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1

Assessing plant response to ambient ozone: growth of young apple trees in open-top chambers and corresponding ambient air plots  

International Nuclear Information System (INIS)

Open-top chambers (OTCs) and corresponding ambient air plots (AA) were used to assess the impact of ambient ozone on growth of newly planted apple trees at the Montague Field research center in Amherst, MA. Two-year-old apple trees (Malus domestica Borkh 'Rogers Red McIntosh') were planted in the ground in circular plots. Four of the plots were enclosed with OTCs where incoming air was charcoal-filtered (CF); four were enclosed with OTCs where incoming air was not charcoal-filtered (NF) and four were not enclosed, allowing access to ambient air conditions (AA). Conditions in both CF and NF OTCs resulted in increased tree growth and changed incidence of disease and arthropod pests, compared to trees in AA. As a result, we were not able to use the OTC method to assess the impact of ambient ozone on growth of young apple trees in Amherst, MA. - Capsule: Conditions in charcoal-filtered and non-filtered open-top chambers affected apple tree growth equally and prevented assessment of ambient ozone effects

2

Assessing plant response to ambient ozone: growth of young apple trees in open-top chambers and corresponding ambient air plots  

Energy Technology Data Exchange (ETDEWEB)

Open-top chambers (OTCs) and corresponding ambient air plots (AA) were used to assess the impact of ambient ozone on growth of newly planted apple trees at the Montague Field research center in Amherst, MA. Two-year-old apple trees (Malus domestica Borkh 'Rogers Red McIntosh') were planted in the ground in circular plots. Four of the plots were enclosed with OTCs where incoming air was charcoal-filtered (CF); four were enclosed with OTCs where incoming air was not charcoal-filtered (NF) and four were not enclosed, allowing access to ambient air conditions (AA). Conditions in both CF and NF OTCs resulted in increased tree growth and changed incidence of disease and arthropod pests, compared to trees in AA. As a result, we were not able to use the OTC method to assess the impact of ambient ozone on growth of young apple trees in Amherst, MA. - Capsule: Conditions in charcoal-filtered and non-filtered open-top chambers affected apple tree growth equally and prevented assessment of ambient ozone effects.

Manning, W.J. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States)]. E-mail: wmanning@microbio.umass.edu; Cooley, D.R. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Tuttle, A.F. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Frenkel, M.A. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States); Bergweiler, C.J. [Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA 01003-9298 (United States)

2004-12-01

3

Assessing effects of ambient ozone on injury and growth of Trifolium subterraneum at four rural sites in the Netherlands with ethylenediurea (EDU)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To assess adverse effects of ambient ozone on injury and growth, EDU (ethylenediurea) and non-EDU-treated plants of subterranean clover (Trifolium subterraneum cv. Geraldton) were exposed to ambient air at four rural sites in the Netherlands. In each of two successive experiments of eight weeks during the 1994 growing season, an intermediate harvest (cutting) was performed after four weeks of exposure. Concentrations of ambient ozone were high in Experiment 1 (June 21–August 16) and relativ...

Tonneijck, A. E. G.; Dijk, C. J.

1997-01-01

4

Establishing a cause and effect relationship for ambient ozone exposure and tree growth in the forest: Progress and an experimental approach  

International Nuclear Information System (INIS)

Much has been written about the effects of ambient ozone on tree growth. Cause and effect has been established with seedlings in chambers. Results from multi-year studies with older tree seedlings, in open-top chambers, have been inconclusive, due to chamber effects. Extrapolation of results from chambers to trees in the forest is not possible. Predictive models for forest tree growth reductions caused by ozone have been developed, but not verified. Dendrochronological methods have been used to establish correlations between radial growth reductions in forest trees and ambient ozone exposure. The protective chemical ethylenediurea (EDU) has been used to protect tree seedlings from ozone injury. An experimental approach is advocated here that utilizes forest trees selected for sensitivity and non-sensitivity to ozone, dendrochronological methods, the protective chemical EDU, and monitoring data for ambient ozone, stomatal conductance, soil moisture potential, air temperature, PAR, etc. in long-term investigations to establish cause and effect relationships. - Progress is reviewed and an experimental approach is proposed to demonstrate a cause and effect relationship for ambient ozone and forest tree growth

5

Contribution of ambient ozone to Scots pine defoliation and reduced growth in the Central European forests: A Lithuanian case study  

International Nuclear Information System (INIS)

The study aimed to explore if changes in crown defoliation and stem growth of Scots pines (Pinus sylvestris L.) could be related to changes in ambient ozone (O3) concentration in central Europe. To meet this objective the study was performed in 3 Lithuanian national parks, close to the ICP integrated monitoring stations from which data on meteorology and pollution were provided. Contribution of peak O3 concentrations to the integrated impact of acidifying compounds and meteorological parameters on pine stem growth was found to be more significant than its contribution to the integrated impact of acidifying compounds and meteorological parameters on pine defoliation. Findings of the study provide statistical evidence that peak concentrations of ambient O3 can have a negative impact on pine tree crown defoliation and stem growth reduction under field conditions in central and northeastern Europe where the AOT40 values for forests are commonly below their phytotoxic levels. - Peak ozone concentrations is one of the key factors affecting Scots pine trees

6

INTERACTION OF SOIL MOISTURE STRESS AND AMBIENT OZONE ON GROWTH AND YIELDS OF SOYBEANS  

Science.gov (United States)

A field experiment was conducted in open-top chambers to determine how interactions of soil moisture stress and exposure to ozone may affect soybean yields. Cultivars Williams and Forrest were grown in 1982 and Williams & Corsoy in 1983. Five levels of O3-including charcoal-filte...

7

Growth, yield and quality attributes of a tropical potato variety (Solanum tuberosum L. cv Kufri chandramukhi) under ambient and elevated carbon dioxide and ozone and their interactions.  

Science.gov (United States)

The present study was designed to study the growth and yield responses of a tropical potato variety (Solanum tuberosum L. cv. Kufri chandramukhi) to different levels of carbon dioxide (382 and 570ppm) and ozone (50 and 70ppb) in combinations using open top chambers (OTCs). Plants were exposed to three ozone levels in combination with ambient CO2 and two ozone levels at elevated CO2. Significant increments in leaf area and total biomass were observed under elevated CO2 in combination with ambient O3 (ECO2+AO3) and elevated O3 (ECO2+EO3), compared to the plants grown under ambient concentrations (ACO2+AO3). Yield measured as fresh weight of potato also increased significantly under ECO2+AO3 and ECO2+EO3. Yield, however, reduced under ambient (ACO2+AO3) and elevated ozone (ACO2+EO3) compared to ACO2 (filtered chamber). Number, fresh and dry weights of tubers of size 35-50mm and>50mm used for direct consumption and industrial purposes, respectively increased maximally under ECO2+AO3. Ambient as well as elevated levels of O3 negatively affected the growth parameters and yield mainly due to reductions in number and weight of tubers of sizes >35mm. The quality of potato tubers was also modified under different treatments. Starch content increased and K, Zn and Fe concentrations decreased under ECO2+AO3 and ECO2+EO3 compared to ACO2+AO3. Starch content reduced under ACO2+AO3 and ACO2+EO3 treatments compared to ACO2. These results clearly suggest that elevated CO2 has provided complete protection to ambient O3 as the potato yield was higher under ECO2+AO3 compared to ACO2. However, ambient CO2 is not enough to protect the plants under ambient O3 levels. Elevated CO2 also provided protection against elevated O3 by improving the yield. Quality of tubers is modified by both CO2 and O3, which have serious implications on human health at present and in future. PMID:24507140

Kumari, Sumita; Agrawal, Madhoolika

2014-03-01

8

Assessing the impact of ambient ozone on growth and yield of a rice (Oryza sativa L.) and a wheat (Triticum aestivum L.) cultivar grown in the Yangtze Delta, China, using three rates of application of ethylenediurea (EDU)  

Energy Technology Data Exchange (ETDEWEB)

Foliar applications of ethylenediurea (abbreviated as EDU) were made at 0, 150, 300 or 450 ppm to field-grown rice and wheat in the Yangtze Delta in China. Rice and wheat responded differently to ambient ozone and EDU applications. For wheat, some growth characteristics, such as yield, seed number per plant, seed set rate and harvest index, increased significantly at 300 ppm EDU treatment, while for rice no parameters measured were statistically different regarding EDU application. The reason may be that the wheat cultivar used may be more sensitive to ozone than the rice cultivar. EDU was effective in demonstrating ozone effects on the wheat cultivar, but not on the rice cultivar. Cultivar sensitivity might be an important consideration when assessing the effects of ambient ozone on plants. - Cultivar sensitivity should be considered when using protective chemical to assess the effects of ambient ozone on plants.

Wang Xiaoke [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: wangxk@rcees.ac.cn; Zheng Qiwei [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Yao Fangfang [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Chen Zhan [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Feng Zhaozhong [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Manning, W.J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States)

2007-07-15

9

Assessing the impact of ambient ozone on growth and yield of a rice (Oryza sativa L.) and a wheat (Triticum aestivum L.) cultivar grown in the Yangtze Delta, China, using three rates of application of ethylenediurea (EDU)  

International Nuclear Information System (INIS)

Foliar applications of ethylenediurea (abbreviated as EDU) were made at 0, 150, 300 or 450 ppm to field-grown rice and wheat in the Yangtze Delta in China. Rice and wheat responded differently to ambient ozone and EDU applications. For wheat, some growth characteristics, such as yield, seed number per plant, seed set rate and harvest index, increased significantly at 300 ppm EDU treatment, while for rice no parameters measured were statistically different regarding EDU application. The reason may be that the wheat cultivar used may be more sensitive to ozone than the rice cultivar. EDU was effective in demonstrating ozone effects on the wheat cultivar, but not on the rice cultivar. Cultivar sensitivity might be an important consideration when assessing the effects of ambient ozone on plants. - Cultivar sensitivity should be considered when using protective chemical to assess the effects of ambient ozone on plants

10

Evaluation of physiological, growth and yield responses of a tropical oil crop (Brassica campestris L. var. Kranti) under ambient ozone pollution at varying NPK levels  

Energy Technology Data Exchange (ETDEWEB)

A field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O{sub 3} concentration varied from 41.65 to 54.2 ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O{sub 3}. - NPK level above recommended alleviates the adverse effects of ambient ozone on a tropical mustard cultivar.

Singh, Poonam [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, Madhoolika [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)], E-mail: madhoo58@yahoo.com; Agrawal, Shashi Bhushan [Laboratory of Air Pollution and Global Climate Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)

2009-03-15

11

Evaluation of physiological, growth and yield responses of a tropical oil crop (Brassica campestris L. var. Kranti) under ambient ozone pollution at varying NPK levels  

International Nuclear Information System (INIS)

A field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O3 concentration varied from 41.65 to 54.2 ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O3. - NPK level above recommended alleviates the adverse effects of ambient ozone on a tropical mustard cultivar

12

[Influence of ozone on snap bean under ambient air in two sites of northern China].  

Science.gov (United States)

Tropospheric ozone (O3) has been assumed the most phytotoxic air pollutant and the snap bean (Phaseolus vulgaris L.) is known to be an ozone-sensitive species. Two genotypes (R123, ozone-tolerance, S156, ozone-sensitivity) of snap bean were explored in three places. The objective of this study was to evaluate whether the snap bean was influenced under the current ambient ozone concentration. The findings indicated that the leaves of bean grown at Research Center for Eco-Environmental Sciences (RCEES), Chinese Academy of Sciences and ChangPing showed visible ozone symptoms under the ambient ozone concentration, and the averaged ozone injury proportion in S156 was 23.5% higher than R123 during the entire growth season. The ozone damage to the snap bean depends on the plant growing stages. The injury symptoms appeared just after flowering, increased from the stages of flowering to pod formation, and reached the maximum at the stages of pod maturation. The ratio of S156/R123 in pod yield was 0.48, and 0.24 and 0.73 in the RCEES, ChangPing and Harbin, respectively. The ratio close to 1 was assumed that the plant growth is not affected by ozone, and the lower ratio is, the more damage caused by ozone. Obviously, the current ambient ozone concentration of Beijing area has significantly caused the yield loss of snap bean. PMID:25338389

Yuan, Xiang-Yang; Zhang, Wei-Wei; Sun, Jing-Song; Hu, En-Zhu; Zhang, Yu-Long; Zhang, Hong-Xing; Tian, Yuan; Feng, Zhao-Zhong

2014-08-01

13

AMBIENT OZONE CAUSES UPPER AIRWAYS INFLAMMATION IN CHILDREN  

Science.gov (United States)

Ozone constitutes a major air-pollutant in western Europe. uring the summer national air quality standards are frequently exceeded which justifies concern about the health effects of ozone at ambient concentrations. e studied upper airways inflammation subsequent to ozone exposur...

14

Sensitivity of four hardwood species to ambient ozone in north central Pennsylvania  

Energy Technology Data Exchange (ETDEWEB)

Studies were performed to determine the injury growth response of four native species to ambient ozone on three ridgetop sites of the Allegheny Plateau of north central Pennsylvania. Open-top chambers were established at each site and seedlings of black cherry (Prunus serotina Ehrh.), yellow poplar (Liriodendron tulipifera L.), red oak (Quercus rubra L.), and red maple (Acer rubrum L.) were exposed to ambient air or to charcoal filtered air containing approximately 95, 60 or 40% of ambient ozone in randomized, complete blocks in 1988 and 1989. Black cherry seedlings were also exposed in 1990. Ozone was greatest in 1988 at all sites, and total ozone during the 3-year study was greatest at the westernmost sites. Foliar stipple injury of black cherry and yellow poplar were correlated positively with ozone within and among sites throughout the study. Premature leaf abscission of both species was significantly greater with higher ozone levels at one site in 1988 and 1989. Ozone stipple was not observed on red maple and red oak seedlings. Ambient ozone did not significantly decrease height, basal diameter, or leaf surface area of any species. Possible explanations for temporal and spatial ozone variation and subsequent plant response are discussed. 36 refs., 5 figs., 7 tabs.

Simini, M.; Skelly, J.M.; Davis, D.D.; Savage, J.E.; Comrie, A.C. (Pennsylvania State Univ., Pennsylvania Park, PA (United States))

1992-01-01

15

Study of ambient ozone phytotoxicity in Ukraine and ozone protective effect of some antioxidants.  

Science.gov (United States)

The aim of the study was to assess ambient ozone phytotoxicity in Kyiv (Ukraine) using bioindicator clover plants (Trifolium subterraneum cv. Geraldton) and to test some natural and synthetic antioxidants as ozone protectants. The results obtained showed that ambient ozone concentrations were high enough to cause visible leaf injury in clover. All used substances showed partial ozone protective effect on clover. Water extracts from the leaves of plants, known to contain flavonoids-antioxidants showed weaker ozone protective effect and were less stable in the field conditions than synthetic antioxidants. Among the studied extracts, those from Ocimum basilicum and Tagetes patula were more effective as ozone protectants than the one from Salvia sclarea. PMID:17703879

Blum, Oleg; Didyk, Nataliya

2007-11-19

16

Measuring the penetration of ambient ozone into residential buildings.  

Science.gov (United States)

Much of human exposure to ambient ozone and ozone reaction byproducts occurs inside buildings. However, there are currently no experimental data on the ability of ozone to penetrate through building envelopes and into residences. This paper presents a method to determine the penetration factor for ozone in buildings, and applies it in an unoccupied test house and seven single-family residences. The mean (±SD) ozone penetration factor was measured as 0.79 ± 0.13 in the eight homes using this method, ranging from 0.62 ± 0.09 to 1.02 ± 0.15. An analysis of tests across the homes revealed that ozone penetration was significantly higher in homes with more painted wood envelope materials, homes with larger air leakage exponents from fan pressurization tests, and older homes. The test method utilizes a large calibrated fan to elevate air exchange rates and steady-state indoor ozone concentrations to levels that can be accurately measured, so there is a potential for overpredicting ozone penetration factors. However, evidence suggests that this bias is likely small in most of the homes, and, even if a bias exists, the measured ozone penetration factors were lower than the usual assumption of unity in seven of the eight tested homes. PMID:22146069

Stephens, Brent; Gall, Elliott T; Siegel, Jeffrey A

2012-01-17

17

Effects of a three-year exposure to ambient ozone on biomass allocation in poplar using ethylenediurea  

International Nuclear Information System (INIS)

We examined the effect of ambient ozone on visible foliar injury, growth and biomass in field-grown poplar cuttings of an Oxford clone sensitive to ozone (Populus maximoviczii Henry × berolinensis Dippel) irrigated with ethylenediurea (EDU) or water for three years. EDU is used as an ozone protectant for plants. Protective effects of EDU on ozone visible injury were found. As a result, poplar trees grown under EDU treatment increased leaves, lateral branches and root density in the third year, although no significant enhancement of stem height and diameter was found. Ambient ozone (AOT40, 24.6 ppm h; diurnal hourly average, 40.3 ppb) may finally reduce carbon gain by reducing the number of branches, and thus sites for leaf formation, in ozone-sensitive poplar trees under not-limiting conditions. -- Highlights: •A fast-growing ozone-sensitive poplar clone was treated with the ozone protectant ethylenediurea (EDU) for three years. •Ambient ozone reduced allocation of biomass to leaves, roots and lateral branches. •Effects on stem length and diameter were not significant. •EDU protected from ozone visible foliar injury and reduction of biomass accumulation. -- Ozone reduced allocation of biomass to leaves, roots and lateral branches, but did not affect stem length and diameter

18

Foliar ozone injury and radial growth of ponderosa pine  

Energy Technology Data Exchange (ETDEWEB)

Foliar injury symptoms and stem diameter growth were measured on well-watered and drought-stressed ponderosa pine seedlings at the end of each of three years of exposure to three levels of ozone: charcoal-filtered air, nonfiltered air, and nonfiltered air plus 1.5 times ambient ozone. Ozone injury indices were constructed by adding percent chlorotic mottle and percent necrosis for each needle age class. Seedlings grown in nonfiltered air plus 1.5 times ambient ozone developed severe foliar injury after two years of exposure and were the only seedlings with significant reductions in radial growth after three seasons of exposure to a mean seasonal ozone concentration of 88 ppB. Foliage that had developed over 30% chlorotic mottle by September of the second year had abscised by September of the following year. Reduction in radial growth was significantly correlated with the amount of foliar injury in well-watered trees, and the best-fit regression equation occurred when percent necrosis was weighted by a factor of four. Regressions between foliar injury indices and radial growth in drought-stressed trees were not significant, nor were regressions between radial growth and foliar injury among well-watered trees with only one year of premature needle abscission. The low correlation between foliar injury and radial growth in well-watered trees and the lack of a significant regression in drought-stressed trees suggest that detection of reductions in stem diameter growth of ponderosa pine in the field in response to ozone injury could be difficult, except for severely injured trees with fewer than two years of foliar retention. 28 refs., 2 figs., 2 tabs.

Temple, P.J. (California Univ., Riverside, CA (United States)); Miller, P.R. (U.S. Forest Service, Riverside, CA (United States))

1994-01-01

19

Protection of plants from ambient ozone by applications of ethylenediurea (EDU): A meta-analytic review  

International Nuclear Information System (INIS)

A meta-analysis was conducted to quantitatively assess the effects of ethylenediurea (EDU) on ozone (O3) injury, growth, physiology and productivity of plants grown in ambient air conditions. Results indicated that EDU significantly reduced O3-caused visible injury by 76%, and increased photosynthetic rate by 8%, above-ground biomass by 7% and crop yield by 15% in comparison with non-EDU treated plants, suggesting that ozone reduces growth and yield under current ambient conditions. EDU significantly ameliorated the biomass and yield of crops and grasses, but had no significant effect on tree growth with an exception of stem diameter. EDU applied as a soil drench at a concentration of 200-400 mg/L has the highest positive effect on crops grown in the field. Long-term research on full-grown tree species is needed. In conclusion, EDU is a powerful tool for assessing effects of ambient [O3] on vegetation. - EDU effectively protect plants against ambient ozone.

20

Climate change, ambient ozone, and health in 50 US cities  

Energy Technology Data Exchange (ETDEWEB)

We investigated how climate change could affect ambient ozone concentrations and the subsequent human health impacts. Hourly concentrations were estimated for 50 eastern US cities for five representative summers each in the 1990s and 2050s, reflecting current and projected future climates, respectively. Estimates of future concentrations were based on the IPCC A2 scenario using global climate, regional climate, and regional air quality models. This work does not explore the effects of future changes in anthropogenic emissions, but isolates the impact of altered climate on ozone and health. The cities' ozone levels are estimated to increase under predicted future climatic conditions, with the largest increases in cities with present-day high pollution. On average across the 50 cities, the summertime daily 1-h maximum increased 4.8 ppb, with the largest increase at 9.6 ppb. The average number of days/summer exceeding the 8-h regulatory standard increased 68%. Elevated ozone levels correspond to approximately a 0.11% to 0.27% increase in daily total mortality. While actual future ozone concentrations depend on climate and other influences such as changes in emissions of anthropogenic precursors, the results presented here indicate that with other factors constant, climate change could detrimentally affect air quality and thereby harm human health.

Bell, M.L. [School of Forestry and Environmental Studies, Yale University, 205 Prospect St., New Haven, CT, 06511 (United States); Goldberg, R. [Center for Climate Systems Research, Columbia University, New York, NY (United States); Hogrefe, C. [Atmospheric Sciences Research Center, State University of New York at Albany, Albany, NY (United States); Kinney, P.L.; Knowlton, K. [Mailman School of Public Health, Columbia University, New York, NY (United States); Lynn, B. [National Aeronautic and Space Administration (NASA) Goddard Institute for Space Studies, New York, NY (United States); Rosenthal, J.; Rosenzweig, C.; Patz, J.A. [Nelson Institute for Environmental Studies, University of Wisconsin at Madison, Madison, WI (United States)

2007-05-15

 
 
 
 
21

Growth response of young slash pine trees to simulated acid rain and ozone stress  

Energy Technology Data Exchange (ETDEWEB)

To assess to impact of acid rain and ozone stress on the growth and physiology of slash pine, four half-sib families were planted in large open-top chambers and exposed 28 months to factorial combinations of three rain acidities (pH 3.3, 4.3, and 5.3) and four concentrations of ozone (subambient produced with carbon filtration, two times ambient, and three times ambient). Growth was assessed by seasonal stem diameter and height increments and by stem volume increment at steady-state conditions. Information on tree physiology was obtained indirectly from estimates of mean unit leaf rate, a measure of the net assimilation capacity of the tree. Among the growth variables, only volume increment showed a consistent year to year response to acid rain and ozone. The acid rain[times]ozone interaction was significant for volume increment each year and was the result of trees in the two times ambient ozone level having greater sensitivity to rain acidity. Both acid rain and ozone significantly affected mean unit leaf rate; however, this effect weakened with time, suggesting some degree of physiological acclimation. Increasing rain acidity significantly increased mean leaf area only during the first growth period. Ozone significantly decreased mean leaf area in all three growth periods, with the effect intensifying each year. Complex family interactions with acid rain and ozone masked any clear family sensitivities to these pollutants. 24 refs., 6 figs., 4 tabs.

Dean, T.J.; Johnson, J.D. (Florida Univ., Gainesville, FL (USA))

1992-01-01

22

Lung function growth and ambient ozone. A three-year population study in school children; Developpement de la fonction pulmonaire et ozone dans l'air ambiant. Une etude sur trois ans en population d'enfant scolarises  

Energy Technology Data Exchange (ETDEWEB)

This study has for objective to analyze at long term the effects of air pollution by ozone on the pulmonary function of children. This study brings to the fore a relationship between summer air pollution and the pulmonary function for children. The principal interest of this work is in the time of three years that allows to approach the long term effects. Different indicators ( relative to ozone exposure) have been used and allow to precise the results ( averages of daily maxima, number of days over the threshold of 60 ppb). The analysis made with a 24 hours exposure allows to check that the short term effect has not been significant. (N.C.)

Frischer, T.; Studnicka, M.; Gartner, C.

1999-12-01

23

Relationships between ambient ozone regimes and white clover forage production using different ozone exposure indexes  

Science.gov (United States)

Plant responses to seasonal exposure to tropospheric ozone (O 3) are mediated by interactions with physical and genetic factors that complicate attempts to develop a measure of O 3 exposure (exposure index) that best relates to plant response. Dozens of exposure indexes have been tested for best fit to yield response data from open-top chamber studies. These tests have limited applicability because of possible confounding caused by variability in experimental protocols used in chamber dose-response studies. A 2-yr study in ambient air at eight locations in the USA measured relative effects of ambient O 3 on forage weight of a sensitive (NC-S) and a resistant (NC-R) clone of white clover. Protocols included uniform growth medium, irrigation, exposure duration and genetics (clones). Plants were harvested to determine NC-S/NC-R forage biomass ratios after each of four 28-day periods. High ratios indicated low O 3 concentrations, and low ratios indicated high concentrations. We used these results in attempts to identify the relative suitability of several exposure indexes in defining O 3 exposure-forage biomass relationships. Indexes were calculated using combinations of O 3 exposure forms (SUM00, SUM06, W95, W126, and AOT04), diurnal and seasonal accumulating times and harvests. Squared correlations ( r2's) between the index and biomass ratio were used as a general indication of relative suitability of the different indexes. Squared correlations were much higher for indexes coupled with harvests 2, 3 and 4, than for harvest 1. Even higher r2's occurred for indexes coupled with the combined mean forage ratio for harvests 2, 3 and 4. Squared correlations were most sensitive to the choice of hourly averaging times. Lowest r2's occurred for the 24 h accumulating period, much higher r2's occurred for the 12 h daylight period, and the highest r2's occurred for periods of 6 h or less during midday, regardless of all other factors. The exposure form was important only for 24 h indexes for which SUM00 gave the lowest r2's. All forms, including SUM00, produced similarly high r2's for 6, 5, and 4 h midday accumulating times.

Heagle, Allen S.; Stefanski, Leonard A.

24

COTTON YIELD LOSSES AND AMBIENT OZONE CONCENTRATIONS IN CALIFORNIA'S SAN JOAQUIN VALLEY  

Science.gov (United States)

Based on controlled experiments and simulation modeling, ozone air pollution has been estimated to cause significant yield losses to cotton. he study reported here was conducted to verify losses for Acala cotton (Gossypium hirsutum L.'SJ2') along a gradient of ambient ozone (O3) ...

25

GROWTH OF COTTON UNDER CHRONIC OZONE STRESS AT TWO LEVELS OF SOIL MOISTURE  

Science.gov (United States)

Recent field research has shown that ambient concentrations of ozone(O3) have the potential to reduce yield of a number of economically important crop species. Less emphasis has been placed on characterization of the effects of 03 on growth of the total plant that ultimately dete...

26

40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...ambient O3 concentrations as listed...Standards for Ozone 2.1Data...8-hour averages. Hourly average concentrations shall be...Secondary Ozone Standards...3-year average of the annual...average O3 concentration is less...

2010-07-01

27

Silver birch and climate change: variable growth and carbon allocation responses to elevated concentrations of carbon dioxide and ozone  

International Nuclear Information System (INIS)

The effects of elevated concentrations of carbon dioxide and ozone were studied on growth, biomass allocation and leaf area of field-grown ozone-tolerant (Clone 4) and ozone-sensitive (Clone 80) European silver birch trees. Seven-year old trees of both types were exposed for three years to outside and chamber control, (1) twice ambient ozone, (2) twice ambient carbon dioxide, and (3) twice ambient carbon dioxide and twice ambient ozone. No effect on biomass allocation was observed when results of the two clones were analyzed together. Total leaf area showed an increase, and leaf abscission appeared delayed in response to elevated carbon dioxide. Elevated ozone caused the dry mass of roots, branches and mean leaf size to decrease, and autumnal leaf abscission occurred earlier than usual in both clones. In general. the effects of elevated ozone were small, however, the interaction between elevated carbon dioxide and elevated oxygen were significant. When results from the two clones were analyzed separately, stem diameter, volume growth and total biomass of Clone 80 increased when exposed to elevated concentrations of carbon dioxide; elevated concentrations of ozone appeared to have no effect. In Clone 4 elevated ozone caused significant decrease in root and branch biomass, but the effects of elevated carbon dioxide were minimal. Responses to elevated ozone exposure were observed only under ambient carbon dioxide conditions. This response is believed to reflect the great response is believed to reflect the greater quantity of carbohydrates available for detoxification and repair under elevated carbon dioxide conditions. Alternatively, the response may be due to decreased stomatal conductance, thus decreased ozone uptake under elevated carbon dioxide conditions. 45 refs., 6 tabs., 4 figs

28

Silver birch and climate change: variable growth and carbon allocation responses to elevated concentrations of carbon dioxide and ozone  

Energy Technology Data Exchange (ETDEWEB)

The effects of elevated concentrations of carbon dioxide and ozone were studied on growth, biomass allocation and leaf area of field-grown ozone-tolerant (Clone 4) and ozone-sensitive (Clone 80) European silver birch trees. Seven-year old trees of both types were exposed for three years to outside and chamber control, (1) twice ambient ozone, (2) twice ambient carbon dioxide, and (3) twice ambient carbon dioxide and twice ambient ozone. No effect on biomass allocation was observed when results of the two clones were analyzed together. Total leaf area showed an increase, and leaf abscission appeared delayed in response to elevated carbon dioxide. Elevated ozone caused the dry mass of roots, branches and mean leaf size to decrease, and autumnal leaf abscission occurred earlier than usual in both clones. In general. the effects of elevated ozone were small, however, the interaction between elevated carbon dioxide and elevated oxygen were significant. When results from the two clones were analyzed separately, stem diameter, volume growth and total biomass of Clone 80 increased when exposed to elevated concentrations of carbon dioxide; elevated concentrations of ozone appeared to have no effect. In Clone 4 elevated ozone caused significant decrease in root and branch biomass, but the effects of elevated carbon dioxide were minimal. Responses to elevated ozone exposure were observed only under ambient carbon dioxide conditions. This response is believed to reflect the greater quantity of carbohydrates available for detoxification and repair under elevated carbon dioxide conditions. Alternatively, the response may be due to decreased stomatal conductance, thus decreased ozone uptake under elevated carbon dioxide conditions. 45 refs., 6 tabs., 4 figs.

Riikonen, J.; Holopainen, T.; Oksanen, E. [University of Kuopio (Finland); Lindsberg, M-M.; Lappi, J.; Peltonen, P.; Vapaavuori, E. [Finnish Forest Research Institute, Suonenjoki Research Station (Finland)

2004-11-01

29

Use of bioindicators and passive sampling devices to evaluate ambient ozone concentrations in north central Pennsylvania  

International Nuclear Information System (INIS)

Passive samplers and bioindicator plants detect ozone air pollution in north central Pennsylvania. - Ambient concentrations of tropospheric ozone and ozone-induced injury to black cherry (Prunus serotina) and common milkweed (Asclepias syriaca) were determined in north central Pennsylvania from 29 May to 5 September 2000 and from 28 May to 18 September 2001. Ogawa passive ozone samplers were utilized within openings at 15 forested sites of which six were co-located with TECO model 49 continuous ozone monitors. A significant positive correlation was observed between the Ogawa passive samplers and the TECO model 49 continuous ozone monitors for the 2000 (r=0.959) and 2001 (r=0.979) seasons. In addition, a significant positive correlation existed in 2000 and 2001 between ozone concentration and elevation (r=0.720) and (r=0.802), respectively. Classic ozone-induced symptoms were observed on black cherry and common milkweed. In 2000, initial injury was observed in early June, whereas for the 2001 season, initial injury was initially observed in late June. During both seasons, injury was noted at most sites by mid- to late-July. Soil moisture potential was measured for the 2001 season and a significant positive relationship (P<0.001) showed that injury to black cherry was a function of cumulative ozone concentrations and available soil moisture

30

Modeling the effects of ozone on soybean growth and yield.  

Science.gov (United States)

A simple mechanistic model was developed based on an existing growth model in order to address the mechanisms of the effects of ozone on growth and yield of soybean [Glycine max. (L.) Merr. 'Davis'] and interacting effects of other environmental stresses. The model simulates daily growth of soybean plants using environmental data including shortwave radiation, temperature, precipitation, irrigation and ozone concentration. Leaf growth, dry matter accumulation, water budget, nitrogen input and seed growth linked to senescence and abscission of leaves are described in the model. The effects of ozone are modeled as reduced photosynthate production and accelerated senescence. The model was applied to the open-top chamber experiments in which soybean plants were exposed to ozone under two levels of soil moisture regimes. After calibrating the model to the growth data and seed yield, goodness-of-fit of the model was tested. The model fitted well for top dry weight in the vegetative growth phase and also at maturity. The effect of ozone on seen yield was also described satisfactorily by the model. The simulation showed apparent interaction between the effect of ozone and soil moisture stress on the seed yield. The model revealed that further work is needed concerning the effect of ozone on the senescence process and the consequences of alteration of canopy microclimate by the open-top chambers. PMID:15092277

Kobayashi, K; Miller, J E; Flagler, R B; Heck, W W

1990-01-01

31

Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation  

International Nuclear Information System (INIS)

In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO3) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO3). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO3 caused, on average, a decrease of 10.2 m3 ha-1 yr-1 in European beech. - Ozone effects on tree growth and stem shape were investigated for Norway spruce and European beech; the study reveals species-specific reaction patterns in growth rate and allometry under ozone exposure.

32

Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation  

Energy Technology Data Exchange (ETDEWEB)

In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO{sub 3}) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO{sub 3}). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO{sub 3} caused, on average, a decrease of 10.2 m{sup 3} ha{sup -1} yr{sup -1} in European beech. - Ozone effects on tree growth and stem shape were investigated for Norway spruce and European beech; the study reveals species-specific reaction patterns in growth rate and allometry under ozone exposure.

Pretzsch, Hans, E-mail: h.pretzsch@lrz.tum.d [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Dieler, Jochen [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Matyssek, Rainer [Chair for Ecophysiology of Plants, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany); Wipfler, Philip [Chair for Forest Growth and Yield Science, Technische Universitaet Muenchen, Am Hochanger 13, D-85354 Freising (Germany)

2010-04-15

33

Effect of ozone on growth and assimilate partitioning in parsley  

Energy Technology Data Exchange (ETDEWEB)

Parsley (Petroselinum crispum (Mill.) Nym. cv. Banquet) incurred leaf injury, reduced growth, and altered assimilate partitioning after exposures to 20 pphm ozone. Total plant dry weight and root dry weight were decreased 23% and 43% respectively, with little effect on leaves. The relative growth rate of fumigated plants was reduced after the initial ozone exposure but leveled off at a steady state above that of the control plants when plant dry weights reached about 4.5 g. Ozone appeared to have its greatest effect on growth during initial exposures. 15 references, 3 figures, 1 table.

Oshima, R.J.; Bennett, J.P.; Braegelmann, P.K.

1978-05-01

34

EFFECTS OF AMBIENT OZONE ON RESPIRATORY FUNCTION IN HEALTHY ADULTS EXERCISING OUTDOORS  

Science.gov (United States)

The effect of exposure to ozone (O3) in ambient air on respiratory function was studied in 30 healthy adult nonsmokers engaged in a regular daily program of outdoor exercise in Tuxedo, NY during the summer of 1985. Each subject did the same exercise each day but exercise intensit...

35

ADJUSTING AMBIENT OZONE AIR QUALITY INDICATORS FOR MISSING VALUES  

Science.gov (United States)

This paper focuses on the adjustment of the exposure indices developed in work on exposure-response studies on crops to deal with missing data patterns in ambient air quality data and present three statistical methods that are fundamentally related to the methods proposed by Davi...

36

IJERPH | Free Full-Text | Impact of Climate Change on Ambient Ozone Level and Mortality in Southeastern United States  

...Impact of Climate Change on Ambient Ozone Level and Mortality in Southeastern United States There is a growing interest in quantifying the health impacts ... This paper examines the risks of future ozone levels on non-accidental mortality across 19 urban communities in Southeastern United States. We present ...modeling framework that integrates data from climate model outputs, historical meteorology and ozone observations, and a health surveillance database. We first modeled ...present-day relationships between observed maximum daily 8-hour average ozone concentrations and meteorology measured during the year 2000. Future ozone concentrations for the period ...

37

Comparative analysis of seed transcriptomes of ambient ozone-fumigated 2 different rice cultivars.  

Science.gov (United States)

High ozone (O3) concentrations not only damage plant life but also cause considerable losses in plant productivity. To screen for molecular factors usable as potential biomarkers to identify for O3-sensitive and -tolerant lines and design O3 tolerant crops, our project examines the effects of O3 on rice, using high-throughput omics approaches. In this study, we examined growth and yield parameters of 4 rice cultivars fumigated for a life-time with ambient air (mean O3: 31.4-32.7 ppb) or filtered air (mean O3: 6.6-8.3 ppb) in small open-top chambers (sOTCs) to select O3-sensitive (indica cv Takanari) and O3-tolerant (japonica cv Koshihikari) cultivars for analysis of seed transcriptomes using Agilent 4 × 44K rice oligo DNA chip. Total RNA from dry mature dehusked seeds of Takanari and Koshihikari cultivars was extracted using a modified protocol based on cethyltrimethylammonium bromide extraction buffer and phenol-chloroform-isoamylalcohol treatment, followed by DNA microarray analysis using the established dye-swap method. Direct comparison of Koshihikari and Takanari O3 transcriptomes in seeds of rice plants fumigated with ambient O3 in sOTCs successfully showed that genes encoding proteins involved in jasmonic acid, GABA biosynthesis, cell wall and membrane modification, starch mobilization, and secondary metabolite biosynthesis are differently regulated in sensitive cv Takanari and tolerant cv Koshihikari. MapMan analysis further mapped the molecular factors activated by O3, confirming Takanari is rightly classified as an O3 sensitive genotype. PMID:24025514

Cho, Kyoungwon; Shibato, Junko; Kubo, Akihiro; Kohno, Yoshihisa; Satoh, Kouji; Kikuchi, Shoshi; Sarkar, Abhijit; Agrawal, Ganesh Kumar; Rakwal, Randeep

2013-11-01

38

US Environmental Protection Agency's ozone epidemiology research program: A strategy for assessing the effects of ambient ozone exposure upon morbidity in exposed populations  

Energy Technology Data Exchange (ETDEWEB)

The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. In order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potential health benefits of improved air quality, the Health Effects Research Laboratory of the U.S. EPA has undertaken an Ozone Epidemiology Research Program. The three questions identified as being of most immediate importance involve the relationship of short-term ambient ozone exposure to acute respiratory illness, the relationship of recurrent exposure to chronic respiratory disease, and the relationship of recurrent exposure to development of acute respiratory illness. (Copyright (c) 1993 Air and Waste Management Association.)

McDonnell, W.F.; Zenick, H.; Hayes, C.G.

1993-01-01

39

The effect of different atmospheric ozone partial pressures on photosynthesis and growth of nine fruit and nut tree species.  

Science.gov (United States)

Nursery stock of peach (Prunus persica L. Batsch, cv. O'Henry), nectarine (P. persica L. Batsch, cv. Fantasia), plum (P. salicina Lindel., cv. Casselman), apricot (P. armeniaca L., cv. Tilton), almond (P. dulcis Mill., cv. Nonpareil), prune (P. domestica L., cv. Improved French), cherry (P. avium L., cv. Bing), oriental pear (Pyrus pyrifolia Rehd., cv. 20th Century), and apple (Malus pumula Mill., cv. Granny Smith) were planted in open-top chambers on April 1, 1988 at the University of California's Kearney Agricultural Center located in the San Joaquin Valley (30 degrees 40' N 119 degrees 40' W). Trees were exposed to three atmospheric ozone partial pressures (charcoal-filtered air (C), ambient air (A), or ambient air + ozone (T)) from August 1 to November 17, 1988. The mean 12-h (0800 to 2000 h) ozone partial pressures measured in open-top chambers during the experimental period were 0.030, 0.051, and 0.117 microPa Pa(-1) in the C, A and T treatments, respectively. Leaf net CO(2) assimilation rate decreased linearly with increasing 12-h mean ozone partial pressure for the almond, plum, apricot, prune, pear, and apple cultivars. Stomatal conductances of apricot, apple, almond, and plum decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, and pear decreased linearly with increasing ozone partial pressure. Net CO(2) assimilation rate, stomatal conductance, and trunk growth of cherry, peach and nectarine were unaffected by the ozone treatments. Reduced leaf gas exchange probably contributed to ozone-induced growth reduction of the susceptible species and cultivars. Several of the commercial fruit tree species and cultivars studied were relatively tolerant to the ozone treatments. PMID:14972900

Retzlaff, W A; Williams, L E; DeJong, T M

1991-01-01

40

Growth and crown architecture of two aspen genotypes exposed to interacting ozone and carbon dioxide.  

Science.gov (United States)

To study the impact of ozone (O3) and O3 plus CO2 on aspen growth, we planted two trembling aspen clones, differing in sensitivity to O3 in the ground in open-top chambers and exposed them to different concentrations of O3 and O3 plus CO, for 98 days. Ozone exposure (58 to 97 microl l(-1)-h. total exposure) decreased growth and modified crown architecture of both aspen clones. Ozone exposure decreased leaf, stem, branch, and root dry weight particularly in the O3 sensitive clone (clone 259). The addition of CO2 (150 microl l(-1) over ambient) to the O3 exposure counteracted the negative impact of O3 only in the O3 tolerant clone (clone 216). Ozone had relatively little effect on allometric ratios such as, shoot/root ratio, leaf weight ratio, or root weight ratio. In both clones, however, O3 decreased the shoot dry weight, shoot length ratio and shoot diameter. This decrease in wood strength caused both current terminals and long shoots to droop and increased the branch angle of termination. These results show that aspen growth is highly sensitive to O3 and that O3 can also significantly affect crown architecture. Aspen plants with drooping terminals and lateral branches would be at a competitive disadvantage in dense stands with limited light. PMID:11789916

Dickson, R E; Coleman, M D; Pechter, P; Karnosky, D

2001-01-01

 
 
 
 
41

Correlation of ambient inhalable bioaerosols with particulate matter and ozone: A two-year study  

International Nuclear Information System (INIS)

In this study, we have examined the relationships between the concentrations of ambient inhalable airborne fungi and pollen with PM1, PM2.5, ozone, organic carbon, selected trace metals (cadmium, copper, lead, and zinc), temperature, and relative humidity. The database was collected in Cincinnati, Ohio, USA, during two consecutive years. Measurements of all environmental variables were performed at the same site continuously 5 days a week except during winter months. The airborne concentrations of biological and non-biological pollutants ranged as follows: total fungi: 184-16 979 spores m-3; total pollen: 0-6692 pollen m-3; PM1: 6.70-65.38 ?g m-3; PM2.5: 5.04-45.02 ?g m-3; and ozone: 2.54-64.17 ppb. Higher levels of total inhalable fungi and particulate matter were found during fall and summer months. In contrast, total pollen concentration showed elevated levels in spring. Peak concentrations of ozone were observed during summer and beginning of fall. Our study concluded that several types of inhalable airborne fungi and pollen, particulate matter, and ozone could be positively correlated as a result of the atmospheric temperature influence. - Synergistic effects of these pollutants may increase incidence of respiratory health problem

42

40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection of Environment ENVIRONMENTAL...SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. H Appendix H to Part 50—Interpretation of the...

2010-07-01

43

Estimating contribution of wildland fires to ambient ozone levels in National Parks in the Sierra Nevada, California  

International Nuclear Information System (INIS)

Data from four continuous ozone and weather monitoring sites operated by the National Park Service in Sierra Nevada, California, are used to develop an ozone forecasting model and to estimate the contribution of wildland fires on ambient ozone levels. The analyses of weather and ozone data pointed to the transport of ozone precursors from the Central Valley as an important source of pollution in these National Parks. Comparisons of forecasted and observed values demonstrated that accurate forecasts of next-day hourly ozone levels may be achieved by using a time series model with historic averages, expected local weather and modeled PM values as explanatory variables. Results on fire smoke influence indicated occurrence of significant increases in average ozone levels with increasing fire activity. The overall effect on diurnal ozone values, however, was small when compared with the amount of variability attributed to sources other than fire. - We have demonstrated that it is possible to produce accurate forecasts of next-day hourly ozone levels in the Sierra Nevada, CA, during fire season.

44

Exposure-plant response of ambient ozone over the tropical Indian region  

Directory of Open Access Journals (Sweden)

Full Text Available A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE and World Health Organization (WHO for vegetation protection (AOT40 have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months. Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November and April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

S. Roy

2009-02-01

45

Effects of ozone on photosynthesis, vegetative growth, and development of woody perennials in the San Joaquin Valley of California. Final report  

Energy Technology Data Exchange (ETDEWEB)

Nursery stock of nine fruit and nut tree species were planted in open-top chambers on April 1, 1988 at the University of California's Kearney Agricultural Center located in the San Joaquin Valley. The trees were then exposed to three levels of atmospheric ozone partial pressures (charcoal filtered air, ambient air, or ambient air + ozone) from 1 August to 17 November 1988. The relationship between leaf net CO2 assimilation rate and 12-hour mean ozone partial pressure decreased linearly with increasing ozone partial pressure for the almond, plum, apricot, pear and apple cultivars. Stomatal conductances of apricot, prune, apple, almond, and plum also decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, pear and apple declined linearly with increasing ozone partial pressure. Net CO2 assimilation rate, stomatal conductance, and trunk growth of cherry, peach, and nectarine were unaffected by the ozone treatments. The results indicate that decreases in leaf gas exchange were probably contributors to decreases in young tree growth of the susceptible species/cultivars.

Williams, L.E.; DeJong, T.M.; Retzlaff, W.A.

1989-10-31

46

Exposure-plant response of ambient ozone over the tropical Indian region  

Directory of Open Access Journals (Sweden)

Full Text Available A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE and World Health Organization (WHO for vegetation protection (AOT40 have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months. Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. There is an underestimation of AOT40 in the model results during the periods of highest ozone concentration from December to March. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November to April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

S. Deb Roy

2009-07-01

47

US Environmental Protection Agency's Ozone Epidemiology Research Program: A strategy for assessing the effects of ambient ozone exposure upon morbidity in exposed populations  

Energy Technology Data Exchange (ETDEWEB)

The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. In order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potential health benefits of improved air quality, the Health Effects Research Laboratory of the U.S. EPA has undertaken an Ozone Epidemiology Research Program. The research strategy which will guide this scientific program is described in this paper. Criteria for selection of important research questions as well as issues which cut across all questions and study designs are discussed. In particular, this program emphasizes the study of effects which reflect morbidity in the population. The three questions identified as being of most immediate importance involve the relationship of short-term ambient ozone exposure to acute respiratory illness, the relationship of recurrent exposure to chronic respiratory disease, and the relationship of recurrent exposure to development of acute respiratory illness. Specific research approaches and initial projects to address these three questions are described.

McDonnell, W.F.; Zenick, H.; Hayes, C.G. (Environmental Protection Agency, Research Triangle Park, NC (United States))

1993-07-01

48

Loblolly pine seedling growth after inoculation with plant growth-promoting rhizobacteria and ozone exposure  

Energy Technology Data Exchange (ETDEWEB)

The conifer tree species with the greatest economic importance in south eastern United States plantations is Loblolly pine. Plantations require intensive fertilization, pesticide application, and irrigation. In these cases growth-promoting rhizobacteria are useful in pest control. While it was once thought that ozone in the troposphere was limited to urban areas, it is now known that it is transported far from its place of origin. Ozone is known to impact plant growth negatively. There have been no previous studies on whether growth-promoting rhizobacteria can decrease the negative effects of ozone. In this study seedlings of Loblolly pine were inoculated with either Bacillus subtilis (Ehrenberg) Cohn or Paenibacillus macerans (Schardinger) Ash. These were exposed to controlled amounts of ozone for 8-12 weeks. All plants showed decreased biomass and increased foliar damage compared to plants that were not exposed to ozone. B. subtilis inoculated plants showed less foliar damage than un-inoculated ones and root dimensions were increased. The use of growth-promoting rhizobacteria is not ready for large-scale commercial application in forestry, but this demonstration of the possible beneficial effects on ozone exposure warrants further investigation. 44 refs., 3 tabs., 2 figs.

Estes, B.L.; Enebak, S.A.; Chappelka, A.H. [Auburn Univ., Auburn, AL (United States). School of Forestry and Wildlife Sciences

2004-07-01

49

Acute effect of ambient ozone on heart rate variability in healthy elderly subjects.  

Science.gov (United States)

Acute ambient ozone (O(3)) exposure is associated with the increased mortality and morbidity of cardiovascular diseases. The dysfunction of cardiac autonomic nervous system (ANS), indicated by the disturbed heart rate variability (HRV), may be the most important underlying mechanism. Previous studies reported the heterogeneous associations between O(3) within several hours' exposure and HRV on general elderly subjects, in which poor surrogate of exposure evaluation and different health status of the subjects may be responsible for the heterogeneous associations. No studies were found focusing on the O(3)-mediated HRV effects within several minutes' exposure on healthy older subjects until recently. We measured the real-time 5-min ambient O(3) concentration and HRV frequency indices in 20 healthy elderly subjects in two surveys, with the 1st and 2nd survey in summer and winter, respectively. Mixed-linear model was used to evaluate the associations between the ambient 5-min average O(3) and concurrent 5-min HRV frequency indices measured during the outdoor period. After adjusting the co-pollutants (ambient PM(2.5) and nitrogen oxides concentrations) and subject characteristics, high frequency (HF) changed -4.87% (95% CI -8.62 to -0.97%) per 10?ppb increment of O(3), whereas decreased low frequency (LF) and increased LFHFR were found to be marginally associated with the elevated O(3) (P values were 0.092 and 0.069). We concluded that the ambient O(3) exert transient decrease effects on HRV, which may induce acute cardiac events. PMID:21522190

Jia, Xiaofeng; Song, Xiaoming; Shima, Masayuki; Tamura, Kenji; Deng, Furong; Guo, Xinbiao

2011-01-01

50

Concentrated ambient fine particles and not ozone induce a systemic interleukin-6 response in humans.  

