597 research outputs found
"Iosif". Fonvizinskij perevod poemy P.-Ž. Bitobe (P.-J. Bitaubé) : problemy žanra i recepcii
No full textYoung Denis Fonvizin’s translation of P.-J. Bitaubé poem in prose “Joseph” (1767) so far generally studied from a biographical or linguistic point of view, is here regarded as an essential step in the evolution of Russian prose in the crucial period of transition from Classicism to Sentimentalism comparing the role of the “poem in prose” both in France and in Russi
Applications of analyticity to scalar meson phenomenology
Get PDFThe scalar mesons have caused much debate amongst hadronic physicists for many years. Even today the number of scalars is hotly contested, and there is almost no agreement on the composition of any of the experimentally observed states, except perhaps for the K*(_0) (1430). This thesis attempts to shed light on both of these problems via the application of analyticity to two different quantities. Recently a number of authors have proposed the existence of a light, strange, scalar meson known as the k. We perform a direct search of the best available πK scattering data to determine whether or not this resonance exists. This is done by constructing contour integrals from these data and determining the number of poles present inside the contour. We do not need to model either the internal dynamics of the state nor the form of the background scattering. The number of poles found tells us the number of resonances present and their positions allow us to estimate the resonance parameters. We find that there is only one resonance in scalar πK scattering below 1800 MeV and this is identified with the established K*(_0)(1430). We find no evidence for the k. Secondly, applying Cauchy's Theorem to the vacuum polarisation function leads to a relation between experimental and theoretical integrals known as a Finite Energy Sum Rule (FESR). FESRs are used to explore the scalar, isoscalar non-strange current and allow us to determine which of the experimentally observed scalar, isoscalar mesons is most likely to be the uũ + dd state. We find that the lightest scalar, isoscalar uũ dd state is not the fo(980) as suggested by some authors, but is rather the light, broad object known as the fo(400 - 1200). We are also able to estimate the average light quark mass and find m(_q)(l GeV(^2)) = 4.7 ± 0.9 MeV which is consistent with the recent estimates of this quantity from unquenched lattice QCD
A VINITI-nek járó tőkés tudományos és műszaki folyóiratok jellemzői
No full textALEKSEEVA, L. Sz.: Harakteristika naucno-tehniceskoj periodiki kapitaliszticeskili stran, postu-pajuscej v VINITI -- NTI, Ser. 1. 2. sz. 1984. p. 24-28
A VINITI-nek járó tőkés tudományos és műszaki folyóiratok jellemzői
No full textALEKSEEVA, L. Sz.: Harakteristika naucno-tehniceskoj periodiki kapitaliszticeskili stran, postu-pajuscej v VINITI -- NTI, Ser. 1. 2. sz. 1984. p. 24-28
A study on L-threonine and L-serine uptake in Escherichia coli K-12
Get PDFIn the current study, we report the identification and characterization of the yifK gene product as a novel amino acid carrier in E. coli K-12 cells. Both phenotypic and biochemical analyses showed that YifK acts as a permease specific to L-threonine and, to a lesser extent, L-serine. An assay of the effect of uncouplers and composition of the reaction medium on the transport activity indicates that YifK utilizes a proton motive force to energize substrate uptake. To identify the remaining threonine carriers, we screened a genomic library prepared from the yifK-mutant strain and found that brnQ acts as a multicopy suppressor of the threonine transport defect caused by yifK disruption. Our results indicate that BrnQ is directly involved in threonine uptake as a low-affinity but high-flux transporter, which forms the main entry point when the threonine concentration in the external environment reaches a toxic level. By abolishing YifK and BrnQ activity, we unmasked and quantified the threonine transport activity of the LIV-I branched chain amino acid transport system and demonstrated that LIV-I contributes significantly to total threonine uptake. However, this contribution is likely smaller than that of YifK. We also observed the serine transport activity of LIV-I, which was much lower compared with that of the dedicated SdaC carrier, indicating that LIV-I plays a minor role in the serine uptake. Overall, these findings allow us to propose a comprehensive model of the threonine/serine uptake subsystem in E. coli cells
