Hellenic Naval Academy

Neurobiomarkers measured in peripheral blood can supplement management strategies following traumatic brain injury (TBI). Dual-assay of glial fibrillary acid protein (GFAP) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) is FDA-approved to inform a decision threshold approach (GFAP > 30µg.L- 1 and/or UCHL1 > 360µg.L- 1) for post-TBI neuroimaging. As physical activity and thermal strain often accompany TBI-prone activities, we investigated whether each molecule's quantification - and, by extension, clinical decisions - could be influenced by exercise-heat stress. In healthy volunteers monitored continuously for body core temperature (Tc), we used the i-STAT Alinity to assess plasma GFAP and UCHL1 responses to exercise in the laboratory (four female, eighteen male trained participants, cycling for 45min in 32°C) and field (three female and 22 male recreational marathon runners, finishing time 231 ± 34min, peak ambient temperature 11°C). Respective ΔTc overall were 1.42 ± 0.37°C and 1.87 [1.53, 2.31] °C. With laboratory exercise, GFAP and UCHL1 did not exceed the manufacturer's decision threshold. Across the marathon, GFAP was stable, whereas UCH-L1 more than doubled (200 [200, 200] vs. 462 [310, 782] µg.L-1, P < 0.0001), breaching the decision threshold for neuroimaging in 18/25 runners. Confounding from more severe exercise-heat stress should be considered when interpreting near-care assay of UCHL1 for TBI management.

Accurate humidity forecasts are crucial for environmental and operational applications, yet Numerical Weather Prediction systems frequently exhibit systematic and random errors. To address this problem, this study introduces a modified hybrid post-processing approach that extends a previously developed methodology, enabling a direct comparison of computational efficiency and predictive capacity. The proposed framework integrates a quadratic Kalman Filter with a Radial Basis Function Neural Network trained via the Orthogonal Least Squares algorithm and updated online through Recursive Least Squares. This modified method was evaluated via a time-window process, using forecasts from the Weather Research and Forecasting model and recorded observations from stations in northern Greece. The results show substantial improvements in forecast accuracy, as the Bias was reduced by over 85%, and the MAE and RMSE decreased by approximately 65% and 58%, respectively, compared with the baseline model. Furthermore, the proposed framework also demonstrates enhanced computational efficiency, reducing processing time by more than 95% relative to the initial methodology.

Negative split pacing—finishing the second half of a race faster than the first—is a hallmark of elite endurance performance and a key indicator of physiological control, fatigue resistance, and strategic pacing literacy. Rather than being an inherent talent, it represents a trainable skill integrating physiological, cognitive, and behavioral regulation. This mini review synthesizes evidence from performance analyses, physiological studies, and coaching practice to outline how negative split capacity can be systematically developed. We summarize training foundations, mesocycle design, and monitoring tools that support its acquisition. Mechanistically, successful negative splits are linked to improved lactate threshold (LT), VO2 kinetics, running economy (RE), central fatigue resistance, and pacing awareness. Practically, progression runs, split-pace long runs, and interval ladders promote these adaptations through controlled exposure to fatigue and deliberate perceptual feedback. A 6-week exemplar mesocycle illustrates how structured planning with pace anchors and feedback loops (HRV, GPS, session-RPE) refines pacing control and race execution. Psychological skills—including attentional focus, restraint, and adaptive decision-making—are essential to resist early surges and preserve finishing capacity. While negative split pacing may be constrained in short/middle-distance events, heat, altitude, or tactical racing, in endurance road events it offers a robust, learnable performance model. Overall, negative split pacing is not merely an outcome of elite talent but a trainable strategy rooted in physiology, cognition, and feedback-informed coaching. With deliberate practice and individualized monitoring, athletes across levels can enhance consistency, resilience, and race-day outcomes.

Background: Functional lumbar segmental instability (FLSI) is a clinically significant subtype of nonspecific low back pain, characterized by impaired motor control during mid-range spinal motion. Despite its prevalence, diagnostic approaches remain fragmented, and no single clinical test reliably captures its complexity. This scoping review aims to synthesize current evidence on the reliability, validity, subclassification, and predictive value of manual tests used in the evaluation of FLSI, and to identify conceptual and methodological gaps in the literature. Methods: A structured search was conducted across five databases (PubMed, Scopus, Web of Science, CINAHL, Embase) between May and August 2025. Twenty-four empirical studies and eleven foundational conceptual sources were included. Data were charted into five thematic domains: conceptual frameworks, diagnostic accuracy, reliability, subclassification models, and predictive value. Methodological appraisal was performed using QUADAS and QAREL tools. Results: The Passive Lumbar Extension Test (PLET) demonstrated the most consistent reliability and clinical utility. The Prone Instability Test (PIT) and Posterior Shear Test (PST) showed variable performance depending on protocol standardization. Subclassification models distinguishing functional, structural, and combined instability achieved high inter-rater agreement. Screening tools for sub-threshold lumbar instability (STLI) showed preliminary feasibility. Predictive validity of manual tests for rehabilitation outcomes was inconsistent, suggesting the need for multivariate models. Conclusions: Manual tests can support the clinical evaluation of FLSI when interpreted within structured diagnostic frameworks. Subclassification models and composite test batteries enhance diagnostic precision, but standardization and longitudinal validation remain necessary. Future research should prioritize protocol harmonization, integration of sensor-based technologies, and stratified outcome studies to guide individualized rehabilitation planning.

