified and verified the increased levels of plasma CTAP-III with ELISA in patients with lung cancer (mean ± SD, 1859 ± 1219 ng/mL) compared to controls (698 ± 434 ng/mL; P<0.001). Our findings demonstrate elevated plasma levels of CTAP-III occur in lung cancer patients. Further studies are required to determine if this chemokine could be utilized in a blood-based biomarker panel for the diagnosis of lung cancer.

Elevated Serum PSA is Associated With Human Herpesvirus 8 Infection and Increased Circulating Cytokine Levels in Men From Tobago.

PubMed

Henning, Jill D; Karamchandani, Jaideep M; Bonachea, Luis A; Bunker, Clareann H; Patrick, Alan L; Jenkins, Frank J

2017-05-01

Serum-prostate specific antigen (PSA) levels have been used for many years as a biomarker for prostate cancer. This usage is under scrutiny due to the fact that elevated PSA levels can be caused by other conditions such as benign prostatic hyperplasia and infections of or injury to the prostate. As a result, the identification of specific pathogens capable of increasing serum levels of PSA is important. A potential candidate responsible for elevated PSA is human herpesvirus 8 (HHV-8). We have reported previously that HHV-8 is capable of infecting and establishing a latent infection in the prostate. In this current study we test the hypothesis that HHV-8 infection is associated with elevated PSA levels. Circulating cytokine levels between men with elevated PSA and controls are also compared. HHV-8 serostatus was determined among men with elevated serum PSA (≥4 ng/ml; n = 168, no prostate cancer on biopsy) and age-matched controls (PSA <4 ng/ml; n = 234), Circulating cytokine levels were determined among a subset of each group (116 with elevated PSA and 85 controls). Men with an elevated serum PSA were significantly more likely to be HHV-8 seropositive (42.9%) than the age-matched cancer-free men (22.2%; OR 2.51; 95%CI 1.48-4.29, P = 00001). Comparison of circulating cytokine levels between men with elevated serum PSA and controls indicated that elevated serum PSA is associated with a pro-inflammatory response with a mixed Th1/Th2 response while HHV-8 infection was associated with significantly higher levels of IL12p70, IL-10, and IL-13 indicating a Th2 immune response. We found a significant association between HHV-8 infection and increased levels of serum PSA. In an age of patient-centered medicine, men with an elevated serum PSA should be considered for HHV-8 serology testing to determine if HHV-8 is responsible for the elevated PSA. Prostate 77: 617-624, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Reactive oxygen species may play an essential role in driving biological evolution: The Cambrian Explosion as an example.

PubMed

Yang, Dong; Guo, Xuejun; Xie, Tian; Luo, Xiaoyan

2018-01-01

The Cambrian Explosion is one of the most significant events in the history of life; essentially all easily fossilizable animal body plans first evolved during this event. Although many theories have been proposed to explain this event, its cause remains unresolved. Here, we propose that the elevated level of oxygen, in combination with the increased mobility and food intake of metazoans, led to increased cellular levels of reactive oxygen species (ROS), which drove evolution by enhancing mutation rates and providing new regulatory mechanisms. Our hypothesis may provide a unified explanation for the Cambrian Explosion as it incorporates both environmental and developmental factors and is also consistent with ecological explanations for animal radiation. Future studies should focus on testing this hypothesis, and may lead to important insights into evolution. Copyright © 2017. Published by Elsevier B.V.

Roles of melatonin in abiotic stress resistance in plants.

PubMed

Zhang, Na; Sun, Qianqian; Zhang, Haijun; Cao, Yunyun; Weeda, Sarah; Ren, Shuxin; Guo, Yang-Dong

2015-02-01

In recent years melatonin has emerged as a research highlight in plant studies. Melatonin has different functions in many aspects of plant growth and development. The most frequently mentioned functions of melatonin are related to abiotic stresses such as drought, radiation, extreme temperature, and chemical stresses. This review mainly focuses on the regulatory effects of melatonin when plants face harsh environmental conditions. Evidence indicates that environmental stress can increase the level of endogenous melatonin in plants. Overexpression of the melatonin biosynthetic genes elevates melatonin levels in transgenic plants. The transgenic plants show enhanced tolerance to abiotic stresses. Exogenously applied melatonin can also improve the ability of plants to tolerate abiotic stresses. The mechanisms by which melatonin alleviates abiotic stresses are discussed. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Earth-atmosphere system and surface reflectivities in arid regions from LANDSAT multispectral scanner measurements

NASA Technical Reports Server (NTRS)

Otterman, J.; Fraser, R. S.

1976-01-01

Programs for computing atmospheric transmission and scattering solar radiation were used to compute the ratios of the Earth-atmosphere system (space) directional reflectivities in the vertical direction to the surface reflectivity, for the four bands of the LANDSAT multispectral scanner (MSS). These ratios are presented as graphs for two water vapor levels, as a function of the surface reflectivity, for various sun elevation angles. Space directional reflectivities in the vertical direction are reported for selected arid regions in Asia, Africa and Central America from the spectral radiance levels measured by the LANDSAT MSS. From these space reflectivities, surface vertical reflectivities were computed applying the pertinent graphs. These surface reflectivities were used to estimate the surface albedo for the entire solar spectrum. The estimated albedos are in the range 0.34-0.52, higher than the values reported by most previous researchers from space measurements, but are consistent with laboratory measurements.

Spectral karyotyping (SKY) analysis of heritable effects of radiation-induced malignant transformation

NASA Astrophysics Data System (ADS)

Zitzelsberger, Horst; Fung, Jingly; Janish, C.; McNamara, George; Bryant, P. E.; Riches, A. C.; Weier, Heinz-Ulli G.

1999-05-01

Radiocarcinogenesis is widely recognized as occupational, environmental and therapeutical hazard, but the underlying mechanisms and cellular targets have not yet been identified. We applied SKY to study chromosomal rearrangements leading to malignant transformation of irradiated thyroid epithelial cells. SKY is a recently developed technique to detect translocations involving non-homologous based on unique staining of all 24 human chromosomes by hybridization with a mixture of whole chromosome painting probes. A tuneable interferometer mounted on a fluorescence microscope in front of a CCD camera allows to record the 400 nm - 1000 nm fluorescence spectrum for each pixel in the image. After background correction, spectra recorded for each pixel are compared to reference spectra stored previously for each chromosome-specific probe. Thus, pixel spectra can be associated with specific chromosomes and displayed in 'classification' colors, which are defined so that even small translocations become readily discernible. SKY analysis was performed on several radiation-transformed cell lines. Line S48T was generated from a primary tumor of a child exposed to elevated levels of radiation following the Chernobyl nuclear accident. Subclones were generated from the human thyroid epithelial cell line (HTori-3) by exposure to gamma or alpha irradiation. SKY analysis revealed multiple translocations and, combined with G-banding, allowed the definition of targets for positional cloning of tumor related genes.

Site-Specific Phosphorylation of Ikaros Induced by Low-Dose Ionizing Radiation Regulates Cell Cycle Progression of B Lymphoblast Through CK2 and AKT Activation.

PubMed

Cho, Seong-Jun; Kang, Hana; Kim, Min Young; Lee, Jung Eun; Kim, Sung Jin; Nam, Seon Young; Kim, Ji Young; Kim, Hee Sun; Pyo, Suhkneung; Yang, Kwang Hee

2016-04-01

To determine how low-dose ionizing radiation (LDIR) regulates B lympho-proliferation and its molecular mechanism related with Ikaros, transcription factor. Splenocytes and IM-9 cells were uniformly irradiated with various doses of a (137)Cs γ-source, and cell proliferation was analyzed. To determine the LDIR-specific phosphorylation of Ikaros, immunoprecipitation and Western blot analysis were performed. To investigate the physiologic function of LDIR-mediatied Ikaros phosphorylation, Ikaros mutants at phosphorylation sites were generated, and cell cycle analysis was performed. First, we found that LDIR enhances B lymphoblast proliferation in an Ikaros-dependent manner. Moreover, we found that LDIR elevates the phosphorylation level of Ikaros protein. Interestingly, we showed that CK2 and AKT are involved in LDIR-induced Ikaros phosphorylation and capable of regulating DNA binding activity of Ikaros via specific phosphorylation. Finally, we identified LDIR-specific Ikaros phosphorylation sites at S391/S393 and showed that the Ikaros phosphorylations at these sites control Ikaros's ability to regulate G1/S cell cycle progression. Low-dose ionizing radiation specifically phosphorylates Ikaros protein at Ser 391/393 residues to regulate cell cycle progression in B lymphoblast. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of elevated temperatures during interruption of irradiation on Harwell Red 4034 PMMA and Kodak Biomax alanine film dosimetry systems

NASA Astrophysics Data System (ADS)

Sidereas, P.; Patil, D. S.; Garcia, R.; Tracy, R. P.; Holzman, J. M.

2007-11-01

In the industrial setting it is not uncommon for a process interruption to occur during irradiation. In this event, dosimeters may be exposed to prolonged periods of elevated temperature without exposure to ionizing radiation. Once the process is restarted, the same dosimeters are exposed to ionizing radiation in order to achieve target dose. The goal of this experiment was to simulate a process interruption within limits and quantify the effects of a combination of factors (heat, time, and fractionation) on dosimeter response. We present an in-depth experimental study on the response of dosimeters that have been irradiated, stored for a fixed period of time at several temperatures, and then re-irradiated. This study was performed using Harwell Red 4034 polymethylmethacrylate (PMMA) and Kodak BioMax alanine film dosimeters.

The effects of space radiation on a chemically modified graphite-epoxy composite material

NASA Technical Reports Server (NTRS)

Reed, S. M.; Herakovich, C. T.; Sykes, G. F.

1986-01-01

The effects of the space environment on the engineering properties and chemistry of a chemically modified T300/934 graphite-epoxy composite system are characterized. The material was subjected to 1.0 x 10 to the 10th power rads of 1.0 MeV electron irradiation under vacuum to simulate 30 years in geosynchronous earth orbit. Monotonic tension tests were performed at room temperature (75 F/24 C) and elevated temperature (250 F/121 C) on 4-ply unidirectional laminates. From these tests, inplane engineering and strength properties (E sub 1, E sub 2, Nu sub 12, G sub 12, X sub T, Y sub T) were determined. Cyclic tests were also performed to characterize energy dissipation changes due to irradiation and elevated temperature. Large diameter graphite fibers were tested to determine the effects of radiation on their stiffness and strength. No significant changes were observed. Dynamic-mechanical analysis demonstrated that the glass transition temperature was reduced by 50 F(28 C) after irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated material. The chemical modification of the epoxy did not aid in producing a material which was more radiation resistant than the standard T300/934 graphite-epoxy system. Irradiation was found to cause crosslinking and chain scission in the polymer. The latter produced low molecular weight products which plasticize the material at elevated temperatures and cause apparent material stiffening at low stresses at room temperature.

Additional Survival Benefit of Involved-Lesion Radiation Therapy After R-CHOP Chemotherapy in Limited Stage Diffuse Large B-Cell Lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, Jeanny; Kim, Il Han, E-mail: ihkim@snu.ac.kr; Cancer Research Institute, Seoul National University College of Medicine, Seoul

Purpose: The purpose of this study was to evaluate the role of involved-lesion radiation therapy (ILRT) after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy in limited stage diffuse large B-cell lymphoma (DLBCL) by comparing outcomes of R-CHOP therapy alone with R-CHOP followed by ILRT. Methods and Materials: We identified 198 patients treated with R-CHOP (median, 6 cycles) for pathologically confirmed DLBCL of limited stage from July 2004 to December 2012. Clinical characteristics of these patients were 33% with stage I and 66.7% with stage II; 79.8% were in the low or low-intermediate risk group; 13.6% had B symptoms; 29.8%more » had bulky tumors (≥7 cm); and 75.3% underwent ≥6 cycles of R-CHOP therapy. RT was given to 43 patients (21.7%) using ILRT technique, which included the prechemotherapy tumor volume with a median margin of 2 cm (median RT dose: 36 Gy). Results: After a median follow-up of 40 months, 3-year progression-free survival (PFS) and overall survival (OS) were 85.8% and 88.9%, respectively. Multivariate analysis showed ≥6 cycles of R-CHOP (PFS, P=.004; OS, P=.004) and ILRT (PFS, P=.021; OS, P=.014) were favorable prognosticators of PFS and OS. A bulky tumor (P=.027) and response to R-CHOP (P=.012) were also found to be independent factors of OS. In subgroup analysis, the effect of ILRT was prominent in patients with a bulky tumor (PFS, P=.014; OS, P=.030) or an elevated level of serum lactate dehydrogenase (LDH; PFS, P=.004; OS, P=.012). Conclusions: Our results suggest that ILRT after R-CHOP therapy improves PFS and OS in patients with limited stage DLBCL, especially in those with bulky disease or an elevated serum LDH level.« less

Flagellin preconditioning enhances the efficacy of mesenchymal stem cells in an irradiation-induced proctitis model.

PubMed

Linard, Christine; Strup-Perrot, Carine; Lacave-Lapalun, Jean-Victor; Benderitter, Marc

2016-09-01

The success of mesenchymal stem cell transplantation for proctitis depends not only on cell donors but also on host microenvironmental factors, which play a major role in conditioning mesenchymal stem cell immunosuppressive action and repair. This study sought to determine if flagellin, a TLR5 ligand, can enhance the mesenchymal stem cell treatment efficacy in radiation-induced proctitis. With the use of a colorectal model of 27 Gy irradiation in rats, we investigated and compared the effects on immune capacity and remodeling at 28 d after irradiation of the following: 1) systemic mesenchymal stem cell (5 × 10(6)) administration at d 7 after irradiation, 2) administration of flagellin at d 3 and systemic mesenchymal stem cell administration at d 7, and 3) in vitro preconditioning of mesenchymal stem cells with flagellin, 24 h before their administration on d 7. The mucosal CD8(+) T cell population was normalized after treatment with flagellin-preconditioned mesenchymal stem cells or flagellin plus mesenchymal stem cells, whereas mesenchymal stem cells alone did not alter the radiation-induced elevation of CD8(+) T cell frequency. Mesenchymal stem cell treatment returned the irradiation-elevated frequency of CD25(+) cells in the mucosa-to-control levels, whereas both flagellin-preconditioned mesenchymal stem cell and flagellin-plus-mesenchymal stem cell treatment each significantly increased not only CD25(+) cell frequency but also forkhead box p3 and IL-2Rα expression. Specifically, IL-10 was overexpressed after flagellin-preconditioned mesenchymal stem cell treatment. Analysis of collagen expression showed that the collagen type 1/collagen type 3 ratio, an indicator of wound-healing maturation, was low in the irradiated and mesenchymal stem cell-treated groups and returned to the normal level only after the flagellin-preconditioned mesenchymal stem cell treatment. This was associated with a reduction in myofibroblast accumulation. In a proctitis model, flagellin-preconditioned mesenchymal stem cells improved colonic immune capacity and enhanced tissue remodeling. © Society for Leukocyte Biology.

Do C-reactive protein level, white blood cell count, and pain location guide the selection of patients for computed tomography imaging in non-traumatic acute abdomen?

PubMed

Ozan, E; Atac, G K; Evrin, T; Alisar, K; Sonmez, L O; Alhan, A

2017-02-01

The value of abdominal computed tomography in non-traumatic abdominal pain has been well established. On the other hand, to manage computed tomography, appropriateness has become more of an issue as a result of the concomitant increase in patient radiation exposure with increased computed tomography use. The purpose of this study was to investigate whether C-reactive protein, white blood cell count, and pain location may guide the selection of patients for computed tomography in non-traumatic acute abdomen. Patients presenting with acute abdomen to the emergency department over a 12-month period and who subsequently underwent computed tomography were retrospectively reviewed. Those with serum C-reactive protein and white blood cell count measured on admission or within 24 h of the computed tomography were selected. Computed tomography examinations were retrospectively reviewed, and final diagnoses were designated either positive or negative for pathology relating to presentation with acute abdomen. White blood cell counts, C-reactive protein levels, and pain locations were analyzed to determine whether they increased or decreased the likelihood of producing a diagnostic computed tomography. The likelihood ratio for computed tomography positivity with a C-reactive protein level above 5 mg/L was 1.71, while this increased to 7.71 in patients with combined elevated C-reactive protein level and white blood cell count and right lower quadrant pain. Combined elevated C-reactive protein level and white blood cell count in patients with right lower quadrant pain may represent a potential factor that could guide the decision to perform computed tomography in non-traumatic acute abdomen.

Effect of estradiol and hydrocortisone on the process of peroxidation of mitochondrial membrane lipids in irradiated rat liver. [/sup 60/Co. gamma. rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saksonov, N.P.

