The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Bhupander Kumar - One of the best experts on this subject based on the ideXlab platform.
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polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial Roadsides of chennai city india levels congener profiles and exposure assessment
Science of The Total Environment, 2016Co-Authors: Paromita Chakraborty, Balasubramanian Prithiviraj, Sakthivel Selvaraj, Bhupander KumarAbstract:Abstract Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53 ng g − 1 ) > e-waste dismantling sites (3.6 ng g − 1 ) > nearby highways (1.7 ng g − 1 ) > suburban industrial Roadsides (1.6 ng g − 1 ). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ 26 PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5 μm) − 6 –10 − 4 ) for both adult and children.
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polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial Roadsides of chennai city india levels congener profiles and exposure assessment
Science of The Total Environment, 2016Co-Authors: Paromita Chakraborty, Balasubramanian Prithiviraj, Sakthivel Selvaraj, Bhupander KumarAbstract:Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53ngg-1)>e-waste dismantling sites (3.6ngg-1)>nearby highways (1.7ngg-1)>suburban industrial Roadsides (1.6ngg-1). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ26PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5μm)
toxicity equivalents (TEQs) for dl-PCBs and potential cancer risk (10-6-10-4) for both adult and children.
Muthukumar V Bagavathiannan - One of the best experts on this subject based on the ideXlab platform.
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surveying the spatial distribution of feral sorghum sorghum bicolor l and its sympatry with johnsongrass s halepense in south texas
PLOS ONE, 2018Co-Authors: Sara Ohadi, Matthew Littlejohn, Mohsen B Mesgaran, William L Rooney, Muthukumar V BagavathiannanAbstract:Sorghum (Sorghum bicolor) is an important grain and forage crop grown across the US. In some areas, sorghum can become feral along Roadsides and other ruderal areas, as a result of seed spill during harvest or transport. In some of these situations, feral sorghum grows in or near established johnsongrass (S. halepense) populations. Johnsongrass, a wild relative of sorghum and an incredibly noxious weed, is capable of hybridizing with cultivated sorghum. Because commercial hybrid sorghum cultivars are produced with cytoplasmic male sterility, progeny of the hybrid crop which compose the founder feral populations also segregate for male sterility. Consequently, male sterility in feral sorghum may increase the risk of outcrossing with johnsongrass. Using field surveys and spatial modelling, the present study aimed at documenting the occurrence of feral sorghum and understanding the anthropogenic and environmental factors that influence its distribution. Further, this research documented the sympatry of feral sorghum and johnsongrass in the roadside habitat. A total of 2077 sites were visited during a systematic field survey conducted in fall 2014 in South Texas. Feral sorghum and johnsongrass were found in 360 and 939 sites, while the species co-existed at 48 sites (2.3% of all surveyed sites). The binary logistic analysis showed a significant association between the presence of feral sorghum and road type, road body-type, micro-topography of the sampling site, nearby land use, and the presence of johnsongrass, but no association with the distance to the nearest grain sorting facility. The probability of finding feral sorghum away from johnsongrass patches was generally higher than finding them co-occur in the same location. A probability map for spatial distribution of feral sorghum was developed using the nearby land use type and the regional habitat suitability for johnsongrass as two key predictors. Overall, results show that feral sorghum and johnsongrass co-occur at low frequencies in the roadside habitats of South Texas, but these low levels still present a significant opportunity for hybridization between the two species outside of cultivated fields.
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multiple herbicide resistance is widespread in roadside palmer amaranth populations
PLOS ONE, 2016Co-Authors: Muthukumar V Bagavathiannan, Jason K NorsworthyAbstract:Herbicide-resistant Palmer amaranth is a widespread issue in row-crop production in the Midsouthern US. Palmer amaranth is commonly found on roadside habitats in this region, but little is known on the degree of herbicide resistance in these populations. Herbicide resistance in roadside Palmer amaranth populations can represent the spread of an adaptive trait across a selective landscape. A large-scale survey was carried out in the Mississippi Delta region of eastern Arkansas to document the level of resistance in roadside Palmer amaranth populations to pyrithiobac and glyphosate, two important herbicides with broad history of use in the region. A total of 215 Palmer amaranth populations collected across 500 random survey sites were used in the evaluations. About 89 and 73% of the surveyed populations showed >90% survival to pyrithiobac and glyphosate, respectively. Further, only 3% of the populations were completely susceptible to glyphosate, while none of the populations was completely controlled by pyrithiobac. Among the 215 populations evaluated, 209 populations showed multiple resistance to both pyrithiobac and glyphosate at varying degrees. Dose-response assays confirmed the presence of high levels of herbicide resistance in the five selected populations (≥ 25-fold compared to a susceptible standard). Results demonstrate the prevalence of multiple-herbicide resistance in roadside Palmer amaranth populations in this region. Growers should be vigilant of Palmer amaranth infestation in Roadsides adjacent to their fields and implement appropriate control measures to prevent likely spread of herbicide resistance into their fields.
