Analysis of Generalized Inverted Exponential Distribution under Adaptive Type-I Progressive Hybrid Censored Competing Risks Data

The estimation of the unknown parameters of generalized inverted exponential distribution under adaptive type-I progressive hybrid censored scheme (AT-I PHCS) with competing risks data will be discussed. The reason why AT-I PHCS has exceeded other failure censored types; Time censored types enable analysts to accomplish their trials and experiments in a shorter time and with higher efficiency. In this regards, we obtain the maximum likelihood estimation of the parameters and the asymptotic confidence intervals for the unknown parameters. Further, Bayes estimates of the parameters which obtained based on squared error and LINEX loss functions under the assumptions of independent gamma priors of the scale parameters. For Bayesian estimation, we take advantage of Markov Chain Monte Carlo techniques to derive Bayesian estimators and the credible intervals. Finally, two data sets with Monte Carlo simulation study and a real data set are analyzed for illustrative purposes

Purification and characterization of alginate lyase from locally isolated marine Pseudomonas stutzeri MSEA04

An alginate lyase with high specific enzyme activity was purified from Pseudomonas stutzeri MSEA04, isolated from marine brown algae. The alginate lyase was purified by precipitation with ammonium sulphate, acetone and ethanol individually. 70% ethanol fraction showed maximum specific activity (133.3 U/mg). This fraction was re-purified by anion exchange chromatography DEAE- Cellulose A-52. The loaded protein was separated into 3 peaks. The second protein peak was the major one which contained 48.2% of the total protein recovered and 79.4% of the total recovered activity. The collected fractions of this peak were subjected to further purification by re-chromatography on Sephadex G-100. Alginate lyase activity was fractionated in the Sephadex column into one major peak, and the specific activity of this fraction reached 116 U/mg. The optimal substrate concentration, pH and temperature for alginate lyase activity were 8 mg/ml, pH 7.5 and 37 °C, respectively. While, Km and Vmax values were 1.07 mg alginate/ ml and 128.2 U/mg protein, respectively. The enzyme was partially stable below 50 °C, and the activity of the enzyme was strongly enhanced by K+, and strongly inhibited by Ba+2, Cd+2, Fe+2 and Zn+2. The purified enzyme yielded a single band on SDS-PAGE with molecular weight (40.0 kDa)

Calibration of a Neutron Polarimeter

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Synthesis and antimicrobial activity of new polyfunctionally substituted pyridines and their fused derivatives

1314-1319Ethyl pyruvate (EP) on reacting with malononitrile or isothiocyanates gives the pyridine derivatives 5 and 9a, b, respectively. Chalcone derivative of EP reacts with malononitrile to yield the pyran derivative which in turn is transformed into pyridine derivative 14. Reactivity of 5 and 9a towards different organic reagents has been investigated . Antimicrobial activity of some newly synthesized pyridines is also reported