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Citation Count: 5
(3+3+2) warped-like product manifolds with Spin(7) holonomy
(Elsevier Science Bv, 2011) Bilge, Ayşe Hümeyra; Bilge, Ayşe Hümeyra
We consider a generalization of eight-dimensional multiply warped product manifolds as a special warped product by allowing the fiber metric to be non-block diagonal. We define this special warped product as a (3 + 3 + 2) warped-like manifold of the form M = F x B. where the base B is a two-dimensional Riemannian manifold and the fibre F is of the form F = F-1 x F-2 where the F-i(i = 1 2) are Riemannian 3-manifolds. We prove that the connection on M is completely determined by the requirement that the Bonan 4-form given in the work of Yasui and Ootsuka [Y. Yasui and T. Ootsuka Spin(7) holonomy manifold and superconnection Class. Quantum Gravity 18(2001)807-816] be closed. Assuming that the F-i are complete connected and simply connected it follows that they are isometric to S-3 with constant curvature k > 0 and the Yasui-Ootsuka solution is unique in the class of (3 + 3 + 2) warped-like product metrics admitting a specific Spin(7) structure. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Citation Count: 3
Abortion services at hospitals in Istanbul
(Taylor & Francis Ltd, 2017) Louıse Şimşek, Mary
Objective: Despite the existence of a liberal law on abortion in Turkey there is growing evidence that actually securing an abortion in Istanbul may prove difficult. This study aimed to determine whether or not state hospitals and private hospitals that accept state health insurance in Istanbul are providing abortion services and for what indications. Method: Between October and December 2015 a mystery patient telephone survey of 154 hospitals 43 public and 111 private in Istanbul was conducted. Results: 14% of the state hospitals in Istanbul perform abortions without restriction as to reason provided in the current law while 60% provide the service if there is a medical necessity. A quarter of state hospitals in Istanbul do not provide abortion services at all. 48.6% of private hospitals that accept the state health insurance also provide for abortion without restriction while 10% do not provide abortion services under any circumstances. Key conclusions: State and private hospitals in Istanbul are not providing abortion services to the full extent allowed under the law. The low numbers of state hospitals offering abortions without restriction indicates a de facto privatization of the service. This same trend is also visible in many private hospitals partnering with the state that do not provide abortion care. While many women may choose a private provider the lack of provision of abortion care at state hospitals and those private hospitals working with the state leaves women little option but to purchase these services from private providers at some times subtantial costs.
Citation Count: 18
Absolute configuration and biological profile of pyrazoline enantiomers as MAO inhibitory activity
(Wiley, 2019) Yelekçi, Kemal; Sarıgül, Sevgi; Bultinck, Patrick; Herrebout, Wouter; Doğan, İlknur; Yelekçi, Kemal; Uçar, Gülberk; Kelekçi, Nesrin Gökhan
A new racemic pyrazoline derivative was synthesized and resolved to its enantiomers using analytic and semipreparative high-pressure liquid chromatography. The absolute configuration of both fractions was established using vibrational circular dichroism. The in vitro monoamine oxidase (MAO) inhibitory profiles were evaluated for the racemate and both enantiomers separately for the two isoforms of the enzyme. The racemic compound and both enantiomers were found to inhibit hMAO-A selectively and competitively. In particular the R enantiomer was detected as an exceptionally potent and a selective MAO-A inhibitor (K-i = 0.85 x 10(-3) +/- 0.05 x 10(-3) mu M and SI: 2.35 x 10(-5)) whereas S was determined as poorer compound than R in terms of K-i and SI (0.184 +/- 0.007 and 0.001). The selectivity of the enantiomers was explained by molecular modeling docking studies based on the PDB enzymatic models of MAO isoforms.
