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Publication Metadata only A case of chordoma invading multiple neuroaxial bones: report of ten years follow up(Turkish Neurosurgery Society, 2013) Aydın, Ahmet Levent; Sasani, Mehdi; Öktenoğlu, Bekir Tunç; Solaroğlu, İhsan; Özer, Ali Fahir; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 102059; 1022Aim: Chordoma is a rare, slow-growing primary malignant tumor of the axial skeleton, arising from the embryonic cells of primitive notochord. Chordomas may arise at different sites of the vertebral column simultaneously or more probably they may metastasise along the neural axis insidiously. Recurrence despite radical surgery and following adjuvant therapy is possible. MaterIal and Methods: A 46-year-old female patient presented weakness and numbness of the lower extremities. She was operated for clivus chordoma five years ago at another institute. Results: First the patient underwent surgery for resection of the tumor at the cervical region. a second surgery was performed to resect tumor on the foramen magnum and at the C1 level. Histologic examination of the removed vertebra confirmed the diagnosis of chordoma involving the vertebral body. Radiotherapy was administered after the second surgery. Follow-up neurological and radiological examinations revealed no abnormal neurological symptoms 2,5 years after second surgery. There were no distant organ metastases. ConclusIon: A patient with diagnosed chordoma of the spine must be investigated with MRI of other regions of the neuraxis to exclude second or even third source of chordoma metastases. In metastatic chordoma cases, radical or gross total resection should be performed for each lesion but if complete surgical resections are impossible, preoperative or postoperative radiation therapy should be planned to improve life expectancy. / AMAÇ: Kordoma, omurganın ender rastlanan, yavaş ilerleyen malign karakterli bir tümörüdür. Primitif notokordun embryo hücrelerinden köken alır. Omurganın farklı bölgelerinde, birbirinden bağımsız kordoma odakları eş zamanlı olarak gelişmeye başlayabilir. Fakat daha sıklıkla, birinci tümör odağından kaynaklanan metastatik kordoma lezyonları tüm nöral aks boyunca yayılabilir. Radikal cerrahiye ve ek onkolojik tedaviye rağmen rekürens sık görülür. YÖNTEM ve GEREÇLER: Bu sunumda tartışılan 46 yaşındaki kadın hasta, bacaklarında kuvvet ve his kaybı şikayetiyle kliniğimize başvurmuştur. Hasta, beş yıl önce, ayrı bir merkezde klivus kordoması tanısıyla opere edilmiştir. BULGULAR: Hasta öncelikle servikal bölgedeki tümör için opere edilmiştir. İkinci seansta foramen magnum ve C1 seviyesindeki tümör çıkarılmıştır. Patolojik inceleme sonucunda, omurga cismini tutan kordoma lezyonu tanısı konmuştur. İkinci cerrahi seansından sonra hasta radyoterapiye yönlendirilmiştir. Bu tedaviden ikibuçuk yıl sonra yapılan değerlendirmede, hastanın nörolojik muayenesinde progresyon gözlenmemiştir. SONUÇ: Omurganın herhangi bir lokalizasyonunda kordoma tanısı konulan bir hastada, tüm spinal bölge manyetik rezonans görüntüleme (MRG) tetkiki ile incelenmelidir. Bu hastalarda birden fazla kordoma odağına rastlanabilir. Birden fazla odak tespit edilmesi durumunda, her ayrı tümör odağı için rezeksiyon planlanmalıdır. Total rezeksiyonun mümkün olmaması durumunda, yaşam süresini uzatmak için operasyon öncesi ve sonrası dönemlerde radyoterapi uygulanmalıdır.Publication Metadata only A new and simple technique for vagal ganglia ablation in a patient with functional atrioventricular block: electroanatomical approach(Turkish Society of Cardiology, 2018) Aksu, Tolga; Guler, Tumer Erdem; Yalin, Kivanc; Bozyel, Serdar; N/A; Mutluer, Ferit Onur; Faculty Member; School of Medicine; Koç University Hospital; N/AIncreased parasympathetic tone may cause symptomatic functional atrioventricular block (AVB) and necessitate pacemaker implantation. In these patients, where there is no structural damage to the conduction system, removal of the vagal activity using radiofrequency ablation seems to be a theoretically rational approach. Several methods have been used to determine suitable areas for vagal ganglia ablation. The aim of this report was to describe a new method to detect parasympathetic innervation sites