Bethune College

Kolkata, India

Bethune College

Kolkata, India
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Nath D.,Vivekananda College | Roy B.,Indian Statistical Institute | Roychoudhury R.,Bethune College
Optics Communications | Year: 2017

Exact expressions are obtained for stationary periodic waves in cubic-quintic nonlinear media with opposite signs of nonlinearity. It is shown that defocussing/focussing quintic nonlinearity can lead to stabilization of snoidal/(cnoidal and dnoidal) periodic waves depending on whether the Kerr medium is focusing/defocusing. Direct numerical simulations confirm results of the linear stability analysis. Different stable patterns e.g. bright solitons and kinks are also obtained under certain conditions. © 2017 Elsevier B.V.

Saha J.,Bethune College | Mitra T.,Bethune College | Gupta K.,Bethune College | Mukherjee S.,Bethune College
International Journal of Pharmacy and Pharmaceutical Sciences | Year: 2012

Saraca asoca (Roxb.)Wilde, (Ashok) belonging to the family Caesalpiniaceae is a universal panacea in the ayurvedic medicine. This versatile plant has anti-cancer, anti-menorrhagic, anti-oxytocic, anti-microbial activity and has extended uses in ayurveda, unani and homeopathy. The present study attempts to investigate the qualitative phytochemical constituents from extracts of the flower of Saraca asoca (Roxb.)Wilde. Tannin, flavonoids, carbohydrates, proteins, steroids have been found in different extracts of the flowers. Phytochemical as well as physicochemical analysis is useful to establish the authenticity of the crude drug form. A sensitive and reliable high performance thin layer chromatographic (HPTLC) method has been developed for qualitative determination of a pharmacologically important active constituent- gallic acid in the dried flowers and leaves of Saraca asoca (Roxb.)Wilde. The assay combines the separation of analytes on precoated silica gel 60 F 254HPTLC plates as stationary phase and Toluene: Ethyl Acetate: Formic Acid: Methyl Alcohol (6:6:1.6:0.4 v/v/v/v) as mobile phase. Detection has been carried out densitometrically at λ =280 nm for gallic acid. This is the first report of occurrence of gallic acid in leaves of S. asoca. Further investigation will be carried out for the quantification of the test compound, gallic acid in Saraca leaf.

Gupta K.,Bose Institute of India | Gupta K.,Bethune College | Gupta B.,Bose Institute of India | Gupta B.,Presidency University of India | And 2 more authors.
Acta Physiologiae Plantarum | Year: 2012

Importance of higher polyamines, spermidine, and spermine, in relation to the mechanism and adaptation to combat abiotic stress has been well established in cereals. Owing to their polycationic nature at physiological pH, polyamines bind strongly to negative charges in cellular components such as nucleic acids, various proteins, and phospholipids. To study the physiological role of polyamine during salinity stress, phosphorylation study was carried out in cytosolic soluble protein fraction isolated from the roots of salt tolerant (Nonabokra) and salt sensitive (M-1-48) rice cultivars treated with none (control), NaCl (150 mM, 16 h), spermidine (1 mM, 16 h) or with abscisic acid (100 μM, 16 h). A calcium independent auto regulatory 42 kDa protein kinase was found to phosphorylate myelin basic protein and casein but not histone. Interestingly, this was the only protein to be phosphorylated in root cytosolic fraction during NaCl/abscisic acid/spermidine treatment indicating its importance in salinity mediated signal transduction. This is the first report of polyamine as well as abscisic acid induced protein kinase activity in rice root in response to salinity stress. © 2011 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

Gupta B.,Bose Institute of India | Gupta B.,Presidency University of India | Gupta K.,Bose Institute of India | Gupta K.,Bethune College | Sengupta D.N.,Bose Institute of India
Acta Physiologiae Plantarum | Year: 2012

Plants respond to abiotic stresses such as salinity, extreme temperature and drought by the activation of complex intracellular signaling cascades that regulate acclimatory biochemical and physiological changes. Protein kinases are major signal transduction factors that play a central role in mediating acclimation to environmental changes in eukaryotic organisms. It is well known that changes in abiotic conditions such as the concentration of ions, temperature and humidity lead to modulation of polyamine contents in plants. However, little is known about the relevant part these polyamines play in abiotic stress responses. Here, we address a specific role of spermidine during high salt stress by studying its interaction with OSPDK, a sucrose nonfermenting 1-related protein kinase2 (SnRK2)-type serine/threonine protein kinase SAPK4 homolog in indica rice. In this report, we demonstrate that spermidine mediates in vitro phosphorylation of OSBZ8, a bZIP class of ABRE-binding transcription factor, by OSPDK. Our results give a first-hand indication of the pivotal role played by polyamines in abiotic stress cell signaling in plants. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

