Games of sharing airport costs

Ankara : The Department of Economics and the Institute of Economics and Social Sciences of Bilkent University, 2009.Thesis (Master's) -- Bilkent University, 2009.Includes bibliographical references leaves 41.In this study, noncooperative games defined for various cooperative solution concepts in airport problems have been addressed. The existence of a relationship between the design of the games and the equilibrium outcomes has been investigated. This study explores the conditions where, in a noncooperative game designed with downstream-subtraction consistent or uniform-subtraction consistent solution concept, the cost allocation proposed by this cooperative solution concept appears as the Nash outcome. Then, the uniqueness of this equilibrium has been examined.Yüksel, Ayşe MügeM.S

Overcoming moral hazard with social networks in the workplace : an experimental approach

The use of social networks in the workplace has been documented by many authors, although the reasons for their widespread prevalence are less well known. In this paper we present evidence based on a lab experiment that suggests quite strongly that social networks are used by employers to reduce worker moral hazard. We capture moral hazard with a dictator game between the referrer and worker. The worker chooses how much to return under different settings of social proximity. Social proximity is captured using Facebook friendship information gleaned anonymously from subjects once they have been recruited. Since employers themselves do not have access to social connections, they delegate the decision to referrers who can select among workers with different degrees of social proximity to themselves. We show that employers choose referrals over anonymous hiring relatively more when they know that the referrer has access to friends, and are willing to delegate more often when the social proximity between referrer and worker is potentially higher. In keeping with this expectation, referrers also choose workers with a greater social proximity to themselves and workers who are closer to referrers indeed pay back more to the referrer. The advantage of the lab setting is that we can isolate directed altruism as the only reason for these results

THE EFFECT OF INTELLIGENCE AND ACADEMIC SUCESS ON SELF-PERCEPTIONS OF PRIMARY SCHOOL STUDENTS

The main aim of this study is to examine the relationship between intelligence levels, self-perception and academic achievement of fourth grade primary school students. The study was carried out with 36 students in a state school in Istanbul. In the study; demographic form containing the achievement scores of Turkish and Mathematics courses and personal information of the students, Wechsler Intelligence Scale for Children-Revised-WISC-R and Piers-Harris Children’s Self Concept Scale were applied. As a result of the findings, it can be said that the gender variable in the 4th grade students of elementary school is not related to the self-perception and academic achievement. In addition, it was found that intelligence score was related to mathematics scores at a high level, related to Turkish scores at a low level. However, there was no significant relationship between intelligence scores and self-concept. It was also shown that the achievement of Turkish and mathematics lessons predicted the information subtest that represents long-term memory in the verbal section of WISC-R and the achievement of the mathematics course predicted digit symbol subtest (psychomotor coordination and speed) in the performance section of WISC-R. In the study, there was not found any effect of intelligence and academic success on children's self-concepts

Reliability and Validity of Attentional Style Questionnaire: Turkish Form

Attention is an important part of cognitive and perceptual processes. Attention includes both external processes related to the environment and internal processes such as heredity. In addition, measuring attention processes, which have two dimensions, top-down and bottom-up, is important in terms of both learning processes and determining some psychopathologies. Based on this, it was aimed to adapt the Attention Style Questionnaire (ASQ) into Turkish in this study. The study group includes of 372 university students. Data collection materials included personal information form, Attention Styles Questionnaire and Control Dimension of Self-regulation Scale. Language validity and criterion-related validity analysis were performed for validity studies. Confirmatory factor analysis and test-retest analysis were utilized for reliability studies. The two-factor structure in the original structure of the scale was confirmed through confirmatory factor analysis results. Furthermore, the ASQ was found to be highly correlated with the Control Dimension of Self-regulation Scale. According to the findings obtained for reliability, Cronbach's alpha coefficients were found as .81 for the cognitive avoidance sub-dimension and .70 for the focusing sub-dimension. Test-retest correlation coefficients were determined as .76 for the cognitive avoidance sub-dimension and .75 for the focusing sub-dimension. Research results indicate that Attention Style Questionnaire is a reliable and valid measurement tool in determining the style of the attention to university students in Türkiye

Investigation of the Death Anxiety and Meaning in Life Levels among Middle-Aged Adults

Life and death constitute a whole, and these concepts become increasingly important in the evaluation of life among middleaged adults. Therefore, this study investigated the correlation between individual levels of death anxiety and meaning in life in terms of certain variables such as gender, age, educational status, marital status, perceived level of devoutness, and witness to death. The sample consisted of 185 individuals (82 males, 103 females; aged 25–55 years) living in Istanbul, Turkey. The data was collected by using a Personal Information Form, the Death Anxiety Scale, and the Meaning in Life Questionnaire. The findings showed that, as the death anxiety and meaning in life subscale levels increased, the meaning in life levels decreased. In addition, it was found that death anxiety does not differ according to the following variables: age (25–35 and 35–55 years), educational status, marital status, perceived religious belief, and living with someone. The results also indicated that women tend to experience more death anxiety than men, and that individuals who witnessed the death of a close person generally feel more death anxiety than those who did not

Examination of the Relationship Between Test Anxiety and Selective Attention Among Adolescents

The purpose of this study is to determine the predictive level of test anxiety and selective attention skills on test performances of adolescents, who are studying in public and private schools and took high school entrance exams in 2015-2016. The sample of this study consists of 258 8th grade students in total, including 134 boys and 124 girls, between 13-14 ages. The data of the study were obtained from d2 Test of Attention, Test Anxiety Inventory and from TEOG exams. After examination of the results of the study, it has been indicated that there is a significant relationship between students’ performance on high school entrance exams and selective attention skills. As the quality of student’s visual scanning accuracy, rule compliance and attention performance increase during the exam, test performance increases as well. Likewise, as the students’ negative thoughts about themselves and negative assessments about failing their exams increase, then test performance decreases.

