Movement Speed Research Articles

The Motility of Mouse Spermatozoa Changes Differentially After 30-Minute Exposure Under Simulating Weightlessness and Hypergravity

Research into the mechanisms by which gravity influences spermatozoa has implications for maintaining the species in deep space exploration and may provide new approaches to reproductive technologies on Earth. Changes in the speed of mouse spermatozoa after 30 min exposure to simulated weightlessness (by 3D-clinostat) and 2 g hypergravity (by centrifugation) were studied using inhibitory analysis. Simulated microgravity after 30 min led to an increase in the speed of spermatozoa and against the background of an increase in the relative calcium content in the cytoplasm. This effect was prevented by the introduction of 6-(dimethylamino) purine, wortmannin, and calyculin A. Hypergravity led to a decrease in the speed of spermatozoa movement, which was prevented by sodium orthovanadate and calyculin A. At the same time, under microgravity conditions, there was a redistribution of proteins forming microfilament bundles between the membrane and cytoplasmic compartments and under hypergravity conditions—proteins forming networks. The obtained results indicate that even a short exposure of spermatozoa to altered gravity leads to the launch of mechanotransduction pathways in them and a change in motility.

Влияние острой токсичности бисфенола А на поведение и локомоторную активность Danio rerio

The results of evaluating the effects of acute exposure of Danio rerio to bisphenol A solutions on behavioral traits and locomotor activity using the open field test are presented. It was found that bisphenol A in the exposure aquariums resulted in impaired movement, hyperactivity, increased mucus secretion, and increased gill cover movements. Fish not exposed to the pollutant in the open field test spent most of their time near the edges of the aquarium, exhibiting moderate exploratory activity. Bisphenol A in the open field test at concentrations greater than 1 mg/l caused a significant increase in mean locomotor speed (to 11.1 cm/s) and a decrease in inactivity time (to 9.9 s). The indices of locomotor activity in Danio rerio, significantly altered by bisphenol A, showed a clear concentration-effect relationship: for inactivity time in the inner circle, R² = 0.6765, and in the outer ring, R² = 0.7140; for movement speed in the inner circle, R² = 0.4365, and in the outer ring, R² = 0.4011. Acute toxicity of bisphenol A resulted in the development of anxiety-like behavior in fish, characterized by hyperactivity, increased exploratory activity, and decreased thigmotaxis.

Finger contact keyboard for typing with tiny movement recognition

Hemiplegic patients often struggle with typing rapidly and accurately using a standard keyboard. This study developed a keyboard in continuous contact with the fingers, allowing for easier and more effective typing. With the proposed keyboard, the user types with their healthy hand and paralyzed hand. The hardware and software of the finger contact keyboard were investigated. In deciding the hardware, we measured the hand shape, finger speed, and muscle fatigue using electromyography, magnetic positioning sensors, and force sensors for eight participants. Using the Pareto solution, we optimized the keyboard’s structure to maximize finger movement speed and minimize muscle fatigue. As the software of the proposed keyboard, we developed an algorithm implementing a neural network to identify intentional typing and tested the algorithm on five participants. The highest average discrimination accuracy was 99.3% when the force threshold was approximately 1.32 N. The mean accuracy achieved using the neural network was 90.8%, which is higher than that achieved using the threshold algorithm (80.4%). In 40 trials, the proposed keyboard achieved the same accuracy and speed as the standard keyboard, and the input time for a patient with hemiplegia was reduced by 16.2%.

Sudden Fall Detection of Human Body Using Transformer Model

In human activity recognition, accurate and timely fall detection is essential in healthcare, particularly for monitoring the elderly, where quick responses can prevent severe consequences. This study presents a new fall detection model built on a transformer architecture, which focuses on the movement speeds of key body points tracked using the MediaPipe library. By continuously monitoring these key points in video data, the model calculates real-time speed changes that signal potential falls. The transformer’s attention mechanism enables it to catch even slight shifts in movement, achieving an accuracy of 97.6% while significantly reducing false alarms compared to traditional methods. This approach has practical applications in settings like elderly care facilities and home monitoring systems, where reliable fall detection can support faster intervention. By homing in on the dynamics of movement, this model improves both accuracy and reliability, making it suitable for various real-world situations. Overall, it offers a promising solution for enhancing safety and care for vulnerable populations in diverse environments.

