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Ashoke Ranjan Thakur

Bio: Ashoke Ranjan Thakur is an academic researcher from Techno India University. The author has contributed to research in topics: Population & DNA supercoil. The author has an hindex of 15, co-authored 57 publications receiving 677 citations. Previous affiliations of Ashoke Ranjan Thakur include Tripura University & West Bengal University of Technology.


Papers
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Journal ArticleDOI
TL;DR: Three bacterial isolates from different sites of East Calcutta Wetland show tolerance to heavy metals and were found to be efficient metal accumulators as evident from Energy Dispersive X Ray Fluorescence analysis and Transmission Electron Microscopy (TEM).
Abstract: The present paper put forth the isolation and complete characterization of three bacterial isolates from different sites of East Calcutta Wetland (ECW). These isolates show tolerance to heavy metals like Ag, Al, Cu, Cr, Co, Ni, Pb and were found to be efficient metal accumulators as evident from Energy Dispersive X Ray Fluorescence (EDXRF) analysis and Transmission Electron Microscopy (TEM). Beyond intracellular accumulation, these isolates also show metal deposition in form of particles inside the cells which can further open up the area of microbe fabricated nanoparticle generation. The heavy metal accumulation in the cell can trigger different response mechanism such as change in cell morphology which was observed by scanning electron microscopy (SEM). The metal uptake property of these isolates can be applied for the heavy metal removal and recovery from industrial effluents.

60 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the reason for the markedly greater efficiency of the Bheris in fish production compared to other water bodies like rain water ponds or sewage fed fish ponds elsewhere.
Abstract: Waste water fed fisheries are a common feature in different parts of the world. Yet not all work as efficiently as those operating at East Calcutta Wetland for more than 70 years now. The objective of this study is to unravel the reason for the markedly greater efficiency of the Bheris in fish production compared to other water bodies like rain water ponds or sewage fed fish ponds elsewhere. The study indicates that plankton growth could be an important factor responsible for greater fish production in the Bheris. The architecture of the Bheri itself acts as a facilitator in the process. It is proposed that planktons can act as biomarker for water quality assessment in fish production.

47 citations

Journal ArticleDOI
TL;DR: In this article, the authors analyzed the health hazard, if any, underlying the use of wastewater and solid waste for green leafy vegetables at East Calcutta Wetland (ECW) and compared to those grown in south eastern parts of West Bengal (Midnapur).
Abstract: East Calcutta Wetland (ECW) is an example of wise use of cities solid and liquid waste through integrated resource recovery, mainly for pisciculture, vegetable as well as paddy cultivation and manure production. Amaranthus caudatus, Amaranthus blithum and Spinacia oleracea grown at ECW were analyzed for their accumulation of elements using Energy Dispersive X Ray Fluorescence (EDXRF) and compared to those grown in south eastern parts of West Bengal (Midnapur). The objective was to analyze the health hazard, if any, underlying the use of wastewater and solid waste for cultivation of green leafy vegetables at ECW. The following results were obtained upon comparing the data collected from the two different sites: (a) higher accumulation in ECW grown plants of elements like Ca, Cu and Pb in Amaranthus caudatus; of Ca in Amaranthus blithum; of Cl and Cu in Spinacia oleracea, (b) for the same species grown in non-ECW site, higher concentration of elements like Mn and Fe in Amaranthus caudatus; of Cl, Mn and Br in Amaranthus blithum; of Ca, Mn, Fe and Br in Spinacia oleracea. The net consumption of the aforementioned elements per person per day was calculated and found to be much below the Recommended Dietary Allowance (RDA) levels in all cases. Thus the vegetables grown out of integrated resource recovery mechanism at East Calcutta Wetland appear to be safe for human consumption. This further corroborated by the healthy appearance of these vegetables. This result has profound implications of far reaching significance for environmental management and health economics.

44 citations

Journal ArticleDOI
TL;DR: Antibiotic sensitivity assay, morphological characterization and biochemical tests, namely protease, oxidase, catalase, lipase, DNase and lecithinase assay were performed with the 15 isolates obtained from urine samples.
Abstract: The present study was conducted to determine the microbial profile in urine samples. Differential and selective chromogenic culture media were used for the rapid detection, identification and enumeration of urinary tract pathogens namely, E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis. Urine samples of normal healthy individuals as well as patients with Urinary Tract Infection (UTI) were screened on hicrome agar plates. The cultivable bacteria present in urine were isolated based on chromogenic detection. Antibiotic sensitivity assay, morphological characterization and biochemical tests, namely protease, oxidase, catalase, lipase, DNase and lecithinase assay were performed with the 15 isolates obtained from urine samples. The molecular analyses of the isolates were done through partial sequencing of the 16SrDNA gene; six of them were found to be novel and submitted in GenBank under the accession numbers EF644491-96. Phylogenetic tree of the isolates were constructed by neighbour joining method.