Abstract Background The purpose of this study was to examine the impact of Life Kinetik (LK) exercises on balance, agility, jumping performance, proprioception, and cognitive functions in recreationally active preadolescents participating in fencing. Methods The study lasted 8 weeks and included 22 preadolescents recreationally engaged in fencing, aged 11.6 ± 1.2 years, with an average weight of 49.5 ± 10.5 kg and an average height of 157.5 ± 10.0 cm. Preadolescents were randomly assigned to either the LK group or the control group. The experimental group participated in LK exercises twice per week, with each session lasting one hour. Results The results indicate that the changes in Stroop, agility, vertical jump, and proprioception test performance between the pre-test and post-test for the control group are not statistically significant. However, the LK group showed statistically significant improvements in Stroop, agility, and vertical jump performance between the pre-test and post-test (p &lt; 0.001). Conversely, the change in proprioception test performance between the pre-test and post-test for the LK training group was not statistically significant. The changes in star balance test performance between the pre-test and post-test for the control group was not statistically significant. In contrast, the LK group showed a statistically significant improvement in star balance test performance between the pre-test and post-test (p &lt; 0.001). Conclusions These findings indicate that while LK exercises are effective in boosting overall athletic performance, they may not be sufficient for developing specific skills such as proprioception. Trial registration: The randomized controlled trial was registered on 04/01/2025 at ClinicalTrials.gov, under the registration number NCT06781268.

The current work proposes the incorporation of an artificial neural network to solve the Gross–Pitaevskii equation (GPE) efficiently, using a few realistic external potentials. With the assistance of neural networks, a model is formed that is capable of solving this equation. The adaptation of the parameters for the constructed model is performed using some evolutionary techniques, such as genetic algorithms and particle swarm optimization. The proposed model is used to solve the GPE for the linear case (γ=0) and the nonlinear case (γ≠0), where γ is the nonlinearity parameter in GPE. The results are close to the reported results regarding the behavior and the amplitudes of the wavefunctions.

In this paper, we investigate the dependence of the resonant carrier transport in an AlGaAs/GaAs double-barrier heterostructure on the electron’s effective mass discontinuity between the well and the barrier layer. We use a one-dimensional model for the effective potential and consider the activation of the resonant tunneling mechanism when a bias is applied between the emitter and the collector. We calculate the system’s Green’s function through semiclassical path integration to obtain the complex spectrum. Electron’s effective mass discontinuity affects our calculations through the contributions of the various propagations inside the heterostructure and the multiple reflections from the turning points. Our findings show that the lowest resonance energy decreases linearly with increasing bias, while the real energy shift of the resonance decreases in a non-linear manner with the mass discontinuity. We also observe that the resonant transport time increases nearly linearly with the mass discontinuity. These results demonstrate the impact of the carrier’s inertia enhancement on the resonance characteristics and are consistent with established concepts in quantum mechanics and previously published works. Furthermore, we identify a critical bias value that distinguishes the behavior of the symmetric and asymmetric heterostructure. Additionally, the derivative of the transport time with respect to mass discontinuity is found to be independent of the applied bias. Our results provide concise analytical relationships involving parameters such as barrier and well thickness and shape, enabling the prediction and optimization of various nanoscale devices’ performance.

Authoritarian Populism and the Challenges for News Journalism: A Discourse Approach is a cutting‑edge study of the practices of news journalism against the background of surging authoritarian populism. This book traces key challenges for news journalism when reporting on authoritarian populism or on topics (such as immigration and terrorism) that are typically leveraged by far‑right actors and platforms as a way of attracting media attention and boosting their popularity with national electorates. It also offers in‑depth analyses of how these challenges are responded to by news journalists in the actual, day‑to‑day practices of news production, as evidenced in the discourse of news. By placing qualitative, critical analysis of discourse at the heart of the systematic inquiry into authoritarian populism in the news media, this book applies a broad methodological framework for studying (a) political performances and their mediated representations, (b) the complex and, often contradictory, normalizing processes at work in the news media, and (c) the attendant challenges and critical tasks for contemporary news journalism. Based on detailed analyses of political and news discourse in various European contexts, and in the US, spanning a decade (2014–2024), this book makes a timely and relevant contribution – as liberal democracies could be facing a new turning point in the global rise of authoritarian populism. This book will be of interest to students and scholars of journalism, media studies, political communication, political science, sociology, and discourse studies who are interested in authoritarian and far‑right populism, related discourses of nationalism and xenophobia, populist communication, and the role of news media and journalism. The Open Access version of this book, available at https://www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND) 4.0 license.