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Rana C.,University Institute of Engineering and Technology | Jain S.K.,National Institute of Technology Kurukshetra
Swarm and Evolutionary Computation | Year: 2014

The use of internet and Web services is changing the way we use resources and communicate since the last decade. Although, this usage has made life easier in many respects still the problem of finding relevant information persists. A naïve user faces the problem of information overload and continuous flow of new information makes the problem more complex. Furthermore, user′s interests also keeps on changing with time. Several techniques deal with this problem and data mining is widely used among them. Recommender Systems (RSs) assist users in finding relevant information on the web and are mostly based on data mining algorithms. This paper addresses the problem of user requirements changing over a period of time in seeking information on web and how RSs deal with them. We propose a Dynamic Recommender system (DRS) based on evolutionary clustering algorithm. This clustering algorithm makes clusters of similar users and evolves them depicting accurate and relevant user preferences over time. The proposed approach performs an optimization of conflicting parameters instead of using the traditional evolutionary algorithms like genetic algorithm. The algorithm has been empirically tested and compared with standard recommendation algorithms and it shows considerable improvement in terms of quality of recommendations and computation time. © 2013 Elsevier B.V. Source


Dubey K.K.,University Institute of Engineering and Technology | Behera B.K.,Md University
New Biotechnology | Year: 2011

Effect of various nutritional components and fermentation parameters on biotransformation of colchicine using Bacillus megaterium ACBT03 to produce 3-demethylated colchicine (3-DMC) has been investigated. Initially, Plackett-Burman (PB) design was used to evaluate the 11 nutritional variables to screen medium component that significantly influences the 3-demethylated colchicine (3-DMC) production. Three most statistically significant nutrients that is starch, glycerol and yeast extract were identified. Response surface methodology was used to optimize fermenter operational factors pH, temperature, impeller tip velocity and aeration rate for high 3-DMC production. The predicted results of 3-DMC yield (7689.13. mg/l) were obtained at 5-l-jar fermenter after optimization of pH 6.8, temperature 28°C, impeller tip velocity 4650. cm/min, and aeration rate 2.0. vvm. The validity of model was confirmed; and the optimum medium designed led a maximum 3-DMC yield of 7335. mg/l, which had 3-4% variation with predicted results. Furthermore, the experiment was scaled up in the 70-l fermenter. © 2010 Elsevier B.V. Source


Gupta M.K.,University Institute of Engineering and Technology | Misra K.,Sanjay Gandhi Post Graduate Institute of Medical Sciences
Journal of Molecular Modeling | Year: 2014

The three-dimensional quantitative structure-activity relationship (3D-QSAR) for inhibitors of thyroid hormone receptors (TR) α and (TR) β was studied. The training set of the TRα model generated a correlation coefficient (R2) = 0.9535, with standard deviation (SD)=0.3016. From the test set of the TRα model, a Q2 value for the predicted activities (= 0.4303), squared correlation (random selection R2- CV=0.6929), Pearson-R (= 0.7294) and root mean square error (RMSE=0.6342) were calculated. The P-value for TRα (= 1.411e-96) and TRβ (= 2.108e-165) models indicate a high degree of self-reliance. For the TRβ model, the training set yielded R2 =0.9424 with SD = 0.3719. From the test set of TRβ, Q2 value (= 0.5336), the squared correlation (R2-CV=0.7201), the Pearson-R (= 0.7852) and RMSE for test set predictions (=0.8630) all strengthen the good predictive competence of the QSAR model derived. Examination of internal as well as external validation supports the rationality and good predictive ability of the best model. Molecular docking explained the conformations of molecules and important amino acid residues at the docking pocket, and a molecular dynamics simulation study further uncovered the binding process and validated the rationality of docking results. The findings not only lead to a better understanding of interactions between these antagonists and thyroid hormone receptors α and β, but also provide valuable information about the impact of structure on activity that will be very beneficial in the design of novel antagonists with preferred activity. © Springer-Verlag 2014. Source


Dubey K.K.,University Institute of Engineering and Technology | Haque S.,Jamia Millia Islamia University | Jawed A.,Chandigarh Institute of Microbial Technology | Singh B.P.,Md University | Behera B.K.,Md University
Process Biochemistry | Year: 2010

A recombinant strain of Escherichia coli with CYP102A1 gene was developed for the demethylation of colchicine into their derivatives. The CYP102A1 gene responsible for demethylation was isolated from Bacillus megaterium ACBT03 and amplified using suitable primers. The amplified product was cloned into pET28a+ expression vector using host E. coli BL21(DE3) cells. The CYP3A4 (product of CYP102A1 gene) protein expression and other parameters like substrate toxicity, product toxicity and enzyme activity were optimized in shake flasks; and further scaled-up to 5l bioreactor with 3l working volume. In 5l bioreactor, dissolved oxygen (DO) was optimized for maximum specific growth and enhanced 3-demethylated colchicine (3-DMC) production. The optimized conditions from shake flasks were scaled-up to 70l bioreactor and resulted into ∼80% conversion of 20mM colchicine in 48h with a volumetric productivity of 6.62mgl -1h -1. Scale-up factors were measured as volumetric oxygen transfer coefficient (k La) i.e., 56h -1 and impeller tip velocity (V tip) i.e., 7.065ms -1, respectively. The kinetic parameters K m, k cat, and k cat/K m of the CYP3A4 enzyme using colchicine as the substrate were determined to be 271±30μM, 8533±25min -1, and 31.49μMmin -1, respectively, when IPTG induced recombinant E. coli culture was used. © 2010 Elsevier Ltd. Source


Verma V.,University of Delhi | Beniwal A.,University of Delhi | Ohlan A.,Md University | Tripathi R.,University Institute of Engineering and Technology
Journal of Magnetism and Magnetic Materials | Year: 2015

Abstract Bi1-xPrxFeO3 samples (0≤x≤0.25 in step of 0.05) were synthesized by the sol-gel technique to investigate the effect of Pr doping on the structural, magnetic and electrical properties of multiferroic bismuth ferrites (BFO). It is observed that Pr doping induces structural changes in BFO and also decreases the secondary phases noticeably. Frequency dependent dielectric properties of pure and doped BFO samples were measured from 300 K to 675 K in the frequency range from 100 Hz to 1 MHz. Enhanced ferromagnetism and improved ferroelectric properties were observed which may be correlated with the structural transformation and grain morphology. © 2015 Elsevier B.V. Source

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