Strong acceleration of glacier area loss in the Greater Caucasus between 2000 and 2020

An updated glacier inventory is important for understanding glacier behaviour given the accelerating glacier retreat observed around the world. Here, we present data from a new glacier inventory for two points in time (2000, 2020) covering the entire Greater Caucasus (Georgia, Russia, and Azerbaijan). Satellite imagery (Landsat, Sentinel, SPOT) was used to conduct a remote-sensing survey of glacier change. The 30 m resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM; 17 November 2011) was used to determine aspect, slope, and elevations, for all glaciers. Glacier margins were mapped manually and reveal that in 2000 the mountain range contained 2186 glaciers with a total glacier area of 1381.5 ± 58.2 km2. By 2020, the area had decreased to 1060.9 ± 33.6 km2 a reduction of 23.2 ± 3.8 % (320.6 ± 45.9 km2) or −1.16 % yr−1 over the last 20 years in the Greater Caucasus. Of the 2223 glaciers, 14 have an area > 10 km2, resulting in the 221.9 km2 or 20.9 % of total glacier area in 2020. The Bezengi Glacier with an area of 39.4 ± 0.9 km2 was the largest glacier mapped in the 2020 database. Glaciers between 1.0 and 5.0 km2 accounted for 478.1 km2 or 34.6 % in total area in 2000, while they accounted for 354.0 km2 or 33.4 % in total area in 2020. The rates of area shrinkage and mean elevation vary between the northern and southern and between the western, central, and eastern Greater Caucasus. Area shrinkage is significantly stronger in the eastern Greater Caucasus (−1.82 % yr−1), where most glaciers are very small. The observed increased summer temperatures and decreased winter precipitation along with increased Saharan dust deposition might be responsible for the predominantly negative mass balances of Djankuat and Garabashi glaciers with long-term measurements. Both glacier inventories are available from the Global Land Ice Measurements from Space (GLIMS) database and can be used for future studies

High-definition electrocardiography potential in identifying the reasons for unstable clinical course of coronary heart disease

Aim: To investigate the correlation between clinical and morphological characteristics of coronary heart disease (CHD) and high-definition electrocardiography (HD-ECG) parameters. Material and methods: In total, 85 patients with unstable angina and ST segment depression (ST-UA) underwent HD-ECG during the angina attack, with late ventricular potential (LVP) analysis. One-year survival data were also analysed. Post-mortem histological examination of cardiac tissue was performed in 6 patients with ST-UA. Results: The important morphologic features of ST-UA included cardiomyocyte (CMC) dystrophy, due to acute and chronic myocardial ischemia, and acute injury in the cardiac conduction areas. LVPs were registered in 27 % of the ST-UA patients, mostly among people with transient myocardial ischemia (69,57 %). In patients who previously underwent myocardial infarction, LVP prevalence was lower (28,57 %). At the early stages of hospitalization, LVP were registered in 14 patients (60,87 %), while pharmacotherapy and clinical course stabilization were associated with decreased LVP prevalence (21,74 %). The study results suggest that in patients with acute coronary syndrome, LVP registration predicts not an adverse outcome, but a better prognosis. Conclusion: ST-UA is characterised by typical changes of CMC and myocardial stroma in posterior septal area, which result in metabolic, energetic, and electrical myocardial instability. LVPs could be used as a marker of functional (ischemic) myocardial heterogeneity in patients with ST-UA. LVP registration could be associated with a better prognosis in this clinical group

Uakitite, VN, a new mononitride mineral from uakit iron meteorite (IIAB)

