Anisotropic Exchange in LiCu2O2{\bf LiCu_2O_2}

We investigate the magnetic properties of the multiferroic quantum-spin system LiCu$_2$O$_2$ by electron spin resonance (ESR) measurements at $X$- and $Q$-band frequencies in a wide temperature range $(T_{\rm N1} \leq T \leq 300$\,K). The observed anisotropies of the $g$ tensor and the ESR linewidth in untwinned single crystals result from the crystal-electric field and from local exchange geometries acting on the magnetic Cu$^{2+}$ ions in the zigzag-ladder like structure of LiCu$_2$O$_2$. Supported by a microscopic analysis of the exchange paths involved, we show that both the symmetric anisotropic exchange interaction and the antisymmetric Dzyaloshinskii-Moriya interaction provide the dominant spin-spin relaxation channels in this material.Comment: 10 pages, 10 Figure

Pension System as Wellbeing Institute

The article proves that it is possible to achieve wellbeing if there is an improvement of both the pension system and change in the citizen’s attitude towards retirement income. The calculations (dynamics of the percentage of the working retirees, both in Russia and TPU, and the average salary) show that the increase in the ratio of the number of retirees and working people can’t lead to the deficit of the budget of the Russian Pension Fund. It is proved that the key way to overcome the deficit is to remove payments, which are not or little connected with earned income (disability and loss of a breadwinner pension, long service pension, and early retirement pension) and save only one function – compensation for loss of earnings. Refusal of the territorial rent (pension’s peg to the minimum of subsistence of a retiree in the region) will also balance the financial state of the Pension Fund. It is mathematically proved that the wellbeing of retirees can be reached if they participate in the compulsory and voluntary pension insurance programs, which are not necessary governmental

Anisotropic Exchange in LiCuVO4_4 probed by ESR

We investigated the paramagnetic resonance in single crystals of LiCuVO$_4$ with special attention to the angular variation of the absorption spectrum. To explain the large resonance linewidth of the order of 1 kOe, we analyzed the anisotropic exchange interaction in the chains of edge-sharing CuO$_6$ octahedra, taking into account the ring-exchange geometry of the nearest-neighbor coupling via two symmetric rectangular Cu-O bonds. The exchange parameters, which can be estimated from theoretical considerations, nicely agree with the parameters obtained from the angular dependence of the linewidth. The anisotropy of this magnetic ring exchange is found to be much larger than it is usually expected from conventional estimations which neglect the bonding geometry. Hence, the data yield the evidence that in copper oxides with edge-sharing structures the role of the orbital degrees of freedom is strongly enhanced. These findings establish LiCuVO$_4$ as one-dimensional compound at high temperatures. PACS: 76.30.-v, 76.30.Fc, 75.30.EtComment: 18 pages, 6 figure

“LITERARY LIVING ROOM” AS A FORM OF WORK ON THE HARMONIZATION OF FAMILY RELATIONSHIPS

The article substantiates the need to create conditions for the development of higher mental functions, emotional and volitional sphere, creative potential of preschoolers, and correction of child-parent relations. One of the forms of interaction between teachers and parents of preschool children is presented. The conclusion is made about the need for psychological and pedagogical support, the formation of students’ reading taste, the development of speech.В статье обоснована необходимость создания условий для развития высших психических функций, эмоционально-волевой сферы, творческого потенциала дошкольников, коррекции детско-родительских отношений.Представлена одна из форм взаимодействия педагогов и родителей детей дошкольного возраста. Сделан вывод о необходимости психолого- педагогического сопровождения, формирования у воспитанников читательского вкуса, развития речи

Adaptation of the sulfophosphovanillin method of analysis of total lipids for various biological objects as exemplified by <i>Drosophila melanogaster</i>

Lipid metabolism is crucial in physiology. In recent decades the model object Drosophila melanogaster has been actively used in the study of the fundamental issues of lipid metabolism and its disorders, including obesity, as well as in the search for therapeutic goals for the treatment of metabolic disorders in humans. Quick and accurate quantification of lipid content is an important step in solving these problems. For the first time the method of quantitative measurement of total lipids with the use of the sulfophosphovanillin (SPV) method was described by Zöllner and colleagues in 1962, and adapted for insects by Van Handel on females of the yellow fever mosquito Aedes aegypti. The advantages of this method compared to traditional gravimetric and chromatographic methods of analysis are the use of a small amount of biological material, lack of need for complex manipulations with the sample, its high sensitivity, reproducibility and simplicity of implementation with a minimum set of equipment. Here, a modification of the Van Handel protocol is described, which allows the method to be adapted for quantitative determination of total lipids for various organisms as exemplified a widely used model, D. melanogaster. To test the effectiveness of the modified method, we measured the content of total lipids in D. melanogaster females carrying hypomorphic mutations of the dilp6 and dfoxo insulin signaling pathway genes compared to the wild-type Canton-S line, and showed that dilp6 took part in the regulation of fat metabolism, while dfoxo did not. The results obtained emphasize the effectiveness of the colorimetric method with the use of SPV reaction and spectrophotometry for the quantitative analysis of total lipids

