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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/6
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Publication Open Access Uluslararası çocuk kaçırmanın hukuki veçhelerine dair Lahey Sözleşmesi çerçevesinde aile hakkına saygı hakkı ve çocuğun üstün menfaatinin korunması: Marcus Frank Cerny başvurusu üzerinden bir inceleme(N/A, 2017) Oba, Meltem Ece; Law SchoolIn this study, the 1980 Hague Convention on the Civil Aspects of International Child Abductions is briefly explained and the Constitutional Court judgement on the Marcus Frank Cerny application is evaluated within the framework of the case law of the European Court of Human Rights.;TR: Bu çalışmada 1980 tarihli Uluslararası Çocuk Kaçırmaların Hukuki Veçhelerine Dair Lahey Sözleşmesi kısaca açıklanarak Marcus Frank Cerny başvurusuna ilişkin Anayasa mahkemesi kararı, İnsan Hakları Avrupa Mahkemesi içtihadı çerçevesinde değerlendirilmiştir.Publication Open Access DNA methylation profiling identifies novel markers of progression in hepatitis B-related chronic liver disease(BioMed Central, 2016) Vatansever, Sezgin; Hardy, Timothy; Sarı, Aysegül Akder; Çakalağaoğlu, Fulya; Avcı, Arzu; Zeybel, Gemma Louise; Bashton, Matthew; Mathers, John C.; Ünsal, Belkis; Mann, Jelena; N/A; Department of Molecular Biology and Genetics; Department of Molecular Biology and Genetics; Zeybel, Müjdat; Karahüseyinoğlu, Serçin; Faculty Member; Faculty Member; School of Medicine; 214694; 110772Background: Chronic hepatitis B infection is characterized by hepatic immune and inflammatory response with considerable variation in the rates of progression to cirrhosis. Genetic variants and environmental cues influence predisposition to the development of chronic liver disease; however, it remains unknown if aberrant DNA methylation is associated with fibrosis progression in chronic hepatitis B. Results: To identify epigenetic marks associated with inflammatory and fibrotic processes of the hepatitis B-induced chronic liver disease, we carried out hepatic genome-wide methylation profiling using Illumina Infinium beadarrays comparing mild and severe fibrotic disease in a discovery cohort of 29 patients. We obtained 310 differentially methylated regions and selected four loci comprising three genes from the top differentially methylated regions: hypermethylation of HOXA2 and HDAC4 along with hypomethylation of PPP1R18 were significantly linked to severe fibrosis. We replicated the prominent methylation marks in an independent cohort of 102 patients by bisulfite modification and pyrosequencing. The timing and causal relationship of epigenetic modifications with disease severity was further investigated using a cohort of patients with serial biopsies. Conclusions: Our findings suggest a linkage of widespread epigenetic dysregulation with disease progression in chronic hepatitis B infection. Cpg methylation at novel genes sheds light on new molecular pathways, which can be potentially exploited as a biomarker or targeted to attenuate inflammation and fibrosis.Publication Open Access Early/fast VLF events produced by the quiescent heating of the lower ionosphere by thunderstorms(American Geophysical Union (AGU), 2017) Kabirzadeh, R.; Marshall, R. A.; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; İnan, Umran Savaş; Faculty Member; College of Engineering; 177880Large and easily distinguishable perturbations of the VLF transmitter signals due to interactions with thundercloud-driven ionospheric modifications have been observed and studied for about three decades. These events are called "early/fast VLF" or "early VLF" events due to their immediate detection (similar to 20 ms) after the causative lightning flash on the ground and the fast rise time of the perturbed signal. Despite many years of study, the physical mechanisms responsible for these perturbations are still under investigation. Modifications of the sustained heating level of the ionosphere due to a lightning flash has been previously proposed as the causative mechanism of early/fast VLF events. The perturbations predicted by this mechanism, however, have been much smaller than experimental observations of 0.2-1 dB or higher. In this study, by using an improved 3-D thundercloud electrostatic upward coupling model which uses a realistic geomagnetic field, we find that the sustained heating model can predict perturbations that are consistent with reported experimental observations. Modifications in the quiescent heating of the lower ionosphere by thundercloud fields by individual lightning flashes may thus account for some observations of early/fast VLF events. Large and easily distinguishable perturbations of the VLF transmitter signals due to interactions with thundercloud-driven ionospheric modifications have been observed and studied for about three decades. These events are called "early/fast VLF" or "early VLF" events due to their immediate detection (similar to 20 ms) after the causative lightning flash on the ground and the