Solution of Massless Spin One Wave Equation in Robertson-Walker Space-time

We generalize the quantum spinor wave equation for photon into the curved space-time and discuss the solutions of this equation in Robertson-Walker space-time and compare them with the solution of the Maxwell equations in the same space-time.Comment: 16 Pages, Latex, no figures, An expanded version of paper published in International Journal of Modern Physics A, 17 (2002) 113

Metacognitions and emotion recognition in Internet Gaming Disorder among adolescents

© 2020 The Author(s) Internet Gaming Disorder (IGD) is associated with considerable psychological distress in adolescents. However, studies which strive to shed light on the developmental background of IGD are still sparse. We aimed to examine the role of metacognitions and emotion recognition in predicting IGD during the early adolescence period. Four hundred and seventy-seven secondary school students were recruited for the study. Participants completed the Internet Gaming Disorder Test (IGDT), the Metacognitions Questionnaire for Children (MCQ-C), and the Children's Version of Reading the Mind in the Eye Test (RMET). Correlation analyses indicated that three factors of the MCQ-C (positive meta-worry, negative meta-worry, and superstition, punishment, and responsibility) and its total score were positively correlated with the majority of factors of the IGDT. The negative factor of the RMET was positively correlated with the salience, tolerance, and relapse factors and total score of the IGDT. Daily internet use was positively correlated with all factors of the IGDT and its total score. Hierarchical regression analyses indicated that daily internet use and metacognitions (in different combinations) were significant independent predictors of IGDT factors and its total score, and that the negative factor of the RMET was a significant independent predictor of the salience and tolerance factors of IGDT and its total score. The implications of these findings are discussed

Genetic diversity and population structure of Turkish native cattle breeds

Cattle are an important livestock species for human life, but certain breeds are at risk of extinction. Maintaining genetic diversity plays an important role in sustainable breeding and conservation programmes in farm animals. The aim of this study was to determine genetic diversity among five Turkish native cattle breeds. A total of 199 Turkish native cattle of the Native Southern Yellow (n = 40), South Anatolian Red (n = 40), Anatolian Grey Cattle (n = 40), Native Black Cattle (n = 39) and East Anatolian Red (n = 40) breeds were investigated using 22 autosomal microsatellite markers. The analysis revealed considerable genetic variation among these breeds. All loci were polymorphic, and a total of 545 alleles were found. Among these loci, only INRA032 was at Hardy-Weinberg equilibrium. Thirty-four private alleles with frequencies greater than 5% were found. Expected heterozygosity and polymorphic information content indexes were 0.87 and 0.88, respectively. Native Southern Yellow, South Anatolian Red and Native Black Cattle breeds were closely related.Keywords: animal genetic resources, microsatellite, genetic relationship, genetic conservatio

The role of desire thinking in the problematic use of social networking sites among adults.

The problematic use of social networking sites (SNS) is associated with several psychiatric disorders. This behavior closely resembles addiction in terms of neurological basis and behavioral patterns. Nevertheless, successful intervention strategies and the etiology of problematic SNS use are not yet thoroughly investigated. We aimed to study whether desire thinking is associated with problematic SNS use among adults when controlling for some confounders, including boredom, affect, and impulsivity. With the help of convenience sampling, we enrolled 546 Turkish adults in this study to whom we administered a sociodemographic form, the Social Media Addiction Scale (SMAS), the Leisure Boredom Scale (LBS), the Positive and Negative Affect Schedule (PANAS), the Barratt Impulsiveness Scale (BIS-11), and the Desire Thinking Questionnaire (DTQ). To explore the association between the variables, we performed Pearson correlational and hierarchical regression analyses. The results showed that higher scores on two sub-dimensions of desire thinking, namely verbal perseveration and imaginal prefiguration, were associated with higher scores on problematic SNS use after we controlled for boredom, affect, and impulsivity. This study demonstrates that desire thinking may play a role in problematic SNS use among adults. We recommend targeting desire thinking as a potential area in treatments which may help alleviate problematic SNS use. [Abstract copyright: © 2022 The Authors. Published by Elsevier Ltd.

Electronic structures and optical spectra of thin anatase TiO2 nanowires through hybrid density functional and quasiparticle calculations

The electronic properties of quasi-one-dimensional anatase TiO2 nanostructures, in the form of thin nanowires having (101) and (001) facets, have been systematically investigated using the standard, hybrid density functional and quasiparticle calculations. Their visible photoabsorption characteristics have also been studied at these levels of theories. The thin stoichiometric nanowire models are predicted to have larger band gaps relative to their bulk values. The band-gap-related features appear to be better described with the screened Coulomb hybrid density functional method compared to the standard exchange-correlation schemes. Depending on the self-consistency in the perturbative GW methods, even larger energy corrections have been obtained for the band gaps of both (101) and (001) titanium dioxide nanowires. © 2014 American Physical Society

Anatase TiO2 nanowires functionalized by organic sensitizers for solar cells: A screened Coulomb hybrid density functional study

