210 research outputs found

    Changes in Arctic Ocean Climate Evinced through Analysis of IPY 2007–2008 Oceanographic Observations

    Get PDF
    Full-depth hydrographical surveys conducted in 2007–2009 during the International Polar Year (IPY) collaboration provide an accurate snapshot of the Arctic Ocean (AO) hydrography at a time when the Arctic Ocean Oscillation (AOO) index was highest in recent record. We construct pan-Arctic temperature and salinity (T/S) reference states from these data using variational optimal interpolation and discuss some key differences between the 2007–2009 state and a similarly constructed climatology from historical 1950–1994 Russian archives. These data provide a recent, known reference state for both qualitative and quantitative future AO climate change studies. Furthermore, we present an analysis of sea-surface height (SSH) and upper-layer circulation constructed from the IPY data via 4DVar data assimilation and use them to examine circulation and freshwater source changes visible during IPY

    MODEL OF GEOMEDIA CONTAINING DEFECTS: COLLECTIVE EFFECTS OF DEFECTS EVOLUTION DURING FORMATION OF POTENTIAL EARTHQUAKE FOCI

    Get PDF
    This paper describes the statistical thermo-dynamical evolution of an ensemble of defects in the geomedium in the field of externally applied stresses. The authors introduce ‘tensor structural’ variables associated with two specific types of defects, fractures and localized shear faults (Fig. 1). Based on the procedure for averaging of the structural variables by statistical ensembles of defects, a self-consistency equation is developed; it determines the dependence of the macroscopic tensor of defects-induced strain on values of external stresses, the original pattern and interaction of defects. In the dimensionless case, the equation contains only the parameter of structural scaling, i.e. the ratio of specific structural scales, including the size of defects and an average distance between the defects.The self-consistency equation yields three typical responds of the geomedium containing defects to the increasing external stress (Fig. 2). The responses are determined from values of the structural scaling parameter. The concept of non-equilibrium free energy for a medium containing defects, given similar to the Ginzburg-Landau decomposition, allowed to construct evolutionary equations for the introduced parameters of order (deformation due to defects, and the structural scaling parameter) and to explore their solutions (Fig. 3).It is shown that the first response corresponds to stable quasi-plastic deformation of the geomedium, which occurs in regularly located areas characterized by the absence of collective orientation effects. Reducing the structural scaling parameter leads to the second response characterized by the occurrence of an area of meta-stability in the behavior of the medium containing defects, when, at a certain critical stress, the orientation transition takes place in the ensemble of interacting defects, which is accompanied by an abrupt increase of deformation (Fig. 2). Under the given observation/averaging scale, this transition is manifested by localized cataclastic deformation (i.e. a set of weak earthquakes), which migrates in space at a velocity several orders of magnitude lower than the speed of sound, as a ‘slow’ deformation wave (Fig. 3). Further reduction of the structural scaling parameter leads to degeneracy of the orientation meta-stability and formation of localized dissipative defect structures in the medium. Once the critical stress is reached, such structures develop in the blow-up regime, i.e. the mode of avalanche-unstable growth of defects in the localized area that is shrinking eventually. At the scale of observation, this process is manifested as brittle fracturing that causes formation of a deformation zone, which size is proportional to the scale of observation, and corresponds to occurrence of a strong earthquake.On the basis of the proposed model showing the behavior of the geomedium containing defects in the field of external stresses, it is possible to describe main ways of stress relaxation in the rock massives – brittle large-scale destruction and cataclastic deformation as consequences of the collective behavior of defects, which is determined by the structural scaling parameter.Results of this study may prove useful for estimation of critical stresses and assessment of the geomedium status in seismically active regions and be viewed as model representations of the physical hypothesis about the uniform nature of deve­lopment of discontinuities/defects in a wide range of spatial scales

    Toward a Reliable Wave Hindcast/Forecast in the Bering Sea

    Get PDF
    1. To validate the quality of available wind products through application of the WAM model Cycle 4.5 and satellite observations. 2. To analyze effects of high resolution atmospheric model downscaling and data assimilation. 3. To analyze summer surface wave condition in the Bering Sea during the years, 2007-2011. 4. To explore the possibility of developing a new algorithm for a dynamically constrained minimizing function without employing the adjoint of the dynamical system