Uakitite was observed in small troilite–daubréelite (±schreibersite) inclusions (up to 100 µm) and in large troilite–daubréelite nodules (up to 1 cm) in Fe-Ni-metal (kamacite) of the Uakit iron meteorite (IIAB), Republic of Buryatia, Russia. Such associations in the Uakit meteorite seemed to form due to high-temperature (>1000 °C) separation of Fe-Cr-rich sulfide liquid from Fe-metal melt. Most inclusions represent alternation of layers of troilite and daubréelite, which may be a result of solid decay of an initial Fe-Cr-sulfide. These inclusions are partially resorbed and mainly located in fissures of the meteorite, which is now filled with magnetite, and rarely other secondary minerals. Phase relations indicate that uakitite is one of the early minerals in these associations. It forms isometric (cubic) crystals (in daubréelite) or rounded grains (in schreibersite). The size of uakitite grains is usually less than 5 µm. It is associated with sulfides (daubréelite, troilite, grokhovskyite), schreibersite and magnetite. Carlsbergite CrN, a more abundant nitride in the Uakit meteorite, was not found in any assemblages with uakitite. Physical and optical properties of uakitite are quite similar to synthetic VN: yellow and transparent phase with metallic luster; Mohs hardness: 9–10; light gray color with a pinky tint in reflected light; density (calc.) = 6.128 g/cm3. Uakitite is structurally related to the osbornite group minerals: carlsbergite CrN and osbornite TiN. Structural data were obtained for three uakitite crystals using the electron backscatter diffraction (EBSD) technique. Fitting of the EBSD patterns for a synthetic VN model (cubic, Fm-3m, a = 4.1328(3) Å; V = 70.588(9) Å3; Z = 4) resulted in the parameter MAD = 0.14–0.37° (best-good fit). Analytical data for uakitite (n = 54, in wt. %) are: V, 71.33; Cr, 5.58; Fe, 1.56; N, 21.41; Ti, below detection limit (<0.005). The empirical formula (V0.91Cr0.07Fe0.02)1.00N1.00 indicates that chromium incorporates in the structure according to the scheme V3+ → Cr3+ (up to 7 mol. % of the carlsbergite end-member). © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Russian Foundation for Basic Research, RFBR: 17-05-00129, IGM SD 0330-2016-0005Government Council on Grants, Russian FederationMinistry of Science and Higher Education of the Russian FederationFunding: The investigations were partly supported by RFBR (grant 17-05-00129) and the State assignment project (IGM SD 0330-2016-0005). This work was also supported by the Initiative Project of Ministry of Science and Higher Education of the Russian Federation and by Act 211 of the Government of the Russian Federation, agreement no. 02.A03.21.0006

Volunteerism as a Tool for Preventing Deviant Behavior in Adolescents

This article is devoted to the prevention of deviant behavior through volunteer activities. The growing number of children in a socially dangerous situation, the deterioration of their physical and mental health, social orphanhood, early crime, the use of alcohol and drugs by children and adolescents - this is the series of problems that exist in modern Russia and is related to the social life of children and adolescents. In this regard, the search for new methods of working with children and adolescents to correct their deviations and improve the quality of their life becomes especially relevant. The volunteer movement has a high educational potential and can be effectively adapted to work with children and adolescents. The authors consider the activities of specific volunteer organizations to attract children and adolescents to the volunteer environment in order to prevent deviant behavior. The article analyzes the possibilities from participation in volunteer movements, as well as voluntary associations of children and adolescents with behavioral problems

Изменение площади и объёма ледников Горного Алтая (Россия) с середины ХХ в. по данным космических съёмок

The paper examines changes in the area and volume of the Katun river basin glaciers, North and South Chu glaciers of the Altai Mountains since the beginning of the USSR glaciers inventarization to the present. For this purpose, we used USSR Glaciers Inventory data, space imagery – CORONA-1968, ALOS PRISM-2008, Landsat and ASTER 2000–2012. In total, glaciers have lost 172.4 km2 (27.4%) of its area.Рассматривается изменение площади и объёма ледников Горного Алтая с начала каталогизации ледников СССР по настоящее время. Для оценки изменений площади ледников использованы данные Каталога ледников СССР и космические снимки со спутников CORONA, ALOS PRISM, Landsat и ASTER.К 2008 г. ледники Катунского, Северо- и Южно-Чуйского хребтов потеряли 172,4 км2 площади, или 27,7%. Суммарное сокращение объёма ледников составило 8,9 км3. Объёмы ледников вычислены с помощью корреляционных зависимостей, полученных по данным полевого радиолокационного зондирования алтайских ледников. Сравнение космических снимков 2004 и 2012 гг. с данными середины прошлого века позволило сделать вывод об увеличении скорости сокращения площади ледников в последнее десятилетие в 1,5–2 раза

Duration of the Process of Complete Synchronizationof Two Coupled Identical Chaotic Systems

We consider the time required for complete synchronization of two identical one-way coupled vander Pol-Duffing oscillators occurring in the regime of dynamic chaos. The influence of the initial phase differ-ence between oscillators on the duration of the process of complete synchronization has been studied. At a fixedphase of chaotic oscillations of the self-excited drive oscillator, the period of time (past the coupling onset) during which the complete synchronization regime is established depends on the phase of the self-excited responseoscillatorComment: 4 pages, 2 figure

