Etkin piyasa hipotezi ve gelişmekte olan piyasaların birlikte hareketi

The main purpose of this study is to investigate stock market cointegration from the market efficiency perspective. Therefore, eleven emerging stock market indices are tested by using weekly data for the period of January 1998-December 2008 and for the sub period of January 2002-December 2008. Comovement among the emerging market countries was analyzed through Johansen cointegration test. The existence of two cointegrating vectors has been found at 5% significance level. However, the firm evidence against the market efficiency could not be established because of the low explanatory power of the results generated from the vector error correction model.Bu çalışmanın amacı hisse senedi piyasaları eşbütünleşimini etkin pazar pespektifinden araştırmaktır. Bu bağlamda 11 gelişmekte olan piyasanın Ocak 1998-Aralık 2008 ve Ocak 2002-Aralık 2008 dönemli haftalık verileri test edilmiştir. Gelişmekte olan ülke piyasalarının birlikte hareketi Johansen eşbütünleşim testi ile incelenmiş ve %5 anlamlılık düzeyinde iki eşbütünleşim vektörü bulunmuştur. Buna rağmen vektör hata düzeltme modelinin açıklama gücünün düşük olmasından dolayı piyasa ekinliğine karşı kesin bir bulgu ortaya konulamamıştır

Efficient Market Hypothesis and Comovement Among Emerging Markets

Bu çalışmanın amacı hisse senedi piyasaları eşbütünleşimini etkin pazar pespektifinden araştırmaktır. Bu bağlamda 11 gelişmekte olan piyasanın Ocak 1998-Aralık 2008 ve Ocak 2002-Aralık 2008 dönemli haftalık verileri test edilmiştir. Gelişmekte olan ülke piyasalarının birlikte hareketi Johansen eşbütünleşim testi ile incelenmiş ve %5 anlamlılık düzeyinde iki eşbütünleşim vektörü bulunmuştur. Buna rağmen vektör hata düzeltme modelinin açıklama gücünün düşük olmasından dolayı piyasa ekinliğine karşı kesin bir bulgu ortaya konulamamıştır.The main purpose of this study is to investigate stock market cointegration from the market efficiency perspective. Therefore, eleven emerging stock market indices are tested by using weekly data for the period of January 1998-December 2008 and for the sub period of January 2002-December 2008. Comovement among the emerging market countries was analyzed through Johansen cointegration test. The existence of two cointegrating vectors has been found at 5% significance level. However, the firm evidence against the market efficiency could not be established because of the low explanatory power of the results generated from the vector error correction model

Efficient Market Hypothesis and Comovement Among Emerging Markets

Bu çalışmanın amacı hisse senedi piyasaları eşbütünleşimini etkin pazar pespektifinden araştırmaktır. Bu bağlamda 11 gelişmekte olan piyasanın Ocak 1998-Aralık 2008 ve Ocak 2002-Aralık 2008 dönemli haftalık verileri test edilmiştir. Gelişmekte olan ülke piyasalarının birlikte hareketi Johansen eşbütünleşim testi ile incelenmiş ve %5 anlamlılık düzeyinde iki eşbütünleşim vektörü bulunmuştur. Buna rağmen vektör hata düzeltme modelinin açıklama gücünün düşük olmasından dolayı piyasa ekinliğine karşı kesin bir bulgu ortaya konulamamıştır.The main purpose of this study is to investigate stock market cointegration from the market efficiency perspective. Therefore, eleven emerging stock market indices are tested by using weekly data for the period of January 1998-December 2008 and for the sub period of January 2002-December 2008. Comovement among the emerging market countries was analyzed through Johansen cointegration test. The existence of two cointegrating vectors has been found at 5% significance level. However, the firm evidence against the market efficiency could not be established because of the low explanatory power of the results generated from the vector error correction model

Makine öğrenmesi teknikleriyle saldırı tespiti: Karşılaştırmalı analiz

İnternet, günlük hayatımızın vazgeçilmez bir parçasıdır. Artan web uygulamaları ve kullanıcı sayısı, veri güvenliği açısından bazı riskleri de beraberinde getirmiştir. Ağ güvenliği için önemli araçlardan biri olan saldırı tespit sistemleri, güvenli iç ağlara yapılan saldırıları ve beklenmeyen erişim taleplerini tespit etmede başarılı bir şekilde kullanılmaktadır. Günümüzde, pek çok araştırmacı, daha etkin saldırı tespit sistemi gerçekleştirilmesi amacıyla çalışma yapmaktadır. Bu amaçla literatürde farklı makine öğrenme teknikleri ile gerçekleştirilmiş pek çok saldırı tespit sistemi vardır. Yapılan bu çalışmada, saldırı tespit sistemlerinde sıklıkla kullanılan makine öğrenme teknikleri araştırılmış, kullandıkları sınıflandırıcılar, veri setleri ve elde edilen başarılar değerlendirilmiştir. Bu amaçla 2007-2013 yılları arasında SCI, SCI Expanded ve EBSCO indekslerince taranan ulusal ve uluslararası dergilerde yayınlanmış 65 makale incelenmiş, sonuçlar, karşılaştırılmalı bir şekilde sunulmuştur. Böylece, gelecekte yapılacak makine öğrenme teknikleri ile saldırı tespiti çalışmalarına bir bakış açısı kazandırılması amaçlanmıştır