Science.gov (United States)

Epidemiological studies have established significant associations between ambient pollutants, including fine particulate matter (PM(2.5)) and ozone (O(3)), and cardiopulmonary morbidity and mortality. One mechanism that has been proposed is a pulmonary/systemic inflammatory response. Although controlled human exposure studies have examined the independent inflammatory responses of PM(2.5) and O(3), no studies have previously examined their joint effects. The study objective was to examine the independent and combined associations between ambient PM(2.5) and O(3) and acute respiratory/inflammatory responses. Using their concentrated ambient particle (CAP) facility for PM(2.5), the authors studied 10 mild asthmatic and 13 nonasthmatic individuals. The 2-h exposures included CAP (range 48-199 microg/m(3)) and filtered air (FA), with/without O(3) (120 ppb), in a randomized block design. Response measures included pulmonary function and inflammatory indices in induced sputum (interleukin [IL]-6, cytology) and blood (IL-6, tumor necrosis factor [TNF]-alpha) measured before and after exposures. Three hours post exposure, there was an increase in blood levels of IL-6, but only after CAP alone exposures; the IL-6 increase was associated with increasing PM(2.5) mass concentration (p = .005). Some individuals switched to shallow breathing during CAP+O(3), possibly accounting for an attenuation of the resultant blood IL-6 response. Asthmatic and nonasthmatic responses were similar. There were no adverse changes in pulmonary function or other inflammatory measures. The study demonstrated an acute IL-6 response to PM(2.5), providing evidence to support the epidemiological findings of associations between ambient levels of particles and cardiopulmonary morbidity and mortality. PMID:20088738

Urch, Bruce; Speck, Mary; Corey, Paul; Wasserstein, David; Manno, Michael; Lukic, Karl Z; Brook, Jeffrey R; Liu, Ling; Coull, Brent; Schwartz, Joel; Gold, Diane R; Silverman, Frances

2010-02-01

51

Photosynthesis and growth response of almond to increased atmospheric ozone partial pressures  

International Nuclear Information System (INIS)

Uniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, cv. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domstica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O3) partial pressures. The trees were planted in open-top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O3 partial pressures lasted from 1 June to 2 Nov. 1989. The mean 12-h [0800-2000 h Pacific Daylight Time (PDT)] O3 partial pressures measured in the open-top chambers during the experimental period were 0.038, 0.060, and 0.112 ?Pa Pa-1 O3 in the charcoal filtered, ambient, and ambient + O3 treatments, respectively. Leaf net CO2 assimilation, trunk cross-sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O3 partial pressures. Mission was unaffected by O3 and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O3 treatments. The results indicate that there are almond cultivars that are sensitive to O3 exposure

52

Photosynthesis and growth response of almond to increased atmospheric ozone partial pressures  

Energy Technology Data Exchange (ETDEWEB)

Uniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, cv. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domstica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O[sub 3]) partial pressures. The trees were planted in open-top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O[sub 3] partial pressures lasted from 1 June to 2 Nov. 1989. The mean 12-h [0800-2000 h Pacific Daylight Time (PDT)] O[sub 3] partial pressures measured in the open-top chambers during the experimental period were 0.038, 0.060, and 0.112 [mu]Pa Pa[sup [minus]1] O[sub 3] in the charcoal filtered, ambient, and ambient + O[sub 3] treatments, respectively. Leaf net CO[sub 2] assimilation, trunk cross-sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O[sub 3] partial pressures. Mission was unaffected by O[sub 3] and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O[sub 3] treatments. The results indicate that there are almond cultivars that are sensitive to O[sub 3] exposure.

Retzlaff, W.A.; Williams, L.E. (Univ. of California, Davis (United States) Kearney Agricultural Center, Parlier, CA (United States)); DeJong, T.M. (Univ. of California, Davis (United States))

53

Factors affecting measured, modeled and reconstructed estimates of personal exposure to ambient ozone in southern California  

Science.gov (United States)

To evaluate those factors which influence the assignment of ozone ( O3) exposures in an epidemiologic context a field study was conducted in the South Coast Air Basin (SoCAB) during the summer of 19% in which time, location, activity (TLA) information and direct measurements of personal O3 exposure were concurrently collected on a group of college students. Current and past O3 exposures were modeled and evaluated as a function of ambient O 3, activity and mobility patterns, indoor ventilation, and recalled TLA information collected one year later. The effect of these factors on the within- and between-subject exposure variability assigned by ecologic (EC) and microenvironment (MEV) models were examined by two-hour intervals, on weekends and weekdays, and by monitoring week compared to personal exposures measured with a passive sampling device (PSD). The students reported spending 85% of their time inside, 7% outside and 8% in- transit. More time was spent outdoors on weekends than on weekdays. Ambient O3 levels were also higher on weekends. In the study area, where a dense O3 monitoring network and the appropriate topography exist fixed-site O3 accurately assigned ambient O3 levels within a 10 mile radius. The variation in the ecologic exposure assignments was low compared to the estimated variation among PSD-measured and MEV-modeled estimates due to the low spatial variation of ambient O3 levels across the SoCAB areas visited by the students. MEV and PSD exposure estimates better captured the variability of personal exposure in any given ambient spatial regimen compared to ecologic exposure assignments. MEV exposure estimates based on recalled TLA patterns, were similar to the MEV estimates based on diary-recorded TLA patterns. For this study population, PSD-measured O3 exposures were estimated to average 32% lower than ``true'' exposure levels due to indoor/outdoor differences in the PSD collection rate. The level of detail obtained from the TLA diary is not necessary for the assignment of current of past O3 exposures in epidemiologic studies. It may be more adventitious to characterize the locations visited, and indoor and outdoor time with the greatest accuracy possible and to use these data to estimate exposure from nearest-monitor ambient O 3 measurements and sets of indoor/outdoor O3 ratios validated to reflect personal exposure within indoor microenvironments.

Gonzales, Melissa

54

Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion  

International Nuclear Information System (INIS)

Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O3]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O3] on crop ecosystem energy fluxes and water use. Elevated [O3] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 deg. C. - Highlights: ? Globally, tropospheric ozone is currently and will likely continue to increase into the future. ? We examine the impact of elevated ozone on water use by soybean at the SoyFACE research facility. ? High ozone grown soybean had reduced rates of evapotranspiration and higher soil moisture. ? Increases in ozone have the potential to impact the hydrologic cycle where these crops are grown. - Soywhere these crops are grown. - Soybean grown in elevated concentrations of ozone is shown to evapotranspire less water compared with soybean canopies grown under current atmospheric conditions.

55

Effects of ambient ozone exposures during the spring and summer of 1994 on pulmonary function of schoolchildren.  

Science.gov (United States)

To investigate the effect of natural exposure to ambient ozone over time, a follow-up study of school-aged children was performed in two small towns in southwestern Germany (Freudenstadt and Villingen) between March and October of 1994. Ozone half-hour mean concentrations were measured continuously and pulmonary function was tested in each child on four occasions (April, June, August, and September). To obtain an average short-term ozone effect, we first analyzed the data from the four time points separately and then constructed a model that included all information. During the study period the median (5th to 95th percentile) of all half-hour values of the ozone concentration was 101 micrograms/m3 or 50.6 ppb (45-179 micrograms/m3 or 22.5-89.8 ppb) in Freudenstadt and 64 micrograms/m3 or 32.1 ppb (1 to 140 micrograms/m3 or 0.5-70.1 ppb) in Villingen. To assess the effects of an individual ozone exposure we related the highest ozone concentration in the respective 24 hours before lung function testing to the results of the subconcentration in the respective 24 hours before lung function testing to the results of the subsequent pulmonary function tests. In the lung function test following the highest ozone exposure, the results of our cross-sectional linear regression analysis showed a significant negative correlation (P = 0.0181) between ozone exposure and forced vital capacity (FVC). In the longitudinal linear regression model we observed a negative statistical correlation between ozone exposure and lung function for the subpopulation living in the town with the high ozone levels (Freudenstadt). The association was more pronounced in boys than girls. For the children in Freudenstadt the decrement of FVC was -12.31 ml/10 micrograms/m3 ozone and the decrease in the forced expiratory volume in 1 second (FEV1) was -11.29 ml/10 micrograms/m3 ozone. PMID:9168508

Ulmer, C; Kopp, M; Ihorst, G; Frischer, T; Forster, J; Kuehr, J

1997-05-01

56

CARRY-OVER EFFECTS OF OZONE ON ROOT GROWTH AND CARBOHYDRATE CONCENTRATIONS OF PONDEROSA PINE SEEDLINGS  

Science.gov (United States)

Ozone exposure decreases belowground carbon allocation and root growth of plants;however,the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood.To evaluate the potential for plant compensation,we followed the prog...

57

Effective interface passivation of a Ge/HfO2 gate stack using ozone pre-gate treatment and ozone ambient annealing  

International Nuclear Information System (INIS)

The physical and electrical properties of a Ge/GeO2/HfO2/Al gate stack are investigated. A thin interfacial GeO2 layer (?1 nm) is formed between Ge and HfO2 by dual ozone treatments, which passivates the Ge/high-k interface. Capacitors on p-type Ge substrates show very promising capacitance-voltage (C—V) characteristics by using in situ pre-gate ozone passivation and ozone ambient annealing after high-k deposition, indicating efficient passivation of the Ge/HfO2 interface. It is shown that the mid-gap interface state density atthe Ge/GeO2 interface is 6.4 × 1011 cm?2 · eV?1. In addition, the gate leakage current density of the Ge/GeO2/HfO2/Al gate stack passivated by the dual ozone treatments is reduced by about three orders of magnitude compared to that of a Ge/HfO2/Al gate stack without interface passivation. (semiconductor technology)

58

An automated monitoring system for VOC ozone precursors in ambient air: development, implementation and data analysis  

Energy Technology Data Exchange (ETDEWEB)

An automated system for the monitoring of volatile organic compound (VOC) ozone precursors in ambient air is described. The measuring technique consists of subambient preconcentration on a cooled trap followed by thermal desorption and GC/FID analysis. First, the technical development, which permits detection limits below 0.05 ppbv to be reached, proceeded in two steps: (1) the determination of optimum sampling parameters (trap composition and conditioning, outlet split, desorption temperature); (2) the development of a reliable calibration method based on a highly accurate standard. Then, a 4-year field application of the hourly measuring chain was carried out at two urban sites. On the one hand, quality control procedures provided the best VOC identification (peak assignment) and quantification (reproducibility, blank system control). On the other hand, the success and performances of the routine experience (88% of the measurements covered more than 40 target compounds) indicated the high quality and suitability of the instrumentation which is actually applied in several French air quality monitoring networks. Finally, an example of data analysis is presented. Data handling identified important organic compound sources other than vehicle exhaust. (orig.)

Badol, C.; Borbon, A.; Locoge, N.; Leonardis, T.; Galloo, J.C. [Departement Chimie et Environnement, Ecole des Mines de Douai, 941 rue Charles Bourseul, BP 838, 59508, Douai Cedex (France)

2004-04-01

59

Characterization of ambient ozone and its precursors around a coking plant.  

Science.gov (United States)

The local-scale relationship between ambient ozone (O3) and its precursors was examined around a coking plant in northern China. The upwind, plant boundary, and downwind locations were selected for investigation during the summer and autumn seasons in 2012. It was found that propene, toluene, and benzene were the top three non-methane hydrocarbon (NMHC) species for O3 formation at plant boundary, while propene, toluene, and m/p-xylene were the top three NMHC species at downwind location. Isoprene was the dominant species for O3 formation at upwind location. It was also found that an O3 depressing process occurred at plant boundary as a result of high NO emissions. Both local photochemistry and transport led to O3 accumulation at the downwind locations. The variation of NMHC concentration during O3 polluted and non-polluted episodes was investigated, and it indicated that NMHC concentration was higher during non-polluted episodes than polluted episodes. The impacts of precursors on O3 formation under different meteorological conditions were also examined. PMID:24504669

Li, Guohao; Cheng, Shuiyuan; Li, Jianbing; Wei, Wei; Wen, Wei; Wang, Gang

2014-05-01

60

Effect of ozone pre-conditioning on quality and antioxidant capacity of papaya fruit during ambient storage.  

Science.gov (United States)

The objective of this study was to compare the physico-chemical characteristics and antioxidant activity of ozone-treated papaya fruit and untreated fruit. Freshly harvested papaya fruit were exposed continuously to ozone fumigation (0, 1.5, 2.5, 3.5 and 5ppm) for 96h prior to ambient storage at 25±3°C and 70±5% relative humidity (RH) for up to 14days. The fruit exposed to 2.5ppm ozone had higher levels of total soluble solids (25.0%), ascorbic acid content (12.4%), ?-carotene content (19.6%), lycopene content (52.1%), and antioxidant activity (30.9%), and also reduced weight loss (11.5%) at day 10 compared to the control. The sensory attributes of papaya treated with 2.5ppm ozone was superior in sweetness and overall acceptability. These results support the application of ozone as a non-thermal and safe food preservation technique for papaya which can benefit both the producers and consumers. PMID:24001808

Ali, Asgar; Ong, Mei Kying; Forney, Charles F

2014-01-01

 
 
 
 
61

Integrated biomonitoring of air quality with plants and lichens: a case study on ambient ozone from central Italy.  

Science.gov (United States)

A biennial integrated survey, based on the use of vascular plants for the bioindication of the effects of tropospheric ozone together with the use of automatic analysers of ozone, as well as the mapping of lichen biodiversity was performed in the area of Castelfiorentino (Tuscany, central Italy). Photochemically produced ozone proved to be a fundamental presence during the warm season, with maximum hourly means reaching 114 ppb, exceeding the information threshold as fixed by EU: the use of supersensitive tobacco Bel-W3 confirmed the opportunity of carrying out detailed cost-effective monitoring surveys. The potential for didactical and educational implications of this methodology are appealing. Critical levels set up for the protection of vegetation have exceeded considerably. The comparison of biomass productivity in sensitive and resistant individuals (NC-S and NC-R white clover clones, in the framework of an European network) provided evidence that ambient ozone levels are associated with relevant reduction (up to 30%) in the performance of sensitive material; effects on flowering were also pronounced. The economic assessment of such an impact deserves attention. Mapping of epiphytic lichen biodiversity--which has been used to monitor air quality worldwide--was not related to ozone geographical distribution as depicted by tobacco response. PMID:17267010

Nali, C; Balducci, E; Frati, L; Paoli, L; Loppi, S; Lorenzini, G

2007-05-01

62

What Causes Aerosol Growth and Ozone Production in Smoke Plumes?  

Science.gov (United States)

The growth of aerosol particles and production of ozone in smoke plumes is the result of a complex interaction between horizontal diffusion, gas-phase oxidation, coagulation, and mass transfer between phases. Models allow us to separate the effects of these processes and predict their impact on the global environment. We present the results of a new model of gas and aerosol chemistry applied to young biomass burning plumes. The model includes heterogeneous chemistry, kinetic mass transfer, coagulation and the formation of secondary organic and inorganic aerosol. Comparison with measurements from SAFARI 2000 (Hobbs et al., 2003, JGR, doi:10.1029/2002JD002352) suggests the baseline model underpredicts ozone formation and the growth of aerosol within the plume. We explore whether the model predictions can be improved by (1) including heterogeneous HONO production, and (2) adding in surrogates for the uncharacterized organic compounds emitted by the biomass burning. Including the heterogeneous reaction NO2 => HONO greatly improves the match for ozone, OH, and aerosol nitrate concentration, but only when the uptake coefficient approaches 10-3, which is over an order of magnitude higher than previously reported values (Stemmler et al., 2006, doi:10.1038/nature04603). Using the reaction NO2 => 0.5 HONO + 0.5 HNO3 with an uptake coefficient of 10-3 (the top of the range recommended by Jacob, 2000, Atm. Env.,34, 2131-2159) provides an even better match for aerosol nitrate, but produces less O3 and OH than the first reaction. Direct measurements of HONO and OH in young biomass plumes would help determine if this chemistry is taking place. We used two surrogates to model the uncharacterized compounds: long chain alkanes and monoterpenes, representing primary and secondary sources of condensable compounds respectively. Complete condensation of the long-chain alkanes can account for nearly all of the observed increase in organic carbon. However, the accommodation coefficient must be near 10-3 or the alkanes will condense too quickly or too slowly. This value is reasonable when compared to measured accommodation coefficients of organic vapors on organic films (Donaldson et al, 2005, Faraday Discuss, doi:10.1039/b418859d). Monoterpenes gradually increase condensed organic carbon even with accommodation coefficients of 0.1, but produced only 35% as much as the alkanes. Production of sulfate and total particulate matter is below observations in all simulations described above. Better characterization of the composition of the condensed organic matter as a function of downwind distance could help determine the source of the organic aerosol growth.

Alvarado, M. J.; Prinn, R. G.

2006-12-01

63

Ozone generation in a kHz-pulsed He-O2 capillary dielectric barrier discharge operated in ambient air  

Science.gov (United States)

The generation of reactive oxygen species using nonequilibrium atmospheric pressure plasma jet devices has been a subject of recent interest due to their ability to generate localized concentrations from a compact source. To date, such studies with plasma jet devices have primarily utilized radio-frequency excitation. In this work, we characterize ozone generation in a kHz-pulsed capillary dielectric barrier discharge configuration comprised of an active discharge plasma jet operating in ambient air that is externally grounded. The plasma jet flow gas was composed of helium with an admixture of up to 5% oxygen. A unipolar voltage pulse train with a 20 ns pulse risetime was used to drive the discharge at repetition rates between 2-25 kHz. Using UVLED absorption spectroscopy centered at 255 nm near the Hartley-band absorption peak, ozone was detected over 1 cm from the capillary axis. We observed roughly linear scaling of ozone production with increasing pulse repetition rate up to a "turnover frequency," beyond which ozone production steadily dropped and discharge current and 777 nm O(5P?5S°) emission sharply increased. The turnover in ozone production occurred at higher pulse frequencies with increasing flow rate and decreasing applied voltage with a common energy density of 55 mJ/cm3 supplied to the discharge. The limiting energy density and peak ozone production both increased with increasing O2 admixture. The power dissipated in the discharge was obtained from circuit current and voltage measurements using a modified parallel plate dielectric barrier discharge circuit model and the volume-averaged ozone concentration was derived from a 2D ozone absorption measurement. From these measurements, the volume-averaged efficiency of ozone production was calculated to be 23 g/kWh at conditions for peak ozone production of 41 mg/h at 11 kV applied voltage, 3% O2, 2 l/min flow rate, and 13 kHz pulse repetition rate, with 1.79 W dissipated in the discharge.

Sands, Brian L.; Ganguly, Biswa N.

2013-12-01

64

Ozone Pollution  

Medline Plus

Full Text Available ... rising temperatures create conditions favorable to forming ozone. Communities will need more help to reduce ozone pollution ... Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: ...

65

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone  

Energy Technology Data Exchange (ETDEWEB)

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought. - Epidemiological assessment of shoot growth suggests an ozone sensitivity of mature beech which is similar to seedlings.

Braun, Sabine [Institute for Applied Plant Biology, Sandgrubenstrasse 25, CH-4124 Schoenenbuch (Switzerland)]. E-mail: sabine.braun@iap.ch; Schindler, Christian [Institute for Social and Preventive Medicine, University of Basel, Steinengraben 49, CH-4051 Basel (Switzerland)]. E-mail: christian.schindler@unibas.ch; Rihm, Beat [Meteotest, Fabrikstrasse 14, CH-3012 Berne (Switzerland)]. E-mail: rihm@meteotest.ch; Flueckiger, Walter [Institute for Applied Plant Biology, Sandgrubenstrasse 25, CH-4124 Schoenenbuch (Switzerland)

2007-04-15

66

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone  

International Nuclear Information System (INIS)

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought. - Epidemiological assessment of shoot growth suggests an ozone sensitivity of mature beech which is similar to seedlings

67

Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, and growth of young spruce trees (Picea abies)  

International Nuclear Information System (INIS)

Spruce saplings were grown under different nitrogen fertilization regimes in eight chamberless fumigation systems, which were fumigated with either charcoal-filtered (F) or ambient air (O3). After the third growing season trees were harvested for biomass and non-structural carbohydrate analysis. Nitrogen had an overall positive effect on the investigated plant parameters, resulting in increased shoot elongation, biomass production, fine root soluble carbohydrate concentrations, and also slightly increased starch concentrations of stems and roots. Only needle starch concentrations and fine root sugar alcohol concentrations were decreased. Ozone fumigation resulted in needle discolorations and affected most parameters negatively, including decreased shoot elongation and decreased starch concentrations in roots, stems, and needles. In fine roots, however, soluble carbohydrate concentrations remained unaffected or increased by ozone fumigation. The only significant interaction was an antagonistic effect on root starch concentrations, where higher nitrogen levels alleviated the negative impact of ozone. - Simultaneous ozone fumigation and nitrogen fertilization have no synergistic impacts on carbohydrate concentrations, biomass, or growth of Picea abies saplings

68

Annual and seasonal trends of ambient ozone concentration and its impact on forest vegetation in Mercantour National Park (South-eastern France) over the 2000-2008 period  

International Nuclear Information System (INIS)

In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000-2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor's emissions from Europe have been reduced over the last 20 years. Decreases in annual averages, median, 25th and 98th percentiles and maxima values were found. The seasonal trend analysis for the high-lying stations showed a decreasing trend for the warm season, when main ozone production is the photochemistry, and an increase for the cold period, caused by a reduced ozone titration. Statistics on Arolla Pine reveal strong correlations between mottling intensity and the high ozone concentrations. Finally, decreases for the ozone concentrations, and associated statistics, AOT40 values and for the mottling intensity on conifers needles were observed. - Trends of ambient ozone concentration, associated statistics and specific ozone-induced symptoms on conifers needles were studied in Mercantour National Park (South-eastern France) over the 2000-2008 period.

69

Scientific basis of the national ambient air quality standards for ozone: How do new discoveries and other concerns modify public health risks and expected benefits?  

Energy Technology Data Exchange (ETDEWEB)

The US EPA, in their recent review of the ozone NAAQS, acknowledged that substantial uncertainties exist with respect to the determination of public health risks due to ambient ozone. In particular, the uncertainties focus on considerable differences of opinion among scientists for the possible health effects at ozone levels near the new 8-hr. ozone National Air Quality Standard (NAAQS) of 0.08 ppm. Information on health or vegetation effects of low ambient ozone levels has been scarce, or extrapolated from studies using levels that are substantially above the new standard level. Uncertainties fall into three categories: (1) the extent of the adversity of public health endpoints; (2) the probability of adverse exposures; and (3) the impact of background levels on the achievability of the new standard. More specifically: (A) Public health effects of low ozone levels have thus far depended primarily on compromised pulmonary function as the biological endpoint of the greatest clinical significance. However, research data published after the standard was promulgated show that the ozone-induced effects represent more a physiological defense mechanism than an adverse effect of low ambient ozone concentrations. In light of these new findings, the alleged ozone action represents only a decline in pulmonary function test performance and not in the vital function of the lungs. This new interpretation not only eliminates the adverse character of pulmonary function decrements, but also largely modifies the proposed estimates of public health risks. (B) Public health risk assessments have indicated that even with compliance of the 1-hour ozone standard, the chances for US populations to encounter an adverse ozone exposure have been practically eliminated.

Vostal, J.J.; Heuss, J.M.; Paul, R.T.; Pezda, S.A.; Ball, J.C.; Wimette, H.J.

1999-07-01

70

78 FR 34177 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...  

Science.gov (United States)

...analyses for the 2008 ozone NAAQS as appropriate...each step of the modeling process. Coordination...able to approve the modeling-based attainment...HEDD) The current modeling guidance addresses...demand days require production of additional power...to coincide with ozone episodes,...

2013-06-06

71

Studies on the biological effects of ozone: 6. Production of transforming growth factor 1 by human blood after ozone treatment.  

Science.gov (United States)

After exposing human whole blood from normal volunteers to ozone concentrations ranging from 22 to 156 micrograms/ml, we have shown that, upon incubation of up to 8 hours, there is a significant release of transforming growth factor beta (TGF-beta 1). In comparison to TGF-beta 1, TGF-beta 2 production is not influenced by ozone concentrations. In line with our previous findings it appears that blood, in the presence of heparin and 5mM Ca,2+ allows a consistent production of tumor necrosis factor a (TNF alpha) and the release of low and non-hazardous levels of free hemoglobin. These data support the contention that autohemotherapy performed after treating blood with ozone followed by reinfusion into the donor, may represent a valuable therapeutic approach for achieving immunoregulatory effects. PMID:7660851

Bocci, V; Luzzi, E; Corradeschi, F; Silvestri, S

1994-01-01

72

OZONE DECREASES SPRING ROOT GROWTH AND ROOT CARBOHYDRATE CONTENT IN PONDEROSA PINE THE YEAR FOLLOWING EXPOSURE  

Science.gov (United States)

Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. he hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. eedling...

73

Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water  

International Nuclear Information System (INIS)

Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O3/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O3/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O3/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

74

Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water  

Energy Technology Data Exchange (ETDEWEB)

Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O{sub 3}/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O{sub 3}/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O{sub 3}/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

Anderson, J.; Wiseman, S.; Franz, E.; Jones, P.; Liber, K.; Giesy, J. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamal El-Din, M.; Marin, J. [Alberta Univ., Edmonton, AB (Canada)

2010-07-01

75

77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards  

Science.gov (United States)

...ozone. The designations for several counties in Illinois, Indiana, and Wisconsin...each state and in areas of Indian county appear in the tables at the end...Marginal. Carbon County Lehigh County Northampton...

2012-05-21

76

Sensitivity and growth of twelve Elatior begonia cultivars to ozone  

Energy Technology Data Exchange (ETDEWEB)

Twelve cultivars of Elatior begonia (Begonia X hiemalis Fotsch.) were exposed to O/sub 3/ at 25 and 50 pphM. The 'Schwabenland' group, 'Whisper 'O' Pink', and 'Improved Krefeld Orange' were the most sensitive, whereas 'Ballerina', 'Mikkell Limelight', and 'Turo' were the least sensitive. 'Rennaisance', 'Heirloom' 'Nixe', and 'Fantasy' were intermediate in sensitivity. The dry weight of foliage (stems plus leaves) of 9 cultivars exposed to O/sub 3/ was significantly less than that of control plants. Ozone at 25 and 50 pphM inhibited flower growth (including peduncles) and development in 4 and 8 of the 12 cultivars, respectively. Differences in flower weight ranged from 43 to 105% of the control at 25 pphM and from 25 to 98% of the control at 50 pphM, depending on cultivar. 1 table.

Reinert, R.A.; Nelson, P.V.

1979-12-01

77

Ambient ozone effects on gas exchange and total non-structural carbohydrate levels in cutleaf coneflower (Rudbeckia laciniata L.) growing in Great Smoky Mountains National Park  

International Nuclear Information System (INIS)

Ozone-sensitive and -tolerant individuals of cutleaf coneflower (Rudbeckia laciniata L.) were compared for their gas exchange characteristics and total non-structural carbohydrates at Purchase Knob, a high elevation site in Great Smoky Mountains National Park, USA. Photosynthesis and stomatal conductance decreased with increased foliar stipple. Sensitive plants had lower photosynthetic rates for all leaves, except the very youngest and oldest when compared to tolerant plants. Stomatal conductance decreased with increasing leaf age, but no ozone-sensitivity differences were found. Lower leaves had less starch than upper ones, while leaves on sensitive plants had less than those on tolerant plants. These results show that ambient levels of ozone in Great Smoky Mountains National Park can adversely affect gas exchange, water use efficiency and leaf starch content in sensitive coneflower plants. Persistence of sensitive genotypes in the Park may be due to physiological recovery in low ozone years. - Highlights: ? Ozone-sensitive and -tolerant cutleaf coneflower (Rudbeckia laciniata L.) were compared. ? Net photosynthesis decreased with increased foliar stipple and leaf age. ? Sensitive plants with visible stipple had lower photosynthetic rates when compared to tolerant plants. ? Stomatal conductance did not differ between sensitivity types. ? Sensitive plants had lower leaf starch content than tolerant plants. - Ambient ozone may cause declines in gas exchange and starch in ozone-sensitive genotypes of cutleaf coneflower.

78

Instrumental recording and biomonitoring of ambient ozone in the Greek countryside.  

Science.gov (United States)

Among eight commercial Greek varieties of tobacco (Nicotiana tabacum L.) tested for their ozone-sensitivity levels, the Zichnomirodata (KK6/5) variety was found to be the most sensitive, although less sensitive than the well-known super-sensitive Bel-W3. Besides qualitative differences in the appearance of macroscopic symptoms these two varieties can be used simultaneously as a reliable pair of ozone bioindicators. The occurrence of ozone in the Greek countryside was surveyed by biomonitoring in 14 rural regions over the country and by a simultaneous biomonitoring and instrumental recording of ozone concentrations at a single remote side (Pournaria, Arcadia). Phytotoxic symptoms were observed mainly on the leaves of Bel-W3 and occasionally on those of Zichnomirodata varieties, suggesting that ozone levels were high enough to affect at least sensitive species. The instrumental monitoring (during a total period of 912 h) revealed maximum hourly O3 concentration 62 ppb, while the thresholds of 30, 40 and 50 ppb were exceeded for 40%, 20% and 6% of the recording period, respectively. The accumulated exposure over 40 ppb (AOT40) for the daylight hours over the 38 monitored days was 680 ppb h. PMID:11482673

Saitanis, C J; Karandinos, M G

2001-08-01

79

Characterization of radicals and high-molecular weight species from alpha-pinene/ozone reaction and ambient aerosol samples  

Science.gov (United States)

Secondary organic aerosol formed during oxidation of different volatile organic compounds is composed from a number of final and intermediate reaction products. The final products include compounds in both low and high molecular weight range called also oligomer species. These compounds can be highly volatile, as well as being semi- or low-volatility compounds. This study characterized intermediate reactive radical products formed from previously often studied alpha-pinene/ozone reaction. In order to passivate those radical species nitrone spin traps were used. 5,5-dimethyl-4,5-dihydro-3H-pyrrole-N-oxide (DMPO), and 5-dietoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) traps were able to successfully trap oxygen- and carbon-centered radicals produced from alpha-pinene/ozone reaction. Electrospray ionization (ESI) in negative ion mode with mass spectrometry (MS) detection was used to scan spectra of formed spin trap adducts and the tandem mass spectrometry (MSn) to elucidate its structures as well as structures of captured radicals. The same method was applied to analyze radical species present in ambient PM2.5 samples. Few carbon- (alkyl) and oxygen- (alkoxyl) centered radicals were captured with DMPO and DEPMPO traps. The second part of this study was focused on high molecular weight (high-MW) species formed from the same reaction (alpha-pinene/ozone), but found also in fine particulate matter fractions of ambient samples. LC/MS/MS analysis of dimer species from chamber study revealed fragments that can originate from peroxide structures. Proposed reaction for these peroxide dimer formation is self reaction of two peroxyl radicals, followed by the loss of oxygen molecule. These findings emphasize the role of peroxyl (ROO) radicals in formation of high-MW products and are in line with the high O:C ratio results reported in other studies. Water soluble organic carbon (WSOC) extracts of three size fractions of the ambient aerosol, PM1--2.5, PM0.1--1, and PMMS analysis. That analysis also confirmed presence of four different classes of compounds in ambient aerosols: carboxylic acids, poly-carboxylic acids, organosulfates, and organonitrates.

Pavlovic, Jelica

80

Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees  

Energy Technology Data Exchange (ETDEWEB)

In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

Olbrich, Maren; Knappe, Claudia; Wenig, Marion; Gerstner, Elke [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Haeberle, Karl-Heinz; Kitao, Mitsutoshi; Matyssek, Rainer [Forest Botany, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Stich, Susanne [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Leuchner, Michael; Werner, Herbert [Bioclimatology, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Schlink, Katja; Mueller-Starck, Gerhard [Section of Forest Genetics, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Welzl, Gerhard [Institute of Developmental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Scherb, Hagen [Institute of Biomathematics and Biometry, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Ernst, Dieter; Heller, Werner [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany); Bahnweg, Guenther, E-mail: bahnweg@helmholtz-muenchen.d [Institute of Biochemical Plant Pathology, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg (Germany)

2010-04-15

 
 
 
 
81

Ozone fumigation (twice ambient) reduces leaf infestation following natural and artificial inoculation by the endophytic fungus Apiognomonia errabunda of adult European beech trees  

International Nuclear Information System (INIS)

In 2006, a controlled infection study was performed in the 'Kranzberger Forst' to address the following questions: (1) Will massive artificial inoculation with Apiognomonia errabunda override the previously observed inhibitory effect of chronic ozone? (2) Can biochemical or molecular markers be detected to account for the action of ozone? To this end six adult beech trees were chosen, three ozone fumigated (2x ozone) and three control trees (ambient = 1x ozone). Spore-sprayed branches of sun and shade crown positions of each of the trees, and uninoculated control branches, were enclosed in 100-L plastic bags for one night to facilitate infection initiation. Samples were taken within a five-week period after inoculation. A. errabunda infestation levels quantified by real-time PCR increased in leaves that were not fumigated with additional ozone. Cell wall components and ACC (ethylene precursor 1-amino cyclopropane-1-carboxylic acid) increased upon ozone fumigation and may in part lead to the repression of fungal infection. - Chronic sublethal ozone exposure reduces both natural and artificial infestation of beech leaves by the endophytic fungus Apiognomonia errabunda.

82

How closely does stem growth of adult beech (Fagus sylvatica) relate to net carbon gain under experimentally enhanced ozone stress?  

International Nuclear Information System (INIS)

The hypothesis was tested that O3-induced changes in leaf-level photosynthetic parameters have the capacity of limiting the seasonal photosynthetic carbon gain of adult beech trees. To this end, canopy-level photosynthetic carbon gain and respiratory carbon loss were assessed in European beech (Fagus sylvatica) by using a physiologically based model, integrating environmental and photosynthetic parameters. The latter were derived from leaves at various canopy positions under the ambient O3 regime, as prevailing at the forest site (control), or under an experimental twice-ambient O3 regime (elevated O3), as released through a free-air canopy O3 fumigation system. Gross carbon gain at the canopy-level declined by 1.7%, while respiratory carbon loss increased by 4.6% under elevated O3. As this outcome only partly accounts for the decline in stem growth, O3-induced changes in allocation are referred to and discussed as crucial in quantitatively linking carbon gain with stem growth. - Highlights: ? We model O3-induced changes in the photosynthetic carbon gain of adult beech trees. ? Elevated O3 decreases gross carbon gain but increases respiratory carbon loss. ? Reduction in net carbon gain only partly accounts for the decline in stem growth. ? O3 effects on the whole-tree allocation is crucial in addition to carbon gains. - Reduction in net carbon gain at - Reduction in net carbon gain at the canopy level only partly accounts for the decline in stem growth under elevated ozone.

83

Impacts of elevated ozone on growth and photosynthesis of Metasequoia glyptostroboides Hu et Cheng.  

Science.gov (United States)

One-year-old Metasequoia glyptostroboides seedlings were exposed to non-filtered ambient air (NF) and elevated ozone (E-O3, NF+60 ppb) in open-top chambers for two years. E-O3 accelerated leaf senescence, as indicated by significant decreases in photosynthetic pigment contents with the elongation of O3 exposure. E-O3 significantly affected gas exchange and carboxylation, inducing reductions in light-saturated photosynthesis (Asat), the maximum activity of Rubisco (Vc,max) and the maximum electron transport rate (Jmax). Chl a/b, Vc,max/Jmax and stomatal limitation (l) were not affected. Stomatal conductance (gs) was significantly decreased by E-O3 in the first year, but remained unchanged in the second year. It can be inferred that the decrease in Asat by E-O3 was mainly attributed to the changes in non-stomatal factors. After two years' exposure, E-O3 caused significant decreases in canopy photosynthesis and leaf mass per area, and a significant increase in the number of branches, but induced slight, not significant decreases in growth and biomass. Therefore, it can be concluded that the carbon accumulation of the species M. glyptostroboides could be negatively affected after long-term exposure to high O3 concentration. PMID:25113463

Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Niu, Junfeng

2014-09-01

84

77 FR 8197 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...  

Science.gov (United States)

...The telephone number for the Public Reading Room is (202) 566-1744. FOR FURTHER...Table 1, below, depicts this proposed translation for classifications as it would apply...Ozone Design Value Classification Table Translation to 8-Hour Design Values for...

2012-02-14

85

The impact of ambient ozone on mountain spruce forests in the Czech Republic as indicated by malondialdehyde  

Energy Technology Data Exchange (ETDEWEB)

Malondialdehyde (MDA), a product of lipid peroxidation and biomarker of oxidative stress, is measured over the long term in spruce Picea abies needles under real conditions in three Czech mountain border areas. The trends presented collate the MDA content in spruce needles with ambient ozone, temperature and precipitation as casual, and defoliation as a subsequent factor for the period 1994-2006. We have found the overall decreasing trends in MDA and defoliation. The highest MDA and defoliation are recorded in the Jizerske, the lowest in the Krusne hory Mts. Out of the examined variables the MDA is predicted best by mean temperature in vegetation season, median of O{sub 3} concentrations and AOT40; these three variables account for 34% of MDA1 and 36% of MDA2 variability. Our hypothesis that higher ambient O{sub 3} exposure results in higher MDA contents in P. abies needles under real conditions has not been approved. - The assumption that higher ambient O{sub 3} exposure results in higher MDA in Picea abies needles has not been approved in our study under real conditions in three Czech mountain forest areas.

Hunova, Iva, E-mail: hunova@chmi.c [Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4-Komorany (Czech Republic); Novotny, Radek; Uhlirova, Hana [Forestry and Game Management Research Institute, Jiloviste Strnady (Czech Republic); Vrablik, Tomas; Horalek, Jan [Czech Hydrometeorological Institute, Na Sabatce 17, 143 06 Prague 4-Komorany (Czech Republic); Lomsky, Bohumir; Sramek, Vit [Forestry and Game Management Research Institute, Jiloviste Strnady (Czech Republic)

2010-07-15

86

40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.  

Science.gov (United States)

...quality standards for ozone. (a) The level...quality standards for ozone measured by a reference...year with maximum hourly average concentrations above 0.12 parts per...promulgation of 8-hour ozone standards...

2010-07-01

87

Impact of ozone on the growth of birch (Betula pendula) saplings  

International Nuclear Information System (INIS)

Significant correlation was found between reductions of growth and daylight AOT40 for Betula pendula saplings. - Saplings of one half-sib family of birch, Betula pendula, were exposed to three levels of ozone in open-top chambers (OTCs) during two growing seasons 1997-1998. The ozone treatments were non-filtered air (NF, accumulated daylight AOT40 over the two growing seasons of 3.0 ?l l-1 h), non-filtered air with extra ozone (NF+, accumulated daylight AOT40 of 27.3 ?l l-1 h) and non-filtered air with additional extra ozone (NF++, accumulated daylight AOT40 of 120 ?l l-1 h). The birch saplings, including the roots, were harvested after the first and second growing seasons. After the first growing season, the NF++ treatment reduced the total wood biomass by 22%, relative to the NF treatment. There was no further reduction of the total wood biomass in the NF++ treatment after the second growing season. The root biomass was reduced by 30% after the first growing season. The shoot/root ratio, as well as the proportional biomass of leaves, were increased by ozone during both years. The ozone impact on the relative growth rate was estimated to -2% per 10 ?l l-1 h daylight AOT40 per growing season

88

Growth response to a changing environment-Impacts of tropospheric ozone dose on photosynthesis of Norway spruce forests in Austria  

Science.gov (United States)

Tropospheric ozone is an important air pollutant, although plants have active defense strategies (e.g. antioxidants), the cumulative ozone dose may lead to chronic damages to plant tissues. Ozone enters into plants through stomata and reacts with other chemicals to create toxic compounds. This affects plant photosynthesis and may reduce CO2 fixation, and consequently growth. Open top cambers (OTC) are usually used to study the effects of elevated ozone levels on photosynthesis; whereas field studies with on site occurring ozone levels are rare. A recent modelling study on Norway spruce stands in Austria exhibited trends in model errors indicating that an increase in ozone dose leads to a reduction in volume increment. This study aims to explore how different ozone doses affect photosynthesis under field conditions and may translate into growth response for 12 stands of Norway spruce, distributed along an ozone concentration gradient across Austria. A LI-6400xt photosynthesis system was utilized to collect physiological parameters including net photosynthesis, stomata conductance, internal CO2 concentration, transpiration, etc. Chlorophyll fluorescence data was collected by using a PEA chlorophyll fluorescence meter, and chlorophyll content was measured. Morphological characteristics and soil samples were also analyzed. Ozone dose to leaf tissue was calculated from external ozone concentration, the conductance of the stomata to ozone, the leaf area index and the time span of the day when ozone uptake takes place. Our results confirm that increasing cumulative ozone dose reduces maximum assimilation rate and carboxylation efficiency under field conditions. Our final goal is to quantify how far this ozone induced reduction in assimilation power ultimately translates into a growth reduction of Norway spruce in Austria.

Liu, Xiaozhen; Pietsch, Stephan; Hasenauer, Hubert

2010-05-01

89

Host location behavior of Cotesia plutellae Kurdjumov (Hymenoptera: Braconidae) in ambient and moderately elevated ozone in field conditions  

Energy Technology Data Exchange (ETDEWEB)

In field O{sub 3}-enrichment experiments increased herbivore densities have been reported, which could be due to negatively affected host location behavior of natural enemies. We addressed the impact of doubling background O{sub 3} on the host location of the parasitoid Cotesia plutellae by conducting 24-h trials in an open-air O{sub 3}-fumigation system during two consecutive years. Two circles (radii 1.40 and 4.00 m) of Plutella xylostella-infested potted cabbage plants were placed in the O{sub 3} and ambient plots. Female wasps were released into each plot from the center, and observed 5 times over a 24-h period to assess their host location capability. Thereafter, plants were kept in laboratory conditions until larvae pupation to determine parasitism rates. No significant differences were detected between ambient and O{sub 3}-enriched environments either in the number of wasps found in the field, or in the percentages of parasitized larvae. This suggests that moderately elevated O{sub 3} will not affect the behavior of this parasitoid. - Atmospheric ozone increases do not directly affect the biological control of the cabbage pest, Plutella xylostella.

Pinto, D.M. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland)], E-mail: delia.pinto@uku.fi; Himanen, S.J. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Nissinen, A. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Agrifood Research Finland, Plant Protection, FIN-31600 Jokioinen (Finland); Nerg, A.-M.; Holopainen, J.K. [Department of Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland)

2008-11-15

90

Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, growth, and nutrient concentrations of young beech trees (Fagus sylvatica)  

Energy Technology Data Exchange (ETDEWEB)

Beech seedlings were grown under different nitrogen fertilisation regimes (0, 20, 40, and 80 kg N ha{sup -1} yr{sup -1}) for three years and were fumigated with either charcoal-filtered (F) or ambient air (O{sub 3}). Nitrogen fertilisation increased leaf necroses, aphid infestations, and nutrient ratios in the leaves (N:P and N:K), as a result of decreased phosphorus and potassium concentrations. For plant growth, biomass accumulation, and starch concentrations, a positive nitrogen effect was found, but only for fertilisations of up to 40 kg N ha{sup -1} yr{sup -1}. The highest nitrogen load, however, reduced leaf area, leaf water content, growth, biomass accumulation, and starch concentrations, whereas soluble carbohydrate concentrations were enhanced. The ozone fumigation resulted in reduced leaf area, leaf water content, shoot growth, root biomass accumulation, and decreased starch, phosphorus, and potassium concentrations, increasing the N:P and N:K ratios. A combined effect of the two pollutants was detected for the leaf area and the shoot elongation, where ozone fumigation amplified the nitrogen effects. - The effects of nitrogen and ozone on growth, carbohydrate concentrations, and nutrients are mainly additive.

Thomas, V.F.D. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)]. E-mail: vera.thomas@iap.ch; Braun, S. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland); Flueckiger, W. [Institute for Applied Plant Biology, Sandgrubenstr. 25/27, 4124 Schoenenbuch (Switzerland)

2006-09-15

91

Effects of ozone on growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat (Triticum aestivum L.)  

Energy Technology Data Exchange (ETDEWEB)

To clarify the effects of O{sub 3} on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O{sub 3} at 60 and 100 nl l{sup -1} (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O{sub 3}. Although there was no significant effect of O{sub 3} on stomatal diffusive conductance to H{sub 2}O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O{sub 3.} The sensitivity of growth, yield, yield components and leaf gas exchange rates to O{sub 3} was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O{sub 3} may detrimentally affect wheat production in Bangladesh. - The exposure to ambient levels of ozone decreases growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat.

Akhtar, Nahid [United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Yamaguchi, Masahiro; Inada, Hidetoshi; Hoshino, Daiki; Kondo, Taisuke [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Izuta, Takeshi, E-mail: izuta@cc.tuat.ac.j [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

2010-05-15

92

EVALUATION OF VARIOUS ALTERNATIVE AMBIENT OZONE STANDARDS BASED ON CROP YIELD LOSS DATA  

Science.gov (United States)

Under the Clean Air Act, the U.S. Environmental Protection Agency establishes primary and secondary national ambient air quality standards (NAAQSs) to protect public health and welfare from known or anticipated adverse effects from criteria air pollutants. he objectives of this p...

93

EFFECTS OF OZONE ON SPORULATION, SPORE GERMINATION, AND GROWTH OF FOMES ANNOSUS  

Science.gov (United States)

Effects of ozone (O3) on certain cultural characteristics of Fomes annosus were investigated in exposure chamber studies. Growth rates of F. annosus decreased and conidial germ tubes were shorter and had fewer branches as O3 dosages increased. F. annosus conidial production was v...

94

The influence of ultraviolet-B radiation on growth, hydroxycinnamic acids and flavonoids of Deschampsia antarctica during Springtime ozone depletion in Antarctica.  

Science.gov (United States)

We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the growth, biomass production and phenylpropanoid concentrations of Deschampsia antarctica during the springtime ozone depletion season at Palmer Station, along the Antarctic Peninsula. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B either by 83% (reduced UV-B) or by 12% (near-ambient UV-B) over the 63 day experiment (7 November 1998-8 January 1999) when ozone depletion averaged 17%. Plants growing under near-ambient UV-B had 41% and 40% lower relative growth rates and net assimilation rates, respectively, than those under reduced UV-B. The former plants produced 50% less total biomass as a result of having 47% less aboveground biomass. The reduction in aboveground biomass was a result of a 29% lower leaf elongation rate resulting in shorter leaves and 59% less total leaf area in plants grown under reduced UV-B. p-Coumaric, caffeic and ferulic acids were the major hydroxycinnamic acids, and luteolin derivatives were the major flavonoids in both insoluble and soluble leaf extracts. Concentrations of insoluble p-coumaric and caffeic acid and soluble ferulic acids were 38%, 48% and 60% higher, respectively, under near-ambient UV-B than under reduced UV-B. There were no UV-B effects on concentrations of insoluble or soluble flavonoids. PMID:15689180

Ruhland, Christopher T; Xiong, Fusheng S; Clark, W Dennis; Day, Thomas A

2005-01-01

95

Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature  

International Nuclear Information System (INIS)

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO2 sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm-1) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag+, instead of Na+, Ca2+, or K+ ions, existing in the natural clinoptilolite form. The samples Ag/SiO2 and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

96

Ozone Pollution  

Medline Plus

Full Text Available ... most ozone-polluted cities. Unfortunately, even with the improvements, people living there are still forced to breathe ... Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: Act Locally What You ...

