Dislocation-induced superfluidity in a model supersolid

Motivated by recent experiments on the supersolid behavior of $^4$He, we study the effect of an edge dislocation in promoting superfluidity in a Bose crystal. Using Landau theory, we couple the elastic strain field of the dislocation to the superfluid density, and use a linear analysis to show that superfluidity nucleates on the dislocation before occurring in the bulk of the solid. Moving beyond the linear analysis, we develop a systematic perturbation theory in the weakly nonlinear regime, and use this method to integrate out transverse degrees of freedom and derive a one-dimensional Landau equation for the superfluid order parameter. We then extend our analysis to a network of dislocation lines, and derive an XY model for the dislocation network by integrating over fluctuations in the order parameter. Our results show that the ordering temperature for the network has a sensitive dependence on the dislocation density, consistent with numerous experiments that find a clear connection between the sample quality and the supersolid response.Comment: 10 pages, 6 figure

Splitting and merging an elongated Bose-Einstein condensate at finite temperature

We analyze coherence effects during the splitting of a quasi one-dimensional condensate into two spatially separated ones and their subsequent merging into a single condensate. Our analysis takes into account finite-temperature effects, where phase fluctuations play an important role. We show that, at zero-temperature, the two split condensates can be merged into a single one with a negligible phase difference. By increasing temperature to a finite value below the critical point for condensation ($T_c$), i.e., $0 \le T/T_c < 1$, a considerable enhancement of phase and density fluctuations appears during the process of splitting and merging. Our results show that if the process of splitting and merging is sufficiently adiabatic, the whole process is quite insensitive to phase fluctuations and even at high temperatures, a single condensate can be produced.Comment: 8 pages, 6 figure

Metastable bound state of a pair of two-dimensional spatially separated electrons in anti-parallel magnetic fields

We propose a new mechanism for binding of two equally charged carriers in a double-layer system subjected by a magnetic field of a special form. A field configuration for which the magnetic fields in adjacent layers are equal in magnitude and opposite in direction is considered. In such a field an additional integral of motion - the momentum of the pair P arises. For the case when in one layer the carrier is in the zero (n=0) Landau level while in the other layer - in the first (n=1) Landau level the dependence of the energy of the pair on its momentum E(P} is found. This dependence turns out to be nonmonotonic one : a local maximum and a local minimum appears, indicating the emergence of a metastable bound state of two carrier with the same sign of electrical charge.Comment: 7 page

Multilingualism in Immigrant Journalism by Ilya Surguchev

The article focuses on the role of foreign language vocabulary in Ilya Surguchev’s journalism (based on the cycle of “The Paris diary,” 1940-1945). The research urgency is caused by the fact that the language of I. Surguchev’s texts, as the emigrant press language in 1940-ies is still unknown. The factors that influenced the formation of the multi-layered structure of I. Surguchev’s language personality are revealed. The features of foreign words, free and bound collocations, idioms, proverbs, quotations in foreign languages: Latin, French, Italian, English, Ukrainian, Chinese etc., functioning in I. Surguchev’s texts, are considered. Classification of foreign language vocabulary, among which there are regular borrowings (internationalisms, exoticism, proper names, quasi- borrowings, marked borrowing, etc.) and occasional ones (the most striking features of idiostyle of the writer). Etymological information about words in foreign language is given. Attention is paid to the features of I. Surguchev’s translation of foreign-language material into Russian. On the metalinguistic level, I. Surguchev’s evaluation of “foreign word” by a phonosematic criterion is revealed. It is concluded that I. Surguchev’s journalism is characterized by multiculturalism, multilingualism, polyphonism, intertextuality, stylistic convergence. Special attention is paid to the I. Surguchev commitment to the preservation of the values of Russian culture

Effects of perturbative exchanges in a QCD-string model

The QCD-string model for baryons derived by Simonov and used for the calculation of baryon magnetic moments in a previous paper is extended to include also perturbative gluon and meson exchanges. The mass spectrum of the baryon multiplet is studied. For the meson interaction either the pseudoscalar or pseudovector coupling is used. Predictions are compared with the experimental data. Besides these exchanges the influence of excited quark orbitals on the baryon ground state are considered by performing a multichannel calculation. The nucleon-Delta splitting increases due to the mixing of higher quark states while the baryon magnetic momenta decrease. The multichannel calculation with perturbative exchanges is shown to yield reasonable magnetic moments while the mass spectrum is close to experiment.Comment: 37 pages Revtex with 2 figures, to be published in Phys. Atom. Nucl. dedicated to the 70th Birthday of Yu. A. Simono