Experiments were conducted on male, mongrel albino rats. They were exposed to /sup 60/Co ..gamma.. radiation once, in a dosage of 600 R. Estradiol and hydrocortisone were given intraperitoneally at the rate of 1 mg/kg, 2 h before irradiation or 2, 24 and 72 h after exposure. The animals were sacrificed 5 days after irradiation. These studies established that single exposure of animals to radiation in a dosage of 600 R leads to activation of processes of peroxidation of membrane lipids of the hepatic mitochondria. When estradiol is given 2 and 4 days before sacrificing, one observes acceleration of processesmore » of peroxidation of lipids without reliable change in malonic dialdehyde content. Administration of estrogen 5 days prior to sacrificing leads to a drop of malonic dialdehyde level, which is indicative of attenuation of the process of lipid peroxidation. Administration of hydrocortisone is associated with elevation of the latency period and level of peroxidation after 5 days, as compared to intact animals. Injection of this hormone 2 days before sacrificing the animals leads to attenuation and decrease in rate of peroxidation. The obtained data indicate that there are different mechanisms involved in the inhibitory effects of estradiol and hydrocortisone on peroxidation of lipids of mitochondrial membranes of the rat liver, activated by irradiation. Thus, it may be assumed that steroid hormones are actively involved in regulation of lipid peroxidation when mammals are exposed to radiation. (ERB)« less

Factors influencing heterogeneity of radiation-induced DNA-damage measured by the alkaline comet assay

PubMed Central

2012-01-01

Background To investigate whether different conditions of DNA structure and radiation treatment could modify heterogeneity of response. Additionally to study variance as a potential parameter of heterogeneity for radiosensitivity testing. Methods Two-hundred leukocytes per sample of healthy donors were split into four groups. I: Intact chromatin structure; II: Nucleoids of histone-depleted DNA; III: Nucleoids of histone-depleted DNA with 90 mM DMSO as antioxidant. Response to single (I-III) and twice (IV) irradiation with 4 Gy and repair kinetics were evaluated using %Tail-DNA. Heterogeneity of DNA damage was determined by calculation of variance of DNA-damage (V) and mean variance (Mvar), mutual comparisons were done by one-way analysis of variance (ANOVA). Results Heterogeneity of initial DNA-damage (I, 0 min repair) increased without histones (II). Absence of histones was balanced by addition of antioxidants (III). Repair reduced heterogeneity of all samples (with and without irradiation). However double irradiation plus repair led to a higher level of heterogeneity distinguishable from single irradiation and repair in intact cells. Increase of mean DNA damage was associated with a similarly elevated variance of DNA damage (r = +0.88). Conclusions Heterogeneity of DNA-damage can be modified by histone level, antioxidant concentration, repair and radiation dose and was positively correlated with DNA damage. Experimental conditions might be optimized by reducing scatter of comet assay data by repair and antioxidants, potentially allowing better discrimination of small differences. Amount of heterogeneity measured by variance might be an additional useful parameter to characterize radiosensitivity. PMID:22520045

Intestinal microbiota reduces genotoxic endpoints induced by high-energy protons.

PubMed

Maier, Irene; Berry, David M; Schiestl, Robert H

2014-01-01

Ionizing space radiation causes oxidative DNA damage and triggers oxidative stress responses, and compromised DNA repair mechanisms can lead to increased risk of carcinogenesis. Young adult mice with developed innate and adaptive immune systems that harbored either a conventional intestinal microbiota (CM) or an intestinal microbiota with a restricted microbial composition (RM) were irradiated with a total dose of 1 Gy delivered by high-energy protons (2.5 GeV/n, LET = 0.2-2 keV/μm) or silicon or iron ions (850 MeV/n, LET ≈ 50 keV/μm and 1 GeV/n, LET = 150 keV/μm, respectively). Six hours after whole-body irradiation, acute chromosomal DNA lesions were observed for RM mice but not CM mice. High-throughput rRNA gene sequencing of intestinal mucosal bacteria showed that Barnesiella intestinihominis and unclassified Bacterodiales were significantly more abundant in male RM mice than CM mice, and phylotype densities changed in irradiated mice. In addition, Helicobacter hepaticus and Bacteroides stercoris were higher in CM than RM mice. Elevated levels of persistently phosphorylated γ-H2AX were observed in RM mice exposed to high-energy protons compared to nonirradiated RM mice, and they also were associated with a decrease of the antioxidant glutathione in peripheral blood measured at four weeks after irradiation. After radiation exposure, CM mice showed lower levels of γ-H2AX phosphorylation than RM mice and an increase in specific RM-associated phylotypes, indicating a down-regulating force on DNA repair by differentially abundant phylotypes in RM versus a radiation-sensitive complex CM.

Intensity and temperature-dependent photoluminescence of tris (8-hydroxyquinoline) aluminum films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ajward, A. M.; Wang, X.; Wagner, H. P.

2013-12-04

We investigate the recombination of excitons in tris (8-hydroxyquinoline) aluminum films by intensity and temperature dependent time-resolved photoluminescence (PL). At low temperature (15 K) and elevated excitation intensity the radiative emission is quenched by singlet-singlet annihilation processes. With rising temperature the PL quenching is strongly reduced resulting in a PL efficiency maximum at ∼170 K. The reduced exciton annihilation is attributed to thermally activated occupation of non-quenchable trapped exciton states. Above 170 K the PL efficiency decreases due to thermal de-trapping of radiative states and subsequent migration to non-radiative centers.

Cancer Mortality Following Radiotherapy for Benign Gynecologic Disorders

PubMed Central

Sakata, Ritsu; Kleinerman, Ruth A.; Mabuchi, Kiyohiko; Stovall, Marilyn; Smith, Susan A.; Weathers, Rita; Wactawski-Wende, Jean; Cookfair, Diane L.; Boice, John D.; Inskip, Peter D.

2012-01-01

The purpose of this study is to quantify cancer mortality in relationship to organ-specific radiation dose among women irradiated for benign gynecologic disorders. Included in this study are 12,955 women treated for benign gynecologic disorders at hospitals in the Northeastern U.S. between 1925 and 1965; 9,770 women treated by radiation and 3,186 women treated by other methods. The average age at treatment was 45.9 years (range, 13–88 years), and the average follow-up period was 30.1 years (maximum, 69.9 years). Radiation doses to organs and active bone marrow were reconstructed by medical physicists using original radiotherapy records. The highest doses were received by the uterine cervix (median, 120 Gy) and uterine corpus (median, 34 Gy), followed by the bladder, rectum and colon (median, 1.7–7.2 Gy), with other abdominal organs receiving median doses ≤1 Gy and organs in the chest and head receiving doses <0.1 Gy. Standardized mortality rate ratios relative to the general U.S. population were calculated. Radiation-related risks were estimated in internal analyses using Poisson regression models. Mortality was significantly elevated among irradiated women for cancers of the uterine corpus, ovary, bladder, rectum, colon and brain, as well as for leukemia (exclusive of chronic lymphocytic leukemia) but not for cancer of the cervix, Hodgkin or non-Hodgkin lymphoma, multiple myeloma, or chronic lymphocytic leukemia. Evidence of a dose-response was seen for cancers of the ovary [excess relative risk (ERR) 0.31/Gy, P < 0.001], bladder (ERR = 0.21/Gy, P = 0.02) and rectum (ERR = 0.23/Gy, P = 0.05) and suggested for colon (ERR = 0.09/Gy, P = 0.10), but not for cancers of the uterine corpus or brain nor for non-chronic lymphocytic leukemia. Relative risks of mortality due to cancers of the stomach, pancreas, liver and kidney were close to 1.0, with no evidence of dose-response over the range of 0–1.5 Gy. Breast cancer was not significantly associated with dose to the breast or ovary. Mortality due to cancers of heavily irradiated organs remained elevated up to 40 years after irradiation. Significantly elevated radiation-related risk was seen for cancers of organs proximal to the radiation source or fields (bladder, rectum and ovary), as well as for non-chronic lymphocytic leukemia. Our results corroborate those from previous studies that suggest that cells of the uterine cervix and lymphopoietic system are relatively resistant to the carcinogenic effects of radiation. Studies of women irradiated for benign gynecologic disorders, together with studies of women treated with higher doses of radiation for uterine cancers, provide quantitative information on cancer risks associated with a broad range of pelvic radiation exposures. PMID:22856888

Flowering responses of insect-pollinated plants to elevated CO{sub 2} levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cushman, J.H.; Koch, G.W.; Chiariello, N.R.

1995-06-01

Elevated atmospheric CO{sub 2} concentrations have been predicted or shown to substantially influence plants, communities and ecosystems in a variety of ways. Here, we examined the effects of elevated CO{sub 2} levels on the timing and magnitude of flowering for two insect-pollinated annual plant species in a serpentine grassland. We focused on Lasthenia californica and Linanthus parviflorus and addressed three questions: (1) Do elevated CO{sub 2} levels influence flowering phenologies and is this species specific? (2) Do elevated CO{sub 2} levels affect flower production and is this due to altered numbers of individuals, flowers per plant, or both? and (3)more » Are effects on flowering due to elevated CO{sub 2} levels per se or changes in environmental conditions associated with methods used to manipulate CO{sub 2} levels? To address these questions, we used the ecosystem experiment at Stanford University`s Jasper Ridge Biological Preserve (San Mateo Co., CA). This system consists of 20 open-topped chambers - half receiving ambient CO{sub 2} (360 ppm) and half receiving elevated CO{sub 2} (720 ppm) - and 10 untreated plots serving as chamber controls. Results from the 1994 season demonstrated that there were species-specific responses to elevated CO{sub 2} levels and the field chambers. For Lasthenia californica, elevated CO{sub 2} per se did not affect relative abundance, inflorescence production, or phenology, but chambers did significantly increase inflorescence production and extend the duration of flowering. For Linanthus parviflorus, elevated CO{sub 2} levels significantly increased relative abundance and flower production, and extended the flowering period slightly, while the chambers significantly decreased flower production early in the season and increased it later in the season.« less

[UV-radiation--sources, wavelength, environment].

PubMed

Hölzle, Erhard; Hönigsmann, Herbert

2005-09-01

The UV-radiation in our environment is part of the electromagnetic radiation, which emanates from the sun. It is designated as optical radiation and reaches from 290-4,000 nm on the earth's surface. According to international definitions UV irradiation is divided into short-wave UVC (200-280 nm), medium-wave UVB (280-320 nm), and long-wave UVA (320-400 nm). Solar radiation which reaches the surface of the globe at a defined geographical site and a defined time point is called global radiation. It is modified quantitatively and qualitatively while penetrating the atmosphere. Besides atmospheric conditions, like ozone layer and air pollution, geographic latitude, elevation, time of the season, time of the day, cloudiness and the influence of indirect radiation resulting from stray effects in the atmosphere and reflection from the underground play a role in modifying global radiation, which finally represents the biologically effective radiation. The radiation's distribution on the body surface varies according to sun angle and body posture. The cumulative UV exposure is mainly influenced by outdoor profession and recreational activities. The use of sun beds and phototherapeutic measures additionally may contribute to the cumulative UV dose.

Wetland Accretion Rate Model of Ecosystem Resilience (WARMER) and its application to habitat sustainability for endangered species in the San Francisco Estuary

USGS Publications Warehouse

Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Thorne, Karen M.; Casazza, Michael L.; Overton, Cory T.; Callaway, John C.; Takekawa, John Y.

2014-01-01

Salt marsh faunas are constrained by specific habitat requirements for marsh elevation relative to sea level and tidal range. As sea level rises, changes in relative elevation of the marsh plain will have differing impacts on the availability of habitat for marsh obligate species. The Wetland Accretion Rate Model for Ecosystem Resilience (WARMER) is a 1-D model of elevation that incorporates both biological and physical processes of vertical marsh accretion. Here, we use WARMER to evaluate changes in marsh surface elevation and the impact of these elevation changes on marsh habitat for specific species of concern. Model results were compared to elevation-based habitat criteria developed for marsh vegetation, the endangered California clapper rail (Rallus longirostris obsoletus), and the endangered salt marsh harvest mouse (Reithrodontomys raviventris) to determine the response of marsh habitat for each species to predicted >1-m sea-level rise by 2100. Feedback between vertical accretion mechanisms and elevation reduced the effect of initial elevation in the modeled scenarios. Elevation decreased nonlinearly with larger changes in elevation during the latter half of the century when the rate of sea-level rise increased. Model scenarios indicated that changes in elevation will degrade habitat quality within salt marshes in the San Francisco Estuary, and degradation will accelerate in the latter half of the century as the rate of sea-level rise accelerates. A sensitivity analysis of the model results showed that inorganic sediment accumulation and the rate of sea-level rise had the greatest influence over salt marsh sustainability.

Explosive morphological diversification of spiny-finned teleost fishes in the aftermath of the end-Cretaceous extinction.

PubMed

Friedman, Matt

2010-06-07

The spiny-finned teleost fishes (Acanthomorpha) include nearly one-third of all living vertebrate species and assume a bewildering array of bodyplans, but the macroevolutionary assembly of modern acanthomorph biodiversity remains largely unexplored. Here, I reconstruct the trajectory of morphological diversification in this major radiation from its first appearance in the Late Cretaceous to the Miocene using a geometric morphometric database comprising more than 600 extinct species known from complete body fossils. The anatomical diversity (disparity) of acanthomorphs is low throughout the Cretaceous, increases sharply and significantly in the wake of the Cretaceous-Palaeogene (K-P) extinction, and shows little change throughout subsequent Cenozoic intervals. This pattern of morphological diversification appears robust to two potential biasing factors: the 'Lagerstätten effect', and the non-random segregation of rare and common taxa along phenotypic axes. Dissecting the trajectory of acanthomorph radiation along phylogenetic lines reveals that the abrupt post-extinction increase in disparity is driven largely by the proliferation of trophically diverse modern groups within Percomorpha, a spiny-fin subclade containing more than 15 000 living species and identified as showing a substantially elevated diversification rate relative to background vertebrate levels. A major component of the Palaeogene acanthomorph radiation reflects colonization of morphospace previously occupied by non-acanthomorph victims of the K-P. However, other aspects of morphological diversification cannot be explained by this simple ecological release model, suggesting that multiple factors contributed to the prolific anatomical radiation of acanthomorphs.

Radiation exposure in the moon environment

NASA Astrophysics Data System (ADS)

Reitz, Guenther; Berger, Thomas; Matthiae, Daniel

2012-12-01

During a stay on the moon humans are exposed to elevated radiation levels due to the lack of substantial atmospheric and magnetic shielding compared to the Earth's surface. The absence of magnetic and atmospheric shielding allows cosmic rays of all energies to impinge on the lunar surface. Beside the continuous exposure to galactic cosmic rays (GCR), which increases the risk of cancer mortality, exposure through particles emitted in sudden nonpredictable solar particle events (SPE) may occur. SPEs show an enormous variability in particle flux and energy spectra and have the potential to expose space crew to life threatening doses. On Earth, the contribution to the annual terrestrial dose of natural ionizing radiation of 2.4 mSv by cosmic radiation is about 1/6, whereas the annual exposure caused by GCR on the lunar surface is roughly 380 mSv (solar minimum) and 110 mSv (solar maximum). The analysis of worst case scenarios has indicated that SPE may lead to an exposure of about 1 Sv. The only efficient measure to reduce radiation exposure is the provision of radiation shelters. Measurements on the lunar surface performed during the Apollo missions cover only a small energy band for thermal neutrons and are not sufficient to estimate the exposure. Very recently some data were added by the Radiation Dose Monitoring (RADOM) instrument operated during the Indian Chandrayaan Mission and the Cosmic Ray Telescope (CRaTER) instrument of the NASA LRO (Lunar Reconnaisance Orbiter) mission. These measurements need to be complemented by surface measurements. Models and simulations that exist describe the approximate radiation exposure in space and on the lunar surface. The knowledge on the radiation exposure at the lunar surface is exclusively based on calculations applying radiation transport codes in combination with environmental models. Own calculations are presented using Monte-Carlo simulations to calculate the radiation environment on the moon and organ doses on the surface of the moon for an astronaut in an EVA suit and are compared with measurements. Since it is necessary to verify/validate such calculations with measurement on the lunar surface, a description is given of a radiation detector for future detailed surface measurements. This device is proposed for the ESA Lunar Lander Mission and is capable to characterize the radiation field concerning particle fluencies, dose rates and energy transfer spectra for ionizing particles and to measure the dose contribution of secondary neutrons.

Elevated Blood Lead Levels in Children Associated With the Flint Drinking Water Crisis: A Spatial Analysis of Risk and Public Health Response.