The adsorption of two different organic molecules cyanidin glucoside (C21O11H20) and TA-St-CA on anatase (101) and (001) nanowires has been investigated using the standard and the range separated hybrid density functional theory calculations. The electronic structures and optical spectra of resulting dye-nanowire combined systems show distinct features for these types of photochromophores. The lowest unoccupied molecular orbital of the natural dye cyanidin glucoside is located below the conduction band of the semiconductor while, in the case of TA-St-CA, it resonates with the states inside the conduction band. The wide-bandgap anatase nanowires can be functionalized for solar cells through electron-hole generation and subsequent charge injection by these dye sensitizers. The intermolecular charge transfer character of Donor-π-Acceptor type dye TA-St-CA is substantially modified by its adsorption on TiO2 surfaces. Cyanidin glucoside exhibits relatively stronger anchoring on the nanowires through its hydroxyl groups. The atomic structures of dye-nanowire systems re-optimized with the inclusion of nonlinear solvation effects showed that the binding strengths of both dyes remain moderate even in ionic solutions. © 2015 AIP Publishing LLC

Two solar eclipses observations in Turkey

In thispap er, the changesin the ionosphere over Turkey due to two solar eclipses are reported. TEC on the eclipse day (26 April 1976) and the intensity of an HF radio wave during itspropagation over 567 km between Ankara and Elazıˇg on the eclipse day (11 August 1999) exhibited a very marked decrease

Exact Solution of Photon Equation in Stationary G\"{o}del-type and G\"{o}del Space-Times

In this work the photon equation (massless Duffin-Kemmer-Petiau equation) is written expilicitly for general type of stationary G\"{o}del space-times and is solved exactly for G\"{o}del-type and G\"{o}del space-times. Harmonic oscillator behaviour of the solutions is discussed and energy spectrum of photon is obtained.Comment: 9 pages,RevTeX, no figure, revised for publicatio

LES-based Study of the Roughness Effects on the Wake of a Circular Cylinder from Subcritical to Transcritical Reynolds Numbers

This paper investigates the effects of surface roughness on the flow past a circular cylinder at subcritical to transcritical Reynolds numbers. Large eddy simulations of the flow for sand grain roughness of size k/D = 0.02 are performed (D is the cylinder diameter). Results show that surface roughness triggers the transition to turbulence in the boundary layer at all Reynolds numbers, thus leading to an early separation caused by the increased momentum deficit, especially at transcritical Reynolds numbers. Even at subcritical Reynolds numbers, boundary layer instabilities are triggered in the roughness sublayer and eventually lead to the transition to turbulence. The early separation at transcritical Reynolds numbers leads to a wake topology similar to that of the subcritical regime, resulting in an increased drag coefficient and lower Strouhal number. Turbulent statistics in the wake are also affected by roughness; the Reynolds stresses are larger due to the increased turbulent kinetic energy production in the boundary layer and separated shear layers close to the cylinder shoulders.We acknowledge “Red Española de Surpercomputación” (RES) for awarding us access to the MareNostrum III machine based in Barcelona, Spain (Ref. FI-2015-2-0026 and FI-2015-3-0011). We also acknowledge PRACE for awarding us access to Fermi and Marconi Supercomputers at Cineca, Italy (Ref. 2015133120). Oriol Lehmkuhl acknowledges a PDJ 2014 Grant by AGAUR (Generalitat de Catalunya). Ugo Piomelli acknowledges the support of the Natural Sciences and Engineering Research Council (NSERC) of Canada under the Discovery Grant Programme (Grant No. RGPIN-2016-04391). Ricard Borrell acknowledges a Juan de la Cierva postdoctoral grant (IJCI-2014-21034). Ivette Rodriguez, Oriol Lehmkuhl, Ricard Borrell and Assensi Oliva acknowledge Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (ref. ENE2014-60577-R).Peer ReviewedPostprint (author's final draft

The effect of glutamate and aspartate on myocardial protection at cardiopulmonary bypass

Objective: To determine whether glutamat and aspartat enriched cold crystalloid cardioplegia which was given in antegrade way has any effect on the myocardial protection during cardiopulmonary bypass. Material and Methods: Thirty-four patients who were electively undergone open heart surgery at Osmangazi University Faculty of Medicine, thoracic and cardiovascular surgery department, between March 2001 and May 2001 were included in this study. The patients were divided in two groups, each consisting of 17 patients. In group 1 coronary artery bypass surgery (CABG) was performed in 11 patients, mitral valve replacement (MVR) in 3 patients, aortic valve replacement (AVR) in 1 patient and AVR and MVR in 2 patients. While in group 2 CABG was performed in 13 patients and MVR was done in 4 patients. Group 1 patients received antegrade glutamat and aspartat (15 mmol/L) enriched cold crystalloid cardioplegia and group 2 patients were given cold crystalloid cardioplegia by antegrade route. Age, gender, diabetes mellitus, hypertension, preoperative myocardial infarction, smoking, ejection fraction, aortic cross-clamp time, need to defibrillation, inotropic support, and intraaortic balloon pump were recorded. The levels of cardiac troponin I (cTI) and creatine kinase myocardial band fraction (CK-MB) were measured in arterial blood samples at five different times. Statistical analysis was performed using Student's t-test and Chi-square test. Results: There were no statistically significant differences in cTI and CK-MB values in blood samples taken at 5 different times pre and postoperatively between group 1 and group 2. Conclusion: It is concluded that glutamat and aspartat enriched cold crystalloid cardioplegia does not have any effect on myocardial protection