Seafloor massive sulfides from mid-ocean ridges: Exploring the causes of their geochemical variability with multivariate analysis

The neovolcanic zones of mid-ocean ridges are host to seawater-derived hydrothermal systems forming seafloor massive sulfide (SMS) deposits. These deposits have high concentrations of base metals and potentially economic enrichment of a wide range of trace elements. The factors controlling this enrichment are currently poorly understood. We have investigated the main factors controlling SMS compositional variability through robust principal component analysis and robust factor analysis of published and newly obtained bulk geochemical data for samples collected from SMS deposits worldwide. We found that a large part of the observed variability is produced by a combination of three independent factors, which are interpreted to reflect (in order of importance): (1) the temperature of deposition, (2) the ridge spreading rate, and (3) zone refining. The first and the third factors are mostly related to processes operating near the seafloor, such as conductive cooling, mixing of the hydrothermal fluids with seawater and metal remobilization, and determine the relative proportions of the main minerals and, thus, of Cu and Zn (Co, Se, Sb, Pb). The ridge spreading rate influences the structure of the oceanic lithosphere, which exerts a major control on the length and depth of the hydrothermal convection cell and on the rock-to-water ratios in the reaction zone, which in turn control the behavior of the precious metals Au and Ag and elements including Ni (Mo, Se). Despite the obvious role of substrate rocks as metal sources, their composition (specifically mafic vs. ultramafic) does not emerge as a statistically significant independent factor

New properties of scalar field dynamics in brane isotropic cosmological models

Several aspects of scalar field dynamics on a brane which differs from corresponding regimes in the standard cosmology are investigated. We consider asymptotic solution near a singularity, condition for inflation and bounces and some detail of chaotic behavior in the brane model. Each results are compared with those known in the standard cosmology.Comment: 13 pages with 2 eps figures, submitted to Astronomy Letter

The issues of implementation of simulation-simulation module in the curriculum of the virtual clinic emergency conditions

The aim of this work was the optimization of the learning process diagnostic and treatment interventions at emergencies in clinic of internal diseases students of 6 course of medical faculty. The object of the study was the simulation of interregional certification centre NSMU, the subject of the study — simulation clinic emergency conditions, emergency medicine. Formulated the hypothesis: based on the mining simulation equipment ("Apollo" and ESC) practical skills in physical name, instrumental examination of the patient and treatment to enhance efficiency and quality assist with emergency status, successful completion of an accreditation graduates with developed check sheet with the sequence of actions in providing medical emergency care to the patient with hypertension issues for the input test control of level of knowledge, questionnaire evaluation of satisfaction of students, list of questions for final test control of knowledge level (Moodle), practical tasks and creation of electronic clinical tasks with the incremental algorithm.Целью работы явилась оптимизация процесса обучения диагностическим и лечебным мероприятиям при неотложных состояниях в клинике внутренних болезней студентов 6 курса лечебного факультета. Объектом исследования стал межрегиональный симуляционно-аттестационный центр НГМУ, предметом исследования — симуляционная клиника неотложных состояний, отделение неотложной терапии. Была сформулирована гипотеза: на основе отработки на симуляционном оборудовании («Аполло» и ESC) практических навыков по физикальному, инструментальному обследованию пациента и лечению, повысить эффективность, качество оказания помощи при неотложном состоянии, успешное прохождение аккредитации выпускниками с помощью разработанных: чек-листа с алгоритмом действий при оказании медицинской неотложной помощи больному с артериальной гипертензией, вопросов для входного тестового контроля, уровня знаний анкеты оценки удовлетворенности обучающихся, перечня вопросов для итогового тестового контроля уровня знаний (система Moodle), ситуационных заданий, а также создания клинических электронных задач с пошаговым алгоритмо

Легочный амилоидоз

Amyloidosis is an orphan disease. Amyloidosis is uncommonly associated with respiratory disorders. The present article is a review of recently published data on pulmonary amyloidosis and a case report of alveolar and septal amyloid lung injury. Clinical heterogeneity of lung lesions in systemic and limited AL amyloidosis (precursor proteins are light chains of immunoglobulins, λ dimer and κ monomer), AA amyloidosis (inflammatory acute-phase proteins), and ATTR amyloidosis (senile and inherited amyloidosis; precursor protein is transthyretin) have been discussed. One chart of the review has been devoted to the pathogenesis of diffuse parenchymatous (unilateral and bilateral) amyloidosis, nodular and tracheobronchial amyloidosis (with amyloid deposits in proximal, medium and distal airways, intrathoracic lymph node involvement (amyloid lymphadenopathy), amyloidosis of the pleura and the diaphragm, and differential diagnosis of these types of pulmonary amyloidosis.Амилоидоз относится к классу орфанных заболеваний. Среди других систем организма с амилоидозом в наименьшей степени ассоциирована дыхательная система. Современные данные по проблеме легочного амилоидоза представлены на основе литературного обзора и авторского описания редкого примера альвеолярно-септальной формы поражения легких; рассмотрены вопросы клинической неоднородности пульмонологической патологии при системном и местном амилоидозе (AL – белок-предшественник – легкие цепи иммуноглобулинов, димер λ и мономер κ; АА – воспалительные острофазовые белки; ATTR – старческий и наследственный, белок-предшественник транстиретин). Один из разделов посвящен патогенезу диффузного паренхиматозного (одностороннего и двустороннего), узлового и трахеобронхиального (с депозитами амилоида в проксимальных, средних или дистальных отделах бронхиального дерева) вариантов болезни, вовлечению в процесс внутригрудных лимфатических узлов (амилоидная аденопатия), плевры и диафрагмы, вопросам дифференциальной диагностики данных вариантов легочного амилоидоза