Workout at a virtual gym: Surrounding avatar's motion speed and exercise intensity effect on the user's time perception.

This study explored the relationship between surrounding avatars and time perception in a virtual reality (VR) gymnasium. Previous research has highlighted that motion speed and exercise intensity significantly influence time perception. In VR, time perception is shaped by various factors, such as an avatar's embodiment at different levels. However, the specific effects of the surrounding avatar on time perception in a VR gymnasium context remain unclear. Thus, this study focuses on two key attributes of the surrounding avatar: (1) motion speeds and (2) exercise intensity. Participants in a VR gymnasium either rode a stationary bike or sat on one while observing avatars performing exercises in the virtual environment(VE). They were then asked to estimate the duration judgment and the feeling of the passage of time for each task. The results revealed that when the surrounding avatars exercised at a faster motion speed, participants perceived the duration of time as longer and felt that time passed more quickly. Additionally, high-intensity exercise led participants to perceive the passage of time as faster.

Enhancing Surface Finish in FDM 3D Printing: The Impact of a Spherical Ironing Tool

This study aims to evaluate the functionality and effectiveness of a new tool for ironing 3D printed components using FDM technology. The ironing process draws inspiration from the ball burnishing process, employing a spherical tool that, by exerting pressure, modifies the component's surface. The process involves heat transfer between the tool and the component to soften and deform the surface more easily. A theoretical analysis of the resulting surface roughness following this process was conducted to identify the parameters at play and their influence. It was found that the two main parameters are the fillet radius and the distance between passes. Additionally, practical tests were carried out to confirm the hypotheses, revealing the influence of three other parameters: tool Z-axis positioning, temperature, and movement speed. The surface after treatment exhibits an average roughness of Ra = 0.378 μm, significantly better than values obtained with ironing performed with the nozzle and with quality comparable to grinding. This lays the groundwork for possible future optimization of parameters based on the component's characteristics and the material used.

Accelerating Precision: Using AI to Fine-Tune Workout Form and Motion Speed

This is an extension of the paper that we published earlier on AI for workout Form Optimization. In the earlier paper, we presented a software solution for workout form optimization using joint angles. Just like the effectiveness of the workout is in the precision of the body form, it also gets hugely impacted by the workout speed, i.e., muscle contraction and relaxation speed. This paper covers a software solution that can be used to give users feedback on their workout speed for specific workout exercises. It uses computer vision and artificial intelligence libraries. The sample implementation is provided on GitHub GitHub - pythonioncoder/Fit-Form-AI. Keywords— Pose Detection AI Libraries, Media pipe, AI Programming, Computer Vision, Artificial Intelligence, Fit Form AI

Manifestation of the FLASH effect in proton irradiation of embryos

Purpose In order to study the FLASH effect using live models, this work compared proton-induced damage to embryos (nine days after fertilization) and one-day-old chicks (18 days after fertilization) from irradiated at different dose rates eggs of Japanese quail (Coturnix coturnix japónica). Materials and methods Eggs were irradiated with protons in different modes depending on the dose rate: in a conventional mode (<1 Gy/s, CONV), in a flash mode (∼100 Gy/s, FLASH) and in a single-pulse flash mode (∼105 Gy/s SPLASH). Results By the criteria of body weight and length, as well as the number of erythrocytes with micronuclei in nine-day-old embryos from eggs irradiated in the spread-out Bragg peak (SOBP) (8.5 Gy), FLASH and SPLASH modes were found to be less traumatic compared with the CONV mode. Among all irradiated embryos, the maximum body weight and length were observed in the SPLASH mode. The lowest death incidence and the smallest number of abnormal erythrocytes were recorded after FLASH and SPLASH irradiation. In chicks that hatched from eggs irradiated in the CONV mode, a tendency for an increase in the number of abnormal erythrocytes was observed. The speed of movement of chicks from FLASH- and SPLASH-irradiated eggs was comparable with that from unirradiated eggs, while chicks from eggs irradiated in the CONV mode were less active than all others. Conclusions The proton irradiation of eggs in SOBP using high dose-rate modes is less damaging for healthy tissues and for the development of embryos and chicks on the cellular, anatomical, and physiological levels.