PubMed

Hanna-Attisha, Mona; LaChance, Jenny; Sadler, Richard Casey; Champney Schnepp, Allison

2016-02-01

We analyzed differences in pediatric elevated blood lead level incidence before and after Flint, Michigan, introduced a more corrosive water source into an aging water system without adequate corrosion control. We reviewed blood lead levels for children younger than 5 years before (2013) and after (2015) water source change in Greater Flint, Michigan. We assessed the percentage of elevated blood lead levels in both time periods, and identified geographical locations through spatial analysis. Incidence of elevated blood lead levels increased from 2.4% to 4.9% (P < .05) after water source change, and neighborhoods with the highest water lead levels experienced a 6.6% increase. No significant change was seen outside the city. Geospatial analysis identified disadvantaged neighborhoods as having the greatest elevated blood lead level increases and informed response prioritization during the now-declared public health emergency. The percentage of children with elevated blood lead levels increased after water source change, particularly in socioeconomically disadvantaged neighborhoods. Water is a growing source of childhood lead exposure because of aging infrastructure.

Elevated Blood Lead Levels in Children Associated With the Flint Drinking Water Crisis: A Spatial Analysis of Risk and Public Health Response

PubMed Central

LaChance, Jenny; Sadler, Richard Casey; Champney Schnepp, Allison

2016-01-01

Objectives. We analyzed differences in pediatric elevated blood lead level incidence before and after Flint, Michigan, introduced a more corrosive water source into an aging water system without adequate corrosion control. Methods. We reviewed blood lead levels for children younger than 5 years before (2013) and after (2015) water source change in Greater Flint, Michigan. We assessed the percentage of elevated blood lead levels in both time periods, and identified geographical locations through spatial analysis. Results. Incidence of elevated blood lead levels increased from 2.4% to 4.9% (P < .05) after water source change, and neighborhoods with the highest water lead levels experienced a 6.6% increase. No significant change was seen outside the city. Geospatial analysis identified disadvantaged neighborhoods as having the greatest elevated blood lead level increases and informed response prioritization during the now-declared public health emergency. Conclusions. The percentage of children with elevated blood lead levels increased after water source change, particularly in socioeconomically disadvantaged neighborhoods. Water is a growing source of childhood lead exposure because of aging infrastructure. PMID:26691115

Airport full-body screening: what is the risk?

PubMed

Mehta, Pratik; Smith-Bindman, Rebecca

2011-06-27

In the past year, the Transportation Security Administration has deployed full-body scanners in airports across the United States in response to heightened security needs. Several groups have opposed the scans, citing privacy concerns and fear of the radiation emitted by the backscatter x-ray scanners, 1 of the 2 types of machines in use. The radiation doses emitted by the scans are extremely small; the scans deliver an amount of radiation equivalent to 3 to 9 minutes of the radiation received through normal daily living. Furthermore, since flying itself increases exposure to ionizing radiation, the scan will contribute less than 1% of the dose a flyer will receive from exposure to cosmic rays at elevated altitudes. The estimation of cancer risks associated with these scans is difficult, but using the only available models, the risk would be extremely small, even among frequent flyers. We conclude that there is no significant threat of radiation from the scans.

Small-scale topography modulates elevational α-, β- and γ-diversity of Andean leaf beetles.

PubMed

Thormann, Birthe; Ahrens, Dirk; Espinosa, Carlos Iván; Armijos, Diego Marín; Wagner, Thomas; Wägele, Johann W; Peters, Marcell K

2018-05-01

Elevational diversity gradients are typically studied without considering the complex small-scale topography of large mountains, which generates habitats of strongly different environmental conditions within the same elevational zones. Here we analyzed the importance of small-scale topography for elevational diversity patterns of hyperdiverse tropical leaf beetles (Coleoptera: Chrysomelidae). We compared patterns of elevational diversity and species composition of beetles in two types of forests (on mountain ridges and in valleys) and analyzed whether differences in the rate of species turnover among forest habitats lead to shifts in patterns of elevational diversity when scaling up from the local study site to the elevational belt level. We sampled beetle assemblages at 36 sites in the Podocarpus National Park, Ecuador, which were equally distributed over two forest habitats and three elevational levels. DNA barcoding and Poisson tree processes modelling were used to delimitate putative species. On average, local leaf beetle diversity showed a clear hump-shaped pattern. However, only diversity in forests on mountain ridges peaked at mid-elevation, while beetle diversity in valleys was similarly high at low- and mid-elevation and only declined at highest elevations. A higher turnover of species assemblages at lower than at mid-elevations caused a shift from a hump-shaped diversity pattern found at the local level to a low-elevation plateau pattern (with similar species numbers at low and mid-elevation) at the elevational belt level. Our study reveals an important role of small-scale topography and spatial scale for the inference on gradients of elevational species diversity.

Exploring the limits of crop productivity: beyond the limits of tipburn in lettuce

NASA Technical Reports Server (NTRS)

Frantz, Jonathan M.; Ritchie, Glen; Cometti, Nilton N.; Robinson, Justin; Bugbee, Bruce

2004-01-01

The productivity of lettuce in a combination of high light, high temperature, and elevated CO2 has not been commonly studied because rapid growth usually causes a calcium deficiency in meristems called tipburn, which greatly reduces quality and marketability. We eliminated tipburn by blowing air directly onto the meristem, which allowed us to increase the photosynthetic photon flux (PPF) to 1000 micromoles m-2 s-1 (57.6 mol m-2 d-1); two to three times higher than normally used for lettuce. Eliminating tipburn doubled edible yield at the highest PPF level. In addition to high PPF, CO2 was elevated to 1200 micromoles m-2 mol-1, which increased the temperature optimum from 25 to 30 degrees C. The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield. Photosynthetic efficiency, measured as canopy quantum yield in a whole-plant gas exchange system, steadily increased up to the highest temperature of 32 degrees C in high CO2. The highest productivity was 19 g m-2 d-1 of dry biomass (380 g d-1 fresh mass) averaged over the 23 days the plants received light. Without the limitation of tipburn, the combination of high PPF, high temperature, and elevated CO2 resulted in a 4-fold increase in growth rate over productivity in conventional environments.

The influence of elevated CO2 on non-structural carbohydrate distribution and fructan accumulation in wheat canopies

NASA Technical Reports Server (NTRS)

Smart, D. R.; Chatterton, N. J.; Bugbee, B.

1994-01-01

We grew 2.4 m2 wheat canopies in a large growth chamber under high photosynthetic photon flux (1000 micromoles m-2 s-1) and using two CO2 concentrations, 360 and 1200 micromoles mol-1. Photosynthetically active radiation (400-700 nm) was attenuated slightly faster through canopies grown in 360 micromoles mol-1 than through canopies grown in 1200 micromoles mol-1, even though high-CO2 canopies attained larger leaf area indices. Tissue fractions were sampled from each 5-cm layer of the canopies. Leaf tissue sampled from the tops of canopies grown in 1200 micromoles mol-1 accumulated significantly more total non-structural carbohydrate, starch, fructan, sucrose, and glucose (p < 0.05) than for canopies grown in 360 micromoles mol-1. Non-structural carbohydrate did not significantly increase in the lower canopy layers of the elevated CO2 treatment. Elevated CO2 induced fructan synthesis in all leaf tissue fractions, but fructan formation was greatest in the uppermost leaf area. A moderate temperature reduction of 10 degrees C over 5 d increased starch, fructan and glucose levels in canopies grown in 1200 micromoles mol-1, but concentrations of sucrose and fructose decreased slightly or remained unchanged. Those results may correspond with the use of fructosyl-residues and release of glucose when sucrose is consumed in fructan synthesis.

Medical radiation, family history of cancer, and benign breast disease in relation to breast cancer risk in young women, USA.

PubMed

Hill, Deirdre A; Preston-Martin, Susan; Ross, Ronald K; Bernstein, Leslie

2002-10-01

In previous studies breast cancer risk has been increased among women who received high doses (above 100-200 cGy) of ionizing radiation or those exposed to lower doses prior to age 20. Some evidence suggests that such risk may be distinctly elevated among women with a family history of breast or ovarian cancer (probably only carriers of specific gene mutations) and women with benign breast disease (BBD). A population-based case-control study in Los Angeles County obtained interview data from 744 women who were aged 40 or younger and diagnosed with breast cancer during 1983-1988, and from 744 matched controls. Women with a positive family history of breast or ovarian cancer reported cancer in a mother, sister, or grandmother. Women with BBD reported a physician diagnosis. Radiation exposure was defined as a history of either radiation therapy or moderate exposure to medical radiography. Breast cancer risk was elevated among women exposed to medical radiation prior to age 20 years (odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.2-1.8), relative to unexposed women. This increased risk was observed only among women with a history of BBD (OR = 2.4, 95% CI = 1.6-3.7). Overall, risk was not associated with exposure to medical radiation after age 20 years, although among women with a positive family history of breast or ovarian cancer, exposed women had an increased risk (OR= 1.8, 95% CI = 1.0-3.1). Breast cancer risk was not increased among women with a family history of breast/ovarian cancer exposed to medical radiation before age 20 years or those with BBD exposed to medical radiation after age 20 years. Study participants may have received radiation doses that are no longer common, hampering study generalizability. Although differences in recall between cases and controls cannot be completely excluded, women with BBD or a family history of breast cancer appear to have greater breast cancer risk following relatively low ionizing radiation exposure than other women in this study.

Responses of photosynthetic properties and chloroplast ultrastructure of two moss crusts from a desert biological soil crust to supplementary UV-B radiation

NASA Astrophysics Data System (ADS)

Hui, Rong; Li, Xinrong; Zhao, Yang; Pan, Yanxia

2016-04-01

Our understanding of plant responses to supplementary ultraviolet-B (UV-B) radiation due to stratospheric ozone depletion has improved over recent decades. However, research on biological soil crusts (BSCs) is scarce and it remains controversial. Laboratory studies were conducted to investigate the influence of UV-B radiation on the Bryum argenteum and Didymodon vinealis isolated from BSCs, which are both dominant species in moss crusts found within patches of shrubs and herbs in the Tengger Desert of northern China. The aim of the current work was to evaluate whether supplementary UV-B radiation affected photosynthetic properties and chloroplast ultrastructure of two moss crusts and whether response differences were observed between the crusts. Four levels of UV-B radiation of 2.75 (control), 3.08, 3.25, and 3.41 W m-2 was achieved using fluorescence tube systems for 10 days, simulating 0, 6, 9, and 12% of stratospheric ozone at the latitude of Shapotou, respectively. We measured photosynthetic apparatus as assessed by chlorophyll a fluorescence parameters, photosynthetic pigment contents, and observations of chloroplast ultrastructure. Additionally, soluble proteins and UV-B absorbing compounds were simultaneously investigated. The results of this study showed that chlorophyll a fluorescence parameters (i.e., the maximal quantum yield of PSII photochemistry, the effective quantum yield of PSII photochemistry, and photochemical quenching coefficient), photosynthetic pigment contents, soluble protein contents, total flavonoid contents and the ultrastructure were negatively influenced by elevated UV-B radiation and the degree of detrimental effects significantly increased with the intensity of UV-B radiation. Moreover, results demonstrated that the negative effects on photosynthesis and chloroplast ultrastructure were more serious in B. argenteum than that in D. vinealis. These results may not only provide a potential mechanism for supplemental UV-B effects on photosynthesis of moss crusts, but also establish a theoretical basis for further studies of adaptation and response mechanisms of desert ecosystems under further ozone depletion.

Mortality associated with bilirubin levels in insurance applicants.

PubMed

Fulks, Michael; Stout, Robert L; Dolan, Vera F

2009-01-01

Determine the relationship between bilirubin levels with and without other liver function test (LFT) elevations and relative mortality in life insurance applicants. By use of the Social Security Death Master File mortality was determined in 1,905,664 insurance applicants for whom blood samples were submitted to the Clinical Reference Laboratory. There were 50,174 deaths observed in this study population. Results were stratified by 3 age/sex groups: females, age <60; males, age <60; and all, age 60+. The median follow-up was 12 years. Relative mortality increased as bilirubin decreased below bilirubin levels seen for the middle 50% of the population. The known association of smoking with lower bilirubin values explained only part of the additional elevated risk at low bilirubin levels. In the absence of other LFT elevations, relative mortality remained unchanged as bilirubin increased beyond levels seen for the middle 50% of the population. When a bilirubin elevation was combined with other LFT elevations, mortality further increased only at the highest elevations of other LFTs, seen only in <2.5% of applicants. Isolated elevations of bilirubin in this healthy screening population were not associated with excess mortality but values below the midpoint were. Other investigations have suggested a cardiovascular cause may underlie the excess mortality associated with low bilirubin. In association with other LFT elevations, bilirubin elevation further increases the mortality risk only at the highest elevations of other LFTs.

Elevation Control on Vegetation Organization in a Semiarid Ecosystem in Central New Mexico

NASA Astrophysics Data System (ADS)

Nudurupati, S. S.; Istanbulluoglu, E.; Adams, J. M.; Hobley, D. E. J.; Gasparini, N. M.; Tucker, G. E.; Hutton, E. W. H.

2015-12-01

Many semiarid and desert ecosystems are characterized by patchy and dynamic vegetation. Topography plays a commanding role on vegetation patterns. It is observed that plant biomes and biodiversity vary systematically with slope and aspect, from shrublands in low desert elevations, to mixed grass/shrublands in mid elevations, and forests at high elevations. In this study, we investigate the role of elevation dependent climatology on vegetation organization in a semiarid New Mexico catchment where elevation and hillslope aspect play a defining role on plant types. An ecohydrologic cellular automaton model developed within Landlab (component based modeling framework) is used. The model couples local vegetation dynamics (that simulate biomass production based on local soil moisture and potential evapotranspiration) and plant establishment and mortality based on competition for resources and space. This model is driven by elevation dependent rainfall pulses and solar radiation. The domain is initialized with randomly assigned plant types and the model parameters that couple plant response with soil moisture are systematically changed. Climate perturbation experiments are conducted to examine spatial vegetation organization and associated timescales. Model results reproduce elevation and aspect controls on observed vegetation patterns indicating that this model captures necessary and sufficient conditions that explain these observed ecohydrological patterns.

Predictors of serum vitamin D levels in African American and European American men in Chicago.

PubMed

Murphy, Adam B; Kelley, Brian; Nyame, Yaw A; Martin, Iman K; Smith, Demetria J; Castaneda, Lauren; Zagaja, Gregory J; Hollowell, Courtney M P; Kittles, Rick A

2012-09-01

Vitamin D deficiency is epidemiologically linked to prostate, breast, and colon cancer. When compared with European American (EA) men, African American (AA) men have increased risk of prostate cancer, but few studies evaluate vitamin D status in AA men. The authors evaluate the biological and environmental predictors of vitamin D deficiency in AA and EA men in Chicago, Illinois, a low ultraviolet radiation environment. Blood samples were collected from 492 men, aged between 40 and 79 years, from urology clinics at three hospitals in Chicago, along with demographic and medical information, body mass index, and skin melanin content using a portable narrow-band reflectometer. Vitamin D intake and ultraviolet radiation exposure were assessed using validated questionnaires. The results demonstrated that Black race, cold season of blood draw, elevated body mass index, and lack of vitamin D supplementation increase the risk of vitamin D deficiency. Supplementation is a high-impact, modifiable risk factor. Race and sunlight exposure should be taken into account for recommended daily allowances for vitamin D intake.

Predictors of Serum Vitamin D Levels in African American and European American Men in Chicago

PubMed Central

Murphy, Adam B.; Kelley, Brian; Nyame, Yaw A.; Martin, Iman K.; Smith, Demetria J.; Castaneda, Lauren; Zagaja, Gregory J.; Hollowell, Courtney M. P.; Kittles, Rick A.

2013-01-01

Vitamin D deficiency is epidemiologically linked to prostate, breast, and colon cancer. When compared with European American (EA) men, African American (AA) men have increased risk of prostate cancer, but few studies evaluate vitamin D status in AA men. The authors evaluate the biological and environmental predictors of vitamin D deficiency in AA and EA men in Chicago, Illinois, a low ultraviolet radiation environment. Blood samples were collected from 492 men, aged between 40 and 79 years, from urology clinics at three hospitals in Chicago, along with demographic and medical information, body mass index, and skin melanin content using a portable narrow-band reflectometer. Vitamin D intake and ultraviolet radiation exposure were assessed using validated questionnaires. The results demonstrated that Black race, cold season of blood draw, elevated body mass index, and lack of vitamin D supplementation increase the risk of vitamin D deficiency. Supplementation is a high-impact, modifiable risk factor. Race and sunlight exposure should be taken into account for recommended daily allowances for vitamin D intake. PMID:22398989

Change in the immunophenotype of a somatotroph adenoma resulting in gigantism

PubMed Central

Thawani, Jayesh P.; Bailey, Robert L.; Burns, Carrie M.; Lee, John Y. K.

