Search

The purpose of this study was to evaluate the distribution of students with varying levels of reading competence according to their selection of metacognitive methods from the 2018 Programme for International Student Assessment (PISA) survey. The research group consisted of 6,890 pupils from the Republic of Turkey who participated in the PISA 2018 study. The data were analyzed using the multivariate exploratory technique of correspondence analysis. In comparison to developing readers, skilled readers favored the metacognitive processes of summarizing, understanding and remembering, and evaluating believability. Awareness of appropriate metacognitive reading strategies should be emphasized in order to increase the reading comprehension of developing readers.

Classical test theory (CTT) and item response theory (IRT) are two fundamental approaches used in scale development research. Although CTT is the preferred methodology in scale development research in the Republic of Turkey, the IRT methodology has started to gain traction in recent years. In this study, we used the systematic review methodology to review scale development research in Turkey that used the IRT procedures. Results revealed that most of the studies were conducted in 2017. Most of the studies have a sufficient sample size. Exploratory factor analysis was used more than confirmatory factor analysis. Some studies failed to choose the proper IRT model, report and interpret item parameters, check IRT assumptions, and report and interpret information functions. We recommend some practical considerations to researchers in terms of IRT assumptions.

Slow flow (SF) that develops after percutaneous coronary intervention (PCI) is significantly associated with poor prognosis in Non-ST elevation myocardial infarction (Non-STEMI) patients. Increased Selvester QRS score and Frontal QRS-T angle [f(QRS-T)] are related to adverse cardiovascular outcomes. We aimed to investigate the predictive role of the Selvester QRS score and f(QRS-T) for the development of post-PCI SF in patients with Non-STEMI.In a retrospective study, 210 patients with Non-STEMI were divided into two groups as SF (29) and Non-SF (181) according to their TIMI coronary flow grade. For all patients the Selvester QRS score and f(QRS-T) were calculated from automatic electrocardiography (ECG) reports. The mean age of the study population was 63 (55-75) years and 102 (68.6%) of patients were male. The Selvester QRS score and f(QRS-T) were higher in the SF group than in the Non-SF group [(5[3-8], 3[2-5]); (67° [42°-88°], 39° [24°-59°]), respectively, all p 0.01]. In a logistic regression analysis, the Selvester QRS score (OR = 4,862; 95% (CI) = 1,131-20,904, p =0.03) and f(QRS-T) (OR = 5,489; 95% (CI)= 11,433-21,034, p =0.01) were found independent predictors of post-PCI SF in Non-STEMI patients. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic values of the Selvester QRS score [86% sensitivity; 44% specificity; cut off 2; (AUC, 0.693)] and f(QRS-T) [62% sensitivity; 73% specificity; cut off 58°; (AUC, 0.778)].The Selvester QRS score and f(QRS-T), both easy-to-calculate ECG parameters, are predictors of post-PCI SF in Non-STEMI patients.

People acquire professional knowledge and skills throughout university education during which their social relations network, orientation and social perceptions are also shaped. Due to the importan...

This study aims to investigate the predictors of reading performance and how reading performance predicts mathematics and science performances in PISA 2018 Assessment. For this purpose, the country in the focus (Turkey), the highest performer (China) in the world, and the lowest performer (Mexico) among the OECD members countries were selected as the research sample. A total of 12058 students participated from China (Male=6283, Female=5775), 6890 students from Turkey (Male=3494, Female=3396), and 7299 students from Mexico (Male=3473, Female=3826) in PISA 2018 Assessment. The results revealed that ‘Index of economic, social and cultural status’, ‘Meta-cognition: assess credibility’, and ‘Meta-cognition: summarizing’ are the most significant factors affecting students’ reading literacy in all three countries. Total explained variance explained is 41%, 41%, and 39% for Turkey, China and Mexico, respectively. ‘Index highest parental occupational status’, ‘Duration in early childhood education and care’, ‘Attitude towards school: learning activities’, and ‘Subjective well-being: Sense of belonging to school’ are not significant predictors for reading literacy of students from all three countries. In addition, regarding the predictivity of reading literacy, total variance explained is 65% in mathematics performance and approximately 77% in science performance for all three countries.

