PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8650
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Article Relationships of Transformational and Paternalistic Leadership Styles With Follower Needs, Multidimensional Work Motivations and Organizational Commitment: a Mediated Model(Sage Publications inc, 2024) Civit, Selinay; Goncu-Kose, AsliPaternalistic Leadership (PL) style is suggested to be an emic manifestation of Transformational Leadership (TL) in cultural contexts characterized by high power distance and collectivism. The present study investigated the effects of TL and PL behaviors on employees' multidimensional work motivation and organizational commitment and the mediating effects of satisfaction of psychological needs (needs for autonomy, competence, and relatedness) in these relationships. Data were collected from 423 white-collar employees and analyzed by Structural Equation Modeling. The findings revealed that TL was significantly related to employees' autonomous and controlled work motivations as well as amotivation via its association with the satisfaction of employees' needs for autonomy, competence, and relatedness. PL was associated with employees' autonomous work motivations and amotivation via satisfaction of employees' need for relatedness. Autonomous motivations were positively associated with affective commitment; whereas controlled motivations were positively related to normative commitment. Amotivation was negatively associated with all types of commitment. The findings are discussed in terms of theoretical and practical implications as well as suggestions for future research.Article -Simultaneous chemometric determination of pyridoxine hydrochloride and isoniazid in tablets bymultivariate regression methods(Wiley-Blackwell, 2010) Dinç, Erdal; Üstündağ, Ögür; Baleanu, DumitruThe sole use of pyridoxine hydrochloride during treatment of tuberculosis gives rise to pyridoxine deficiency. Therefore, a combination of pyridoxine hydrochloride and isoniazid is used in pharmaceutical dosage form in tuberculosis treatment to reduce this side effect. In this study, two chemometric methods, partial least squares (PLS) and principal component regression (PCR), were applied to the simultaneous determination of pyridoxine (PYR) and isoniazid (ISO) in their tablets. A concentration training set comprising binary mixtures of PYR and ISO consisting of 20 different combinations were randomly prepared in 0.1 M HCl. Both multivariate calibration models were constructed using the relationships between the concentration data set (concentration data matrix) and absorbance data matrix in the spectral region 200-330 nm. The accuracy and the precision of the proposed chemometric methods were validated by analyzing synthetic mixtures containing the investigated drugs. The recovery results obtained by applying PCR and PLS calibrations to the artificial mixtures were found between 100.0 and 100.7%. Satisfactory results obtained by applying the PLS and PCR methods to both artificial and commercial samples were obtained. The results obtained in this manuscript strongly encourage us to use them for the quality control and the routine analysis of the marketing tablets containing PYR and ISO drugs. CopyrightArticle Citation - WoS: 7Citation - Scopus: 7Locus of Control as a Mediator of the Relationships Between Motivational Systems and Trait Anxiety(Sage Publications inc, 2024) Turan, Aysu; Demir, Yagmur; Kaynak, HandeThe Reinforcement Sensitivity Theory, first proposed by Gray and later revised, describes three motivational systems: Behavioral Inhibition System (BIS), Behavioral Activation System (BAS), and Fight-Flight-Freeze System (FFFS). Studies have shown that high BIS and FFFS activation are positively related to anxiety symptoms, yet the relationship between BAS and anxiety remains unclear. Research data have also suggested that anxiety symptoms occur with the loss of perceived control. Thus, although studies on the direct effect of locus of control (LOC) on trait anxiety have accumulated for many years, the issue of how LOC may mediate the relationship between BIS/BAS/FFFS sensitivity and anxiety has not been addressed. This study aimed to explore the mediating role of LOC orientation on trait anxiety among young adults in association with these three motivational systems. Cross-sectional data were obtained from 422 volunteers. The BIS/BAS Scale, Trait Anxiety Inventory, and Rotter's Internal-External LOC Scale were applied. A series of mediation analyses were performed to estimate total, indirect, and direct effects. The results showed that BIS and FFFS positively predicted trait anxiety. In addition, LOC positively predicted trait anxiety and BIS. The results of the mediation analyses indicated that LOC functioned as a partial mediator between BIS and trait anxiety. This finding revealed that a high BIS level, one of the motivational systems, was associated with external LOC, which in turn contributed to reporting high trait anxiety in young adults. Hence, BIS and external LOC orientation could be suggested as risk factors for trait anxiety. As the external LOC orientation of individuals with high punishment sensitivity increased, their trait anxiety levels also increased. Therefore, it was suggested that it might be useful to be aware that LOC orientations of individuals with BIS sensitivity may pose a risk for trait anxiety.Article Citation - WoS: 43Citation - Scopus: 50Detection of Hip Osteoarthritis by Using Plain Pelvic Radiographs With Deep Learning Methods(Springer, 2020) Ureten, Kemal; Arslan, Tayfun; Gultekin, Korcan Emre; Demir, Ayse Nur Demirgoz; Ozer, Hafsa Feyza; Bilgili, YaseminObjective The incidence of