Search Results (191)

Background/Objectives: Professional mixed martial arts (MMA) athletes routinely partake in practices to elicit rapid weight loss before official weigh-in, followed by aggressive rehydration and nutritional recovery before competition. Although weight-cutting strategies have been widely described, there is limited information characterizing nutrient intake, food group selection, and fluid consumption during the pre-weigh-in, post-weigh-in, and fight-day periods. This cross-sectional study examined self-reported dietary intake of professional MMA fighters during the 24 h before weigh-in, post-weigh-in, and on fight day. Methods: Participants self-reported all foods and beverages consumed during three distinct competition phases: pre-weigh-in, post-weigh-in, and fight day. Changes in energy, macronutrient, fiber, sodium, and fluid intake across competition phases were evaluated using linear mixed-effects models. Results: The pre-weigh-in period was characterized by severe carbohydrate and fiber restriction with reduced fluid intake, whereas post-weigh-in intake shifted toward aggressive carbohydrate, fluid, and sodium replenishment alongside reduced fat consumption. Food group analysis demonstrated systematic elimination of vegetables, dairy products, legumes, whole grains, fried foods, and other high-fiber foods before weigh-in, with continued restriction of high-fat and high-fiber foods throughout the recovery period. Conclusions: These findings provide a comprehensive characterization of nutrient intake, food selection, and fluid consumption across the final stages of professional MMA competition preparation. Full article

Background/Objectives: Dental trauma is recognized as a global public health problem due to its prevalence and psychosocial consequences. This study aimed to verify the prevalence of traumatic dental injuries in practitioners of combat sports and whether they were associated with sociodemographic and sports variables in a capital city in southeastern Brazil. Methods: This cross-sectional observational study included 284 athletes over 18 years of age from 17 academies that offered combat sports. Data collection was performed by a single examiner through individual interviews and a questionnaire addressing sociodemographic profile, access to oral health services, sport modality, experience with dental trauma during combat sports, mouthguard use, and guidance on dental injuries. Descriptive analyses, frequency tables, the Chi-square test (p < 0.05), and Odds Ratio were used. Results: Most participants were male (n = 203; 71.48%), aged up to 25 years (n = 75; 26.41%). The most practiced sports were Jiu-Jitsu (n = 79; 27.82%) and Kickboxing (n = 77; 27.11%). Among participants who suffered dental trauma (n = 19; 6.69%), single episodes predominated (n = 9; 47.37%), enamel fractures were most frequent (n = 7; 36.84%), and anterior teeth were the most affected (n = 9; 47.36%). Most were not using a mouthguard at the time of trauma (n = 15; 78.95%), although they considered mouthguard use important (n = 229; 80.63%), and most had not received guidance on dental trauma (n = 237; 83.45%). Age group was significantly associated with dental trauma (p = 0.016; OR = 3.33; 95% CI: 1.167–9.524). Conclusions: The prevalence of dental trauma among fighters was low. Mouthguard adherence was inconsistent, post-trauma management was inadequate, and most respondents had never received guidance on dental trauma. Public health policies should strengthen awareness and prevention of dental injuries in sports. Full article

People want to hear stories of war. When a storyteller is the person who has fought at the forefront, audiences find the story even more engaging. For fighters who lived through traumatic experiences, life and death demand new definitions. This study uncovers the narratives through in-depth interviews with six women who fought or witnessed the civil war in Nepal to explore how such narratives transform into collective memory. Combining different methods within the thematic analysis and narrative mode for interpreting stories and utilizing research poetry as a tool for art-based analysis, this study explores how these women share their unique perceptions of the conflict in terms of violence, victory, war, peace, family and relationships. Full article

Background: Dermatophilus congolensis, a Gram-positive actinomycete, is a well-known animal pathogen but a rare cause of human skin infections. Human dermatophilosis is an infection associated with tropical environments and animal contact that remains frequently underdiagnosed. Case Presentation: We report a case of recurrent folliculitis in a 34-year-old male Muay Thai fighter returning from Thailand to Spain. The patient presented with pustular lesions on his lower limbs following frequent leg shaving and close physical contact during training. Microbiological culture from skin swabs yielded beta-hemolytic colonies, identified as D. congolensis by MALDI-TOF MS. Identification was confirmed through Whole-Genome Sequencing (WGS), which also revealed an absence of antimicrobial resistance genes. Despite the lack of established EUCAST breakpoints, the isolate showed low MICs for most tested antibiotics. The patient was treated with doxycycline, although clinical follow-up was not possible due to travel. Conclusions: This case highlights D. congolensis as an emerging differential diagnosis for persistent folliculitis in travelers and athletes. Our findings suggest a potential horizontal transmission route through contact sports and fomites (e.g., mats) in high-humidity settings. Full article

