Kinematic Parameters Research Articles

Studying the main characteristics of the Geminid meteor shower from baseline video observations in 2021

The Geminid meteor shower has been studied using data obtained by the method of baseline video observations during the period from December 01, 2021 to December 17, 2021. The meteors were examined in the brightness range from –3m to 2m and with an angular track length of at least 2°; the sample size was 327 events. The behavior of the shower is considered in terms of the interacting DRG (December ρ-Geminids) and GEM (Geminids) branches, which are closely related to each other and share a common origin. The shower activity was ZHR=127, Flux=19 at the general maximum of DRG+GEM (λsol~261.8°) and ZHR=32, Flux=4 at the putative local maximum of DRG (λsol~258.8°). Daily drift values were obtained for GEM (Δα=0.84°, Δδ=–0.27°, Δλec=0.75°, Δβ=–1.17°) and DRG (Δα=1.29°, Δδ=0.09°, Δλec=1.09°, Δβ=0.23°) in the equatorial and ecliptic coordinate systems; the intrinsic drift in the λec–λsol system was 0.09° and –0.26° for the DRG and GEM components respectively. We have found the opposite nature of the drift of both branches with a tendency for them to intersect at the point α=112.1°, δ=32.5°, λsol=259.8°. We have determined the kinematic and orbital parameters of meteoroids and have identified differences between the most probable geocentric velocities for the DRG (vg=35 km/s) and GEM (vg=34 km/s) branches. The morphology of the distribution of orbits within the plume has been studied. We give recommendations for reliably determining whether the meteors belong to one or another branch.

Исследование основных характеристик метеорного потока Геминиды по данным базисных видеонаблюдений 2021 г.

The Geminid meteor shower has been studied using data obtained by the method of baseline video observations during the period from December 01, 2021 to December 17, 2021. The meteors were examined in the brightness range from –3m to 2m and with an angular track length of at least 2°; the sample size was 327 events. The behavior of the shower is considered in terms of the interacting DRG (December ρ-Geminids) and GEM (Geminids) branches, which are closely related to each other and share a common origin. The shower activity was ZHR=127, Flux=19 at the general maximum of DRG+GEM (λsol~261.8°) and ZHR=32, Flux=4 at the putative local maximum of DRG (λsol~258.8°). Daily drift values were obtained for GEM (Δα=0.84°, Δδ=–0.27°, Δλec=0.75°, Δβ=–1.17°) and DRG (Δα=1.29°, Δδ=0.09°, Δλec=1.09°, Δβ=0.23°) in the equatorial and ecliptic coordinate systems; the intrinsic drift in the λec–λsol system was 0.09° and –0.26° for the DRG and GEM components respectively. We have found the opposite nature of the drift of both branches with a tendency for them to intersect at the point α=112.1°, δ=32.5°, λsol=259.8°. We have determined the kinematic and orbital parameters of meteoroids and have identified differences between the most probable geocentric velocities for the DRG (vg=35 km/s) and GEM (vg=34 km/s) branches. The morphology of the distribution of orbits within the plume has been studied. We give recommendations for reliably determining whether the meteors belong to one or another branch.

SEISMICITY of the CRIMEAN-BLACK SEA REGION in 2020

In 2020, the monitoring of the seismic situation in the Crimean-Black Sea region was carried out by a network of nine digital seismic stations located on the Crimean Peninsula. The catalog includes infor mation on 88 events with energy classes Kп=4.4–11.3. An updated map of the energy representativeness Kmin of earthquakes with an increased area within the isolines Kmin=7–8 is presented. The restored observations at the Kerch station increased the sensitivity of the network in the eastern part of the region. The existing network of stations provides without gaps the registration of earthquakes with a magnitude of M≥4.0, and for the main seismic zones: Sevastopol, Yalta, Alushta, Sudak, Kerch Peninsula – with a magnitude of M≥3.0. On the basis of the information obtained, a catalog of earthquakes with the main kinematic and dynamic parameters was compiled, an analysis was carried out and the features of seismicity of individual regions of the region were indicated. A detailed description of the seismic situation in various districts of the region is given. The period under consid eration is characterized by moderate seismic activity in the region, which is below the long-term average. The greatest activation of seismic processes was observed in 2020 in the Kerch-Anapa and Northwestern areas. In the Kerch-Anapa area, two tangible earthquakes with a maximum observed intensity of I=4–5 occurred in five settle ments on the coast of the Caucasus. An earthquake of the maximum energy class Kп=11.3, moment magnitude Mw=4.03 was realized on March 15, at 05h36m. The released seismic energy in the Northwestern area in 2020 significantly exceeded the 10-year average. Solutions of focal mechanisms were obtained for the 2 strongest earth quakes.

