The Experts below are selected from a list of 342 Experts worldwide ranked by ideXlab platform
William J Manning - One of the best experts on this subject based on the ideXlab platform.
-
the first toxicological study of the antiozonant and research tool ethylene diurea edu using a lemna minor l bioassay hints to its mode of action
Environmental Pollution, 2016Co-Authors: Eugenios Agathokleous, Elena Paoletti, Akrivichara Mouzakipaxinou, Costas J Saitanis, William J ManningAbstract:The antiozonant and research tool ethylene diurea (EDU) is widely studied as a phytoprotectant against the widespread pollutant ground-surface ozone. Although it has been extensively used, its potential toxicity in the absence of ozone is unknown and its mode of action is unclear. The purpose of this research was to toxicologically assess EDU and to further investigate its mode of action using Lemna minor L. as a model organism. Application of EDU concentrations greater than 593 mg L(-1) (practically 600 mg L(-1)) resulted in adverse inhibition of colony growth. As no-observed-toxic-effects concentration (NOEL) we recommend a concentration of 296 mg L(-1) (practically 300 mg L(-1)). A hormetic response was detected, i.e. stimulatory effects of low EDU concentrations, which may indicate overcompensation in response to disruption in homeostasis. Growth inhibition and suppressed biomass were associated with impacted chlorophyll a fluorescence (ΦPSII, qP and ETR). Furthermore, EDU increased mesophyll thickness, as indicated by frond succulence index. Applications of concentrations ≥593 mg L(-1) to uncontrolled environments should be avoided due to potential toxicity to sensitive organisms and the environment.
-
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
Environmental Pollution, 2009Co-Authors: Elena Paoletti, William J Manning, N Contran, Anna Maria FerraraAbstract:Twenty-four experiments where EDU was used to protect plants from ozone (O(3)) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O(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 ( 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(3) exposure. Preliminary results suggest developing an effective soil application method for forest trees is warranted.
-
dynamics of growth and biomass partitioning in field grown bush bean phaseolus vulgaris l treated with the antiozonant ethylenediurea edu
Agriculture Ecosystems & Environment, 1993Co-Authors: Reinhard Kostkarick, William J ManningAbstract:Abstract The anti-ozonant ethylenediurea (EDU) approach was used to assess the effects of ambient ozone (O3) air pollution on development, growth and biomass partitioning in bush bean (Phaseolus vulgaris L. cultivar ‘BBL 290’) during five staggered plantings in 1989 and 1990. The (EDU) was applied as a soil drench twice during plant development: after unfolding of primary leaves and at early flowering. The concentration of EDU used (100 mg l−1) was considerably lower than in earlier studies, but had proven to protect bean plants from O3 injury without altering growth in previous greenhouse studies. Plants were harvested in 5 day intervals from emergence through maturity. Ambient O3 was low during the five plantings (24 h mean: 28–33 nl l−1; 7 h mean: 45–49 nl−1 O3), but number of hours and cumulative exposure > 90 nl l−1 O3 during the fifth planting was considerably higher compared with the other growth intervals. Total plant weight of EDU-treated plants fell below that of untreated plants after the second application of EDU during most of the plantings. During the fifth planting, however, total dry weight of EDU-treated plants was equal to that of untreated ones. Pod dry weight exhibited a similar pattern, and relative pod weight was reduced by EDU during late pod development in two plantings. Patterns of biomass allocation to other plant organs (foliage, stem, root) were not altered by the EDU treatments. The reduction in pod weight of EDU-treated plants was not due to a reduced number of flowers or young pods, which was actually slightly increased by the EDU treatments, but was caused by an increased rate of pod abscission during maturity. It is concluded that the second EDU soil drench was timed too early to provide protection throughout pod development and maturation. Increases in flower and bud duration and a delay in primary leaf abscission demonstrated the action of EDU in delaying maturation and senescence. From these results it is suggested that repeated soil drenches of EDU may cause reductions in the total plant weight and pod weight of a O3-sensitive bean cultivar if the exposure to ambient O3 is low. Conclusions for the further use of EDU are discussed.
