No association of serum PSA with vitamin D or total oxidant-antioxidant capacity in healthy men

Background and aim: Vitamin D deficiency and oxidative stress were suggested to be related to prostate cancer risk. We aimed to investigate the association of serum PSA concentration with vitamin D and total oxidant/antioxidant levels.

Materials and methods: A total of 95 healthy men were enrolled for the cross sectional study. Serum PSA, 25(OH)D, serum total oxidant status, and total antioxidant status were measured.

Results: Serum PSA was significantly negatively correlated with serum total oxidant status (r=??0.309, p?=?.003) but there was no significant correlation between PSA and 25(OH)D (p?=?.383) or total antioxidant levels (p?=?.233). After adjustment for age BMI and smoking status with multiple regression analysis, there was no significant association between serum PSA and total oxidant status.

Conclusion: We find no evidence for an association between PSA and vitamin D levels or serum total oxidant/antioxidant levels.     

Occupational burnout and cyberloafing among teachers: Analysis of personality traits,individual and occupational status variables as predictors

One of the phenomena that causes remarkable losses in terms of productivity and cost in organizations is occupational burnout. Burnout is encountered in different occupational groups. However, in professions that are in contact with a large number of people as part of their responsibilities, such as teaching, burnout is a problem that is far more on the foreground. In addition, emotional burnout, which is seen as the first step before occupational burnout, can cause workers to feel insufficient at the point of carrying out tasks related to their duties, leading to behaviour that is out of their fields such as cyberloafing. Addressing this situation in terms of teaching profession, the feeling of inadequacy in educational activities during the course may prevent the teacher from fulfilling any responsibilities while using a device that has internet access. In this context, the aim of this study is to investigate the factors that predict the cyberloafing and burnout levels of teachers working in different fields. This research is a relational research. This research was carried out with the participations of 194 teachers from different branches working in various provinces in Turkey. In this study, a personal information form and three different data collection tools were used. Analysis of the collected data was performed by hierarchical linear multiple regression analysis. The 9 models, created separately with cyberloafing and burnout, were found to be significant in the study. Demographic variables, ICT usage status variables, occupational variables and personality traits were used in these models. Therefore, all the hypotheses included in the research were accepted. As a result of the research, demographic variables were found to be the most important model to predict teachers’ occupational burnout. The most important model explaining teachers’ cyberloafing situations is their ICT usage.     

Gender as Symbolic Capital and Violence: The Case of Corporate Elites in Turkey

Based on a Bourdieusian approach, drawing on qualitative analyses of 63 life interviews, our study demonstrates that gender is performed as both symbolic capital and violence by corporate elites within the dominant ideologies of patriarchy and family in Turkey. Our analysis reveals that, in the male‐dominated context of Turkey, female elites appear to favour male alliances as a tactical move in order to acquire and maintain status in their organizations, whereas male elites appear to remain blind to the privileges and constraints of their own gendered experience of symbolic capital and violence. Our study also illustrates that gender order is still preserved, despite beliefs to the contrary that equality in education, skills, experience and job performance may liberate women and men from gender‐based outcomes at work.     

Multi-objective simulation optimization using data envelopment analysis and genetic algorithm: Specific application to determining optimal resource levels in surgical services

Simulation is a powerful tool for modeling complex systems with intricate relationships between various entities and resources. Simulation optimization refers to methods that search the design space (i.e., the set of all feasible system configurations) to find a system configuration (also called a design point) that gives the best performance. Since simulation is often time consuming, sampling as few design points from the design space as possible is desired. However, in the case of multiple objectives, traditional simulation optimization methods are ineffective to uncover the efficient frontier. We propose a framework for multi-objective simulation optimization that combines the power of genetic algorithm (GA), which can effectively search very large design spaces, with data envelopment analysis (DEA) used to evaluate the simulation results and guide the search process. In our framework, we use a design point's relative efficiency score from DEA as its fitness value in the selection operation of GA. We apply our algorithm to determine optimal resource levels in surgical services. Our numerical experiments show that our algorithm effectively furthers the frontier and identifies efficient design points.     