Background: Ascending aortic dilatation (AAD) is a clinical entity, which is closely related to acute aortic syndromes and can be mortal if not detected at an early stage. Interatrial block (IAB) is a conduction delay between the both atriums, and is associated with cardiovascular diseases. We think that IAB may accompany with obese patients with AAD, and the diameter of ascending aorta may be correlated with P-wave duration. Thus, in the current study, we aimed to evaluate the association between AAD and IAB in obese patients. Methods: A total of 318 consecutive obese subjects who were presented to our outpatient clinic for routine follow-up were enrolled into the study. Standard 12-lead ECGs were recorded. Clinical characteristics, echocardiographic data, and laboratory results of the patients were obtained. Results: The mean age of the patients was 62.7 ± 10.3 years, and 199 (62.5%) of the patients were female. The frequency of IAB was significantly higher and P-wave duration was significantly increased in the AAD (+) patients than in the AAD (-) subjects (p < 0.001 and p < 0.001, respectively). The strongest correlation was found between ascending aortic diameter and P-wave duration (r = 0.713, p < 0.001). In linear regression analysis, P-wave duration (β = 0.695, p < 0.001) and left atrial volume index (LAVI) (β = 0.611, p = 0.005) were found to be independent predictors of ascending aortic diameter. Conclusion: We demonstrated that prolongation of P-wave duration and increased LAVI values were significantly associated with ascending aortic diameter. Therefore, we think that P-wave duration may be used in the follow-up of the AAD patients.

Aim: Elabela (ELA) is a peptide of the apelinergic system and is known to play a role in endothelial homeostasis and vascular pathobiology. In this study, the relationship between carotid artery stenosis, which is the main culprit, and ELA level in patients with non-cardioembolic ischemic stroke was investigated. Materials & methods: Cross-sectional observation included two groups of 40 patients with critical carotid artery stenosis and 40 patients with age–sex matched noncritical carotid artery stenosis. Results: ELA levels were significantly higher in the noncritical stenosis group. ELA had a significantly moderate negative correlation with the carotid score (r = -0.334, p = 0.003), maximal carotid plaque length (r = -0.413, p

The aim of this study was to examine the moderator role of gender and socioeconomic status (SES) factors in the relationship between students' metacognitive skills and reading performance. The sample of the study was 6890 students in the age group of 15 years-old who participated in the Programme for International Student Assessment (PISA) in 2018 from Turkey. 3396 of the participants (49.30%) were female and 3494 (50.70%) of them were male. Of the participants, 2273 (32.99%) were classified as low, 2273 (32.99%) as medium and 2344 (34.02%) as high socioeconomic level. Moderator effects were tested with the multi-group structural equation modelling approach. Results revealed that SES and gender moderated the relationship between metacognitive skills and reading when controlling for other variables. Female students scored lower than male students in low and medium SES group, however they scored higher in the high SES group even after controlling for metacognitive skills, liking reading, and self-concept of perception of competence and difficulty. This means gender differences in reading scores were largely driven by SES. Therefore, the effect of these two factors should be taken into consideration while working on metacognition and reading. Moreover, it was advised to integrate training of metacognitive strategies in school curriculum and encourage reading engagement in order to reduce the effect of those factors.

In exploratory factor analysis, although the researchers decide which items belong to which factors by considering statistical results, the decisions taken sometimes can be subjective in case of having items with similar factor loadings and complex factor structures. The aim of this study was to examine the validity of classifying items into dimensions with exploratory graph analysis (EGA), which has been used in determining the number of dimensions in recent years and machine learning methods. A Monte Carlo simulation was performed with a total number of 96 simulation conditions including average factor loadings, sample size, number of items per dimension, number of dimensions, and distribution of data. Percent correct and Kappa concordance values were used in the evaluation of the methods. When the findings obtained for different conditions were evaluated together, it was seen that the machine learning methods gave results comparable to those of EGA. Machine learning methods showed high performance in terms of percent correct values, especially in small and medium-sized samples. In all conditions where the average factor loading was .70, BayesNet, Naive Bayes, RandomForest, and RseslibKnn methods showed accurate classification performances above 80% like EGA method. BayesNet, Simple Logistic and RBFNetwork methods also demonstrated acceptable or high performance under many conditions. In general, Kappa concordance values also supported these results. The results revealed that machine learning methods can be used for similar conditions to examine whether the distribution of items across factors is done accurately or not.

