35 research outputs found
Periodization of Urban Development in the Golden Horde State
The paper attempts to find regularities in the process of formation, development and disappearance of the towns of the Golden Horde State. The emergence of a large number of big and medium-sized towns in the Eastern European steppe in a short period by historical standards and their equally rapid disappearance is probably the most striking phenomenon in the history of the Golden Horde. This process largely depended on the evolution and well-being of the still understudied sedentary rural settlements. Seven periods in the history of urban development of the Golden Horde are defined, each having its characteristic features and regularities. On the whole, the process of foundation, development and disappearance of Golden Horde cities covered a chronological range of under two centuries from the 1240s to the 1420s
Effect of Cultural Priming on Social Behavior and EEG Correlates of Self-Processing
Humans are social beings and the self is inevitably conceptualized in terms of social environment. The degree to which the self is perceived as fundamentally similar or fundamentally different from other people is modulated by cultural stereotypes, such as collectivism and individualism. These stereotypes are not hardwired in our brains and individuals differ in the degree to which they adopt the attitudes that define their culture. Moreover, individuals can acquire multiple sets of cultural knowledge and, depending on the context, either individualistic or collectivistic cultural mindset could be activated. In this study, we used cultural priming techniques to activate either individualistic or collectivistic mindset and investigated the association between source-level EEG connectivity in the default mode network (DMN) and spontaneous self-related thoughts in the subsequent resting state. Afterward, participants performed a social interaction task, in which they were allowed to choose between friendly, avoidant, or aggressive behavior. After collectivism priming, self-related thoughts were associated with increased connectivity of DMN with the right temporoparietal junction (TPJ), which is involved in taking the perspective of others and is more active in representatives of collectivistic cultures, whereas after individualism priming they were associated with increased connectivity with the temporal pole, which is involved in self/other discrimination and is more active in representatives of individualistic cultures. Individual differences in the intensity of post-priming self-related thoughts and the strength of DMN-temporal pole connectivity predicted individual differences in behavior during the social interaction task, with individualistic mindset predisposing to more friendly and trustful social behavior
Surgical treatment of patients with symptomatic Kimmerle's anomaly using video endoscopy
Background: Clinical manifestations of Kimmerle’s anomaly are detected in 5.5 to 20% of patients. The main reason for the development of symptoms is prolonged compression of the V3 (atlantic) segment of the vertebral artery in the bone ring as a result of the atlantooccipital membrane’s exostosis. To date, the final tactics for treating patients with Kimmerle’s anomaly has not been determined. The effectiveness of conservative methods of therapy does not exceed 40%. The aim Of this study was to evaluate the results of a minimally invasive surgical treatment of patients with symptomatic Kimmerle’s anomaly using video endoscopic assistance. Methods: In the period from 2020 to 2022, 15 patients were operated on. The indication for the surgical treatment was the lack of the conservative therapy’s effect for 1 year from the onset of the disease, aggravation of the disease symptoms, a decrease in the blood flow through the vertebral artery at the Kimmerle’s anomaly side when turning the head. The vertebral artery decompression was performed using video endoscopy through a posterior median approach in two (13%) patients and through a paravertebral intermuscular approach (4 cm incision in the occipitocervical region in the projection of the Kimmerle’s anomaly) in thirteen (87%) patients. Results: The outcome of the disease was assessed at the time of discharge from the hospital, as well as in 6 and in 12 months after the operation. Following the surgical treatment, all the patients showed the complete regression of symptoms and restoration of the blood flow velocities in the vertebral artery. There were no complications after the operation. The use of video endoscopy made it possible to reduce the size of the surgical wound from 12 cm to 4 cm, which contributed to a decrease in the intensity of pain in the postoperative period, early activation and a decrease in the duration of the inpatient treatment. Conclusion: With the proper selection of patients with Kimmerle’s anomaly, decompression of the V3 segment of the VA using video endoscopy is a safe and effective method of treatment
Long-term results of microvascular decompression with video endoscopy in the treatment of patients with atypical trigeminal neuralgia
Background: The incidence of atypical trigeminal neuralgia (aNTN) varies from 1 to 7 per 100,000 population per year. The main cause of its development is compression of the trigeminal nerve (TN) root by a vein and/or artery in the cerebellar cistern. To date, the final tactics of treatment for patients with aNTN has not been specified. The effectiveness of conservative methods of therapy does not exceed 50%.
