Inter-annual and decadal changes in teleconnections drive continental-scale synchronization of tree reproduction

Climate teleconnections drive highly variable and synchronous seed production (masting) over large scales. Disentangling the effect of high-frequency (inter-annual variation) from low-frequency (decadal trends) components of climate oscillations will improve our understanding of masting as an ecosystem process. Using century-long observations on masting (the MASTREE database) and data on the Northern Atlantic Oscillation (NAO), we show that in the last 60 years both high-frequency summer and spring NAO, and low-frequency winter NAO components are highly correlated to continent-wide masting in European beech and Norway spruce. Relationships are weaker (non-stationary) in the early twentieth century. This finding improves our understanding on how climate variation affects large-scale synchronization of tree masting. Moreover, it supports the connection between proximate and ultimate causes of masting: indeed, large-scale features of atmospheric circulation coherently drive cues and resources for masting, as well as its evolutionary drivers, such as pollination efficiency, abundance of seed dispersers, and natural disturbance regimes

Математическая оценка гемолиза канального центробежного насоса

The objective of this work is to conduct research on a mathematical model to assess hemolytic characteristics in a channel centrifugal blood pump developed by us with 2000–3400 rpm impeller speed range and 100–250 mmHg pressure drop in different parts of the pump flow path. Hemolysis index was measured at 1 to 10 L/min flow rate. The result was an estimate of the average magnitude of the shear stress (SS), taking into account the distribution in the pump, which ranged from 40 to 60 Pa. The most critical areas of the pump in terms of blood injury were evaluated. The maximum SSs were determined: 456 Pa in the impeller wheel zone and 533.3 Pa in the adjacent area of the body, with an exposure time of 0.0115 s and 0.0821 s respectively. In these zones, maximum hemolysis index values were 0.0420 and 0.0744 respectively. Based on the data obtained, these zones were optimized in terms of minimizing hemolysis.Целью работы является проведение исследований на математической модели по оценке гемолитических характеристик в разработанном нами канальном центробежном насосе в диапазоне скоростей рабочего колеса 2000–3400 об/мин и перепадом давления 100–250 мм рт. cт. в разных отделах проточного тракта насоса. Расчетный индекс гемолиза проведен при скоростях потока от 1 до 10 л/мин. Результатом работы явилась оценка среднего значения касательного напряжения (КН) с учетом распределения в насосе, которое составило от 40 до 60 Па. Были проведены оценки наиболее критичных с точки зрения травмы крови зон насоса. В результате расчетов определены максимальные КН в зоне РК 456 Па и прилежащей зоне корпуса 533,3 Па, при соответствующем времени экспозиции 0,0115 и 0,0821 с. В этих зонах наблюдаются максимальные значения ИГ 0,0420 и 0,0744. На основании полученных данных была проведена оптимизация данных зон с точки зрения минимизации гемолиза

Bush Encroachment of Forest-steppe Landscapes in the Mongolian Part of the Lake Baikal Basin

The character of competitive relationships between woody and shrub vegetation in the southern (Mongolian) part of the Lake Baikal basin was studied via model polygons. Depending on the environmental conditions, native forests are being replaced by different types of shrubs. The main factors contributing to these changesare the aridization of the climate and human activity. It is shown that the current state of shrub communities and their progressive dynamics along the southern border of boreal forests in Mongolia allow us to consider them stable cenoses, which prevent a natural renewal of coniferous (pine, larch) forests in this region. However, some shrub species may be considered indicators of ecotopes’ suitability for natural or artificial reforestation because their ecological requirements are similar to those of forest trees. Keywords: Lake Baikal basin, ecotone area, destruction of forests, bush encroachmen

Two centuries of masting data for European beech and Norway spruce across the European continent

