Morphological Deformities in Anuran Amphibians from the Khoper River Valley in the “Privolzhskaya Lesostep’” Nature Reserve and Adjacent Territories

In summer 2016, we investigated Ostrovtsovskaya Lesostep’ (Penza region, Russia) and caught more than 130 specimens belonging to 4 species of anuran amphibians. We found a symmetric case of “hyperxanthism” of the eyes (a new type of anomaly among amphibians) in one Rana arvalis specimen, one asymmetric amely in Bombina bombina, and 21 specimens of Pelophylax ridibundus (19% of total sample) with deformed fore and hind limbs. We define some anomalies as “Rostand’s anomaly P” (in its extreme manifestations). The potential reasons of the morphological anomalies were discussed

Application of dynamic priorities for controlling the characteristics of a queuing system

This paper considers the development and modification of an imitation model of a queuing system. The initial model uses the laws of control (discipline of expectation and service) with mixed priorities. The work investigates the model with three types of entities (absolute priority, relative priority and priority-free ones) in the regime of overload, i.e. a system with losses. Verification and validation of the created imitation model confirmed its adequateness and accuracy of received results. The application of dynamic priorities for changing the laws of model control substantially alters certain system characteristics. The creation of the model in MatLab Simulink environment with the use of SimEvents and Stateflow library modules allowed creating a fairly complex queuing system and obtain new interesting results

Morphological Deformities in Anuran Amphibians from the Khoper River Valley in the “Privolzhskaya Lesostep’” Nature Reserve and Adjacent Territories

In summer 2016, we investigated Ostrovtsovskaya Lesostep’ (Penza region, Russia) and caught more than 130 specimens belonging to 4 species of anuran amphibians. We found a symmetric case of “hyperxanthism” of the eyes (a new type of anomaly among amphibians) in one Rana arvalis specimen, one asymmetric amely in Bombina bombina, and 21 specimens of Pelophylax ridibundus (19% of total sample) with deformed fore and hind limbs. We define some anomalies as “Rostand’s anomaly P” (in its extreme manifestations). The potential reasons of the morphological anomalies were discussed.We would like to replace old acknowledgements with: “Authors are grateful to A. Dubois, S.N. Litvinchuk and V.L. Vershinin for valuable advices about classification of anomalies. We are thankful to A.N. Dobrolyubov for opportunity to work on the territory of nature reserve «Privolzhskaya Lesostep’».The work was supported by the RFBR (№ 18-04-00640 А, №16-34-00119 and № 15-29-02550) and by the grant of Mari State University (№ 2017-06b from 11.01.2017).

Использование интеллектуальных технологий для анализа чрезвычайных ситуаций на железнодорожном транспорте

Запропоновано використання інтелектуальних технологій для аналізу надзвичайних ситуацій на залізничному транспорті, а також при формуванні рекомендацій керівникам ліквідації швидкоплинних техногенних надзвичайних ситуацій і схеми дій оперативних груп.Use of intellectual technologies is offered for analysis of extraordinary situations on a rail transport and also for formation of recommendations to the supervisors over liquidation of extraordinary fleeting technogenic situations. Charts of actions of the operative teams in such situations are given.Предложено использование интеллектуальных технологий для анализа чрезвычайных ситуаций на железнодорожном транспорте, а также при формировании рекомендаций руководителям ликвидации быстротекущих техногенных чрезвычайных ситуаций и схемы действий оперативных групп

Improvement of Protective Oxide Layers Formed by Highfrequency Plasma Electrolytic Oxidation on Mg-RE Alloy with LPSO-Phase

