Modeling of the number of divorce in Turkey using the Generalized Poisson, Quasi-Poisson and Negative Binomial Regression

In this study, it has been aimed to model the numbers of divorce in Turkey between years 2001- 2009 using Generalized Poisson, Quasi-Poisson and Negative Binomial Regression methods. Data set of this study has been based on the data obtained from Turkish Statistical Institute (TUIK). Response variable-the annual rate of divorce- has been categorized into four groups with respect to the length of ex-married life of divorced couples. Explanatory variables have been designated as average age of the first marriage of men and women, the professional work life ratio of married women, the percentage of university graduates in both men and women. For Poisson models, overdispersion parameters have been detected respectively 32.413, 7.277, 16.158 and 26.361. Furthermore Pearson and G2 statistics have revealed that Poisson models are not appropriate for data set. When Quasi Poisson regression was employed, it has been detected that residual deviances are rather close to Poisson residuals. Finally, Negative binomial regression has been conducted. Overdispersion is a common phenomenon in Poisson modeling. In such data sets certain generalizations of Poisson regression and negative binomial regression modeling are used. In present study negative binomial regression has been detected as approved method.Bu çalışmada, 2001-2009 yılları arasında Türkiye’deki boşanma sayılarının Genelleştirilmiş Poisson, Quasi Poisson ve Negatif Binomiyal Regresyon metotlarına gore modellenmesi amaçlanmıştır. Çalışmanın veri seti, Türk İstatistik Kurumu (TÜİK)’den elde edilmiştir. Cevap değişkeni olan yıllık boşanma sayısı, boşanmış çiftlerin evil kalma sürelerine göre dört gruba ayrılmıştır. Çalışmanın veri seti Türkiye İstatistik Kurumu (TÜİK)’ndan elde edilen bilgiler ile oluşturulmuştur. Cevap değişkeni olan yıllık boşanma sayısı, boşanan çiftlerin evli kalma sürelerine göre dört gruba ayrılmıştır. Açıklayıcı değişkenler olarak, erkek ve kadınların ilk evlilik yaşı ortalamaları, evli kadının iş hayatına katılma oranı, erkek ve kadınlarda yüksek okul mezunu olma oranları ele alınmıştır. Poisson modelleri için aşırı yayılım parametresi sırasıyla 32.413, 7.277, 16.158 ve 26.361 olarak belirlenmiştir. Ayrıca Pearson ve G2 istatistikleri de Poisson modellerinin veri seti için uygun olmadığını göstermiştir. Quasi Poisson uygulandığında ise artıkların dağılımı Poisson modellerine çok yakın çıkmıştır. Sonuç olarak Negatif Binomiyal Regresyon kullanılmıştır. Aşırıyayılım, Poisson modellemesinde yaygın bir fenomendir. Bu gibi veri setlerinde Poisson Regresyonun çeşitli genelleştirmeleri ve Negatif Binomiyal Regresyon kullanılır. Bu çalışmada Negatif Binomiyal Regresyonun uygun olduğuna karar verilmiştir

Modeling of the Impact of Initial Mold Temperature, Al5Ti1B and Al10Sr Additions on the Critical Fraction of Solid in Die Casting of Aluminum Alloys using Fuzzy Expert System

In the casting of liquid metal, the feeding stops when the mushy zone is clogged and does not allow the transfer of feeding liquid. The growing resistance of the solid dendrites against the fluidity of the feeding liquid is defined as the critical fraction of solid (CFS). CFS value varies depending on many factors such as alloy solidification range, initial mold temperature, and the grain size. Therefore, in many casting simulation applications, it is quite common to get inconsistent results due to insufficient information about the CFS. In this study, a fuzzy expert system (FES) model has been developed in order to determine the value of the CFS in the die casting process, based on the parameters of the alloy type, the initial mold temperature, Al5Ti1B addition and Al10Sr addition. In order to create the rule base for the FES model, 54 die casting experiments have been carried out. The CFS values obtained using the FES model has revealed that the developed model of the FES predicts the CFS value in a high performance

Risk factors for exacerbations and pneumonia in patients with chronic obstructive pulmonary disease: a pooled analysis.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are at risk of exacerbations and pneumonia; how the risk factors interact is unclear. METHODS: This post-hoc, pooled analysis included studies of COPD patients treated with inhaled corticosteroid (ICS)/long-acting β2 agonist (LABA) combinations and comparator arms of ICS, LABA, and/or placebo. Backward elimination via Cox's proportional hazards regression modelling evaluated which combination of risk factors best predicts time to first (a) pneumonia, and (b) moderate/severe COPD exacerbation. RESULTS: Five studies contributed: NCT01009463, NCT01017952, NCT00144911, NCT00115492, and NCT00268216. Low body mass index (BMI), exacerbation history, worsening lung function (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage), and ICS treatment were identified as factors increasing pneumonia risk. BMI was the only pneumonia risk factor influenced by ICS treatment, with ICS further increasing risk for those with BMI <25 kg/m2. The modelled probability of pneumonia varied between 3 and 12% during the first year. Higher exacerbation risk was associated with a history of exacerbations, poorer lung function (GOLD stage), female sex and absence of ICS treatment. The influence of the other exacerbation risk factors was not modified by ICS treatment. Modelled probabilities of an exacerbation varied between 31 and 82% during the first year. CONCLUSIONS: The probability of an exacerbation was considerably higher than for pneumonia. ICS reduced exacerbations but did not influence the effect of risks associated with prior exacerbation history, GOLD stage, or female sex. The only identified risk factor for ICS-induced pneumonia was BMI <25 kg/m2. Analyses of this type may help the development of COPD risk equations

