Hydrodynamic model of the penetration of a magnetic field into a plasma with two ion species

Hydrodynamic equations are presented that describe the dynamics of a plasma with two ion species in a magnetic field such that . It is shown that there exists a range of values of the ratio of the plasma density to the magnetic field, ν_ii/ω_Bi<(Z ² M/m)^1/4, within which the frictional force caused by ion-ion collisions dominates over that caused by electron-ion collisions. In this range, the effective conductivity, which governs the magnetic field diffusion, is lower than the conventional electron-ion conductivity by a factor of $\sqrt {M/m}$ and can be as low as σ ? enc/B. The equations derived for this three-component plasma make it possible to self-consistently incorporate local changes in the partial mass and partial charge of each of the ion species in relative motion. The characteristic features of the equations obtained are analyzed by applying them to describe the propagation of a current sheath in a transmission line filled with a multispecies plasma. An analogy is drawn between magnetic phenomena in a plasma with two ion species and in a so-called dusty plasma.     

Experimentelle Untersuchung,Modellierung und optimale Berechnung eines mehrstufigen Säulenfermentors II. Experimentelle Bestimmung der Parameter und Koeffizienten des mathematischen Modells

Using a system analysis for the investigation of all processes which occur in a biochemical reactor on the micro and macro level, a mathematical model was worked out. It characterizes the model of the kinetics and stoichiometry of the growth of microorganisms and the rules of hydrodynamics and mass transfer in form of blocks. Relating to the discussed mathematical total model [11], experimental data on which the calculation of the model parameters is based are described in this second part of the paper. They were determined not only directly from the cultivation process, but also from experiments with model media.     

Inversion polymorphism in the malaria mosquito Anopheles messeae. VII. Fertility and the population genetics structure of the species

The role of chromosomal inversional complexes of different fecundity has been studied in the process of formation of karyotypic populational structure. Females with homozygotes 2R11 and "north-est" inversional combinations are shown to have maximal total egg production, while females with three or four inversional heterozygotes from XL01, XL12, 2R01, 3R01 and 3L01 demonstrated lower level of fecundity. It is found that the seasonal conversion from r-selection to K-selection occurs in the period of population "prosperity" (July). The results of such conversion are destruction of "northest" genocomplexes and reduction of relative fecundity of inversional homozygotes 2R11-Alternative tendencies take place at the beginning of the reproductive period.     

Combinatorial approaches to harmacophoric heterocycles: A solid-phase synthesis of 3,1-benzoxazine-4-ones

An efficient solid-phase synthesis of 3,1-benzoxazine-4-ones is described. Immobilized amino acid based functionalized urea derivatives 2 undergo a high yielding heterocyclization under mild conditions in presence of coupling reagents (DIC, TsCl/Py, or Ac2O) to afford 3,1-benzoxazine-4-ones 6. The method offers broad scope for structural and chemical diversity, and is amenable for combinatorial synthesis of 3,1-benzoxazine-4-ones libraries with potential for discovery of novel serine protease inhibitors. Copyright 1998 John Wiley & Sons, Inc.     

Morphology and Infraciliature of Three Species of Eutintinnus (Ciliophora; Tintinnina) with Guidelines for Interpreting Protargol-Stained Tintinnine Ciliates

ABSTRACT. The infraciliatures of three Chesapeake Bay species of Eutintinnus conforming in lorica morphology to E. angustatus, E. pectinis , and E. tenuis were compared following Protargol silver impregnation. The kinetome of these species had a number of shared attributes including: 1) a right and left field that were of similar length and kinetal spacing; 2) two, rarely three, long dorsal kineties composed of monokinetids; 3) a ventral kinety; and 4) the absence of a true posterior kinety. Nonetheless, the specific organization of infraciliary components varied considerably among species. For example, the organization of the ventral kinety and several kineties along the border of the left field was different in all three species. In addition, the dorsal kineties of E. angustatus differed positionally from those of E. pectinis and E. tenuis . Some divergence in oral infraciliature was also noted, with the arrangement of infundibular oral polykinetids in E. pectinis and E. tenuis being distinct from that of E. angustatus . The amount of variation in the infraciliature of Eutintinnus spp. was much greater than previously noted for congeneric species of tintinnines and supports the separation E. angustatus, E. pectinis , and E. tenuis at the generic or subgeneric level.     

Functioning of amino acid operons in Escherichia coli strains with an altered transcription and translation apparatus. II. The effect of mutations in genes coding ribosomal protein S5 and translation elongation factor G on the functioning of the ilv operon

It has been shown in our previous study that mutations in genes relA, relC and rpsL result in the delay in Escherichia coli ilv operon derepression; the complete inhibition of derepression of the ilv operon is observed in the double mutants having alterations in rpsL and relA or relC genes. At present, some mutations occurring in the fus gene and altering the structure of the translational elongation G factor have been also found to delay derepression of E. coli ilv operon and complete inhibition in fusr and rel double mutants. Phenotypical ile and val auxotrophy is also detected in the double E. coli mutants with spectinomycin resistance mutation in rpsE gene coding for the structure of ribosomal S5 protein and mutations in relA or relC genes. The suggestion of participation of the ilv operon in regulation of other E. coli amino acid operons expression is discussed.     

Analysis of Urotomy and Regeneration in Agamid Lizards of the Genus Mantheyus (Reptilia: Sauria: Agamidae: Draconinae) Using X-ray Methods and a Computed Microtomography

Biology Bulletin - The results of an analysis of manifestations and combinations of urotomy and regeneration in the caudal part of the vertebral column in agamid lizards of the subfamily Draconinae...     

Changes in electrical brain activity in patients with panic disorders

Brain electrical activity was recorded in 38 patients with typical and in 42 patients with atypical panic disorders, also in 30 normal controls. Compared to controls, patients both with typical and with atypical panic disorders differed significantly in reduced spectral power of the EEG alpha band in the right hemisphere. Moreover, in patients with typical panic disorders, the spectral power of the EEG beta1 band was increased in the frontal, temporal, central, and parietal areas of the right hemisphere. In patients with atypical panic disorders, the spectral power of the theta band was increased in the temporal areas of the right hemisphere. The changes in the EEG activity in patients with typical panic disorders are supposed to reflect an increase in activity of non-specific systems of the mesencephalic reticular formation, and the EEG changes in patients with atypical panic attacks may be associated with increased activity of the temporolimbic brain structures.     

The use of endogenous <Emphasis Type="Italic">P</Emphasis>300 event-related potentials of the brain for assessing cognitive functions in healthy subjects and in clinical practice

Assessment of higher mental functions, objective detection of cognitive impairments, and investigation of pathophysiological mechanisms underlying these impairments in various neuropsychological diseases are of great importance for neuropsychophysiology. The endogenous event-related potential (ERP) approach is one of the instrumental neurophysiological methods that are currently used for assessing these complicated processes because recorded potentials reflect the intrinsic brain activity and changes in these potentials are caused by endogenous factors of the brain activity. The P300 cognitive evoked potential, induced by selective attention to a stimulus, has been the most widely used endogenous ERP. This potential may be helpful for studying mechanisms of mental disturbances, as it reflects neuronal processes connected with nonspecific activating reticulothalamic systems, as well as with limbic and neocortical mechanisms of selective attention and short-term memory.