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Wind–solar towers are a relatively new method of capturing renewable energy from solar and wind power. Solar radiation is collected and heated air is forced to move through the tower. The thermal updraft propels a wind turbine to generate electricity. Furthermore, the top of the tower's vortex generators produces a pressure differential, which intensifies the updraft. Data were gathered from a wind–solar tower system prototype developed and established at Kyushu University in Japan. Aiming to predict the power output of the system, while knowing a set of features, the data were evaluated and utilized to build a regression model. Sensitivity analysis guided the feature selection process. Several machine learning models were utilized in this study, and the most appropriate model was chosen based on prediction quality and temporal criteria. We started with a simple linear regression model but it was inaccurate. By adding some non-linearity through using polynomial regression of the second order, the accuracy increased considerably sufficiently. Moreover, deep neural networks were trained and tested to enhance the power prediction performance. These networks performed very well, having the most powerful prediction capabilities, with a coefficient of determination R 2 = 0.99734 after hyper-parameter tuning. A 1-D convolutional neural network achieved less accuracy with R 2 = 0.99647 , but is still considered a competitive model. A reduced model was introduced trading off some accuracy ( R 2 = 0.9916 ) for significantly reduced data collection requirements and effort. [ABSTRACT FROM AUTHOR]

With the rapid development of gene therapy technology in recent years, its abuse as a method of sports doping in athletics has become a concern. However, there is still room for improvement in gene-doping testing methods, and a robust animal model needs to be developed. Therefore, the purposes of this study were to establish a model of gene doping using recombinant adeno-associated virus vector-9, including the human erythropoietin gene (rAAV9-hEPO), and to establish a relevant testing method. First, it was attempted to establish the model using rAAV9-hEPO on mice. The results showed a significant increase in erythrocyte volume accompanied by an increase in spleen weight, confirming the validity of the model. Next, we attempted to detect proof of gene doping by targeting DNA and RNA. Direct proof of gene doping was detected using a TaqMan-qPCR assay with certain primers/probes. In addition, some indirect proof was identified in RNAs through the combination of a TB Green qPCR assay with RNA sequencing. Taken together, these results could provide the foundation for an effective test for gene doping in human athletes in the future. [ABSTRACT FROM AUTHOR]

Abstract:Introduction: Kendo, a Japanese martial art, requires rigorous physical and mental training. Kendo practitioners who engage in daily mental training may experience a disparity between their subjective perception of exertion and the actual physiological load on their bodies. Methods: Fifteen healthy adult female kendo practitioners were recruited as participants. Participants were asked to report levels of exertion using the Ratings of Perceived Exertion (RPE) during a progressive, load-incremented stress test. The participants' heart rate at the time of reporting RPE13, which is considered a "somewhat hard" level of exertion, as well as heart rate at the anaerobic threshold (AT) to measure actual load, were compared to the maximum heart rate measurement obtained during the test. Results: The participants' heart rates at RPE13 were found to be higher than those at AT, based on their values as percentages of maximum heart rates. Conclusion: This study discovered that kendo practitioners engaged in regular mental training exhibited a higher heart rate at "somewhat hard" exertion (RPE13) compared to the anaerobic threshold (AT), indicating a relative increase in RPE. Additional research is necessary to determine if this effect is attributable to mental training. [ABSTRACT FROM AUTHOR]

The study explores the relationship between phase angle (PhA), an indicator of cellular health, and metabolic health parameters among junior sumo wrestlers in Japan. Given the demanding lifestyle and high‐energy diets of sumo wrestlers that predispose them to metabolic syndrome post‐retirement, this study focuses on a younger cohort. The primary aim is to evaluate if PhA could serve as an early indicator of metabolic health issues within this unique demographic. A total of 14 sumo wrestlers aged 9–17 years were assessed to determine the relationship between PhA and various metabolic markers, including glycated hemoglobin (HbA1c), using a TANITA MC‐780A‐N body composition analyzer and standard blood tests. Bivariate regression analysis and Pearson's correlation revealed a negative relationship between PhA and HbA1c even after adjusting for age and weight (ß = −0.496, r2 = 0.776, r = −0.756, p = 0.004). The results indicate a significant negative relationship between PhA and HbA1c levels, suggesting that lower PhA values, which indicate poorer cellular integrity, are associated with higher HbA1c levels, signifying impaired glycemic control. These findings underscore the potential of PhA as a valuable biomarker for monitoring metabolic health in young sumo wrestlers, with implications for early intervention and management strategies. [ABSTRACT FROM AUTHOR]