Spatio-Temporal and Mechanical Analysis of Bench Press Phases: Barbell Kinematics and Dynamics Across Different Load Intensities

This study aimed (1) to explore the spatio-temporal phases of the execution of the bench press (BP) exercise based on barbell acceleration and power; (2) to describe barbell velocity, acceleration, mechanical power, and mechanical work at different load intensities; and (3) to analyse differences in kinematic and mechanical parameters. Twenty-one men (21.4 ± 1.5 years; 175.1 ± 6.7 cm; 75.8 ± 7.7 kg; 1RM: 91.7 ± 13.7 kg) and nine women (21.7 ± 2.3 years; 163.3 ± 10.8 cm; 57.2 ± 6.8 kg; 1RM: 38.9 ± 10.5 kg) were evaluated during the eccentric and concentric phases of the BP at different load intervals: interval 1 (55 to 75% 1RM), interval 2 (>75 to 85% 1RM) and interval 3 (>85 to 100% 1RM). Both temporal (duration) and mechanical variables (velocity, acceleration, mechanical power and mechanical work of the barbell) were determined using the Xsens MVN Link System. Mechanical variables were compared among the three different intervals. Interval 3 displayed greater duration compared to intervals 1 and 2. Barbell acceleration and power showed four different phases of BP movement, corresponding to the second and third phases of the exercise, bar braking (eccentric) and bar acceleration (concentric), respectively; the first and fourth phases are mainly determined by gravity instead of muscle intervention. Velocity and acceleration were different among the three different intervals during both the eccentric and concentric phases (p < 0.05). No differences were found between intervals 2 and 3 in mechanical power or mechanical work during the eccentric phase. In conclusion, the BP exercise has four phases considering barbell acceleration and power. The maximum and mean velocity and acceleration during BP performance decrease as load intensity increases. Maximum and mean mechanical power, and mechanical work, decrease progressively in the second and third intervals for both the eccentric and concentric phases. Thus, kinematics and mechanical parameters vary depending on load intensities.

How Does Induced Deceleration of One Treadmill’s Belt in the Pre-Swing Gait Phase Change Gait Pattern?

This study aimed to investigate how external perturbations caused by the treadmill belt’s deceleration during the pre-swing phase affect gait kinematics and kinetics in young adults. Twenty-one healthy young females walked on a treadmill in a virtual environment (GRAIL, Motek), where unexpected perturbations were applied to the left belt, mimicking a ‘trip-like’ effect at toe-off. The spatiotemporal, kinematic, and kinetic parameters were analyzed during two cycles. The first cycle involved the first perturbation and the response to it. The second included a gait cycle without the perturbation (treadmill gait). The perturbation resulted in an increased stride duration for both limbs when compared to the treadmill gait. The perturbed limb had a longer support phase, while the reactive limb had the longest double stance phase. The responding limb exhibited more than double the ankle plantarflexion compared to the normal treadmill gait and the perturbed limb. At the hip joint, both limbs showed significantly higher values, with a 40.8% increase in flexion and a 227% increase in extension for the perturbed limb, and a 24.5% increase in flexion and a 212% increase in extension for the responding limb, compared to the treadmill gait. Muscle torque was generally lower in most joints for both limbs, except for notably higher hip and knee extensor values for the perturbed limb. The responding limb exhibited lower values for the ankle, knee, and hip joints, indicating unexpected muscle activity patterns. Studying treadmill belt deceleration during pre-swing gait can provide valuable insights into biomechanical adaptations and motor control strategies.

