İstanbul Galata Üniversitesi Kurumsal Akademik Arşivi
DSpace@Galata, İstanbul Galata Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Psychological Flexibility and Academic Self-Efficacy
(Hogrefe AG, 2026) Aksoy, Şeyhmus; Konuk, Ayşe; Alkhulayfi, Abdulmohsen Mohammed Abdullah; Gomez-Salgado, Juan; Yıldırım, Murat
Introduction: Despite the beneficial effects of academic self-efficacy, there is a relatively limited focus on the academic self-efficacy of higher education students compared to studies on student self-efficacy in other educational stages. Aim: The present study employs a moderated mediation model to investigate whether well-being literacy mediates the relationship between psychological flexibility and academic self-efficacy, while also exploring how burnout-driven selfstigma is associated with these direct and indirect relationships. Methods: A cross-sectional research design was employed in the present study. The sample comprised 316 students (82.6% female; M = 22.28, SD = 3.38). Participants completed the Academic Self-Efficacy Scale, the Psychological Flexibility Scale, the Well-Being Literacy Scale, and the Burnout-Driven Self-Stigma Scale. Results: Our study indicated that psychological flexibility was associated with reduced academic selfefficacy both directly and indirectly through well-being literacy. However, conditional direct and indirect effect results suggested that higher levels of burnout-driven self-stigma were related to decreased positive direct and indirect effects. Discussion/Conclusion: This study provides evidence to improve our understanding of how psychological flexibility relates to academic self-efficacy. While research on burnout-related self-stigma and well-being literacy remains limited, this study highlights how these variables were examined within the proposed model as potential moderator and mediator constructs.
Asynchronous recovery of medial and lateral gastrocnemius mechanical properties and jump performance following localized plantar flexor fatigue
(BMC, 2026) Şahbaz, Yasemin; İlez, Ali; Batur, Nergiz
Objective: To investigate the acute and short-term (24 h) effects of localized plantar flexion fatigue on muscle mechanical properties, countermovement jump (CMJ) kinetics, and dynamic balance, focusing on recovery profiles of the gastrocnemius medialis (MG) and lateralis (LG). Design: Prospective, repeated-measures experimental study. Methods: Twenty-eight healthy volunteers (n = 28) performed a standardized unilateral isometric plantar flexion fatigue protocol until task failure (Borg CR-10 ≥ 8). Assessments were conducted at baseline, immediately post-fatigue, and 24 h post-fatigue (24 h). Outcomes included myotonometric properties (tone, stiffness, elasticity, relaxation time, and creep) of the MG and LG via MyotonPRO, CMJ kinetics via force plate, and dynamic balance via the Modified Star Excursion Balance Test (mSEBT). Results: Significant Time × Region interactions were found for stiffness (P = 0.038, ηp² = 0.276) and relaxation time (P = 0.024, ηp² = 0.171). Both muscle heads showed an acute decrease in stiffness (P < 0.001); however, LG stiffness recovered by 24 h (P = 0.330), while MG stiffness remained reduced (P < 0.05). Although CMJ height recovered at 24 h (P = 0.842), eccentric and braking phase durations remained prolonged (P < 0.001; ηp² = 0.357 and ηp² = 0.264), indicating altered neuromuscular strategies. For dynamic balance, a delayed impairment was observed in anterior reach distance, which declined only at 24 h compared to baseline (P = 0.021, ηp² = 0.133). Conclusion: Localized plantar flexion fatigue induces region-specific mechanical alterations and asynchronous recovery. Restoration of jump height at 24 h masks persistent deficits in eccentric phase durations and MG stiffness. These findings highlight a “neuromuscular vulnerability window” at 24 h post-fatigue, where delayed impairments in MG mechanics and anterior stability may increase potential susceptibility to injury despite apparent recovery. Practically, monitoring head-specific muscle mechanics, rather than global performance outcomes, is critical during this 24 h window to optimize training modification and guide objective return-to-play decisions. Trial registration: NCT07457398 (Registration date: February 25, 2026). © The Author(s) 2026.
