Search Results (118)

Background/Objectives: The aim of this study was to compare the efficacy of correcting myopia and myopic astigmatism between small incision lenticule extraction (SMILE) surgery performed using VisuMax 500 and that using VisuMax 800. Methods: Patients who underwent myopia correction using either VisuMax 500 (493 eyes of 249 patients) or VisuMax 800 (169 eyes of 85 patients) employing the nomogram of VisuMax 500 were enrolled in this retrospective case–control study. At 2 months after the operation, the percentage of eyes achieving a postoperative uncorrected distance visual acuity (UDVA) of 20/20 and residual refractive error were compared between the two groups. Additionally, the percentage of eyes with refractive astigmatism angle of error within ±15° and the mean absolute angle of error were analyzed. Results: In the VisuMax 500 and 800 groups, 99% and 97% of eyes achieved a postoperative UDVA of 20/20, respectively. Postoperative residual astigmatism was similar between the two groups, but residual myopia was significantly lower in the VisuMax 800 group (−0.09 ± 0.50 cylinder diopters [CD]) compared to the VisuMax 500 group (−0.21 ± 0.49 CD; p-value = 0.005). Additionally, 84% of eyes in the VisuMax 800 group achieved astigmatism correction within ±15° of the intended meridian, significantly outperforming the 71% in the VisuMax 500 group (p-value = 0.002), with a significantly smaller mean absolute angle of error (8.3 ± 12.2° and 14.1 ± 20.1°; p-value < 0.001). Conclusions: Both VisuMax 500 and VisuMax 800 effectively corrected myopia. However, in terms of the accuracy of astigmatism axis correction, VisuMax 800 demonstrated superior precision compared to VisuMax 500. This study may be limited by perceived bias associated with evaluating two platforms from the same manufacturer. Full article

Objective: Recent work has challenged the notion that preferred substrate oxidation is a key determinant of exercise performance. This investigation tested middle-distance running performance, in the fed state, to control for glycogen and exercise-induced hypoglycemia (EIH) confounders. Methods: In a randomized crossover fashion, all while controlling dietary intake, activity, and body weight, recreational distance runners completed either a 5K (n = 15; VO_2max: 58.3 ± 6.2 mL/kg/min) or a 10K (n = 15; VO_2max: 54.51 ± 5.9 mL/kg/min) middle-distance run after consuming isocaloric low-carbohydrate high-fat (LCHF) and high-carbohydrate low-fat (HCLF) pre-exercise meals. Time trial (TT) performance (sec), carbohydrate/fat substrate oxidation, blood metabolites, heart rate (HR), ratings of perceived exertion (RPE), and subjective fullness and thirst were measured throughout. Results: LCHF pre-exercise nutrition reliably altered substrate oxidation and metabolite profiles compared to HCLF, evidenced by significant increases in fat oxidation (77% higher) and reductions in RER (5% lower), with corresponding shifts in carbohydrate oxidation. Despite distinct preferred substrate oxidation profiles during exercise, the 5 and 10 km TT performances were similar between conditions (p = 0.646/p = 0.118). RER was significantly lower (p = 0.002) after the LCHF condition compared to HCLF. Capillary R-βHB increased modestly after LCHF, while blood glucose increased after HCLF only. The LCHF meal was 35% more filling than the HCLF meal. Preferred substrate oxidation did not significantly modulate middle-distance running performance. Conclusion: This work supports recent findings that substrate oxidation is not a primary determinant of aerobic performance, as previously conceived. Full article

