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Bilkent Theses
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Relation of perceptual fluency with metamemory judgments and recognition memory
(Bilkent University, 2024-05) Dalkıran, Sultan Rengin
Previous research has shown that perceptual fluency differentially affects metamemory judgments and actual recognition performance. In this sense, the perceptual-fluency hypothesis asserts that fluent items are considered more memorable and are likely to receive higher metamemory judgments than disfluent items, which is replicated in multiple studies. Despite a demonstrated positive effect of perceptual fluency on metamemory judgments, the relationship between perceptual fluency and recognition memory performance is less clear. Therefore, in this study, we aimed to further investigate the distinctive effects of perceptual fluency on metamemory judgments and actual recognition performance for pictures. Respectively, in Experiment 1, subjects (n = 30) were presented with blurred or clear pictures and prompted with judgments of learning (JOLs) ratings at study, followed by a recognition test. In Experiment 2, our main focus was on the direct association between perceptual fluency and actual recognition performance. Hence, the second experiment was similar to the first one except subjects (n = 48) were not prompted with JOLs and multiple sources of manipulations (blurriness and inversion) were implemented to induce perceptual disfluency. The results showed that neither metamemory judgments nor actual recognition performance significantly differed in response to perceptual fluency. Thus, in contrast to many other studies, the current study failed to support the perceptual fluency hypothesis even though our results about actual recognition performance aligned with past research.
Three dimensional electrode integration on microwave resonator sensors for microparticle sensing in microfluidics
(Bilkent University, 2024-06) Alataş, Yağmur Ceren
Position dependency of the particle-induced signal can be mitigated by using a 3-dimensional (3D) electrode configuration at the sidewalls of the microfluidic channel in electrical sensors. The first method to obtain 3D electrodes was filling Galinstan, Galium-Indium alloy with low melting point, to dead-end PDMS cavities at the sidewalls of a microfluidic channel positioned on a split ring resonator (SRR). Due to electrical contact between coplanar resonator electrodes and Galinstan cavities, the electric field between coplanar resonator electrodes was extended to form a uniform electric field along the height of the microfluidic channel. Galinstan was used in this application due to its low melting point, non-toxicity, and high conductivity. This architecture was used for size-based classification of 20-and 30\textmu m polystyrene (PS) microparticles without any post-processing for particle trajectory. However, the signal-to-noise ratio (SNR) was low due to the presence of PDMS spacers between the Galinstan cavities and the microfluidic channel, which were placed to avoid leakage of liquid metal into the microfluidic channel. In the later method, 3D electrodes made of solid material, epoxy-based, negative photoresist SU8, were fabricated and positioned inside a microfluidic channel to boost the signal-to-noise ratio. SU8 pillars with tens of micrometers height were patterned at the sensing region and metalized using sputter deposition to form a conformal profile on the electrodes. A fused silica substrate containing the SU8 microelectrodes, microfluidic channel, and coplanar connection electrodes was mounted on a microstrip transmission line resonator on PCB. The electric field on the resonator electrodes was extended to form a uniform electric field inside the microfluidic channel between the SU8 microelectrodes through wirebonding on connection electrodes. This sensor architecture was also used for size-based classification of 12-and 20\textmu m polystyrene microparticles without any trajectory correction. As a result of positioning 3D electrodes in direct contact with the microfluidic channel, the signal-to-noise ratio increased by 10 folds. Furthermore, a split ring resonator was integrated with a Coulter counter operating at low frequencies to measure the size and dielectric permittivity of a microparticle simultaneously. SU8 microelectrodes were fabricated at the tip of low and high-frequency sensing electrodes, positioned inside the microfluidic channel, forming the sensing region. The signals induced in the split ring resonator and Coulter counter can be simultaneously processed to get information about the size and type of the particle. Polystyrene and polyethylene microparticles with different dielectric permittivity and size were differentiated with this sensor. It was realized that polyethylene microparticles contained additives, which were not explicitly stated, however, the presence of titanium dioxide was detected using energy-dispersive X-ray spectroscopy (EDX). It was concluded that as a result of using a microwave resonator, it was possible to detect the presence of titanium dioxide inside the polyethylene microparticles and differentiate polystyrene and polyethylene particles.
