The Effects of Investor Behavior on Market Predictability

This study aimed to test the effects of investor behavior on the predictability of the market by testing CAPM estimation errors in negative growth period and growth period of the market. This study also aims to draw attention to the existence of some factors that may affect the CAPM estimation errors. Negative growth period is the period in which irrational behavior is likely to occur. Growth period is the period when irrational behaviors are less common. CAPM estimation errors calculated by jensen’s alpha, sharpe ratio, sortino ratio and treynor ratio were compared by T-Test and Mann-Whitney U Test during negative growth periods and growth periods.USA-S&P 500, Germany-DAX 100, England-FTSE 100, France-CAC All Tradable, Canada-S&P TSX, Japan-Nikkei 225 developed countries and their indices and India S&P BSE 200, China-SSE Composite, South Africa &-FTSE JSE African All Share, Turkey-BIST 100 developing countries and their indices included in the study. Between January 31,2005 and December 31,2018 monthly closing prices of the indices, monthly closing prices of stocks listed in consumer staples sectors and consumer discretionary sectors were used.As a result of the study, it has been observed that CAPM estimation errors calculated by jensen’s alpha and treynor ratio in consumer staples and consumer discretionary sectors in developed and developing countries do not differ during negative growth periods and growth periods of the market. It cannot be said that CAPM is more reliable or unreliable in negative growth periods compared to growth periods. It has been determined that CAPM estimation errors calculated by sharpe ratio and sortino ratio differ during negative growth periods and growth periods. It can be said that CAPM is less reliable in negative growth periods compared to growth periods

Bina maketlerinin eğitim materyali olarak kullanılması ve öğrenme üzerindeki etkisi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Yapı Eğitimi bölümünde öğrenci başarısını ve derse olan ilgiyi artırmak amacıyla, bir bina maketinin eğitim materyali olarak kullanılması incelenmiştir. Son yıllarda hızla önemini artıran maket materyalinin tanımı, çeşitleri ve kullanım alanları belirtilerek, temsil ettiği nesnenin somut bir örneği olması sebebiyle, öğrenme ve öğretimde kullanılması ele alınmıştır.Araştırma kapsamında, Yapı Eğitimi 1. Sınıf öğrencilerine, Teknik Resim dersinin ?Plandan kesit çıkartma? konusu anlatılırken uygulanabilecek kolaylıkta bir proje hazırlanarak, projenin plan ve kesitlerini gösteren bir maketi yapılmıştır. Daha sonra öğrenciler ?Deney? ve ?Kontrol? olmak üzere iki gruba ayrılarak, öğrencilerin konuyla ilgili ön bilgi ve tutumları ölçülmüş, ardından kontrol grubunda öğretmen merkezli, deney grubunda ise maket üzerinde konu anlatımı yapılmıştır. Anlatımlar sonunda her iki grubunda başarı ve tutumları tekrar ölçülerek sonuçlar değerlendirilmiştir. Değerlendirmede maket destekli öğretim tekniğinin kullanıldığı Deney grubunda, başarı ve tutumun, öğretmen merkezli anlatım tekniğiyle ders işlenen kontrol grubuna göre daha fazla yükseldiği görülmüştür.A building model were exemined to used as a model of the education material, student success and increase for their interest in course in section of construction training. In recent years, the quickly increasing importance of the definition of the model material, variations and using of areas by inditacing, due to represents a concrete example of the object, has been taken up in learning and teaching. In the research coverage a model has been built to showing of projet?s plans and sections, a project are prepared in a convenience that can be applied in Technical Drawing course "Creating a cross-section of the Plan" for Construction Education first class students.Afterward students divided into two groups by ?Experimental and Control?, students' attitudes and prior knowledges were evaluated about subject, after subject description was made on the model Experimental group and teacher-centered in the control group. At the end of expression both of groups? success and attitude were evaluated by measuring the results. Success and attitudes observed to increase more than the evaluation techniques used by model-aided education in the experimental group according as teacher-centered lessons in control group