97

Reduction of stem growth and site dependency of leaf injury in Massachusetts black cherries exhibiting ozone symptoms  

International Nuclear Information System (INIS)

Ozone symptomatic trees had a reduced stem growth and symptom expression was enhanced on moister and better growing stands. - Leaf ozone symptoms in natural ecosystems are increasingly reported but ozone effects on tree growth and the mediation of site conditions are still little documented. This study tests two hypotheses: (1) leaf injury in black cherry is associated with decline in radial growth, (2) symptoms are more prevalent on mesic sites. On sites supporting black cherry across Massachusetts, tree growth and leaf ozone injury were surveyed in 1996 using a randomized plot network established in the 1960s. Forty-seven percent of 120 trees sampled for ozone symptoms were symptomatic with generally low levels of injury. Over a 31-year period symptomatic trees had 28% lower stem growth rates than asymptomatic trees. Ozone symptom expression was enhanced in well growing stands on moister, cooler and more elevated sites. Ozone appeared to increase environmental stress and had a more pronounced effect on growth in better growing black cherry stands. This complicates management decisions as thinning increases growth and moisture availability

98

Effect of increased carbon dioxide concentrations on stratospheric ozone  

International Nuclear Information System (INIS)

During the past several years, much attention has been focused on the destruction of ozone by anthropogenic pollutants such as the nitrogen oxides and chlorofluoromethane. Little or no attention has been given to the influence on ozone of an increased carbon dioxide concentration for which a measurable growth has been observed. Increased carbon dioxide can directly affect ozone by perturbing atmospheric temperatures, which will alter ozone production, whose rate displays a fairly strong temperature dependence. This paper presents one-dimensional model results for the steady state ozone behavior when the CO2 concentration is twice its ambient level which account for coupling between chemistry and temperature. When the CO2 level doubled, the total ozone burden increased in relation to the ambient burden by 1.2--2.5%, depending on the vertical diffusion coefficient used. Above 30 km. In this region the relation variations were insensitive to the choice of diffusion coefficient. Below 30 km, ozone concentrations were smaller than the unperturbed values and were sensitive to the vertical diffusion profile in this region (10--30 km). Ozone decreases in the lower stratosphere because of a reduction in ozone-producing solar radiation, which results in smaller downward ozone fluxes from the region at 25--30 km relative to the flux values for the ambient atmosphere. These offsetting changes occurring in the upper and lower stratosphere act to minimize the nd lower stratosphere act to minimize the variation in total ozone

99

Statistical estimation of ozone exposure metrics  

Energy Technology Data Exchange (ETDEWEB)

Data from recent experiments at North Carolina State University and other locations provide a unique opportunity to study the effect of ambient ozone on the growth of clover. The data consist of hourly ozone measurements over a 140 day growing season at eight sites in the US, coupled with clover growth response data measured every 28 days. The objective is to model an indicator of clover growth as a function of ozone exposure. A common strategy for dealing with the numerous hourly ozone measurements is to reduce these to a single summary measurement, a so-called exposure metric, for the growth period of interest. However, the mean ozone value is not necessarily the best summarization, as it is widely believed that low levels of ozone have a negligible effect on growth, whereas peak ozone values are deleterious to plant growth. There are also suspected interactions with available sunlight, temperature and humidity. A number of exposure metrics have been proposed that reflect these beliefs by assigning different weights to ozone values according to magnitude, time of day, temperature and humidity. These weighting schemes generally depend on parameters that have, to date, been subjectively determined. We propose a statistical approach based on profile livelihoods to estimate the parameters in these exposure metrics. (author)

Blankenship, E.E. [University of Nebraska, Lincoln, NE (United States). Dept. of Biometry; Stefanski, L.A. [North Carolina State University, Raleigh, NC (United States). Dept. of Statistics

2001-07-01

100

Seeding ice growth at ambient conditions using nano graphene oxide  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water wetting on a hydrophobic surface at ambient conditions is disallowed by the nonpolar nature of the surface and high vapor pressure of water. However, the presence of sub-millimeter sized hydrophilic patches allows the waxy wings of desert beetles to become wettable by morning mist. Here, we show that a sprinkle of graphene oxide nanoflakes (nanoGOs) is effective in condensing water nanodroplets and seeding ice epitaxy on graphite at ambient conditions. By controlling r...

Zheng, Yi; Su, C. L.; Lu, Jiong; Loh, Kian Ping

2013-01-01

 
 
 
 
101

Erratum to "Structural and physiological responses to ozone in Manna ash (Fraxinus ornus L.) leaves of seedlings and mature trees under controlled and ambient conditions".  

Science.gov (United States)

Leaf-level microscopical symptom structure and physiological responses were investigated in seedlings experimentally exposed to ozone (O3) in indoor chambers (150 ppb, 8 hd(-1) per 7 weeks), and field trees of Manna ash (Fraxinus ornus) exposed to ambient O3 (max 93 ppb per one growing season). Ozone-induced leaf injury, including leaf reddening and stippling, was observed in both seedlings and mature trees, but the morphology of injury in the stipples differed, being hypersensitive-like (HR-like) in the chamber seedlings and accelerated cell senescence (ACS) in the field trees. In both exposure conditions, the main structural impact of O3 was on the mesophyll and especially the upper assimilating cell layers. The main physiological impact was on carbon assimilation and on stomatal sluggishness. These effects were not due to stomatal structural injury and were more severe in juvenile compared to mature trees because of environmental (water availability, light) and constitutional (gas exchange capacity) factors and differences in the cell physiology processes (HR-like vs. ACS) triggered by ozone stress. Given the plasticity of plant responses to ozone stress, dose/response relationships for tree seedlings in the indoor chambers cannot be extrapolated to mature trees unless ambient conditions are closely simulated. PMID:20238440

Paoletti, Elena; Contran, Nicla; Bernasconi, Petra; Günthardt-Goerg, Madeleine S; Vollenweider, Pierre

2010-03-15

102

Structural and physiological responses to ozone in Manna ash (Fraxinus ornus L.) leaves of seedlings and mature trees under controlled and ambient conditions.  

Science.gov (United States)

Leaf-level microscopical symptom structure and physiological responses were investigated in seedlings experimentally exposed to ozone (O3) in indoor chambers (150 ppb, 8 h d(-1)/7 weeks), and field trees of Manna ash (Fraxinus ornus) exposed to ambient O3 (max 93 ppb/one growing season). Ozone-induced leaf injury, including leaf reddening and stippling, was observed in both seedlings and mature trees, but the morphology of injury in the stipples differed, being hypersensitive-like (HR-like) in the chamber seedlings and accelerated cell senescence (ACS) in the field trees. In both exposure conditions, the main structural impact of O3 was on the mesophyll and especially the upper assimilating cell layers. The main physiological impact was on carbon assimilation and on stomatal sluggishness. These effects were not due to stomatal structural injury and were more severe in juvenile compared to mature trees because of environmental (water availability, light) and constitutional (gas exchange capacity) factors and differences in the cell physiology processes (HR-like vs. ACS) triggered by ozone stress. Given the plasticity of plant responses to ozone stress, dose/response relationships for tree seedlings in the indoor chambers cannot be extrapolated to mature trees unless ambient conditions are closely simulated. PMID:19136142

Paoletti, Elena; Contran, Nicla; Bernasconi, Petra; Günthardt-Goerg, Madeleine S; Vollenweider, Pierre

2009-02-15

103

Differential protection of ethylenediurea (EDU) against ambient ozone for five cultivars of tropical wheat  

International Nuclear Information System (INIS)

The antiozonant EDU (ethylenediurea) was used to assess the impact of ambient O3 under field conditions on five cultivars of tropical wheat (Triticum aestivum L.). EDU solution (0 ppm and 400 ppm) was applied as soil drench (100 ml plant-1) 10 days after germination (DAG) at an interval of 12 days. EDU-treated plants showed significant increments in stomatal conductance, photosynthetic rate, variable fluorescence, total chlorophyll, ascorbic acid, proline and protein contents and protective enzymes (POX, SOD and APX) activities in HUW468, HUW510 and HUW234 cultivars, while, a reverse trend was observed for lipid peroxidation. EDU application restored grain yield significantly by maintaining higher levels of antioxidants, metabolites and enzymes in cultivars HUW468 and HUW510. Sonalika and PBW343 showed least response of measured parameters under EDU treatment suggesting their greater resistance to O3. EDU, thus proved its usefulness in screening suitable wheat cultivars for areas experiencing elevated concentrations of O3. - EDU successfully screened the sensitivity of tropical wheat cultivars to ambient O3 under natural field conditions.

104

Differential protection of ethylenediurea (EDU) against ambient ozone for five cultivars of tropical wheat  

Energy Technology Data Exchange (ETDEWEB)

The antiozonant EDU (ethylenediurea) was used to assess the impact of ambient O{sub 3} under field conditions on five cultivars of tropical wheat (Triticum aestivum L.). EDU solution (0 ppm and 400 ppm) was applied as soil drench (100 ml plant{sup -1}) 10 days after germination (DAG) at an interval of 12 days. EDU-treated plants showed significant increments in stomatal conductance, photosynthetic rate, variable fluorescence, total chlorophyll, ascorbic acid, proline and protein contents and protective enzymes (POX, SOD and APX) activities in HUW468, HUW510 and HUW234 cultivars, while, a reverse trend was observed for lipid peroxidation. EDU application restored grain yield significantly by maintaining higher levels of antioxidants, metabolites and enzymes in cultivars HUW468 and HUW510. Sonalika and PBW343 showed least response of measured parameters under EDU treatment suggesting their greater resistance to O{sub 3}. EDU, thus proved its usefulness in screening suitable wheat cultivars for areas experiencing elevated concentrations of O{sub 3}. - EDU successfully screened the sensitivity of tropical wheat cultivars to ambient O{sub 3} under natural field conditions.

Singh, Shalini [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, S.B., E-mail: sbagrawal56@gmail.co [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India); Agrawal, Madhoolika [Lab of Air Pollution and Global Climatic Change, Ecology Research Circle, Department of Botany, Banaras Hindu University, Varanasi 221005 (India)

2009-08-15

105

Indirect prediction of surface ozone concentration by plant growth responses in East Asia using mini-open top chambers.  

Science.gov (United States)

We developed small and mobile open top chambers (mini-OTC) measuring 0.6 m (W)?×?0.6 m (D)?×?1.2 m (H) with an air duct of 0.6 m (W)?×?0.23 m (D)?×?1.2 m (H). The air duct can be filled with activated charcoal to blow charcoal filtered air (CF) into the chamber, as opposed to non-filtered ambient air (NF). Ozone sensitive radish Raphanus sativus cv. Red Chime and rosette pakchoi Brassica campestris var. rosularis cv. ATU171 were exposed to NF and CF in mini-OTCs at different locations in East Asia. A total of 29 exposure experiments were conducted at nine locations, Shanghai, China, Ha Noi, Vietnam, Lampang, Phitsanulok and Pathumtani, Thailand, and Hiratsuka, Kisai, Abiko and Akagi, Japan. Although no significant relationships between the mean concentrations of ambient O(3) during the experimental period and the growth responses were observed for either species, multiple linear regression analysis suggested a good relationship between the biomass responses in each species and the O(3) concentration, temperature, and relative humidity. The cumulative daily mean O(3) (ppb/day) could be indirectly predicted by NF/CF based on the dry weight ratio of biomass, mean air temperature, and relative air humidity. PMID:22752963

Kohno, Yoshihisa; Matsumura, Hideyuki; Miwa, Makoto; Yonekura, Tetsushi; Aihara, Keiji; Umponstira, Chanin; Le, Vo Thanh; Ngoc, Nguyen Thuy; Viet, Phanm Hung; Wei, Ma

2013-03-01

106

Ambient formaldehyde and its contributing factor to ozone and OH radical in a rural area  

Science.gov (United States)

Formaldehyde (HCHO), as well as correlative pollutants was measured from 1 to 31 July in 2007 at Mazhuang, a rural site located in the east of China. Gaseous HCHO was scrubbed from the air with an acidic 2,4-dinitrophenylhydrazine (DNPH) solution, which leaded to the reaction of HCHO with DNPH and produced a stable product, 2,4-dinitrophenylhydrazone, followed by online analysis by high-performance liquid chromatography (HPLC) coupled with Ultraviolet detector. During the observation period, mixing ratios of HCHO ranged from 0.2 ppbv to 6.2 ppbv, with an average of 1.5 ± 0.67 ppbv. HCHO shows an evident diurnal variation, the maximum appeared during 12:00-14:00. The average concentration diurnal variations of measured HCHO, ozone (O 3), Methylhydroperoxides (MHP, CH 3OOH), hydrogen peroxide (H 2O 2), nitrogen oxides (NO x) and meteorological parameters were compared. The similar variations of HCHO, O 3 and radiation imply that photo-oxidation of hydrocarbons might be the major source for HCHO. Based on the maximum incremental reactivity (MIR) coefficient of HCHO, the calculation shows that HCHO contributes about 20% to total observed O 3 during the study period. In order to compare the contributions of O 3, HCHO and HONO to OH radical, photolysis rate parameters ( J-values) of the three compounds were calculated by the Tropospheric Ultraviolet and Visible (TUV) Radiation Model (4.4 version). Based on the comparison, this study reaches the conclusion that O 3 is the dominant source of OH radical at Mazhuang. This study also uses P(HCHO)/P(O 3) which represents the ratio of contrbutions of HCHO and O 3 to OH radical, to discuss the action of HCHO in OH radical soucers. The result shows that P(HCHO)/P(O 3) is 12.5% on average, with the maximum of 21.0% at 13:00 P.M. and minimum of 7.5% before 9:00 A.M. and after 17:00 P.M..Therefore HCHO is also an important source of OH radical and cannot be ignored.

Xiaoyan, Wang; Huixiang, Wang; Shaoli, Wang

2010-06-01

107

Physiological and foliar symptom response in the crowns of Prunus serotina, Fraxinus americana and Acer rubrum canopy trees to ambient ozone under forest conditions.  

Science.gov (United States)

The crowns of five canopy dominant black cherry (Prunus serotina Ehrh.), five white ash (Fraxinus americana L.), and six red maple (Acer rubrum L.) trees on naturally differing environmental conditions were accessed with scaffold towers within a mixed hardwood forest stand in central Pennsylvania. Ambient ozone concentrations, meteorological parameters, leaf gas exchange and leaf water potential were measured at the sites during the growing seasons of 1998 and 1999. Visible ozone-induced foliar injury was assessed on leaves within the upper and lower crown branches of each tree. Ambient ozone exposures were sufficient to induce typical symptoms on cherry (0-5% total affected leaf area, LAA), whereas foliar injury was not observed on ash or maple. There was a positive correlation between increasing cumulative ozone uptake (U) and increasing percent of LAA for cherry grown under drier site conditions. The lower crown leaves of cherry showed more severe foliar injury than the upper crown leaves. No significant differences in predawn leaf water potential (psi(L)) were detected for all three species indicating no differing soil moisture conditions across the sites. Significant variation in stomatal conductance for water vapor (g(wv)) was found among species, soil moisture, time of day and sample date. When comparing cumulative ozone uptake and decreased photosynthetic activity (P(n)), red maple was the only species to show higher gas exchange under mesic vs. drier soil conditions (P < 0.05). The inconsistent differences in gas exchange response within the same crowns of ash and the uncoupling relationship between g(wv) and P(n) demonstrate the strong influence of heterogeneous environmental conditions within forest canopies. PMID:15519730

Schaub, M; Skelly, J M; Zhang, J W; Ferdinand, J A; Savage, J E; Stevenson, R E; Davis, D D; Steiner, K C

2005-02-01

108

Growth response of Pinus ponderosa seedlings and mature tree branches to acid rain and ozone exposure  

International Nuclear Information System (INIS)

Forests of the central and southern Sierra Nevada in California have been subjected to chronic damage by ozone and other atmospheric pollutants for the past several decades. Until recently, pollutant exposure of northern Sierra Nevada forests has been mild but increasing population and changes in land use throughout the Sacramento Valley and Sierra Nevada foothills may lead to increased pollutant damage in these forests. Although, better documented in other regions of the United States, little is known regarding the potential for acidic precipitation damage to Sierra Nevada forests. Only recently have studies directed towards understanding the potential interactive effects of ozone and acidic precipitation been undertaken. A key issue in resolving potential regional impacts of pollutants on forests is the extent to which research results can be scaled across genotypes and life-stages. Most of the pollution research to date has been performed using seedlings with varying degrees of genetic control. It is important to determine if the results obtained in such studies can be extrapolated to mature trees and to different genetic sources. In this paper, we present results from a one-year study examining the interactive effects of foliar exposure to acidic rain and ozone on the growth of ponderosa pine (Pinus ponderosa), a conifer known to be sensitive to ozone. The response to pollutants is characterized for both seedlings and mature tree branches of three genotypes grown in a common environment

109

Factors affecting the effects of EDU on growth and yield of field-grown bush beans (Phaseolus vulgaris L.), with varying degrees of sensitivity to ozone  

Energy Technology Data Exchange (ETDEWEB)

The effects of foliar applications of ethylenediurea (EDU) on responses to ozone by field-grown bush bean (Phaseolus vulgaris L.) lines 'S156' (O{sub 3}-sensitive) and 'R123' (O{sub 3}-tolerant), and cultivars 'BBL 290' (O{sub 3}-sensitive) and 'BBL 274' (O{sub 3}-tolerant) were investigated during the 2001 and 2002 growing seasons. EDU was applied weekly to designated plants between primary leaf expansion and pod senescence. Results were compared with control plants at harvests made at pod maturation and pod senescence. In 2001, average hourly ambient O{sub 3} concentrations ranged between 41 and 59 ppb for a total of 303 h; in 2002, for 355 h. EDU applications prior to pod maturation significantly increased the number of marketable pods in 'R123', but not for the other cultivars. Harvests at pod senescence showed significant improvements in crop yield production in EDU-treated 'S156' plants, whereas for EDU-treated 'R123' plants significant reductions were determined in above-ground biomass and seed production. In contrast, results from 'BBL 290' and 'BBL 274' at both harvest points were inconclusive. Growth and reproductive responses of O{sub 3}-sensitive and O{sub 3}-tolerant bush bean plants to EDU applications varied, depending on developmental stages, duration of EDU applications, and fluctuations in ambient O{sub 3}. - Plant sensitivity to ozone, stage of plant development, number of applications of EDU and ambient ozone affect bean plant responses to EDU.

Elagoez, Vahram [Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003 (United States)]. E-mail: velagoz@nsm.umass.edu; Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003 (United States)

2005-08-15

110

EFFECTS OF ACIDITY OF SIMULATED RAIN AND ITS JOINT ACTION WITH AMBIENT OZONE ON MEASURES OF BIOMASS AND YIELD IN SOYBEAN  

Science.gov (United States)

An experiment was performed to determine whether the presence of ozone modified the effects of acidity of simulated rain on growth and yield of soybean. Beeson, a type II cultivar, was grown in field chambers and exposed to simulated rain at 3 levels of acidity. Each level was ap...

111

The Influence of Ozonization For DO, BOD and Bacterial Growth in The Liquid Waste From Tanning Leather Industry  

International Nuclear Information System (INIS)

The research of ozonization influence of dissolved oxygen (DO), biological oxygen demand (BOD) and the bacterial growth in the liquid waste from tanning leather industry has been done. The objectives of this research was to studied the influence of ozonization for decomposition process of the organic compound in these waste by indicator of BOD decreased, increased of DO and decomposer bacterial growth. The ozonization was carried out by time variation 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195 and 210 minutes. Each samples of the waste has been ozonized keep in the sterile reaction tube for isolated of bacterial and the other keep in the bottle for BOD and DO measurement. These research results show that ozonization with 16.243 x 10-4 mg/second debit for 3 hours can decreased of BOD were 19.61 %, and ozonization for 3.5 hours can increased of DO were 82.5%. The other hand, 3 hours ozonization can decreased of kind of bacterial growth were 80 %. (author)

112

Growth and production of buckwheat (Fagopyrum esculentum) treated with reduced, ambient, and enhanced UV-B radiation.  

Science.gov (United States)

The effect of enhanced UV-B radiation on buckwheat (Fagopyrum esculentum Moench. variety 'Darja'), an important high elevation crop, was studied in order to estimate its vulnerability in changing UV-B environment. Plants were grown in outdoor experiments from July to October under reduced and ambient UV-B levels, and an UV-B level simulating 17% ozone depletion in Ljubljana. During the development the following parameters were monitored: light saturated photosynthetic activity, transpiration, potential and effective photochemical efficiencies of photosystem II, the contents of photosynthetic pigments and methanol soluble UV-B absorbing compounds. At the end of the experiment, growth rate and production of seeds were estimated. In the following growth season the seeds collected from plants exposed to different UV-B treatments were tested for germination capacity. Total UV-B absorbing compounds during plant development were increased by UV-B radiation, photosynthetic pigments (chlorophyll a and b and carotenoids) decreased. Photosynthetic rate was lowered in an early stage of development. UV-B treatment resulted in the increase in the transpiration rate and consequently the decrease in water use efficiency (WUE). The disturbances in water economy and in photosynthesis affected the reproduction potential negatively; the production of seeds in plants cultivated under ambient and enhanced UV-B was 57 and 39% of the production of specimens treated with reduced UV-B, respectively. The germination of seeds collected from treated plants revealed on average about 95% success, independently of the treatment, but the time needed for germination was the shortest for seeds developed under enhanced UV-B level treatment. Enhanced UV-B radiation affected water relations and production of buckwheat, but not the potential of seeds for germination. PMID:11849980

Gaberscik, Alenka; Voncina, Meta; Trost, Tadeja; Germ, Mateja; Olof Björn, Lars

2002-02-01

113

Effects of ozone on managed pasture: I. Effects of open-top chambers on microclimate, ozone flux, and plant growth.  

Science.gov (United States)

Open-top chambers (OTC) were established in a field of managed pasture, and environmental parameters were recorded inside and outside to study the influence of OTCs on radiation, air temperature (T(air)), saturation vapour pressure deficit (svpd), and soil water content in relationship to plant growth and yield. Canopy development in OTCs supplied with non-filtered air (NF) and in ambient (AA) plots was followed by measuring leaf area index (LAI). The dry matter yield was determined after three growth periods in each of two consecutive seasons. Boundary layer conductance (g(bw)) and wind speed (u) were measured along a vertical profile, and day-time flux were measured along a vertical profile, and day-time flux of O(3) was estimated throughout the experiment on the basis of a mass balance. The vertical profile of u showed values in the range 1-1.2 m s(-1) at the top of the canopy, and maximum g(bw) was 20-25 mm s(-1). Average reduction in global radiation in OTCs was 25%, and volumetric soil water content was reduced by about 5%. Daily mean T(air) was increased by 1.3 degrees C, mean daily maximum svpd by 0.08 kPa, and the temperature sum (degree days with base temperature of +5 degrees C) by 12%. Fluctuations in the difference in daily mean T(air) and svpd during the daytime between OTCs and ambient air were related to canopy structure. Differences were largest after each cut and declined with increasing LAI. A small effect of changes in LAI on T(air) and svpd occurred during periods with low soil water content. The flux of O(3) in OTCs was largest (>100 microg m(-2) min(-1)) before and smallest (atmospheric moisture was larger than in the open field, and the increase in daily mean T(air) was strongly influenced by the stage of canopy development. Changes in microclimate and incoming radiation affected pasture development. LAI was slightly reduced in OTCs as compared to AA plots. The total accumulated dry matter yield for all six growth periods was only about 7% lower in OTCs, but the contribution of clover to total forage mass declined during the experiment. OTCs had no significant effect on weeds. The results indicate that OTCs reduced the competitiveness of clover, and that the increase in growth of grasses compensates for the loss in clover yield. The shift in species composition caused by OTCs must be considered when studying the effect of pollutants on pasture. PMID:15091621

Fuhrer, J

1994-01-01

114

Development of a multi-factor model for predicting the effects of ambient ozone on the biomass of white clover.  

Science.gov (United States)

Results are presented from the UN/ECE ICP Vegetation (International Cooperative Programme on effects of air pollution on natural vegetation and crops) experiments in which ozone(O(3))-resistant (NC-R) and -sensitive (NC-S) clones of white clover (Trifolium repens cv. Regal) were exposed to ambient O(3) episodes at 14 sites in eight European countries in 1996, 1997 and 1998. The plants were grown according to a standard protocol, and the forage was harvested every 28 days for 4-5 months per year by excision 7 cm above the soil surface. Biomass ratio (NC-S/NC-R) was related to the climatic and pollutant conditions at each site using multiple linear regression (MLR) and artificial neural networks (ANNs). Twenty-one input parameters [e.g. AOT40, 7-h mean O(3) concentration, daylight vapour pressure deficit (VPD), daily maximum temperature] were considered individually and in combination with the aim of developing a model with high r(2) and simple structure that could be used to predict biomass change in white clover. MLR models were generally more complex, and performed less well for unseen data than non-linear ANN models. The ANN model with the best performance had five inputs with an r(2) value of 0.84 for the training data, and 0.71 for previously unseen data. Two inputs to the model described the O(3) conditions (AOT40 and 24-h mean for O(3)), two described temperature (daylight mean and 24-h mean temperature), and the fifth input appeared to be differentiating between semi-urban and rural sites (NO concentration at 17:00). Neither VPD nor harvest interval was an important component of the model. The model predicted that a 5% reduction in biomass ratio was associated with AOT40s in the range 0.9-1.7 ppm x h (microl l(-1) h) accumulated over 28 days, with plants being most sensitive in conditions of low NO(x), medium-range temperature, and high 24-h mean O(3) concentration. PMID:15092887

Mills, G; Ball, G; Hayes, F; Fuhrer, J; Skärby, L; Gimeno, B; De Temmerman, L; Heagle, A

2000-09-01

115

ACUTE EFFECTS OF OZONE ON HEART RATE AND BODY TEMPERATURE IN THE UNANESTHETIZED, UNRESTRAINED RAT MAINTAINED AT DIFFERENT AMBIENT TEMPERATURES  

Science.gov (United States)

The present studies were conducted to investigate the concentration-response characteristics of acute ozone (O3) exposure on the cardiovascular and thermoregulatory function of the unanesthetized, unrestrained rat, and to examine the modulating effects produced by changes in ambi...

116

Meta-analysis of the association between short-term exposure to ambient ozone and respiratory hospital admissions  

International Nuclear Information System (INIS)

Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through ? 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publicat-city studies further suggested publication bias.

117

Phytotoxicity and growth responses of ornamental bedding plants to ozone and sulfur dioxide  

Energy Technology Data Exchange (ETDEWEB)

No appreciable signs of phytotoxicity were observed for 4 days following fumigation of plants (including begonias, petunias, snapdragons) with ozone of up to 80 parts per hundred million or sulfur dioxide of up to 400 pphm for 2 hr. Thereafter, there was considerable necrosis, particularly on begonias fumigated with the highest concentration of the pollutants. Growth suppression was reflected in reduced shoot and flower wt, and to a lesser degree in reduced flower number. Overall, begonias and petunias were the most sensitive. Coleus and snapdragons were moderately sensitive, while marigold, celosia, impatiens and salvia were tolerant. White Tausendschon was the most sensitive begonia cultivar while blue-flowered Capri was the most sensitive petunia. Mixed color petunias exhibited varying degrees of tolerance. Scarlet rainbow coleus was more sensitive than Pastel Rainbow. Measurements of growth alterations in plants were found very useful in determining latent forms of air pollutant injury.

Adedipe, N.O.; Barrett, R.F.; Ormrod, D.P.

1972-01-01

118

Linking changes in ozone to changes in emissions and meteorology  

International Nuclear Information System (INIS)

Estimation of trends in ozone air quality is a complex problem because of the strong influence of meteorology on ozone and its precursors. In this paper we present a physically-consistent methodology to link changes in ozone to changes in precursor emissions in the presence of meteorological fluctuations. Time series ozone concentrations (O3), nitrogen oxides (NOx) and non-methane hydrocarbons (NMHC) measured from 1985 to 1993 in the Los Angeles Air Basin are first separated into different time scales using the Kolmogorov-Zurbenko (KZ) filter. Linear regression analysis is performed on meteorological variables and ozone and its precursors on each time scale. The downward trend in the daily hourly maxima of O3 is about twice that in the daily hourly mean O3. The results demonstrate that emission control programs implemented over Southern California were very effective in improving ambient ozone levels during a period of robust economic growth. (Author)

119

77 FR 43521 - Final Rule To Implement the 1997 8-Hour Ozone National Ambient Air Quality Standard...  

Science.gov (United States)

...Contingency Measure Requirements; Deletion of Obsolete 1-Hour Ozone...intersection with the range line common to Range 16 West and Range...north along the range line common to Range 31 East and Range...north along the range line common to Range 31 East and...

2012-07-25

120

Growth and production of buckwheat (Fagopyrum esculentum) treated with reduced, ambient, and enhanced UV-B radiation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The effect of enhanced UV-B radiation on buckwheat (Fagopyrum esculentum Moench. variety ‘Darja’), an important high elevation crop, was studied in order to estimate its vulnerability in changing UV-B environment. Plants were grown in outdoor experiments from July to October under reduced and ambient UV-B levels, and an UV-B level simulating 17% ozone depletion in Ljubljana. During the development the following parameters were monitored: light saturated photosynthetic activity, transpirat...

Gaberscik, Alenka; Voncina, Meta; Trost, Tadeja; Germ, Mateja; Bjo?rn, Lars Olof

2002-01-01

 
 
 
 
121

40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...Quality Standards for Ozone 1. General ...with maximum hourly average concentrations above 0.12 ppm...maximum hourly average ozone measurement that is...with maximum hourly average ozone concentrations above the level of...

2010-07-01

122

40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone  

Science.gov (United States)

...The computed 8-hour average ozone concentrations shall be reported to...possible running 8-hour average ozone concentrations for each calendar day...daily maximum 8-hour average ozone concentration for each calendar...

2010-07-01

123

Ozone exposure induces the activation of leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species  

International Nuclear Information System (INIS)

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O3) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppbv of O3 (NF+). The photochemical maximal efficiency, Fv/Fm, decreased in NF+ plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of ?13C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF+ treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in ?15N were found in all species during the second year when exposed in the NF+ OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, ?15N, chlorophyll, leaf area, LMA and biomass occurred at ambient O3 concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF+ treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness. - Ozone induces species-specific leaf senescence-related processes and morphological and growth changes in seedlings of Mediterranean tree species

124

Does a simulated upland grassland community respond to increasing background, peak or accumulated exposure of ozone?  

Science.gov (United States)

Tropospheric ozone concentrations are increasing, which may result in elevated background concentrations at rural high-altitude sites. In this study simulated upland grassland communities containing seven species were exposed to ozone treatments in solardomes for 12 weeks in each of two consecutive summers. Ozone profiles, based on future ozone predictions, were of elevated background concentrations, episodic peaks of ozone and a combination of the two. During the winter between the two exposures the communities were kept outdoors in ambient air. Whereas previous studies have demonstrated that peaks of ozone cause detrimental effects to vegetation, this study shows that for simulated grassland communities an increase in background ozone concentration in the absence of peaks of ozone also corresponded with increased senescence. In many cases senescence was further increased when peaks of ozone were also present. The species used showed no acclimation to ozone and the same relationship between senescence and ozone dose occurred in both years of the study. A decrease in cumulative biomass was demonstrated for Anthoxanthum odoratum, which contributed to a decrease in total community biomass and grass:forb ratio. These results indicate that current and future ozone concentrations could cause detrimental effects on growth and vitality of natural grassland communities and that for some species the consequences of increased background ozone concentration are as severe as that of increased peaks.

Hayes, Felicity; Mills, Gina; Jones, Laurence; Ashmore, Mike

2010-11-01

125

Effects of salinity and ozone, individually and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties.  

Science.gov (United States)

The aim of this study was to determine the effects of ozone and salinity, singly and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties. Chickpea plants were grown in non-saline and saline conditions, with and without a repeated exposure to ozone. Salinity at a concentration of 30 mM NaCl caused a substantial reduction in plant height, number of leaves and the dry weights of the leaves, stems and roots. Biomass allocation to the leaves increased, predominantly at the expense of the roots. Ozone at a concentration of 85 nmol mol(-1) for 6 h per day for 25 days reduced plant height and dry weights but had no effect on leaf number. The results show substantial effects of salinity and ozone on chickpea growth and ion concentrations. When ozonated plants are grown in the presence of salinity, further reductions in growth occur. PMID:12395854

Welfare, Karen; Yeo, Anthony R; Flowers, Timothy J

2002-01-01

126

DEVELOPMENT OF SULFUR DIOXIDE AND OZONE EXPOSURE PROFILES THAT MIMIC AMBIENT CONDITIONS IN THE RURAL SOUTHEASTERN UNITED STATES  

Science.gov (United States)

A design for constructing experimental mixed-pollutant exposure profiles that reflect regional O3 and SO2 ambient air quality is described. The profiles were developed using hourly concentration data from monitoring sites in the southeastern United States where slash pine is indi...

127

Effects of elevated carbon dioxide and ozone on the growth and yield of potatoes (Solanum tuberosum) grown in open-top chambers  

International Nuclear Information System (INIS)

Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 ?mol mol-1 CO2) and two ozone concentrations (ambient and an 8 h day -1 seasonal mean of 50 nmol mol-1 O3) between emergence and final harvest. Periodic non-destructive measurements were made and destructive harvests were carried out at three key developmental stages (24, 49 and 101 days after emergence) to establish effects on growth and tuber yield. Season-long exposure to elevated O3 reduced above-ground dry weight at final harvest by 8.4% (P2 and O3 for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO2 on plant height, leaf number or green leaf area ratio. However, destructive harvests at tuber initiation and 500 deg Cd after emergence showed that above-ground dry weight (8 and 7% respectively) and tuber yield (88 and 44%) were significantly increased (P-1 CO2 treatment. Responses to 550 and 680 ?mol mol-1 CO2 were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO2 enrichment. Significant effects2 enrichment. Significant effects on the above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P2, particularly in the smaller size categories. The results show that the O3 treatment imposed was insufficient to reduce tuber yields and that, although elevated CO2 enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. (Author)

128

Ice crystal nucleation and growth in contrails forming at low ambient temperatures  

Science.gov (United States)

A model of ice crystal nucleation and growth in a diluting aircraft exhaust plume is used to evaluate the physical processes responsible for the ice number densities and size distributions measured on May 4, 1996. Predicted ice crystal size distributions are compared with observations at about 70 seconds plume age. The simulated crystals grow to about 2 µm radius within 2-3 seconds, then remain approximately constant in size until 30-60 seconds plume age when crystal sublimations begins. The calculated crystal size distribution has approximately the same volume mode radius as the observed size distribution (1-2 µm) however, the model does not predict as many crystals larger than 2 µm radius as indicated by the measurements. Due to the low ambient temperature (-61°C), large ice supersaturations are generated in the plume, and all exhaust soot particles and ambient aerosols entrained into the plume before about 1 second plume age are activated to ice nuclei. The simulations indicate that if the soot particle emission index is on the order of 2×1012 particles (kg fuel)-1 or lower and freshly nucleated sulfate aerosols are too small to freeze in the young plume, then the majority of the contrail ice crystals may be nucleated on ambient aerosols entrained into the exhaust plume.

Jensen, E. J.; Toon, O. B.; Pueschel, R. F.; Goodman, J.; Sachse, G. W.; Anderson, B. E.; Chan, K. R.; Baumgardner, D.; Miake-Lye, R. C.

129

Visible injury, crown condition, and growth responses of selected Italian forests in relation to ozone exposure  

International Nuclear Information System (INIS)

The impact of ozone on forest ecosystems in Italy is monitored within the CONECOFOR programme. Ozone levels are measured in 30 plots using passive samplers. Response parameters used are: crown condition (transparency), BAI (basal area increment), and visible symptoms on spontaneous vegetation. Levels of AOT40 are above the concentration-based critical level of 5 ppmh in all sites, but the evidence of impact on forest vegetation remains limited. Ozone is a predictor of crown transparency residuals in beech sites over two consecutive years, but the variance explained amounts to less than 10%. The relation between BAI reduction and ozone is even less certain. Transparency and BAI are more readily explainable in terms of ecological conditions of the site and climate fluctuations. The interpretation of visible symptoms is doubtful, and is conditioned by the prevailing ecological factors in the areas. - Despite considerable exceedance of internationally agreed exposure limits, evidence of ozone effects on selected Italian forest sites is limited.

130

Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms  

Energy Technology Data Exchange (ETDEWEB)

We studied the effects of relatively low levels of O{sub 3} (40-50 ppb) and CO{sub 2}-enrichment (+ 100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O{sub 3}. However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO{sub 2} did not amend the detrimental effects of O{sub 3} on aboveground biomass. Elevated CO{sub 2} alone had only minor effects. An O{sub 3}-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem. - Species- and parameter-specific differences found in O{sub 3} responses and CO{sub 2} amelioration in wild plants under competitive environment.

Raemoe, Kaisa [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland)]. E-mail: kaisa.koivisto@helsinki.fi; Kanerva, Teri [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland); Nikula, Suvi [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland); Ojanperae, Katinka [MTT, Agrifood Research Finland, Environmental Research, 31600 Jokioinen (Finland); Manninen, Sirkku [Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65, 00014 Helsinki (Finland)

2006-11-15

131

Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms  

International Nuclear Information System (INIS)

We studied the effects of relatively low levels of O3 (40-50 ppb) and CO2-enrichment (+ 100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O3. However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO2 did not amend the detrimental effects of O3 on aboveground biomass. Elevated CO2 alone had only minor effects. An O3-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem. - Species- and parameter-specific differences found in O3 responses and CO2 amelioration in wild plants under competitive environment

132

Growth and nutritive quality of Poa pratensis as influenced by ozone and competition  

International Nuclear Information System (INIS)

Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O3) stress. A phytometer-based approach was utilized to investigate O3 effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species (Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000-2002 to charcoal-filtered air + 25 ppb O3 (control) or non-filtered air + 50 ppb O3 (elevated O3). Biomass production was not affected by O3, but foliar injury symptoms were observed in May 2002. Early-season O3 exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O3 was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O3 exposure. - Early-season O3 exposure decreased nutritive quality of Poa pratensis, and nutritive quality response to O3 was not altered by interspecific competition

133

Growth and nutritive quality of Poa pratensis as influenced by ozone and competition  

Energy Technology Data Exchange (ETDEWEB)

Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O{sub 3}) stress. A phytometer-based approach was utilized to investigate O{sub 3} effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species (Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000-2002 to charcoal-filtered air + 25 ppb O{sub 3} (control) or non-filtered air + 50 ppb O{sub 3} (elevated O{sub 3}). Biomass production was not affected by O{sub 3}, but foliar injury symptoms were observed in May 2002. Early-season O{sub 3} exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O{sub 3} was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O{sub 3} exposure. - Early-season O{sub 3} exposure decreased nutritive quality of Poa pratensis, and nutritive quality response to O{sub 3} was not altered by interspecific competition.

Bender, J. [Institute of Agroecology, Federal Agricultural Research Centre (FAL), Bundesallee 50, 38116 Braunschweig (Germany)]. E-mail: juergen.bender@fal.de; Muntifering, R.B. [Department of Animal Sciences, Auburn University, AL 36849 (United States); Lin, J.C. [Department of Animal Sciences, Auburn University, AL 36849 (United States); Weigel, H.J. [Institute of Agroecology, Federal Agricultural Research Centre (FAL), Bundesallee 50, 38116 Braunschweig (Germany)

2006-07-15

134

Growth and nutritive quality of Poa pratensis as influenced by ozone and competition.  

Science.gov (United States)

Interspecific plant competition has been hypothesized to alter effects of early-season ozone (O3) stress. A phytometer-based approach was utilized to investigate O3 effects on growth and nutritive quality of Poa pratensis grown in monoculture and in mixed cultures with four competitor-plant species (Anthoxanthum odoratum, Achillea millefolium, Rumex acetosa and Veronica chamaedrys). Mesocosms were exposed during April/May 2000-2002 to charcoal-filtered air+25 ppb O3 (control) or non-filtered air+50 ppb O3 (elevated O3). Biomass production was not affected by O3, but foliar injury symptoms were observed in May 2002. Early-season O3 exposure decreased relative food value of P. pratensis by an average of 8%, which is sufficient to have nutritional implications for its utilization by herbivores. However, forage quality response to O3 was not changed by interspecific competition. Lack of injury and nutritive quality response in P. pratensis harvested in September may reflect recovery from early-season O3 exposure. PMID:16290915

Bender, J; Muntifering, R B; Lin, J C; Weigel, H J

2006-07-01

135

Rice LTG1 is involved in adaptive growth and fitness under low ambient temperature.  

Science.gov (United States)

Low temperature (LT) is one of the most prevalent factors limiting the productivity and geographical distribution of rice (Oryza sativa L.). Although significant progress has been made in elucidating the effect of LT on seed germination and reproductive development in rice, the genetic component affecting vegetative growth under LT remains poorly understood. Here, we report that rice cultivars harboring the dominant LTG1 (Low Temperature Growth 1) allele are more tolerant to LT (15-25°C, a temperature range prevalent in high-altitude, temperate zones and high-latitude areas), than those with the ltg1 allele. Using a map-based cloning strategy, we show that LTG1 encodes a casein kinase I. A functional nucleotide polymorphism was identified in the coding region of LTG1, causing a single amino acid substitution (I357K) that is associated with the growth rate, heading date and yield of rice plants grown at LT. We present evidence that LTG1 affects rice growth at LT via an auxin-dependent process(es). Furthermore, phylogenetic analysis of this locus suggests that the ltg1 haplotype arose before the domestication of rice in tropical climates. Together, our data demonstrate that LTG1 plays an important role in the adaptive growth and fitness of rice cultivars under conditions of low ambient temperature. PMID:24635058

Lu, Guangwen; Wu, Fu-Qing; Wu, Weixun; Wang, Hong-Jun; Zheng, Xiao-Ming; Zhang, Yunhui; Chen, Xiuling; Zhou, Kunneng; Jin, Mingna; Cheng, Zhijun; Li, Xueyong; Jiang, Ling; Wang, Haiyang; Wan, Jianmin

2014-05-01

136

Ozone decomposition on Ag/SiO{sub 2} and Ag/clinoptilolite catalysts at ambient temperature  

Energy Technology Data Exchange (ETDEWEB)

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO{sub 2} sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm{sup -1}) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag{sup +}, instead of Na{sup +}, Ca{sup 2+}, or K{sup +} ions, existing in the natural clinoptilolite form. The samples Ag/SiO{sub 2} and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

Nikolov, Penko, E-mail: penmail@mail.bg [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Genov, Krassimir; Konova, Petya [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Milenova, Katya; Batakliev, Todor; Georgiev, Vladimir [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Kumar, Narendra [Laboratory of Industrial Chemistry, Process Chemistry Centre, Abo Akademi University, Biskopsgatan 8, 20500 Abo/Turku (Finland); Sarker, Dipak K. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Pishev, Dimitar [University of Chemical Technology and Metallurgy, 1756 Sofia (Bulgaria); Rakovsky, Slavcho [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2010-12-15

137

Future impacts of distributed power generation on ambient ozone and particulate matter concentrations in the San Joaquin Valley of California.  

Science.gov (United States)

Distributed power generation-electricity generation that is produced by many small stationary power generators distributed throughout an urban air basin-has the potential to supply a significant portion of electricity in future years. As a result, distributed generation may lead to increased pollutant emissions within an urban air basin, which could adversely affect air quality. However, the use of combined heating and power with distributed generation may reduce the energy consumption for space heating and air conditioning, resulting in a net decrease of pollutant and greenhouse gas emissions. This work used a systematic approach based on land-use geographical information system data to determine the spatial and temporal distribution of distributed generation emissions in the San Joaquin Valley Air Basin of California and simulated the potential air quality impacts using state-of-the-art three-dimensional computer models. The evaluation of the potential market penetration of distributed generation focuses on the year 2023. In general, the air quality impacts of distributed generation were found to be small due to the restrictive 2007 California Air Resources Board air emission standards applied to all distributed generation units and due to the use of combined heating and power. Results suggest that if distributed generation units were allowed to emit at the current Best Available Control Technology standards (which are less restrictive than the 2007 California Air Resources Board standards), air quality impacts of distributed generation could compromise compliance with the federal 8-hr average ozone standard in the region. PMID:22263420

Vutukuru, Satish; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald

2011-12-01

138

The relationship of ambient ozone and PM(2.5) levels and asthma emergency department visits: possible influence of gender and ethnicity.  

Science.gov (United States)

ABSTRACT An investigation of the relationship of air pollution and emergency department (ED) visits for asthma was an opportunity to assess environmental risks for asthma exacerbations in an urban population. A total of 6,979 individuals with a primary discharge diagnosis of asthma presented to 1 of 6 EDs in the Pittsburgh, Pennsylvania, area between 2002 and 2005. Using a case-crossover methodology, which controls for the effects of subject-specific covariates such as gender and race, a 2.5% increase was observed in asthma ED visits for each 10 ppb increase in the 1-hour maximum ozone level on day 2 (odds ratio [OR] = 1.025, p PM(2.5)) had an effect both on the total population on day 1 after exposure (1.036, p PM(2.5) had no significant effect on Caucasian Americans alone. The disparity in risk estimates by race may reflect differences in residential characteristics, exposure to ambient air pollution, or a differential effect of pollution by race. PMID:22524651

Glad, Jo Ann; Brink, LuAnn Lynn; Talbott, Evelyn O; Lee, Pei Chen; Xu, Xiaohui; Saul, Melissa; Rager, Judith

2012-01-01

139

Ozone Pollution  

Medline Plus

Full Text Available ... in areas with unhealthful levels of ozone. What Is Ozone? Ozone is a molecule of three oxygen atoms. Ozone attacks ... actual number who breathe unhealthy levels of ozone is likely much larger, since this number does not ...

140

Effects of salinity and ozone, individually and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties  

International Nuclear Information System (INIS)

Plants exposed to ozone, under high salinity conditions, further decline in growth. - The aim of this study was to determine the effects of ozone and salinity, singly and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties. Chickpea plants were grown in non-saline and saline conditions, with and without a repeated exposure to ozone. Salinity at a concentration of 30 mM NaCl caused a substantial reduction in plant height, number of leaves and the dry weights of the leaves, stems and roots. Biomass allocation to the leaves increased, predominantly at the expense of the roots. Ozone at a concentration of 85 nmol mol-1 for 6 h per day for 25 days reduced plant height and dry weights but had no effect on leaf number. The results show substantial effects of salinity and ozone on chickpea growth and ion concentrations. When ozonated plants are grown in the presence of salinity, further reductions in growth occur

 
 
 
 
141

Effects of salinity and ozone, individually and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties  

Energy Technology Data Exchange (ETDEWEB)

Plants exposed to ozone, under high salinity conditions, further decline in growth. - The aim of this study was to determine the effects of ozone and salinity, singly and in combination, on the growth and ion contents of two chickpea (Cicer arietinum L.) varieties. Chickpea plants were grown in non-saline and saline conditions, with and without a repeated exposure to ozone. Salinity at a concentration of 30 mM NaCl caused a substantial reduction in plant height, number of leaves and the dry weights of the leaves, stems and roots. Biomass allocation to the leaves increased, predominantly at the expense of the roots. Ozone at a concentration of 85 nmol mol{sup -1} for 6 h per day for 25 days reduced plant height and dry weights but had no effect on leaf number. The results show substantial effects of salinity and ozone on chickpea growth and ion concentrations. When ozonated plants are grown in the presence of salinity, further reductions in growth occur.

Welfare, Karen; Yeo, A.R.; Flowers, T.J

2002-12-01

142

Fine root dynamics of mature European beech (Fagus sylvatica L.) as influenced by elevated ozone concentrations  

Energy Technology Data Exchange (ETDEWEB)

Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate. - Doubling of ozone concentrations in mature European beech affected the seasonal timing of fine root turnover rather than the turnover rate.

Mainiero, Raphael, E-mail: raphael.mainiero@iap.c [Department for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Kazda, Marian, E-mail: marian.kazda@uni-ulm.d [Department for Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm (Germany); Haeberle, Karl-Heinz, E-mail: haeberle@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany); Nikolova, Petia Simeonova, E-mail: nikolova@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany); Matyssek, Rainer, E-mail: matyssek@wzw.tum.d [Technische Universitaet Muenchen, Ecophysiology of Plants, Department of Ecology, Am Hochanger 13, 85354 Freising (Germany)

2009-10-15

143

Fine root dynamics of mature European beech (Fagus sylvatica L.) as influenced by elevated ozone concentrations  

International Nuclear Information System (INIS)

Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate. - Doubling of ozone concentrations in mature European beech affected the seasonal timing of fine root turnover rather than the turnover rate.

144

Tropospheric ozone increases over the southern Africa region: bellwether for rapid growth in Southern Hemisphere pollution?  

Science.gov (United States)

Increases in free-tropospheric (FT) ozone based on ozonesonde records from the early 1990s through 2008 over two subtropical stations, Irene (near Pretoria, South Africa) and Réunion (21° S, 55° E; ~2800 km NE of Irene in the Indian Ocean), have been reported. Over Irene a large increase in the urban-influenced boundary layer (BL, 1.5-4 km) was also observed during the 18-year period, equivalent to 30% decade-1. Here we show that the Irene BL trend is at least partly due to a gradual change in the sonde launch times from early morning to the midday period. The FT ozone profiles over Irene in 1990-2007 are re-examined, filling in a 1995-1999 gap with ozone profiles taken during the Measurements of Ozone by Airbus In-service Aircraft (MOZAIC) project over nearby Johannesburg. A multivariate regression model that accounts for the annual ozone cycle, El Niño-Southern Oscillation (ENSO) and possible tropopause changes was applied to monthly averaged Irene data from 4 to 11 km and to 1992-2011 Réunion sonde data from 4 to 15 km. Statistically significant trends appear predominantly in the middle and upper troposphere (UT; 4-11 km over Irene, 4-15 km over Réunion) in winter (June-August), with increases ~1 ppbv yr-1 over Irene and ~2 ppbv yr-1 over Réunion. These changes are equivalent to ~25 and 35-45% decade-1, respectively. Both stations also display smaller positive trends in summer, with a 45% decade-1 ozone increase near the tropopause over Réunion in December. To explain the ozone increases, we investigated a time series of dynamical markers, e.g., potential vorticity (PV) at 330-350 K. PV affects UT ozone over Irene in November-December but displays little relationship with ozone over Réunion. A more likely reason for wintertime FT ozone increases over Irene and Réunion appears to be long-range transport of growing pollution in the Southern Hemisphere. The ozone increases are consistent with trajectory origins of air parcels sampled by the sondes and with recent NOx emissions trends estimated for Africa, South America and Madagascar. For Réunion trajectories also point to sources from the eastern Indian Ocean and Asia.

