307 research outputs found

    Influence of exogenous urea on photosynthetic pigments, 14CO2 uptake, and urease activity in Elodea densa-environmental implications

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    This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L-1) on photosynthetic pigments (measured spectrophotometrically), uptake of 14CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L-1) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L-1) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L-1, respectively. However, exogenous urea in high concentration (1,000 mg L-1) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa. © 2013 Springer-Verlag Berlin Heidelberg

    Influence of temperature and high acetate concentrations on methanogenensis in lake sediment slurries

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    Methanogenesis from main methane precursors H2/CO2 and acetate was investigated in a temperature range of 2-70 °C using sediments from Lake Baldegg, Switzerland. Psychrophilic, psychrotrophic, mesophilic, and thermophilic methanogenic microbial communities were enriched by incubations for 1-3 months of nonamended sediment slurries at 5, 15, 30, and 50 °C. Isotope experiments with slurries amended with 14C-labeled bicarbonate and 14C-2-acetate showed that in the psychrophilic community (enriched at 5 °C), about 95% of methane originated from acetate, in contrast to the thermophilic community (50 °C) where up to 98% of methane was formed from bicarbonate. In the mesophilic community (30 °C), acetate was the precursor of about 80% of the methane produced. When the hydrogen-carbon dioxide mixture (H2/CO2) was used as a substrate, it was directly converted to methane under thermophilic conditions (70 and 50 °C). Under mesophilic conditions (30 °C), both pathways, hydrogenotrophic and acetoclastic, were observed. At low temperatures (5 and 15 °C), H2/CO2 was converted into methane by a two-step process; first acetate was formed, followed by methane production from acetate. When slurries were incubated at high partial pressures of H2/CO2, the high concentrations of acetate produced of more than 20 mM inhibited acetoclastic methanogenesis at a temperature below 15 °C. However, slow adaptation of the psychrophilic microbial community to high acetate concentrations was observe

    Modern digital technologies and telecommunications mechanisms in the implementation of socio-economic policy at the local and regional level

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    The purpose of the work is to modernize the organizational and economic support of the regional economy management processes based on digital technologie

    The Importance of Conducting a Demonstration Exam in the Training of Mid-Level Specialists in the Field of Electric Power Industry

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    The article discusses the prospect of conducting a demonstration exam in the institutions of secondary vocational education. The concept of “demonstration exam” is revealed, the comparative analysis of knowledge and skills included in the WorldSkills Standard for the competence “Electrical installation” and in the Federal state educational standard of secondary vocational education for the specialty 13.02.11 Technical operation and maintenance of electrical and electromechanical equipment (by industry) is carried out. The article attempts to reveal the main administrative and managerial barriers to integrating WorldSkills requirements into the system of secondary vocational education.Рассматривается перспектива проведения демонстрационного экзамена на базе средних профессиональных образовательных организаций. Раскрыто понятие «демонстрационный экзамен», проведена сравнительная характеристика знаний и умений специалиста, выделенных в стандарте WorldSkills по компетенции «Электромонтаж» и в федеральном государственном образовательном стандарте среднего профессионального образования по специальности 13.02.11 Техническая эксплуатация и обслуживание электрического и электромеханического оборудования (по отраслям). Предпринята попытка раскрыть основные административно-управленческие барьеры интеграции требований WorldSkills в систему среднего профессионального образования

    Melatonin in Th17/Treg differentiation: the contribution of the hormone's own production by T lymphocytes

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    The hormone melatonin is involved in regulation of functioning of almost all organs and systems of the organism. In the immune system, T lymphocytes are an important target of melatonin: they express specific melatonin receptors with different affinities – membrane MT1 and MT2 and nuclear RORa, as well as intracellular molecules that nonspecifically bind melatonin at high concentrations. Moreover, many in vitro studies reveal their own production of melatonin by T lymphocytes in response to polyclonal activation and its involvement as autocrine or paracrine factor in the induction of IL-2 and IL-2 receptor (IL-2R) synthesis by T cells, with melatonin receptors involvement in implementation of these effects. Since IL-2/IL-2R-dependent signal is a key event in T lymphocytes proliferative response induction, intrinsic melatonin seems to be directly involved at least in the clonal expansion of these cells. In this work, we investigated the contribution of T cells’ melatonin to regulation of the next stage of T lymphocyte activation, namely, the differentiation of T helper populations Th17 and Treg. It was shown that blockade of both membrane and nuclear melatonin receptors did not cause statistically significant changes in Th17 differentiation, although the trend was fixed for a decrease. Simultaneously, CD4+FoxP3+Т cells level decreased under the nonselective blockade of membrane hormone receptors, and Treg-associated cytokine TGF-b concentration in activated cultures supernatants decreased both in case of MT1/MT2 nonselective blockade and MT2 selective blockade. The data indicate that melatonin produced by T lymphocytes in culture can contribute to the control of naive CD4+T cell differentiation into Treg in vitro, and the hormone effects are mediated by membrane melatonin receptors. The presence of a large number targets with different affinities for melatonin in T lymphocytes determines the key role of the hormone concentration in its effects on these cells. And when interpreting data on melatonin-dependent regulation of Treg, it is important to take into account the hormone’s own production by lymphocytes, since T cells’ melatonin can mask the exogenous hormone effects or interfere with its action due to competitive binding to hormone receptors