Estimating the compressive strength of fly ash added concrete using artificial neural networks

The aim of this study is to develop an artificial intelligence that predicts the compressive strength of fly ash substituted concretes using material mixing ratios. Within the scope of the study, 5 different fly ash mixed concrete samples were estimated. The strength values were estimated using artificial neural networks before the produced samples were subjected to the pressure test. In order to develop the artificial neural network, it is introduced as a dataset of 1030 different mixing ratios consisting of experimental results in the existing literature. In order to estimate the compressive strength, varying ratios of 8 different materials such as water, cement, fly ash entering the mixture are analyzed. As a result of the study, it has been observed that the predictions made using artificial neural networks are very close to the strength values obtained from the experiment

An Alternative Surgical Procedure for a Patient with Critically Restenosed and Kinked Carotid Artery: Graft Interposition

According to the literature data, the prevalence of restenosis after carotid endarterectomy ranges between 6 and 36%. The etiological factor is intimal hyperplasia for early period, whereas it is atherosclerosis for late period. A 67-year-old male patient admitted to our clinic with a history of headache and minor stroke. His medical history was significant for right carotid endarterectomy 8 years ago. Recent Doppler ultrasound and digital substraction angiography revealed 75% stenosis and kinking corresponding to the segment distal to the endarterectomy region. Surgical endarterectomy is the treatment of choice in critical carotid stenosis. Endovascular therapy is primarily considered for patients if there is restenosis after carotid endarterectomy. However, the treatment modality is controversial in cases with concomitant carotid stenosis and kinking of internal carotid artery. We present our surgical approach to a case with significant stenosis and kinking of internal carotid artery. We performed a 6-mm-PTFE graft interposition between common and internal carotid artery and resection of the kinking segment

The accessory head of the biceps brachii muscle originating from the brachialis muscle: A case report

Rutin diseksiyon çalışmaları sırasında 65 yaşında bir erkek kadavranın sol kolunda biseps kasının bir aksesuvar başına rastlandı. Bu oluşum brakiyalis kasından ve medial intermusküler septumdan köken alıyordu. Beslenmesi brakiyal arterden gelen kısa musküler bir dal ile sağlanmaktaydı. İnnervasyonunu ise muskülokutanöz sinirden kısa ayrılan ince bir dal gerçekleştirmekteydi. Aksesuvar başın genellikle brakiyalis kasının üst-iç kısmından kaynaklandığı bilinmektedir; olgumuzda ise alt-iç kısımdan kaynaklanmaktaydı.An accessory head of the biceps brachii muscle was found in the left arm of a 65-year-old male cadaver during routing dissection studies. It originated from the brachialis muscle and medial intermuscular septum. The arterial supply was provided by a short muscle branch of the brachial artery and its neural innervation by a short thin branch of the musculocutaneus nerve. In general, the accessory head originates from the upper-medial component of the brachialis muscle, whereas it stemmed from the lower-medial component in this case

Kardiyak cerrahide miyokardiyal koruma açısından intermittant antegrad kardiyopleji ile antegrad/retrograd sürekli kardiyoplejinin karşılaştırılması