43 citations

Journal ArticleDOI
TL;DR: In this paper, the elemental analysis of these products showed no metal toxicity due to their cultivation using waste resource and thus East Calcutta Wetland can be sited as the best example of integrated resource recovery.
Abstract: Calcutta has a unique waste management system which uses the traditional non conventional practice for treating both the solid as well as soluble waste for its 12 million inhabitants . It not only detoxifies the waste but also generates resources for the existing society in form of employment as well as edibles like sufficient vegetable, fish as well as paddy for consumption. The elemental analysis of these products showed no metal toxicity due to their cultivation using waste resource. Thus East Calcutta Wetland can be sited as the best example of integrated resource recovery.

42 citations


Cited by
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Book ChapterDOI
01 Jan 1976
TL;DR: A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in Solubility with rise in temperature.
Abstract: A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

1,573 citations

Book
01 Jan 2010
TL;DR: In this paper, the authors highlight and illustrate the approach adopted by TEEB: namely to show how economic concepts and tools can help equip society with the means to incorporate the values of nature into decision making at all levels.
Abstract: The aim of this synthesis is to highlight and illustrate the approach adopted by TEEB: namely to show how economic concepts and tools can help equip society with the means to incorporate the values of nature into decision making at all levels.

958 citations

Journal ArticleDOI
TL;DR: In this paper, the authors tried to explain the concept behind bioindicators and plankton, with particular emphasis on their potential to be used as Bioindicators for water quality assessment and outcomes relating to this.
Abstract: Bioindicators are living organisms such as plants, planktons, animals, and microbes, which are utilized to screen the health of the natural ecosystem in the environment. They are used for assessing environmental health and biogeographic changes taking place in the environment. Each organic entity inside a biological system provides an indication regarding the health of its surroundings such as plankton responding rapidly to changes taking place in the surrounding environment and serving as an important biomarker for assessing the quality of water as well as an indicator of water pollution. Even the health of aquatic flora is best reflected by plankton, which acts as an early warning signal. In this review we have tried to explain the concept behind Bioindicators and plankton, with particular emphasis on their potential to be used as Bioindicators for water quality assessment and outcomes relating to this.

354 citations

Journal ArticleDOI
TL;DR: In this paper, a surface-functionalized silica nanoparticle (SNP) was tested against rice weevil Sitophilus oryzae and its efficacy was compared with bulk-sized silica (individual particles larger than 1 μm).
Abstract: Fumigants and residual insecticides are commonly used to combat stored grain pests. In recent years, consumer awareness of the health hazard from residual toxicity and the growing problem of insect resistance to these conventional insecticides have led the researchers to look for alternative strategies for stored grains protection. For example, diatomaceous earth (DE) can be effective against stored grain insects. In this study, DE was used to design amorphous nano sized hydrophilic, hydrophobic, and lipophilic silica in 15–30 nm size range. Nanocides are expected to reduce the volume of application and kinetics of development of resistance in pests. We hypothesized that surface-functionalized silica nanoparticle (SNP) might be a viable alternative to conventional pesticides. Entomotoxicity of SNP was tested against rice weevil Sitophilus oryzae and its efficacy was compared with bulk-sized silica (individual particles larger than 1 μm). Amorphous SNP was found to be highly effective against this insect pest causing more than 90% mortality, indicating the effectiveness of SNP to control insect pests.

227 citations

Book ChapterDOI
14 Jun 2013
TL;DR: In most cases the term biodegradation is generally used to describe almost any biologically mediated change in a substrate, and the process is called "mineralization".
Abstract: Biodegradation is defined as the biologically catalyzed reduction in complexity of chemical compounds [1]. Indeed, biodegradation is the process by which organic substances are broken down into smaller compounds by living microbial organisms [2]. When biodegradation is complete, the process is called "mineralization". However, in most cases the term biodegra‐ dation is generally used to describe almost any biologically mediated change in a substrate [3].

191 citations