Estimation and Validation of Knee Joint Kinematic Parameters Using IMU Sensors in a Wearable Device

Abstract In physiotherapy, joint kinematics is conventionally analyzed using the universal mechanical goniometer involving manual measurements and is only possible for static assessments of biomechanical parameters. The aim of the present research is to estimate and validate the knee joint kinematic parameters using the inertial sensor in a wearable device. A video motion analysis study is performed using ‘Kinovea’ software for measurement validation. No statistical difference is observed in hypothesis testing (t-test, p>0.7). The Pearson correlation coefficient (r2) and intraclass correlation coefficient values are observed to be 0.99 and >0.99, respectively, for a 95% confidence interval in the inter-rater reliability test. Further, data normality using the ‘Kolmogorov-Smirnov’ test, and Bland-Altman analysis is performed to validate quantitative agreements. The Standard error measurement confirms the reliability between the two systems. The developed device can be used as an alternative to the universal mechanical goniometer to measure joint kinematics in dynamic movements.

Applying closed-loop equations for kinematic analysis of an eight-bar walking mechanism

Bionic mechanisms are used in constructing robotic systems that perform complex tasks similar to the movement of animals. With advancements in scientific research and breakthroughs in simulation techniques and computational methods, the design of these systems has become increasingly detailed and refined. This paper proposes using the closed-loop method to analyze the operational characteristics of a wheelless walking mechanism designed to traverse complex terrains. In addition to evaluating fundamental factors affecting system operation, the study determines kinematic parameters such as leg trajectory, movement velocity, and tilt angle. The results demonstrate the effectiveness of numerical methods in analyzing and simulating real-world systems, thus extending the use of computational tools for analyzing similar linkages.

The dynamical lineage of isolated, HI-rich ultra-diffuse galaxies

Ultra-diffuse galaxies (UDGs) exhibit morphological similarities with other low-luminosity galaxies, indicating a possible evolutionary connection. We investigated for the common dynamical characteristics of isolated, HI-rich UDGs with other low-luminosity field galaxies, namely the low surface brightness galaxies (LSBs) and the dwarf irregulars (dIrrs). We considered samples of each of the UDGs, LSBs, and the dIrrs. We first obtained scaling relations involving mass and structural parameters for the LSB and the dIrr samples and superposed the UDGs on them. We then carried out a two-sample Anderson-Darling test to analyse whether the UDGs belong to the population of the LSBs or the dIrrs. Thereafter, we constructed distribution function-based stellar-dynamical models of these galaxies to determine their kinematical parameters. We followed up with the Mann-Whitney U-test to determine if our UDG, LSB, and dIrr samples belong to different parent populations so far as kinematics is concerned. Finally, we conducted principal component analyses involving both structural and kinematical parameters to identify the key properties accounting for the variance in the data for the respective galaxy populations. From the galaxy scaling relation studies, we note that the UDGs and the LSBs constitute statistically different populations. However, for the UDGs and the dIrrs, the null hypotheses of these statistical tests cannot be rejected for the following scaling relations: (i) stellar mass versus atomic hydrogen mass, (ii) stellar mass versus dynamical mass, and (iii) dark matter core density versus core radius mass scaling. Interestingly, the dynamical models suggest that the UDGs, LSBs, and the dIrrs constitute different galaxy populations, as reflected by their radial-to-vertical velocity dispersion and the rotational velocity-to-total stellar velocity dispersion. Finally, we observe that the total HI and stellar mass mostly regulate the variance in the structural and kinematical data for both the UDGs and the dIrrs, while the ratio of radial-to-vertical velocity dispersion and the total HI mass dominate the variation in the LSBs. The UDGs and the LSBs represent statistically different galaxy populations with respect to their mass and structural properties. However, the statistical studies do not negate the fact that the structural parameters of the UDGs and the dIrrs follow the same normal distributions. However, the UDGs, LSBs, and the dIrrs constitute very different populations as far as their kinematical parameters are concerned. Finally, we note that the variation in the structural and kinematical data of both the UDGs and the dIrrs is mostly accounted for by their stellar mass and HI mass, whereas for the LSBs, the variance is explained by the ratio of the radial-to-vertical stellar dispersion followed by the HI mass. Thus, we may conclude that the UDGs and dIrrs share a common dynamical lineage.