Citation Count: 0
Algı mı, söylem mi? Kopenhag Okulu ve yeni-klasik gerçekçilikte güvenlik tehditleri
(Uluslararası İlişkiler Konseyi Derneği İktisadi İşletmesi, 2011) Akgül Açıkmeşe, Sinem
Bu makale, güvenlik tehditlerinin ortaya çıkışı bakımından yeni-klasik gerçekçilikteki algısal yaklaşımla, Kopenhag Okulunun söylemle inşaya dayalı yöntemini karşılaştırmaktadır. Makalenin hareket noktası, güvenlik tehditlerinin içeriği ve güvenlik aktörleri bakımından farklı perspektifl ere sahip bu iki yaklaşımın güvenliğin çalışılmasında metodolojik benzerlikler içermesi nedeniyle karşılaştırılabilir olduğu varsayımıdır. Makale, tehditlerin ortaya çıkışı bakımından yeni-klasik gerçekçiliğin algılara dayalı öznel yaklaşımının Kopenhag Okulu tarafından kısmen benimsendiğini vurgulayarak, Okulun söyleme dayalı özneler-arası alternatif bir model geliştirdiğini aktarmaktadır. Bu çerçevede, makale öncelikle Güvenlik Çalışmaları yazınında güvenlik tehdidinin içeriği konusundaki tartışmalara yer vermektedir. Ardından, yeni-klasik gerçekçiliği çatısında barındıran Gerçekçi Güvenlik Çalışmalarının tehdidin içeriği ve ortaya çıkışına dair varsayımlarını karşılaştırmalı olarak değerlendirmekte ve yeni-klasik gerçekçiliğin algısal perspektifi ni analiz etmektedir. Son olarak, Kopenhag Okulunun tehditlerle ilgili analizinin çerçevesini oluşturan güvenlikleştirme yaklaşımının tehditlerin kapsamı ve dayanağına dair tespitlerini Okulun kullandığı söz edimi, siyaset teorisi ve söylem analizi perspektifl erinden yeni-klasik gerçekçilikle karşılaştırmalı olarak incelemektedir.
Citation Count: 0
Amplitude and Frequency Modulations with Cellular Neural Networks
(Springer, 2015) Tander, Baran; Özmen, Atilla
Amplitude and frequency modulations are still the most popular modulation techniques in data transmission at telecommunication systems such as radio and television broadcasting gsm etc. However the architectures of these individual systems are totally different. In this paper it is shown that a cellular neural network with an opposite-sign template can behave either as an amplitude or a frequency modulator. Firstly a brief information about these networks is given and then the amplitude and frequency surfaces of the generated quasi-sine oscillations are sketched with respect to various values of their cloning templates. Secondly it is proved that any of these types of modulations can be performed by only varying the template components without ever changing their structure. Finally a circuit is designed simulations are presented and performance of the proposed system is evaluated. The main contribution of this work is to show that both amplitude and frequency modulations can be realized under the same architecture with a simple technique specifically by treating the input signals as template components.
Citation Count: 12
An Analysis of International Relations Academics in Turkey and their approaches to the field: TRIP 2014 Faculty Survey Results
(Uluslararası İlişkiler Konseyi Derneği, 2016) Aydın, Mustafa; Hisarlıoğlu, Fulya; Yazgan, Korhan
Despite the increasing interest in the studies inquiring the limits autonomous character of and the interactions between the International Relations (IR) discipline and other academic fields the scope and scale of empirical research on these issues are relatively small. In order to contribute to the discussion on the limits and peculiarities of the IR discipline and to shed light on the development current status and major characteristics of the IR studies in Turkey its place in the global IR discipline and the views of LR. scholars on major issues on the global regional and national agenda two surveys were conducted by the International Relations Council of Turkey (IRCT) in 2007 and 2009. Later on the IRTC collaborated with the Institute for the Theory and Practice of International Relations at the College of William and Mary to conduct further surveys in 2011 and 2014. This paper presents findings of the last survey on Turkey based on the worldwide research simultaneously conducted in 31 different countries in September 2014.
