Influence of the Hall effect on the plasma dynamics in an MTF/MAGO chamber

The role of the Hall effect in experiments on the magnetic implosion of a D-T plasma in a cylindrical MTF/MAGO chamber fed from a helical explosive magnetic generator is investigated. The plasma dynamics is simulated numerically by a 2D code developed for solving the set of MHD equations with account of the Hall effect. In simulations, the generator, the break switch, and other units were replaced with LR circuits. It is shown that taking into account the Hall effect provides better agreement between numerical simulations and experimental data.     

About the characters of thermoprotection in influence of osmolites on bacteria

The influence of the length of staying of Escherichia coli B/r cells in hypertonic NaCl solution before heating at 52 and 60 degrees C on the magnitude of salt thermoprotection was investigated. In addition, the dependence of the isotonic and thermoprotective NaCl concentrations on the exposure temperature was investigated. It was shown that the volume of cell osmotic thermoprotection was independent on the length of preliminary staying of microorganisms in hypertonic NaCl solution. It was also shown that the magnitude of isotonic and thermoprotective osmolite concentrations increased with the increase in the exposure temperature. The analysis of the data obtained and published in literature indicates that the compensating mechanism is involved in salt bacteria thermoprotection rather than the dehydratation one.     

Nucleotide Sequences of Plasmodium vivaxA-Type rDNA ITS1, 5.8S,and ITS2. Elaboration of Retrospective PCR Diagnostics of Malaria Using Stained Thick Blood Smears

Stages life cycle of the malaria parasite differ in the rate of replication and the structural properties of functionally active A-, S-, and O-type ribosomes. Regions of A-type rDNA including ITS1, 5.8S, and ITS2 from two strains of Plasmodium vivaxwith different incubation periods were amplified and sequenced. No substantial differences in the sequences of two strains were revealed. Phylogenetic analysis of the obtained and homologous sequences of ITS1 rDNA of A, S, and O types of P. vivax; A and S types of P. falciparum; and Cryptosporidium parvum, Eimeria maxima, Toxoplasma gondiias outgroup, by the maximum parsimony method using PAUP 4.0 revealed that divergence of ITS1 might have occurred after speciation and at different rates in individual lineages of the Plasmodiumgenus. Basing on the results of the analysis of orthologous sequences of P. vivaxand P. falciparum, we developed genus- and species-specific primers for PCR diagnostics of malaria, as well as a one-step effective method of DNA isolation from Giemsa–Romanovsky-stained thick blood smears. It was demonstrated that stained preparations could be a reliable source of plasmodial DNA, and the quality of preparations and storage time (10–20 years) did not interfere with the results of PCR analysis.     

Allee effect makes possible patchy invasion in a predator–prey system

The dynamics of interacting ecological populations results from the interplay between various deterministic and stochastic factors and this is particularly the case for the phenomenon of biological invasion. Whereas the spread of invasive species via propagation of a population front was shown to appear as a result of deterministic processes, the spread via formation, interaction and movement of separate patches has been recently attributed to the influence of environmental stochasticity. An appropriate understanding of the comparative importance of deterministic and stochastic mechanisms is still lacking, however. In this paper, we show that the patchy invasion appears to be possible also in a fully deterministic predator–prey model as a result of the Allee effect.     

A model of enzymatic decarboxylation of glutamic acid

Interaction of glutamate decarboxylase with its adequate substrate and some quasi-substrates was studied by spectrokinetic, quantum-chemical and some other approaches. It was shown that in the course of decarboxylation an abortive transamination of pyridoxal-5'-phosphate leading to the enzyme inactivation does occur. Identification of intermediate coenzyme-substrate complexes allowed to formulate a model of enzymatic decarboxylation taking into account both the main and abortive reactions. The analysis of electronic structure of the intermediates revealed some of the factors determining the functional specificity of the reaction under study.     

Riboflavin operon in Bacillus subtilis contains additional promoters

Using the methods of molecular cloning permitted to show that riboflavin operon of Bacillus subtilis contains four promoters. Three of them are functionally active in the Bacillus subtilis system. The main promoter of the operon with regulatory region was cloned in plasmid pPL603. Cells containing the constructed plasmid pGM32 are resistant to chloramphenicol. The level of resistance is regulated by concentration of riboflavin (the effector of operon). The following model of rib-operon has been proposed: (Formula: see text).     

Transport of low molecular weight substances in protein crystals and films

Diffusion of synthetic dyes in lysozyme crystals and bovine serum albumin (BSA) amorphous films is shown to depend on the size of diffusate molecule far more strongly than in solutions. The diffusion coefficient increases from 10(-8) to 10(-13) cm2 sec-1 on about 1.5 divided by 2--fold increase in diffusate dimensions, the diffusion being completely arrested on reaching the limiting dimensions of about 14 A and 12 A for BSA films and lysozyme crystals, respectively. The diffusion in lysozyme crystals is anisotropic, with a diffusion maximum directed along their screw axes. The diffusion coefficient dependence on the charge of diffusate and its binding to proteins is discussed.     

Dynamics of relaxation of the triboelectric charge on the surface of the horny layer of the epidermis

Some results are presented of relaxation process of the triboelectric charge placed on the outer surface of human epidermis ("stratum cornium"). In measurements the characteristic time of the relaxation process was equal to tau approximately 10 divided by 10(3) sec. The measured values of tau and capacity of the high-resistivity stratum of epidermis (C approximately 10(+4) pF/sm2) lead to resistivity of "stratum cornium" R approximately 10(9) divided by 10(11) omega X sm2.