Tree masting is one of the most intensively studied ecological processes. It affects nutrient fluxes of trees, regeneration dynamics in forests, animal population densities, and ultimately influences ecosystem services. Despite a large volume of research focused on masting, its evolutionary ecology, spatial and temporal variability and environmental drivers are still matter of debate. Understanding the proximate and ultimate causes of masting at broad spatial and temporal scales will enable us to predict tree reproductive strategies and their response to changing environment. Here we provide broad spatial (distribution range-wide) and temporal (century) masting data for the two main masting tree species in Europe, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.). We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys. The dataset has a total of 1747 series and 18348 yearly observations from 28 countries and covering a time span of years 1677-2016 and 1791-2016 for beech and spruce, respectively. For each record, the following information is available: identification code; species; year of observation; proxy of masting (flower, pollen, fruit, seed, dendrochronological reconstructions); statistical data type (ordinal, continuous); data value; unit of measurement (only in case of continuous data); geographical location (country, Nomenclature of Units for Territorial Statistics NUTS-1 level, municipality, coordinates); first and last record year and related length; type of data source (field survey, peer reviewed scientific literature, grey literature, personal observation); source identification code; date when data were added to the database; comments. To provide a ready-to-use masting index we harmonized ordinal data into five classes. Furthermore, we computed an additional field where continuous series with length >4 years where converted into a five classes ordinal index. To our knowledge, this is the most comprehensive published database on species-specific masting behaviour. It is useful to study spatial and temporal patterns of masting and its proximate and ultimate causes, to refine studies based on tree-ring chronologies, to understand dynamics of animal species and pests vectored by these animals affecting human health, and it may serve as calibration-validation data for dynamic forest models.The paper was partly funded by the “Fondo di Ricerca Locale 2015-2016” of the University of Torino and by the Stiftelsen Stina Werners fond (grant SSWF 10-1/29-3 to I.D.)

Разработка конструкции и 3D-модели устройства динамической фильтрации микропузырьков для систем искусственного кровообращения

The use of extracorporeal circulation systems (cardiopulmonary bypass pumps, ECMO) can lead to brain and coronary artery microembolism, which significantly reduces postoperative rehabilitation and often leads to severe complications. Microembolism occurs when oxygen or air microbubbles (MBs) enter the arterial system of patients. Existing CPB pumps come with built-in bubble trap systems but cannot remove bubbles in the circuit. ECMO devices have arterial filters but cannot reliably filter out <40 μm bubbles in a wide flow range. We have proposed an alternative method that involves the use of an efficient dynamic bubble trap (DBT) for both large and small bubbles. The design includes development of two DBT variants for hemodynamic conditions of adult and pediatric patients. The device is installed in the CPB pump and ECMO outlet lines. It provides sufficient bubble separation from the lines in a blood flow of 3.0–5.0 L/min for adults and 0.5–2.0 L/min for children. The developed computer models have shown that MBs smaller than 10 μm can be filtered. The use of this device will greatly reduce the likelihood of air embolism and provide the opportunity to reconsider the concept of expensive arterial filters.При использовании систем экстракорпорального кровообращения (АИК, ЭКМО) существует вероятность микроэмболии сосудов головного мозга и сердца, что существенно снижает постоперационную реабилитацию и нередко приводит к тяжелым осложнениям. Микроэмболия возникает из-за попадания микропузырьков (МП) кислорода или воздуха в артериальную систему пациентов. Существующие системы АИК имеют встроенные системы регистрации МП, но не включают системы удаления МП в контуре. Аппараты ЭКМО имеют артериальные фильтры, но не могут обеспечить надежную фильтрацию МП размером меньше 40 мкм в широком диапазоне расхода. Нами предложен альтернативный метод, который предполагает применение эффективного устройства динамической фильтрации (УДФ) как больших, так и малых пузырьков. Проектирование включает разработку двух вариантов УДФ для условий гемодинамики как взрослого, так и педиатрического пациентов. Устройство устанавливается в выходной магистрали АИК и ЭКМО и обеспечивает достаточную сепарацию пузырьков из магистралей в диапазоне кровотока 3,0–5,0 л/мин для взрослого пациента и 0,5–2,0 л/мин для педиатрического пациента. Разработанные компьютерные модели показали возможность сепарации МП размером менее 10 мкм. Применение данного устройства позволит уменьшить вероятность воздушной эмболии в несколько раз и позволит пересмотреть концепцию применения дорогостоящих артериальных фильтров

