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Professor Alexander M. Seagal (1887–1968), was one of the first Russian cardiologists to identify cardiac arrhythmias as a separate independent problem in cardiology. In addition to numerous works on various issues of therapy and cardiology, he is the author of apparently the first Russian monograph on arrhythmology, "Rhythms of Cardiac Activity and Their Disorders," entirely devoted to cardiac arrhythmias and which went through two editions in Soviet times (1935 and 1958). An analysis of the mechanisms of not only pathological rhythms, but also physiological ones was carried out, an original clinical and electrocardiographic classification of bradycardias ("neurogenic" and "myogenic") and paroxysmal tachycardias was given, the electrophysiological and pathohistological basis of arrhythmias known at that time and methods of their treatment were analyzed. The book shows variants of arrhythmias that are still rare today ("cardiac alternation", etc.), and describes clinical variants of paroxysmal tachycardias, including atypical ones — induced by allergic triggers. In all cases of clinical examples, not only the clinical description and ECG picture of the arrhythmia are provided, but also the necessary therapeutic measures and prognosis. The clinic of arrhythmogenic syncope and other arrhythmic symptoms, which are still relevant in our time, is analyzed. Being a famous music connoisseur, A. M. Seagal used an original approach to recording the tones and rhythms of the heart, using a musical staff. Many clinical observations and conclusions are interesting and relevant in our time. A. M. Seagal was undoubtedly the one who stood at the origins of Russian arrhythmology, as a separate direction in cardiology.

Aim of the study: to assess the prevalence of arterial hypertension in athletes with high BP values during an exercise test.Methods: out of 2313 athletes 14–18 (15.5 ± 1.4) years old, according to the results of VEM, 128 (6 %; 60 m) people with high blood pressure values at maximum load were identified, 86 (67 %) of them underwent ABPM. The patient were divided into 2 groups: with normal — 62 (72 %) and high office BP – 24 (28 %).Results: athletes with high office BP values had a significantly higher BMI. We did not note any significant differences in ABPM between the two groups. 71 % had arterial hypertension, 65 % had masked arterial hypertension.Conclusions: in young elite athletes with high values of BP during exercise, 71 % are diagnosed arterial hypertension according to ABPM; in 65% masked arterial hypertension has detected, which dictates the need for ABPM in this group of athletes.

Long QT syndrome (LQTS) assessment is based on the QT/ÖRR equation (the so-called Bazett's formula) and calculating the corrected QT (QTc). However, this formula reliably estimates the QT interval in the heart rate range (HR) of 60-90 bpm, which makes it difficult to diagnose LQTS in patients with sinus bradycardia, typical of this disease.Aim. To improve the LQTS diagnosis in patients with sinus bradycardia using the handgrip strength test.Material and methods. A total of 188 patients aged 5-53 years (16 [13;17]) were examined: group I — 40 healthy children aged 9-17 years (14 [12;16]); group II — 98 athletes with sinus bradycardia 60 bpm. The patients had an electrocardiogram recorded twice before and after the handgrip test. Heart rate, QT and QTc intervals were analyzed.Results. In all groups, after using the expander, there was a significant increase in heart rate, QT interval shortening and QTc interval prolongation. QTc interval prolongation after the handgrip test >460 ms was a highly sensitive marker of LQTS (Se 96%, Sp 60%).Conclusion. Proposed handgrip test for sinus bradycardia makes it possible to increase heart rate, which ensures a more correct use of the Bazett's formula for assessing the corrected QT interval (QTc). QTc interval prolongation over 460 ms after the handgrip test is a highly sensitive additional marker for identifying patients with LQTS.