without the need to use additional equipment or extend procedure time. A 51-year-old man was referred to the clinic for implantation of a permanent pacemaker because of symptomatic second-degree AVB and recurrent syncope. The functional nature of the AVB and a supra-Hisian location were verified with standard electrocardiography, Holter recordings, atropine sulfate test, and a standard electrophysiological study. Using conventional recordings, the electrograms were divided into 3 subgroups and sites demonstrating a fractionated pattern were targeted. All of the fractionated electrogram sites considered suitable for usual ganglion settlement were ablated. Biatrial ablation was initiated from the left atrial side. During left atrial ablation, the intrinsic basic cycle length of sinus node accelerated to 800 milliseconds despite AVB persistence. Subsequently, 1:1 atrioventricular conduction was achieved when ablation was applied around the coronary sinus ostium. The patient was completely asymptomatic, experiencing no episodes of dizziness or syncope, and was taking no medications at the end of 9 months of follow-up. In conclusion, electroanatomically guided vagal ganglia ablation may be a good alternative to pacemaker implantation in well-selected patients with functional AVB.Publication Metadata only A new paradigm on the identity-security nexus in international relations: ontological security theory(Uluslararasi Iliskiler Konseyi Dernegi, 2020) Adısönmez, Umut Can; Department of International Relations; Rumelili, Bahar; Faculty Member; Department of International Relations; College of Administrative Sciences and Economics; 51356Recently, Ontological Security Theory (OST) has found itself a significant place in the International Relations (IR) literature. The theory has provided scholars with a novel analytical framework to explain state behavior and to understand the socio-psychological dynamics underlying the production of a state's self-image and self-narratives. Particularly, the OST has unsettled disciplinary assumptions regarding the primacy of physical security, and offered a framework to analyze the dialectical relationship between state and society in the making, (re)making and protecting of the state's subjective sense of self. The primary aim of this article is to introduce the main arguments and research areas to Turkey's IR community. Additionally, the drawbacks that emanate from the OST's insufficient engagement with critical approaches to security and the extant literature on identity in IR are assessed. / Geçtiğimiz yıllarda Ontolojik Güvenlik Teorisi (Ontological Security Theory – OGT) Uluslararası İlişkiler (Uİ) disiplininde kendine önemli bir yer edindi. Teori, devlet davranışlarını devletin öz-anlatıları üzerinden anlamlandırırken, bu öz-anlatıların yeniden üretilmesinin altında yatan sosyo-psikolojik dinamikleri de ortaya koydu. Özellikle, fiziksel güvenliğin öncüllüğünü tartışmaya açarak ve öz-anlatılar yoluyla devlet kimliğinin oluşması ve korunması süreçlerinde devlet-toplum arasındaki diyalektik ilişkiyi ortaya koyarak önemli katkıları oldu. Bu makalenin birincil amacı OGT’nin ana argümanlarını ve araştırma konularını Türkiye Uİ camiasına tanıtmaktır. Aynı zamanda OGT’nin mevcut eleştirel güvenlik kavramları ve kimlik yazını ile bağlantısının yetersizliğinden kaynaklanan eksiklikleri değerlendirilmektedir.Publication Open Access A new risk-scoring system for colorectal cancer and polyp screening by Turkish Colorectal Cancer and Polyp Study Group(Aves, 2022) Erdem, L.; Akbal, E.; Koçak, E.; Tucer, D.; Üçbilek, E.; Uyanıkoğlu, A.; Dolapçıoğlu, C.; Şirin, G.; Alkım, H.; Soylu, A.; Doğanay, L.; Kürbüz, A.K.; Özdil, K.; Alagözlü, H.; Erürker Öztürk, T.; Sezikli, M.; Adalı, G.; Çoban, M.; Hülagü, S.; Değertekin, H.; Atasoy, A.; Akyüz, F.; Gaffarlı, İ.; Saruç, M.; Altıntaş, E.; Sezgin, O.; Tözün N.; Ahıshalı, Emel; School of MedicineBackground: colorectal cancer is one of the most commonly diagnosed types of cancer worldwide. An early diagnosis and detection of colon cancer and polyp can reduce mortality and morbidity from colorectal cancer. Even though there are a variety of options in screening tests, the question remains on which test is the most effective for the early detection of