-
dose response studies with the antiozonant ethylenediurea edu applied as a soil drench to two growth substrates on greenhouse grown varieties of phaseolus vulgaris l
Environmental Pollution, 1993Co-Authors: Reinhard Kostkarick, William J ManningAbstract:Abstract To study plant growth and yield effects of the antiozonant ethylenediurea (EDU), which is frequently used for ozone crop loss assessments, dose-response studies were carried out with potted bean plants under greenhouse conditions in winter and spring. Two cultivars of Phaseolus vulgaris L., differing in sensitivity to ozone (O3), were grown in unfiltered air on a sandy loam rich in organic matter and on a vermiculite-clay mixture. Four treatments of EDU at concentrations from 300 to 800 mg liter−1 were given as a soil drench during plant development. Foliar symptoms of EDU phytoxicity were observed at all doses, and plant biomass, particularly pod dry weight, was considerably reduced to increasing doses of EDU. Primary and first trifoliate leaf weight in EDU-treated plants increased as did the number of buds, indicating an extension of vegetative growth and a delay of reproductive processes. ‘BBL 290’ beans, which are O3-sensitive, were injured by EDU more than the O3-tolerant ‘BBL 274’. The phytotoxic effects of EDU were more pronounced in the synthetic growth substrate than in field soil. In a second experiment, EDU was applied in concentrations from 100 to 400 mg liter−1 to ‘BBL 290’ plants, exposed to filtered air or simulated levels of O3 pollution. In field soil, plant growth and biomass partitioning in filtered air was only slightly altered by EDU, although leaf injury due to EDU occured. In the vermiculite-clay mix, the biomass of most plant organs, particularly that of roots, was linearly reduced with increasing EDU doses. O3 did not cause any alteration in plant biomass in field soil-grown and EDU-treated plants. Ozone leaf injury, which affected 67% of primary leaf area in non-treated plants, was completely suppressed by EDU doses as low as 100 mg liter−1. This indicates that low concentrations of EDU, which do not affect plant growth in field soil, provide sufficient protection from O3 injury. The need for careful EDU dose-response studies prior to field assessments is emphasized.
Sungseen Choi - One of the best experts on this subject based on the ideXlab platform.
-
influence of rubber composition on migration behaviors of Antiozonants in carbon black filled rubber vulcanizates composed of nr sbr and br
Journal of Applied Polymer Science, 2001Co-Authors: Sungseen ChoiAbstract:Migration behaviors of Antiozonants in carbon black-filled rubber vulcanizates with different rubber compositions of natural rubber (NR), styrene–butadiene rubber (SBR), and butadiene rubber (BR) were studied at constant temperatures of 40–100°C and outdoors. Three single rubber-based vulcanizates, three biblends, and three triblends were used. N-Phenyl-N′-isopropyl-p-phenylenediamine (IPPD) and N-phenyl-N′-(1,3-dimethylbutyl)-p-phenylenediamine (HPPD) were employed as Antiozonants. Migration rates of the Antiozonants became faster with increasing the temperature. The order of the migration rates in the single rubber-based vulcanizates was BR > NR > SBR. The migration rates in the vulcanizates containing SBR, on the whole, increased with decreasing the SBR content, while those in the vulcanizates containing BR decreased with decreasing the BR content. Difference in the migration behaviors of the Antiozonants depending on the rubber composition was explained both by the intermolecular interactions of the Antiozonants with the matrix and by interface formed between dissimilar rubbers in the blends. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 237–242, 2001
-
Correlation between migration behaviors of Antiozonants and temperature
Journal of Applied Polymer Science, 2001Co-Authors: Sungseen ChoiAbstract:Migration behaviors of Antiozonants depending on temperature were studied using a carbon black-filled NR vulcanizate containing N-phenyl-N′-isopropyl-p-phenylenediamine (IPPD) and N-phenyl-N′-(1,3-dimethylbutyl)-p-phenylenediamine (HPPD) as Antiozonants. The experimental temperatures were 100, 90, 80, and 70°C. Migration rates of them increased steeply by increasing the temperature. The correlation between the migration rates and the temperature was investigated using the half (t1/2)- and quarter (t1/4)-lifetimes of the migrants remaining in the vulcanizate after the migration. The plot of log t versus 1/T was well fitted by the linear equation: The correlation coefficients were higher than 0.995. It was found that the migration behavior and temperature had a correlation of log t = b/T + c, where t and T are the migration time and temperature, b is Ea/R, and c is the constant. The activation energies for the migration were 36.48 and 37.93 kJ/mol for IPPD and HPPD, respectively. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1566–1570, 2001
