The origin and relations of the anterior choroidal artery: an anatomical study

There has recently been an increase in surgical interventions to the inferior temporal lobe. The aim of the present study is to examine the anatomical structure and relations of the anterior choroidal artery, which extends to this region. A mixture of latex and ink was injected into the internal carotid and basilar arteries of 15 brains from fresh cadavers. In 18 out of 30 cases (60%) the anterior choroidal artery arose from the posteroinferior aspect of the internal carotid artery, in 8 (22.2%) from the posterolateral aspect and in 4 (2%) from its anterior part. The diameter of the anterior choroidal artery was 0.94 mm on average (0.7-1.2) and the average distance from the posterior communicating artery was 5.3 mm (3.8-8 mm); its distance to the bifurcation of the carotid was found to be 4.0 mm on average (2.2-8 mm). The cisternal segment of the anterior choroidal artery and the optic tract formed a neurovascular bundle. The branches arising from the plexal segment supply the lateral geniculate body, the thalamus and the optic tract. The resulting knowledge of the neurovascular relations of the anterior choroidal artery provides a safe surgical approach to the inferior temporal lobe

Menkul kıymetler borsalarındaki mevsimselliklerin İstanbul Menkul Kıymetler Borsası’nda (İMKB) incelenmesi

Ankara : Bilkent Univ., 1993.Thesis (Master's) -- Bilkent University, 1993.Includes bibliographical references leaves 64-65.This study empirically examines stock market seasonality in the Istanbul Stock Exchange Market (IMKB) , Turkey. Current evidence from the studies for other capital markets around the world provides that there are strong seasonalities in the stock returns in most of these capital markets. The seasonality , when it exists, is associated with the turn of the year, the week, as well as with holidays. The turn of the week effect appears to be negative on Monday or Tuesday returns; turn of the year effect appears to be high for January or April returns;and holiday effect appears to have higher returns on the trading days prior to holidays in most of the capital markets in developed countries. This study, however, presents the evidence that so called weekend effect and the day-of-the-week effect do not exist in IMKB. The mean returns on Thursdays are negative and it cannot be accepted statistically. I find a turn of the year effect with high January returns and holiday effect with high mean returns, averaging four times the mean return for the remaining days of the year as in the other capital markets. The returns for the IMKB daily index for 1988-1991 period are examined in this study, as well as the weekend and turn of the year effect for the individual stocks of 29 large and 34 small firms.Erbil, A. FuatM.S

Osteoselection supported by phase separeted polymer blend films

Cataloged from PDF version of article.The instability of implants after placement inside the body is one of the main obstacles to clinically succeed in periodontal and orthopedic applications. Adherence of fibroblasts instead of osteoblasts to implant surfaces usually results in formation of scar tissue and loss of the implant. Thus, selective bioadhesivity of osteoblasts is a desired characteristic for implant materials. In this study, we developed osteoselective and biofriendly polymeric thin films fabricated with a simple phase separation method using either homopolymers or various blends of homopolymers and copolymers. As adhesive and proliferative features of cells are highly dependent on the physicochemical properties of the surfaces, substrates with distinct chemical heterogeneity, wettability, and surface topography were developed and assessed for their osteoselective characteristics. Surface characterizations of the fabricated polymer thin films were performed with optical microscopy and SEM, their wettabilities were determined by contact angle measurements, and their surface roughness was measured by profilometry. Long-term adhesion behaviors of cells to polymer thin films were determined by F-actin staining of Saos-2 osteoblasts, and human gingival fibroblasts, HGFs, and their morphologies were observed by SEM imaging. The biocompatibility of the surfaces was also examined through cell viability assay. Our results showed that heterogeneous polypropylene polyethylene/polystyrene surfaces can govern Saos-2 and HGF attachment and organization. Selective adhesion of Saos-2 osteoblasts and inhibited adhesion of HGF cells were achieved on micro-structured and hydrophobic surfaces. This work paves the way for better control of cellular behaviors for adjustment of cell material interactions. © 2014 Wiley Periodicals, Inc

The relationship of the parotid duct to the buccal and zygomatic branches of the facial nerve; an anatomical study with parameters of clinical interest

There have been studies concerning the protection of the facial nerve during plastic surgery intended for the parotid gland. The close relationship between the parotid duct and the buccal and zygomatic branches of the facial nerve is studied here. The dissections were performed on 10 fixed cadavers at the Anatomy Dissection Laboratory of Ankara University in 2004. The reference points used for surgery of this region were taken into consideration as the landmarks for morphometric measurements. In 7 of the cases the zygomatic branch was double and in 3 it was single. In 4 of the 7 cases with a double zygomatic branch both superior and inferior branches crossed the parotid duct. In the remaining 3 cases the superior branches of the zygomatic nerve coursed through the zygomatic major and minor muscles. In 9 of all the cases the zygomatic branch of the facial nerve crossed the duct anteriorly and in one it did so posteriorly (case 10). The buccal branch was single in 4 of the cases and double in 6. Among these one of the most precise measurements was the distance between the lateral canthus and the intersection point of the zygomatic branch and the duct with a coefficient of variation of 9.9%. With the use of this reliable measurement the intersection point of the zygomatic branch and the duct may be estimated to be within 5.16 ± 1.01 centimetres of the lateral canthus. Facial nerve paralysis is the most important complication of superficial face surgery and the anatomy of this region must thus be taken into detailed consideration by surgeons

Multiple Orbitoides d’Orbigny lineages in the Maastrichtian? Data from the Central Sakarya Basin (Turkey) and Arabian Platform successions (Southeastern Turkey and Oman)