The purpose of this study was to examine the performance of Naive Bayes, k-nearest neighborhood, neural networks, and logistic regression analysis in terms of sample size and test data rate in classifying students according to their mathematics performance. The target population was 62728 students in the 15-year-old group who were participated in the Programme for International Student Assessment (PISA) in 2012 from The Organisation for Economic Co-operation and Development (OECD) countries. The performance of each algorithm was tested by using 11%, 22%, 33%, 44% and 55% of each dataset for small (500 students), medium (1000 students) and large (5000 students) sample sizes. 100 replications were performed for each analysis. As the evaluation criteria, accuracy rates, RMSE values, and total elapsed time were used. RMSE values for each algorithm were statistically compared by using Friedman and Wilcoxon tests. The results revealed that while the classification performance of the methods increased as the sample size increased, the increase of training data ratio had different effects on the performance of the algorithms. The Naive Bayes showed high performance even in small samples, performed the analyzes very quickly, and was not affected by the change in the training data ratio. Logistic regression analysis was the most effective method in large samples but had a poor performance in small samples. While neural networks showed a similar tendency, its overall performance was lower than Naive Bayes and logistic regression. The lowest performances in all conditions were obtained by the k-nearest neighborhood algorithm.

Bu calismanin amaci, 2012 yilinda yapilan Uluslararasi Ogrenci Degerlendirme Programi (PISA) uygulamasi ogrenci anketinden alinan bir veri uzerinde klasik test ve madde tepki kurami yontemleri ile yapilan degisen madde fonksiyonu (DMF) analizlerinin sonuclarini karsilastirmaktir. Arastirmanin calisma grubu matematik calisma disipliniyle ilgili 9 maddeye ait kayip verisi olmayan Turk ogrenciler arasindan rastgele ornekleme yontemiyle secilen 990 ogrencidir. Matematik basarisi bakimindan, ogrencilerin %45’i alt grupta, %55’i ise ust grupta yer almistir. Veri analiz yontemleri olarak Mantel-Haenszel, lojistik regresyon ve olabilirlik orani yontemleri kullanilmistir. Analizlerde JMETRIK, DIFAS, Zumbo SPSS Syntax, IRTLRDIF ve IRTPRO yazilimlari kullanilmistir. Arastirma sonuclarina gore, tum yontemlere ve yazilimlara gore ‘odevi zamaninda tamamlama’ maddesinde DMF oldugu belirlenmistir. Tum yontemlerin ve yazilimlarin sonuclari kismen benzerlikler gostermekle birlikte farkliliklar da icermektedir. Arastirmadan elde edilen bulgular ve ilgili alan yazin isiginda teori ve pratige donuk bazi onerilerde bulunulmustur.

