Spontaneous Symmetry Breaking in Two-Channel Asymmetric Exclusion Processes with Narrow Entrances

Multi-particle non-equilibrium dynamics in two-channel asymmetric exclusion processes with narrow entrances is investigated theoretically. Particles move on two parallel lattices in opposite directions without changing them, while the channels are coupled only at the boundaries. A particle cannot enter the corresponding lane if the exit site of the other lane is occupied. Stationary phase diagrams, particle currents and densities are calculated in a mean-field approximation. It is shown that there are four stationary phases in the system, with two of them exhibiting spontaneous symmetry breaking phenomena. Extensive Monte Carlo computer simulations confirm qualitatively our predictions, although the phase boundaries and stationary properties deviate from the mean-field results. Computer simulations indicate that several dynamic and phase properties of the system have a strong size dependency, and one of the stationary phases predicted by the mean-field theory disappears in the thermodynamic limit.Comment: 13 page

Theoretical Investigation of Totally Asymmetric Exclusion Processes on Lattices with Junctions

Totally asymmetric simple exclusion processes on lattices with junctions, where particles interact with hard-core exclusion and move on parallel lattice branches that at the junction combine into a single lattice segment, are investigated. A simple approximate theory, that treats the correlations around the junction position in a mean-field fashion, is developed in order to calculate stationary particle currents, density profiles and a phase diagram. It is shown that there are three possible stationary phases depending on the state of each of the lattice branch. At first-order phase boundaries, where the density correlations are important, a modified phenomenological domain-wall theory, that accounts for correlations, is introduced. Extensive Monte Carlo computer simulations are performed to investigate the system, and it is found that they are in excellent agreement with theoretical predictions.Comment: 16 pages, 7 figure

The development of blockchain technology in Russia : outlook and trends

Purpose: The article addresses the issue of new scientific decisions shaping with respect to the study of problems, current trends and perspectives of blockchain technology usage in the Russian Federation. Design/methodology/approach: To achieve the objectives of this study the increasing interest to blockchain technology in Russia was discussed. Findings: The article determined main problems in blockchain technology which includes gaps in legislative regulation; the existence of a considerable number of projects that are undergoing the development stage and that have not proved own economic feasibility yet; incomplete understanding of the blockchain spheres’ implementation by state officials, society and business representatives as well as expected outcomes according to the amount and time of their receiving; disputes on cryptocurrencies turnover in the country’s territory and their influence in the national economy. Practical implications: The study has demonstrated the interest growth mainly by businesses to the usage of blockchain technology in order to improve own competitiveness and to obtain additional benefits, including the form of their profits. Originality/value: The research has also determined the area of further key studies in blockchain technology usage in Russia and the world.peer-reviewe

Two-Channel Totally Asymmetric Simple Exclusion Processes

Totally asymmetric simple exclusion processes, consisting of two coupled parallel lattice chains with particles interacting with hard-core exclusion and moving along the channels and between them, are considered. In the limit of strong coupling between the channels, the particle currents, density profiles and a phase diagram are calculated exactly by mapping the system into an effective one-channel totally asymmetric exclusion model. For intermediate couplings, a simple approximate theory, that describes the particle dynamics in vertical clusters of two corresponding parallel sites exactly and neglects the correlations between different vertical clusters, is developed. It is found that, similarly to the case of one-channel totally asymmetric simple exclusion processes, there are three stationary state phases, although the phase boundaries and stationary properties strongly depend on inter-channel coupling. An extensive computer Monte Carlo simulations fully support the theoretical predictions.Comment: 13 pages, 10 figure

Rigorous results on spontaneous symmetry breaking in a one-dimensional driven particle system

We study spontaneous symmetry breaking in a one-dimensional driven two-species stochastic cellular automaton with parallel sublattice update and open boundaries. The dynamics are symmetric with respect to interchange of particles. Starting from an empty initial lattice, the system enters a symmetry broken state after some time T_1 through an amplification loop of initial fluctuations. It remains in the symmetry broken state for a time T_2 through a traffic jam effect. Applying a simple martingale argument, we obtain rigorous asymptotic estimates for the expected times ~ L ln(L) and ln() ~ L, where L is the system size. The actual value of T_1 depends strongly on the initial fluctuation in the amplification loop. Numerical simulations suggest that T_2 is exponentially distributed with a mean that grows exponentially in system size. For the phase transition line we argue and confirm by simulations that the flipping time between sign changes of the difference of particle numbers approaches an algebraic distribution as the system size tends to infinity.Comment: 23 pages, 7 figure