Changes in lung function in European adults born between 1884 and 1996 and implications for the diagnosis of lung disease:a cross-sectional analysis of ten population-based studies

Background: During the past century, socioeconomic and scientific advances have resulted in changes in the health and physique of European populations. Accompanying improvements in lung function, if unrecognised, could result in the misclassification of lung function measurements and misdiagnosis of lung diseases. We therefore investigated changes in population lung function with birth year across the past century, accounting for increasing population height, and examined how such changes might influence the interpretation of lung function measurements. Methods: In our analyses of cross-sectional data from ten European population-based studies, we included individuals aged 20-94 years who were born between 1884 and 1996, regardless of previous respiratory diagnoses or symptoms. FEV1, forced vital capacity (FVC), height, weight, and smoking behaviour were measured between 1965 and 2016. We used meta-regression to investigate how FEV1 and FVC (adjusting for age, study, height, sex, smoking status, smoking pack-years, and weight) and the FEV1/FVC ratio (adjusting for age, study, sex, and smoking status) changed with birth year. Using estimates from these models, we graphically explored how mean lung function values would be expected to progressively deviate from predicted values. To substantiate our findings, we used linear regression to investigate how the FEV1 and FVC values predicted by 32 reference equations published between 1961 and 2015 changed with estimated birth year. Findings: Across the ten included studies, we included 243 465 European participants (mean age 51·4 years, 95% CI 51·4-51·5) in our analysis, of whom 136 275 (56·0%) were female and 107 190 (44·0%) were male. After full adjustment, FEV1 increased by 4·8 mL/birth year (95% CI 2·6-7·0; p<0·0001) and FVC increased by 8·8 mL/birth year (5·7-12·0; p<0·0001). Birth year-related increases in the FEV1 and FVC values predicted by published reference equations corroborated these findings. This height-independent increase in FEV1 and FVC across the last century will have caused mean population values to progressively exceed previously predicted values. However, the population mean adjusted FEV1/FVC ratio decreased by 0·11 per 100 birth years (95% CI 0·09-0·14; p<0·0001). Interpretation: If current diagnostic criteria remain unchanged, the identified shifts in European values will allow the easier fulfilment of diagnostic criteria for lung diseases such as chronic obstructive pulmonary disease, but the systematic underestimation of lung disease severity. Funding: The European Respiratory Society, AstraZeneca, Chiesi Farmaceutici, GlaxoSmithKline, Menarini, and Sanofi-Genzyme

Problematic online behaviors among adolescents and emerging adults: associations between cyberbullying perpetration, problematic social media use, and psychosocial factors

Over the past two decades, young people's engagement in online activities has grown markedly. The aim of the present study was to examine the relationship between two specific online behaviors (i.e., cyberbullying perpetration, problematic social media use) and their relationships with social connectedness, belongingness, depression, and self-esteem among high school and university students. Data were collected from two different study groups via two questionnaires that included the Cyberbullying Offending Scale, Social Media Use Questionnaire, Social Connectedness Scale, General Belongingness Scale, Short Depression-Happiness Scale, and Single Item Self-Esteem Scale. Study 1 comprised 804 high school students (48% female; mean age 16.20 years). Study 2 comprised 760 university students (60% female; mean age 21.48 years). Results indicated that problematic social media use and cyberbullying perpetration (which was stronger among high school students) were directly associated with each other. Belongingness (directly) and social connectedness (indirectly) were both associated with cyberbullying perpetration and problematic social media use. Path analysis demonstrated that while age was a significant direct predictor of problematic social media use and cyberbullying perpetration among university students, it was not significant among high school students. In both samples, depression was a direct predictor of problematic social media use and an indirect predictor of cyberbullying perpetration. However, majority of these associations were relatively weak. The present study significantly adds to the emerging body of literature concerning the associations between problematic social media use and cyberbullying perpetration

A proposal for a CT driven classification of left colon acute diverticulitis

Computed tomography (CT) imaging is the most appropriate diagnostic tool to confirm suspected left colonic diverticulitis. However, the utility of CT imaging goes beyond accurate diagnosis of diverticulitis; the grade of severity on CT imaging may drive treatment planning of patients presenting with acute diverticulitis. The appropriate management of left colon acute diverticulitis remains still debated because of the vast spectrum of clinical presentations and different approaches to treatment proposed. The authors present a new simple classification system based on both CT scan results driving decisions making management of acute diverticulitis that may be universally accepted for day to day practice