WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394

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  • Article
    Widening the Moral Circle: Perceived Responsibility and Guilt as Mediators of Moral Expansiveness and pro-Environmental Behavior
    (Springer, 2026) Sari, Erkin; Coskun, Muhammet; Cingoz-ulu, Banu; Candanoglu, Inci
    Previous research has shown that moral constructs, such as personal norms, play a significant role in shaping individuals' pro-environmental engagement. However, the specific influence of moral expansiveness on such behaviors has received limited attention in the existing literature. This study aims to investigate the relationship between moral expansiveness and pro-environmental engagement within the Turkish context, which is particularly vulnerable to the impacts of climate change. It specifically examines the mediating roles of perceived environmental responsibility and environmental guilt to better understand the mechanisms underlying this association. In total, 244 undergraduate students (167 women, 76 men, 1 did not state; Mage = 21.95, SDage = 2.58) participated in the current study in exchange for course credit. Findings indicated that moral expansiveness indirectly predicted pro-environmental behaviors through both perceived environmental responsibility and environmental guilt, although its direct effect was not significant. Perceived environmental responsibility and environmental guilt both significantly predicted pro-environmental behaviors. Additionally, individuals with more left-leaning political views reported higher levels of pro-environmental behavior. This study highlights how broader moral concern can support sustainability, while contributing to the inclusion of non-Western contexts in environmental psychology.
  • Article
    Enhanced Mg–Zn–Ca Alloys Reinforced with Rare Earth Oxides for Biomedical Applications: Experimental Insights and ANFIS-Based Modeling
    (Springer, 2026) Mozafari, Farzin; Deka, Surja; Mallick, Ashis
    To enhance the corrosion resistance, biocompatibility, tribological, and mechanical properties of magnesium (Mg) alloys intended for biomedical implants, a new approach utilizing a microwave-sintered in situ hot extrusion-based powder metallurgy process was used to develop Mg-4Zn-0.5Ca/xCeO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} (x = 0.5, 1, and 1.5 vol%) nanocomposites. The introduction of ceria nanoparticles (CONPs) has improved the compression characteristics of the nanocomposites in comparison with the monolithic Mg, and the ternary base alloy. The corrosion test results revealed that the alloy and nanocomposites promoted the formation of the magnesium hydroxide (Mg(OH)2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document}) and hydroxyapatite (HA) layers on the sample surface. Among all samples, Mg-4Zn-0.5Ca /1.0CeO2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_2$$\end{document} demonstrated the lowest corrosion rate. In vitro cytocompatibility assessments were conducted through an extract assay method for different time periods, employing MG-63 cells. The developed alloy and nanocomposites demonstrated no harmful effects on MG-63 cells. An investigation into the dry sliding tribological characteristics of the alloy and nanocomposites at varied loads revealed several wear mechanisms, including abrasion, adhesion, delamination, oxidation, and plastic deformation. The addition of CONPs significantly enhanced the wear resistance of the nanocomposites. Our results provide a new venue to enhance the biocompatibility and in vitro degradation behavior of well-established Mg-Zn-Ca alloys, with a particular focus on the mechanical integrity of the developed samples for their clinical usage. An Adaptive Neuro-Fuzzy Inference system (ANFIS)-based modeling approach was also developed to individually characterize nanocomposite corrosion, cell viability, and wear behavior. The predictions offer compelling evidence of the reliability and accuracy of the proposed modeling strategy.
