Subhas Chandra Santra
University of Kalyani, Dept. of Environmental Science, Faculty Member
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... RAJARSHI MITRA, RABINDRA N BHATTACHARYA, SUGATA HAZRA, SC SANTRA ... Santhakumar, V, AKE Haque, RN Bhattacharya (2003): 'Economics and Institutions for the Sustainable Use of Coastal Wetlends: A Study in India and... more
... RAJARSHI MITRA, RABINDRA N BHATTACHARYA, SUGATA HAZRA, SC SANTRA ... Santhakumar, V, AKE Haque, RN Bhattacharya (2003): 'Economics and Institutions for the Sustainable Use of Coastal Wetlends: A Study in India and Bangladesh', Report of SANEI Project, p ...
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... The outstanding claim of Ecology as a branch of study is that it Is concerned with living ... succession : Community building in time and space 25 4 Biospheric diversity and stability 43 5 ... solar radiation and atmospheric... more
... The outstanding claim of Ecology as a branch of study is that it Is concerned with living ... succession : Community building in time and space 25 4 Biospheric diversity and stability 43 5 ... solar radiation and atmospheric absorption vary; and the surface differs in the ability to absorb ...
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Phytoplanktons of Bhagirathi-Hooghly Estuary: An illustrative account. SC Santra, UC Pal Indian Biologist 21:11, 1-27, 1989. The phytoplankton of Bhagirathi-Hooghly Estuary, West Bengal, India (ie lower stretch of the River Ganga) were... more
Phytoplanktons of Bhagirathi-Hooghly Estuary: An illustrative account. SC Santra, UC Pal Indian Biologist 21:11, 1-27, 1989. The phytoplankton of Bhagirathi-Hooghly Estuary, West Bengal, India (ie lower stretch of the River Ganga) were studied from 1984-87. ...
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A comprehensive study on traffic noise level at twenty four pre-selected road transaction of Calcutta Metropolis was carried out during 1993-94. Noise levels were measured at each of twenty four sites, based on predetermined sampling... more
A comprehensive study on traffic noise level at twenty four pre-selected road transaction of Calcutta Metropolis was carried out during 1993-94. Noise levels were measured at each of twenty four sites, based on predetermined sampling interval and altogether 2880 observations were generated by recording data continuously for 24 hours. The Lcq 24, exceedence levels, LD, LN, LDN, LNP and TNI were determined. Traffic flow density as measured along with noise data recording were then compared for establishing relationship with noise level. Finally the clustering of the sites were made based on variable viz. Lcq 24 and traffic follow density.
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Temporal variations of the ambient mixing ratio of greenhouse gas (CH(4) and N(2)O) in a riparian rice-based agro-ecosystem of tropical region were studied during 2005-2006 in coastal Odisha. The endeavour was made with the hypothesis... more
Temporal variations of the ambient mixing ratio of greenhouse gas (CH(4) and N(2)O) in a riparian rice-based agro-ecosystem of tropical region were studied during 2005-2006 in coastal Odisha. The endeavour was made with the hypothesis that the ambient mixing ratio of CH(4) and N(2)O depends on the changes in the flux of CH(4) and N(2)O from the rice fields in the riparian rice ecosystems. A higher ambient mixing ratio of CH(4) was recorded during the tillering to grain filling stages of the rice crop, during both dry and wet seasons. The higher ambient mixing ratio of CH(4) during the wet season may attribute to the higher CH(4) emission from the rice field. The average mixing ratio of CH(4) was recorded as 1.84 ± 0.05 ppmv and 1.85 ± 0.06 ppmv during 2005 and 2006, respectively. The ambient CH(4) mixing ratio was recorded negatively correlated with the average ambient temperature. The N(2)O mixing ratio ranged from 261.57 to 399.44 ppbv with an average of 330.57 ppbv during 2005. However, the average mixing ratio of N(2)O was recorded as 318.83 ± 20.00 ppbv during 2006. The N(2)O mixing ratio was recorded to be negatively correlated with rainfall and average ambient temperature. Significant negative correlation (r = -0.209) of N(2)O with sunshine hours may attribute to the photochemical break down of N(2)O. The temporal variation of N(2)O flux from the rice field does not affect the ambient mixing ratio of N(2)O in the same way as in the case of the ambient mixing ratio of CH(4). However, the higher mixing ratio of N(2)O during the fallow period of the post monsoon period may attribute to the N(2)O flux from soil. Results indicate that intensively cultivated coastal ecosystems can be a major source of ambient greenhouse gas.
