Polystyrene-based nanocomposites with different fillers: fabrication and mechanical properties

The paper presents a comprehensive analysis of elastic properties of polystyrene-based nanocomposites filled with different types of inclusions: small spherical particles (SiO2 and Al2O3), alumosilicates (montmorillonite, halloysite natural tubules and Mica) and carbon nanofillers (carbon black and multi-walled carbon nanotubes). Composites were fabricated by melt technology. The analysis of composite melts showed that the introduction of Montmorillonite, Multi-walled carbon nanotubes, and Al2O3 particles provided an increase in melt viscosity by an average of 2 to 5 orders of magnitude over the pure polystyrene. Block samples of composites with different filler concentrations were prepared, and their linear and nonlinear elastic properties were studied. The introduction of more rigid particles led to a more profound increase in the elastic modulus of the composite, with the highest rise of about 80% obtained with carbon fillers. Carbon black particles provided also an enhanced strength at break of about 20% higher than that of pure polystyrene. The nonlinear elastic moduli of composites were shown to be more sensitive to addition of filler particles to the polymer matrix than the linear ones. The nonlinearity coefficient $\beta$ comprising the combination of linear and nonlinear elastic moduli of a material demonstrated considerable changes correlating with changes of the Young's modulus. The absolute value of $\beta$ showed rise in 1.5-1.6 times in the CB- and HNT-containing composites as compared to that of pure PS. The changes in nonlinear elasticity of fabricated composites were compared with measurements of the parameters of bulk nonlinear strain waves in them. Variations of wave velocity and decay decrement correlated with observed enhancement of materials nonlinearity

«Зеленое» финансирование и ESG: возможность для устойчивого социально-экономического развития

The implementation of the sustainable development strategy and the formation of a “green” economy model provide for the reorientation of financial resources, accounting by economic entities and public authorities and management of ESG-principles and the development of “green” financing tools.The purpose of the paper is to develop theoretical provisions and modeling of the impact of “green” financing on the socio-economic development of the subjects of the Russian Federation.Methods of data mining were used with temporary delays and corresponding lags responses of endogenous indicators, as well as cluster and correlation analysis. The result of the study was the specification of the economic content of the definition of “green” financing, as well as the construction of econometric models of the degree of interrelationship between “green” financing and the socio-economic development of the regions of Russia. The authors described the economic content of the definition of “green” financing, developed econometric models of the degree of interdependence of “green” financing and socioeconomic growth of Russia’s regions, calculated an integral indicator of sustainable socio-economic development of the regions of the Russian Federation taking into account ESGfactors (social risks, environmental risks, quality of management). Clustering of Russian regions according to the level of influence of “green” financing on their socio-economic development has also been carried out.The article concludes that the relationship between the level of socio-economic development of the regions of the Russian Federation and the volume of “green” financing is direct, strong, and can be expressed by increasing linear regression. The prospects for further research may be related to the assessment of the real needs of the volumes of “green” financing in the context of ensuring sustainable economic growth.Реализация стратегии устойчивого развития и формирование модели «зеленой» экономики предусматривают переориентацию финансовых ресурсов, учет хозяйствующими субъектами и органами государственной власти и управления ESG-принципов и развитие инструментов «зеленого» финансирования.Цель работы —  развитие теоретических положений и моделирование влияния «зеленого» финансирования на социально-экономическое развитие субъектов Российской Федерации.Использованы методы интеллектуального анализа данных с учетом временных запаздываний и соответствующих лаговых откликов эндогенных показателей, а также кластерный и корреляционный анализ. Авторы конкретизировали экономическое содержание дефиниции «зеленое» финансирование, построили эконометрические модели степени взаимосвязи «зеленого» финансирования и социально-экономического развития регионов России, рассчитали интегральный показатель устойчивого социально-экономического развития регионов РФ с учетом ESG-факторов (социальные риски, экологические риски, качество управления). Также осуществлена кластеризация регионов России по уровню влияния «зеленого» финансирования на их социально-экономическое развитие.Сделан вывод о том, что связь между уровнем социально-экономического развития регионов РФ и объемом «зеленого» финансирования —  прямая, сильная, может быть выражена возрастающей линейной регрессией. Перспективы дальнейших исследований могут быть связаны с оценкой реальных потребностей объемов «зеленого» финансирования в контексте обеспечения устойчивого экономического роста