2014-01-01

Background: Examining the pathologic progression of a pituitary adenoma from the point of a prepubescent child to an adult with gigantism affords us an opportunity to consider why patients may develop secretory or functioning tumors and raises questions about whether therapeutic interventions and surveillance strategies could be made to avoid irreversible phenotypic changes. Case Description: A patient underwent a sublabial transsphenoidal resection for a clinically non-functioning macroadenoma in 1999. He underwent radiation treatment and was transiently given growth hormone (GH) supplementation as an adolescent. His growth rapidly traversed several percentiles and he was found to have elevated GH levels. The patient became symptomatic and was taken for a second neurosurgical procedure. Pathology and immunohistochemical staining demonstrated a significantly higher proportion of somatotroph cells and dense granularity; he was diagnosed with a functional somatotroph adenoma. Conclusions: While it is likely that the described observations reflect the manifestations of a functional somatotroph adenoma in development, it is possible that pubertal growth, GH supplementation, its removal, or radiation therapy contributed to the described endocrine and pathologic changes. PMID:25396071

Modeling tidal marsh distribution with sea-level rise: evaluating the role of vegetation, sediment, and upland habitat in marsh resiliency.

PubMed

Schile, Lisa M; Callaway, John C; Morris, James T; Stralberg, Diana; Parker, V Thomas; Kelly, Maggi

2014-01-01

Tidal marshes maintain elevation relative to sea level through accumulation of mineral and organic matter, yet this dynamic accumulation feedback mechanism has not been modeled widely in the context of accelerated sea-level rise. Uncertainties exist about tidal marsh resiliency to accelerated sea-level rise, reduced sediment supply, reduced plant productivity under increased inundation, and limited upland habitat for marsh migration. We examined marsh resiliency under these uncertainties using the Marsh Equilibrium Model, a mechanistic, elevation-based soil cohort model, using a rich data set of plant productivity and physical properties from sites across the estuarine salinity gradient. Four tidal marshes were chosen along this gradient: two islands and two with adjacent uplands. Varying century sea-level rise (52, 100, 165, 180 cm) and suspended sediment concentrations (100%, 50%, and 25% of current concentrations), we simulated marsh accretion across vegetated elevations for 100 years, applying the results to high spatial resolution digital elevation models to quantify potential changes in marsh distributions. At low rates of sea-level rise and mid-high sediment concentrations, all marshes maintained vegetated elevations indicative of mid/high marsh habitat. With century sea-level rise at 100 and 165 cm, marshes shifted to low marsh elevations; mid/high marsh elevations were found only in former uplands. At the highest century sea-level rise and lowest sediment concentrations, the island marshes became dominated by mudflat elevations. Under the same sediment concentrations, low salinity brackish marshes containing highly productive vegetation had slower elevation loss compared to more saline sites with lower productivity. A similar trend was documented when comparing against a marsh accretion model that did not model vegetation feedbacks. Elevation predictions using the Marsh Equilibrium Model highlight the importance of including vegetation responses to sea-level rise. These results also emphasize the importance of adjacent uplands for long-term marsh survival and incorporating such areas in conservation planning efforts.

Application of Geographic Information System Methods to Identify Areas Yielding Water that will be Replaced by Water from the Colorado River in the Vidal and Chemehuevi Areas, California, and the Mohave Mesa Area, Arizona

USGS Publications Warehouse

Spangler, Lawrence E.; Angeroth, Cory E.; Walton, Sarah J.

2008-01-01

Relations between the elevation of the static water level in wells and the elevation of the accounting surface within the Colorado River aquifer in the vicinity of Vidal, California, the Chemehuevi Indian Reservation, California, and on Mohave Mesa, Arizona, were used to determine which wells outside the flood plain of the Colorado River are presumed to yield water that will be replaced by water from the Colorado River. Wells that have a static water-level elevation equal to or below the elevation of the accounting surface are presumed to yield water that will be replaced by water from the Colorado River. Geographic Information System (GIS) interpolation tools were used to produce maps of areas where water levels are above, below, and near (within ? 0.84 foot) the accounting surface. Calculated water-level elevations and interpolated accounting-surface elevations were determined for 33 wells in the vicinity of Vidal, 16 wells in the Chemehuevi area, and 35 wells on Mohave Mesa. Water-level measurements generally were taken in the last 10 years with steel and electrical tapes accurate to within hundredths of a foot. A Differential Global Positioning System (DGPS) was used to determine land-surface elevations to within an operational accuracy of ? 0.43 foot, resulting in calculated water-level elevations having a 95-percent confidence interval of ? 0.84 foot. In the Vidal area, differences in elevation between the accounting surface and measured water levels range from -2.7 feet below to as much as 17.6 feet above the accounting surface. Relative differences between the elevation of the water level and the elevation of the accounting surface decrease from west to east and from north to south. In the Chemehuevi area, differences in elevation range from -3.7 feet below to as much as 8.7 feet above the accounting surface, which is established at 449.6 feet in the vicinity of Lake Havasu. In all of the Mohave Mesa area, the water-level elevation is near or below the elevation of the accounting surface. Differences in elevation between water levels and the accounting surface range from -0.2 to -11.3 feet, with most values exceeding -7.0 feet. In general, the ArcGIS Triangulated Irregular Network (TIN) Contour and Natural Neighbor tools reasonably represent areas where the elevation of water levels in wells is above, below, and near (within ? 0.84 foot) the elevation of the accounting surface in the Vidal and Chemehuevi study areas and accurately delineate areas around outlying wells and where anomalies exist. The TIN Contour tool provides a strict linear interpolation while the Natural Neighbor tool provides a smoothed interpolation. Using the default options in ArcGIS, the Inverse Distance Weighted (IDW) and Spline tools also reasonably represent areas above, below, and near the accounting surface in the Vidal and Chemehuevi areas. However, spatial extent of and boundaries between areas above, below, and near the accounting surface vary among the GIS methods, which results largely from the fundamentally different mathematical approaches used by these tools. The limited number and spatial distribution of wells in comparison to the size of the areas, and the locations and relative differences in elevation between water levels and the accounting surface of wells with anomalous water levels also influence the contouring by each of these methods. Qualitatively, the Natural Neighbor tool appears to provide the best representation of the difference between water-level and accounting-surface elevations in the study areas, on the basis of available well data.

Emerging role of thalidomide in the treatment of gastrointestinal bleeding.

PubMed

McFarlane, Michael; O'Flynn, Lauren; Ventre, Rachel; Disney, Benjamin R

2018-04-01

Thalidomide was initially synthesised in 1954 and marketed as a sedative and antiemetic for morning sickness. It was withdrawn in 1961 due to the realisation that it was teratogenic with over 10 000 children born with congenital abnormalities. Since then it has been used for treatment of dermatological and oncological conditions, including myeloma. In 1994, it was found to have a potent antiangiogenic effect via downregulation of vascular endothelial growth factor (VEGF). This has led to its use in gastrointestinal bleeding, as vascular abnormalities such as angiodysplasia have been found to have elevated VEGF levels. This article will review the current evidence of the use of thalidomide in bleeding associated with gastrointestinal vascular malformations, including angiodysplasia, gastric cancer and radiation-induced proctitis.

Association of Elevated High Sensitivity Cardiac Troponin T(hs-cTnT) Levels with Hemorrhagic Transformation and 3-Month Mortality in Acute Ischemic Stroke Patients with Rheumatic Heart Disease in China

PubMed Central

Xiong, Yao; Liu, Bian; Hao, Zilong; Tao, Wendan; Liu, Ming

2016-01-01

Background and Objective Elevated levels of high sensitivity cardiac troponin T (hs-cTnT) occur in a substantial proportion of patients with acute ischemic stroke (AIS) and can predict poor outcome and mortality after stroke. Whether elevated hs-cTnT levels can also predict hemorrhagic transformation (HT) or prognosis in AIS patients with rheumatic heart disease (RHD) remains unclear. Methods Data from the Chengdu Stroke Registry on consecutive AIS patients with RHD admitted to West China Hospital within1 month of stroke onset from October 2011 to February 2014 were examined. Clinico-demographic characteristics, HT, functional outcomes and stroke recurrence were compared between patients with elevated hs-cTnT levels(≥14ng/L) and patients with normal hs-cTnT levels (<14ng/L). Results The final analysis involved 84 patients (31 males; mean age, 61.6±12.2years), of whom serum hs-cTnT levels were elevated in 58.3%. Renal impairment was independently associated with elevated hs-cTnT levels (OR 4.184, 95%CI 1.17 to 15.01, P = 0.028), and patients with elevated hs-cTnT levels were at significantly higher risk of HT, 3-month mortality and 3-month disability/mortality (all P≤0.029). After controlling for age, sex, hypertension, renal impairment and National Institutes of Health Stroke Scale score on admission, the risk of HT and 3-month mortality was, respectively, 4.0- and 5.5-fold higher in patients with elevated hs-cTnT levels than in patients with normal hs-cTnT levels. Conclusion Elevated hs-cTnT levels are independently associated with HT and 3-month mortality in AIS patients with RHD. These results with a small cohort should be verified and extended in large studies. PMID:26849554

Association of Elevated High Sensitivity Cardiac Troponin T(hs-cTnT) Levels with Hemorrhagic Transformation and 3-Month Mortality in Acute Ischemic Stroke Patients with Rheumatic Heart Disease in China.

PubMed

Liu, Junfeng; Wang, Deren; Xiong, Yao; Liu, Bian; Hao, Zilong; Tao, Wendan; Liu, Ming

2016-01-01

Elevated levels of high sensitivity cardiac troponin T (hs-cTnT) occur in a substantial proportion of patients with acute ischemic stroke (AIS) and can predict poor outcome and mortality after stroke. Whether elevated hs-cTnT levels can also predict hemorrhagic transformation (HT) or prognosis in AIS patients with rheumatic heart disease (RHD) remains unclear. Data from the Chengdu Stroke Registry on consecutive AIS patients with RHD admitted to West China Hospital within 1 month of stroke onset from October 2011 to February 2014 were examined. Clinico-demographic characteristics, HT, functional outcomes and stroke recurrence were compared between patients with elevated hs-cTnT levels (≥14 ng/L) and patients with normal hs-cTnT levels (<14 ng/L). The final analysis involved 84 patients (31 males; mean age, 61.6±12.2 years), of whom serum hs-cTnT levels were elevated in 58.3%. Renal impairment was independently associated with elevated hs-cTnT levels (OR 4.184, 95%CI 1.17 to 15.01, P = 0.028), and patients with elevated hs-cTnT levels were at significantly higher risk of HT, 3-month mortality and 3-month disability/mortality (all P≤0.029). After controlling for age, sex, hypertension, renal impairment and National Institutes of Health Stroke Scale score on admission, the risk of HT and 3-month mortality was, respectively, 4.0- and 5.5-fold higher in patients with elevated hs-cTnT levels than in patients with normal hs-cTnT levels. Elevated hs-cTnT levels are independently associated with HT and 3-month mortality in AIS patients with RHD. These results with a small cohort should be verified and extended in large studies.

High prevalence of elevated blood lead levels in both rural and urban Iowa newborns: Spatial patterns and area-level covariates

PubMed Central

Zahrieh, David; Young, Sean G.; Oleson, Jacob; Ryckman, Kelli K.; Wels, Brian; Simmons, Donald L.; Saftlas, Audrey

2017-01-01

Lead in maternal blood can cross the placenta and result in elevated blood lead levels in newborns, potentially producing negative effects on neurocognitive function, particularly if combined with childhood lead exposure. Little research exists, however, into the burden of elevated blood lead levels in newborns, or the places and populations in which elevated lead levels are observed in newborns, particularly in rural settings. Using ~2300 dried bloods spots collected within 1–3 days of birth among Iowa newborns, linked with the area of mother’s residence at the time of birth, we examine the spatial patterns of elevated (>5 μg/dL) blood lead levels and the ecological-level predictors of elevated blood lead levels. We find that one in five newborns exceed the 5 μg/dL action level set by the US Centers for Disease Control & Prevention (CDC). Bayesian spatial zero inflated regression indicates that elevated blood lead in newborns is associated with areas of increased pre-1940s housing and childbearing-age women with low educational status in both rural and urban settings. No differences in blood lead levels or the proportion of children exceeding 5 μg/dL are observed between urban and rural maternal residence, though a spatial cluster of elevated blood lead is observed in rural counties. These characteristics can guide the recommendation for testing of infants at well-baby appointments in places where risk factors are present, potentially leading to earlier initiation of case management. The findings also suggest that rural populations are at as great of risk of elevated blood lead levels as are urban populations. Analysis of newborn dried blood spots is an important tool for lead poisoning surveillance in newborns and can direct public health efforts towards specific places and populations where lead testing and case management will have the greatest impact. PMID:28520816

Creatine kinase elevation, lactacidemia, and metabolic myopathy in adult patients with diabetes mellitus.

PubMed

Frank, Marlies; Finsterer, Josef

2012-01-01

To determine the frequency of elevated creatine kinase (CK) levels among patients with diabetes mellitus and to determine how often elevated CK is attributable to primary myopathy. In this prospective study, we investigated how often CK, aspartate amino-transferase, alanine aminotransferase, and resting lactate were elevated among consecutive diabetic patients attending our clinic. Those with elevated CK values were offered a neurologic workup. Ninety-nine patients with diabetes mellitus, aged 19 to 87 years, were assessed between May 2008 and April 2010. Seven patients had type 1 diabetes and 92 patients had type 2 diabetes. CK, aspartate aminotransferase, alanine aminotransferase, and resting lactate were elevated in 19 of 99, 25 of 99, 22 of 99, and 24 of 98 patients, respectively. Eleven of 19 patients with increased CK were self-injecting insulin. Ten of 24 patients with elevated serum lactate took metformin. Seven of 19 patients with elevated CK consented to neurologic workup. Two of the 7 had elevated resting lactate. In all 7 patients, the findings from neurologic investigation were indicative of a metabolic defect and further diagnostic evaluation was recommended. In diabetic patients attending our clinic, elevated CK levels occur in one-fifth and lactacidemia occurs in one-quarter. Elevated CK levels are attributable to a primary metabolic myopathy in most cases. Elevated CK levels in the setting of diabetes mellitus require further neurologic evaluation.

Studies of the Solar Radiations' Influence About Geomembranes Used in Ecological Landfill

NASA Astrophysics Data System (ADS)

Vasiluta, Petre; Cofaru, Ileana Ioana; Cofaru, Nicolae Florin; Popa, Dragos Laurentiu

2017-12-01

The study shown in this paper presents the behavior of geomembranes used at the ecological landfills. The influences of the solar radiations has a great importance regarding the correct mounting of the geomembranes. The mathematical model developed for the determination anytime and anywhere in the world for the next values and parameters: apparent solar time, solar declination, solar altitude, solar azimuth and incidence angle, zone angle, angle of sun elevation, solar declination, solar constant, solar flux density, diffuse solar radiation, global radiation, soil albedo, total radiant flux density and relational links of these values. The results of this model was used for creations an AutoCAD subroutines useful for choosing the correct time for correct mounting anywhere of the geomembranes

Solar Spectral Radiative Forcing Due to Dust Aerosol During the Puerto Rico Dust Experiment

NASA Technical Reports Server (NTRS)

Pilewskie, P.; Bergstrom, R.; Rabbette, M.; Livingston, J.; Russell, P.; Gore, Warren J. (Technical Monitor)

2000-01-01

During the Puerto Rico Dust Experiment (PRIDE) upwelling and downwelling solar spectral irradiance was measured on board the SPAWAR Navajo and downwelling solar spectral flux was measured at a surface site using the NASA Ames Solar Spectral Flux Radiometer. These data will be used to determine the net solar radiative forcing of dust aerosol and to quantify the solar spectral radiative energy budget in the presence of elevated aerosol loading. We will assess the variability in spectral irradiance using formal principal component analysis procedures and relate the radiative variability to aerosol microphysical properties. Finally, we will characterize the sea surface reflectance to improve aerosol optical depth retrievals from the AVHRR satellite and to validate SeaWiFS ocean color products.

Evaluation of Light Collection System for Pion and Kaon Experiments in Hall C at Jefferson Lab

NASA Astrophysics Data System (ADS)

Roustom, Salim

2017-09-01

The neutral pion and the kaon are opportune to study the hadron structure through General Parton Distributions, which can be viewed as spatial densities at different momenta of the quarks inside the proton. To study hadron structure with pion or kaon experiments in Hall C at 12 GeV Jefferson Lab, one must analyze the final state neutral pions and kaons and their decay products. For the analysis of these particles, dedicated detectors based on the Cherenkov or scintillation mechanism are used, e.g. the HMS and SHMS aerogel detectors and the PbWO4-based Neutral Particle Spectrometer. A critical part of these detectors is the light collection system. Photomultiplier Tubes (PMTs) have many advantages, however, they are sensitive to magnetic fields and can get damaged by elevated helium levels in the atmosphere. An alternative to PMTs are Avalanche Photodiodes (APDs). APDs are sensitive to background noise, temperature, and radiation. It is thus important to evaluate the benefits of each light collection system and optimize operating conditions to ensure performance over a reasonably long time. I will present a performance study of PMTs exposed to elevated levels of helium and a comparison of APDs as alternatives, as well as new, compact readout methods. Supported in part by NSF Grants PHY-1714133, PHY-1530874, PHY-1306227 and PHY-1306418.