fast rise time of the perturbed signal. Despite many years of study, the physical mechanisms responsible for these perturbations are still under investigation. Modifications of the sustained heating level of the ionosphere due to a lightning flash has been previously proposed as the causative mechanism of early/fast VLF events. The perturbations predicted by this mechanism, however, have been much smaller than experimental observations of 0.2-1 dB or higher. In this study, by using an improved 3-D thundercloud electrostatic upward coupling model which uses a realistic geomagnetic field, we find that the sustained heating model can predict perturbations that are consistent with reported experimental observations. Modifications in the quiescent heating of the lower ionosphere by thundercloud fields by individual lightning flashes may thus account for some observations of early/fast VLF events.Publication Open Access User interface paradigms for visually authoring mid-air gestures: a survey and a provocation(CEUR-WS, 2014) Department of Media and Visual Arts; Department of Computer Engineering; Department of Media and Visual Arts; Department of Computer Engineering; Baytaş, Mehmet Aydın; Yemez, Yücel; Özcan, Oğuzhan; Faculty Member; Faculty Member; College of Social Sciences and Humanities; College of Engineering; N/A; N/A; 12532Gesture authoring tools enable the rapid and experiential prototyping of gesture-based interfaces. We survey visual authoring tools for mid-air gestures and identify three paradigms used for representing and manipulating gesture information: graphs, visual markup languages and timelines. We examine the strengths and limitations of these approaches and we propose a novel paradigm to authoring location-based mid-air gestures based on space discretization.Publication Open Access A stochastic representation for mean curvature type geometric flows(Institute of Mathematical Statistics (IMS), 2003) Touzi, N.; Department of Mathematics; Department of Mathematics; Soner, Halil Mete; Faculty Member; College of Administrative Sciences and EconomicsA smooth solution {Gamma(t)}(tis an element of[0,T]) subset of R-d of a parabolic geometric flow is characterized as the reachability set of a stochastic target problem. In this control problem the controller tries to steer the state process into a given deterministic set T with probability one. The reachability set, V(t), for the target problem is the set of all initial data x from which the state process X-X(v)(t) is an element of T for some control process v. This representation is proved by studying the squared distance function to Gamma(t). For the codimension k mean curvature flow, the state process is dX(t) = root2P dW(t), where W(t) is a d-dimensional Brownian motion, and the control P is any projection matrix onto a (d - k)-dimensional plane. Smooth solutions of the inverse mean curvature flow and a discussion of non smooth solutions are also given.Publication Open Access Comparative spectroscopic investigation of Tm3+: tellurite glasses for 2-mu m lasing applications(Multidisciplinary Digital Publishing Institute (MDPI), 2018) Kurt, Adnan; Speghini, Adolfo; Bettinelli, Marco; Department of Electrical and Electronics Engineering; Department of Physics; Department of Electrical and Electronics Engineering; Department of Physics; Çankaya, Hüseyin; Görgülü, Adil Tolga; Sennaroğlu, Alphan; Researcher; Master Student; Faculty Member; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); College of Engineering; College of Sciences; N/A; N/A; 23851We performed a comparative spectroscopic analysis on three novel Tm3+: tellurite-based glasses with the following compositions Tm2O3: TeO2-ZnO (TeZnTm), Tm2O3: TeO2-Nb2O5 (TeNbTm), and Tm3+: TeO2-K2O-Nb2O5 (TeNbKTm), primarily for 2-mu m laser applications. Tellurite glasses were prepared at different doping concentrations in order to investigate the effect of Tm3+ ion concentration as well as host composition on the stimulated emission cross sections and the luminescence quantum efficiencies. By performing Judd-Ofelt analysis, we determined the average radiative lifetimes of the H-3(4) level to be 2.55 +/- 0.07 ms, 2.76 +/- 0.03 ms and 2.57 +/- 0.20 ms for the TeZnTm, TeNbTm and TeNbKTm samples, respectively. We clearly observed the effect of the cross-relaxation, which becomes significant at higher Tm2O3 concentrations, leading to the quenching of 1460-nm emission and enhancement of 1860-nm emission. Furthermore, with increasing Tm2O3 concentrations, we observed a decrease in the fluorescence lifetimes as a result of the onset of non-radiative decay. For the H-3(4) level, the highest obtained quantum efficiency was 32% for the samples with the lowest Tm2O3 ion concentration. For the 1860-nm emission band, the average emission cross section was determined to measure around 6.33 +/- 0.34 x 10(-21) cm(2), revealing the potential of thulium-doped tellurite gain media for 2-mu m laser applications in bulk and fiber configurations.Publication Open Access Pneumonia in HIV-infected