Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
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Item A SYNTHETIC TMRNA PLATFORM FOR ELUCIDATION OF BACTERIAL PROTEOME REMODELING UNDER STRESS(2022) Turner, Randi; McIver, Kevin; Cell Biology & Molecular Genetics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Translational reprogramming is a key component of the bacterial stress response and is a function of mRNA stability, protein turnover and proteolysis. Total proteome measurements give a view of the stable proteome but can fail to capture dynamic changes under stress, including incomplete polypeptides that result from cleaved mRNAs or stalled translation events. Bacteria employ a nearly ubiquitous native ribosome rescue system, transfer-messenger RNA (tmRNA), that rapidly resolves stalled translational complexes and tags the incomplete polypeptides for degradation. Characterization of these tmRNA-tagged polypeptides could reveal previously unknown aspects of the bacterial stress response. To address this information gap, we have developed a synthetic tmRNA platform that reprograms the native system to allow for co-translational labeling of the incomplete polypeptides in live bacteria. A short tag reading frame (TRF) encoded on native tmRNA facilitates the addition of a natural peptidyl degradation tag to the polypeptides, and therefore offers an attractive modular domain to introduce synthetic peptide tag sequences and study the “degradome”. To study translational remodeling under stress, we modified the native tmRNA with an 6x-HIS isolation tag with the specific purpose of stabilizing, isolating, and characterizing the degradome in Escherichia coli. Using our inducible system, we have successfully isolated 6xHis-tagged proteins, verified dynamic controlled tagging, assessed broad-spectrum tag introduction with mass spectrometry. Our results capture known tmRNA substrates and excitingly show that tagged protein profiles are markedly different under stress. We investigated the shifting degradome in cells experiencing translational stress associated with serine starvation induced by serine hydroxamate. In cells lacking RelE, the mRNA interferease toxin that cleaves mRNA in the ribosome A site, we find a dramatic shift away from catalytic protein degradation and distinct, disparate enrichment of ribosomal proteins in the degradome under stress. These latter results suggest a new specific role for RelE in regulating ribosome protein abundance under translational stress conditionsItem Characterization of programmed -1 ribosomal frameshift signals in the interleukin 2 receptor gamma mRNA(2016) Flickinger, Zachary Flickinger; Dinman, Jonathan D; Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Programmed -1 ribosomal frameshift (-1 PRF) signals are predicted to be present in ~10% of eukaryotic mRNA, suggesting a conserved role for -1 PRF in eukaryotic mRNA translation. This work focuses on -1 PRF in the interleukin 2 receptor gamma (IL2RG) mRNA. IL2RG is a component of receptors for six cytokines responsible for lymphocyte proliferation and differentiation. Altered expression of IL2RG is linked to immunodeficiency and lymphoma. We verified that the IL2RG mRNA has one potential -1 PRF signal in exon 3 that stimulates -1 frameshifting and a second in exon 8 that is definitively a -1 PRF signal. Both of these signals redirect the ribosome to a premature termination codon, suggesting -1 PRF alters IL2RG expression via NMD. Testing the effect of cancer patient associated mutations discovered in the exon 8 -1 PRF signal may elucidate a role for IL2RG -1 PRF in normal physiology and pathological phenotypes.Item Crowdsourced Monolingual Translation(2012) Hu, Chang; Bederson, Benjamin B; Resnik, Philip; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)An enormous potential exists for solving certain classes of computational problems through rich collaboration among crowds of humans supported by computers. Solutions to these problems used to involve human professionals who are expensive to hire or difficult to find. Despite significant advances, fully automatic systems still have much room for improvement. Recent research has involved recruiting large crowds of skilled humans (``crowdsourcing''), but crowdsourcing solutions are still restricted by the availability of those skilled human participants. With translation, for example, professional translators incur high cost and are not always available; machine translation systems have been greatly improved recently, but still can only provide passable translation, and for only limited language pairs at that; crowdsourced translation is limited by the availability of bilingual humans. This dissertation describes crowdsourced monolingual translation, where monolingual translation is translation performed by monolingual people. Crowdsourced monolingual translation is a collaborative form of translation performed by two crowds of people who speak the source or the target language respectively, with machine translation as the mediating device. A general protocol to handle crowdsourced monolingual translation is introduced along with three systems that implement the protocol. The MonoTrans system initially established the feasibility of the protocol. Then, MonoTrans2 enabled lab experiments with a second implementation of the protocol. MonoTrans2 was also applied to a an emergency-response scenario in a developing country (Haiti). The MonoTrans Widgets system was deployed to a large crowd of casual web users with a third implementation of the protocol. These systems were studied in various settings, and were found to supply improvement in quality over both