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distribution of arable weed populations along eastern arkansas mississippi delta Roadsides factors affecting weed occurrence
Weed Technology, 2015Co-Authors: Nicholas E Korres, Muthukumar V Bagavathiannan, Jason K Norsworthy, Andy MauromoustakosAbstract:Abstract The occurrence of 36 arable weed species across 13 counties in the eastern Arkansas–Mississippi Delta area on 489 randomly selected road sites was surveyed in 2012. Palmer amaranth, johnsongrass, large crabgrass, barnyardgrass, prickly sida, and broadleaf signalgrass were the top six weed species, with occurrence noted at 313, 294, 261, 238, 176, and 136 sites, respectively. Factors found to affect weed occurrence along Mississippi Delta Roadsides included topographical characteristics, weed species, ditch slope, road type, and nearby land use. Among roadside topographical characteristics, road shoulder was found to strongly affect weed occurrence. In addition, paved and gravel road types with moderate roadside slope explained most of the variability of weed occurrence at each sampling site. Additionally, nearby arable land use affected weed occurrence more so than natural, residential, and pastoral land. Barnyardgrass, johnsongrass, and Palmer amaranth were 3.6 to 4.3 times more likely to occur ...
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distribution of arable weed populations along eastern arkansas mississippi delta Roadsides occurrence distribution and favored growth habitats
Weed Technology, 2015Co-Authors: Nicholas E Korres, Muthukumar V Bagavathiannan, Jason K Norsworthy, Andy MauromoustakosAbstract:Abstract A survey was conducted in 2012 across 13 counties in the eastern Arkansas–Mississippi Delta area on 489 randomly selected road sites to assess the distribution of the most commonly occurring arable weeds. Among the 36 species recorded, Palmer amaranth, johnsongrass, large crabgrass, barnyardgrass, prickly sida, and broadleaf signalgrass were the top six weed species, occurring at 313, 294, 261, 238, 176, and 136 sites, respectively. Barnyardgrass, johnsongrass, and Palmer amaranth were present at 34, 32, and 31% of all sampling occasions (site by roadside topographical characteristic). Habitat preferences varied between weed species. Palmer amaranth, large crabgrass, and johnsongrass exhibited a preference for disturbed habitats as well as field shoulders. Conversely, barnyardgrass, yellow nutsedge, hemp sesbania, and giant ragweed exhibit a preference for moist environments similar to these found in roadside ditches. Herbicide use on Roadsides is subject to many environmental regulations and pub...
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occurrence of alfalfa medicago sativa l populations along Roadsides in southern manitoba canada and their potential role in intraspecific gene flow
Transgenic Research, 2011Co-Authors: Muthukumar V Bagavathiannan, Robert H Gulden, Rene C Van AckerAbstract:Alfalfa is a highly outcrossing perennial species that can be noticed in Roadsides as feral populations. There remains little information available on the extent of feral alfalfa populations in western Canadian prairies and their role in gene flow. The main objectives of this study were (a) to document the occurrence of feral alfalfa populations, and (b) to estimate the levels of outcrossing facilitated by feral populations. A roadside survey confirmed widespread occurrence of feral alfalfa populations, particularly in alfalfa growing regions. The feral populations were dynamic and their frequency ranged from 0.2 to 1.7 populations km−1. In many cases, the nearest feral alfalfa population from alfalfa production field was located within a distance sufficient for outcrossing in alfalfa. The gene flow study confirmed that genes can move back and forth between feral and cultivated alfalfa populations. In this study, the estimated outcrossing levels were 62% (seed fields to feral), 78% (feral to seed fields), 82% (hay fields to feral) and 85% (feral to feral). Overall, the results show that feral alfalfa plants are prevalent in alfalfa producing regions in western Canada and they can serve as bridges for gene flow at landscape level. Management of feral populations should be considered, if gene flow is a concern. Emphasis on preventing seed spill/escapes and intentional roadside planting of alfalfa cultivars will be particularly helpful. Further, realistic and pragmatic threshold levels should be established for markets sensitive to the presence of GE traits.
