Colorism and Love for Fair Skin : Exploring Digitization’s Effect on India’s Arranged Marriage Matrimonial Advertisements

Dhiman Chattopadhyay,Sriya Chattopadhyay 한국언론학회 2019 Asian Communication Research Vol.16 No.1

Bioprocess Considerations for Production of Secondary Metabolites by Plant Cell Suspension Cultures

Chattopadhyay, Saurabh,Farkya, Sunita,Srivastava, Ashok K.,Bisaria, Virendra The Korean Society for Biotechnology and Bioengine 2002 Biotechnology and Bioprocess Engineering Vol.7 No.3

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stage etc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.

Modeling and Analysis of Warranty Cost for 2D-Policies Associated with Sale of Second-hand Products

Chattopadhyay G.,Yun Won-Young The Korean Reliability Society 2006 International Journal of Reliability and Applicati Vol.7 No.1

The market for second hand products has been growing for a variety of reasons (e.g., new products appearing at a faster rate and the expected life of products increasing due to rapid advances in technology). The demand for warranties for second-hand products has been growing along with the growth of the market for second-hand products. Warranty for new products (consumer durables, industrial and commercial, and specialized defense products) has received a lot of attention. In contrast, warranties for second-hand product have received very little attention. Often, dealers of second-hand product such as cars offer 2D-warranties (Year and Kilometers). The expected warranty cost associated with a second-hand product for 2D-Policies is a function of the age of the item and its usage (as it affects failures over the warranty period), the warranty terms and the servicing strategy used by the dealer. This paper deals with development of models for warranty cost analysis along with the decision on sale price and warranty cover for 2D-Warranty policies associated with sale of second-hand products.

Defects in Tussah(Tasar) Silk Yarn

Chattopadhyay, R.,Das, Subrata,Gulrajani, M. L.,Sen, Kushal 한국잠사학회 1995 한국잠사곤충학회지 Vol.37 No.2

The aim of the present work is to investigate the level of faults present in tussah silk yarn as detected on an Uster instrument for four different varieties of commercially available tussah(tasar) silk yarns. The structure of these faults were analysed further so as to understand the mechanism and source of their generation.

Peroxidase Activity during Leaf Infection of Mulberry (Morus alba L.) with Brown Leaf Spot Fungus Myrothecium roridum

Chattopadhyay Soumen,Krishnan Natraj,Maji Manas D. Korean Society of Sericultural Science 2006 International Journal of Industrial Entomology Vol.12 No.1

Peroxidase activity was measured in brown leaf spot pathogen (Myrothecium roridum) inoculated potted mulberry (Morus alba) during pre-symptomatic to various symptom development stages and compared with corresponding healthy leaf tissues. The enzyme showed a pH optimum of 7.0 and the activity was linearly increased up to 15 min of incubation. The peroxidase had a broad substrate specificity and the rates of oxidation were in the rank of pyrogallol> guaiacol> ascorbate at pH 7.0. Catechol at 10 mM inhibited 89% of guaiacol-peroxidase and 76% pyrogallol-peroxidase activities, indicated higher non-specific peroxidation in pyrogallol dependent assay system in mulberry than guaiacol. The optimum requirement for the guaiacol dependent assay was 0.2 ml (${\approx}40-60{\mu}g$ equivalent of protein) of crude enzyme source. Excepting the 8th leaf from the apex, the peroxidase activity did not vary appreciably in different leaf positions. In pre-symptomatic phases, an initial (1 to 5 min) rise of peroxidase activity was noticed in inoculated leaves, and then maintained a plateau up to 300 min. In contrary, non-infected tissue showed a slightly increased trend of enzyme level up to 420 min. In infected tissue, a sharp transient increase (3.1 fold) of peroxidase activity appeared between 300 - 420 min post infections. Afterwards, significantly different but steady maintenance of enzyme levels were observed in two treatments. On the other hand, during symptom development, a sharp increase in peroxidase activity was noticed up to 4th grade of lesion appearance (25.1 % to 50% of leaf area infection), and then declined slightly. However, in non-infected but same age healthy leaves, such huge fluctuations of enzyme level did not apparent. A high positive correlation $(R^2=0.92)$ between peroxidase activity and leaf spot development grades was also marked. The result implies that pre-symptomatic burst (between 1 - 5 and 300 - 420 min) and subsequent increased trend of guaiacol peroxidase activity may require for the symptomatic manifestation of Myrothecium leaf spot in mulberry.

Evaluation of analgesic and antiinflammatory activity of Ophiorrhiza nicobarica, an ethnomedicine from Nicobar Islands, India

Chattopadhyay, Debprasad,Das, Sonali,Mandal, Asit Baran,Arunachalam, G,Bhattacharya, SK Kyung Hee Oriental Medicine Research Center 2007 Oriental pharmacy and experimental medicine Vol.7 No.4