Strawberry resistance to the major fungal phytopathogens: R-genes and their DNA markers

The garden strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier (1785) is a perennial herbaceous plant of the Rosaceae family; it is cultivated all around the world. It accounts for more than half of the global volume of berries production. In Russia, more than 160 tons of garden strawberries are grown annually, but according to Russian scientists, this crop has a much higher productivity potential. Various pathogens, including bacterial, viral and fungal infections, negatively affect the productivity of strawberry. Anthracnose (caused by Colletotrichum Corda.), crown rot (Phytophthora cactorum Lebert & Cohn), red core disease (Phytophthora fragariae var. fragariae Hickman), fusarium wilt (Fusarium oxysporum f. sр. fragariae Winks & Williams ) and strawberry powdery mildew (Podosphaera aphanis [Sphaerotheca macularis] (Wallr.) U. Braun & S. Takam) are among the most important fungal diseases of strawberry. This review discusses the current data about the known genes and quantitative trait loci (QTLs) associated with resistance to listed plant pathogens. The review also offers information about molecular markers of different types: SDRF, AFLP, SSR, SCAR, SNP, associated with these genes/QTLs and used in the molecular screening of strawberry collections for practical purposes

Directions to improve economic efficiency of regional production

The paper provides theoretical grounding and the directions for improving the economic efficiency of the regional feedstuff production. The study develops a conceptual model of distributing management functions of feedstuff production between the regional authorities of state sectoral and economic management and the district level. The authors suggest the methodology for calculating potential capacity of intraregional feedstuff market, considering the demands of all categories of agricultural manufacturers. The study examines possibilities for implementing the strategy of diversified growth and development of the intraregional feedstuff market, including the terms of interaction between the large and micro-business inside the industry and cooperation of micro-business feedstuff manufacturers with agricultural production. The authors have developed the methodology for assessing the efficiency of feedstuff production, based on the aggregate estimation of the management organization, conditions for the development of feedstuff production and changes in the feedstuff production and livestock breeding industry.peer-reviewe

Molecular screening of the VIR strawberry varieties collection for the presence of a marker for the anthracnose black rot resistance gene <i>Rca2</i>

Background. Anthracnose black rot caused by the phytopathogenic fungus Colletotrichum acutatum Simmonds became an extremely harmful disease of strawberries in Southern Russia. The disease is widespread throughout the world, and relatively recently it appeared in Russia. Yield losses due to the disease reach up to 80%; besides, the pathogen causes significant plant losses in mother plantations. The most reliable protection against the pathogen is the cultivation of resistant varieties. In strawberries, resistance is controlled by different genes, including Rca2. To identify this gene, molecular markers STS_Rca2_240 and STS-Rca2_417 have been developed. The purpose of this study was to use the markers for screening the VIR collection of strawberry varieties at the VIR Maikop Experiment Station (Maikop ES VIR). Material and methods. The present work studied 135 varieties of Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier, 83 domestic and 52 foreign ones. The domestic varieties included 17 created at the Maikop ES. Plants were evaluated for anthracnose field resistance in the Republic of Adygea from 2018 to 2021. Molecular screening was performed using STS_Rca2_240 and STS-Rca2_417, the molecular markers closely linked to the Rca2 gene. Microsatellite primers EMFv020 were used to control the PCR. The cultivar ‘Sudarushka’, in which the presence of STS_Rca2_240 marker was described in the literature, served as a positive control. Results and discussion. The marker Rca2_240 was detected in 22 cultivars from 135 studied. Among domestic varieties, the frequency of the marker was 18.1%, while among the foreign varieties it was slightly lower and amounted to 13.0%. Among the 17 varieties created at the Maykop SE, the marker was found in three: ‘Majkopskaya rannyaya’, ‘Peryt’, and ‘Shapsugskaya’. The association of the diagnostic fragment with resistance was 73.0%. The marker efficiency was not very high due to the significant number of resistant varieties which do not generate the diagnostic fragments. The resistance in such varieties can be provided by other genes, for example, FaRCa1. The STS-Rca2_417 marker was not effective during screening. Conclusion. Twenty-two varieties with the STS_Rca2_240 marker were identified in the VIR collection, maintained at the Maykop ES VIR, 16 of which were resistant to C. acutatum. These varieties represent a valuable breeding material. The STS-Rca2_240 marker can be used as an important diagnostic trait for the certification of varieties