A cosmological reconstruction of the Higgs vacuum expectation value

We present a simple toy model of cosmic acceleration driven purely by a self-interacting scalar field embedded in theory of grand unification. The scalar self-interaction is Higgs-like and provokes a spontaneous symmetry breaking. The coefficient of the quadratic term in the self-interaction potential has an evolution and it leads to a cosmic variation of proton-to-electron mass ratio, μ. We perform a cosmological reconstruction from the kinematic parameter jerk and discuss a few cosmological consequences of the theory. We also compare the theoretically calculated μ variation with the observations of molecular absorption spectra from Cesium Atomic Clock data.

Protective effect of epidermal growth factor on cryopreservation of dromedary camel epididymal spermatozoa: Evidence from in vitro and in silico studies

Epidermal growth factor (EGF) plays a crucial role in maintaining male reproductive capacity in mammals, however, its protective effects on cryopreserved dromedary camel epididymal spermatozoa have not been thoroughly investigated. This study aims to investigate the potential protective role of EGF on cryopreserved camel epididymal spermatozoa, supported by evidence from a molecular docking study. We assessed sperm motility, kinematics parameters, oxidative stress, ultrastructural changes, apoptosis, and molecular docking markers in camel epididymal spermatozoa following cryopreservation. Camel epididymal spermatozoa (n=30 pairs of testes) were collected from local slaughterhouses. The epididymal spermatozoa were diluted with a freezing medium (SHOTOR extender) supplemented with different concentrations of EGF; 0 (EGF0), 50 (EGF50), 100 (EGF100), 200 (EGF200), and 400 (EGF400) ng/mL in SHOTOR extender and cryopreserved using a standard protocol. All EGF groups showed significant improvements in sperm progressive motility, viability, and sperm membrane function after equilibration at 5 °C for 24hours. Regarding frozen-thawed samples, sperm progressive motility and some kinematic parameters (DAP, VSL, VCL and AHL) were significantly higher in the EFG400 group compared to the other groups (P < 0.01). A significant increase in the percentage of live/acrosome-intact sperm was observed, accompanied by a significant decrease in malondialdehyde levels in all EGF groups (P < 0.05). Both the EGF200 and EGF400 groups showed significantly higher sperm viability and significantly lower percentages of apoptotic and necrotic sperm compared to the other groups (P < 0.05). EGF supplementation preserved the ultrastructural integrity and cryotolerance of epididymal camel spermatozoa. The docking analysis indicated that EGF exhibited higher binding affinity with apoptosis sperm markers, including caspase-3 and bcl-2-associated X (Bax) proteins, with binding energies of -502.0 and -621.0kcal/mol, respectively. In conclusion, the addition of EGF to SHOTOR extender was found to have beneficial effects on sperm motility, kinematics parameters, sperm viability, acrosome integrity, sperm ultrastructural features, and reduced oxidative stress and apoptosis-like changes in cryopreserved epididymal camel sperm.

A Comparison of Throwing Arm Kinetics and Ball Velocity in Professional Baseball Pitchers with the Fastest Maximum Joint and Segment Velocities.

Significant associations have been established among individual maximum joint and segment velocities with throwing arm kinetics and ball velocity in baseball. Investigate how pitches with the fastest maximum joint and segment velocities, in both ideal and non-ideal sequence order, may impact ball velocity and throwing arm kinetics in professional baseball pitchers. Professional(n=338) pitchers threw 8-12 fastball pitches while evaluated with 3D-motion capture (480 Hz). Pitches (ideal and non-ideal sequence order) were classified as 'High Velocity' for each segment/joint velocity subcategory or 'Population' with any pitch eligible for inclusion in multiple subcategories. Kinematic and kinetic parameters were compared among subgroups with post-hoc regression analysis. Population pitches in ideal sequence order (pitches: 71, pitchers:19) had significantly faster ball velocity than Population pitches in non-ideal order (pitches: 3685, pitchers: 338) (39.0±1.5 vs. 38.2±2.2m/s respectively, p<0.001). Irrespective of sequence, the Lead knee extension velocity subgroup had faster ball velocity (38.9±1.8ms), compared to Population (38.2±2.2m/s) (p<0.001, d=0.4). For non-ideal sequence pitches, for every 1091°/s increase in maximum shoulder internal rotation velocity, shoulder superior force increased by 3.67%Body Weight (BW). Pitches in ideal order, for every 1414°/s in maximum shoulder internal rotation velocity, there was an increase in shoulder superior force by 4.29%BW, elbow medial force by 5.33%BW, and elbow distractive force by 9.33%BW. Proper sequence order plays an important role in maximizing ball velocity with minimal implications for throwing arm kinetics. When throwing non-ideal sequence, increasing maximum lead knee extension velocity positively impacts ball velocity, while increasing other velocities has negative implications on throwing arm kinetics.

