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Publication Open Access A preliminary study of tracking B-cell kinetics in patients with lung transplantation by monitoring kappa-deleting recombination excision circles(BAYCINAR MEDICAL PUBL-BAYCINAR TIBBI YAYINCILIK, 2022) Akbulut, Zeynep; Akdeniz, Tuba; Vayvada, Mustafa; Kalamanoğlu, Merih; Yeğinsu, Ali; Yanıkkaya Demirel, Gülderen; Kutlu, Cemal Asım; Maltepe University; Yeditepe University; Bahcesehir University; Istanbul Yeni Yuzyil University; Yeditepe University; Bahcesehir UniversityBackground: This study aims to evaluate humoral immune system response by measuring copy numbers of kappa-deleting recombination excision circles (KREC) gene segment from B lymphocytes in patients with lung transplantation. Methods: Between September 2015 and November 2016, a total of 11 patients (8 males, 3 females, mean age: 45.4 +/- 12.0 years, range, 23 to 59 years) who underwent lung transplantation with different primary indications were included. The copy numbers of KREC gene segment were quantified using real-time polymerase chain reaction method in peripheral blood samples collected pre- and post-transplantation. The samples of the patients were compared with the KREC levels in deoxyribonucleic acid extracted from blood samples of healthy children. Results: There was no significant change in KREC levels between pre- and post-operation (p=0.594 and p=0.657), although the median values indicated that the highest increase in the KREC levels (7x10(5)-12x10(5) , 85-170) was on Day 7 of transplantation. There was a positive correlation between the KREC levels (mL in blood) and lymphocytes at 24 h after transplantation (p=0.043) and between KREC copies per 10(6) of blood and age on Day 7. Conclusion: Our preliminary results suggest that KREC levels as an indicator of B lymphocyte production are elevated after lung transplantation. A prognostic algorithm by tracking B cell kinetics after post-transplantation for long-term follow-up can be developed following the confirmation of these preliminary results with more patient samples.Publication Open Access Trace Elements in the Soil-Plant Systems of Copper Mine Areas-A Case Study From Murgul Copper Mine From the Black Sea Region of Turkey(TECH SCIENCE PRESS, 2019) Ozturk, Munir; Altay, Volkan; Kucuk, Mahir; Yalcin, Ibrahim Ertugrul; Ege University; Ege University; Hatay Mustafa Kemal University; Bahcesehir UniversityThis study presents a case study on the heavy metal analysis of soil and plant samples around the Murgul copper mine, one of the first and most important mining areas in Turkey. An attempt has been made to investigate the status of trace elements like Al3+, Fe2+, Cu2+, Zn2+, Pb2+, Ni2+, Co2+ and Cd2+ in soils and plants. The sampling localities were taken from 500 m, 600 m, and 1000 m altitudes around the factory and at 1400 m in the forest zone. The aboveground parts and foliage ash of Silene compacta, Tussilago farfara, Smilax excelsa, Rhododendron ponticum, R. luteum, and herbal mix were analysed. The results of analysis have revealed the minimum and maximum concentrations measured in the plants as follows, aluminium (20-8985 mg kg(-1)), cadmium (0.0-0.5 mg kg(-1)), cobalt (0.0-5.5 mg kg(-1)), copper (0.0-347.5 mg kg(-1)), iron (25-9320 mg kg(-1)), lead (2-51 mg kg(-1)), nickel (1.5-16.5 mg kg(-1)), and zinc (13.0-221.0 mg kg(-1)). In the soil the concentrations of aluminium, cadmium, cobalt, copper, iron, lead, nickel, and zinc vary between 33-457, 0.0-0.0, 0.0-0.4, 0.1-88.7, 14-50, 0.3-4.1, 0.2-0.8, and 4.0-20.3 mg kg(-1) respectively. These findings enlighten the fact that copper is generally toxic in the soils as well as plants. Silene compacta has been recorded as a high copper accumulator, behaving as a healthy plant on the polluted sites of the area alongside the Murgul creek (especially at 600 m). This study stresses the fact that it is imperative to assess and monitor the levels of heavy metals in the environment due to anthropogenic activities, including mining, for evaluation of human exposure and for sustainable environment.Publication Metadata only Cognitive Backgrounds of Problem Solving: A Comparison of Open-ended vs. Closed Mathematics Problems(MODESTUM LTD, 2015) Bahar, Abdulkadir; Maker, C. June; Bahcesehir University; University of ArizonaProblem solving has been a core theme in education for several decades. Educators and policy makers agree on the importance of the role of problem solving skills for school and real life success. A primary purpose of this study was to investigate the influence of cognitive abilities on mathematical problem solving performance of elementary students. The author investigated this relationship by separating performance in open-ended and closed situations. Findings of the study indicated that