Consumption of Lactiplantibacillus plantarum TWK10 (TWK10) has beneficial probiotic effects, improves exercise endurance performance, regulates body composition, and mitigates aging‐related problems in mice and humans. Here, we investigated the effects of heat‐killed TWK10 on exercise endurance performance, muscle weight and strength, fatigue, and body composition in a double‐blind, placebo‐controlled clinical trial. Thirty healthy males aged 20–40 years were assigned to the Control group or heat‐killed TWK10 group (TWK10‐HK) in a balanced order according to each individual's initial maximal oxygen uptake. After 6‐week administration, the exercise endurance time in the TWK10‐HK was significantly increased (p = 0.0028) compared with that in the Control group. The grip strength on the right and left hands of the subjects was significantly increased (p = 0.0002 and p = 0.0140, respectively) in the TWK10‐HK compared with that in the Control group. Administration of heat‐killed TWK10 resulted in a significant increase (p = 0.0275) in muscle weight. After 6‐week administration, serum lactate, and ammonia levels were significantly lower in the TWK10‐HK group than in the Control group during the exercise and recovery periods. These findings demonstrate that heat‐killed TWK10 has significant potential to be used as a postbiotic for humans. [ABSTRACT FROM AUTHOR]

Wind tunnel experiments were conducted by installing wind-acceleration structures on both sides of a straight-bladed vertical-axis wind turbine (VAWT) to improve the output performance of the turbine. In the case of Venturi-shape structures, a curved shape with a large outlet opening produced a higher power output than straight or brimmed Venturi shapes. More importantly, two simple flat plates installed upstream of the wind turbine achieved the highest power enhancement of 2.4 times the power of the bare wind turbine. From the analysis of the flow visualization results, the power enhancement was attributed to the increase in lift force on the blades in the upstream region due to the acceleration of the gap flow between the flat plates, and the decrease in drag force on the blades toward the upstream region due to stagnation of the flow behind the plates. [ABSTRACT FROM AUTHOR]

Hyperthermia increases intravascular adenosine triphosphate (ATP) and is associated with greater hyperthermia‐induced cutaneous vasodilation. Hyperthermia may also increase skin interstitial fluid ATP thereby activating cutaneous vascular smooth muscle cells and sweat glands. We evaluated the hypothesis that whole‐body heating would increase skin interstitial fluid ATP, and this response would be associated with an increase in cutaneous vasodilation and sweating. Nineteen (8 females) young adults underwent whole‐body heating using a water‐perfusion suit to increase core temperature by ~1°C during which time cutaneous vascular conductance (CVC, ratio of laser‐Doppler blood flow to mean arterial pressure) and sweat rate (ventilated capsule technique) were measured at four forearm skin sites to minimize between‐site variations. Dialysate from the skin sites were collected via intradermal microdialysis. Heating increased serum ATP, CVC, and sweat rate (all p ≤ 0.031). However, heating did not modulate dialysate ATP (median, baseline vs. end‐heating: 2.38 vs. 2.70 nmol/ml) (p = 0.068), though the effect size was moderate (Cohen's d = 0.566). While the heating‐induced increase in CVC was not correlated with changes in serum ATP (r = 0.439, p = 0.060), we observed a negative correlation (rs = −0.555, p = 0.017) between dialysate ATP and CVC. We did not observe a significant correlation between the heating‐induced sweating and serum, dialysate, or sweat ATP (rs = 0.091 to −0.322, all p ≥ 0.222). Altogether, we showed that passive heating increases ATP in blood and possibly skin interstitial fluid, with the latter potentially blunting cutaneous vasodilation. However, ATP does not appear to modulate sweating. [ABSTRACT FROM AUTHOR]