Inlarge-scale assessments like Programme for International Students Assessment(PISA) and the Trends in International Mathematics and Science Study (TIMSS),plausible values are often used as students’ ability estimations. In thosestudies, stratified sampling method is employed in order to draw participants,and hence, the data gathered has a hierarchical structure. In the context oflarge-scale assessments, plausible values refer to randomly drawn values fromposterior ability distribution. It is reported that using one of plausiblevalues or mean of those values as independent variable in linear models maylead to some estimation errors. Moreover, it is observed that sampling weightssometimes are not used during analysis of large-scale assessment data. Thisstudy aims to investigate the influence of three approaches on the parametersof linear and hierarchical linear regression models: 1) using only oneplausible value, 2) using all plausible values, 3) incorporating samplingweights or not. Data used in the present study is obtained from school andstudent questionnaires in PISA (2015) Turkey database. Results revealed thatthe use of sampling weights and number of plausible values has significanteffects on regression coefficients, standard errors and explained variance forboth regression models. Findings of the study were discussed in details andsome conclusions were drawn for practice and further research., Uluslararası ÖğrenciDeğerlendirme Programı (PISA) ve Uluslararası Matematik ve Fen EğilimleriÇalışması (TIMSS) gibi geniş ölçekli uygulamalarda öğrenci yeteneğine ilişkinkestirimler olarak makul değerler kullanılır. Bu çalışmalarda katılımcılartabakalı örnekleme yöntemi ile çekilmektedir. Bu durum elde edilen verilerin,çok sayıdaki tabakadan oluşan hiyerarşik bir yapıda olmasının önünü açmaktadır.Geniş ölçekli değerlendirme çalışmaları bağlamında makul değerler, sonsalyetenek dağılımından rastgele elde edilen değerler olarak tanımlanmaktadır.Doğrusal modellerde tek bir makul değerin veya tüm makul değerlerinortalamasının bağımsız değişken olarak kullanılmasının yanlı sonuçlara sebepolabildiği bilinmektedir. Aynı zamanda bu geniş ölçekli çalışmaların verileriile analizler yapılırken örnekleme ağırlıklarının göz ardı edildiği sıkçagözlenmektedir. Bu çalışmanın amacı, çoklu doğrusal regresyon ve hiyerarşikdoğrusal modellerde 1) tek makul değer kullanımının, 2) tüm makul değerlerinkullanımının, 3) ağırlık kullanma durumunun parametre kestirimlerine etkisiniaraştırmaktır. Çalışmada PISA 2015 uygulamasının Türkiye verilerindenyararlanılmıştır. Araştırmada, örnekleme ağırlıkları kullanma durumunun vemakul değerlerin kullanım şeklinin kat sayıların, standart hataların veaçıklanan varyans oranının kestirilmesinde önemli rolleri olduğubelirlenmiştir. Bulgular detaylı bir biçimde tartışılmış ve uygulama ve gelecekaraştırmalar için bazı öneriler sunulmuştur.

BACKGROUND: Vitamin D (VitD) has important prohormone functions in a wide range of clinical processes. Although it is known that individuals with VitD deficiency have cardiac autonomic dysfunction, there are no convincing data regarding the effect of VitD replacement. We aimed to evaluate the impact of VitD replacement on cardiac autonomic dysfunction. METHODS: Fifty‐two apparently healthy subjects with VitD deficiency and 50 healthy control subjects were enrolled. Prior to VitD replacement, 24‐hr Holter recordings were obtained, and HRV parameters were recorded. VitD levels were measured 2 months later after replacement, and control 24‐hr Holter recordings were analyzed. RESULTS: The mean age of the patients was 36.04 ± 7.6 years, and 53.9% were female. SDNN (68.58 ± 13.53 vs. 121.02 ± 27.45 ms, p = .001), SDANN (95.96 ± 22.26 vs. 166.48 ± 32.97 ms, p = .001), RMSSD (23 vs. 59 ms, p

Bu calismanin amaci, normal gelisim gosteren lise ogrencilerinin ozel gereksinimli bireylere yonelik sosyal mesafelerini veya kabul duzeylerini belirlemektir. Bu amac dogrultusunda, psikolojik boyut uzerine maddeleri yerlestirme yaklasimlarindan olan ve denek tepkilerine dayanarak maddeleri olceklemeyi hedefleyen Guttman tipi bir olcek olusturulmustur. Arastirmanin calisma grubu, Adiyaman ilindeki cesitli okullarda okuyan lise ogrencilerinden tabakali ve amacli ornekleme yoluyla secilen 492 katilimcidir. Tarama modelinde olan bu calismada, lise ogrencilerinin ozel gereksinimli bireylerle ayni mahallede, okulda, sinifta, grupta ve sirada bulunmaya ne duzeyde istekli olduklari belirlenmistir. Tum ozel gereksinim gruplari icin yeniden uretilebilirlik (>0,90) ve olceklenebilirlik (>0,60) katsayilarinin onerilen olcutleri karsiladigi ve olcek maddelerinin onsel dizilimlerinin oldukca yerinde oldugu gorulmustur. Arastirma bulgularina gore, lise ogrencilerinin ortalama kabul duzeyleri acisindan, zihin engelli ve otizmli bireylerle ayni mahallede, okulda ve sinifta okumayi tercih ettikleri; ayni grupta calismayi veya sira arkadasi olmayi tercih etmedikleri gorulmustur. Ogrenme guclugu olan, isitme, gorme ve fiziksel engelli bireylerle ayni mahallede, okulda, sinifta ve grupta calismayi tercih ettikleri ancak sira arkadasi olmayi tercih etmedikleri anlasilmistir. Ustun zekali/yetenekli bireylerle ise sozu edilen tum ortamlarla birlikte ayni sirada oturmayi da tercih ettikleri gorulmustur. Lise ogrencilerinin sinif duzeyleri acisindan engelli bireylere yaklasim duzeyleri arasinda anlamli farklilik bulunamamistir (p>0.05). Arastirmada bulgular tartisilarak bazi onerilerde bulunulmustur.