This study reports the analgesic, anti-inflammatory and membrane-stabilizing property of alcoholic extract of Ophiorrhiza nicobarica (ON), a wild herb, used as an anti-infective ethnomedicine of Nicobarese and Shompen tribes of Great Nicobar Island, India. We for the first time investigated the analgesic and antiinflammatory potential of this herb in acute, subacute and chronic model of inflammation in Swiss albino mice and Wistar albino rats, along with sheep RBC-induced sensitivity and membrane stabilization. The acetic acid induced writhing, tail flick and tail immersion tests are used as a model for evaluating analgesic activity; while the carrageenin-induced paw oedema was used as the model for acute inflammation, dextran-induced oedema as sub-acute and cotton-pellateinduced granuloma as chronic inflammatory model. The probable mode by which ON mediate its effect on inflammatory conditions was studied on sheep RBC-induced sensitivity and membrane stabilization. The in vitro results revealed that the ON extract possesses significant (P < 0.05) dose dependent analgesic and antiinflammatory activity at 200 and 300 mg/kg and its fractions at 50 mg/kg, p.o. respectively, compared to the control groups. However, the extract failed to exhibit membrane-stabilizing property as it unable to reduce the level of haemolysis of RBC exposed to hypotonic solution. The acute toxicity studies of ON extract in rats and mice revealed that the extract was nontoxic even up to 3.0 g/kg body weight of the animals, with a high safety profile. We have isolated ursolic acid, ${\beta}$-sitosterol and harmaline respectively, from the bioactive part of the extract. The results indicated that the O. nicobarica is indeed beneficial in primary health care, and suggest that its anti-inflammatory activity may not be related to membrane-stabilization.

THEORY OF EXTENSIONS OF BICLOSURE SPACES AND BASIC QUASI-PROXIMITIES

Chattopadhyay, K.C.,Hazra, R.N. Department of Mathematics 1990 Kyungpook mathematical journal Vol.30 No.2

Towards Identifying Evolving Mathematical Creativity in School Children : A Conceptual Framework

( Chattopadhyay Siddhartha Sankar ),( Sinha Dilip Kumar ) 한국수학교육학회 2011 수학교육 학술지 Vol.2011 No.-

As the title implies, the paper aims at seeking modes for possible identification of moments of mathematical creativity in its ebb and flow among gifted school children, following which a conceptual framework is aimed at. An individualistic consideration from a wider standpoint, a perception of mathematical creativity is studiedly sought for in this work. Possible layers of creativity in several classroom milieus are also looked for. Deciphering or even noticing mathematical creativity is also undertaken. The coupling from an experiential point of view is presented. Creativity ratios, obviously, in the field of mathematics are presented so that creative incidents or events can be well focused. That mathematical creativity can be well sustained forms a major interest of this paper. Nonlinearity stemming essentially from coupling in the experiential arena is also discussed. Evolving forms of mathematical creativity become discernible through the perceptual space about creativity. Few designs and patterns emerge from such dynamical exercises on mathematical creativity.

Optically Controlled Silicon MESFET Modeling Considering Diffusion Process

Chattopadhyay, S.N.,Motoyama, N.,Rudra, A.,Sharma, A.,Sriram, S.,Overton, C.B.,Pandey, P. The Institute of Electronics and Information Engin 2007 Journal of semiconductor technology and science Vol.7 No.3

An analytical model is proposed for an optically controlled Metal Semiconductor Field Effect Transistor (MESFET), known as Optical Field Effect Transistor (OPFET) considering the diffusion fabrication process. The electrical parameters such as threshold voltage, drain-source current, gate capacitances and switching response have been determined for the dark and various illuminated conditions. The Photovoltaic effect due to photogenerated carriers under illumination is shown to modulate the channel cross-section, which in turn significantly changes the threshold voltage, drainsource current, the gate capacitances and the device switching speed. The threshold voltage $V_T$ is reduced under optical illumination condition, which leads the device to change the device property from enhancement mode to depletion mode depending on photon impurity flux density. The resulting I-V characteristics show that the drain-source current IDS for different gate-source voltage $V_{gs}$ is significantly increased with optical illumination for photon flux densities of ${\Phi}=10^{15}\;and\;10^{17}/cm^2s$ compared to the dark condition. Further more, the drain-source current as a function of drain-source voltage $V_{DS}$ is evaluated to find the I-V characteristics for various pinch-off voltages $V_P$ for optimization of impurity flux density $Q_{Diff}$ by diffusion process. The resulting I-V characteristics also show that the diffusion process introduces less process-induced damage compared to ion implantation, which suffers from current reduction due to a large number of defects introduced by the ion implantation process. Further the results show significant increase in gate-source capacitance $C_{gs}$ and gate-drain capacitance $C_{gd}$ for optical illuminations, where the photo-induced voltage has a significant role on gate capacitances. The switching time ${\tau}$ of the OPFET device is computed for dark and illumination conditions. The switching time ${\tau}$ is greatly reduced by optical illumination and is also a function of device active layer thickness and corresponding impurity flux density $Q_{Diff}$. Thus it is shown that the diffusion process shows great potential for improvement of optoelectronic devices in quantum efficiency and other performance areas.

Non-invasive Methods for Determination of Cellular Growth in Podophyllum hexandrum Suspension Cultures

Chattopadhyay, Saurabh,Bisaria, V.S.,Scheper, T.,Srivastava, A.K. The Korean Society for Biotechnology and Bioengine 2002 Biotechnology and Bioprocess Engineering Vol.7 No.6

Culture conductivity and on-line NADH fluorescence were used to measure cellular growth in plant cell suspension cultures of Podophyllum hexandrum. An inverse correlation between dry cell weight and medium conductivity was observed during shake flask cultivation. A linear relationship between dry cell weight and culture NADH fluorescence was obtained during the exponential phase of batch cultivation In a bioreactor under the pH stat (pH 6) conditions. It was observed that conductivity measurement were suitable for biomass characterisation under highly dynamic uncontrolled shake flask cultivation conditions. However, if the acid/alkali feeding is done for pH control the conductivity measurement could not be applied. On the other hand the NADH fluorescence measurement allowed online-in situ biomass monitoring of rather heterogenous plant cell suspension cultures in bioreactor even under the most desirable pH stat conditions.