-
migration behaviors of Antiozonants in triblend vulcanizates of nr sbr and br
Elastomers and Composites, 2000Co-Authors: Sungseen ChoiAbstract:NR, SBR, BR 둥 3가지 고무로 이루어진 가류물에서 고무 조성비가 노화방지제의 이동 거동에 미치는 영향에 대해 연구하였다. 3가지 고무 중 2가지의 함량은 동일하게 하였고 나머지 하나만 다르게 하였다. IPPD와 HPPD를 오존노화방지제로 사용하였다. 실험은 $60^{\circ}C$ 에서 21일간 방치하는 것과 옥외에서 4개월간 방치하는 것으로 진행하였다. 노화방지제의 이동 속도는 고무 조성비가 NR/SBR/BR = 1/1/0.2에서 1/1/1로 증가함에 따라 증가하다가 1/1/1에서 최대를 나타내 후 다시 감소하였다. 3가지 고무로 이루어진 가류물에서 고무 조성비에 따른 노화방지제의 이동 거동의 변화는 고무와 노화방지제 간의 친화력, 고무에 대한 노화방지제의 융해도, 그리고 이질 고무간에 형성된 경계면 등으로 설명할 수 있었다. 【Influence of rubber composition on migration of Antiozonants to the surface in ternary rubber-based vulcanizates composed of natural rubber (NR) styrene-butadiene rubber (SBR), and butadiene rubber (BR) was studied. Of the three rubbers, contents of two rudders were same and only the other one content was different (variable rubber) IPPD and HPPD were employed as Antiozonants. Migration experiments were performed at $60^{\circ}C$ for 21 days and outdoors for 4 months. Migration rates of the Antiozonants increase by increasing the content ratio of the variable rubber in the vulcanizares from NR/SBR/BR=1/1/0.2 to 1/1/1 and then decrease with an increase of the content ratio of the variable rudder from 1/1/1 to 1/1/5. Migration behaviors of the Antiozonants in the ternary rudder-based vulcanizates depending on the rubber composition were explained by the intermolecular interactions between rubber and antiozonant, by the solubility difference of the Antiozonants for the rubbers, and by the interface formed between dissimilar rubbers in the triblends.】
-
migration behaviors of Antiozonants in binary rubber based vulcanizates of nr sbr and br
Journal of Applied Polymer Science, 1999Co-Authors: Sungseen ChoiAbstract:Influence of rubber composition on migration of N-phenyl-N′-isopropyl-p-phenylenediamine (IPPD), and N-phenyl-N′-(1,3-dimethylbutyl)-p-phenylenediamine (HPPD) to the surface in binary rubber-based vulcanizates of natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) was studied. Migration experiments were performed at 60 and 80°C for 21 days and outdoors for 4 months. Migration rates of IPPD and HPPD in the vulcanizates of SBR/NR and BR/NR blends outdoors increased by decreasing the content of NR, and those in the vulcanizates of BR/SBR blends decreased with an increase of the content of BR. Migration behaviors of the Antiozonants in the vulcanizates of SBR/NR and BR/NR blends at 60 and 80°C, on the whole, showed trends similar to the outdoor results. Migration rates of the Antiozonants in the vulcanizates of BR/SBR blends at 60 and 80°C showed some differences. Variation of migration behaviors of the Antiozonants in the binary rubber-based vulcanizates depending on rubber composition was explained by the interface between dissimilar rubbers and the intermolecular interactions between the matrices and the Antiozonants. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3130–3136, 1999
-
migration behaviors of Antiozonants to the surface in nr vulcanizates depending on the season the effect of wax
Journal of Applied Polymer Science, 1999Co-Authors: Sungseen ChoiAbstract:Influence of wax film on the surface of a a rubber vulcanizate on migration of Antiozonants was studied using NR vulcanizates containing various types of waxes. The waxes have different molecular weight distributions. N-phenyl-N'-isopropyl-p-phenyl-enediamine (IPPD), N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (HPPD), N,N'-di(sec-butyl)-p-phenylenediamine (SBPPD), and N,N'-di(1,4-dimethylpentyl)-p-phenylenediamine (DMPPD) were used as Antiozonants. Migration experiments were performed outdoors for two months in the summer, fall, and winter. The migration rates of the Antiozonants in the vulcanizate without wax are faster than those in the vulcanizates with waxes. The Antiozonants migrate slower in the vulcanizate containing wax with a high-molecular-weight distribution than in the vulcanizate with a low one. In the summer, the migration rates of SBPPD and DMPPD are faster than those of IPPD and HPPD, respectively. But, in the fall, the migration rates of SBPPD and DMPPD are slower than those of IPPD and HPPD, respectively. The differences of migration behaviors of the Antiozonants, depending on season and wax type, was discussed.