Firefighting is a high-risk occupation involving intense physical exertion and hazardous environments. Occupational exposures, including combustion byproducts, contribute to long-term cancer risk and acute burn injuries. While line-of-duty fatalities have declined, substantial morbidity remains, particularly among female and wildland firefighters who have historically been underrepresented in research. A narrative review was conducted using PubMed, Scopus, and Google Scholar to identify relevant studies published after 2010. Search terms included firefighter, fatality, injury, cardiovascular disease, occupational exposure, cancer, wildland, and female. Articles were synthesized using the NIOSH Hierarchy of Controls framework. Cardiovascular events and overexertion remain leading contributors to line-of-duty deaths, while non-fatal injuries are commonly musculoskeletal. Occupational exposures, related to dermal absorption of toxins and improper use of protective equipment, contribute to burn injuries and may increase long-term cancer risk. Wildland firefighters face risks in the expanding wildland-urban interface, such as prolonged smoke exposure and extended exertion, which may elevate cardiopulmonary and cancer risks. Female firefighters face challenges related to ergonomic mismatch with protective equipment primarily designed for male body dimensions. Firefighters face health risks from a variety of environmental and operational factors. Risk mitigation must transition from a reliance on PPE to higher-level engineering and administrative controls. Future research should prioritize longitudinal health tracking and standardized equipment for diverse fire service populations. Full article

Repetitive head impacts (RHIs) in combat and contact sports are associated with long-term neuropsychological consequences. The present study explores episodic memory performance, with a focus on pattern separation, a memory process associated with hippocampal function, in athletes characterized by different exposure profiles to RHIs. The study included 26 fighters (boxing, Mixed Martial Arts, Muay Thai), 20 rugby players, and 26 age-matched controls. Participants completed the Mnemonic Similarity Task (MST) and additional cognitive measures (Digit Span, Digit Symbol Substitution Test, Attentional Matrices, and N-back tasks). Group differences were assessed using ANCOVAs. Results indicated that fighters exhibited significantly poorer pattern separation performance compared to both rugby players and controls. Rugby players also performed worse than controls on the pattern separation measure, revealing a graded pattern of performance across groups. Additionally, fighters demonstrated slower reaction times during the MST and lower performance on the N-back tasks relative to both comparison groups. Overall, athletes participating in sports characterized by different exposure profiles to RHIs showed distinct patterns of cognitive performance, with the most pronounced differences observed in fighters. These findings highlight pattern separation as a potentially sensitive cognitive marker in athletes participating in combat and contact sports and underscore the need for longitudinal studies incorporating objective measures of head-impact exposure. Full article

This work examines a complex-valued data partition within the improved Loewner Framework to enhance the efficiency of modal parameter identification for aerospace structures. The method is applied to the General Dynamics F-16 Ground Vibration Test dataset, assessing accuracy and computational performance against the standard real-valued formulation. The complex-valued approach reduces execution time by an order of magnitude while preserving the quality of the identified poles. The extracted modal parameters align well with established benchmark results, confirming the suitability of the proposed formulation for reliable and scalable modal analysis of aircraft structures. Full article

Aerospace canopies require both high impact resistance and optical transparency for pilot safety and aerodynamic shielding. While polycarbonate (PC) and poly(methyl methacrylate) (PMMA) are widely utilized, their vulnerability to strain-rate-dependent failure during high-velocity bird strikes necessitates advanced reinforcement strategies. This study presents a multiscale computational framework for nanoparticle-reinforced PC nanocomposites. To circumvent the prohibitive computational costs of atomistic simulations, a novel Strain-Rate Dependent Micromechanics (SRDM) framework is proposed for silica-, alumina-, and zirconia-reinforced PC systems, integrating the Goldberg constitutive model with Halpin–Tsai micromechanics to generate rate-dependent stress–strain responses and calibrate Johnson–Cook (J-C) parameters for impact-scale simulations. Unlike conventional approaches relying on atomistic simulations or empirical fitting, the proposed framework directly links micromechanical nanocomposite modeling with finite element bird-strike simulations. Bird-strike analyses were performed in LS-DYNA on a generic fighter canopy model. The framework further incorporates literature-based optical transparency criteria considering nanoparticle size and refractive-index compatibility. Among the investigated nanofillers, silica-reinforced PC provided the most favorable response. At the most critical impact location, the maximum canopy deformation decreased from 118.6 mm for neat PC to 61.9 mm, corresponding to an approximately 48% reduction. Although the reinforced canopy exhibited a reduction in peak internal energy absorption from approximately 10 kJ to 5 kJ due to its increased stiffness and reduced plastic deformation, it provided improved deformation resistance and structural stability under impact loading. Overall, this work provides a computationally efficient framework for designing bird-strike-resistant transparent nanocomposite canopy structures using nanofiller systems previously reported in the literature to preserve optical transparency. Full article