An Earth Mover's Distance-Based Self-Supervised Framework for Cellular Dynamic Grading in Live-Cell Imaging.

Cellular appearance and its dynamics frequently serve as a proxy measurement of live-cell physiological properties. The computational analysis of cell properties is considered to be a significant endeavor in biological and biomedical research. Deep learning has garnered considerable success across various fields. In light of this, various neural networks have been developed to analyze live-cell microscopic videos and capture cellular dynamics with biological significance. Specifically, cellular dynamic grading (CDG) is the task that provides a predefined dynamic grade for a live-cell according to the speed of cellular deformation and intracellular movement. This task involves recording the morphological and cytoplasmic dynamics in live-cell microscopic videos. Similar to other medical image processing tasks, CDG faces challenges in collecting and annotating cellular videos. These deficiencies in medical data limit the performance of deep learning models. In this article, we propose a novel self-supervised framework to overcome these limitations for the CDG task. Our framework relies on the assumption that increasing or decreasing cell dynamic grades is consistent with accelerating or decelerating cell appearance change in videos, respectively. This consistency is subsequently incorporated as a constraint in the loss function for the self-supervised training strategy. Our framework is implemented by formulating a probability transition matrix based on the Earth Mover's Distance and imposing a loss constraint on the elements of this matrix. Experimental results demonstrate that our proposed framework enhances the model's ability to learn spatiotemporal dynamics. Furthermore, our framework outperforms the existing methods on our cell video database.

Blocking microtubule deacetylation inhibits anaphase chromosome movements in crane-fly spermatocytes.

Chromosome movement speeds during anaphase are regulated by depolymerization of microtubules. Several models describe chromosome movement during cell division but none of them consider post-translational modifications of tubulin, even though such modifications help specify microtubules for unique cellular activities. Among these modifications, acetylation of Lysine 40 is one of the common post-translational modifications. Acetylation of microtubules greatly improves their stability, especially when subjected to cooling or drug treatment. Since kinetochore microtubules are acetylated in a variety of eukaryote cells, we wondered whether deacetylation of kinetochore microtubules was necessary in order for microtubules to be able to depolymerize during anaphase. HDAC6 (Histone Deacetylase 6) deacetylates acetylated tubulin. To study whether tubulin must be deacetylated during anaphase, we added to living cells two different HDAC6 inhibitors (Tubacin and Trichostatin A), separately, as chromosomes moved poleward in anaphase. Both HDAC6 inhibitors altered chromosome movement: chromosomes either completely stopped moving, or moved more slowly, or sometimes continued movement without speed changes. The effects of the inhibitors on chromosome movement are reversible: half-bivalents either restarted anaphase movement by themselves before washing out the inhibitor or resumed their poleward movement after the inhibitor was washed out. We suggest that kinetochore microtubules need to be deacetylated in order for normal anaphase movements to occur.