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In the present study, the magnitude of contamination of vegetables with heavy metals (Pb, Zn, Cd, Cr, Cu and Zn) was determined in a long-term wastewater-irrigated agricultural land. Heavy metal concentrations in vegetables were several... more
In the present study, the magnitude of contamination of vegetables with heavy metals (Pb, Zn, Cd, Cr, Cu and Zn) was determined in a long-term wastewater-irrigated agricultural land. Heavy metal concentrations in vegetables were several folds higher in wastewater-irrigated site compared to clean water-irrigated area. The wastewater-irrigated crops analysed in this study are heavily contaminated with heavy metals. Concentrations of Pb, Zn, Cd and Cr in all the sewage-fed vegetables were beyond the safe limit of FAO/WHO and Indian standard. Contamination is at its highest level in radish and spinach. Daily intake values of Pb, Cd and Ni through consumption of sewage-fed vegetables exceeded the recommended oral dose of metal for both adult and children. The study concludes that wastewater irrigation led to accumulation of heavy metals in vegetables causing potential health risk to consumers.
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This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at... more
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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... Bouhoum and Amahmid (2002) found protozoan cysts and helminth eggs on vegetables irrigated with ... Al Salem, SS and Tarazi, HM (1992) 'Wastewater reuse and helminth infestation in ... Geldreich, EE and Bordner, RH (1971)... more
... Bouhoum and Amahmid (2002) found protozoan cysts and helminth eggs on vegetables irrigated with ... Al Salem, SS and Tarazi, HM (1992) 'Wastewater reuse and helminth infestation in ... Geldreich, EE and Bordner, RH (1971) 'Faecal contamination of fruits and vegetables ...
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... to cropping systems and practice of agriculture method; however, policy makers may find it ... tuberosum)-sesame (Sesame indicum) (R-Po-S); rice-maize-(Zea mays)-pigeonpea (Cajanus ... The gas chromatogram was calibrated using the... more
... to cropping systems and practice of agriculture method; however, policy makers may find it ... tuberosum)-sesame (Sesame indicum) (R-Po-S); rice-maize-(Zea mays)-pigeonpea (Cajanus ... The gas chromatogram was calibrated using the standard gas (Scotty® II analyzed gases; M ...
Research Interests: Climate Change, Potato, Maize, Profitability, Global warming potential, and 14 moreOryza Sativa, Methane, Greenhouse Gas Emissions, High Temperature, Greenhouse Gas, Nitrous Oxide, Sunflower, Solanum Tuberosum, Grain Yield, Ecological Applications, Cropping System, Helianthus Annuus, Cicer arietinum, and Yield potential
The phenology of most of the aquatic macrophytes as studied in three distinct zones was found to be influenced by physico-chemical properties of water as well as several other environmental properties like light availability and water... more
The phenology of most of the aquatic macrophytes as studied in three distinct zones was found to be influenced by physico-chemical properties of water as well as several other environmental properties like light availability and water temperature. Among the physico-chemical properties of water salinity played significant role on the overall phenological behaviour of species. The vegetative growth in Zone B was slightly delayed in most of the species than other two zones.Flowering and fruiting periodicity was more seasonal in Zone A than the rest two zones. The extended period of flowering may be seen in Zone A and Zone C. Pollinators are mostly dipteran insects, although hydrophylly and transitional pollination was also recorded in several species. More than one pollinators for individual plant were also evidenced in case of plant species having large showy flowers.Fruiting in Zone B was somewhat lower than other two zones. Most of the species showed hydrochores, although ornithochory, ichthyochory was also evidenced in several plants.On the whole, environmental factors like light, temperature, rainfall, physico-chemical properties of water immensely influence the aquatic macrophytic plant association as well as reproductive