colorectal cancer. In this prospective study, we aimed to develop a simple, useful, effective, and reliable scoring system to detect colon polyp and colorectal cancer. Methods: we enrolled 6508 subjects over the age of 18 from 16 centers, with colonoscopy screening. The age, smoking status, alcohol consumption, body mass index, polyp incidence, polyp size, number and localization, and pathologic findings were recorded. Results: the age, male gender, obesity, smoking, and family history were found as independent risk factors for adenomatous polyp. We have developed a new scoring system which can be used for these factors. With a score of 4 or above, we found the following: sensitivity 81%, specificity 40%, positive predictive value 25.68%, and negative predictive value 89.84%, for adenomatous polyp detection; and sensitivity 96%, specificity 39%, positive predictive value 3.35%, negative predictive value 99.29%, for colorectal cancer detection. Conclusion: even though the first colorectal cancer screening worldwide is generally performed for individuals over 50 years of age, we recommend that screening for colorectal cancer might begin for those under 50 years of age as well. Individuals with a score ? 4 must be included in the screening tests for colorectal cancer.Publication Metadata only A new technique for the surgical treatment of atlantoaxial instability: C1 lateral mass and C2-3 transfacet screwing(Turkish Neurosurgical Soc, 2018) N/A; N/A; N/A; N/A; Şentürk, Salim; Akyoldaş, Göktuğ; Yaman, Onur; Özer, Ali Fahir; Doctor; Faculty Member; Doctor; Faculty Member; N/A; School of Medicine; N/A; School of Medicine; Koç University Hospital; N/A; Koç University Hospital; N/A; 203677; 219524; 1022Atlantoaxial instability is a special entity that may be caused by many disorders such as trauma, tumor, arthritis, congenital malformation and infection. Atlantoaxial fixation is needed to provide stability, prevent neurological deficits and correct deformity. The aim of this report is to introduce an alternative technique for the treatment of atlantoaxial instability in patients who have vertebral artery anomaly, anomalous C2 or osteoporosis. C1-2-3 fixation was performed in a 50-year-old male patient with atlantoaxial instability due to os odontoideum. C1 lateral masses were identified and screw placement was performed. C2 facet joints were identified bilaterally. The superior margin of the junction of pedicle and the lamina was used as the entry point and 3.5x22 mm screws were inserted from C2 facet joint to the C3 facet joint in the mediolateral and craniocaudal direction under fluoroscopic guidance with caution. The posterior fixation screws were interconnected with two rods. Finally, autologous grafts were placed posterolaterally to encourage the fusion. The patient"s complaints were relieved after the surgery. C1-C2 instability was not seen in the postoperative radiological examinations. In the surgical treatment of C1-2 instability, our technique could help reduce the possibility of vertebral artery injury in patients who have a vertebral artery course anomaly or when it is difficult to place C2 pedicle screws due to anomalous C2 pedicles and osteoporosis. High fusion rate could be achieved with this technique due to passing through the four cortical surfaces. No wire or allograft was required. Thus, the instrumentation cost could be reduced.Publication Open Access A practitioner’s guide to handling irregularities resulting from the 2014 revisions of the Turkish Household Labor Force Survey(Boğaziçi Üniversitesi İktisadi ve İdari Bilimler Fakültesi, 2021) Poyraz, Meltem; Department of Economics; Demirci, Murat; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; 272082We document the implications of the 2014 revisions to the Turkish Household Labor Force Survey and offer guidance on how to handle the irregularities in population and unemployment statistics that resulted from two particular revisions. First, new population projections were adopted to assign survey weights. Second, a narrower definition of unemployment was adopted. We propose methods to adjust the survey weights for the pre-2014 period in order to discern changes in population statistics by age groups and regions without interruption