Türk şirket birleşmelerinin satın alınan şirketlerin hisse senedi fiyatları üzerindeki etkileri

Cataloged from PDF version of article.This paper investigates stock-market reactions to mergers and partial sales of non-financial Turkish firms. Turkish targets earn average cumulative abnormal returns (CAR) of 8.56 percent in the three-day window around merger announcements when bidders purchase control rights and 2.25 percent when they do not. The results indicate that acquirers pay a premium to purchase control rights. The smaller magnitude of target CAR in Turkish mergers (relative to CAR of around 20 percent in US and 10 percent in Europe) may be explained by: 1) the reduction in the power of event study method to capture the effect of merger announcements due to information leakages and misidentification of announcement dates; and 2) the differences in Turkish regulatory, operational and competitive environment

Anatomic assessment of the left main bifurcation and dynamic bifurcation angles using computed tomography angiography

Background: An understanding of the left main coronary artery (LMCA) anatomy is important for accurate diagnosis and therapy. We aimed to investigate LMCA anatomy via 128-multisliced coronary computed-tomography-angiography (CCTA) in patients with normal LMCA. Materials and methods: A total of 201 CCTA studies were included in this study. Anatomical features of LMCA including cross-sectional areas of the LMCA ostial, LMCA distal, left anterior descending artery (LAD) ostial and left circumflex artery (LCX) ostial, and degree of tapering and LMCA bifurcation angles (BA) in the form of LMCA-LCX BA, LMCA-LAD BA, LAD-LCX BA at end-diastole and end-systole. Results: The mean age was 55 ± 11; 55.7% of patients were males. Right coronary artery was dominant in 173 (86.1%) patients. Mean LMCA length was 10.0 ± 4.5 mm. The mean values of LMCA ostial, LMCA distal, LAD ostial and LCX ostial areas were 18.2 ± 5.1 mm2, 13.2 ± 4.0 mm2, 9.0 ± 3.2 mm2 and 7.6 ± ± 2.8 mm2, respectively. LMCA ostial-distal area, LMCA distal-LAD ostial area and LMCA distal-LCX ostial area ratios were ≥ 1.44 – < 1.69 in 47 (23.4%), 53 (26.4%), 47 (23.4%) patients, respectively, and were ≥ 1.69 – < 1.96 in 19 (9.5%), 24 (11.9%), 40 (19.9%) patients respectively. Systolic motion modifies LMCA BAs; systolic motion begets an increment of LMCA-LAD angle in 72.6% of patients and decrement of LAD-LCX angle in 75.6% of patients. Patients with T-shaped LAD-LCX BA was shown to have significantly longer LMCA, larger LAD ostial area, larger LCX ostial area and higher diastolic-to-systolic range (DSR) of LAD-LCX BA compared to patients with Y-shaped LAD-LCX BA. Conclusions: LMCA with T-shaped distal BA was found to have significantly longer LMCA, larger LAD ostial area, larger LCX ostial area and higher DSR of distal BA compared to patients with Y-shaped distal BA. These findings may provide useful information for LMCA bifurcation stenting or designing dedicated stents for LMCA

Evaluation of vertebral artery dominance, hypoplasia and variations in the origin: angiographic study in 254 patients

Background: The aim of this study was to determine the dimensional characteristics and variations in the origin of vertebral arteries (VA). Materials and methods: We retrospectively reviewed angiographic studies in 254 patients (133 males, 121 females) for the evaluation of diameter differences in VA. We examined different criteria from the literature (difference of ≥ 0.3 mm, ≥ 0.8 mm, ≥ 1 mm between the widths of two VA and diameter ratio more than 1.4) to find out the dominant VA, rate of co-dominance and hypoplasia. The differences among groups were analysed using the c2 and Kruskal-Wallis test. Also concordance analysis test was used to determine correspondence between the tests. We also noticed the variations in the origin of VA. Results: The average diameter of VA in 254 patients was 3.21 ± 0.7 mm on the right, and 3.16 ± 0.7 mm on the left. The average diameter difference was found 0.88 ± 0.7 mm. The rate of hypoplasia was found 7.1% on the right and 9.4% on the left. Among 254 patients according to the criterion of any diameter difference; right side was found wider in 126 (49.6%) patients and left side was found wider in 120 (47.2%) patients. The criterion of 0.3 mm or greater difference showed right VA dominance in 107 (42.1%) patients, left VA dominance in 99 (39%) patients. Co-dominance was mainly observed when we used the criteria of 0.8 mm and 1 mm or greater difference and diameter ratio more than 1.4. We found out harmony of two criterion of difference of ≥ 0.8 mm and ≥ 1 mm (concordance analysis test, 76.1%). There was no statistically significant relation between age, gender and any dominance criteria (p > 0.05). The majority of VA showed classical origin arising from both subclavian arteries with a rate of 94.9%. Conclusions: The most striking result we have found is the dominance of the right VA in diameter by using all different criteria unlike with previous reports in the literature.