Гранулематоз с полиангиитом: астмаподобное и псевдопневмоническое начало болезни

A case of granulomatosis with polyangiitis is described in the article. The patient experienced 3year paroxysmal asthmalike syndrome with granulomatous lesion of the subglottic portion of the larynx that further developed into multifocal destructive lesions of the lungs without clinical signs of glomerulonephritis and with positive response to combined therapy with cytostatic agents, rituximab and systemic steroids. The main criteria of granulomatosis with polyangiitis in this patient were high levels of ANCA and antiproteinase3 antibodies. Therefore, granulomatosis with polyangiitis is characterized by polymorphic onset of lung disease with coexisting paroxysmal respiratory syndrome, infiltrative and destructive pulmonary lesions.Представлено описание случая гранулематоза с полиангиитом, характеризовавшегося трехлетним пароксизмальным астмаподобным симптомокомлексом (на фоне гранулематозных изменений в подскладочном пространстве гортани), последующей трансформацией в многофокусное деструктивное поражение легких (при отсутствии клинических признаков гломерулонефрита) с положительным терапевтическим ответом при назначении комбинированного лечения цитостатическим препаратом, ритуксимабом, системными глюкокортикостероидами

Hydrogen and chlorine abundances in the Kimberley formation of Gale crater measured by the DAN instrument on board the Mars Science Laboratory Curiosity rover

The Dynamic Albedo of Neutron (DAN) instrument on board the Mars Science Laboratory Curiosity rover acquired a series of measurements as part of an observational campaign of the Kimberley area in Gale crater. These observations were planned to assess the variability of bulk hydrogen and neutron‐absorbing elements, characterized as chlorine‐equivalent concentration, in the geologic members of the Kimberley formation and in surface materials exposed throughout the area. During the traverse of the Kimberley area, Curiosity drove primarily over the “Smooth Hummocky” unit, a unit composed primarily of sand and loose rocks, with occasional stops at bedrock of the Kimberley formation. During the Kimberley campaign, DAN detected ranges of water equivalent hydrogen (WEH) and chlorine‐equivalent concentrations of 1.5–2.5 wt % and 0.6–2 wt %, respectively. Results show that as the traverse progressed, DAN observed an overall decrease in both WEH and chlorine‐equivalent concentration measured over the sand and loose rocks of the Smooth Hummocky unit. DAN measurements of WEH and chlorine‐equivalent concentrations in the well‐exposed sedimentary bedrock of the Kimberley formation show fluctuations with stratigraphic position. The Kimberley campaign also provided an opportunity to compare measurements from DAN with those from the Sample Analysis at Mars (SAM) and the Alpha‐Particle X‐ray Spectrometer (APXS) instruments. DAN measurements obtained near the Windjana drill location show a WEH concentration of ~1.5 wt %, consistent with the concentration of low‐temperature absorbed water measured by SAM for the Windjana drill sample. A comparison between DAN chlorine‐equivalent concentrations measured throughout the Kimberley area and APXS observations of corresponding local surface targets and drill fines shows general agreement between the two instruments

Hydrogen and chlorine abundances in the Kimberley formation of Gale crater measured by the DAN instrument on board the Mars Science Laboratory Curiosity rover

The Dynamic Albedo of Neutron (DAN) instrument on board the Mars Science Laboratory Curiosity rover acquired a series of measurements as part of an observational campaign of the Kimberley area in Gale crater. These observations were planned to assess the variability of bulk hydrogen and neutron‐absorbing elements, characterized as chlorine‐equivalent concentration, in the geologic members of the Kimberley formation and in surface materials exposed throughout the area. During the traverse of the Kimberley area, Curiosity drove primarily over the “Smooth Hummocky” unit, a unit composed primarily of sand and loose rocks, with occasional stops at bedrock of the Kimberley formation. During the Kimberley campaign, DAN detected ranges of water equivalent hydrogen (WEH) and chlorine‐equivalent concentrations of 1.5–2.5 wt % and 0.6–2 wt %, respectively. Results show that as the traverse progressed, DAN observed an overall decrease in both WEH and chlorine‐equivalent concentration measured over the sand and loose rocks of the Smooth Hummocky unit. DAN measurements of WEH and chlorine‐equivalent concentrations in the well‐exposed sedimentary bedrock of the Kimberley formation show fluctuations with stratigraphic position. The Kimberley campaign also provided an opportunity to compare measurements from DAN with those from the Sample Analysis at Mars (SAM) and the Alpha‐Particle X‐ray Spectrometer (APXS) instruments. DAN measurements obtained near the Windjana drill location show a WEH concentration of ~1.5 wt %, consistent with the concentration of low‐temperature absorbed water measured by SAM for the Windjana drill sample. A comparison between DAN chlorine‐equivalent concentrations measured throughout the Kimberley area and APXS observations of corresponding local surface targets and drill fines shows general agreement between the two instruments

The initiating rate of a heterogeneous reaction

A stochastic model of nucleation and subsequent growth of new phase islands on solid surfaces is proposed and expressions for the mean induction time and its variance are obtained in an explicit form. The intermediate stage of the new surface phase evolution is studied under conditions of the supersaturation gradually decreasing as a result of the growth of the islands. The island size distribution as well as the supersaturation and the fraction of the surface area covered with the new phase are found as functions of time. It is proved that both the induction period and decrease in surface metastability must be taken into account when trying to treat the surface reaction kinetics, and some conclusions of conventional models with no allowance for the aforementioned factors have certainly to be revised