Authors:Aymen Mabrouk, Yosra Chebbi, Anis Raddaoui, Asma Krir, Amen Allah Messadi, Wafa Achour, and Lamia Thabet
water for 10 min. Lastly, centrifuge step was operated at 12,000 rpm at 4 °C for 10 min. The supernatant containing DNA was transferred to a sterile micro tube and stored at −20 °C. All isolates were screened by simplex PCR for the following β
Immobilization of the bacteria A. simplex by-2-13 was obtained by irradiation polymerization with an electron beam and gamma-radiation at 0°C. Prednisone acetate (P. A.) was derived from cortisone acetate (C. A.) by 1,2-dehydrogenation, catalyzed by immobilized A. simplex by-2-13. The immobilized bacteria were used 10 times in succession with a transformation percentage ranging from 77 to 86% for electron beam radiation and 79 to 99% for gamma radiation. Dehydrogenation, was carried out at pH 7.2, 34°C, 180–200 r.p.m. for 24 hours. 3% (v/v) anhydrous alcohol was added to the system at onset. Scanning electron micrographs documented the structure of the immobilized bacteria. In this work, the effect of absorbable doses of radiation and the reaction time of non-immobilized bacteria on dehydrogenase activity were studied. The effect of pH, temperature and concentration of substrate were also studied.
We indicate some qualitative properties of Fleming--Viot second order differential operators on the d-dimensional simplex, such as an inductive characterization of its domain and some spectral properties connected with the
asymptotic behavior of the generated semigroup. These properties turn out to be very useful in the approximation of the solution
of the evolution problem associated with Fleming--Viot operators, which are very important as diffusion models in population
Authors:Lorentz Jäntschi, Sorin Hodişan, Claudia Cimpoiu, Anamaria Hosu, Eugen Darvasi, and Teodor Hodişan
Modeling of thin-layer chromatographic separation of androstane isomers to find the optimum mobile phase is described in this paper. The isomers of androstane are present in a variety of samples, so achieving their optimum thin-layer chromatographic separation is very important. A mathematical model was developed and tested. The model takes into account the interaction between solvents and uses a complex function for modeling, so it provides reliable results. The proposed mathematical model gives results similar to those obtained by use of other optimization models, for example the ‘Simplex’ and ‘Prisma’ methods.
Authors:Sandra Babić, Alka Horvat, and Marija Kaštelan-Macan
A method for optimization of a TLC separation based on use of a genetic algorithm is described. The procedure was tested by optimization of the reversed-phase HPTLC separation of a mixture of six pesticides and satisfactory optimum results were obtained. The performance of the genetic algorithm was tested by measurement of the number of generations, the population size, the mutation probability, and the crossover probability. Three separation criteria (
**) were examined as fitness functions. The genetic algorithm was compared with the simplex method.
Authors:K. I. Kis, P. T. Taylor, G. Wittmann, H. R. Kim, B. Toronyi, and T. Mayer-Gürr
To solve a geophysical inverse problem means applying measurements to determine the parameters of the selected model. The inverse problem is formulated as the Bayesian inference. The Gaussian probability density functions are applied in the Bayes's equation. The CHAMP satellite gravity data are determined at the altitude of 400 km altitude over the South part of the Pannonian Basin. The model of interpretation is the right vertical cylinder. The parameters of the model are obtained from the minimum problem solved by the Simplex method.
Authors:P. Hashemi, M. M. Abolghasemi, S. Ahmadi, and A. R. Ghiasvant
Headspace-solvent microextraction (HS-SME) and hydrodistillation coupled with GC-MS have been used for isolation and identification of the volatile components that characterize Myrtus communis L. aroma. In the HS-SME method a suspended micro-drop of n-butanol was used as solvent. The effect of six different parameters on extraction efficiency, including sample weight, drop volume, extraction temperature, conditioning time, extraction time, and ionic strength were optimized using a simplex optimization method. The volatile components were studied both by HS-SME and an ordinary hydrodistillation method and the major components identified were 1,8-cineol, α-pinene, limonene, and linalool.
Becker, Y., Hadar, J., Tabor, E., Ben-Hur, T., Raibstein, I., Rosen, A., et al.: A sequence in HpaI-P fragment of herpes simplex virus-1 DNA determines intraperitoneal virulence in mice. Virology 149 , 255