Sanyal S.,Bethune College | Banerjee S.,University of Calcutta
Archives of Polish Fisheries | Year: 2013

In this study, the thermotolerent fecal coliform (Th FC) bacterial population (n = 81) in a waste-fed aquaculture system was examined for multiple antibiotic resistance and the possession of transferable drug resistance factors (R factors). Multiple antibiotic resistant (MAR) coliforms were found to be common in the sewage-fed pond environment, with 83% of the screened MAR isolates harboring plasmids of > 10 kilo base pair (kb). The transfer of resistance was confirmed by mating experiments in 92% of plasmid-positive MAR coliforms with a nalidixic acid (NA) resistant strain, Escherichia coli ATCC (American Tissue Type Cell Culture) 14948 recipient in the presence of DNase (Deoxyribonuclease). Antibiotic resistance profiles of some mated progenies (70.83%) indicated that transfer was unidirectional. DNase-treated cell-free supernatants did not transform, which excluded transduction. A DNase-resistant conjugation-like mechanism probably plays a major role in the transfer of resistance factors. Physical evidence of transmissible resistance factors in fish suggests a potential health risk to humans and animals, including farmed fish. ©Inland Fisheries Institute in Olsztyn.

Chakraborty T.,Bethune College | Giri B.C.,Jadavpur University
Operational Research | Year: 2014

The paper studies the joint effect of shift, inspections, imperfect preventive maintenance (PM) and imperfect rework of defective items on optimal decisions for a deteriorating production system. At the time of inspection during a production run, either PM or restoration is done depending on the state of the production process. There is a probability that PM action may shift the process from 'in-control' state to 'out-of-control' state. During the 'out-of-control' phase, the system produces some defective items which go for rework at the end of the production run. A portion of the reworked items may also fail repairing. The model is formulated for the case of general inspections and analyzed under two well known inspection policies-periodic inspection policy and constant cumulative hazard inspection policy. For numerical examples, a comparison of the outcomes of the model with and without reworks under these two inspection policies is made. It is observed that the periodic inspection policy performs better than the constant cumulative hazard policy. © 2013 Springer-Verlag Berlin Heidelberg.

Sinha A.,Jadavpur University | Roychoudhury R.,Bethune College | Roychoudhury R.,Advanced Center for Nonlinear and Complex Phenomena
Journal of Mathematical Physics | Year: 2013

We present an analytical study for the scattering amplitudes (Reflection |R| and Transmission |T|), of the periodic PT symmetric optical potential V(x) = W0(cos2x + i vo sin 2x)confined within the region 0 ≤ x ≤ L, embedded in a homogeneous medium having uniform potential W0. The confining length L is considered to be some integral multiple of the period π. We give some new and interesting results. Scattering is observed to be normal (|T|2 ≤ 1, |R|2 ≤ 1) for V0 ≤ 0.5, when the above potential can be mapped to a Hermitian potential by a similarity transformation. Beyond this point (V0 > 0.5) scattering is found to be anomalous (|T|2, |R|2 not necessarily ≤1). Additionally, in this parameter regime of V0, one observes infinite number of spectral singularities ESS at different values of V0. Furthermore, for L = 2nπ, the transition point V0 = 0.5 shows unidirectional invisibility with zero reflection when the beam is incident from the absorptive side (Im[V(x)] < 0) but with finite reflection when the beam is incident from the emissive side (Im[V(x)] > 0), transmission being identically unity in both cases. Finally, the scattering coefficients |R|2 and |T|2 always obey the generalized unitarity relation: ||T|2- 1| = √|RR|2|RL|2, where subscripts R and L stand for right and left incidence, respectively. © 2013 AIP Publishing LLC.

