Browse Articles

Maintenance of approach velocity despite increasing internal load during repeated pole vault attempts

Abstract Biomechanical analyses identify approach velocity—particularly in the final meters—as the primary mechanical determinant of vertical displacement in pole vault; yet how this velocity changes across repeated attempts performed below personal best height remains a practically important but largely untested question. As part of an applied field-based preparatory-phase protocol, we monitored the metabolic, cardiovascular, and perceptual responses of pole vaulters during four vault attempts performed 20 cm below their personal bests, and examined whether approach velocity was maintained in the final 5 m under these conditions. Eleven competitive pole vaulters (4 women, 7 men; age 20.3 ± 2.6 years) performed four consecutive vault attempts at heights 20 cm below their personal bests, with 3.5–4 min recovery intervals. Blood lactate (BL), heart rate (HR), and ratings of perceived exertion (RPE; Borg CR-10) were measured at predetermined time points throughout the protocol. Approach velocity and step kinematics (step length [SL], step frequency [SF], and contact time [CT]) over the final 5 m were derived from two-dimensional video analysis. Phase-related changes, load-velocity and step kinematic-velocity associations, subgroup interaction effects, and individual load change correlations were assessed using linear mixed-effects models (LMM) and Pearson correlation analyses. BL and HR showed no significant change between successive attempts (A 1 –A 4 ; all p Tukey > 0.05), whereas RPE increased significantly between A 3 and A 4 . At A 4(11) , neither BL nor RPE differed significantly from resting values (BL: p Tukey = 0.375; RPE: : p Tukey = 0.894); HR reached warm-up levels but remained significantly above rest ( p Tukey = 0.001). Approach velocity and all step parameters did not show a significant change throughout the four attempts (all p > .05). Neither exploratory model identified a significant relationship between velocity and physiological load indicators or step kinematics (all p > .05). Individual trajectory analysis revealed heterogeneity in velocity and kinematic strategies beneath the group-level mean. Subgroup interaction analyses revealed significant Attempt × Group effects for approach velocity in both the V 1 ( F(3 , 27)  = 11.80, p < .001) and V 3 ( F(3 , 24)  = 9.28, p < .001) models, with Velocity-Declining athletes demonstrating significantly greater velocity decrements at A 3 and A 4 . Pole vaulters showed no detectable change in approach velocity across four consecutive attempts despite rising effort perception and progressive metabolic stress. The heterogeneity in individual kinematic strategies underscores the need for cautious interpretation of group-level findings.

Synergy and Competition of Dual Chirality in the Chirality-Induced Spin Selectivity of Supramolecular Helices

Prevalence and factors influencing work-related musculoskeletal disorders among sonographers in Gamo and Wolaita zones, southern Ethiopia: a cross-sectional study

Chemical grafting of waste polystyrene with acrylic acid and subsequent amine functionalization to enhance polystyrene modified bitumen characteristics

Abstract The rigid polystyrene (PS) waste could be an alternative bitumen modifier, which brings great economic and environmental efficiency. However, because of low polarity and high rigidity nature of PS, it sometimes poses some difficulties in compatibility, elasticity, and storage stability. To address these limitations, the present study proposed an alternative chemical modification method for waste polystyrene through grafting with acrylic acid followed by a reaction with diethylenetriamine to produce PS-g-AM. Functionalized groups of the polymer were confirmed by performing FT-IR and 1 H-NMR spectroscopy which approved that PS-g-AM was successfully synthesized and identified. The synthesized PS − g−AM was mixed with bitumen with percentages of 3, 5, 7 and 10wt% from total binder weight. A multi-scale correlation between microscopic mechanisms and macroscopic performance is integrated. The microscopic characterization including FTIR and AFM techniques were performed and successfully verified the good compatibility via hydrogen bonding interaction between PS-g-AM and bitumen. Also, the macroscopic characterization including storage stability, and elastic recovery test demonstrated that the prepared PS-g-AM modified binders (7wt%) showed significantly a high storage stability (≤ 0.3), and better elastic recovery (55%) compared to untreated PS modifier (2.5), and (25%) respectively. The dynamic mechanical properties are also studied and the results revealed a considerable improvement in rutting resistance (G/sin δ) PG degree increased from 70 to 76, tan δ reduction. In summary, results confirmed that chemical grafting turned PS from a hardening agent to an efficient elastic modifier into asphalt and provided great opportunity for a high-performance sustainable method of modifying the asphalt.