Evaluation of quality of life in patients undergoing surgery for benign prostatic hyperplasia

Abstract

Introduction: Benign prostatic hyperplasia (BPH) is one of the most common diseases in the world and also one of the most common causes of urinary complaints that occur with increasing age. Thus, BPH should be addressed with surgical procedures. To contribute to the relevant literature, the present study aims to investigate the effects of surgical therapies for BPH on the patients quality of life.

Materials and methods: This study included 120 patients who underwent surgery for BPH at a Training and Research Hospital. The short-form health survey (SF-36) was administered to the patients before the surgery and at three months after the surgery. Eight parameters of the SF-36 and mental (MCS) and physical (PCS) component summary scores were calculated. The Student’s t-test, Wilcoxon, and chi-square test were used in the statistical analysis.

Results: When the eight parameters within the SF-36 health questionnaire were examined separately, the findings showed that patients quality of life increased significantly with respect to physical functioning, social functioning, and role limitations because of emotional problems , vitality, bodily pain, general health perceptions, and mental health domains three months after surgery (p?<?.001). The PCS and MCS significantly increased after surgery (p?<?.001).

Conclusion: The SF-36 questionnaire results showed that a significant improvement in the patients quality of life was observed in patients who underwent surgery for BPH. Our findings suggest that SF-36 could be considered a reliable evaluation test to be used in the patients with BPH after surgery.     

Thermal,viscoelastic and mechanical properties' optimization of polyphenylene sulfide via optimal processing parameters using the Taguchi method

Thermal, viscoelastic and mechanical properties of polyphenylene sulfide (PPS) were optimized as a function of extrusion and injection molding parameters. For this purpose, design of experiments approach utilizing Taguchi's L₂₇ (3⁷) orthogonal arrays was used. Effect of the parameters on desired properties was determined using the analysis of variance. Differential scanning calorimeter (DSC) tests were performed for the analysis of thermal properties such as melting temperature (T_m) and melting enthalpy (ΔH_M). Dynamic mechanical analysis (DMA) tests were performed for the analysis of viscoelastic properties such as damping factor (tan?δ) and glass transition temperature (T_g). Tensile tests were performed for the analysis of mechanical properties such as tensile strength and modulus. With optimized process parameters, verification DSC, DMA and tensile tests were performed for thermal, viscoelastic and mechanical properties, respectively. The Taguchi method showed that ‘barrel temperature’ and its level of ‘340°C’ were seen to be the most effective parameter and its level; respectively. It was suggested that PPS can be reinforced for further improvement after optimized thermal, viscoelastic and mechanical properties.     

An approximate entropy test for randomness

We develop an entropy-based test for randomness of binary time series of finite length. The test uses the frequencies of contiguous blocks of different lengths. A simple condition ib the block lengths and the length of the time series enables one to estimate the entropy rate for the data, and this information is used to develop a statistic to test the hypothesis of randomness. This static measures the deviation of the estimated entropy of the observed data from the theoretical maximum under the randomness hypothesis. This test offers a real alternative to the conventional runs test. Critical percentage points, based on simulations, are provided for testing the hypothesis of randomness. Power calculations using dependent data show that the proposed test has higher power against the runs test for short series, and it is similar to the runs test for long series. The test is applied to two published data sets that wree investigated by others with respect to their randomness.     

Local Convergence Rate of Mean Squared Error in Density Estimation

The local convergence rate of a multivariate density estimators based on the certain delta-sequence is studied. In contrast to known results, the conditions on the density are formulated in terms of the modulus of continuity. The main contribution of this study is relaxing the corresponding smoothing conditions in terms of arbitrary modulus of continuity type majorant. In particular, when the density f ∈ L ^p (R ^d ) satisfies Lipschitz condition of order γ = 1 at x, the rate of convergency contains terms with logarithm, which is the best possible convergency rate.