  • Article
    Alexithymia, Rumination and Binge Drinking: The Mediating Role of Drinking Motives
    (Springer, 2026) Sokmez, Asli Bugay; Coskun, Muhammet; Alpay, Pelin; Kovács, Lilla Nóra; Kocsel, Natália; Kökönyei, Gyöngyi
    The objective of this study was to investigate whether the relationship between alexithymia and rumination, reflecting deficits in emotion processing and difficulties in emotion regulation, and binge drinking is mediated by drinking motives. A cross-sectional study was conducted with university students (N = 367, Mage = 22.38) who reported alcohol use in the past 30 days. Participants completed an online questionnaire comprising the Toronto Alexithymia Scale, the Alcohol Use Disorders Identification Test, the Drinking Motives Questionnaire, the Ruminative Response Scale, and the UPPS Impulsive Behaviour Scale. Binge drinking in the past 30 days was measured with a single item. The results of the mediation analyses indicated that the Difficulties in Identifying Feelings (DIF) component of alexithymia was directly related to risky drinking indexed by binge drinking in the past 30 days or the Alcohol Use Disorders Identification Test (AUDIT). The relationship between the DIF and the AUDIT was mediated by coping motives. Additionally, social motives mediated the relationship between reflection and binge drinking, while coping motives mediated the relationship between brooding and AUDIT, as well as between reflection and AUDIT. These findings confirm the importance of investigating emotion regulation as a proximal factor of risky drinking.
  • Article
    Prosocial Behavior as Bridge and Buffer: Exploring Its Dual Role between Stress and Mental Health in Emerging Adults
    (Springer, 2026-03-16) Coskun, Muhammet; Arslan, Gokmen; Genc, Emel; Caprara, Gian Vittorio
    The present study investigated the dual role of prosocial behavior among emerging adults in a non-Western cultural con-text. Within this scope, first, adaptation and validation of the Adult Prosocialness Behavior Scale (PBS) was carried out for Turkish population. Then, it tested both mediating and moderating functions of prosocial behavior in the links from stress to subjective wellbeing (SWB) and quality of life. To this end, a sample of 419 emerging adults (41.3% males and 58.7% females) completed an online survey. Results revealed Turkish version of the APBS to be a reliable and valid mea-surement tool for assessing prosocial behavior. Regarding the main hypotheses, serial multiple mediation analysis revealed that perceived stress predicted quality of life through the sequential pathway of prosocial behavior and SWB. Additionally, the moderated-mediation analysis confirmed the moderating role of prosocial behavior in the relationship between stress. Nevertheless, moderated mediation index did not reveal a significant conditional indirect effect of prosocial behavior for the indirect path from stress on quality of life through SWB. Overall, findings suggest that prosocial behavior plays a dual role as both a 'bridge' (mediator) and a 'buffer' (moderator) in the relationship between stress and mental health.
  • Article
    Environmental Sustainability in Fragile States: The Role of Corruption Control, Political Stability, and Household Consumption in Somalia
    (Springer, 2026-03-28) Mohamed, Amir Mohamud; Warsame, Abdimalik Ali; Dirie, Khadar Ahmed
    The maintenance of environmental sustainability represents a worldwide pressing issue, especially for Somalia as an emerging nation that deals with environmental degradation because of unstable political leadership combined with corruption and financial limitations. This study analyzes the impact of corruption control, political stability, and household consumption on environmental degradation in Somalia. The study employs the kernel regularized machine learning method (KRLS) and a time-varying Granger causality approach. The KRLS addresses regression and classification tasks without depending on assumptions of linearity or additivity, whereas the time-varying Granger causality fixes instabilities caused by structural breaks, regime shifts, and provides a cause-effect relationships for specific years. The empirical results of the KRLS indicate that corruption control enhances environmental quality by reducing environmental degradation, whereas household consumption impedes it. Additionally, political stability has no discernible impact on environmental degradation. The time-varying Granger causality result revealed no significant causality from corruption control to environmental degradation in the forward and rolling windows. Two episodes of Granger causalities (2009-2011 and 2013-2016) are observed from corruption control to environmental degradation, and one episode of causality (2001-2004) from political stability to environmental degradation was detected in the recursive result. Finally, four episodes of causalities (2005-2007, 2008-2011, and 2014-2015) are observed from household consumption to environmental degradation in Somalia in the recursive result. This could be justified by the fact that climate consequences-droughts and floods-inhibit livelihood sources such as livestock and agriculture. Hence, people put pressure on forests in search of alternative income sources. Nevertheless, the study delivers practical recommendations to policymakers about using governance structures and economic decisions along with institutional mechanisms for creating sustainable environmental practices.