Multidimensional liminal threshold of the city of Ankara: The Namazgâh Hill
(Bilkent University, 2024-06) Dağlı, Muhammed Said
Namazgâhs, which can be seen in many Ottoman cities, are open-air places of worship and they stand out as an overly comprehensive and ambivalent concept that can vary in their functions, qualities and quantities. Throughout its history, the Namazgâh and the Namazgâh Hill in Ankara have served different functions: as a gathering place, a place of worship, a cemetery and a gateway to the city. While the origins of this Namazgâh remain a mystery, these various functions became particularly evident during the War of Independence, a critical period that contributed to the establishment of the new Republic. The aim of this thesis is to compile existing sources on the Namazgâh Hill, to determine as much as possible which functions it assumed and under what circumstances, to show that it is a multidimensional liminal space for the city of Ankara, to explain that it not only hosted liminal transformations but also underwent liminal transformations itself, and as a result, to create a comprehensive historical narrative of the site. For this purpose, the Ottoman and Republic State Archives, paintings, engravings, photographs, newspapers of the period, the memories of people who used to live or have visited Ankara, and ethnographic studies about this city will be used.
A fictionalist social ontology
(2024-05) Bakkal, Erim
In this thesis, I explore how a fictionalist approach can be applied to social ontology, especially for conferred kinds, in the context of action explanation and prediction by comparing this view with various realist views. Chapter 1 is concerned with clarifying constitution accounts and the criteria for comparison. Chapter 2 gives three different kinds of problems against this realist view, which makes this view less credible. Chapter 3 introduces conferralist accounts. Chapter 4 will deal with the question of whether conferralist accounts can solve these problems. I will argue that even if the second problem is solved, the first and third problems still arise in conferralism. In Chapter 5, I propose a fictionalist social ontology. Thus, in Chapter 6, I argue that social fictionalism solves the problems in question.
Longevity and circadian rhythm in Caenorhabditis elegans: the impact of lithium chloride
(Bilkent University, 2024-06) Temirci, Elif Sena
Lithium chloride (LiCl) is a popular treatment for various neurological disorders, especially bipolar disorders. While its complete mechanism of action remains partially elucidated, LiCl has been found to support new memory formation by triggering the construction of new neurons, reducing senescence, and regulating the circadian rhythm, particularly in bipolar patients, where it counteracts their abnormally fast biological clock. The circadian rhythm is vital in determining efficiency, understanding energy consumption, and biochemical balance for all organisms. This
rhythm includes regulating body functions by the day/night cycle. Caenorhabditis elegans (C. elegans) is one of the most robust organisms for modeling circadian rhythm, although it lives in the soil. Therefore, by employing C. elegans as a model system, valuable insights could be gained for these complex processes. This study aims to elucidate the complex relationship between LiCl, circadian rhythms, and longevity, as disruptions in these pathways are implicated in neurodegenerative diseases and age-related cognitive and motor decline. In this project, white light was employed to manipulate the circadian rhythm in C. elegans, with one group additionally receiving LiCl treatment in addition to light exposure. The study focused on longevity, response to environmental factors, and circadian rhythm. To elucidate the effect on longevity, lifespan measurements showed that LiCl treatment extended the lifespan of C. elegans under both light and dark conditions, with a shorter lifespan observed in the light. Additionally, when comparing the effect of specific developmental time points, the signs of aging appeared later in the dark compared to the light. The differential gene expression of longevity genes suggested that LiCl treatment could impact gene expression, particularly the age-1 gene, but not the daf-16 gene. Furthermore, the response to environmental changes was examined imilarly and it was observed that C. elegans responded to the circadian rhythm disruption caused by light and LiCl administration. In conclusion, this study suggests that LiCl treatment has the potential to mitigate the adverse effects of circadian rhythm disruptions and reverse the aging process of C. elegans.
Dare to share? how anti-disinformation policies affect online news-sharing behavior in Türkiye
(Bilkent University, 2024-05) Küçükoruç, Selin
For the past decades, governments and social media companies have attempted to combat the spread of misinformation online by developing new regulations around online technologies. While these attempts have successfully curbed the spread of misinformation in many instances, there have also been cases where such regulations have violated the freedom of expression due to the uncertainty surrounding the definition of misinformation (Cipers et al., 2023). This thesis aims to explore how these strategies to combat misinformation affect the way ordinary citizens engage with news online in an authoritarian-leaning context. In doing so, it investigates the impact of recent counter-misinformation regulation in Turkiye, publicly known as the disinformation or censorship law, on news-sharing behavior. Employing a 2x2 between-subjects online survey experiment among 228 Turkish college student, the study seeks to understand whether exposure to information about the law and the mode of online identity (anonymous vs. real) affects individuals’ news-sharing tendencies. Although the salience of the law and the different modes of online identity does not significantly affect news-sharing attitudes as a model, the salience of the law alone has a significant negative relationship with sharing likelihood when all control variables were included in the analysis. Overall, the findings highlight the importance of striking a balance between countering misinformation and protecting freedom of expression online.