The object of research in the paper is the technology of manufacturing segments of the rotor rim of large hydrogenerators-motors. The subject of study is the design and geometrical state of the rotor rim during the operation of hydraulic units. The goal is to make a three-dimensional mechanical calculation of the rotor segment for the further determination of the most optimal technology for the rotor rim manufacturing. The following tasks are set: to study the peculiarities of the manufacturing technology of the rotor rim segments; to perform an analytical calculation and a three-dimensional calculation with the determination of the average values of stresses and deformations in the rotor segment. The used methods are: finite element method of mathematical modeling of the thermal stress state of nodes. The following results were obtained: a description of the two main manufacturing technologies of the rotor rim segments, namely the stamping method and the laser cutting method, was provided. The advantages and disadvantages of each technological process were analyzed, and it was determined that the laser cutting method should be used in the production of powerful small-scale hydrogenerators. Three-dimensional models of the rotor segment were developed and a three-dimensional mechanical calculation of this model was performed, as a result of which the value of the displacement of the rotor of the hydrogenerator at the nominal frequency of rotation, as well as the average values of the stresses in the spoke and the rim of the rotor, were obtained. Based on the results of calculations, it was established that significant tolerances in the manufacture of rotor segments can lead to changes in the shape of the rotor during its further operation, the appearance of additional vibrations and further affect the performance of the hydraulic unit. The scientific novelty consists in a combined approach to the estimation of the average values of stresses and deformation of the rotor rim, taking into account the technology of its manufacture, which includes elements of analytical mechanical calculation and calculation in a three-dimensional setting.

Russian Society of Cardiology (RSC)Developed with the special contribution of the Russian Functional Diagnostics Association, Russian Holter Monitoring and Non-invasive Electrophysiology Society, Russian Pediatric Cardiology Association.

It is known that in children at rest, BP values depend on height, but this aspect is not taken into account when analyzing the maximum BP during exercise.Objective: to determine the maximum value of BP in young elite athletes, depending on height and gender.Materials and methods: 2313 (age 15.5 ± 1.4 years, 45% of young men) young elite athletes, members of national teams of the Russian Federation in 40 sports, were examined. All subjects underwent bicycle ergometry according to the PWC170 protocol, blood pressure was measured manually at each stage of the load, and its maximum values were determined during the entire test.Results: The maximum BP values in boys were higher than in girls: systolic blood pressure (SBP) 195 ± 25 vs 175 ± 20 mmHg, p < 0.001, diastolic blood pressure (DBP) 80 ± 11 vs 80 ± 10 mm Hg, p < 0.05. A relationship was found between the maximum value of blood pressure on load and growth (r = 0.55; p < 0.001). Normative tables are proposed for assessing the maximum values of SBP and load, depending on growth.Conclusion: In young elite athletes, the maximum BP value during VEM according to the PWC170 protocol depends not only on gender, but also on height. The maximum values of SBP during exercise in tall young elite athletes can reach 250 mm Hg in boys and 210 mm Hg in girls.

Aim. To refine the LWR coefficients for the Baikal omul Coregonus migratorius (Georgi, 1775).Material and Methods. The data set (number of fish, standard length (SL), weight (W), sex and morpho‐ecological group (MEG) for the study of the LWR coefficients were taken from the Baikal Omul database. The analysis includes data from 3,091 specimens of Baikal omul, collected in May to June 2003, 2006 and 2007 and in September 2004 in the area adjacent to the delta of the Selenga River. The construction of regression models of LWR was carried out for all data without taking into account gender and MEG. In addition, regression models of LWR data were obtained, grouped by gender and belonging to a certain MEG.Results. Dependencies with close values of the coefficients of the power function are obtained. There were no significant differences between fish of different sexes and MEG, the coefficients differing at the level of statistical error. It is shown that the LWR in fish during feeding periods of different years is quite stable.Conclusion. We offer the equation W=10,9(SLdm)3.02 that has acceptable coefficients for C. migratorius resource estimations during feeding period without carrying out controlled fishing.