Моделювання сейсмічної реакції прошарку ґрунту в рамках нелокальної моделі суцільного середовища

According to modern research, the seismic risks of the destruction of buildings and constructions depend not only on the proximity of their location to the earthquake epicenters, but also on the reaction of soil massifs lying beneath them. Particularly important is the proportionality of the set of resonant frequencies of the soil massif and the natural frequencies of the objects located on it. It is well known that soils are rheologically complex media that cannot be described in terms of simple mathematical models. This stimulates to develop new or to modify already known models. To describe the dynamics of a heterogeneous soil massif, the model, which is a spatially nonlocal generalization of the linear Kelvin-Voigt model, is used. The work purpose is to estimate the response of the soil layer to shear strain when the soil massif is characterized by significant heterogeneity. Based on the boundary value problem solution describing standing waves in a soil layer, the dependence of the amplification of wave amplitude at the layer surface on the harmonic disturbance frequency applied to the underlying bedrock is derived. It is shown that the model describes the damping of oscillations at high frequencies and the shift of resonant frequencies towards lower frequencies. To evaluate these effects, the length of the frequency interval containing the main of the spectrum is investigated on the basis of asymptotic analysis methods. Conclusions about the influence of soil heterogeneity on its resonance properties are formulated by means of comparative analysis of the results obtained in the framework of the classical Kelvin-Voigt model and its nonlocal generalization. The proposed approach of soil layer response analysis is promising for practical use in seismic microzoning.Согласно современным исследованиям, сейсмические риски разрушения зданий и сооружений зависят не только от близости их расположения к эпицентрам землетрясений, но и от реакции грунтовых массивов, которые под ними залегают. Особенно важна соизмеримость набора резонансных частот грунтового массива и собственных частот расположенных на нем объектов. Известно, что почвы являются реологически сложными средами, которые невозможно описать в рамках простых математических моделей, поэтому возникает необходимость разработки новых или модификации уже известных моделей. Для описания динамики неоднородного грунтового массива применена модель, которая является пространственно нелокальным обобщением линейной математической модели Кельвина-Фойгта. Цель работы — оценка реакции слоя грунта на сдвиговое деформирование, когда грунтовый массив характеризуется существенной неоднородностью. На основе решения краевой задачи для грунтового слоя в форме стоячих волн построена зависимость коэффициента усиления амплитуды волны на поверхности слоя от частоты гармонического возмущения, приложенного к подошве массива. Показано, что модель описывает затухание колебаний на высоких частотах и сдвиг резонансных частот в низкочастотную область. Для оценки этих эффектов на основе методов асимптотического анализа исследована длина частотного интервала, который содержит основную часть спектра. Выводы о влиянии неоднородности грунта на его резонансные свойства сформулированы с помощью сравнения результатов, полученных в рамках классической модели Кельвина-Фойгта и ее нелокального обобщения. Предложенный подход анализа отклика слоя грунта перспективен для практического использования в инженерном деле, при проведении работ по сеймическому микрорайонированию.Згідно із сучасними дослідженнями, сейсмічні ризики руйнування будівель і споруд залежать не тільки від близькості їх розташування до епіцентрів землетрусів, а також від реакції ґрунтових масивів, які під ними залягають. Особливо важливим є співмірність набору резонансних частот ґрунтового масиву та власних частот розташованих на ньому об’єктів. Відомо, що ґрунти є реологічно складними середовищами, які неможливо описати в рамках простих математичних моделей, тому виникає необхідність розробки нових чи модифікації вже відомих моделей. Для опису динаміки неоднорідного ґрунтового масиву застосовано модель, яка є просторово нелокальним узагальненням лінійної математичної моделі Кельвіна-Фойгта. Метою роботи є оцінювання реакції прошарку ґрунту на зсувне деформування, коли ґрунтовий масив суттєво неоднорідний. На основі розв’язку крайової задачі для ґрунтового прошарку у формі стоячих хвиль побудовано залежність коефіцієнта підсилення амплітуди хвилі на поверхні прошарку від частоти гармонічного збурення, прикладеного до підошви масиву. Показано, що модель описує затухання коливань на високих частотах та зсув резонансних частот у низькочастотну область. Для оцінювання цих ефектів на основі методів асимптотичного аналізу досліджено довжину частотного інтервалу, який містить основну частину спектра. Висновки щодо впливу неоднорідності ґрунту на його резонансні властивості сформульовано шляхом аналізу результатів, отриманих у рамках класичної моделі Кельвіна-Фойгта та її нелокального узагальнення. Запропонований підхід аналізу відгуку прошарку ґрунту є перспективним для практичного використання в інженерній справі, при проведенні робіт із сейсмічного мікрорайонування

