Search Results (10,443)

Background: Handball involves unilateral, high-demand actions that increase injury risk. The Windlass mechanism (WM) is a position-dependent plantar fascia tensioning system, activated by dorsiflexion of the first metatarsophalangeal joint, which increases medial longitudinal arch stiffness and contributes to foot stability. WM activation can be mechanically simulated using hallux wedges to induce controlled dorsiflexion, allowing graded engagement of the mechanism under standardized conditions. The primary aim of this study was to investigate how different wedge inclinations, with and without visual biofeedback, affect foot muscle activity during squats in elite female handball players. Methods: Seventeen elite female handball players performed squats at 65% of one-repetition maximum under six conditions combining three wedge inclinations (0°, 10°, 30°) with the presence or absence of visual biofeedback. Electromyographic activity (RMS and %MVC) of intrinsic and extrinsic foot muscles was recorded. Results: A significant increase in left abductor hallucis activation with the 10° wedge without biofeedback. Visual biofeedback significantly increased RMS and %MVC in intrinsic foot muscles and increased RMS in the left gastrocnemius (p < 0.05). No significant interaction was observed between wedge inclination and biofeedback. Conclusions: Controlled activation of the WM via hallux wedges and the use of visual biofeedback modulate foot muscle activity during squats. These strategies may be considered in training programs aimed at improving foot stability and reducing injury risk in elite female handball players. Full article

A keloid is a benign fibroproliferative cutaneous disorder characterized by excessive extracellular matrix deposition, which is driven by persistent fibroblast proliferation and aberrant wound healing. Its complex pathogenesis involves genetic susceptibility, chronic inflammation, mechanical tension and dysregulated cellular signaling, resulting in poor clinical efficacy and high recurrence rates. Cellular senescence has recently become a central focus in exploring keloid pathophysiology, offering a novel perspective for elucidating its initiation, progression and recurrence. This review systematically summarizes the biological roles of cellular senescence in keloid pathology: it elaborates on the basic concepts and core molecular features of cellular senescence, details the spatial heterogeneity of senescent cell accumulation, the activation and pathological effects of senescence-associated secretory phenotype (SASP), and clarifies the molecular link between senescence-resumed proliferation (SRP) and keloid recurrence and treatment resistance. It also summarizes advances in senescence-related markers, the regulatory roles of the p53/p21 and Wnt/β-catenin pathways, and potential senescence-targeted therapies (senolytic, senomorphic, signaling intervention, cell reprogramming). Finally, we discuss the challenges and future perspectives for translating senescence research into clinical keloid treatments, aiming to provide a novel theoretical framework and therapeutic targets for keloid management. Full article

This qualitative study investigates the challenges teachers face when teaching English as a foreign language (EFL) to deaf (in this article, deaf (lower case) refers to the audiological condition of hearing loss, whereas Deaf (capitalized) is used to denote individuals who identify as members of the Deaf community and share a common sign language and distinct cultural values) and hard-of-hearing (DHH) students in German schools for the Deaf. The study is situated within a structural–theoretical professionalization framework, which focuses on the relationship between institutional conditions, teacher education structures, and professional action. Semi-structured interviews were conducted with 16 teachers of DHH students and the data were examined using qualitative content analysis. The findings reveal five central areas of challenge: (1) heterogeneity of the student body; (2) limited time (for preparing and adapting materials); (3) restricted subject-matter and sign-language competence, including missing links between EFL didactics and Deaf education in teacher training; (4) uncertainties surrounding the language design of EFL instruction, particularly the role of American Sign Language (ASL), German Sign Language (DGS), and written English; and (5) the lack of consistent, accessible exam formats and standards. Teachers report substantial insecurity due to the absence of coherent concepts, policy frameworks, and specialized training pathways, which fosters divergent classroom practices and tensions within teaching staff. The results highlight an urgent need for systematic integration of Deaf education, sign language training, and EFL pedagogy in teacher education, as well as for evidence-based guidelines on language classroom practice and assessment for DHH learners. Full article

This article examines the geopolitical transformation of the European Union within the context of polycrisis and intensified strategic rivalry following the events of 2022. It addresses the question of whether the EU’s response to contemporary crises represents a mere temporary adjustment triggered by an emergency, or rather a more permanent reconfiguration of European integration. Methodologically, the paper employs a qualitative research design combining conceptual analysis, interdisciplinary theoretical synthesis, and document-based comparative process-tracing of selected post-2022 policy responses, including sanctions policy, energy governance, and geoeconomic industrial policy. The analysis demonstrates that the EU has not evolved into a coherent, sovereign geopolitical actor, but rather into a more strategically adaptive and selectively integrated compound polity. This transformation is characterised by differentiated institutional deepening, expanded executive coordination, and growing tensions between efficiency, legitimacy, and democratic accountability. The article contributes to debates on European integration by conceptualising its current trajectory as a hybrid adaptation to a fragmented global order. Full article