Thompson, A. M.; Balashov, N. V.; Witte, J. C.; Coetzee, J. G. R.; Thouret, V.; Posny, F.

2014-09-01

145

Use of AIRS, OMI, MLS, and TES Data in Assessing Forest Ecosystem Exposure to Ozone  

Science.gov (United States)

Ground-level ozone at high levels poses health threats to exposed flora and fauna, including negative impacts to human health. While concern is common regarding depletion of ozone in the stratosphere, portions of the urban and rural United States periodically have high ambient levels of tropospheric ozone on the ground. Ozone pollution can cause a variety of impacts to susceptible vegetation (e.g., Ponderosa and Jeffrey pine species in the southwestern United States), such as stunted growth, alteration of growth form, needle or leaf chlorosis, and impaired ability to withstand drought-induced water stress. In addition, Southern Californian forests with high ozone exposures have been recently subject to multiyear droughts that have led to extensive forest overstory mortality from insect outbreaks and increased incidence of wildfires. Residual forests in these impacted areas may be more vulnerable to high ozone exposures and to other forest threats than ever before. NASA sensors collect a wealth of atmospheric data that have been used recently for mapping and monitoring regional tropospheric ozone levels. AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), MLS (Microwave Limb Sounder), and TES (Tropospheric Emission Spectrometer) data could be used to assess forest ecosystem exposure to ozone. Such NASA data hold promise for providing better or at least complementary synoptic information on ground-level ozone levels that Federal agency partners can use to assess forest health trends and to mitigate the threats as needed in compliance with Federal laws and mandates. NASA data products on ozone concentrations may be able to aid applications of DSTs (decision support tools) adopted by the USDA FS (U.S. Department of Agriculture Forest Service) and by the NPS (National Park Service), such as the Ozone Calculator, in which ground ozone estimates are employed to assess ozone impacts to forested vegetation.

Spruce, Joseph P.

2007-01-01

146

Minor effects of long-term ozone exposure on boreal peatland species Eriophorum vaginatum and Sphagnum papillosum  

DEFF Research Database (Denmark)

The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded into the soil of an open-air experimental field for four growing seasons. The open-air ozone exposure field consists of eight circular plots of which four were fumigated with elevated ozone concentration (doubled ambient) and four were ambient controls. The results showed that E. vaginatum and S. papillosum can tolerate ozone better than expected. Elevated ozone concentration did not affect overall relative length growth of E. vaginatum or S. papillosum. The leaf cross-section area of E. vaginatum leaves was 8% bigger in the ozone treatment compared to that in the ambient control. Ultrastuctural variables did not show any significant treatment effect in E. vaginatum or in S. papillosum. Total chlorophyll (a + b) concentration tended to increase in early growing season under ozone exposure. During the first growing season, elevated ozone concentration decreased methanol-extractable, UV-absorbing compounds in E. vaginatum. The results suggest that E. vaginatum and S. papillosum are ozone tolerant plant species and are likely able to cope with expected increase in tropospheric ozone concentration

Mörsky, SK; Haapala, JK

2011-01-01

147

Impacts of different plant functional types on ambient ozone predictions in the Seoul Metropolitan Areas (SMA), Korea  

Science.gov (United States)

Plant functional type (PFT) distributions affect the results of biogenic emission modeling as well as O3 and PM simulations using chemistry-transport models (CTMs). This paper analyzes the variations of both surface biogenic VOC emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. Also, this paper attempts to provide important implications for biogenic emissions modeling studies for CTM simulations. MM5-MEGAN-SMOKE-CMAQ model simulations were implemented over the Seoul Metropolitan Areas in Korea to predict surface O3 concentrations for the period of 1 May to 31 June 2008. Starting from MEGAN biogenic emissions analysis with three different sources of PFT input data, US EPA CMAQ O3 simulation results were evaluated by surface O3 monitoring datasets and further considered on the basis of geospatial and statistical analyses. The three PFT datasets considered were "(1)KORPFT", developed with a region specific vegetation database; (2) CDP, adopted from US NCAR; and (3) MODIS, reclassified from the NASA Terra and Aqua combined land cover products. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BT) are the most significant contributor, followed by needleleaf trees (NT), shrub (SB), and herbaceous plants (HB) to the total biogenic volatile organic compounds (BVOCs). In addition, isoprene from BT and terpene from NT were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. Multiple regression analyses with the different PFT data (?O3 vs. ?PFTs) suggest that KORPFT can provide reasonable information to the framework of MEGAN biogenic emissions modeling and CTM O3 predictions. Analyses of the CMAQ performance statistics suggest that deviations of BT areas can significantly affect CMAQ isoprene and O3 predictions. From further evaluations of the isoprene and O3 prediction results, we explored the PFT area-loss artifact that occurs due to geographical disparity between the PFT and leaf area index distributions, and can cause increased bias in CMAQ O3. Thus, the PFT-loss artifact must be a source of limitation in the MEGAN biogenic emission modeling and the CTM O3 simulation results. Time changes of CMAQ O3 distributions with the different PFT scenarios suggest that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 10 ppb. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of representative PFT distributions becomes more critical for O3 air quality modeling (or forecasting) in support of air quality decision-making and human health studies.

Kim, H.-K.; Woo, J.-H.; Park, R. S.; Song, C. H.; Kim, J.-H.; Ban, S.-J.; Park, J.-H.

2013-09-01

148

Gas exchange and chlorophyll fluorescence of pea (Pisum sativum L.) plants in response to ambient ozone at a rural site in Egypt.  

Science.gov (United States)

Egyptian pea cultivars (Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top chambers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009-2013) at a rural site in northern Egypt. Net photosynthetic rates (PN), stomatal conductance (gs), intercellular CO2 (Ci) and chlorophyll fluorescence were measured. Ozone (O3) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation. PN of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cultivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O3. The maximum impairment in PN was recorded in the cultivar Victory (46%) in 2013 when the highest O3 levels were recorded (90 nL L(-1)). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between PN and Ci, indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The PN vs. Ci curves were fitted to a non-rectangular hyperbolic model. The actual quantum yield (?PSII) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively. PMID:25169873

Ismail, I M; Basahi, J M; Hassan, I A

2014-11-01

149

In situ growth of high temperature superconductor thin films with evaporation techniques using an ozone jet  

International Nuclear Information System (INIS)

This paper reports on high quality YBa2Cu3O7 thin films grown in situ on various substrates (SrTiO3, Al2O3, Si) using MBE techniques and an ozone jet. The yttrium and copper are evaporated from electron gun sources and the barium is evaporated from a Knudsen cell. All sources are controlled by a single mass spectrometer feedback system to obtain the correct fluxes at high partial ozone pressures. During deposition the partial ozone pressure at the substrate position is estimated to be 10-3-10-2 mbar. The substrate holder temperature is 700 degrees C. The real substrate temperature is estimated to be lower than 650 degrees C. The films are analyzed with R(T), X-ray diffraction and RBS measurements. SEM photographs are taken of the surface

150

Impacts of different plant functional types on ambient ozone predictions in the Seoul Metropolitan Areas (SMAs), Korea  

Science.gov (United States)

Plant functional type (PFT) distributions affect the results of biogenic emission modeling as well as O3 and particulate matter (PM) simulations using chemistry-transport models (CTMs). This paper analyzes the variations of both surface biogenic volatile organic compound (BVOC) emissions and O3 concentrations due to changes in the PFT distributions in the Seoul Metropolitan Areas, Korea. The Fifth-Generation NCAR/Pennsylvania State Meso-scale Model (MM5)/the Model of Emissions of Gases and Aerosols from Nature (MEGAN)/the Sparse Matrix Operator Kernel Emissions (SMOKE)/the Community Multiscale Air Quality (CMAQ) model simulations were implemented over the Seoul Metropolitan Areas in Korea to predict surface O3 concentrations for the period of 1 May to 31 June 2008. Starting from a performance check of CTM predictions, we consecutively assessed the effects of PFT area deviations on the MEGAN BVOC and CTM O3 predictions, and we further considered the basis of geospatial and statistical analyses. The three PFT data sets considered were (1) the Korean PFT, developed with Korea-specific vegetation database; (2) the CDP PFT, adopted from the community data portal (CDP) of US National Center for Atmospheric Research in the United States (NCAR); (3) MODIS PFT, reclassified from the NASA Terra and Aqua combined land cover products. Although the CMAQ performance check reveals that all of the three different PFT data sets are applicable choices for regulatory modeling practice, noticeable primary data (i.e., PFT and Leaf Area Index (LAI)) was observed to be missing in many geographic locations. Based on the assessed effect of such missing data on CMAQ O3 predictions, we found that this missing data can cause spatially increased bias in CMAQ O3. Thus, it must be resolved in the near future to obtain more accurate biogenic emission and chemistry transport modeling results. Comparisons of MEGAN biogenic emission results with the three different PFT data showed that broadleaf trees (BTs) are the most significant contributor, followed by needleleaf trees (NTs), shrub (SB), and herbaceous plants (HBs) to the total BVOCs. In addition, isoprene from BTs and terpene from NTs were recognized as significant primary and secondary BVOC species in terms of BVOC emissions distributions and O3-forming potentials in the study domain. A geographically weighted regression analysis with locally compensated ridge (LCR-GWR) with the different PFT data (?O3 vs. ?PFTs) suggests that addition of BT, SB, and NT areas can contribute to O3 increase, whereas addition of an HB area contributes to O3 decrease in the domain. Assessment results of the simulated spatial and temporal changes of O3 distributions with the different PFT scenarios reveal that hourly and local impacts from the different PFT distributions on occasional inter-deviations of O3 are quite noticeable, reaching up to 13 ppb. The simulated maximum 1 h O3 inter-deviations between different PFT scenarios have an asymmetric diurnal distribution pattern (low in the early morning, rising during the day, peaking at 05:00 p.m., and decreasing during the night) in the study domain. Exponentially diverging hourly BVOC emissions and O3 concentrations with increasing ambient temperature suggest that the use of different PFT distribution data requires much caution when modeling (or forecasting) O3 air quality in complicated urban atmospheric conditions in terms of whether uncertainties in O3 prediction results are expected to be mild or severe.

Kim, H.-K.; Woo, J.-H.; Park, R. S.; Song, C. H.; Kim, J.-H.; Ban, S.-J.; Park, J.-H.

2014-07-01

151

Ellipsometric study of ambient-produced overlayer growth rate on YBa2Cu3O(7-x) films  

Science.gov (United States)

An ellipsometric study of ambient-reaction-produced BaCO3 overlayer growth on laser-ablated YBCO is presented as a function of time. The effects of the anisotropy of YBCO on the ellipsometric data inversion process are discussed, and it is concluded that with certain restrictions on the data acquisition method, the anisotropic substrate can be adequately modeled by its isotropic pseudodielectric function for the purpose of overlayer thickness estimation. It is found that after an initial period of rapid growth attributed to the chemical reaction of the exposed surface bonds, the BaCO3 overlayer growth is linear at 1-2 A per day. This slow growth rate is attributed to the complexity of the BaCO3-forming reaction, together with the need for ambient reactants to diffuse through the overlayer.

Sieg, Robert M.; Alterovitz, Samuel A.; Warner, Joseph D.

1993-01-01

152

Enhancement of growth, photosynthetic performance and yield by exclusion of ambient UV components in C3 and C4 plants.  

Science.gov (United States)

A field experiment was conducted under tropical climate for assessing the effect of ambient UV-B and UV-A by exclusion of UV components on the growth, photosynthetic performance and yield of C3 (cotton, wheat) and C4 (amaranthus, sorghum) plants. The plants were grown in specially designed UV exclusion chambers, wrapped with filters that excluded UV-B (amaranthus) compared to monocots (wheat, sorghum) after UV exclusion. The results indicated a suppressive action of ambient UV-B on growth and photosynthesis; dicots were more sensitive than monocots in this suppression while no great difference in sensitivity was found between C3 and C4 plants. Experiments indicated the suppressive action of ambient UV on carbon fixation and yield of C3 and C4 plants. Exclusion of solar UV-B will have agricultural benefits in both C3 and C4 plants under tropical climate. PMID:24041852

Kataria, Sunita; Guruprasad, K N; Ahuja, Sumedha; Singh, Bupinder

2013-10-01

153

Effects of elevated carbon dioxide and ozone on the growth and yield of potatoes (Solanum tuberosum) grown in open-top chambers  

Energy Technology Data Exchange (ETDEWEB)

Potato (Solanum tuberosum cv. Bintje) was grown in open-top chambers under three carbon dioxide (ambient and seasonal mean concentrations of 550 and 680 {mu}mol mol{sup -1} CO{sub 2}) and two ozone concentrations (ambient and an 8 h day {sup -1} seasonal mean of 50 nmol mol{sup -1} O{sub 3}) between emergence and final harvest. Periodic non-destructive measurements were made and destructive harvests were carried out at three key developmental stages (24, 49 and 101 days after emergence) to establish effects on growth and tuber yield. Season-long exposure to elevated O{sub 3} reduced above-ground dry weight at final harvest by 8.4% (P<0.05), but did not affect tuber yields. There was no significant interaction between CO{sub 2} and O{sub 3} for any of the growth and yield variables examined. Non-destructive analyses revealed no significant effect of elevated CO{sub 2} on plant height, leaf number or green leaf area ratio. However, destructive harvests at tuber initiation and 500 deg Cd after emergence showed that above-ground dry weight (8 and 7% respectively) and tuber yield (88 and 44%) were significantly increased (P<0.05) in the 550 {mu}mol mol{sup -1} CO{sub 2} treatment. Responses to 550 and 680 {mu}mol mol{sup -1} CO{sub 2} were not significantly different for most parameters examined, suggesting the existence of an upper limit to the beneficial influence of CO{sub 2} enrichment. Significant effects on the above-ground dry weight and tuber yield were no longer apparent at final harvest, although tuber numbers were increased (P<0.05) under elevated CO{sub 2}, particularly in the smaller size categories. The results show that the O{sub 3} treatment imposed was insufficient to reduce tuber yields and that, although elevated CO{sub 2} enhanced crop growth during the early stages of the season, this beneficial effect was not sustained to maturity. (Author)

Lawson, T.; Craigon, J.; Black, C.R.; Colls, J.J.; Tulloch, A.-M.; Landon, G. [Nottingham Univ., School of Biosciences, Loughborough (United Kingdom)

2001-07-01

154

Ozone Pollution  

Medline Plus

Full Text Available ... Report Card Widget Or Enter Your Zip Code: Ozone Pollution More than 4 in 10 people in ... areas with unhealthful levels of ozone. What Is Ozone? Ozone is a molecule of three oxygen atoms. ...

155

Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide  

International Nuclear Information System (INIS)

In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests

156

Bioassaying for ozone with pollen systems.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. Tube growth rates in the presence of a range of ozone dosages, of pollen populations exhibiting differing ozone sensitivity can be measured and different grow...

Feder, W. A.

1981-01-01

157

Restoration of normoxia by ozone therapy may control neoplastic growth: a review and a working hypothesis.  

Science.gov (United States)

In contrast to normal tissues, tumors thrive in hypoxic environments. This appears to be because they can metastasize and secrete angiopoietins for enhancing neoangiogenesis and further tumor spread. Thus, during chronic ischemia, normal tissues tend to die, while neoplasms tend to grow. During the past two decades, it has been shown in arteriopathic patients that ozonated autohemotherapy is therapeutically useful because it increases oxygen delivery in hypoxic tissues, leading to normoxia. Although several oxygenation approaches have been tested, none is able to restore normoxia permanently in patients with cancer. We postulate that a prolonged cycle of ozonated autohemotherapy may correct tumor hypoxia, lead to less aggressive tumor behavior, and represent a valid adjuvant during or after chemo- or radiotherapy. Moreover, it may re-equilibrate the chronic oxidative stress and reduce fatigue. PMID:15865491

Bocci, Velio; Larini, Alessandra; Micheli, Vanna

2005-04-01

158

Growth of lithium silicate crystals inside porous silicon film and their exploitation for ozone detection  

Energy Technology Data Exchange (ETDEWEB)

Silicon dioxide was formed by oxidizing porous silicon film and annealed, in a next step, at 920 deg. C with lithium nitrate embedded in its structure. These operations have produced the two lithium silicates, Li{sub 2}Si{sub 2}O{sub 5} and Li{sub 2}SiO{sub 3}, as it has been confirmed by the X-ray diffraction measurements. At relative high temperature (230 deg. C), the experimental ionic conductivity of this achieved sample has doubled in presence of ozone flow. A comparison with other samples, prepared with varieties of metallic nitrates and by following the same experimental procedures as for the former one, has proved that the sample prepared with zirconium was also good for ozone detection.

Ben Saad, K. [Centre de Recherches et des Technologies de l' Energie, Laboratoire de Nanomateriaux et des Systemes pour l' energie, BP 95, 2050 Hammam-Lif (Tunisia)], E-mail: BenSaadKhaled2005@yahoo.fr; Hamzaoui, H. [Centre de Recherches et des Technologies de l' Energie, Laboratoire des procedes chimique, BP 95, 2050 Hammam-Lif (Tunisia); Labidi, A. [Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, BP 51, La Marsa 2070, Tunis (Tunisia); Bessais, B. [Centre de Recherches et des Technologies de l' Energie, Laboratoire de Nanomateriaux et des Systemes pour l' energie, BP 95, 2050 Hammam-Lif (Tunisia)

2008-04-30

159

Effects of growth medium and fertilizer rate on the yield response of soybeans exposed to chronic doses of ozone  

Energy Technology Data Exchange (ETDEWEB)

The objectives were to determine whether wide variation in fertilizer rates or type of growth medium would affect the response of soybeans, Glycine max 'Davis' exposed to chronic doses of ozone (O/sub 3/) in open-top field chambers. Responses to O/sub 3/ were compared for plants grown in the ground or in pots containing an artificial growth medium. In 1977, the yield of plants grown in pots containing soil, sand, and a mixture of perlite, peat moss, and vermiculite was greater than that of plants grown in the ground; in 1978, the reverse was true. However, the percentage yeild loss caused by O/sub 3/ was not affected by the growth medium either year. Separate tests were made for potted plants that received different levels of fertilizer. At moderate fertilizer rates, the yield response to different doses of O/sub 3/ was not significantly affected by fertilizer rate for either year. In 1978, plants with no fertilizer added were severely stunted and even relatively high doses of O/sub 3/ did not further decrease yield. The results suggest that plant response to O/sub 3/ will be fairly uniform over a range of substrate types and fertilizer rates when edaphic conditions are adequate to insure normal plant growth. 17 references, 5 figures, 2 tables.

Heagle, A.S.; Letchworth, M.B.; Mitchell, C.A.

1983-01-01

160

Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030  

Directory of Open Access Journals (Sweden)

Full Text Available A regional air quality simulation framework including the Weather Research and Forecasting modelling system (WRF, the Community Multi-scale Air Quality modeling system (CMAQ, and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitorings, ozone zondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2, nitrogen oxides (NOx, and volatile organic compound (VOC emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around north eastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

S. Chatani

2014-04-01

 
 
 
 
161

Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.  

Science.gov (United States)

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production. PMID:24086640

Landesmann, Jennifer B; Gundel, Pedro E; Martínez-Ghersa, M Alejandra; Ghersa, Claudio M

2013-01-01

162

Ozone Pollution  

Medline Plus

Full Text Available ... higher ozone readings and more frequent high ozone days. Sunlight and heat create conditions that increase the ... Fortunately, these cities had significantly fewer unhealthy ozone days than they had a decade ago thanks to ...

163

Photosynthesis, dark respiration, and growth of Rumex patientia L. exposed to ultraviolet irradiance (288 to 315 nanometers) simulating a reduced atmospheric ozone column  

Energy Technology Data Exchange (ETDEWEB)

Net photosynthesis, dark respiration, and growth of Rumex patientia L. exposed to a ultraviolet irradiance (288-315 nanometers) simulating a 0.18 atm cm stratospheric ozone column were determined. The ultraviolet irradiance corresponding to this 38% ozone decrease from normal was shown to be an effective inhibitor of photosynthesis and leaf growth. The repressive action on photosynthesis accumulated through time whereas leaf growth was retarded only during the initial few days of exposure. Small increases in dark respiration rates occurred but did not continue to increase with longer exposure periods. A reduction in total plant dry weight and leaf area of approximately 50% occurred after 22 days of treatment, whereas chlorophyll concentrations remained unaltered. 29 references, 7 figures, 1 table.

Sisson, W.B.; Caldwell, M.M.

1976-01-01

164

EFFECTS OF SIMULATED ACIDIC RAIN APPLIED ALONE AND IN COMBINATION WITH AMBIENT RAIN ON GROWTH AND YIELD OF FIELD-GROWN SNAP BEAN  

Science.gov (United States)

Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four...

165

Photochemical roles of rapid economic growth and potential abatement strategies on tropospheric ozone over South and East Asia in 2030  

Science.gov (United States)

A regional air quality simulation framework including the Weather Research and Forecasting modeling system (WRF), the Community Multi-scale Air Quality modeling system (CMAQ), and precursor emissions to simulate tropospheric ozone over South and East Asia is introduced. Concentrations of tropospheric ozone and related species simulated by the framework are validated by comparing with observation data of surface monitoring, ozonesondes, and satellites obtained in 2010. The simulation demonstrates acceptable performance on tropospheric ozone over South and East Asia at regional scale. Future energy consumption, carbon dioxide (CO2), nitrogen oxides (NOx), and volatile organic compound (VOC) emissions in 2030 under three future scenarios are estimated. One of the scenarios assumes a business-as-usual (BAU) pathway, and other two scenarios consider implementation of additional energy and environmental strategies to reduce energy consumption, CO2, NOx, and VOC emissions in China and India. Future surface ozone under these three scenarios is predicted by the simulation. The simulation indicates future surface ozone significantly increases around India for a whole year and around northeastern China in summer. NOx is a main driver on significant seasonal increase of surface ozone, whereas VOC as well as increasing background ozone and methane is also an important factor on annual average of surface ozone in East Asia. Warmer weather around India is also preferable for significant increase of surface ozone. Additional energy and environmental strategies assumed in future scenarios are expected to be effective to reduce future surface ozone over South and East Asia.

Chatani, S.; Amann, M.; Goel, A.; Hao, J.; Klimont, Z.; Kumar, A.; Mishra, A.; Sharma, S.; Wang, S. X.; Wang, Y. X.; Zhao, B.

2014-09-01

166

Linking changes in ozone to changes in emissions and meteorology  

Energy Technology Data Exchange (ETDEWEB)

Estimation of trends in ozone air quality is a complex problem because of the strong influence of meteorology on ozone and its precursors. In this paper we present a physically-consistent methodology to link changes in ozone to changes in precursor emissions in the presence of meteorological fluctuations. Time series ozone concentrations (O{sub 3}), nitrogen oxides (NO{sub x}) and non-methane hydrocarbons (NMHC) measured from 1985 to 1993 in the Los Angeles Air Basin are first separated into different time scales using the Kolmogorov-Zurbenko (KZ) filter. Linear regression analysis is performed on meteorological variables and ozone and its precursors on each time scale. The downward trend in the daily hourly maxima of O{sub 3} is about twice that in the daily hourly mean O{sub 3}. The results demonstrate that emission control programs implemented over Southern California were very effective in improving ambient ozone levels during a period of robust economic growth. (Author)

Chan, D. [Albany Univ., Dept. of Earth and Atmospheric Sciences, Albany, NY (United States); Rao, S.T. [Albany Univ., Dept. of Earth and Atmospheric Sciences, Albany, NY (United States)]|[Albany Univ., Dept. of Biometry and Statistics, Albany, NY (United States); Zurbenko, I.G. [Albany Univ., Dept. of Biometry and Statistics, Albany, NY (United States); Porter, P.S. [Albany Univ., Dept. of Biometry and Statistics, Albany, NY (United States)]|[Idaho Univ., Dept. of Civil Engineering, Idaho Falls, ID (United States)

1999-07-01

167

Effects of ozone exposures on epicuticular wax of ponderosa pine needles  

International Nuclear Information System (INIS)

Two-year-old ponderosa pine (Pinus ponderosa L.) seedlings were exposed during the 1989 and 1990 growing seasons to ozone in open-top chambers placed in a forested location at Shirley Meadow, Greenhorn Mountain Range, Sierra Nevada. The ozone treatments were as follows: charcoal-filtered air (CF); charcoal-filtered air with addition of ambient concentrations of ozone (CF + O3); and charcoal-filtered air with addition of doubled concentrations of ozone (CF + 2 x O3). Ozone effects on ponderosa pine seedlings progressed and accumulated over two seasons of exposure. Throughout the first season, increased visible injury and accelerated senescence of the foliage were noted. Subsequently, during the second season of ozone exposure, various physiological and biochemical changes in the foliage took place. All these changes led to reduced growth and biomass of the seedlings. Epistomatal waxes of needles from the CA + 2 x O3 treatment had an occluded appearance. This phenomenon may be caused by earlier phenological development of needles from the high-ozone treatments and disturbed development and synthesis of waxes. It may also be caused by chemical degradation of waxes by exposures to high ozone concentrations. (orig.)

168

How closely does stem growth of adult beech (Fagus sylvatica) relate to net carbon gain under experimentally enhanced ozone stress?  

Science.gov (United States)

The hypothesis was tested that O(3)-induced changes in leaf-level photosynthetic parameters have the capacity of limiting the seasonal photosynthetic carbon gain of adult beech trees. To this end, canopy-level photosynthetic carbon gain and respiratory carbon loss were assessed in European beech (Fagus sylvatica) by using a physiologically based model, integrating environmental and photosynthetic parameters. The latter were derived from leaves at various canopy positions under the ambient O(3) regime, as prevailing at the forest site (control), or under an experimental twice-ambient O(3) regime (elevated O(3)), as released through a free-air canopy O(3) fumigation system. Gross carbon gain at the canopy-level declined by 1.7%, while respiratory carbon loss increased by 4.6% under elevated O(3). As this outcome only partly accounts for the decline in stem growth, O(3)-induced changes in allocation are referred to and discussed as crucial in quantitatively linking carbon gain with stem growth. PMID:22487316

Kitao, Mitsutoshi; Winkler, J Barbro; Löw, Markus; Nunn, Angela J; Kuptz, Daniel; Häberle, Karl-Heinz; Reiter, Ilja M; Matyssek, Rainer

2012-07-01

169

Final report on the ongoing key comparison BIPM.QM-K1: Ozone at ambient level, comparison with EAA (September 2011)  

Science.gov (United States)

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of Austria maintained by the Umweltbundesamt GmbH (EAA) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range of 0 nmol/mol to 500 nmol/mol. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Viallon, Joële; Moussay, Philippe; Idrees, Faraz; Wielgosz, Robert; Froehlich, Marina; Wolf, Andreas

2011-01-01

170

Radial diffusive samplers for determination of 8-h concentration of BTEX, acetone, ethanol and ozone in ambient air during a sea breeze event  

Science.gov (United States)

The radial diffusive sampler Radiello ® filled with Carbograph 4 was evaluated for monitoring BTEX, ethanol and acetone concentrations for 8-hour exposure time. The sampling rates were first evaluated in an exposure chamber under standard conditions. Benzene and toluene showed the highest sampling rates with satisfactory standard deviations. Ethylbenzene and xylenes showed medium sampling rates but higher standard deviations that can be attributed to a low affinity of these compounds with the adsorbent medium for short sampling time. Acetone has a fair result because of the increase of its partial pressure in the vicinity of the adsorbent surface in the course of sampling. The Carbograph 4 adsorbent does not seem to be suitable for sampling ethanol, likely because of its high volatility. The influences of three environmental factors (temperature (T), relative humidity (RH) and concentration level (C)) on the sampling rates were also evaluated, following a fractional factorial design at two factor levels (low and high). Results were only investigated on benzene, toluene and acetone. Temperature and relative humidity are found to be the most important factors leading to variability of the benzene and toluene sampling rates. The applicability of the sampler for 8-hour sampling was demonstrated by the results of a measurement campaign carried out during a sea breeze event. Mapping of benzene, toluene and acetone concentrations showed the highest concentrations in the industrial zone following the wind direction coming from the North. Nevertheless, the sea breeze tends to reduce the spread of the industrial plumes. On the contrary, the ozone map presents the lowest concentrations at the same industrial area indicating a net consumption of ozone. The highest ozone concentrations were found in the southeastern zone suggesting a local ozone formation.

Roukos, Joelle; Locoge, Nadine; Sacco, Paolo; Plaisance, Hervé

2011-01-01

171

Ozone Watch  

Science.gov (United States)

This is the Ozone Hole Watch web site, where you can check on the latest status of the ozone layer over the South Pole. Satellite instruments monitor the ozone layer, and their data is used to create the images that depict the amount of ozone. The web site also contains links for classroom activities and instructional materials.

National Aeronautics and Space Administration (NASA)

172

Ozone Pollution  

Medline Plus

Full Text Available ... 22 had worse ozone problems. Weather played a factor. The warmer summers in 2010 and 2012 contributed to higher ozone readings and more frequent high ozone days. Sunlight and heat create conditions that increase the risk of high ozone levels. Fortunately, these cities had ...

173

Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment  

Energy Technology Data Exchange (ETDEWEB)

An assessment of the effects of tropospheric ozone (O{sub 3}) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O{sub 3} and three N levels. Increased O{sub 3} exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O{sub 3}-induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O{sub 3} limits for the protection of herbaceous vegetation. - Research highlights: Forage quality (foliar protein and fiber content) and phenology are more O{sub 3}-sensitive than growth parameters in the Mediterranean annual grass Briza maxima. The effects of N supplementation depended on meteorological conditions and plant physiological activity. Increase in nitrogen supplementation counterbalanced the O{sub 3}-induced increase in senescence biomass. Nutritive quality and phenology should be considered in new definitions of the O{sub 3} limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O{sub 3}-sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

Sanz, J., E-mail: j.sanz@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Bermejo, V., E-mail: victoria.bermejo@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Muntifering, R., E-mail: muntirb@auburn.ed [Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Gonzalez-Fernandez, I., E-mail: ignacio.gonzalez@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Gimeno, B.S., E-mail: benjamin.gimeno@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Elvira, S., E-mail: susana.elvira@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Alonso, R., E-mail: rocio.alonso@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain)

2011-02-15

174

MOVPE growth of Al xIn1-xP using tertiarybutylphosphine in pure N2 ambient  

International Nuclear Information System (INIS)

We have investigated metalorganic vapor phase epitaxy (MOVPE) growth of Al xIn1-xP alloy using tertiarybutylphosphine (TBP) as the phosphorus source in pure N2 ambient. The effect of the substrate temperature on the aluminum composition of Al xIn1-xP epilayers during the MOVPE growth has been studied. When the source flow rates were kept unchanged, the aluminum composition of the Al xIn1-xP epilayer increased monotonically when the substrate temperature, T g, was raised from 580 deg. C to 660 deg. C during the growth. It became saturated when T g reached 660 deg. C and above. The crystalline quality of the grown Al xIn1-xP epilayers has been investigated by X-ray diffraction and photoluminescence measurements. A linear relationship between the aluminum composition of the Al xIn1-xP epilayer and TMAl/(TMAl + TMIn) source flow ratio has been obtained when grown at the optimized growth temperature of T g = 630 deg. C. It has also been observed that the aluminum incorporation coefficient of Al xIn1-xP epilayers decreased when the V/III source flow ratio was increased during the MOVPE growth

175

Long-term prediction of fish growth under varying ambient temperature using a multiscale dynamic model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Feed composition has a large impact on the growth of animals, particularly marine fish. We have developed a quantitative dynamic model that can predict the growth and body composition of marine fish for a given feed composition over a timespan of several months. The model takes into consideration the effects of environmental factors, particularly temperature, on growth, and it incorporates detailed kinetics describing the main metabolic processes (protein,...

Radde Nicole; Bar Nadav S

2009-01-01

176

Evaluation of the anti-oxidant ethylene diurea (EDU) as a protectant against ozone effects on crops (Growth chamber trials)  

Energy Technology Data Exchange (ETDEWEB)

A field study conducted during the summer of 2000 showed that when the antioxidant ethylene diurea (EDU) was applied to crops there was an increase in several parameters. The authors designed a series of controlled-environment trials to test the following: were the effects of EDU the result of EDU-mediated protection against ozone (O{sub 3}) or were they from the plant growth promoting effects of EDU independent of O{sub 3}. The three major objectives were: (1) to modify an existing gas exposure system to expose plants to O{sub 3} and to test the stability and reliability of the system, (2) to perform O{sub 3} exposure trials using wheat, barley, field pea and canola to observe the effects of O{sub 3}, and (3) to test whether the effects of EDU could be attributed to protection against O{sub 3} injury or to the plant growth promoting effects independent of O{sub 3}. The modification to the gas exposure system involved the installation of an O{sub 3} delivery system and a monitoring system. Stability of the system was tested using radish plants. The symptoms of O{sub 3} injury on radish leaves began after two weeks of exposure. It appeared as mottled bleached areas which became red. Mottled chlorotic areas appeared on wheat and barley, which led to complete chlorosis, necrosis and eventually abscission. After two weeks of exposure, field pea developed tendril curl, and canola plants displayed no visible signs of injury from O{sub 3} exposure. The results of the study indicated that the effects of EDU can be species- and cultivar-specific. 15 refs., 11 tabs., 8 figs.

Archambault, D.J.; Li, X. [Alberta Research Council, Vegreville, AB (Canada). Environmental Technologies

2003-02-01

177

Long-term prediction of fish growth under varying ambient temperature using a multiscale dynamic model  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Feed composition has a large impact on the growth of animals, particularly marine fish. We have developed a quantitative dynamic model that can predict the growth and body composition of marine fish for a given feed composition over a timespan of several months. The model takes into consideration the effects of environmental factors, particularly temperature, on growth, and it incorporates detailed kinetics describing the main metabolic processes (protein, lipid, and central metabolism known to play major roles in growth and body composition. Results For validation, we compared our model's predictions with the results of several experimental studies. We showed that the model gives reliable predictions of growth, nutrient utilization (including amino acid retention, and body composition over a timespan of several months, longer than most of the previously developed predictive models. Conclusion We demonstrate that, despite the difficulties involved, multiscale models in biology can yield reasonable and useful results. The model predictions are reliable over several timescales and in the presence of strong temperature fluctuations, which are crucial factors for modeling marine organism growth. The model provides important improvements over existing models.

Radde Nicole

2009-11-01

178

Relative effects of elevated background ozone concentrations and peak episodes on senescence and above-ground growth in four populations of Anthoxanthum odoratum L.  

Science.gov (United States)

Four populations of Anthoxanthum odoratum from North Wales, UK, were exposed to the following combinations of mean background and peak concentrations of ozone for 12 weeks in solardomes: LL (14.3 ppb, 18.9 ppb, respectively), LH (14.8 ppb, 52.3 ppb), HL (28.9 ppb, 35.7 ppb) and HH (30.5 ppb, 72.1 ppb). Elevated ozone rapidly induced premature senescence, with effect increasing in the order: LLpm) were very different at 10.6 ppmh and 4.1 ppmh, respectively. Overall, linear correlations between whole plant senescence were stronger for AOT0 than for AOT40. Intraspecific variation in the senescence response to the different profiles was observed after 11 weeks of exposure. Effects on growth and tillering were less pronounced than effects on senescence. PMID:18980787

Dawnay, Louise; Mills, Gina

2009-02-01

179

Ozone dose-response relationships for spring oilseed rape and broccoli  

Science.gov (United States)

Tropospheric ozone is an important air pollutant with known detrimental effects for several crops. Ozone effects on seed yield, oil percentage, oil yield and 1000 seed weight were examined for spring oilseed rape ( Brassica napus cv. Ability). For broccoli ( Brassica oleracea L. cv. Italica cv. Monaco) the effects on fresh marketable weight and total dry weight were studied. Current ozone levels were compared with an increase of 20 and 40 ppb during 8 h per day, over the entire growing season. Oilseed rape seed yield was negatively correlated with ozone dose indices calculated from emergence until harvest. This resulted in an R2 of 0.24 and 0.26 ( p rape. The reduction of oilseed rape yield showed the highest correlation with the ozone uptake during the vegetative growth stage: when only the first 47 days after emergence were used to calculate POD 6, R2 values increased up to 0.476 or even 0.545 when the first 23 days were excluded. The highest ozone treatments, corresponding to the future ambient level by 2100 (IPCC, Meehl et al., 2007), led to a reduction of approximately 30% in oilseed rape seed yield in comparison to the current ozone concentrations. Oil percentage was also significantly reduced in response to ozone ( p < 0.001). As a consequence oil yield was even more severely affected by elevated ozone exposure compared to seed yield: critical levels for oil yield dropped to 3.2 ppm h and 3.9 mmol m -2. For broccoli the applied ozone doses had no effect on yield.

De Bock, Maarten; Op de Beeck, Maarten; De Temmerman, Ludwig; Guisez, Yves; Ceulemans, Reinhart; Vandermeiren, Karine

2011-03-01

180

Ozone Pollution  

Medline Plus

Full Text Available ... ago (or in our earliest reports). However, rising temperatures create conditions favorable to forming ozone. Communities will ... help to reduce ozone pollution in the warmer temperatures expected from the changing climate. Los Angeles remained ...

 
 
 
 
181

Ozone Pollution  

Medline Plus

Full Text Available ... ozone problems. Weather played a factor. The warmer summers in 2010 and 2012 contributed to higher ozone ... have much better air quality compared to ten years ago (or in our earliest reports). However, rising ...

182

Ozone Pollution  

Medline Plus

Full Text Available ... Card Widget Or Enter Your Zip Code: Ozone Pollution More than 4 in 10 people in the ... Communities will need more help to reduce ozone pollution in the warmer temperatures expected from the changing ...

183

Ozone Pollution  

Medline Plus

Full Text Available ... 140.5 million people live in the 296 counties that received an F for ozone levels. These ... does not include people who live in adjacent counties in metropolitan areas where no monitors exist. Ozone ...

184

Single crystal growth of MgB 2 by using Mg-self-flux method at ambient pressure  

Science.gov (United States)

Single crystals of magnesium diboride (MgB 2) have been grown at ambient pressure by using Mg-self-flux method. We chose the marketed MgB 2 powder as the raw material and Mg as the flux. The temperature was raised from room temperature to 1035°C for 4 h and maintained so for 2 h and then cooled down to room temperature slowly and then the single crystals of MgB 2 with hexagonal shape and a superconducting transition at about 37 K were obtained. The X-ray powder diffraction confirmed the MgB 2 phase, scanning electron microscope observed the single crystal images and electron diffraction patterns by using high-resolution transmission electron microscope confirmed the structure of MgB 2 single crystal. A new mechanism of liquid-assisted solid-state re-crystallization for growth of MgB 2 single crystal is proposed.

Du, Wei; Xu, Dong; Zhang, Hongbin; Wang, Xinqiang; Zhang, Guanghui; Hou, Xianqin; Liu, Heyi; Wang, Yanling

2004-07-01

185

Growth of YBa2(Cu, Co)4O8 single crystals under ambient pressure and their superconducting properties  

International Nuclear Information System (INIS)

We report the growth of superconducting YBa2(Cu, Co)4O8 single crystals using KOH flux under ambient pressure and their superconducting properties. The average size of the YBa2(Cu, Co)4O8 single crystals is 0.3 x 0.3 x 0.2 mm3. The superconducting transition temperature (Tc) of the parent material is found to be 81 K, indicating a stoichiometric oxide superconductor. The Tc and the c-axis length of YBa2(Cu, Co)4O8 single crystals decrease systematically with increasing the Co-doping content. A comparison of the magnetic irreversibility with the flux-creep theory from the viewpoint of homogeneity/inhomogeneity is made. (author)

186

Crystal growth and ambient and high pressure study of the re-entrant superconductor Tm(2)Fe(3)Si(5).  

Science.gov (United States)

Tm(2)Fe(3)Si(5) is known to undergo a transition to the superconducting state (at ambient or applied pressure depending on the sample) at a temperature T(c1)(?1.8 K), and at a lower temperature T(N)(?1 K) it undergoes a transition into a long range antiferromagnetically ordered state. Superconductivity is simultaneously destroyed and the sample re-enters the normal state at T(c2) = T(N). The conditions reported in the literature for the observation of superconductivity in Tm(2)Fe(3)Si(5) are sample dependent, but it is now accepted that stoichiometric Tm(2)Fe(3)Si(5) superconducts only under pressure. Here we report single-crystal growth of stoichiometric Tm(2)Fe(3)Si(5) which does not superconduct at ambient pressure down to 100 mK. Measurements of the anisotropic static magnetic susceptibility ?(T) and isothermal magnetization M(H), ac susceptibility ?(ac)(T), electrical resistivity ?(T) and heat capacity C(T) at ambient pressure and ?(ac)(T) at high pressure are reported. The magnetic susceptibility along the c axis, ?(c)(T), shows a curvature over the whole temperature range and does not follow the Curie-Weiss behavior, while the magnetic susceptibility along the a axis, ?(a)(T), follows a Curie-Weiss behavior between 130 and 300 K with a Weiss temperature ? and an effective magnetic moment ?(eff) which depend on the temperature range of the fit. The easy axis of magnetization is perpendicular to the c axis and ?(a)/?(c) = 3.2 at 1.8 K. The ambient pressure ?(ac)(T) and C(T) measurements confirm bulk antiferromagnetic ordering at T(N) = 1.1 K. The sharp drop in ?(ac)(T) below the antiferromagnetic transition is suggestive of the existence of a spin gap. We observe superconductivity only under applied pressures P?2 kbar. The temperature-pressure phase diagram showing the non-monotonic dependence of the superconducting transition temperature T(c) on pressure P is presented. PMID:21694333

Singh, Yogesh; Ramakrishnan, S

2008-06-11

187

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours  

Directory of Open Access Journals (Sweden)

Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulphur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

T. Petäjä

2005-01-01

188

Effects of SO2 oxidation on ambient aerosol growth in water and ethanol vapours  

Directory of Open Access Journals (Sweden)

Full Text Available Hygroscopicity (i.e. water vapour affinity of atmospheric aerosol particles is one of the key factors in defining their impacts on climate. Condensation of sulphuric acid onto less hygroscopic particles is expected to increase their hygrocopicity and hence their cloud condensation nuclei formation potential. In this study, differences in the hygroscopic and ethanol uptake properties of ultrafine aerosol particles in the Arctic air masses with a different exposure to anthropogenic sulfur pollution were examined. The main discovery was that Aitken mode particles having been exposed to polluted air were more hygroscopic and less soluble to ethanol than after transport in clean air. This aging process was attributed to sulfur dioxide oxidation and subsequent condensation during the transport of these particle to our measurement site. The hygroscopicity of nucleation mode aerosol particles, on the other hand, was approximately the same in all the cases, being indicative of a relatively similar chemical composition despite the differences in air mass transport routes. These particles had also been produced closer to the observation site typically 3–8 h prior to sampling. Apparently, these particles did not have an opportunity to accumulate sulphuric acid on their way to the site, but instead their chemical composition (hygroscopicity and ethanol solubility resembled that of particles produced in the local or semi-regional ambient conditions.

A. Laaksonen

2004-11-01

189

Use of the antiozonant ethylenediurea (EDU) in Italy: Verification of the effects of ambient ozone on crop plants and trees and investigation of EDU's mode of action  

Energy Technology Data Exchange (ETDEWEB)

Twenty-four experiments where EDU was used to protect plants from ozone (O{sub 3}) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O{sub 3}-caused visible injury and growth reductions in crop and forest species respectively. EDU was mainly applied as soil drench to crops and by stem injection or infusion into trees. Visible injury was delayed and reduced but not completely. In investigations on mode of action, EDU was quickly (<2 h) uptaken and translocated to the leaf apoplast where it persisted long (>8 days), as it cannot move via phloem. EDU did not enter cells, suggesting it does not directly affect cell metabolism. EDU delayed senescence, did not affect photosynthesis and foliar nitrogen content, and stimulated antioxidant responses to O{sub 3} exposure. Preliminary results suggest developing an effective soil application method for forest trees is warranted. - EDU was successful as a tool in determining ozone effects on vegetation in Italy, but while progress was made, its mode of action remains unresolved.

Paoletti, Elena, E-mail: e.paoletti@ipp.cnr.i [IPP-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy); Contran, Nicla [Department of Biotechnology and Biology, University of Milano-Bicocca, Piazza della Scienza 1, Milan (Italy); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States); Ferrara, Anna M. [IPLA, Corso Casale 476, I-10128 Turin (Italy)

2009-05-15

190

ECONOMIC EFFECTS OF OZONE ON AGRICULTURE  

Science.gov (United States)

Past attempts to assess the monetary impacts of ozone or other air pollutants on agriculture have had only sparse plant science information on which to base an assessment. This paper reports on an economic assessment of the effects of simulated changes in ambient ozone on U.S. ag...

191

Relative effects of elevated background ozone concentrations and peak episodes on senescence and above-ground growth in four populations of Anthoxanthum odoratum L  

Energy Technology Data Exchange (ETDEWEB)

Four populations of Anthoxanthum odoratum from North Wales, UK, were exposed to the following combinations of mean background and peak concentrations of ozone for 12 weeks in solardomes: LL (14.3 ppb, 18.9 ppb, respectively), LH (14.8 ppb, 52.3 ppb), HL (28.9 ppb, 35.7 ppb) and HH (30.5 ppb, 72.1 ppb). Elevated ozone rapidly induced premature senescence, with effect increasing in the order: LL < LH < HL < HH. By week 11, the LH and HL treatments had induced similar amounts of whole plant senescence even though the AOT40{sub 12} values (accumulated between 8am and 8pm) were very different at 10.6 ppm h and 4.1 ppm h, respectively. Overall, linear correlations between whole plant senescence were stronger for AOT0 than for AOT40. Intraspecific variation in the senescence response to the different profiles was observed after 11 weeks of exposure. Effects on growth and tillering were less pronounced than effects on senescence. - Elevated background ozone concentrations induce premature senescence to a greater extent than peak episodes.

Dawnay, Louise [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW (United Kingdom); School of Biological Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW (United Kingdom); Mills, Gina [Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW (United Kingdom)], E-mail: gmi@ceh.ac.uk

2009-02-15

192

Ozone Depletion  

Science.gov (United States)

The Environmental Protection Agency's (EPA) Ozone Depletion site contains scientific, policy, and practical information for the general public and for industry in particular. Information for the public includes introductory materials on ozone depletion science, the nature of the harmful effects on the environment and on human health, personal protective measures against UV radiation, individual actions to help protect the ozone layer, lists of ozone depleting substances, background on chlorofluorocarbons (CFCs), the Antarctic ozone hole, and the UV Index. Information for businesses that use or manufacture ozone-depleting substances (ODS) includes lists of these substances (including their ozone-depletion potential (ODP), global warming potential (GWP), and CAS numbers), the benefits of CFC phase-out, methyl bromide, and substitutes for ozone-depleting substances. Reference materials are provided on United States laws and regulations concerning ODS and are accompanied by compliance guidance for regulations issued under the Clean Air Act. Other notable resources include the Executive Summary of Scientific Assessment of Ozone Depletion (1994), an ODS Management Technologies Database, downloadable stratospheric ozone depletion interactive software, images and animations of the Antarctic ozone hole, downloadable data from the EPA's Ultraviolet Monitoring Program, and a glossary. External links are also provided to various dynamic interactive, and database resources hosted by the National Aeronautics and Space Administration (NASA) and the National Oceanographic and Atmospheric Administration (NOAA).

193

Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone  

Energy Technology Data Exchange (ETDEWEB)

In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac){sub 2}], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1?±?0.01?nm/cycle within the wide ALD temperature window of 175–300?°C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure, refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnO{sub x}–Si interface. The resistivity of the SnO{sub x} films was calculated to be 0.3?? cm. Results of this work demonstrate the possibility of introducing Sn(acac){sub 2} as tin precursor to deposit conducting ALD SnO{sub x} thin films on a silicon surface, with clean interface and no formation of undesired SiO{sub 2} or other interfacial reaction products, for transparent conducting oxide applications.