This study aimed to examine the importance levels of mathematics-specific trend variables in PISA (Programme for International Student Assessment) 2003 and 2012 in predicting mathematics performance across years with a two-step analysis method. The sample of the study was 9703 Turkish students (N2003=4855 and N2012=4848) selected by clustered and systematic sampling methods. As data analysis methods, multilayer perceptron and radial basis functions techniques of artificial neural networks and multiple linear regression were used. In the two-step analysis, first, the least erroneous model was selected as the analysis method. Then, variable importance analysis was performed with this method. The results with the lowest relative errors were obtained by the multilayer perceptron when compared to radial basis functions. The results of neural network analysis had similar or lower error rates when compared to multiple linear regression. In both PISA cycles, significant predictors were mathematics self-efficacy, mathematics interest, student-teacher relations in school, attitudes towards the school, mathematics self-concept, mathematics instrumental motivation, and teacher support in mathematics classes, respectively. The results were discussed in the light of relevant literature.

This paper aims to review the scale development research published in Turkey between 2006 and 2016 with regard to their processes of exploratory (EFA) and confirmatory factor analysis (CFA). Within this scope, the distribution of the studies according to years and factor analyses, the extent to which their hypotheses came through for both analysis methods, and the distribution of EFA and CFA results according to the published papers were investigated. In this way, we aimed to infer significant results on the practical application of EFA and CFA which are frequently referred in theory. Hence, the present research incorporates a descriptive document analysis on 131 scale development studies published in the fields of education and social sciences in the journals indexed in The Scientific and Technological Research Council of Turkey (TÜBİTAK) TR Dizin data base between 2006 and 2016. Frequency tables, column charts, histogram, line charts, and measures of central tendency were used to analyse the data. More than 70% of 131 scale development studies were carried out after 2013. The maximum number of studies was published in 2015, and the minimum number in 2008. Only EFA was used in 59 articles, only CFA was used in 4 articles, and both analysis methods were employed in 58 articles. The remaining 10 papers used none of the analyses and included only item analyses. The average sample sizes were 395 participants for EFA and 529 participants for CFA. Sample sizes were accordingly adequate in terms of the factor analyses. EFA and CFA were conducted over the same sample in 36 papers, whereas the analyses were based on different samples in 22 ones. In terms of estimation, 65% of 117 EFA using papers employed Principle Component Analysis (PCA), 2% used Maximum Likelihood Estimation (MLE), 1% used Parallel Analysis (PA), and 3% used Principle Axis Factoring (PAF), while 29% did not specify their method of estimation. The hypotheses of EFA analyses were examined in 93% of the papers. Scree plots were taken into consideration when determing the number of factors in 50% of the papers. Varimax rotation method was used in 67% of the EFA using papers. The total variance explained was 53.05%. The analytical hypotheses were not examined in 87% of the 62 studies conducted with CFA; 51 of them included track diagrams and 52 included factor loadings. 