Environmental and climatic factors influencing the distribution of sub-fossil cladocerans in thermokarst lakes in northeastern Siberia, Russia

Surface sediments of thermokarst lakes along the temperature gradient were sampled in northwestern Siberia. The lakes were distributed through three environmental zones: typical tundra, southern tundra and forest-tundra, which were all situated within the continuous permafrost zone. Our investigation showed that the cladoceran communities in the lakes of the region are represented by diverse, abundant communities as reflected by the taxonomic richness and high diversity indices. The differences in the cladoceran assemblages were related to the limnological and geographical position, vegetation type, climate and water chemistry. The constrained redundancy analysis (RDA) indicated that the TJuly, water depth and both sulphate (SOf ~) and silicium (Si4*) concentrations statistically significant (p < 0.05) explained the variance in the cladoceran assemblage

Готовность педагогов организаций общего образования к оказанию первой помощи в случаях остановки сердца

RELEVANCE The problem of sudden cardiac arrest and sudden death among the students of educational institutions is highly relevant for the Russian Federation. In order to plan interventions aimed at improving effectiveness of management and reducing mortality from cardiac arrest in educational institutions, a clear understanding of level of readiness and motivation of teachers to provide help to a cardiac arrest victim is necessary.  AIM OF STUDY To evaluate willingness of teachers of general education institutions to provide cardiopulmonary resuscitation (CPR) in cases of cardiac arrest, and to investigate factors and relationships that determine readiness of teachers to give help.  MATERIAL AND METHODS In February–March 2021, an online questionnaire survey of teaching staff of general education institutions was conducted in the Republic of Crimea. As part of the survey, respondents were asked to evaluate their willingness to attempt CPR on a loved one, a stranger or a pupil on a five-point Likert scale, and to indicate potential barriers for performing CPR. The survey was voluntary and anonymous.  RESULTS The questionnaire was completed by 5,921 teachers. Of all respondents, 9.2% were males, 31.6% — aged over 50 years, 32.3% — work in urban areas. The proportion of teachers who expressed absolute willingness to perform CPR on a loved one, a stranger or a pupil was 63.6% (n=3,766), 34.8% (2,058) and 41.0% (2,427), respectively. At the same time, 13.6% (804), 31.0% (1,836) and 30.6% (1,809), respectively, indicated that they would probably not or definitely not attempt CPR. A high readiness to perform resuscitation (4–5 points) was confirmed to be associated with previous CPR training (p&lt;0.001) and with higher level of CPR knowledge (p≤0.006). The main barriers to providing resuscitation were “lack of CPR knowledge and skills” (indicated by 31.4–36.3% of the respondents depending on the type of presumed cardiac arrest victim) and “fear of causing harm to a victim” (49.2–51.4%).  CONCLUSION Considerable portion of teachers of general education institutions demonstrate low level of readiness to provide life-saving help in case of cardiac arrest. Lack of CPR knowledge and skills constitute the main barrier to attempting resuscitation. In order to improve survival from cardiac arrest in educational institutions, comprehensive organisational interventions are required, which should primarily focus on ensuring full coverage of teachers with high-quality training and retraining in resuscitation. АКТУАЛЬНОСТЬ Проблема внезапной остановки сердца и смерти учащихся и воспитанников образовательных учреждений Российской Федерации сохраняет высокую актуальность. Для планирования мер, направленных на повышение эффективности оказания помощи и снижение летальности при остановке сердца в учреждениях образования, требуется ясное представление об уровне готовности и мотивации педагогических работников к оказанию первой помощи.  ЦЕЛЬ Оценить готовность педагогических работников организаций общего образования к оказанию первой помощи в случаях остановки сердца, изучить факторы и зависимости, определяющие готовность педагогов к оказанию помощи.  МАТЕРИАЛ И МЕТОДЫ В феврале–марте 2021 года проведено онлайн-анкетирование педагогических работников организаций общего образования Республики Крым. В рамках опроса респонденты оценивали по пятибалльной шкале Likert собственную готовность к проведению сердечно-легочной реанимации (СЛР) при остановке сердца у близкого человека, незнакомого человека и обучающегося и указывали потенциальные препятствия для проведения СЛР. Участие в анкетировании было анонимным и добровольным.  РЕЗУЛЬТАТЫ Онлайн-анкету заполнил 5921 респондент. Из них мужчин — 9,2%, лиц старше 50 лет — 31,6%, работающих в городе — 32,3%. Доля педагогов, выразивших абсолютную готовность к проведению СЛР при остановке сердца у близкого человека, незнакомого человека или обучающегося, составила соответственно 63,6% (n=3766), 34,8% (2058) и 41,0% (2427). При этом соответственно 13,6% (804), 31,0% (1836) и 30,6% (1809) указали, что скорее не будут или точно не будут проводить реанимацию. Подтверждена связь высокой готовности (4–5 баллов) к проведению СЛР с предшествующим обучением реанимации (p&lt;0,001) и более высоким уровнем соответствующих знаний (p≤0,006). Основными препятствиями для оказания помощи при остановке сердца определены «недостаток знаний и навыков реанимации» (указали 31,4–36,3% опрошенных в зависимости от того, кем являлся предполагаемый пострадавший) и «боязнь причинить вред пострадавшему» (49,2–51,4%).  ЗАКЛЮЧЕНИЕ Значительная доля педагогов организаций общего образования имеет низкий уровень готовности к оказанию первой помощи в случае остановки сердца. Недостаток знаний и навыков сердечно-легочной реанимации выступает одним из ключевых препятствий для оказания помощи. Для повышения эффективности оказания помощи в случаях остановки сердца в образовательных учреждениях требуются комплексные организационные преобразования в системе первой помощи, приоритетом которых является обеспечение полного охвата педагогов качественным и регулярным обучением теоретическим основам и навыкам базовой сердечно-легочной реанимации.