Amaç: Bu çalışmada kardiyak cerrahide miyokardiyal koruma açısından intermittant antegrad kardiyopleji ile antegrad/retrograd sürekli kardiyopleji karşılaştırıldı. Ça­lış­ma­pla­nı:­ Ekim 2010 - Ocak 2011 tarihleri arasında kliniğimizde kardiyak cerrahi ameliyatı uygulanan 106 hasta çalışmaya alındı. Hastalar, intermittant antegrad kardiyopleji uygulananlar (grup 1; 18 kadın, 14 erkek) ve antegrad/retrograd sürekli kardiyopleji uygulananlar (grup 2; 16 kadın, 58 erkek) olmak üzere iki gruba ayrıldı ve ameliyat sonrası elde edilen sonuçlar karşılaştırıldı. İşlem sürecinde troponin-I, kreatin kinaz-miyokard bandı (CK-MB) düzeyleri, kardiyopulmoner baypas (KPB) ve kros klemp süreleri, kardiyopleji toplam miktarları ve potasyum kullanımı değerlendirildi. Bul gu lar: Bulgularımıza göre, ortalama troponin-I ve CK-MB değerleri grup 1’de grup 2’den daha yüksekti. Ancak bu farklılık istatistiksel olarak anlamlı değildi. Grup 1’de troponin-I ve CK-MB değerleri kros-klemp ve KPB süresi ile korele iken, grup 2’de troponin-I ve CK-MB değerleri kros-klemp ve KPB süresi ile korele değildi. So­nuç:­ Troponin-I, CK-MB düzeyleri ile KPB ve kros-klemp zamanları arasında anterograd/retrograd sürekli kardiyopleji uygulanan grupta korelasyon bulunmadı. Buna göre, antegrad/ retrograd sürekli kardiyopleji ile efektif miyokardiyal koruma sağlandığında, troponin-I ve CK-MB değerleri etkilenmedi ve miyokardiyal koruma daha iyiydi. Anterograd/retrograd sürekli kardiyopleji daha iyi miyokardiyal koruma sağlasa da anterograd kardiyopleji sırasında aort basıncı istenen düzeylerde tutulabilmesi için monitörize edilmeli ve retrograd kardiyopleji sırasında da retrograd kanül doğru yerde tutulmalıdır. Anah­tar­söz­cük­ler: Kardiyopleji, koroner baypas cerrahi, miyokardiyal yaralanma, miyokardiyal koruma.Background:­ This study aims to compare intermittent antegrade cardioplegia and antegrade/retrograde continuous cardioplegia in terms of myocardial protection in cardiac surgery. Methods: Hundred six patients who underwent cardiac surgery in our clinic between October 2010 and January 2011 were included in the study. Patients were divided into two groups as patients who received intermittent antegrade cardioplegia (group 1; 18 females, 14 males) and who received antegrade/retrograde continuous cardioplegia (group 2; 16 females, 58 males), and postoperative results were compared. Troponin-I, creatine kinase-myocardial band (CK-MB) levels, durations of cardiopulmonary bypass (CPB) and cross-clamping, total amounts of cardioplegia, and potassium utilization during the process were evaluated. Results:­ According to our results, mean troponin-I and CK-MB levels were higher in group 1 than group 2. However, this difference was not statistically significant. While troponin-I and CK-MB values were correlated to durations of cross-clamping and CPB in group 1, troponin-I and CK-MB values were not correlated to durations of cross-clamping and CPB in group 2. Conclusion:­ No correlation was detected between troponin I, CK-MB levels, and durations of CPB and cross-clamping in the group which received anterograde/retrograde continuous cardioplegia. Therefore, troponin-I and CK-MB levels were not affected and myocardial protection was better once effective myocardial protection was obtained by antegrade/retrograde continuous cardioplegia. Although antegrade/retrograde continuous cardioplegia provides better myocardial protection, aortic pressure must be monitored to be kept between desired levels during antegrade cardioplegia, and the retrograde cannula must be kept in the appropriate place during retrograde cardioplegia

Diagnosis and management of carotid body tumor: a report of seven cases

Bozok, Sahin/0000-0002-1256-5055WOS: 000314377200038Paragangliomas are rare asymptomatic painless tumors, originating from paraganglionic bodies of autonomous nerve system of the embriological neural crest and increasing gradually. Despite their gradual developing nature, it is critical to reach early diagnosis and tailor surgical plan for carotid body tumors due to their potential of being malignant and local aggressive development, as well as invasion or pressure on the adjacent vascular and neural tissues. in this article, we present seven cases who were admitted with the complaints of pain and swelling in the neck and were diagnosed with carotid body tumor based on the further investigations and were surgically treated in the light of literature review and different surgical modalities were discussed

