A method has been developed for detecting inexact repeats in character sequences that can use alphabets consisting of any number of randomly selected characters. Reduction of the problem of detecting ...repeats in character data to the problem of detecting repeats in continuous numerical sequences is proposed. A theorem is proved on the one-to-one representation of a character sequence by a bundle of continuous functions of a discrete argument. To detect and visualize repeats, a similarity dot matrix is used, which is calculated on the basis of a metric in the space of expansion coefficients of function bundle fragments. The problem of choosing the parameters of the method based on the estimation of the correlation integral is discussed.
For a nonlocal initial-boundary value problem for a one-dimensional heat equation with not strongly regular boundary conditions of general type, an approximate difference scheme with weights is ...constructed. A correct and stable algorithm for the numerical solving of the difference problem is proposed. It is proven that the difference scheme with weights is stable and its solution converges to the exact solution of the differential problem in the grid L2h-norm. Stability conditions are established. An estimate of the numerical solution with respect to the initial data and the right-hand side of the difference problem is given.
In Russian Arctic seas, observations of surface methane concentrations (CH
4
), ozone, nitrogen and carbon oxides, as well as the content of
isotope and black carbon (BC, soot aerosol), were carried ...out from onboard of the R/V
Academician Mstislav Keldysh
. The areas of local methane releasing from bottom sediments were investigated. It was shown that the studied methane releasing on the Arctic shelf are of a local nature and, on the whole, insignificantly affect the composition of the atmosphere in the region. The average concentration of methane in the surface air in the Arctic seas is mainly determined by large-scale processes of air mass transfer. An analysis of the distribution of black carbon along the route of the vessel was carried out. It was found that the excess in the concentration of black carbon over the background values is observed occasionally during advection of air masses from the mainland and from the areas of associated gases burning and forest fires. The effect of emissions from a ship’s chimney on the data obtained was analyzed.
Introduction. The achievement of the goal of the World Health Organization to eliminate viral hepatitis B by 2030 seems to be problematic partly due to the presence of escape mutants of its ...etiological agent, hepatitis B virus (HBV) (iHepadnaviridae: Orthohepadnavirus: Hepatitis B virus/i), that are spreading mainly in the risk groups. Specific routine diagnostic assays aimed at identification of HBV escape mutants do not exist.The study aimed the evaluation of the serological fingerprinting method adapted for routine detection of escape mutations in 143 and 145 aa positions of HBV surface antigen (HBsAg).Material and methods. HBV DNA from 56 samples of HBsAg-positive blood sera obtained from donors, chronic HBsAg carriers and oncohematology patients has been sequenced. After the identification of mutations in HBsAg, the samples were tested in the enzyme-linked immunosorbent assay (ELISA) kit «Hepastrip-mutant-3K».Results and discussion. Escape mutations were detected mainly in patients with hematologic malignancies. Substitutions in 143 and 145 aa were found in 10.81% and in 8.11% of such patients, respectively. The G145R mutation was recognized using ELISA kit in almost all cases. The kit specifically recognized the S143L substitution in contrast to the S143T variant. The presence of neighbor mutation D144E can be assumed due to it special serological fingerprint.Conclusion. ELISA-based detection of escape mutations S143L, D144E and G145R can be used for routine diagnostics, especially in the risk groups. The diagnostic parameters of the kit can be refined in additional studies. This immunoassay and methodology are applicable for the development and quality control of vaccines against escape mutants.
The results of studies of atmospheric aerosol over the territory of Russia are of great interest from the point of view of ecological and climatic problems. The paper presents the results of spatial ...and temporal variability of Aerosol Optical Depth (AOD) over the European territory of the Russian Federation in the period 1999 - 2016 yy. The assessments were carried out using the original AOD extraction method based on ground-based observations of the Russian actinometric network, and also on the satellite observations of MODIS. The general regularities of spatial variations in the aerosol optical depth over Russia are revealed: a monotonic decrease from the southwest to the northeast with localized areas having different aerosol loads due to the global and regional factors of their formation. The AOT increase in spring and summer is associated with a seasonal increase in temperature and humidity and with changes in the underlying surface. "Purification" of the atmosphere from aerosol is caused by the absence of large volcanic eruptions and by industrial "calm" conditions during the last decade. Negative tendencies are less pronounced in the fall than in spring and summer. To compare the atmospheric AOT values obtained from the MODIS, AERONET and GMS data, we have compiled a combined archive of daily AOT values synchronized in pairs for the 3 types of observations (GMS, MODIS and AERONET): "Aerosol optical thickness of the atmosphere by satellite and ground observations ". The data of the comparison of terrestrial and satellite data for AOD are presented only in averaged form and need further consideration.
