294 research outputs found

    Research of Certain Pathogenic Characteristics of Clinical Isolates of Staphylococci of Skin Biome

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    A serious problem in patients with atopic dermatitis (AD) is the frequent attachment of a secondary skin infection. Among the microbes colonizing the skin of patients suffering from AD, S. aureus takes the lead. According to different authors, from the skin of 80–95 % of patients are sown Staphylococcus aureus. The survival of bacteria in a biotope is promoted by the persistent properties of microorganisms.Aim of the research: to determine the adhesive properties and antilysozyme activity of clinical strains of staphylococci isolated from the skin of patients with allergic dermatosis.The study included 50 patients with atopic dermatitis and 20 practically healthy individuals, from which 140 laboratory strains of staphylococci were isolated: 101 strains from patients with AD and 39 control strains. Bacteriological studies to isolate microorganisms and determine a number of pathogenic characteristics were carried out using the methods of classical bacteriology.The severity of antilysozyme activity (ALA) and adhesive properties of strains isolated from affected areas of the skin was significantly higher than in cultures isolated from intact skin areas, both qualitatively and quantitatively. The obtained data made it possible to assume a certain complicating role of these factors on the course of AD

    Siamese fighting fish

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    Spiral Chain O4 Form of Dense Oxygen

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    Oxygen is in many ways a unique element: the only known diatomic molecular magnet and the capability of stabilization of the hitherto unexpected O8 cluster structure in its solid form at high pressure. Molecular dissociations upon compression as one of the fundamental problems were reported for other diatomic solids (e.g., H2, I2, Br2, and N2), but it remains elusive for solid oxygen, making oxygen an intractable system. We here report the theoretical prediction on the dissociation of molecular oxygen into a polymeric spiral chain O4 structure (\theta-O4) by using first-principles calypso method on crystal structure prediction. The \theta-O4 stabilizes above 2 TPa and has been observed as the third high pressure phase of sulfur (S-III). We find that the molecular O8 phase remains extremely stable in a large pressure range of 0.008 - 2 TPa, whose breakdown is driven by the pressure-induced instability of a transverse acoustic phonon mode at zone boundary, leading to the ultimate formation of \theta-O4. Remarkably, stabilization of \theta-O4 turns oxygen from a superconductor into an insulator with a wide band gap (approximately 5.9 eV) originating from the sp3-like hybridized orbitals of oxygen and the localization of valence electrons. (This is a pre-print version of the following article: Li Zhu et al, Spiral chain O4 form of dense oxygen, Proc. Natl. Acad. Sci. U.S.A. (2011), doi: 10.1073/pnas.1119375109, which has been published online at http://www.pnas.org/content/early/2011/12/27/1119375109 .)Comment: 13 apages, 3 figure

    Development and support of small innovative entrepreneurship in Europe and the USA

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    Modern business practice shows that small innovative entrepreneurship needs special support in the context of rapid development of science and technology. To implement the outlined, various business support programs are being developed at a rapid pace, which are being actively implemented in practice. The aim of the article is to present the conceptual features of the development and support of small innovative entrepreneurship in Europe and the United States. The purpose of the academic paper is to present the conceptual features of supporting small innovative entrepreneurship in Europe and the United States of America

    Comparative analysis of strategic approaches to asset allocation in passive investment portfolio management

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    У статті окреслено різницю між актив- ною та пасивною стратегіями управління інвестиційним портфелем, останню визначено як більш доступну для широкого кола інвесторів. Розглянуто динаміку чотирьох інвестиційних портфелів із різним рівнем диверсифікації, сформованих за чотирма стратегічними підходами пасивного управління з інструментів, що репрезентують певний клас активів, за останні двадцять років та проаналізовано показники ефективності зазначених портфелів, такі як баланс наприкінці періоду інвестування, середньорічний приріст капіталу, середньорічна волатильність, коефіцієнт Бета та інші. Розглянуто основні переваги та недоліки кожного з утворених портфелів. Визначено підхід, який за комплексним аналізом показників є найбільш оптимальним та дає змогу сформувати найбільш ефективний інвестиційний портфель. Досліджено вплив чотирьох рівнів диверсифікації та п’яти способів ребалансування на показники портфеля.The article outlines the difference between active and passive investment portfolio management strategies. Passive strategies, although not on average more profitable than active ones, they are also less risky and are suitable for investors with a risk-conservative profile of investment preferences. Passive strategies are also available to a wider range of investors, as they do not require special skills in analyzing and managing the investment portfolio. Analyzed the dynamics of four investment portfolios with different levels of diversification, formed by four strategic approaches of passive management from instruments representing a certain asset class, over the last twenty years and analyzed the performance of these portfolios, such as final balance, CAGR, standard deviation, Beta coefficient, maximal drawdown, Sharpe ratio, gain/loss ratio, minimal investment amount and underwater period. The main advantages and disadvantages of each of the formed are analyzed: Passive stock portfolio reflects the United States stock market. The main advantage of such a portfolio is the lowest minimal required initial balance. The main disadvantage is the extremely high drawdown of -50.89%, so this portfolio is the least acceptable for risk-averse investors. Moderate investment portfolio showed the highest return among all other simulated portfolios. However, the maximum drawdown may be unacceptable for investors with a risk-conservative preference profile, the minimal required initial balance is higher, and with the need to rebalance, the cost of commissions paid over the period of ownership increases. Conservative investment portfolio is the most acceptable for conservative investors, as its return is even higher than the return on the passive stock portfolio, but it is the least risky, as evidenced by the best volatility, maximum drawdown, Beta and Sharpe ratios. However, this portfolio is less accessible to investors due to the higher minimal required initial balance. Risk-conservative investment portfolio includes gold, which has historically been a protective and anti-inflationary asset. The profitability of the portfolio is second only to the moderate portfolio, and the risk – to the conservative. It has the best rate of return on risk taken, as well as the most rapid correction and the lowest beta ratio. Having the largest number of assets in the warehouse, it also has the highest entry threshold. The approach which according to the complex analysis of indicators is the most optimum and allows to form the most effective investment portfolio is defined. The impact of four levels of diversification and five ways of rebalancing on portfolio performance has been studie