Stability of Terrestrial Planets in the Habitable Zone of Gl 777 A, HD 72659, Gl 614, 47 Uma and HD 4208

We have undertaken a thorough dynamical investigation of five extrasolar planetary systems using extensive numerical experiments. The systems Gl 777 A, HD 72659, Gl 614, 47 Uma and HD 4208 were examined concerning the question of whether they could host terrestrial like planets in their habitable zones (=HZ). First we investigated the mean motion resonances between fictitious terrestrial planets and the existing gas giants in these five extrasolar systems. Then a fine grid of initial conditions for a potential terrestrial planet within the HZ was chosen for each system, from which the stability of orbits was then assessed by direct integrations over a time interval of 1 million years. The computations were carried out using a Lie-series integration method with an adaptive step size control. This integration method achieves machine precision accuracy in a highly efficient and robust way, requiring no special adjustments when the orbits have large eccentricities. The stability of orbits was examined with a determination of the Renyi entropy, estimated from recurrence plots, and with a more straight forward method based on the maximum eccentricity achieved by the planet over the 1 million year integration. Additionally, the eccentricity is an indication of the habitability of a terrestrial planet in the HZ; any value of e>0.2 produces a significant temperature difference on a planet's surface between apoapse and periapse. The results for possible stable orbits for terrestrial planets in habitable zones for the five systems are summarized as follows: for Gl 777 A nearly the entire HZ is stable, for 47 Uma, HD 72659 and HD 4208 terrestrial planets can survive for a sufficiently long time, while for Gl 614 our results exclude terrestrial planets moving in stable orbits within the HZ.Comment: 14 pages, 18 figures submitted to A&

Реакция ледников Центрального Кавказа в 2001–2010 гг. на изменения температуры и количества осадков

This paper examines changes in surface area and terminus retreat of glaciers in the Greater Caucasus Mountains between 2001 and 2010 using ASTER imagery. The use of consistent high-resolution imagery such as ASTER significantly reduces uncertainties in measurements of glacier shrinkage and retreat and enables assessments at decadal intervals which are important for both scientists and regional decision-makers. Two ASTER images acquired on 15 September 2001 and 29 September 2010 covering central sector of the Greater Caucasus Ridge and the Elbrus glaciated massif were used for glacier mapping. Outlines of 179 glaciers were mapped of which 108 glaciers are located on the northern macroslope of the Greater Caucasus and on Mt Elbrus in the Baksan River catchment (Russia) and 71 are located on the southern macroslope in the Inguri River catchment (Georgia). In total, glaciers lost 5% of their area. Glacier wastage was higher in the Inguri catchment at 5.6%; in the Baksan catchment, glaciers lost 4.3% of their area. Termini positions of 28 valley glaciers were measured on ASTER and aerial photographs to compare rates of glacier retreat in 2001–2010 and 1987–2001.The rate of this recession increased, this fact confirmed by field studies in Baksan basin. Glacier mass balance observations at Garabashi glacier  indicate strong reduction in cumulative mass balance since 1998 providing further evidence on glacier wastage. The observed shrinkage of Caucasus glaciers is mainly connected with increasing in summer temperatures.Increase in precipitation has not compensated for an increase in temperature between 1987–2001 and 2001–2010 periods. Оценено изменение размеров ледников Центрального Кавказа с 2001 по 2010 г. Для количественной оценки сокращения площади ледников Центрального Кавказа в бассейнах рек Баксан и Ингури за этот период использованы материалы повторной космической съёмки. В среднем эта величина составила 5%. По сравнению с предыдущим периодом наблюдений (1987–2001 гг.) средняя скорость отступания языков ледников увеличилась. Причины сокращения площади ледников анализировались на основе данных непрерывного многолетнего ряда балансовых наблюдений на леднике Гарабаши (Эльбрус), а также материалов наблюдений за изменениями температуры и количества осадков на метеостанции Терскол. Сокращение размеров оледенения хорошо коррелирует с ростом летних температур в высокогорье Кавказа, несмотря на увеличение количества зимних осадков

СОСТАВ, ВОЗРАСТ И ГЕОДИНАМИЧЕСКАЯ ПОЗИЦИЯ ЩЕЛОЧНЫХ ПОРОД БОРГОЙСКОГО И БОЦИНСКОГО МАССИВОВ (ДЖИДИНСКАЯ ЩЕЛОЧНАЯ ПРОВИНЦИЯ)