behaviour of the plant species.Es wurde beobachtet, daß die Phänologie zahlreicher aquatischer Makrophyten aus drei verschiedenen untersuchten Zonen sowohl durch die physiko-chemischen Eigenschaften des Wassers, als auch durch andere Umweltbedingungen wie Lichtanteil und Wassertemperatur beeinflußt wird. Unter den physikochemischen Eigenschaften spielt der Salzgehalt des Wassers im allgemeinen phänologischen Verhalten der Arten eine signifikante Rolle. Das vegetative Wachstum in Zone B war gegenüber den beiden anderen Zonen leicht verzögert.Blüh- und Frucht-Peridiozität war in Zone A stärker saisonbedingt als in den beiden übrigen. Die längste Blühperiode liegt in Zone A und Zone C. Die Bestäubung erfolgt zumeist durch Diptera-Insekten, obgleich bei einigen Arten auch hydrophylle und gegenseitige Bestäubung beobachtet wurde. Mehr als ein „Bestäüber” einer einzelnen Pflanze wurde bei Arten mit auffallend großen Blüten beobachtet.Der Fruchtansatz war in Zone B etwas geringer als in den Zonen A und C. Die meisten Arten zeigten Hydrochorie, daneben Ornithochorie und auch Ichthyochorie wurde bei einigen Pflanzen beobachtet.Insgesamt gesehen beeinflussen die Umweltfaktoren wie Licht, Temperatur, Regen, physiko-chemische Eigenschaften des Wassers die Assoziation der aquatischen Makrophyten ebenso wie das Reproduktionsverhalten der Pflanzen in erheblichem Maße.
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Plant canopies act as absorbers of air-borne dust particles. Characterization of the dusts present over the leaf surfaces can indicate the nature of contaminant present in the surrounding area and possible sources as well. Dust... more
Plant canopies act as absorbers of air-borne dust particles. Characterization of the dusts present over the leaf surfaces can indicate the nature of contaminant present in the surrounding area and possible sources as well. Dust particulates get adsorbed on both the surfaces of leaves, however more dust particulates get deposited on the upper surface. These dusts contain many inorganic elements, which were analyzed in the present study. For the present investigation, SEMEDS technique used to characterize the dusts adsorbed over the leaf surfaces. Using SEMEDS the samples were analyzed by two types of methods i.e. point analysis and elemental mapping. Both the methods showed the presence of elements like Si, Al, Fe, Mg, and Ca in the dusts adsorbed over the leaf surfaces. Thus, SEMEDS can be used for in situ air pollution monitoring using tree leaves from the area concerned.► Analysis of trace element distribution over leaf surfaces. ► SEMEDS can be used for air pollution bio-monitoring. ► SEMEDS can give idea about the chemical nature of the particulates present on leaf surfaces.
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Research Interests: Neuroscience, Psychology, Kinetics, Neurochemistry, Calcium, and 42 moreEnzyme Inhibitors, Noise Induced Hearing Loss, Macrophages, Marine And Environmental Pollution, Apoptosis, Signal Transduction, Biological Sciences, X Rays, Cell line, Environmental Sciences, Humans, Nitriles, Mice, Tyrosine Kinase Receptor, Nitric oxide, Chronic Disease, Animals, Male, Comparative Analysis, Phosphorylation, Hearing Loss, Mitogen Activated Protein Kinase, Norepinephrine, Clinical Sciences, CHEMICAL SCIENCES, Hydrogen Peroxide, T lymphocytes, Rats, Time Factors, Catechols, Circulation, Transfection, Nitrogen Oxides, Recombinant Proteins, Cochlea, Cell Survival, Protons, Neurosciences, Gtp Binding Proteins, Molecular and Cellular Biochemistry, Biochemistry and cell biology, and Brain stem
Arsenic poisoning due to contaminated groundwater in West Bengal, India, has been thought to be limited to the Lower Ganga Plain (LGP). Skin lesions in villagers led us to evaluate arsenic exposure in the Moyna and Adrebok villages of 24... more