Citation Count: 0
Araştırma Merkezlerinin Yükselişi, Türkiye’de Dış Politika ve Ulusal Güvenlik Kültürü
(Uluslararası İlişkiler Konseyi Derneği İktisadi İşletmesi, 2012) Çelik, Nihat
[Abstract Not Available]
Citation Count: 1
Assessing protein-ligand binding modes with computational tools: the case of PDE4B
(Springer, 2017) Akdoğan, Ebru Demet; Aviyente, Viktorya; Akten, Ebru Demet; Monard, Gerald
In a first step in the discovery of novel potent inhibitor structures for the PDE4B family with limited side effects we present a protocol to rank newly designed molecules through the estimation of their IC values. Our protocol is based on reproducing the linear relationship between the logarithm of experimental IC values [(IC)] and their calculated binding free energies (). From 13 known PDE4B inhibitors we show here that (1) binding free energies obtained after a docking process by AutoDock are not accurate enough to reproduce this linear relationship
Citation Count: 0
Atlantik Paktı’ndan NATO’ya: Türkiye Büyük Millet Meclisi’nde Türkiye’nin konumu ve uluslararası rolü tartışmalarından bir kesit
(Uluslararası İlişkiler Konseyi Derneği İktisadi İşletmesi, 2012) Koharik Yanık, Lerna
Bu makale Türkiye’nin Kuzey Atlantik İttifakı’na (NATO) giriş sürecinde dış politika söylemleri aracılığıyla oluşan kimliği, eleştirel jeopolitik çerçevesinde irdelemektedir. Bu makalenin ana tezi ülkelerin dış politika yoluyla oluşturdukları kimliklerin sadece konum, kültür ve değerden ibaret olmadığı, bu denkleme bir de ülkelerin üstlendikleri uluslararası işlevin eklenmesi gerektiğidir. Türkiye örneğini değerlendirmek amacıyla Türkiye’nin NATO’ya girişinden hemen önce ve sonrasında Türkiye Büyük Millet Meclisi’nde (TBMM) yapılan çeşitli konuşmalar incelenmiştir. Varılan sonuç bu yıllarda konum, kültür ve değer olarak kendini Batılı sayan Türkiye’nin Doğu’ya uzanmayı görev olarak bellediği ve dolayısıyla üstü kapalı bir eşiksel kimlik yaratıldığıdır.
Citation Count: 0
Back to Full Employment
(Routledge Journals Taylor & Francis Ltd, 2013) Orhangazi, Özgür
[Abstract Not Available]
Citation Count: 2
Bargaining with nonanonymous disagreement: Decomposable rules
(Elsevier Science Bv, 2011) Gürsel Tapkı, İpek; Tapkı, İpek Gürsel
We analyze bargaining situations where the agents' payoffs from disagreement depend on who among them breaks down the negotiations. We model such problems as a superset of the standard domain of Nash (1950). We first show that this domain extension creates a very large number of new rules. In particular, decomposable rules (which are extensions of rules from the Nash domain) constitute a nowhere dense subset of all possible rules. For them, we analyze the process through which "good" properties of rules on the Nash domain extend to ours. We then enquire whether the counterparts of some well-known results on the Nash (1950) domain continue to hold for decomposable rules on our extended domain. We first show that an extension of the Kalai-Smorodinsky bargaining rule uniquely satisfies the Kalai and Smorodinsky (1975) properties. This uniqueness result, however, turns out to be an exception. We characterize the uncountably large classes of decomposable rules that survive the Nash (1950), Kalai (1977), and Thomson (1981) properties. (C) 2011 Elsevier B.V. All rights reserved.
Citation Count: 3
Bayesian compressive sensing for ultra-wideband channel estimation: algorithm and performance analysis
(Springer, 2015) Erküçük, Serhat; Erküçük, Serhat; Çırpan, Hakan Ali
Due to the sparse structure of ultra-wideband (UWB) channels compressive sensing (CS) is suitable for UWB channel estimation. Among various implementations of CS the inclusion of Bayesian framework has shown potential to improve signal recovery as statistical information related to signal parameters is considered. In this paper we study the channel estimation performance of Bayesian CS (BCS) for various UWB channel models and noise conditions. Specifically we investigate the effects of (i) sparse structure of standardized IEEE 802.15.4a channel models (ii) signal-to-noise ratio (SNR) regions and (iii) number of measurements on the BCS channel estimation performance and compare them to the results of -norm minimization based estimation which is widely used for sparse channel estimation. We also provide a lower bound on mean-square error (MSE) for the biased BCS estimator and compare it with the MSE performance of implemented BCS estimator. Moreover we study the computation efficiencies of BCS and -norm minimization in terms of computation time by making use of the big- notation. The study shows that BCS exhibits superior performance at higher SNR regions for adequate number of measurements and sparser channel models (e.g. CM-1 and CM-2). Based on the results of this study the BCS method or the -norm minimization method can be preferred over the other one for different system implementation conditions.