the cognitive abilities explained 32.3% (open-ended) and 48.2% (closed) of the variance in mathematical problem solving performance as a whole. Mathematical knowledge and general intelligence were found to be the only variables that contributed significant variance to closed problem solving performance. General creativity and verbal ability were found to be the only variables that contributed significant variance to open-ended problem solving performance.Publication Open Access A mentorship model for teacher education: Young STEM researchers and practitioners program(MEHMET TEKEREK, 2022) Yabas, Defne; Bozoğlu, Hayriye Sinem; Bahçeşehir ÜniversitesiThe current research is about the impact of the young STEM researchers and practitioners program implemented within the STEM: Integrated teaching project. The aim of the program is to incorporate STEM integrated teaching knowledge in the teacher preparation period. In this phenomenological study, we explored five pre-school teachers' program experiences and their STEM conceptions. Data were collected with semi-structured interviews, including questions about the impact and elements of the program and participants' STEM conceptions. Content analysis showed that awareness for STEM education, development of integrated teaching knowledge, and program elements were the emergent themes about the program experience. Teacher candidates responded to the models that include real-world problems and engineering as contexts as most desirable when shown STEM education models to understand their STEM conceptions. The young STEM researchers and practitioners program can be evaluated as a developing model to be incorporated into teacher education programs. Further research can explore how pre-service teachers form their STEM conceptions and develop their integrated teaching knowledge.Publication Open Access Fizyoterapi ve Rehabilitasyon Öğrencilerinin Öğrenme Stili Tercihlerine Göre Akademik Başarı, Akademik Öz Güven ve Eğitim Ortamı Algısının Karşılaştırılması(2025) Açar, Görkem; Delibay, Aylin Aydoğdu; Kiloatar, Hümeyra; Turan, Onur; Bahçeşehir Üniversitesi; Kütahya Sağlık Bilimleri Üniversitesi; İstanbul Atlas ÜniversitesiBu çalışmanın amacı lisans düzeyindeki fizyoterapi ve rehabilitasyon öğrencilerinin farklı öğrenme stili tercihlerine göre akademik başarılarını, akademik özgüvenlerini ve öğrenme çevrelerini incelemekti. Çalışmaya lisans düzeyindeki 180 fizyoterapi ve rehabilitasyon öğrencisi dahil edilmiştir. Bireylerin öğrenme stili tercihleri Kolb Öğrenme Stili Envanteri-3 ile, öğrenme çevreleri Dundee Mevcut Eğitim Ortamı Değerlendirme Ölçeği (DREEM) ile, özgüvenleri ise Akademik Özgüven Ölçeği (AÖÖ) ile değerlendirilmiştir. Bireylerin akademik başarıları Genel Akademik Not Ortalamaları aracılığıyla değerlendirilmiştir. Farklı öğrenme stillerini tercih eden bireylerin Akademik Özgüven Ölçeği ile ölçülen akademik özgüvenleri benzerdi (p>0,05). Farklı öğrenme stillerini tercih eden bireylerin DREEM anketiyle ölçülen öğrenme çevresi algıları istatistiksel olarak farklıydı (p<0,05). Özümseyen öğrenme stilini tercih eden öğrencilerinin DREEM puanı ayrıştıran ve yerleştiren öğrenme stilini tercih eden bireylere göre daha düşük bulundu (p<0,05). Farklı öğrenme stillerini tercih eden bireylerin akademik başarıları istatistiksel olarak farklı bulundu (p<0,05). Değiştiren ve ayrıştıran öğrenme stillerine sahip öğrenciler arasında (χ² = 16.36, p = 0.0025), ayrıca yerleştiren ve ayrıştıran öğrenme stillerine sahip öğrenciler arasında (χ² = 16.37, p = 0.0025) istatistiksel olarak anlamlı farklılıklar bulunmuştur. Bu çalışma, fizyoterapi ve rehabilitasyon öğrencilerinde öğrenme stili tercihlerinin akademik başarı ve öğrenme ortamı algısı üzerinde anlamlı bir etkisi olduğunu ortaya koymuştur. Özümseyen öğrenme stiline sahip öğrencilerin eğitim ortamına yönelik memnuniyet düzeylerinin daha düşük olduğu, ayrıştırıcı öğrenme stiline sahip öğrencilerin ise akademik başarılarının daha düşük olduğu bulunmuştur. Buna karşılık, akademik özgüven düzeyleri öğrenme stilleri arasında anlamlı bir farklılık göstermemiştir. Bu bulgular, farklı öğrenme stillerine uygun eğitim stratejilerinin geliştirilmesinin, fizyoterapi ve rehabilitasyon eğitiminde öğrenci memnuniyetini ve akademik başarıyı artırabileceğini göstermektedir.Publication Open Access A note on the numerical approach for the reaction-diffusion problem with a free boundary condition(2010) Özuğurlu, Ersin; Ozugurlu, Ersin, Department of Mathematics and Computer Science, Bahçeşehir Üniversitesi, Istanbul, TurkeyThe equation modelling the evolution of a foam (a complex porous medium consisting of a set of gas bubbles surrounded by liquid films) is solved numerically. This model is described by the reaction-diffusion differential equation with a free boundary. Two numerical