Adenine and guanine recognition of stop codon is mediated by different N domain conformations of translation termination factor eRF1

Positioning of release factor eRF1 toward adenines and the ribose-phosphate backbone of the UAAA stop signal in the ribosomal decoding site was studied using messenger RNA (mRNA) analogs containing stop signal UAA/UAAA and a photoactivatable cross-linker at definite locations. The human eRF1 peptides cross-linked to these analogs were identified. Cross-linkers on the adenines at the 2nd, 3rd or 4th position modified eRF1 near the conserved YxCxxxF loop (positions 125–131 in the N domain), but cross-linker at the 4th position mainly modified the tripeptide 26-AAR-28. This tripeptide cross-linked also with derivatized 3′-phosphate of UAA, while the same cross-linker at the 3′-phosphate of UAAA modified both the 26–28 and 67–73 fragments. A comparison of the results with those obtained earlier with mRNA analogs bearing a similar cross-linker at the guanines indicates that positioning of eRF1 toward adenines and guanines of stop signals in the 80S termination complex is different. Molecular modeling of eRF1 in the 80S termination complex showed that eRF1 fragments neighboring guanines and adenines of stop signals are compatible with different N domain conformations of eRF1. These conformations vary by positioning of stop signal purines toward the universally conserved dipeptide 31-GT-32, which neighbors guanines but is oriented more distantly from adenines

Modeling of plasma jet of vacuum arc with copper-chromium cathode under action of strong axial magnetic field

This paper deals with the computer simulation of a vacuum arc with composite cathode under action of external axial magnetic using hybrid model. The described hybrid model treats the electrons as a massless fluid and ions as macroparticles. It is shown that the average charge state of ions in a jet of a vacuum arc increases with increasing magnetic field. The calculation results are consistent with experimental data. © 2019 IOP Publishing Ltd. All rights reserved.Russian Science Foundation, RSF: 18-19-00069This work was supported by Russian Science Foundation (project No. 18-19-00069)

Внегоспитальная остановка кровообращения в Республике Крым: анализ эпидемиологии и практики оказания помощи

Introduction. Efficient organization of measures aimed at decreasing mortality from out-of-hospital cardiac arrest (OHCA) warrants a clear understanding of OHCA epidemiology and performance of the prehospital care system in such cases. The study was aimed at performing respective analysis and identifying the ways for improving prehospital management of OHCA in the Republic of Crimea.Material and methods. Annual data from the Crimean OHCA and Resuscitation Registry for 2018 were utilized. All OHCA cases attended by emergency medical services (EMS) with attempted cardiopulmonary resuscitation (CPR) were included, regardless of cardiac arrest etiology or patients’ age (n=419). For ensuring conformity and comparability of the study results, data collection and analysis were executed in correspondence with the statements of the Utstein recommendations.Results. The overall incidence of EMS-attended OHCA in the Republic of Crimea was 673.3 per 100,000 population per year, the incidence of OHCA with attempted CPR – 21.9 per 100,000 population per year, the proportion of CPR attempts out of all OHCA cases – 3.3%. Mean patient age was 66.9 years, and 52.7% were male. The etiology was cardiac in 42.5% cases. In 71.8% cases OHCA was witnessed by EMS, in 25.5% – by a bystander before EMS arrival. Bystanders initiated CPR in 5.7% cases. The initial rhythm was asystole in 80.4% of all cases. When excluding EMS-witnessed cases, the mean EMS response time was 13 min. 5.0% patients had a sustained return of spontaneous circulation at hospital admission. Survival was associated with lower EMS response time (p=0.027), administration of shock (p&lt;0.001) and advanced airway management with endotracheal tube or laryngeal mask (p=0.047).Conclusion. High incidence of OHCA, low rates of CPR commencement and low rates of survival from OHCA in the Republic of Crimea determine the necessity of implementing a comprehensive program to improve prehospital care in the region. Considering the critical relevance of early intervention in OHCA and the revealed low bystander CPR rate, the measures for involving community into the process of prehospital care should form the basis of this program.Введение. Рациональная организация мероприятий по снижению летальности при внегоспитальной остановке кровообращения (ВГОК) требует ясного понимания эпидемиологии и особенностей функционирования системы догоспитальной помощи в случаях ВГОК. Цель исследования состояла в проведении соответствующего анализа и определении направлений оптимизации догоспитальной помощи при ВГОК в Республике Крым.Материал и методы. Использованы данные Крымского регистра случаев ВГОК и сердечно-легочной реанимации (СЛР) за 2018 г. В анализ включены все случаи ВГОК с предпринятой СЛР, зафиксированные службой скорой медицинской помощи (СМП), независимо от причины ВГОК и возраста пациентов (n=419). Для обеспечения согласованности и сопоставимости результатов исследования сбор и анализ данных проводился в соответствии с положениями международных рекомендаций Utstein.Результаты. Общая частота случаев ВГОК, зафиксированных СМП в Республике Крым, составляет 673,3 случая на 100 000 населения в год, частота случаев ВГОК с предпринятой СЛР — 21,9 на 100 000 населения в год, доля случаев проведения СЛР в общем числе случаев ВГОК — 3,3%. Средний возраст пациентов — 66,9 года, пациентов мужского пола — 52,7%. В 42,5% случаев к развитию ВГОК привела патология сердца. В 71,8% случаев ВГОК наступила в присутствии бригады СМП, а в 25,5% случаев — в присутствии свидетелей до приезда СМП. Очевидцы проводили СЛР в 5,7% случаев. В 80,4% случаев первоначально была выявлена асистолия. При ВГОК, развившейся до приезда СМП, среднее время от приема вызова до прибытия СМП составило 13 минут, 5,0% пациентов после успешной реанимации были переданы персоналу больницы. Выживание оказалось статистически значимо связано с меньшим периодом до прибытия СМП (p=0,027), проведением дефибрилляции (p&lt;0,001) и обеспечением проходимости дыхательных путей с помощью ларингеальной маски или эндотрахеальной трубки (p=0,047).Выводы. Высокая встречаемость ВГОК, низкая частота проведения СЛР и высокая летальность при ВГОК в Республике Крым определяют необходимость реализации комплексной программы, направленной на оптимизацию догоспитальной помощи в регионе. Учитывая критическую важность раннего оказания помощи при ВГОК и низкую частоту проведения СЛР очевидцами, основу программы должны составлять мероприятия по привлечению населения к оказанию первой помощи