Accurate aerodynamic modeling of aircraft during post-stall maneuvers remains challenging due to massive flow separation, vortex breakdown, and unsteady hysteresis. This paper presents a gray-box system identification framework that integrates a Long Short-Term Memory (LSTM) network into the physical equations of aircraft motion. Unlike black-box methods that sacrifice interpretability, the proposed architecture preserves the rigid-body Newton-Euler equations while replacing empirical aerodynamic coefficient models with an LSTM network. The LSTM directly predicts the aerodynamic coefficients, which are transformed into forces and moments via exact physical laws, ensuring hard constraint satisfaction. Validation using real flight test data from a large-scale (3/8) fighter aircraft at angles of attack up to 80° demonstrates that the method achieves regression coefficients exceeding 0.96 for all coefficients on unseen data, with near-zero mean errors. Quantitative comparisons show that the proposed method reduces prediction error by 50–70% compared to black-box LSTM and PINN baselines. The framework offers a practical balance of accuracy, interpretability, and extrapolation reliability for post-stall aerodynamic identification. Full article

Flight dynamics modeling is a fundamental cornerstone of aircraft design, simulation, and control. Traditional approaches rely on aerodynamic look-up tables for numerical integration, which suffer from high data-acquisition costs, poor extrapolation capability, and difficulty in assimilating flight test data. This paper proposes an architectural integration of physics-informed neural networks (PINNs), graph neural networks (GNNs), and known flight mechanics equations for flight dynamics modeling. Without requiring aerodynamic coefficient labels, the method predicts flight state derivatives using state-transition data. The approach encodes the structural knowledge of flight mechanics equations into graph topology and a physics computation layer (PhysicsLayer), so that the neural network only needs to learn the unknown aerodynamic coefficients while all remaining physical relationships are computed by the governing equations. Using an F-16 fighter six-degree-of-freedom model as the verification platform, an ablation study involving Direct-MLP, PINN, PIGNN, and GNN is conducted. Results show that the PIGNN architecture improves single-step derivative prediction accuracy by 86.6% over Direct-MLP, 60.9% over pure PINN, and 90.8% over GNN. In 499-step (approximately 5 s) rollout state prediction, the PIGNN Core RMSE is 1.1554, with approximately linear error growth within the first 100 steps indicating well-controlled short-range error accumulation. The graph-structural prior enables the network to learn aerodynamic coefficients that closely match the F-16 reference aerodynamic database without aerodynamic coefficient supervision. The results demonstrate that combining graph-based dependency modeling with hard physical constraints is effective for interpretable flight dynamics surrogate modeling. Full article

The increasing number of UAVs performing commercial and amateur flights necessitates the introduction of safe design principles for airborne platform architectures and UAV control algorithms. This article presents an approach to designing such solutions. UAVConfigurator is software designed for simulating the dynamics of a Commercial Off-The-Shelf (COTS) Fighter UAV airframe, developed in the MATLAB/Simulink environment. This application simplifies the design and testing of control software for unmanned systems, and is intended for use by UAV designers, researchers, and students. It serves as a Software-In-the-Loop (SIL) simulator, allowing users to build and test new algorithms in simulated environments before transitioning to real UAVs. The software accurately models UAV dynamics, as confirmed by flight tests, owing to its integration with advanced aerodynamic computations. It includes models of essential UAV components and enables users to simulate sensor failures. Additionally, it features an ISA atmosphere model. The aerodynamics model developed for the airframe enables users to conduct Hardware-In-the-Loop (HIL) simulations without requiring independent calculations of force and moment values, making it a unique tool in UAV simulation. Users also have the flexibility to modify the models of each component, including verifying system performance after using new onboard devices. The presented model allows users to design their own algorithms, coded on the Flight Computer or Mission Computer, to execute missions according to their own ideas. Full article