Received: 17.04.23. Revised: 17.05.23. Accepted: 23.05.23. Available online: 29.05.23.PEO of Mg-RE (LPSO) alloy allows improving its corrosion behaviour and surface mechanical properties.Increase of pulse frequency under PEO allows decreasing the porosity and heterogeneity of the oxide layers.The best corrosion resistance and adhesive strength demonstrate the oxide layer obtained in aluminate electrolyte under high-frequency PEO.Oxide layers on Mg97Y2Zn1 magnesium alloy with strengthening LPSO-phase were formed by plasma electrolytic oxidation (PEO) in bipolar mode with frequency variation of forming current pulses (50 and 500 Hz) and addition of sodium aluminate or sodium silicate to alkali phosphate fluoride electrolyte. Microstructure, chemical and phase composition, corrosion and mechanical properties of the oxide layers formed were investigated. With increasing current frequency for both electrolytes, an increase in homogeneity of the oxide layers structure and a decrease in their porosity and fracturing at constant thickness were recorded. The oxide layers formed at 500 Hz even with some decrease in hardness have better adhesive strength and 2 orders of magnitude higher short-term corrosion resistance values. PEO of Mg-alloy with LPSO-phase in the electrolyte with addition of sodium aluminate in combination with increased pulse frequency (500 Hz) allows forming the best-quality uniform oxide layer with high hardness, adhesive strength and corrosion resistance properties. The use of electrolyte with addition of sodium silicate reduced the adhesive strength by 1.5 times and brought down the long-term corrosion resistance of oxide layers by an order of magnitude, as compared with the electrolyte with sodium aluminate. The reason for a significant improvement in the complex of protective properties of the oxide layers with an increase in the current pulse frequency is supposed to be a decrease in the power and duration of individual microarc discharges with simultaneous increase in their number per unit oxidized area.Financial support is provided by the Russian Science Foundation (grant No. 20-79-10262), https://rscf.ru/project/20-79-10262/

Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Oxide layers on Mg97Y2Zn1 magnesium alloy with strengthening LPSO-phase were formed by plasma electrolytic oxidation (PEO) in bipolar mode with frequency variation of forming current pulses (50 and 500 Hz) and addition of sodium aluminate or sodium silicate to alkali phosphate fluoride electrolyte. Microstructure, chemical and phase composition, corrosion and mechanical properties of the oxide layers formed were investigated. With increasing current frequency for both electrolytes, an increase in homogeneity of the oxide layers structure and a decrease in their porosity and fracturing at constant thickness were recorded. The oxide layers formed at 500 Hz even with some decrease in hardness have better adhesive strength and 2 orders of magnitude higher short-term corrosion resistance values. PEO of Mg-alloy with LPSO-phase in the electrolyte with addition of sodium aluminate in combination with increased pulse frequency (500 Hz) allows forming the best-quality uniform oxide layer with high hardness, adhesive strength and corrosion resistance properties. The use of electrolyte with addition of sodium silicate reduced the adhesive strength by 1.5 times and brought down the long-term corrosion resistance of oxide layers by an order of magnitude, as compared with the electrolyte with sodium aluminate. The reason for a significant improvement in the complex of protective properties of the oxide layers with an increase in the current pulse frequency is supposed to be a decrease in the power and duration of individual microarc discharges with simultaneous increase in their number per unit oxidized area

Скелетная изомеризация гептанов в присутствии суперкислотных катализаторов различной природы

The sequence of the formation of multi-branched heptane isomers was studied in liquid and gaseous phases over different liquid and solid superacid catalysts. It was found that this sequence does not depend on the phase state, catalyst nature, and conditions, evidencing in favor of common reaction mechanism. The 2,4-dimethylpentane transformation into 2,2-dimethylpentane can be explained by the intermediate formation of cyclobutyl carbocation.Экспериментально изучена последовательность образования разветвленных изомеров при превращении н-гептана в жидкой и газовой фазах под действием различных жидких и твердого суперкислотных катализаторов. Найдено, что эта последовательность не зависит от фазового состояния, природы катализаторов и условий, что свидетельствует об общем механизме реакции. Превращение 2,4-диметилпентана в 2,2-диметилпентан можно объяснить промежуточным образованием циклобутильного карбкатиона