The aim of this study was to evaluate the results of microvascular decompression using video endoscopy in the treatment of patients with atypical trigeminal neuralgia.
Methods: In the period from 2014 to 2021, 34 patients with aNTN were operated on, of which 18 (53%) patients had neuropathic pain (more than 4 points on the DN4 scale), and 15 (44%) patients had transformation of classical trigeminal neuralgia into atypical neuralgia. The conservative therapy (carbamazepine, gabapentin, pregabalin), administered to all the patients in the preoperative period, was not accompanied by a significant relief of pain syndrome. The maximum intensity of pain upon admission to the hospital was, according to the visual analog scale (VAS), 10 points, according to the BNI (Barrow Neurological Institute) Pain Intensity Scale V (severe, persistent pain). All the patients underwent microvascular decompression of the trigeminal nerve root with the use of Teflon; in 12 (35%) patients, in addition to microscopy, video endoscopy was used. The average follow-up period after the surgery was 3.41.7 years (from 1 to 5 years).
Results: In all (100%) patients, the pain was completely eliminated (BNI I) after the surgery. A total five-year excellent and good outcome of the disease on the J. Miller and BNI scale (I -II) was noted in 80% (n=27) of patients with aNTN. The risk of pain recurrence after microvascular decompression was 14% (n=3) in the first three years, and 34% (n=4) after 5 years. The use of video endoscopy made it possible to identify the blood vessels compressing the root of the trigeminal nerve with a minimal displacement of the cerebellum and cranial nerves when visualizing the neurovascular conflict.
Conclusion: The microvascular decompression method with video endoscopy is effective in the treatment of patients with aNTN
The dependence of the time delay on the shape of the wave packet tunneling through the potential barrier
The problem of quasi-monochromatic wave packet tunneling through a potential rectangular barrier is studied. It is shown that the approach to calculating the time delay of a wave packet called ``phase time’’ is not universally correct though well known in the literature. In this paper we discuss the mathematical reasons for this discrepancy, and substantiate another, more correct analytical method for calculating the time delay in the approximation of wide barriers. This time depends on the shape of the envelope complex wave function falling on the barrier. Analytical results for the Gaussian wave packet are presented
DEVELOPMENT OF EXPERIMENTAL DESIGN METHODS OF EVALUATING PARAMETERS CHARACTERIZING CONTROLLABILITY AND STABILITY OF MOTOR CAR WITH ALL STEERABLE WHEEL
The purpose is the development and introduction of experimental design methods of determining the parameters of controllability and stability of motor cars with its front and rear steerable wheels into field test practice. A block-diagram of criteria evaluating the controllability and stability has been devised to permit matching the experimental evaluations and the results of instrumental measurements; a diagram extablishing the relationship between the movement conditions and control actions has been suggested; a mathematical model and software used for describing joint front and rear wheels steering has been constructed. It has been established that a change in angle between the longitudinal axis of the motor car and the velocity vector of its ceter of mass, as well as the difference in the delayed reaction response to the angular rate of turn of the car and to the lateral acceleration determine the formation of the law of joint front and rear wheel steeringAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio
The most widespread glazed imports of Crimean production and some issues relating to East European trade in the 14th century
The authors examine morphological and technological features and distribution of the four most massive types of glazed closed vessels produced in towns of south-eastern Crimea (Solkhat, Kaffa, Sudak). Starting from the late 13th – early 14th centuries, the Crimean producers of glazed ceramics had reached a far better development compared to other ceramic centers of the Golden Horde. For almost 50–70 years the Crimean glazed ceramics had dominated the whole territory of Eastern Europe. The most common finds are pharmaceutical amphorae, albarello and two types of jars – the stamped jars and the wine jars with a narrow long body. The authors illustrated informational capacities of the analysis of massive finds, which is a good tool to obtain some new historical information, particularly, to study European trade in the best years of the Golden Horde towns. They showed how studying archaeological stuff can substantially complement the written accounts about the trade crisis after the events in Azak (Tana) in September 1343
