Optical rogue waves in coupled fiber Raman lasers.

For coupled linear cavity-random fiber Raman lasers, for the first time, to the best of our knowledge, we demonstrate a new mechanism of emergence of the random pulses, with the anomalous statistics satisfying optical rogue waves' criteria experimentally. The rogue waves appear as a result of the coupling of two Raman cascades, namely, a linear cavity laser with a wavelength of 1.55 µm and a random laser with a wavelength nearly 1.67 µm, along with coupling of the orthogonal states of polarization (SOPs). The coherent coupling of SOPs causes localization of the trajectories in the vicinity of these states, whereas polarization instability drives escape taking the form of chaotic oscillations. Antiphase dynamics in two cascades result in the suppression of low amplitude chaotic oscillations and enable the anomalous spikes, satisfying rogue waves criteria.

Vector-Resonance-Multimode Instability.

The modulation and multimode instabilities are the main mechanisms which drive spontaneous spatial and temporal pattern formation in a vast number of nonlinear systems ranging from biology to laser physics. Using an Er-doped fiber laser as a test bed, here for the first time we demonstrate both experimentally and theoretically a new type of a low-threshold vector-resonance-multimode instability which inherits features of multimode and modulation instabilities. The same as for the multimode instability, a large number of longitudinal modes can be excited without mode synchronization. To enable modulation instability, we modulate the state of polarization of the lasing signal with the period of the beat length by an adjustment of the in-cavity birefringence and the state of polarization of the pump wave. As a result, we show the regime's tunability from complex oscillatory to periodic with longitudinal mode synchronization in the case of resonance matching between the beat and cavity lengths. Apart from the interest in laser physics for unlocking the tunability and stability of dynamic regimes, the proposed mechanism of the vector-resonance-multimode instability can be of fundamental interest for the nonlinear dynamics of various distributed systems.

[The prevalence and possibilities of serological diagnostic of reoviral infection.]

The information about manifestations and possible associations of reoviral infection is covered. The original results of studying prevalence, clinical significance and possibilities of serodiagnostic of reoviral infection under various pathological conditions. It is demonstrated that reoviral infection is widespread among adult population (60.6%) and children (48.7%). It is established that with age seroprevalence to reoviruses increases. The etiological significance of retroviruses under various acute diseases predominantly respiratory ones is substantiated. It is established that average titer of antibodies to reoviruses increases in children with acute hepatitis of unclear etiology and in adults with chronic non-tumorous diseases of liver. The significance of studying of pair serums in diagnostic of reoviral infection is emphasized having regard to high level of seroprevalence.

ADAPTATION OF HUMAN ROTAVIRUS STRAINS OF GROUP A TO THE REPRODUCTION IN PASSAGED CELL CULTURES.

The incidence of rotavirus gastroenteritis in the world still has no tendency to reduction. The development of an effective vaccine would reduce or, in the future, even defeat this highly contagious dangerous disease. However, both in Russia and abroad there is still no developed technique for adapting and cultivating strains of the human rotavirus A that would stably produce a high "yield" of virus progeny in transplanted culture cells. The phenomenon of gene exchange for the segmented genome of rotavirus was used by foreign researchers to create the rotavirus vaccine using reassortant strains which are the result of joint cultivation of low-titer (1-2·106 virions per ml) human rotavirus strains and rotavirus strains of animals, such as monkey rotavirus SA-11 or Nebraska calf rotavirus diarrhea providing a relatively high "yield" of virus progeny (1·107-1·108). It is clear that such vaccine compositions will not be able to replace a full-fledged vaccine of human rotavirus strains of different serotypes, but they can be used for the time being as a solution to the problem. Ideally, a rotavirus vaccine is needed that includes the full set of G and P serotypes of rotaviruses circulating in the territory of their application. The paper describes an original technique for adaptation and cultivation of human rotaviruses of group A on the culture of transplantable cells developed by the authors. This technique allows 5·108 virions to be obtained per 1 ml of culture fluid. High-titer cultivated strains of human rotavirus that can be used as vaccine strains were obtained, as well as highly-active antigens for the construction of diagnostic test-systems.

[Statistical indices in medicine and epidemiology and their classification].

Mathematical statistics deals with abstract notions, while medicine solves complicated and many-sided problems. For this reason medical statistics faces some moot points in the interpretation of a number of notions and the classification of statistical indices. In the present article the definition of variables and statistical indices is formulated and their characterization is given. An attempt is made to provide the systematization and natural classification of the latter. Statistical indices are defined as the characteristics of statistical totalities. To classify statistical indices, the most essential signs are used: the character of a variable (external relations), the trend of study (internal content), the form of expression (calculation), derived indices and characteristics (comparison and the results of analysis).