90% of the papers did not give any information on parameter estimation method. All indices, except the Parsimony Goodness of Fit Index (PGFI), were acceptable as model fit indices in the papers. The results from the papers examined were evaluated in the light of the relevant literature in the last section of the present paper, and some suggestions were made in reference to both theory and practice., Bu çalışmanın amacı, Türkiye’de 2006-2016 yılları arasında yayınlanan ölçek geliştirme çalışmalarını açımlayıcı faktör analizi (AFA) ve doğrulayıcı faktör analizinin (DFA) kullanımı bakımından incelemektir. Bu kapsamda, yapılan çalışmaların yıllara ve kullanılan faktör analizi türüne göre nasıl bir dağılım gösterdiği, her iki analiz yöntemi için varsayımların sağlanma durumları ile açımlayıcı ve doğrulayıcı faktör analizi sonuçlarının makalelere göre nasıl bir dağılım gösterdiği incelenmiştir. Böylece, teorik olarak sıkça değinilen AFA ve DFA’nın pratikte nasıl uygulandığına yönelik önemli bulguların elde edilmesi amaçlanmıştır. Derleme çalışması niteliğinde olan bu araştırmada, 2006 ile 2016 yılları arasında Türkiye Bilimsel ve Teknik Araştırma Kurumu (TÜBİTAK) Dergi Park veri tabanında taranan dergilerde eğitim ve sosyal bilimler alanlarında yayınlan toplam 131 ölçek geliştirme çalışması incelenmiştir. Verilerin incelenmesinde frekans tabloları, yüzdeler, sütun, histogram ve çizgi grafikleri ve merkezi eğilim ölçüleri kullanılmıştır. Araştırmada incelenen 131 ölçek geliştirme çalışmasının %70’inden fazlası 2013 yılından sonra yapılmıştır. En fazla çalışma 2015 yılında, en az çalışma ise 2008 yılında yapılmıştır. Makalelerin 59’unda sadece AFA, dördünde sadece DFA ve 58’inde her iki analiz birlikte yapılmış, onunda ise her iki analiz de yapılmamış sadece madde analizlerine yer verilmiştir. AFA için kullanılan ortalama örneklem büyüklüğü 395 kişiyken DFA için 529 kişidir. Buna göre, faktör analizleri için örneklem büyüklüklerinin genel olarak yeterli olduğu görülmüştür. 36 çalışmada AFA ve DFA aynı örneklem üzerinde gerçekleştirilirken, 22’sinde farklı örneklemler üzerinde analizler yapılmıştır. AFA yapılan 117 çalışmanın %65’inde kestirim yöntemi olarak Temel Bileşenler Analizi (TBA), %2’sinde Maximum Likelihood Estimation (MLE), %1’inde Paralel Analiz (PA) ve %3’ünde Parallel Axis Factoring (PAF) kullanılmış, %29’unda belirtilmemiştir. AFA analizinin varsayımları çalışmaların %93’ünde incelenmiştir. Faktör sayısına karar verirken çalışmaların %50’sinde yamaç grafiği göz önünde bulundurulmuştur. AFA yapılan araştırmaların %67’sinde Varimax döndürme yöntemi kullanılmıştır. Açıklanan ortalama toplam varyans oranı %53.05’tir. DFA yapılan 62 çalışmanın %87’sinde analizin varsayımları incelenmemiş, 51’inde yol diyagramları, 52’sinde faktör yükleri verilmiştir. Çalışmaların %90’ında parametre kestirim yöntemiyle ilgili herhangi bir bilgi verilmemiştir. Çalışmalarda model uyum/uyumsuzluk indeksleri olarak Parsimony Goodness of Fit Index (PGFI) dışında diğer tüm indekslerin kabul edilebilir düzeyde olduğu görülmüştür. Çalışmanın son bölümünde incelenen araştırmalardan elde edilen bulgular, ilgili alan-yazın ışığında değerlendirilerek, teori ve uygulamaya dönük bazı önerilerde bulunulmuştur.

