202 research outputs found
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 çalıĆmada, 2001-2009 yılları arasında TĂŒrkiyeâdeki boĆanma sayılarının GenelleĆtirilmiĆ Poisson, Quasi Poisson ve Negatif Binomiyal Regresyon metotlarına gore modellenmesi amaçlanmıĆtır. ĂalıĆmanın veri seti, TĂŒrk Ä°statistik Kurumu (TĂÄ°K)âden elde edilmiĆtir. Cevap deÄiĆkeni olan yıllık boĆanma sayısı, boĆanmÄ±Ć Ă§iftlerin evil kalma sĂŒrelerine göre dört gruba ayrılmıĆtır. ĂalıĆmanın veri seti TĂŒrkiye Ä°statistik Kurumu (TĂÄ°K)ândan elde edilen bilgiler ile oluĆturulmuĆtur. Cevap deÄiĆkeni olan yıllık boĆanma sayısı, boĆanan çiftlerin evli kalma sĂŒrelerine göre dört gruba ayrılmıĆtır. Açıklayıcı deÄiĆkenler olarak, erkek ve kadınların ilk evlilik yaĆı ortalamaları, evli kadının iĆ hayatına katılma oranı, erkek ve kadınlarda yĂŒksek okul mezunu olma oranları ele alınmıĆtır. Poisson modelleri için aĆırı yayılım parametresi sırasıyla 32.413, 7.277, 16.158 ve 26.361 olarak belirlenmiĆtir. Ayrıca Pearson ve G2 istatistikleri de Poisson modellerinin veri seti için uygun olmadıÄını göstermiĆtir. Quasi Poisson uygulandıÄında ise artıkların daÄılımı Poisson modellerine çok yakın çıkmıĆtır. Sonuç olarak Negatif Binomiyal Regresyon kullanılmıĆtır. AĆırıyayılım, Poisson modellemesinde yaygın bir fenomendir. Bu gibi veri setlerinde Poisson Regresyonun çeĆitli genelleĆtirmeleri ve Negatif Binomiyal Regresyon kullanılır. Bu çalıĆmada Negatif Binomiyal Regresyonun uygun olduÄuna karar verilmiĆtir
Batch and continuous removal of heavy metals from industrial effluents using microbial consortia
Bio-removal of heavy metals, using microbial biomass, increasingly attracting scientific attention due to their significant role in purification of different types of wastewaters making it reusable. Heavy metals were reported to have a significant hazardous effect on human health, and while the conventional methods of removal were found to be insufficient; microbial biosorption was found to be the most suitable alternative. In this work, an immobilized microbial consortium was generated using Statistical Design of Experiment (DOE) as a robust method to screen the efficiency of the microbial isolates in heavy metal removal process. This is the first report of applying Statistical DOE to screen the efficacy of microbial isolates to remove heavy metals instead of screening normal variables. A mixture of bacterial biomass and fungal spores was used both in batch and continuous modes to remove Chromium and Iron ions from industrial effluents. Bakery yeast was applied as a positive control, and all the obtained biosorbent isolates showed more significant efficiency in heavy metal removal. In batch mode, the immobilized biomass was enclosed in a hanged tea bag-like cellulose membrane to facilitate the separation of the biosorbent from the treated solutions, which is one of the main challenges in applying microbial biosorption at large scale. The continuous flow removal was performed using fixed bed mini-bioreactor, and the process was optimized in terms of pH (6) and flow rates (1 ml/min) using Response Surface Methodology. The most potential biosorbent microbes were identified and characterized. The generated microbial consortia and process succeeded in the total removal of Chromium ions and more than half of Iron ions both from standard solutions and industrial effluents
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
COVID-19 infection in adult patients with hematological malignancies: a European Hematology Association Survey (EPICOVIDEHA)
Background: Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. Methods: The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. Results: The study sample includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients (n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (MarchâMay 2020) and the second wave (OctoberâDecember 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value < 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. Conclusions: This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.EPICOVIDEHA has received funds from Optics COMMITTM (COVID-19 Unmet Medical Needs and Associated Research Extension) COVID-19 RFP program by GILEAD Science, United States (Project 2020-8223)
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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