The Borgoy and Botsy massifs are a part of the Dzhida alkaline province of the Western Transbaikalia. It has been stated that the rocks of the Borgoy massif were formed during the period from 246 to 243 Ma, which coincides with the formation period of the Permian-Triassic alkaline magmatic rocks common in the Vitim province. The age obtained from the zircons in the Botsy massif (121±1.0 Ma) is typical of the final stage of the transformation of the rocks related to rifting and alkali basalt lava flow. The presence of negative Nb-Ta anomaly and a relative enrichment in Rb, Ba, Sr and U imply interaction between the material of the plume and the earlier accretionary complexes of the subduction zones.Боргойский и Боцинский массивы входят в состав Джидинской щелочной провинции Западного Забайкалья. Установлено, что породы Боргойского массива были сформированы в интервале 246–243 млн лет и совпадают с пермско-триасовым этапом формирования щелочных магматических пород, распространенных в Витимской провинции. Полученный возраст по цирконам Боцинского массива (121±1.0 млн лет) характеризует заключительный этап преобразования пород, связанный с рифтогенезом и излиянием щелочных базальтов. Наличие отрицательной Nb-Ta-аномалии и относительное обогащение Rb, Ba, Sr и U свидетельствуют о вероятном взаимодействии вещества плюма с ранее сформированными аккреционными комплексами зон субдукции

Изоформы актина и неопл астическая трансформация

The cytoplasmic actins (β and γ) play crucial roles during key cellular processes like adhesion, migration, polarization and cytokinesis. The understanding of their specific underlying mechanisms would be of major relevance not only for fundamental research but also for clinical applications, since modulations of actin isoforms are directly or indirectly correlated with severe pathologies. The major goal of the research was to elucidate the function of the actin isoforms during motile activities, adhesions and cell division and to investigate whether their expression and/or structural organization is related to pathological function. Selective depletion of β- and γ-cytoplasmic actins allowed attributing functional diversities of β- and γ-сytoplasmic actins. β-Сytoplasmic actin plays a preferential role in contractile activities, whereas γ-cytoplasmic actin mainly participates in the formation of a submembranous network necessary for cell shape flexibility and motile activity. The roles of isoforms in regulating the integrity of adherens and tight junctions respectively were demonstrated. Unique roles of β- and γ-cytoplasmic actins in normal cells were shown. Similar results were obtained in cancer cells compared with normal epithelial cells in culture and in human pathological tissue sections of mammary gland, colon, lung and cervix. Malignant cell transformation requires changes in the ability of cells to migrate. The disruption of actin cytoskeleton and intercellular adhesions is an important component of the acquisition of invasive properties in epithelial malignancies.Цитоплазматические изоформы актина (β и γ) играют важную роль в ключевых клеточных процессах, таких как адгезия, миграция, поляризация и цитокинез. Понимание специфических механизмов, лежащих в основе этих процессов, является связующим звеном между фундаментальными и клиническими исследованиями, так как модуляции актиновых изоформ прямо или косвенно связаны с различными патологиями. Исследованию функций цитоплазматических изоформ актина, связанных с подвижностью и делением нормальных и опухолевых клеток, адгезионными структурами, а также изучению соответствия их экспрессии и / или структурной организации нормальным и патологическим функциям клеток посвящен данный обзор. Селективная редукция β- или γ-цитоплазматических актинов позволила определить функциональные различия между этими изоформами. Преимущественную роль в сократительных и адгезионных активностях играет β-актин, тогда как цитоплазматический γ-актин участвует в образовании подмембранной сети, необходимой для клеточной пластичности и подвижности. Определяющую роль в установлении и поддержании нормальной архитектуры и динамики эпителиальных плотных и адгезионных межклеточных контактов играет связь с актиновым цитоскелетом. Продемонстрирована уникальная роль β- и γ-актинов в регуляции и поддержании целостности адгезионных и плотных межклеточных контактов соответственно. Похожие результаты были получены при сравнении опухолевых клеток с нормальными эпителиальными клетками в культуре и на срезах патологических тканей молочной железы, кишечника, легких и шейки матки человека. Изоформ-специфичная перестройка актинового цитоскелета и адгезионных межклеточных контактов является важным шагом в приобретении инвазивности эпителиальными опухолями