Classification of malignant/benign groups in lung cancer by machine learning and investigation of feature significance of parameters
(Walter de Gruyter GmbH, 2026) Çalışkan, Gönül; Alataş, Emre; Köksal, Sevilay; Akyel, Reşit; Çavdar, İffet; Alçin, Göksel; Arslan, Esra; Çiftçi-Küsbeci, Tuba; Dereli, Elçin; Akgün, Elif; Tanyıldızı-Kökkülünk, Handan; Yiğit, Şafak
This study aimed to apply machine learning (ML) models to enhance lung cancer (LC) classification, distinguishing malignant from benign tumors, using data from 73 patients. The dataset included PET/CT biomarkers and demographic factors, with SMOTE applied to address class imbalance. Three models were evaluated using 10-fold cross-validation to compare Random Forest (RF), Decision Tree (DT), Extra Trees Classifier (ETC), and XGBoost algorithms based on accuracy and AUC. ETC performed best in Model 1 (86% accuracy, AUC 0.95), RF in Model 2 (94% accuracy, AUC 0.97), and XGBoost in Model 3 (94% accuracy, AUC 0.98). XGBoost consistently outperformed others, particularly in Model 3, which included age and smoking. Feature importance analysis highlighted SUVmax as the most predictive variable, with smoking having a moderate influence and gender being minimal. Integrating clinical and lifestyle data with PET/CT parameters significantly improved LC classification. XGBoost emerged as the most effective model, demonstrating that comprehensive models enhance diagnostic accuracy beyond traditional metrics. © 2026 the author(s), published by De Gruyter, Berlin/Boston.
Are sacral stress fractures in young women truly rare? a retrospective MRI analysis of 1970 patients
(BMC, 2026) Bayram, Yusuf; Doğan, Selman; Yalvaç, Bestami; Aksoy, Süleyman Hilmi; Karataş, Muhammed Enes
Background Sacral stress/insufficiency fractures (SSFs) are underrecognized causes of postpartum low-back/pelvic pain and are frequently misattributed to lumbar disc disease. To determine the MRI-based detection rate and clinical/ imaging characteristics of SSFs in women aged 18–50 years undergoing lumbosacral MRI, with subgroup analyses for postpartum versus non-postpartum status. Methods Retrospective review of 2400 lumbosacral MRI examinations (January 2020–December 2024) corresponding to 1970 unique women. SSFs were identified by a fellowship-trained musculoskeletal radiologist. Prespecified exclusions (chronic corticosteroid use, major pelvic trauma, incomplete follow-up) yielded the analytic cohort. Group comparisons reported effect sizes (Hedges’ g for continuous; risk difference [RD]/odds ratio [OR] for binary) with 95% CIs. Results Crude MRI-based detection rate: 1.52% (30/1,970; 95% CI, 1.07–2.17); analytic MRI-based detection rate: 1.17% (23/1,970; 95% CI, 0.78–1.75). Median age 34 years (range 22–49); 10/23 (43.5%) postpartum. Five cases (21.7%) were initially misdiagnosed. Fractures most often involved the sacral ala (right 12, left 10, bilateral 1). Compared with non-postpartum patients, postpartum patients had lower hemoglobin (**11.5 vs 12.6 g/dL; p = 0.007; Hedges’ g = 1.21, 95% CI 0.34–2.09) and hematocrit (**33.9% vs 37.3%; p = 0.007; g = 1.21, 95% CI 0.34–2.09); vitamin D was lower but nonsignificant (**15.4 vs 20.3 ng/mL; p = 0.204; g = 0.53, 95% CI − 0.28–1.34). Overall vitamin D status (n = 21): deficient < 20 ng/mL 11/21 (52.4%), insufficient 8/21 (38.1%), sufficient ≥ 30 ng/mL 2/21 (9.5%). The reported frequency reflects an MRI-based detection rate within a selected cohort of symptomatic women undergoing lumbosacral MRI and should not be interpreted as the true population prevalence of sacral stress fractures. Conclusion Sacral stress fractures in young women, particularly in the postpartum period, may be underrecognized in symptomatic patients presenting with persistent lo
The relationship between income inequality and energy poverty in the context of sustainable development goals: A micro-instrumental variables estimation in Türkiye
(Elsevier, 2026) Günay, Simge; Kayacan, Bekir; Uçal, Meltem
Energy poverty has adverse consequences on individuals’ lives. It endangers their health, interrupts their education, and may even undermine equality both within and between them. Since income inequality remains a significant problem on the path to achieving sustainable development in Türkiye, identifying its determinants on a micro scale is of great importance. In this regard, this study analysed the relationship of energy poverty to personal income inequality in Türkiye, utilising the TurkStat 2017-2020 income and living conditions survey micro-panel dataset. Instrumental variables estimation was used, and robustness checks were applied to achieve this aim. According to this, energy poverty is negatively related to personal income inequality. To check for heterogeneity, this relationship was re-examined within three income groups. The findings suggested that while energy poverty is positively related to personal income inequality at the bottom of the income distribution, it is negatively related to personal income inequality at the top of the income distribution. This study mainly contributes to the literature by providing the first micro-level evidence on the relationship between income inequality and energy poverty. A combination of targeted social and energy policies is required to tackle both energy poverty and income inequality on the micro scale in Türkiye.