Background: To evaluate and compare cardiorespiratory function, assessed by the 6-minute walk test (6MWT), and musculoskeletal function, assessed by the handgrip strength test and the sit-to-stand test (STS10) in post-coronavirus disease 2019 (COVID-19) patients. Participants were stratified based on the time since infection (≤6 months and >6 months) and compared with matched healthy controls. Methods: A total of 111 participants were recruited and divided into three groups (n = 37/group). Cardiorespiratory function was assessed using the 6MWT, while musculoskeletal function was evaluated through the handgrip strength test and the STS10. Results: All three groups had normal body mass index values. Group 2 demonstrated significantly lower handgrip strength and a shorter 6MWT distance compared to both Group 1 and Group 3. Additionally, Group 2 required significantly more time to complete the STS10 than Group 1. Following the 6MWT, Group 2 exhibited significantly higher heart rate and systolic blood pressure compared to both Group 1 and Group 3. Diastolic blood pressure was significantly lower in Group 3 compared to the other two groups. Furthermore, Group 2 had significantly lower pulse oxygen saturation than both Group 1 and Group 3. The rate of perceived exertion was significantly lower in Group 1 than in Group 2. Additionally, leg fatigue was significantly lower in Group 1 compared to both Group 2 and Group 3. Conclusions: These findings highlight significant differences in physical performance and physiological responses between post-COVID-19 patients and healthy individuals, emphasizing the potential long-term effects of SARS-CoV-2 infection on cardiorespiratory and musculoskeletal function. Full article

While foraging tunnels of the red imported fire ant, Solenopsis invicta, have been well studied, much less is known about the tunnels constructed between neighboring nests, despite their perceived importance in intra-colony exchange and collaboration. In this study, we investigated such tunnels by excavating 80 pairs of nests (with distances of <1 m between nests) located in different types of habitats. For each pair of nests, we recorded the number of inter-nest tunnels and observed their shape, diameter, subsurface depth, and ant presence within them. Moreover, we analyzed the relationships between the probability of constructing inter-nest tunnels and several nest/habitat characteristics, including distance between nests, colony social form, nest size, soil type, and vegetation cover, as well as the relationships between tunnel numbers and these factors. The results show that the number of inter-nest tunnels ranges from one to 11. These tunnels open to the two nests at terminals, are elliptical in cross-section, <1.5 cm in diameter, and mostly at 1–3 cm (range 1–12 cm) subsurface depth. Among the 36 pairs of nests possessing tunnels, 31 pairs (86.1%) had worker or alate ants within their tunnels. Polygynous colonies are more likely (52.4%) to construct inter-nest tunnels than monogynous colonies (17.6%). Nest pairs that have a small nest, located in habitats with higher vegetation cover and loamy or sandy loam soil, tend to have inter-nest tunnels. We also showed that the capacity of constructing inter-nest tunnels falls in the regime similar to foraging tunnels. As nests were treated with chemicals, 33 nests were relocated and 47 new nests resulted within 2 weeks, but no definite tunnels were constructed between original nests and corresponding new nests. Our results highlight the significance of including such tunnels when analyzing intra-colony exchange, collaboration, and adaptive strategies in S. invicta. Uses of tunnels by fire ants during nest relocation, and the requirement of destroying them during control program implementation, were discussed. Full article

Swarm robots often need to cover the designated area to complete specific tasks. While robots possess local perception and limited communication capabilities, they struggle to handle coverage issues in dynamic environments. This paper proposes a self-organizing algorithm for swarm robots based on Dynamic Virtual Force (DVF) to cover dynamic areas. Robots in the swarm can locally perceive their surrounding robots and dynamically select adjacent ones to generate virtual repulsion, thereby controlling their movement. The algorithm enables swarm robots to be rapidly and evenly deployed in unknown areas, adapt to dynamic area changes, and solve the problem of symmetrical robot distribution during coverage. It also allows for adaptive coverage of different density areas, divided as needed. Experimental validation across 20 benchmark scenarios (including obstacles, dynamic boundaries, and multi-density zones) demonstrates that the DVF method outperforms existing approaches in coverage rate, total robot movement distance, and coverage uniformity. The results validate its effectiveness and superiority in addressing area coverage problems. By addressing these challenges, the DVF algorithm can be widely applied to forest firefighting, oil spill cleanup in the ocean, and other swarm robot tasks. Full article