Spontaneous symmetry breaking in a two-lane model for bidirectional overtaking traffic

First we consider a unidirectional flux \omega_bar of vehicles each of which is characterized by its `natural' velocity v drawn from a distribution P(v). The traffic flow is modeled as a collection of straight `world lines' in the time-space plane, with overtaking events represented by a fixed queuing time tau imposed on the overtaking vehicle. This geometrical model exhibits platoon formation and allows, among many other things, for the calculation of the effective average velocity w=\phi(v) of a vehicle of natural velocity v. Secondly, we extend the model to two opposite lanes, A and B. We argue that the queuing time \tau in one lane is determined by the traffic density in the opposite lane. On the basis of reasonable additional assumptions we establish a set of equations that couple the two lanes and can be solved numerically. It appears that above a critical value \omega_bar_c of the control parameter \omega_bar the symmetry between the lanes is spontaneously broken: there is a slow lane where long platoons form behind the slowest vehicles, and a fast lane where overtaking is easy due to the wide spacing between the platoons in the opposite direction. A variant of the model is studied in which the spatial vehicle density \rho_bar rather than the flux \omega_bar is the control parameter. Unequal fluxes \omega_bar_A and \omega_bar_B in the two lanes are also considered. The symmetry breaking phenomenon exhibited by this model, even though no doubt hard to observe in pure form in real-life traffic, nevertheless indicates a tendency of such traffic.Comment: 50 pages, 16 figures; extra references adde

Phase diagram of two-lane driven diffusive systems

We consider a large class of two-lane driven diffusive systems in contact with reservoirs at their boundaries and develop a stability analysis as a method to derive the phase diagrams of such systems. We illustrate the method by deriving phase diagrams for the asymmetric exclusion process coupled to various second lanes: a diffusive lane; an asymmetric exclusion process with advection in the same direction as the first lane, and an asymmetric exclusion process with advection in the opposite direction. The competing currents on the two lanes naturally lead to a very rich phenomenology and we find a variety of phase diagrams. It is shown that the stability analysis is equivalent to an `extremal current principle' for the total current in the two lanes. We also point to classes of models where both the stability analysis and the extremal current principle fail

Assessment of allergen tolerance breakdown levels in local and classical allergic rhinitis

Local allergic rhinitis, a new endotype of allergic rhinitis discerned by researchers of the Spanish Allergy School, is now in the focus of interest of international allergological community. A special feature of local allergic rhinitis, which, being similar to conventional signs of allergic rhinitis, is, however, characterized by absence of systemic atopy manifestations, e.g., an increased total serum IgE content and positive allergic skin tests. In order to assess the level of tolerance breakdown to allergens in local and classical allergic rhinitis, we have studyed concentrations of IL-4, IL-22, and IFNγ in three biological fluids, blood, nasal secretions, and skin exudate. The whole study cohort consisted of 82 patients aged 18 to 60 years with established allergic rhinitis. The diagnosis was based on counseling by allergologist/immunologist, including clinical case history and possible inheritance of atopy as well as videorhinoscopy performed by an ENT specialist. The procedure of videorhinoscopy allowed to specify allergic origin of rhinitis and exclude the patients with non-allergic forms of the disease, but it did not enable us to differentiate between the endotypes of classic and local allergic rhinitis. Subsequently, all patients have been divided into two subgroups based on the criteria of systemic atopy: (1) with a high content of serum total IgE and positive skin allergy tests (n = 41) and (2) with a significantly lower concentration of IgE and negative allergy tests (n = 41). It was concluded that the patients with classic allergic rhinitis prevailed in the 1st subgroup, whereas local rhinitis predominated in the 2nd group. The study of IL-4, IL-22 and IFNγ concentrations in the three biological fluids allowed us to presume that the 1st subgroup was characterized by increased content of IL-4 and IL-22 in blood and skin exudate in comparison with controls, and the 2nd subgroup showed a decrease in IFNγ to control values. The cytokine concentrations in nasal secretions were not representative for the subgroups studied. The result has been interpreted as the absence of tolerance breakdown to causal allergens in the patients with local allergic rhinitis at the systemic level. The obtained data could be used in development of a diagnostic biomarker system for this specific endotype of allergic rhinitis, thus avoiding potential diagnostic errors which occurred in the past, when this endotype was classified as non-allergic form of the disease, thus administering non-adequate treatment, e.g., allergen-specific immunotherapy, which could be prescribed in these cases