The neuroendocrine stress-response in insects: the history of the development of the concept

The neuroendocrine stress-response is an effective defense mechanism against adverse influences of various nature. This reaction is universal and appears in response to stimuli that are unusual not just for living and habitat of the species, but also for each population. Here we review a progressive change of theoretical concepts, approaches and methods of research in this scientific field: beginning with the development of the stress concept by H. Selye and up to the present day. In 1982 H. Selye defined stress as a combination of stereotypical phylogenetic programmed  reactions of the organism that are caused by any strong, superstrong or extreme influences and are followed by a reorganization of the organism’s adaptive forces. The stress-causing agent was named a stressor. In the dy namics of the complex of nonspecific protectiveadaptive reactions that respond to a stressful influence aimed at cultivating the organism’s resistance to any factor, it is possible to logically identify three stages (“the Selye triad”): 1) alarm state, 2) resistance state, 3) exhaustion state. The duration and the expression of each stage can vary depending on the nature and strength of the stressor agent, the species of the animal and the physiological state of the organism. The lack of a hypothalamic-pituitary-adrenocortical system in insects was considered a proof of their inability to develop a stress reaction of the warm-blooded animals’ type. Nevertheless, since the early 1980s, enough evidence of the development of stress reaction in insects has been gathered, which emphasizes the conservative nature of the stress reaction in mammals and insects. The similarity in the neurochemical and physiological changes in invertebrates and vertebrates in response to a stressful influence indicates that the response to a stressor is a complex of ancient mechanisms preserved in evolution. Insects present unique opportunities for experimentation, which can allow us to understand the basic mechanisms of stress reactions. In insect larvae the mechanism of stress reaction has been studied in detail. In this century, the main efforts of researchers are aimed at studying the mechanisms of stress reaction in imago and genetic control of its individual links. The study of stress reaction in insects has both theoretical importance, as it demonstrates the convergence of evolutionary pathways of adaptive transformations in such distant taxa as insects and mammals, and practical importance, since the patterns of this reaction’s mechanisms can be used in modeling hereditary or acquired human diseases, in developing breeding methods for economically valuable insects and in finding ways to fight insect pest

Pedagogical dialogue: cognitive strategies of philological education in Russia and abroad

The article presents an overview of an International scientific and pedagogical forum "The Image of Russia in global educational space: language, history, culture", which was held on May 23-26 2019 at Ural State Pedagogical University (Russia, Yekaterinburg) and Jilin University of international studies (China, Changchun).В статье представлен обзор Международного научно-педагогического форума "Образ России в глобальном образовательном пространстве: язык, история, культура", который был проведен с 23 по 26 мая 2019 года в Уральском государственном педагогическом университете (Россия, Екатеринбург) и Цзилиньском университете международных исследований (Китай, Чанчунь)

Electron spin resonance and exchange paths in the orthorhombic dimer system Sr2VO4

We report on magnetization and electron spin resonance (ESR) measurements of Sr$_{2}$VO$_4$ with orthorhombic symmetry. In this dimer system the $V^{4+}$ ions are in tetrahedral environment and are coupled by an antiferromagnetic intra-dimer exchange constant $J/k_B \approx$ 100 K to form a singlet ground state without any phase transitions between room temperature and 2 K. Based on an extended-H\"{u}ckel-Tight-Binding analysis we identify the strongest exchange interaction to occur between two inequivalent vanadium sites via two intermediate oxygen ions. The ESR absorption spectra can be well described by a single Lorentzian line with an effective g-factor $g$ = 1.89. The temperature dependence of the ESR intensity is well described by a dimer model in agreement with the magnetization data. The temperature dependence of the ESR linewidth can be modeled by a superposition of a linear increase with temperature with a slope $\alpha$ = 1.35 Oe/K and a thermally activated behavior with an activation energy $\Delta/k_B$ = 1418 K, both of which point to spin-phonon coupling as the dominant relaxation mechanism in this compound.Comment: 5 pages, 4 figure