Probing local photocurrent in inorganic CsPbBr3 perovskite films by scanning probe microscopy

Hybrid organic-inorganic halide perovskites are among the most promising materials for solar cells. Rapid growth of their power conversion efficiency (PCE) from 3.8% in 2009 [1] to more than 22% in 2017 [2] made them attractive for commercial applications. However, rapid degradation of organic-inorganic perovskites under operating conditions – photon flux, electric field, heating – remains unsolved in spite of tremendous research effort [3,4]. Their fully inorganic counterparts possess similar optoelectronic properties [5] and better stability [6]. Still, their PCE is below 10%, which requires further investigation and optimization

Paleontological records indicate the occurrence of open woodlands in a dry inland climate at the present-day Arctic coast in western Beringia during the Last Interglacial

Permafrost records, accessible at outcrops along the coast of Oyogos Yar at the Dmitry Laptev Strait, NE-Siberia, provide unique insights into the environmental history of Western Beringia during the Last Interglacial. The remains of terrestrial and freshwater organisms, including plants, coleopterans, chironomids, cladocerans, ostracods and molluscs, have been preserved in the frozen deposits of a shallow paleo-lake and indicate a boreal climate at the present-day arctic mainland coast during the Last Interglacial. Terrestrial beetle and plant remains suggest the former existence of open forest-tundra with larch (Larix dahurica), tree alder (Alnus incana), birch and alder shrubs (Duschekia fruticosa, Betula fruticosa, Betula divaricata, Betula nana), interspersed with patches of steppe and meadows. Consequently, the tree line was shifted to at least 270. km north of its current position. Aquatic organisms, such as chironomids, cladocerans, ostracods, molluscs and hydrophytes, indicate the formation of a shallow lake as the result of thermokarst processes. Steppe plants and beetles suggest low net precipitation. Littoral pioneer plants and chironomids indicate intense lake level fluctuations due to high evaporation. Many of the organisms are thermophilous, indicating a mean air temperature of the warmest month that was greater than 13 °C, which is above the minimum requirements for tree growth. These temperatures are in contrast to the modern values of less than 4 °C in the study area. The terrestrial and freshwater organism remains were found at a coastal exposure that was only 3.5. m above sea level and in a position where they should have been under sea during the Last Interglacial when the global sea level was 6-10. m higher than the current levels. The results suggest that during the last warm stage, the site was inland, and its modern coastal situation is the result of tectonic subsidence. © 2010 Elsevier Ltd

The integrated exploration of Raifa lake sediments and dendrochronological analysis of Raifa forestry pines

© 2006-2017 Asian Research Publishing Network (ARPN). All rights reserved.The article presents some results of comprehensive research on the properties of Raifa lake bottom sediments and dendrochronological study of Raifa forestry pines (Russia). A preliminary seismic acoustic investigations have been carried out, which allowed to select the sampling site (E 48 ° 43'40.6" N 55 ° 54'21.7"). The length of core sample was 32 cm. Laboratory studies of the core, including the study of the elemental composition, magneto-mineralogical and carcinologic analysis revealed the features of sedimentation mass formation