This study aimed to investigate the effects of augmented reality (AR) treadmill walking training on cognitive function, body composition, physiological responses, and acceptance among older adults. Additionally, it analyzed the relationships between body composition, physiological responses, and the acceptance of AR technology. A randomized controlled trial was conducted, recruiting 60 healthy older adults, who were assigned to either the experimental group (AR treadmill walking training) or the control group (traditional treadmill walking training). The assessments included cognitive function evaluation (stride length, walking speed, and balance test), body composition (BMI, skeletal muscle mass, fat mass, and body fat percentage), and physiological responses (heart rate, calorie expenditure, exercise duration, and distance covered). Furthermore, the AR Acceptance Scale was used to assess perceived ease of use, perceived usefulness, attitudes, and behavioral intentions. The results indicated that AR treadmill walking training had significant positive effects on improving cognitive function, optimizing body composition, and enhancing physiological responses among older adults. Compared with the traditional training group, the experimental group demonstrated better performance in stride length, walking speed, and balance tests, with increased skeletal muscle mass and reduced body fat percentage. Additionally, improvements were observed in heart rate regulation, calorie expenditure, exercise duration, and distance covered, reflecting enhanced exercise tolerance. Moreover, older adults exhibited a high level of acceptance toward AR technology, particularly in terms of attitudes and behavioral intentions, as well as perceived usefulness. This study provides empirical support for the application of AR technology in promoting elderly health and suggests that future research should explore personalized adaptation strategies and long-term effects to further expand the potential value of AR technology in elderly exercise. Full article

Time-of-flight sensors have emerged as a viable solution for real-time distance sensing in robotic safety applications due to their compact size, fast response, and contactless operation. This study addresses one of the key challenges with time-of-flight sensors, focusing on how they perceive and evaluate the environment, particularly in the presence of complex geometries and reflective surfaces. Using a Universal Robots UR5e arm in a controlled indoor workspace, two different sensors were tested across eight scenarios involving objects of varying shapes, sizes, materials, and reflectivity. Quantitative metrics including the root mean square error, mean absolute error, area difference, and others were used to evaluate measurement accuracy. Results show that the sensor’s field of view and operating principle significantly affect its spatial resolution and object boundary detection, with narrower fields of view providing more precise measurements and wider fields of view demonstrating greater resilience to specular reflections. These findings offer valuable insights into selecting appropriate ToF sensors for integration into robotic safety systems, particularly in environments with reflective surfaces and complex geometries. Full article

Background/Objectives: Despite extensive research on caffeine’s (CAF’s) ergogenic effects, evidence regarding its impact on anaerobic performance in female athletes remains limited and inconclusive. The aim of this study was to investigate the acute effects of 6 mg/kg⁻¹ caffeine on anaerobic performance, functional strength, agility, and ball speed in female soccer players. Methods: A randomized, double-blind, placebo-controlled crossover design was employed. Thirteen moderately trained female soccer players (age: 21.08 ± 1.11 years; height: 161.69 ± 6.30 cm; weight: 59.69 ± 10.52 kg; body mass index (BMI): 22.77 ± 3.50 kg/m²; training age: 7.77 ± 1.16 years; habitual caffeine intake: 319 ± 160 mg/day) completed two experimental trials (caffeine vs. placebo (PLA)), separated by at least 48 h. Testing sessions included performance assessments in vertical jump (VJ), running-based anaerobic sprint test (RAST), bilateral leg strength (LS), handgrip strength (HS), single hop for distance (SH), medial rotation (90°) hop for distance (MRH), change of direction (COD), and ball speed. Rating of perceived exertion (RPE) was also recorded. Results: CAF ingestion significantly improved minimum (p = 0.011; d = 0.35) and average power (p = 0.007; d = 0.29) during RAST. A significant increase was also observed in SHR (single leg hop for distance right) performance (p = 0.045; d = 0.44). No significant differences were found in VJ, COD, ball speed, LS, HS, SHL, MRHR, or MRHL (p > 0.05). RPE showed a moderate effect size (d = 0.65) favoring the CAF condition, though not statistically significant (p = 0.110). Conclusions: In conclusion, acute CAF intake at a dose of 6 mg/kg⁻¹ may enhance anaerobic capacity and lower-limb functional strength in female soccer players, with no significant effects on jump height, agility, or upper-body strength. Full article

