Theoretical X-Ray Absorption Debye-Waller Factors

An approach is presented for theoretical calculations of the Debye-Waller factors in x-ray absorption spectra. These factors are represented in terms of the cumulant expansion up to third order. They account respectively for the net thermal expansion $\sigma^{(1)}(T)$, the mean-square relative displacements $\sigma^2(T)$, and the asymmetry of the pair distribution function $\sigma^{(3)}(T)$. Similarly, we obtain Debye-Waller factors for x-ray and neutron scattering in terms of the mean-square vibrational amplitudes $u^2(T)$. Our method is based on density functional theory calculations of the dynamical matrix, together with an efficient Lanczos algorithm for projected phonon spectra within the quasi-harmonic approximation. Due to anharmonicity in the interatomic forces, the results are highly sensitive to variations in the equilibrium lattice constants, and hence to the choice of exchange-correlation potential. In order to treat this sensitivity, we introduce two prescriptions: one based on the local density approximation, and a second based on a modified generalized gradient approximation. Illustrative results for the leading cumulants are presented for several materials and compared with experiment and with correlated Einstein and Debye models. We also obtain Born-von Karman parameters and corrections due to perpendicular vibrations.Comment: 11 pages, 8 figure

Symmetry of the remanent state flux distribution in superconducting thin strips: Probing the critical state

The critical-state in a thin strip of YBaCuO is studied by magneto-optical imaging. The distribution of magnetic flux density is shown to have a specific symmetry in the remanent state after a large applied field. The symmetry was predicted [PRL 82, 2947 (1999)] for any Jc(B), and is therefore suggested as a simple tool to verify the applicability of the critical-state model. At large temperatures we find deviations from this symmetry, which demonstrates departure from the critical-state behavior. The observed deviations can be attributed to an explicit coordinate dependence of $j_c$ since both a surface barrier, and flux creep would break the symmetry in a different way.Comment: 5 pages including 5 eps figures, submitted to PR

Investigation of nonlinearity in inverse problems of satellite dynamics

В данной работе представлены результаты исследования полной и внутренней нелинейностей применительно к далеким спутникам Юпитера, наблюдавшихся на короткой дуге. Выявлена взаимосвязь между нелинейностью и условиями спутниковых наблюдений. В частности, показано, что полная нелинейность очень сильная, когда период наблюдений меньше 0.1 от орбитального периода, в то время как внутренняя нелинейность достаточно слабая для всех спутников, что указывает на возможность применения нелинейных методов для адекватного моделирования их орбитальной неопределенности.The report presents the results of a study of the total and intrinsic nonlinearities as applied to the outer satellites of Jupiter observed on a short arc. The relationship between the nonlinearities and the conditions of satellite observations is revealed. In particular, it is shown that the total nonlinearity is very strong when the observation period is less than 0.1 of the orbital period, while the intrinsic nonlinearity is weak enough for all satellites, which indicates the possibility of using nonlinear methods for adequate modeling of their orbital uncertainty.Работа выполнена в рамках государственного задания Министерства науки и высшего образования Российской Федерации (тема № 0721-2020-0049)