[Morbidity: terminology, mechanisms of formation and classification]. / Zabolevaemost': terminologiia, mekhanizmy formirovaniia i klassifikatsiia.

In the 70-ies of the last century the evolution of the epidemic process doctrine resulted in developing population approach to morbidity analysis, in addition to the traditional focal approach. On the one hand, this led to the discussion on the possibility of applying such notion to non-infectious diseases and, on the other hand, to the discussion on the mechanisms of the development and formation of different manifestations in infectious diseases. In both cases the discussion was centered on the phenomenon of morbidity. The present article deals with the nature of morbidity as a phenomenon and the acceptability of general scientific approaches in the interpretation of seasonal and cyclic character of morbidity from the viewpoint of the wave process in an open system. On the basis of the data presented in this work the terms used in epidemiology in considering manifestations of the epidemic process are discussed. The improved classification of morbidity by qualitative and quantitative signs for infectious diseases is proposed.

[The manifestations of an epidemic process in a respiratory streptococcal infection among ships' crews under commercial sailing conditions]. / Proiavleniia épidemicheskogo protsessa respiratornoi streptokokkovoi infektsii sredi ékipazhei sudov v usloviiakh promyslovogo reisa.

Morbidity in respiratory streptococcal infection in 6 ships of the State Fishery Amalgamation "Dal'ryba" during 8 voyages was analyzed. During voyages morbidity rate is determined by sporadic cases, seasonal rises at the time of the voyage and epidemic outbreaks. Spring and summer months constitute the period of risk for seasonal morbidity rises during voyages and epidemic outbreaks at the time of the formation of the crew. The minimal size of the crew in which the activation of the epidemic process took place was 350 persons. In lesser crews (250-300 persons) seasonal rises in morbidity were observed only in the presence of frequent and intensive change-over of crew members.

[Streptococcal respiratory infection in large organized children's collectives and experience in optimizing its prevention]. / Respiratornaia streptokokkovaia infektsiia v krupnykh organizovannykh detskikh kollektivakh i opyt optimizatsii ee profilaktiki.

Epidemiological analysis of the manifestations of respiratory streptococcal infection in the all-year-round pioneer camp "Ocean" over 1984-1990 and in similar large organized groups of children revealed some common regularities manifested as consecutively repeating morbidity rises in acute respiratory diseases, tonsillitis, scarlet fever over a year (rotations 1-3 and 9). Time course of the disease incidence over each rotation (month) had a specific pattern as well. Trials of our newly developed system of prevention and treatment with tomicid showed its high effectiveness, which manifested by a drop in the morbidity level and changes in the structure and dynamics of respiratory streptococcal infection.

[A comprehensive evaluation of the biological properties of the causative agents of typhoid fever isolated from patients and carriers]. / Kompleksnaia otsenka biologicheskikh svoistv vozbuditelei briushnogo tifa, vydelennykh ot bol'nykh i nositelei.

The biological properties of 106 S. typhi cultures were studied; of these, 59 cultures were isolated from 45 chronic carriers and 47 cultures, from 23 typhoid fever patients. According to the degree of their virulence (CPD50 in the continuous cell-line culture Hep-2), the strains isolated from the patients were more virulent than those isolated from the chronic carriers. The mean value of lg CPD50 was 5.76 +/- 0.04 for the patients and 6.86 +/- 0.03 for the chronic carriers. The strains isolated from the patients showed greater variability in the degree of their virulence. The study of the plasmid spectrum showed that 9.4 +/- 5.6% of the strains contained plasmids. From the patients plasmid-containing strains were isolated more frequently than from the carriers (14.9 +/- 2.5% and 5.1 +/- 2.9%). Multiresistance to antibiotics in combination with the presence of plasmids was detected in 6 strains isolated from the typhoid patients with morbidity having the character of outbreaks.

[The manifestations of an epidemic process of typhoid infection in Moscow]. / Proiavleniia épidemicheskogo protsessa briushnotifoznoi infektsii v Moskve.

The work deals with the results of typhoid morbidity in Moscow for the period of 1980-1988. The morbidity rate varied from 0.98 to 0.17 cases per 100,000 of population with a tendency towards decrease. In the structure of morbidity local cases accounted for 46.8% and cases of infection contacted outside Moscow accounted for 53.2%. The morbidity level was low throughout the whole territory, only in two districts morbidity rate was significantly higher (P = 95%) than the average morbidity rate in the whole of the city. In the group of local cases morbidity had no pronounced seasonal character, in contrast to cases due to infection contacted outside the city which were mostly registered in summer and autumn. Persons aged 21-30 years were found to be the most affected age group. The general factors, and not the contact route, are supposed to play the main role in the realization of the mechanism of infection transfer. Under modern conditions, some manifestations of the epidemic process of typhoid infection can be detected only at the level of the whole city, or even the whole country.