Giriş:Stabil koroner arter hastalığında doğrudan stent veperkütan translüminal koroner anjiyoplasti (PTKA) sonrasında stentlemeyöntemlerinin koroner kan akımı üzerine etkisini karşılaştıran yeterli veriyoktur. Çalışmamızda, doğrudan stent ve PTKA sonrası stentleme yöntemlerininkoroner kan akımı üzerine etkisi TIMI kare sayısı (TKS) kullanılarakkarşılaştırıldı.Hastalarve Yöntem: 2008-2012 yılları arasındaperkütan koroner girişim (PKG) yapılan hastalar taranarak, doğrudan stentlemeuygulanmış 55 hasta ve PTKA sonrası stentleme uygulanmış 42 hasta çalışmayaalındı. Hastaların PKG kayıtları izlendi. Her hasta için işlem öncesi vesonrası TKS hesaplandı. İki tedavi grubu işlem öncesi ve sonrası TKS açısındankarşılaştırıldı.Bulgular:Doğrudan stent grubunda ortalama TKS işlemöncesinde 18.72 kare/saniye, işlem sonrasında 16.12 kare (fark 2.6 kare/saniye)bulundu; PTKA sonrası stent grubunda ise bu değerler sırasıyla 18.13kare/saniye ve 16.63 kare/saniye (fark 1.5 kare/saniye) idi. İşlem sonrasıTKS’deki azalma açısından iki grup arasındaki fark anlamlı idi (p< 0.001).Sonuç: Bulgularımız, stabil koroner arterhastalığında doğrudan stentleme yönteminin koroner kan akımını iyileştirmedePTKA sonrası stentlemeye göre daha başarılı olduğunu gösterdi. Bu bulgu,doğrudan stentleme ile daha iyi mikrovasküler dolaşım sağlandığını düşündürmektedir., Introduction:There are limited data comparing the effects ofdirect stenting and stenting after balloon percutaneous transluminal coronaryangioplasty (PTCA) on coronary flow in patients with stable coronary artery disease(CAD). This study was designed to evaluate the effects of direct stenting andstenting after balloon PTCA on coronary flow using TIMI frame count (TFC) inpatients with stable CAD.Patientsand Methods: After a retrospective review of patients who underwentpercutaneous coronary intervention (PCI) from 2008 to 2012, we identified andincluded 55 patients who underwent direct stenting and 42 patients who receivedstenting after balloon PTCA. PCI records of the two study groups were reviewedto re-calculate pre- and post-PCI TFCs for comparison.Results:The average pre- and post-procedural TFC valueswere 18.72 frames per second (fps) and 16.12 fps (difference 2.6 fps),respectively, in the direct stenting group. The corresponding TFC values were18.13 fps and 16.63 fps (difference 1.5 fps) in the stenting after balloon PTCAgroup. The two groups differed significantly with respect to post-proceduraldecreases in TFC (p< 0.001).Conclusion:Our findings show that, compared to stenting afterballoon PTCA, direct stenting is more successful in terms of improved antegradecoronary blood flow in stable CAD patients, which suggests that direct stentingmay contribute to better microvascular circulation.

In patients admitted to outpatient clinics with chest pain, changes in the ST-segments of electrocardiogram (ECG) readings are the most widely used criteria during treadmill ECG tests to determine myocardial ischaemia, despite its poor accuracy. In this study, we evaluated the benefit of combining elongation of P-wave duration (Pdur) and abnormal heart rate recovery (HRR) parameters in addition to changes in the ST-segments for the detection of myocardial ischaemia with treadmill ECG testing.Patients (n = 369) with chest pain who underwent both a treadmill ECG test and myocardial perfusion scintigraphy (MPS) were enrolled. P-wave duration was measured at rest and at the end of the first minute of the recovery phase and elongation of the P-wave was calculated. Abnormal HRR was defined as the failure of a decreasing HR at the end of the first minute of the recovery phase10% of the maximum HR reached during treadmill ECG testing. The sensitivity, specificity, positive and negative predictive values, diagnostic accuracy values, and likelihood ratios (LRs) of changes in the ST-segments, P-wave elongation, abnormal HRR, and the combination of these three variables for predicting myocardial ischaemia detected by MPS, were calculated separately-in patients without previous coronary artery disease (CAD) and in those with CAD.Elongation of Pdur by 20 ms or longer and abnormal HRR during treadmill ECG test were more common in patients with reversible perfusion defects in MPS than in those without perfusion defects (both P0.001). When patients were divided into two groups according to the presence or absence of a history of CAD, the addition of elongation of Pdur 20 ms and abnormal HRR to the development of significant changes in the ST-segments detected myocardial ischaemia with 46.7% sensitivity, 97.8% specificity, 67.2% negative predictive value, 88.9% positive predictive value, and 70% diagnostic accuracy in 77 patients with previous CAD. The LR+ of the combination of the three variables was 12.27. The addition of elongation of Pdur 20 ms and abnormal HRR to the development of significant changes in the ST-segments detected myocardial ischaemia with 52.7% sensitivity, 98.7% specificity, 89.9% negative predictive value, 90.6% positive predictive value, and 90% diagnostic accuracy in 292 patients without previous CAD. The LR+ of the combination of the three variables to detect myocardial ischaemia was calculated to be 41.48 in patients without a history of CAD.The addition of elongation of Pdur and abnormal HRR to the conventionally used criterion of changes in the ST-segments in patients with suspected myocardial ischaemia increased the specificity and positive and negative predictive values of treadmill ECG testing for detecting myocardial ischaemia, which might reduce the need for other expensive noninvasive techniques. The diagnostic utility of adding these two parameters was more obvious in patients with no history of CAD.

