Features of the structural organization of phytoplankton of coastal shallow water of Volga and Volga-Kama reaches of the Kuibyshev reservoir

Kuibyshev reservoir (Russia) is the sixth step of Volga cascade and ranks first in area in Europe and sec-ond in the world among all the reservoirs created in the river valleys. A characteristic feature of Kuibyshev res-ervoir is the presence of extended shallow water areas, which total area with the depth of up to 2 m is up to 15% of the total area of the reservoir, while a considerable part of shallow water overgrows with macrophytes. The most extended areas of overgrown shallow waters are located in Volga and Volga-Kama reaches of the reservoir. Biological communities of shallow waters function in the increased fluctuation of the environment modes and are characterized by specific structural and functional organization, which main feature is the ad-aptation mechanisms of biocoenosis components and maintenance of its stability in dynamic environment. To determine the formation features of structure of phytoplankton in different biotopes of shallow waters of Kui-byshev reservoir, we studied the latter in Typha angustifolia L., Phragmites australis (Cav.) Trin. Ex Steud. thickets and in open water areas (thickets-free). We were conducting studies in 2002-2005 in two shallow bays of Volga and Volga-Kama reaches differing in the severity of human impact, protection from wind and wave action and other conditions. As a result of studies we have revealed that the most aligned phytoplankton communities with a high species diversity are common to areas with macrophyte beds where anthropogenic impact is minimized. Environmental conditions in shallow open water are less stable than in macrophyte thick-ets, which is due to the dynamics of water masses in the water. We also revealed a tendency to the quantita-tive increase in heterotrophic algae in polluted thicket communities compared to areas with superior water quality. Maximum qualitative and quantitative characteristics of phytoplankton are common to protected shallow waters of the contaminated and poorly flowing bays also characterized by significant differences in species composition between the shallow open water and macrophyte thickets, while there is a slight differ-ence in the overall quantitative indicators between the thickets and the shallow open waters. Impact of mac-rophytes on plankton algae vegetation in water hypertrophicity is slightly expressed, and the nutrients abounding in this area do not serve as a limiting factor for algae

Characteristics of algocenoses of small water reservoirs at the territory of the National Park "Nizhnyaya Kama" being influenced by oil production

There was investigated chemical composition of water and bottom sediments as well as characteristics of algocenoses (number of species, population, biomass, saprobity index, Shannon index for population and biomass) in 8 water reservoirs at the territory of the National Park "Nizhnyaya Kama" (the Republic of Tatarstan, Russia). The water reservoirs under investigation are polluted with oil as a result of accidental spills at time of its transportation and production which has been carried out at the water shed area since the sixties of the 20th century. Oil products accumulation in bottom sediments was revealed, their content in sediments exceeded the content in water by 47-889 times. There were determined dominant complexes of algae species depending on the range of oil products content in water and bottom sediments. A response reaction of algae to high oil products concentration in water (0.48-1.44 mg/l) and bottom sediments (9137-17780 mg/kg) is expressed by reduction of species diversity and decrease of quantitative characteristics of algae up to complete disappearance. Through a correlation analysis there was identified a dependency between algal community indices (number of species, biomass, Shannon index for population) and a content of nutrient substances (ammonium salts, nitrites) as well as of ferrum. No significant correlation dependencies between oil products content in water, bottom sediments and the algal community indices were revealed

Seasonal dynamics of planktonic algae in the right bank of the Volga reach of the Kuibyshev Reservoir

