MARS
MARS is a repository service of Mason Publishing and the Digital Scholarship Center (DiSC) at the George Mason University Libraries. MARS provides enduring, stable, well-indexed access to a wide range of scholarship from the Mason community, such as Electronic Theses and Dissertations (ETDs), articles, presentations, reports, and creative work. Learn more about publishing, sharing, and preserving research data with the George Mason University Institutional Dataverse, and our other repository services.
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The Use of Morphophonological Cues in Noun Processing: The Case of the Arabic Definite Article
(2023) Aldakheelallah, Hind; Lukyanenko, Cynthia A C
Listeners use a variety of cues in the speech signal to aid them in identifying nouns. For instance, English speakers use the phonological distinction between a and an to facilitate processing of following nouns (Nozari & Mirman, 2016; Gambi et al., 2018). Listeners’ use of cues is also modulated by the identity of the talker: listeners are less likely to use cues in nonnative talkers’ speech (Bosker et al., 2014; Schiller et al., 2020). Using visual-world eye-tracking, the current study explored native listeners’ use of morphophonologi-cal cues on the Arabic definite article in native- and foreign-accented speech. The Arabic definite article /ʔal-/ provides at least three morphophonological cues to the identity of a following noun. First, the coda /l/ assimilates to following coronal consonants but not to noncoronal consonants (Coronal condition: /ʔaddulfin/ “the dolphin” vs. s/ʔalbab/ “the door”). This assimilation carries two additional sub-phonemic cues depending on the coronal onset: coarticulation associated with emphatics (Emphasis condition: /ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔassullam/ “the ladder”) and longer pre-voicing associated with voiced stops (Voicing condition: /ʔattut/ “the berries” vs. /ʔaddud/ “the worms”). In two experiments, participants saw picture-pairs accompanied by auditory instructions in Modern Standard Arabic to click on one of them. In Informative trials, the two pictures’ names differed in their initial consonants (/ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔassullam/ “the ladder”). In Uninformative trials, initial consonants were the same (/ʔaˤsˤsˤaruχ/ “the rocket” vs. /ʔaˤsˤsˤaqr/ “the falcon”). In Experiment 1, participants listened to native-accented Arabic and in Experiment 2, they listened to foreign-accented Arabic. If listeners use the available cues, they should look at the target image earlier and/or longer in informative than uninformative trials. If foreign-accented speech disrupts language processing, cue use will be more evident in Experiment 1 than in Experiment 2. Fixation latency and proportion looks-to-target were measured and analyzed. As predicted, in Experiment 1, mixed effects models showed shorter latencies and higher accuracy in informative than uninformative trials in the Emphasis condition and shorter latencies in the Coronal condition. In Experiment 2, models revealed shorter latencies in the Emphasis condition and higher accuracy in the Coronal condition. No statistically significant effects were found in the Voicing condition for either experiment. These results suggest that native listeners use some of the morphophonological cues on the Arabic definite article to facilitate noun processing. However, the cue use depended on the condition and the identity of the talker. Moreover, unlike previous findings that listeners do not rely on phonological cues in foreign-accented speech, the current results show that foreign-accented speech reduces phonological cue use but does not completely block it. Thus, the current study provides some insights on the use of small phonemic and sub-phonemic article-related cues in noun processing including morphophonological processes of assimilation and coarticulation as well as adds to our understanding of the effects of foreign-accented speech on online language processing in general and on Arabic processing in specific.
The Economics of Cybersecurity Information
(2023) Hodgins, Mark W; Leeson, Peter T
The digital economy is a ubiquitous part of U.S. society that relies on an ever increasing supply of data to connect people and organizations. The wealth of underlying data imposes cybersecurity requirements, which are far from guaranteed. Sensational headlines of costly cyberattacks are published on a recurring basis. Multiple causal factors exist for why failure may occur, yet the prevailing belief is that the market is full of poor security products because suppliers shift risk to consumers without their knowledge or recourse. Is the leading theory that the cybersecurity market fails due to information problems accurate? This dissertation critically evaluates the conventional wisdom. In order to determine whether the current beliefs are misguided, a thorough understanding of the specific arguments and supporting evidence is necessary. The first essay reviews the theoretical and empirical claims of information asymmetry. My analysis decomposes the consumer’s alleged information challenges into several categories, which are high search costs from a lack of technical expertise, low incentives to expend effort to improve their acumen, and the lack of quality indicators. Persistent information challenges ostensibly incentivize suppliers to engage in moral hazard by reallocating resources away from cybersecurity and towards observable product attributes. The multitude of software vulnerabilities and data breaches is widely cited as evidence of adverse selection. Evaluating the prospects of market failure necessitates an understanding of who the predominant cybersecurity consumers are and what information seeking incentives and abilities they possess. The second essay focuses on the identity of a consumer class that the market failure narrative broadly neglects, the business consumer. I find that firms, universities, and other organizations are the predominant consumer and that individuals procure the majority of their cybersecurity indirectly through them. I argue that business consumers possess strong incentives to invest in cybersecurity information due to operational and financial losses from a cyberattack. Moreover, my research finds that business consumers possess unique abilities, through the labor market and contracting, to acquire cyber information. In contrast to conventional wisdom, today’s software vendors invest significantly in cybersecurity activities, which would only occur if consumers could acquire relevant information and credibly punish bad security. Given the results of the second essay, corporate shareholders should possess strong incentives to control agency costs associated with cybersecurity production. The third essay applies institutional economics to analyze the extent to which firms invest in corporate mechanisms that ameliorate cybersecurity information problems. Empirically, I evaluate the proxy statements of vendors and businesses consumers over time, finding that the vast majority modified their board of directors’ governance to improve cybersecurity monitoring. I also show how a competitive market for management leads to employment outcomes that are reflective of cybersecurity performance. Together, corporate governance and the market management help align the incentives of board directors and firm management with the shareholders.