  • Article
    Enhanced Photoluminescence via Plasmonic Gold Nanoparticles and Improved Stability of Perovskite Nanocrystals in Macroporous (Polydimethylsiloxane) PDMS Matrices
    (Springer, 2025-10-09) Ocal, Sema Karabel; Tiras, Kevser Sahin; Onses, M. Serdar; Mutlugun, Evren
    In this work, we report a simple and cost-effective method for improving both the environmental stability and photoluminescence quantum efficiency (PLQY) of perovskite nanocrystals (PNCs). Through their embedding in a specially designed macroporous polydimethylsiloxane (MPDMS) matrix and incorporation of plasmonic gold nanoparticles (Au NPs), remarkable improvements are achieved. The resulting MPDMS@PNC composites are seen to retain near-unity quantum efficiency even after 24-h immersion in water and are observed to retain over 85% of the original efficiency even at 75 degrees C, displaying excellent thermal stability. More interestingly, by incorporating Au NPs and subjecting the material to mechanical pressure, the lifetime of the PNCs gets further increased. This is due to the more intimate spatial arrangement of Au NPs in the porous matrix, enhancing localized surface plasmon resonance (LSPR) coupling and thereby enhancing the photoluminescence (PL) of the PNCs. In general, this approach offers a scalable and robust route to designing stable, high-performance perovskite-based materials for next-generation optoelectronic applications.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Pangenome Analysis and Genome-Guided Probiotic Evaluation of Cyclic Dipeptides Producing Levilactobacillus Brevis DY55bre Strain From a Lactic Acid Fermented Shalgam to Assess Its Metabolic, Probiotic Potentials, and Cytotoxic Effects on Colorectal Cancer Cells
    (Springer, 2025-10-01) Yetiman, Ahmet E.; Horzum, Mehmet; Kanbur, Ertan; Cadir, Mehmet; Bahar, Dilek; Gurbuz, Serife; Akbulut, Mikail
    This study investigates the genetic, metabolic, and probiotic characteristics of Levilactobacillus brevis DY55bre, a strain isolated from the traditional Turkish fermented beverage, shalgam. Whole-genome sequencing revealed a circular genome of 2.485 Mb with a GC content of 45.72%, predicted 2791 genes, and multiple CRISPR-Cas systems. Pangenome analysis demonstrated an open structure, with 18.9% core genes and 103 strain-specific genes, highlighting its genetic diversity. The DY55bre exhibits heterofermentative carbohydrate metabolism due to the presence of the araBAD operon and the lack of 1-phosphofructokinase (pfK) and fructose-1,6-bisphosphate aldolase enzymes. Probiotic evaluation revealed firm survival under simulated gastrointestinal conditions, including resistance to acidic pH (as low as 3.0) and bile salts (up to 1%), along with significant adhesion to intestinal epithelial cell lines (HT29;59.3%, Caco-2;87%, and DLD-1;60.8%). The strain exhibited high auto-aggregation (84.55%) and cell surface hydrophobicity (56.69%), essential for gut colonization. Safety assessments confirmed its non-hemolytic nature and absence of horizontally acquired antibiotic resistance genes. Notably, GC-MS analysis identified bioactive cyclic dipeptides, Cyclo(D-Phe-L-Pro) and Cyclo(L-Leu-L-Pro), which demonstrated cytotoxic effects against colorectal cancer cell lines, with IC50 values of 7.71 mg/mL for HT29 and 3.19 mg/mL for DLD-1. The cell-free supernatant exhibited antimicrobial activity against pathogens, likely due to the synergistic effects of cyclic dipeptides, organic acids, and other metabolites. Antioxidant assays revealed significant ABTS+ (76.63%) and DPPH (34.25%) radical scavenging activities, while cholesterol assimilation tests showed a 27.29% reduction. These findings position the DY55bre as a promising candidate for functional foods, nutraceuticals, and therapeutic applications, warranting further in vivo validation.
