Laser sounding of instantaneous and mean speed of wind using correlation method

The correlation methods for laser sounding of wind speed are based on mutual processing of lidar signals scattered from several spatially separated volumes at each altitude investigated. The time of atmospheric aerosol transport between the scattering volumes estimated by the position of maximum of the mutual correlation function is the measure of corresponding wind speed. In this case the distance between the scattering volumes (the measuring base), defining the time of aerosol movement through the measuring base also determines the lidar possibilities for measuring the instantaneous (during the time interval of several seconds) or the mean wind speed (some minutes). Based on the experimental investigations performed using two lidars, these possibilites are analyzed

Abrikosov vortex escape from a columnar defect as a topological electronic transition in vortex core

We study microscopic scenario of vortex escape from a columnar defect under the influence of a transport current. For defect radii smaller than the superconducting coherence length the depinning process is shown to be a consequence of two subsequent topological electronic transitions in a trapped vortex core. The first transition at a critical current $j_L$ is associated with the opening of Fermi surface segments corresponding to the creation of a vortex--antivortex pair bound to the defect. The second transition at a certain current $j_d > j_L$ is caused by merging of different Fermi surface segments, which accompanies the formation of a freely moving vortex.Comment: 5 pages, 4 figure

The Bean-Livingston barrier at a superconductor/magnet interface

The Bean-Livingston barrier at the interface of type-II superconductor/soft-magnet heterostructures is studied on the basis of the classical London approach. This shows a characteristic dependence on the geometry of the particular structure and its interface as well as on the relative permeability of the involved magnetic constituent. The modification of the barrier by the presence of the magnet can be significant, as demonstrated for a cylindrical superconducting filament covered with a coaxial magnetic sheath. Using typical values of the relative permeability, the critical field of first penetration of magnetic flux is predicted to be strongly enhanced, whereas the variation of the average critical current density with the external field is strongly depressed, in accord with the observations of recent experiments.Comment: RevTeX 4; revised version; accepted in Journal of Physics: Condensed Matte

Armenia and Belarus: caught between the EU's and Russia's conditionalities?

This article looks into Armenia's and Belarus’ engagement with the European Union's (EU) and Russia's conditionalities, the two EU Eastern Partnership (EaP) countries that are also members of the Russia-led Eurasian Economic Union (EAEU). While paying attention to political, economic (including energy and technical) as well as security dimensions of the EU's and Russia's approaches, as proposed in the present special section, the article demonstrates that the conditionalities extended by the EU and Russia to the two countries in question have differed. In their turn, Armenia and Belarus have reacted differently to Russia's and the EU's conditionalities. Against the backdrop of the changing significance ascribed to both the EU's and Russia's policies towards their common neighbourhood since the 1990s, the present contribution identifies and analyses factors that account for the diverging positions of Armenia and Belarus, including the type of regime, the geopolitical considerations, the stakes in the economic and energy spheres and the predisposition to integration. The article shows that in the resulting complex context, Armenia and Belarus have been able to influence the shape and content of the EU's and Russia's conditionalities, although in a different way and to a different extent.Ministry of Education and Science (UID/CPO/ 00758/2013

Rabies re-emergence after long-term disease freedom (Amur Oblast, Russia)

Retrospective descriptive epizootological study was conducted in the Amur Oblast (Russian Far East), where a rabies outbreak was reported in 2018. The aim of the study was to analyze probable routes of rabies introduction and features of its spatial and temporal spread in the territory that remained free from this infection from 1972 to 2018. In 2018–2021, altogether 1,416 animals were examined for the infection with the rabies virus. Forty-seven animal rabies cases were confirmed; the proportion of wild animals (Vulpes vulpes, Nyctereutes procyonoides, Canis lupus) amounted to 66%. The first cases were detected within 30 km from the state border with China. Nucleotide sequences of the nucleoprotein gene of three rabies virus isolates were determined and their belonging to the Arctic-like-2 genetic lineage was established. Genetically closest rabies virus isolates have been found in Heilongjiang Province (China, 2011, 2018) and Jewish Autonomous Oblast (Russia, 1980). GIS and open Earth remote sensing data were used to map the rabies cases. After 2018, the epizootic spread within the forest-steppe landscapes of the Zeya-Bureya Plain, where human and animal rabies cases had been earlier reported (until 1972). The front of the epizootic spread in a north-eastern direction at an average speed of 59 (16–302) km during one epizootic cycle. The introduction of the rabies virus was most likely along the Amur River valley from downstream regions of Russia and China that are rabies infected