The Socialist Yugoslav Second World War memorials, works of large-scale memorial sculpture scattered across former Yugoslavia’s successor states, have gained international artistic recognition yet deteriorated significantly since the 1990s dissolution of the country. This deterioration has been particularly severe in Bosnia and Herzegovina, where ethnic and political divisions have complicated their commemorative value. This study employs the concept of “dissonant landscape” to reframe these memorials as integral components of a larger Yugoslav modernist cultural landscape rather than isolated problematic structures. By situating memorials within broader contexts of everyday heritage and collective memory, the framework enables complex interpretations that transcend simplistic ideological readings. The memorials, as dissonant heritage, are invested with multiple meanings by different ethnic–religious groups, and may function as catalysts for cultural dialogue and reconciliation. Methodologically, this study relies on conceptual analysis in the realm of critical heritage studies, combined with a case study of the Monument to the Fallen Fighters of the National Liberation War from Drvar, a relatively understudied memorial recently prioritized by local conservation efforts, and it includes analysis of previously unpublished archival material, field observation, interviews with local authorities and survey with the citizens of Drvar. This study establishes a new perspective on the heritage potential of Yugoslav memorials that may serve as bases of innovative preservation policies, grounded in reconciliation and cultural tourism. Full article

This paper investigates an optimal cooperative guidance strategy for the active defense of an early-warning aircraft (EWA) escorted by two fighters against an incoming missile. The proposed framework extends classical three-body defense models (Target–Missile–Interceptor) into a more realistic four-body engagement (Target–Missile–Interceptor 1–Interceptor 2), allowing explicit coordination among multiple defenders. By projecting the 3D engagement kinematics onto two orthogonal 2D planes—a validated simplification for typical aerial combat geometries—a tractable dynamic model is obtained. Within this model, an analytical cooperative guidance law is derived using optimal control theory and the calculus of variations, minimizing a multi-objective cost function that combines miss distance, control effort, intercept geometry, and coordination terms. Extensive Monte Carlo simulations across 23 attack directions and multiple initial ranges demonstrate that the proposed method achieves an interception success rate of 99%, with an average miss distance of below 5 m. Robustness tests further confirm stable performance under target maneuver uncertainty, sensor noise, and modeling deviations. The algorithm features closed-form control commands with low computational complexity, enabling real-time onboard implementation. Full article

Instrumented mouthguards (iMGs) enable in vivo monitoring of head-impact exposure by reporting event-level peak linear acceleration (PLA) and peak angular acceleration (PAA) in contact sports. This case study describes head impacts in a world-class Muay Thai fighter during routine sparring sessions over a two-week period leading into a competitive bout. Seven sparring sessions were monitored using an iMG (PROTeQT, HitIQ), and only manufacturer (in-mouth)-flagged events above the device’s 8 g trigger threshold were analyzed. Event-level data were exported from the manufacturer portal; raw time-series signals and proprietary signal-processing parameters were not accessible, and no independent video verification was performed. Across the camp, 590 impacts were recorded. Mean PLA values were modest across sessions (7.6 to 19.5 g), with one event exceeding 106 g (max PLA 162.2 g). In contrast, PAA exhibited greater variability, with multiple device-flagged events exceeding 7900 rad/s², particularly in Sessions 4, 6, and 7, where maximum PAA values reached 19,862 to 26,850 rad/s². Overall, these data indicate that sparring was predominantly low in translational loading, while occasionally producing high recorded rotational peaks. Because outputs are device- and processing-pipeline-specific and were not independently verified, threshold-based severity banding and extreme peaks should be interpreted cautiously. This case demonstrates the potential utility of iMG monitoring to characterize session-to-session variability in sparring exposure and to inform practical sparring load management strategies aimed at reducing cumulative head-impact burden. Full article

This study examined differences in finishing techniques and positional contexts across three temporal windows in the Ultimate Fighting Championship (2003–2004, 2013–2014, and 2023–2024), revealing differences consistent with a shift from greater diversity to a specialized and systematized model. Analysis of 906 finalized bouts demonstrated a marked concentration of submission finishes, with rear naked choke increasing from 15.8% to 46.8% (p ≤ 0.001), while back control was the dominant positional context (45.5%, p ≤ 0.001). In striking-based finishes, punches maintained prevalence, evolving from 77.4% (2003–2004) to 86.1% (2023–2024, p ≤ 0.001), whereas kicks declined from 20.5% to 11.3% (p ≤ 0.001). Submissions increased from 37.0% to 52.0% of all finalized bouts (p ≤ 0.001). These findings indicate a growing emphasis on specific finishing techniques, with modern mixed martial arts demonstrating increased distributional concentration in the methods used to finalize bouts. The increased frequency of certain techniques (e.g., rear naked choke and punches) among finalized fights may reflect strategic preferences, training priorities, or rule-driven changes in technique effectiveness, but cannot be interpreted as evidence of inherent technical superiority without additional data on success rates or efficiency metrics. Our data suggest that contemporary fighters have developed more direct and systematized approaches to finishing fights, reflecting the evolution of training methodologies and competitive strategies. Full article