Changes in Functional Connectivity Relate to Modulation of Cognitive Control by Subthalamic Stimulation.

Subthalamic (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) patients not only improves kinematic parameters of movement but also modulates cognitive control in the motor and non-motor domain, especially insituations of high conflict. The objective of this study was to investigate the relationship between DBS-induced changes in functional connectivity at rest and modulation of response- and movement inhibition by STN-DBS in a visuomotor task involving high conflict. During DBS ON and OFF conditions, we conducted a visuomotor task in 14 PD patients who previously underwent resting-state functional MRI (rs-fMRI) acquisitions DBS ON and OFF as part of a different study. In the task, participants had to move a cursor with a pen on a digital tablet either toward (automatic condition) or in the opposite direction (controlled condition) of a target. STN-DBS induced modulation of resting-state functional connectivity (RSFC) as a function of changes in behavior ON versus OFF DBS was estimated using link-wise network-based statistics. Behavioral results showed diminished reaction time adaptation and higher pen-to-target movement velocity under DBS. Reaction time reduction was associated with attenuated functional connectivity between cortical motor areas, basal ganglia, and thalamus. On the other hand, increased movement velocity ON DBS was associated with stronger pallido-thalamic connectivity. These findings suggest that decoupling of a motor cortico-basal ganglia network underlies impaired inhibitory control in PD patients undergoing subthalamic DBS and highlight the concept of functional network modulation through DBS.

Semen cryopreservation and storage in liquid nitrogen: Impact on chromatin compaction.

Sperm cryopreservation is a consolidate option for long-term male fertility preservation. The freezing/thawing procedure causes detrimental effects to spermatozoa, including damage to viability, motility, membrane composition, and DNA, whereas the effect on sperm chromatin compaction is less studied. The primary aim of this study was to investigate the impact of cryopreservation on sperm chromatin compaction. Furthermore, the effect of cryopreservation on sperm parameters (motility, viability, chromatin compaction, and DNA fragmentation) was also assessed in relation to the storage time in liquid nitrogen. Semen samples, collected from 126 (92 normozoospermic and 34 oligozoospermic) patients undergoing routine semen analysis in the Andrology Laboratory of Careggi University Hospital of Florence, were frozen by conventional fast vapor freezing method. Sperm motility, viability, kinematic parameters (by computer-aided sperm analysis [CASA]), chromatin compaction (by staining with both aniline blue [AB] and Chromomycin A3 [CMA3]), and sperm DNA fragmentation (sDF, by TUNEL/Propidium Iodide [PI]) were evaluated before freezing and after thawing at different timepoints. After 7 days of storage, a significant decline in sperm motility, viability, and kinematics parameters, as well as a significant increase in the percentage of sperm positivity to CMA3, AB, and sDF, were observed. It is noteworthy that while motility and viability decreased in almost all subjects, the increase in CMA3 and AB positivity was observed in 68.0% and 79.2% of samples, respectively. A progressive deterioration of sperm motility and viability, less evident for chromatin structure, was observed at longer times of storage (28 and 180 days). Our results indicate that freezing/thawing procedures can alter chromatin structure. A reduction in protamine content and/or a modification in chromatin assembly can be hypothesized. Furthermore, the length of storage in liquid nitrogen appears to progressively affect sperm parameters, although it should be confirmed in larger cohort of subjects. Current sperm cryopreservation protocols need to be improved with new strategies and personalized procedures aimed to minimize the damage.

