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In the paper, a simple theory of quantum inteference in a loop structure caused by spin coherent transport and the Larmor precession of the electron spin is presented. A "spin ballistic" regime is supposed to occur, when the phase relaxation length for the spin part of the wavefunction (Lɸ(s)) is much greater than the phase relaxation length for the "orbital part" (Lɸ(e)). In the presence of an additional magnetic field, the spin part of the electron wavefunction acquires a phase shift due to additional spin precession around that field. If the structure length L is chosen to be Lɸ(s)) > Lɸ(e)) it is possible to "wash out" the quantum interference related to the phase coherence of the "orbital part" of the wavefunction, retaining at the same time that related to the phase coherence of the spin part and, hence, to reveal corresponding conductance oscillations. Different mechanisms of spin relaxation, such as Elliot - Yafet, the scattering by the edges and surface the structure and the precession ones, as well as their influence on the spin coherent transport are considered. The quantum interference in time-dependent magnetic field, quantum beats in mesoscopic loop structure, are also discussed. The similarities between this effect and Josephson, scalar Aharonov - Bohm and Aharonov - Casher effects, as well as their differences are treated and possible application of the effect to the construction of the device, complementary to superconducting quantum interference device is analyzed. [ABSTRACT FROM AUTHOR]

Background: One of the most popular varieties of rugby is Rugby Union, in which a team consists of 15 players. Rugby Union is a full-contact sport, and players must demonstrate strength, endurance, speed and agility. During the match, players participate in multiple physical collisions and tackles, short-duration and high-intensity sprinting efforts. In addition, one of the elements affecting the effectiveness of the player's game can be the reaction time of the rugby player to the visual stimulus and the ability to read the game and react to the situations on the pitch. The level of psychomotor abilities of a person or a player practising sports can be influenced by various factors, including age, body height, body weight, type of sport practised or level of training. The study aimed to analyse the psychomotor abilities of professional rugby union players, investigate the relationship between the selected anthropometric characteristics and psychomotor abilities, and compare obtained results with the control group., Methods: The study covered 22 players of the Polish National Team (age: 29.3 ± 5.4) and 27 students in the control group (age: 24.3 ± 3.9). The tests were carried out using the Test2Drive computer system of tests. For psychomotor abilities analysis, four tests were used: Simple Reaction Test, Choice Reaction Time Test, Hand-Eye Coordination Test and Spatial Orientation Test. The statistical analysis compares groups using basic statistical measures, and statistically significant differences between groups were checked. In addition, multiple linear regression was used., Results: The analysis showed statistically significant differences between the groups in the simple reaction time test and the movement time for the test assessing reaction time with choice and eye-hand coordination. Multiple regression analysis conducted for both groups showed a statistically significant influence of some anthropometric parameters on the examined psychomotor abilities. The calculated multiple regression models had a high fit., Conclusions: The analysis showed that professional Rugby Union players have shorter movement time than the control group. For reaction time, statistically significant differences were observed only for simple reaction time. Moreover, linear regression analysis showed that body height and weight affect the selected psychomotor abilities., (© 2023. BioMed Central Ltd., part of Springer Nature.)

The aim of the study was to verify the correlation between the frequency of blinking and aerobic physical exercise. The research subjects were 13 healthy man aged 23.3 ± 1 year. Measurements of the blink rate and eye closure times were performed during a progressive aerobic test on a cycle ergometer. During the test, power was gradually increased every minute by 25 W, starting from 50 W. Data acquisition involved using a GoPro camera mounted to the helmet of the research subject. The test continued until the research subject refused to continue. The subjects did not know the goal of the test, in order to ensure objectivity and obtain natural results. The largest number of statistically significant differences was observed between the initial stages and 250 W, as well as between 250 W and 325 W. The analysis showed no significant differences in blink rate, eye closure time, and single blink time in terms of heart rate ranges. Regression models were also determined for eye closure time, blink frequency, and single blink time. The analysis showed that blink frequency and eye closure time were determined by a group of factors (the value of cycle ergometer load power, heart rate, body weight, adipose tissue mass, fat-free mass, and total body water and body surface ratio).

Combat tasks involving special units often put a mental and physical strain on the soldiers. During the military operation, soldiers may struggle with multiple difficulties such as extreme physical effort, sleep deprivation, weather conditions, limited access to food and stress. These circumstances require a high level of cognitive ability (including psychomotor abilities) to overcome the physiological stress response and to be able to quickly and efficiently make decisions under stressful situations, especially in combat. The aim of the study was to assess the level of the psychomotor abilities of candidates for the Polish Special Forces. The study comprised 48 candidates for the Polish Special Forces (age: [Formula: see text]), 40 athletes (age: [Formula: see text]) and 40 non-athletes (age: 24). The study was performed using Test2Drive software. Four computer-based tests were used to assess the following psychomotor abilities: simple reaction time, choice reaction time, hand-eye coordination and two-dimensional visuomotor coordination/spatial orientation test (SPANT). The analysis demonstrated statistically significant differences in reaction time and motor time between the study groups. The shortest reaction time in each test was observed in athletes, while the shortest motor time was observed in soldiers. All the psychomotor tests, except for the number of correct answers in SPANT, demonstrated statistically significant differences between the studied groups. It was also found that military training had a positive effect on the motor time in every psychomotor test. As regards the reaction time, it was observed that the athletes were characterised with better reaction times than the special forces candidates. The study has confirmed that military training and sports training have a positive effect on the level of psychomotor abilities, especially motor time., (© 2022. The Author(s).)

The purpose of this study was to report sex- and age-specific physical fitness level in Polish children aged 4 to 7. 11.709 children participated in the study, including 5.684 girls and 6.025 boys aged 4 to 7 who attended kindergarten institutions throughout Poland. Physical fitness was assessed using four tests developed by Sekita including shuttle run 4 × 5 m with moving the block, standing long jump, throwing 1 kg medicine ball with two hands above the head and 20 m run. Percentile charts were developed separately for males and females using the LMS method. Boys showed higher physical fitness values than girls. In addition, an increase in the level of physical fitness was observed along with the age of the subjects. The developed reference values by age and sex in the field of physical fitness can be used for diagnostic purposes and assessing the level of physical fitness of preschool children. In addition, they can be helpful for healthcare professionals, parents and teachers to develop children's motor activation programs and monitor their physical fitness.

The aim of the study was to assess selected cognitive abilities depending on age, anthropometric parametres, physical fitness and technical skills in the group of young players training football. The study covered a group of 258 young players practicing football (age: 12.1± 2.03), who were divided into 5 age categories (8-9 years old, 10-11 years old, 12-13 years old, 14-15 years old, 16-17 years old). Selected cognitive abilities include: simple reaction time (SIRT), complex reaction time (CHORT), hand-eye coordination (HECOR) and spatial orientation (SPANT). Studies were performed using Test2Drive computer tests. In addition, the level of physical fitness was measured using: The standing long jump, 30 m sprint, 20 m shuttle run test (without and with the ball) and slalom (without and with the ball). The analysis showed a statistically significant relationship between age and cognitive abilities. There was also a statistically significant correlation between fitness tests and reaction time in individual cognitive tests. There were no statistically significant relationships between technical skills and cognitive abilities. The study confirms that age and physical fitness affect the level of cognitive abilities.