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181.
Lead isotopic ratios (LIR) of eight common food items, street dust, coal, diesel, sediments, lead ore and rainwater from India have been reported for the first time in this paper. This study characterized the source and extent of lead pollution in the different foodstuff consumed in Kolkata, a major metropolis of eastern India. The atmospheric lead input to the food items, sold openly in busy roadside markets of the city, has been quantified. The mean 207/206 and 208/206 LIRs of the eight food items ranged from 0.8847 to 0.8924 and 2.145 to 2.167, respectively. Diesel had the highest mean 207/206 and 208/206 values of 0.9015 and 2.1869, respectively, apart from the lead ore. The food items had a mean lead concentration between 3.78 and 43.35 mg kg?1. The two ratio scatter plots of all the different environmental matrices were spread linearly between the uncontaminated Ichapur sediment and diesel. The 207/206 LIRs of the coal with a mean of 0.8777 did not fall in the linear trend, while the street dust and food samples overlapped strongly. The rainwater sample had a 207/206 LIR of 0.9007. Contaminated sediments in Dhapa, the repository of the city’s municipal garbage, had a mean 207/206 LIR of 0.8658. The corresponding value obtained from the sewage-fed vegetable grown there was 0.8058. The present study indicated that diesel was one of the main contributor to Pb pollution. The atmospheric lead contribution to the food items was in the range of 68.48–86.66 %.  相似文献   
182.
Biofilm-forming marine bacterium Pseudomonas aeruginosa JP-11 was isolated from coastal marine sediment of Paradeep Port, Odisha, East Coast, India, which resisted up to 1,000 ppm of cadmium (Cd) as cadmium chloride in aerobic conditions with a minimal inhibitory concentration of 1,250 ppm. Biomass and extracellular polymeric substances (EPS) secreted by the cells effectively removed 58.760?±?10.62 and 29.544?±?8.02 % of Cd, respectively. The integrated density of the biofilm-EPS observed under fluorescence microscope changed significantly (P?≤?0.05) in the presence of 50, 250, 450, 650 and 850 ppm Cd. ATR-FTIR spectroscopy showed a peak at 2,365.09/cm in the presence of 50, 250, 450 and 650 ppm Cd which depicts the presence of sulphydryl group (–SH) within the EPS, whereas, a peak shift to 2,314.837/cm in the presence of 850 ppm Cd suggested the major role of this functional group in the binding with cadmium. On exposure to Cd at 100, 500 and 1,000 ppm, the expression profiles of cadmium resistance gene (czcABC) in the isolate showed an up-regulation of 3.52-, 17- and 24-fold, respectively. On the other hand, down-regulation was observed with variation in the optimum pH (6) and salinity (20 g l?1) level. Thus, the cadmium resistance gene expression increases on Cd stress up to the tolerance level, but an optimum pH and salinity are the crucial factors for proper functioning of cadmium resistance gene.  相似文献   
183.
A state-wise assessment of methane (CH(4)) budget for Indian paddies, based on a decadal measurement data across India is presented for the calendar year (CY) 1994, the base year for India's Initial National Communication (NATCOM) to the United Nations Framework Convention on Climate Change (UNFCCC), along with national trend from CY 1979 to 2006. The NATCOM CH(4) emission factors (EFs) for Indian paddy cultivation areas, generally having less than 0.7% of soil organic carbon (SOC), have been estimated as 17.48+/-4 g m(-2) for irrigated continuously flooded (IR-CF), 6.95+/-1.86 g m(-2) for rain-fed drought prone (RF-DP), 19+/-6 g m(-2) for rain-fed flood prone (RF-FP) and deep-water (DW), 6.62+/-1.89 g m(-2) for irrigated intermittently flooded single aeration (IR-IF-SA) and 2.01+/-1.49 g m(-2) for IR-IF multiple aeration (MA) paddy water regimes. The state-wise study for 1994 has indicated national CH(4) budget estimate of 4.09+/-1.19 Tg y(-1) and the trend from 1979 to 2006 was in the range of 3.62+/-1 to 4.09+/-1.19 Tg y(-1). Four higher emitting or "hot spot" states (West Bengal, Bihar, Madhya Pradesh and Uttar Pradesh) have accounted for 53.9% of total CH(4) emission with RF-FP paddy water regime as the major contributor. CH(4) emissions were enhanced by factors such as SOC ( approximately 1.5 times due to increase in SOC by approximately 1.8 times), paddy cultivars (approximately 1.5 times), age of seedlings (approximately 1.4 times), and seasons (approximately 1.8 times in Kharif or monsoon than in Rabi or winter season).  相似文献   
184.
A systematic effort was made to assess the emission of methane from paddy fields using closed chamber technique. Methane emission measurements were performed over a year during the Kharif (wet season), Rabi (dry season), and fallow periods. Various soil parameters like redox potential, organic carbon and ferrous ion were determined to evaluate their control on methane emissions. Diurnal measurement of the flux showed a minimum (0.44?mg?m?2?h?1) in the morning (8?a.m.), which increased gradually to a value of 1.16?mg?m?2?h?1 till the evening due to the rise in soil temperature. The seasonally integrated flux (E SIF) for CH4 was calculated. The E SIF for methane during Kharif and Rabi crops were found to be 5.97?g?m?2 and 2.59?g?m?2, respectively. It was observed that the methane flux was maximum during flowering and fertilizer application stages for both paddy cropping seasons. The redox potential was low and the ferrous ion was higher during flowering and tiller stages. The methane emission was higher at E AIF) was calculated for methane to make a budget estimate of methane emission from rice cultivated under rain fed drought prone water regime.  相似文献   
185.
Objective: Crash reports contain precoded structured data fields and a crash narrative that can be a source of rich information not included in the structured data. The narrative can be useful for identifying vulnerable roadway users, such as agricultural workers. However, using the narratives often requires manual reviews that are time consuming and costly. The objective of this research was to develop a simple and relatively inexpensive, semi-automated tool for screening crash narratives and expediting the process of identifying crashes with specific characteristics, such as agricultural crashes.