Background/Objectives: Long-distance runners with exercise-induced hypertension (EIH) are at increased risk for cardiovascular complications. Although blood flow restriction (BFR) training has shown promise in improving vascular function, hemodynamic response, and cardiorespiratory fitness, its effects in EIH runners remain understudied. This study aimed to evaluate the effects of BFR training on cardiovascular responses and exercise performance in this population as a potential non-pharmacological therapy. Methods: Middle-aged male long-distance runners aged 40–65 with peak systolic blood pressure (SBP) ≥ 210 mmHg during graded exercise testing were randomly assigned to either a BFR group (n = 18) or a non-BFR control group (n = 15) using a computer-generated random sequence. There were no significant differences in baseline characteristics between the groups. Both groups performed aerobic training at 40–60% HRR for 20 min twice weekly for 8 weeks. SBP, diastolic blood pressure (DBP), rate pressure product (RPP), ventilatory threshold (VT), VO_₂max, and perceived exertion were assessed before and after the intervention at rest, during exercise, and during recovery. Results: Compared to the non-BFR group, the BFR group showed statistically significant reductions in resting and maximal SBP and DBP (p < 0.05), along with significant increases in VO_₂max and VT (p < 0.05). During submaximal exercise and post-exercise recovery, SBP and RPP were significantly lower in the BFR group (p < 0.05). The reductions in maximal SBP and DBP were significantly greater in the BFR group than in the control group. Conclusions: BFR training led to reduced myocardial workload and enhanced cardiovascular efficiency in male runners with EIH. These findings suggest that BFR training may be a viable non-pharmacological therapy for mitigating cardiovascular risks associated with EIH. Future studies should explore the long-term effects of BFR in broader populations and assess its applicability in clinical settings. Full article

Introduction: Walking is perceived as the most important bodily function for persons with multiple sclerosis (pwMS) and is impaired in more than 70% of pwMS. In addition, the effect of multiple sclerosis (MS) on gait pattern increases in fast walking and during fatiguing exercises, altering the spatiotemporal gait parameters and walking reserve. Objectives: The objective of this study is to investigate the impact of a 12 min intermittent-walking protocol on spatiotemporal gait parameters and on the fatigability of pwMS, as well as the association with perceived exertion and reported symptoms of fatigue. Methods: Twenty-six persons with relapse-remitting MS and twenty-eight healthy controls (HCs) were included in this cross-sectional study. The Modified Fatigue Impact Scale and the Symbol Digit Modality Test were used to evaluate fatigue symptoms and cognitive function, respectively. Participants walked six times during an uninterrupted 2-min period. Before, during the rest periods and after the last 2 min walk, the rate of perceived exertion (RPE) was measured using the Borg Scale, and the spatiotemporal gait parameters were assessed with GaitRite. The cut-off value of 10% deceleration of the distance walked index classified pwMS into two groups: MS Fatigable (MS-F) and MS Non-Fatigable (MS-NF). One-way and two-way Analyses of variance (ANOVAs) were used to verify the effect of time and groups, respectively. Results: PwMS walked slower, travelled shorter distances, and presented shorter step lengths compared to HCs. No effects of the intermittent-walking protocol were found for all pwMS, but the MS-F group had deteriorated walking speed, step length, and cadence. Walking dysfunction was associated with perceived fatigability, reported symptoms of fatigue, cognitive function, and disability. Reported symptoms of fatigue was associated with perceived exertion but not with performance fatigability. Conclusions: Changes in gait parameters were weak to moderately associated with performance fatigability and the perception of effort and disability but not with reported fatigue symptoms, highlighting distinct constructs. The walking speed reserve and step length reserve also emerged as potential early markers of performance decline. Full article

