Search Results (6,011)

Snakeflies (Raphidioptera) are generally assumed to have the most gradual (and plesiomorphic) type of holometabolous metamorphosis, often including saproxylic larvae. Herein we investigate the diversity of snakeflies over time. We explore morphological details that have rarely been in focus of scientific studies such as the clavate organs of the legs. In total, 165 new immature snakefly specimens, mostly from 100 million-year-old (Cretaceous) Kachin amber, are reported. Combined with data from the literature, we assembled a dataset of 550 specimens, including immatures and adults from Cretaceous (over 200 immatures) and Eocene amber and from the extant fauna. From these, we extracted shape data of different body regions—ten subsets in total with over 2500 analysed shapes. Our analysis supports earlier observations (based on relative lengths) that snakefly larvae were much more diverse in their morphology in the past compared to their modern representatives. Furthermore, we recognise a strong morphological separation of modern larvae and adults (with pupae being intermediate), while in fossils the overlap of representatives of both life phases is quite strong. This supports earlier qualitative observations that the ontogeny of Cretaceous snakeflies was even more gradual (and likely plesiomorphic for Raphidioptera and presumably Holometabola) than in extant snakeflies. The analyses revealed that some Cretaceous and Eocene snakeflies had a slender head and prothorax morphology that is absent nowadays. This supports a difference between the modern and Eocene fauna. Additionally, a gap analysis was performed for the best-sampled subsets to explore morphological constraints in snakefly morphology. Full article

To address head-end three-phase current unbalance and terminal power-quality deterioration caused by uneven three-phase load allocation in a low-voltage transformer area (LVTA), this paper proposes a DC-link-voltage-control-based phase-wise unbalanced power compensation strategy for a head-to-tail flexible interconnection structure embedded in the LVTA. The proposed structure consists of two three-phase four-leg converters sharing a common DC bus and connected to the head end and tail end of the LVTA, respectively. Different from conventional phase-wise compensation methods in which the DC side mainly acts as a power-transfer channel, the proposed strategy uses the DC-link voltage control of the head-end converter as the core of compensation power generation. Specifically, the outer DC-link voltage loop generates the total active compensation power, which is then allocated among the three phases according to the measured phase-power unbalance of the LVTA, thereby yielding the phase-wise compensation current references. Combined with phase-wise quasi-proportional-resonant current control, the compensation currents of different phase legs can be regulated without explicit positive-, negative-, and zero-sequence decomposition. Meanwhile, the tail-end converter adopts PQ control to support terminal power regulation and improve the terminal voltage quality of the LVTA. To provide a theoretical basis for the proposed method, a switching-cycle averaged model of the three-phase four-leg converter is established, and the leg-level phase-wise control characteristics are analyzed under the assumptions of a stiff DC link and symmetrical converter parameters. A control-oriented equivalent LVTA model is developed in MATLAB/Simulink. The proposed strategy is validated under steady-state unbalanced, RL load, load-disturbance, and equivalent feeder-impedance conditions. In addition, a conventional positive-, negative-, and zero-sequence compensation method is introduced as a benchmark for quantitative comparison. The simulation results demonstrate that the proposed method can effectively suppress the head-end three-phase current unbalance, maintain the DC-link voltage around its reference value, and improve the terminal voltage quality of the LVTA. Compared with the conventional sequence-component-based compensation method, the proposed strategy achieves effective unbalance mitigation while avoiding explicit sequence extraction and reducing the complexity of the compensation-current generation process. This study provides a feasible control framework for three-phase unbalance mitigation in flexible low-voltage transformer areas. Full article

