ザバイカルの匈奴遺跡における青銅鏡の出土状況 [露文]

特集：モンゴル国とその隣接地域の考古学調

Development of spacer fluids and cement slurries compositions for lining of wells at high temperatures

Article is devoted to creation of new compositions of process solutions for lining of directional wells at high temperatures. Developed compositions provide high durability characteristics of cement stone. It is shown that with an increase in packing density of cementing slurry components durability characteristics increase and porosity and permeability of cement stone decrease, whereas an increase in temperature and pressure leads to a significant increase in compressive and bending durability, which is associated with presence of quartz in them. It has been established that introduction of special structure-forming additives to the composition of developed cementing solutions allows formation of sedimentation-resistant cement systems that can provide an increase in durability characteristics of cement stone and, in general, quality lining of directional wells. Study of rheological properties of developed cementing compositions showed that the systems have high yield strength at increased temperatures and pressures. Developed compositions of water-based spacer fluids increase the cleansing degree for both casing and rocks surfaces from mud and clay cake residues, which improves the cementing quality of oil and gas wells. Mechanism for increasing the washing ability of spacer fluids and durability characteristics of cement stone, depending on composition and properties of their constituent components, is disclosed

First Search for Axion-Like Particles in a Storage Ring Using a Polarized Deuteron Beam

Based on the notion that the local dark-matter field of axions or axion-like particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we performed the first experiment to search for ALPs using a storage ring. For that purpose, we used an in-plane polarized deuteron beam stored at the Cooler Synchrotron COSY, scanning momenta near 970 MeV/c. This entailed a scan of the spin precession frequency. At resonance between the spin precession frequency of deuterons and the ALP-induced EDM oscillation frequency there will be an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and consequently the spin precession frequency were ramped to search for a vertical polarization change that would occur when the resonance is crossed. At COSY, four beam bunches with different polarization directions were used to make sure that no resonance was missed because of the unknown relative phase between the polarization precession and the axion/ALP field. A frequency window of 1.5-kHz width around the spin precession frequency of 121 kHz was scanned. We describe the experimental procedure and a test of the methodology with the help of a radiofrequency Wien filter located on the COSY ring. No ALP resonance was observed. As a consequence an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.Comment: 25 pages, 24 figures, 7 tables, 67 reference

Rare insects of the Oka Reserve recommended for inclusion in the Red Data Book of the Russian Federation

The paper presents data on nine rare insect species of the Oka State Nature Biosphere Reserve recommended for inclusion in the Red Data Book of the Russian Federation (Animals). These are Dytiscus latissimus, Carabus menetriesi, Calosoma sycophanta, Osmoderma barnabita, Protaetia speciosissima, P. fieberi, Bombus armeniacus, Parnopes grandior and Parnassius apollo. Carabus menetriesi, Osmoderma barnabita, Parnopes grandior are few in number. But these species are consistently observed in the Oka Reserve. Some species have not been registered in the Oka Reserve for a long time: Protaetia speciosissima and P. fieberi (either not since 1998), Bombus armeniacus (not since 1985), Parnassius apollo (not since 1998), Dytiscus latissimus (not since 2009). Calosoma sycophanta's existence is known only on the base of literature data

Analytical Learning Guided by Empirical Technology: An Approach to Integration (Extended Abstract)

An approach to integration of the analytical and empirical learning strategies for solving the theory-based concept specialization problem is proposed. The emphasis is on learning correct concepts within conjunctive description language isolated from supplied domain theory. In order to overcome expressive limitations of such language, the analytical learning component is guided by a specific empirical version space technology. The approach learns incrementally a correct pure conjunctive or DNF concept definition in dependance on the domain theory

Heavy-tailed mixture GARCH volatility modeling and Value-at-Risk estimation

This paper presents a heavy-tailed mixture model for describing time-varying conditional distributions in time series of returns on prices. Student-t component distributions are taken to capture the heavy tails typically encountered in such financial data. We design a mixture MT(m)-GARCH(p, q) volatility model for returns, and develop an EM algorithm for maximum likelihood estimation of its parameters. This includes formulation of proper temporal derivatives for the volatility parameters. The experiments with a low order MT(2)-GARCH(1, 1) show that it yields results with improved statistical characteristics and economic performance compared to linear and nonlinear heavy-tail GARCH, as well as normal mixture GARCH. We demonstrate that our model leads to reliable Value-at-Risk performance in short and long trading positions across different confidence levels