machine translation and monolingual post-editing.Item Ribosomal Protein L11: A Cog in the Nanomachine(2011) Rhodin, Michael Hoover Johannes; Dinman, Jonathan D; Molecular and Cell Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Comprised of two major subunits of both rRNA and proteins, the ribosome is a biological nanomachine, acting as the central player in the process of protein translation. Recent advances in molecular imaging have enabled the visualization of the disparate functional centers within the ribosome, leading to the question of how these critical regions coordinate their actions and communicate with each other. This work examines the essential ribosomal protein L11, located in the central protuberance of the large subunit. L11 maintains connections with the 5S rRNA, H84 of the 25S rRNA, comes in close proximity to the T-loop of the bound peptidyl tRNA, and shares an intersubunit bridge with small subunit protein S18. L11 was found to have a critical dynamic loop which samples the occupancy status of the P-site pocket of the ribosome and communicates this information through H84. L11's intersubunit bridge (the B1b/c bridge) mediates an intersubunit communication network from the decoding center to the peptidyl transferase center of the ribosome. L11 is also involved in proper subunit joining. Mutations in L11 were found to have effects on A- and P-site tRNA binding, translational fidelity, and growth and viability of yeast cells.Item Neoliberalism in Translation: Economic Ideas and Reforms in Spain and Romania(2011) Ban, Cornel; Conca, Ken; Tismaneanu, Vladimir; Government and Politics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Most political economists studying the global spread of neoliberalism have seen it as a form of policy diffusion. Recently constructivist political economists have pointed to the important role of the spread of neoliberal economic ideas in this process. However, they have not provided a theoretical framework for understanding the mechanisms through which neoliberal ideas travel across national policy spheres. To address this gap, this dissertation draws on the claim made by some sociologists that ideas do not stay the same as they travel from one social setting to another, but are "translated" by idea entrepreneurs called "translators". More specifically, this dissertation aims to specify what shapes the result of translation, the pace at which it occurs, and the means through which it can shape policy. In doing this, it makes three contributions to the study of political economy. First, it argues that the content of adopted neoliberal ideas is shaped by the context-specific choices made by translators who employ "framing," "grafting" and "editing" as translation devices. Secondly, the pace of translation is shaped by the density of transnational ties between domestic policy stakeholders and external advocates of neoliberalism. Finally, translated neoliberal ideas are likely to serve as templates for economic policies when they are shared by an intellectually coherent policy team inside a cabinet that can effectively control economic policy decisions. To make thesearguments, the dissertation draws on a comparative historical analysis of the spread of neoliberalism in two "crucial cases": postauthoritarian Spain and Romania.Item DAY OF THE BORDER GUARDS(2010) Young, Katherine Elizabeth; Plumly, Stanley; Creative Writing; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This collection of poems examines themes of love, disillusionment, betrayal, and personal redemption. Set in locations ranging from Tomsk, Siberia, to a baseball stadium in Washington, D.C., these poems employ both traditional poetic form and free verse to explore the promise and peril of human connections across eras, borders, and cultures. The poems draw on the author's many years of living, working, and studying poetry in Russia and the former Soviet Union: in content and style, they are indebted to the traditions of Russian as well as English poetry. The thesis also includes six translations of poems from the Russian-language originals by award-winning poet Inna Kabysh, whose work is largely unavailable to English-language readers.Item Representation(s): A Mutable Process for a Transitioning Urban Landscape(2009) LaCharite-Lostritto, Lisa; Ambrose, Michael; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)To understand the medium is to understand the affects the medium has on the changes and the scale and form of human association and action over time, not only as the medium is being introduced, but also the unconscious and unforeseeable effects the cultural matrix within which the medium operates. Marshall McLuhan Difference is not simply the collapsing [or circulation] of identity, it is also the rendering of space and time as fragmented, transformable, interpenetrated, beyond any fixed formulation, no longer guaranteed by the a priori or by the universalisms of science. Elizabeth Grosz Media can be leveraged as a way to evaluate and inform the built environment. By using media as more than just a communicative necessity, media is capable of directing process. This process seeks to construct a representational framework and narrative through the investigation and translation of cultural, historical, and conceptual contexts. Architecture, as media, functions as a perceptual tool toward the fusion of process and a meta-physical and physical experience. This thesis asks the question: How can these complex contexts create a framework within which the media operates and informs the built environment? The validity of this research in the context of the culture of architectural education