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The use of interactive teaching methods such as situational tasks, business games in practical classes in epidemiology and military epidemiology with cadets increases the quality and efficiency of the educational process. They are considered as a kind of methodological resource that allows for practice-oriented training of cadets. In the course of the classes, the peculiarities of the implementation of teaching methods are taken into account, which have an important role and significance in the formation of professional and general competencies among cadets.

The analysis of P-wave magnitudes for 37 shallow earthquakes of the Alpine-Himalayan tectonic belt determined by the Homogeneous Magnitude System (HMS) technique using short- and medium-period standard instruments is carried out. The results are compared with spectral magnitudes obtained with the broadband instrument with digital registration at the Central Seismological Observatory (Grafenberg, FRG). It is shown that for the majority of the earthquakes the HMS magnitudes reveal basic spectral features of seismic radiation from the shallow event foci, though they are insufficient for the analysis of complicated cases. Thus, both the HMS and the spectral magnitude approaches are complementary and highly desirable for seismological practice.

After a special investigation into the stability of seismic stations of the Eurasian continent, a system of reference stations for routine determination of earthquake magnitudes has been selected. A method for determining station corrections in a network of continental dimensions has been developed and tested for PV waves observed by eight Eurasian stations, taking into account the dependence of station corrections on source region. It is assumed that such a homogeneous system of reference stations can eliminate the largest discrepancies in the magnitude determinations.

Amplitude curves for seismic P-, S- and L-waves have been constructed on the basis of the homogeneous magnitude system of the Eurasian continent. The optimum amplitude curves are compared with the standard amplitude curves used in seismological practice.

Routine determination of network magnitudes by means of the Eurasian homogeneous magnitude system (HMS) is described and tested on a selection of recent shallow earthquakes. The HMS earthquake magn ...

Causes of inconsistency in magnitudes determined by broad-band and short-period instruments and by different systems of observations are elucidated. In so doing, both observations of standard stations of USSO of the USSR and those of Soviet frequency selecting seismic stations (чисс) are employed. On the basis of large statistic material of the stationare network of USSO, a dependence of spectral constitution ofP waves and frequency-temporal fields constructed for some earthquakes have been revealed as well as a dependence of magnitude values upon an arrival time of maximal particle velocity. It has been shown that the range of measuring (A/T)max should be enlarged at least to 15 sec. A conclusion is drawn that the most stable magnitude consistent with the Catalogue by Gutenberg is the one determined by medium-period instruments.

Resume The effects of mutations towards ultraviolet sensitivity in yeast UV-sensitive mutants were induced by the action of UV light and were isolated by the replica plating method. Highly homozygous stocks of yeast Saccharomyces cerevisiae descending from race XII were utilized as material for the present investigation. Two mutants, designated uvs 1 and uvs 2 , carrying nonallelic mutations of radiosensitivity, were studied more carefully. UV sensitivity appeared to be of a recessive monogenic character; heterozygous diploids were UV-resistant and segregated 1:1 resistant and sensitive clones in the random ascospore samples. The UV sensitivity of the strains bearing mutants uvs 1 and uvs 2 differs. The haploid uvs 1 mutant and the haploid uvs 2 mutant have sensitivities 25 and 1.8 times higher, respectively, than the wild-type haploid. The uvs 1 mutants exhibit an exponential survival curve, while the uvs 2 mutants and the wild-type haploid have sigmoidal shaped curves. The radioresistance of the isogenic strains, carrying the mutations at the uvs 1 locus, increases with polyploidy. We were able to study the effect of uvs mutations on the frequency of induced genic mutations due to the fact that the resistant mutants could easily be detected in the media with a high serine concentration. The results indicate that the uvs 1 and uvs 2 mutations significantly increase the sensitivity of haploids to mutagenic action of UV light. The uvs 1 and uvs 2 mutations also result in an increase in sensitivity to mutagenic action of UV light in regard to cytoplasmic determinants. The diploids homozygous for uvs 1 and uvs 2 mutations proved to be highly sensitive to the action of UV light causing recombination when the frequency of induced mitotic recombination in resistant and sensitive diploids heterozygous for ad 1 and ad 2 genes was recorded. The frequency of spontaneous mutations independent of adenine was recorded in haploids of genotype ad 2 , ad 2 uvs 1 and ad 2 uvs 2 . The mutations towards UV sensitivity cause a sharp increase in spontaneous mutability, the rise being especially significant due to uvs 2 mutations. The specific features of uvs 2 mutants of Saccharomyces are similar to those of UV-sensitive mutants of E. coli ; therefore, one might suggest that the uvs mutants in yeast also have a less efficient or blocked system for repair of UV damage in the DNA. The fact that the UV-sensitive mutants are sensitive not only to the lethal action of UV light but also to the mutagenic and recombinogenic ones suggests that similar molecular damages of the DNA underlie all these effects. The induction of cytoplasmic mutations in UV-sensitive mutants suggests that the repair system under consideration is localized not only in the nucleus but also in the cytoplasm of the cell. The sharp increase in spontaneous mutability in UV-sensitive mutants indicates that the main function of the repair system is to maintain the stability of genetic material under natural conditions.