over time and to calculate the unemployment rates according to both broader and narrower definitions since 2004. / Bu çalışmada TÜİK Hanehalkı İşgücü Anketi’ninde 2014 yılında yapılan düzenlemelerden kaynaklanan bazı sonuçları bulguluyor, nüfus ve işsizlik istatistiklerinde yapılan revizyonların özellikle ikisinden kaynaklanan sorunların nasıl ele alınması gerektiği hakkında yol gösteriyoruz. İlk revizyon, anket ağırlıklarının dayandırıldığı yeni nüfus projeksiyonlarının kabul edilmesidir. İkincisi ise, dar tanımlı bir işsizlik tanımına geçilmesidir. Bu çalışmada 2014 öncesindeki anket ağırlıklarını nüfus istatistiklerinde yaş bazında ve bölgesel olarak kopma olmayacak şekilde yeniden ayarlamak ve işsizlik oranlarını geniş ve dar tanımlı olarak 2004 yılından itibaren hesaplamak için yöntemler öneriyoruz.Publication Metadata only A tribute to Dr. Freddie H. Fu: remembering a “good friend”(Aves, 2021) Taşkıran, Emin; Kılıçoğlu, Önder; Pınar, Halit; Demirhan, Mehmet; Faculty Member; School of Medicine; 9882The orthopaedic community is deeply saddened by the loss of renowned orthopaedic surgeon Dr. Freddie H. Fu, on September 24. A relentless and irreconcilable disease has taken the “good friend” from us at the very early age of 70, when he was dwelling at the highest summit of the mountain of success he built with his own hands. Freddie was definitely a legend, but he has never been inaccessible. Apart from thousands of people he treated or restored to a higher degree of sportive performance, he built countless number of personal relationships with friends, fellows, students, and people from every possible area of the community. He never ceased to connect himself to the society and made everyone feel endeared to him, as a reason why many is mourning today and not only the orthopaedic community.Publication Metadata only Abo and rh blood groups and risk of myelomeningocele(Turkish Neurosurgical Soc, 2020) Isik, Semra; Cevik, Serdar; Turhan, Ali Haydar; Hanimoglu, Hakan; N/A; Baygül, Arzu Eden; Faculty Member; School of Medicine; 272290AIM: To investigate the relationship between the distribution of ABO or Rhesus (Rh) blood group antigens and the incidence of myelomeningocele. MATERIAL and METHODS: A retrospective data was reviewed for all myelomeningocele patients operated at a tertiary academic hospital between years 2014 and 2019. Age, sex, delivery method, physical and neurological examination findings, and radiological findings alongside with blood type of each patient were recorded. The data of blood group distribution among the study patients was compared to the data of healthy individuals in the same region. RESULTS: Patients with group B and AB showed a higher chance of developing myelomeningocele. Rh-positive blood group was associated with high incidence of myelomeningocele (93.5%), whereas Rh-negative blood group showed least association (6.5%). Rh-positive blood group was also found to be more frequent in patients with myelomeningocele with hydrocephalus and Chiari malformation. CONCLUSION: The findings of this study show that ABO and Rh blood groups have an effect on the development of myelomeningocele under the influence of environmental or genetic factors.Publication Metadata only Access pattern-aware data placement for hybrid DRAM/NVM(TUBITAKScientific and Technical Research Council Turkey, 2017) Department of Computer Engineering; Erten, Didem Unat; Faculty Member; Department of Computer Engineering; College of Engineering; 219274in recent years, increased interest in data-centric applications has led to an increasing demand for large capacity memory systems. Nonvolatile memory (NVM) technologies enable new opportunities in terms of process-scaling and energy consumption, and have become an attractive memory technology that serves as a secondary memory at low cost. However, NVM has certain disadvantages for write references, due to its high dynamic energy consumption for writes and low bandwidth compared to DRaM writes. in this paper, we propose an access-aware placement of objects in the application code for two types of memories. Given the desired power savings and acceptable performance loss, our placement algorithm suggests candidate variables for NVM. We present an evaluation of