The method for estimation of linear multidimensional dynamic control systems perturbed by only one of the phase coordinates is developed in the paper. Only one phase coordinate without perturbation ...is available for measurement in the system. A robust algorithm for ellipsoidal estimation is developed, which minimizes the trace of the matrix of ellipsoid that approximates admissible set of point estimates. Application of the method and efficiency of the algorithm are shown on the example of estimating the heading angle of an artificial Earth satellite during its orbital motion. The onboard local vertical reference and angular velocity sensors are used for the estimation.
Bistable dynamical systems are widely employed to robustly encode classical bits of information. However, they owe their robustness to inherent losses, making them unsuitable to encode quantum ...information. Surprisingly, there exists a loss mechanism, known as two-photon dissipation, that provides stability without inducing decoherence. An oscillator exchanging pairs of photons with its environment is expected to reach macroscopic bit-flip times between dynamical states containing only a handful of photons. However, previous implementations have observed bit-flip times saturating in the millisecond range. In this experiment, we design a superconducting resonator endowed with two-photon dissipation, and free of all suspected sources of instabilities and inessential ancillary systems. We attain bit-flip times exceeding 100 s in between states containing about 40 photons. Although a full quantum model is necessary to explain our data, the preparation of coherent superposition states remains inaccessible. This experiment demonstrates that macroscopic bit-flip times are attainable with mesoscopic photon numbers in a two-photon dissipative oscillator.
An analysis of the CO and CH4 total column (TC) as well as aerosol optical depth (AOD) data in background and urban Eurasian regions for different time-periods and seasons from 1998 to 2018 years is ...presented. Trend estimates based on long-term spectroscopic datasets of OIAP RAS for Moscow, Zvenigorod (ZSS, Moscow province), Beijing (joint site of OIAP RAS and IAP CAS) and NDACC stations located in Eurasia are compared between themselves and with similar assessments obtained from satellite data. The comparison of satellite and ground-based trend estimates was provided for the days of synchronous measurements only. Analysis results of the satellite observations of AIRS v6 of CO and CH4 TC and MODIS AOD data are confirmed by ground-based trend estimates. Significant decrease of anthropogenic CO in the megacities Moscow (2.9±0.6%/yr) and Beijing (1.2±0.2%/yr) for autumn months of 1998-2018 was found according to ground-based spectroscopic observations. In spite of total anthropogenic CO emission decrease (for Europe and China) and the decrease of wild-fires emissions in Central North Eurasia (0-90° E, 42-75° N) in 2008-2018 we found CO TC stabilization or even increasing for summer and autumn months of 2008-2018 in background regions of Northern Eurasia. Decrease of AOD over Central and Southern Europe as well as over China (1-5%/yr) was observed since 2007. Since 2007-2008 an increase in CH4 TC positive trend values over Northern Europe as well as for tropical belt of Eurasia was obtained.
We present observation results of methane (CH4), its isotopic signature (δ13CCH4) and carbon dioxide (CO2) surface concentrations, made aboard the research vessel (R/V) "Akademik Mstislav Keldysh" in ...the Russian Arctic seas in summer 2019. The main goal of the study is to determine the possible sources of methane. As a result of the study, localized areas with an increased methane concentration (up to 2092 ppb) in the surface layer are identified. It may be related to the advection of water masses rich in organic matter from the Ob and Yenisei Rivers. In addition, increased methane concentrations (up to 2010 ppb) are observed in the Kara Sea near the Yamal Peninsula, where gas deposits are concentrated, and active methane emissions from wetland ecosystems are noted. We conclude that the average concentration of methane in surface air in the Arctic seas is determined mainly by large-scale transport of air masses.
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