    Quasi-16-day periodic meridional movement of the equatorial ionization anomaly

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    Based on the daytime location of the equatorial ionization anomaly (EIA) crest derived from GPS observations at low latitude over China during the 2005–2006 stratospheric sudden warming (SSW), a quasi-16-day periodic meridional movement of EIA crest with the maximum amplitude of about 2 degrees relative to the average location of EIA crest has been revealed. In addition, periodic variations that are in phase with the meridional EIA movement are also revealed in the equatorial electrojet (EEJ) and F2 layer peak height (<i>hm</i>F2) over Chinese ionosonde stations Haikou and Chongqing. The quasi-16-day periodic component in Dst index is weak, and the 16-day periodic component does not exist in F10.7 index. Such large-scale periodic meridional movement of EIA crest is likely related to the globally enhanced stratospheric planetary waves coupled with anomalous stratospheric zonal wind connected with SSW. In addition, such large-scale periodic movement of EIA should be global, and can affect the ionospheric morphology around the low-latitude belt near the EIA region. Further case analysis, simulation and theoretical studies must proceed in order to understand the periodic movements of EIA connected with the different periodic atmospheric variations

    The dynamics of Odessa region hotel business development

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    У статті проаналізовано сучасний стан готельного бізнесу Одеської області з урахуванням діяльності як готелів юридичних осіб, так і фізичних осіб-підприємців. Простежено залежність туристичного іміджу Одеської області та потенціалу залучення іноземних інвестицій у розвиток готельного господарства від посткризової стабілізації стану країни. Виявлено місце Одеської області серед інших адміністративно-територіальних одиниць України за показниками експлуатаційної програми та проаналізовано динаміку змін за 2015–2017 рр. Проведено дослідження розподілу туристів за країнами, із яких вони приїжджали до Одеської області, з виявленням останніх тенденцій та констатацією стабілізації туристичної галузі. Розраховано темпи зростання кількості та місткості готелів по областях України з виявленням лідерів та аналізом динаміки змін у розрізі окремо готелів юридичних осіб та фізичних осіб- підприємців. Проаналізовано коефіцієнт використання місткості як індикатор ділової активності готельного господарства з виявленням його недосконалості в аналізі як самостійного окремого елемента на прикладі Луганської області. Розраховано місце Одеської області за структурними підрозділами сфери сервісу готелів за 2015–2017 рр. з виявленням позицій, за якими готелі області відстають та мають потенціал розвитку. Приведено показники доходу від наданих готельних послуг Одеської області з виявленням великого відставання від показників м. Києва. Визначено основні тенденції готельного господарства Одеської області за останні три роки та надано рекомендації щодо вдосконалення її конкурентних позицій.The article analyzes the current state of the hotel business of Odessa region, taking into account the activity of both hotels of legal entities and individuals-entrepreneurs. The dependence of the tourist image of Odessa region and the potential of attracting foreign investments into the development of the hotel economy from the post-crisis stabilization of the country’s state is traced. The place of Odessa region among other administrative-territorial units of Ukraine on the indicators of the operational program was revealed and changes dynamics for 2015–2017 is analyzed

    Lithologic-paleogeographic characteristics of the Bobrikovskian sedimentation stage in the Orenburg region

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    Terrigenous beds of the Bobrikivskian horizon are among the principal production facilities in the Orenburg region. Diverse views on the formation environments of the deposits testify to the complex structure of the study object and emphasize the actuality of the current research. The paper deals with the structure, composition and formation environments of the Bobrikovskian horizon in the Orenburg region. Complex sedimentological examinations of the core material from the prospect-appraisal and exploratory wells have been made. Formation settings of the Bobrikovskian horizon have been reconstructed, a paleogeographic chart has been developed. Productive strata are peculiar for non-uniform structure, which is mostly controlled by the bed genesis. Aleurite-sandy and clayey rocks were formed either in the marine basin zones with active hydrodynamics of the sedimentation environment (coastal-marine, shallow-water marine facies of the near and the far zones), or in an accumulative alluvial-deltaic plain. At that, the principal sedimentation regulator consisted of the environment itself and the unstable sedimentation processes against the background of the basin general gradual subsidence in the Early Visean. Those fast-acting factors account for the frequent facies conversions of the aleurite-sandy rocks into clayey ones and for the lenticular- discontinuous structure of the strata, considerably complicating exploration and development of the hydrocarbon deposits. Peculiarities of the area tectonic structure and development, paleorelief of the bottom and the evolution character of the sedimentation basin have predestined development of a particular type of the Bobrikovskian horizon section within the specified facies-paleogeographic zones in the southeast of the Volga-Ural anteclise. Promising explorations are associated with the sections represented by alternating sandstones, aleurolites and argillites peculiar for higher contents of sandy material (up to 70%) and confined to the deltaic and coastalmarine facies-paleogeographic zones. Those may result in discoveries of hydrocarbon pools in non-structural and combined traps
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