Cerebellar Infarction in Childhood: Delayed-Onset Complication of Mild Head Trauma

How to Cite This Article: Oz II, Bozay Oz E, Şerifoğlu I, Kaya N, Erdem O. Cerebellar Infarction in Childhood: Delayed-Onset Complication of Mild Head Trauma. Iran J Child Neurol. Summer 2016; 10(3):82-85.Objective Cerebellar ischemic infarction is a rare complication of minor head trauma. Vertebral artery dissection, vasospasm or systemic hypo perfusion can cause infarct. However, underlying causes of the ischemic infarct cannot be explained in nearly half of cases. The accurate diagnosis is essential to ensure appropriate treatment. Here we report a five yr old boy patient of cerebellar infraction after minor head trauma, admitted to emergency serves of Bulent Ecevit University, Turkey in 2013. We aimed to remind minor head trauma that causes cerebellar infarction during childhood, and to review the important points of the diagnosis, which should be keep in mind. ReferencesSchutzman SA, Greenes DS. Pediatric minor head trauma. Ann Emerg Med 2001;37(1):65-74.Shaffer L, Rich PM, Pohl KR, Ganesan V. Can mild head injury cause ischaemic stroke? Arch Dis Child 2003;88(3):267-9.Lin JJ, Lin KL, Chou ML, Wong AM, Wang HS. Cerebellar infarction in the territory of the superior cerebellar artery in children. Pediatr Neurol 2007;37(6):435-7.Matsumoto H, Kohno K. Posttraumatic cerebral infarction due to progressive occlusion of the internal carotid artery after minor head injury in childhood: a case report. Childs Nerv Syst 2011;27(7):1169-75.Williams LS, Garg BP, Cohen M, Fleck JD, Biller J. Subtypes of ischemic stroke in children and young adults. Neurology 1997;49(6):1541-5.Kieslich M, Fiedler A, Heller C, Kreuz W, Jacobi G. Minor head injury as cause and co-factor in the aetiology of stroke in childhood: a report of eight cases. J Neurol Neurosurg Psychiatry 2002;73(1):13-6.O’Brien NF, Reuter-Rice KE, Khanna S, Peterson BM, Quinto KB. Vasospasm in children with traumatic brain injury. Intensive Care Med 2010;36(4):680-7.Barkovich A, Schwartz E. Brain and Spine Injuries in Infancy and Childhood. In: Barkovich A, Raybaud C, editors. Pediatric Neuroimaging. 5th ed. Philidelphia, PA: Lippincott Williams & Wilkins; 2012. p. 335-8.Lansberg MG, Albers GW, Beaulieu C, Marks MP. Comparison of diffusion-weighted MRI and CT in acute stroke. Neurol 2000;54(8):1557-61. 

The Effects of Irisin on N?-Nitro-L-arginine Methyl Ester Hydrochloride-Induced Hypertension in Rats

Background: The cause of about 95% of hypertension, an important public health problem, is unknown. Intensive studies are underway to understand the physiopathology of hypertension. Irisin, a newly discovered hormone, has been reported to dilate vascular smooth muscle and lower blood pressure acutely. Aims: To investigate the effects of chronic irisin treatment on blood pressure and renal functions in a hypertension model established by nitric oxide synthase inhibition by treatment with N?-nitro-L-arginine methyl ester hydrochloride. Study Design: Animal experimentation. Methods: Male Sprague?Dawley rats were divided into four groups (n=8). Control and irisin groups received an intravenous saline injection, hypertension and hypertension + irisin (hypertension + irisin) groups received 1.5 mg/100 g N?-nitro-L-arginine methyl ester hydrochloride. N?-nitro-L-arginine methyl ester hydrochloride (150 mg/L) was added to the drinking water of rats in groups hypertension and hypertension + irisin for three weeks. In the second week of the experiment, irisin (50 nmol/day) was given to rats in groups irisin and hypertension + irisin, and saline was administered to rats in groups control and hypertension for two weeks through subcutaneously placed osmotic minipumps. Blood pressure was measured by the tail-cuff plethysmography method. On the twenty-first day of the experiment, 24-hour urine, blood, and both kidneys of the rats were collected. Results: The hypertension group had elevated systolic, diastolic, and mean arterial blood pressure values compared with the control group, with decreased glutathione levels in tissue and serum, but an increase in serum oxidized glutathione level (p<0.05). Histopathologically, increased tubular injury, cast formation, glomerular sclerosis, and peritubular fibrosis levels were observed (p<0.05). Irisin treatment did not cause any significant change in blood pressure, renal functions, and injury scores. However, renal nitric oxide levels significantly increased, and endothelial nitric oxide synthase immunoreactivity was determined to be reduced (p<0.05). Conclusion: Treatment with chronic irisin at a physiological dose does not reduce blood pressure in an experimental model of hypertension. In different models of experimental hypertension, the effects of irisin administration at different doses and at different periods should be thoroughly investigated