Citation Count: 6
Between anchors and aspirations: a new family of bargaining solutions
(Springer, 2019) Keskin, Kerim; Keskin, Kerim; Özcan-Tok, Elif
We study the salience and power of reference points in determining the effective anchors and aspirations in bargaining problems. Along this line we enrich the analysis of the standard bargaining model with two new parameters: the first parameter can be interpreted as the effectiveness (or salience) of the reference point in determining the anchor whereas the second parameter can be interpreted as its effectiveness in shaping agents' aspirations. Utilizing these parameters we provide a unifying framework for the study of bargaining problems with a reference point. The two-parameter family of bargaining solutions we obtain encompasses some well-known solutions as special cases. We offer multiple characterizations for each individual member of this family as well as two characterizations for the whole solution family in bilateral bargaining problems.
Citation Count: 5
Biclustering Expression Data Based on Expanding Localized Substructures
(Springer-Verlag Berlin, 2009) Erten, Cesim; Sözdinler, Melih
Biclustering gene expression data is the problem of extracting submatrices of genes and conditions exhibiting significant correlation across both the rows and the columns of a data matrix of expression values. We provide a method LEB (Localize-and-Extract Biclusters) which reduces the search space into local neighborhoods within the matrix by first localizing correlated structures. The localization procedure takes its roots from effective use of graph-theoretical methods applied to problems exhibiting a similar structure to that of biclustering. Once interesting structures are localized the search space reduces to small neighborhoods and the biclusters are extracted from these localities. We evaluate the effectiveness of our method with extensive experiments both using artificial and real datasets.
Citation Count: 11
Bivariate Pseudo-Gompertz distribution and concomitants of its order statistics
(Elsevier Science Bv, 2013) Gebizlioğlu, Ömer Lütfi; Gebizlioğlu, Ömer Lütfi
This paper presents a new bivariate Pseudo-Gompertz distribution that sprouts from the classical Gompertz distribution and possesses the features of pseudo-distribution functions. In addition to some standard properties of the proposed distribution distributions of order statistics and their concomitants for samples drawn from the new distribution are obtained. The survival and hazard functions of the concomitants are shown and their values are tabled. Interpretations of the results are given in connection with risk events and risk management. (C) 2013 Elsevier B.V. All rights reserved.
Citation Count: 12
Blind Dockings of Benzothiazoles to Multiple Receptor Conformations of Triosephosphate Isomerase from Trypanosoma cruzi and Human
(Wiley-VCH Verlag GmbH, 2011) Akdoğan, Ebru Demet; Ural, Gulgun; Akten, Ebru Demet; Doruker, Pemra
We aim to uncover the binding modes of benzothiazoles which have been reported as specific inhibitors of triosephosphate isomerase from the parasite Trypanosoma cruzi (TcTIM) by performing blind dockings on both TcTIM and human TIM (hTIM). Detailed analysis of binding sites and specific interactions are carried out based on ensemble dockings to multiple receptor conformers obtained from molecular dynamics simulations. In TcTIM dimer dockings the inhibitors preferentially bind to the tunnel-shaped cavity formed at the interface of the subunits whereas non-inhibitors mostly choose other sites. In contrast TcTIM monomer binding interface and hTIM dimer interface do not present a specific binding site for the inhibitors. These findings point to the importance of the tunnel and of the dimeric form for inhibition of TcTIM. Specific interactions of the inhibitors and their sulfonate-free derivatives with the receptor residues indicate the significance of sulfonate group for binding affinity and positioning on the TcTIM dimer interface. One of the inhibitors also binds to the active site which may explain its relatively higher inhibition effect on hTIM.
