Synchronization of parallel-connected plasma opening switches and switching the current to the load

The possibility of using plasma opening switches (POSs) to create superpower generators is considered. To decrease the linear density of the charge passed through a POS of reasonable size, it is proposed to use a compact multimodule POS system. The design of an individual POS module is presented. The compact arrangement of the modules is ensured by an external magnetic field. It is proposed to use a sharpening spark gap to increase the efficiency of a multimodule POS operating with a low-inductance load. The results are presented of experiments on synchronizing two POS modules and switching the current to a low-inductance load.     

The problem of the adaptive norm in human populations

The results of some investigations recently fulfilled in the framework of population-genetics approach to the problem of adaptive norm in human populations are summarized in this review. The main items considered are: methods of identification of morphologically "average" phenotypes, the role of stabilizing selection in maintaining the population adaptive norm, the problem of joint variation of monogenic and polygenic traits ant its relevance to "norm" and pathology. The significance of the concept of adaptive norm for preventive medicine and genetic monitoring is discussed.     

Population genetic study of differential fertility in man (illustrated by habitual abortion). IV. Distribution of blood groups and frequency of incompatible marriages

Hereditary variation of 5 immunological systems coded by 8 loci was compared in 148 couples and 100 women with repeated spontaneous abortions in anamnesis (experimental group) and 141 couples and 100 women with normal fertility (control group). Marked differences in distributions of genotypes and frequencies of 3 systems (MNSs, Rhesus, Duffy) and frequency of AB0-incompatible couples were found between control and experimental groups. An average value of observed heterozygosity in experimental group was lower, as compared to the expected value. Possible influence of immunological factors on recurrent fetal wastage is discussed.     

Population genetics approach to the problem of the nonspecific biological resistance of the human body. I. Statement of the problem and basis for the approach. Distribution parameters of anthropometric markers of normal and ill newborn infants and nurslings

Distributions of two metrical characters-the weight and the body length at birth are considered in several groups of healthy, diseased and dead newborns and infants. Significant differences in statistical parameters of these distributions (mean, standard deviation, skewness and kurtosis) are demonstrated for normal and malformated children. The increased number of children with minimal deviations from the mean values of characters (adaptive norm) is observed among healthy newborns, while in groups of diseased and dead children the frequency of individuals with extreme (especially low) values is increased. The principle of classification of individuals based simultaneously on two characteris is suggested and the problem of "average phenotype" classification by the number of characters is discussed.     

Allozyme Polymorphism of Swiss Stone Pine <Emphasis Type="Italic">Pinus cembra</Emphasis> L. in Mountain Populations of the Alps and the Eastern Carpathians

Swiss stone pine Pinus cembra L. is a species with fragmented range, occurring in the Alpine-East Carpathian mountain system. Seeds of P. cembra are dispersed by nutcrackers, which offers potential possibilities for gene exchange among populations. Using isozyme analysis, we have examined five samples from two parts of the Swiss stone pine range: the Alps (Switzerland and Austria) and the Carpathians (two samples from the northern macroslope of the Gorgany Ridge, Eastern Carpathians, Ivano-Frankivs'ka oblast and one sample from Zakarpats'ka oblast of Ukraine). The allele frequencies of 30 isozyme loci, coding for enzymes ADH, FDH, FEST, GDH, GOT, IDH, LAP, MNR, MDH, PEPCA, 6-PGD, PGI, PGM, SDH, SKDH, SOD, were analyzed using cluster analysis and Principal Component Analysis. Two clusters, corresponding to the isolated Alpine and Carpathian parts of the range, were found. The main contribution to these differences were made by loci Adh-1, Adh-2, Fest-2, Lap-3, Mdh-4, and Sod-4. The interpopulation differentiation proved to be somewhat higher than that typical for pines (F_ST = 7.4%), but within the limits characteristic for taxonomically close species. Thus, isolation of the populations did not lead to their marked differentiation, which may be explained by gene flow and balancing selection, which equalizes gene frequencies across the fragmented species area. Interlocus (F_ST heterogeneity (from 0.003 to 0.173) suggests adaptive significance of some of the allozyme polymorphisms or linkage of some loci with adaptive genes. The Carpathian populations were shown to have higher gene diversity than the Alpine ones (expected heterozygosities 0.095–0.114 and 0.060–0.080, respectively). A deficiency of heterozygotes (as compared to the Hardy-Weinberg proportions), observed in the embryo sample, was probably explained by inbreeding. The reduction in the area of Carpathian pine forests in Holocene, caused by the global climatic changes and the anthropogenic impact, is hazardous for the gene pool of the species. The maintenance of genetic uniqueness of both Carpathian populations of P. cembra in general, and individual stands in particular, requires special measures for protection of Swiss stone pine in the Eastern Carpathians.     

Interspecific genetic variability of the oyster mushroom Pleurotus ostreatus as revealed by allozyme gene analysis

Allozyme variation in natural populations of basidiomycetes fungus Pleurotus ostreatus (88 individuals) from three regions of central Russia was studied. The species was shown to have 92.86% of polymorphic allozyme loci and expected heterozygosity He = 0.49. The mean number of alleles per locus was 3.5. The genetic differences among populations were supported by F-statistics (FST = 0.750). The low level of inbreeding (FIS = 0.018) suggests that the P. ostreatus populations are panmictic, and the main reproduction mode involves basidiospores dispersing at long distances. Using cluster analysis, geographically isolated populations and intersterile groups were differentiated within the complex P. ostreatus species.     

Population-genetical study of differential fertility in humans (based on an example of habitual abortion). I. Approach to the problem and analysis of morpho-physiological and demographic traits

It was shown that women from the studied group of married couples, suffering from repeated spontaneous abortions (the main group), have earlier menarche and their husbands are taller, as compared with the control group of couples with normal reproductive performance. The degree of similarity between mates in age and stature appeared to be lower in the main group than in the control group. The variation of the characters under study is supposed to provide an auxiliary criterion in selecting couples at high risk of repeated spontaneous abortions.