Mu down regulation EEG-neurofeedback training combined to motor imagery facilitates early consolidation in a sequential finger tapping task

Objective.Motor imagery (MI) has demonstrated positive effects on motor performance and triggers activation in the motor cortex (MC). EEG-Neurofeedback (EEG-NF) is a neuromodulation technique that provides real-time feedback on one's brain activity, enabling self-regulation of brain states. While there is increasing evidence of humans controlling the activity of various brain networks, including the MC, through EEG-NF, the tangible benefits of this self-regulation on motor performance remain uncertain. This study investigates the potential benefits of EEG-NF training in explicit learning of a sequential movement, in comparison to MI training and to a combined EEG-NF and MI training.Approach.Ninety-one right-handed healthy adults were randomly assigned to one of four groups (a)NF(n= 24), (b)MI(n= 22), (c)MI + NF(n= 23) and (d)control(n= 22). Participants performed a sequential finger tapping task before and after (immediately, 20 min and 24 h) a single 30 min training session. Motor performance, movement speed and event related desynchronization data were analyzed.Main results.MI training led to a better motor performance compared to control condition immediately after training that was sustained at the 20 min retest time point (p= 0.02 and 0.05). In contrast, EEG-NF training alone did not yield better motor performance compared to control condition at any time-point (p> .05). Remarkably, only the combination of both trainings led to superior motor performance 24 h after training in comparison to control group (p= 0.02). Additionally, all experimental groups successfully decreased mu rhythm amplitude throughout most of the training.Significance.Combined EEG-NF and MI training appears particularly promising for enhancing motor consolidation holding the potential to advance rehabilitation approaches.

Analysis of air consumption and moving speed by firefighters during full-scale search & rescue experiments in a tunnel

Experiments were carried out in a 420 m long dead-end tunnel to assess air consumption and movement speed. The operation consisted of a 417 m walk to locate and rescue a victim. Seven teams of 5 blindfolded firefighters were sent into the tunnel with a single-bottle SCBA, a stretcher and a mobility cane. 14 firefighters (i.e., 44%) had to use ‘reserve air’. Hence it is not considered safe to carry out such an operation. However, all the crews noticed the sign that they used half of the available air in their bottle, so it is possible to start the S&R operation in a tunnel and safely return at the 175 bar mark. The average time to completion was 35.2 minutes. All crews became better at using the cane, leading to a higher average movement speed (0.50 m/s) out of the tunnel than into the tunnel (0.39 m/s). The average air consumption per walking meter was 2.20 L/m going in and 1.33 L/m going out. The average air consumption rate was 49.9L/min going into the tunnel and 38.9 L/min going out of the tunnel. It is shown that speed plays an important role. Faster firefighters have a lower total air consumption.

An evacuation model considering pedestrian group behavior under violent attacks

In recent years, violent attacks have garnered significant attention from the international community and gradually evolved into a global issue. In responding to such emergencies, effective emergency evacuation is an essential means to ensure public safety. In order to explore the pedestrian evacuation dynamics in violent attacks and understand the behavioral characteristics of individuals and the dynamic interactions of groups during the evacuation process, this paper proposes an agent-based cellular automata evacuation model. First, each agent is assigned several internal attributes such as life value, panic value, and movement speed, and the assignments fully take into account the heterogeneity of individuals. Next, by setting the attack strategy of attackers and the evacuation mechanism of pedestrians, the complex system is modeled from a microscopic perspective. Finally, the effects of critical factors on the pedestrian evacuation process, such as panic coefficient, crowd structure, group ratio, attack distance and intensity, attacker location and number, and counterattack probability, are discussed through simulation. The results show that the tension caused by moderate panic is beneficial, but excessive panic will lead to increased evacuation time and fatalities. Meanwhile, the group behavior among pedestrians causes them to move relatively lagging, and the evacuation efficiency decreases as the group scale increases. Additionally, increases in attack intensity, attack distance, and attacker number all result in more casualties, and the consequences are most severe when multiple attackers operate separately, but counterattacks by pedestrians can significantly improve the overall safety of evacuation. Our study can provide some reference and basis for emergency management under violent attacks.