is to show that architecture is more than simply applied knowledge and skills translated through conventions of visual communication. Architecture is a way of seeing and thinking that requires understanding of media beyond the idea of tool and production to an idea of performance, process, and methodology.Item In the Margins: Representations of Otherness in Subtitled French Films(2008-05-05) Turek, Sheila; Eades, Caroline; French Language and Literature; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Translation involves integration of a multitude of disciplines and perspectives from which to compare two or more cultures. When translation is extended to film dialogue, in subtitling, the target language viewer unfamiliar with the source language must rely upon the subtitles to access the film's dialogue provided within the space of the verbal exchange, and often the subtitles offer an altered version of the dialogue, particularly given the time and space constraints of the medium. Subtitling, a unique form of translation, not only involves interlingual transfer but also intersemiotic transfer from a spoken dialogue to a written text. This work examines the linguistic treatment of three marginalized groups--homosexuals, women, and foreigners--as expressed in subtitles. In many instances, translation of certain elements in the films, such as forms of address and general referential language, change the meaning for the TL viewer. Cultural references present in the oral dialogue often get omitted or modified in the subtitles, altering the TL viewer's perception of the narrative and characters. These differently rendered translations have connotative qualities that are often differ significantly from the oral dialogue. In many cases, epithets and grammatically gendered language in the SL dialogue get diluted or omitted in the TL subtitles; likewise, power relationships expressed through use of forms of address, such as titles or tutoiement and vouvoiement, cannot be adequately conveyed, and the TL viewer is excluded from this nuanced form of discourse. Cultural references providing supplemental information, including non-dialogic text, are not always rendered in the subtitles, depriving the TL viewer of additional layers of meaning. In dual-language films featuring foreigners, nuances expressed by code switching and code mixing cannot be completely represented in the subtitles. Close analysis of subtitles within the framework of the sociolinguistic and cultural interpretations of the resultant TL dialogue reveals a great deal about the transmission and reception of cultural ideas and has not been addressed to this extent from this perspective. It is to be hoped that this study will inspire interest in further explorations of this nature and contribute to the ever-growing corpus of research in subtitling studies.Item Wiring the ribosome: functions of ribosomal proteins L3 and L10, and 5S rRNA(2006-09-29) Petrov, Alexey; Dinman, Jonathan D; Cell Biology & Molecular Genetics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The ribosome is a megadalton complex that performs protein synthesis with tremendous speed and accuracy. Atomic resolution ribosome structures have been resolved within the last five years. These have provided the 3-dimensional locations of all ribosomal components, and have revealed structures of the active centers. However, the precise mechanisms of the various functions performed by the ribosome are still unknown. This work is an attempt to understand some of the functional relationships between different active centers of the ribosome (or the "wiring" of the ribosome), and mechanisms by which such communication occurs. Here we present an analysis of three ribosomal components: ribosomal proteins L3 and L10, and 5S rRNA. Studies of L3 suggest that accommodation of aminoacyl-tRNAs (aa-tRNA) may be the mechanism that induces the "active" conformation of the peptidyl transferase center. We have proposed a mechanism in which rRNA movement associated with aa-tRNA accommodation facilitates conformational changes in the peptidyl transferase center (PTC) through the formation of a network of hydrogen bond interactions. A saturation mutagenesis analysis of 5S rRNA disproves the previous notion that 5S rRNA is a resilient molecule. An analysis of naturally occurring 5S rRNA variants suggests that this molecule may participate in posttranscriptional regulation of gene expression via the nonsense-mediated mRNA decay (NMD) pathway. Lastly, a random mutagenesis analysis of ribosomal protein L10 has resulted in the creation of a powerful toolbox that will be used for elucidation of ribosome export/maturation pathways. Future structure/functional analyses of these mutants may also help to reveal roles of helices 38 and 89 of 25S rRNA.Item A Familiar Curve of Vein: Poems and Translations(2004-05-18) Keefe, Anne; Plumly, Stanley; Creative WritingThe themes in this collection of poems center on issues of gender and memory. The poems are self-consciously aware of their status as art objects, and gender and power dynamics are examined within the artistic process through ekphrastic interaction with the visual. The collection also includes new verse translations of Spanish-language poets, Julia de Burgos, Pablo Neruda, and Federico García Lorca. These translations adhere less strictly to literal line-by-line readings, and instead, focus on conveying the emotional content of the original texts. The translations are balanced by original poems that explore moments of separation and coalescence between the cultures of two languages by creating a space in which both English and Spanish are musical possibilities.