This study presents a comprehensive symmetry-breaking analysis framework for a twelve-legged Jansen walking robot, integrating finite element analysis (FEA) with adaptive neuro-fuzzy inference system (ANFIS) surrogate modeling. A systematic dataset of 210 cases was generated by combining 21 single- and multi-leg failure scenarios across 10 load levels (20–200 N) on the PLA-based 3D-printed prototype. Two novel dimensionless metrics are introduced: the Resilience Index (RI), quantifying the proportional stress increase relative to the baseline, and the Asymmetry Index (AI), measuring leg-reaction force distribution imbalance. Results identify a clear fault-tolerance threshold between two- and four-leg failures: single-leg failures remain at LOW risk (RI < 0.20), while three-leg asymmetric failures (S18) reach CRITICAL level (RI = 1.13, ~97% of PLA yield strength). A hybrid machine learning framework is proposed, applying ANFIS to maximum stress (R² = 0.817) and safety factor (R² = 0.936) predictions, while reserving FEA tables for bimodal outputs. The ANFIS surrogate achieves approximately 10⁶× speedup over FEA (262.6 μs vs. 5–8 min), enabling real-time fault diagnosis and digital twin applications. The framework is generalizable to other multi-legged robotic systems requiring fault-tolerance evaluation. Full article

Background: Recreational mini-football is associated with a high incidence of lower-limb injuries, largely driven by neuromuscular deficits and insufficient exposure to structured preventive training. This study aimed to evaluate the effects of a hybrid injury-prevention program combining the FIFA 11+ protocol with customized neuromuscular interventions on functional performance and injury-related risk factors. Methods: Forty male recreational mini-football players were included in a retrospective analysis of data collected during the routine implementation of a 12-week hybrid preventive training program. Participants were allocated to an intervention group (n = 20) or control group (n = 20) according to routine training practices rather than randomization. The intervention was performed twice weekly. Outcome measures included lower-limb strength (Kineo system), dynamic balance (Y-Balance Test), functional hop performance (Single Hop and Side Hop tests), and agility/change-of-direction ability (Illinois and 505 tests). Results: The intervention group demonstrated significantly greater improvements in lower-limb peak force across all muscle groups (all adjusted p < 0.001), as well as in single-leg hop, side hop, and agility/change-of-direction performance (all adjusted p < 0.001) compared to controls. No significant changes were observed in dynamic balance outcomes. Conclusions: A hybrid neuromuscular training program combining FIFA 11+ with customized exercises was associated with improvements in lower-limb strength, hop performance, and agility/change-of-direction ability in recreational mini-football players. These findings suggest that integrating customized exercises into standardized training programs may enhance functional performance and positively influence modifiable factors associated with injury risk. Full article

(1) Background: Changes in midsole hardness may affect lower-limb impact loading during forefoot strike (FFS) running in children, yet the biomechanical basis for discriminating elevated VALR-related loading remains unclear. (2) Methods: Fourteen school-aged boys performed FFS running tests in experimental shoes with four midsole hardness levels (37, 42, 47, and 52 Shore C). Lower-limb kinematics and surface electromyography (sEMG) data were collected during the dominant leg stance phase. After preprocessing, VALR was calculated from 336 valid trials, and 28 stance-phase biomechanical features were extracted, yielding a final machine-learning dataset of 324 trials after excluding incomplete feature data. VALR was used to compare loading changes and define trial-level elevated-loading labels based on the median VALR value. Classification models were evaluated under participant-level GroupKFold validation, and XGBoost was retained for exploratory SHAP analysis. (3) Results: VALR showed an upward trend with increasing hardness, but no statistically supported change point was identified. XGBoost achieved an accuracy of 75.93%, precision of 74.14%, recall of 79.63%, F1-value of 0.768, and pooled out-of-fold AUC of 0.738. SHAP analysis indicated that distal and non-sagittal kinematic features contributed most to model classification. (4) Conclusions: Elevated VALR-related loading during children’s FFS running may be characterized by a multi-feature model-based pattern rather than a fixed midsole hardness threshold. Full article