Research of Influence of Elements of Yoga on Flexibility and Health of Dancers at the Initial Stage of Enablement

The article considers the possibility of using yoga elements to increase the flexibility of children engaged in dancing. Yoga is now widely used in sports. The effect is noticeable in such disciplines as swimming, running and biking. We did not find any work to study the effectiveness of yoga in dancers. Experimental studies have shown not only the effectiveness of using yoga in the process of stretching dancers, but also the positive effect of asana on the health indicators of the people involved.В статье рассматривается возможность применения элементов йоги для повышения гибкости у танцоров первого года обучения. Йога в настоящее время находит широкое применение в спорте. Эффект заметен в таких дисциплинах, как плавание, бег и велосипедный спорт. Работ по изучению эффективности йоги у танцоров нами обнаружено не было. Экспериментальное исследование позволило выявить не только эффективность использования йоги в процессе растяжки танцоров, но и положительное влияние асан на показатели здоровья занимающихся

Antioxidant defense system: regulation of metabolic processes, genetic determinants, methods of determination

An increase in peroxidation activity is considered as a nonspecific process characteristic of the pathogenesis of various diseases accompanied by antioxidant deficiency. As bioregulators that can increase defense, antioxidants are important links in a multi-stage system of regulation and coordination of various body functions. The structure and function of enzymes involved in the regulation of oxidative stress can be significantly affected by genetic polymorphism. To date, the role of genes encoding the activity of enzymes of the antioxidant system in the pathogenesis of many diseases remains unexplored, which is of great interest to researchers from various fields. The article presents a review and analysis of data from modern scientific literature on the role of antioxidant defense components in the regulation of metabolic processes, their genetic determinant, and summarizes data on modern methods for the determination of some antioxidants. When writing the review, the database of the scientific electronic library eLibrary was used, the keywords are oxidative stress, free radical oxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, antioxidant response element, research methods; filters – publication years 2012–2022, publications with full text, publications available for viewing; English-language database of medical and biological publications, created by the National Center for Biotechnology Information (NCBI), keywords – lipid peroxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, oxidative stress, metabolism, methods