Spatial heterogeneity of soil properties of recreational areas of Volgograd

The article presents the developed soil maps and maps of spatial variability of soil properties (pH, total salt and carbonate content, organic carbon, density) in some recreational areas of Volgograd. The anthropogenic soils in the studied recreational areas include various urbostratozems (Urbic Technosols (Transportic)), Ekranic Technosols (Transportic), as well as quasizems (Phaeozems (Tehnic)), among the agrogenic ones – accumulation-carbonate agrozems (Cambisols (Aric, Protocalcic). Natural soils are represented by light and dark humus soils, chestnut soils, solonetz, as well as stratozems and psammozems. According to the data of isolinear mapping, it was found that acid-alkaline properties of soils of green zones vary from slightly alkaline to alkaline depending on the soil horizon and anthropogenic load. The mapping did not reveal salinization of the upper 0–30 cm layer. Values of organic carbon vary greatly (1–10%) and are conditioned by the presence or absence of meliorative artificial layers, as well as by the character of territory use. The content of calcium carbonates in the upper 30 cm is small and varies from 0.7 to 5%. It is established that the physical properties (density) directly depend on the level of anthropogenic load, increasing in footpaths and lawns. Spatial assessment of the properties of urban soils is important for identifying areas with an excess or on the contrary – low content of certain chemical and physical indicators for the planning of landscaping and gardening of urban areas

The bone panaris in children

The most widespread festering-inflammatory disease of brush is a panaris. Panaris — an acute purulent inflammation of the finger tissue. Forms panaris, accompanied by lesions of bone , the most difficult to treatment. Analyzed the case histories of 64 children hospitalized in the Department of purulent surgery DGKB № 9 for 2017-2019 with clinical bone panaris. In the study, disease duration before resorting to the surgeon was on average 5.8 days. 37.5% of patients were self-treatment. Outpatient treatment by a surgeon in the community was conducted in 32.8% of cases. In the analysis of anamnestic data in 14 children developed a bone panaris finger after trauma. In most cases, damaged distal phalanx of the second finger of the left and right hand. All patients complained of pain in the finger, swelling, local hyperemia of the skin. The clinical picture of bone panaris dominated local changes. The x-ray revealed the heterogeneity of the bone structure in 4 patients, the violation of the integrity of the cortical layer in 1 child, marginal bone destruction phalanx in 43 children, sequestration of the nail phalanx in 3 patients, no changes were detected in 13 patients. Treatment of bone panaris surgery. In the complex post-operative care included: anti-bacterial, antihistamines, preparation that improve blood rheology and local treatment with antiseptic bandage, physiotherapy. Diagnosis of bone panaris based on clinical and radiological data. The main method of treatment is surgicalСамым распространенным гнойно-воспалительным заболеванием кисти является панариций. Панариций — острое гнойное воспаление тканей пальца. Формы панариция, сопровождающиеся поражениями костей, наиболее сложны для лечения. Проанализированы истории болезни 64 детей, госпитализированных в отделение гнойной хирургии ДГКБ № 9 за 2017-2019 годы с клиническим панарицием кости. В исследовании продолжительность заболевания до обращения к хирургу составила в среднем 5,8 дня. 37,5% пациентов прошли самолечение. Амбулаторное ле- чение хирургом по месту жительства проводилось в 32,8% случаев. При анализе анамнестических данных у 14 детей развитие костного панариция произошло после травмы. В большинстве случаев повреждена дистальная фаланга второго пальца левой и правой кисти. Все больные предъявляли жалобы на боли в пальце, отеки, локальную гиперемию кожи. В клинической картине костного панариция преобладали местные изменения. Рентген выявил неоднородность структуры кости у 4 пациентов, нарушение целостности кортикального слоя у 1 ребенка, разрушение краевой фаланги кости у 43 детей, секвестрация фаланги ногтя у 3 пациентов, изменений не выявлено у 13 пациентов. Лечение костного панариция хирургическое. В комплекс послеоперационного ухода входят: антибактериальные, антигистаминные препараты, препараты, улучшающие реологию крови, и местное лечение антисептическими повязками, физиотерапия. Диагностика костного панариция основана на клинических и рентгенологических данных. Основным методом лечения является хирургически

Continuity theorems for the M/M/1/nM/M/1/n queueing system

In this paper continuity theorems are established for the number of losses during a busy period of the $M/M/1/n$ queue. We consider an $M/GI/1/n$ queueing system where the service time probability distribution, slightly different in a certain sense from the exponential distribution, is approximated by that exponential distribution. Continuity theorems are obtained in the form of one or two-sided stochastic inequalities. The paper shows how the bounds of these inequalities are changed if further assumptions, associated with specific properties of the service time distribution (precisely described in the paper), are made. Specifically, some parametric families of service time distributions are discussed, and the paper establishes uniform estimates (given for all possible values of the parameter) and local estimates (where the parameter is fixed and takes only the given value). The analysis of the paper is based on the level crossing approach and some characterization properties of the exponential distribution.Comment: Final revision; will be published as i