Kannan Selvaraj, Sathees [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Feinerman, Alan [Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Takoudis, Christos G., E-mail: takoudis@uic.edu [Departments of Bioengineering and Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)

2014-01-15

194

Plant Species Sensitivity Distributions for ozone exposure  

International Nuclear Information System (INIS)

This study derived Species Sensitivity Distributions (SSD), representing a cumulative stressor-response distribution based on single-species sensitivity data, for ozone exposure on natural vegetation. SSDs were constructed for three species groups, i.e. trees, annual grassland and perennial grassland species, using species-specific exposure–response data. The SSDs were applied in two ways. First, critical levels were calculated for each species group and compared to current critical levels for ozone exposure. Second, spatially explicit estimates of the potentially affected fraction of plant species in Northwestern Europe were calculated, based on ambient ozone concentrations. We found that the SSD-based critical levels were lower than for the current critical levels for ozone exposure, with conventional critical levels for ozone relating to 8–20% affected plant species. Our study shows that the SSD concept can be successfully applied to both derive critical ozone levels and estimate the potentially affected species fraction of plant communities along specific ozone gradients. -- Highlights: ? Plant Species Sensitivity Distributions were derived for ozone exposure. ? Annual grassland species, as a species assemblage, tend to be most sensitive to ozone. ? Conventional critical levels for ozone relate to 8–20% affected plant species. ? The affected fraction of plant species for current ozone exposure in Northwestern Europe is estimated. -- Species Sensitivity Distributions offer opportunities in ozone risk assessment to both derive critical levels and estimate the affected fraction of a plant community

195

On the influence of the ambient environment on the fatigue crack growth process in steels  

International Nuclear Information System (INIS)

A comparison of the crack opening and fatigue crack growth characteristics of three tempered martensitic steels; a modified 4135, 2 1/4Cr 1Mo and a modified 9Cr 1Mo; in air and in vacuum (3 x 105torr) has been carried out. In vacuum, roughness-induced closure is responsible for closure in the near-threshold region and the level of closure is independent of ??. The presence of oxygen in the environment (50% relative humidity) can increase the overall closure level by as much as 50% in the case of 4135 and 2 1/4Cr 1Mo steels, but does not contribute significantly to closure in the case of the 9Cr 1Mo steel. Roughness-induced closure increases increasing the tempering temperature, but the extent of the environmental effect on closure in a given alloy is a lot less dependent on the tempering temperature. Rewelding is not responsible for the high threshold levels found in vacuum. Oxide film rupture and as well as hydrogen embrittlement increase the crack growth rate in air compared to the observed in vacuum. (Author)

196

Variation in the relationship between ozone exposure and crop yield as derived from simple models of crop growth and ozone impact  

Science.gov (United States)

Causes of variation in O 3 dose-crop yield loss relationship ( D-R) were studied with the models of crop growth and O 3 effects. In the growth model, biomass accumulation was assumed to be proportional to solar radiation intercepted by the plant leaves. The O 3 impact was modeled as a linear function of the O 3 concentration less the background O 3. The models were combined to give analytical expressions of D-R between mean O 3 concentration ( overlineQ) and relative yield loss. The effects of O 3 on canopy photosynthesis and leaf abscission in reproductive growth were addressed. The O 3 impact on photosynthesis was modeled as a reduced canopy light-use efficiency (LUE). The resultant yield loss was proportional to overlineQ with the modification ( M) due to the fluctuations in O 3 and a weighting factor ( w), and to the correlation between them. The weighting factor is defined as daily biomass accumulation in the background O 3. If the sensitivity of canopy LUE is much higher during reproductive growth, the D-R was further modified by the ratio of weighted sum of O 3 during reproductive growth to that through a whole season. The D-R for the O 3 effect on leaf abscission was a hyperbolic function of overlineQ with modifications by M. The above analysis thus identified fluctuations in O 3 and the weighting factor as possible causes of the variation in the D-R.

Kobayashi, Kazuhiko

197

Ozone measurement systems: associated instrumentation and calibration  

Directory of Open Access Journals (Sweden)

Full Text Available The harmful effects produced by ozone have lead to a vast regulation to define and establish the quality goals of ambient air, based on common methods and criteria. The surveillance nets of atmospheric pollution are worldwide extended systems and the applied technology for the ozone measurement is nowadays quite standardized. The aim of this paper is to give a general view of the most common systems used in the ozone measurement in ambient air from a practical point of view. The used instrumentation and the usual calibration methods will be described.

J. Bellido

2006-01-01

198

In situ laser ablation plasma diagnostics in the film growth regime: Effects of ambient background gases  

International Nuclear Information System (INIS)

The propagation of the laser-induced plasma formed by KrF irradiation of Y1Ba2Cu3O7 has been characterized in background pressures of oxygen and argon typically used for thin film growth. The ion current transmitted through the background gases was recorded along the normal to the irradiated pellet as a function of distance in order to measure the decreasing velocity and magnitude of the expanding plasma current due to collisional slowing and attenuation of the laser plume. The integrated ion charge delivered to a substrate at low pressures can be described by elastic scattering giving a general integral cross sections of ?e[O2] = 3.2 x 10-16 cm2 and ?e[Ar] = 2.7 x 10-16 cm2. At higher pressures, inelastic scattering leads to increased recombination and reactive conversion of ions indicated by increased fluorescence of all the species, which becomes dominated by fluorescence of YO and BaO. Spatially resolved fluorescence measurements indicate that the luminous boundary to the plasma follows a weak shock front which coincides with the ion flux propagation. The ion transmission is found to drop exponentially with distance and background pressure, in agreement with a simple scattering model which yields general scattering cross sections for ion-argon ?i-Ar = 2.1 x 10-16 cm2 and ion-oxygen ?i-O2 = 2.3 x 10-16 cm2 interactions in background pressures up to 300 mTorr. The general features of the plume deceleration are described in terms of a drag force model. 9 refs., 5 figs

199

Ozone Depletion  

Science.gov (United States)

The ozone layer forms a thin shield in the upper atmosphere, protecting life onEarth from the suns ultraviolet (UV) rays. In the 1980s, scientists began accumulating evidence that the ozone layer was being depleted. Depletion of the ozone layer results in increased UV radiation reaching the Earths surface, which in turn can lead to a greater chance of overexposure to UV radiation and the related health effects of skin cancer, cataracts, and immune suppression.

U.S. Environmental Protection Agency (EPA;Office of Air and Radiation)

2008-04-25

200

Effect of Ambient Temperature and Light Intensity on Growth Performance and Carcass Characteristics of Heavy Broiler Chickens at 56 Days of Age  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of ambient temperature, light intensity and their interaction on growth performance and carcass characteristics of broilers were investigated in 2 trials. The experiment was consisted of a factorial arrangement of treatments in a randomized complete block design. The 9 treatments consisted of 3 levels (Low = 15.6, Moderate = 21.1, High = 26.7oC of temperatures from d 21-56 d of age and 3 levels (0.5, 3.0, 20 lx of light intensities from 8-56 d of age at 50% RH. Five hundred and forty Ross 708 chicks were randomly distributed into 9 environmentally controlled chambers (30 males and 30 females chicks/chamber at 1 d of age. Feed and water were provided ad libitum. Birds were provided a four phase-feeding program (starter: 1 to 14 d, grower: 15-28 d, finisher: 29-42 d and withdrawal: 43-56 d. At 56 d of age, both feed intake and birds’ weight were recorded for the growth performance. Also, 20 (10 males and 10 females birds from each chamber were processed to determine weights and yields. Broilers subjected to high ambient temperature of 26.7oC had significantly (P0.05 lower BW, BWG, FI, carcass weight and pectoralis major and minor weights along with a significant (P0.05 increased in FCR when compared with low and moderate ambient temperatures broilers. Plasma corticosterone concentrations were not statistically affected by temperature, light intensity or their interaction, suggesting an absence of stress. These results indicate that exposure of modern heavy weight broilers to high ambient temperature of 26.7oC in comparison with low and moderate ambient temperatures has a negative effect on growth performance and carcass characteristics, suggesting that they need to be grown under lower ambient temperature than previously reported.

S.D. Collier

2010-01-01

 
 
 
 
201

Ozone, antioxidant spray and meloidogyne hapla effects on tobacco  

Science.gov (United States)

The relationship between ozone and the northern root-knot nematode on tobacco was investigated. Seedlings of tobacco ( Nicotiana tabacum L.) cv. Virginia 115 were inoculated and not inoculated with root-knot ( Meloidogyne hapla (Chitwood) prior to transplanting to a field plot. One-half the plants were sprayed at weekly intervals with an antioxidant, EDU at the rate of 1 kg ha -1 to protect against oxidant injury. O 3 concentrations in excess of 80 ppb were recorded 14 times during the summer of 1982. Ambient ozone inhibited growth and yield of tobacco inoculated and not inoculated with M. hapla. Tobacco inoculated with nematode alone developed significantly more ozone injury than other treatments indicating that tobacco infected with M. hapla is more susceptible to ambient O 3. Significantly 20% more galls developed on plants with nematode inoculation compared to plants with nematode inoculation + EDU indicating that EDU indirectly reduced gall development in tobacco. Plants protected with EDU also showed an increase in dry weight of shoot, root and biomass.

Bisessar, S.; Palmer, K. T.

202

Ozone, antioxidant spray and Meloidogyne hapla effects on tobacco  

Energy Technology Data Exchange (ETDEWEB)

The relationship between ozone and the northern root-knot nematode on tobacco was investigated. Seedlings of tobacco (Nicotiana tabacum L.) cv. Virginia 115 were inoculated and not inoculated with root-knot (Meloidogyne hapla (Chitwood) prior to transplanting to a field plot. One-half the plants were sprayed at weekly intervals with an antioxidant, EDU at the rate of 1 kg ha/sup -1/ to protect against oxidant injury. O/sub 3/ concentrations in excess of 80 ppb were recorded 14 times during the summer of 1982. Ambient ozone inhibited growth and yield of tobacco inoculated and not inoculated with M. hapla. Tobacco inoculated with nematode alone developed significantly more ozone injury than other treatments indicating that tobacco infected with M. hapla is more susceptible to ambient O/sub 3/. Significantly 20% more galls developed on plants with nematode inoculation compared to plants with nematode inoculation + EDU indicating that EDU indirectly reduced gall development in tobacco. Plants protected with EDU also showed an increase in dry weight of shoot, root and biomass.

Bisessar, S.; Palmer, K.T.

1984-01-01

203

Effect of different arbuscular mycorrhizal fungi on growth and physiology of maize at ambient and low temperature regimes.  

Science.gov (United States)

The effect of four different arbuscular mycorrhizal fungi (AMF) on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT) and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress. PMID:24895680

Chen, Xiaoying; Song, Fengbin; Liu, Fulai; Tian, Chunjie; Liu, Shengqun; Xu, Hongwen; Zhu, Xiancan

2014-01-01

204

California statewide assessment of the effects of ozone on crop productivity  

Energy Technology Data Exchange (ETDEWEB)

The California Air Resources Board (CARB) initiated a Crop Loss Assessment Program to develop a process whereby all available information could be put into a format usable for a statewide assessment of yield losses to crops from ozone. The yield loss information was used in conjunction with economic analysis to determined the impacts of different ozone/ambient air quality standards. The results to date (using 1984 as a trial year) indicate the usefulness of the process for general assessments of the effects of ozone on crop productivity, not only for California but potentially for other areas. Modifications in these projected loss estimates will be made as new information becomes available concerning loss equations, air monitoring sites, and growth seasons on a county and crop basis, and for data collected after 1984.

Olszyk, D.M.; Cabrera, H.; Thompson, C.R.

1988-07-01

205

Effect of ozone on the in vitro synthesis and release of inflammatory mediators and growth factors by alveolar macrophages derived from patients with chronic bronchopulmonary inflammation; Wirkung von Ozon auf die in vitro-Bildung und -Freisetzung von Entzuendungsmediatoren und Wachstumsfaktoren durch Alveolarmakrophagen bei Patienten mit chronisch bronchopulmonalen Entzuendungen  

Energy Technology Data Exchange (ETDEWEB)

The effect of ozone exposure on cytokine release was studied in alveolar macrophages (AM) from patients with chronic inflammatory lung disease. AM of 87 patients entered 99 exposure experiments (13 at 150 {mu}g, 32 at 300 {mu}g, 16 at 700 {mu}g, and 38 at 1000 {mu}g ozone/m{sup 3}). AM were exposed in a biphasic system consisting of membrane-culture insert of high porosity (transwell). AM were directly exposed to ozone for 1 h, followed by 4 h of culture covered with serum-free medium. The parameters were determined in culture supernatant by ELISA (interleukin (IL) 1{alpha}, {beta}, IL6, IL8, TNF{alpha}), by bioassay (TNF{alpha}), and by enzyme assay (LDH). By increased LHD activities in culture supernatants of ozone exposed AM, a significant cytotoxic effect was identified for ozone concentrations equal to or higher than 300 {mu}g/m{sup 3}. Spontaneous release of IL1{alpha}, {beta} and IL8 slightly increased after ozone exposure (p<0,05 at 150 {mu}g ozone). TNF was released in reduced quantities (p<0,05 at 300 {mu}g; p<0,01 at 1000 {mu}g ozone/m{sup 3}). Patients with chronic bronchitis, fibrosis, and sarcoidosis differed significantly in basic cytokine release of IL1{alpha}, IL1{beta}, IL8, and TNF, with sarcoidosis patients showing the highest levels of cytokines measured. Nevertheless, the ozone induced changes for the various cytokines were not significantly different between the above patient groups. The most obvious effect of ozone could be observed after additional stimulation of AMs with LPS. LPS induced secretion of TNF and IL6 were shown to be strongly inhibited by ozone, even at ambient concentrations (150 and 300 {mu}g/m{sup 3}). Little effect was seen regarding IL8, IL1{alpha}, and {beta}. The murine macrophage cell line J774A.1, which proved to respond to LPS stimulation in a similar reduction of TNF release after ozone exposure, was used as a model to study LPS receptor binding. After ozone exposure at 300 {mu}g/m{sup 3} LPS-FITC binding was reduced significantly demonstrating impaired receptor function, whereas detection of receptor by monoclonal anti-CD14-antibody was not altered significantly. In conclusion, ozone impairs macrophage functions even at ambient concentrations, which might interfere with host defence mechanisms. Some, but not all patients might therefore risk of aggravation of their respective disease. Response to ozone seemed to be influenced rather by the individual`s conditions than by the underlying disease. (orig.) [Deutsch] Unter der Fragestellung, ob und wie Ozon die Freisetzung von Entzuendungsmediatoren aus Alveolarmakrophagen (AM) bei Patienten mit chronisch entzuendlichen Lungenerkrankungen beeinflussen kann, wurden im Projekt die AM von 87 Patienten in 99 in vitro Expositionsexperimenten untersucht (13 bei 150 {mu}g, 32 bei 300 {mu}g, 16 bei 700 {mu}g und 38 bei 1000 {mu}g Ozon/m{sup 3}). Die AM wurden in Transwell-Membrankulturgefaessen exponiert und waren apikal der Gasphase 1 Stunde direkt ausgesetzt. Die Befeuchtung erfolgte kapillar von unten durch die poroese Membran hindurch. Nach weiteren 4 Stunden Kultur mit Medium bedeckt, wurden die Parameter im Kulturueberstand gemessen. Eine signifikant toxische Wirkung ist anhand der erhoehten LDH-Aktivitaet im Kulturueberstand der ozonexponierten AM ab 300 {mu}g/m{sup 3} nachweisbar. Von Patient zu Patient gab es fuer die einzelnen Parameter eine grosse individuelle Variabilitaet bezueglich Richtung und Hoehe der Ozonantwort. Die spontane Freisetzung von IL1 {alpha} und {beta} sowie IL8 zeigt im Mittel eine diskrete Zunahme nach Ozon (p<0,05 bei 150 {mu}g), waehrend fuer TNF zumeist eine Hemmung festzustellen ist (p<0,05 bei 300 {mu}g; p<0,01 bei 1000 {mu}g Ozon). Die Patientengruppen Sarkoidose, Fibrose und Bronchitis unterscheiden sich in ihrer Basisfreisetzung, wobei die AM von Sakroidosepatienten fuer die untersuchten Zytokine die hoechsten Sekretionsraten aufweisen. Die ozonbedingte Sekretionsaenderung zeigt keine signifikanten Unterschiede in Hoehe und Auslenkung zwischen den Patientengruppen. Der staerkst

Muley, T.; Segraefe, P.; Ebert, W. [Thoraxklinik Heidelberg (Germany). Abt. Klinische Chemie und Bakteriologie; Wiebel, M.; Schulz, V. [Thoraxklinik Heidelberg (Germany). Innere Medizin und Pneumologie

1997-10-01

206

Three days after a single exposure to ozone, the mechanism of airway hyperreactivity is dependent on substance P and nerve growth factor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone causes persistent airway hyperreactivity in humans and animals. One day after ozone exposure, airway hyperreactivity is mediated by release of eosinophil major basic protein that inhibits neuronal M2 muscarinic receptors, resulting in increased acetylcholine release and increased smooth muscle contraction in guinea pigs. Three days after ozone, IL-1?, not eosinophils, mediates ozone-induced airway hyperreactivity, but the mechanism at this time point is largely unknown. IL-1? increase...

Verhein, Kirsten C.; Hazari, Mehdi S.; Moulton, Bart C.; Jacoby, Isabella W.; Jacoby, David B.; Fryer, Allison D.

2011-01-01

207

Competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile Norway spruces and European beech  

Energy Technology Data Exchange (ETDEWEB)

Potential interactions of carbon dioxide and ozone on carbohydrate concentrations and contents were studied in Norway spruce and European beech saplings to test the hypotheses that (1) prolonged exposure to elevated carbon dioxide does not compensate for the limiting effects of ozone on the accumulation of sugars and starches, or biomass partitioning to the root; and (2) growth of mixed-species planting will repress plant responses to elevated ozone and carbon dioxide. Norway spruce and European beech saplings were acclimated for one year to ambient and elevated carbon dioxide, followed by exposure to factorial combinations of ambient and elevated ozone and carbon dioxide during the next two years. In spruce trees, sugar and starch content was greater in saplings exposed to elevated carbon dioxide; in beech, the response was the opposite. The overall conclusion was that the results did not support Hypothesis One, because the adverse effects were counteracted by elevated carbon dioxide. Regarding Hypothesis Two, it was found to be supportive for beech but not for spruce. In beech, the reduction of sugars and starch by elevated ozone and stimulation by elevated carbon dioxide were repressed by competitive interaction with spruce, whereas in spruce saplings elevated concentrations of carbon dioxide resulted in higher concentrations of sugar and starch, but only in leaves and coarse roots and only when grown in combination with beech. Elevated ozone in spruce saplings produced no significant effect on sugar or starch content either in intra- or interspecific competition. 57 refs., 1 tab., 5 figs.

Liu, X.; Rennenberg, H. [University of Freiburg, Inst. of Forest Botany and Tree Physiology, Freiburg (Germany); Kozovits, A. R.; Grams, T. E.; Blaschke, H.; Matyssek, R. [Technische Universitat Munchen, Dept. of Ecology and Ecophysiology of Plants, Freising (Germany)

2004-09-01

208

Ozone Pollution  

Medline Plus

Full Text Available ... ozone levels. These people live where the monitored air quality places them at risk for premature death, aggravated ... 2011. Fortunately, even these places have much better air quality compared to ten years ago (or in our ...

209

Ozone Pollution  

Medline Plus

Full Text Available ... Spring Forward by Reducing your Asthma & Allergy Triggers Smart links footer - Homepage Key Findings Ozone Pollution Year Round Particle Short Term Particle Cleanest Cities People at Risk Protect Yourself Methodology City Rankings ...

210

Ozone Pollution  

Science.gov (United States)

... Spring Forward by Reducing your Asthma & Allergy Triggers Smart links footer - Homepage Key Findings Ozone Pollution Year Round Particle Short Term Particle Cleanest Cities People at Risk Protect Yourself Methodology City Rankings ...

211

Ozone Pollution  

Medline Plus

Full Text Available ... St. Louis, Tulsa (OK), Cincinnati, Philadelphia, Louisville (KY), Oklahoma City, Chicago, Pittsburgh, Fort Collins (CO) Birmingham (AL), ... Ozone 1 Complete names for all these metropolitan areas can be found in the tables showing the ...

212

Ozone Pollution  

Medline Plus

Full Text Available ... 10 people in the United States (44.8%) live in areas with unhealthful levels of ozone. What ... Health Risks . More than 140.5 million people live in the 296 counties that received an F ...

213

Ozone Pollution  

Medline Plus

Full Text Available ... Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect Yourself Our Fight What We Do Our Story Personal Stories Clean Air Timeline Take Action Press ...

214

Ozone as an ecotoxicological problem  

Energy Technology Data Exchange (ETDEWEB)

Ozone is quantitatively the dominating oxidant in photochemical air pollution. Other compounds like hydrogen peroxide, aldehydes, formate, peroxyacetyl nitrate (PAN) and nitrogen dioxide are present too, and several of these are known to be phytotoxic, but under Danish conditions the concentration of these gases are without significance for direct effects on vegetation. Therefore, it is the effects of ozone on plant growth that will be described below. (EG) 65 refs.

Mortensen, L. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark)

1996-11-01

215

Ozone and increased nitrogen supply effects on the yield and nutritive quality of Trifolium subterraneum  

Science.gov (United States)

The influence of ambient ozone (O 3) concentrations and nitrogen (N) fertilization, singly and in combination, on the growth and nutritive quality of Trifolium subterraneum was assessed. This is an important O 3-sensitive species of great pastoral value in Mediterranean areas. Plant material was enclosed in open-top chambers (OTCs). Three O 3 levels were established: Filtered air with O 3 concentrations below 15 ppb (CFA), non-filtered air with O 3 concentrations in the range of ambient levels (NFA), and non-filtered air supplemented with 40 ppb O 3 over ambient levels (NFA+). Similarly, three N levels were defined: 5, 15 and 30 kg ha -1. The increase in O 3 exposure induced a reduction of the clover aerial green biomass and an increase of senescent biomass. Ozone effects were more adverse in the root system, inducing an impairment of the aerial/subterranean biomass ratio. Compared with the CFA treatment, nutritive quality of aerial biomass was 10 and 20% lower for NFA and NFA+ treatments, respectively, due to increased concentrations of acid detergent fiber, neutral detergent fiber and lignin. The latter effect appears to be related to senescence acceleration. The increment in N supplementation enhanced the increase of ADF concentrations in those plants simultaneously exposed to ambient and above-ambient O 3 concentrations, and reduced the incremental rate of foliar senescence induced by the pollutant.

Sanz, J.; Muntifering, R. B.; Bermejo, V.; Gimeno, B. S.; Elvira, S.

216

Growth at elevated ozone or elevated carbon dioxide concentration alters antioxidant capacity and response to acute oxidative stress in soybean (Glycine max)  

Energy Technology Data Exchange (ETDEWEB)

Soybeans (Glycine max Merr.) were grown at elevated carbon dioxide concentration ([CO{sub 2}]) or chronic elevated ozone concentration ([O{sub 3}]; 90 ppb), and then exposed to an acute O{sub 3} stress (200 ppb for 4 h) in order to test the hypothesis that the atmospheric environment alters the total antioxidant capacity of plants, and their capacity to respond to an acute oxidative stress. Total antioxidant metabolism, antioxidant enzyme activity, and antioxidant transcript abundance were characterized before, immediately after, and during recovery from the acute O{sub 3} treatment. Growth at chronic elevated [O{sub 3}] increased the total antioxidant capacity of plants, while growth at elevated [CO{sub 2}] decreased the total antioxidant capacity. Changes in total antioxidant capacity were matched by changes in ascorbate content, but not phenolic content. The growth environment significantly altered the pattern of antioxidant transcript and enzyme response to the acute O{sub 3} stress. Following the acute oxidative stress, there was an immediate transcriptional reprogramming that allowed for maintained or increased antioxidant enzyme activities in plants grown at elevated [O{sub 3}]. Growth at elevated [CO{sub 2}] appeared to increase the response of antioxidant enzymes to acute oxidative stress, but dampened and delayed the transcriptional response. These results provide evidence that the growth environment alters the antioxidant system, the immediate response to an acute oxidative stress, and the timing over which plants return to initial antioxidant levels. The results also indicate that future elevated [CO{sub 2}] and [O{sub 3}] will differentially affect the antioxidant system.

Gillespie, K.M.; Rogers, A.; Ainsworth, E. A.

2011-01-31

217

Seasonal differences and within-canopy variations of antioxidants in mature spruce (Picea abies) trees under elevated ozone in a free-air exposure system  

International Nuclear Information System (INIS)

The effect of free-air ozone fumigation and crown position on antioxidants were determined in old-growth spruce (Picea abies) trees in the seasonal course of two consecutive years (2003 and 2004). Levels of total ascorbate and its redox state in the apoplastic washing fluid (AWF) were increased under double ambient ozone concentrations (2 x O3), whilst ascorbate concentrations in needle extracts were unchanged. Concentrations of apoplastic and symplastic ascorbate were significantly higher in 2003 compared to 2004 indicating a combined effect of the drought conditions in 2003 with enhanced ozone exposure. Elevated ozone had only weak effects on total glutathione levels in needle extracts, phloem exudates and xylem saps. Total and oxidised glutathione concentrations were higher in 2004 compared to 2003 and seemed to be more affected by enhanced ozone influx in the more humid year 2004 compared to the combined effect of elevated ozone and drought in 2003 as observed for ascorbate. - Antioxidant defence in sun and shade needles of Picea abies under free-air ozone fumigation in the seasonal course of two consecutive years

218

Intraspecific variation in sensitivity to ambient ultraviolet-B radiation in growth and yield characteristics of eight soybean cultivars grown under field conditions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The present study was conducted with eight cultivars of soybean (Glycine max) to determine the effect of exclusion of solar UV-B on the vegetative growth (plant height, leaf area, no. of nodes), UV absorbing compounds (implicated in UV protection) and crop yield (No. of pods and seed weight) and to [...] determine the cultivar difference in their sensitivity to ambient UV-B. Exclusion of solar UV-B enhanced the vegetative growth and yield of all the soybean cultivars. The results showed a significant inverse association between the enhancement in vegetative growth and number of pods among the cultivars tested, indicating differences in the carbon partitioning amongst the cultivars by the way of exclusion of solar UV-B. NRC-7, Pusa-24 and JS-335 showed maximum promotion in vegetative growth and less enhancement in crop yield after solar UV-B exclusion. Kalitur, JS71-05, Hardee, PK-472 and PK-1029 showed improved performance both in terms of number of pods/plant and seed weight after solar UV-B exclusion. An enhancement in the crop yield by exclusion of solar UV-B indicated poor response of the cultivar to the ambient solar UV-B; these cultivars would be more suitable at latitudes, which received less UV-B. According to UV-SI, sensitivity of eight Indian soybean cultivars to ambient level of UV-B (280-320 nm) radiation had the following descending order; PK-472 > JS-335 > Hardee > Kalitur > JS71-05 > Pusa-24 > NRC-7 > PK-1029. These findings suggest the way to select the best-suited cultivar for particular latitude.

Sanjay S., Baroniya; Sunita, Kataria; G.P., Pandey; Kadur N., Guruprasad.

219

Intraspecific variation in sensitivity to ambient ultraviolet-B radiation in growth and yield characteristics of eight soybean cultivars grown under field conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted with eight cultivars of soybean (Glycine max to determine the effect of exclusion of solar UV-B on the vegetative growth (plant height, leaf area, no. of nodes, UV absorbing compounds (implicated in UV protection and crop yield (No. of pods and seed weight and to determine the cultivar difference in their sensitivity to ambient UV-B. Exclusion of solar UV-B enhanced the vegetative growth and yield of all the soybean cultivars. The results showed a significant inverse association between the enhancement in vegetative growth and number of pods among the cultivars tested, indicating differences in the carbon partitioning amongst the cultivars by the way of exclusion of solar UV-B. NRC-7, Pusa-24 and JS-335 showed maximum promotion in vegetative growth and less enhancement in crop yield after solar UV-B exclusion. Kalitur, JS71-05, Hardee, PK-472 and PK-1029 showed improved performance both in terms of number of pods/plant and seed weight after solar UV-B exclusion. An enhancement in the crop yield by exclusion of solar UV-B indicated poor response of the cultivar to the ambient solar UV-B; these cultivars would be more suitable at latitudes, which received less UV-B. According to UV-SI, sensitivity of eight Indian soybean cultivars to ambient level of UV-B (280-320 nm radiation had the following descending order; PK-472 > JS-335 > Hardee > Kalitur > JS71-05 > Pusa-24 > NRC-7 > PK-1029. These findings suggest the way to select the best-suited cultivar for particular latitude.

Sanjay S. Baroniya

2011-01-01

220

Effects of ozone on crops in north-west Pakistan  

International Nuclear Information System (INIS)

Although ozone is well-documented to reduce crop yields in the densely populated Indo-Gangetic Plain, there is little knowledge of its effects in other parts of south Asia. We surveyed crops close to the city of Peshawar, in north-west Pakistan, for visible injury, linking this to passive measurements of ozone concentrations. Foliar injury was found on potato, onion and cotton when mean monthly ozone concentrations exceeded 45 ppb. The symptoms on onion were reproduced in ozone fumigation experiments, which also showed that daytime ozone concentrations of 60 ppb significantly reduce the growth of a major Pakistani onion variety. Aphid infestation on spinach was also reduced at these elevated ozone concentrations. The ozone concentrations measured in April–May in Peshawar, and used in the fumigation experiment, are comparable to those that have been modelled to occur over many parts of south Asia, where ozone may be a significant threat to sensitive crops. -- Highlights: ? Visible ozone injury to onion, cotton and potato was identified in north-west Pakistan. ? The symptoms on onion were reproduced by exposure to elevated ozone. ? Elevated ozone levels also significantly reduced onion growth. ? Levels of aphid infestation on spinach were lower under elevated ozone. ? These effects were observed at ozone levels that have been modelled to occur widely across south Asia. -- Ozone concentrations in NW Pakistan have adverse effects on sensitive crop species

 
 
 
 
221

Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains  

DEFF Research Database (Denmark)

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 268C), one (HC; 168C to 268C) or no (CC; 168C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Nielsen, Birte LindstrØm

2012-01-01

222

Influence of ozone on induced resistance in soybean to the Mexican bean beetle (Coleoptera: Coccinellidae)  

Energy Technology Data Exchange (ETDEWEB)

The influence of ozone (O{sub 3}) on induced resistance in soybean, Glycine max (L.) Merr., cv. Williams 82, was investigated. Feeding by larval soybean looper, Pseudoplusia includens (Walker), was used to induce resistance, and the feeding preference of the Mexican bean beetle, Epilachna varivetis Mulsant, was used to indicate induced resistance. Greenhouse grown soybean plants at the V9 growth stage (eight open trifoliolates) were used in all experiments. One day following feeding injury by the soybean looper, the injured plants and the uninjured controls were exposed to three concentrations of ozone in transparent mylar chambers; level in ambient air (about 0.025 ppm), 0.06 ppm, or 0.1 ppm. Plants were exposed for 5 h a day for a period of 2-4 d. Ozone exposure at the levels used in this study produced no visible injuries to leaves. Low doses (up to 4-d-exposure to 0.06 ppm or 2-d exposure to 0.1 ppm) of ozone overrode the resistance in soybean that had been induced by the feeding of soybean looper larvae. Higher doses (3- or 4-d exposure to 0.1 ppm) of ozone actually resulted in a greater acceptability by the Mexican bean beetle of plants injured by the soybean looper than of uninjured plants. Doses of ozone used in these experiments did not significantly alter the feeding preference of the Mexican bean beetle for the uninjured plants. Because ozone pollution and herbivore injury are commonly experienced by plants in nature, the results of this study add another perspective to insect-plant interactions.

Lin, Hengchen; Kogan, M. (Univ. of Illinois, Champaign (USA)); Endress, A.G. (Illinois Natural History Survey, Champaign, IL (USA))

1990-08-01

223

40 CFR 52.726 - Control strategy: Ozone.  

Science.gov (United States)

...Illinois' ozone plan, and they remain...as part of the program conduct inspections...Year Inspection Program Plan. (g) Approval...the photochemical assessment ambient monitoring...Illinois State Implementation Plan. This...

2010-07-01

224

Ozone matters  

International Nuclear Information System (INIS)

Starting out with a critical look at the political aspects of sustainability programmes in the United Kingdom - with a particular emphasis on the 'spin' put on the topic by politicians - this editorial article discusses the problem of summer ozone pollution in urban and countryside areas. The measures - such as catalytic converters on cars - already being taken in part to reduce the emission of pollutants from which the ozone is formed are reviewed. The influence of climatic effects are also discussed. The author calls for increased efforts in reducing levels of air pollution and discusses those that are considered the most important

225

No alarming ozone loss from stratospheric water vapor  

Science.gov (United States)

At sufficiently low temperatures, water vapor in the lowermost stratosphere can cause ambient sulfate aerosol to grow, providing surfaces on which chlorine can activate to a form that destroys ozone. Ozone depletion in the stratosphere can allow harmful ultraviolet radiation to reach Earth's surface.

Balcerak, Ernie

2013-08-01

226

Ozone depletion zone and ozone smog. Ozone chemistry fundamentals  

International Nuclear Information System (INIS)

This book elucidates the fundamentals of the ozone theory. The knowledge verified through measurements is compiled, and the gaps in the knowledge of ozone are defined. While the knowledge of ozone appears to be well-established the gaps in the knowledge are responsible for uncertainties. Measurement methods for determination of the atmospheric concentration of ozone are described. Details are given about the basic processes of atmospheric ozone formation and ozone depletion and about the role of CFC. The factors which determine ozone concentrations in the southern hemisphere are described first because South Pole ozone formation processes, in spite of their complexity, are not as complex as North Pole ozone formation processes. The differences between these processes in the two polar regions are described. (orig.)

227

Ambient atmosphere bonding of titanium foil to a transparent conductive oxide and anodic growth of titanium dioxide nanotubes  

Energy Technology Data Exchange (ETDEWEB)

Titania nanotubes were fabricated by anodization of titanium foil bonded to fluorine-doped tin oxide-coated glass (FTO) by an adhesion layer of low-melting-temperature metals. The bonding layer characteristics depended on pressure and ambient environment. The bonding composition is similar to lead-free solder and the addition of antimony improved wetting further. This process presents a rapid, low-cost method for obtaining high-quality, anodizable Ti foil on FTO. (author)

Perez-Blanco, Jonathan M. [Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (United States); Barber, Greg D. [Department of Chemistry and Materials Research Institute, Materials Research Institute and Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, PA 16802 (United States)

2008-09-15

228

Ground-level ozone in Alberta  

Energy Technology Data Exchange (ETDEWEB)

Polluting chemicals arising from both human and natural sources such as nitrogen oxides, volatile organic compounds (VOCs), and sulfur oxide interact with the atmosphere to produce further polluting chemical substances such as ozone, nitric acid, sulfuric acid and aerosols, which, affected by factors such as their emission rate, transport and dispersion, chemical alteration and removal rates, produces their particular concentration. For its part, ozone is an important part of the atmosphere, and is present at ground-level. Because its concentration is affected by human and natural factors it has a highly variable concentration which makes determination of the natural background levels difficult. An investigation was carried out with the following objectives: to find out what agencies, industries and associations are building up databanks on ambient ozone and its precursors, nitrogen oxides and VOCs in the province of Alberta; to built up a library of references and reports on these aspects of ozone and related chemical products beginning with the year 1980; based on the literature gathering of this relevant information to summarize it in a literature review; to carry out an analysis considering both the results of the gathered literature, and a comparison between Alberta's ambient level of ozone and both proposed reference levels and Canada-Wide Standards options for ground-level ozone; and to prepare a detailed report on the findings and of their analysis. Cities such as Calgary and Edmonton attract ozone and act as effective sinks because nitric oxide emitted by the cities interacts with ozone, which in turn produces byproduct gases such as peroxyacetyl nitrate, nitric acid and particulate nitrate. There is reliable and internationally recognized literature on ambient ozone concentrations in the province of Alberta. For cities in Alberta the Canadian and Alberta standard of one hour maximum ozone concentrations of 82 ppb has been met with only a few exceptions in recent years and for rural Alberta the ambient ozone concentrations are higher than the city values. This is also true for the 24 hour objective in Alberta.

Sandhu, H.S. [Atmospheric Science and Management Associates, Edmonton, AB (Canada)

1999-04-01

229

Ozone Pollution  

Medline Plus

Full Text Available ... lower income groups are often disproportionately affected by air pollution which put them at higher risk for illnesses. ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

230

Ozone Pollution  

Medline Plus

Full Text Available ... in any metro area will have monitors. FACT: Air pollution hovers at unhealthy levels in almost every major ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

231

Ozone Pollution  

Medline Plus

Full Text Available ... most polluted metropolitan areas—some substantially—in 2010-2012 compared to 2009-2011. Of the 25 metro ... a factor. The warmer summers in 2010 and 2012 contributed to higher ozone readings and more frequent ...

232

Ozone Pollution  

Medline Plus

Full Text Available ... outside face increased risk from the effects of air pollution. Help us Fight For Air! | See more facts » ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

233

Ozone Pollution  

Medline Plus

Full Text Available ... in any metro area will have monitors. FACT: Air pollution is a serious health threat. It sends people ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

234

Ozone Pollution  

Medline Plus

Full Text Available ... groups are especially vulnerable to the effects of air pollution, such as: infants, older adults and people with ... View State Map Compare Your Air Compare Your Air Select Your State Health Risks Ozone Pollution Particle Pollution Children’s Health Disparities & Near Highways Protect ...

235

MOVPE growth of Al {sub x}In{sub 1-x}P using tertiarybutylphosphine in pure N{sub 2} ambient  

Energy Technology Data Exchange (ETDEWEB)

We have investigated metalorganic vapor phase epitaxy (MOVPE) growth of Al {sub x}In{sub 1-x}P alloy using tertiarybutylphosphine (TBP) as the phosphorus source in pure N{sub 2} ambient. The effect of the substrate temperature on the aluminum composition of Al {sub x}In{sub 1-x}P epilayers during the MOVPE growth has been studied. When the source flow rates were kept unchanged, the aluminum composition of the Al {sub x}In{sub 1-x}P epilayer increased monotonically when the substrate temperature, T {sub g}, was raised from 580 deg. C to 660 deg. C during the growth. It became saturated when T {sub g} reached 660 deg. C and above. The crystalline quality of the grown Al {sub x}In{sub 1-x}P epilayers has been investigated by X-ray diffraction and photoluminescence measurements. A linear relationship between the aluminum composition of the Al {sub x}In{sub 1-x}P epilayer and TMAl/(TMAl + TMIn) source flow ratio has been obtained when grown at the optimized growth temperature of T {sub g} = 630 deg. C. It has also been observed that the aluminum incorporation coefficient of Al {sub x}In{sub 1-x}P epilayers decreased when the V/III source flow ratio was increased during the MOVPE growth.

Zhao Jinghua [Photonics Research Center, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Tang Xiaohong [Photonics Research Center, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)]. E-mail: exhtang@ntu.edu.sg; Yin Zongyou [Photonics Research Center, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Sentosa, Deny [Photonics Research Center, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2007-03-26

236

The Antarctic Ozone Hole  

Science.gov (United States)

Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For…

Jones, Anna E.

2008-01-01

237

Issues on urban ozone: Natural hydrocarbons, urbanization and ozone control strategies  

Energy Technology Data Exchange (ETDEWEB)

Using the Atlanta metropolitan area as a case study, the author has examined the effects of urbanization and its associated heat island on urban ozone concentrations. As cities grow, two important effects take place: the amount of trees is reduced and there is an increase in ambient temperature due to the urban heat island effect. As the temperature increases, more ozone is photochemically produced, more anthropogenic hydrocarbons are released into the atmosphere, and more biogenic hydrocarbons are emitted from the remaining trees. This increase in hydrocarbons helps produce even more ozone. Numerical simulations using conditions of a typical summertime day in Atlanta suggest that these processes are able to offset the reductions in anthropogenic hydrocarbon emissions caused by emission controls. To study ozone control strategies, the author has developed a photochemical model that utilizes ozone and ozone precursors observations as input data, and is therefore independent of the highly uncertain processes of emission inventories and transport. In contrast with the operation of the current emission-based models, the observation-based model (OBM) is relatively easy to implement and very fast to operate. Using numerical simulations of different meteorological and chemical conditions in Atlanta, he has shown that the ozone sensitivities obtained with the observation-based model, are in very good agreement with similar ozone sensitivities derived using an emission-based model that includes transport. He also illustrated the potential utility of the OBM by applying it to the ozone non-attainment problem in Baton Rouge, Louisiana.

Cardelino, C.A.

1991-01-01

238

Ozone in the atmosphere : ozone depletion  

Science.gov (United States)

What processes cause a depletion of the ozone layer? This informational page, part of an interactive laboratory series for grades 8-12, explores natural and human-made destruction of the ozone layer. Here students read about the instability of ozone atoms and the naturally changing quantities of ozone in the air. Volcanoes, the oceans, and other natural processes provide chemicals that break down ozone. Chemical equations of the breakdowns are provided. A discussion of the use of chlorofluorocarbons reveals a link to the destruction of the ozone layer. Students view an animation that shows how chlorofluorocarbons break down ozone into oxygen molecules. A summation of the ozone depletion problem discusses the loss of ozone around the South Pole and possible effects on Australia. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

239

Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration  

International Nuclear Information System (INIS)

Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO2]) and elevated ozone concentration ([O3]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO2] and [O3] predicted for ?2050. The responses of two clones were compared during the first month of spring leaf out when CO2 fumigation had begun, but O3 fumigation had not. Trees in elevated [CO2] plots showed a stimulation of leaf area index (36%), while trees in elevated [O3] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO2], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO2]; however, the two clones responded differently to long-term growth at elevated [O3]. The O3-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O3] (-32%), while the tolerant clone, 216, had larger mature leaf area at el, 216, had larger mature leaf area at elevated [O3] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O3], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO2] and suppressed by elevated [O3] in aspen (Populus tremuloides).

240

Growth of ponderosa pine seedlings as affected by air pollution  

Science.gov (United States)

The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

 
 
 
 
241

Assessment of growth and yield losses in two Zea mays L. cultivars (quality protein maize and nonquality protein maize) under projected levels of ozone.  

Science.gov (United States)

Rapid industrialization and economic developments have increased the tropospheric ozone (O3) budget since preindustrial times, and presently, it is supposed to be a major threat to crop productivity. Maize (Zea mays L.), a C4 plant is the third most important staple crop at global level with a great deal of economic importance. The present study was conducted to evaluate the performance of two maize cultivars [HQPM1: quality protein maize (QPM)] and [DHM117: nonquality protein maize (NQPM)] to variable O3 doses. Experimental setup included filtered chambers, nonfiltered chambers (NFC), and two elevated doses of O3 viz. NFC+15 ppb O3 (NFC+15) and NFC+30 ppb O3 (NFC+30). During initial growth period, both QPM and NQPM plants showed hormetic effect that is beneficial due to exposure of low doses of a toxicant (NFC and NFC+15 ppb O3), but at later stages, growth attributes were negatively affected by O3. Growth indices showed the variable pattern of photosynthate translocation under O3 stress. Foliar injury in the form of interveinal chlorosis and reddening of leaves due to increased production of anthocyanin pigments was observed at higher concentrations of O3. One-dimensional gel electrophoresis of leaves taken from NFC+30 showed reductions of major photosynthetic proteins, and differential response was observed between the two test cultivars. Decline in the number of male flowers at elevated O3 doses suggested damaging effect of O3 on reproductive structures which might be a cause of productivity losses. Variable carbon allocation pattern particularly to husk leaves, foliar injury, and damage of photosynthetic proteins led to significant reductions in economic yield at higher O3 doses. PCA showed that both the cultivars responded more or less similarly to O3 stress in their respective groupings of growth and yield parameters, but magnitude of their response was variable. It is further supported by difference in the significance of correlations between variables of yield and AOT40. Cultivar response reflects that QPM performed better than NQPM against elevated O3. PMID:24114383

Singh, Aditya Abha; Agrawal, S B; Shahi, J P; Agrawal, Madhoolika

2014-02-01

242

Ambient Space and Ambient Sensation  

DEFF Research Database (Denmark)

The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness, dehierarchization, ubiquity and the production of unfocused sensations in contrast to the conventional notion of the aesthetic experience as a focused contemplation of a stationary object.

Schmidt, Ulrik

243

Deciduous shrubs for ozone bioindication: Hibiscus syriacus as an example  

Energy Technology Data Exchange (ETDEWEB)

Ozone-like visible injury was detected on Hibiscus syriacus plants used as ornamental hedges. Weekly spray of the antiozonant ethylenediurea (EDU, 300 ppm) confirmed that the injury was induced by ambient ozone. EDU induced a 75% reduction in visible injury. Injury was more severe on the western than on the eastern exposure of the hedge. This factor of variability should be considered in ozone biomonitoring programmes. Seeds were collected and seedlings were artificially exposed to ozone in filtered vs. not-filtered (+30 ppb) Open-Top Chambers. The level of exposure inducing visible injury in the OTC seedlings was lower than that in the ambient-grown hedge. The occurrence of visible injury in the OTC confirmed that the ozone sensitivity was heritable and suggested that symptomatic plants of this deciduous shrub population can be successfully used as ozone bioindicators. EDU is recommended as a simple tool for diagnosing ambient ozone visible injury on field vegetation. - An Italian population of the deciduous shrub Hibiscus syriacus, a common ornamental species in temperate zones, is recommended as ozone bioindicator.

Paoletti, Elena [Institut Plant Protection (IPP), National Council Research (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy)], E-mail: e.paoletti@ipp.cnr.it; Ferrara, Anna Maria [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Calatayud, Vicent; Cervero, Julia [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Giannetti, Fabio [Istituto per le Piante da Legno e l' Ambiente (IPLA), Corso Casale 476, 10132 Turin (Italy); Sanz, Maria Jose [Fundacion C.E.A.M., Charles R. Darwin 14, Parc Tecnologic, 46980 Paterna, Valencia (Spain); Manning, William J. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9320 (United States)

2009-03-15

244

Ozone Pollution  

Medline Plus

Full Text Available ... AirNow National Association of Clean Air Agencies U. S. Environmental Protection Agency sites: Clean School Bus USA Information for Citizens and Communities National Ambient Air Quality Standards Protect the Environment: ...

245

EFFECTS OF INCREASING DOSES OF SULFUR DIOXIDE AND AMBIENT OZONE ON TOMATOES: PLANT GROWTH, LEAF INJURY, ELEMENTAL COMPOSITION, FRUIT YIELDS, AND QUALITY  

Science.gov (United States)

Jet star, an indeterminant tomato cultivar, was exposed to 0.011, 0.059, 0.118, 0.235, and 0.468 ppm SO2 in open-top field chambers supplied with nonfiltered(NF) air and to 0.005, 0.113, and 0.466 ppm SO2 in chambers with charcoal-filtered(CF) air. Treatments were given 5 hr/day,...

246

EFFECT OF 'IN VIVO' OZONE EXPOSURE TO DORSET SHEEP, AN ANIMAL MODEL WITH LOW LEVELS OF ERYTHROCYTE GLUCOSE-6-PHOSPHATE DEHYDROGENASE ACTIVITY  

Science.gov (United States)

Considerable interest has recently been directed to the possible extrapulmonary effects caused by exposure to ambient ozone. Studies have now demonstrated that ozone exposure may result in chromosomal aberrations in circulating lymphocytes of Chinese hamsters, altered drug metabo...

247

Competition modifies effects of enhanced ozone/carbon dioxide concentrations on carbohydrate and biomass accumulation in juvenile Norway spruces and European beech  

International Nuclear Information System (INIS)

Potential interactions of carbon dioxide and ozone on carbohydrate concentrations and contents were studied in Norway spruce and European beech saplings to test the hypotheses that (1) prolonged exposure to elevated carbon dioxide does not compensate for the limiting effects of ozone on the accumulation of sugars and starches, or biomass partitioning to the root; and (2) growth of mixed-species planting will repress plant responses to elevated ozone and carbon dioxide. Norway spruce and European beech saplings were acclimated for one year to ambient and elevated carbon dioxide, followed by exposure to factorial combinations of ambient and elevated ozone and carbon dioxide during the next two years. In spruce trees, sugar and starch content was greater in saplings exposed to elevated carbon dioxide; in beech, the response was the opposite. The overall conclusion was that the results did not support Hypothesis One, because the adverse effects were counteracted by elevated carbon dioxide. Regarding Hypothesis Two, it was found to be supportive for beech but not for spruce. In beech, the reduction of sugars and starch by elevated ozone and stimulation by elevated carbon dioxide were repressed by competitive interaction with spruce, whereas in spruce saplings elevated concentrations of carbon dioxide resulted in higher concentrations of sugar and starch, but only in leaves and coarse roots and only when grown in combination with beech. Elevated ozone in spruce saplings proech. Elevated ozone in spruce saplings produced no significant effect on sugar or starch content either in intra- or interspecific competition. 57 refs., 1 tab., 5 figs

248

Source apportionment of ambient volatile organic compounds in Beijing.  

Science.gov (United States)

The ambient air quality standard for ozone is frequently exceeded in Beijing in summer and autumn. Source apportionments of volatile organic compounds (VOCs), which are precursors of ground-level ozone formation, can be helpful to the further study of tropospheric ozone formation. In this study, ambient concentrations of VOCs were continuously measured with a time resolution of 30 min in August 2005 in Beijing. By using positive matrix factorization (PMF), eight sources for the selected VOC species were extracted. Gasoline-related emissions (the combination of gasoline exhaust and gas vapor), petrochemicals, and liquefied petroleum gas (LPG) contributed 52, 20, and 11%, respectively, to total ambient VOCs. VOC emissions from natural gas (5%), painting (5%), diesel vehicles (3%), and biogenic emissions (2%) were also identified. The gasoline-related, petrochemical, and biogenic sources were estimated to be the major contributors to ozone formation potentials in Beijing. PMID:17626435

Song, Yu; Shao, Min; Liu, Ying; Lu, Sihua; Kuster, William; Goldan, Paul; Xie, Shaodong

2007-06-15

249

Secondary maxima in ozone profiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone profiles from balloon soundings as well as SAGE II ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is related to...

Lemoine, R.