osteoarthritis is gradually increasing in public due to aging and increase in obesity. Various imaging methods are used in the diagnosis of hip osteoarthritis, and plain pelvic radiography is the first preferred imaging method in the diagnosis of hip osteoarthritis. In this study, we aimed to develop a computer-aided diagnosis method that will help physicians for the diagnosis of hip osteoarthritis by interpreting plain pelvic radiographs. Materials and methods In this retrospective study, convolutional neural networks were used and transfer learning was applied with the pre-trained VGG-16 network. Our dataset consisted of 221 normal hip radiographs and 213 hip radiographs with osteoarthritis. In this study, the training of the network was performed using a total of 426 hip osteoarthritis images and a total of 442 normal pelvic images obtained by flipping the raw data set. Results Training results were evaluated with performance metrics such as accuracy, sensitivity, specificity, and precision calculated by using the confusion matrix. We achieved accuracy, sensitivity, specificity and precision results at 90.2%, 97.6%, 83.0%, and 84.7% respectively. Conclusion We achieved promising results with this computer-aided diagnosis method that we tried to develop using convolutional neural networks based on transfer learning. This method can help clinicians for the diagnosis of hip osteoarthritis while interpreting plain pelvic radiographs, also provides assistance for a second objective interpretation. It may also reduce the need for advanced imaging methods in the diagnosis of hip osteoarthritis.Article Citation - WoS: 16Citation - Scopus: 16Measuring Dysfunctional Grief Due To a Covid-19 Loss: a Turkish Validation Study of the Pandemic Grief Scale(Routledge Journals, Taylor & Francis Ltd, 2022) Evren, Cuneyt; Evren, Bilge; Dalbudak, Ercan; Topcu, Merve; Kutlu, NilayThe global death toll to date of the COVID-19 pandemic has been enormous, and millions of people are grieving these losses. The aim of the current study is to validate a Turkish version of the Pandemic Grief Scale (PGS), which is a brief English-language mental health screener to identify probable cases of dysfunctional grief associated with a COVID-19 death. Participants were assessed using the PGS, Patient Health Questionnaire-4 (PHQ-4) and Work and Social Adjustment Scale (WSAS). We surveyed 758 Turkish native speakers who participated online. Confirmatory factor analysis showed that the factor structure of the PGS was satisfactory. The scale was internally consistent with a Cronbach's alpha of 0.77 and a composite reliability of 0.90. The PGS demonstrated construct validity with strong correlations with suicidal ideation and substance use coping. Positive correlations of the PGS with the PHQ-4 and the WSAS demonstrated adequate convergent validity. The PGS discriminates well between persons with and without dysfunctional grief using an optimized cut score of >= 3 (89% sensitivity and 72% specificity). The PGS also demonstrates incremental validity by explaining most of the variance (43%) in functional impairment due to a COVID-19 loss beyond measures of depression and generalized anxiety. These findings closely replicate the original validation study on the PGS in English and suggest that the current Turkish version of the PGS is a valid and reliable measure to assess the severity of dysfunctional grief associated with a COVID-19 death.Article Citation - WoS: 6Citation - Scopus: 4Predictors of Stress Generation in Turkish Young Adults: the Role of Rumination and Excessive Reassurance Seeking(John Wiley & Sons Ltd, 2020) Tuna, EzgiThe stress generation model posits that not only stressful life-events predict depressive symptoms, but also depressive-prone individuals think and behave in ways that make them more vulnerable to experience life-stress. Evidence has supported the bi-directional relationship between stress and depressive symptoms, and there has been an attempt in identifying vulnerability factors for stress generation. Yet, there is a need for studies focusing on multiple risk factors and a replication of findings in non-Western samples. The aim of the present study was to examine the role of rumination and excessive reassurance seeking (ERS) in stress generation in a sample of Turkish young adults. A sample of 318 Turkish college students reported on their rumination, ERS, intensity of stressful life-events and depressive symptoms. A subsample of 162 participants also completed a measure of life-events 5 months later. Cross-sectional results showed that rumination and ERS contribute to life-stress over and above depressive symptoms and gender. Mediational analyses indicated that ERS does not mediate the relationship between rumination and life-stress at 5 months. Rather, rumination fully mediated the relationship between ERS and future life-stress. Results provide evidence for stress generation, and highlight the interconnection between rumination and ERS.Article Citation - WoS: 161Citation - Scopus: 156Measuring Anxiety Related To Covid-19: a Turkish Validation Study of the Coronavirus Anxiety Scale(Routledge Journals, Taylor & Francis Ltd, 2022) Evren, Bilge; Dalbudak, Ercan; Topcu, Merve; Kutlu, Nilay; Evren, CuneytThe aim of the current study is to validate the Turkish version of the Coronavirus Anxiety Scale (CAS). Participants were assessed across the CAS, Obsession with COVID-19 Scale (OCS) and Fear of COVID-19 Scale. We surveyed 1023 Turkish native speakers who participated online. Confirmatory factor analysis showed that the factor structure of the CAS was satisfactory. The scale was internally consistent with a Cronbach's alpha of 0.80. Positive correlations of