    Dibenzo[ f,h]furazano[3,4- b]quinoxalines: Synthesis by Intramolecular Cyclization through Direct Transition Metal-Free C-H Functionalization and Electrochemical, Photophysical, and Charge Mobility Characterization

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    Herein, we describe the synthesis of unsymmetrically substituted dibenzo[f,h]furazano[3,4-b]quinoxalines by intramolecular cyclization through direct transition metal-free C-H functionalization. The electrochemical and photophysical properties for several polycycles have been measured. In thin films of the dibenzo[f,h]furazano[3,4-b]quinoxalines, hole mobility is in the order of 10-4 cm2 V-1 s-1. The results show that the HOMO and LUMO energy levels are appropriate for using the compounds as hole-transport materials in thin-film devices, in particular, organic and perovskite solar cells. Copyright © 2020 American Chemical Society.Russian Foundation for Basic Research, RFBR: 18-33-00103-mol_aRussian Science Foundation, RSF: 18-13-00409The research was financially supported by the Russian Science Foundation (project no. 18-13-00409). Y.A.K would like to acknowledge the financial support for the part of the synthetic section from the Russian Foundation for Basic Research (research project no. 18-33-00103-mol_a). The authors are grateful to Grigory A. Kim for carrying out the DFT calculations, which were performed by using “Uran” supercomputer of the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences. NMR experiments were carried out by using equipment of the Center for Joint Use “Spectroscopy and Analysis of Organic Compounds” at the Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences

    Cryptic Diversity in Paramecium multimicronucleatum Revealed with a Polyphasic Approach

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    Paramecium (Ciliophora) systematics is well studied, and about twenty morphological species have been described. The morphological species may include several genetic species. How-ever, molecular phylogenetic analyses revealed that the species diversity within Paramecium could be even higher and has raised a problem of cryptic species whose statuses remain uncertain. In the present study, we provide the morphological and molecular characterization of two novel Paramecium species. While Paramecium lynni n. sp., although morphologically similar to P. multimicronucleatum, is phylogenetically well separated from all other Paramecium species, Paramecium fokini n. sp. appears to be a cryptic sister species to P. multimicronucleatum. The latter two species can be distinguished only by molecular methods. The number and structure of micronuclei, traditionally utilized to discriminate species in Paramecium, vary not only between but also within each of the three studied species and, thus, cannot be considered a reliable feature for species identification. The geographic distribution of the P. multimicronucleatum and P. fokini n. sp. strains do not show defined patterns, still leaving space for a role of the geographic factor in initial speciation in Paramecium. Future findings of new Paramecium species can be predicted from the molecular data, while morphological characteristics appear to be unstable and overlapping at least in some species

    Этика и этикет

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    The article attempts to differentiate and even contrast the two different models of moral thinking and behavior. One of them considered morality as strict and even rigorist following etiquette - rules, rituals, commandments, laws, canons. Breach of the etiquette or neglecting it is considered unethical, a manifestation of immorality, wickedness. Thus, etiquette and morality are identified. Such a conception of morality results from the ethical paradigm of Aristotle. But there is another, opposite paradigm - the ethics of Kant, in which morality is understood not as a form of behavior, but as an ontological entity. And in this (Kantian) moral paradigm etiquette has only to a service value.В статье предпринята попытка разграничения двух различных моделей нравственного мышления и поведения. Одна из них под нравственностью понимает строгое и даже ригористичное следование этикету - нормам, ритуалу, заповедям, законам, канонам. Нарушение этикета или пренебрежение им считается неэтичным, проявлением безнравственности, аморальности. Таким образом, этикет и нравственность отождествляются. Подобное понимание нравственности имеет своим истоком этическую парадигму Аристотеля. Но существует и иная, противоположная парадигма - этика И. Канта, в которой нравственность понимается не как форма поведения, а как онтологическая сущность. И в этой (кантовской) нравственной парадигме этикету придаётся лишь служебное значение
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