Stochastically Guided Disjunctive Version Space Learning

This paper presents an incremental concept learning approach to identification of concepts with high overall accuracy. The main idea is to address the concept overlap as a central problem when learning multiple descriptions. Many traditional inductive algorithms, as those from the disjunctive version space family considered here, face this problem. The approach focuses on combinations of confident, possibly overlapping, concepts with an original stochastic complexity formula. The focusing is efficient because it is organized as a simulated annealing-based beam search. The experiments show that the approach is especially suitable for developing incremental learning algorithms with the following advantages: first, it generates highly accurate concepts; second, it overcomes to a certain degree the sensitivity to the order of examples; and third, it handles noisy examples

Evaluation of diagnostic criteria and choice of treatment tactics for patients with infectious spondylodiscitis based on a case series

Objective. To present a brief description of a series of clinical cases of infectious spondylodiscitis with an assessment of the used diagnostic criteria in terms of their influence on the choice of sanifying treatment tactics. Material and Methods. A continuous retrospective study of 39 cases of spondylodiscitis was carried out. Level of evidence is IIIC. The level of ESR, serum C-reactive protein, the results of the study of biopsy materials, and CT and MRI data were evaluated. Criteria of neurological deficit, instability of the spinal motion segment, and recommendations for assessing the clinical and radiological severity of the disease were used to select the treatment tactics. Treatment success was defined as primary wound healing, absence of recurrent infection and/or death, and satisfaction with treatment according to the EQ-5D and EQ-VAS scales at a follow-up period of 22.5 months. Results. The average age of patients was 57.4 years. Primary spondylodiscitis accounted for 82 %, the predominant localization of the pathological focus was the lumbar spine (56.4 %), and staphylococci were predominant etiologic agents (59.1 %). On average, the increase in ESR was 45 mm/h, C-reactive protein – 57 ng/l, and D-dimer – 1235 pg/ml. The level of pain before sanation according to the VAS scale was 6.79 points, after the operation it was 2.3 points (p < 0.05). Instability of the spinal motion segment according to the SINS scale was revealed in 36 cases, paravertebral abscess according to MRI – in 51.3 % of cases, and neurological deficit – in 38.5 % of cases. Severe spondylodiscitis according to the SponDT scale was noted in 53.8 %, moderate – in 43.6 %, and mild – in 2.6 % of patients. According to the clinical and radiological classification of infectious spondylodiscitis severity (SSC), grade I was present in 2 patients, grade II – in 21, and grade III – in 6. Compliance of the chosen treatment tactics with current recommendations was noted in 94,9 % of cases. Recurrence of infection was observed in 7.7 %; lethal outcome – in 5.1 %. Satisfaction with the quality of life according to EQ-5D was 0.74 points, and according to EQ-VAS – 73.88 points. Conclusions. The integrated use of criteria for neurological deficit, instability of spinal motion segments, and severity of the disease according to the SponDT classification with the account of Pola’s recommendations on treatment tactics made it possible to choose the optimal treatment tactics and achieve satisfactory results in the sanation of patients with infectious spondylodiscitis

Linear-Chain Nanostructured Carbon with a Silver Film Plated on Metal Components Has a Promising Effect for the Treatment of Periprosthetic Joint Infection

Background: Due to the aging of the world population, the number of joint diseases, along with the number of arthroplasties, has increased, simultaneously increasing the amount of complications, including periprosthetic joint infection (PPI). In this study, to combat a PPI, we investigated the antimicrobial properties of the new composite cover for titanium implants, silver-doped carbyne-like carbon (S-CLC) film. Methods: The first assay investigated the antimicrobial activity against Pseudomonas aeruginosa and releasing of silver ions from S-CLC films into growth media covered with S-CLC with a thickness of 1, 2, and 4 mm. The second assay determined the direct antibacterial properties of the S-CLC film&rsquo;s surface against Staphylococcus aureus, Enterococcus faecalis, or P. aeruginosa. The third assay studied the formation of microbial biofilms of S. aureus or P. aeruginosa on the S-CLC coating. Silver-doped carbyne-like carbon (S-CLC)-covered or titanium plates alone were used as controls. Results: S-CLC films, compared to controls, prevented P. aeruginosa growth on 1 mm thickness agar; had direct antimicrobial properties against S. aureus, E. faecalis, and P. aeruginosa; and could prevent P. aeruginosa biofilm formation. Conclusions: S-CLC films on the Ti surface could successfully fight the most common infectious agent in PPI, and prevented biofilm formation