Arsenic poisoning due to contaminated groundwater in West Bengal, India, has been thought to be limited to the Lower Ganga Plain (LGP). Skin lesions in villagers led us to evaluate arsenic exposure in the Moyna and Adrebok villages of 24 Porgana (s) West Bengal, India in the LGP where tube wells water was used for drinking water. Results of this investigation are indicated that the groundwater of Moyna and Adrebok villages have been severely affected by As (arsenic). Most of the tubewells exceeded Arsenic (As) concentration upper limit of Indian standard (50μg/L). Few people were affected by chronic bronchitis and whole body infection. The concentration of total arsenic in urine, hair, and nails has been proposed as an indicator of environmental exposure to arsenic. The positive associations between arsenic contents measured in the urine, hair, and nails indicate the degree of severity of arsenic exposure. The arsenic concentrations were found very high in nails with respect to hair and urine. However, arsenic concentrations in hair and urine were found very high. The correlation statistics indicate that the As concentrations in nails, hair and urine are highly correlated with the concentrations of ground water. The arsenic concentrations in urine, hair and nail were increased with the increase of age upto 42 year. The arsenic concentrations in hair and nail were increased more in compare to urine sample. Interestingly the arsenic concentration in urine, hair and nail were decreased from 43 year. As arsenic shows strong reactivity and therefore affinity towards thiol compounds, it preferentially accumulates in peripheral keratin-rich tissues such as skin, nail, and hair. The cases showed significantly higher arsenic accumulation in nail and hair. This load, coupled with the genetic idiosyncrasies of the arsenic-metabolizing genes, determines whether a particular individual will be susceptible to arsenic toxicity.
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A new polymer supported Cu(II) Schiff base complex was synthesized. The solid complex was characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA)... more
A new polymer supported Cu(II) Schiff base complex was synthesized. The solid complex was characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis diffuse reflectance spectroscopy (DRS), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Its homogeneous analogue was also prepared. The catalytic performances of the copper complex in oxidation reactions were evaluated for both homogeneous and heterogeneous systems. The copper(II) complex was found to be efficient catalyst for the oxidation of alkenes, alkanes and aromatic alcohols in the presence of hydrogen peroxide as oxidant at room temperature. The catalytic investigation revealed that the solid complex performs better than the homogeneous one as an oxidation catalyst. The solids containing the immobilized complex can be recovered from the reaction medium and reused almost five times, maintaining good catalytic activity. Furthermore, the in vitro toxicity of the ligand and complex was tested against the growth of bacterial species, viz., Staphylococcus aureus and Escherichia coli.A polymer supported copper(II) Schiff base complex has been synthesized and characterized. The complex is tested as catalyst for the oxidation of various alkenes, alkanes and aromatic alcohols with 30% H2O2 in acetonitrile at room temperature. Moderate conversions and yield of products are obtained for the catalyst. Antibacterial activity was also studied with its homogeneous analogue.► A new heterogeneous and homogeneous Cu(II) complex has been synthesized. ► Both Cu(II) complexes oxidized alkenes with 30% H2O2 in air at room temperature. ► Both Cu(II) complexes oxidized alkanes and aromatic alcohols under above conditions. ► Homogeneous Cu(II) complex shows antibacterial activity. ► Heterogeneous Cu(II) complex can be recycled up to five times.
Research Interests: Chemical Engineering, Molecular, Old Copper Complex, Copper, Escherichia coli, and 12 moreAntimicrobial activity, Staphylococcus aureus, Hydrogen Peroxide, Antibacterial activity, Scanning Electron Microscope, Room Temperature, Fourier transform infrared spectroscopy, Thermogravimetric Analysis, Schiff Base, Heterogeneous Systems, Catalytic Activity, and Diffuse Reflectance Spectroscopy
Abstract Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three... more
Abstract Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three high yielding, one hybrid and four local rice varieties to investigate the uptake, distribution and phytotoxicity of arsenic in rice plant. 5, 10, 20, 30 and 40 mg kg− 1 dry weights arsenic dosing was applied in pot soil and the results were compared with the control samples. All the studied high ...