From hours spent in waiting rooms amidst uncertainty to the experience of recovering from medical treatments, the lived time of illness is marked by intervals of suspended sense. By disorienting our relation to the future, illness disrupts and reconfigures lived time from within, shaping how we navigate our intersubjective milieu and make sense of our unfolding lives. In this paper, we introduce the phenomenological concept of “protentional friction” as a way of understanding these experiences. Drawing upon Simone de Beauvoir’s work on subjectivity and becoming, alongside Henri Bergson’s and Eugène Minkowski’s emphasis on durée and élan, we demonstrate how protentional friction allows us to negotiate the tensions of our situation, orient ourselves toward the future through projects, and gear into the ongoing work of sense-making. As a counterbalance to normalizing cultural discourses surrounding illness, we reinterpret the idea of the “quotidian” as the everyday practice of sense-making to find and sustain an equilibrium. Full article

In goafs formed by underground mineral resource extraction, the remaining pillars are often subjected to uniaxial loading at different loading rates, and their mechanical responses and failure mechanisms directly affect the long-term stability of the goafs. This study uses rock-like materials to conduct uniaxial compression tests at loading rates ranging from 0.001 mm/min to 0.05 mm/min, combined with acoustic emission (AE) monitoring, to systematically investigate the effects of loading rate on the mechanical properties, energy distribution, constitutive model, and AE characteristics of the material. The results show that an increase in loading rate significantly enhances the stiffness and strength of the material, promotes a transition in failure mode from a shear–tension composite to tension-dominated, intensifies brittle characteristics, and simultaneously inhibits full crack development and fragments generation. In terms of energy evolution, an increased loading rate enhances the pre-peak total strain energy and elastic strain energy storage but reduces the efficiency of energy dissipation, leading to an intensified mismatch between energy storage and dissipation capacities at peak stress. A damage variable induced by loading rate was proposed, and a damage constitutive model considering the loading rate was established, with the theoretical curves showing good agreement with the experimental data. AE characteristic analysis further reveals that an increase in loading rate causes the crack type to transition from shear-dominated to tension-dominated, and the fluctuating increase in the b-value reflects a reduction in pre-peak fracture scale and a decrease in the degree of material fragmentation. The research findings are expected to deepen the understanding of the damage and failure mechanisms of rock materials under different loading rates, thereby laying a research foundation for the stability assessment of goaf pillars and disaster warning. Full article

This paper addresses the optimal management of photovoltaic (PV) systems and distribution static synchronous compensators (D-STATCOMs) in modern electrical distribution networks. A mixed-integer nonlinear programming (MINLP) model is formulated which co-optimizes device placement, sizing, and multi-period dispatch to minimize the total annualized system costs while satisfying AC power flow and operational constraints. To solve this challenging problem, a decomposition methodology is proposed, wherein the binary location decisions for the PVs and D-STATCOMs are treated as predefined inputs, upon the basis of site selections commonly reported in the literature. With the integer variables fixed, the problem is reduced to a continuous nonlinear programming (NLP) subproblem for optimal capacity sizing and operational scheduling, which is solved using the interior point optimizer (IPOPT) via the Julia/JuMP environment. The core contribution of this work lies in its comprehensive demonstration of the economic superiority of variable reactive power injection over conventional fixed compensation schemes. Through numerical validation on standard 33- and 69-bus test systems, it is shown that a variable D-STATCOM operation yields substantial and consistent economic gains. Compared to optimized fixed-injection solutions, variable injection provides additional annual savings averaging USD 120,516 (33-bus feeder) and USD 125,620 (69-bus grid), corresponding to a further 3.4% reduction in total costs. These benefits prove robust across different device location sets identified by various metaheuristic algorithms, and they scale effectively to larger network topologies. The results demonstrate that transitioning to variable power injection is not merely an incremental improvement but a fundamental advancement for achieving techno-economic optimality in distribution system planning. The proposed methodology provides utilities with a computationally efficient framework for determining near-optimal PV and D-STATCOM management strategies by first fixing deployment locations based on established planning insights and then rigorously optimizing sizing and dispatch, in order to maximize economic returns while ensuring reliable network operation. Full article