Tales of future weather

Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like

Влияние нейроаксиального блока на изменения гемодинамики у рожениц

The results of the multicentric study on «The safety of the spinal anesthesia during the caesarean section» describing the analysis of the hemodynamic changes due to neuroaxial block in parturients were presented. Thirteen clinics participated in the study. The volume of the sampling includes 2228 spinal anesthesia protocols. The study results confirm the consistency of some well-known regulations and standards of the safe performance of spinal anesthesia. Moreover, the following facts were revealed: the preinfusion during the spinal anesthesia does not have a preventive effect on arterial hypotension; the increase of the infusion volume results in elevating of the arterial hypotension frequency during spinal anesthesia; the bandaging of the lower extremities is a serious measure to prevent the hemodynamic complications; the application of 6% pentastarch solution for the postin-fusion is an effective method to prevent the arterial hypotension during spinal anesthesia for the cesarean section.Представлены результаты мультицентрового исследования «Безопасность спинномозговой анестезии во время операции кесарева сечения», относящиеся к изучению изменений гемодинамики у рожениц под влиянием нейроаксиального блока. В исследовании приняло участие 13 клиник. Объем изучаемой выборки составил 2228 протоколов спинномозговой анестезии. Результаты исследования подтвердили состоятельность ряда общеизвестных положений и стандартов безопасности проведения спинномозговой анестезии. Кроме того, было выявлено, что преинфузия при спинномозговой анестезии в акушерстве не оказывает профилактического действия в отношении артериальной гипотонии; увеличение объема преинфузии способствует повышению частоты случаев артериальной гипотонии во время спинномозговой анестезии; бинтование нижних конечностей является серьезной мерой профилактики гемодинамических осложнений; применение 6% раствора пентакрахмала в качестве постинфузии является эффективным методом профилактики артериальной гипотонии при спинномозговой анестезии операций кесарева сечения

Влияние состава бинарного растворителя CH3CN-H2O на кинетику окисления циклогексена п-бензохиноном в растворах катионных комплексов палладия(II)

During the study of cyclohexene oxidation by p-benzoquinones into cyclohexanone in water-organic solutions of cationic complexes of palladium(II) it was demonstrated that the initial reaction rate R0 depends complicatedly on water molar fraction for three studied solvents: acetonitrile (AN), dimethylformamide, and dimethylsulfoxide. In order to explain the obtained bimodal dependence for the example of AN-water system, modeling of phase equilibrium in the studied system was performed. The existence of two- and three-phase immiscibility areas as well as a three-component heteroazeotrope was found. By UV spectroscopy it was stated that varying of water molar fraction in the binary solvent substantially changes the state of starting cationic complexes [Pd(АН)x(H2O)4-x]2+. For mathematical description of medium effect on R0 value three models were proposed taking into account different factors, such as: a) physico-chemical properties of binary solvent; b) composition of possible associates AN-water; c) composition of starting [Pd(АН)x(H2O)4-x]2+ complexes. The adequate description of bimodal dependency was obtained in the model considering the changes of [Pd(АН)x(H2O)4-x]2+ complexes composition with simultaneous presence of an associate of (АН)2(H2O) composition.В ходе изучения кинетики окисления циклогексена п-бензохиноном до циклогексанона в водно-органических растворах катионных комплексов палладия(II) показано, что начальная скорость реакции R0 сложным образом зависит от мольной доли воды для трех изученных растворителей: ацетонитрил (АН), диметилформамид и диметилсульфоксид. На примере системы ацетонитрил-вода проведено моделирование фазовых равновесий в исследуемой системе, позволившее выявить наличие областей двух- и трехфазного расслаивания, а также трехкомпонентного гетероазеотропа. Методом УФ-спектроскопии установлено, что изменение мольной доли воды в бинарном растворителе существенно меняет состояние исходных катионных комплексов [Pd(АН)x(H2O)4-x]2+. Для математического описания эффектов влияния среды на величину R0 предложены три модели, учитывающие такие факторы, как: а) физико-химические свойства бинарного растворителя, б) состав возможных ассоциатов ацетонитрил-вода, в) состав исходных комплексов Pd(II). Адекватное описание бимодальной зависимости получено в рамках модели, рассматривающей изменение состава комплексов [Pd(АН)x(H2O)4-x]2+ с одновременным присутствием ассоциата состава (АН)2(H2O)