  • Conference Object
    Citation - WoS: 50
    Citation - Scopus: 56
    You May Not Reap What You Sow: How Employees' Moral Awareness Minimizes Ethical Leadership's Positive Impact on Workplace Deviance
    (Springer, 2017-08-02) Gok, Kubilay; Sumanth, John J.; Bommer, William H.; Demirtas, Ozgur; Arslan, Aykut; Eberhard, Jared; Yigit, Ahmet
    Although a growing body of research has shown the positive impact of ethical leadership on workplace deviance, questions remain as to whether its benefits are consistent across all situations. In this investigation, we explore an important boundary condition of ethical leadership by exploring how employees' moral awareness may lessen the need for ethical leadership. Drawing on substitutes for leadership theory, we suggest that when individuals already possess a heightened level of moral awareness, ethical leadership's role in reducing deviant actions may be reduced. However, when individuals lack this strong moral disposition, ethical leadership may be instrumental in inspiring them to reduce their deviant actions. To enhance the external validity and generalizability of our findings, the current research used two large field samples of working professionals in both Turkey and the USA. Results suggest that ethical leadership's positive influence on workplace deviance is dependent upon the individual's moral awareness-helpful for those employees whose moral awareness is low, but not high. Thus, our investigation helps to build theory around the contingencies of ethical leadership and the specific audience for whom it may be more (or less) influential.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    Whether and When Did Bitcoin Sentiment Matter for Investors? Before and During the COVID-19 Pandemic
    (Springer, 2023-12-21) Aysan, Ahmet Faruk; Mugaloglu, Erhan; Polat, Ali Yavuz; Tekin, Hasan
    Using a wavelet coherence approach, this study investigates the relationship between Bitcoin return and Bitcoin-specific sentiment from January 1, 2016 to June 30, 2021, covering the COVID-19 pandemic period. The results reveal that before the pandemic, sentiment positively drove prices, especially for relatively higher frequencies (2-18 weeks). During the pandemic, the relationship was still positive, but interestingly, the lead-lag relationship disappeared. Employing partial wavelet tools, we factor out the number of COVID-19 cases and deaths and the Equity Market Volatility Infectious Disease Tracker index to observe the direct relationship between a change in sentiment and return. Our results robustly reveal that, before the pandemic, sentiment had a positive effect on return. Although positive coherence still existed during the pandemic, the lead-lag relationship disappeared again. Thus, the causal relationship that states that sentiment leads to return can only be integrated into short-term trading strategies (up to six weeks frequency).
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Thermal Conductivity and Interfacial Energy of Solid Bi in the Bi-Ag Eutectic System
    (Springer, 2015-05-15) Altintas, Yemliha; Ozturk, Esra; Aksoz, Sezen; Keslioglu, Kazim; Marasli, Necmettin; Maraşlı, Necmettin; Keşlioğlu, Kâzım; Altıntas, Yemliha; Keşlioğlu, Kazım
    The equilibrated grain boundary groove shapes for solid Bi (Bi-2.87 at.%Ag) in equilibrium with Bi-Ag eutectic liquid have been observed from quenched sample with a radial heat flow apparatus. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of solid Bi have been determined from the observed grain boundary groove shapes. The variation of thermal conductivity with temperature for eutectic solid phase (Bi-4.7 at.%Ag) has been measured. The ratio of thermal conductivity of equilibrated eutectic liquid phase to eutectic solid phase has also been measured with a Bridgman-type growth apparatus at the melting temperature. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of solid Bi in equilibrium with Bi-Ag eutectic liquid were determined to be (9.2 +/- A 0.6) x 10(-8) K m, (52.7 +/- A 6.3) x 10(-3) J m(-2) and (102.4 +/- A 13.3) x 10(-3) J m(-2), respectively, from observed grain boundary groove shapes.