Improving the Ranking of Russian Smart Cities

Вследствие тенденций цифровизации и урбанизации большую роль в реализации парадигмы устойчивого развития стал играть умный город, выступая основным объектом управления устойчивым развитием. Умный город должен стать устойчивым умным городом, и первый шаг в этом направлении - разработка системы «диагностики текущего состояния», или рейтинга умных городов, который учитывает не только международные стандарты, специфику развития российских городов, но и компоненты устойчивости развития. Гипотеза исследования состоит в том, что методика рейтингования должна отражать эти компоненты и быть основой для анализа динамики устойчивого развития в разрезе выбранных критериев и факторов. В основе разработанной методики, позволяющей оценивать города с численностью населения свыше 100 тыс. чел. в разрезе социальной, экологической, экономической и управленческой компонент лежат теория многомерных сравнений и метод расстояний. Комплексная оценка умного города включает 71 показатель, показатели сгруппированы в 8 критериев: человек, социальная сплоченность, экономика, управление, экология и окружающая среда, транспорт, градостроительство, технологии. Разработан рейтинг, включающий 171 город, и выявлены региональные особенности российских умных городов в разрезе представленных критериев. Статистической базой выступили российские и зарубежные статистические базы данных, а также данные отраслевых агентств. В пятерку разработанного рейтинга вошли города Москва, Санкт-Петербург, Балашиха, Краснодар и Казань. Среди значимых вывяленных региональных особенностей - лидерство Центрального федерального округа, а также сильная дифференциация по группам показателей «градостроительство» и «технологии». Ежегодный расчет комплексной оценки позволяет выявить динамику развития умных городов, оценить эффективность принимаемых решений и ход их реализации, планировать развитие городского хозяйства в рамках реализации федеральных и региональных проектов цифровизации РФ, а также принимать решения по повышению устойчивости городских агломераций при реализации проекта «Умный город».Digitalisation and urbanisation have led to smart city becoming a key element of the concept of sustainable development, acting as an object of sustainable development management. Thus, a smart city must become a sustainable smart city. The first step is the creation of the system of current state diagnostics or smart city ranking. This ranking should consider international standards, the specificity of Russian urban development, as well as various components of sustainable development. It is hypothesised that the ranking methodology reflecting these components can be used to analyse the dynamics of sustainable development based on the chosen criteria and factors. To assess social, environmental, economic and management components of cities with a population of more than 100,000 people, the proposed technique relies on the theory of multiple comparisons and the distance method. The comprehensive assessment of smart cities includes 71 indicators grouped into 8 criteria: people, social cohesion, economy, management, ecology and the environment, transport, urban planning, technology. The study analysed Russian and international statistical databases, as well as data from industry agencies. The ranking of 171 cities was developed; regional features of Russian smart cities were identified using the selected criteria. The cities of Moscow, St. Petersburg, Balashikha, Krasnodar and Kazan are at the top of the ranking. The leadership of the Central Federal District and a significant differentiation by the criteria “urban planning” and “technology” are the key regional features. Annual comprehensive assessment can be used to track the dynamics of the development of smart cities, evaluate the effectiveness of decision-making and implementation, plan urban development based on federal and regional digitalisation projects, as well as create strategies to enhance the sustainability of Russian smart cities

Molecular genetic and bacteriological methods of bovine mycoplasmosis diagnosis

Mycoplasmas are bacteria that are extremely unstable in vitro as they lack a rigid cell wall. They are most often detected in association with other pathogens, including those that can become L-forms if treated with antibiotics. Mycoplasma colonies, as well as colonies of L-form bacteria, have a typical «fried egg» appearance, therefore it is necessary to differentiate them for the accurate diagnosis and choice of treatment. The paper presents data on mycoplasma infection diagnosis in cattle and results of differentiation of isolated mycoplasma and L-form bacteria colonies using multiple passaging and real-time polymerase chain reaction. For that, 177 samples were collected from animals with mycoplasmosis clinical signs, 45 of them were tested using molecular genetic method, 132 samples were subjected to bacteriological testing. Mycoplasma DNA was detected in 71.1% of samples, and specific colonies were detected in 3.8% of samples. Such biochemical tests of mycoplasma species identification as arginine hydrolysis, blood serum liquefaction, film and grain formation, inoculation into Tween-80-containing medium, hemadsorption and hemolysis of erythrocytes do not allow an objective assessment of the species belonging to mycoplasmas, but, according to the results obtained, the isolated species most likely belongs to Mycoplasma dispar, which is pathogenic for cattle. Real-time polymerase chain reaction is undoubtedly the most accurate and rapid diagnostic method for mycoplasmosis, but a preliminary diagnosis can also be established bacteriologically within 2–7 days. In addition, during microbiological testing, it is possible to assess the antibiotic resistance of mycoplasma isolates, thereby developing an optimal and high-quality scheme of the disease treatment and prevention

Incidence and prognostic value of acute kidney injury in pulmonary embolism: data from the SIRENA registry