ADJUSTMENT OF THE ELEMENTS OF THE FLOW PART OF THE HIGH-EFFICIENCY OF PUMP- TURBINE

The problem of the development of pumped storage power plants in Ukraine is considered, especially in the conditions of military operations, which damaged the energy infrastructure and created capacity shortage. The pumped storage power plants will help stabilize the power system by storing energy during periods of low load and efficiently using it during peak needs or accidents. All this has a positive impact on the role of energy autonomy and the integration of renewable energy sources. Efficiency increase of the hydro-turbine equipment of the PSPP requires the improvement of the water passage of the reversible hydraulic machines. This work shows that the creation of high-efficiency reversible hydraulic equipment depends on the correct selection of the geometry of the pater passage elements of the reversible hydraulic machines, consequently ensure the necessary level of energy characteristics of the hydraulic equipment. The equation of the optimal mode was used for the calculated assessment of kinematic and energy characteristics, analysis of their formation and search for rational variants that provide the specified requirements for the runner energy characteristics of the reversible hydraulic machines. Calculations are carried out using dimensionless kinematic parameters, which simplifies the process and eliminates the need for complex calculations. The numerical analysis data on the influence of the hydrodynamic parameters of the water passage on the parameters of the optimal mode can be used both for profiling the blade system of the runner, with the aim of improving energy characteristics (increasing power, efficiency level, etc.), and for modifying the blade system. The numerical study method for finding optimal variants of the runner blade system is given. The proposed approach was used to estimate the kinematic and energy characteristics of water passages of Francis turbines, as well as high-head reversible hydraulic machines ОRО200 and ОRО500 (both for basic and modified variants of the water passage).

Dynamic Model and PD Control with Forces Compensation of Dual-Stage Gough-Stewart Platform

This paper investigates a dual-stage Gough-Stewart platform. The lower platform is responsible for simulating the oscillations of moving vehicles such as cars, ships, and airplanes. The upper platform is connected to devices that require either balance stabilization or motion stabilization according to specific requirements. The dynamic model of the robot system is derived in a general form based on the Lagrange equations of motion with Lagrange multipliers. Using these equations in a compact form, a PD controller with forces compensation in task space is designed for the robot system. Oscillation generation and balance stabilization are computed and simulated using the kinematic and dynamic parameters of two Bosch Rexroth robots. The computation and simulation results demonstrate the dynamic model's accuracy and the controller's effectiveness.

A Prospective Study on Gait Impairment in Patients With Symptomatic Lumbar Canal Stenosis and Impact of Surgical Intervention on Gait Function.

Prospective observational cohort study. To analyze the effect of decompression surgery on gait characteristics in patients with stenosis. Also, to test the hypothesis that patient-reported functional outcomes and gait parameters (spatiotemporal, kinetic, and kinematic measures) will improve postoperatively and achieve normal values when compared with matched healthy controls. Lumbar spinal stenosis is one of the leading causes of disability among elderly population. Gait impairment is one of the primary symptoms of degenerative conditions involving lumbar spine. Research suggests that decompressive surgery can positively influence gait parameters in patients with spinal stenosis. Studies have shown improvements in walking speed, stride length, and balance post-surgery. Thirty-two patients with single-level lumbar stenosis and 32 healthy volunteers were prospectively recruited. All patients underwent gait analysis preoperatively and 6 months postoperatively as per standard protocol. Spatiotemporal, kinematic, and kinetic parameters were analyzed. Stepwise linear regression models were used to detect significant relationships between changes in functional score (Visual Analogue Scale/Oswestry Disability Index) and gait parameters. Significant improvement was noted in functional scores(P<0.05) 6 months post-surgery. Spatiotemporal (swing phase, mean velocity, cadence, stride length, step length, and step width) and kinetic parameters (hip, knee, and ankle power) were significantly better after surgery, reaching normal levels. Kinematic parameters significantly improved after surgery but did not reach normal levels when compared with controls. A significant correlation was found between changes in functional scores with changes in certain kinematic parameters (knee-power, ankle plantarflexion, swing time, peak ankle dorsiflexion in swing, peak-hip, and knee flexor moment). Decompression surgery in lumbar stenosis produces improvement in gait parameters, pain scores, and functional outcomes that significantly improve gait posture and speed.

Effect of zinc on sperm recovered by swim-up.