Reinhard Kostkarick - One of the best experts on this subject based on the ideXlab platform.
-
dynamics of growth and biomass partitioning in field grown bush bean phaseolus vulgaris l treated with the antiozonant ethylenediurea edu
Agriculture Ecosystems & Environment, 1993Co-Authors: Reinhard Kostkarick, William J ManningAbstract:Abstract The anti-ozonant ethylenediurea (EDU) approach was used to assess the effects of ambient ozone (O3) air pollution on development, growth and biomass partitioning in bush bean (Phaseolus vulgaris L. cultivar ‘BBL 290’) during five staggered plantings in 1989 and 1990. The (EDU) was applied as a soil drench twice during plant development: after unfolding of primary leaves and at early flowering. The concentration of EDU used (100 mg l−1) was considerably lower than in earlier studies, but had proven to protect bean plants from O3 injury without altering growth in previous greenhouse studies. Plants were harvested in 5 day intervals from emergence through maturity. Ambient O3 was low during the five plantings (24 h mean: 28–33 nl l−1; 7 h mean: 45–49 nl−1 O3), but number of hours and cumulative exposure > 90 nl l−1 O3 during the fifth planting was considerably higher compared with the other growth intervals. Total plant weight of EDU-treated plants fell below that of untreated plants after the second application of EDU during most of the plantings. During the fifth planting, however, total dry weight of EDU-treated plants was equal to that of untreated ones. Pod dry weight exhibited a similar pattern, and relative pod weight was reduced by EDU during late pod development in two plantings. Patterns of biomass allocation to other plant organs (foliage, stem, root) were not altered by the EDU treatments. The reduction in pod weight of EDU-treated plants was not due to a reduced number of flowers or young pods, which was actually slightly increased by the EDU treatments, but was caused by an increased rate of pod abscission during maturity. It is concluded that the second EDU soil drench was timed too early to provide protection throughout pod development and maturation. Increases in flower and bud duration and a delay in primary leaf abscission demonstrated the action of EDU in delaying maturation and senescence. From these results it is suggested that repeated soil drenches of EDU may cause reductions in the total plant weight and pod weight of a O3-sensitive bean cultivar if the exposure to ambient O3 is low. Conclusions for the further use of EDU are discussed.
-
dose response studies with the antiozonant ethylenediurea edu applied as a soil drench to two growth substrates on greenhouse grown varieties of phaseolus vulgaris l
Environmental Pollution, 1993Co-Authors: Reinhard Kostkarick, William J ManningAbstract:Abstract To study plant growth and yield effects of the antiozonant ethylenediurea (EDU), which is frequently used for ozone crop loss assessments, dose-response studies were carried out with potted bean plants under greenhouse conditions in winter and spring. Two cultivars of Phaseolus vulgaris L., differing in sensitivity to ozone (O3), were grown in unfiltered air on a sandy loam rich in organic matter and on a vermiculite-clay mixture. Four treatments of EDU at concentrations from 300 to 800 mg liter−1 were given as a soil drench during plant development. Foliar symptoms of EDU phytoxicity were observed at all doses, and plant biomass, particularly pod dry weight, was considerably reduced to increasing doses of EDU. Primary and first trifoliate leaf weight in EDU-treated plants increased as did the number of buds, indicating an extension of vegetative growth and a delay of reproductive processes. ‘BBL 290’ beans, which are O3-sensitive, were injured by EDU more than the O3-tolerant ‘BBL 274’. The phytotoxic effects of EDU were more pronounced in the synthetic growth substrate than in field soil. In a second experiment, EDU was applied in concentrations from 100 to 400 mg liter−1 to ‘BBL 290’ plants, exposed to filtered air or simulated levels of O3 pollution. In field soil, plant growth and biomass partitioning in filtered air was only slightly altered by EDU, although leaf injury due to EDU occured. In the vermiculite-clay mix, the biomass of most plant organs, particularly that of roots, was linearly reduced with increasing EDU doses. O3 did not cause any alteration in plant biomass in field soil-grown and EDU-treated plants. Ozone leaf injury, which affected 67% of primary leaf area in non-treated plants, was completely suppressed by EDU doses as low as 100 mg liter−1. This indicates that low concentrations of EDU, which do not affect plant growth in field soil, provide sufficient protection from O3 injury. The need for careful EDU dose-response studies prior to field assessments is emphasized.