Gupta K.,Bethune College | Chatterjee C.,Presidency University of India | Gupta B.,Presidency University of India
Biologia | Year: 2012

The present study was conducted to determine the culturable bacterial profile from Kestopur canal (Kolkata, India) and analyze their heavy metal tolerance. In addition to daily sewage including solid and soluble wastes, a considerable load of toxic metals are released into this water body from industries, tanneries and agriculture, household as well as health sectors. Screening out microbes from such an environment was done keeping in mind their multifunctional application especially for bioremediation. Heavy metals are major environmental pollutants when present in high concentration in soil and show potential toxic effects on growth and development in plants and animals. Some edible herbs growing in the canal vicinity, and consumed by people, were found to harbour these heavy metals at sub-toxic levels. The bioconcentration factor of these plants being <1 indicates that they probably only absorb but not accumulate heavy metals. All the thirteen Grampositive bacteria isolated from these plants rhizosphere were found to tolerate high concentration of heavy metals like Co, Ni, Pb, Cr, Fe. Phylogenetic analysis of their 16S rDNA genes revealed that they belonged to one main taxonomic group - the Firmicutes. Seven of them were found to be novel with 92-95% sequence homology with known bacterial strains. Further microbiological analyses show that the alkaliphilic Bacillus weihenstephanensis strain IA1 and Exiguobacterium aestuarii strain CE1, with selective antibiotic sensitivity along with high Ni2+ and Cr6+ removal capabilities, respectively, can be prospective candidates for bioremediation. © 2012 Versita Warsaw and Springer-Verlag Wien.

Khanra S.,Bethune College | Datta S.,Bethune College | Mondal D.,International Center for Diarrheal Disease Research | Saha P.,Saha Institute of Nuclear Physics | And 3 more authors.
Acta Tropica | Year: 2012

Visceral Leishmaniasis or Kala-azar (KA) is a serious health concern in India. In the present study, Restriction Fragment Length Polymorphism (RFLP) of three genetic markers viz., Internal Transcribed Spacer (ITS), ITS1 and heat shock protein 70 (hsp70) have been employed for typing the clinical isolates [n= 15] of KA and post Kala-azar Dermal Leishmaniosis (PKDL) collected from India and Bangladesh in the period of 2006-2010. Experimentally, ITS, ITS1 and hsp70 regions of genomes of all the clinical isolates were separately amplified by PCR and then digested with restriction enzymes: ITS with Alu1, EcoR1 and Msp1, ITS1 with Hae III and Rsa1 and hsp70 with Hae III. The resultant fragments were analyzed by agarose gel electrophoresis and the RFLP profiles of the clinical isolates were compared with that of the WHO reference strains for Leishmania donovani (DD8) and Leishmania tropica (K27), respectively. Also, the ITS1 regions of all the clinical isolates along with the two WHO reference strains were sequenced and a phylogram was constructed to ascertain the extent of similarity or dissimilarity. Interestingly, the RFLP profiles of one of the isolates showed a significant homology with K27 and the phylogram revealed its closeness with the same putting credence to our earlier typing of isolates by RAPD method. This observation also supported an earlier report claiming that both the species are responsible for KA in India and thus, emphasizes urgent need for thorough systematic characterization of the clinical isolates of Indian KA as appropriate treatment regime relies primarily on proper diagnosis. © 2012 Elsevier B.V.

Manna M.,Bethune College | Chakraborty P.,Bethune College
Journal of Environmental Biology | Year: 2012

The East Calcutta Wetland (ECW), a Ramsar site in India, acts asthe only sink for both city sewages as well as effluents from the surrounding small- scale industries and isalarmingly polluted with heavy metals. The three best edible majorcarp species rohu (Labea iv hita,) , catla (Catla catla,) and mrigala (Cirrhinus mrigala) were undertaken to monitor lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) by cellulose acetate electrophoresis (CAE) to assess the effects of pollutants, if any. Crude tissue extracts were prepared from brain, eye, heart, skeletal muscle and kidney tissue respectively from each type of fish. No differences were not found in MDH of catla from both sites for all tissues analyzed in this study. Rohu also showed similar mobilityfor all tissues except for heart tissue which was distinctly different in fishes from ECW site than that of its counterpart from non ECW site. On the other hand, MDH of two tissues of mrigala, eye and muscle respectively showed different migration patterns. LDH profiles for all tissues of three fish species from both the sites were consistently similar, only the expression levels of muscle LDH of mrigala and kidney LDH of rohu varied little. © 2012 Triveni Enterprises.

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