Turbulence-induced square-root broadening of the Raman fiber laser output spectrum.

The output characteristics of the conventional one-stage Raman fiber laser (RFL) are described in an optical wave turbulence formalism. Simple analytical expressions describing RFL output power and its spectral shape are presented, and square-root law for the output spectrum broadening law has been discovered. The indications of the turbulent-like spectral broadening in other types of cw fiber lasers and propagation phenomena in fibers are also discussed.

Spectral broadening in Raman fiber lasers.

We present an analytical theory based on wave kinetic equations that describes a Raman fiber laser (RFL) generation spectrum. It is shown both theoretically and experimentally that the quasi-degenerate four-wave mixing between different longitudinal modes is the main broadening mechanism in the one-stage RFL at high powers. The shape and power dependence of the intracavity Stokes wave spectrum are in excellent quantitative agreement with predictions of the theory.

[A new species of black flies in the genus Montisimulium (Diptera: Simuliidae) from the environs of Alma-Ata].

A new species of blackflies, Montisimulium peskovi sp. n. from the northern Tien Shan (Kazakhstan Republic) is described.

[Prophylactic effectiveness of a live recombinant influenza type A vaccine in immunizing children aged 3-14 years].

Children aged 3 to 14 were immunized with live recombinant influenza A vaccine; about 120,000 children were followed up for 6 months. Analysis of the morbidity (excepting ARVI and influenza) of the immunized and control groups permitted a conclusion about the safety of the preparation. The protective index of vaccine efficacy during influenza epidemic caused by A/Taiwan/1/86(H1N1) virus was 1.

[The modelling of a persistent parainfluenza infection].

A model of parainfluenza persistent infection was developed in guinea pigs, based on the use of the suckling-adapted virus and an immunosuppressor cyclophosphan. The latter increased the titre of virus and its antigen and duration of their detection in the organs, but the dynamics of these findings was different, and also delayed the time of appearance and slightly prolonged the period of detection of antibody.

[Immunodiagnostic methods in interpreting an outbreak of respiratory syncytial virus infection].

In the determination of the etiology of the outbreak of respiratory viral diseases, caused mainly by respiratory syncytial (RS) virus, on the basis of the comparison of the results of different laboratory tests and some epidemiological and clinical data high specificity of the detection of RS virus antigen and antibodies to it by means of erythrocyte diagnostica (newly developed antibody and commercial antigenic preparations) has been revealed. In the epidemiological situations the rapid methods of the detection of viral antigen are of prime importance.

[Epidemiological surveillance of influenza based on research data on collective immunity].

In 1976-1984 the dynamic study of communal immunity to influenza A and B virus strains was made with the aim of the etiological prognostication of influenza epidemic. On the basis of the study of the immune status of the adult and child population to the virus strains, actually circulating in October-November, the possibility of prognosing the tendency in the development of the epidemiological situation in influenza in the following year was established.

[Influenza morbidity in the Kazakh SSR 1977-1984].

In 1977-1984, 6 epidemic outbreaks of influenza were recorded in the republic of which 2 were due to influenza A (H1N1), 2 to A (H3N2) and 2 to influenza B virus. The epidemics of influenza H1N1 (1977-1978, 1981) and H3N3 (1979-1980, 1983) were characterized by gradual decrease of their intensity as manifested by lowering of the morbidity rate and frequency of virus isolation. On the contrary, epidemics of influenza B showed a certain trend to increase.

[Formation and protective functions of antibodies to neuraminidase of the influenza A virus].

The features of production and protective properties of antineuraminidase antibodies in subjects of various ages with influenza infection caused by currently important influenza A virus strains of H1N1 and H3N2 serosubtypes were studied. In children, antineuraminidase antibodies were found to accumulate less intensively than in adults and in infants under 1 year they were detected extremely rarely. In young infants, their titres after the disease decreased more rapidly than antihemagglutinin titres.

[Comparative study of the effectiveness of inactivated influenza vaccine preparations].

The reactogenicity, safety, immunogenicity and epidemiological effectiveness of inactivated virion vaccinal preparations from strains A (H3N2) Texas 1/77a, A (H1N1) and split adsorbed influenza chemical vaccine, as well as the character of local and systemic reactions to these vaccines were studied. The vaccinees showed a high percentage of seroconversions (42-69.4%) with antibody titers increasing 5 times and more.

[Complex study of population immunity to 3 influenza A virus antigens].

In 5 large cities of the USSR a four-year study of the population immunity to 3 antigens of influenza A virus (hemagglutinin, neuraminidase and ribonucleoprotein antigens) was carried out. The time course of immunity to these antigens had a similar character. The high level of population immunity to actual hemagglutinin and neuraminidase, observed for 2 years, in succession, indicated the possibility of shift-life changes in these surface antigens.

[Formation, persistence period and protective role of antihemagglutinins to earlier circulating influenza A viruses].

Surveys of the population immunity as well as blood sera from human subjects vaccinated with vaccine strains done by the HI test showed the immunity to previously prevalent influenza A viruses to be maintained by anamnestic stimulation of immunogenesis occuring during circulation of the current agent. The intensity of anamnestic immunity stimulation is determined by the degree of relationship of the current strain hemagglutinin with the similar antigen of previously prevalent viruses. Circulating antibodies have a certain protective effect only against those influenza A viruses which are antigenically related within the drift alteration of hemagglutinin.

[Characteristics of the state the population's immunity in the influenza epidemic of 1977-1978].

During the influenza epidemic of 1977--1978, as well as during the epidemics of 1968 and 1972, the levels of population immunity proved to be a factor which led to the disappearance of the old antigenic variants of group A influenza virus from circulation. At the same time this factor had no influence on the regulating action affecting the selection of new strains. The appearance of the new antigenic variants of group A influenza virus in circulation seemed to depend mainly on the biological properties of the infective agent.