Elena Paoletti - One of the best experts on this subject based on the ideXlab platform.
-
the first toxicological study of the antiozonant and research tool ethylene diurea edu using a lemna minor l bioassay hints to its mode of action
Environmental Pollution, 2016Co-Authors: Eugenios Agathokleous, Elena Paoletti, Akrivichara Mouzakipaxinou, Costas J Saitanis, William J ManningAbstract:The antiozonant and research tool ethylene diurea (EDU) is widely studied as a phytoprotectant against the widespread pollutant ground-surface ozone. Although it has been extensively used, its potential toxicity in the absence of ozone is unknown and its mode of action is unclear. The purpose of this research was to toxicologically assess EDU and to further investigate its mode of action using Lemna minor L. as a model organism. Application of EDU concentrations greater than 593 mg L(-1) (practically 600 mg L(-1)) resulted in adverse inhibition of colony growth. As no-observed-toxic-effects concentration (NOEL) we recommend a concentration of 296 mg L(-1) (practically 300 mg L(-1)). A hormetic response was detected, i.e. stimulatory effects of low EDU concentrations, which may indicate overcompensation in response to disruption in homeostasis. Growth inhibition and suppressed biomass were associated with impacted chlorophyll a fluorescence (ΦPSII, qP and ETR). Furthermore, EDU increased mesophyll thickness, as indicated by frond succulence index. Applications of concentrations ≥593 mg L(-1) to uncontrolled environments should be avoided due to potential toxicity to sensitive organisms and the environment.
-
mycorrhizal status of an ozone sensitive poplar clone treated with the antiozonant ethylene diurea
European Journal of Forest Research, 2014Co-Authors: Marina Katanic, Elena Paoletti, Sasa Orlovic, Tine Grebenc, Hojka KraigherAbstract:The antiozonant ethylene diurea is proven to prevent growth reductions in forest trees induced by ozone. The community of mycorrhizal fungi could be useful indicator of environmental stress. In this study, response of mycorrhizal fungi and fine roots to a 4-year exposure to ambient ozone and treatment with antiozonant was investigated in ozone-sensitive poplar clone under field conditions. The community of ectomycorrhizal fungi and root length colonization with ectomycorrhizal, arbuscular mycorrhizal fungi, and root endophytic fungi was analyzed in antiozonant-treated poplar plants and in poplar plants irrigated with water. In general, plants protected by antiozonant showed higher total number of fine roots, number of ectomycorrhizal types, Shannon–Weaver diversity index, and Species richness index compared to the plants treated with water. The ectomycorrhizal community shifted from contact exploration type in the trees irrigated with water to short-distance exploration type in ethylene diurea-treated trees. Ozone protectant may beneficially affect the belowground community of mycorrhizal fungi colonizing roots of ozone-sensitive poplar clone.
-
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
Environmental Pollution, 2009Co-Authors: Elena Paoletti, William J Manning, N Contran, Anna Maria FerraraAbstract:Twenty-four experiments where EDU was used to protect plants from ozone (O(3)) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O(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 ( 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(3) exposure. Preliminary results suggest developing an effective soil application method for forest trees is warranted.
S S Choi - One of the best experts on this subject based on the ideXlab platform.
-
strain and anisotropic effects on migration behaviors of Antiozonants in carbon black filled natural rubber vulcanizates
Polymer Testing, 2002Co-Authors: S S ChoiAbstract:Abstract The influence of strain and anisotropy on the migration behavior of Antiozonants in carbon black-filled natural rubber vulcanizates was studied at constant temperatures of 50–90 °C and outdoors. N -Phenyl- N ′-isopropyl- p -phenylenediamine (IPPD) and N -phenyl- N ′-(1,3-dimethylbutyl)- p -phenylenediamine (HPPD) were employed as Antiozonants. Migration rates of the Antiozonants in the strained vulcanizates are faster than in the non-strained ones. The migration rates in the vulcanizate strained parallel to the milling direction are slightly slower than those in the vulcanizate strained perpendicularly to the milling direction at high temperatures.