We present the complete solution concerning to transport properties of coupled transverse electromagnetic and shear acoustic waves propagating via a piezoelectric slab embedded into a homogeneous dielectric medium. Since the electroacoustics of our setup is governed by four electromagnetoelastic eigenmodes, we had to succeed in developing a 4 × 4 transfer matrix method to analytically resolve the problem. As a result, the exact frequency spectra of the transmission, reflection, and transformation transport coefficients were obtained and analyzed in detail for two basic cases where the piezoelectric slab subjected by electromagnetic/acoustic perturbation generates acoustic/electromagnetic response. We establish that wave transformation is effectively realized in vicinities of electromagnetic and acoustic Fabry–Pérot resonances. Surprisingly, as a consequence of the problem geometry and accepted 4 mm symmetry of the piezoelectric medium, the phenomenon of the resonant parity selection arises: in the vicinity of an electromagnetic Fabry–Pérot resonance of the given (odd/even) parity, only acoustic Fabry–Pérot resonances with opposite (even/odd) parity are excited in the coefficient of generation. The piezoelectric coupling vanishes when the parities of both resonances coincide. The changes in transmission and reflection spectra turn out to be more sophisticated. The phenomenon is observed due to quite great distinction between electromagnetic and acoustic wave numbers provided by the fundamental difference between light and sound velocities. In our analysis, particular attention is also paid to the ability of increasing the mutual transformation of electromagnetic and acoustic fluxes.

Aim. The aim of the study was to estimate the coefficients of the equation TSmax=f(SL) considering the characteristics of an acoustic scattering model based on the morphological characteristics of the swim bladder of the Coregonus migratorius (Georgi, 1775). Material and Methods. Ninety‐nine living specimens of C. migratorius served as the study material. For each specimen, the target strength in the cage was measured using an Kongsberg Simrad EY500 echo sounder and the morphology of the swim bladder was studied. Measurements, analysis of images and data were conducted using Image Pro 6.0. Excel and SciLab software resources. Results. We determined the main morphological characteristics of the swim bladder in C. migratorius as well as the correspondence of its dimensions and proportions in relation to the length of the fish’s body. The coefficients of the equation TS=20log(SL)‐60, calculated on the results of the acoustic scattering model of a prolate spheroid, agree well with the coefficients calculated from maximum values obtained in the cage experiment. During the conversion of the coefficients relating to the allometric changes in the length of the swim bladder relative to fish length, the equation TS=23.2log(SL)‐64.4 was obtained. A comparative analysis of the available equations of the target strength for C. migratorius with those obtained in the study was undertaken. Conclusion. The equation obtained on the model of the swim bladder as a prolate spheroid adequately describes the dependence of the maximum values of the target strength on the body length of the C. migratorius and confirms the previously obtained dependence by maximum values of TS in the cage experimental conditions and can serve as a basis for further theoretical studies.

Aim. The continuous monitoring of changes in ecosystems must be carried out in connection with global climate changes that affect the state of water bodies. Remote sensing methods have many advantages as a promising method for monitoring biocenoses in large water bodies. We carried out a comprehensive study comparing the results obtained using the latest instruments and methods to expand their further application to the continuous monitoring of water bodies.Material and Methods. The field research was undertaken using hydroacoustic sensors, submersible holographic camera and high‐resolution thermal sensors in addition to the classical methods of studying the zooplankton ecology – the Juday net and CTD probe. Water temperature, chlorophyll, photosynthetically active radiation and other parameters were measured with an AAQ‐Rinko probe. We provided data for one vertical up to a depth of 100 m.Results. The main components of mesozooplankton during the ice period are different age stages of the endemic crustacean Epischura baikalensis Sars 1900 and several rotifer species. The article discusses the heterogeneity of the environment and the distribution of plankton detected by various instruments.Conclusion. The experimental results obtained with the help of a set of devices show that the distribution of zooplankton is very strongly dependent on the physical parameters of the environment. The use of remote sensing methods is an important step towards the automation of basic monitoring of the ecosystem of Lake Baikal and other water bodies. The obtained field data will make it possible to further improve the pattern recognition algorithm in the software of the holographic installation for the specific conditions of Lake Baikal. The results of the vertical distribution and migrations of zooplankton in connection with environmental parameters are assumed to be processed using mathematical modeling methods.

Russian Society of Cardiology (RSC).With the participation of Russian Scientific Society of Clinical Electrophysiology, Arrhythmology and Cardiac Pacing, Russian Association of Pediatric Cardiologists, Society for Holter Monitoring and Noninvasive Electrocardiology.Approved by the Scientific and Practical Council of the Russian Ministry of Health.