The paper deals with the seasonal dynamics and spatial distribution patterns of planktonic algae in the right bank of the Kuibyshev reservoir (the Volga river) during growing season (June-September) of 2015. The Kuibyshev reservoir (Republic of Tatarstan, Russia), formed as a result of the river Volga stanching with a dam of the Volga hydroelectric station, has a pronounced coastal asymmetry. Along the right bank there stretches the Volga Upland and rocky Zhiguli Mountains. The left bank is mostly flat and low-lying. The large difference between the right and left banks causes the differing hydrological conditions along the reservoir, which affect the living conditions of aquatic organisms, and especially planktonic algae - phytoplankton. The total abundance and biomass of planktonic algae ranged 0.45-1584.21 mln.cells/l and 0.44-109.35 mg/l. The algae, quantitavely dominating in the phytoplankton, are those of phylum Cyanophyta,Chlorophyta,Dinophytaand class Bacillariophycea. In 2015, the level dynamics in the reservoir was high and stable, close to the normal headwater level - 53 m, resulting in quite short and not so intense phenomenon of "blooming" water as can be seen usually in the summer and summer-autumn period in Kuibyshev reservoir. During the study, the coefficients of Spierman correlation between the indices of phytoplankton, air temperature, water temperature and water level fluctuation were calculated, and some relations were found. A negative correlation (r= -0.65 at p<0.05) was observed between the quantitative indices of phytoplankton (the total abundance and biomass) and the water level. Together with the decline in water level an increase in the content of the blue-green algae was observed (r= -0.7 both for abundance and biomass at p<0.05). No significant correlations between water temperature, air temperature and the indicators of algal communities were observed. The results of this study will be used in the monitoring and forecasting research of the rivers of the Republic of Tatarstan

Seasonal dynamics of phytoplankton communities residing in different types of shallow waters in the Kuibyshev Reservoir (Russia)

© 2015, The Author(s). Unstable water level regime in the Kuibyshev Reservoir affects coastline formation as well as allocation and development of aquatic vegetation on the coast. These factors determine the composition and structure of biocenosis in shallow waters of the reservoir. The aim of this study was to reveal the patterns of formation, distribution and dynamics in phytoplankton communities in the shallow coastal waters on two reaches of the Kuibyshev Reservoir (Volga and Volga-Kama, Russia). These reaches differ by the extent of anthropogenic influence, protection from wind and waves and other environmental conditions. The research was done during the growing season of 2002 in the thickets of Typha angustifolia L. and Phragmites australis (Cav.) Trin. Ex Steud., as well as in the open water areas. Seasonal changes in the total biomass and abundance of phytoplankton in the thickets of macrophytes and in the open areas of the reservoir differed little. On the outer edge of the thickets, where intensive contact with the open water occurs, the highest algal species diversity and abundance were revealed, which is known as the “edge effect”. Two peaks of phytoplankton development with maximums in June–July and late August were observed. By the end of the summer, a decrease in water level led to the autumn outbreak in volvocine algae abundance and biomass. The maintaining of an optimal water level in the reservoir is recommended for controlling of water “blooming” and thus maintaining high water quality

Species composition of planktonic algae of termokarst lakes of Khatanga River Basin (Krasnoyarsk Region, Russia)

Objective of this study was to determine the species composition of modern planktonic algae in the range of thermokarst lakes of Khatanga River basin (Krasnoyarsk region, Russia). The Khatanga River flows in the North-Siberian lowland in the south-eastern part of the Taimyr Peninsula and flows into the Khatanga Gulf of the Laptev Sea. The river basin has about 112 thousand lakes with a total area of 12 thousand sq.km. Today, M.K. Ammosov North-Eastern Federal University (Yakutsk), A. Wegener Institute for Marine and Polar Research (AWI, Potsdam, Germany), and Kazan Federal University has entered into agreement on cooperation in the sphere of science and higher professional education. In the framework of this agreement, in August 2013, an expedition was conducted to study the limnological characteristics of the lakes in Yakutia in order to reconstruct the Holocene history, during which the algological water samples from and hydro-chemical and morphometric data on 18 lakes were obtained. During the observation period, we found 164 algae taxa belonging to 6 different groups in phytoplankton of the investigated water bodies. The greatest number of taxa were identified in the groups of diatoms and chlorococcaceae. According to the ecological and geographical characteristics, the dominant species in these lakes are cosmopolitan and boreal algae. In relation to halobility, most species are indifferent and oligohalobic, and in terms of pH the most common are the indifferent and alkaliphile + alkalibiontic organisms

Seasonal and year-to-year dynamics of phytoplankton in connection with the level regime of the Kuibyshev Reservoir

The results of long-term observations are USED to analyze the seasonal and year-to-year variations of the abundance and biomass of planktonic algae in connection with the seasonal dynamics of water level in the Kuibyshev Reservoir. The dynamics of level regime in the reservoir in combination with climate conditions are a determining factor for phytoplankton development. The adverse effects of eutrophication (in particular, water blooming) can be reduced by maintaining an optimal water level in the reservoir'not below the normal water level (53 m BS) in the summer. © Pleiades Publishing, Ltd. 2009