The aim of this study was to compare carcass composition, meat quality, digestive tract morphometry, and leg bone dimensions of Pekin and Muscovy ducks. The study involved 40 birds, including 10 males and 10 females from each genotype, reared to market age. Carcass traits, physicochemical properties of breast and leg muscles, texture parameters, internal organ development, intestinal measurements, and selected dimensions of the femur and tibia were evaluated. The results demonstrated a significant effect of duck genotype (p < 0.05) on carcass weight, dressing percentage, and the proportion of neck, wings, and skin with subcutaneous fat. Genotype also affected meat color (L*, a*, b*), intramuscular fat and collagen content, cooking loss, pH, electrical conductivity, and selected texture parameters of breast muscles. Differences were also observed in the mass and proportion of internal organs, most intestinal morphometric traits, and selected bone measurements. Sex had a significant effect on body and carcass weight, selected meat quality traits, intestinal measurements, and leg bone dimensions, with males generally showing greater body size and more developed skeletal structures. Significant interactions between genotype and sex were observed for several analyzed traits. The findings indicate that both genotype and sex substantially affect slaughter traits and meat quality characteristics of ducks. Full article

Background: Radiculopathy originating from a previously fused lumbar segment is a clinically relevant but often underrecognized problem. Progressive foraminal stenosis may develop due to postoperative structural changes, leading to mechanical irritation of the exiting nerve root. Transforaminal endoscopic lumbar foraminotomy (TELF) is a minimally invasive option, but its role in this setting is not well defined. Methods: In this retrospective cohort study, we included 36 consecutive patients who underwent TELF for symptomatic foraminal stenosis at a previously fused segment between 2020 and 2023. Clinical outcomes were assessed using the visual analog scale (VAS) for leg pain, Oswestry Disability Index (ODI), and modified MacNab criteria, with follow-up of up to 2 years. Radiographic and intraoperative findings were reviewed to explore the underlying mechanisms. Results: The mean VAS score improved significantly from 8.36 preoperatively to 2.00 at 2 years, and the mean ODI decreased from 70.9% to 16.8%. According to the modified MacNab criteria, 86.1% of the patients achieved excellent or good outcomes. Intraoperative findings revealed fibrotic or hypertrophic foraminal stenosis in 86.1% patients (n = 31), whereas 13.9% of patients (n = 5) showed pedicle screw-related nerve root irritation. Five patients experienced transient postoperative dysesthesia, and no postoperative instability was observed. Conclusions: Radiculopathy at the fused segment is primarily caused by progressive mechanical foraminal compromise after fusion. TELF provides effective symptom relief through direct decompression and may serve as a less invasive alternative to revision fusion in selected patients. Full article

Paralympic water polo requires classification systems that reflect sport-specific functional performance under ecologically valid conditions. This pilot study proposes a task-specific kinematic profiling framework for deriving objective, biomechanically interpretable descriptors of residual motor function. Five male national-level water polo athletes—three with eligible motor impairments and two able-bodied reference participants—performed standardized sport-specific tasks comprising upright floating, vertical propulsion, unilateral passing, non-contested shooting, and contested shooting under physical opposition. Stereoscopic video, OpenPose-based three-dimensional reconstruction, and phase-based analysis were used to extract features and composite indices of postural control, propulsion capacity, upper-limb residual function, and resistance to perturbation. Automatic ball-release detection matched manual frame-level verification in all 128 analyzed ball-related trials. Within the task-specific indices, where higher scores indicate greater functional burden, core values ranged from 0.05–0.15 for upright floating, 0.29–0.68 for combined arm-and-leg vertical propulsion, and 0.040–0.148 for contested shooting across the available subject–side combinations. The profiles showed task- and side-specific differences in stabilization, propulsion, and post-contact motor reorganization. The framework uses pose estimation as a quantitative measurement tool and treats visibility interruptions as functionally meaningful events rather than noise. It is not intended to replace official classification procedures, but to provide transparent and interpretable candidate descriptors for future evidence-based classification research in Paralympic water polo. Full article