Ultrasonographically detected hepatosteatosis independently predicts the presence and severity of coronary artery disease

Objectives: The aim of our study was to evaluate the association between the presence and severity of CAD and NAFLD. Methods: The study group consisted of 153 patients who underwent coronary angiographies. Patients were categorized into CAD and non-CAD groups. CAD severity was determined by the number of CAD-involved arteries and the vessel score multiplied by Gensini score, the latter judging CAD severity. Fatty liver was diagnosed by abdominal ultrasonography (USG), with the patients being categorized by the degree of hepatosteatosis, as Grade 0, Grade 1, and Grade 2-3. Results: Among the whole study population, 47.1% of patients (n=72) were female and 52.9% of patients (n=81) were male. Forty-three patients had normal coronary arteries; 27 patients had non-critical CAD and side branch disease; and 83 patients had clinically significant CAD (stenosis>50%). The rate of CAD and Gensini score were significantly different between Grade 0, 1 and 2-3 hepatosteatosis groups (p<0.05). Patients with CAD had a significantly higher AST level than those without (p< 0.05). Conclusion: Ultrasonographically detected hepatosteatosis independently predicts the presence and severity of CAD. Keywords: Nonalcoholic fatty liver disease; gensini score; obesity

Instant determination of the artemisinin from various Artemisia annua L. extracts by LC-ESI-MS/MS and their in-silico modelling and in vitro antiviral activity studies against SARS-CoV-2

Introduction Numerous efforts in natural product drug development are reported for the treatment of Coronavirus. Based on the literature, among these natural plants Artemisia annua L. shows some promise for the treatment of SARS-CoV-2. Objective The main objective of our study was to determine artemisinin content by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS), to investigate the in vitro biological activity of artemisinin from the A. annua plants grown in Turkey with various extracted methods, to elaborate in silico activity against SARS-CoV-2 using molecular modelling. Methodology Twenty-one different extractions were applied. Direct and sequential extractions studies were compared with ultrasonic assisted maceration, Soxhlet, and ultra-rapid determined artemisinin active molecules by LC-ESI-MS/MS methods. The inhibition of spike protein and main protease (3CL) enzyme activity of SARS-CoV-2 virus was assessed by time resolved fluorescence energy transfer (TR-FRET) assay. Results Artemisinin content in the range 0.062-0.066%. Artemisinin showed significant inhibition of 3CL protease activity but not Spike/ACE-2 binding. The 50% effective concentration (EC50) of artemisinin against SARS-CoV-2 Spike pseudovirus was found greater than 50 mu M (EC45) in HEK293T cell line whereas the cell viability was 94% of the control (P < 0.01). The immunosuppressive effects of artemisinin on TNF-alpha production on both pseudovirus and lipopolysaccharide (LPS)-induced THP-1 cells were found significant in a dose dependent manner. Conclusion Further studies of these extracts for COVID-19 treatment will shed light to seek alternative treatment options. Moreover, these natural extracts can be used as an additional treatment option with medicines, as well as prophylactic use can be very beneficial for patients

Does the Change in the Indications of Endoscopic Sinonasal Surgery Continue? Data between 1994-2018

Objective: Endoscopic sinonasal surgery (ESS) has changing over the years in parallel with the developments in endoscopy devices, video-imaging techniques, and surgical instruments. In the present study we investigated whether the indications of patients who underwent surgery over a period of 25 years have accommodated to these changes.Methods: We retrospectively evaluated 1173 patients who underwent surgery in our clinic from 1994 through 2007, and 954 patients who underwent surgery from 2008 through 2018. The patients were divided into three groups as follows: chronic rhinosinusitis with polyps (CRSwNP), chronic rhinosinusitis without polyps (CRSsNP), and others. The changes in the indications during the first 14 years and the following 11 years were compared, and the results were statistically evaluated.Results: A significant decrease was observed in the number of patients who underwent surgery following the diagnosis of CRSsNP (p<0.001). In addition, a statistically significant increase was found in CRSwNP (p<0.001) and other (p<0.001) indications.Conclusion: When ESS indications identified in our clinic were reviewed, it was observed that the increasing trend in CRSwNP rate in the first 14 years continued, there was a significant increase in non-CRS indications in the last 11 years, and there has been an increase in patients with fungal sinusitis, especially in this group

Examination of the relationship between test anxiety and selective attention among adolescents [Ergenlerde sınav kaygısı ve seçici dikkat arasındaki ilişkinin incelenmesi]

The purpose of this study is to determine the predictive level of test anxiety and selective attention skills on test performances of adolescents, who are studying in public and private schools and took TEOG (Transition from Basic Education to Secondary Education) exam in 2015-2016. The sample of this study consists of 258 8th grade students in total, including 134 boys and 124 girls, between 13-14 ages. The data of the study were obtained from d2 Test of Attention, Test Anxiety Inventory and from TEOG exams. After examination of the results of the study, it has been indicated that there is a significant relationship between students’ performance on TEOG exams and selective attention skills. As the quality of student’s visual scanning accuracy, rule compliance and attention performance increase during the exam, test performance increases as well. Likewise, as the students’ negative thoughts about themselves and negative assessments about failing their exams increase, then test performance decreases. © 2018, Ankara University. All rights reserved