Longitudinal Study of Intestinal Symptoms and Fecal Continence in Patients With Conformal Radiotherapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geinitz, Hans, E-mail: hans.geinitz@lrz.tu-muenchen.d; Thamm, Reinhard; Keller, Monika

2011-04-01

Purpose: To prospectively assess the intestinal symptoms and fecal continence in patients who had undergone conformal radiotherapy (CRT) for prostate cancer. Methods and Materials: A total of 78 men who had undergone definitive CRT for prostate cancer were evaluated. The patients were assessed before, during (treatment Weeks 4 and 6), and 2, 12, and 24 months after CRT completion. The intestinal symptoms and fecal continence were evaluated with comprehensive standardized questionnaires. Results: The intestinal symptoms were mostly intermittent, with only a small minority of patients affected daily. Defecation pain, fecal urge, and rectal mucous discharge increased significantly during therapy. Defecationmore » pain and rectal mucous discharge had returned to baseline levels within 8 weeks and 1 year after CRT, respectively. However, fecal urge remained significantly elevated for {<=}1 year and then returned toward the pretreatment values. The prevalence of rectal bleeding was significantly elevated 2 years after CRT. Fecal continence deteriorated during CRT and remained impaired at 1 year after treatment. Incontinence was mostly minor, occurring less than once per week and predominantly affecting incontinence for gas. Conclusion: Intestinal symptoms and fecal incontinence increased during prostate CRT. Except for rectal bleeding, the intestinal symptoms, including fecal incontinence, returned to baseline levels within 1-2 years after CRT. Thus, the rate of long-term late radiation-related intestinal toxicity was low.« less

Development and Use of Genetic Methods for Assessing Aquatic Environmental Condition and Recruitment Dynamics of Native Stream Fishes on Pacific Islands

DTIC Science & Technology

2014-04-01

colonization may also limit the potential for intra-island speciation and adaptive radiations (MacArthur and Wilson 1963, Zink et al. 1996, Chubb et...et al. 2012), and nitrogen stable isotope ratios of algae, macroinvertebrates (i.e., gastropods ) and A. stamineus were used as a time-integrated...elevations are a genetic subset of coastal and lower elevation populations due to adaptive differences in climbing ability and predator avoidance

47 CFR 73.509 - Prohibited overlap.

Code of Federal Regulations, 2011 CFR

2011-10-01

... by Figure 1a, curves in Figure 1 must be used. (3) The effective radiated power (ERP) that is the maximum ERP for any elevation plane on any bearing will be used. (d) An application for a change (other...

47 CFR 73.509 - Prohibited overlap.

Code of Federal Regulations, 2010 CFR

2010-10-01

... by Figure 1a, curves in Figure 1 must be used. (3) The effective radiated power (ERP) that is the maximum ERP for any elevation plane on any bearing will be used. (d) An application for a change (other...

Leukemia and exposure to ionizing radiation among German uranium miners.

PubMed

Möhner, Matthias; Lindtner, Manfred; Otten, Heinz; Gille, Hans-G

2006-04-01

It is well known that uranium miners are at an increased risk of lung cancer. Whether they also have an increased risk for other cancer sites remains under discussion. The aim of this study was to examine the leukemia risk among miners. An individually matched case-control study of former uranium miners in East Germany was conducted with 377 cases and 980 controls. Using conditional logistic regression models, a dose-response relationship between leukemia risk and radon progeny could not be confirmed. Yet, a significantly elevated risk is seen in the category > or = 400 mSv when combining gamma-radiation and long-lived radionuclides. The results suggest that an elevated risk for leukemia is restricted to employees with a very long occupational career in underground uranium mining or uranium processing. Moreover, the study does not support the hypothesis of an association between exposure to short-lived radon progeny and leukemia risk. Copyright 2006 Wiley-Liss, Inc.

Lung, Laryngeal and Other Respiratory Cancer Incidence among Japanese Atomic Bomb Survivors: An Updated Analysis from 1958 through 2009

DOE PAGES

Cahoon, Elizabeth K.; Preston, Dale L.; Pierce, Donald A.; ...

2017-03-21

The Life Span Study (LSS) of Japanese atomic bomb survivors is comprised of a large, population-based cohort offering one of the best opportunities to study the relationship between exposure to radiation and incidence of respiratory cancers. Risks of lung, laryngeal and other cancers of the respiratory system were evaluated among 105,444 LSS subjects followed from 1958 to 2009. During this period, we identified 2,446 lung, 180 laryngeal and 115 other respiratory (trachea, mediastinum and other ill-defined sites) first primary incident cancer cases. Ten additional years of follow-up, improved radiation dose estimates, revised smoking data, and updated migration information were thenmore » used to investigate the joint effects of radiation and smoking using Poisson regression methods. For nonsmokers, the sexaveraged excess relative risk per Gy (ERR/Gy) for lung cancer (at age 70 after radiation exposure at age 30) was estimated as 0.81 (95% CI: 0.51, 1.18) with a female-to-male ratio of 2.83. There was no evidence of curvature in the radiation dose-response relationship overall or by sex. Lung cancer risks increased with pack-years of smoking and decreased with time since quitting smoking at any level of radiation exposure. Similar to the previously reported study, which followed cohort members through 1999, the ERR/Gy for lung cancer was significantly higher for low-to-moderate smokers than for heavy smokers, with little evidence of any radiation-associated excess risk in heavy smokers. Of 2,446 lung cancer cases, 113 (5%) could be attributed to radiation exposure. Of the 1,165 lung cancer cases occurring among smokers, 886 (76%) could be attributed to smoking. While there was little evidence of a radiation effect for laryngeal cancer, a nonsignificantly elevated risk of other respiratory cancers was observed. However, significant smoking effects were observed for both laryngeal (ERR per 50 pack-years ¼ 23.57; 95% CI: 8.44, 71.05) and other respiratory cancers (ERR per 50 pack-years¼1.21; 95% CI: 0.10, 3.25)« less

Lung, Laryngeal and Other Respiratory Cancer Incidence among Japanese Atomic Bomb Survivors: An Updated Analysis from 1958 through 2009

PubMed Central

Cahoon, Elizabeth K.; Preston, Dale L.; Pierce, Donald A.; Grant, Eric; Brenner, Alina V.; Mabuchi, Kiyohiko; Utada, Mai; Ozasa, Kotaro

2017-01-01

The Life Span Study (LSS) of Japanese atomic bomb survivors is comprised of a large, population-based cohort offering one of the best opportunities to study the relationship between exposure to radiation and incidence of respiratory cancers. Risks of lung, laryngeal and other cancers of the respiratory system were evaluated among 105,444 LSS subjects followed from 1958 to 2009. During this period, we identified 2,446 lung, 180 laryngeal and 115 other respiratory (trachea, mediastinum and other ill-defined sites) first primary incident cancer cases. Ten additional years of follow-up, improved radiation dose estimates, revised smoking data, and updated migration information were used to investigate the joint effects of radiation and smoking using Poisson regression methods. For nonsmokers, the sex-averaged excess relative risk per Gy (ERR/Gy) for lung cancer (at age 70 after radiation exposure at age 30) was estimated as 0.81 (95% CI: 0.51, 1.18) with a female-to-male ratio of 2.83. There was no evidence of curvature in the radiation dose-response relationship overall or by sex. Lung cancer risks increased with pack-years of smoking and decreased with time since quitting smoking at any level of radiation exposure. Similar to the previously reported study, which followed cohort members through 1999, the ERR/Gy for lung cancer was significantly higher for low-to-moderate smokers than for heavy smokers, with little evidence of any radiation-associated excess risk in heavy smokers. Of 2,446 lung cancer cases, 113 (5%) could be attributed to radiation exposure. Of the 1,165 lung cancer cases occurring among smokers, 886 (76%) could be attributed to smoking. While there was little evidence of a radiation effect for laryngeal cancer, a nonsignificantly elevated risk of other respiratory cancers was observed. However, significant smoking effects were observed for both laryngeal (ERR per 50 pack-years = 23.57; 95% CI: 8.44, 71.05) and other respiratory cancers (ERR per 50 pack-years = 1.21; 95% CI: 0.10, 3.25). PMID:28323575

Lung, Laryngeal and Other Respiratory Cancer Incidence among Japanese Atomic Bomb Survivors: An Updated Analysis from 1958 through 2009.

PubMed

Cahoon, Elizabeth K; Preston, Dale L; Pierce, Donald A; Grant, Eric; Brenner, Alina V; Mabuchi, Kiyohiko; Utada, Mai; Ozasa, Kotaro

2017-05-01

The Life Span Study (LSS) of Japanese atomic bomb survivors is comprised of a large, population-based cohort offering one of the best opportunities to study the relationship between exposure to radiation and incidence of respiratory cancers. Risks of lung, laryngeal and other cancers of the respiratory system were evaluated among 105,444 LSS subjects followed from 1958 to 2009. During this period, we identified 2,446 lung, 180 laryngeal and 115 other respiratory (trachea, mediastinum and other ill-defined sites) first primary incident cancer cases. Ten additional years of follow-up, improved radiation dose estimates, revised smoking data, and updated migration information were used to investigate the joint effects of radiation and smoking using Poisson regression methods. For nonsmokers, the sex-averaged excess relative risk per Gy (ERR/Gy) for lung cancer (at age 70 after radiation exposure at age 30) was estimated as 0.81 (95% CI: 0.51, 1.18) with a female-to-male ratio of 2.83. There was no evidence of curvature in the radiation dose-response relationship overall or by sex. Lung cancer risks increased with pack-years of smoking and decreased with time since quitting smoking at any level of radiation exposure. Similar to the previously reported study, which followed cohort members through 1999, the ERR/Gy for lung cancer was significantly higher for low-to-moderate smokers than for heavy smokers, with little evidence of any radiation-associated excess risk in heavy smokers. Of 2,446 lung cancer cases, 113 (5%) could be attributed to radiation exposure. Of the 1,165 lung cancer cases occurring among smokers, 886 (76%) could be attributed to smoking. While there was little evidence of a radiation effect for laryngeal cancer, a nonsignificantly elevated risk of other respiratory cancers was observed. However, significant smoking effects were observed for both laryngeal (ERR per 50 pack-years = 23.57; 95% CI: 8.44, 71.05) and other respiratory cancers (ERR per 50 pack-years = 1.21; 95% CI: 0.10, 3.25).

Lung, Laryngeal and Other Respiratory Cancer Incidence among Japanese Atomic Bomb Survivors: An Updated Analysis from 1958 through 2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cahoon, Elizabeth K.; Preston, Dale L.; Pierce, Donald A.

The Life Span Study (LSS) of Japanese atomic bomb survivors is comprised of a large, population-based cohort offering one of the best opportunities to study the relationship between exposure to radiation and incidence of respiratory cancers. Risks of lung, laryngeal and other cancers of the respiratory system were evaluated among 105,444 LSS subjects followed from 1958 to 2009. During this period, we identified 2,446 lung, 180 laryngeal and 115 other respiratory (trachea, mediastinum and other ill-defined sites) first primary incident cancer cases. Ten additional years of follow-up, improved radiation dose estimates, revised smoking data, and updated migration information were thenmore » used to investigate the joint effects of radiation and smoking using Poisson regression methods. For nonsmokers, the sexaveraged excess relative risk per Gy (ERR/Gy) for lung cancer (at age 70 after radiation exposure at age 30) was estimated as 0.81 (95% CI: 0.51, 1.18) with a female-to-male ratio of 2.83. There was no evidence of curvature in the radiation dose-response relationship overall or by sex. Lung cancer risks increased with pack-years of smoking and decreased with time since quitting smoking at any level of radiation exposure. Similar to the previously reported study, which followed cohort members through 1999, the ERR/Gy for lung cancer was significantly higher for low-to-moderate smokers than for heavy smokers, with little evidence of any radiation-associated excess risk in heavy smokers. Of 2,446 lung cancer cases, 113 (5%) could be attributed to radiation exposure. Of the 1,165 lung cancer cases occurring among smokers, 886 (76%) could be attributed to smoking. While there was little evidence of a radiation effect for laryngeal cancer, a nonsignificantly elevated risk of other respiratory cancers was observed. However, significant smoking effects were observed for both laryngeal (ERR per 50 pack-years ¼ 23.57; 95% CI: 8.44, 71.05) and other respiratory cancers (ERR per 50 pack-years¼1.21; 95% CI: 0.10, 3.25)« less

A data-led comparison of simple canopy radiative transfer models for the boreal forest

NASA Astrophysics Data System (ADS)

Reid, T.; Essery, R.; Rutter, N.; King, M.

2012-12-01

Given the computational complexity of numerical weather and climate models, it is worthwhile developing very simple parameterizations for processes such as the transmission of radiation through forest canopies. For this reason, the land surface schemes in global models, and most snow hydrological models, tend to use simple one-dimensional approaches based on Beer's Law or two-stream approximations. Such approaches assume a continuous canopy structure that may not be suitable for the varied, heterogeneous forest cover in boreal regions, especially in winter when snow in the canopy and on the ground may either block radiation or produce multiple reflections between the ground and the trees. There is great benefit in comparing models to real transmissivity values calculated from radiation measurements below and above Arctic canopies. In particular, there is a lack of data for leafless boreal deciduous forests, where canopy gaps are prevalent even at low solar elevation angles near the horizon. In this study, models are compared to radiation data collected in an area of boreal birch forest near Abisko, Sweden in March/April 2011 and mixed conifer forest at Sodankylä, Finland in March/April 2012. Arrays comprising ten shortwave pyranometers were deployed for periods of up to 50 days, under forest plots of varying canopy structures and densities. In addition, global and diffuse shortwave irradiances were recorded at nearby open sites representing the top-of-canopy conditions. A model is developed that explicitly accounts for both diffuse radiation and direct beam transmission on a 5-minute timestep, by using upward-looking hemispherical photographs taken from every pyranometer site. This model reproduces measured transmissivity, although with a slight underestimation, especially at low solar elevations - this could be attributed to multiple reflections that are not accounted for in the model. On the other hand, models based on Beer's Law tend to underestimate the canopy transmissivity significantly, especially for leafless birch canopies where the required assumption of a continuous canopy breaks down. These findings are important for the often sparse, heterogeneous forest cover in boreal regions, where forest edges and canopy gaps are plentiful. They could also have an impact on estimations of overall land surface albedo. Moreover, all models are sensitive to the partitioning of top-of-canopy radiation into its direct and diffuse components, which is complicated by the low solar elevations in the Arctic. More research is required to decide the best way of quantifying the diffuse fraction, using data alongside both physical and empirical models.

Serum anti-Ku86 is a potential biomarker for early detection of hepatitis C virus-related hepatocellular carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nomura, Fumio, E-mail: fnomura@faculty.chiba-u.jp; Sogawa, Kazuyuki; Noda, Kenta

Highlights: Black-Right-Pointing-Pointer Overexpression of Ku86 in human liver cancer was shown by immunohistochemistry. Black-Right-Pointing-Pointer Serum anti-Ku86 was significantly elevated in early hepatocellular carcinoma. Black-Right-Pointing-Pointer Anti-Ku86 may be more sensitive than the conventional markers for early detection. Black-Right-Pointing-Pointer Serum anti-Ku86 significantly decreased after surgical resection of liver tumors. Black-Right-Pointing-Pointer Elevation of serum anti-Ku86 in other non-liver solid tumors was minimal. -- Abstract: Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is one of the most common cancers worldwide and the third most common cause of cancer-related death. Imaging studies including ultrasound and computed tomography are recommended for early detectionmore » of HCC, but they are operator dependent, costly and involve radiation. Therefore, there is a need for simple and sensitive serum markers for the early detection of hepatocellular carcinoma (HCC). In our recent proteomic studies, a number of proteins overexpressed in HCC tissues were identified. We thought if the serum autoantibodies to these overexpressed proteins were detectable in HCC patients. Of these proteins, we focused on Ku86, a nuclear protein involved in multiple biological processes and aimed to assess the diagnostic value of serum anti-Ku86 in the early detection of HCC. Serum samples were obtained prior to treatment from 58 consecutive patients with early or relatively early hepatitis C virus (HCV)-related HCC and 137 patients with HCV-related liver cirrhosis without evidence of HCC. Enzyme immunoassays were used to measure serum levels of autoantibodies. Serum levels of anti-Ku86 antibodies were significantly elevated in HCC patients compared to those in liver cirrhosis patients (0.41 {+-} 0.28 vs. 0.18 {+-} 0.08 Abs at 450 nm, P < 0001). Setting the cut-off level to give 90% specificity, anti-Ku86 was positive in 60.7% of stage I solitary tumor <2 cm in diameter, whereas the sensitivities of alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist II (PIVKA-II) were 17.8% and 21.4%, respectively. The results of ROC analyses indicated the better performance of anti-Ku86 for early detection of HCC. Serum anti-Ku86 levels decreased after surgical resection of the tumors in the 12 HCC cases tested, Elevation of anti-Ku86 in solid tumors other than liver was minimal. Serum anti-Ku86 is a potential biomarker for early detection of HCV-related HCC. Further studies in a larger number of HCC patients with various etiologies are needed to further evaluate the diagnostic and pathophysiological roles of elevation of serum anti-Ku86 in early HCC.« less

Elevated CO2 levels affects the concentrations of copper and cadmium in crops grown in soil contaminated with heavy metals under fully open-air field conditions.