Methods: Crash records for Louisiana from 2010 to 2015 were obtained from the Louisiana Department of Transportation (LaDOTD). Records with narratives were extracted and stratified by vehicle type. The majority of analyses focused on a vehicle type of farm equipment (Type T). Two keyword lists, an inclusion list and an exclusion list, were created based on the published literature, subject-matter experts, and findings from a pilot project. Next, a semi-automated tool was developed in Microsoft Excel to identify agricultural crashes. Lastly, the tool’s performance was assessed using a gold standard set of agricultural narratives identified through manual review.

Results: The tool reduced the search space (e.g., number of narratives that need manual review) for narratives requiring manual review from 6.7 to 59.4% depending on the research question. Sensitivity was high, with 96.1% of agricultural crash narratives being correctly classified. Of the gold standard agricultural narratives, 58.3% included an equipment keyword and 72.8% included a farm equipment brand.

Conclusion: This article provides information on how crash narratives can supplement structured crash data. It also provides an easy-to-implement method to facilitate incorporating narratives into safety research along with keyword lists for identifying agricultural crashes.  相似文献   

186.
Environmental Science and Pollution Research - The control of storage insect pests is largely based on synthetic pesticides. However, due to fast growing resistance in the targeted insects,...  相似文献   
187.
Environment, Development and Sustainability - Sundarban area of the lower Gangetic plain experiences embankment failure almost every year due to the formation of toe undercuts. Waves generated due...  相似文献   
188.
Das AC  Debnath A 《Chemosphere》2006,65(6):1082-1086
A field experiment has been conducted with four systemic herbicides viz., butachlor [N-(butoxymethyl)-2-chloro-2',6'-diethyl-acetanilide], fluchloralin [N-(2-chloroethyl)-(2,6-dinitro-N-propyl-4-trifluoromethyl) aniline], oxadiazon [5-terbutyl-3-(2,4-dichloro-5-isopro poxyphenyl)-1,3,4-oxadiazol-2-one] and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenyl)-4-(trifluoromethyl) benzene] at their recommended field rates (2.0, 1.5, 0.4 and 0.12kga.i.ha(-1), respectively) to investigate their effects on growth and activities of aerobic non-symbiotic N(2)-fixing bacteria and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in the rhizosphere soils as well as yield of the rice crop (Oryza sativa L cv. IR-36). Application of herbicides, in general, highly stimulated the population and activities of the target microorganisms, which resulted in a greater amount of atmospheric nitrogen fixation and phosphate solubilization in the rhizosphere soils of the test crop. The greater microbial activities subsequently augmented the mineralization and availability of nitrogen and phosphorus in the soil solution, which in turn increased the yield of the crop. Among the herbicides, oxyfluorfen was most stimulative followed by fluchloralin and oxadiazon in augmenting the microbial activities in soil. Butachlor also accentuated the mineralization and availability of nitrogen due to higher incitement of non-symbiotic N(2)-fixing bacteria in paddy soil. The grain and straw yields of the crop were also significantly increased due to the application of oxyfluorfen (20.2% and 21%) followed by fluchloralin (13.1% and 15.4%) and butachlor (9.1% and 10.2%), respectively.  相似文献   
189.
Journal of Material Cycles and Waste Management - Dwindling fossil fuels, and the rise in energy demand have urged us to explore alternative renewable energy forms. An integrated process of dark...  相似文献   
190.
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