the proposed technique on two applications and study the energy and performance consequences of different placements.Publication Open Access Acil serviste hekimler fonksiyonel nörolojik belirti bozukluğu ve somatik belirti bozukluğunu nasıl yönetiyor? Bir vinyet çalışması(Türk Nöropsikiyatri Derneği, 2021) Kılıç, Özge; Altunöz, Umut; Eser, Hale Yapıcı; Necef, Işıl; Çakmak, Özgür Öztop; Aktaş, Can; Faculty Member; Faculty Member; Faculty Member; School of Medicine; Koç University Hospital; 134359; N/A; 299358; N/AIntroduction: we aimed to explore how physicians from different specialties approach the management of functional neurological symptom (conversion) and somatic symptom disorders in the emergency department compared with pulmonary embolism and how physicians’ professional and personal characteristics influence their diagnostic preferences. Methods: using a vignette methodology, and cross-sectional design, three emergency department case vignettes of possible functional neurological symptom, somatic symptom disorder, and pulmonary embolism were presented to physicians from internal medicine, emergency medicine, and psychiatry. A structured survey including questions on diagnosis and management of these cases, and physicians’ professional and personal characteristics (childhood trauma, attachment style) was conducted. Results: physicians from internal medicine and emergency medicine tended to consider functional neurological symptom disorder as ‘malingering’ while psychiatrists tended to diagnose the pulmonary embolism case as a psychiatric condition. Emergency medicine physicians preferred to manage functional neurological symptom disorder themselves, while other doctors endorsed recommending a psychiatric consultation. In the univariable model, being a physician from psychiatry, emergency medicine, or internal medicine; being a specialist, history of childhood sexual abuse, dismissive, and fearful attachment styles of doctors were significant predictors of diagnosing functional neurological symptom disorder as malingering. Being a psychiatrist stayed as the only significant predictor in the multivariable model. Conclusion: objectively-aberrant functional neurological symptoms and subjective somatic symptoms may be creating different reactions in physicians. In the emergency department, physicians’ diagnostic and treatment preferences of conversion disorder may be influenced by lack of training in conversion disorder, rather than their personal characteristics. / Amaç: farklı uzmanlık dallarından hekimlerin acil serviste fonksiyonel nörolojik (konversiyon) belirti bozukluğu ve bedensel belirti bozukluğunu yönetimini, pulmoner embolinin yönetimi ile karşılaştırarak incelemeyi ve hekimlerin mesleki ve kişisel özelliklerinin tanı tercihlerini nasıl etkilediğini araştırmayı amaçladık. Yöntem: vinyet yöntemi ve kesitsel tasarım kullanıldı. Olası fonksiyonel nörolojik belirti bozukluğu, bedensel belirti bozukluğu ve pulmoner emboli tanısı ile acil servise başvuran üç olgu, iç hastalıkları, acil tıp ve psikiyatri hekimlerine sunuldu. Bu olguların tanı ve tedavisine, ve hekimlerin mesleki ve kişisel özellikleri (çocukluk çağı travması, bağlanma biçimi) ne yönelik sorular içeren yapılandırılmış anket uygulandı. Bulgular: dahiliye ve acil tıp hekimleri, fonksiyonel nörolojik belirti bozukluğunu “temaruz” olarak görme eğilimindeyken, psikiyatristler pulmoner emboli vakasını psikiyatrik bir durum olarak görme eğilimindeydiler. Acil tıp hekimleri, fonksiyonel nörolojik belirti bozukluğunu kendileri yönetmeyi tercih ederken, diğer doktorlar psikiyatri konsültasyonu önerdi. Tek değişkenli modelde psikiyatri, acil tıp veya dahiliye hekimi olmak; uzman olmak, çocukluk çağı cinsel istismarı, kayıtsız ve korkulu bağlanma biçimleri, fonksiyonel nörolojik belirti bozukluğunu temaruz olarak tanımlamayı yordamaktaydı. Çok değişkenli modelde tek anlamlı yordayıcı psikiyatri uzmanlık dalıydı. Sonuç: nesnel olarak gözlenen anormal fonksiyonel nörolojik belirtiler ve öznel bedensel belirtiler hekimlerde farklı tepkilere yol açıyor olabilir. Acil serviste hekimlerin konversiyon bozukluğu tanı ve tedavi tercihleri, kişisel özelliklerinden ziyade konversiyon bozukluğu konusundaki eğitim eksikliğinden etkileniyor olabilir.