Background/Objectives: Chronic diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs) remain a major source of morbidity, healthcare utilization, and limb loss, despite adherence to established standards of care protocols and the widespread availability of advanced wound technologies. Many advanced modalities only target isolated aspects of wound healing and fail to address the complex, interdependent pathophysiology of chronic wounds, particularly tissue hypoxia, edema, impaired microcirculation, and persistent inflammation. Cyclical Pressurized Topical Wound Oxygen (TWO₂) therapy is a home-based, multimodal intervention that combines humidified topical oxygen delivery with cyclical non-contact compression to address these core drivers simultaneously. Methods: This review synthesizes mechanistic rationale and evidence from randomized controlled trials, long-term venous ulcer studies, and real-world comparative effectiveness analyses. Emphasis is placed on the large cohort study by Yellin et al., which directly compared TWO₂ with other advanced modalities including negative pressure wound therapy (NPWT), skin substitutes, and growth factor therapies. Results: Across these studies, TWO₂ therapy is consistently associated with improved healing durability, reduced recurrence, and substantial reductions in hospitalization and amputation rates compared with both standard care and advanced wound therapies. Conclusions: The convergence of randomized and real-world evidence supports TWO₂ therapy as a clinically meaningful and mechanism-driven adjunctive treatment option for patients with chronic, high-risk lower-extremity wounds. Full article

Objectives: Explore and compare the effects of 8-week time-restricted eating (TRE), walking exercise, and their combination on fat and lean muscle distribution in female college students with hidden obesity. Methods: A total of 68 participants were randomly assigned to four groups: Control (CON), TRE, Exercise (EXE), and TRE + EXE. An 8-week intervention was begun according to a predetermined experimental plan, comparing changes in body fat and lean tissue indices before and after the intervention. Results: Before and after the intervention, the TRE group showed a significant decrease in body mass, body mass index (BMI), and total lean mass (p < 0.05). The EXE group saw a significant reduction in visceral fat area, visceral fat mass, and visceral fat volume (p < 0.01). The TRE + EXE group experienced a significant decrease in android lean mass (p < 0.05); Comparing before and after the intervention, there were no statistically significant differences in the body fat percentage, total fat mass, fat and lean in the android and gynoid areas, and %fat in trunk/%fat in legs among the CON, TRE, EXE, and TRE + EXE groups (p > 0.05). After the intervention, there were no significant differences in the body fat percentage, total fat mass, total lean mass, fat and lean in the android and gynoid areas, %fat in trunk/%fat in legs, visceral fat area, visceral fat mass, visceral fat volume, subcutaneous fat area, subcutaneous fat mass, and subcutaneous fat volume among the four groups (p > 0.05). Conclusions: An 8-week TRE intervention in young women with hidden obesity reduced body mass and BMI but also decreased total lean mass, potentially compromising metabolic health, with no statistically significant changes in total body fat or regional fat distribution. Walking exercise showed significant reductions in visceral adiposity indicators (VFA, VFM, VFV), whereas the combined TRE + EXE group did not achieve comparable reductions. These findings suggest that while isolated TRE facilitates body mass loss, it carries a distinct risk of muscle tissue loss and may not confer comparable benefits on visceral fat reduction as walking exercise. However, the generalizability of these preliminary observations is constrained by methodological limitations including retrospective registration, participant attrition, and restricted statistical power. Consequently, these exploratory outcomes must be interpreted with caution, warranting future robust, large-scale trials with enhanced compliance monitoring to optimize prescriptive guidelines for this specific cohort. Full article