Effect of Sn doping on sinterability and electrical conductivity of strontium hafnate

Received: 16.02.23. Revised: 13.03.23. Accepted: 14.03.23. Available online: 17.03.23.SEM and XRD experiments were done using the facilities of the shared access centre "Composition of compounds” (Institute of High-Temperature Electrochemistry, Ural Branch of the Russian Academy of Sciences). The authors are grateful to Artem Tarutin for the help with the meas-urements of conductivity by the DC 4-probe method.Ceramic samples SrHfxSn1–xO3–δ (x = 0–0.16) were obtained by the solid-phase method.Sn doping enhances the sintering ability of ceramics.Sn doping results in an increase in conductivity by more than 2 orders of magnitude.The effect of isovalent substitution of hafnium by tin in strontium hafnate on sinterability and electrical conductivity was studied for the first time. The ceramic samples SrHfxSn1–xO3–δ (x = 0–0.16) were synthesized by solid-state reaction and sintered at 1600 °C for 5 h. The samples were examined using the methods of X-ray diffraction, scanning electron microscopy, impedance spectroscopy, and four-probe direct current technique. It was shown that all samples were phase pure and had the orthorhombic structure of SrHfO3 with the Pnma space group. Sn doping resulted in an increase in grain size, relative density and conductivity; the sample with x = 0.08 demonstrated the highest conductivity, which was ~830 times greater than that of undoped strontium hafnate at 600 °C. The conductivity of SrHf0.92Sn0.08O3–δ was 4.1∙10–6 S cm–1 at 800 °C in dry air. The possible reasons for the effect of Sn on the electrical properties of strontium hafnate were discussed

Development of Approaches to the Study of the Interaction of Biologically Active Thioterpenoids with Model Membranes

© 2017, Springer Science+Business Media, LLC. It was shown that the synthesized camphene sulfone, in contrast to acetylsalicylic acid and clopidogrel, completely inhibits the activation of platelets induced by adrenaline and arachidonic acid, and reduces the influence of ADP, collagen, and ristocetin. Detailed NMR studies and molecular dynamics simulations using model SDS membranes indicated that the sulfone is embedded by its bicyclic part inside the SDS micelle, whereas -SO 2 (CH 2 ) 2 OH fragment of sulfone is located on the outer part of the micelle and accessible for solvent. It was ascertained that hemocoagulant activity of sulfone is caused by its capability of inhibition of platelet activation and suppression of catalytic activity of phospholipid surface participating in formation of coagulation complexes of clotting factors

Drosophila Lipophorin Receptors Mediate the Uptake of Neutral Lipids in Oocytes and Imaginal Disc Cells by an Endocytosis-Independent Mechanism

Lipids are constantly shuttled through the body to redistribute energy and metabolites between sites of absorption, storage, and catabolism in a complex homeostatic equilibrium. In Drosophila, lipids are transported through the hemolymph in the form of lipoprotein particles, known as lipophorins. The mechanisms by which cells interact with circulating lipophorins and acquire their lipidic cargo are poorly understood. We have found that lipophorin receptor 1 and 2 (lpr1 and lpr2), two partially redundant genes belonging to the Low Density Lipoprotein Receptor (LDLR) family, are essential for the efficient uptake and accumulation of neutral lipids by oocytes and cells of the imaginal discs. Females lacking the lpr2 gene lay eggs with low lipid content and have reduced fertility, revealing a central role for lpr2 in mediating Drosophila vitellogenesis. lpr1 and lpr2 are transcribed into multiple isoforms. Interestingly, only a subset of these isoforms containing a particular LDLR type A module mediate neutral lipid uptake. Expression of these isoforms induces the extracellular stabilization of lipophorins. Furthermore, our data indicate that endocytosis of the lipophorin receptors is not required to mediate the uptake of neutral lipids. These findings suggest a model where lipophorin receptors promote the extracellular lipolysis of lipophorins. This model is reminiscent of the lipolytic processing of triglyceride-rich lipoproteins that occurs at the mammalian capillary endothelium, suggesting an ancient role for LDLR–like proteins in this process

