195 research outputs found
Effects of fires on vascular plant and microalgae communities of steppe ecosystems
The article is focused on a hypothesis verification: the higher plants, microalgae and cyanobacteria may be used in bioindication of steppe ecosystem restoration dynamics after fires. On the territory of the Askania Nova biosphere reserve (Ukraine) 4 stationary polygons were investigated: SP1 – steppe area which had not been exposed to fire for 20 years preceding our study, as well as areas where single fires occurred in 2001 (SP2), 2005 (SP3), and a site where fires occurred in 2001 and 2004 (SP4). The investigation revealed the dynamics of height and projected area of the higher vegetation according to seasons during two years (2010 and 2011), as well as abundance and biomass of microalgae and cyanoprokaryotes in the soil layer by the layer of the depth to 15 cm. It was found that the effects of pyrogenic load re-main evident for several years after the fires, manifesting in decrease of the height and projected area of herbage, the number and biomass of algae and cyanobacteria in the soil, especially to the depth of 5 cm. Multivariate general linear models were used to test the significance of the dependence of quantitative characteristics of vegetation, microalgae, and cyanoprokaryotes on environmental predictors (season, year, soil layer, and fire). In the model, 75.2% of the grass height variability and 91.6% of the grass projected area variability could be explained by the predictors under consideration. In the series SP1 → SP2 → SP3 → SP4 the grass height and projected area decreased. The differences in the projected area of the grass stand were most evident in spring. The model explained 89.1% of the variation in abundance and 91.6% of the variation in biomass of Bacillariophyceae. The abundance of Bacillariophyceae was greater in the upper soil layer than in the lower layer and decreased with depth. The abundance of this group of algae decreased in the series SP1 → SP2 → SP3 → SP4 at depths of 0–5 and 5–10 cm. Changes in abundances of Chlorophyta, Streptophyta, Heterokontophyta (Xanthophyceae and Eustigmatophyceae) equaling 47.6% could also be explained by the model. The abundance of this group of algae was greatest in the upper soil layer. In the upper soil layer, the maximum abundance of Chlorophyta, Streptophyta, and Heterokontophyta (Xanthophyceae and Eustigmatophyceae) was recorded for Polygon SP1 and the minimum for Polygon SP3. Within the model, 48.0% of the variation in biomass of Chlorophyta, Streptophyta, and Heterokontophyta (Xanthophyceae and Eustigmatophyceae) was explained by the environmental predictors. The biomass trend was cohe-rent with the population trend. A special feature was that there was a significant increase in biomass at 10–15 cm depth at Polygon SP3 compared to other polygons at this depth. The model was able to explain 61.8% of the variation in abundance and 66.7% of the variation in cyanobacteria biomass. The highest abundance of cyanobacteria was found in the upper soil layer of polygon SP1. Somewhat lower num-bers of cyanobacteria were at polygons SP2 and SP4, and the lowest were found in the upper soil layer at polygon SP3. In turn, the highest number of cyanobacteria was found particularly at this polygon in the 5–10 cm layer. The biomass in the 0–5 cm layer was coherent with the abundance pattern of this group. The research results confirmed that the quantitative characteristics of the higher vegetation (height and projected area) as well as of microalgae and cyanobacteria (abundance and biomass) may be used in bioindication of the dynamics of post-pyrogenic processes in steppe ecosystems
The influence of mechanochemical modification on prevention of toxic ability of humic acids towards phenanthrene in aquatic environment
Целью работы является количественная оценка взаимодействия фенантрена с модифицированными гуминовыми кислотами в водной среде. Изменение структуры и свойств ГК после модификации было изучено методами ИК-, {1}Н ЯМР - спектроскопии и потенциометрического титрования. Доказано что применение тиомочевины в качестве модифицирующего агента значительно увеличивает связывающую способность гуминовых кислот по отношению к фенантрену
Effect of mechanical activation on the composition if mineral components in humic acids isolated from carbons
It is shown that the mechanical activation of oxidized and brown coals is accompanied by an increase in the yield of humic acids and in their content of functional groups. It was demonstrated by atomic-emission spectroscopy that, under a high-intensity mechanical treatment, mineral elements are redistributed in the coal substance and incorporated into the structure of humic acids
Оценка влияния интеллектуального капитала вузов на интеллектуальный капитал регионов их локации
The paper presents the study’s results, which allow to reveal the role and importance of universities’ intellectual capital in the formation of a comprehensive assessment of the indicators of regional intellectual capital.Based on the study of theoretical materials and methods on the problems of intellectual capital of universities and regions, systems of indicators of their evaluation were composed. Hypotheses about the mutual influence of the intellectual capital of the region and universities, as well as their individual elements were put forward.As a result of hypothesis testing, based on the results of correlation-regression analysis, hypotheses about the influence of the universities’ intellectual capital as well as their individual elements (human and reputational capital) on the regions’ intellectual capital, as well as the influence of the universities’ intellectual capital on regions’ human capital were confirmed with an above-average level.El documento presenta los resultados del estudio, que permiten revelar el papel y la importancia del capital intelectual de las universidades en la formación de una evaluación integral de los indicadores del capital intelectual regional.Sobre la base del estudio de los materiales y métodos teóricos sobre los problemas del capital intelectual de las universidades y regiones, se compusieron sistemas de indicadores de su evaluación. Se expusieron hipótesis sobre la influencia mutua del capital intelectual de la región y las universidades, así como sus elementos individuales.Como resultado de la prueba de hipótesis, basada en los resultados del análisis de correlación-regresión, las hipótesis sobre la influencia del capital intelectual de las universidades y sus elementos individuales (capital