Background/Objectives: To determine whether ESS provides superior clinical, radiologic, or perioperative outcomes compared with non-ESS surgical strategies in lumbar spondylolisthesis. Methods: We conducted a PRISMA-guided systematic review and meta-analysis comparing ESS with non-ESS strategies specifically for lumbar spondylolisthesis. PubMed, Web of Science, Scopus, and CENTRAL were searched from inception to December 2025, plus reference-list screening. Primary outcomes were mean change in VAS back pain, VAS leg pain, and Oswestry Disability Index (ODI); secondary outcomes included radiologic measures (disc height, lumbar lordosis angle, fusion rate) and perioperative outcomes (blood loss, operative time, length of stay, complications). Results: Eighteen studies (16 retrospective cohorts, 1 RCT, 1 case–control) involving 1200 patients with lumbar spondylolisthesis (2019–2025) were included. ESS showed no significant differences versus non-ESS in mean change in VAS back pain (13 studies; MD −0.07), VAS leg pain (14 studies; MD 0.08), or ODI (12 studies; MD 0.51). No statistically significant differences were detected in radiological outcomes (disc height, lumbar lordosis angle, and fusion rate). ESS was associated with reduced blood loss (MD −132.98) and shorter hospital stay (MD −2.86 days), with no difference in operative time (MD 3.96) or postoperative complications (RR 0.86). Subgroup analyses compared endoscopic fusion with MIS fusion, open fusion, and non-endoscopic decompression. Endoscopic versus MIS fusion showed lower blood loss (MD: −50.9 mL) and shorter hospital stay (MD: −1.4 days) but longer operative time (MD: +17.2 min), with no differences in clinical outcomes. Comparisons involving decompression and open fusion were limited by the small number of studies and should be considered exploratory. Conclusions: For lumbar spondylolisthesis, no statistically significant differences were detected between ESS and non-endoscopic approaches in pain, disability, radiologic outcomes, or complication rates, with potential perioperative advantages in blood loss and length of stay. However, these findings should be interpreted cautiously because the available evidence is predominantly retrospective, procedurally heterogeneous, and affected by substantial variation in follow-up duration. Full article

The vertical landing of quadrotor unmanned aerial vehicles (UAVs) involves highly transient impact dynamics that generate significant vibrations on the UAV body, particularly under uncertain touchdown conditions such as uneven terrain, asymmetric ground contact, and high-impact landing. In this study, a robust semi-active vibration control framework is proposed for a quadrotor UAV equipped with a four-point soft landing gear system. The UAV is modeled as a three-degree-of-freedom rigid body including heave, pitch, and roll motions, while each landing gear leg is represented by an equivalent spring-damper mechanism with adaptively controllable damping characteristics. To evaluate the effectiveness of the proposed framework, PID (Proportional–Integral–Derivative), GA-PID (Genetic Algorithm-Based Proportional–Integral–Derivative), Fuzzy–PID (Fuzzy Logic-Based Proportional–Integral–Derivative), and ANFIS-PID (Adaptive Neuro-Fuzzy Inference System-Based Proportional–Integral–Derivative) controllers are comparatively investigated under five different landing scenarios. The nonlinear touchdown dynamics are implemented in the MATLAB/Simulink environment using a state-space-based simulation model. The results demonstrate that intelligent adaptive control methods significantly improve landing stability and vibration attenuation compared to the conventional PID controller. Among all methods, the ANFIS-PID controller achieved the best overall performance. Under the most severe landing condition, the peak vertical displacement was reduced from 0.114 m to 0.025 m, while the maximum pitch and roll angles decreased from approximately 11° to nearly 2°. Additionally, the settling time was reduced from nearly 10 s to below 3 s. Full article

Objectives: This study investigated the effects of exercise selection and rest interval duration on post-exercise cardiac autonomic modulation following resistance exercise (RE). Methods: Eleven (4 females) resistance-trained individuals performed a single RE session consisting of either a multi-joint exercise (back squat) or a single-joint exercise (leg extension), using rest intervals of 1 or 2 min between sets. Heart rate variability (HRV) was assessed at baseline (pre-exercise) and 30 min following the RE session. RR intervals were recorded for 15 min with participants resting in the supine position on an examination bed in a quiet environment. For HRV analysis, a 5-min artifact-free segment of RR intervals was selected and processed using Kubios HRV software, version 4.3.0 (Kubios Oy, Kuopio, Finland). The HRV metrics analyzed included the root mean square of successive differences (RMSSD), low-frequency normalized (LF), the low-frequency/high-frequency (LF/HF) ratio, and the standard deviation of transverse dispersion (SD1). Results: A significant main effect of time was observed for RMSSD, LF, and the LF/HF ratio. The back squat exercise elicited a significant reduction (p < 0.05) in vagal-related indices (RMSSD and SD1) regardless of interval duration. Longer rest intervals were associated with increased (p < 0.05) sympathetic modulation, as reflected by higher LF and LF/HF values 30 min post-exercise. No significant time × group interactions were observed for most HRV variables. Conclusions: Exercise selection and rest interval duration differentially influence post-exercise cardiac autonomic responses following RE. Multi-joint exercises induce greater vagal withdrawal, whereas longer rest intervals favor sympathetic predominance during recovery. These findings highlight the importance of manipulating RE variables to manage autonomic stress and recovery. Full article