    МОДЕЛЬ ГЕОСРЕДЫ С ДЕФЕКТАМИ: КОЛЛЕКТИВНЫЕ ЭФФЕКТЫ РАЗВИТИЯ НЕСПЛОШНОСТЕЙ ПРИ ФОРМИРОВАНИИ ПОТЕНЦИАЛЬНЫХ ОЧАГОВ ЗЕМЛЕТРЯСЕНИЙ

    Get PDF
    This paper describes the statistical thermo-dynamical evolution of an ensemble of defects in the geomedium in the field of externally applied stresses. The authors introduce ‘tensor structural’ variables associated with two specific types of defects, fractures and localized shear faults (Fig. 1). Based on the procedure for averaging of the structural variables by statistical ensembles of defects, a self-consistency equation is developed; it determines the dependence of the macroscopic tensor of defects-induced strain on values of external stresses, the original pattern and interaction of defects. In the dimensionless case, the equation contains only the parameter of structural scaling, i.e. the ratio of specific structural scales, including the size of defects and an average distance between the defects.The self-consistency equation yields three typical responds of the geomedium containing defects to the increasing external stress (Fig. 2). The responses are determined from values of the structural scaling parameter. The concept of non-equilibrium free energy for a medium containing defects, given similar to the Ginzburg-Landau decomposition, allowed to construct evolutionary equations for the introduced parameters of order (deformation due to defects, and the structural scaling parameter) and to explore their solutions (Fig. 3).It is shown that the first response corresponds to stable quasi-plastic deformation of the geomedium, which occurs in regularly located areas characterized by the absence of collective orientation effects. Reducing the structural scaling parameter leads to the second response characterized by the occurrence of an area of meta-stability in the behavior of the medium containing defects, when, at a certain critical stress, the orientation transition takes place in the ensemble of interacting defects, which is accompanied by an abrupt increase of deformation (Fig. 2). Under the given observation/averaging scale, this transition is manifested by localized cataclastic deformation (i.e. a set of weak earthquakes), which migrates in space at a velocity several orders of magnitude lower than the speed of sound, as a ‘slow’ deformation wave (Fig. 3). Further reduction of the structural scaling parameter leads to degeneracy of the orientation meta-stability and formation of localized dissipative defect structures in the medium. Once the critical stress is reached, such structures develop in the blow-up regime, i.e. the mode of avalanche-unstable growth of defects in the localized area that is shrinking eventually. At the scale of observation, this process is manifested as brittle fracturing that causes formation of a deformation zone, which size is proportional to the scale of observation, and corresponds to occurrence of a strong earthquake.On the basis of the proposed model showing the behavior of the geomedium containing defects in the field of external stresses, it is possible to describe main ways of stress relaxation in the rock massives – brittle large-scale destruction and cataclastic deformation as consequences of the collective behavior of defects, which is determined by the structural scaling parameter.Results of this study may prove useful for estimation of critical stresses and assessment of the geomedium status in seismically active regions and be viewed as model representations of the physical hypothesis about the uniform nature of deve­lopment of discontinuities/defects in a wide range of spatial scales. В работе описана статистико-термодинамическая эволюция ансамбля дефектов в геосреде в поле внешнего приложенного напряжения. Авторами вводятся тензорные  структурные переменные, ассоциированные с двумя характерными типами дефектов: трещинами и локализованными сдвигами (рис. 1). Процедура осреднения структурных переменных по статистическому ансамблю дефектов позволила получить уравнение самосогласования, определяющее зависимость макроскопического тензора деформации, индуцированной дефектами, от величины внешних напряжений, исходной структуры и взаимодействия дефектов, которое в безразмерном случае содержит только один параметр – параметр структурного скейлинга. Параметр структурного скейлинга определяется отношением характерных структурных масштабов: размером дефектов и средним расстоянием между дефектами.В результате решения уравнения самосогласования получено три характерных реакции геосреды с дефектами на рост внешнего напряжения (рис. 2), которые определяются величиной параметра структурного скейлинга. Формулировка неравновесной свободной энергии для среды с дефектами в форме, аналогичной разложению Гинзбурга-Ландау, позволила записать эволюционные уравнения для введенных параметров порядка (деформации, обусловленной дефектами, и параметра структурного скейлинга) и исследовать их собственные  решения (рис. 3).Показано, что первая реакция соответствует устойчивому квазипластическому деформированию среды, локализованному в регулярно расположенных пространственных областях, характеризующихся отсутствием коллективных ориентационных эффектов. Уменьшение параметра структурного скейлинга приводит ко второй реакции, которая характеризуется появлением области метастабильности в поведении среды с дефектами, когда при некотором критическом напряжении происходит ориентационный переход в ансамбле взаимодействующих дефектов, сопровождающийся резким скачком деформации (рис. 2). При этом на масштабе наблюдения (осреднения) этот переход проявляется в виде локализованной катакластической деформации (множества слабых землетрясений), мигрирующей по пространству со скоростью, на порядки меньшей скорости звука – «медленной» деформационной волны (рис. 3). Дальнейшее уменьшение параметра структурного скейлинга приводит к вырождению ориентационной метастабильности и формированию в среде локализованных диссипативных дефектных структур, которые при достижении критического напряжения развиваются в режиме с обострением – режиме лавинно-неустойчивого роста дефектов в локализованной пространственной области, уменьшающейся с течением времени. На масштабе наблюдения этот процесс проявляется в виде хрупкого разрушения с формированием зоны разрушения, соизмеримой с самим масштабом наблюдения, и соответствует появлению сильного землетрясения.Таким образом, построенная модель поведения геосреды с дефектами в поле внешних напряжений позволяет описать основные способы релаксации напряжений массивами горных пород: хрупкое крупномасштабное разрушение и катакластическое деформирование, которые являются следствиями коллективного поведения дефектов, определяемого величиной параметра структурного скейлинга.Полученные результаты могут быть полезны для оценки критических напряжений и состояний геосреды в сейсмоактивных районах, а также могут рассматриваться как модельные представления физической гипотезы о единстве природы развития несплошностей (дефектов) на широком спектре пространственных масштабов