Radiologic findings and percutaneous treatment of a rare giant soft tissue hydatid cyst

The aim of this report is to present the radiologic findings and discuss the percutaneous treatment of an extremely rare giant soft tissue hydatid cyst located in the left thigh in a 44-year-old woman. Ultrasound showed a well circumscribed giant soft tissue cyst, and computed tomography revealed a well defined unilocular hypodense cystic mass originating from the adductor muscles and extending through the subcutaneous tissue without bony relations. On magnetic resonance imaging, the cystic mass was hypointense on T1 and hyperintense on T2-weighted images. Percutaneous treatment was performed successfully by catheterization technique with hypertonic saline and alcohol. No complications and recurrence were observed during the procedure, in the postprocedure or in the follow up period

Anthropometric measurements of the orbita and gender prediction with three-dimensional computed tomography images

Background: The aim of the study was to investigate the orbital anthropometric variations in the normal population using three-dimensional computed tomography (3D-CT) images and to define the effects of age and gender on orbital anthropometry.Materials and methods: Three-dimensional orbita CT of 280 patients, obtained for various reasons, were retrospectively evaluated in 772-bed referral and tertiary-care hospital between April 2011 and June 2012. Using 3D images, orbital width, height, biorbital-interorbital diameter and orbital index were measured. Measurements were obtained comparing right and left sides and male to female. The relation of the results with age and gender was analysed.Results: Right orbit was found to be wider than left (p < 0.0001). Male patients had wider (p < 0.0001) and higher (p = 0.0001) orbits. Right orbital index was found to be smaller than the left one (p = 0.005). No differences were found between the genders in terms of right and left orbital indexes (p > 0.05). Biorbital (p < 0.0001) and interorbital (p = 0.01) widths were found to be higher in males. There was no relation between the age change and the parameters defined (p > 0.05).Conclusions: No relation was found between age and orbital measurements. It was concluded that orbital images obtained with 3D-CT may be used as a method for gender evaluation

Prediction of nasal morphology in facial reconstruction: Validation and recalibration of the Rynn method

Background Prediction of the nose from the skull remains an important issue in forensic facial approximation. In 2010, Rynn et al. published a method of predicting nose projection from the skull. With this method, three craniometric measurements (x, y, z) are taken, and these are then used in regression formulae to estimate the nasal dimensions. Aim The purpose of this study was to examine and test the accuracy of the Rynn et al. method and if necessary to adapt the formulae for this population. Subjects and methods A sample of 90 CT scans of Turkish adults was used in the study. The actual and predicted dimensions were compared using t-test. The age of the individuals ranged from 20 to 40 years by sex. Results The descriptive statistics and correlations were calculated, and the actual and predicted measurements were compared. The differences between the actual and predicted values were statistically significant (p < 0.01), with −1 mm for males and −1.5 mm for females. Validation accuracies ranged from 76 to 92% in females and 72 to 82% in males. Recalibration equation accuracies ranged from 88 to 100% in females and 90 to 100% in males. Conclusion The results showed that the recalibration of the Rynn et al. method and its formulae gave satisfactory results with less error and can be employed in facial approximation cases

The value of proton mr-spectroscopy in the differentiation of brain tumours from non-neoplastic brain lesions

Purpose: Our aim was to evaluate the efficacy of Proton-MR Spectroscopy for the differentiation of cranial masses from non-neoplastic brain disorders. Material and method: 33 patients with intracranial mass lesions, 29 patients with non-neoplastic brain lesions: Ischemic-demyelinating-metabolic-benign cystic mass group; As a whole 62 patients: 30 males and 32 females were included in this study. Results: In brain tumours, average Cho/NAA ratio 2.84-NAA/Cr ratio was 0.97, Cho/Cr ratio 2.42 and Cho/MI ratio was 3.51. In non-neoplastic group; NAA/Cr ratio was extremely higher than tumour group, the other ratios were far lower than cranial mass lesions. Average Cho/NAA ratio: 0.50 ± 0.15, Cho/Cr ratio: 1.05 ± 0.14, Cho/MI ratio: 1.07 ± 0.73. Conclusion: Higher Cho/NAA and Cho/MI ratios with lower NAA/Cr ratio were most likely to be malignant. Additional lipid and lactate peaks were generally seen in malignant group

DESIGN OF GEODETIC NETWORKS BASED ON OUTLIER IDENTIFICATION CRITERIA: AN EXAMPLE APPLIED TO THE LEVELING NETWORK

We present a numerical simulation method for designing geodetic networks. The quality criterion considered is based on the power of the test of data snooping testing procedure. This criterion expresses the probability of the data snooping to identify correctly an outlier. In general, the power of the test is defined theoretically. However, with the advent of the fast computers and large data storage systems, it can be estimated using numerical simulation. Here, the number of experiments in which the data snooping procedure identifies the outlier correctly is counted using Monte Carlos simulations. If the network configuration does not meet the reliability criterion at some part, then it can be improved by adding required observation to the surveying plan. The method does not use real observations. Thus, it depends on the geometrical configuration of the network; the uncertainty of the observations; and the size of outlier. The proposed method is demonstrated by practical application of one simulated leveling network. Results showed the needs of five additional observations between adjacent stations. The addition of these new observations improved the internal reliability of approximately 18%. Therefore, the final designed network must be able to identify and resist against the undetectable outliers – according to the probability levels

Perception of Ticks and Tick-Borne Diseases Worldwide

In this comprehensive review study, we addressed the challenge posed by ticks and tick-borne diseases (TBDs) with growing incidence affecting human and animal health worldwide. Data and perspectives were collected from different countries and regions worldwide, including America, Europe, Africa, Asia, and Oceania. The results updated the current situation with ticks and TBD and how it is perceived by society with information bias and gaps. The study reinforces the importance of multidisciplinary and international collaborations to advance in the surveillance, communication and proposed future directions to address these challenges