12 research outputs found
The feeder system of the Toba supervolcano from the slab to the shallow reservoir
The Toba Caldera has been the site of several large explosive eruptions in the recent geological past, including the world’s largest Pleistocene eruption 74,000 years ago. The major cause of this particular behaviour may be the subduction of the fluid-rich Investigator Fracture Zone directly beneath the continental crust of Sumatra and possible tear of the slab. Here we show a new seismic tomography model, which clearly reveals a complex multilevel plumbing system beneath Toba. Large amounts of volatiles originate in the subducting slab at a depth of ∼150 km, migrate upward and cause active melting in the mantle wedge. The volatile-rich basic magmas accumulate at the base of the crust in a ∼50,000 km3 reservoir. The overheated volatiles continue ascending through the crust and cause melting of the upper crust rocks. This leads to the formation of a shallow crustal reservoir that is directly responsible for the supereruptions
Нарушение формирования пола 45,Х/46,XY: клинико-лабораторная характеристика пациентов
Aim. To study the clinical and laboratory characteristics of patients with disorders of sex development (DSD) 45,Х/46,ХY.Materials and methods. The study included 248 patients with genital malformations from early neonatal period to 18 years. The group of patients with DSD 45,Х/46,ХY was formed according to the results of cytogenetic and molecular cytogenetic examination. Anthropometric data, external and internal genitalia, hormonal parameters in mini-pubertal, neutral and pubertal periods were assessed; histological examination of the gonads and screening of development malformations were performed.Results. DSD of 46,ХY karyotype was revealed in 48% (120/248) cases, 46,ХХ DSD – 38% (93/248), DSD with sex chromosome pathology – 14% (35/248) patients. Chromosome DSD was represented by Klinefelter syndrome, Shereshevsky – Ulrich – Turner syndrome, chimeric DSD, and ovotesticular DSD, but the majority of patients had mosaicism 45,Х/46,ХY (65%). In the group of patients with NFP 45,X/46,XY, the median degree of masculinization of the external genitalia by the scale of the external masculinization score (EMS) was 3 [1; 5,5]. Among the defects of external genitalia in most cases (82%, 18/22) there was a combination of cryptorchidism with hypospadias. Derivatives of the Mueller ducts were detected in 91% (20/22) of patients. Most patients (77%) adapt the male passport field. There were no statistically significant differences in the structure of the external and internal genitalia between the groups of patients adapted in the male and female passport fields.The analysis of hormonal indexes revealed a positive correlation between the content of basal testosteron in the mini-pubertal period and the index of masculinization of the external genitalia by the EMS scale (p = 0,002; r = 0,9). In the period of mini-puberty an increase in the level of gonadotropic hormones was detected in 89% (8/9) of children, a combined increase of luteinizing and follicle-stimulating hormones (FSH) being observed in 33% (3/9), an isolated increase of FSH – in 56% (5/9) of cases. In the pubertal period hypergonadotropic hypogonadism was revealed in 75% (3/4) of patients.The results of the histological study of the gonads were heterogenous. Gonads are represented by a different degree of dysgenesis of testicular tissue: from a mild, histologically-like gonad in cryptorchidism to streak and ovotestis.Among the extragonadal manifestations of the disease, inguinal hernia (86%), heart defects (77%) and kidney defects (36%) are prominent. Pathological growth retardation was diagnosed in 23% of children.Conclusion. In the structure of the disease chromosomal DSD accounts for 14% of observations. A group of patients with DSD 45,X/46,XY is heterogenous in the degree of gonadal dysgenesis, the structure of the external and internal genitalia.Цель исследования. Изучить клинико-лабораторную характеристику пациентов с нарушением формирования пола (НФП) 45,Х/46,ХY.Материал и методы. В исследование включены 248 пациентов с неправильным строением наружных гениталий от раннего неонатального периода до 18 лет. По результатам цитогенетического и молекулярно-цитогенетического обследований сформирована группа пациентов с НФП, обусловленного мозаицизмом 45,Х/46,ХY. Проведена оценка антропометрических показателей, наружных и внутренних гениталий, гормональных показателей в мини-пубертате, нейтральном и пубертатном периодах, гистологическое исследование гонад, скрининг пороков развития.Результаты. НФП с кариотипом 46,ХY выявлено в 48% (120/248) случаев, с кариотипом 46,ХХ – в 38% (93/248), НФП с патологией половых хромосом – в 14% (35/248) наблюдений. Хромосомное НФП представлено следующими вариантами: синдромы Кляйнфельтера, Шерешевского – Ульриха – Тернера, химеризм, овотестикулярное, но большую часть составили пациенты с мозаицизмом 45,Х/46,ХY (65%). В группе пациентов с НФП 45,Х/46,ХY медиана cтепени маскулинизации наружных гениталий по шкале External Masculinization Score (EMS) составила 3 [1; 5,5]. Среди пороков развития наружных гениталий в большинстве случаев (82%, 18/22) имело место сочетание крипторхизма с гипоспадией. Дериваты Мюллеровых протоков выявлены у 91% (20/22) пациентов. Большая часть пациентов (77%) адаптируется в мужском паспортном поле. Не выявлено статистически значимых различий в строении наружных и внутренних гениталий между группами пациентов, адаптируемых в мужском и женском паспортном поле.