    IMPROVEMENT OF TREATMENT OF UNFORMED DUODENAL AND HIGH JEJUNAL FISTULAS

    Get PDF
    This article shows many years of surgical experience of treatment of unformed duodenal and high jejunal fistulas using specific combined methods in main treatment group. The review covers the period from 2000 to 2016 years, which includes treatment of 132 patients who suffered from unformed duodenal and high jejunal fistulas. The research was conducted on the basis of the Republic Clinical hospital of G.G. Kuvatov in Bashkortostan. We followed the purpose of analysis and evaluation of the structure and quantity of early postoperative complications, including purulent-septic complications, as well as postoperative lethality, by comparing the main and control groups of treated patients, who received different kinds of therapy of unformed duodenal and jejunal fistulas. The treatment complex (main treatment group) consists of local use of collagen to strengthen intestinal sutures; selective injections of angioprotectors to blood vessels to improve microcirculation and trophic tissues; laser and antibiotic therapy for better eradication of microorganisms. The obtained results showed that the technique developed by us allowed to reduce the frequency of inconsistency of intestinal sutures, the number of newly formed intestinal fistula and purulent-septic complications in the treatment of patients with unformed duodenal and high jejunal fistulas

    Клинико-этиологическая характеристика смешанных инфекций у детей в стационаре г. Ижевска