Geochemistry of ice in frost mounds in the valley of the River Sentsa (Oka plateau, East Sayan)
Get PDFTe authors examined the chemical composition of underground ice sampled from the frost mounds located in the loose (unconsolidated) sediments of the Sentsa River valley (Oka plateau, Eastern Sayan) with the purpose of reconstruction the formation history of these cryogenic creations. Numerous frost mounds of various sizes are mainly composed of alternating icy loams, sandy loams, and lenses of pure ice. Samples of underground ice taken in the outcrops of the river ledges and cores from wells together with samples of river and lake waters were analyzed by traditional hydrochemical techniques (methods) in the center "Geodynamics and geochronology" (Institute of the Earth's Crust of the Siberian branch of RAS, Irkutsk). It was found that the chemical composition of pure ice melts from lenses and layers of the frost mounds is hydrocarbonate calcium (HCO3 Ca, SO4-HCO3 Ca and NH4-HCO3 Ca) with mineralization of 6.5 – 15.6 mg/L, pH = 5.6÷6.1. Mineralization of melts of texture-forming ice, taken from icy ground (i.e. with fractions of enclosing loams) was much higher – from 50 to 792.5 mg/L. River and lake water is ultra-fresh with 99–132 mg/L salinity, and according to geochemical type it is hydrocarbonate calcium (HCO3 Ca). Te specifc features of chemical composition of the underground ice (high content of ammonium salts and sulfates) depend on a water-rock interaction, the presence of organic matter in the loose (unconsolidated) sediments and a repeated volcanic activity in the late Pleistocene–Holocene. Te frost mounds are confned to a lacustrine sediments area in the backwater zone that was formed by the Late Pleistocene terminal moraine. Teir formation in the Holocene took place as a result of segregational ice formation during freezing of water-saturated lake sediments, and, presumably, repeated injections of underground waters of the under-channel and floodplain aquifers hydraulically connected with river waters. Tus, the genesis of the studied frost mounds is probably a mixed segregation-injection process
The role of osteoblast cells in the pathogenesis of unicameral bone cysts
No full textPurposeThe pathogenesis of unicameral bone cysts (UBCs) remains largely unknown. Osteoclasts have been implicated, but the role of osteoblastic cells has, to date, not been explored. This study investigated the pathophysiology of UBCs by examining the interactions between the cyst fluid and human bone marrow stromal cells (hBMSCs) and the effect of the fluid on osteogenesis.MethodsFluid was aspirated from two UBCs and analysed for protein, electrolyte and cytokine levels. Graded concentrations of the fluid were used as culture media for hBMSCs to determine the effects of the fluid on hBMSC proliferation and osteogenic differentiation. The fibrocellular lining was analysed histologically and by electron microscopy.ResultsAlkaline phosphatase (ALP) staining of hBMSCs that were cultured in cyst fluid demonstrated increased cell proliferation and osteogenic differentiation compared to basal media controls. Biochemical analysis of these hBMSCs compared to basal controls confirmed a marked increase in DNA content (as a marker of proliferation) and ALP activity (as a marker of osteogenic differentiation) which was highly significant (p < 0.001). Osteoclasts were demonstrated in abundance in the cyst lining. The cyst fluid cytokine profile revealed levels of the pro-osteoclast cytokines IL-6, MIP-1? and MCP-1 that were 19×, 31× and 35× greater than those in reference serum.ConclusionsCyst fluid promoted osteoblastic growth and differentiation. Despite appearing paradoxical that the cyst fluid promoted osteogenesis, osteoblastic cells are required for osteoclastogenesis through RANKL signalling. Three key cytokines in this pathway (IL-6, MIP-1?, MCP-1) were highly elevated in cyst fluid. These findings may hold the key to the pathogenesis of UBCs, with implications for treatment methods
Efficiency of using a new generation feed additive for dairy cows in the North