Kinetics vs Thermodynamics: Engineering Photoredox Reactivity from an Upper Excited State of Fe ^II

A 1D-CNN with advanced data augmentation for robust speech emotion recognition

A Molecular Playground for Spin-State Ice and Coupled Electron–Spin Dynamics

Lung inflammation after repeated exposure to LPS and glyphosate in female mice

Abstract Agricultural work involves exposure to airborne pollutants including dust and pesticides that can cause respiratory effects, yet little is known about these impacts in females. The inflammatory effects of inhaled glyphosate, alone or in combination with common agricultural exposures like lipopolysaccharide (LPS), remain unclear. The objective was to evaluate the inflammatory potential of single and combined exposures to glyphosate and LPS in female mice using physiological and structural measures, and synchrotron imaging. C57BL/6 female mice ( n  = 20) were intranasally treated with glyphosate (GLY), LPS, LPS + glyphosate (LG), or HBSS (CTL) for 5 days. On day 5, an additional group of mice were transported to the Canadian Light Source synchrotron (CLS) for multiple image x-radiography (MIR) to assess lung injury. Following treatment, mice were euthanized and bronchoalveolar lavage fluid (BAL) and lung tissue were collected. Mice exposed to LG had significantly higher airway restriction; expression of pro-inflammatory cytokines/chemokines TNF-α, KC, IL-6, MCP-1, and MIP-2; levels of myeloperoxidase expression; greater recruitment of cells into the alveolar regions, disruption to the bronchial epithelium in the lungs, and compromised lung air-tissue interfaces in the MIR images compared to other treatment groups. It is likely that inflammatory adaptation is already occurring in the female mice by five days of exposure. These results reveal that female mice exposed to LG displayed physiological, structural, and lung injury effect that were different from mice exposed to LPS and GLY alone.

Covalent Functionalization of Dawson-Type Polyoxometalates to Achieve a Zero to Three-Dimensional Transition for Enhanced Proton Conductivity

Integrated histochemical, biochemical, and ultrastructural analyses elucidate synergistic virulence mechanisms of Curvularia lunata in maize

An efficient triple-domain YOLOv8 for real-time aluminum profile defect detection

Oxidative Hetero-Coupling: Iron- and Copper-Mediated 1,2-Dicarbofunctionalization

Advanced PV-enabled heat generation system with precise thermal power regulation

Ligand-Based Redox Chemistry at the Mo-Containing Active Site of <i>Cupriavidus necator</i> Formate Dehydrogenase

Balancing accuracy and efficiency in lumbar spine image segmentation using multi-scale attention and residual learning

Glycoengineered Host-Guest Nanoparticles Potentiate Alzheimer’s Disease Therapy via Lesion-Specific Modulation of Tau Pathology

Voltage compensation of manufacturing errors applied to artificial band gaps in nanoscale transistor

Liquid-Phase CO <b> ₂ </b> Capture by a Nonaqueous Cooperative Absorption Mechanism

Verification of the factors of individuality through avatar’s speech generation system

Abstract In recent years, extensive research has been conducted on avatars, and multiple studies have demonstrated their effectiveness as a medium for remote operation. While avatars are effective when teleoperated, they must also be capable of autonomous behavior in the absence of an operator. In particular, avatars whose appearance closely resembles that of a real individual need to possess conversational abilities that reflect the personality of the person being modeled. This paper presents the development of a speech generation system that produces personality-consistent utterances using a large language model (LLM) and speech synthesis technology. We call this system AvatarLLM. Through system evaluation, we examined the factors contributing to the perception of individuality. Experimental results indicated that the utterances generated by AvatarLLM were perceived as more likely reproducing the modeled individual than those of the actual person. Furthermore, we found that the perceived identity of the utterances could influence the perceived identity of the voice itself.

A Bioinspired OH-Sponge Catalyst Enables Ultrawide-Voltage and Durable Electrosynthesis of Glycolic Acid from Plastic Waste