Citation Count: 0
Building Modern Turkey: State Space and Ideology in the Early Republic
(Cambridge Univ Press, 2016) Bozdoğan, Sibel
[Abstract Not Available]
Citation Count: 3
Busy tone based coexistence algorithm for WRAN and WLAN systems in TV white space
(Inst Engineering Technology-IET, 2018) Baykaş, Tunçer; Erküçük, Serhat; Baykaş, Tunçer
TV White Space (TVWS) refers to frequency band reserved only for licensed terrestrial TV broadcasting and is opened to unlicensed use under regulatory conditions. While regulations protect licensed systems from interference interference among unlicensed systems is left mainly to manufacturers. Consequently there is a need to develop new coexistence approaches between TVWS networks. Busy tone broadcasting is a coexistence method which can be used by TVWS networks to announce the selected frequency band is occupied. In this paper a busy tone based coexistence algorithm is proposed for IEEE 802.11af and IEEE 802.22 networks and analyzed by considering different client distributions experiencing log-normal shadowing where the exact interfering packet rate and successful packet transmission rate expressions are obtained and validated by simulations for different scenarios. The results show that with the proposed coexistence approach a WLAN can reliably detect the busy tone signal to change its frequency band and can reduce interference to WRAN. Even if there is no available frequency band for the WLAN the WRAN still maintains its enhanced successful packet transmission performance. The deployment of the proposed algorithm is important for successful coexistence between cognitive wireless networks where interference is not regulated such as in TVWS bands.
Citation Count: 5
Calculating Level Densities of Heavy Nuclei by the Shell Model Monte Carlo Method
(Academic Press Inc Elsevier Science, 2014) Alhassid, Yoram; Özen, Cem; Nakada, Hitoshi
The microscopic calculation of nuclear level densities in the presence of correlations is a difficult many-body problem. The shell model Monte Carlo method provides a powerful technique to carry out such calculations using the framework of the configuration-interaction shell model in spaces that are many orders of magnitude larger than spaces that can be treated by conventional methods. We present recent applications of the method to the calculation of level densities and their collective enhancement factors in heavy nuclei. The calculated level densities are in close agreement with experimental data.
Citation Count: 18
Carboxylic acid derivatives display potential selectivity for human histone deacetylase 6: Structure-based virtual screening molecular docking and dynamics simulation studies
(Elsevier Science, 2018) Yelekçi, Kemal; Yelekçi, Kemal
Human histone deacetylase 6 (HDAC6) has been shown to play a major role in oncogenic cell transformation via deacetylation of alpha-tubulin making it a viable target of anticancer drug design and development. The crystal structure of HDAC6 catalytic domain 2 has been recently made available providing avenues for structure-based drug design campaign. Here in our continuous effort to identify potentially selective HDAC6 inhibitors structure-based virtual screening of similar to 72 461 compounds was carried out using Autodock Vina. The top 100 compounds with calculated Delta G < -10 kcal/mol were manually inspected for binding mode orientation. Furthermore the top 20 compounds with reasonable binding modes were evaluated for selectivity by further docking against HDAC6 and HDAC7 using Autodock4. Four compounds with a carboxylic fragment displayed potential selectivity for HDAC6 over HDAC7 and were found to have good druglike and ADMET properties. Their docking complexes were then submitted to 10 ns-molecular dynamics (MD) simulation using nanoscale MD (NAMD) software to examine the stability of ligand binding modes. These predicted inhibitors remained bound to HDAC6 in the presence of water and ions and the root-mean-square deviation (RMSD) radius of gyration (Rg) and nonbond distance (protein-ligand) profiles suggested that they might be stable over time of the simulation. This study may provide scaffolds for further lead optimization towards the design of HDAC6 inhibitors with improved selectivity. (C) 2018 Elsevier Ltd. All rights reserved.

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