This study aims to investigate plane geometry problem-solving strategies of prospective mathematics teachers using dynamic geometry software (DGS) and paper-and-pencil (PPB) environments after receiving an instruction with GeoGebra (GGB). Four plane geometry problems were used in a multiple case study design to understand the solution strategies developed by 2 prospective teachers. The results revealed that although the participants mostly used algebraic solutions in the PPB environment, they preferred geometric solutions in the GGB environment even though algebraic solutions were still possible (the software did not preclude them). Furthermore, different proofing strategies were developed in each environment. This suggests that changing the environment may prompt students to seek for additional solutions, which, in turn, results in a deeper understanding of the problem. As such, using both environments simultaneously in solving the same problems appears to bring about important benefits.

Mathematical modeling has come into prominenceduring the last few decades in many countries’ mathematics teaching curricula.It combines real life situations with mathematical context. Although evaluatingstudents’ mathematical modeling performances with a unique Likert typeinstrument is questionable, having an instrument about their self-efficacybeliefs in mathematical modeling may help to comment about their ideas relatedto their competencies in mathematical modeling. The purpose of this study is todevelop a reliable and valid measurement scale to determine mathematicalmodeling self-efficacy of mathematics teacher candidates. For this purpose, thedraft and final form of the scale were applied to a total of 562 pre-serviceelementary mathematics teachers from various public universities in Turkey. Thefindings of study revealed that the scale is unidimensional according to theresults of exploratory factor analysis. The unidimensionality of the scale wasvalidated by confirmatory factor analysis. The reliability of mathematicalmodeling self-efficacy scale was very high (.97). Finally, it was found thatthis scale is an appropriate measurement tool to evaluate students’self-efficacy beliefs on their mathematical modeling competencies. Somesuggestions related to the scale and for further studies were given at the end., Mathematical modeling has come into prominence during the last few decades in many countries’ mathematics teaching curricula. It combines real life situations with mathematical context. Although evaluating students’ mathematical modeling performances with a unique Likert type instrument is questionable, having an instrument about their self-efficacy beliefs in mathematical modeling may help to comment about their ideas related to their competencies in mathematical modeling. The purpose of this study is to develop a reliable and valid measurement scale to determine mathematical modeling self-efficacy of mathematics teacher candidates. For this purpose, the draft and final form of the scale were applied to a total of 562 pre-service elementary mathematics teachers from various public universities in Turkey. The findings of study revealed that the scale is unidimensional according to the results of exploratory factor analysis. The unidimensionality of the scale was validated by confirmatory factor analysis. The reliability of mathematical modeling self-efficacy scale was very high (.97). Finally, it was found that this scale is an appropriate measurement tool to evaluate students’ self-efficacy beliefs on their mathematical modeling competencies. Some suggestions related to the scale and for further studies were given at the end.

Article history: Received 25 August 2015 Accepted 26 August 2015 Available online 30 August 2015 [1] Emilio Di Lorenzo, Rosario Sauro, Michele Capasso, Francesca Lanni, Tonino Lanzillo, Giannignazio Carbone, Fiore Manganelli, Vittorio Palmieri, Vincenzo Serino, Maria Rosaria Pagliuca, Giuseppe Rosato, Harry Suryapranata, Giuseppe De Luca, Longterm results of the RAndomized Comparison of Everolimus-Eluting Stents and SirolimusEluting stent in patients with ST Elevation Myocardial Infarction (RACESMI trial), Int. J. Cardiol. 202 (2015) 177–182 (2). [2] G. De Luca, H. Suryapranata, J.P. Ottervanger, E.M. Antman, Time delay to treatment and mortality in primary angioplasty for acute myocardial infarction: every minute