Okayama Prefectural University

The present study reports on a preliminary experiment designed to experimentally verify the effectiveness of a newly developed rehabilitation support system using a torqueload wrist manipulandum. Evidence-based rehabilitation requires devices that can objectively and quantitatively evaluate motor function, yet conventional methods often rely on subjective assessments or limited clinical indicators. To overcome these limitations, we constructed a system capable of assessing two representative neural motor control strategies: feedback (FB) and feedforward (FF) control. In order to evaluate the feasibility and effectiveness of the proposed system, experimental trials were conducted with nine healthy participants. The device allows torque loads to be applied in arbitrary directions to wrist movements. Pursuit tasks were used to assess FB control, and step tasks to assess FF control. Participants performed both tasks under three leftward torque-load conditions ($0,0.9$, and 1.5 kgf.cm) simulating a resistive (pseudo-spastic) environment. Response time and positional error were analyzed as outcome measures. The results confirmed that the system could successfully differentiate neural control strategies. FB control showed delayed responses and increased positional errors, while FF control exhibited enhanced internal model formation under mild spasticity. This preliminary verification demonstrates that the proposed system can experimentally evaluate adaptive processes of FB and $F F$ control under different task environments. These findings support its potential as a platform for quantitative assessment and rehabilitation support. Future clinical studies are required to further validate the system and explore its contribution to functional recovery in stroke patients.

This paper proposes a new high efficiency power amplifier configuration injecting envelope components. The proposed configuration has the saturated power amplifier for continuous wave and the liner amplifier for extracted envelope signal from the input signal to the proposed configuration. The envelop component is extracted from the input signal, while that is injected to the input signal in the input side of the saturated power amplifier. The linear power amplifier attains the same gain of the saturated power amplifier for the extracted envelope component. At the output port of the saturated power amplifier, the extracted envelope component is injected into the output signal of the saturated power. From this process, the proposed power amplifier can achieve high efficiency amplification with acceptable the out-of-band distortion level. The calculation results show that validity of the proposed configuration. In ideal case, the proposed power amplifier can attain the efficiency of about 64% at the third-order intermodulation component to the fundamental component of -45 dBc, when the saturated efficiency of saturated power amplifier is 80%. These results show the potential of proposed configuration.

This study analyzes the actual transmitted power from 5G beamforming radio base stations (BF-RBSs) to clarify the effectiveness and issues of an actual maximum approach specified in the International Electrotechnical Commission 62232:2025. The actual maximum approach is a new compliance assessment method for electromagnetic field exposure levels from BF-RBSs based on time-averaged transmitted power. In this study, the actual maximum transmitted power every 5 or 30 min from more than 400 BF-RBSs using millimeter waves in urban areas in Japan was collected using a network management system over a period of one month. For each BF-RBS, normalized actual transmitted power was derived as the ratio of actual to configured maximum transmitted power. As a result of this measurement, the maximum value of normalized actual transmitted power was approximately −3 dB when the number of sets of user equipment (UEs) in the BF-RBS was less than two with high data traffic. Moreover, statistical analysis results of the measurement data shows that the actual maximum approach may underestimate the electromagnetic field exposure levels from a BF-RBS with three or fewer UEs when the actual transmitted power of the BF-RBSs is not monitored and controlled to maintain a level below the threshold.

A method is proposed to build an advanced knowledge base for preventing trouble and quickly recovering from trouble, which will contribute to the safe and stable operation and maintenance of large-scale, complex technical systems. This was developed based on the authors' conceptual research into structuring past trouble knowledge and the findings of three years of joint experimental research conducted by the authors on heliotron fusion plasma experimental facility. In the future, the feasibility of the advanced intellectual infrastructure will be verified through the implementation of a system that applies a higher harmonics system for electrical equipment to diagnose deterioration of electric pumps that make up the cooling system of neutron beam injection equipment.