Simulation of steady-state cuttings transport through a horizontal annulus channel
The current study is devoted to simulating cuttings transport by drilling fluid through a horizontal section of borehole with an annular cross section. Drill pipe rotates in fixed eccentric position. Steady-state flow is
considered. Cuttings are rigid spheres with equal diameters. The carrying fluid is drilling mud with Herschel-Bulkley rheology. Suspension rheology depends on local shear rate and particles concentration. Continuous mixture model with algebraic equation for particles slipping velocity is used. Two hydrodynamic regimes are considered: axial flow without drill pipe rotation and with drill pipe rotation. In the case of axial flow was shown that increasing of power index n and consistency factor k increases pressure gradient and decreases cuttings concentration. Increasing of yield
stress leads to increasing of pressure gradient and cuttings concentration. Cuttings concentration achieves constant value for high yield stress and not depends on it. Rotation of the drill pipe significantly changes the flow
structure: pressure loss occurs and particles concentration decreases in the cross section. Two basic regimes of rotational flow are observed: domination of primary vortex around drill pipe and domination secondary vorticity structures. Transition between regimes leads to significant changes of flow integral parameters
Simulation of steady-state cuttings transport through a horizontal annulus channel
The current study is devoted to simulating cuttings transport by drilling fluid through a horizontal section of borehole with an annular cross section. Drill pipe rotates in fixed eccentric position. Steady-state flow is
considered. Cuttings are rigid spheres with equal diameters. The carrying fluid is drilling mud with Herschel-Bulkley rheology. Suspension rheology depends on local shear rate and particles concentration. Continuous mixture model with algebraic equation for particles slipping velocity is used. Two hydrodynamic regimes are considered: axial flow without drill pipe rotation and with drill pipe rotation. In the case of axial flow was shown that increasing of power index n and consistency factor k increases pressure gradient and decreases cuttings concentration. Increasing of yield
stress leads to increasing of pressure gradient and cuttings concentration. Cuttings concentration achieves constant value for high yield stress and not depends on it. Rotation of the drill pipe significantly changes the flow
structure: pressure loss occurs and particles concentration decreases in the cross section. Two basic regimes of rotational flow are observed: domination of primary vortex around drill pipe and domination secondary vorticity structures. Transition between regimes leads to significant changes of flow integral parameters
Test–Retest Reliability of a Social Interaction Task
Accurate repeatability of experimental data is the basis of professional scientific research. In this study we analyzed three consecutive experiments: The subjects had to complete a questionnaire three times under similar conditions within a 2–3 week interval to ensure reproducibility of the original data from experiment to experiment, using the method of test–retest reliability. Absolute reliability was assessed by the standard error of measurement (SEM) and smallest real difference (SRD). The relative reliability was estimated by calculating the intraclass correlation coefficients (ICC3,1) (average measures) and the results demonstrate almost perfect agreement. The social interaction model was applied for organization of the experimental study. In this virtual model, the participants had to choose one of three types of reactions (i.e., attacking, avoiding, or friendly) to stimuli-facial expressions (i.e., angry, fearful, sad, neutral, and happy). The results show significant correlation between personal characteristics and social interactions. The results of the influence of such personal characteristics as agreeableness, collectivism, extraversion, neuroticism, and those shown on the Relational-interdependent Self-Construal Scale and State-Trait Anxiety Inventory are highly consistent with other researchers’ data and common sense