2004-01-01

250

Influence of ozone on cold acclimation in sugar maple seedlings  

Energy Technology Data Exchange (ETDEWEB)

A study was carried out with the aim of determining: a) if exposure to ozone gas induces changes in the key parts of cold acclimation in maple seedlings; and b) if the putative changes effect the process of cold acclimation. Two year old seedlings were exposed to two concentrations of ozone, ambient ozone (low ozone), and threefold ambient ozone concentrations (high ozone) from June to September. During the fall, winter and spring, the seedlings were left outdoors to acclimate to natural winter conditions. The freezing tolerance of stems and root tissues was determined for high ozone and low ozone treated seedlings over the winter period. Concomitant determination of the concentrations of starch, sucrose, raffinose, and stachyose in the sugar maple roots as well as ABA concentration in the xylem sap were carried out to assess the molecular changes associated with the cold acclimation of seedlings in the two treatments. Exposure to high concentrations of ozone did not decrease the freezing tolerance of sugar maple roots and improved the freezing tolerance of the stems in the fall. During the period of cold acclimation, an eightfold increase in sucrose concentration occurred in roots and stems, while starch concentration decreased. In roots, the accumulation of soluble sugars coincided with the period of lowest soil temperature. This showed that temperature has a major influence on the amount of sugar formed and the degree of freezing tolerance. There were no ozone treatment effects on either starch hydrolysis or sucrose accumulation in roots. Sucrose is a membrane and protein stabilizer during winter drying. In roots, the concentrations of the galactose containing oligosaccharides, raffinose and stachyose, were higher in the high ozone treatment than in the low ozone treatment, and stachyose indicated a similar response in stems. There is a relation between the increase in ABA concentration and cold acclimation in the sugar maple. 29 refs., 7 figs.

Bertrand, A. [Agriculture and Agri-Food Canada, Sainte-Foy, PQ (Canada) Research Station; Robitaille, G. [Natural Resources Canada, Ste. Foy, PQ (Canada) Canadian Forest Service; Nadeau, P.; Castonguay, Y. [Agriculture and Agri-Food Canada, Sainte-Foy, PQ (Canada) Research Station

1999-07-01

251

Ozone disintegration kinetics in the reactor for tyres decomposition  

International Nuclear Information System (INIS)

The results of theoretical and experimental research of ozone disintegration kinetics in the chemical reactor which is developed for decomposition of tyres in the ozone-air environment are presented. Analytical expression for dependence of ozone concentration in the reactor from time and from parameters of the task, such as volume speed of ozone-air mixture feed on a reactor input, concentration of ozone on the input to the reactor, volume speed of output of the used mixture, reactor size, and square of its internal surface is obtained. It is shown that at the same speed of ozone-air mixture pro rolling through the reactor, with growth of ozone concentration on the input, value of stationary concentration in the reactor grows, remaining always less than concentration on the input. It is also shown that at the same ozone concentration on the input, with growth of speed of ozone-air mixture pro rolling through the reactor, value of stationary ozone concentration in the reactor also grows, remaining always less than ozone concentration on the input. The ozone disintegration kinetics in the reactor in a wide range of speed of ozone-air mixture pro rolling through the reactor (0.15, 0.30, 0.45, 0.60 m3/hour) and various ozone concentration on the input (5, 10, 15, 20 g/m3) is experimentally studied. It is shown that experimental results with good accuracy coincide with the theoretical. Direct experiment showed the essential influence of the internal surface of the reactor ce of the internal surface of the reactor on the ozone disintegration kinetics.

252

Secondary maxima in ozone profiles  

Directory of Open Access Journals (Sweden)

Full Text Available Ozone profiles from balloon soundings as well as SAGEII ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is connected to ozone variability and trend at Uccle and account for a large part of the total ozone and lower stratospheric ozone variability.

R. Lemoine

2004-01-01

253

Study on variation of lipids during different growth phases of living cyanobacteria using easy ambient sonic-spray ionization mass spectrometry.  

Science.gov (United States)

Lipids are important components of cell membranes and thylakoids in cyanobacteria, and they play vital roles in various biological activities. Real-time tracing of the variation of membrane lipids can provide insights of the physiological status of cyanobacterial cells. In this work, easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was utilized to investigate the changes of acidic lipids in unicellular (Synechocystis 6803, Synechococcus 7002) and filamentous (Anabaena 7120) cyanobacteria during different growth phases. A sqdX mutant with a reduced synthesis of sulfoquinovosyl diacylglycerol (SQDG) was constructed to verify the acquired data of EASI-MS. Principal component analysis (PCA) was performed to compare the acquired data, enabling the discrimination of different species of cyanobacteria in day-to-day analysis. The results showed that the three representative cyanobacteria and their growth status can be easily determined on the basis of the lipids components detected by EASI-MS. Very interestingly, significant decreases of the ratios of SQDG/PG and dramatic changes of the unsaturation level of lipids were observed in different culture times in these cyanobacteria, and these two unique characters can be used describe the aging of cyanobacteria. PMID:24945367

Liu, Yiqun; Zhang, Jialing; Nie, Honggang; Dong, Chunxia; Li, Ze; Zheng, Zhenggao; Bai, Yu; Liu, Huwei; Zhao, Jindong

2014-07-15

254

Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters / Crescimento de Crassostrea gasar cultivada em ambientes marinho e estuarino em águas brasileiras  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi avaliar o crescimento da ostra-do-mangue Crassostrea gasar cultivada em ambiente marinho e estuarino. As ostras foram cultivadas por 11 meses em sistema de espinhel, em dois locais de estudo - São Francisco do Sul e Florianópolis -, em Santa Catarina. A concentração de [...] clorofila-?, a temperatura e a salinidade da água foram registradas semanalmente. As ostras foram medidas mensalmente (tamanho da concha e ganho de peso) para avaliar o crescimento. No final do período de cultivo, os pesos médios de carne úmida, carne seca e concha foram determinados, bem como a distribuição das ostras por classes de tamanho. Seis modelos não lineares (logístico, exponencial, Gompertz, Brody, Richards e Von Bertalanffy) foram ajustados aos dados de crescimento das ostras. As médias finais de tamanho da concha foram maiores em São Francisco do Sul do que em Florianópolis. Além disso, as ostras cultivadas em São Francisco do Sul apresentaram distribuição mais uniforme nas classes de tamanho do que aquelas cultivadas em Florianópolis. Os maiores valores médios de peso de carne úmida e peso de concha foram observados em São Francisco do Sul, enquanto o peso da carne seca não diferiu entre os locais. O ambiente estuarino é mais promissor para o cultivo de ostras. Abstract in english The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites - São Francisco do Sul and Florianópolis -, in the state of Santa Catarina, Southe [...] rn Brazil. Water chlorophyll-? concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy) were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters.

Gustavo Ruschel, Lopes; Carlos Henrique Araujo de Miranda, Gomes; Cláudio Rudolfo, Tureck; Claudio Manuel Rodrigues de, Melo.

255

The crustal structure in north Tibet revealed by joint inversion of receiver functions and ambient noise tomography: implications for the growth of the Tibetan Plateau  

Science.gov (United States)

Northern Tibet is bounded by the Kunlun Fault in the north with the East Kunlun-Qaidam block. The conjunction region is at a nascent stage of plateau growth resulting from the collision between Indian and Eurasian plate starting ~50 million years ago, which is one of best areas to study the growth mechanism of the Tibetan Plateau. In this study, by investigating the crustal structure, we aim to address two questions: (1) whether the Tibetan plateau is growing northward and (2) if so, what is the growth mechanism, crustal shortening or channel flow. To construct the crustal velocity structures in northern Tibet and its surrounding regions, we analyze continuous ambient noise data collected from several seismic arrays, including the Northeast Tibet Seismic Experiment (NETS), A Seismic Collaborative Experiment in Northeastern Tibet (ASCENT) and Chinese provincial networks operating during 2007 and 2010, totaling ~280 stations and ~33 000 inter-station paths, and then generate Rayleigh phase velocity maps at 10-60 sec periods using ambient noise tomography. We also obtain receiver functions for each station from teleseismic events. A 3-D Vsv model is constructed from joint inversion of receiver functions and surface wave dispersion curves using a Bayesian Monte Carlo method. The large number of stations and high dense of ray path coverage adopted in our study results in a model with a lateral resolution reaching 50-100 km, which helps to reveal the detailed distribution of mid-crustal low velocity zones (LVZs). Our 3D model reveals strong LVZs at the middle crust between 20 and 40 km across northern Tibet with broad features similar to previous ambient noise tomography but with more details showing significant west-east variations of LVZs along the Kunlun Fault. In the west part, LVZs are confined to regions of the Kunlun Fault and the eastern Kunlun Mountain but do not appear beneath the Qaidam Basin; while in the east part beyond the east boundary of the Qaidam Basin, LVZs are observed to extend and penetrate northward into the East Kunlun and Qinling Orogens over ~100 km beyond the Kunlun Fault. The strong contrast of the distribution of LVZs in the west and east parts of the study region mainly results from the distinct tectonic units neighboring northern Tibet with a strong crust of the Qaidam Basin in the west blocking the penetration of LVZs but a probably weak crust in the Qinling Mountains allowing the flow of LVZs. Comparable mid-crustal LVZs are also observed in the northwest Qilian Orogen. There is no obvious connection between the LVZs beneath the Qilian Orogen and those in northern Tibet, which probably suggests different generation mechanisms and sources for LVZs. The distribution and extent of LVZs in our model provide new constraints in understanding and distinguishing the existing models of the Tibetan growth.

Jiang, C.; Yang, Y.; Zheng, Y.

2013-12-01

256

Enxertia, produção e qualidade de tomateiros cultivados em ambiente protegido / Grafting, production and quality of tomato growth in protected environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com o objetivo de verificar os efeitos da enxertia na produção e qualidade de tomateiros cultivados em ambiente protegido, conduziu-se um experimento em Viçosa, Minas Gerais (MG). Seis tratamentos foram avaliados no delineamento em blocos casualizados, com três repetições, resultantes da combinação [...] de duas cultivares de tomate 'Débora' e 'Sta. Clara', enxertadas sobre os porta-enxertos 'Anchor T' e 'BGH 3472', além das duas cultivares de pés francos. A enxertia foi realizada por encostia. Os tratamentos enxertados com 'BGH 3472' e os pés francos Débora e Sta. Clara apresentaram as maiores produtividades comerciais. Não houve variação no teor de SST dos frutos, e o pH da polpa dos frutos foi menor nas combinações 'Anchor T'/Sta. Clara e 'BGH 3472'/Débora. Observou-se maior ATT nos frutos de Débora e menor nos frutos de Sta. Clara. A relação SST/ATT foi maior nos frutos da combinação 'Anchor T'/Sta. Clara, comparados aos frutos das combinações 'BGH 3472'/Débora e 'Anchor T'/Débora. Abstract in english In order to check the effects of grafting in the production and quality of tomato grown in unheated greenhouse, an experiment was conducted in Viçosa, Minas Gerais State, Brazil. Six treatments were evaluated in randomized block design with three replications, resulting from the combination of two t [...] omato cultivars Débora and Sta. Clara, grafted on two rootstocks 'Anchor T' and 'BGH 3472' in addition of the two ungrafted cultivars. The grafting method utilized was used. The treatments with the rootstock 'BGH 3472' and the cultivars 'Débora' and 'Sta. Clara' presented greatest commercial yields. There was no change in the content of SST. Fruit pH was smaller at the combinations 'Anchor T'/Sta.Clara and 'BGH 3472'/Débora Clara. It was observed greater ATT in the pulp of the fruits of Débora and smaller in the fruits of Sta. Clara. SST/ATT ratio was greater in fruits of the combination 'Anchor T'/Sta.Clara when compared with the fruits of the combinations between BGH 3472/Débora and BGH and 'Anchor T'/Débora.

Rodolfo Araujo, Loos; Fabiano Ricardo Brunele, Caliman; Derly José Henriques da, Silva.

257

Enxertia, produção e qualidade de tomateiros cultivados em ambiente protegido Grafting, production and quality of tomato growth in protected environment  

Directory of Open Access Journals (Sweden)

Full Text Available Com o objetivo de verificar os efeitos da enxertia na produção e qualidade de tomateiros cultivados em ambiente protegido, conduziu-se um experimento em Viçosa, Minas Gerais (MG. Seis tratamentos foram avaliados no delineamento em blocos casualizados, com três repetições, resultantes da combinação de duas cultivares de tomate 'Débora' e 'Sta. Clara', enxertadas sobre os porta-enxertos 'Anchor T' e 'BGH 3472', além das duas cultivares de pés francos. A enxertia foi realizada por encostia. Os tratamentos enxertados com 'BGH 3472' e os pés francos Débora e Sta. Clara apresentaram as maiores produtividades comerciais. Não houve variação no teor de SST dos frutos, e o pH da polpa dos frutos foi menor nas combinações 'Anchor T'/Sta. Clara e 'BGH 3472'/Débora. Observou-se maior ATT nos frutos de Débora e menor nos frutos de Sta. Clara. A relação SST/ATT foi maior nos frutos da combinação 'Anchor T'/Sta. Clara, comparados aos frutos das combinações 'BGH 3472'/Débora e 'Anchor T'/Débora.In order to check the effects of grafting in the production and quality of tomato grown in unheated greenhouse, an experiment was conducted in Viçosa, Minas Gerais State, Brazil. Six treatments were evaluated in randomized block design with three replications, resulting from the combination of two tomato cultivars Débora and Sta. Clara, grafted on two rootstocks 'Anchor T' and 'BGH 3472' in addition of the two ungrafted cultivars. The grafting method utilized was used. The treatments with the rootstock 'BGH 3472' and the cultivars 'Débora' and 'Sta. Clara' presented greatest commercial yields. There was no change in the content of SST. Fruit pH was smaller at the combinations 'Anchor T'/Sta.Clara and 'BGH 3472'/Débora Clara. It was observed greater ATT in the pulp of the fruits of Débora and smaller in the fruits of Sta. Clara. SST/ATT ratio was greater in fruits of the combination 'Anchor T'/Sta.Clara when compared with the fruits of the combinations between BGH 3472/Débora and BGH and 'Anchor T'/Débora.

Rodolfo Araujo Loos

2009-02-01

258

Effects of ambient background gases on YBCO plume propagation under film growth conditions: Spectroscopic, ion probe, and fast photographic studies  

International Nuclear Information System (INIS)

The formation, composition, and propagation of KrF laser-produced plasmas from Y1Ba2Cu3O7-x have been studied with emphasis on topics relevant to film growth by pulsed-laser deposition. Spatially and temporally resolved, high-resolution optical absorption and emission spectroscopy, fast ion probes, and fast photography [obtained with a gated, image-intensified CCD array detector (ICCD)] are employed to investigate both emitting and non-emitting species in the laser plume as well as the overall shape and propagation of the laser plasma in background gases of oxygen and xenon. Transient optical absorption spectroscopy is applied to study the composition of the plume of ejected material from the dense layer near the target surface to distances of several centimeters. Optical absorption persists long after the decay of plasma fluorescence, indicating a slower component to plume transport. The absorption of YO formed by YBCO ablation in vacuum and by-yttrium ablation in oxygen is presented. Fast electric ion probes are utilized to measure velocities and total collected charge of the positive ions in the expanding YBCO laser plasma from near-threshold, vacuum conditions into the high fluence, background gas conditions utilized for thin-film growth. The exponential attenuation of the positive ion flux transmitted through 50--300 mTorr background oxygen is measured and used to define an attenuation coefficient. The showing of the laser plasma and formation of shock structures due to gas collisions is studied by ion probe measurements and fast ICCD photography. A comparison between shock wave propagation and drag models is presented to describe the arrival time and shape of the ion probe current waveform with distance. 11 refs, 11 figs

259

Ozone mass transfer and kinetics experiments  

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted at the Hanford Site to determine the most efficient pH and temperature levels for the destruction of complexants in Hanford high-level defense waste. These complexants enhance migration of radionuclides in the soil and inhibit the growth of crystals in the evaporator-crystallizer. Ozone mass transfer and kinetics tests have been outlined for the determination of critical mass transfer and kinetics parameters of the ozone-complexant reaction.

Bollyky, L.J.; Beary, M.M.

1981-12-01

260

Utilization of ammonium as a nitrogen source: effects of ambient acidity on growth and nitrogen accumulation by soybean  

Science.gov (United States)

Dry matter accumulation of plants utilizing NH4+ as the sole nitrogen source generally is less than that of plants receiving NO3- unless acidity of the root-zone is controlled at a pH of about 6.0. To test the hypothesis that the reduction in growth is a consequence of nitrogen stress within the plant in response to effects of increased acidity during uptake of NH4+ by roots, nonnodulated soybean plants (Glycine max [L.] Merr. cv Ransom) were grown for 24 days in flowing nutrient culture containing 1.0 millimolar NH4+ as the nitrogen source. Acidities of the culture solutions were controlled at pH 6.1, 5.1, and 4.1 +/- 0.1 by automatic additions of 0.01 N H2SO4 or Ca(OH)2. Plants were sampled at intervals of 3 to 4 days for determination of dry matter and nitrogen accumulation. Rates of NH4+ uptake per gram root dry weight were calculated from these data. Net CO2 exchange rates per unit leaf area were measured on attached leaves by infrared gas analysis. When acidity of the culture solution was increased from pH 6.1 to 5.1, dry matter and nitrogen accumulation were reduced by about 40% within 14 days. Net CO2 exchange rates per unit leaf area, however, were not affected, and the decreased growth was associated with a reduction in rates of appearance and expansion of new leaves. The uptake rates of NH4+ per gram root were about 25% lower throughout the 24 days at pH 5.1 than at 6.1. A further increase in solution acidity from pH 5.1 to 4.1 resulted in cessation of net dry matter production and appearance of new leaves within 10 days. Net CO2 exchange rates per unit leaf area declined rapidly until all viable leaves had abscised by 18 days. Uptake rates of NH4+, which were initially about 50% lower at pH 4.1 than at 6.1 continued to decline with time of exposure until net uptake ceased at 10 days. Since these responses also are characteristic of the sequence of responses that occur during onset and progression of a nitrogen stress, they corroborate our hypothesis.

Tolley-Henry, L.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

1986-01-01

 
 
 
 
261

Ambient has Become Strained. Identification of Acacia dealbata Link Volatiles Interfering with Germination and Early Growth of Native Species.  

Science.gov (United States)

Acacia dealbata Link is a widespread invader in Mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. Due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (VOCs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives Trifolium subterraneum, Lolium multiflorum, Medicago sativa, and also on its own seeds. We reported that VOCs from flowers significantly reduced germination in L. multiflorum and A. dealbata; moreover, root length, stem length, aboveground and belowground biomass were also reduced in all species studied. Volatile organic compounds from flowers and the mixture also increased significantly malondialdehyde content in T. subterraneum and L. multiflorum. The effects of VOCs on antioxidant enzymatic activities were species dependent. Flowers enhanced peroxidase but decreased superoxide dismutase activity in T. subterraneum. In contrast, VOCs released from leaves increased the activity of superoxide dismutase in L. multiflorum. GC/MS analyses revealed 27 VOCs in the volatile fraction from flowers, 12 of which were exclusive to this fraction. Within them, heptadecadiene, n-nonadecane, n-tricosane, and octadecene represent 62 % of the fraction. We present evidence that the VOCs released from A. dealbata flowers strongly inhibited germination and seedling growth of selected species, and mainly on its own seedlings. As far as we know, this is the first evidence of phytotoxicity induced by VOCs in invasive species belonging to the Acacia genus. PMID:25260655

Souza-Alonso, Pablo; González, Luís; Cavaleiro, Carlos

2014-09-01

262

Dinâmica do crescimento, distribuição de matéria seca e produção de pimentão em ambiente protegido / Growth dynamic, dry matter distribution and sweet pepper yield in unheated greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Caracterizou-se o crescimento, a partição de matéria seca e a produção de pimentão, híbrido Elisa, em ambiente protegido. O experimento foi delineado em blocos casualizados com seis repetições e 16 tratamentos, de março a dezembro, durante 224 dias a partir do transplante (DAT). As mudas foram trans [...] plantadas em 27/04, no espaçamento de 1,0 x 0,6 m. Cada tratamento correspondeu a uma época de amostragem, realizada a cada 14 DAT. Em cada amostragem, foram avaliadas as características relacionadas ao crescimento da planta e a produção de frutos maduros. A massa seca na parte aérea atingiu o máximo de 368 g planta-1, aos 224 DAT. As produções de matéria seca do fruto, caule e folhas aumentaram ao longo do tempo atingindo os valores máximos de 189, 79 e 109 g planta-1 aos 224 DAT, respectivamente. Da mesma forma aconteceu com a área foliar por planta, altura da planta e a taxa de crescimento absoluto, cujos valores máximos foram 9056 cm², 91 cm e 4,11 g m-2 dia-1, respectivamente. Conclui-se que o crescimento da planta foi contínuo ao longo do ciclo sendo que os frutos acumularam a maior quantidade de matéria seca. A produção total de frutos maduros foi 51.960 kg ha-1 ou 232 kg ha-1 dia-1 de permanência da cultura no ambiente protegido. Os frutos comerciais corresponderam a 92,8% da produção total. Abstract in english The nutrient uptake, the partitioning of dry matter and sweet pepper fruit yield were characterized under unheated greenhouse conditions. The experiment was carried out from March to December, and the randomized block design was used with 6 replicates and 16 treatments. Seedlings of Elisa cv. were t [...] ransplanted to the field in 1 x 0.6 m spacing on April, 27th. Each treatment corresponded to a sampling time accomplished every 14 days from transplanting. At 224 days after transplanting (DAT) to the plastic house, the pepper plants presented 91 cm of height with a leaf area of 9056 cm² plant-1 and 189, 79 and 109 g plant-1 of fruit dry matter, stem and leaves, respectively, also presenting an absolute growth rate with maximum value of 4.11 g m-2 day-1. Plant growth was continuous along the plant cycle and fruits accumulated the highest amount of dry matter. Total ripened fruit yield was 51,960 kg ha-1 or 232 kg ha-1 day-1 of crop permanence in the greenhouse. Marketable fruits were represented by 92.8% of the total yield.

Paulo Cezar R., Fontes; Emerson N., Dias; Derly José Henriques da, Silva.

263

Ozone and the Atmosphere  

Science.gov (United States)

This web site, hosted by NASA, discusses the chemical composition and evolution of Earth's atmosphere, focusing on the protective layer of ozone in the stratosphere. The destructive properties of tropospheric ozone are also presented. Diagrams and animation sequences are used to visually depict the delicate structure of the ozone molecule and the chemical reactions involved in its formation and destruction. Ozone destroying pollutants were first identified in 1973. Since that time there has been a considerable amount of controversy surrounding the subject of ozone depletion. More than 20 years of ozone-related scientific studies, international meetings, and global industrial agreements are summarized in the last section of this site.

Center, Distributed A.; Nasa

264

Antarctic ozone depletion  

International Nuclear Information System (INIS)

Antarctic ozone depletion is most severe during the southern hemisphere spring, when the local reduction in the column amount may be as much as 50 percent. The extent to which this ozone poor air contributes to the observed global ozone loss is a matter of debate, but there is some evidence that fragments of the 'ozone hole' can reach lower latitudes following its breakup in summer. Satellite data show the seasonal evolution of the ozone hole. A new dimension has been added to Antarctic ozone depletion with the advent of large volcanic eruptions such as that from Mount Pinatubo in 1991. (author). 5 refs., 1 fig

265

Air pollution by ozone across Europe during summer 2008. Overview of exceedances of EC ozone threshold values for April-September 2008  

Energy Technology Data Exchange (ETDEWEB)

This report provides an evaluation of ground-level ozone pollution in Europe for April-September 2008, based on information submitted to the European Commission under Directive 2002/3/EC on ozone in ambient air. Since Members States have not yet finally validated the submitted data, the conclusions drawn in this report should be considered as preliminary. (au)

2009-07-01

266

The correlation between anticyclone frequency and midlatitude ozone variability  

Science.gov (United States)

Attribution and interpretation of ozone trends and variability requires knowledge of changes in stratospheric dynamics. One method commonly used to deduce the contributions of dynamical effects to ozone variability and trends is to separate ozone data based on sampled air mass type. Here we will analyze ozone distributions in three different air mass types-vortex, anticyclone, and ambient. This represents a significant improvement over previous work that considers only vortex and extra-vortex air masses, but fails to take into account the contribution of anticyclones to the extra-vortex air. This work will determine whether there is a correlation between stratospheric anticyclone frequency and observed ozone interannual variability. Data from EOS-MLS, as well as historical and ongoing data from occultation instruments, will be used in conjunction with simulations from the Whole Atmosphere Community Climate Model (WACCM). Taking advantage of the global sampling by the Aura instruments, we will provide an estimate of the extent to which anticyclones affect overall ozone variability. Global ozone distributions and the inferred dynamical contribution to ozone variability will then be compared to WACCM simulations. This will provide a valuable diagnostic check of both the model chemistry and dynamics. The information gained from the Aura investigation will be applied to analyses of the longer term, but geographically more sparse, occultation data, and to long-term WACCM simulations, to infer dynamical effects on ozone trends.

Harvey, L.; Randall, C. E.; Salawitch, R. J.; Trepte, C. R.

2005-12-01

267

Crescimento e qualidade de mudas de pinhão-manso produzidas em ambiente protegido / Growth and quality of physic nut seedlings produced in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Devido ao recente Programa de Produção de Biocombustíveis do Brasil, o interesse comercial tem crescido em relação à produção de pinhão-manso (Jatropha curcas L.). Informações sobre esta cultura ainda são escassas, o que remete a necessidade de mais pesquisas que possam estabelecer condições de adap [...] tabilidade desta cultura em diferentes condições. Neste contexto, realizou-se um experimento para estudar o crescimento e a qualidade das mudas de pinhão-manso, produzidas em ambiente protegido; as mudas foram monitoradas até o momento de serem transplantadas para o campo. Foi analisada a influência dos tipos e volumes de recipientes, juntamente com diferentes substratos e formas de adubação; o consumo de água também foi analisado durante o experimento. De acordo com os resultados, as melhores taxas de crescimento e qualidade de mudas até a condição de transplantio, foram obtidas com a combinação do substrato comercial, maior tubete e adubo de liberação lenta. Abstract in english There has been an increasing interest in the commercial production of physic nut (Jatropha curcas L.) due to the recent Brazilian Program of Biofuel Production. Information on this crop is still scarce and more research is necessary to set the grounds of crop adaptability in different local conditio [...] ns. An experiment was set up on this issue under greenhouse environment. Growth and quality of physic nut seedlings was monitored up to transplanting time. The influence of types and volumes of seedling containers was analysed along with different substrates and fertilization strategies. The water use was also detailed in the trial. Results showed the best achievements of growth rate and seedling quality, at appropriate transplanting time, were reached from the combination of the commercial substrate, largest containers and fertilizers of slow nutrient liberation.

Janaina, Paulino; Marcos V., Folegatti; Danilton L., Flumignan; Cornélio A., Zolin; Cícero R. A., Barboza Júnior; Sônia M. de S., Piedade.

268

Crescimento e qualidade de mudas de pinhão-manso produzidas em ambiente protegido Growth and quality of physic nut seedlings produced in greenhouse  

Directory of Open Access Journals (Sweden)

Full Text Available Devido ao recente Programa de Produção de Biocombustíveis do Brasil, o interesse comercial tem crescido em relação à produção de pinhão-manso (Jatropha curcas L.. Informações sobre esta cultura ainda são escassas, o que remete a necessidade de mais pesquisas que possam estabelecer condições de adaptabilidade desta cultura em diferentes condições. Neste contexto, realizou-se um experimento para estudar o crescimento e a qualidade das mudas de pinhão-manso, produzidas em ambiente protegido; as mudas foram monitoradas até o momento de serem transplantadas para o campo. Foi analisada a influência dos tipos e volumes de recipientes, juntamente com diferentes substratos e formas de adubação; o consumo de água também foi analisado durante o experimento. De acordo com os resultados, as melhores taxas de crescimento e qualidade de mudas até a condição de transplantio, foram obtidas com a combinação do substrato comercial, maior tubete e adubo de liberação lenta.There has been an increasing interest in the commercial production of physic nut (Jatropha curcas L. due to the recent Brazilian Program of Biofuel Production. Information on this crop is still scarce and more research is necessary to set the grounds of crop adaptability in different local conditions. An experiment was set up on this issue under greenhouse environment. Growth and quality of physic nut seedlings was monitored up to transplanting time. The influence of types and volumes of seedling containers was analysed along with different substrates and fertilization strategies. The water use was also detailed in the trial. Results showed the best achievements of growth rate and seedling quality, at appropriate transplanting time, were reached from the combination of the commercial substrate, largest containers and fertilizers of slow nutrient liberation.

Janaina Paulino

2011-01-01

269

Crescimento e qualidade de mudas de pinhão-manso produzidas em ambiente protegido / Growth and quality of physic nut seedlings produced in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Devido ao recente Programa de Produção de Biocombustíveis do Brasil, o interesse comercial tem crescido em relação à produção de pinhão-manso (Jatropha curcas L.). Informações sobre esta cultura ainda são escassas, o que remete a necessidade de mais pesquisas que possam estabelecer condições de adap [...] tabilidade desta cultura em diferentes condições. Neste contexto, realizou-se um experimento para estudar o crescimento e a qualidade das mudas de pinhão-manso, produzidas em ambiente protegido; as mudas foram monitoradas até o momento de serem transplantadas para o campo. Foi analisada a influência dos tipos e volumes de recipientes, juntamente com diferentes substratos e formas de adubação; o consumo de água também foi analisado durante o experimento. De acordo com os resultados, as melhores taxas de crescimento e qualidade de mudas até a condição de transplantio, foram obtidas com a combinação do substrato comercial, maior tubete e adubo de liberação lenta. Abstract in english There has been an increasing interest in the commercial production of physic nut (Jatropha curcas L.) due to the recent Brazilian Program of Biofuel Production. Information on this crop is still scarce and more research is necessary to set the grounds of crop adaptability in different local conditio [...] ns. An experiment was set up on this issue under greenhouse environment. Growth and quality of physic nut seedlings was monitored up to transplanting time. The influence of types and volumes of seedling containers was analysed along with different substrates and fertilization strategies. The water use was also detailed in the trial. Results showed the best achievements of growth rate and seedling quality, at appropriate transplanting time, were reached from the combination of the commercial substrate, largest containers and fertilizers of slow nutrient liberation.

Janaina, Paulino; Marcos V., Folegatti; Danilton L., Flumignan; Cornélio A., Zolin; Cícero R. A., Barboza Júnior; Sônia M. de S., Piedade.

2011-01-01

270

Ozone and Your Health  

Science.gov (United States)

... and Your Health Particle Pollution Public Health Issues Ozone and Your Health Share Compartir  Breathing in ... can be harmful to your health. How can ozone affect my health? If you have asthma, bronchitis, ...

271

Salud y medio ambiente: Health and environment  

Directory of Open Access Journals (Sweden)

Full Text Available Motivado por la importancia del control del medio ambiente se realiza un panel con los estudiantes de la especialidad de Tecnología de la Salud en el municipio de Matanzas, con el objetivo de fomentar en estos una conciencia ambientalista y de esta forma sensibilizar a los mismos, para ser defensores en la protección del medio ambiente y así elevar el conocimiento en cuanto a materia ambiental. Desde el triunfo revolucionario en 1959, la protección del medio ambiente y el uso racional de los recursos naturales ha sido objetivo estratégico nacional. Y en medio de la difícil situación económica actual, los esfuerzos por encausar la recuperación económica y la protección ambiental con un enfoque integral, constituyen un importante desafío para los cubanos. La contaminación de ríos y arroyos por contaminantes químicos se ha convertido en uno de los problemas ambientales más graves de nuestra sociedad. El ozono es un contaminante que produce afectaciones a la salud. La explotación forestal debe ser realizada sobre la base de garantizar la repoblación. Son diversos los factores que determinan el crecimiento elevado de la población en los países subdesarrollados. La concentración de la población, la industria y el transporte automotor en zonas urbanas ha producido un desequilibrio ecológico con grave afectación a la higiene del ambiente. Cuba, a pesar de ser un país subdesarrollado, el crecimiento económico y la industrialización han llevado aparejadas medidas consecuentes para la protección del ambiente y el desarrollo sostenible. Los riesgos como consecuencia de los fenómenos naturales o provocados por las actividades humanas están íntimamente relacionados con la naturaleza de los mismos. En todos los casos se hacen necesario priorizar los servicios de saneamiento básico esenciales para garantizar la salud de la población .Due to the importance of the environmental control, we carried out a debate with the students of the specialty of Health Technologies in the municipality of Matanzas with the objective of forming an environmental awareness and inducing them to be defenders of the environmental protection, and also raising their knowledge on the environmental matters. Since the triumph of the Cuban revolution in 1959, environmental protection and rational use of the natural resources have been a national strategic objective. Inserted in the current difficult economic situation, the efforts for achieving the economic recuperation and environmental protection through an integral approach are an important challenge for Cubans. Rivers and brooks contamination by chemical substances has become one of the most serious environmental problems in our society. Ozone is a contaminant producing health affections. Forestal exploitation should be carried on the bases of warranting repopulation. Several factors determine a high growth of population in the underdeveloped countries. The concentration of population, industries and auto transport in urban areas has produced an ecological disequilibrium with serious damage of the environmental hygiene. Although Cuba is an underdeveloped country, the economic growth and industrialization have been led together with tenacious measures to protect the environment and a sustainable development. Risks due to natural phenomena or caused by human activity are tightly related with their nature. In all the cases it is necessary to pay an especial attention to the services and measures guarantying the population health.

Jesús Méndez Martínez

2009-10-01

272

Salud y medio ambiente: Health and environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Motivado por la importancia del control del medio ambiente se realiza un panel con los estudiantes de la especialidad de Tecnología de la Salud en el municipio de Matanzas, con el objetivo de fomentar en estos una conciencia ambientalista y de esta forma sensibilizar a los mismos, para ser defensore [...] s en la protección del medio ambiente y así elevar el conocimiento en cuanto a materia ambiental. Desde el triunfo revolucionario en 1959, la protección del medio ambiente y el uso racional de los recursos naturales ha sido objetivo estratégico nacional. Y en medio de la difícil situación económica actual, los esfuerzos por encausar la recuperación económica y la protección ambiental con un enfoque integral, constituyen un importante desafío para los cubanos. La contaminación de ríos y arroyos por contaminantes químicos se ha convertido en uno de los problemas ambientales más graves de nuestra sociedad. El ozono es un contaminante que produce afectaciones a la salud. La explotación forestal debe ser realizada sobre la base de garantizar la repoblación. Son diversos los factores que determinan el crecimiento elevado de la población en los países subdesarrollados. La concentración de la población, la industria y el transporte automotor en zonas urbanas ha producido un desequilibrio ecológico con grave afectación a la higiene del ambiente. Cuba, a pesar de ser un país subdesarrollado, el crecimiento económico y la industrialización han llevado aparejadas medidas consecuentes para la protección del ambiente y el desarrollo sostenible. Los riesgos como consecuencia de los fenómenos naturales o provocados por las actividades humanas están íntimamente relacionados con la naturaleza de los mismos. En todos los casos se hacen necesario priorizar los servicios de saneamiento básico esenciales para garantizar la salud de la población . Abstract in english Due to the importance of the environmental control, we carried out a debate with the students of the specialty of Health Technologies in the municipality of Matanzas with the objective of forming an environmental awareness and inducing them to be defenders of the environmental protection, and also r [...] aising their knowledge on the environmental matters. Since the triumph of the Cuban revolution in 1959, environmental protection and rational use of the natural resources have been a national strategic objective. Inserted in the current difficult economic situation, the efforts for achieving the economic recuperation and environmental protection through an integral approach are an important challenge for Cubans. Rivers and brooks contamination by chemical substances has become one of the most serious environmental problems in our society. Ozone is a contaminant producing health affections. Forestal exploitation should be carried on the bases of warranting repopulation. Several factors determine a high growth of population in the underdeveloped countries. The concentration of population, industries and auto transport in urban areas has produced an ecological disequilibrium with serious damage of the environmental hygiene. Although Cuba is an underdeveloped country, the economic growth and industrialization have been led together with tenacious measures to protect the environment and a sustainable development. Risks due to natural phenomena or caused by human activity are tightly related with their nature. In all the cases it is necessary to pay an especial attention to the services and measures guarantying the population health.

Jesús, Méndez Martínez; Arelis, Alberto Palenzuela; Ernesto, Morales Santana.

273

On the impact of temperature on tropospheric ozone concentration levels in urban environments  

Science.gov (United States)

The influence of temperature on tropospheric ozone (O3) concentrations in urban and photochemically polluted areas in the greater Athens region are investigated in the present study. Hourly values of the ambient air temperature used for studying the urban heat island effect in Athens were recorded at twenty-three experimental stations while ozone concentration values were measured at three of the above-mentioned stations and for a period of two years (1996-1997). The linear correlation between ozone concentration and air temperature values as well as the temporal variation of temperature and ozone concentration, for the above-mentioned experimental stations, were calculated and analysed. Moreover, a neural network approach was used for investigating the impact of temperature on the ozone concentration values over the greater Athens area. The neural network model used ambient air temperature as one of its input parameters and it was found that temperature is a predominant parameter, affecting considerably the ozone concentration values.

Stathopoulou, E.; Mihalakakou, G.; Santamouris, M.; Bagiorgas, H. S.

2008-06-01

274

Long term ozone trends in the Lake Michigan airshed  

Energy Technology Data Exchange (ETDEWEB)

Emissions-related improvements in ambient ozone are difficult to detect, because ozone changes are dominated by short-term variations due to meteorological fluctuations. Rao and Zurbenko (RZ) have developed a statistical filtering method to separate a time-series of ozone air quality data into its short-term, seasonal, and long-term components. The resulting long-term ozone trend has most meteorological influences removed and thus can reasonably be attributed to emissions changes. In this paper, the authors use the RZ method to derive long-term, emissions-related ozone trends from data collected at five ozone monitoring sites near Lake Michigan. They compare trends in peak daily 8-hour averages of ozone to trends in peak daily 1-hour averages, for the period 1980--95. Temperature is employed as a surrogate for all meteorological influences on ozone. Ozone data for these sites are available only for the monitoring period April 15 to October 15 each year. The results indicate that three sites have statistically significant trends, averaging an annual reduction of 1.12% for 8-hour ozone averages. The 1-hour trends for these sites averaged an annual reduction of 1.07%. The two remaining sites indicated a trend in both 1- and 8-hour ozone averages that was either marginal or not statistically significant. These results are comparable with RZ-derived ozone trends for Lake Michigan shoreline sites as calculated by others. However, the available 6-month data sets used here did not allow a complete verification of the RZ method for these sites because plots and correlations could not be compared with its theoretical assumptions which are based on year-round data sets.

Smith, B.E.; Adamski, W.J. [Wisconsin Dept. of Natural Resources, Madison, WI (United States). Bureau of Air Management

1997-12-31

275

OZONE BYPRODUCT FORMATION  

Science.gov (United States)

The use of ozone for water treatment has been increasing as ozone has great potential for degrading water pollutants and inactivating viruses, Giardia cysts, and Cryptosporidium oocysts. Although it appears that ozone generates less undesirable disinfection by-products (DBPs) th...

276

Emergência e crescimento inicial de Tabebuia heptaphylla (Vell.) Toledo em ambientes contrastantes de luz / Emergency and initial growth of Tabebuia heptaphylla (Vell.) Toledo in contrasting light environments  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Tabebuia heptaphylla (Vell.) Toledo, popularmente conhecida como ipê-roxo ou ipê-roxo-desete-folhas, é uma Bignoniaceae nativa da Mata Atlântica, de importância econômica, medicinal e ornamental, além de ser indicada para reflorestamentos. Entretanto, informações ecofisiológicas sobre essa espécie a [...] inda são escassas. Assim, visando dispor de informações que auxiliem na sua propagação e conservação, este trabalho avaliou a emergência e crescimento inicial dessa espécie em regimes contrastantes de luz. Foram realizados dois experimentos independentes. O primeiro em condições controladas, com os tratamentos 70% de sombreamento e a pleno sol; e o segundo em ambiente natural, com os tratamentos clareira e sub-bosque. Entre os parâmetros utilizados para avaliar a emergência sob influência das intensidades luminosas, apenas a porcentagem de emergência diferiu estatisticamente no ambiente natural, sendo superior na clareira. Em condições controladas, houve significância para a velocidade de emergência, sendo maior nas plantas submetidas ao a pleno sol. A espécie apresentou reduzido crescimento inicial no sub-bosque, sendo todos os parâmetros estatisticamente inferiores em relação às plantas da clareira, com exceção da razão de área foliar e área foliar específica. Em condições controladas, os resultados que diferiram significativamente foram todos superiores nas plantas a pleno sol. O estudo evidenciou que a espécie apresenta capacidade de formar plântulas em diferentes regimes de luz, inclusive sob forte sombreamento natural, porém essa condição reduz significativamente seu crescimento inicial, sendo este favorecido por maiores intensidades luminosas. Abstract in english Tabebuia heptaphylla (Vell.) Toledo, known as "ipê-roxo" or" ipê-roxo-de sete-folhas", is a native species of Atlantic Forest, with an economic, medicinal and ornamental role, suitable for reforestation. However, ecophysiological information about it is scarce. In order to provide information about [...] propagation and conservation for this specie, the present study evaluated emergence and early growth of this species in different light exposure. We lead two independent trials. In the first we considered controlled conditions, with two treatments: 70% shade and full sun. The second was developed in a natural environment, with two treatments: gap and understory environments. From the total parameters used to evaluate the emergence of the species under influence of light intensities, only the emergence percentage was statistically different from the natural environment, with high values observed at gap treatment. Significant differences were observed in controlled environment, considering the emergence speed. This variable was higher in plants grown under full sun. Slower initial growth was observed for plants regenerated in the understory, compared to the plants growing in gaps, except for following characteristics: leaf area ration and specific leaf area. In controlled conditions, the results with higher significant differences were observed for plants under full sun. The study shows that the species has the capacity to germinate in different light conditions, even under strong natural shading. However, this condition reduces significantly its initial growth, which is favored by higher light intensities.

Viviane Peixoto, Borges; Maria Angélica Pereira de Carvalho, Costa; Rogério Ferreira, Ribas.

2014-06-01

277

Crescimento e produção do tomateiro cultivado sob condições de campo e de ambiente protegido / Tomato plant growth and fruit yield under field and protected conditions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Foram realizados dois experimentos, na Universidade Federal de Viçosa, objetivando caracterizar o crescimento e a produção de frutos pelo tomateiro cultivado sob condições de campo e de ambiente protegido. O primeiro, com a cultivar Santa Clara, cultivada a campo no sistema de cerca cruzada e sete c [...] achos. O segundo, em estufa plástica, com o híbrido EF-50, conduzidas verticalmente e mantendo-se oito cachos. Ambos os experimentos foram delineados em blocos ao acaso, com quatro repetições. O primeiro constituído por oito e o segundo, por nove tratamentos. Em ambos os experimentos, os frutos acumularam mais matéria seca que os demais órgãos da planta. No primeiro experimento, os valores máximos de matéria seca total e de frutos, altura de planta, taxa de crescimento absoluto (G), taxa crescimento relativo (R), taxa assimilatória líquida (E) e índice de área foliar (L) foram 406,0 g planta-1; 207,0 g planta-1; 146,0 cm; 8.552,0 mg planta-1 dia-1; 87,0 mg g-1 dia-1; 38,0 mg dm-2 dia-1 e 4,1, respectivamente. Em ambiente protegido, os valores máximos daquelas características enumeradas anteriormente foram 398,0 g planta-1; 269,0 g planta-1; 85,0 cm; 5.710,0 mg planta-1 dia-1; 54,0 mg g-1 dia-1; 464,0 mg dm-2 dia-1 e 4,5, respectivamente. A produção total de frutos, no primeiro experimento, foi 94,8 t ha-1; destes, 93% foram classificados como comerciais, equivalente a 738,0 kg ha-1 dia-1. No segundo experimento, a produção total de frutos foi 115,4 t ha-1; destes, 94% foram classificados como comerciais, equivalente a 807,0 kg ha-1 dia-1. Abstract in english Two experiments were conducted at Universidade Federal de Viçosa (Brazil) to evaluate tomato plant growth and fruit yield under field and protected conditions. In the first experiment, tomato cv. Santa Clara was grown in the field and supported with stakes and each with seven clusters. In the second [...] one tomato hybrid EF-50 was grown in plastic greenhouse and plants were vertically trellised and pruned at eight clusters stage. Both experiments were designed as randomized complete blocks, with four replicates. In the first and second experiment eight and nine treatments were evaluated, respectively. In both experiments, the fruits accumulated more dry matter than the other organs of the plant. In the first experiment, the highest values of plant and fruit dry matters, plant height, absolute growth rate (G), relative growth rate (R), net assimilation rate (E), and leaf area index (L) were 406.0 g plant-1; 207.0 g plant-1; 146.0 cm; 8,552.0 mg plant-1 day-1; 87.0 mg g-1 day-1; 38.0 mg dm-2 day-1 and 4.1, respectively. In the second experiment, the highest values for the above characteristics were 398.0 g plant-1; 269.0 g plant-1; 85.0 cm; 5,710.0 mg plant-1 day-1; 54.0 mg g-1 day-1; 464.0 mg dm-2 day-1 and 4.9, respectively. In the first experiment, total fruit yield reached 96.8 t ha-1; 93% of them were classified as marketable, corresponding to 738.0 kg ha-1 day-1 yield. In the second experiment, total yield was 115.4 t ha-1 with 94% of them graded as marketable, corresponding to 807.0 kg ha-1 day-1 yield.

Jamil Abdalla, Fayad; Paulo Cezar Rezende, Fontes; Antônio Américo, Cardoso; Fernando Luiz, Finger; Francisco Affonso, Ferreira.

2001-11-01

278

Crescimento e produção do tomateiro cultivado sob condições de campo e de ambiente protegido Tomato plant growth and fruit yield under field and protected conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Foram realizados dois experimentos, na Universidade Federal de Viçosa, objetivando caracterizar o crescimento e a produção de frutos pelo tomateiro cultivado sob condições de campo e de ambiente protegido. O primeiro, com a cultivar Santa Clara, cultivada a campo no sistema de cerca cruzada e sete cachos. O segundo, em estufa plástica, com o híbrido EF-50, conduzidas verticalmente e mantendo-se oito cachos. Ambos os experimentos foram delineados em blocos ao acaso, com quatro repetições. O primeiro constituído por oito e o segundo, por nove tratamentos. Em ambos os experimentos, os frutos acumularam mais matéria seca que os demais órgãos da planta. No primeiro experimento, os valores máximos de matéria seca total e de frutos, altura de planta, taxa de crescimento absoluto (G, taxa crescimento relativo (R, taxa assimilatória líquida (E e índice de área foliar (L foram 406,0 g planta-1; 207,0 g planta-1; 146,0 cm; 8.552,0 mg planta-1 dia-1; 87,0 mg g-1 dia-1; 38,0 mg dm-2 dia-1 e 4,1, respectivamente. Em ambiente protegido, os valores máximos daquelas características enumeradas anteriormente foram 398,0 g planta-1; 269,0 g planta-1; 85,0 cm; 5.710,0 mg planta-1 dia-1; 54,0 mg g-1 dia-1; 464,0 mg dm-2 dia-1 e 4,5, respectivamente. A produção total de frutos, no primeiro experimento, foi 94,8 t ha-1; destes, 93% foram classificados como comerciais, equivalente a 738,0 kg ha-1 dia-1. No segundo experimento, a produção total de frutos foi 115,4 t ha-1; destes, 94% foram classificados como comerciais, equivalente a 807,0 kg ha-1 dia-1.Two experiments were conducted at Universidade Federal de Viçosa (Brazil to evaluate tomato plant growth and fruit yield under field and protected conditions. In the first experiment, tomato cv. Santa Clara was grown in the field and supported with stakes and each with seven clusters. In the second one tomato hybrid EF-50 was grown in plastic greenhouse and plants were vertically trellised and pruned at eight clusters stage. Both experiments were designed as randomized complete blocks, with four replicates. In the first and second experiment eight and nine treatments were evaluated, respectively. In both experiments, the fruits accumulated more dry matter than the other organs of the plant. In the first experiment, the highest values of plant and fruit dry matters, plant height, absolute growth rate (G, relative growth rate (R, net assimilation rate (E, and leaf area index (L were 406.0 g plant-1; 207.0 g plant-1; 146.0 cm; 8,552.0 mg plant-1 day-1; 87.0 mg g-1 day-1; 38.0 mg dm-2 day-1 and 4.1, respectively. In the second experiment, the highest values for the above characteristics were 398.0 g plant-1; 269.0 g plant-1; 85.0 cm; 5,710.0 mg plant-1 day-1; 54.0 mg g-1 day-1; 464.0 mg dm-2 day-1 and 4.9, respectively. In the first experiment, total fruit yield reached 96.8 t ha-1; 93% of them were classified as marketable, corresponding to 738.0 kg ha-1 day-1 yield. In the second experiment, total yield was 115.4 t ha-1 with 94% of them graded as marketable, corresponding to 807.0 kg ha-1 day-1 yield.