Investigation of survivin gene polymorphism in patients with gastric carcinoma

Objectives: Despite decreasing incidence of gastric cancerin worldwide, it is still a major health problem. Everyyear, 30.000 new gastric cancer cases emerging, and itis the second most common cancer in Turkey. Gastriccancer is a complex multifactorial disease, emerging byinteraction between genetic and environmental factors.Survivin, apoptosis inhibitory protein is over-expressed incancer tissue. In this study, association between Survivin-31G/C polymorphism and gastric carcinoma was investigated.Materials and Methods: 46 gastric carcinoma patientswho had been admitted at Düzce University Researchand Practice Hospital, Laboratory of Pathology and 42healthy individuals have been included in the study. Sampleshave been subjected to genetic analysis by PCRRFLPmethod in Medical Genetics Department laboratoryat Düzce University.Results: GG genotype was found in 16 (34.8%), GCgenotype in 21 (45.7%), CC genotype in 9 (19.6%) in patientgroup. In control group, genotype distribution werefound 13 (31%), 26 (61.9%) and 3 (7.1%) respectively.The statistically significant difference was not found whencompared between patient and control groups. However,we observed the increased occurrence of gastric cancerassociated with CC genotype (OR=1.52).Conclusions: In our knowledge, this study is the first toevaluate the relationship between gastric carcinoma andSurvivin -31G/C polymorphism in Turkish population. Ourresults show that there is no any association betweengastric carcinoma and Survivin -31G/C polymorphismin the community which is represented by our study andcontrol groups. However, it was concluded that CC genotypemay create the susceptibility to gastric cancer.Key words: Polymorphism, gastric carcinoma, survivinggene, apoptosi

Askin's Tumor in an Adult: Case Report and Findings on 18F-FDG PET/CT

Primitive neuroectodermal tumor (PNET) of the chest wall or Askin's tumor is a rare neoplasm of chest wall. It most often affects children and adolescents and is a very rare tumor in adults. In this case report, we present an Askin's tumor occurred in a 73-year-old male. The patient was admitted with a history of 3-month lower back pain and cough. In computed tomography, there was a lesion with dimensions of 70 × 40 × 65 mm in the superior segment of the lower lobe of the left lung. Positron emission tomography/computed tomography with 18F-flourodeoxyglucose revealed a pleural-based tumor in the left lung with a maximum standardized uptake value of 4.36. No distant or lymph node metastases were present. The patient had gone through surgery, and wedge resection of the superior segment of left lobe and partial resection of the ipsilateral ribs were performed. Pathology report with immunocytochemistry was consistent with PNET and the patient received chemotherapy after that

Acute Supramaximal Exercise-Induced Adiponectin Increase in Healthy Volunteers: Involvement of Natriuretic Peptides

Exercise may modulate lipolysis via leading to natriuretic peptide secretion and beta-adrenergic activation. Adiponectin, an adipose-secreted multifunctional signaling protein, may be the missing link between exercise and lipolytic activity. In this study, we aimed to investigate the effects of supramaximal exercise on plasma levels of adiponectin, atrial natriuretic peptide (ANP), and B-type natriuretic peptide (BNP) in healthy humans. Thirty-one healthy young adult volunteers (male/female, 15/16; mean age±SD, 20.7±1.7 years) underwent a 30-second Wingate anaerobic exercise test on a cycle ergometer and venous blood sampling before and after the exercise test. Plasma ANP and BNP levels were assayed by radioimmunoassay, whereas adiponectin levels were assayed by enzyme-linked immunosorbent assay. Systolic and diastolic blood pressures, heart rate, hematocrit levels and blood lactate were also measured before and after exercise. The mean plasma adiponectin level significantly increased following a 30-second anaerobic exercise test compared to resting level (17.45±4.70 vs 31.29±5.16 μg/mL, respectively, p<0.001). The mean plasma ANP and BNP levels remained comparable before and after the 30-second anaerobic exercise. A 30-sec supramaximal exercise session enhanced circulating adiponectin levels in both gender groups, whereas ANP and BNP levels exerted non-significant alterations. We suggest that acute anaerobic exercise may affect secretory function of adipose tissue which seems not related with natriuretic peptide secretion