Tranboundary Water Interaction- The Role of Weaker Riparian States
(2023) Sakhi, Farishta; Cobb, Sara Dr.
Abstract: Trans-boundary regional water conflict is complex in nature. As a multidimensional and multilayered problem, it involves multiple stakeholders with diverse sets of values and interests. Power asymmetry is the reason for the inequitable water distribution among riparian states. Asymmetric power is very evident in the outcomes of trans-boundary water dynamics and the adaptation process for trans-boundary water governance. Most of the scholarships on trans-boundary regional water interaction highlight the role of power in shaping interaction between stronger and weaker riparian states in a manner that safeguards the rights of stronger riparian states. Various kinds of structures and relations guide the water discourse through nation-states and institutions and in the context of asymmetric power relations, these structures are sometimes hegemonic entailing high-power asymmetries, making the cooperation processes extremely complex, time-consuming, and inequitable. This situation further consolidates the role of hydrohegemon to exploit the weaker riparian state in most of the regional water conflict resolution settings. Thus, resulting in long-term regional conflicts, poor water management, degradation of environmental resources, and possibility of water wars as many scholars would predict. However, I argue that hydro hegemony is multilayered, and it is not only the riparian states with more power that can influence the course of interaction but also the weaker riparian states can influence and challenge the status quo by using right strategies to safeguard their water rights. In this research, firstly I will explore the kinds of power involved in shaping the riparian relations and I envisage that weaker riparian adopts strategies and tools that ensure their leverage and will impact the outcomes of conflict resolution in their favor. Furthermore, I argue that weaker riparian utilizes tools that ensure their rights in both the negotiation phase, formulation of water negotiations and implementation mechanisms. I will investigate qualitatively cases of regional water conflict resolution among the riparian states with power asymmetry and the tools and practices adopted by weaker riparian states at different level of conflict resolution in which the weaker riparian has adopted tools, practices, and strategies to safeguard their water rights and not lose in the face of hydro hegemony. I will also explore the role of power in shaping water interaction when weaker riparian states lack major support for their water development project and how this inter dependency affects the riparian states relations. I will conduct interviews to understand how the role of actors in each case aided in laying out the playing ground for equitable water interaction. For this study power asymmetry will be analyzed quality in cases of Afghanistan and its riparian, India and Nepal and Tajikistan and Uzbekistan relations over the Rogun Dam The study will unveil some of the strategies adopted by the weaker riparian states to influence or challenge power asymmetry and safeguard its water rights. This dissertation reflects the status of information related to Trans boundary Water Affairs in Afghanistan until the year, 2021.
Doping Effects on 2D TMDs and Monolayer FETs with PN-Junction or Heterojunction Channels
(2023) Benyan Eshun, Kwesi; Li, QIliang
The major challenges in the scaling of metal-oxide-semiconductor field effect transistors (MOSFETs) include large source-to-drain leakage and small on/off current ratio, especially when the channel length is below 10nm. As the devices are being shrunk into nanoscale, it is increasingly difficult, if not impossible, to precisely control the dopant position and number in low-dimensional nanomaterials. To address these challenges, we designed and investigated a new type of short-channel FETs based on two-dimensional (2D) transition metal dichalcogenides (TMDCs) with a PN junction or heterojunction at the middle of the channel. The first step is to investigate the doping effects on the electrical properties of n-type and p-type 2D TMDCs, like MoS2 monolayer. In the comprehensive first-principle computational study of 2D TMDC FETs, different gate length and channel materials have been investigated and compared, with a focus on the analysis of ballistic transport, energy band alignment and their impact on channel current density. The results indicate that the off-state leakage current and on/off current ratio are significantly improved in the FETs with a junction channel, in comparison with the FETs with homogeneous channel. Also, the 2DTMDC semiconductors should be protected from unintentional or intentional doping if they are used in the transistors in future integrated circuits. This new junction-channel approach, leveraged with the intrinsic advantages offered by 2D TMDC monolayers, suggests a new and very attractive strategy to construct future nanoelectronic transistors.
Age and cholinergic mechanisms of mitochondrial signaling and toxicity in neural cells
(2023) Sinclair, Patricia; Kabbani, Nadine
Aging is a physiological process that entails physical and cognitive change however why some people experience age-related dementia due to neurodegeneration is not well understood. The most common form of neurodegeneration is non-familial, sporadic, Alzheimer’s disease (AD) that is highly associated with aging. AD is also significantly higher in women than in men. Neurodegeneration of acetylcholine producing neurons, involved in memory and cognition, is a known hallmark in early AD and most FDA-approved medications operate as restorative pro-cholinergic drugs. In addition to the cholinergic deficit, AD is associated with the buildup of various amyloid type proteins (amyloid-beta and tau) within the brain. Studies show elevated levels of the neurotoxic amyloid beta 42 (A?42) within the brain of AD patients. A?42 appears to bind many cellular targets but recent compelling evidence points to an important role of altered mitochondrial function in amyloid-mediated neurodegeneration. This study uses mass spectrometry proteomics, bioinformatics, and functional cellular assays to uncover A?42 mediated damage to neuronal mitochondria. Using whole-cell proteomic analysis I demonstrate specific changes in mitochondrial protein pathways in response to A?42. In addition, I examine the involvement of the ?7 nAChR in mitochondrial responses to A?42 and test the effect of estrogen withdrawal on mitochondrial health and function. The overall findings indicate an important role for mitochondrial proteins in homeostatic responses to A?42 presentation and suggest an important role for estrogen signaling in mitochondrial neuroprotection.