Biological activity comparative evaluation of the gene-Activated bone substitutes made of octacalcium phosphate and plasmid DNA carrying VEGF and SDF genes: Part 1 - in vitro

High need for effective bone substitutes and drawbacks of the materials approved for clinical use determine the increasing activity of biomedical research in this area. We have developed gene-Activated bone substitutes consisting of a scaffold based on octacalcium phosphate (OCP) and one of the two variants of plasmid DNA carrying either a gene for vascular endothelial growth factor (VEGF) or two genes encoding VEGF and stromal derived factor- 1α (SDF-1α). The aim of the study was to evaluate the cytotoxicity of the gene-Activated materials and their components, as well as biological activity in vitro. We found that both OCP and gene-Activated bone substitutes did not have any cytotoxicity, but reduced the proliferative activity of human bone marrow-derived multipotent mesenchymal stromal cells: material with doublegene construct decreased cell culture doubling rate of 24.3% more compared with the material carrying plasmid DNA encoding only VEGF. Both gene-Activated materials led to an increase in therapeutic genes mRNA levels, but the material with double-gene system enhanced VEGF protein production greater. Thus, the gene-Activated bone substitutes characterized by the absence of cytotoxic properties and possessed a specific activity increasing expression of the therapeutic genes. However, further studies are needed to detail the identified characteristics and assess the feasibility of the defined biological action in vivo

Разработка устройства канюли для удаления газовой фракции в системах дренажа крови

The development of low-traumatic surgical drains aimed at maximum possible separation of blood and air, is an important trend in modern medicine. The objective of this work is to create an inexpensive, user-friendly and low-traumatic dynamic blood aspiration system (DBAS). The system allows effective separation of blood and air when drawing blood from a wound under vacuum conditions required for blood aspiration. The operating principle of the system is to separate liquid and gas fractions of the blood-air mixture by modifying the blood intake cannula. The effect is achieved by applying the principles of centrifugal forces of a rotating blood-air flow combined with Archimedes lift forces.Разработка малотравматичных дренажных систем, работа которых направлена на максимально возможное разделение крови и воздуха, является актуальным направлением в современной медицине. Цель данной работы состояла в создании недорогой, удобной в пользовании и малотравматичной системы динамической аспирации крови. Система позволяет эффективно разделить кровь и воздух при заборе крови из раны в условиях вакуума, требуемого для аспирации крови. Принцип действия разработки заключается в разделении жидкой и газовой фракций смеси «кровь–воздух» за счет модификации канюли забора крови. Эффект достигается по технологии применения принципов центробежных сил вращающегося потока «кровь–воздух» в сочетании с подъемными архимедовыми силами

Оценка эффективности новой системы генерации пульсирующего потока в роторных насосах вспомогательного кровообращения. Исследование на математической модели

Objective: to study the effect of a pulsatile flow-generation (PFG) device on the basic hemodynamic parameters of the circulatory system using a mathematical model.Results. Modelling and simulation showed that the use of PFG significantly (76%) increases aortic pulse pressure. The proposed mathematical model adequately describes the dynamics of the circulatory system and metabolism (oxygen debt) on physical activity in normal conditions and heart failure, and the use of non-pulsatile and pulsatile circulatory-assist systems. The mathematical model also shows that the use of PFG device blocks the development of rarefaction in the left ventricular cavity associated with a mismatch of blood inflow and outflow in diastolic phase when there is need to increase systemic blood flow by increasing the rotary pump speed.Цель работы: на математической модели исследовать влияние устройства генерации пульсирующего потока (ГПП) на основные гемодинамические параметры системы кровообращения.Результаты. В результате моделирования показано значительное (76%) увеличение пульсового давления в аорте при использовании ГПП. Предложенная математическая модель адекватно описывает динамику системы кровообращения и метаболизма (кислородный долг) на физическую нагрузку в условиях нормы и сердечной недостаточности и применения непульсируюшей и пульсирующей системы вспомогательного кровообращения. На математической модели показано также, что применение устройства ГПП блокирует развитие разрежения в полости левого желудочка, связанного с несоответствием притока и оттока крови в диастолической фазе, при необходимости увеличения системного кровотока за счет повышения скорости роторного насоса