Yikai Zhou - One of the best experts on this subject based on the ideXlab platform.
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analysis of phthalate esters in soils near an electronics manufacturing facility and from a non industrialized area by gas purge microsyringe extraction and gas chromatography
Science of The Total Environment, 2015Co-Authors: Wei Wu, Jinqi Wang, Xuerong Chen, Jia Hu, Yikai ZhouAbstract:Abstract Here, a novel technique is described for the extraction and quantitative determination of six phthalate esters (PAEs) from soils by gas purge microsyringe extraction and gas chromatography. Recovery of PAEs ranged from 81.4% to 120.3%, and the relative standard deviation ( n = 6) ranged from 5.3% to 10.5%. Soil samples were collected from Roadsides, farmlands, residential areas, and non-cultivated areas in a non-industrialized region, and from the same land-use types within 1 km of an electronics manufacturing facility ( n = 142). Total PAEs varied from 2.21 to 157.62 mg kg − 1 in non-industrialized areas and from 8.63 to 171.64 mg kg − 1 in the electronics manufacturing area. PAE concentrations in the non-industrialized area were highest in farmland, followed (in decreasing order) by Roadsides, residential areas, and non-cultivated soil. In the electronics manufacturing area, PAE concentrations were highest in roadside soils, followed by residential areas, farmland, and non-cultivated soils. Concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), and di- n -butyl phthalate (DnBP) differed significantly ( P r 2 = 0.944, P r 2 = 0.860, P
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analysis of phthalate esters in soils near an electronics manufacturing facility and from a non industrialized area by gas purge microsyringe extraction and gas chromatography
Science of The Total Environment, 2015Co-Authors: Wei Wu, Jinqi Wang, Xuerong Chen, Jia Hu, Yikai ZhouAbstract:Here, a novel technique is described for the extraction and quantitative determination of six phthalate esters (PAEs) from soils by gas purge microsyringe extraction and gas chromatography. Recovery of PAEs ranged from 81.4% to 120.3%, and the relative standard deviation (n = 6) ranged from 5.3% to 10.5%. Soil samples were collected from Roadsides, farmlands, residential areas, and non-cultivated areas in a non-industrialized region, and from the same land-use types within 1 km of an electronics manufacturing facility (n = 142). Total PAEs varied from 2.21 to 157.62 mg kg− 1 in non-industrialized areas and from 8.63 to 171.64 mg kg− 1 in the electronics manufacturing area. PAE concentrations in the non-industrialized area were highest in farmland, followed (in decreasing order) by Roadsides, residential areas, and non-cultivated soil. In the electronics manufacturing area, PAE concentrations were highest in roadside soils, followed by residential areas, farmland, and non-cultivated soils. Concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), and di-n-butyl phthalate (DnBP) differed significantly (P < 0.01) between the industrial and non-industrialized areas. Principal component analysis indicated that the strongest explanatory factor was related to DMP and DnBP in non-industrialized soils and to butyl benzyl phthalate (BBP) and DMP in soils near the electronics manufacturing facility. Congener-specific analysis confirmed that diethylhexyl phthalate (DEHP) was a predictive indication both in the non-industrialized area (r2 = 0.944, P < 0.01) and the industrialized area (r2 = 0.860, P < 0.01). The higher PAE contents in soils near the electronics manufacturing facility are of concern, considering the large quantities of electronic wastes generated with ongoing industrialization.
Paromita Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial Roadsides of chennai city india levels congener profiles and exposure assessment
Science of The Total Environment, 2016Co-Authors: Paromita Chakraborty, Balasubramanian Prithiviraj, Sakthivel Selvaraj, Bhupander KumarAbstract:Abstract Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53 ng g − 1 ) > e-waste dismantling sites (3.6 ng g − 1 ) > nearby highways (1.7 ng g − 1 ) > suburban industrial Roadsides (1.6 ng g − 1 ). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ 26 PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5 μm) − 6 –10 − 4 ) for both adult and children.