Background/Objectives: The extent to which patient-reported outcome measures (PROMs) reflect objective functional recovery after surgical repair of acute Achilles tendon rupture remains unclear. This study aimed to evaluate the relationship between PROMs and objective functional performance, particularly the heel-rise test-based limb symmetry index (LSI). Methods: This retrospective cohort study included male patients who underwent primary open repair for acute Achilles tendon rupture between 2015 and 2023 and had a minimum follow-up of 12 months. Subjective outcomes were assessed using the Achilles Tendon Total Rupture Score (ATRS) and the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle–Hindfoot Score. Objective functional performance was evaluated using a single-leg heel-rise test, and LSI was calculated as the percentage performance of the injured limb relative to the uninjured limb. Patients were stratified into two groups according to LSI: ≥90% and <90%. Correlations between PROMs and LSI were analyzed using Spearman’s rank correlation coefficient. Results: A total of 76 male patients were included. The median age was 42 years (IQR, 35–46; range, 27–74), and the median follow-up duration was 41 months (IQR, 26–53; range, 12–80). The median ATRS was 97 points (IQR, 94–99), and the median AOFAS score was 98 points (IQR, 90–100). The median LSI was 87.5% (IQR, 81.4–93.3), and only 31 patients (40.8%) achieved an LSI ≥ 90%. Injured-side heel-rise performance was significantly higher in the LSI ≥ 90% group than in the LSI < 90% group (24.4 ± 5.4 vs. 21.6 ± 5.9 repetitions, p = 0.039). However, ATRS and AOFAS scores did not differ significantly between the groups. No significant correlation was found between LSI and either ATRS (Spearman’s rho = 0.190, p = 0.100) or AOFAS score (Spearman’s rho = 0.218, p = 0.058). Conclusions: Although PROM scores were high following surgical repair of acute Achilles tendon rupture, objective functional assessment revealed persistent limb-symmetry deficits in a substantial proportion of patients. ATRS and AOFAS scores showed no significant correlation with heel-rise LSI, suggesting that PROMs may not fully capture objective functional recovery. Therefore, PROMs should be interpreted alongside performance-based measures, particularly in patients with high functional demands. Full article

This study evaluated the effects of intensive indoor, free-range, and free-range feed-restricted rearing strategies on the growth performance, carcass traits, and meat quality of indigenous Gerze chickens. A total of 252 one-day-old chicks were allocated to three treatments: free-range (FR), free-range feed-restricted (FRR), and intensive indoor-reared (IN) groups. Outdoor access and Skip-a-Day feed restriction began at 8 weeks of age, and birds were reared until 16 weeks. At slaughter, 16 chickens per group, balanced by sex, were selected for carcass and meat-quality analyses. Although the IN group showed higher live weights at several intermediate ages, final body weight did not differ significantly between the FR and IN groups, whereas FRR birds had lower final body weight. Feed conversion ratio and cumulative feed consumption did not differ among groups, but these pen-level results should be interpreted cautiously. The IN group had a higher dressing percentage and abdominal fat ratio, whereas edible giblet ratios were greater in the FR and FRR groups. Free-range rearing affected selected meat-quality traits, including lower leg L* and a* values and higher pH values. These findings provide production-oriented evidence that Gerze chickens may be suitable for local free-range systems, while Skip-a-Day feed restriction requires further evaluation. Full article