Background/Objectives: Sleep and recovery are critical for optimising exercise performance. However, the efficacy of melatonin supplementation in improving sleep quality and next-day physical performance remains unclear. This study examined the effects of melatonin ingestion on sleep and performance-related outcomes the following day in trained males. Methods: In a randomised, double-blind, placebo-controlled crossover study, 12 trained males (age: 21.92 ± 2.84 years) ingested 6 mg of melatonin (MEL) or a placebo (PLA) the night before performing the 5 m shuttle test (5mSRT). Before and after the 5mSRT, blood samples were collected. Peak heart rate (HR_peak) and rating of perceived exertion (RPE) were recorded throughout the test. Perceived recovery status (PRS) and delayed onset muscle soreness (DOMS) were measured before, 5 min, 24 h, 48 h, and 72 h after the test. The sleep/wake cycle was monitored during the night after ingestion. Results: Data were analysed using paired t-tests, Wilcoxon tests, and two-way ANOVAs, with significance set at p < 0.05. Compared to PLA, MEL did not modify any sleep parameters or blood markers (all p > 0.05). However, MEL improved total distance, fatigue index, the percentage decrement between sprints, and HR_peak (all p < 0.05) in the 5mSRT compared to PLA. MEL also enhanced PRS values up to 72 h post-exercise and reduced DOMS (all p < 0.05). Conclusion: In summary, 6 mg of melatonin taken at night enhanced next-day high-intensity exercise performance and improved perceived recovery up to 72 h post-exercise. Full article

Traditional Jiangnan water towns in China serve as important cultural heritage sites and tourist destinations. Existing studies have revealed a potential connection between environmental elements and spatial perception in these towns. However, there remains a lack of research systematically investigating whether and how these environmental elements influence subjective evaluation indicators, such as spatial attractiveness, and the mechanisms underlying the interactions between these elements. To further understand these mechanisms, we used Nanxun Old Town as our study site, employed computer vision techniques to perform semantic segmentation on street-view images, extracted the visual proportions of environmental elements, and conducted quantitative correlation analysis with subjective attractiveness evaluations. The findings indicate that different environmental elements in water towns shape spatial imagery in diverse ways, thereby influencing perceived attractiveness. Firstly, though space-defining elements such as buildings and water generally contribute positively to perceived attractiveness, their proportions should be controlled within a reasonable range to maintain a spatial scale that aligns with the traditional imagery of water towns. Secondly, foreground elements like boats and lanterns, although occupying a smaller proportion, can effectively enhance the space when properly combined. Finally, the influence of elements such as bridges and buildings depends on the specific viewing distance and angle. These findings, based on an interpretable analytical framework, reveal that the effects of environmental elements on spatial attractiveness are context-dependent and nonlinear, varying with their proportions, combinations, and perspectives. This approach offers a more comprehensive understanding of the mechanisms by which environmental elements shape spatial attractiveness, providing a scientific foundation for regulating key visual components and optimizing spatial composition for sustainable traditional water town environment management. Full article

The P300 event-related potential, evoked by attending to specific sensory stimuli, is utilized in non-invasive brain–computer interface (BCI) systems and is considered the only interface through which individuals with complete paralysis can operate devices based on their intention. Conventionally, visual stimuli used to elicit P300 have been presented using displays; however, placing a display directly in front of the user obstructs the field of view and prevents the user from perceiving their surrounding environment. Moreover, every time the user changes posture, the display must be repositioned accordingly, increasing the burden on caregivers. To address these issues, we propose a novel system that employs wirelessly controllable LED visual stimulus presentation devices distributed throughout the surrounding environment, rather than relying on traditional displays. The primary challenge in the proposed system is the communication delay associated with wireless control, which introduces errors in the timing of stimulus presentation—an essential factor for accurate P300 analysis. Therefore, it is necessary to evaluate how such delays affect P300 detection accuracy. The second challenge lies in the variability of visual stimulus strength due to differences in viewing distance caused by the spatial distribution of stimulus devices. This also requires the validation of its impact on P300 detection. In Experiment 1, we evaluated system performance in terms of wireless communication delay and confirmed an average delay of 352.1 ± 30.9 ms. In Experiment 2, we conducted P300 elicitation experiments using the wireless visual stimulus presentation device under conditions that allowed the precise measurement of stimulus presentation timing. We compared P300 waveforms across three conditions: (1) using the exact measured stimulus timing, (2) using the stimulus timing with a fixed compensation of 350 ms for the wireless delay, and (3) using the stimulus timing with both the 350 ms fixed delay compensation and an additional pseudo-random error value generated based on a normal distribution. The results demonstrated the effectiveness of the proposed delay compensation method in preserving P300 waveform integrity. In Experiment 3, a system performance verification test was conducted on 21 participants using a wireless visual presentation device. As a result, statistically significant differences (p < 0.01) in amplitude between target and non-target stimuli, along with medium or greater effect sizes (Cohen’s d: 0.49–0.61), were observed under all conditions with an averaging count of 10 or more. Notably, the P300 detection accuracy reached 85% with 40 averaging trials and 100% with 100 trials. These findings demonstrate that the system can function as a P300 speller and be utilized as an interface equivalent to conventional display-based methods. Full article