methods, namely the fixed-point and the averaging in time and forward differences in space (the Crank-Nicolson scheme), both in combination with Newtons method, are proposed for solving the governing equations. The solution of Burgers equation is considered as a special case. We present the Crank-Nicolson scheme combined with Newtons method for the reaction-diffusion differential equation appearing in a foam breaking phenomenon. Copyright © Australian Mathematical Society 2010. © 2011 Elsevier B.V., All rights reserved.Publication Open Access Full analytical model for obtaining surface plasmon resonance modes of metal nanoparticle structures embedded in layered media(Optical Society of American (OSA) [email protected], 2010) Şimşek, Ergün; Ŝimŝek, Ergün, Department of Electrical and Electronic Engineering, Bahçeşehir Üniversitesi, Istanbul, TurkeyThis work addresses the need for a fully-retarded theoretical model for surface plasmons on metal nanoparticle chains and arrays embedded in a multilayered medium. The proposed method uses dyadic layered medium Green's functions not only to obtain the electric field created by an oscillating electric dipole but also to modify the polarizability of nanoparticles in a multilayered medium appropriately. Theoretically calculated resonance frequencies show a very good agreement with the experimental results found in the literature. Theoretical results suggest that surface plasmon propagation lengths of 1 μm are possible using silver or gold nanoparticles embedded in a multilayered medium. © 2010 Optical Society of America. © 2014 Elsevier B.V., All rights reserved.Publication Open Access Evaluation of e-learning web sites using fuzzy axiomatic design based approach(2010) Büyüközkan, Gülҫin; Arsenyan, Jbid; Ertek, Gürdal; Büyüközkan, Gülҫin, Department of Industrial Engineering, Galatasaray Üniversitesi, Istanbul, Turkey; Arsenyan, Jbid, Department of Industrial Engineering, Bahçeşehir Üniversitesi, Istanbul, Turkey; Ertek, Gürdal, Faculty of Engineering and Natural Sciences, Sabancı Üniversitesi, Tuzla, TurkeyHigh quality web site has been generally recognized as a critical enabler to conduct online business. Numerous studies exist in the literature to measure the business performance in relation to web site quality. In this paper, an axiomatic design based approach for fuzzy group decision making is adopted to evaluate the quality of e-learning web sites. Another multi-criteria decision making technique, namely fuzzy TOPSIS, is applied in order to validate the outcome. The methodology proposed in this paper has the advantage of incorporating requirements and enabling reductions in the problem size, as compared to fuzzy TOPSIS. A case study focusing on Turkish e-learning websites is presented, and based on the empirical findings, managerial implications and recommendations for future research are offered. © 2010 Elsevier B.V., All rights reserved.Publication Open Access Oscillation of second-order mixed-nonlinear delay dynamic equations(2010) Ünal, Mehmet; Ağacık, Zafer A.; Ünal, Mehmet, Department of Software Engineering, Bahçeşehir Üniversitesi, Istanbul, Turkey; Zafer, Agacik A., Department of Mathematics, Middle East Technical University (METU), Ankara, TurkeyNew oscillation criteria are established for second-order mixed-nonlinear delay dynamic equations on time scales by utilizing an interval averaging technique. No restriction is imposed on the coefficient functions and the forcing term to be nonnegative. Copyright © 2010 M. Ünal and A. Zafer. © 2010 Elsevier B.V., All rights reserved.Publication Open Access An occlusion insensitive adaptive focus measurement method(Optical Society of American (OSA) [email protected], 2010) Aydın, Tarkan; Akgül, Yusuf Sinan; Aydin, Tarkan, Department of Computer Engineering, Gebze Teknik Üniversitesi, Gebze, Turkey, Department of Mathematics and Computer Science, Bahçeşehir Üniversitesi, Istanbul, Turkey; Akgül, Yusuf Sinan, Department of Computer Engineering, Gebze Teknik Üniversitesi, Gebze, TurkeyThis paper proposes a new focus measurement method for Depth From Focus to recover depth of scenes. The method employs an all-focused image of the scene to address the focus measure ambiguity problem of the existing focus measures in the presence of occlusions. Depth discontinuities are handled effectively by using adaptively shaped and weighted support windows. The size of the support window can be increased conveniently for more robust depth estimation without introducing any window size related Depth From Focus problems. The experiments on the real and synthetically refocused images show that the introduced focus measurement method works effectively and efficiently in real world applications. © 2010 Optical Society of America. © 2014 Elsevier B.V., All rights reserved.