Dynamics of soil freezing and thawing in the agroforestry landscape

The article presents the dynamics of soil freezing and thawing in the agroforestry landscape of the dry-steppe zone. These processes in winters with unstable snow cover have their own characteristics. The purpose of this study was to investigate the character of soil freezing and thawing in the agroforestry landscape under conditions of low snowfall winters. Observations were carried out in the winter period of 2020–2021 at the existing runoff-erosion research station in Volgograd. The dynamics of soil freezing and thawing was studied using Danilin freeze-thaw meters installed in the field and in the center of a four-row forest belt. Simultaneously, snow cover height was measured in triplicate with a snow measuring rod. The weather conditions were characterized by alternating thaws, which promoted snow cover melt, and frosts, which increased the depth of soil freezing. The formation of a 10-15 cm snow cover did not affect soil freezing. In the absence of snow on the background of a brief thaw, the lower boundary of the frozen layer in the field decreased by 11 cm compared to the forest belt, which even in the leafless state affected the inflow of solar thermal energy. Average freezing at the end of winter was 85 cm in the field and 67 cm in the forest belt. Thawing in the field was faster. During the first two weeks, the rate of soil thawing averaged 2.3 cm/day in the field and 1.3 cm/day in the forest belt. After that, the depth of freezing in the whole agroforestry landscape became equal. During the next two weeks, the thawing rate doubled. After complete soil thawing in the field in the forest belt, the thickness of the frozen layer averaged 32 cm

On the frequency of oscillations in the pair plasma generated by a strong electric field

We study the frequency of the plasma oscillations of electron-positron pairs created by the vacuum polarization in an uniform electric field with strength E in the range 0.2 Ec < E < 10 Ec. Following the approach adopted in [1] we work out one second order ordinary differential equation for a variable related to the velocity from which we can recover the classical plasma oscillation equation when E -> 0. Thereby, we focus our attention on its evolution in time studying how this oscillation frequency approaches the plasma frequency. The time-scale needed to approach to the plasma frequency and the power spectrum of these oscillations are computed. The characteristic frequency of the power spectrum is determined uniquely from the initial value of the electric field strength. The effects of plasma degeneracy and pair annihilation are discussed.Comment: to appear in Physics Letters

Phase-sensitive amplification of 11 WDM channels across bandwidth of 8 nm in a fibre optic parametric amplifier

We experimentally demonstrate phase-sensitive fibre optic parametric amplification with gain >10dB and optical noise figure below 3dB for 11 channels spaced of 100 GHz. We employ all-fibre dispersion management to achieve a wideband phase-matching between signals and their copies

Ground Beetles (Coleoptera, Carabidae) Assemblages Features Formation in Large and Medium Industrial Cities of Russia (The Case Study in Kazan, Kemerovo and Grozny)

The article presents the results of the analysis of the Carabid fauna of three cities: Grozny, Kemerovo, Kazan. It was established that communities of ground beetles clearly respond to varying degrees of recreation by changing the biotopic distribution and ecological structure: the emergence of super dominant species, a decrease in the abundance of zoophages, an increase in the share of stratobionts, and the presence of indicator species

The Bubble regime of laser-plasma acceleration: monoenergetic electrons and the scalability

The Bubble regime of electron acceleration in ultra-relativistic laser plasma is considered. It has been shown that the bubble can produce ultra-short dense bunches of electrons with quasi-monoenergetic energy spectra. The first experiment in this regime done at LOA has confirmed the peaked electron spectrum (J. Faure, et al., {\it submitted}, 2004). The generated electron bunch may have density an order of magnitude higher than that of the background plasma. The bubble is able to guide the laser pulse over many Rayleigh lengths, thus no preformed plasma channel is needed for high-energy particle acceleration in the bubble regime. In the present work we discuss a simple analytical model for the bubble fields as well as the scaling laws.Comment: accepted for publication in Plasma Physics and Controlled Fusion, 200

Strong laser fields as a probe for fundamental physics

Upcoming high-intensity laser systems will be able to probe the quantum-induced nonlinear regime of electrodynamics. So far unobserved QED phenomena such as the discovery of a nonlinear response of the quantum vacuum to macroscopic electromagnetic fields can become accessible. In addition, such laser systems provide for a flexible tool for investigating fundamental physics. Primary goals consist in verifying so far unobserved QED phenomena. Moreover, strong-field experiments can search for new light but weakly interacting degrees of freedom and are thus complementary to accelerator-driven experiments. I review recent developments in this field, focusing on photon experiments in strong electromagnetic fields. The interaction of particle-physics candidates with photons and external fields can be parameterized by low-energy effective actions and typically predict characteristic optical signatures. I perform first estimates of the accessible new-physics parameter space of high-intensity laser facilities such as POLARIS and ELI.Comment: 7 pages, Key Lecture at the ELI Workshop and School on "Fundamental Physics with Ultra-High Fields", 9 September - 2 October 2008 at Frauenworth Monastery, German