Jamil Abdalla Fayad

2001-11-01

279

Growth analysis of sweet pepper cultivated in coconut fiber in a greenhouse Análise de crescimento de pimentão cultivado em fibra de coco em ambiente protegido  

Directory of Open Access Journals (Sweden)

Full Text Available Knowledge about the growth of crops allows the planning of rational cultivation methods which contribute to achieve greater potential of plant species, besides supplying information for the construction of descriptive mathematical models of growth. The growth curve of sweet pepper (Eppo hybrid, cultivated in coconut fiber in a greenhouse with fertirrigation, was determined. The experiment consisted initially of 160 plants divided into four blocks. Two plants were analyzed per block every 21 days after transplanting, ending at 189 days after transplant. The cultivation was carried out in plastics pots of 13 L containing coconut fiber, which were arranged in double rows, spaced 0.5 x 0.8 m between simple rows and 1.1 m between double rows. In each harvest the plant growth, production and quality of mature fruits were evaluated. The dry mass of the shoot increased with time, following the experimental model exponential of first order, reaching a maximum of 451.5 g/plant, 189 days after transplanting (DAT. The production of dry mass of leaves, stem, root and fruit also increased over time reaching maximum values of 68.7, 65.8, 11.5 and 302.9 g/plant, respectively, at 189 DAT. The same occurred with the leaf area per plant, plant height and the absolute rate of growth, whose maximum values were 6.183,5 cm², 136.9 cm and 4.4 g/plant/day, respectively. The growth of the plant was continuous throughout the cycle, and the highest amount of dry mass was accumulated in fruits, reaching a marketable production of 97.3 t ha-1. All fruits were classified as Extra.O conhecimento sobre o crescimento das culturas permite o planejamento de métodos de cultivo racional, que contribuirá para alcançar um maior potencial de espécies vegetais, além de fornecer informações para a construção de modelos matemáticos descritivos de crescimento. Diante disto, o objetivo deste estudo foi determinar a curva de crescimento do pimentão amarelo (híbrido Eppo cultivado em fibra de coco em ambiente protegido com fertirrigação. O experimento compreendeu inicialmente 160 plantas, divididas em quatro blocos, sendo colhidas duas por bloco a cada 21 dias após o transplante, finalizando-se aos 189 dias após o transplante. O cultivo de pimentão foi feito em vasos plásticos de 13 L contendo fibra de coco, distribuídos em fila dupla, com espaçamento de 0,5 x 0,8 m entre fileiras simples e 1,1 m entre fileiras duplas. Em cada colheita foram avaliados o crescimento das plantas e a produção e qualidade de frutos maduros. A massa seca da parte aérea aumentou com o tempo, seguindo um modelo exponencial de primeira ordem, atingindo um máximo de 451,5 g/planta aos 189 dias após o transplante (DAT. A produção de massa seca de folhas, caule, raiz e frutos também aumentou ao longo do tempo, seguindo o mesmo modelo, atingindo valores máximos de 68.7, 65.8, 11.5 e 302.9 g/planta, respectivamente, aos 189 DAT. O mesmo ocorreu com a área foliar por planta, altura da planta e a taxa de crescimento absoluto, cujos valores máximos foram de 6.183,5 cm², 136.9 cm e 4.4 g/planta/dia, respectivamente. O crescimento das plantas foi contínuo ao longo do ciclo, sendo que a maior quantidade de massa seca foi acumulada nos frutos, cuja produção comercial chegou a 97.3 t ha-1, sendo totalmente classificados como Extra.

Hamilton César de O Charlo

2011-09-01

280

Growth analysis of sweet pepper cultivated in coconut fiber in a greenhouse / Análise de crescimento de pimentão cultivado em fibra de coco em ambiente protegido  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O conhecimento sobre o crescimento das culturas permite o planejamento de métodos de cultivo racional, que contribuirá para alcançar um maior potencial de espécies vegetais, além de fornecer informações para a construção de modelos matemáticos descritivos de crescimento. Diante disto, o objetivo des [...] te estudo foi determinar a curva de crescimento do pimentão amarelo (híbrido Eppo) cultivado em fibra de coco em ambiente protegido com fertirrigação. O experimento compreendeu inicialmente 160 plantas, divididas em quatro blocos, sendo colhidas duas por bloco a cada 21 dias após o transplante, finalizando-se aos 189 dias após o transplante. O cultivo de pimentão foi feito em vasos plásticos de 13 L contendo fibra de coco, distribuídos em fila dupla, com espaçamento de 0,5 x 0,8 m entre fileiras simples e 1,1 m entre fileiras duplas. Em cada colheita foram avaliados o crescimento das plantas e a produção e qualidade de frutos maduros. A massa seca da parte aérea aumentou com o tempo, seguindo um modelo exponencial de primeira ordem, atingindo um máximo de 451,5 g/planta aos 189 dias após o transplante (DAT). A produção de massa seca de folhas, caule, raiz e frutos também aumentou ao longo do tempo, seguindo o mesmo modelo, atingindo valores máximos de 68.7, 65.8, 11.5 e 302.9 g/planta, respectivamente, aos 189 DAT. O mesmo ocorreu com a área foliar por planta, altura da planta e a taxa de crescimento absoluto, cujos valores máximos foram de 6.183,5 cm², 136.9 cm e 4.4 g/planta/dia, respectivamente. O crescimento das plantas foi contínuo ao longo do ciclo, sendo que a maior quantidade de massa seca foi acumulada nos frutos, cuja produção comercial chegou a 97.3 t ha-1, sendo totalmente classificados como Extra. Abstract in english Knowledge about the growth of crops allows the planning of rational cultivation methods which contribute to achieve greater potential of plant species, besides supplying information for the construction of descriptive mathematical models of growth. The growth curve of sweet pepper (Eppo hybrid), cul [...] tivated in coconut fiber in a greenhouse with fertirrigation, was determined. The experiment consisted initially of 160 plants divided into four blocks. Two plants were analyzed per block every 21 days after transplanting, ending at 189 days after transplant. The cultivation was carried out in plastics pots of 13 L containing coconut fiber, which were arranged in double rows, spaced 0.5 x 0.8 m between simple rows and 1.1 m between double rows. In each harvest the plant growth, production and quality of mature fruits were evaluated. The dry mass of the shoot increased with time, following the experimental model exponential of first order, reaching a maximum of 451.5 g/plant, 189 days after transplanting (DAT). The production of dry mass of leaves, stem, root and fruit also increased over time reaching maximum values of 68.7, 65.8, 11.5 and 302.9 g/plant, respectively, at 189 DAT. The same occurred with the leaf area per plant, plant height and the absolute rate of growth, whose maximum values were 6.183,5 cm², 136.9 cm and 4.4 g/plant/day, respectively. The growth of the plant was continuous throughout the cycle, and the highest amount of dry mass was accumulated in fruits, reaching a marketable production of 97.3 t ha-1. All fruits were classified as Extra.

Hamilton César de O, Charlo; Sueyde F de, Oliveira; Renata, Castoldi; Pablo F, Vargas; Leila T, Braz; José Carlos, Barbosa.

2011-09-01

 
 
 
 
281

Physiological and foliar injury responses of Prunus serotina, Fraxinus americana, and Acer rubrum seedlings to varying soil moisture and ozone  

Energy Technology Data Exchange (ETDEWEB)

High soil water availability favors ozone uptake, increases foliar injury, and exacerbates the negative ozone effect on gas exchange of seedlings of deciduous tree species. - Sixteen black cherry (Prunus serotina, Ehrh.), 10 white ash (Fraxinus americana, L.) and 10 red maple (Acer rubrum, L.) 1-year old seedlings were planted per plot in 1997 on a former nursery bed within 12 open-top chambers and six open plots. Seedlings were exposed to three different ozone scenarios (ambient air: 100% O{sub 3}; non-filtered air: 98% ambient O{sub 3}; charcoal-filtered air: 50% ambient O{sub 3}) within each of two different water regimes (nine plots irrigated, nine plots non-irrigated) during three growing seasons. During the 1998 and 1999 growing season, leaf gas exchange, plant water relations, and foliar injury were measured. Climatic data, ambient- and chamber-ozone-concentrations were monitored. We found that seedlings grown under irrigated conditions had similar (in 1998) but significantly higher gas exchange rates (in 1999) than seedlings grown within non-irrigated plots among similar ozone exposures. Cherry and ash had similar ozone uptake but cherry developed more ozone-induced injury (<34% affected leaf area, LAA) than ash (<5% LAA), while maple rarely showed foliar injury, indicating the species differed in ozone sensitivity. Significantly more severe injury on seedlings grown under irrigated conditions than seedlings grown under non-irrigated conditions demonstrated that soil moisture altered seedling responses to ambient ozone exposures.

Schaub, M.; Skelly, J.M.; Steiner, K.C.; Davis, D.D.; Pennypacker, S.P.; Zhang, J.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E

2003-07-01

282

The origin of ozone  

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Full Text Available Highest atmospheric ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson circulation. This is considered the main mechanism to generate mid- and high latitude ozone. By applying the climate-chemistry models E39/C and MAECHAM4/CHEM, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analysed, by incorporating a diagnostics ('marked ozone origin tracers' into the models, which allows to identify the origin of ozone. In most regions the simulated local ozone concentration is dominated by local ozone production, i.e. less than 50% of the ozone at higher latitudes of the stratosphere is produced in the tropics, which conflicts with the idea that the tropics are the global source for stratospheric ozone. Although episodic stratospheric intrusions occur basically everywhere, the main ozone stratosphere-to-troposphere exchange is connected to exchange processes at the sub-tropical jet-stream. The simulated tropospheric influx of ozone amounts to 420 Tg per year, and originates in the Northern Hemisphere from the extra-tropical stratosphere, whereas in the Southern Hemisphere a re-circulation of tropical tropospheric ozone contributes most to the influx of ozone into the troposphere. In the model E39/C, the upper troposphere of both hemispheres is clearly dominated by tropical tropospheric ozone (40%–50% except for northern summer hemisphere, where the tropospheric contribution (from the tropics as well as from the Northern Hemisphere does not exceed 20%.

V. Grewe

2006-01-01

283

Chemical control of ozone damage on watermelon  

Energy Technology Data Exchange (ETDEWEB)

Foliar air pollution damage resulting from ambient ozone was essentially eliminated on watermelon, Citrullus lanatus, with the use of N-(2-(2-oxo-1-imidazolidinyl)ethyl)-N'-phenylurea applied as a combination of soil and foliar applications. Use of this experimental plant protectant resulted in higher yields with Sugar Baby watermelon due to increased melon size and an increase in the number of marketable melons. Sugar content was also significantly increased.

Fieldhouse, D.J.

1978-01-01

284

AIR QUALITY CRITERIA FOR OZONE AND RELATED PHOTOCHEMICAL OXIDANTS VOLUME I OF III (Final, 1996)  

Science.gov (United States)

The U.S. Environmental Protection Agency (EPA) promulgates the National Ambient Air Quality Standards (NAAQS) on the basis of scientific information contained in air quality criteria documents. The previous ozone (O3) criteria document, Air Quality Criteria for Ozone and Other Ph...

285

Manifestation of solar activity processes in the Earth ozone layer  

International Nuclear Information System (INIS)

Statistical analysis of total ozone and its vertical distribution was carried out on the base of data obtained by rocket soundings with the aim to reveal influence of solar activity. THe coherence between monthly mean total ozone data series for six latitudinal zones in the Northern Hemisphere and solar spots has weak but steady maxima for 9 and 13-15 years periods of oscillations. The value of coherence does not exceed 0.15 and growth to the higher latitudes. The analysis of ozone profiles for middle latitudes reveals the decrease in ozone concentration between 30-50 km for winter and increase for autumn. 20 refs.; 3 figs

286

Earth's ozone layer  

International Nuclear Information System (INIS)

The paper contain the actual results of investigations of the influence of the human activity on the Earth's ozone layer. History of the ozone measurements and of the changes in its concentrations within the last few years are given. The influence of the trace gases on both local and global ozone concentrations are discussed. The probable changes of the ozone concentrations are presented on the basis of the modelling investigations. The effect of a decrease in global ozone concentration on human health and on biosphere are also presented. (author). 33 refs, 36 figs, 5 tabs

287

Tropospheric Ozone, the Polluter  

Science.gov (United States)

This site provides a brief overview of ground-level ozone, also known as tropospheric ozone, where it is largely considered a pollutant and is often called bad ozone. It can damage living tissue and break down certain materials and longer exposure will increase the negative effects. Ozone is a naturally occurring gas found in the troposphere and other parts of the atmosphere where its concentrations are not uniform. However, the ozone that is a byproduct of certain human activities does become a problem at ground level and this is what we think of as bad ozone. The site discusses the negative effects of tropospheric ozone and has photographs of the damage to plants caused by it. The site serves as a reference and has links to two student activities.

288

Estrés oxidativo en un modelo de ratón quemado tratado con Aloe b, ozono y factor de crecimiento epidérmico Oxidative stress in a model of burnt mouse treated with Aloe b, ozone and epidermal growth factor  

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Full Text Available La enfermedad por quemadura estimula la respuesta inflamatoria sistémica y el daño múltiple de órganos, su expresión morfológica. Con el propósito de identificar el comportamiento del estrés oxidativo mediante el malondialdehído, la superóxido dismutasa y la catalasa y su modificación con el empleo del tratamiento sistémico con Aloe b, ozono o factor de crecimiento epidérmico, se elaboró un modelo de quemadura seca de un área de 11 %, en ratones hembras, balb/c de 20 ± 2 g (n= 24. Se aplicó eutanasia en diferentes tiempos, se estudiaron los órganos con evaluación cualitativa en grados de intensidad y las variables bioquímicas se obtuvieron del riñón y del hígado. La prueba G se empleó para conocer la dependencia entre las variables y la prueba t se usó al comparar porcentajes. El análisis de varianza bifactorial y la prueba de rango múltiple de Duncan se empleó en las variables del estrés oxidativo estudiadas. Se siguieron las normas éticas en el trabajo con los animales. Existió dependencia entre los diferentes grupos y la vitalidad (G= 268,83*** superior en los grupos tratados. Los grupos no tratados tuvieron mayor intensidad del daño múltiple de órganos y peor respuesta del estrés oxidativo. Los grupos con mejor evolución fueron el tratado con ozono y el tratado con factor de crecimiento epidérmico. El tratamiento inmediatamente después de la quemadura con ozono y factor de crecimiento epidérmico resultó favorable para la evolución y supervivencia de los animales.Burn disease stimulates systemic inflammatory response and its morphologic expression that is multiple organ failure. With the objective of identifying the behaviour of oxidative stress through malonaldehyde, superoxide dismutase, and catalase, and its change by using the systemic treatment based on Aloe b, ozone or epidermal growth factor, a dry burn model of a 11 % area in balb/c female mice of 20 ± 2 g (n= 24 was designed. Eutanasia was applied at different moments, organs were studied with qualitative evaluation of intensity degrees, and biochemical variables were analyzed from the kidney and the liver of mice. Test G served to find out dependence among variables and Test t was used to compare percentages. Bifactoral variance analysis and Duncan´s multiple range test were used in the studied oxidative stress variables. Ethical standards on work with animals were complied with. Dependence was observed among the various groups and survival rate (G= 268,83*** was higher in the treated groups. Untreated groups showed more intensive multiple organ damage and worse oxidative stress response. The groups treated with ozone and epidermal growth factor showed better recovery. The treatment with ozone and epidermal growth factor immediately after burning favored recovery and survival of balb/c mice.

Teresita Montero González

2006-09-01

289

Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes  

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Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based on ozone concentration with others based on ozone flux models.

Gerardo Merola

2007-03-01

290

Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes  

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Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based on ozone concentration with others based on ozone flux models.

Gerardo Merola

2011-02-01

291

Ozone pollution: rising concentrations despite French and EU efforts  

International Nuclear Information System (INIS)

Ozone is the main indicator of photochemical pollution which is caused by a complex combination of primary pollutants formed by chemical reactions in the troposphere, in the presence of sunlight. These primary pollutants, otherwise known as precursors of ozone (nitrogen oxides, volatile organic compounds and carbon monoxide), are emitted both by natural sources and human activities. In urban areas, during the summer months, ozone is often the main cause of deterioration in air quality. Directive 2002/3/EC relating to ozone in ambient air entered into force on 9 September 2003, superseding the first ozone Directive (92/72/CE) of 21 September 1992. In the last 10 years, monitoring of ozone pollution has considerably progressed in France (the number of analysers has increased tenfold). Emissions of the ozone precursors fell significantly (-27%) between 1990 and 2000 in France as a result of combined efforts in all sectors of activity. However, between 1994 and 2002, ozone levels remained above the information threshold for the protection of human health and vegetation on average more than 100 days a year in rural areas and over 40 days a year in urban and peri-urban areas. Efforts undertaken both in France and other European countries aim to improve the situation and ensure compliance with the requirements of Directive 2002/3/EC. (author)

292

Indoor/outdoor concentrations of ozone and peroxyacetyl nitrate (PAN).  

Science.gov (United States)

Photochemical pollutants such as ozone and peroxyacetyl nitrate (PAN) could adversely affect human health, especially with relation to effects on lung function. For a realistic assessment of ambient concentrations, both outdoor and indoor measurements of ozone and PAN are required, because people stay indoors for most of the time. Indoor/outdoor concentration ratios, indoor half-life times and indoor chemistry including physicochemical reactions on surfaces are quite well known for ozone, but not for PAN. While ozone is removed very rapidly mainly by heterogeneous reactions on surfaces or by gasphase reactions with e.g. carpet emissions, no such processes are known for PAN at present. The main removal process for PAN is thermal decay. Indoor concentrations of ozone and PAN can be a significant fraction of those outdoors highly depending on the ventilation pattern. Our measurements in various kinds of non-air-conditioned rooms show maximal indoor concentrations between 80 and 100% of those outdoors for ozone and PAN, respectively. Average indoor/outdoor ratios were calculated of 0.5 for ozone and between 0.7 and 0.9 for PAN. The half-life times ranged between only a few minutes for ozone and 0.5 to 1 h for PAN. PMID:9195863

Jakobi, G; Fabian, P

1997-05-01

293

Effects of SO/sub 2/ and ozone on crop physiology and productivity. Final report  

Energy Technology Data Exchange (ETDEWEB)

Growth and productivity of several crop cultivars were related to physiological and biochemical parameters. In laboratory studies seed germination was not sensitive to SO/sub 2/ and ozone but root growth was sensitive. SO/sub 2/ inhibited pollen tube growth; ozone had no effect on pollen viability. Differential SO/sub 2/ sensitivity in corn cultivars was related to cellular uptake and detoxification. SO/sub 2/ induced ethylene production in a sensitive corn cultivar without visible injury. In bean cultivars sensitivity to ozone was correlated with stomatal uptake. Ozone decreased plant growth and pod yield, and lowered leaf water potential prior to bloom.

Laeuchli, A.; Timm, H.

1985-08-26

294

Third year effects of cloudwater and ozone on red spruce seedlings  

International Nuclear Information System (INIS)

The reduction in growth of high elevation red spruce in the eastern US has been attributed in part to greater exposure to atmospheric pollution which occurs at high elevation. The authors objective was to evaluate the impact of ambient ozone and cloudwater deposition on the growth of red spruce seedlings at a high elevation site. Potted native and Phyton-grown (Phyton Technologies) red spruce seedlings were exposed in open-top field chambers at Whitetop Mountain, Virginia (elevation 1,680) for the third season to treatments of: (1) exclusion of clouds and 50% reduction in ambient O3 (COE), (2) O3 with clouds excluded (CO), (3) exposure to clouds and O3, as control chambers (CC), and (4) open plots (AA). Plant biomass components and diameter increment growth for both seedling types were not affected by treatments. Photosynthesis was not enhanced by removal of cloudwater and O3. Respiration (Rd) generally was not affected by treatments; however, Rd in native seedling needles of previous year and two-year previous growth was significantly greater in CC than CO and COE on several sampling dates, indicating that cloudwater and O3 may be causing higher Rd

295

Ozone chemistry in aqueous solution : ozone decomposition and stabilisation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ozone is used in many applications in the industry as an oxidising agent for example for bleaching and sterilisation. The decomposition of ozone in aqueous solutions is complex, and is affected by many properties such as, pH, temperature and substances present in the water. Additives can either accelerate the decomposition rate of ozone or have a stabilising effect of the ozone decay. By controlling the decomposition of ozone it is possible to increase the oxidative capacity of ozone. In this...

Eriksson, Margareta

2005-01-01

296

Influenza virus infection, ozone exposure, and fibrogenesis  

Energy Technology Data Exchange (ETDEWEB)

Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage.

Jakab, G.J.; Bassett, D.J. (Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (USA))

1990-05-01

297

Air Quality Guide for Ozone  

Science.gov (United States)

... Code: State : National Summary Air Quality Guide for Ozone You may have seen the Air Quality Index ... limit outdoor exertion. What You Should Know About Ozone and Your Health Ozone in the air we ...

298

Liquefied petroleum gas effect on ozone formation in Mexico city  

Science.gov (United States)

An experimental study of outdoor smog chambers was carried out to determine effects of liquefied petroleum gas (LPG) on maximum ozone (O 3 max). 60% additions of commercial LPG and 60%-propane/40% butane mixture of the initial concentration were introduced into eight smog chambers containing morning ambient air of Mexico City metropolitan area (MCMA). The ozone concentrations in each chamber were monitored throughout the day to determine the maximum of ozone. Dilution experiments of 50% total hydrocarbons and associated compounds to LPG in morning ambient air were carried out too. The results showed, that by increasing 60% of the associated compounds to LPG in the air of MCMA or diminishing 50% of them, had not an appreciable influence. The largest effect on ozone formation is determined by total nonmethane hydrocarbon (tNMHC) contained in the atmosphere, being the maximum of ozone formed in the smog chambers, on the average it diminished a 55%. C 3 and C 4 compounds associated to LPG only contribute a 14% of the total ozone formation.

Luis, Jaimes-Lopez J.; Julio, Sandoval-Fernández; Uriel, González-Macías; Emmanuel, González-Ortíz.

299

Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield  

International Nuclear Information System (INIS)

The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO2 and O3, alone and in combination. As compared to the plants grown in charcoal filtered air (ACO2), growth and yield of the plants increased under elevated CO2 (ECO2) and decreased under combination of ECO2 with elevated O3 (ECO2 + EO3), ambient O3 (ACO2 + AO3) and elevated O3 (EO3). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO3. Foliar starch and organic carbon contents increased under ECO2 and ECO2 + EO3 and reduced under EO3 and ACO2 + AO3. Foliar N content declined in all treatments compared to ACO2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO2 is not enough to counteract O3 impact, but elevated CO2 has potential to counteract the negative effects of future O3 level. -- Highlights: ? Elevated CO2 enhanced the growth and yield of palak. ? Ambient and elevated ozone reduced the growth and yield of the test plant. ? Elevated CO2 reduced negative effects of elevated O3 by reducing oxidative stress. ? Higher amelioration was recorded at elevated CO2 + O3 compared to ambient CO2 + O3. -- Predicted levels of CO2 have greater ameliorative potential against negative effects of elevated ozone compared to present day CO2 against ambient ozone

300

Ozone depletion interactive lab  

Science.gov (United States)

What is the process by which CFCs destroy ozone? This informational piece, part of an interactive laboratory series for grades 8-12, explores the destruction of the ozone layer by chlorofluorocarbons. Here students view a four-step animation that shows how ultraviolet light breaks chlorine free from a CFC molecule. The chlorine then destroys an ozone molecule. Additional steps show how the process can be continuous. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

 
 
 
 
301

Ozone as a fungicide  

Energy Technology Data Exchange (ETDEWEB)

Investigations were carried out to determine the fungicidal value of ozone, factors affecting its toxicity to fungi, the practical application of ozone to the mold problem in apple storage and the effect on the amount of rot in apples during and after storage. Ozone inhibited and caused failure of spore germination and caused plasmolysis in spores depending on the length of treatment or concentrations used.

Watson, R.D.

1942-01-01

302

Adsorption air cleaning from ozone.  

Science.gov (United States)

Not much has been written about air cleaning from ozone. The aim of this paper was to demonstrate the possibility of adsorption air cleaning from ozone. The second aim was to investigate the dependence of the efficiency of ozone removal from the air on the height of the adsorber layer and on concentrations of ozone, and to obtain empirical formulas for calculating the efficiency of ozone treatment. Equipment for air cleaning from ozone and nitrogen and sulphur dioxides is suggested. PMID:14577947

Baltrenas, Pranas; Paliulis, Dainius; Vasarevicius, Saulius; Simaitis, Ramutis

2003-01-01

303

Semiconductor Sensors Application for Definition of Factor of Ozone Heterogeneous Destruction on Teflon Surface  

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Full Text Available In our paper we present the results of our research, which was carried out by means of semiconductor sensor techniques (SCS, which allowed evaluating heterogeneous death-rate of ozone (γ Teflon surface. When ozone concentration is near to Ambient Air Standard value, γ is assessed to be equal to 6,57*10-7. High technique response provide possibility to determine ozone contents in the air media and the percentage of ozone, decomposed on the communication surfaces and on the surfaces of installation in the low concentration range (1–100 ppb.

Nataliya V. Finogenova

2003-12-01

304

Ozone carcinogenesis in vitro and its co-carcinogenesis with radiation  

International Nuclear Information System (INIS)

Ozone (O/sub 3/), a reactive species of oxygen, is an important natural constituent of the atmosphere. Background levels of ozone in the lower atmosphere may range up to 0.1 ppm and are modified by geographic elevation, solar radiation and climatic conditions. Since some ozone effects are radiomimetic, its actions may be enhanced in the presence of ionizing radiation from background and/or manmade sources. While stratospheric ozone spares the earth from excess solar ultraviolet (UV) radiation, high levels of ozone in the environment are toxic and present a health hazard to man. Excess environmental exposure to ozone can result from a variety of sources. Ozone is a key component in oxidant smog and in the vicinity of high electric voltage equipment when in operation. Ozone is widely used as a disinfectant for air and water, in bleaches, waxes, textiles, oils. and inorganic synthesis. Enhanced levels of ozone are found in planes flying at high altitudes. Because of the toxic nature of ozone and its potential hazard to man, its levels in the environment are subject to government regulation. The current standard is set at an hourly average of 235 ?g/m/sup 3/ (0.12 ppm) not to be exceeded more than once per year. Urban areas with high levels of photochemical smog (e.g. Southern California) may experience high ambient ozone levels which can reach 0.5 ppm

305

YIELD RESPONSE OF HEAD LETTUCE ('LACTUCA SATIVA' L.) TO OZONE  

Science.gov (United States)

Head lettuce (Lactuca sativa L. cv 'Empire') was grown in the field and exposed in open-top chambers to proportional increments of ozone (O3) from full charcoal filtration (CF) to twice ambient O3 concentrations(NF x 2.0). Severe foliar injury developed on young plants exposed to...

306

40 CFR 52.1683 - Control strategy: Ozone.  

Science.gov (United States)

...measures) of the Clean Air Act do not apply to these...c)(9) of the Clean Air Act for each of these...assessment monitoring stations network included in New York's...process to address regional transport; adopt additional...ozone national ambient air quality standard:...

2010-07-01

307

INJURY RESPONSE OF 'PHASEOLUS VULGARIS' TO OZONE FLUX DENSITY  

Science.gov (United States)

The paper by Amiro et al. (1984) provides significant insight concerning the effect of ozone on plants. Their data clearly distinguish between the terms air pollutant exposure (ambient concentration averaged over time) and air pollutant flux density (amount of pollutant absorbed ...

308

Interação genótipo-ambiente em algumas características produtivas de gado de corte no Brasil Genotype environmental interaction in some growth traits of beef cattle in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Este estudo teve por objetivo medir o efeito da interação genótipo-ambiente (IGA em algumas características de crescimento em bovinos Nelore. Os dados foram coletados em duas fazendas, em regiões distintas do Estado de Minas Gerais, Sul (faz I e Noroeste (faz II, e correspondem aos pesos de 2.896 animais à pré-desmama (PD, 2.605 à desmama (DM e 1.522 à pós-desmama (SA, com 9.911 no arquivo de genealogia. Apenas animais criados em pasto foram utilizados para as análises. Os efeitos de época de nascimento (mês-ano, sexo e fazenda foram reunidos em grupos de contemporâneos. Os componentes de (covariância foram estimados pelo programa MTDFREML. Nas análises conjuntas de duas características as estimativas de herdabilidade dos efeitos diretos foram 0,24, 0,16, e 0,17 (faz I e 0,25, 0,24, e 0,17 (faz II, para PD, DM e SA, respectivamente. As correlações de ordem dos valores genéticos entre fazendas para as características PD, DM e SA foram, respectivamente, 0,74, 0,76 e 0,51. Na mesma ordem, as correlações genéticas entre fazendas foram 0,96, 0,95 e 0,53. Estes resultados não evidenciaram efeito da IGA até a desmama, porém após a desmama seu efeito foi grande, sugerindo que se deva fazer uma avaliação regional para escolha de reprodutores Nelore se se utilizar essa última característica como critério de seleção.The objective of this study was to measure the genotype-environment interaction (GEI effect on some growth traits in Nellore cattle. Data from 2,896 records of pre-weaning (PW, 2,605 of weaning (WW and 1,522 of post-yearling (YW weights with a total of 9,911 pedigree animals from two farms of different regions of Minas Gerais State, South (farm I and Northeast (farm II were analyzed. Contemporary groups consider the effects of month-year of birth, sex, and herd. Only data from animals raised under pasture conditions were used. Covariance components were estimated by MTDFREML. Direct heritability obtained from bivariate analyses were 0.24, 0.16 and 0.17 (farm I and 0.25, 0.24 and 0.17 (farm II for PW, WW and YW, respectively. The ranking correlations between farms were 0.74, 0.76 and 0.51 and genetic correlations between farms were 0.96, 0.95 and 0.53 for PW, WW and YW, respectively. These results showed that there was no evidence of GEI up to weaning time but there was a significant effect of this interaction on the post-yearling weight. If selection criterion includes growth traits measured after weaning, regional evaluation should be recommended for bulls choice.

V.C.P. Ferreira

2001-06-01

309

Interação genótipo-ambiente em algumas características produtivas de gado de corte no Brasil / Genotype environmental interaction in some growth traits of beef cattle in Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este estudo teve por objetivo medir o efeito da interação genótipo-ambiente (IGA) em algumas características de crescimento em bovinos Nelore. Os dados foram coletados em duas fazendas, em regiões distintas do Estado de Minas Gerais, Sul (faz I) e Noroeste (faz II), e correspondem aos pesos de 2.896 [...] animais à pré-desmama (PD), 2.605 à desmama (DM) e 1.522 à pós-desmama (SA), com 9.911 no arquivo de genealogia. Apenas animais criados em pasto foram utilizados para as análises. Os efeitos de época de nascimento (mês-ano), sexo e fazenda foram reunidos em grupos de contemporâneos. Os componentes de (co)variância foram estimados pelo programa MTDFREML. Nas análises conjuntas de duas características as estimativas de herdabilidade dos efeitos diretos foram 0,24, 0,16, e 0,17 (faz I) e 0,25, 0,24, e 0,17 (faz II), para PD, DM e SA, respectivamente. As correlações de ordem dos valores genéticos entre fazendas para as características PD, DM e SA foram, respectivamente, 0,74, 0,76 e 0,51. Na mesma ordem, as correlações genéticas entre fazendas foram 0,96, 0,95 e 0,53. Estes resultados não evidenciaram efeito da IGA até a desmama, porém após a desmama seu efeito foi grande, sugerindo que se deva fazer uma avaliação regional para escolha de reprodutores Nelore se se utilizar essa última característica como critério de seleção. Abstract in english The objective of this study was to measure the genotype-environment interaction (GEI) effect on some growth traits in Nellore cattle. Data from 2,896 records of pre-weaning (PW), 2,605 of weaning (WW) and 1,522 of post-yearling (YW) weights with a total of 9,911 pedigree animals from two farms of di [...] fferent regions of Minas Gerais State, South (farm I) and Northeast (farm II) were analyzed. Contemporary groups consider the effects of month-year of birth, sex, and herd. Only data from animals raised under pasture conditions were used. Covariance components were estimated by MTDFREML. Direct heritability obtained from bivariate analyses were 0.24, 0.16 and 0.17 (farm I) and 0.25, 0.24 and 0.17 (farm II) for PW, WW and YW, respectively. The ranking correlations between farms were 0.74, 0.76 and 0.51 and genetic correlations between farms were 0.96, 0.95 and 0.53 for PW, WW and YW, respectively. These results showed that there was no evidence of GEI up to weaning time but there was a significant effect of this interaction on the post-yearling weight. If selection criterion includes growth traits measured after weaning, regional evaluation should be recommended for bulls choice.

V.C.P., Ferreira; V.M., Penna; J.A.G., Bergmann; R.A., Torres.

310

Effect of temperature coupling on ozone depletion prediction  

Science.gov (United States)

The effects of chlorine perturbations on both the temperature and the ozone distribution in the stratosphere have been studied using a simplified radiative-photochemical model. The model solves the hydrostatic equation for total density in a self-consistent manner as the temperature is changed. Radiative coupling is found to have a significant effect on both the thermal structure and the ozone distribution, particularly in the 35-50-km region. By increasing the ClX mixing ratio by 5.0 ppbv, the temperature in this region is decreased by 5 to 10 K with a slight increase below 30 km. The local ozone depletion around 40 km due to added ClX is smaller compared with the estimate made by keeping the temperature fixed to the ambient condition. However, the integrated effect of radiative coupling is to increase the calculated column ozone depletion by 15% to 25% in this model.

Chandra, S.; Butler, D. M.; Stolarski, R. S.

1978-01-01

311

Influence of urban ozone in the measurements of the total ozone column in Mexico City  

Energy Technology Data Exchange (ETDEWEB)

In this paper we examine measurements of the thickness of the total ozone column between 1986 and 1989 in Mexico City. We consider the contribution of the surface ozone in measurement of the total ozone column made with the Dobson Spectrophotometer located at the Solar Radiation Laboratory (National University), in the southwest of Mexico City. We consider different depths of the mixing layer depending on the season and we compare our results with those reported for Mauna Loa in Hawaii and Poona in India, at the same latitude as Mexico City. In conclusion we confirm that in highly polluted areas the surface ozone has an important effect on measurements of the total ozone column. [Spanish] En este trabajo se examinan las mediciones del grosor de la columna total de ozono entre 1986 y 1989 en la Ciudad de Mexico. En esta revision se considera la contribucion del ozono superficial a las mediciones efectuadas con el Espectrofotometro Dobson instalado en el Laboratorio de Radiacion Solar de la UNAM al suroeste de la Ciudad de Mexico. Consideramos diferentes capas de mezcla para el ozono dependiendo del periodo estacional y comparamos los resultados obtenidos con los valores de las mediciones reportadas para Mauna Loa en Hawai y Poona en la India, ambos a latitudes similares a la de la Ciudad de Mexico. Nuestra conclusion es que en regiones urbanas con alta contaminacion ambiental, el ozono superficial afecta apreciablemente las mediciones del grosor de la columna total de ozono.

Juarez, A.; Gay, C. [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico); Bravo, J. L. [Instituto de Geofisica, UNAM, Mexico, D.F. (Mexico)

1995-01-01

312

Ozonation of sediments from an urban lake: an exploratory investigation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english An exploratory investigation was conducted on the effects of application of ozone on the removal of organic and inorganic contaminants and the reduction of settleable solids in urban lake sediments. Homogenized sediment samples were treated in a batch reactor with an external recirculation loop and [...] ozone feed from a Venturi injector. The ozone generating system was fed with ambient air with small footprint and operational simplicity. Ozone mass application (g/h) and contact time (min) were varied over wide ranges during testing. The effects of the ozone mass applied per unit time and the contact time on contaminant removal efficiencies were analyzed and a trade - off between the costs of ozonation and of solids treatment and disposal was proposed. The minimum ozone mass application required for total contaminant removal apparently depended on the type of organic contaminant present. An apparent influence of inorganic contaminant speciation on the removal efficiency was found and discussed.

F. A, Lage Filho; L. R. F, Carvalho; M. L. A, Lopes.

2011-09-01

313

Ozonation of sediments from an urban lake: an exploratory investigation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english An exploratory investigation was conducted on the effects of application of ozone on the removal of organic and inorganic contaminants and the reduction of settleable solids in urban lake sediments. Homogenized sediment samples were treated in a batch reactor with an external recirculation loop and [...] ozone feed from a Venturi injector. The ozone generating system was fed with ambient air with small footprint and operational simplicity. Ozone mass application (g/h) and contact time (min) were varied over wide ranges during testing. The effects of the ozone mass applied per unit time and the contact time on contaminant removal efficiencies were analyzed and a trade - off between the costs of ozonation and of solids treatment and disposal was proposed. The minimum ozone mass application required for total contaminant removal apparently depended on the type of organic contaminant present. An apparent influence of inorganic contaminant speciation on the removal efficiency was found and discussed.

F. A, Lage Filho; L. R. F, Carvalho; M. L. A, Lopes.

314

Ozone, area social conditions, and mortality in Mexico City  

International Nuclear Information System (INIS)

We investigated whether the association of daily mortality and ambient ozone differs by age and area social conditions of the region of residence using a time-series analysis. The study setting was metropolitan Mexico City, a high altitude city situated in a valley, with an estimated 20 million inhabitants, large socioeconomic gradients, and ozone levels frequently exceeding international standards. We stratified daily deaths by six census-derived socioeconomic indicators, based on characteristics of the county where decedents lived. We used Poisson regression to model the association between daily mortality and ozone levels (on the day of death and the previous day) in separate models, stratified by area socioeconomic level and age, and controlling for time trends and temperature. Ozone was positively associated with total mortality [0.65% increase per 10 ppb increment, 95% confidence interval (CI): 0.02%, 1.28%] and for mortality among those over age 65 [1.39% increase per 10 ppb increment, 95% CI: 0.51%, 2.28%]. Associations between ozone and all-age mortality did not show any consistent patterns according to socioeconomic gradients. We conclude that elderly people are at higher risk for ozone-associated mortality. Though county-level social indicators in Mexico City were not strong markers of vulnerability to ozone-associated acute mortality in this analysis, complex associations between individual and area-level factors may exist that would require additional data and further analyses to elucidate

315

Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere  

Energy Technology Data Exchange (ETDEWEB)

A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O{sub 3}: non-filtered (NF) ambient air or NF+ 40 ppb O{sub 3} (NF+). During O{sub 3} exposure, soil sampling was performed at two dates according to different plant growth stages. O{sub 3} exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O{sub 3} concentrations may influence the dynamic of decomposition processes and the turnover of nutrients. - Ozone reduced the individual densities of enchytraeids, collembolans and soil mites in the rhizosphere of winter wheat indirectly via the plant-soil-system.

Schrader, Stefan, E-mail: stefan.schrader@vti.bund.d [Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Biodiversity, Bundesallee 50, 38116 Braunschweig (Germany); Bender, Juergen; Weigel, Hans-Joachim [Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Biodiversity, Bundesallee 50, 38116 Braunschweig (Germany)

2009-12-15

316

Elevated carbon dioxide and/or ozone concentrations induce hormonal changes in Pinus tabulaeformis.  

Science.gov (United States)

We investigated endogenous plant hormones and needle growth in Pinus tabulaeformis plants grown in open-top chambers and exposed to ambient or elevated concentrations of carbon dioxide (CO(2)) and/or ozone (O(3)). Exposure to elevated CO(2) for 100 days significantly increased the change in fresh needle weight, indole-3-acetic acid (IAA), isopentenyl-adenosine (iPA), and dihydrozeatin riboside (DHZR) content. Abscisic acid (ABA) content decreased, and no effect was observed on zeatin riboside (ZR) content or changes in needle dry weight. The ratios of IAA/ABA and total cytokinins (CKs)/ABA [Formula: see text] were increased. Elevated O(3) significantly decreased IAA and ZR, and decreased the ratios of IAA/ABA and CKs/ABA. Ozone treatment increased ABA content but did not change iPA or DHZR content or change fresh or dry needle weights. The combination treatment significantly increased ABA content and the IAA/ABA ratio but decreased the total CKs/ABA ratio and had no effect on CKs or IAA content or change in fresh and dry needle weights. The results indicate that elevated CO(2) ameliorated the effects of elevated O(3) on tree growth. PMID:21611809

Li, Xue-Mei; Zhang, Li-Hong; Ma, Lian-Ju; Li, Yue-Ying

2011-07-01

317

Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere  

International Nuclear Information System (INIS)

A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O3: non-filtered (NF) ambient air or NF+ 40 ppb O3 (NF+). During O3 exposure, soil sampling was performed at two dates according to different plant growth stages. O3 exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O3 concentrations may influence the dynamic of decomposition processes and the turnover of nutrients. - Ozone reduced the individual densities of enchytraeids, collembolans and soil mites in the rhizosphere of winter wheat indirectly via the plant-soil-system.

318

Natural hydrocarbons, urbanization, and urban ozone  

Energy Technology Data Exchange (ETDEWEB)

Using the Atlanta metropolitan area as a case study, the authors examine the effects of urbanization and its associated heat island on urban ozone concentrations. Air quality data from Atlanta suggest that urban ozone concentrations are enhanced by increases in ambient temperature. Model calculations suggest that this enhancement is caused by the effect of temperature on the atmospheric chemistry of peroxyacetyl nitrate (PAN), as well as the temperature dependence of natural and anthropogenic hydrocarbon emissions. A comparison of summertime temperatures in Atlanta and a nearby rural station, suggests that Atlanta's temperature over the past 15 years has increased by about 2{degree}C due to urbanization and its concomitant intensification of the urban heat island. Numerical simulations using conditions of a typical summertime day in Atlanta suggest that this rise in temperature could have, (1) resulted in a significant increase in the net emissions of natural hydrocarbons in the area in spite of the loss of about 20% of the areas forests over the same period, and (2) negated the beneficial effects on summertime ozone concentrations that would have been obtained from a 50% reduction in anthropogenic hydrocarbon emissions. Because a NO{sub x}-based ozone abatement strategy appears to be less sensitive to temperature increases than does a hydrocarbon-based strategy, a NO{sub x} strategy may prove to be more effective in the future if temperatures continue to rise as a result of urbanization and the greenhouse effect.

Cardelino, C.A.; Chameides, W.L. (Georgia Institute of Technology, Atlanta (USA))

1990-08-20

319

Natural hydrocarbons, urbanization, and urban ozone  

Science.gov (United States)

Using the Atlanta metropolitan area as a case study, we examine the effects of urbanization and its associated heat island on urban ozone concentrations. Air quality data from Atlanta suggest that urban ozone concentrations are enhanced by increases in ambient temperature. Model calculations suggest that this enhancement is caused by the effect of temperature on the atmospheric chemistry of peroxyacetyl nitrate (PAN), as well as the temperature dependence of natural and anthropogenic hydrocarbon emissions. A comparison of summertime temperatures in Atlanta and a nearby rural station, suggests that Atlanta's temperature over the past 15 years has increased by about 2°C due to urbanization and its concomitant intensification of the urban heat island. Numerical simulations using conditions of a typical summertime day in Atlanta suggest that this rise in temperature could have, (1.) resulted in a significant increase in the net emissions of natural hydrocarbons in the area in spite of the loss of about 20% of the area's forests over the same period, and (2.) negated the beneficial effects on summertime ozone concentrations that would have been obtained from a 50% reduction in anthropogenic hydrocarbon emissions. Because a NOx-based ozone abatement strategy appears to be less sensitive to temperature increases than does a hydrocarbon-based strategy, a NOx strategy may prove to be more effective in the future if temperatures continue to rise as a result of urbanization and the "greenhouse effect".

Cardelino, C. A.; Chameides, W. L.

1990-08-01

320

COTTON YIELD RESPONSES TO OZONE AS MEDIATED BY SOIL MOISTURE AND EVAPOTRANSPIRATION  

Science.gov (United States)

Cotton (Gossypium hirsutum L. cv. 'SJ-2'), grown in open-top chambers in the Central Valley of California, was exposed to 6 ozone (O3) treatments ranging from charcoal-filtered (CF) to ambient plus 0.10 ppm O3 (1981) or twice ambient O3 concentrations (1982) for the entire growin...

 
 
 
 
321

Ground-Level Ozone  

Science.gov (United States)

Ground level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile ... the major sources of NOx and VOC. Breathing ozone can trigger a variety of health problems, particularly ...

322

Surface Ozone in Kiev  

Science.gov (United States)

The study of total ozone over Kiev and its concentration changes with height in the troposphere has been made on the base of ground-based observations with the infrared Fourier-spectrometer in the Main Astronomical Observatory of National Academy of Sciences of Ukraine (MAO NASU) as part of ESA-NIVR-KNMI project no 2907 "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles "(2005-2008) [1,2,4]. Ground-level ozone in Kiev for an episode of its high concentrations in August 2000 was also simulated with the model of urban air pollution UAM-V [5,6]. In 2008 the satellite data Aura-OMI on profiles of ozone in the atmosphere OMO3PR became available (http://disc.sci.gsfc.nasa.gov/ Aura/data-holdings/OMI/ omo3pr_v003.shtml). They include ozone content in the lower layer of the atmosphere, beginning from 2005, which can be used to evaluate the ground-level ozone in all cities of Ukraine. The comparison of the data of ozone air pollution in Kiev (ozone - the pollutant of the first class of danger) and medical statistics data of of respiratory system (RS) diseases of the city population was carried out with the package "Statistica". A regression analysis, prognostic regression modelling, and retrospective prognosis of the epidemiological situation with respect to RS pathologies in Kiev in 2000-2006 were performed.

Shavrina, A. V.; Mikulskaya, I. A.; Kiforenko, S. I.; Blum, O. B.; Sheminova, V. A.; Veles, A. A.

323

Responses of sensitive and tolerant bush beans (Phaseolus vulgaris L.) to ozone in open-top chambers are influenced by phenotypic differences, morphological characteristics, and the chamber environment  

International Nuclear Information System (INIS)

Responses of bush bean (Phaseolus vulgaris L.) lines 'S156' (O3-sensitive) and 'R123' (O3-tolerant), and cultivars 'BBL 290' (O3-sensitive) and 'BBL 274' (O3-tolerant) to ambient ozone (O3) were investigated during the 2001 and 2002 growing seasons. Seedlings were grown in pots inside open-top chambers (OTCs), with charcoal filtered (CF) and non-filtered (NF) ambient air, and in non-chambered ambient air (AA) plots. Growth parameters from individual plants were evaluated after harvests at the end of vegetative (V4) and reproductive (R10) growth phases. Results at V4 indicated that CF did not provide additional benefits over NF in 'S156' in 2001 and 2002. In contrast, exposure to CF significantly impaired the growth of 'R123'. At the end of R10, 'S156' produced more pods, most of which remained immature, and contained fewer seeds or were more frequently aborted, whereas pods produced in 'R123' reached pod maturation and senescence more consistently. Despite increased seed weights inside the OTCs, as observed in 'S156', differences between the two lines were insignificant when grown outside OTCs. Results from the 'BBL 290'/'BBL 274' pair, especially at V4 phase, remained inconclusive. Plant morphological characteristics, variabilities in environmental conditions, and 'chamber effects' inside OTCs were influential in determining plant response to ambient O3. - Phenotypic differences, morphological characteristics, and 'chamber effects' inside OTCs are equally influential in determining the responses of beans to O3

324

Absolute quality of the Ozone Monitoring Instrument ozone columns and ozone profiles  

Science.gov (United States)

We will present an absolute quality assessment of the total ozone column and vertical ozone profile data products from the Ozone Monitoring Instrument (OMI) onboard the NASA EOS-Aura satellite obtained by validation. OMI is an imaging UV-visible spectrometer mapping global ozone on a daily basis. Total ozone data have been derived using two algorithms; OMI-TOMS based on the TOMS version 8 algorithm and OMI- DOAS using the hyperspectral features of OMI. Vertical ozone profiles are derived from OMI nadir observation by optimal estimation. Column ozone was validated against a network of Dobson and Brewer ground stations, with airborne data gathered during NASA AVE campaigns and through comparisons of both ozone data products yielding absolute differences in DU. Most discovered instrumental shortcomings and algorithmic errors have been corrected in the collection 3 level-1B and ozone data sets and are publicly available. OMI ozone profiles have been validated against ozone profiles from the Microwave Limb Sounder (MLS), also onboard NASA EOS-Aura, yielding absolute differences in VMR. The primary OMI mission goal of continuing the NASA TOMS ozone record is achievable with either total column ozone data product. Daily global OMI ozone column and ozone profile data are well suited for estimating tropospheric ozone columns. Performing ozone trend studies and air quality studies requires the essential information presented here.

Kroon, M.; Veefkind, J. P.; de Haan, J.; McPeters, R. D.; Bhartia, P. K.; Balis, D.; Petropavlovskikh, I.; Froidevaux, L.; Shetter, R. E.; Levelt, P. F.

2008-12-01

325

40 CFR Appendix D to Part 50 - Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere  

Science.gov (United States)

...displayed on a recorder. 2. An analyzer based on this principle...and Visible Regions of the Spectrum”, Proc. Phys. Soc. ...Photolysis. VI. The Ultraviolet Spectrum”, J. Chem. Phys., 59...of Ambient Air Monitoring Analyzers for Ozone, EPA...