    Get PDF
    Aim: to study the structure, features of the findings and treatment of mixed infections in children at the present stage.Materials and methods. 85 case histories of children aged 5 months to 17 years and 10 months were examined, the final diagnosis of which included 2 or more infections on the basis of the children's infectious diseases department City Clinical Hospital № 7 of Izhevsk. Children with acute infectious pathology (acute intestinal infections, acute respiratory infections, herpes infections) are hospitalized in this hospital. Diagnostic methods: polymerase chain reaction, ELISA, bacteriological.Results. Mixed infections are equally common in both boys and girls, while there is a predominance of mixed infections in young children (up to 1 year and from 1 year to 3 years) 62.4%. The structure of infectious morbidity is consistently dominated by acute enteric infection – 83.5% cases and acute respiratory infections – 53.0% cases. The progression of SARS-CoV-2-associated and herpes-associated mixed infections is characterized by a pronounced polymorphism of clinical manifestations. The etiological factor for each nosology was deciphered only in 17.7%; in 43.5% of cases, only one etiological factor was verified in the laboratory; in 38.8% of cases, no etiological factor was confirmed in the laboratory.Цель: изучить структуру, особенности клинического течения и лечения смешанных инфекций у детей на современном этапе.Материалы и методы. На базе детского инфекционного отделения БУЗ УР «ГКБ №7 МЗ УР» г. Ижевска нами были исследованы 85 историй болезни детей в возрасте от 5 месяцев до 17 лет 10 месяцев, заключительный диагноз которых включал 2 и более инфекции. В данный стационар госпитализируются дети с острой инфекционной патологией: острые респираторные инфекции (ОРИ), острые кишечные инфекции (ОКИ), герпесвирусные инфекции. Диагностические методы: ПЦР, ИФА, бактериологический.Результаты. Микст-инфекции одинаково часто встречаются как у мальчиков, так и у девочек, при этом отмечается преобладание микст-инфекций у детей младшего возраста (до 1 года и от 1 года до 3-х лет) – в 62,4%. В структуре инфекционной заболеваемости стабильно доминируют ОКИ – 83,5% случаев и ОРИ – 53% случаев. Течение SARS-CoV-2-ассоциированных и герпесвирусных-ассоциированных микст-инфекций характеризуется выраженным полиморфизмом клинических проявлений. Этиологический фактор для каждой нозологии был расшифрован только в 17,7%; в 43,5% случаев лабораторно был верифицирован только один этиологический фактор; в 38,8% случаев ни один этиологический фактор не был подтвержден лабораторно

    Major challenges in clinical management of TB/HIV coinfected patients in Eastern Europe compared with Western Europe and Latin America

    Get PDF
    Objectives Rates of TB/HIV coinfection and multi-drug resistant (MDR)-TB are increasing in Eastern Europe (EE). We aimed to study clinical characteristics, factors associated with MDR-TB and predicted activity of empiric anti-TB treatment at time of TB diagnosis among TB/HIV coinfected patients in EE, Western Europe (WE) and Latin America (LA). Design and Methods Between January 1, 2011, and December 31, 2013, 1413 TB/HIV patients (62 clinics in 19 countries in EE, WE, Southern Europe (SE), and LA) were enrolled. Results Significant differences were observed between EE (N = 844), WE (N = 152), SE (N = 164), and LA (N = 253) in the proportion of patients with a definite TB diagnosis (47%, 71%, 72% and 40%, p<0.0001), MDR-TB (40%, 5%, 3% and 15%, p<0.0001), and use of combination antiretroviral therapy (cART) (17%, 40%, 44% and 35%, p<0.0001). Injecting drug use (adjusted OR (aOR) = 2.03 (95% CI 1.00–4.09), prior anti-TB treatment (3.42 (1.88–6.22)), and living in EE (7.19 (3.28–15.78)) were associated with MDR-TB. Among 585 patients with drug susceptibility test (DST) results, the empiric (i.e. without knowledge of the DST results) anti-TB treatment included ≥3 active drugs in 66% of participants in EE compared with 90–96% in other regions (p<0.0001). Conclusions In EE, TB/HIV patients were less likely to receive a definite TB diagnosis, more likely to house MDR-TB and commonly received empiric anti-TB treatment with reduced activity. Improved management of TB/HIV patients in EE requires better access to TB diagnostics including DSTs, empiric anti-TB therapy directed at both susceptible and MDR-TB, and more widespread use of cART

    A new health care index predicts short term mortality for TB and HIV co-infected people