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This work focuses on the effect of gamma radiation on seed born fungi (in vitro) on Oryza sativa (Swarna, Initial Evaluation Trial-5656). The responses of fungi to gamma radiation (0-4.2 kGy; 0.12 kGy/h) were studied in individual... more
This work focuses on the effect of gamma radiation on seed born fungi (in vitro) on Oryza sativa (Swarna, Initial Evaluation Trial-5656). The responses of fungi to gamma radiation (0-4.2 kGy; 0.12 kGy/h) were studied in individual cultures of major seed-borne fungi including Alternaria alternata, Aspergillus flavus, Trichoderma viride and Curvularia geniculata. The inactivation of individual fungal-viability was noted between 1.0-2.0 kGy for A. alternata and A. flavus and 0.5-1.0 kGy for T. viride and C. geniculata. Complete inhibition was observed at <2.5 kGy. Formations of multiple germ tubes were noted in A. alternata and A. flavus at 2 kGy and 2.5 kGy, respectively. A. flavus required a higher dose to reduce viability to 10% (D(10)) value in comparison to other selected fungi. Different fungi exhibited different radiosensitivity. The dose range of 2-2.5 kGy was effective in killing all selected fungi. The fungi showing a higher D(10) value exhibited multiple germ tubes.
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Arsenic contaminated groundwater uses for irrigation potentially lead the incidence of arsenic into food chain. In present study we examined total arsenic concentrations in 32 types of vegetables and 7 types of pulses. Range of total... more
Arsenic contaminated groundwater uses for irrigation potentially lead the incidence of arsenic into food chain. In present study we examined total arsenic concentrations in 32 types of vegetables and 7 types of pulses. Range of total arsenic concentration in edible parts of vegetables collected from grown fields was 0.114–0.910 mg/kg. Highest arsenic values were in spinach 0.910 mg/kg. Vegetable samples were grouped into leafy, non-leafy-fruity, root-tubers. 18 common types of vegetables and pulses were collected through market basket survey, total arsenic were approximately 100 mg lower than those observed for the vegetables collected from the fields.
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ABSTRACTAn effective 60Co gamma irradiation method for the removal of contaminating surface microorganisms (fungi) of mung (Vigna mungo L.) and wheat (Triticum aestivum L.) stored seeds, without the loss of germination capacity and... more
ABSTRACTAn effective 60Co gamma irradiation method for the removal of contaminating surface microorganisms (fungi) of mung (Vigna mungo L.) and wheat (Triticum aestivum L.) stored seeds, without the loss of germination capacity and minimum loss of nutritional values, are described. Significant depletion of surface fungal population on wheat (96%) and mung (94%) was noticed within 2 kGy, while complete inhibition of surface fungal population was observed at 4.2 kGy. Although the irradiation did not significantly alter the germination potential of the treated grains, it reflected delay in germination as a function of absorbed dose. The seed membrane permeability and nutritional values like carbohydrate and protein content of the radiation-exposed seed were significantly altered. The radiosensitivity of wheat was found more than that of the mung. It was also observed that the germinating potential of the treated seeds did not alter significantly. However, membrane permeability of seeds was altered as a result of gamma irradiation. Precisely, the investigation reflected that the dose range from 1 to 2 kGy was most effective for seed sterilization, keeping their viability and minimum loss of nutritional value like protein and carbohydrate intact.An effective 60Co gamma irradiation method for the removal of contaminating surface microorganisms (fungi) of mung (Vigna mungo L.) and wheat (Triticum aestivum L.) stored seeds, without the loss of germination capacity and minimum loss of nutritional values, are described. Significant depletion of surface fungal population on wheat (96%) and mung (94%) was noticed within 2 kGy, while complete inhibition of surface fungal population was observed at 4.2 kGy. Although the irradiation did not significantly alter the germination potential of the treated grains, it reflected delay in germination as a function of absorbed dose. The seed membrane permeability and nutritional values like carbohydrate and protein content of the radiation-exposed seed were significantly altered. The radiosensitivity of wheat was found more than that of the mung. It was also observed that the germinating potential of the treated seeds did not alter significantly. However, membrane permeability of seeds was altered as a result of gamma