The effect of combined hyperbaric oxygen and iloprost treatment on the prevention of spinal cord ischaemia-reperfusion injury: an experimental study

Bozok, Sahin/0000-0002-1256-5055; Durakoglugil, Emre/0000-0001-5268-4262WOS: 000325763500005PubMed: 23946499Hyperbaric oxygen (HBO) has been shown to be effective in preventing neurological injuries in animal models of ischaemia, whereas iloprost (IL) prevents ischaemia-related mitochondrial dysfunction and reduces infarction size after focal cerebral ischaemia in animal models. the aim of the present study was to investigate the effect of combined HBO and IL treatment on spinal cord ischaemia-reperfusion (IR) injury by neurological, histopathological and biochemical methods in an experimental study. Eighty New Zealand white male rabbits were randomly allocated into one of five study groups. the HBO group received a single session of HBO treatment and the IL group received an infusion of 25 ng/kg/min IL; the HBO + IL group received both HBO and IL and the control group received only 0.9% saline; the fifth group was the sham group. Levels of S100 beta protein, neuron-specific enolase (NSE) and nitric oxide (NO) were measured at onset, at the end of ischaemia period and at the 24th and 48th hour of reperfusion. Physical activity was assessed using Tarlov criteria 24, and the spinal cords of the sacrificed rabbits were evaluated histopathologically. Additionally, tissue malondialdehyde (MDA) and antioxidant enzyme activities [total superoxide dismutase (SOD); catalase (CAT) and glutathione peroxidase (GSH-Px) were assessed. Neurological scores in the HBO, IL and HBO + IL groups were statistically significantly better compared with the control group at the 24th (P = 0.001 for all) and 48th hour (P = 0.001 for all). Histopathological scores in the HBO, IL and HBO + IL groups were also significantly better compared with the control group (P = 0.003, 0.001 and 0.001, respectively). Whereas MDA, NSE, S100 beta protein and NO concentrations were significantly lower, CAT and GSH-PX levels were significantly higher in either sham or treatment groups compared with the control group. Since we demonstrated beneficial effects on spinal cord IR injury, we think that both HBO and IL, either alone or in combination, may be reasonable in the treatment of IR injury. Furthermore, there did not appear to be synergistic effects with combined treatment. More research is needed for practical application in humans, following thoracoabdominal aortic surgery

Mini-plate fixation via sinus tarsi approach is superior to cannulated screw in intra-articular calcaneal fractures: A prospective randomized study

WOS: 000441599800001PubMed ID: 30101667Objective: Intra-articular displaced calcaneal fractures are common fractures and are often treated with surgical interventions. Sinus tarsi approach provides secure access to lateral wall and joint facets. The aim of the study is to compare cannulated screw (CS) fixation and mini-plate (MP) fixation via sinus tarsi approach with Sanders types 2 and 3 fracture of calcaneus. Methods: Sixty patients with Sanders types 2 and 3 calcaneal fracture underwent surgical intervention were randomly allocated into two groups as group MP fixation and group CS fixation regarding osteosynthesis method for 5-year period. Open reduction via sinus tarsi approach was performed in both groups. Demographic variables, time to surgery (TS), operation duration (OD), length of hospital stay (LOS), surgical complications, and reoperations were recorded. Pre- and postoperative Gissane and Bohler angles; calcaneal length, height, and width; ankle anterior-posterior (AP) and lateral X-rays; and computed tomography were also recorded for radiological evaluation and fracture characteristics. Maryland Foot Score (MFS) was used to evaluate functional outcomes. Results: Preoperative age, type of fracture, calcaneal length, height, and Gissane and Bohler angles, TS, LOS, and OD were not different between the groups. The postoperative calcaneal widening was significantly better restored in group MP compared with that of group CS. The incidence of reoperation and algoneurodystrophy was statistically higher in group CS than group MP. MFS in group MP was also higher than group CS at final visit. Conclusion: MP fixation via sinus tarsi approach is superior to CS fixation in Sanders types 2 and 3 calcaneal fractures