При анализе гормональных показателей выявлена положительная корреляционная взаимосвязь между содержанием базального тестостерона в период мини-пубертата и индексом маскулинизации наружных гениталий по шкале EMS (р = 0,002; r = 0,9). В период мини-пубертата повышение уровня гонадотропных гормонов выявлено у 89% (8/9) детей, из которых сочетанное повышение лютеинизирующего гормона и фолликулостимулирующего гормона (ФСГ) отмечено в 33% (3/9), изолированное повышение ФСГ в 56% (5/9) случаев. В пубертатном периоде у 75% (3/4) пациентов выявлен гипергонадотропный гипогонадизм.По результатам гистологического исследования гонад отмечена гетерогенная картина. Гонады представлены различной степенью дисгенезии тестикулярной ткани: от легкой, близкой к гистологическому строению гонад при крипторхизме, до streak и овотестис.Среди внегонадных проявлений заболевания лидируют паховые грыжи (86%), пороки сердца (77%) и почек (36%). Патологическая задержка роста диагностирована у 23% детей.Выводы. В структуре заболевания на хромосомное НФП приходится 14% наблюдений. Группа пациентов с НФП 45,Х/46,ХY гетерогенна по степени дисгенезии гонад, строению наружных и внутренних половых органов
Cuba’s place among the US foreign policy interests (XIX – middle of the XX centuries)
This article deals with the role of Cuba in the U.S. foreign policy interests in the XIX – middle of the XX centurie. The aim of the article is to characterize the general line of the U.S. foreign policy and to analyze its priorities. Particular attention is paid to the place of the Latin American region in the system of American national priorities. There were analyzed the factors which influenced on the formation of the U.S. policy towards Cuba and determined the nature of its qualitative changes in the given period. As a result of the research the author comes to the conclusion that the U.S. policy towards Cuba and its place among Washington’s foreign policy priorities in XIX – middle of the XX centuries had been changing greatly throught its history. In the XIX century, when the U.S. had their state-building process, Cuba had been considered as a potential member of the United States of America. By the beginning of the XX century, Washington had refused the inclusion of Cuba as a member of the U.S. But the USA got almost complete control over domestic and foreign policy of the island. At the same time, Cuba was included in the general vector of the US Latin American policy. After the victory of the revolution in 1959 and the beginning of the Soviet-Cuban cooperation, the U.S. had regarded Cuba through the confrontation with the Soviet Union in the framework of the Cold War. Cuba had taken one of the top places among the U.S. national interests
Multi-criteria Optimization in Solving the Problem of Expanding Production Capacity of an Enterprise as a Method of Modeling Strategic Directions for the Development of Production Systems
Managing production capacity of industrial enterprises is an important element of the strategy for the development of production systems. The relevance of effective decision support methods in managing production capacity especially increases in the current conditions of a long-term decline in investment activity of Russian industrial enterprises and, as a result, a shortage of modern high-tech equipment, which becomes a significant limiting factor in the development of territorially oriented production systems. The article presents approaches to mathematical modeling and optimization of production capacity of industrial enterprises in solving the problem of its expansion under given budget constraints. The proposed mathematical model includes key parameters of the technical and economic planning of production capacity of a technological site and serves as a tool to justify the choice of an acceptable method for its expansion. The multicriteria optimization methods used in the model serve in this case as a means of formalized description and reaching a reasonable compromise based on the required values of the target parameter and budget constraints, as well as preferences of the decision maker. The article contains an example of the numerical implementation of the developed model in the management of production capacity of a machining site; the example illustrates practical applicability of this model and the result of multicriteria optimization from the standpoint of restrained pessimism of the decision maker
Analyzing and forecasting road traffic accidents and their consequences: a case study of the Udmurt republic
The article addresses the issue of road traffic accidents and their impact on population mortality and socio-economic processes in the region. Attention is given to the tasks of accident prediction and the assessment of the severity of their consequences. The dynamics of road accidents and their consequences in Udmurt Republic are analyzed using time series. The research reveals variations in the number of accidents over different time periods and seasonal fluctuations. Econometric models are constructed to predict the number of accidents and the severity of their consequences. These models take into account seasonal components, trends, and autoregressive processes. The forecasts for the number of accidents and their severity enable the development of measures for traffic management and road safety