PHYSICS PERSPECTIVES ON HUMAN LOCOMOTION: INVESTIGATING THE MECHANICS OF WALKING PATTERNS

This study investigated the gait metric differences between males and females aged 18 to 22. Our investigation revealed some significant changes in gait metrics between the two genders. Firstly, males exhibited greater leg and step lengths than females. Males exhibited wider strides, suggesting typical anthropometric variations. Except for BMI and cadence, males had more variation in practically every other gait metric, whereas females had more variability. There was a non-significant positive connection between BMI and gait metrics such as height, stride length, and step width, with BMI having a minor effect on those measures. Overall, both genders showed a distinct pattern of variability, revealing individual variances in gait analysis across the same genders. A direct correlation was observed between the Froude number and height, indicating that individuals with a higher Froude number exhibit a more dynamic and faster walking style. This phenomenon can be ascribed to the biomechanical superiority that taller individuals may possess, enabling them to generate longer strides and achieve higher speeds. A thorough study of walking speed and gait parameters revealed difficulty in finding the right balance between stability, efficiency, and speed in human movement. Understanding these connections will help people develop more efficient training programs, assistive technologies, and more efficient and safe walking in general.

Magnetically-driven robotic microscrew for the oviduct recanalization

Blocked fallopian tubes, leading to tubal factor infertility, seriously affect fertility and pregnancy. The current mainstream surgical approach for tubal recanalization is based on conventional catheters and guidewires to clear the blockage. However, it is challenging to treat the distal tubal obstruction due to the large size of the tubal catheter and the poor steerability of the guidewire. Here, we present a magnetically driven robotic microscrew to clear blocked fallopian tubes based on a helical rotating mode. The microscale screw-shaped microrobot is fabricated by 3D microfabrication technology. The motion direction and speed of the microrobot are modulated by customizing the pattern and parameters of the control magnetic field. The microscrew structure generates mechanical force to drill the blockage, and then the destroyed fragments are transported to the tail of the robots via the vortex flow surrounding the microscrew. Finally, we demonstrate the recanalization effect of the proposed microrobot in the fallopian tube-mimicking phantom. The recanalizing microscrew represents a potential strategy for developing autonomous tools to treat the blockage of small lumens.

The Mathematical Relationship Between Volume, Speed, And Density At Seven Approached Intesections In The City Of Banda Aceh

Abstract At Simpang Tujuh Ulee Kareng, there is an intersection with more than four approaches called Simpang Tujuh Ulee Kareng, where traffic congestion is frequently a transportation issue. Simpang Tujuh Ulee Kareng has a relatively high traffic volume. The aim of this study is to determine the extent of delays at the Seven Approaches Intersection of Ulee Kareng and identify the optimal conditions analyzed using mathematical relationships between volume, speed, and density, employing three models: Greenshields, Greenberg, and Underwood. The required data includes traffic volume, speed, geometric factors, and traffic movement at the intersection. The analysis of the seven approaches unsignalized intersection using the HCM 2010 method indicates that the road performance results in a LOS F with a delay of 113.7 seconds. Regarding the mathematical relationship between volume, speed, and density, the Greenberg model, represented by the equation S=144.0162 - 24.1823LnD, was found to be the most suitable model for the Speed-Density (S-D) relationship under existing conditions, achieving the highest R2 value of 59.36%.

Modelling study on pedestrian evacuation dynamics considering exit selection behaviour under flood disaster

Flood spreading in metro stations is a dangerous hazard that frequently causes casualties and property losses. However, pedestrian evacuation under flood spreading scenarios has not been fully investigated. To fill this gap,we propose an extend Floor-Field model incorporating flood spreading and exit selection behaviour of individuals. In the model, the dynamic flood spreading process on metro platforms is expressed by using a simulation software named Mike21. The optimal exit selected by pedestrians in each step is decided on three factors, that is pedestrian density around the exit, pedestrian distance to the exit, and water depth at the exit. Meanwhile, the movement speed of pedestrain also changes with the water depth at each time step. Based on this, the transition probability to neighbor cell including static field, dynamic field, height field, and water flow field is calculated. This results in a flood evacuation model considering the pedestrian's behaviour when choosing an exit. The effects of flooding, pedestrian density, different exit selection behaviours, water flow field, and inlet flow on evacuation were thoroughly analysed. The analysis demonstrates that the likelihood of flooding significantly impacts the evacuation of pedestrians from the subway station; the more flooding is taken into account, the more influential the impact. In addition, the effect of inlet flow on evacuation is also noteworthy; considering exit selection behaviour can significantly increase the effectiveness of evacuation. The study's findings can be used to develop evacuation plans for flooded metro stations.