2010-07-01

326

Desempenho e orientação do crescimento do pepino japonês em ambiente protegido / Performance and growth conduction of Japanese cucumber in protected environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliou-se a produção de pepino japonês Tsuyataro, com diferentes métodos de orientação do crescimento das hastes, a partir do controle de brotações laterais das hastes e do número de hastes por planta, realizados através da poda. O trabalho foi desenvolvido no período de outubro a dezembro de 2010, [...] em ambiente protegido em Tangará da Serra-MT, adotando-se o delineamento em blocos casualizados, distribuídos em esquema fatorial 2x3. O primeiro fator foi constituído de desbrota, ou seja, realização ou não da retirada dos ramos laterais das hastes e o segundo fator foi constituído pelo controle do número de hastes por planta: uma, duas e três hastes/planta, em cinco repetições. Foram avaliadas as características número de frutos total e comercial; taxa de frutos comerciais, comprimento, diâmetro, relação comprimento/diâmetro do fruto, produtividade total e comercial de frutos por planta; e massa média dos frutos do pepino. A condução da haste principal sem a retirada dos ramos laterais foi o tratamento que apresentou superioridade com relação ao número de frutos total e comercial por planta (19,4 e 16,0), e também maior produtividade total e comercial de frutos (4.235,8 e 3.438,3 g/planta). Já a poda das brotações laterais promoveu aumento no comprimento, diâmetro e na massa média dos frutos do pepino de 24,5 para 25,1 cm; 3,4 para 3,5 cm e 212,1 para 228,3 g/fruto, respectivamente. Abstract in english The production of the Japanese cucumber Tsuyataro was evaluated using methods of stems growth conduction, controlling the lateral buds and number of stems per plant, through pruning. The research was carried out from October to December 2010, in a protected environment in Tangará da Serra, Mato Gros [...] so state, Brazil, using a randomized blocks design, with five replications, in a factorial scheme (2x3). The first factor was the pruning, i.e., removal or not of lateral stems and the second factor was constituted of the control of number of stems: one, two and three stems per plant, with five replications. We evaluated the following characteristics: total and marketable number of fruits, commercial fruits rate, fruit length, fruit diameter, fruit length/diameter ratio, total and marketable yield of fruit per plant and fruit average weight. The treatment with conduction of the main stem without removal of lateral buds had better performance on total and marketable number of fruits per plant (19.4 and 16.0) and higher total and marketable yield of fruits (4,235.8 and 3,438.3 g per plant). The pruning of lateral buds provided increase in length, diameter and average mass of cucumber fruits of 24.5 to 25.1 cm; 3.4 to 3.5 cm and 212.1 to 228.3 g per fruit, respectively.

Adalberto, Santi; Walcylene LMP, Scaramuzza; Danilo MJ, Soares; José Fernando, Scaramuzza; Rivanildo, Dallacort; Willian, Krause; Rafael Cesar, Tieppo.

327

Crescimento do pinhão-manso irrigado com águas salinas em ambiente protegido / Growth of Jatropha irrigated with saline water in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Considerando as potencialidades de uso do pinhão manso (Jatropha curcas L.) como fonte energética e a carência de resultados de pesquisa relativos ao seu cultivo, realizou-se este trabalho com o fim primordial de se estudar os efeitos da salinidade da água de irrigação sobre o crescimento das planta [...] s, em ambiente protegido. A pesquisa foi desenvolvida entre abril e outubro de 2007, no Centro de Tecnologia e Recursos Naturais (CTRN) da UFCG-PB. As plantas foram cultivadas em lisímetros de drenagem (200 L), contendo 230 kg de material de solo devidamente adubado, não-salino, não-sódico, classificado como Argissolo Acinzentado eutrófico. Os tratamentos consistiram de cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1, a 25 ºC), no delineamento experimental em blocos casualizados, com quatro repetições, sendo cada parcela constituída pela média de duas plantas cultivadas em lisímetros separados. Avaliaram-se altura de planta, diâmetro caulinar, número de folhas e área foliar aos 37, 58, 79, 100, 121, 142 e 163 dias após a semeadura; ao final do período de estudos, o pinhão-manso irrigado com água de CEa de 3,0 dS m-1 teve a altura de planta, o diâmetro caulinar, o número de folhas e a área foliar reduzidos em 9,07, 17,63, 23,41 e 42,58%, respectivamente. Abstract in english The objective of this work was to evaluate the effects of irrigation water salinity on the growth of Jatropha curcas L. in greenhouse. The research was carried out during April and October of 2007, in a greenhouse of the Department of Agricultural Engineering of the Natural Resources and Technology [...] Center (CTRN) of Federal University of Campina Grande, Paraíba, Brazil. The plants were grown in drainage lysimeters (200 L) with 230 kg of non-saline, non-sodic soil adequately fertilized, classified as Gray Argisol eutrophic. The treatments consisted of five levels of electrical conductivity of the irrigation water - CEw (0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1, at 25 ºC). The experimental design was in randomized blocks with 4 replications, each replication represented by the average of 2 plants cultivated in separate lysimeters. Plant height, stem diameter, number of leaves and leaf area were evaluated at 37, 58, 79, 100, 121, 142 and 163 days after sowing (DAS). At 163 DAS, Jatropha irrigated with ECw equal to 3.0 dS m-1 had plant height, stem diameter, number of leaves and leaf area reduced by 9.07, 17.63, 23.41 and 42.58%, respectively.

Aparecida R., Nery; Luis N., Rodrigues; Maria B. R., Silva; Pedro D., Fernandes; Lúcia H. G., Chaves; José, Dantas Neto; Hans R., Gheyi.

328

Crescimento do pinhão-manso irrigado com águas salinas em ambiente protegido / Growth of Jatropha irrigated with saline water in greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Considerando as potencialidades de uso do pinhão manso (Jatropha curcas L.) como fonte energética e a carência de resultados de pesquisa relativos ao seu cultivo, realizou-se este trabalho com o fim primordial de se estudar os efeitos da salinidade da água de irrigação sobre o crescimento das planta [...] s, em ambiente protegido. A pesquisa foi desenvolvida entre abril e outubro de 2007, no Centro de Tecnologia e Recursos Naturais (CTRN) da UFCG-PB. As plantas foram cultivadas em lisímetros de drenagem (200 L), contendo 230 kg de material de solo devidamente adubado, não-salino, não-sódico, classificado como Argissolo Acinzentado eutrófico. Os tratamentos consistiram de cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1, a 25 ºC), no delineamento experimental em blocos casualizados, com quatro repetições, sendo cada parcela constituída pela média de duas plantas cultivadas em lisímetros separados. Avaliaram-se altura de planta, diâmetro caulinar, número de folhas e área foliar aos 37, 58, 79, 100, 121, 142 e 163 dias após a semeadura; ao final do período de estudos, o pinhão-manso irrigado com água de CEa de 3,0 dS m-1 teve a altura de planta, o diâmetro caulinar, o número de folhas e a área foliar reduzidos em 9,07, 17,63, 23,41 e 42,58%, respectivamente. Abstract in english The objective of this work was to evaluate the effects of irrigation water salinity on the growth of Jatropha curcas L. in greenhouse. The research was carried out during April and October of 2007, in a greenhouse of the Department of Agricultural Engineering of the Natural Resources and Technology [...] Center (CTRN) of Federal University of Campina Grande, Paraíba, Brazil. The plants were grown in drainage lysimeters (200 L) with 230 kg of non-saline, non-sodic soil adequately fertilized, classified as Gray Argisol eutrophic. The treatments consisted of five levels of electrical conductivity of the irrigation water - CEw (0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1, at 25 ºC). The experimental design was in randomized blocks with 4 replications, each replication represented by the average of 2 plants cultivated in separate lysimeters. Plant height, stem diameter, number of leaves and leaf area were evaluated at 37, 58, 79, 100, 121, 142 and 163 days after sowing (DAS). At 163 DAS, Jatropha irrigated with ECw equal to 3.0 dS m-1 had plant height, stem diameter, number of leaves and leaf area reduced by 9.07, 17.63, 23.41 and 42.58%, respectively.

Aparecida R., Nery; Luis N., Rodrigues; Maria B. R., Silva; Pedro D., Fernandes; Lúcia H. G., Chaves; José, Dantas Neto; Hans R., Gheyi.

2009-10-01

329

Crescimento do pinhão-manso irrigado com águas salinas em ambiente protegido Growth of Jatropha irrigated with saline water in greenhouse  

Directory of Open Access Journals (Sweden)

Full Text Available Considerando as potencialidades de uso do pinhão manso (Jatropha curcas L. como fonte energética e a carência de resultados de pesquisa relativos ao seu cultivo, realizou-se este trabalho com o fim primordial de se estudar os efeitos da salinidade da água de irrigação sobre o crescimento das plantas, em ambiente protegido. A pesquisa foi desenvolvida entre abril e outubro de 2007, no Centro de Tecnologia e Recursos Naturais (CTRN da UFCG-PB. As plantas foram cultivadas em lisímetros de drenagem (200 L, contendo 230 kg de material de solo devidamente adubado, não-salino, não-sódico, classificado como Argissolo Acinzentado eutrófico. Os tratamentos consistiram de cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1, a 25 ºC, no delineamento experimental em blocos casualizados, com quatro repetições, sendo cada parcela constituída pela média de duas plantas cultivadas em lisímetros separados. Avaliaram-se altura de planta, diâmetro caulinar, número de folhas e área foliar aos 37, 58, 79, 100, 121, 142 e 163 dias após a semeadura; ao final do período de estudos, o pinhão-manso irrigado com água de CEa de 3,0 dS m-1 teve a altura de planta, o diâmetro caulinar, o número de folhas e a área foliar reduzidos em 9,07, 17,63, 23,41 e 42,58%, respectivamente.The objective of this work was to evaluate the effects of irrigation water salinity on the growth of Jatropha curcas L. in greenhouse. The research was carried out during April and October of 2007, in a greenhouse of the Department of Agricultural Engineering of the Natural Resources and Technology Center (CTRN of Federal University of Campina Grande, Paraíba, Brazil. The plants were grown in drainage lysimeters (200 L with 230 kg of non-saline, non-sodic soil adequately fertilized, classified as Gray Argisol eutrophic. The treatments consisted of five levels of electrical conductivity of the irrigation water - CEw (0.6, 1.2, 1.8, 2.4 and 3.0 dS m-1, at 25 ºC. The experimental design was in randomized blocks with 4 replications, each replication represented by the average of 2 plants cultivated in separate lysimeters. Plant height, stem diameter, number of leaves and leaf area were evaluated at 37, 58, 79, 100, 121, 142 and 163 days after sowing (DAS. At 163 DAS, Jatropha irrigated with ECw equal to 3.0 dS m-1 had plant height, stem diameter, number of leaves and leaf area reduced by 9.07, 17.63, 23.41 and 42.58%, respectively.

Aparecida R. Nery

2009-10-01

330

Desempenho e orientação do crescimento do pepino japonês em ambiente protegido / Performance and growth conduction of Japanese cucumber in protected environment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliou-se a produção de pepino japonês Tsuyataro, com diferentes métodos de orientação do crescimento das hastes, a partir do controle de brotações laterais das hastes e do número de hastes por planta, realizados através da poda. O trabalho foi desenvolvido no período de outubro a dezembro de 2010, [...] em ambiente protegido em Tangará da Serra-MT, adotando-se o delineamento em blocos casualizados, distribuídos em esquema fatorial 2x3. O primeiro fator foi constituído de desbrota, ou seja, realização ou não da retirada dos ramos laterais das hastes e o segundo fator foi constituído pelo controle do número de hastes por planta: uma, duas e três hastes/planta, em cinco repetições. Foram avaliadas as características número de frutos total e comercial; taxa de frutos comerciais, comprimento, diâmetro, relação comprimento/diâmetro do fruto, produtividade total e comercial de frutos por planta; e massa média dos frutos do pepino. A condução da haste principal sem a retirada dos ramos laterais foi o tratamento que apresentou superioridade com relação ao número de frutos total e comercial por planta (19,4 e 16,0), e também maior produtividade total e comercial de frutos (4.235,8 e 3.438,3 g/planta). Já a poda das brotações laterais promoveu aumento no comprimento, diâmetro e na massa média dos frutos do pepino de 24,5 para 25,1 cm; 3,4 para 3,5 cm e 212,1 para 228,3 g/fruto, respectivamente. Abstract in english The production of the Japanese cucumber Tsuyataro was evaluated using methods of stems growth conduction, controlling the lateral buds and number of stems per plant, through pruning. The research was carried out from October to December 2010, in a protected environment in Tangará da Serra, Mato Gros [...] so state, Brazil, using a randomized blocks design, with five replications, in a factorial scheme (2x3). The first factor was the pruning, i.e., removal or not of lateral stems and the second factor was constituted of the control of number of stems: one, two and three stems per plant, with five replications. We evaluated the following characteristics: total and marketable number of fruits, commercial fruits rate, fruit length, fruit diameter, fruit length/diameter ratio, total and marketable yield of fruit per plant and fruit average weight. The treatment with conduction of the main stem without removal of lateral buds had better performance on total and marketable number of fruits per plant (19.4 and 16.0) and higher total and marketable yield of fruits (4,235.8 and 3,438.3 g per plant). The pruning of lateral buds provided increase in length, diameter and average mass of cucumber fruits of 24.5 to 25.1 cm; 3.4 to 3.5 cm and 212.1 to 228.3 g per fruit, respectively.

Adalberto, Santi; Walcylene LMP, Scaramuzza; Danilo MJ, Soares; José Fernando, Scaramuzza; Rivanildo, Dallacort; Willian, Krause; Rafael Cesar, Tieppo.

2013-12-01

331

Simplified prediction of Staphylococcus aureus growth in a cooked meat product exposed to changing environmental temperatures in warm climates / Predición simplificada del crecimiento de Staphylococcus aureus en productos cárnicos cocidos expuestos a temperaturas ambientes cambiantes en climas cálidos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in spanish En este trabajo se utiliza un método simplificado para predecir el crecimiento de Staphylococcus aureus en un producto cárnico pasteurizado dejado por varias horas a temperatura ambiente diurna en zonas de clima cálido. En la predicción, se utilizaron datos de la temperatura horaria para un día calu [...] roso típico de enero (mes más caliente del año) en varias ciudades de la Argentina y datos de la literatura sobre tiempos de generación y tiempo lag de la bacteria inoculada en un producto cárnico pasteurizado. Los resultados indicaron que cuando el producto se deja a temperatura ambiente diurna durante varias horas, no se debe utilizar para la predicción un valor de temperatura promedio (ej.: temperatura media diaria), sino que hay que tener en cuenta la evolución de este parámetro a lo largo del período considerado. Abstract in english In this work, a simplified method is used to estimate the growth of Staphylococcus aureus in a pasteurized meat product left for several hours at environmental temperatures (diurnal time) in warm climates of different cities in Argentina. Hourly temperature data for a warm January (the hottest month [...] of the year) day, and literature data on the kinetics of S. aureus growth inoculated in a pasteurized meat product were used for calculations. As shown by results, if a cooked meat product is left exposed to environmental temperature at diurnal time, predictions made when using a constant temperature value (i.e. average daily) may not be accurate. Growth estimations in contaminated food left under ambient conditions during diurnal time, should consider the changing environmental temperature for correct results.

R., Baeza; C. E., Rössler; D. M., Mielnicki; M. C., Zamora; J., Chirife.

332

Ozone and nitrogen effects on yield and nutritive quality of the annual legume Trifolium cherleri  

Science.gov (United States)

Two independent experiments were performed in an Open-Top Chamber facility to determine the response of biomass and nutritive quality of the annual legume Trifolium cherleri to increased levels of ozone (O3) and nitrogen (N) deposition, two main drivers of global change. Plants growing in pots were exposed to three O3 treatments: charcoal-filtered air (CFA); non-filtered air, reproducing ambient O3 levels of the site (NFA); and non-filtered air supplemented with 40 nl l-1 (NFA+). Nitrogen was added in biweekly doses to achieve final doses of 5 (N5), 15 (N15) and 30 kg ha-1 (N30), reproducing the N deposition range in the Iberian Peninsula. Ozone negatively affected all the growth-related parameters and increased plant senescent biomass. The pollutant affected subterranean biomass to a greater extent than aerial biomass, resulting in altered aerial/subterranean ratio. Effects in the second experiment followed the same pattern as in the first, but were of lesser magnitude. However, these differences between assays could not be explained adequately by the absorbed O3 fluxes (Phytotoxic Ozone Dose, POD). Concentrations of cell-wall constituents related to nutritive quality increased with the O3 exposure, reducing the Relative Food Value index (RFV) that indicates decreased nutritive quality of the forage. Nitrogen stimulated all growth-related parameters, but increased the aboveground biomass more than the subterranean biomass. No effects of N fertilizer were detected for the nutritive quality parameters. A significant interaction between O3 and N was found in the second experiment. N further enhanced the increase of senescent biomass caused by O3. Results indicate that O3 is a potentially significant environmental stress factor in terms of structure and diversity of Mediterranean pastures.

Sanz, J.; González-Fernández, I.; Calvete-Sogo, H.; Lin, J. S.; Alonso, R.; Muntifering, R.; Bermejo, V.

2014-09-01

333

Physiological and foliar injury responses of Prunus serotina, Fraxinus americana, and Acer rubrum seedlings to varying soil moisture and ozone.  

Science.gov (United States)

Sixteen black cherry (Prunus serotina, Ehrh.), 10 white ash (Fraxinus americana, L.) and 10 red maple (Acer rubrum, L.) 1-year old seedlings were planted per plot in 1997 on a former nursery bed within 12 open-top chambers and six open plots. Seedlings were exposed to three different ozone scenarios (ambient air: 100% O3; non-filtered air: 98% ambient O3; charcoal-filtered air: 50% ambient O3) within each of two different water regimes (nine plots irrigated, nine plots non-irrigated) during three growing seasons. During the 1998 and 1999 growing season, leaf gas exchange, plant water relations, and foliar injury were measured. Climatic data,ambient- and chamber-ozone-concentrations were monitored. We found that seedlings grown under irrigated conditions had similar (in 1998) but significantly higher gas exchange rates (in 1999) than seedlings grown within non-irrigated plots among similar ozone exposures. Cherry and ash had similar ozone uptake but cherry developed more ozone-induced injury (maple rarely showed foliar injury, indicating the species differed in ozone sensitivity. Significantly more severe injury on seedlings grown under irrigated conditions than seedlings grown under non-irrigated conditions demonstrated that soil moisture altered seedling responses to ambient ozone exposures. PMID:12713930

Schaub, M; Skelly, J M; Steiner, K C; Davis, D D; Pennypacker, S P; Zhang, J; Ferdinand, J A; Savage, J E; Stevenson, R E

2003-01-01

334

Red spruce response to ozone and cloudwater after three years exposure  

International Nuclear Information System (INIS)

This study reports on the results of a 3-yr study conducted at a high elevation site in the southern Appalachians to determine if cloudwater and ozone (O3) adversely affect the growth of red spruce seedlings (Picea rubens Sarg.). Field chambers were established at Whitetop Mountain, VA (elevation 1689 m), in 1988. Three replicate chamber treatments were constructed to produce the following treatments: (I) exclusion of clouds and O3 (COE), (II) ambient O3 with clouds removed (CE), and (III) exposure to both clouds and O3 (CC). Ambient air plots (AA) were also included in order to assess possible chamber effects. After 3 yr, seedlings were impacted little by the reduction in pollution levels within the CE and COE chambers. No differences in seedling diameter growth were found for either seedling type, and height growth differences that were detected indicated more height growth in treatments with ambient O3 and cloudwater. Minimal biomass effects were also found. Increased nutrient leaching of needle Ca and Mg was observed in cloudwater treatments, but needle concentrations were not reduced to deficiency levels. Removal of both cloudwater and O3 (COE) did not enhance photosynthesis (Ps) rates for native or GSM seedlings. However, Ps of seedlings in which only cloudwater was removed (CE) was lower in 1-yr-old needles (C+1) of native and GSM seedlings, and in 2-yr-old needles (C+2) of native seedlings. Thesld needles (C+2) of native seedlings. These lower Ps rates of CE seedlings were correlated with lower needle N concentrations, indicating that cloudwater NO3- and NH4+ may have provided a fertilizer effect within AA and CC treatments. Respiration of current year needles of native seedlings was not affected by treatments; however, respiration was lower in older needles in which O3 and cloudwater were removed

335

Estrés oxidativo en un modelo de ratón quemado tratado con Aloe b, ozono y factor de crecimiento epidérmico / Oxidative stress in a model of burnt mouse treated with Aloe b, ozone and epidermal growth factor  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish La enfermedad por quemadura estimula la respuesta inflamatoria sistémica y el daño múltiple de órganos, su expresión morfológica. Con el propósito de identificar el comportamiento del estrés oxidativo mediante el malondialdehído, la superóxido dismutasa y la catalasa y su modificación con el empleo [...] del tratamiento sistémico con Aloe b, ozono o factor de crecimiento epidérmico, se elaboró un modelo de quemadura seca de un área de 11 %, en ratones hembras, balb/c de 20 ± 2 g (n= 24). Se aplicó eutanasia en diferentes tiempos, se estudiaron los órganos con evaluación cualitativa en grados de intensidad y las variables bioquímicas se obtuvieron del riñón y del hígado. La prueba G se empleó para conocer la dependencia entre las variables y la prueba t se usó al comparar porcentajes. El análisis de varianza bifactorial y la prueba de rango múltiple de Duncan se empleó en las variables del estrés oxidativo estudiadas. Se siguieron las normas éticas en el trabajo con los animales. Existió dependencia entre los diferentes grupos y la vitalidad (G= 268,83***) superior en los grupos tratados. Los grupos no tratados tuvieron mayor intensidad del daño múltiple de órganos y peor respuesta del estrés oxidativo. Los grupos con mejor evolución fueron el tratado con ozono y el tratado con factor de crecimiento epidérmico. El tratamiento inmediatamente después de la quemadura con ozono y factor de crecimiento epidérmico resultó favorable para la evolución y supervivencia de los animales. Abstract in english Burn disease stimulates systemic inflammatory response and its morphologic expression that is multiple organ failure. With the objective of identifying the behaviour of oxidative stress through malonaldehyde, superoxide dismutase, and catalase, and its change by using the systemic treatment based on [...] Aloe b, ozone or epidermal growth factor, a dry burn model of a 11 % area in balb/c female mice of 20 ± 2 g (n= 24) was designed. Eutanasia was applied at different moments, organs were studied with qualitative evaluation of intensity degrees, and biochemical variables were analyzed from the kidney and the liver of mice. Test G served to find out dependence among variables and Test t was used to compare percentages. Bifactoral variance analysis and Duncan´s multiple range test were used in the studied oxidative stress variables. Ethical standards on work with animals were complied with. Dependence was observed among the various groups and survival rate (G= 268,83***) was higher in the treated groups. Untreated groups showed more intensive multiple organ damage and worse oxidative stress response. The groups treated with ozone and epidermal growth factor showed better recovery. The treatment with ozone and epidermal growth factor immediately after burning favored recovery and survival of balb/c mice.

Teresita, Montero González; José, Hurtado de Mendoza Amat; José Carlos, García Piñeiro; Niurka A., Llopiz Janer; Silvia, Menéndez Cepero; Jorge, Berlanga Acosta.

2006-09-01

336

Aspects of UV-absorption spectroscopy on ozone in effluents of plasma jets operated in air  

International Nuclear Information System (INIS)

Cold plasmas operating under atmospheric conditions have been in the focus of scientific attention not only due to their use in plasma medicine. Many of these plasma sources most notably produce ozone. This work presents a detailed ozone analysis on an atmospheric-pressure plasma jet operated in ambient air using ultraviolet (UV) absorption spectroscopy. A special focus is placed on the question whether other species are involved, or is the absorption signal due to ozone. For this, the wavelength dependence of the optical depth was measured and compared with the theoretical optical depth including the cross section of ozone. The results show that in the case of a MHz frequency driven atmospheric-pressure argon plasma jet the absorption signal in the UV range is solely due to ozone. Furthermore, this finding is verified by spectroscopic measurements in the IR spectral range. Additional space-resolved ozone density measurements are performed in the effluent of this jet with small oxygen admixtures by means of UV absorption spectroscopy. A funnel-shaped spatial ozone profile is found for all investigated oxygen admixtures. The highest ozone density develops on the effluent axis and in close vicinity to the jet nozzle. The maximal detected value is 1.5 × 1016 cm-3 for an oxygen admixture of 1%. In order to compare the results with non-space-resolved ozone detection methods the ozone net production rate is calculated.culated.

337

Ozone lidar monitoring  

International Nuclear Information System (INIS)

An ozone lidar system was installed at the National Institute for Environmental Studies (36 deg. N, 140 deg. E) in March, 1988 and observation of ozone profiles commenced from August 1988. The lidar system consists of XeCl, XeF and KrF excimer lasers, 2 m and 56 cm telescope optics and data processing systems. Since the Ozone Lidar Monitoring Program of the Center for the Environmental Research started in October 1990, frequent measurements (more than 50 times per year) have been made. After checking the statistical and systematic errors, the ozone profiles were archived. Comparisons between the lidar data and SAGE II satellite data were done for mutual validation and gave good results. Seventy four vertical profiles of ozone archived for the period from August 1990 through December 1991 are presented in this report. The seasonal and altitudinal variations of stratospheric ozone distribution can be explained by generally understood transport and photochemical reaction processes. Longer term monitoring is required to detect trends in the vertical profile of ozone

338

Artificial ozone holes  

CERN Document Server

This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

Dolya, S N

2014-01-01

339

Ozone column and solar zenith angle effects on ozone photolysis  

Science.gov (United States)

The photodissociation of ozone is a primary source of highly reactive hydroxyl radicals that drive daytime atmospheric chemistry. Thus, understanding the radiative processes that effect measurement and modeling of ozone photolysis is critically important to photochemistry. This study examines a counterintuitive relationship between ozone photolysis and variations in total ozone column and solar zenith angle. Results from the National Center for Atmospheric Research (NCAR) Tropospheric Ultraviolet and Visible (TUV) clear sky radiation model indicate that a higher ozone column has a diminishing relative effect on the ozone photolysis for solar zenith angles increasing beyond approximately 65 degrees. This is attributable to the increase in the ozone airmass at high solar zenith angles that results in a decrease in UV-B photons and shifts the ozone photolysis action spectra to higher wavelengths. The effects of modeling variations in altitude, albedo, aerosol attributes and ozone columns are examined and compared with measured data from the NCAR CCD actinic flux spectroradiometers (CAFS).

Hall, S. R.; Ullmann, K.; Madronich, S.; Anderson, B. E.; Hair, J. W.

2010-12-01

340

Growth rates of nucleation mode particles in Hyytiälä during 2003?2009: variation with particle size, season, data analysis method and ambient conditions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the lifetime of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were esti...

Kulmala, M.; Rinne, J.; Peta?ja?, T.; Dal Maso, M.; Patokoski, J.; Manninen, H. E.; Ho?rrak, U.; Asmi, E.; Aalto, P. P.; Hirsikko, A.; Yli-juuti, T.; Nieminen, T.; Riipinen, I.

2011-01-01

 
 
 
 
341

Improvements to the Passive Ozone Measurement System Used by GLOBE Schools  

Science.gov (United States)

A study was conducted to improve the accuracy of the passive ozone sensor Eco-Badge test card/Zikua system (Vistanomics, Inc). Specifically we have determined the relationship between ozone concentration and absorbance (color change) of the tin(II)-diphenylcarbazide complex used on the test cards, and the dependence of the color change upon temperature and humidity. Over 700 ambient measurements of hourly test card absorbances with concurrent temperature and humidity, as well as an independent measurement of ambient ozone (2B Technologies, Model 202) collected during the summer 2006 were used to derive a calibration equation for ozone concentration that compensates for temperature and humidity interactions and provides an uncertainty estimate of the measured ozone using rigorous statistical methods. The equation was then applied to previously reported GLOBE surface ozone data to correct for temperature and humidity. Several GLOBE sites were chosen that had consistently reported concomitant measurements of ozone, temperature and humidity and were also in close proximity geographically to an EPA ozone monitoring station. Preliminary results suggest improved agreement between the revised data and EPA values.

Pippin, M. R.; Mertens, A. E.; Bush, L. C.; Parker, P. A.; Fishman, J.

2007-12-01

342

Impacts of uncertainty in AVOC emissions on the summer RO x budget and ozone production rate in the three most rapidly-developing economic growth regions of China  

Science.gov (United States)

High levels of uncertainty in non-methane volatile organic compound (NMVOC) emissions in China could lead to significant variation in the budget of the sum of hydroxyl (OH) and peroxy (HO2, RO2) radicals (RO x = OH + HO2 + RO2) and the ozone production rate [P(O3)], but few studies have investigated this possibility, particularly with three-dimensional air quality models. We added diagnostic variables into the WRF-Chem model to assess the impact of the uncertainty in anthropogenic NMVOC (AVOC) emissions on the RO x budget and P(O3) in the Beijing-Tianjin-Hebei region, Yangtze River Delta, and Pearl River Delta of China. The WRF-Chem simulations were compared with satellite and ground observations, and previous observation-based model studies. Results indicated that 68% increases (decreases) in AVOC emissions produced 4%-280% increases (2%-80% decreases) in the concentrations of OH, HO2, and RO2 in the three regions, and resulted in 35%-48% enhancements (26%-39% reductions) in the primary RO x production and ˜ 65% decreases (68%-73% increases) of the P(O3) in Beijing, Shanghai, and Guangzhou. For the three cities, the two largest contributors to the RO x production rate were the reaction of O1D + H2O and photolysis of HCHO, ALD2, and others; the reaction of OH + NO2 (71%-85%) was the major RO x sink; and the major contributor to P(O3) was the reaction of HO2 + NO (˜ 65%). Our results showed that AVOC emissions in 2006 from Zhang et al. (2009) have been underestimated by ˜ 68% in suburban areas and by > 68% in urban areas, implying that daily and hourly concentrations of secondary organic aerosols and inorganic aerosols could be substantially underestimated, and cloud condensation nuclei could be underestimated, whereas local and regional radiation was overestimated.

Wang, Feng; An, Junling; Li, Ying; Tang, Yujia; Lin, Jian; Qu, Yu; Chen, Yong; Zhang, Bing; Zhai, Jing

2014-11-01

343

Chloroplastic and stomatal aspects of ozone-induced reduction of net photosynthesis in plants  

Energy Technology Data Exchange (ETDEWEB)

The present thesis relates to ozone-induced reduction of photosynthesis in plants. As a photochemical oxidant O{sub 3} is formed by the interaction of hydrocarbons, nitrogen oxides and oxygen in sunlight. Ozone (O{sub 3}) is the most phytotoxic of all the air pollutants and is known to reduce plant growth and net photosynthesis, cause stomatal closure, induce visible injury, accelerate senescence and induce or inhibit transcription of a variety of genes with a corresponding increase/decrease in protein products. The underlying cellular mechanisms for many of these changes are unknown. Following fields are investigated: Ozone-induced reduction of net photosynthesis; ozone and the photosynthetic apparatus in the chloroplasts; ozone and stomata; ozone effects on plant membranes; protection against ozone injury in plants. 249 refs., 22 figs., 4 tabs.

Torsethaugen, Gro

1998-09-01

344

Ozone: The secret greenhouse gas; Ozon: den hemmelige drivhusgassen  

Energy Technology Data Exchange (ETDEWEB)

The atmospheric ozone not only protects against harmful ultraviolet radiation; it also contributes to the greenhouse effect. Ozone is one of the jokers to make it difficult to calculate the climatic effect of anthropogenic emissions. The greenhouse effect and the ozone layer should not be confused. The greenhouse effect creates problems when it becomes enhanced, so that the earth becomes warmer. The problem with the ozone layer, on the contrary, is that it becomes thinner and so more of the harmful ultraviolet radiation gets through to the earth. However, ozone is also a greenhouse gas and so the greenhouse effect and the ozone layer are connected.

Berntsen, Terje; Tjernshaugen, Andreas

2001-07-01

345

Ozone and Your Health  

Science.gov (United States)

... health effects at lower ozone levels. experience chest tightness or pain when taking a deep breath. Reduce ... even though they have none of the risk factors listed above. There may be a genetic basis ...

346

Ozone health effects  

International Nuclear Information System (INIS)

Ozone is a principal component of photochemical air pollution endogenous to numerous metropolitan areas. It is primarily formed by the oxidation of NOx in the presence of sunlight and reactive organic compounds. Ozone is a highly active oxidizing agent capable of causing injury to the lung. Lung injury may take the form of irritant effects on the respiratory tract that impair pulmonary function and result in subjective symptoms of respiratory discomfort. These symptoms include, but are not limited to, cough and shortness of breath, and they can limit exercise performance. The effects of ozone observed in humans have been primarily limited to alterations in respiratory function, and a range of respiratory physiological parameters have been measured as a function of ozone exposure in adults and children. These affects have been observed under widely varying (clinical experimental and environmental settings) conditions

347

eu directive on ozone  

...against harmful effects on human health from exposure to ozone. The...for the protection of human health and for the protection of...providing effective protection of human health and the environment. Long-term...

348

Ozone: Concentration variabilities in a seasonally dry tropical climate  

International Nuclear Information System (INIS)

This paper reports seasonal and diurnal variations in the ambient air concentrations of ozone in Varanasi city, India for the years 1989 and 1990. Different monitoring zones were established in the city on the basis of pollution sources, traffic densities, and structure of built-up areas. At most of the monitoring stations, two-hourly ozone concentrations frequently exceeded 60 ?g m-3 during summer months. However, the zone dominated by residential colonies, offices, and cultivated land showed maximum O3 concentrations less than 60 ?g m-3. Higher concentrations of ozone were mainly recorded in warmer months between 11 am to 4 pm. The highest concentration of 160 ?g m-3 O3 was recorded in the month of April at Zone I which was mainly due to emissions from heavy-duty automobiles. Monthly average ozone concentrations were significantly correlated with temperature, relative humidity, wind speed, and atmospheric pressure. The frequency distribution of 2-h mean ozone concentrations was close to the logarithmic normal. Maximum 2-h mean O3 concentrations in some areas of Varanasi city were above the limit that has been shown to cause significant vegetation damage. The temporal variation in ozone concentrations was mainly due to the variations in meteorological conditions

349

Photochemical processes and ozone production in Finnish conditions  

Energy Technology Data Exchange (ETDEWEB)

Photochemical ozone production is observed in March-September. Highest ozone concentrations and production efficiencies are observed in spring in the northern parts and in summer in the southern parts of the country. VOC concentrations are relatively low compared to continental areas in general. During the growing season a substantial part of the total reactive mass of VOCs is of biogenic origin. Large forest areas absorb ozone substantially, decreasing the ambient ozone concentrations in central and northern parts of Finland where long-range transport of ozone is relatively important compared to local production. The aim of the work conducted at Finnish Meteorological Institute has been to characterise concentrations of photochemically active species in the boundary layer and their photochemical formation and deposition including the effects on vegetation. Also interactions between the boundary layer and free troposphere of ozone have been studied. In the future, fluxes of both biogenic species and air pollutants will be measured and the models will be further developed so that the photochemical and micrometeorological processes could be better understood

Laurila, T.; Hakola, H. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.

1996-12-31

350

Fields of ozone applications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The powerful oxidative action of ozone provides basis for development of novel or improved technologies which are widely used in ecology and industry. Special attention is paid to purification of waste gases, water, and soils. The disinfection and cleaning of drinking and process water are considered in detail. Applications of ozone in chemical, pharmaceutical and perfume industries, cosmetics, cellulose, paper and sugar industries, flotation, microelectronics, and man...

Rakovsky, Slavcho; Anachkov, Metody; Zaikov, Gennady

2009-01-01

351

Assessment of ozone effects on local rice cultivar by portable ozone fumigation system in Hanoi, Vietnam.  

Science.gov (United States)

This study examined the effects of troposphere ozone (O3) on rice by developing a portable ozone fumigation system and applied to the field in Hanoi, Vietnam. The system was nearly identical to the open top chamber but designed to easily and cheaply assess the O3 sensitivity of local agricultural crops in the actual field. The rice (Oryza sativa L.) was exposed to ozone during the flowering stage at peri-urban experimental site of Hanoi. The fumigation protocols covered five different levels, namely; non-filtered air (ambient) as the control treatment, 32, 62, 85 and 113 ppb in 7-h mean. It was found that observed impacts corresponded well to similar open-top chamber studies in other Asian countries. The methodology and the system left a large room for improvement and called for very careful interpretation and pre-conditions (e.g. low ambient O3 concentration). However, the portable O3 exposure in the field might open a door to the less developed countries to implement the phytotoxic risk assessment of the local agricultural species. PMID:18670900

Van, Dinh Thi Hai; Ishii, Satoshi; Oanh, Nguyen Thi Kim

2009-08-01

352

The ozone backlash  

Energy Technology Data Exchange (ETDEWEB)

While evidence for the role of chlorofluorocarbons in ozone depletion grows stronger, researchers have recently been subjected to vocal public criticism of their theories-and their motives. Their understanding of the mechanisms of ozone destruction-especially the annual ozone hole that appears in the Antarctic-has grown stronger, yet everywhere they go these days, they seem to be confronted by critics attacking their theories as baseless. For instance, Rush Limbaugh, the conservative political talk-show host and now-best-selling author of The Way Things Ought to Be, regularly insists that the theory of ozone depletion by CFCs is a hoax: bladerdash and poppycock. Zoologist Dixy Lee Ray, former governor of the state of Washington and former head of the Atomic Energy Commission, makes the same argument in her book, Trashing the Planet. The Wall Street Journal and National Review have run commentaries by S. Fred Singer, a former chief scientists for the Department of Transportation, purporting to shoot holes in the theory of ozone depletion. Even the June issue of Omni, a magazine with a circulation of more than 1 million that publishes a mixture of science and science fiction, printed a feature article claiming to expose ozone research as a politically motivated scam.

Taubes, G.

1993-06-11

353

Ozone depletion calculations  

International Nuclear Information System (INIS)

Models of stratospheric chemistry have been primarily directed toward an understanding of the behavior of stratospheric ozone. Initially this interest reflected the diagnostic role of ozone in the understanding of atmospheric transport processes. More recently, interest in stratospheric ozone has arisen from concern that human activities might affect the amount of stratospheric ozone, thereby affecting the ultraviolet radiation reaching the earth's surface and perhaps also affecting the climate with various potentially severe consequences for human welfare. This concern has inspired a substantial effort to develop both diagnostic and prognostic models of stratospheric ozone. During the past decade, several chemical agents have been determined to have potentially significant impacts on stratospheric ozone if they are released to the atmosphere in large quantities. These include oxides of nitrogen, oxides of hydrogen, chlorofluorocarbons, bromine compounds, fluorine compounds and carbon dioxide. In order to assess the potential impact of the perturbations caused by these chemicals, mathematical models have been developed to handle the complex coupling between chemical, radiative, and dynamical processes. Basic concepts in stratospheric modeling are reviewed

354

Enviropedia: Introduction to Ozone Depletion  

Science.gov (United States)

This resource describes the depletion of ozone in the upper atmosphere, which filters out incoming radiation in the cell-damaging ultraviolet (UV) part of the spectrum. Other topics include a detailed description of the chemical interaction between chlorofluorocarbons (CFCs) and ozone and a list of other ozone depleting chemicals. Information is also available on the ozone layer, ozone holes above Antarctica and the Arctic, the polar vortex, methods of measuring and monitoring ozone depletion and efforts to reverse the problem, including the Montreal Protocol.

355

Ozone: The secret greenhouse gas  

International Nuclear Information System (INIS)

The atmospheric ozone not only protects against harmful ultraviolet radiation; it also contributes to the greenhouse effect. Ozone is one of the jokers to make it difficult to calculate the climatic effect of anthropogenic emissions. The greenhouse effect and the ozone layer should not be confused. The greenhouse effect creates problems when it becomes enhanced, so that the earth becomes warmer. The problem with the ozone layer, on the contrary, is that it becomes thinner and so more of the harmful ultraviolet radiation gets through to the earth. However, ozone is also a greenhouse gas and so the greenhouse effect and the ozone layer are connected

356

Consequences of ozone depletion for terrestrial plant productivity  

International Nuclear Information System (INIS)

Many plants are greatly affected by increases in UV-B radiation but there is tremendous variability in their sensitivity. Plants have evolved natural adaptations such as anatomical, morphological and biochemical features which protect them from UV-B radiation. The extent of these natural adaptations may be related to the geographic origin of the species. For example, species originating from areas receiving high ambient levels of UV-B radiation were found to be highly resistant to UV-B radiation. In sensitive species, photosynthetic activity may be reduced by direct effects on photosynthetic enzymes and metabolic pathways or by indirect effects on photosynthetic pigments or stomatal function. The fluence response of these changes has yet to be clearly demonstrated in most cases. These biochemical and physiological responses may result in reduced growth (plant height, dry weight, leaf area, etc.) photosynthetic activity and flowering. Approximately half of the species tested appear sensitive and sensitivity also differs greatly among cultivars of the same species. Increases in UV-B radiation resulting from stratospheric ozone depletion could alter productivity in some species, as shown in field studies with soybean and loblolly pine. However, in order to assess the magnitude of such changes, we must further understand the mechanisms of UV-B protection in tolerant species and damage in sensitive species as well as the potential indirect effects such as changes in competindirect effects such as changes in competitive interactions or ecosystem processes

357

The VOC-ozone connection: a grassland case study  

Science.gov (United States)

Tropospheric ozone (O3) is formed in the presence of sunlight through the interaction of volatile organic compounds (VOCs) and NOX (NO, NO2). A photochemical equilibrium exists between NO, NO2 and O3; however in the presence of VOCs this equilibrium is broken and additional O3 is produced. O3 damages plants in several ways, most importantly by reducing net photosynthesis and growth. The extent of this damage depends on the time-integrated absorbed O3 flux (i.e. the dose), which is a function of leaf stomatal conductance and ambient O3 concentration, and further influenced by plant species specific defence mechanisms. VOCs are produced by plants through a variety of pathways and in response to large number of different driving forces. A large variety of VOCs are emitted by plants in response to stress conditions, including the foliar uptake of O3. Here we present preliminary data from an ongoing study where concurrent measurements of the fluxes of VOCs and O3 are made above a managed mountain grassland in Tyrol/Austria. Fluxes of several different VOCs are measured by means of the eddy covariance method and a proton transfer reaction mass spectrometer (PTR-MS). Fluxes of O3 are measured by both the eddy covariance method and a modified Bowen-ratio approach. The data analysis will try to identify whether VOC emissions change with the time-integrated uptake of O3 by plants.

Wohlfahrt, G.; Hoertnagl, L.; Bamberger, I.; Schnitzhofer, R.; Dunkel, J.; Hammerle, A.; Graus, M.; Hansel, A.

2008-12-01

358

Evaluation of vegetation near coal-burning power plants in southwestern Pennsylvania. II. Ozone injury on foliage of hybrid poplar. [USA - Pennsylvania  

Energy Technology Data Exchange (ETDEWEB)

The objective of this study was to determine if the incidence or severity of foliar injury induced by regional, ambient ozone was influenced by local emissions from a complex of coal-burning power plants in southwestern Pennsylvania. Plantings of an ozone-sensitive hybrid poplar clone (Populus maxiomwizii x trichocarpa, clone NE 388) were established in 1972 at various distances and directions from the power plants. Foliar injury caused by ambient ozone was evaluated annually from 1973 to 1990 in early to mid-August. Data are presented for the 12-year period, 1979 to 1990 inclusive, for which the most complete data sets were available. Injury from ambient ozone varied spatially and temporally, but with little relationship to power plant location. There was an apparent negative relationship between emission trends and ozone-induced symptoms, but only for one power plant. The correlation between annual mean levels of ozone-induced stipple and frequency of days (per year) with a 1-hr ozone maximum exceeding 0.04 ppm was weak, but significant. Ozone-induced bifacial necrosis was not observed on the foliage of the hybrid poplar during the drought year of 1988 in spite of record high levels of ozone; however, ozone-induced stipple was observed. 21 refs., 4 figs., 2 tabs.

Davis, D.D.; Hutnik, R.J.; McClenahen, J.R. (Pennsylvania State University, University Park, PA (USA). Dept. of Plant Pathology)

1993-05-01

359

Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches  

International Nuclear Information System (INIS)

We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O3) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O3, i.e. O3 levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O3 and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels. - Northern birches are responsive to ambient ozone levels.

360

The effect of winter stress on Ilex aquifolium L.previously fumigated with ozone.  

Science.gov (United States)

European Holly (Ilex aquifolium) received either charcoal-filtered air (CFA) or CFA with 70 nl l(-1) ozone added for 7 h day(-1) over a 28 day period. Plants were then transferred into cooling incubators for hardening (4 degrees C day/2 degrees C night; day length 12 h) for 7 days and then to the frosting stage (2 degrees C day and -5, -10 or -15 degrees C night) for 4 days. The plants were then placed in ambient conditions. Treatment produced significant differences in chlorophyll fluorescence data. Stomatal conductance was significantly higher for the ozone treatments though both showed a general decline over all temperature regimes. Ozone also significantly increased electrolyte leakage and reduced winter survival. These results show that ambient concentrations of ozone can reduce the tolerance of I. aquifolium to freezing stress, which may have serious implications for its establishment and survival. PMID:16707198

Ranford, Jonathan; Reiling, Kevin

2007-01-01

 
 
 
 
361

Effect of ambient-level gas-phase peroxides on foliar injury, growth, and net photosynthesis in Japanese radish (Raphanus sativus)  

Energy Technology Data Exchange (ETDEWEB)

To investigate the effects of ambient-level gas-phase peroxides concurrent with O{sub 3} on foliar injury, photosynthesis, and biomass in herbaceous plants, we exposed Japanese radish (Raphanus sativus) to clean air, 50 ppb O{sub 3}, 100 ppb O{sub 3}, and 2-3 ppb peroxides + 50 ppb O{sub 3} in outdoor chambers. Compared with exposure to 100 ppb O{sub 3}, exposure to 2-3 ppb peroxides + 50 ppb O{sub 3} induced greater damage in foliar injury, net photosynthetic rates and biomass; the pattern of foliar injury and the cause of net photosynthetic rate reduction also differed from those occurring with O{sub 3} exposure alone. These results indicate for the first time that sub-ppb peroxides + 50 ppb O{sub 3} can cause more severe damage to plants than 100 ppb O{sub 3}, and that not only O{sub 3}, but also peroxides, could be contributing to the herbaceous plant damage and forest decline observed in Japan's air-polluted urban and remote mountains areas. - Ambient-level gas-phase peroxides coexisted with 50 ppb O{sub 3} may contribute to the herbaceous plants damage and forest decline observed in Japan.

Chen Xuan, E-mail: xuan66chen@yahoo.co.j [Chinese Research Academy of Environmental Science, No.8, Dayangfang, Anwai, Chaoyang District, Beijing 100012 (China); Aoki, Masatoshi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu-shi, Tokyo 183-8509 (Japan); Takami, Akinori [National Institute for Environmental Studies, Onogawa 16-2, Tsukuba-shi, Ibaraki 305-8506 (Japan); Chai Fahe [Chinese Research Academy of Environmental Science, No.8, Dayangfang, Anwai, Chaoyang District, Beijing 100012 (China); Hatakeyama, Shiro [Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu-shi, Tokyo 183-8509 (Japan)

2010-05-15

362

Effect of ambient-level gas-phase peroxides on foliar injury, growth, and net photosynthesis in Japanese radish (Raphanus sativus)  

International Nuclear Information System (INIS)

To investigate the effects of ambient-level gas-phase peroxides concurrent with O3 on foliar injury, photosynthesis, and biomass in herbaceous plants, we exposed Japanese radish (Raphanus sativus) to clean air, 50 ppb O3, 100 ppb O3, and 2-3 ppb peroxides + 50 ppb O3 in outdoor chambers. Compared with exposure to 100 ppb O3, exposure to 2-3 ppb peroxides + 50 ppb O3 induced greater damage in foliar injury, net photosynthetic rates and biomass; the pattern of foliar injury and the cause of net photosynthetic rate reduction also differed from those occurring with O3 exposure alone. These results indicate for the first time that sub-ppb peroxides + 50 ppb O3 can cause more severe damage to plants than 100 ppb O3, and that not only O3, but also peroxides, could be contributing to the herbaceous plant damage and forest decline observed in Japan's air-polluted urban and remote mountains areas. - Ambient-level gas-phase peroxides coexisted with 50 ppb O3 may contribute to the herbaceous plants damage and forest decline observed in Japan.

363

Magnitude, decadal changes, and impact of regional background ozone transported into the greater Houston, Texas, area.  

Science.gov (United States)

Two independent analyses of the daily maximum 8 h average ozone concentrations measured during the high ozone season (May through October) at Continuous Ambient Monitoring Stations are used to quantify the regional background ozone transported into the Houston-Galveston-Brazoria (HGB) area. The dependence on wind direction is examined, and long-term trends are determined using measurements made between 1998 and 2012. Both analyses show that the regional background ozone has declined during periods of continental outflow: i.e., the conditions associated with most high ozone episodes in HGB. The changes in regional background ozone found for northeasterly and southeasterly flow are -0.50 ± 0.54 and -0.79 ± 0.65 (95% confidence limit) ppbv yr(-1), respectively, which correspond to decreases of ?7-11 ppbv between 1998 and 2012. This finding is consistent with the summertime downward trend of -0.45 ppbv yr(-1) (range of sites: -0.87 to +0.07 ppbv yr(-1)) for ozone in the eastern U.S. between 1990 and 2010 reported by Cooper et al. and shows that changing background concentrations are at least partially responsible for