Peru’s recent national mental health (MH) reforms aim to decentralise care and expand access to MH services for rural populations by integrating services into primary healthcare through the expansion of Community Mental Health Centres (CMHCs). Evidence on the implementation of these reforms at the local level remains limited. This qualitative study aimed to (i) describe the structure and implementation framework of MH services, (ii) analyse local understandings of MH; and (iii) examine pathways to care and identify barriers and facilitators to MH service implementation from both the supply (service providers) and demand (users and community members) perspectives. MH services were mapped across three provinces of northern Peru using a review of national MH policies, 2 focus group discussions, and 31 semi-structured interviews. Data were analysed thematically to explore local understandings of MH, pathways to care, and health system barriers. Local understandings of MH are shaped by cultural beliefs, social norms, and economic conditions, with many individuals experiencing distress initially relying on family networks or traditional healers. Stigma and expectations of a quick recovery hinder engagement with formal services. While the expansion of CMHCs has improved geographical access to specialised care in rural areas through proximity and being patient-centred, the implementation of respectful provider interactions remains uneven. Weak referral pathways and limited coordination between primary care centres and CMHCs frequently shift the responsibility for navigating care onto users and their families. Family involvement and culturally sensitive practices foster trust and support continued engagement. Persistent challenges include the limited capacity of service providers, high staff turnover, and the follow-up mechanisms, stigma, and tensions between cultural and biomedical understandings of MH. Peru’s expansion of CMHCs represents a significant health system reform to improve equitable access for rural populations. To sustain these gains, it will be necessary to strengthen workforce stability, clarify referral processes, and integrate culturally responsive approaches within primary care systems, offering lessons for similar resource-constrained contexts. Full article

C3H-type zinc finger proteins play essential roles in plant responses to abiotic stresses, as well as in the regulation of growth, development, and signal transduction. Birch (Betula platyphylla Suk.), an ecologically adaptable tree species widely distributed in northern regions, has not yet been systematically characterized for its C3H gene family. In this study, a total of 15 BpC3Hs were identified from a genome-wide analysis of birch. Their physiochemical properties, gene structures, conserved motifs and domains were systematically analyzed. Promoter analysis identified cis-acting elements associated with stress responses, hormone signaling, and developmental regulation. Transcriptome data further showed that most BpC3Hs were responsive to salt, drought, high/low-temperature stresses, and light/dark treatment, and showed differential expression patterns in tension wood and opposite wood. Additionally, they displayed stage-specific expression patterns during male inflorescence development. This study lays a foundation for future functional characterization of the C3H gene family in birch and its application in molecular breeding for stress resistance. Full article

While macroscopic stress significantly impacts the performance of metallic components, the underlying atom–electron coupling mechanisms governed by distinct crystal symmetries remain insufficiently understood. To address this gap, this work systematically investigates the structural and electronic evolution of representative metallic materials under applied stress. Experimentally, X-ray diffraction (XRD) revealed complex macroscopic residual stress distributions in cold rolled titanium alloy and silicon steel. Motivated by these engineering observations, first-principles density functional theory (DFT) calculations were conducted to uncover the underlying physical mechanisms. Specifically, the responses of face-centered cubic (FCC) aluminum and copper, body-centered cubic (BCC) iron, and hexagonal close-packed (HCP) titanium crystals were investigated under tension and compression using the RPBE functional. Stress-dependent elastic properties, density of states (DOS), band structures, and phonon spectra were calculated. Results show that tension softens all metals (Al becomes mechanically unstable), whereas compression stiffens their lattices. Electronically, tensile loading sharpens DOS peaks near the Fermi level and shifts conduction bands closer to it, whereas compression smooths DOS peaks and shifts bands away. Phonon analysis indicates Cu and Ti remain dynamically stable, while Al and Fe exhibit phonon mode softening under high tension. These stress-induced changes highlight crucial atom–electron coupling mechanisms, providing a theoretical basis for tailoring metallic performance via stress engineering. Full article

Ultrasonic cavitation is a key mechanism in the dispersion and erosion of solid materials in liquids; however, the influence of processing conditions and medium properties on its efficiency in ultrasonic baths remains poorly systematized. Despite the widespread use of ultrasonic baths in materials processing, general optimization principles are lacking, and operating parameters are typically determined empirically for each system. In this work, cavitation activity was quantitatively assessed using an aluminum foil erosion test, with the foil clamped in a plastic frame to evaluate the mechanical effects of cavitation. The effects of ultrasonic power, frequency, treatment time, temperature, solvent nature, and vessel material on the foil mass loss were systematically investigated. The results demonstrate that both the instrumental parameters and physicochemical properties of the dispersion medium, including viscosity and surface tension, significantly affect the cavitation activity. Solvents with lower cavitation thresholds and favorable acoustic properties promote more intense erosion, while the vessel material and geometry also influence energy transmission to the liquid. This study provides a systematic framework for assessing the cavitation dose in ultrasonic baths and offers practical guidelines for optimizing ultrasonic dispersion processes and improving their reproducibility. Full article