ХИРУРГИЧЕСКОЕ ЛЕЧЕНИЕ ДОБРОКАЧЕСТВЕННЫХ И ЗЛОКАЧЕСТВЕННЫХ ОПУХОЛЕЙ СЕРДЦА И СРЕДОСТЕНИЯ У ДЕТЕЙ

SUMMARY. Authors operated on 24 children with tumors of the heart and mediastinum. Analysis of the results showed that a third of patients with tumors of the thymus has had a rapid malignancy. This fact allows to conclude about the necessity of the surgery soon after the detection of tumors, despite the absence of clinical signs of the chest organs lesion. РЕЗЮМЕ. Были прооперированы 24 ребенка с новообразованиями сердца и средостения. Анализ полученных результатов показал, что у трети больных с опухолями вилочковой железы отмечается их быстрое озлокачествление. Указанное обстоятельство позволяет прийти к заключению о необходимости выполнения операции вскоре после выявления новообразования, несмотря на отсут­ствие клинических признаков, свидетельствующих о поражении органов грудной клетки.

МОДИФИЦИРОВАННАЯ МЕТОДИКА КОРРЕКЦИИ ДИСКРЕТНЫХ И ДИФФУЗНЫХ СУБАОРТАЛЬНЫХ СТЕНОЗОВ

We report a new original method of management for subaortic stenosis. When performing myectomy from the transaortic access of Morrow, the significant problem is poor visualization of the interventricular septum. The key to the successful implementation of the septal myectomy is achieving sufficient length, width and depth of resection of the hypertrophied interventricular septum. The authors introduced a new modification called “fixed needle technique” in order to visualize the entire region of septal hypertrophy and achieve safe extended myectomy of ventricular hypertrophy. Three needles of 21 gauge (0.8 mm) are introduced into the interventricular septum immidiately under the fibrous ring of the aortic valve, and reache the distal part of the hypertrophic portion. The right and left needles limit the width of resection and its depth is limited with the central needle. Each needle is a marker for the width, length and depth of resection. Needles allow to fix the interventricular septum and improve exposure of septal hypertrophy. The described technique allows to perform the required myectomy of the same thickness. The technique provides high-quality visualization of the interventricular septum and adequately removes hypertrophied part of myocardium in challenging patients with discrete subaortic stenosis and idiopathic hypertrophic cardiomyopathy.Представлена новая авторская методика коррекции субаортального стеноза. Во время операции миоэктомии трансаортальным доступом по Морроу существенной проблемой считается плохая визуализация межжелудочковой перегородки. Ключом к успешному выполнению септальной миоэктомии служит достижение достаточной протяженности, ширины и глубины резекции гипертрофированной межжелудочковой перегородки. Авторы внедрили новую модификацию, названную «техника фиксированной иглы» с целью визуализации всей области септальной гипертрофии и достижения безопасной расширенной миоэктомии межжелудочковой гипертрофии. Три иглы 21-го размера (0,8 мм) вводятся в межжелудочковую перегородку непосредственно под фиброзным кольцом аортального клапана и достигают дистальной части гипертрофированного участка. Правая и левая иглы ограничивают ширину резекции, а центральная игла — ее глубину. Каждая игла является маркером для ширины, длины и глубины резекции. Иглы позволяют стабилизировать межжелудочковую перегородку и улучшают экспозицию септальной гипертрофии. Описанная техника позволяет выполнить необходимый объем миоэктомии одинаковой толщины. Методика обеспечивает качественную визуализацию межжелудочковой перегородки и позволяет адекватно проводить удаление гипертрофированного участка миокарда у столь сложной категории пациентов как при дискретных субаортальных стенозах, так и при идиопатической гипертрофической кардиомиопатии