Use of Polarization Lidar for Investigation of Meteorological Formations

This paper presents the results of theoretical and experimental, investigations of depolarization characteristics of different meteorological formations. Experimental investigations are carried out with a monostatic lidar. The ruby laser radiation is polarized in a vertical plane. The radiation reflected is accepted by a lens system of 150 rom in diameter and a viewing angle of 12' and further it is divided by Wollaston prism into the components polarized orthogonally. In this case the principal plane of the prism is exposed parallel with the laser polarization plane. Investigations show the degree of radiation polarization, reflected from water clouds, to be changed within 1/0.7 (seldom up to 0.6) depending on their density. In most cases a signal reflected from the cloud leading edge is polarized completely. The time shift is observed between polarized and crosspolarized components of a Fignal, reflected from a cloud, depending on the density of a meteorological object. While penetrating into the cloud depth a degree of polarization decreases up to 0.8-0.7, and the character of this decrease is different for various types of clouds. For crystal clouds the shift between the components of the reflected signal is not observed and the magnitude of polarization degree amounts to 0.1/0.3 in comparison with water clouds. The polarization degree of radiation reflected by fog is not less than 0.6, and that in the rains of average intensity (about 5 mm/h) is always about 1. The authors have suggested an algorithm of numerical solution of nonstationary transfer equation in the vector form to forecast the influence of multiple scattering effects on polarization characteristics of the lidar light signal. The method of statistical simulation (Monte-Carlo technique) forms the basis of the algorithm. Numerical estimates obtained for a model of stratocumulus at lambda = 0.6943 microns under boundary conditions close to the conditions of natural experiment being discussed proved to be in a good agreement with the results of observation. Specifically, Fig. 1 shows the profiles of polarization (p) versus depth (L) of the following drop formations: fog (curve 1) with horizontal meteorological visibility of 4 km two stratocumulus at a height of 1100 m with the attenuation factors delta = 0.01m(exp -1) (curve 2) and delta = 0.05m(exp -1) (curve 3). Curve 3 shows the results of numerical estimates and the value of their statistical error

ЦИРРОЗ ПЕЧЕНИ ПРИ ХРОНИЧЕСКОМ ГЕПАТИТЕ С У ДЕТЕЙ

The research presents the analysis of the factors of macro-and microorganism facilitating the formation of liver cirrhosis (LC) in CHC in children. 20 patients with liver cirhossis of hepatitis C virus etiology have been observed. No reliable correlation between such factors as sex, age, route of infection, previous and concomitant diseases, genotype of the pathogen, duration of the infection has been discovered. The clinical, biochemical and ultrasound characteristics of liver cirrhosis of HCV-etiology in children have been presented. The changes of the frequency of occurrence of certain subtypes of the virus and the prevailing route of HCV-infection in recent years have been shown.В работе представлена оценка факторов микро- и макроорганизма, способствующих формированию цирроза печени (ЦП) при ХГС у детей. Наблюдалось 20 больных с ЦП HCV-этиологии. Отмечено отсутствие достоверной связи таких факторов, как пол, возраст и способ инфицирования, наличие и характер предшествующих и сопутствующих заболеваний, генотип возбудителя и длительность инфицирования. Дана клинико-биохимическая и ультразвуковая характеристика ЦП HCV-этиологии у детей. Показано изменение частоты встречаемости отдельных субтипов вируса и преобладающего пути инфицирования HCV за последнее время

ИССЛЕДОВАНИЕ ЗНАЧИМОСТИ ОБНАРУЖЕНИЯ НУКЛЕОКАПСИДНОГО АНТИГЕНА ВИРУСА ГЕПАТИТА С У ДЕТЕЙ С ХРОНИЧЕСКИМ ГЕПАТИТОМ С

The aim of this study was to investigate the clinical and diagnostic significance of the detection of core-antigen of hepatitis C virus (HCV) in children with chronic hepatitis C (CHC). Sera of 101 patients and 24 non-infected participants were analyzed. Core-antigen was determined by chemiluminescent method using «ARCHITECT HCV Ag» (Abbott, USA). HCV RNA was detected by highly sensitive OT-PCA. The presence of liver fibrosis was established by non-invasive methods. Antibody to core-antigen was detected by ELISA using commercial test-systems. A correlation was found between concentration of core-antigen and HCV RNA, viral subtypes, ALT level, and presence of liver fibrosis. High sensitivity and specificity of the chemiluminescent method for the detection of core antigen in children with CHC was shown. For the first time three ranges of core-antigen concentrations were proposed. Цель исследования — изучить клинико-диагностическое значение обнаружения нуклеокапсидного (core) антигена вируса гепатита С у детей с хроническим гепатитом С. Анализировали сыворотки крови 101 больных и 24 неинфицированных участников. Сore-антиген определяли хемилюминисцентным методом (Architect HCV Ag, «Abbott», США), РНК ВГС — методом ОТ-ПЦР, фиброз печени — неинвазивными методами, специфические антитела — методом ИФА. Установлена зависимость между содержанием core-антигена и РНК ВГС, субтипами вируса, уровнем АЛТ и фиброзом печени. Показаны высокая чувствительность и специфичность хемилюминисцентного метода определения core-антигена у детей с ХГС. Впервые предложены три диапазона концентраций core-антигена

ЗНАЧЕНИЕ КОЛИЧЕСТВЕННОГО ОПРЕДЕЛЕНИЯ CORE-АНТИГЕНА В СЫВОРОТКЕ КРОВИ У ДЕТЕЙ С ГЕПАТИТОМ С

The clinical and pathogenetic significance of determining HCV core-antigen (HCV core-Ag) in serum of children with hepatitis C was investigated firstly. A direct correlation between the concentration of HCV core-Ag and viral load (VL) was revealed (r = 0,91). Children with high core-Ag (above 2500 fmol/L) showed indirect evidence for the immunosuppressive action of HCV core-Ag and occurrence of liver fibrosis more frequent (p < 0,05). In this grouP of children the prevalence of HCV subtype 3a was revealed (p < 0,05). Впервые исследовано клинико-патогенетическое значение определения HCV core-антигена (НСV core-Ag) в сыворотке крови больных гепатитом С детей. Установлена прямая корреляция между концентрацией НСV core-Ag и вирусной нагрузкой (ВН) (r = 0,91). У детей с высоким содержанием core-Ag (выше 2500 фмоль/л) получены косвенные данные в пользу иммуносупрессивного действия HCV core-Ag, а также более частое возникновение фиброза печени (p < 0,05). В этой группе обнаружено преобладание HCV субтипа 3а (p < 0,05).