    Get PDF
    BACKGROUND: Using 2004–2007 TB:HIV Study data from Europe and Latin America, we previously generated a health care index (HCI) for TB and HIV co-infected people. With improvements in diagnostic and management practices, we have now updated the HCI with new data. METHODS: We evaluated nine aspects of health care in Cox proportional hazards models on time from TB diagnosis to death. Kaplan-Meier methods were used to estimate the probability of death by HCI quartile. RESULTS: Of 1396 eligible individuals (72% male, 59% from Eastern Europe), 269 died within 12 months. Use of rifamycin/isoniazid/pyrazinamide-based treatment (HR 0.67, 95% CI 0.50–0.89), TB drug susceptibility testing (DST) and number of active TB drugs (DST + <3 drugs (HR 1.09, 95% CI 0.80–1.48), DST + ≥3 drugs (HR 0.49, 95% CI 0.35–0.70) vs. no DST), recent HIV-RNA measurement (HR 0.64, 95% CI 0.50–0.82) and combination antiretroviral therapy use (HR 0.72, 95% CI 0.53–0.97) were associated with mortality. These factors contributed respectively 5, –1, 8, 5 and 4 to the HCI. Lower HCI was associated with an increased probability of death; 30% (95% CI 26–35) vs. 9% (95% CI 6–13) in the lowest vs. the highest quartile. CONCLUSION: We found five potentially modifiable health care components that were associated with mortality among TB-HIV positive individuals. Validation of our HCI in other TB cohorts could enhance our findings

    Результаты реализации проекта по борьбе с сердечно-сосудистыми заболеваниями в региональном сосудистом центре

    Get PDF
    The article presents an analysis of the outcome of the project dedicated to cardiovascular disease prevention in the Regional Vascular Center, the analysis involved the assessment of changes in the characteristics of deceased patients. The study made it possible to identify changes in mortality rate, the impact of new diagnostic and treatment techniques and administrative decisions on the change in mortality, as well as aspects that prevent further reduction in mortality. Aim. To assess the results of the implementation of new methodological approaches to cardiovascular diseases prevention, myocardial infarction in particular, in the Regional Vascular Center. Methods. The study involved the analysis of the data (entered in real time) from the Emergency Cardiac Care Department of the Сardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, and data from the Department`s database containing anamnestic and clinical characteristics of patients, and recording of deaths in the period from 2014 to 2019. Statistical data processing was performed using the StatSoft Statistica software (ver. 10.0).  Results. From 2014 to 2019, percutaneous coronary intervention (PCI) in myocardial infarction (MI) increased from 48 to 67.4% (p˂0.05); the primary PCI in MI with ST segment elevation (STEMI) increased from 24% to 32% (p˂0.001), the overall frequency of PCI in STEMI (primary + rescue + delayed) increased from 59.6% to 73% (p˂0.05); PCI in MI without ST segment elevation (NSTEMI) increased from 23.9% to 43.9% (p˂0.001), the frequency of intra-aortic balloon counterpulsation increased from 0.6% to 1.5% (p˂0.05), the frequency of mechanical ventilation did not change (8,3 and 8,5%), moreover the widespread use of ticagrelor and prasugrel was noted. At the same time, hospital mortality of patients with MI decreased from 9.8 to 8.0% (p&gt;0,05): in patients with STEMI it decreased from 10.7% to 7.7% (p = 0.047), in patients with NSTEMI there was no change in mortality, it remained equal to 8–9%. Implementation of coronary reperfusion strategies that do not involve streptokinase is associated with a decrease in hospital mortality of patients with STEMI. Conclusion. The widespread introduction of modern invasive and medicinal technologies has led to a decrease in mortality of patients with STEMI. Further increasing the number of available invasive procedures – PCI, intra-aortic balloon counterpulsation and mechanical ventilation for the purposes of reducing mortality of patients with MI seems questionable.В статье представлен анализ результатов реализации проекта по борьбе с сердечно-сосудистыми заболеваниями в региональном сосудистом центре, основанный на изменении характеристики умерших больных. Исследование позволило определить изменения в структуре летальности, влияние внедрения новых лечебно-диагностических методик и административных решений на изменение летальности, а также аспекты, препятствующие дальнейшему снижению летальности. Цель. Оценить результаты внедрения новых организационно-методических подходов при инфаркте миокарда (ИМ) в региональном сосудистом центре. Материалы и методы. Проанализированы данные электронных таблиц, которые вели в онлайн-режиме в отделении неотложной кардиологии НИИ кардиологии Томского НИМЦ, информация из базы данных отделения, содержащая анамнестические и клинические данные о больных, а также журналы учета летальных исходов в 2014 и 2019 гг. Результаты. С 2014 до 2019 г. частота чрескожных коронарных вмешательств (ЧКВ) при ИМ увеличилась с 48 до 67,4% (р˂0,05): частота первичного ЧКВ при инфаркте миокарда с элевацией сегмента ST (STEMI) – с 24 до 32% (р˂0,001), общая частота ЧКВ при STEMI (первичная + спасительная + отсроченная) – с 59,6 до 73% (р˂0,05), частота ЧКВ при инфаркте миокарда без элевации сегмента ST (NSTEMI) – с 23,9 до 43,9% (p˂0,001), частота использования внутриаортальной баллонной контрпульсации – с 0,6 до 1,5% (р˂0,05), частота проведения искусственной вентиляции легких не изменилось – 8,3 и 8,5% соответственно; начато широкое использование тикагрелора и прасугрела. За это же время госпитальная летальность при ИМ снизилась с 9,8 до 8,0% (p&gt;0,05). Это произошло за счет снижения летальности при STEMI с 10,7 до 7,7% (p = 0,047); при NSTEMI изменения летальности не зафиксировано: 8 и 9% соответственно. Отказ от стрептокиназы в пользу других методов коронарной реперфузии ассоциирован со снижением госпитальной летальности при STEMI. Заключение. Внедрение и расширение применения современных инвазивных и лекарственных технологий привело к снижению летальности при STEMI. Эффективность дальнейшего увеличения количества имеющихся инвазивных процедур – ЧКВ, внутриаортальной баллонной контрпульсации и искусственной вентиляции легких – для снижения летальности при ИМ представляется сомнительной