PubMed

Guo, Hongyan; Zhu, Jianguo; Zhou, Hui; Sun, Yuanyuan; Yin, Ying; Pei, Daping; Ji, Rong; Wu, Jichun; Wang, Xiaorong

2011-08-15

Elevated CO(2) levels and the increase in heavy metals in soils through pollution are serious problems worldwide. Whether elevated CO(2) levels will affect plants grown in heavy-metal-polluted soil and thereby influence food quality and safety is not clear. Using a free-air CO(2) enrichment (FACE) system, we investigated the impacts of elevated atmospheric CO(2) on the concentrations of copper (Cu) or cadmium (Cd) in rice and wheat grown in soil with different concentrations of the metals in the soil. In the two-year study, elevated CO(2) levels led to lower Cu concentrations and higher Cd concentrations in shoots and grain of both rice and wheat grown in the respective contaminated soil. Elevated CO(2) levels slightly but significantly lowered the pH of the soil and led to changes in Cu and Cd fractionation in the soil. Our study indicates that elevated CO(2) alters the distribution of contaminant elements in soil and plants, thereby probably affecting food quality and safety.

A revised radiation package of G-packed McICA and two-stream approximation: Performance evaluation in a global weather forecasting model

NASA Astrophysics Data System (ADS)

Baek, Sunghye

2017-07-01

For more efficient and accurate computation of radiative flux, improvements have been achieved in two aspects, integration of the radiative transfer equation over space and angle. First, the treatment of the Monte Carlo-independent column approximation (MCICA) is modified focusing on efficiency using a reduced number of random samples ("G-packed") within a reconstructed and unified radiation package. The original McICA takes 20% of CPU time of radiation in the Global/Regional Integrated Model systems (GRIMs). The CPU time consumption of McICA is reduced by 70% without compromising accuracy. Second, parameterizations of shortwave two-stream approximations are revised to reduce errors with respect to the 16-stream discrete ordinate method. Delta-scaled two-stream approximation (TSA) is almost unanimously used in Global Circulation Model (GCM) but contains systematic errors which overestimate forward peak scattering as solar elevation decreases. These errors are alleviated by adjusting the parameterizations of each scattering element—aerosol, liquid, ice and snow cloud particles. Parameterizations are determined with 20,129 atmospheric columns of the GRIMs data and tested with 13,422 independent data columns. The result shows that the root-mean-square error (RMSE) over the all atmospheric layers is decreased by 39% on average without significant increase in computational time. Revised TSA developed and validated with a separate one-dimensional model is mounted on GRIMs for mid-term numerical weather forecasting. Monthly averaged global forecast skill scores are unchanged with revised TSA but the temperature at lower levels of the atmosphere (pressure ≥ 700 hPa) is slightly increased (< 0.5 K) with corrected atmospheric absorption.

Elevation trends and shrink-swell response of wetland soils to flooding and drying

USGS Publications Warehouse

Cahoon, Donald R.; Perez, Brian C.; Segura, Bradley D.; Lynch, James C.

2011-01-01

Given the potential for a projected acceleration in sea-level rise to impact wetland sustainability over the next century, a better understanding is needed of climate-related drivers that influence the processes controlling wetland elevation. Changes in local hydrology and groundwater conditions can cause short-term perturbations to marsh elevation trends through shrink—swell of marsh soils. To better understand the magnitude of these perturbations and their impacts on marsh elevation trends, we measured vertical accretion and elevation dynamics in microtidal marshes in Texas and Louisiana during and after the extreme drought conditions that existed there from 1998 to 2000. In a Louisiana marsh, elevation was controlled by subsurface hydrologic fluxes occurring below the root zone but above the 4 m depth (i.e., the base of the surface elevation table benchmark) that were related to regional drought and local meteorological conditions, with marsh elevation tracking water level variations closely. In Texas, a rapid decline in marsh elevation was related to severe drought conditions, which lowered local groundwater levels. Unfragmented marshes experienced smaller water level drawdowns and more rapid marsh elevation recovery than fragmented marshes. It appears that extended drawdowns lead to increased substrate consolidation making it less resilient to respond to future favorable conditions. Overall, changes in water storage lead to rapid and large short-term impacts on marsh elevation that are as much as five times greater than the long-term elevation trend, indicating the importance of long-term, high-resolution elevation data sets to understand the prolonged effects of water deficits on marsh elevation change.

Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

NASA Astrophysics Data System (ADS)

Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

2015-12-01

During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen oxides to the observed ozone production in the boundary layer.

Regulation of eIF2α phosphorylation in hindlimb-unloaded and STS-135 space-flown mice

NASA Astrophysics Data System (ADS)

Zhao, Liming; Tanjung, Nancy; Swarnkar, Gaurav; Ledet, Eric; Yokota, Hiroki

2012-09-01

Various environmental stresses elevate the phosphorylation level of eukaryotic translation initiation factor 2 alpha (eIF2α) and induce transcriptional activation of a set of stress responsive genes such as activating transcription factors 3 and 6 (ATF3 and ATF6), CCAAT/enhancer-binding protein homologous protein (CHOP), and Xbp1 (X-box binding protein 1). These stress sources include radiation, oxidation, and stress to the endoplasmic reticulum, and it is recently reported that unloading by hindlimb unloading is such a stress source. No studies, however, have examined the phosphorylation level of eIF2α (eIF2α-p) using skeletal samples that have experienced microgravity in space. In this study we addressed a question: Does a mouse tibia flown in space show altered levels of eIF2α-p? To address this question, we obtained STS-135 flown samples that were harvested 4-7 h after landing. The tibia and femur isolated from hindlimb unloaded mice were employed as non-flight controls. The effects of loading were also investigated in non- flight controls. Results indicate that the level of eIF2α-p of the non-flight controls was elevated during hindlimb unloading and reduced after being released from unloading. Second, the eIF2α-p level of space-flown samples was decreased, and mechanical loading to the tibia caused the reduction of the eIF2α-p level. Third, the mRNA levels of ATF3, ATF6, and CHOP were lowered in space-flown samples as well as in the non-flight samples 4-7 h after being released from unloading. Collectively, the results herein indicated that a release from hindlimb unloading and a return to normal weight environment from space provided a suppressive effect to eIF2α-linked stress responses and that a period of 2-4 h is sufficient to induce this suppressive outcome.

The topographic distribution of annual incoming solar radiation in the Rio Grande River basin

NASA Technical Reports Server (NTRS)

Dubayah, R.; Van Katwijk, V.

1992-01-01

We model the annual incoming solar radiation topoclimatology for the Rio Grande River basin in Colorado, U.S.A. Hourly pyranometer measurements are combined with satellite reflectance data and 30-m digital elevation models within a topographic solar radiation algorithm. Our results show that there is large spatial variability within the basin, even at an annual integration length, but the annual, basin-wide mean is close to that measured by the pyranometers. The variance within 16 sq km and 100 sq km regions is a linear function of the average slope in the region, suggesting a possible parameterization for sub-grid-cell variability.

Skin Cancer Surveillance Behaviors Among Childhood Cancer Survivors.

PubMed

Stapleton, Jerod L; Tatum, Kristina L; Devine, Katie A; Stephens, Sue; Masterson, Margaret; Baig, Amna; Hudson, Shawna V; Coups, Elliot J

2016-03-01

The risk of developing skin cancer is elevated among childhood cancer survivors (CCS), particularly among those treated with radiation. This survey study examined the skin cancer surveillance behaviors of 94 CCS. Approximately 48% of CCS had ever conducted skin self-examination (SSE) and 31% had ever received a physician skin examination. Rates of physician skin examination were 2.5 times higher among CCS treated with radiation compared to those without radiation. However, rates of SSEs did not differ based on treatment history. These findings highlight the need to promote skin cancer surveillance as an important aspect of CCS survivorship care. © 2015 Wiley Periodicals, Inc.

Enhanced resistance of the Pamirs high-mountain strain of Cryptococcus albidus to UV radiation of an ecological range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strakhovskaya, M.G.; Lavrukhina, O.G.; Fraikin, G.Y.

The results of a comparative analysis of the resistance of Pamirs high-mountain and lowland strains of the yeast Cryptococcus albidus to UV radiation of an ecological range are presented. A high-mountain strain, adapted to elevated UV radiation in its habitat, was found to be more resistant to UV light of a total ecorange (290-400 nm), including medium-wave (290-320 nm) and long-wave (320-400 nm) UV ranges. The enhanced UV light resistance of the high-mountain strain can be explained by efficient functioning of the excision DNA repair system. 7 refs., 3 tabs.

Electromagnetic Acoustic Transducers for Robotic Nondestructive Inspection in Harsh Environments.

PubMed

Choi, Sungho; Cho, Hwanjeong; Lindsey, Matthew S; Lissenden, Cliff J

2018-01-11

Elevated temperature, gamma radiation, and geometric constraints inside dry storage casks for spent nuclear fuel represent a harsh environment for nondestructive inspection of the cask and require that the inspection be conducted with a robotic system. Electromagnetic acoustic transducers (EMATs) using non-contact ultrasonic transduction based on the Lorentz force to excite/receive ultrasonic waves are suited for use in the robotic inspection. Periodic permanent magnet EMATs that actuate/receive shear horizontal guided waves are developed for application to robotic nondestructive inspection of stress corrosion cracks in the heat affected zone of welds in stainless steel dry storage canisters. The EMAT's components are carefully selected in consideration of the inspection environment, and tested under elevated temperature and gamma radiation doses up to 177 °C and 5920 krad, respectively, to evaluate the performance of the EMATs under realistic environmental conditions. The effect of gamma radiation is minimal, but the EMAT's performance is affected by temperatures above 121 °C due to the low Curie temperature of the magnets. Different magnets are needed to operate at 177 °C. The EMAT's capability to detect notches is also evaluated from B-scan measurements on 304 stainless steel welded plate containing surface-breaking notches.

On modeling the organization of landscapes and vegetation patterns controlled by solar radiation

NASA Astrophysics Data System (ADS)

Istanbulluoglu, E.; Yetemen, O.

2014-12-01

Solar radiation is a critical driver of ecohydrologic processes and vegetation dynamics. Patterns of runoff generation and vegetation dictate landscape geomorphic response. Distinct patterns in the organization of soil moisture, vegetation type, and landscape morphology have been documented in close relation to aspect in a range of climates. Within catchments, from north to south facing slopes, studies have shown ecotone shifts from forest to shrub species, and steep diffusion-dominated landforms to fluvial landforms. Over the long term differential evolution of ecohydrology and geomorphology leads to observed asymmetric structure in the planform of channel network and valley morphology. In this talk we present examples of coupled modeling of ecohydrology and geomorphology driven by solar radiation. In a cellular automata model of vegetation dynamics we will first show how plants organize in north and south facing slopes and how biodiversity changes with elevation. When vegetation-erosion feedbacks are coupled emergent properties of the coupled system are observed in the modeled elevation and vegetation fields. Integrating processes at a range of temporal and spatial scales, coupled models of ecohydrologic and geomorphic dynamics enable examination of global change impacts on landscapes and ecosystems.

[The efficacy of polychromatic visible and infrared radiation used for the postoperative immunological rehabilitation of patients with breast cancer].

PubMed

zhevago, N A; Samoĭlova, K A; Davydova, N I; Bychkova, N V; Glazanova, T V; Chubukina, Zh V; Buĭniakova, A I; Zimin, A A

2012-01-01

The immunological rehabilitation of the patients with oncological problems after the completion of standard anti-tumour therapy remains a topical problem in modern medicine. The up-to-date phototherapeutic methods find the increasingly wider application for the treatment of such patients including the use of monochromatic visible (VIS) and near infrared (nIR) radiation emitted from lasers and photodiodes. The objective of the present study was to substantiate the expediency of postoperative immune rehabilitation of the patients with breast cancer (BC) by means of irradiation of the body surface with polychromatic visible (pVIS) in combination with polychromatic infrared (pIR) light similar to the natural solar radiation without its minor UV component. The study included 19 patients with stage I--II BC at the mean age of 54.0 +/- 4.28 years having the infiltrative-ductal form of the tumour who had undergone mastectomy. These patients were randomly allocated to two groups, one given the standard course of postoperative rehabilitation (control), the other (study group) additionally treated with pVIS + pIR radiation applied to the lumbar-sacral region from days 1 to 7 after surgery. A Bioptron-2 phototherapeutic device, Switzerland, was used for the purpose (480-3400 nm, 40 mW/cm2, 12 J/cm2, with the light spot diameter of 15 cm). The modern standard immunological methods were employed. It was found that mastectomy induced changes of many characteristics of cellular and humoral immunity; many of them in different patients were oppositely directed. These changes were apparent within the first 7 days postoperatively. The course of phototherapy (PT) was shown to prevent the postoperative decrease in the counts of monocytes and natural killer (NK) cells, the total amount of CD3+ -T-lymphocytes (LPC), CD4+ -T-helpers, activated T-lymphocytes (CD3+ HLA-DR+ cells) and IgA levels as well as intracellular digestion rate of neutrophil-phagocyted bacteria. Moreover PT promoted faster normalization of postoperative leukocytosis and activation of cytotoxic CD8+ -T-LPC, reduced the elevated concentration of immune complexes in blood. Among the six tested cytokines, viz. IL-1beta, TNF-alpha, IL-6, IL-10, IFN-alpha, and IFN-gamma, only the latter two underwent significant elevation of their blood concentrations (IL-6 within 1 day) and IFN-gamma (within 7 days after mastectomy). The course of PT resulted in the decrease of their levels to the initial values. The follow-up of the treated patients during 4 years revealed neither recurrence of the disease nor the appearance of metastases.

Radiation combined with thermal injury induces immature myeloid cells.

PubMed

Mendoza, April Elizabeth; Neely, Crystal Judith; Charles, Anthony G; Kartchner, Laurel Briane; Brickey, Willie June; Khoury, Amal Lina; Sempowski, Gregory D; Ting, Jenny P Y; Cairns, Bruce A; Maile, Robert

2012-11-01

The continued development of nuclear weapons and the potential for thermonuclear injury necessitates the further understanding of the immune consequences after radiation combined with injury (RCI). We hypothesized that sublethal ionization radiation exposure combined with a full-thickness thermal injury would result in the production of immature myeloid cells. Mice underwent either a full-thickness contact burn of 20% total body surface area or sham procedure followed by a single whole-body dose of 5-Gy radiation. Serum, spleen, and peripheral lymph nodes were harvested at 3 and 14 days after injury. Flow cytometry was performed to identify and characterize adaptive and innate cell compartments. Elevated proinflammatory and anti-inflammatory serum cytokines and profound leukopenia were observed after RCI. A population of cells with dual expression of the cell surface markers Gr-1 and CD11b were identified in all experimental groups, but were significantly elevated after burn alone and RCI at 14 days after injury. In contrast to the T-cell-suppressive nature of myeloid-derived suppressor cells found after trauma and sepsis, myeloid cells after RCI augmented T-cell proliferation and were associated with a weak but significant increase in interferon γ and a decrease in interleukin 10. This is consistent with previous work in burn injury indicating that a myeloid-derived suppressor cell-like population increases innate immunity. Radiation combined injury results in the increase in distinct populations of Gr-1CD11b cells within the secondary lymphoid organs, and we propose these immature inflammatory myeloid cells provide innate immunity to the severely injured and immunocompromised host.

On the radiative effects of light-absorbing impurities on snowpack evolution

NASA Astrophysics Data System (ADS)

Dumont, M.; Tuzet, F.; Lafaysse, M.; Arnaud, L.; Picard, G.; Lejeune, Y.; Lamare, M.; Morin, S.; Voisin, D.; Di Mauro, B.