Femtosecond laser direct writing of fiber bragg grating with high-speed and high-resolution scanning technique

We employed two fabrication methods, a laser scanning system and a phase mask, to produce Fiber Bragg Gratings (FBGs). A micro-scanning adapter was used to enable high-speed and high-resolution laser focusing inside the optical fiber via a scanner and an objective lens. By continuously moving the fiber-fixed stage while adjusting the scanner repetition speed, micropatterns with various periods were generated. This approach allowed for the detection of FBG signals at multiple wavelengths.Laser direct writing, utilizing a high-speed and high-resolution laser scanning system, facilitated FBG production without the need to remove the fiber coating. This method provided a straightforward way to control the FBG wavelength, signal intensity, and bandwidth by adjusting the scanner and stage movement speeds. The use of femtosecond lasers for FBG fabrication offers the additional advantage of reduced material dependence, enabling FBG production in various optical fibers without requiring additional processing steps compared to conventional methods.

Axial Field of View Expansion by Switchable Halbach Dipole Rings: A Simulation Study

Abstract In Magnetic particle imaging (MPI), the spatial encoding of the particle response is achieved by a magnetic gradient field called selection field. In this work a selection field generator based on two pairs of nested and freely rotatable Halbach cylinders in dipole configuration generating a gradient field in form of a linear field free region (FFR) is proposed. Through adequate rotation of the Halbach dipoles the FFR can be moved continuously along the cylinder axis. To understand and evaluate the movement of the FFR for different sequences of dipole rotations a simulation study is conducted. The simulation is based on the approximation of a permanent magnet’s field as a magnetic dipole field, so that the Halbach cylinder field results from the superposition of circularly arranged magnetic dipole moments. By the summation of four Halbach dipole fields the selection field can be calculated. It has turned out that the opposite rotation and the matching field strengths of the dipoles of a pair are prerequisites for the movement of the FFR. With regard to the gradient field strengths and the movement speed of the FFR within a potential imaging area, a phase-shifted rotation of two pairs seems promising for the use in MPI.

Optimizing Well Trajectories for Enhanced Oil Production in Naturally Fractured Reservoirs: Integrating Particle Swarm Optimization with an Innovative Semi-Analytical Model Framework

Summary Well trajectory optimization is a crucial component in the drilling engineering of naturally fractured reservoirs. The complex heterogeneity and anisotropy of such reservoirs significantly affect the pressure drop distribution within the well and, consequently, the oil well’s output, impacting the economic benefits of the well. Therefore, optimizing the well segment trajectory is key to efficient reservoir development. However, traditional well trajectory optimization methods primarily focus on geological structures and drilling engineering costs, often overlooking future production benefits of the oil well. This paper proposes a new method that first establishes a semi-analytical production prediction model capable of describing complex well trajectories. Although the semi-analytical model has unique advantages in well trajectory description, it typically treats the reservoir as a homogeneous entity, which complicates handling complex reservoir characteristics. To overcome this limitation, we combined optimization algorithms and neural networks to construct a framework for addressing reservoir heterogeneity (Semianalytical Model Framework for Unconventional Wells in Heterogeneous Reservoirs, USAMF-HR), enhancing the semi-analytical model’s ability to describe reservoir heterogeneity. Building on this framework, we applied the particle swarm optimization (PSO) algorithm and introduced constraints on the rationalization of initial well trajectories, as well as limits on particle movement speed and displacement, with the maximization of net present value (NPV) as the objective function, to optimize well trajectory coordinates. Through specific case analysis, the reasonableness and practicality of this method have been verified. The results show that this method can quickly and effectively plan the optimal well trajectory, significantly increasing productivity while reducing costs.