Magnetic wall-climbing robots have great potential applications for the maintenance and inspection of large steel structures. However, they are susceptible to overturning when climbing over obstacles on vertical walls, primarily due to localized failures in the adhesion and shifts in the center of gravity. To address this issue, this paper presents an improved robot design featuring a passive adaptive tracked mobility module and a link-spring anti-overturning module. The adaptive tracked mobility module, incorporating spring tensioning mechanisms and belt press wheels, enables dynamic conformity to uneven walls and maintains stable magnetic adhesion. The link-spring anti-overturning module converts the front-end lift during obstacle crossing into an anti-overturning moment applied to the rear end of the robot. Notably, there is no need for additional drivers or control units. The structural design and three-dimensional modeling of the robot are carried out. Its working principle is analyzed, and parametric modeling and simulation analysis are performed. A physical prototype is developed and obstacle-crossing experiments are conducted on a vertical wall. The results demonstrate that the adaptive tracked mobility module and the anti-overturning module can successfully assist the robot in climbing over an obstacle with a maximum height of 23 mm, and the robot exhibits excellent stability while climbing over continuous obstacles and moving on uneven vertical walls. Full article

This study examines how Saudi consumers evaluate the commodification of cultural symbols in fashion amid intensified heritage branding and symbolic market expansion. It addresses a gap in the literature on internal cultural commodification, where tensions surrounding authenticity, legitimacy, and commercialization emerge within the same cultural community rather than across clearly separate cultural groups. Drawing on a culturally grounded application of the Theory of Planned Behavior and related literature on consumer ethnocentrism and moral evaluation, the study investigates how perceived authenticity, perceived cultural appropriation, ethical sense, and consumer ethnocentrism shape attitudes toward cultural commodification and purchase intention in the Saudi fashion context. Data were collected through an Arabic-language questionnaire-based survey of Saudi consumers (N = 552) using a non-probability purposive sampling approach. The measurement model employed reflective scales adapted from prior literature and was assessed for reliability and validity. To strengthen methodological rigor, the analysis also considered common method bias diagnostics. The proposed relationships were tested using partial least squares structural equation modeling (PLS-SEM) with bootstrapping. The findings indicate that perceived authenticity is positively associated with attitudes toward cultural commodification and relates to purchase intention primarily through attitudes. Perceived cultural appropriation is negatively associated with both attitudes and purchase intention, suggesting both a direct deterrent effect and an indirect pathway via attitudes. Consumer ethnocentrism shows a negative association with purchase intention and a weaker negative association with attitudes, while its moderating role appears statistically significant but limited in magnitude. Ethical sense displays a more complex pattern, combining negative indirect effects through evaluative pathways with a positive direct association with intention, consistent with qualified rather than purely restrictive participation in symbolic consumption. The study contributes to the literature by clarifying how consumer responses to heritage-based fashion commercialization are shaped by representational, ethical, and normative evaluations in a non-Western setting. Practically, it suggests that fashion brands operating in Saudi heritage markets should manage authenticity claims, symbolic legitimacy, and appropriation risk with greater cultural and ethical sensitivity. Full article

This trend is inevitable when aluminum electrolyte raw materials containing a higher content of LiF and KF are being widely used. Though these substances are often used as regulators in aluminum electrolysis due to their high corrosivity, measuring the physical parameters of the electrolyte through ordinary measurement methods is difficult. In this paper, electrolytes with different Li and K contents at different temperatures were synthesized as simulation samples, and viscosity and surface tension were measured by a new method. The results showed that in the aluminum electrolyte with a cryolite ratio of three, KF and LiF had similar impacts on viscosity when the mechanisms were completely different. As the content increased, KF reduced the viscosity of the material through the ion lattice spacing effect, and the high mobility of LiF contributed greatly to the viscosity reduction. However, the viscosity reduced significantly only when there was a higher KF concentration. The effects of the two regulators on the surface tension were different. The rising LiF content presented a greater effect on the surface tension, and the temperature was also a main factor affecting the surface tension of the electrolyte. When the two were added together in the electrolyte, a high content of KF helped reduce the surface tension. The research in this paper plays a role in promoting the exploration of phase parameters of aluminum electrolytes with high Li and K content. Full article

This paper examines the sixth-order generalized Boussinesq equation, which describes the dynamics of shallow-water waves, including the effects of surface tension. The study introduces Kudryashov’s R-function neural network approach for the first time, aiming to provide exact solutions to the nonlinear differential equation that represents the mathematical model of the sixth-order generalized Boussinesq equation. This technique incorporates the solutions of a nonlinear differential equation into neural networks, using them as an activation function within the hidden layer. In line with previous research on this topic, two categories of solutions are derived: solitary wave and shock wave solutions. Additionally, this paper includes 3D and 2D graphs to visually represent the solutions obtained. Full article