Aim. This study aims to discuss the validity of introducing restrictions on the catch of Coregonus migratorius (Georgi, 1775) with a forecast of the likely environmental consequences of doing so.Discussion. We show the results of the analysis of the assessment of the state of C. migratorius stocks and the reasons for their decline. We indicate that the biostatistical and hydroacoustical methods for estimating fish numbers, which are traditionally used to substantiate allowable catches, have some disadvantages and limitations. We consider unrecorded catches and unfavourable natural and climatic environmental factors to be reasons for the decline in C. migratorius stocks. We discuss ecological and anthropogenic factors of changes in stocks of this commercially important species for the region. We show the anticipated ecological effects of currently established limits.Conclusion. The results of changes in the modelling of the number and age composition of fish with different protection strategies indicate that maintaining a low level of replenishment stock the limits would not increase commercial stocks of C. migratorius. Restrictions imposed on the commercial and amateur fishing would significantly increase environmental risks through increase of poaching (including during the spawning period) as well as as a consequence of amateur fishing of other commercially valuable fish species.

Visual search (VS) for multiple targets is especially error prone. One of these errors is called subsequent search misses (SSM) and represents a decrease in accuracy at detecting a second target after a first target has been found. One of the possible explanations of SSM errors is working memory (WM) resource depletion. Three experiments investigated the role of WM in SSM errors using a dual task paradigm. The first experiment investigated the role of object WM using a classical color change detection task. In the second and the third experiments, a modified change detection task was applied, using shape as the relevant feature. The results of our study revealed no effect of additional WM task on second target detection in dual-target VS. To this end, SSM errors are not related to WM resource depletion. On the contrary, WM task performance was violated by dual-target VS as compared to single-target VS, when the targets in VS task were defined by the same feature used in the WM task.

We theoretically study eigenstates of electromagnetic field inside a one-dimensional photonic crystal containing a defect slab of layered superconductor. Basing on the transfer matrix formalism along with the electrodynamics of Josephson plasma, we obtain the dispersion relations describing the THz electromagnetic modes localized on defect. We consider both symmetric and antisymmetric configuration of defect in photonic crystal. The comparison of the dispersion spectra of the localized states for the layered-superconducting defect and the pure insulating defect reveals the features of the studied system.

The article discusses the topical problem concerning the development of road network in Sakha Republic. Due to the vast territory of the region, its socio(economic development largely depends on the efficient functioning of the transportation system. The article briefly dwells on the participation of Road Faculty of the North-Eastern Federal University in solving the task of road construction in the region.

Mycobacterium tuberculosis can proficiently enter macrophages and diminish complement activation on its cell surface. Within macrophages, the mycobacterium can suppress macrophage apoptosis and survive within the intracellular environment. Previously, we have shown that complement regulatory proteins such as factor H may interfere with pathogen–macrophage interactions during tuberculosis infection. In this study, we show that Mycobacterium bovis BCG binds properdin, an upregulator of the complement alternative pathway. TSR4+5, a recombinant form of thrombospondin repeats 4 and 5 of human properdin expressed in tandem, which is an inhibitor of the alternative pathway, was also able to bind to M. bovis BCG. Properdin and TSR4+5 were found to inhibit uptake of M. bovis BCG by THP-1 macrophage cells in a dose-dependent manner. Quantitative real-time PCR revealed elevated pro-inflammatory responses (TNF-α, IL-1β, and IL-6) in the presence of properdin or TSR4+5, which gradually decreased over 6 h. Correspondingly, anti-inflammatory responses (IL-10 and TGF-β) showed suppressed levels of expression in the presence of properdin, which gradually increased over 6 h. Multiplex cytokine array analysis also revealed that properdin and TSR4+5 significantly enhanced the pro-inflammatory response (TNF-α, IL-1β, and IL-1α) at 24 h, which declined at 48 h, whereas the anti-inflammatory response (IL-10) was suppressed. Our results suggest that properdin may interfere with mycobacterial entry into macrophages via TSR4 and TSR5, particularly during the initial stages of infection, thus affecting the extracellular survival of the pathogen. This study offers novel insights into the non-complement related functions of properdin during host–pathogen interactions in tuberculosis.