Background: Disadvantaged children often enter kindergarten with delays in fundamental motor skill (FMS) competence, which is critical for future physical activity engagement. The Summer Success—Successful Kinesthetic Instruction for Preschoolers (SS-SKIP) program was designed to address these developmental gaps, with a short, intensive intervention. This pilot study evaluated the impact of a 4-week SS-SKIP program on FMS, perceived motor competence (PMC), and executive function (EF). Methods: Twenty-one preschool children (mean age = 62.62 ± 4.61 months) from disadvantaged communities participated in an intensive, month-long (240 min) program. FMS were assessed using the Test of Gross Motor Development-2 (TGMD-2), PMC was evaluated using the Pictorial Scale for Perceived Competence, and EF was measured via the Head–Toes–Knees–Shoulders (HTKS), Go/No-Go, and Sorting cards tests. Standing long jump was measured in meters. A pretest–post-test design assessed program impact using 2 Gender X 2 Session MANOVAs/ANOVAs on dependent variables. Results: Analysis of differences in baseline measures of FMS competence and EF by Gender and Session revealed no significant main effects of Gender, Session, or their interaction across measures (all p > 0.05). Repeated measures ANOVAs by Gender revealed a significant main effect for Time for locomotor standard scores (p < 0.001), object control standard scores (p < 0.001), and HTKS scores (p < 0.001), indicating improvement from pretest to post-test. By contrast, jump distance, PMC, Go/No-Go and Card Sorting scores were non-significant (p > 0.05). Conclusions: A short, intense SS-SKIP FMS intervention significantly enhanced FMS and improved HTKS performance. This pilot study was limited by the lack of a control group and small N. These findings underscore the potential of short, targeted interventions in addressing early motor delays in disadvantaged preschoolers, warranting further investigation into their long-term impacts. Full article

This study proposes an advanced intelligent vehicle path-following control system using deep reinforcement learning, with a particular focus on the role of road geometry perception in motion planning and control. The system is structured around a three-degree-of-freedom (3-DOF) vehicle model, which facilitates the extraction of critical dynamic features necessary for robust control. The longitudinal control architecture integrates a Deep Deterministic Policy Gradient (DDPG) agent to optimise longitudinal velocity and acceleration, while lateral vehicle control is handled by a Deep Q-Network (DQN). To enhance situational awareness and adaptability, the system incorporates key input variables, including ego vehicle speed, speed error, lateral deviation, lateral error, and safety distance to the preceding vehicle, all in the context of road geometry and vehicle dynamics. In addition, the influence of road curvature is embedded into the control framework through perceived acceleration (sensed by vehicle occupants), allowing for more accurate and responsive adaptation to varying road conditions. The vehicle control system is tested in a simulated environment with a lead car in front with realistic speed profiles. The system outputs continuous values for acceleration and steering angle. The results of this study suggest that the proposed intelligent control system not only improves driver assistance but also has potential applications in autonomous driving. This framework contributes to the development of more autonomous, efficient, safety-aware, and comfortable vehicle control systems. Full article