patients(Aves, 2016) Önür, Seda Tural; Dalar, Levent; Yalçın, Arzu Didem; İliaz, Sinem; Doctor; Koç University Hospital; 168584Acquired immune deficiency syndrome (AIDS) is an immune system disease caused by the human immunodeficiency virus (HIV). The purpose of this review is to investigate the correlation between an immune system destroyed by HIV and the frequency of pneumonia. Observational studies show that respiratory diseases are among the most common infections observed in HIV-infected patients. In addition, pneumonia is the leading cause of morbidity and mortality in HIV-infected patients. According to articles in literature, in addition to antiretroviral therapy (ART) or highly active antiretroviral therapy (HAART), the use of prophylaxis provides favorable results for the treatment of pneumonia. Here we conduct a systematic literature review to determine the pathogenesis and causative agents of bacterial pneumonia, tuberculosis (TB), nontuberculous mycobacterial disease, fungal pneumonia, Pneumocystis pneumonia, viral pneumonia and parasitic infections and the prophylaxis in addition to ART and HAART for treatment. Pneumococcus-based polysaccharide vaccine is recommended to avoid some type of specific bacterial pneumonia.Publication Open Access Multidimensional wave packet dynamics within the fluid dynamical formulation of the Schrodinger equation(American Institute of Physics (AIP) Publishing, 1998) Rabitz, H.; Department of Mathematics; Department of Mathematics; Aşkar, Attila; Dey, Bijoy K.; Faculty Member; Faculty Member; College of Sciences; 178822; N/AThis paper explores the quantum fluid dynamical (QFD) representation of the time-dependent Schrodinger equation for the motion of a wave packet in a high dimensional space. A novel alternating direction technique is utilized to single our each of the many dimensions in the QFD equations. This technique is used to solve the continuity equation for the density and the equation for the convection of the flux for the quantum particle. The ability of the present scheme to efficiently and accurately describe the dynamics of a quantum particle is demonstrated in four dimensions where analytical results are known. We also apply the technique to the photodissociation of NOCl and NO2 where the systems are reduced to two coordinates by freezing the angular variable at its equilibrium value.Publication Open Access An information theoretical analysis of broadcast networks and channel routing for FRET-based nanoscale communications(Institute of Electrical and Electronics Engineers (IEEE), 2012) Kuşcu, Murat; Malak, Derya; Akan, Özgür Barış; Faculty Member; College of EngineeringNanoscale communication based on Forster Resonance Energy Transfer (FRET) enables nanomachines to communicate with each other using the excited state of the fluorescent molecules as the information conveyer. In this study, FRET-based nanoscale communication is further extended to realize FRET-based nanoscale broadcast communication with one transmitter and many receiver nanomachines, and the performance of the broadcast channel is analyzed information theoretically. Furthermore, an electrically controllable routing mechanism is proposed exploiting the Quantum Confined Stark Effect (QCSE) observed in quantum dots. It is shown that by appropriately selecting the employed molecules on the communicating nanomachines, it is possible to control the route of the information flow by externally applying electric field in FRET-based nanonetworks.Publication Open Access Compressed training based massive MIMO(Institute of Electrical and Electronics Engineers (IEEE), 2019) Yılmaz, Baki Berkay; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Erdoğan, Alper Tunga; Faculty Member; College of Engineering; 41624Massive multiple-input-multiple-output (MIMO) scheme promises high spectral efficiency through the employment of large scale antenna arrays in base stations. In time division duplexed implementations, co-channel mobile terminals transmit training information such that base stations can estimate and exploit channel state information to spatially multiplex these users. In the conventional approach, the optimal choice for training length was shown to be equal to the number of users, K. In this paper, we propose a new semiblind framework, named as "MIMO Compressed Training," which utilizes information symbols in addition to training symbols for adaptive spatial multiplexing. We show that this framework enables us to reduce (compress) the training length down to a value close to log(2) (K), i.e., the logarithm of the number of users, without any sparsity assumptions on the channel matrix. We also derive a prescription for the required packet length for proper training. The framework is built upon some convex optimization settings that enable efficient and reliable algorithm implementations. The numerical experiments demonstrate the strong potential of the proposed approach in terms of increasing the number of users per cell and improving the link quality.