Generating tree method and applications to pattern-avoiding inversion sequences
(Bilkent University, 2024-05) Gezer, Melis
An inversion sequence of length n is an integer sequence e = e1 · · · en such that 0 ≤ ei < i for each 0 ≤ i ≤ n. We use In to denote the set of inversion sequences of length n. Let [k] := {0, 1, · · · , k − 1} denote the alphabet and τ be a word of length k over this alphabet. A pattern of length k is simply a word over the alphabet [k]. We say an inversion sequence e ∈ In contains the pattern τ of length k if it contains a sub-sequence of length k that is order isomorphic to τ; otherwise, e avoids the pattern τ . For a given pattern τ , we use In(τ ) to denote the set of all τ -avoiding inversion sequences of length n. Firstly, we review the enumeration of inversion sequences that avoid patterns of length three. We then study an enumeration method
based on generating trees and the kernel method to enumerate pattern-avoiding inversion sequences for general patterns. Then, we provide sampling
algorithms for pattern-avoiding inversion sequences and apply them to some specific patterns. Based on extensive simulations, we study some statistics such as the number of zeros, the number of distinct elements, the number of repeated elements, and the maximum elements. Finally, we present a bijection between In(0312) and In(0321) that preserves these statistics.
How can bundle cosmopsychism solve the subject-derivation problem
(Bilkent University, 2024-05) Celayir, Berk
Cosmopsychism is the view that the universe as a whole is conscious and metaphysi-
cally grounds all conscious subjects. While this position has the important advantage
of avoiding the fundamental problems of physicalism, dualism and micropsychism,
it faces a challenge called the subject-derivation problem, that is, it must explain
how all the different conscious subjects derive from a singular cosmic subject. In this
thesis, I will argue that the subject-derivation problem cannot be solved as long as a
singular cosmic subject is assumed, and I will propose a new model for solving this
problem, which I call Bundle Cosmopsychism. The main idea of my thesis is that a
bundle of cosmic subjects subsuming the entire phenomenal statespace can ground
all subjects in an irreducibly collective way.
Mary Wollstonecraft’s revolution in manners and the kickback of constructed femininity
(Bilkent University, 2024-05) Çiftci, Sena
In my thesis, by using Simone De Beauvoir's concept of ‘the other’ from her book
Second Sex, I attempt to solve the issue of how some features of produced
femininity, such as submission, caretaking, sentimentality, and so forth, increase
women's oppression. I argue that discriminatory practices that are explicitly gendered
and imposed on a single gender have been producing negative outcomes, regarding
the problem explained. Also, it should be acknowledged that adhering to these
practices should not be promoted as necessary to be identified as a woman. I propose
to follow the revolution in female manners advocated by Mary Wollstonecraft in A
Vindication of the Rights of Women as a plausible and effective answer to ‘the
otherness’ of women in society. Here I argue that the main reason for the plausibility
is the said revolution’s inclusivity. Since Wollstonecraft argues that the revolution in
female manners can be attained only by equal distribution of knowledge of the right
kind of virtues and national education to all genders, inclusivity should be a given.
The Politics of diversion: autocratic regimes and the use of force in times of domestic predicaments
(Bilkent University, 2024-05) Sevindik, Ali
When faced with a hard-to-solve domestic crisis, leaders may appeal to workaround the predicament instead of trying to solve the issue to ensure their survival as the political authority. One of the instrumental ways of overcoming the challenges of the domestic crisis through diverting the attention of public opinion could be using force against an ethnic or political group within the borders or against a country. The literature is dominated by research that heavily focuses on the diversionary motivations of democracies as they have electoral processes that give an opportunity to citizens to reward or punish the leaders for their successes or failures. However, very few studies examine the diversionary motivations of autocracies. In this thesis, I aimed to address this gap and contribute to the literature by examining the diversionary motivations of different types of autocratic regimes. I hypothesized that personalist and military autocracies are more conflict-prone than other autocracies in times of domestic crises. I constructed monadic and dyadic datasets by compiling available data. The monadic dataset consists of 258 observations of 59 countries between 1990-2001 whereas the dyadic dataset contains 123,819 observations of dyad-years between 1990-2001. To test my hypotheses, I conducted logistic regression analyses. My findings from the analyses demonstrated mixed results for the relations among domestic crises, regime type, and external and internal use of force but affirmed that personalist autocracies are more inclined to use force when faced with a domestic crisis vis-à-vis non-personalist autocracies.