irradiation. Precisely, the investigation reflected that the dose range from 1 to 2 kGy was most effective for seed sterilization, keeping their viability and minimum loss of nutritional value like protein and carbohydrate intact.PRACTICAL APPLICATIONSThere are many reports on radiation sterilization of stored seeds without any consideration of the nutritional quality of the seeds, which is very important for quality control. We should look upon change of quality of seed during seed sterilization. We need to protect/or estimate minimal loss of the nutritional value of stored seed by loss and benefit assessment. The significance and originality of this manuscript is that we try to look for an effective 60Co gamma irradiation method for the removal of contaminating surface microorganisms (fungi) of mung (Vigna mungo L.) and wheat (Triticum aestivum L.) stored seeds, without the loss of germination capacity and minimum loss of nutritional values. The study was concentrated on germination pattern, protein, carbohydrate and intensity of seed membrane damage during radiation processing. Also, our present work emphasized on radiosensitivity of different seed-borne fungi that frequently infected seed grain during storage. This study may help to sterilize the stored seed with consideration of nutritional value.There are many reports on radiation sterilization of stored seeds without any consideration of the nutritional quality of the seeds, which is very important for quality control. We should look upon change of quality of seed during seed sterilization. We need to protect/or estimate minimal loss of the nutritional value of stored seed by loss and benefit assessment. The significance and originality of this manuscript is that we try to look for an effective 60Co gamma irradiation method for the removal of contaminating surface microorganisms (fungi) of mung (Vigna mungo L.) and wheat (Triticum aestivum L.) stored seeds, without the loss of germination capacity and minimum loss of nutritional values. The study was concentrated on germination pattern, protein, carbohydrate and intensity of seed membrane damage during radiation processing. Also, our present work emphasized on radiosensitivity of different seed-borne fungi that frequently infected seed grain during storage. This study may help to sterilize the stored seed with consideration of nutritional value.
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The widespread incidence of chronic arsenicosis in the Bengal Delta has led to intensive research on arsenic (As) enrichment in groundwater as well as accumulation in foodstuffs, as there are potential health risks associated with... more
The widespread incidence of chronic arsenicosis in the Bengal Delta has led to intensive research on arsenic (As) enrichment in groundwater as well as accumulation in foodstuffs, as there are potential health risks associated with exposure to As from both sources. This study deals with human As exposure through the drinking of groundwater, consumption of locally grown foodstuffs (e.g., crops and vegetables) and cooked food in Nadia district, West Bengal. Groundwater and foodstuffs were collected and analyzed with FI-HG-AAS to estimate the total As content. Urine samples collected from human subjects were analyzed to asses the As exposure. Two major crops, boro and aman rice, showed a considerable amount of As, with mean values of 194 and 156 μg kg−1, respectively. Significant levels of As were also found in other common crops and vegetables cultivated in this area (for example, the mean As in Arum and radish was 780 and 674 μg kg−1, respectively). Total intake of As from foodstuffs by adults (560 μg day−1) and children (393 μg day−1) in the area was found to be at alarming levels. Arsenic exposure was demonstrated by the presence of As in urine (ranging between 154 and 276 μg L−1), with overall As retention of 50-60 %. The results of this study further indicate the potential risk of As exposure to local inhabitants through the food chain which is associated with continuous consumption of As-contaminated foodstuffs. Therefore, more action needs to be taken to control the contamination pathways (such as the water-soil-crop system) to protect humans from continuous ingestion of As through foodstuffs.
Research Interests: Arsenic, Groundwater, Multidisciplinary, India, Humans, and 18 moreChild, Flow Injection Analysis, Female, Male, Drinking Water, Oryza Sativa, West Bengal, Vegetables, Adult, Health risk, Food Contamination, Arsenic Contamination, Species Specificity, Human Subjects, Food Chain, Cropping System, Environmental Exposure, and Science Health
Here we report a simple strategy for selective detection of cadmium ions by manipulating the electron transfer pathways of surface-engineered quantum dots.
