Nonlinear evolution of short-wavelength torsional Alfvén waves

We analyze nonlinear evolution of torsional Alfvén waves in a straight magnetic flux tube filled in with a low-β plasma, and surrounded with a plasma of lower density. Such magnetic tubes model, in particular, a segment of a coronal loop or a polar plume. The wavelength is taken comparable to the tube radius. We perform a numerical simulation of the wave propagation using ideal magnetohydrodynamics. We find that a torsional wave nonlinearly induces three kinds of compressive flows: the parallel flow at the Alfvén speed, which constitutes a bulk plasma motion along the magnetic field, the tube wave, and also transverse flows in the radial direction, associated with sausage fast magnetoacoustic modes. In addition, the nonlinear torsional wave steepens and its propagation speed increases. The latter effect leads to the progressive distortion of the torsional wave front, i.e., nonlinear phase mixing. Because of the intrinsic non-uniformity of the torsional wave amplitude across the tube radius, the nonlinear effects are more pronounced in regions with higher wave amplitudes. They are always absent at the axes of the flux tube. In the case of a linear radial profile of the wave amplitude, the nonlinear effects are localized in an annulus region near the tube boundary. Thus, the parallel compressive flows driven by torsional Alfvén waves in the solar and stellar coronae, are essentially non-uniform in the perpendicular direction. The presence of additional sinks for the wave energy reduces the efficiency of the nonlinear parallel cascade in torsional Alfvén waves

STATISTICS AS INSTRUMENT OF COUNTERACTION TO INDIVIDUAL TERRORISM

The statistics applied in the international practice have universal character and, according to authors of article, can be applied in relation to individual terrorism. Authors come to a conclusion that in this case not only the number of individually conducted terrorist attacks in a year will be taken into consideration (or for any other period of time), but also that damage which was caused (a death toll and the wounded and cumulative damages of material property as a result of individual terrorist attacks). The research conducted by authors showed that similar approach allows to receive a general characteristic of scales and consequences of individual terrorism in society

STATISTICS AS INSTRUMENT OF COUNTERACTION TO INDIVIDUAL TERRORISM

The statistics applied in the international practice have universal character and, according to authors of article, can be applied in relation to individual terrorism. Authors come to a conclusion that in this case not only the number of individually conducted terrorist attacks in a year will be taken into consideration (or for any other period of time), but also that damage which was caused (a death toll and the wounded and cumulative damages of material property as a result of individual terrorist attacks). The research conducted by authors showed that similar approach allows to receive a general characteristic of scales and consequences of individual terrorism in society

Off-limb EUV observations of the solar corona and transients with the CORONAS-F/SPIRIT telescope-coronagraph

The SPIRIT telescope aboard the CORONAS-F satellite (in orbit from 26 July 2001 to 5 December 2005), observed the off-limb solar corona in the 175 Å (Fe IX, X and XI lines) and 304 Å (He II and Si XI lines) bands. In the coronagraphic mode the mirror was tilted to image the corona at the distance of 1.1...5 <I>R</I><sub>sun</sub> from the solar center, the outer occulter blocked the disk radiation and the detector sensitivity was enhanced. This intermediate region between the fields of view of ordinary extreme-ultraviolet (EUV) telescopes and most of the white-light (WL) coronagraphs is responsible for forming the streamer belt, acceleration of ejected matter and emergence of slow and fast solar wind. We present here the results of continuous coronagraphic EUV observations of the solar corona carried out during two weeks in June and December 2002. The images showed a "diffuse" (unresolved) component of the corona seen in both bands, and non-radial, ray-like structures seen only in the 175 Å band, which can be associated with a streamer base. The correlations between latitudinal distributions of the EUV brightness in the corona and at the limb were found to be high in 304 Å at all distances and in 175 Å only below 1.5 <I>R</I><sub>sun</sub>. The temporal correlation of the coronal brightness along the west radial line, with the brightness at the underlying limb region was significant in both bands, independent of the distance. On 2 February 2003 SPIRIT observed an expansion of a transient associated with a prominence eruption seen only in the 304 Å band. The SPIRIT data have been compared with the corresponding data of the SOHO LASCO, EIT and UVCS instruments

The main problems of building the system of statistical indicators in the field of cryonics

Cryonics as rather inconsistent, but constantly developing sphere of activity of modern society cannot be adequately estimated by means of separate private indicators or even their enlarged groups. This requires the development of a system of indicators that includes not only the traditional parameters of material and technical base and human capacity, but also the scale, intensity, results and consequences of cryonic activities. The key problems of the system of indicators of critical activity statistics, its features and possible approaches to its construction have been considered in the article

Analysis of the incidence of community-acquired pneumonia and acute otitis media in children during the first four years of life in different age groups vaccinated with pneumococcal 13-valent vaccine Prevenar

Objective: to analyze the incidence of community-acquired pneumonia and acute otitis media in children during the first four years of life in different age groups vaccinated with pneumococcal 13-valent vaccine Prevenar.Materials and methods: medical records of 590 children aged 1 to 5 years were analyzed. All subjects were divided into 2 groups. The first group consisted of vaccinated children (n = 490), born in 2014, and vaccinated against pneumococcal 13-valent vaccine Prevenar. The second group consisted of unvaccinated children (n = 100) born in 2013 and not vaccinated. Each group was divided into subgroups depending on the age period (1—2 years, 2—3 years, 3—4 years, 4—5 years).Results: it is established that the conduct of specific prophylaxis of pneumococcal infection vaccine Prevenar-13 in children during the first 4 years of life effectively reduces the incidence of community-acquired pneumonia (in 7,6 times) and acute otitis media (in 8,5 times). The effectiveness of the vaccine was observed in all age groups. In cases of development of an inoculated child acute otitis reduces the risk of severe forms and complications of the disease. Analysis of the course of the post-vaccination period indicates a high level of safety and good tolerability of the vaccine.Conclusion: Implementation of specific prophylaxis of pneumococcal 13-valent vaccine Prevenar in children during the first four years of life according to the calendar of vaccination effectively reduces the incidence of community-acquired pneumonia (87 %) and acute otitis media (42,8 %) in all age subgroups. In cases of development of an inoculated child acute otitis reduces the risk of severe forms and complications of the disease. Analysis of the course of the post-vaccination period indicates a high level of safety and good tolerability of the vaccine