2017-12-01

The presence of light absorbing impurities in snow strongly decreases snow reflectance leading to an increase in the amount of solar energy absorbed by the snowpack. This effect is also known as impurities direct radiative effect. The change in the amount of energy absorbed by the snowpack modifies the temperature profile inside the snowpack and in turn snow metamorphism (impurities indirect radiative effects). In this work, we used the detailed snowpack model SURFEX/ISBA-Crocus with an explicit representation of snow light-absorbing impurities content (Tuzet et al., 2017) fed by medium-resolution ALADIN-Climate atmospheric model to represent dust and black carbon atmospheric deposition fluxes. The model is used at two sites: Col de Porte (medium elevation site in the French Alps) and Torgnon (high elevation site in the Italian Alps). The simulations are compared to in-situ observations and used to quantify the effects of light-absorbing impurities on snow melt rate and timing. The respective parts of the direct and indirect radiative effects of light-absorbing impurities in snow are also computed for the two sites, emphasizing the need to account for the interactions between snow metamorphism and LAI radiative properties, to accurately predict the effects of light-absorbing impurities in snow. Moreover, we describe how automated hyperspectral reflectance can be used to estimate effective impurities surface content in snow. Finally we demonstrate how these reflectances measurements either from in situ or satellite data can be used via an assimilation scheme to constrain snowpack ensemble simulations and better predict the snowpack state and evolution.

Pre–Radiation Therapy Fluorine 18 Fluorodeoxyglucose PET Helps Identify Patients with Esophageal Cancer at High Risk for Radiation Pneumonitis

PubMed Central

Castillo, Richard; Pham, Ngoc; Castillo, Edward; Aso-Gonzalez, Samantha; Ansari, Sobiya; Hobbs, Brian; Palacio, Diana; Skinner, Heath

2015-01-01

Purpose To examine the association between pre–radiation therapy (RT) fluorine 18 fluorodeoxyglucose (FDG) uptake and post-RT symptomatic radiation pneumonitis (RP). Materials and Methods In accordance with the retrospective study protocol approved by the institutional review board, 228 esophageal cancer patients who underwent FDG PET/CT before chemotherapy and RT were examined. RP symptoms were evaluated by using the Common Terminology Criteria for Adverse Events, version 4.0, from the consensus of five clinicians. By using the cumulative distribution of standardized uptake values (SUVs) within the lungs, those values greater than 80%–95% of the total lung voxels were determined for each patient. The effect of pre-chemotherapy and RT FDG uptake, dose, and patient or treatment characteristics on RP toxicity was studied by using logistic regression. Results The study subjects were treated with three-dimensional conformal RT (n = 36), intensity-modulated RT (n = 135), or proton therapy (n = 57). Logistic regression analysis demonstrated elevated FDG uptake at pre-chemotherapy and RT was related to expression of RP symptoms. Study subjects with elevated 95% percentile of the SUV (SUV95) were more likely to develop symptomatic RP (P < .000012); each 0.1 unit increase in SUV95 was associated with a 1.36-fold increase in the odds of symptomatic RP. Receiver operating characteristic (ROC) curve analysis resulted in area under the ROC curve of 0.676 (95% confidence interval: 0.58, 0.77), sensitivity of 60%, and specificity of 71% at the 1.17 SUV95 threshold. CT imaging and dosimetric parameters were found to be poor predictors of RP symptoms. Conclusion The SUV95, a biomarker of pretreatment pulmonary metabolic activity, was shown to be prognostic of symptomatic RP. Elevation in this pretreatment biomarker identifies patients at high risk for posttreatment symptomatic RP. © RSNA, 2015 PMID:25584706

Part II. Initial molecular and cellular characterization of high nitric oxide-adapted human tongue squamous cell carcinoma cell lines.

PubMed

Tarjan, Gabor; Haines, G Kenneth; Vesper, Benjamin J; Xue, Jiaping; Altman, Michael B; Yarmolyuk, Yaroslav R; Khurram, Huma; Elseth, Kim M; Roeske, John C; Aydogan, Bulent; Radosevich, James A

2011-02-01

It is not understood why some head and neck squamous cell carcinomas, despite having identical morphology, demonstrate different tumor aggressiveness, including radioresistance. High levels of the free radical nitric oxide (NO) and increased expression of the NO-producing enzyme nitric oxide synthase (NOS) have been implicated in tumor progression. We previously adapted three human tongue cancer cell lines to high NO (HNO) levels by gradually exposing them to increasing concentrations of an NO donor; the HNO cells grew faster than their corresponding untreated ("parent") cells, despite being morphologically identical. Herein we initially characterize the HNO cells and compare the biological properties of the HNO and parent cells. HNO/parent cell line pairs were analyzed for cell cycle distribution, DNA damage, X-ray and ultraviolet radiation response, and expression of key cellular enzymes, including NOS, p53, glutathione S-transferase-pi (GST-pi), apurinic/apyrimidinic endonuclease-1 (APE1), and checkpoint kinases (Chk1, Chk2). While some of these properties were cell line-specific, the HNO cells typically exhibited properties associated with a more aggressive behavior profile than the parent cells (greater S-phase percentage, radioresistance, and elevated expression of GST-pi/APE1/Chk1/Chk2). To correlate these findings with conditions in primary tumors, we examined the NOS, GST-pi, and APE1 expression in human tongue squamous cell carcinomas. A majority of the clinical samples exhibited elevated expression levels of these enzymes. Together, the results herein suggest cancer cells exposed to HNO levels can develop resistance to free radicals by upregulating protective mechanisms, such as GST-pi and APE1. These upregulated defense mechanisms may contribute to their aggressive expression profile.

A Baroclinic Nocturnal Low-Level Jet over the Great Plains

NASA Astrophysics Data System (ADS)

Shapiro, A.; Gebauer, J.; Fedorovich, E.

2016-12-01

The nocturnal low-level jet (LLJ) is a warm-season atmospheric boundary layer phenomenon common to the Great Plains of the United States and other places worldwide. Low-level jets develop around sunset in fair weather conditions conducive to strong radiative cooling and reach peak intensity in the pre-dawn hours. Key precursors to their formation are the establishment of a strongly turbulent dry convective boundary layer during the afternoon and a rapid cessation of the turbulence during the early evening transition. The two main physical mechanisms underpinning the generation of nocturnal low-level jets over the Great Plains are associated with diurnal variations in turbulent mixing (Blackadar mechanism) and in heating/cooling of the gently sloping terrain (Holton mechanism). These two mechanisms were recently combined within a single unified theory (Shapiro et al. 2016) in which analytical solutions of the Boussinesq equations of motion and thermal energy were obtained. In the present study we apply the unified theory to the case where the free-atmosphere geostrophic wind is zero, and there is strong daytime heating of the slope. When appropriately tuned, the analytical model predicts the low elevation (jet nose within 250 m of the ground) and strong wind maximum (> 15 m/s) characteristic of the strongly baroclinic jet observed over northern Kansas on 10 June 2015 during Intensive Observing Period 7 of the Plains Elevated Convection at Night (PECAN) field experiment. Although there is generally good agreement between the tuned model and observations (including soundings and aircraft data), our main interest is in investigating the profound roles of the free-atmosphere stratification, daytime heating, and daytime/nighttime mixing on jet strength and structure.

[Prevalence of Elevated Lipoprotein (a) Levels in Patients < 60 Years of Age with Retinal Vein Occlusion].

PubMed

Kuhli-Hattenbach, C; Hellstern, P; Miesbach, W; Kohnen, T; Hattenbach, L-O

2018-01-01

The potential impact of elevated Lipoprotein (a) [Lp(a)] levels on retinal venous occlusive (RVO) diseases with regard to age and various risk factors has not been studied extensively. In a retrospective case-control study, thrombophilia data of 106 young patients (< 60 years at the time of the RVO or a previous thromboembolic event) with RVO and 76 healthy subjects were evaluated. Elevated Lp(a) plasma levels were significantly more prevalent among RVO patients (29.2 %) than among controls (9.2 %; p = 0.0009). Lp(a) levels were found to be significantly (p = 0.012) different between patients and controls. Moreover, we found that an unusual personal or family history of thromboembolism was a strong predictor of elevated Lp(a) (p = 0.03). We observed a significant correlation between elevated Lp(a) and other coagulation disorders (p = 0.005). Multivariate analysis showed that elevated lipoprotein(a) levels (OR: 3.5; p = 0.003) were an independent risk factor for the development of RVO. Elevated plasma levels of Lp(a) are associated with the development of RVO. Selective screening of young patients and subjects with a personal or family history of thromboembolism may be helpful in identifying RVO patients with elevated Lp(a). Georg Thieme Verlag KG Stuttgart · New York.

Selenium and mercury have a synergistic negative effect on fish reproduction.

PubMed

Penglase, S; Hamre, K; Ellingsen, S

2014-04-01

Selenium (Se) can reduce the negative impacts of mercury (Hg) toxicity on growth and survival, but little is known about how these two elements interact in reproduction. In the following study we explored the effects of organic Hg and Se on the growth, survival and reproduction of female zebrafish (Danio rerio). Fish were fed one of four diets from 73 until 226 dpf in a 2 × 2 factorial design, using selenomethionine (SeMet) and methylmercury (MeHg) as the Se and Hg sources, respectively. Each diet contained Se at either requirement (0.7 mg Se/kg DM) or elevated levels (10 mg Se/kgDM), and Hg at either low (0.05 mg Hg/kg DM) or elevated (12 mg Hg/kg DM) levels. Between 151 and 206 dpf the female fish were pairwise crossed against untreated male fish and the mating success, fecundity, embryo survival, and subsequent overall reproductive success were measured. Elevated dietary Se reduced Hg levels in both the adult fish and their eggs. Elevated dietary Hg and Se increased egg Se levels to a greater extent than when dietary Se was elevated alone. At elevated maternal intake levels, egg concentrations of Se and Hg reflected the maternal dietary levels and not the body burdens of the adult fish. Elevated dietary Hg reduced the growth and survival of female fish, but these effects were largely prevented with elevated dietary Se. Elevated dietary Se alone did not affect fish growth or survival. Compared to other treatments, elevated dietary Hg alone increased both mating and overall reproductive success with <100 days of exposure, but decreased these parameters with >100 days exposure. Elevated dietary Se decreased fecundity, embryo survival, and overall reproductive success. The combination of elevated Se and Hg had a synergistic negative effect on all aspects of fish reproduction compared to those groups fed elevated levels of either Se or Hg. Overall the data demonstrate that while increased dietary Se may reduce adverse effects of Hg on the growth and survival in adult fish, it can negatively affect fish reproductive potential, and the effect on reproduction is enhanced in the presence of elevated Hg. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison between Silicon-Carbide and diamond for fast neutron detection at room temperature

NASA Astrophysics Data System (ADS)

Obraztsova, O.; Ottaviani, L.; Klix, A.; Döring, T.; Palais, O.; Lyoussi, A.

2018-01-01

Neutron radiation detector for nuclear reactor applications plays an important role in getting information about the actual neutron yield and reactor environment. Such detector must be able to operate at high temperature (up to 600° C) and high neutron flux levels. It is worth nothing that a detector for industrial environment applications must have fast and stable response over considerable long period of use as well as high energy resolution. Silicon Carbide is one of the most attractive materials for neutron detection. Thanks to its outstanding properties, such as high displacement threshold energy (20-35 eV), wide band gap energy (3.27 eV) and high thermal conductivity (4.9 W/cm·K), SiC can operate in harsh environment (high temperature, high pressure and high radiation level) without additional cooling system. Our previous analyses reveal that SiC detectors, under irradiation and at elevated temperature, respond to neutrons showing consistent counting rates as function of external reverse bias voltages and radiation intensity. The counting-rate of the thermal neutron-induced peak increases with the area of the detector, and appears to be linear with respect to the reactor power. Diamond is another semi-conductor considered as one of most promising materials for radiation detection. Diamond possesses several advantages in comparison to other semiconductors such as a wider band gap (5.5 eV), higher threshold displacement energy (40-50 eV) and thermal conductivity (22 W/cm·K), which leads to low leakage current values and make it more radiation resistant that its competitors. A comparison is proposed between these two semiconductors for the ability and efficiency to detect fast neutrons. For this purpose the deuterium-tritium neutron generator of Technical University of Dresden with 14 MeV neutron output of 1010 n·s-1 is used. In the present work, we interpret the first measurements and results with both 4H-SiC and chemical vapor deposition (CVD) diamond detectors irradiated with 14 MeV neutrons at room temperature.

Serum biochemical markers in lung cancer.

PubMed Central

Burt, R. W.; Ratcliffe, J. G.; Stack, B. H.; Cuthbert, J.; Kennedy, R. S.; Corker, C. S.; Franchimont, P.; Spilg, W. G.; Stimson, W. H.

1978-01-01

The prevalence of elevated serum levels of 5 potential tumour-associated antigens was determined in patients with lung cancer sampled at the time of initial presentation, using age- and sex-matched patients with benign lung disease as controls. Elevated levels (greater than upper 95th centile of controls) were found as follows: carcinoembryonic antigen (CEA), 17%; pregnancy-associated alpha-macroglobulin (PAM), 16%; casein 14%; human chorionic gonadotrophin (HCG) 6%; alpha-foetoprotein (AFP), 1.5%. The prevalence of elevated CEA levels (but not other markers) was higher in patients with evidence of extra-thoracic tumour spread (23%) mainly due to anaplastic tumours and adenocarcinomas. A degree of concordance of elevated marker levels occurred with CEA, HCG, casein and AFP, but there was a striking discordance of elevated CEA and PAM levels. Simultaneous assays of CEA and PAM will detect the majority of patients with elevations of any of the markers studied, and are likely to be the most useful biochemical markers in following the response of lung tumours to therapy. PMID:77672

Snow cover distribution over elevation zones in a mountainous catchment

NASA Astrophysics Data System (ADS)

Panagoulia, D.; Panagopoulos, Y.

2009-04-01

A good understanding of the elevetional distribution of snow cover is necessary to predict the timing and volume of runoff. In a complex mountainous terrain the snow cover distribution within a watershed is highly variable in time and space and is dependent on elevation, slope, aspect, vegetation type, surface roughness, radiation load, and energy exchange at the snow-air interface. Decreases in snowpack due to climate change could disrupt the downstream urban and agricultural water supplies, while increases could lead to seasonal flooding. Solar and longwave radiation are dominant energy inputs driving the ablation process. Turbulent energy exchange at the snow cover surface is important during the snow season. The evaporation of blowing and drifting snow is strongly dependent upon wind speed. Much of the spatial heterogeneity of snow cover is the result of snow redistribution by wind. Elevation is important in determining temperature and precipitation gradients along hillslopes, while the temperature gradients determine where precipitation falls as rain and snow and contribute to variable melt rates within the hillslope. Under these premises, the snow accumulation and ablation (SAA) model of the US National Weather Service (US NWS) was applied to implement the snow cover extent over elevation zones of a mountainous catchment (the Mesochora catchment in Western-Central Greece), taking also into account the indirectly included processes of sublimation, interception, and snow redistribution. The catchment hydrology is controlled by snowfall and snowmelt and the simulated discharge was computed from the soil moisture accounting (SMA) model of the US NWS and compared to the measured discharge. The elevationally distributed snow cover extent presented different patterns with different time of maximization, extinction and return during the year, producing different timing of discharge that is a crucial factor for the control and management of water resources systems.

Comparison of the Sensitivity of Surface Downward Longwave Radiation to Changes in Water Vapor at Two High Elevation Sites

NASA Technical Reports Server (NTRS)

Chen, Yonghua; Naud, Catherine M.; Rangwala, Imtiaz; Landry, Christopher C.; Miller, James R.

2014-01-01

Among the potential reasons for enhanced warming rates in many high elevation regions is the nonlinear relationship between surface downward longwave radiation (DLR) and specific humidity (q). In this study we use ground-based observations at two neighboring high elevation sites in Southwestern Colorado that have different local topography and are 1.3 kilometers apart horizontally and 348 meters vertically. We examine the spatial consistency of the sensitivities (partial derivatives) of DLR with respect to changes in q, and the sensitivities are obtained from the Jacobian matrix of a neural network analysis. Although the relationship between DLR and q is the same at both sites, the sensitivities are higher when q is smaller, which occurs more frequently at the higher elevation site. There is a distinct hourly distribution in the sensitivities at both sites especially for high sensitivity cases, although the range is greater at the lower elevation site. The hourly distribution of the sensitivities relates to that of q. Under clear skies during daytime, q is similar between the two sites, however under cloudy skies or at night, it is not. This means that the DLR-q sensitivities are similar at the two sites during daytime but not at night, and care must be exercised when using data from one site to infer the impact of water vapor feedbacks at another site, particularly at night. Our analysis suggests that care should be exercised when using the lapse rate adjustment to infill high frequency data in a complex topographical region, particularly when one of the stations is subject to cold air pooling as found here.