Aim. To evaluate the incidence and severity of acute kidney injury (AKI), as well as its ability to reclassify the risk of premature mortality and association with inhospital mortality in patients with pulmonary embolism (PE) in the Russian population.Material and methods. From April 2018 to April 2019, the SIRENA Russian Multicenter Registry included patients with PE, as well as the deceased, in whom the PE was detected by autopsy. AKI was diagnosed according to current KDIGO guidelines (2012). Creatinine calculated according to the MDRD equation and corresponding to a glomerular filtration rate of 75 ml/min/1,73 m2 (baseline) was taken as the initial one, with subsequent assessment relative to the parameter value upon admission. The risk stratification of early death was carried out in accordance with the current ESC clinical guidelines (2019).Results. A total of 604 patients with PE were examined (men — 293 (49%), women — 311 (51%), mean age — 64±15 years). AKI was diagnosed in 223 (37%) of them. Stage 1 AKI was detected in 146 (65%), 2 — in 55 (25%), 3 — in 22 (10%) patients. Prior chronic kidney disease was recorded in 61 (10%) patients. Seventy-one (12%) patients had a high risk of death, 364 (61%) — intermediate risk, and 164 (27%) — low risk. The AKI incidence increased as the severity of PE increased: at low risk of death — 26%, intermediate — 38%, high — 59% (p<0,0001). In total, 107 (18%) patients died in the hospital. AKI led to an increase in mortality within following risk groups: at low risk, this effect was a trend (6 (5%) vs 6 (14%); p=0,052); at intermediate and high risk, significant differences was obtained (30 (13%) vs 41 (30%), p<0,001; 4 (14%) vs 19 (45%), p=0,006, respectively). Multivariate Cox regression demonstrated that AKI is a predictor of inhospital death (odds ratio (OR), 3,66 (95% confidence interval (CI): 2,37-5,66; p<0,0001), regardless of increased troponin levels (OR, 1,31 (95% CI: 0,80-2,14; p=0,28) and right ventricular dysfunction (OR, 1,23 (95% CI: 0,74-2,04; p=0,42).Conclusion. Thirty-seven percent of Russian patients with PE have AKI diagnosed by baseline creatinine. In 2/3 of the examined patients, stage 1 AKI is observed. The AKI incidence increases as the severity of PE increases. The presence of AKI reclassifies patients into a higher risk category for death and is associated with a significant increase in inhospital mortality

Shorter Disease Duration Is Associated With Higher Rates of Response to Vedolizumab in Patients With Crohn's Disease But Not Ulcerative Colitis.

Background & aimsPatients with Crohn's disease (CD), but not ulcerative colitis (UC), of shorter duration have higher rates of response to tumor necrosis factor (TNF) antagonists than patients with longer disease duration. Little is known about the association between disease duration and response to other biologic agents. We aimed to evaluate response of patients with CD or UC to vedolizumab, stratified by disease duration.MethodsWe analyzed data from a retrospective, multicenter, consortium of patients with CD (n = 650) or UC (n = 437) treated with vedolizumab from May 2014 through December 2016. Using time to event analyses, we compared rates of clinical remission, corticosteroid-free remission (CSFR), and endoscopic remission between patients with early-stage (≤2 years duration) and later-stage (>2 years) CD or UC. We used Cox proportional hazards models to identify factors associated with outcomes.ResultsWithin 6 months initiation of treatment with vedolizumab, significantly higher proportions of patients with early-stage CD, vs later-stage CD, achieved clinical remission (38% vs 23%), CSFR (43% vs 14%), and endoscopic remission (29% vs 13%) (P < .05 for all comparisons). After adjusting for disease-related factors including previous exposure to TNF antagonists, patients with early-stage CD were significantly more likely than patients with later-stage CD to achieve clinical remission (adjusted hazard ratio [aHR], 1.59; 95% CI, 1.02-2.49), CSFR (aHR, 3.39; 95% CI, 1.66-6.92), and endoscopic remission (aHR, 1.90; 95% CI, 1.06-3.39). In contrast, disease duration was not a significant predictor of response among patients with UC.ConclusionsPatients with CD for 2 years or less are significantly more likely to achieve a complete response, CSFR, or endoscopic response to vedolizumab than patients with longer disease duration. Disease duration does not associate with response vedolizumab in patients with UC

Flux-Induced Vortex in Mesoscopic Superconducting Loops

We predict the existence of a quantum vortex for an unusual situation. We study the order parameter in doubly connected superconducting samples embedded in a uniform magnetic field. For samples with perfect cylindrical symmetry, the order parameter has been known for long and no vortices are present in the linear regime. However, if the sample is not symmetric, there exist ranges of the field for which the order parameter vanishes along a line, parallel to the field. In many respects, the behavior of this line is qualitatively different from that of the vortices encountered in type II superconductivity. For samples with mirror symmetry, this flux-induced vortex appears at the thin side for small fluxes and at the opposite side for large fluxes. We propose direct and indirect experimental methods which could test our predictions.Comment: 6 pages, Latex, 4 figs., uses RevTex, extended to situations far from cylindrical symmetr