Curling is a target‐based team sport played in a cold environment. The type of stress curling players face during a curling match remains to be determined. In the present study, 16 Japanese curling players performed a practice curling match (six ends lasting 90 min), wherein the following variables were documented: core and skin temperatures, heart rate, thermal sensation and comfort, urine‐specific gravity, body fluid loss, salivary cortisol, α‐amylase activity, salivary secretory immunoglobulin A (SIgA), and fractionated exhaled nitric oxide (FeNO, a respiratory stress marker). Pre‐match resting core temperature was 37.24 ± 0.31°C, which increased up to 37.73 ± 0.41°C during the match (p < 0.001). Facial skin temperatures decreased after the match (all p ≤ 0.015), whereas finger skin temperatures remained unchanged (p ≥ 0.375). Thermal discomfort increased following the match but thermal sensation remained unchanged. Following the match, players lost 0.29 ± 0.15 L body fluid (sweat, respiratory evaporation, and urine), which was nearly compensated by fluid ingestion of 0.22 ± 0.13 L (p = 0.119). Nevertheless, urine‐specific gravity increased from 1.021 ± 0.010 to 1.024 ± 0.008 after the match (p = 0.012), with 31% and 50% players being dehydrated at pre‐ and post‐match, respectively. Salivary cortisol decreased (p < 0.001) after the match without changes in salivary SIgA, α‐amylase activity, and FeNO (all p ≥ 0.113). Therefore, during a curling match, the core temperature and thermal discomfort increase, whereas the face skin temperature decreases. Additionally, players may undergo dehydration before the match, which could be exacerbated after the match. [ABSTRACT FROM AUTHOR]

The present study aimed to test the hypothesis that changes in the dermal tissue dielectric constant (TDC) and biomechanical properties of the skin would be correlated with the indicators related to dehydration. Ten healthy adult men were enrolled in three trials: no fluid intake (DEH), ad libitum fluid intake (AL-HYD), and programmed fluid intake (P-HYD) after exercise in a randomised crossover design. The participants performed a pedalling exercise at 60% heart rate reserve until 2% body mass loss. At 120 min after exercise, an incremental exercise test was carried out. Aerobic capacity, body composition, TDC, biomechanical properties of the skin (pliability, viscoelasticity, and total recovery), and indicators related to dehydration in the serum and urine were measured before and 120 min after exercise. Higher values of the pliability and viscoelasticity, and lower value of the total recovery on the hand were demonstrated in the P-HYD trial compared to the DEH trial (all P < 0.05). Changes in the TDC were significantly correlated with changes in body mass, total body water, serum osmolarity, and hematocrit (all P < 0.05). Changes in the biomechanical properties of the hand were significantly correlated with changes in body mass, hematocrit, and urine specific gravity (all P < 0.05). The present study showed that the changes in skin characteristics correlated with the body water and dehydration-associated indicators in the serum and urine, thus suggesting that skin characteristics may be useful in the assessment of dehydration. Highlights This study was the first to investigate the effect of dehydration and rehydration on the TDC and biomechanical properties of the skin upon instrumental measure, and not manual testing. This study confirmed the decline in aerobic capacity by dehydration and immediate recovery with sufficient rehydration. Changes in the TDC and the biomechanical properties of the skin correlated with the body water and dehydration-associated indicators in the serum and urine. Skin characteristics may be useful in the assessment of dehydration. [ABSTRACT FROM AUTHOR]

Seismic isolation is widely used in several countries, and the number of seismically isolated buildings has increased rapidly in recent decades. Seismic isolation extends the natural period of a building to decrease the absolute acceleration and seismic force. As there is a trade-off between the absolute acceleration and displacement, a soft layer results in a large displacement for a large seismic wave, but the hard one causes the large absolute acceleration even for a small seismic wave. The restoring force of a Duffing spring is given by the third and first orders of the displacement. This spring has been applied to protect a building from large earthquake waves. However, the influence of the coefficient of the Duffing spring that determines the dynamic characteristics of the system has not been clarified. Thus, a used Duffing spring may not be appropriate for seismic resistance. Moreover, most studies are based on analytical methods, and the advantages of the Duffing isolation have not been verified in an actual system. To address these problems, this paper reveals the influence of the coefficient of the Duffing spring on structural responses to seismic waves. Moreover, this paper devised a way to implement a Duffing spring for seismic isolation and carried out experiments to verify the validity in actual systems. The experimental results presented that the Duffing spring was effective in protecting a building in actual systems. [ABSTRACT FROM AUTHOR]