Zinc is known to influence chromatin stability, motility and protection against oxidative stress. While swim-up remains the preferred method for selecting sperm in Assisted Reproductive Technologies (ART), concerns arise regarding sperm DNA fragmentation associated with this procedure. Given zinc's significant role in protecting sperm DNA integrity and motility, we aimed to investigate the impact of zinc supplementation during the swim-up process on sperm quality. Semen samples from 203 normozoospermic men were used. Samples were divided into fractions and swim-up procedure was applied using human tubal fluid (mHTF) supplemented with three different concentrations of zinc or medium without supplementation as control. DNA fragmentation, chromatin maturity, reactive oxygen species (ROS) levels, motility and protein phosphorylation levels analyses were addressed to each fraction. The sperm DNA fragmentation was reduced in sperm recovered by swim-up in media with all concentrations of zinc assayed with respect to the control (p < 0.0001). Aniline blue staining showed better chromatin maturity in sperm recovered with 2.5- and 3.5-mM zinc (p = 0.045; p = 0.021). Kinematic parameters such as curvilinear velocity and beat-cross frequency showed improvement with 2.5mM zinc (p = 0.0080 and p = 0.0400), whereas straightness, linearity, and hypermotility showed improvement with 5mM zinc (p = 0.0075, p = 0.0069, and p = 0.0244). Protein phosphorylation patterns showed changes associated with treatment with zinc, and only 5mM zinc treatment showed a decrease in ROS levels. The addition of zinc to mHTF provided optimal physiological conditions for sperm recovered through swim-up. This supplementation should be considered for selecting sperm for use in ART.

Investigation of the kinematics of turning a wheeled vehicle with a variable track

BACKGROUND: The trapezoidal lever mechanism used in the steering drive for turning steerable wheels to change the direction of movement of a wheeled vehicle does not fully meet the conditions for observing rolling wheels without slipping and conforming to the correct kinematics of rotation, which is especially evident when adjusting the track. AIMS: assessment of the degree of discrepancy between the actual kinematics of the turn and the kinematics of the correct turn when changing the track of the tractor. MATERIALS AND METHODS: Analytical methods were used in the work, which made it possible to obtain some computational dependencies, perform a numerical analysis of the curvilinear motion of a tractor with a variable track for different parameters of the steering trapezoid, and on this basis establish patterns between the geometric characteristics of the steering trapezoid and the kinematic parameters. RESULTS: Rational geometric characteristics of the steering trapezoid, which make it possible to obtain the kinematic parameters of rotation closest to the required ones, are set for the most commonly used value of the width of the pivot track. For the Belarus-80.1 tractor, it corresponds to 1.02 m. At the same time, for example, at an angle of rotation of the inner steerable wheel of 25°, the minimum turning radius realized by the steering trapezoid is 0.6521 m (10.44%), and at 40° by 0.2829m (9.27%) differs from their values obtained from the pure rolling condition. When changing the track width of the machine, there is a violation of the initial geometric characteristics of the trapezoid and the corresponding mismatch of the kinematic parameters of the rotation carried out by the steering trapezoid and by the correct rotation increases. A comparison of the minimum turning radii at an angle of 25° and a pivot track of 1.42 m showed an increase of 3.2340 m (35.83%), and at 40° — by 0.8956 m (20.21%). CONCLUSION: To ensure the correct turn, it is necessary to conduct a thorough theoretical analysis of the never mechanism of the steering trapezoid and improve its design on this basis.

Investigating the correlation of GRP78 with sperm motility and kinematic parameters insights into male fertility

Investigating the correlation of GRP78 with sperm motility and kinematic parameters insights into male fertility

REMOVAL SYSTEM FOR UNMANNED GROUND VEHICLES USING A MODULAR ROBOTIC ARM

A removal system for Unmanned Ground Vehicles (UGVs) equipped with a modular robotic arm designed for hazardous and unstructured environments is presented. The system is based on commercially available solution that enables the manipulation of objects and removal of obstacles in complex terrains, such as disaster zones, battlefields, and industrial sites. The operational environment, teleoperation capabilities, and associated challenges are thoroughly addressed. Recent developments in All Terrain Vehicle-based unmanned platforms are discussed, demonstrating their suitability for rapid and versatile implementation in special-purpose missions. A model of an unmanned platform with an integrated robotic arm is proposed to enhance the existing range of medium-sized UGVs. The system configuration tailored for special-purpose missions is outlined, and kinematic parameters, along with stress tests, are provided to confirm its high adaptability to a diverse range of operational scenarios.