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polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial Roadsides of chennai city india levels congener profiles and exposure assessment
Science of The Total Environment, 2016Co-Authors: Paromita Chakraborty, Balasubramanian Prithiviraj, Sakthivel Selvaraj, Bhupander KumarAbstract:Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53ngg-1)>e-waste dismantling sites (3.6ngg-1)>nearby highways (1.7ngg-1)>suburban industrial Roadsides (1.6ngg-1). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ26PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5μm)
toxicity equivalents (TEQs) for dl-PCBs and potential cancer risk (10-6-10-4) for both adult and children.
Wei Wu - One of the best experts on this subject based on the ideXlab platform.
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analysis of phthalate esters in soils near an electronics manufacturing facility and from a non industrialized area by gas purge microsyringe extraction and gas chromatography
Science of The Total Environment, 2015Co-Authors: Wei Wu, Jinqi Wang, Xuerong Chen, Jia Hu, Yikai ZhouAbstract:Abstract Here, a novel technique is described for the extraction and quantitative determination of six phthalate esters (PAEs) from soils by gas purge microsyringe extraction and gas chromatography. Recovery of PAEs ranged from 81.4% to 120.3%, and the relative standard deviation ( n = 6) ranged from 5.3% to 10.5%. Soil samples were collected from Roadsides, farmlands, residential areas, and non-cultivated areas in a non-industrialized region, and from the same land-use types within 1 km of an electronics manufacturing facility ( n = 142). Total PAEs varied from 2.21 to 157.62 mg kg − 1 in non-industrialized areas and from 8.63 to 171.64 mg kg − 1 in the electronics manufacturing area. PAE concentrations in the non-industrialized area were highest in farmland, followed (in decreasing order) by Roadsides, residential areas, and non-cultivated soil. In the electronics manufacturing area, PAE concentrations were highest in roadside soils, followed by residential areas, farmland, and non-cultivated soils. Concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), and di- n -butyl phthalate (DnBP) differed significantly ( P r 2 = 0.944, P r 2 = 0.860, P
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analysis of phthalate esters in soils near an electronics manufacturing facility and from a non industrialized area by gas purge microsyringe extraction and gas chromatography
Science of The Total Environment, 2015Co-Authors: Wei Wu, Jinqi Wang, Xuerong Chen, Jia Hu, Yikai ZhouAbstract:Here, a novel technique is described for the extraction and quantitative determination of six phthalate esters (PAEs) from soils by gas purge microsyringe extraction and gas chromatography. Recovery of PAEs ranged from 81.4% to 120.3%, and the relative standard deviation (n = 6) ranged from 5.3% to 10.5%. Soil samples were collected from Roadsides, farmlands, residential areas, and non-cultivated areas in a non-industrialized region, and from the same land-use types within 1 km of an electronics manufacturing facility (n = 142). Total PAEs varied from 2.21 to 157.62 mg kg− 1 in non-industrialized areas and from 8.63 to 171.64 mg kg− 1 in the electronics manufacturing area. PAE concentrations in the non-industrialized area were highest in farmland, followed (in decreasing order) by Roadsides, residential areas, and non-cultivated soil. In the electronics manufacturing area, PAE concentrations were highest in roadside soils, followed by residential areas, farmland, and non-cultivated soils. Concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), and di-n-butyl phthalate (DnBP) differed significantly (P < 0.01) between the industrial and non-industrialized areas. Principal component analysis indicated that the strongest explanatory factor was related to DMP and DnBP in non-industrialized soils and to butyl benzyl phthalate (BBP) and DMP in soils near the electronics manufacturing facility. Congener-specific analysis confirmed that diethylhexyl phthalate (DEHP) was a predictive indication both in the non-industrialized area (r2 = 0.944, P < 0.01) and the industrialized area (r2 = 0.860, P < 0.01). The higher PAE contents in soils near the electronics manufacturing facility are of concern, considering the large quantities of electronic wastes generated with ongoing industrialization.