Using Satellites to Investigate the Sensitivity of Longwave Downward Radiation to Water Vapor at High Elevations

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Miller, James R.; Landry, Chris

2012-01-01

Many studies suggest that high-elevation regions may be among the most sensitive to future climate change. However, in situ observations in these often remote locations are too sparse to determine the feedbacks responsible for enhanced warming rates. One of these feedbacks is associated with the sensitivity of longwave downward radiation (LDR) to changes in water vapor, with the sensitivity being particularly large in many high-elevation regions where the average water vapor is often low. We show that satellite retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Clouds and the Earth's Radiant Energy System (CERES) can be used to expand the current ground-based observational database and that the monthly averaged clear-sky satellite estimates of humidity and LDR are in good agreement with the well-instrumented Center for Snow and Avalanche Studies ground-based site in the southwestern Colorado Rocky Mountains. The relationship between MODIS-retrieved precipitable water vapor and surface specific humidity across the contiguous United States was found to be similar to that previously found for the Alps. More important, we show that satellites capture the nonlinear relationship between LDR and water vapor and confirm that LDR is especially sensitive to changes in water vapor at high elevations in several midlatitude mountain ranges. Because the global population depends on adequate fresh water, much of which has its source in high mountains, it is critically important to understand how climate will change there. We demonstrate that satellites can be used to investigate these feedbacks in high-elevation regions where the coverage of surface-based observations is insufficient to do so.

Contribution of Spaceflight Environmental Factors to Vision Risks

NASA Technical Reports Server (NTRS)

Zanello, Susana B.

2011-01-01

The risk of visual impairment and elevated intracranial pressure as a result of low-earth orbit microgravity exposure has directed our attention and research efforts to the eye. While the alterations observed in astronauts returning from long duration missions include vision and neuroanatomical changes observed by non-invasive methods, other effects and subsequent tissue responses at the molecular and cellular level can only be studied by accessing the tissue itself. As a result of this need, several studies are currently taking place within the Human and Health Countermeasures Element (HHC) that use animal models for eye research. The rodent eye has many similarities to the human eye, and both rats and mice have historically been used as models of human eye disease, aiding in the identification of the disease genes, elucidation of mechanisms of disease, as well as in the assessment of therapeutic treatments. These studies attempt to answer two central questions in the etiology of possible vision alterations in the environment of space exploration missions. The first is: what effects and response mechanisms take place in the different eye structures at the cellular and molecular level? The second question is directed to elucidate the contribution of the various environmental stressors (radiation, nutrition, fluid shift) to these effects. Collaborative approaches with internal and external investigators have allowed performing these studies in a most cost-effective fashion, providing preliminary data and laying the bases for testing further hypotheses in future and specifically designed animal experiments. From a study centered on the radioadaptive response in mice, we have learned that the retina responds to low and high dose gamma radiation by elevating antioxidant-related genes at early time points (4hrs) and that this response returns to control levels after 1 day post-irradiation. We are expanding this research with another collaborative study that investigates the combined effects of radiation exposure and iron overload on sensitivity to radiation injury in rat eyes. All main eye structures will be analyzed in this study: retina, lens and cornea. A study in collaboration with the Space Human Factors and Habitability Element (SHFH) investigates the effects of lunar dust exposure on the rat cornea. It is anticipated that common underlying oxidative stress mechanisms of damage may be observed as a result of these three stressors: radiation, nutritional iron and lunar dust. The contribution of fluid shift is addressed by a study using rats subjected to hindlimb suspension. The hypothesis to be tested in this study is that the mechanical stress imparted by the pressure differential across the optic disc and lamina cribosa will impact oxygenation (therefore causing oxidative stress and hypoxia) and cell survival. This study also includes the assessment of two nutritional antioxidant countermeasures: epigallocatechin gallate (green tea) and resveratrol. Finally, as a result of two successful tissue sharing efforts, we are proceeding with the analysis of eye samples of mice aboard two shuttle missions: STS-133 and STS-135. Results from the STS-133 study are presented in an independent abstract. Briefly, the results show that spaceflight represents a source of environmental stress that directly translates into oxidative and cellular stress in the retina. Similar analysis is also planned for the cornea. These samples add large value to our current vision research as they provide data on the direct effects of low-earth orbit spaceflight on eye structures and physiology.

Physiological Limits along an Elevational Gradient in a Radiation of Montane Ground Beetles

PubMed Central

Slatyer, Rachel A.; Schoville, Sean D.

2016-01-01

A central challenge in ecology and biogeography is to determine the extent to which physiological constraints govern the geographic ranges of species along environmental gradients. This study tests the hypothesis that temperature and desiccation tolerance are associated with the elevational ranges of 12 ground beetle species (genus Nebria) occurring on Mt. Rainier, Washington, U.S.A. Species from higher elevations did not have greater cold tolerance limits than lower-elevation species (all species ranged from -3.5 to -4.1°C), despite a steep decline in minimum temperature with elevation. Although heat tolerance limits varied among species (from 32.0 to 37.0°C), this variation was not generally associated with the relative elevational range of a species. Temperature gradients and acute thermal tolerance do not support the hypothesis that physiological constraints drive species turnover with elevation. Measurements of intraspecific variation in thermal tolerance limits were not significant for individuals taken at different elevations on Mt. Rainier, or from other mountains in Washington and Oregon. Desiccation resistance was also not associated with a species’ elevational distribution. Our combined results contrast with previously-detected latitudinal gradients in acute physiological limits among insects and suggest that other processes such as chronic thermal stress or biotic interactions might be more important in constraining elevational distributions in this system. PMID:27043311

Temperature elevation in the fetus from electromagnetic exposure during magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Kikuchi, Satoru; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi

2010-04-01

This study computationally assessed the temperature elevations due to electromagnetic wave energy deposition during magnetic resonance imaging in non-pregnant and pregnant woman models. We used a thermal model with thermoregulatory response of the human body for our calculations. We also considered the effect of blood temperature variation on body core temperature. In a thermal equilibrium state, the temperature elevations in the intrinsic tissues of the woman and fetal tissues were 0.85 and 0.61 °C, respectively, at a whole-body averaged specific absorption rate of 2.0 W kg-1, which is the restriction value of the International Electrotechnical Commission for the normal operating mode. As predicted, these values are below the temperature elevation of 1.5 °C that is expected to be teratogenic. However, these values exceeded the recommended temperature elevation limit of 0.5 °C by the International Commission on Non-Ionizing Radiation Protection. We also assessed the irradiation time required for a temperature elevation of 0.5 °C at the aforementioned specific absorption rate. As a result, the calculated irradiation time was 40 min.

Reply to comment by Rainer Facius et al. on "U.S. Government shutdown degrades aviation radiation monitoring during solar radiation storm"

NASA Astrophysics Data System (ADS)

Tobiska, W. Kent; Gersey, Brad; Wilkins, Richard; Mertens, Chris; Atwell, William; Bailey, Justin

2014-05-01

The premise of this comment perpetuates an unfortunate trend among some radiation researchers to minimize potential risks to human tissue from low-radiation sources. In fact, this discussion on the risk uncertainties of low-dose radiation further illustrates the need for more measurements and a program of active monitoring, especially when solar eruptive events can substantially elevate the radiation environment. This debate also highlights the context of a bigger problem; i.e., how do we as professionals act with due diligence to take the immense body of knowledge of space weather radiation effects on human tissue and distil it into ideas that regulatory agencies can use to maximize the safety of a population at risk. The focus of our article on radiation risks due to solar energetic particle events starts with our best assessment of risks and is based on the body of scientific knowledge while, at the same time, erring on the side of public safety. The uncertainty inherent in our assessment is accepted and described with this same philosophy in mind.

Ultraviolet Radiation–Induced Cataract in Mice: The Effect of Age and the Potential Biochemical Mechanism

PubMed Central

Zhang, Jie; Yan, Hong; Löfgren, Stefan; Tian, Xiaoli; Lou, Marjorie F.

2012-01-01

Purpose. To study the effect of age on the morphologic and biochemical alterations induced by in vivo exposure of ultraviolet radiation (UV). Methods. Young and old C57BL/6 mice were exposed to broadband UVB+UVA and euthanized after 2 days. Another batch of UV-exposed young mice was monitored for changes after 1, 2, 4, and 8 days. Age-matched nonexposed mice served as controls. Lens changes were documented in vivo by slit-lamp biomicroscopy and dark field microscopy photographs ex vivo. Lens homogenates were analyzed for glutathione (GSH) level, and the activities of thioredoxin (Trx), thioltransferase (TTase), and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Glutathionylated lens proteins (PSSGs) were detected by immunoblotting using GSH antibody. Western blot analysis was also done for the expression levels of TTase and Trx. Results. Both age groups developed epithelial and superficial anterior subcapsular cataract at 2 days postexposure. The lens GSH level and G3PD activity were decreased, and PSSGs were elevated in both age groups, but more prominent in the older mice. TTase and Trx activity and protein expression were elevated only in the young mice. Interestingly, lens TTase and Trx in the young mice showed a transient increase, peaking at 2 days after UV exposure and returning to baseline at day 8, corroborated by lens transparency. Conclusions. The lenses of old mice were more susceptible to UV radiation–induced cataract. The upregulated TTase and Trx likely provided oxidation damage repair in the young mice. PMID:23010639

High-Intensity Targeted Screening for Elevated Blood Lead Levels Among Children in 2 Inner-City Chicago Communities

PubMed Central

Dignam, Timothy A.; Evens, Anne; Eduardo, Eduard; Ramirez, Shokufeh M.; Caldwell, Kathleen L.; Kilpatrick, Nikki; Noonan, Gary P.; Flanders, W. Dana; Meyer, Pamela A.; McGeehin, Michael A.

2004-01-01

Objectives. We assessed the prevalence of elevated blood lead levels (≥ 10 micrograms of lead per deciliter of blood), risk factors, and previous blood lead testing among children in 2 high-risk Chicago, Ill, communities. Methods. Through high-intensity targeted screening, blood lead levels were tested and risks were assessed among a representative sample of children aged 1 to 5 years who were at risk for lead exposure. Results. Of the 539 children who were tested, 27% had elevated blood lead levels, and 61% had never been tested previously. Elevated blood lead levels were associated with chipped exterior house paint. Conclusions. Most of the children who lived in these communities—where the prevalence for elevated blood lead levels among children was 12 times higher than the national prevalence—were not tested for lead poisoning. Our findings highlight the need for targeted community outreach that includes testing blood lead levels in accordance with the American Academy of Pediatrics’ recommendations. PMID:15514235

Evolutionary radiation of earless frogs in the Andes: molecular phylogenetics and habitat shifts in high-elevation terrestrial breeding frogs

PubMed Central

Lehr, Edgar; Rabosky, Daniel L.

2018-01-01

The loss of hearing structures and loss of advertisement calls in many terrestrial breeding frogs (Strabomantidae) living at high elevations in South America are common and intriguing phenomena. The Andean frog genus Phrynopus Peters, 1873 has undergone an evolutionary radiation in which most species lack the tympanic membrane and tympanic annulus, yet the phylogenetic relationships among species in this group remain largely unknown. Here, we present an expanded molecular phylogeny of Phrynopus that includes 24 nominal species. Our phylogeny includes Phrynopus peruanus, the type species of the genus, and 10 other species for which genetic data were previously unavailable. We found strong support for monophyly of Phrynopus, and that two nominal species—Phrynopus curator and Phrynopus nicoleae—are junior synonyms of Phrynopus tribulosus. Using X-ray computed tomography (CT) imaging, we demonstrate that the absence of external hearing structures is associated with complete loss of the auditory skeletal elements (columella) in at least one member of the genus. We mapped the tympanum condition on to a species tree to infer whether the loss of hearing structures took place once or multiple times. We also assessed whether tympanum condition, body size, and body shape are associated with the elevational distribution and habitat use. We identified a single evolutionary transition that involved the loss of both the tympanic membrane and tympanic annulus, which in turn is correlated with the absence of advertisement calls. We also identified several species pairs where one species inhabits the Andean grassland and the other montane forest. When accounting for phylogenetic relatedness among species, we detected a significant pattern of increasing body size with increasing elevation. Additionally, species at higher elevations tend to develop shorter limbs, shorter head, and shorter snout than species living at lower elevations. Our findings strongly suggest a link between ecological divergence and morphological diversity of terrestrial breeding frogs living in montane gradients. PMID:29492332

Effects of Elevated CO2 on Levels of Primary Metabolites and Transcripts of Genes Encoding Respiratory Enzymes and Their Diurnal Patterns in Arabidopsis thaliana: Possible Relationships with Respiratory Rates

PubMed Central

Watanabe, Chihiro K.; Sato, Shigeru; Yanagisawa, Shuichi; Uesono, Yukifumi; Terashima, Ichiro; Noguchi, Ko

2014-01-01

Elevated CO2 affects plant growth and photosynthesis, which results in changes in plant respiration. However, the mechanisms underlying the responses of plant respiration to elevated CO2 are poorly understood. In this study, we measured diurnal changes in the transcript levels of genes encoding respiratory enzymes, the maximal activities of the enzymes and primary metabolite levels in shoots of Arabidopsis thaliana grown under moderate or elevated CO2 conditions (390 or 780 parts per million by volume CO2, respectively). We examined the relationships between these changes and respiratory rates. Under elevated CO2, the transcript levels of several genes encoding respiratory enzymes increased at the end of the light period, but these increases did not result in changes in the maximal activities of the corresponding enzymes. The levels of some primary metabolites such as starch and sugar phosphates increased under elevated CO2, particularly at the end of the light period. The O2 uptake rate at the end of the dark period was higher under elevated CO2 than under moderate CO2, but higher under moderate CO2 than under elevated CO2 at the end of the light period. These results indicate that the changes in O2 uptake rates are not directly related to changes in maximal enzyme activities and primary metabolite levels. Instead, elevated CO2 may affect anabolic processes that consume respiratory ATP, thereby affecting O2 uptake rates. PMID:24319073

Thermoregulation of water foraging honeybees--balancing of endothermic activity with radiative heat gain and functional requirements.

PubMed

Kovac, Helmut; Stabentheiner, Anton; Schmaranzer, Sigurd

2010-12-01

Foraging honeybees are subjected to considerable variations of microclimatic conditions challenging their thermoregulatory ability. Solar heat is a gain in the cold but may be a burden in the heat. We investigated the balancing of endothermic activity with radiative heat gain and physiological functions of water foraging Apis mellifera carnica honeybees in the whole range of ambient temperatures (T(a)) and solar radiation they are likely to be exposed in their natural environment in Middle Europe. The mean thorax temperature (T(th)) during foraging stays was regulated at a constantly high level (37.0-38.5 °C) in a broad range of T(a) (3-30 °C). At warmer conditions (T(a)=30-39 °C) T(th) increased to a maximal level of 45.3 °C. The endothermic temperature excess (difference of T(body)-T(a) of living and dead bees) was used to assess the endogenously generated temperature elevation as a correlate of energy turnover. Up to a T(a) of ∼30 °C bees used solar heat gain for a double purpose: to reduce energetic expenditure and to increase T(th) by about 1-3 °C to improve force production of flight muscles. At higher T(a) they exhibited cooling efforts to get rid of excess heat. A high T(th) also allowed regulation of the head temperature high enough to guarantee proper function of the bees' suction pump even at low T(a). This shortened the foraging stays and this way reduced energetic costs. With decreasing T(a) bees also reduced arrival body weight and crop loading to do both minimize costs and optimize flight performance. Copyright © 2010 Elsevier Ltd. All rights reserved.

Atomic bomb testing and its effects on global male to female ratios at birth.

PubMed

Grech, Victor

2015-01-01

Fallout from atomic bomb testing may travel great distances before precipitating. Males are born in excess of females in a ratio that approximates 0.515 (M/T: male live births divided by total live births. Radiation increases M/T by causing lethal malformations that affect female more than male foetuses, decreasing total births. This study was carried out in order to ascertain whether the effects of increased background radiation levels from atomic weapon testing had any widespread effects on M/T and births in the Americas, Europe, Asia and Australasia in relation to the Partial Test Ban Treaty of 1963. Annual live births by gender were obtained from a World Health Organization dataset and annual number of atomic bomb tests were also obtained (historical data). Overall, 94.5% of births studied showed a uniform reduction in M/T between the early 1950s to the late 1960s, followed by an increase to the mid-1970s, with a subsequent decline. A negative correlation of M/T with total births was found in 66% of births studied, and these were the regions which exhibited the rising M/T pattern in the 1970s. The birth deficit for countries with significant correlations of total births with M/T (North America, Europe and Asia) was estimated at 10090701. A rising M/T was found in most regions in temporal association with atomic weapon testing. Most of these regions also had an associated decline in total births. Elevated levels of man-made ambient radiation may have reduced total births, affecting pregnancies carrying female pregnancies more than those carrying male pregnancies, thereby skewing M/T toward a higher male proportion.