The standard reconstruction of species of Orbitoides d’Orbigny into a single lineage during the late Santonian to the end of the Maastrichtian is based upon morphometric data from Western Europe. An irreversible increase in the size of the embryonic apparatus, and the formation of a greater number of epi-embryonic chamberlets (EPC) with time, is regarded as the main evolutionary trends used in species discrimination. However, data from Maastrichtian Orbitoides assemblages from Central Turkey and the Arabian Platform margin (Southeastern Turkey and Oman) are not consistent with this record. The Maastrichtian Besni Formation of the Arabian Platform margin in Southeastern Turkey yields invariably biconvex specimens, with small, tri- to quadrilocular embryons and a small number of EPC, comparable to late Campanian Orbitoides medius (d’Archiac). The upper Maastrichtian Taraklı Formation from the Sakarya Basin of Central Turkey contains two distinct, yet closely associated forms of Orbitoides, easily differentiated by both external and internal features. Flat to biconcave specimens possess a small, tri- to quadrilocular embryonic apparatus of Orbitoides medius-type and a small number of EPC, whereas biconvex specimens possess a large, predominantly bilocular embryonic apparatus, and were assigned to Orbitoides ex. interc. gruenbachensis Papp–apiculatus Schlumberger based on morphometry. The flat to biconcave specimens belong to a long overlooked species Orbitoides pamiri Meriç, originally described from the late Maastrichtian of the Tauride Mountains in SW Turkey. This species is herein interpreted to be an offshoot from the main Orbitoides lineage during the Maastrichtian, as are forms that we term Orbitoides ‘medius’, since they recall this species, yet are younger than normal occurrence with the accepted morphometrically defined lineage. The consistent correlation between the external and internal test features in O. pamiri implies that the shape of the test is not an ecophenotypic variation, but appears to be biologically controlled. We, therefore, postulate that more than one lineage of Orbitoides exists during the Maastrichtian, with a lineage that includes O. ‘medius’ and O. pamiri displaying retrograde evolutionary features

Topography driven spreading

Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a model system of spreading droplets of a nonvolatile liquid on surfaces having lithographically produced pillars is used to show that superwetting also modifies the dynamics of spreading. The edge speed-dynamic contact angle relation is shown to obey a simple power law, and such power laws are shown to apply to naturally occurring surfaces

Development of a novel platform for greater situational awareness in the urban military terrain

The conflicts in Afghanistan and Iraq and the more recent war in the Gaza Strip have emphasized the need for novel platforms which provide for greater situational awareness in the urban terrain. Without intelligent systems, which can accurately provide real-time information, collateral damage to property will result, together with unnecessary civilian deaths. This situation is exacerbated by the fact that within the next decade 75% of the world’s population will be living in urban areas. This paper outlines the current state of unmanned aerial vehicles throughout the world and presents a novel design of a multiple rotary wing platform which has great potential for both military and civilian application areas

L-MYC gene polymorphism and risk of thyroid cancer

L-myc gene polymorphism is a representative genetic trait responsible for an individual’s susceptibility to several cancers. However, there have been no reports concerning the association between thyroid cancer and L-myc gene polymorphism. Aim: To analyze the distribution of L-myc gene polymorphism in Turkish patients with thyroid disorders and thyroid cancers. Methods: We used a molecular genotyping method, polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). We studied 138 patients of whom 47 had multinodular goiter, 13 had follicular cancer and 69 had papillar cancer, in comparison with control group of 109 healthy individuals. Results: No significant difference in the distribution of genotypes was observed between thyroid patients and controls. Carrying SS or LS genotype revealed a 1.96-fold (95% CI 0.573–6.706) risk for the occurrence of follicular cancer when compared with controls, and 3.11-fold (95% CI 0.952–10.216), when compared with multinodular goiter patients (p = 0.04). Conclusion: We suggest that L-myc genotype profiling together with other susceptibility factors, may be useful in the screening for thyroid nodular malignancy.Для ряда опухолей человека показана корреляция между риском развития опухоли и определенным вариантом гена L-MYC. Данные о наличии такой связи при раке щитовидной железы к настоящему времени отсутствуют. Цель: проанализировать распределение полиморфных типов гена L-MYC в популяции больных с доброкачественными и злокачественными поражениями щитовидной железы, включая рак щитовидной железы, в Турции. Методы: для анализа полиморфизма гена L-MYC использован метод молекулярного генотипирования, в частности, метод определения полиморфизма длины рестрикционных фрагментов, основанный на полимеразной цепной реакции (PCR-RFLP). Определение проводили в лейкоцитах 138 больных, в том числе 48 больных с узловым зобом, 13 больных фолликулярным раком щитовидной железы и 69 больных папиллярным раком. Контрольную группу составляли 109 здоровых лиц. Результаты: статистически достоверных различий в распределении исследуемых генотипов у больных с патологией щитовидной железы и здоровых лиц не выявили. Показано, что относительный риск фолликулярного рака щитовидной железы у больных-носителей генотипа SS или LS составляет 1,96 по сравнению со здоровыми лицами (при 95% доверительном интервале от 0,573 до 6,706) и 3,11 по сравнению с больными с узловым зобом (при 95% доверительном интервале от 0,952 до 10,216) (р = 0,04). Выводы: по нашему предположению, определение профиля полиморфизма гена L-MYC с учетом других факторов, определяющих предрасположенность к развитию опухолей, может быть полезным при скрининге озлокачествления узелковых образований щитовидной железы

A Common Network of Functional Areas for Attention and Eye Movements

AbstractFunctional magnetic resonance imaging (fMRI) and surface-based representations of brain activity were used to compare the functional anatomy of two tasks, one involving covert shifts of attention to peripheral visual stimuli, the other involving both attentional and saccadic shifts to the same stimuli. Overlapping regional networks in parietal, frontal, and temporal lobes were active in both tasks. This anatomical overlap is consistent with the hypothesis that attentional and oculomotor processes are tightly integrated at the neural level