3-(1-Cyclohexyl-2-(cyclohexylamino)-4-(4-ethoxyphenyl)-6-oxo-1,6-dihydropyrimidin-5-yl)-1-methylquinoxalin-2(1<i>H</i>)-one
The reaction of 3-cyclohexyl-2-(cyclohexylimino)-6-(4-ethoxyphenyl)-5-(4-methyl-3-oxo-3,4-dihydroquinoxalin-2-yl)-2,3-dihydro-4H-1,3-oxazin-4-one with ammonium acetate afforded 3-(1-cyclohexyl-2-(cyclohexylamino)-4-(4-ethoxyphenyl)-6-oxo-1,6-dihydropyrimidin-5-yl)-1-methylquinoxalin-2(1H)-one in a good yield. The compound was fully characterized
Synthesis of pyrimido[1,6-a]quinoxalines via intermolecular trapping of thermally generated acyl(quinoxalin-2-yl)ketenes by Schiff bases
Acyl(quinoxalin-2-yl)ketenes generated by thermal decarbonylation of 3-acylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones react regioselectively with Schiff bases under solvent-free conditions to form pyrimido[1,6-a]quinoxaline derivatives in good yields
Mathematical modeling of the temperature regime in industrial premises
Comfortable temperature conditions in any room are provided by heating systems, thermal insulation properties of enclosing structures, external environmental conditions. Practical experience, literature analysis show that the existing temperature control systems in industrial premises have disadvantages. Eliminating is possible by using a multi-circuit functional control structure, allowing to reduce the inertia of the temperature control system by taking into account the outdoor temperature, the influence of natural light on the temperature inside the production facility. For its operation, a practically oriented mathematical model is needed, which allows taking into account the influence of a large number of external factors on the temperature regime with minimal delay. A mathematical model has been developed for use as a program in industrial electronics devices for predicting, correcting the temperature field, regulating the temperature regime in the production areas of a room at any point. Based on experimental data, the analysis of the results of the adequacy of the mathematical model shows that the temperature values obtained by the mathematical model of forecasting, correction of the temperature regime fall within the confidence interval and are within the standard deviation. The mechanism of technical implementation is proposed and the prospects of its use are shown
The feeder system of the Toba supervolcano from the slab to the shallow reservoir
The Toba Caldera has been the site of several large explosive eruptions in the recent geological past, including the world’s largest Pleistocene eruption 74,000 years ago. The major cause of this particular behaviour may be the subduction of the fluid-rich Investigator Fracture Zone directly beneath the continental crust of Sumatra and possible tear of the slab. Here we show a new seismic tomography model, which clearly reveals a complex multilevel plumbing system beneath Toba. Large amounts of volatiles originate in the subducting slab at a depth of ∼150 km, migrate upward and cause active melting in the mantle wedge. The volatile-rich basic magmas accumulate at the base of the crust in a ∼50,000 km3 reservoir. The overheated volatiles continue ascending through the crust and cause melting of the upper crust rocks. This leads to the formation of a shallow crustal reservoir that is directly responsible for the supereruptions
Structure of magma reservoirs beneath Merapi and surrounding volcanic centers of Central Java modeled from ambient noise tomography
International audienceWe present a three-dimensional model of the distribution of S-wave velocity in the upper crust to a depth of 20 km beneath Central Java based on the analysis of seismic ambient noise data recorded by more than 100 seismic stations in 2004 associated with the MERAMEX project. To invert the Rayleigh wave dispersion curves to construct 2-D group-velocity maps and 3-D distributions of S-wave velocity, we have used a new tomographic algorithm based on iterative linearized inversion. We have performed a series of synthetic tests that demonstrate significantly higher resolution in the upper crust with this model compared to the local earthquake travel-time tomography (LET) model previously applied for the same station network. Beneath the southern flank of Merapi, we identify a large low-velocity anomaly that can be split into two layers. The upper layer reflects the ∼1 km thick sedimentary cover of volcanoclastic deposits. The deeper anomaly at depths of ∼4-8 km may represent a magma reservoir with partially molten rock that feeds several volcanoes in Central Java. Beneath the Merapi summit, we observe another low-velocity anomaly as deep as 8 km that may be associated with the active magma reservoir that feeds the eruptive activity of Merapi. In the southern portion of the study area, in the lower crust, we identify a low-velocity anomaly that may represent the top of the pathways of volatiles and melts ascending from the slab that was previously inferred from the LET model results. We observe that this anomaly is clearly separate from the felsic magma reservoirs in the upper crust