humano y reputacional) en el capital intelectual de las regiones, así como en La influencia del capital intelectual de las universidades en el capital humano de las regiones se confirmó con un nivel superior al promedio.O artigo apresenta os resultados do estudo, que permitem revelar o papel e a importância do capital intelectual das universidades na formação de uma avaliação abrangente dos indicadores do capital intelectual regional.Com base no estudo de materiais e métodos teóricos sobre os problemas de capital intelectual de universidades e regiões, foram constituídos sistemas de indicadores de sua avaliação. Hipóteses sobre a influência mútua do capital intelectual da região e das universidades, bem como seus elementos individuais foram apresentadas.Como resultado do teste de hipóteses, baseado nos resultados da análise de correlação-regressão, hipóteses sobre a influência do capital intelectual das universidades, bem como seus elementos individuais (capital humano e reputacional) sobre o capital intelectual das regiões, bem como a A influência do capital intelectual das universidades sobre o capital humano das regiões foi confirmada com um nível acima da média.В работе представлены результаты исследования, которые позволяют выявить роль и значение интеллектуального капитала вузов в формировании комплексной оценки показателей регионального интеллектуального капитала.На основе изучения теоретических материалов и методов по проблематике интеллектуального капитала университетов и регионов были выделены системы показателей их оценки. Были выдвинуты гипотезы о взаимном влиянии интеллектуального капитала региона и вузов, а также их отдельных элементов.В результате проверки гипотез на основании обработки результатов корреляционно-регрессионного анализа были подтверждены гипотезы с уровнем выше среднего о наличии влияния интеллектуального капитала вузов, а также отдельных их элементов (человеческого и репутационного капитала) на интеллектуальный капитал регионов, а также интеллектуального капитала вузов на человеческий капитал регионов
The influence of mechanochemical modification on prevention of toxic ability of humic acids towards phenanthrene in aquatic environment
The aim of the research work is to quantify interaction between phenanthrene with modified humic acids in aquatic environment. The changes in the structure and properties of humic acids after modifications were studied with 1Н NMR spectroscopy and potentiometric titration methods. Our research demonstrates that the application of thiourea as a modified agent increases the binding capacity of humic acids towards phenanthrene
Interaction of nucleotide excision repair factors RPA and XPA with DNA containing bulky photoreactive groups imitating damages
Interaction of nucleotide excision repair factors-replication protein A (RPA) and Xeroderma pigmentosum complementing group A protein (XPA)-with DNA structures containing nucleotides with bulky photoreactive groups imitating damaged nucleotides was investigated. Efficiency of photoaffinity modification of two proteins by photoreactive DNAs varied depending on DNA structure and type of photoreactive group. The secondary structure of DNA and, first of all, the presence of extended single-stranded parts plays a key role in recognition by RPA. However, it was shown that RPA efficiently interacts with DNA duplex containing a bulky substituent at the 5′-end of a nick. XPA was shown to prefer the nicked DNA; however, this protein was cross-linked with approximately equal efficiency by single-stranded and double-stranded DNA containing a bulky substituent inside the strand. XPA seems to be sensitive not only to the structure of DNA double helix, but also to a bulky group incorporated into DNA. The mechanism of damage recognition in the process of nucleotide excision repair is discussed.</p
Interaction of nucleotide excision repair factors RPA and XPA with DNA containing bulky photoreactive groups imitating damages
Interaction of nucleotide excision repair factors-replication protein A (RPA) and Xeroderma pigmentosum complementing group A protein (XPA)-with DNA structures containing nucleotides with bulky photoreactive groups imitating damaged nucleotides was investigated. Efficiency of photoaffinity modification of two proteins by photoreactive DNAs varied depending on DNA structure and type of photoreactive group. The secondary structure of DNA and, first of all, the presence of extended single-stranded parts plays a key role in recognition by RPA. However, it was shown that RPA efficiently interacts with DNA duplex containing a bulky substituent at the 5′-end of a nick. XPA was shown to prefer the nicked DNA; however, this protein was cross-linked with approximately equal efficiency by single-stranded and double-stranded DNA containing a bulky substituent inside the strand. XPA seems to be sensitive not only to the structure of DNA double helix, but also to a bulky group incorporated into DNA. The mechanism of damage recognition in the process of nucleotide excision repair is discussed.</p
Pedagogical functions and potential of volunteering activities in social upbringing of student youth
This study aims to reveal the pedagogical resource of volunteering activities as an efficient form of students’ full-fledged socialization. It is based on the methodology of the activity and sociocultural approaches to psychological development of personalit
Features of shear transformation texture in seamless pipes
Microstructure and texture in seamless 0.08C-Cr-Mo-V, 0.25C-Cr-Mo-V-Nb, 0.08-13Cr-3Ni-Mo-V-Nb, and 18Cr-9Ni steel pipes are studied in the as-rolled and heat-treated states using orientation EBSD microscopy. It has been found that all types of microstructure (ferrite, martensite, and bainite) in products, both after hot rolling and after heat treatment, have well-defined axial crystallographic texture, where the direction is predominately perpendicular to the pipe surface. It is demonstrated that texture formation in heat-treated states is inherited due to the following factors important for the rules of orientation selection during the γ→α phase transformation: 1) occurrence of stable orientation of austenite grains resulted from straining; 2) special misorientation (boundaries) of austenite grains where transformation starts; 3) orientation relationships known for phase transformation; 4) thermal stresses in a product, formed during cooling. The latter can be considered as factor determining special texture in seamless steel pipes. © 2018 Author(s)
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