the CAS with the OCS and the Fear of COVID-19 Scale demonstrated adequate convergent validity. These findings suggest that the CAS is a valid and reliable measure to assess the severity of dysfunctional coronavirus related anxiety.Article Citation - WoS: 65Citation - Scopus: 74Detection of Rheumatoid Arthritis From Hand Radiographs Using a Convolutional Neural Network(Springer London Ltd, 2020) Ureten, Kemal; Erbay, Hasan; Maras, Hadi HakanIntroduction Plain hand radiographs are the first-line and most commonly used imaging methods for diagnosis or differential diagnosis of rheumatoid arthritis (RA) and for monitoring disease activity. In this study, we used plain hand radiographs and tried to develop an automated diagnostic method using the convolutional neural networks to help physicians while diagnosing rheumatoid arthritis. Methods A convolutional neural network (CNN) is a deep learning method based on a multilayer neural network structure. The network was trained on a dataset containing 135 radiographs of the right hands, of which 61 were normal and 74 RA, and tested it on 45 radiographs, of which 20 were normal and 25 RA. Results The accuracy of the network was 73.33% and the error rate 0.0167. The sensitivity of the network was 0.6818; the specificity was 0.7826 and the precision 0.7500. Conclusion Using only pixel information on hand radiographs, a multi-layer CNN architecture with online data augmentation was designed. The performance metrics such as accuracy, error rate, sensitivity, specificity, and precision state shows that the network is promising in diagnosing rheumatoid arthritis.Article Citation - WoS: 31Citation - Scopus: 32A Comparative Study on Biodegradation and Mechanical Properties of Pressureless Infiltrated Ti/Ti6al4v-mg Composites(Elsevier Science Bv, 2016) Karakas, M. Serdar; Esen, Ziya; Butev, EzgiThe mechanical response and biodegradation behavior of pressureless Mg-infiltrated Ti-Mg and Ti6Al4V-Mg composites were investigated by compression and simulated body fluid immersion tests, respectively. Prior porous preforms were surrounded uniformly with magnesium as a result of infiltration and the resultant composites were free of secondary phases and intermetallics. Although the composites' compressive strengths were superior compared to bone, both displayed elastic moduli similar to that of cortical bone and had higher ductility with respect to their starting porous forms. However, Ti-Mg composites were unable to preserve their mechanical stabilities during in-vitro tests such that they fractured in multiple locations within 15 days of immersion. The pressure generated by H-2 due to rapid corrosion of magnesium caused failure of the Ti-Mg composites through sintering necks. On the other hand, the galvanic effect seen in Ti6Al4V-Mg was less severe compared to that of Ti-Mg. The degradation rate of magnesium in Ti6Al4V-Mg was slower, and the composites were observed to be mechanically stable and preserved their integrities over the entire 25-day immersion test. Both composites showed bioinert and biodegradable characteristics during immersion tests and magnesium preferentially corroded leaving porosity behind while Ti/Ti6Al4V remained as a permanent scaffold. The porosity created by degradation of magnesium was refilled by new globular agglomerates. Mg(OH)(2) and CaHPO4 phases were encountered during immersion tests while MgCl2 was detected during only the first 5 days. Both composites were classified as bioactive since the precipitation of CaHPO4 phase is known to be precursor of hydroxyapatite formation, an essential requirement for an artificial material to bond to living bone. (C) 2016 Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Comparative Analysis on Wavelet-Based Detection of Finite Duration Low-Amplitude Signals Related To Ventricular Late Potentials(Iop Publishing Ltd, 2004) Mousa, A; Yilmaz, AVentricular late potentials (VLPs) are considered as a noninvasive marker of patients with myocardial infarction, who are prone to the development of ventricular tachycardia. This paper investigates the effects of variations in physical properties of myocardial infarcts in terms of their effects on the parametric variations in VLP analysis. A sufficiently large set of signals underlining the behavior of physical parameters was employed to represent the effect of physical size, position, orientation and type of infarct. The approximated signals are variations from real electrocardiography signals by adding potentials representing late potentials based on duration, frequency, amplitude and position. The aim is not to exactly model VLP but rather to generate an approximate set of signals to examine the performance of the standard methods for different possibilities in infarct dynamics. We investigate some of the detection approaches together with their related assumptions, and try to pinpoint the drawbacks and inaccuracies of these methods and also their assumptions. The three widely accepted criteria-QRS duration, root-mean-square and duration of the signal at the end of QRS for VLP detection-were used in the investigation. Results from the application of these parameters to the set of signals are presented. In addition we investigate the physical nature of an infarct and list a number of possible reasons that might be the cause of a low success rate for the detection of additive potentials. To improve the performance of the common methods, two more wavelet transform parameters are added to those of the standard methods. The method derived from this analysis is presented as an alternative means for the detection of late signals named as delayed potentials, a more general class that includes VLP as a subset.