Modeling Kelvin wave cascades in superfluid helium

We study two different types of simplified models for Kelvin wave turbulence on quantized vortex lines in superfluids near zero temperature. Our first model is obtained from a truncated expansion of the Local Induction Approximation (Truncated-LIA) and it is shown to possess the same scalings and the essential behaviour as the full Biot-Savart model, being much simpler than the later and, therefore, more amenable to theoretical and numerical investigations. The Truncated-LIA model supports six-wave interactions and dual cascades, which are clearly demonstrated via the direct numerical simulation of this model in the present paper. In particular, our simulations confirm presence of the weak turbulence regime and the theoretically predicted spectra for the direct energy cascade and the inverse wave action cascade. The second type of model we study, the Differential Approximation Model (DAM), takes a further drastic simplification by assuming locality of interactions in k-space via using a differential closure that preserves the main scalings of the Kelvin wave dynamics. DAMs are even more amenable to study and they form a useful tool by providing simple analytical solutions in the cases when extra physical effects are present, e.g. forcing by reconnections, friction dissipation and phonon radiation. We study these models numerically and test their theoretical predictions, in particular the formation of the stationary spectra, and closeness of numerics for the higher-order DAM to the analytical predictions for the lower-order DAM

Synthis and Phisical And Chemical; Properties of SiO[2]-B[2]O[3] and SiO[2]-P[2]O[5] Thin Film Systems and Powders

The SiO[2]-B[2]O[3] and SiO[2]-P[2]O[5] films were synthesized by using film forming solutions having a P[2]O[5] content of up to 30% and B[2]O[3] up to 40%. Properties of the filmforming solutions and binary oxides were examined. The physical and chemical processes occurring in the solution during the heat treatment of films were examined. The conditions for producing films of different thicknesses were determined. The kinetic parameters were calculated

Quantum Turbulence

The present article reviews the recent developments in the physics of quantum turbulence. Quantum turbulence (QT) was discovered in superfluid $^4$He in the 1950s, and the research has tended toward a new direction since the mid 90s. The similarities and differences between quantum and classical turbulence have become an important area of research. QT is comprised of quantized vortices that are definite topological defects, being expected to yield a model of turbulence that is much simpler than the classical model. The general introduction of the issue and a brief review on classical turbulence are followed by a description of the dynamics of quantized vortices. Then, we discuss the energy spectrum of QT at very low temperatures. At low wavenumbers, the energy is transferred through the Richardson cascade of quantized vortices, and the spectrum obeys the Kolmogorov law, which is the most important statistical law in turbulence; this classical region shows the similarity to conventional turbulence. At higher wavenumbers, the energy is transferred by the Kelvin-wave cascade on each vortex. This quantum regime depends strongly on the nature of each quantized vortex. The possible dissipation mechanism is discussed. Finally, important new experimental studies, which include investigations into temperature-dependent transition to QT, dissipation at very low temperatures, QT created by vibrating structures, and visualization of QT, are reviewed. The present article concludes with a brief look at QT in atomic Bose-Einstein condensates.Comment: 13 pages, 5 figures, Review article to appear in J. Phys. Soc. Jp

Competition between dynamical and sequential reaction channels in ^{197}Au+^{197}Au collisions at a bombarding energy of 23A MeV

Competition between the two reaction channels: sequential breakup and neck fragmentation has been studied in peripheral and semi-peripheral collisions of the 197 Au+ 197 Au system at bombarding energy of 23A MeV. It was found that the emission of heavy (A < 50) neck-originating fragments occurs in about 22% of ternary breakup events, making this reaction channel highly competitive with the sequential breakup of the projectile- or target-like fragment (78% of events)

Evolution of chronic heart failure syndrome in a patient with myocardial infarction and complex rhythm disturbances

Abstract: today the problem of chronic heart failure as a complication of myocardial infarction and other cardiovascular diseases continues to be relevant, due to the increase in the prevalence of heart failure, especially the severe stage of heart disease and the main causes of deaths of this cohort of patients. The article presents a clinical case of chronic heart failure syndrome with complex rhythm disturbances in the patient against the background of the transferred transmural myocardial infarction and hypertension. The authors demonstrated that after a thorough assessment of the risk and benefit of various treatment methods, the therapeutic and surgical tactics of management of the patient in this clinical situation were correctly chosen, which allowed not only to prolong life, but also to improve the quality of life of the patient. Thus, in this clinical case, we show the importance of personalized therapy in the progression of chronic heart failure syndrome in patients with combined cardiovascular disease.На сегодняшний день проблема хронической сердечной недостаточности, как осложнение инфаркта миокарда и другой сердечно-сосудистой патологии продолжает оставаться актуальной, связно это с увеличением распространенности сердечной недостаточности, особенно тяжелой стадии поражения сердца и основными причинами летальных исходов данной когорты пациентов. В статье представлен клинический случай синдрома хронической сердечной недостаточности со сложными нарушениями ритма у пациента на фоне перенесенного трансмурального инфаркта миокарда и гипертонической болезни. Авторами продемонстрировано, как после тщательной оценки риска и пользы различных методов лечения была правильно подобрана терапевтическая и хирургическая тактика ведения больного в данной клинической ситуации, что позволило не только продлить жизнь, но и улучшить качество жизни пациента. Таким образом, данным клиническим случаем мы показываем важность персонифицированной терапии при прогрессировании синдрома хронической сердечной недостаточности у пациентов с сочетанной сердечно-сосудистой патологией

Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology

Tractability in Constraint Satisfaction Problems: A Survey

International audienceEven though the Constraint Satisfaction Problem (CSP) is NP-complete, many tractable classes of CSP instances have been identified. After discussing different forms and uses of tractability, we describe some landmark tractable classes and survey recent theoretical results. Although we concentrate on the classical CSP, we also cover its important extensions to infinite domains and optimisation, as well as #CSP and QCSP