No full textResearch work to evaluate the effectiveness of using a feed additive in the form of a bolus was carried out in the conditions of the livestock complex of Horobut LLC in the Megino-Kangalassky ulus of the Republic of Sakha (Yakutia). The duration of the scientific and economic experiment was 281 days: from January 16 to October 23, 2023. The diet of dairy cows consisted of 10.0 kg of mixed-grass hay, 16.0 kg of silage and 2.0 kg of feed. Cows in the experimental group with a farm diet received the feed additive "Calcitop bolus" at a dose of 1 bolus per head once during lactation. In the studied diets, the ratio of metabolic energy to dry matter was 8.30 with a norm of 8.57, digestible protein to metabolic energy was 7.86 with a norm of 8.10. In terms of milk yield, the experimental group of cows that received a mineral and vitamin supplement in their diet turned out to be more economically effective, so milk productivity for 281 days of lactation amounted to 2725.7 kg, while more milk was obtained than from analogues of control cows by 204.3 kg or by 8.1% (**P<0.99). The high milk yield was 573.1 kg and was higher by 31.1 kg, respectively. The consumption of concentrates per 1 kg of milk was 206.2 g and reduced the consumption of concentrates for the production of 1 kg of milk compared to the control by 8.97%. Calculation of the economic efficiency of milk production showed that the cost of producing 1 quintal of milk from cows in the experimental group was 82.0 rubles lower than in the control group. At the same time, profit from the sale of milk increased by 26.8%, the level of profitability of milk production amounted to 7.8%. All indicators characterizing the biological value of milk fluctuated slightly and corresponded to the indicators of high-quality natural milk. Therefore, the use of the feed additive "Calcitop Bolus" for Simmental cows made it possible to balance the diets in terms of missing nutrients
Methods of conflict management at the aviation industry enterprises
Get PDFThe article deals with the management of hidden conflicts at the enterprises of the aviation industry. At present, a topical issue for the management of companies is the resource effectiveness of personnel, obtained as a result of the development or implementation of a management decision. The author emphasizes the importance of the conflict management process as a key tool for personnel management, on which the success of the company and sometimes the very existence of the enterprise, largely depends. The purpose of this work is to describe the conflict management methodology at the enterprises of the aviation industry by developing a model for identifying conflicts at an early stage. The main aspects of identifying conflict situations on the basis of modern theory and practice of conflict management are revealed. In this regard, the necessity for the top management of enterprises to make competent, economically sound management decisions is substantiated. A model for identifying hidden conflicts between employees is proposed
A study on L-threonine and L-serine uptake in Escherichia coli K-12
Get PDFIn the current study, we report the identification and characterization of the yifK gene product as a novel amino acid carrier in E. coli K-12 cells. Both phenotypic
and biochemical analyses showed that YifK acts as a permease specific to L-threonine and, to a lesser extent, L-serine. An assay of the effect of uncouplers and composition of the reaction medium on the transport activity indicates that
YifK utilizes a proton motive force to energize substrate uptake. To identify the remaining threonine carriers, we screened a genomic library prepared from the yifK-mutant strain and found that brnQ acts as a multicopy suppressor of
the threonine transport defect caused by yifK disruption. Our results indicate that BrnQ is directly involved in threonine uptake as a low-affinity but high-flux transporter, which forms the main entry point when the threonine concentration
in the external environment reaches a toxic level. By abolishing YifK and BrnQ activity, we unmasked and quantified the threonine transport activity of the LIV-I branched chain amino acid transport system and demonstrated that LIV-I contributes significantly to total threonine uptake. However, this contribution is likely smaller than that of YifK. We also observed the serine transport activity of LIV-I, which was much lower compared with that of the dedicated SdaC carrier, indicating that LIV-I plays a minor role in the serine uptake. Overall, these findings allow us to propose a comprehensive model of the threonine/serine uptakesubsystem in E. coli cells
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