The sectional curvature remains positive when taking quotients by certain nonfree actions

We study some cases when the sectional curvature remains positive under the taking of quotients by certain nonfree isometric actions of Lie groups. We consider the actions of the groups $S^1$ and $S^3$ such that the quotient space can be endowed with a smooth structure using the fibrations $S^3/S^1{\simeq}S^2$ and $S^7/S^3\simeq S^4$. We prove that the quotient space carries a metric of positive sectional curvature, provided that the original metric has positive sectional curvature on all 2-planes orthogonal to the orbits of the action.Comment: 26 pages, 1 figure. Changed the spelling of the author's nam

Tuning of tunneling current noise spectra singularities by localized states charging

We report the results of theoretical investigations of tunneling current noise spectra in a wide range of applied bias voltage. Localized states of individual impurity atoms play an important role in tunneling current noise formation. It was found that switching "on" and "off" of Coulomb interaction of conduction electrons with two charged localized states results in power law singularity of low-frequency tunneling current noise spectrum ($1/f^{\alpha}$) and also results on high frequency component of tunneling current spectra (singular peaks appear).Comment: 7 pages, 4 figure

Association of rs12722 COL5A1gene variation with risk of anterior cruciate ligament rupture

Objective: to determine the influence of rs12722 (C/T)COL5A1 gene variation on ACL rupture in Europeans of Ural region of Russia. Materials and methods: the case group included 173 patients with diagnosed anterior cruciate ligament (ACL) ruptures; control group included 370 asymptomatic persons. Both groups were similar on a sex, age, growth, weight and BMI. Results: the following genotypic frequencies were observed (in %): case group - a T/T of 34,1, C/T of 46,8, C/C of 19,1; control group - a T/T of 25,4, C/T of 50,8, C/C 23,8. Genotypic frequencies in both groups met Hardy-Weinberg equilibrium. Significant difference of allelic frequencies was revealed between two groups (p = 0,039). Persons with a T/T genotype had a significantly increased risk of ACL ruptures in comparison with persons with C/T + C/C genotypes (x2 = 4,408, p = 0,036, OR = 1,52, 95% confidence interval: 1,027 - 2,249). Conclusions: this is the first study that shown the association of rs12722 COL5A1 gene variation with risk of an ACL rupture in Russian population

On the phenomenology of a Z' coupling only to third-family fermions

The phenomenology of an additional U(1) neutral gauge boson Z' coupled to the third family of fermions is discussed. One might expect such a particle to contribute to processes where taus, b and t quarks are produced. Precision data from LEP1 put severe constraints on the mixing and heavy-boson mass. We find that the effects of such a particle could not be observed at hadronic colliders, be it at the Tevatron or the LHC, because of the QCD background. At LEP2 and future e^+e^- linear colliders, one could instead hope to observe such effects, in particular for b\bar b final states.Comment: 36 pages, LaTeX, including 12 figure

Solvencia del Instituto de Gestión de la Ciudad en Estimaciones de la Población del Sur de Rusia: Historia y Perspectivas

Este artículo interpreta los resultados de una encuesta sociológica masiva realizada entre la población de los municipios de la región de Rostov y la República de Adygea, con el fin de determinar la viabilidad social del Instituto de gestión de la ciudad. La competencia social se define como el logro de los principales objetivos establecidos para el Instituto de gestión de la ciudad, principalmente, la participación de gerentes profesionales para mejorar los indicadores de desarrollo socioeconómico de los territorios. Se definen cuatro aspectos como criterios de evaluación: confianza en la reforma, objetivos de la reforma, satisfacción con la reforma y expectativa de las consecuencias de la reforma. Los autores llegaron a la conclusión de que una masa significativa de la población no confía en la reforma, ve en ella otros objetivos que los declarados por el legislador, no está satisfecha con los resultados y teme la aparición de consecuencias negativas de su implementación. Al mismo tiempo, hay otros resultados de la introducción de la gestión de la ciudad, ya que hay grupos estables de encuestados que expresaron una actitud positiva hacia ella, lo que se muestra de manera consistente en todos los aspectos de la evaluación, incluido el rechazo de la importancia de institución de alcaldes electos

High orders of perturbation theory: are renormalons significant?

According to Lipatov, the high orders of perturbation theory are determined by saddle-point configurations (instantons) of the corresponding functional integrals. According to t'Hooft, some individual large diagrams, renormalons, are also significant and they are not contained in the Lipatov contribution. The history of the conception of renormalons is presented, and the arguments in favor of and against their significance are discussed. The analytic properties of the Borel transforms of functional integrals, Green functions, vertex parts, and scaling functions are investigated in the case of \phi^4 theory. Their analyticity in a complex plane with a cut from the first instanton singularity to infinity (the Le Guillou - Zinn-Justin hypothesis) is proved. It rules out the existence of the renormalon singularities pointed out by t'Hooft and demonstrates the nonconstructiveness of the conception of renormalons as a whole. The results can be interpreted as an indication of the internal consistency of \phi^4 theory.Comment: 28 pages, 8 figures include