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Microbial reduction of arsenate [As(V)] plays an important role in arsenic (As) mobilization in aqueous environments. In this study, we investigated reduction of arsenate by different bacterial isolates such as OSBH1 (GU329913), OSBH2... more
Microbial reduction of arsenate [As(V)] plays an important role in arsenic (As) mobilization in aqueous environments. In this study, we investigated reduction of arsenate by different bacterial isolates such as OSBH1 (GU329913), OSBH2 (GU329914), OSBH3 (GU329915), OSBH4 (GU329916) and OSBH5 (GU329917), isolated from the oil sludge of a sewage treatment plant operated by the China Petroleum Refinery Company in Kaohsiung, southern Taiwan. Bacterial strains of pure culture were identified by 16S rRNA analysis (≥99 % nucleotide similarity). Morphological and 16S rRNA analysis show that the isolate OSBH1 is similar to E. coli, OSBH2 is similar to P. stutzeri, OSBH3 is similar to P. putida, OSBH4 is similar to P. aeruginosa, and OSBH5 is similar to B. Cereus. The As(V) was transformed to As(III) in the presence of isolates OSBH2 and OSBH5 by a detoxification process. The potential reduction rates of As(V) were higher in the presence of isolate OSBH5 compared to the isolate OSBH2. The microbial growth (cell/mL) of isolate OSBH5 was significantly higher in culture medium compared to OSBH2. The bacterial isolates such as OSBH1, OSBH3 and OSBH4 were found to be incapable of transforming the As(V). It is concluded that the activity of the oil-degrading bacterial isolates described in this work contributes to the mobilization of As in the more toxic As(III) form that affects biotic life.
Research Interests: Arsenic, Multidisciplinary, Escherichia coli, Taiwan, Pseudomonas, and 13 morePolymerase Chain Reaction, Detoxification, Bacillus Cereus, Sewage Treatment Plant, Species Specificity, Petroleum Pollution, Oxidation-Reduction, Arsenates, Nucleotides, Science Health, Microbial Growth, Molecular Sequence Data, and culture medium
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This study presents a methodology to classify rice cultural types based on water regimes using multi-temporal synthetic aperture radar (SAR) data. The methodology was developed based on the theoretical understanding of radar scattering... more
This study presents a methodology to classify rice cultural types based on water regimes using multi-temporal synthetic aperture radar (SAR) data. The methodology was developed based on the theoretical understanding of radar scattering mechanisms with rice crop canopy, considering crop phenology and variation in water depth in the rice field, emphasizing the sensitivity of SAR to crop geometry and water. The logic used was the characteristic decrease in SAR backscatter that is associated with the puddled or transplanted field due to specular reflection for little exposure of crop, with increase in backscatter as the crop growth progresses due to volume scattering. Besides, the multiple interactions between SAR and vegetation/water also lead to an increase in backscatter as the crop growth progresses. Classification thresholds were established based on the information provided by each pixel in each image, the pixel's typical temporal behaviour due to crop phenology and changing water depth in rice field and their corresponding SAR signature. Based on this logic, the study site (i.e. South 24 Paraganas district, West Bengal) was classified into three major rice cultural types, namely shallow water rice (SWR; 5 cm ≤ water depth ≤ 30 cm), intermediate water rice (IWR; 30 cm ≤ water depth ≤ 50 cm) and deep water rice (DWR; water depth > 50 cm) during the kharif season. These three types represent most of the traditional rice-growing areas of India. The methodology was validated with the field data collected synchronously with the satellite passes. Classification results showed an overall accuracy of 98.5% (95.5% kappa coefficient) compared with a maximum-likelihood classifier (MLC) with an overall accuracy of 95.5% (84.2% of kappa coefficient) with 95% confidence interval. The relationship between field parameters, especially exposed plant height and water depth with SAR backscatter, was explored to design empirical models for each of the three rice classes. Significant relationships were observed in all the rice classes (coefficient of determination, R 2, value more than 0.85) even though they had similar growth profiles but varied with water depth. The two main conclusions drawn from this study are (i) the importance of multi-temporal SAR data for the classification of rice culture types based on water regimes and (ii) the advantages and flexibility of the knowledge-based classifier for classification of RADARSAT-1 data. However, being empirical, the approach needs modification according to the current rainfall pattern and rice-growing practice.