Особливості ембріо- та морфогенезу яєць трихурисів врх in vitro

One of the main factors hampering the development of livestock is the proliferation of a large number of diseases, both contagious and non-contagious etiology. Parasitic diseases of cattle and, in the first place, helminthiasis occupy a significant proportion of the diseases of contagious etiology. The dominant position among the helminthiasis of the digestive organs in ruminants is nematodosis of the gastrointestinal tract, in particular trichyrosis, the economic losses of which consist of a decrease in the productivity of animals due to the development of inflammatory processes in the thick intestine. Trihuris are geoellimits, which are localized predominantly in the blind and colon of the gastrointestinal tract. Females of the parasite lay eggs, which, with fecal animals, are released into the environment, where they are formed and reaches the invasive stage of the larva. Terms of preinvasive development depend on temperature. At a temperature of 30 ° in the eggs of T. ovis, the larva is formed after 17 days, and at 13–17 ° – after 118 days. At 10 º and below, the development of eggs is suspended, but they remain viable for several months. At temperatures above 38 ° the eggs die. According to U. A. Magometbekova (1953), in eggs of T. skrjabini, which parasitized in sheep, at 25–30 ° an invasive larva can be detected in 44–46 days after the eggs enter the environment. Eggs are bad for drying. The results of cultivation of eggs of T. skrjabini, the females of which parasitized in cattle, in vitro at a temperature of 27 ° for 51 days are given. The features of embryo and morphogenesis of eggs of pathogens during cultivation were studied. From the thick intestine of young cattle, by the method of a complete helminthological section by K.I. Scriabin, sexually mature nematodes were isolated, from which female gonads received immature eggs that were cultivated. It was found that at temperatures of 27 °C eggs T. skrjabini, parasitized in the thick intestine of cattle, pass into the stage of invasive larvae from the 27th day and completely stop their development to 51 days. During the period of cultivation, the length of eggs and caps is increased by 2.0 and 20.0%, the width of eggs and caps is reduced by 2.3 and 3.9%, compared to the cultivars. Reduced egg shell thickness by the 27th day of cultivation (by 2.1%) with a subsequent cessation of changes in this index.Одним із головних факторів, які стримують розвиток скотарства, є розповсюдження значної кількості хвороб як заразної, так і незаразної етіології. Серед хвороб заразної етіології значну питому вагу займають паразитарні хвороби великої рогатої худоби і насамперед – гельмінтози. Домінуюче становище серед гельмінтозів органів травлення у жуйних займають нематодози шлунково-кишкового тракту, зокрема трихуроз, економічні збитки від якого починаються зі зниження продуктивності тварин внаслідок розвитку запальних процесів у товстому відділі кишечнику. Трихуриси – це геогельмінти, які локалізуються переважно в сліпій та ободовій кишках шлунково-кишкового тракту. Самки паразита відкладають яйця, які з фекаліями тварин виділяються у зовнішнє середовище, де в них формується і досягає інвазійної стадії личинка. Строки преінвазійного розвитку залежать від температури. При температурі 30 ° в яйцях Т. ovis личинка формується через 17 днів, а при 13–17 ° – через 118 днів. За температури 10 ° і нижче розвиток яєць призупиняється, але вони декілька місяців залишаються життєздатними. За температури вище 38 º яйця гинуть. Згідно спостережень У.А. Магометбекова (1953), в яйцях Т. skrjabini, які паразитували у овець, при 25–30 º інвазійну личинку можна виявити через 44–46 днів після потрапляння яєць у зовнішнє середовище. Яйця погано переносять висушування. У статті наведені результати культивування яєць Т. skrjabini, самки яких паразитували у великої рогатої худоби, в умовах in vitro при температурі 27 º протягом 51 доби. Вивчено особливості ембріо- та морфогенезу яєць збудників під час культивування. Із товстого відділу кишечнику молодняку великої рогатої худоби методом повного гельмінтологічного розтину за К.І. Скрябіним, були виділені статевозрілі нематоди, з гонад самок яких були отримані незрілі яйця, які були піддані культивуванню. Встановлено, що при температурі 27 ºС яйця Т. skrjabini, що паразитують у товстому відділі кишечнику великої рогатої худоби, переходять в стадію інвазійної личинки з 27 – доби та повністю припиняють свій розвиток до 51 доби. За період культивування довжина яєць та кришечок збільшується на 2,0 та 20,0%, ширина яйця та кришечки зменшується на 2,3 та 3,9% проти показників до культивування. Визначено зменшення товщини оболонки яєць до 27-го дня культивування (на 2,1%) з подальшим припиненням змін цього показника

Luttinger Liquid in the Core of Screw Dislocation in Helium-4

On the basis of first-principle Monte Carlo simulations we find that the screw dislocation along the hexagonal axis of an hcp He4 crystal features a superfluid core. This is the first example of a regular quasi-one-dimensional supersolid, and one of the cleanest cases of a regular Luttinger-liquid system. In contrast, the same type of screw dislocation in solid Hydrogen is insulating.Comment: replaced with revised versio

Adoption of the governmental affordable medicines programme by ukrainians.

Ensuring that the local population has access to medicines is one of the functions of a modern democratic state and an important element of social policy. The question of the affordability of medicines to the public is extremely important. This is also due to the fact that, unlike in European countries, Ukraine did not have a system of medicines reimbursement. To date, the reimbursement Affordable Medicines Programme has been in effect since April 2017 and is applicable to patients with cardiovascular disease, bronchial asthma, and type II diabetes. In total, 258 medicines are included in the Programme, 64 of which can be obtained free of charge and the others with a small extra payment. The respondents' perceptions of the Programme were conducted through a secondary analysis based on the third wave of the «Health Index. Ukraine» which was held in 2018 by the International Renaissance Foundation, the School of Public Health of the National University of Kyiv Mohyla Academy, and the Kyiv International Institute of Sociology. This study aims to present the results of the research of the attitude of Ukrainians to the government Affordable Medicines Programme and their perception of its implementation. The total number of respondents to this survey totaled more than 10,000 household rep­resentatives. The results of the research indicate a positive assessment of the respondents who participated in the survey «Health Index. Ukraine» (76% in 2018), which is confirmed by other research of the Kyiv International Institute of Sociology (63% in 2019) and by international experts. The results of the survey do not allow us to draw any official conclusions about the impact of the Programme on the health of Ukrainians, but during the interview 60.6% of the respondents said that the Programme «helped improve health»; in addition, positive changes in health were indicated by the most financially vulne­rable categories of the population. It is also noted that 80–82% of prescriptions were reimbursed to Programme participants