    Major differences in organization and availability of health care and medicines for HIV/TB coinfected patients across Europe

    No full text
    Objectives The aim of the study was to investigate the organization and delivery of HIV and tuberculosis (TB) health care and to analyse potential differences between treatment centres in Eastern (EE) and Western Europe (WE). Methods Thirty-eight European HIV and TB treatment centres participating in the TB:HIV study within EuroCoord completed a survey on health care management for coinfected patients in 2013 (EE: 17 respondents; WE:21; 76% of all TB:HIV centres). Descriptive statistics were obtained for regional comparisons. The reported data on health care strategies were compared with actual clinical practice at patient level via data derived from the TB:HIV study. Results Respondent centres in EE comprised: Belarus (n = 3), Estonia (1), Georgia (1), Latvia (1), Lithuania (1), Poland (4), Romania (1), the Russian Federation (4) and Ukraine (1); those in WE comprised: Belgium (1), Denmark (1), France (1), Italy (7), Spain (2), Switzerland (1) and UK (8). Compared with WE, treatment of HIV and TB in EE are less often located at the same site (47% in EE versus 100% in WE; P < 0.001) and less often provided by the same doctors (41% versus 90%, respectively; P = 0.002), whereas regular screening of HIV-infected patients for TB (80% versus 40%, respectively; P = 0.037) and directly observed treatment (88% versus 20%, respectively; P < 0.001) were more common in EE. The reported availability of rifabutin and second- and third-line anti-TB drugs was lower, and opioid substitution therapy (OST) was available at fewer centres in EE compared with WE (53% versus 100%, respectively; P < 0.001). Conclusions Major differences exist between EE and WE in relation to the organization and delivery of health care for HIV/TB-coinfected patients and the availability of anti-TB drugs and OST. Significant discrepancies between reported and actual clinical practices were found in EE
    corecore