КЛИНИКО-ЭПИДЕМИОЛОГИЧЕСКИЕ ОСОБЕННОСТИ РЕСПИРАТОРНО-СИНЦИТИАЛЬНОЙ ВИРУСНОЙ ИНФЕКЦИИ У ДЕТЕЙ ПЕРВОГО ГОДА ЖИЗНИ

The purpose was to study the clinical and epidemiological features of respiratory syncytial virus infection in hospitalized children the first year of life with lower respiratory tract diseases in different regions of the Russian Federation (Russia) during the 2015–2016 epidemic season.Materials and methods: in the original study data of a multicentre observational study conducted on the basis of children’s hospitals in St. Petersburg, Arkhangelsk, Kazan, and Saratov are presented. Etiology of acute respiratory viral infections were confirmed by examination of smears from the posterior pharyngeal wall by polymerase chain reaction. The study sample included 991 child’s first year of life with lesions of the lower respiratory tract.Results. In the etiological structure of the surveyed children in the season of 2015-2016, RSVI ranged from 14% to 46,2%, an average of 33%. RSVI dominated in the Centers of St. Petersburg (38,3%), Arkhangelsk (36.2%) and Kazan (42.5 per cent).RSVI significantly more often (p&lt;0.01) leads to the development of bronchiolitis (29.4% against 16.3% and 10.0%, with rhinovirus infection and parainfluenza, respectively. Patients with RSUI often develop pneumonia (23,5%) vs 20.6% and 20,0% with rhinovirus infection, and parainfluenza. Patients with RSVI often suffer severe forms of the disease require oxygen support (13,8%) and treatment in the departmentof intensive care (15,9%).Seasonal peaks of hospitalization due to RSVI in all Centres were recorded in December-April 2015 and 2016. Regional differences in monthly intensity of hospitalization of children with RSVI were established.Thus, the high prevalence of RSVI among children in the first year of life, especially with heavy and complicated forms of lower respiratory tract disorders requiring intensive care benefits, represents a socially important issue, which requires monitoring for effective prevention in children at risk. Целью настоящего исследования являлось изучение клинико-эпидемиологических особенностей респираторно-синцитиальной вирусной инфекции (РСВИ) у госпитализированных по поводу заболеваний нижних дыхательных путей детей первого года жизни в различных регионах Российской Федерации (РФ) в эпидемический сезон 2015–2016 гг.Материалы и методы: в оригинальном исследовании представлены данные многоцентрового наблюдательного исследования, проведенного на базе детских стационаров Санкт-Петербурга, Архангельска, Казани, Саратова. Этиологию острых респираторных вирусных инфекций подтверждали исследованием мазков с задней стенки глотки методом полимеразной цепной реакции. Всего обследован 991 ребенок первого года жизни с поражением нижних дыхательных путей.Результаты: в этиологической структуре обследованных детей в сезон 2015–2016 гг. РСВИ составляла от 14% до 46,2%. РСВИ доминировала в центрах Санкт-Петербурга (38,3%), Архангельска (36,2%) и Казани (42,5%). РСВИ достоверно чаще приводит к развитию бронхиолита (29,4%), чем риновирусная инфекция и парагрипп (16,3% и 10,0% соответственно) (р&lt;0,01), а также пневмонии – 23,5% против 20,6% и 20,0% при риновирусной инфекции и парагриппе. Пациенты с РСВИ чаще переносят тяжелые формы заболевания, требуют кислородной поддержки (13,8%) и лечения в условиях отделения реанимации и интенсивной терапии (15,9%). Сезонные пики госпитализации, обусловленной РСВИ, во всех центрах регистрировали в декабре – апреле 2015 и 2016 гг. Установлены региональные различия в помесячной интенсивности госпитализации детей с ОРВИ.Таким образом, высокая распространенность РСВИ среди детей первого года жизни, особенно с тяжелыми и осложненными формами поражения нижних дыхательных путей, с необходимостью реанимационного пособия, представляет социально-значимую проблему, что требует проведения мониторинга для эффективной профилактики у детей групп риска.