Background Sensitivity to everyday sounds shows considerable individual variation. This study aimed to identify distinct dimensions of auditory sensitivity and examine how psychosocial and developmental factors, such as early auditory environments and personality traits, shape individual differences in non-clinical adults. In addition, we explored sensitivity to low-salience sounds that are typically perceived as non-intrusive by most people but elicit discomfort in a minority of individuals. Methods A cross-sectional web-based survey was conducted between September and November 2024 with 380 Japanese adults (aged 18-56), using a self-developed questionnaire informed by prior research and pilot testing. Participants rated their affective reactions to 39 everyday sounds. Factor analysis extracted latent auditory sensitivity components. Multiple regression analyses examined the predictive roles of childhood auditory environment and personality traits measured via standardized psychological scales. Results Based on factor analysis of participants' ratings across 39 everyday sounds, two underlying dimensions of auditory sensitivity were identified. These were labeled WLS1 and WLS2, reflecting different patterns of sensitivity: WLS1 represents sensitivity to subtle, non-salient sounds, while WLS2 reflects heightened reactivity to loud or sharp auditory stimuli. WLS1 was significantly predicted by childhood exposure to parental vocal discipline (β = 0.19, 95% confidence interval (CI) (0.07-0.31), p = 0.002), emotional reactivity (β = 0.23, 95% CI (0.09-0.36), p = 0.001), and interpersonal assertiveness (β = 0.24, 95% CI (0.10-0.37), p < 0.001). WLS2 was associated with female gender (β = 0.50, 95% CI (0.27-0.72), p < 0.001), insomnia from worry (β = 0.15, 95% CI (0.04-0.27), p = 0.006), fatigue (β = 0.30, 95% CI (0.17-0.43), p < 0.001), and impulsivity (β = 0.14, 95% CI (0.04-0.24), p = 0.008). A third factor, W1, reflecting sensitivity to ambient mechanical sounds that over 80% of participants rated as non-intrusive, was predicted by orderliness (β = 0.16, 95% CI (0.03-0.25), p = 0.012), emotional sensitivity (β = 0.21, 95% CI (0.08-0.34), p = 0.002), and a preference for uniqueness (β = 0.29, 95% CI (0.15-0.44), p < 0.001). Conclusions Auditory sensitivity is multifactorial and shaped by both developmental auditory experiences and personality dimensions. The results suggest that distinct psychological pathways underlie responsiveness to subtle versus intense auditory stimuli.

Introduction: Acute kidney injury associated with the consumption of Beni-koji CholesteHelp supplements, which contain red yeast rice (Beni-Koji), has become a significant public health concern in Japan. While renal biopsy findings from several case reports have suggested tubular damage, no definitive causal relationship has been established, and the underlying mechanisms of kidney injury remain poorly understood. The complexity of identifying toxic substances in supplements containing various bioactive compounds makes conventional investigative approaches both time-consuming and challenging. This highlights an urgent need to establish a reliable platform for assessing organ-specific toxicity in such supplements. In this study, we utilized a kidney organoid model derived from adult rat kidney stem cells (KS cells) to assess the potential tubular toxicity of these supplements. Methods: KS cell clusters were cultured in three-dimensional system supplemented with growth factors to promote kidney organoids. The organoids were subsequently exposed to Beni-koji CholesteHelp supplements or cisplatin, followed by histological and molecular analyses to evaluate structural impacts. Results: Established organoids had the kidney-like structures including tubular-like structures and glomerulus-like structures at the tips of multiple tubules. Treatment with Beni-koji CholesteHelp supplements induced significant tubular damage in the organoids, characterized by epithelial cell thinning, structural disruption, and increase in cleaved-caspase 3-positive apoptotic tubular cells, similar to the organoids treated with cisplatin. Conclusion: These findings provide the first evidence suggesting that certain toxicants in specific batches of Beni-koji CholesteHelp supplements cause direct renal tubular injury. This KS cell-based organoid system represents a cost-effective, reproducible, and technically simple platform for nephrotoxicity screening.

We propose incorporation of adaptive transmission probability to ALOHA-Q, which is a framed slotted ALOHA-based random access protocol ingeniously integrating Q-learning for slot selection in a frame. The transmission probability is also adaptively controlled based on Q-learning. Performance of the proposed protocol is confirmed by means of computer simulation. Numerical results show that the proposed protocol can mitigate performance degradation of ALOHA-Q under overloaded traffic condition and exhibits comparable performance to ALOHA-Q for moderate traffic condition.