EPIDEMIOLOGICAL AND EPIZOOTIOLOGICAL ANALYSIS OF THE SITUATION ON TULAREMIA IN THE RUSSIAN FEDERATION IN 2016 AND FORECAST FOR 2017

123 cases of human infection with Francisella tularensis were registered in the territory of the Russian Federation in 2016. 90 % of the total number was reported by three Federal Districts: North-Western, Siberian, and Central ones. Epizootic manifestations of varying intensity were detected in 56 regions. A considerable number of tularemia cases were observed in the Republic of Karelia, Nenets Autonomous District, Omsk and Ryazan Regions, and in Saint-Petersburg. Conspicuous are some recent peculiarities of tularemia manifestations: non-specificity of clinical symptoms, especially at early stages of the disease, their increasing variability against the background of mixed infections with tularemia and other natural-focal infections agents. The most expressed symptoms are fever and lymphatic adenitis; the patients are diagnosed with tularemia during initial days of the sought treatment in 40-45 % of the cases. Based on the data on morbidity rates in humans, epizootiological condition of natural tularemia foci, the numbers of isolated cultures and incidence of the vectors and carriers of the agent, as well as taking into consideration the scope of preventive vaccination in the regions, identified were the territories in which epidemic complication are most likely to occur in 2017

Outbreak of Anthrax in the Yamalo-Nenets Autonomous District in 2016, Epidemiological Peculiarities

In 2016, in the territory of Yamalo-Nenets Autonomous District an outbreak of anthrax took place, 2650 reindeers were infected. As a consequence of contacts with affected and fallen animals, 36 cases of human infection occurred, of which one was fatal. Performed full-extent complex of anti-epidemic, anti-epizootic, and preventive measures, prompt organization of operations at the regional level allowed for localization of large-scale anthrax focus within the minimum possible time. Based on the lessons learned, identified were the ways to further enhancement of epidemiological surveillance and prophylaxis of anthrax under current conditions

Multidrug Resistance of <i>F. tularensis</i> subsp. <i>holarctica</i>, Epizootiological and Epidemiological Analysis of the Situation on Tularemia in the Russian Federation in 2022 and Forecast for 2023

The review provides concise information on the innate ability of cells of the tularemia pathogen, Francisella tularensis subsp. Holarctica, to resist antimicrobials through a variety of mechanisms, leading to its multi-resistance. In total, taking into account new territories, 120 cases of human infection were registered in the Russian Federation in 2022. Epizootic manifestations of the infection of varying degrees of intensity were detected in 58 constituent entities. Against this background, sporadic cases of tularemia in humans were reported in 18 regions of the country. An outbreak of tularemia occurred in the Stavropol Territory; the disease of mild and moderate severity was found in 76 people. The increased incidence of tularemia persists in the Republic of Karelia with severe cases of the disease in the absence of immunoprophylaxis of this infection in the region. A total of 61 cultures of the tularemia pathogen F. tularensis subsp. holarctica, out of which 20 erythromycin-resistant strains were isolated in the Stavropol Territory. In addition, 8 cultures of F. tularensis subsp. mediasiatica from a silt sample and mites Dermacentor silvarum and Haemaphysalis concinna caught in the Republic of Altai were isolated. On the territory of the Russian Federation in 2022, 930 999 people were vaccinated and revaccinated against tularemia. Based on the analysis of the data obtained in 2022, epidemic complications in 2023 in the form of sporadic cases of the disease among the unvaccinated population are most likely to occur in the territories of the Central Federal District – in the Vladimir, Ryazan and Smolensk Regions; Northwestern Federal District – in the Arkhangelsk Region and the Republic of Karelia; Southern Federal District – in the Volgograd and Rostov Regions. The situation in the North Caucasian Federal District will remain tense in the Stavropol Territory; in the Volga Federal District – in the territories of the Saratov Region, as well as in the Kirov Region and the Republic of Mordovia; Ural Federal District – in Khanty-Mansi and Yamalo-Nenets Autonomous Districts; Siberian Federal District – in certain territories of Omsk, Kemerovo, Tomsk, Novosibirsk, Irkutsk Regions, Altai, Krasnoyarsk Territories; in the Far Eastern Federal District, the most intense epizootic activity of natural tularemia foci is in Primorsky Krai

Epizootic and Epidemic Situation on Tularemia in the Russian Federation in 2015 and Prognosis for 2016

Analyzed are the data on epizootiological and epidemiological surveillance of tularemia foci, situated in the territory of 85 constituent entities of the Russian Federation. Positive findings, obtained in the process of examination of small mammals, Ixodidae ticks, mosquitoes, and environmental objects, using immunological and molecular-genetic methods; isolated tularemia agent cultures; as well as tularemia incidence rates among the population have made provisions for the assessment of circulation and infection activity in the Regions. In period of 2015, 71 cases of human infection with tularemia have been registered. Given is a brief characteristics of activity of the natural tularemia foci and epidemic situation in the territory of the Russian Federation in 2015. Specified are the regions where preventive vaccination is on a low level. Given is the differentiation of RF territories according to the risk of exposure to tularemia infection for 2016