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ABSTRACT The present work describes radiation-induced effects of major seeds like Oryza sativa Cv-2233, Oryza sativa Cv-Shankar, Cicer arietinum Cv-local and seed-borne fungi like Alternaria sp., Aspergillus sp., Trichoderma sp. and... more
ABSTRACT The present work describes radiation-induced effects of major seeds like Oryza sativa Cv-2233, Oryza sativa Cv-Shankar, Cicer arietinum Cv-local and seed-borne fungi like Alternaria sp., Aspergillus sp., Trichoderma sp. and Curvularia sp. 60Co gamma source at 25 °C emitting gamma ray at 1173 and 1332 keV energy was used for irradiation. Dose of gamma irradiation up to 3 kGy (0.12 kGy/h) was applied for exposing the seed and fungal spores. Significant depletion of the fungal population was noted with irradiation at 1–2 kGy, whereas germinating potential of the treated grain did not alter significantly. However, significant differential radiation response in delayed seed germination, colony formation of the fungal spores and their depletion of growth were noticed in a dose-dependent manner. The depletion of the fungal viability (germination) was noted within the irradiation dose range of 1–2 kGy for Alternaria sp. and Aspergillus sp., while 0.5–1 kGy for Trichoderma sp. and Curvularia sp. However, complete inhibition of all the selected fungi was observed above 2.5 kGy.
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Ninety-seven subjects belonging to 40 families in a village in Cambodia were examined in a health camp where all the cases with skin disease assembled. These people had evidences of chronic arsenic exposure from reports of testing of... more
Ninety-seven subjects belonging to 40 families in a village in Cambodia were examined in a health camp where all the cases with skin disease assembled. These people had evidences of chronic arsenic exposure from reports of testing of water samples and of hair and/or nail studied. Seventy cases were diagnosed to be suffering from arsenicosis (Clinically and laboratory confirmed according to WHO criteria) as all these cases had evidences of pigmentation and/or keratosis characteristic of arsenicosis and history of exposure of arsenic contaminated water and/or elevated level of arsenic in hair and/or in nail. Highest number of cases belonged to age group of 31 to 45 yrs, both the sexes are more or less affected equally. Evidence of both pigmentation and keratosis were found in 60 cases (85.7%) while only pigmentation and only keratosis was found in 6 (8.5%) and 4 (5.7%) cases respectively. It was interesting to find 37.04% of children below the age of 16 years had skin lesions of arsenicosis. The youngest child having definite evidence of keratosis and pigmentation was aged 8 years, though two children aged 4 and 5 yrs had feature of redness and mild thickening of the palms. The minimum and maximum arsenic values detected in the nails were 1.06 and 69.48 mg/Kg respectively and the minimum and maximum arsenic values in hair were 0.92 and 25.6 mg/Kg respectively. No correlation was observed between arsenic concentration in drinking water and arsenic level in nail and hair. This is the first report of clinical and laboratory confirmed cases of arsenicosis in Cambodia.
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S. C. SANTRA, SWAT1 GUPTA and SUNIRMAL CHANDA ... Santra. S. C., Gupta, S. & Chanda, S. 1991, Air pollutants and aeroallergens interaction. - Grana 30: 63-66, 1991. Odense, September 1991. ISSN 0017-3134 Clinical tests... more
S. C. SANTRA, SWAT1 GUPTA and SUNIRMAL CHANDA ... Santra. S. C., Gupta, S. & Chanda, S. 1991, Air pollutants and aeroallergens interaction. - Grana 30: 63-66, 1991. Odense, September 1991. ISSN 0017-3134 Clinical tests were performed with pollen ...
Research Interests:
... domestic and working environments with microbiological contaminants or other biopollutants is a major health problem in a tropical country like India. ... Similar studies were carried out by Riley (1972, 1974), Parker (1973), Winkler... more
... domestic and working environments with microbiological contaminants or other biopollutants is a major health problem in a tropical country like India. ... Similar studies were carried out by Riley (1972, 1974), Parker (1973), Winkler (1970), Brach-man (1974), and Rose & Varkey ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
[The Journal of the Acoustical Society of America 101, 943 (1997)]. Debashis Chakrabarty, Subhas Chandra Santra, Abirlal Mukherjee, Biva Roy, Prasun Das. Abstract. ... Cult. [bold 50](8), 6264. Shrivastava, JP, Shah, RK, and Desai, MN... more
[The Journal of the Acoustical Society of America 101, 943 (1997)]. Debashis Chakrabarty, Subhas Chandra Santra, Abirlal Mukherjee, Biva Roy, Prasun Das. Abstract. ... Cult. [bold 50](8), 6264. Shrivastava, JP, Shah, RK, and Desai, MN ([bold 1986]). ...