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A Graphene-based RNA Biosensor to Determine Riboswitch-Ligand Interactions:
Get PDFThesis advisor: Michelle M. MeyerThesis advisor: Jeffery A. ByersRiboswitches are a class of regulatory structures located in the 5’ untranslated region of many bacterial mRNAs. Validating riboswitch-ligand interactions has historically been costly and low-throughput. Recently, graphene field-effect transistors (G-FETs) have emerged as effective biosensors in detecting interactions of such regulators with charged, high molecular weight analytes. However, a bottleneck still exists in detecting relatively neutral small molecules. The Bacillus subtilis guanine riboswitch (Xpt) within the xpt-pbuX operon contains a purine-responsive aptamer region with affinity for guanine, hypoxanthine, and other purine analogs. The G-FET sensor revealed successful detection of Xpt-hypoxanthine interactions at saturating concentrations. The specificity of Xpt was also demonstrated by a lack of signal detection when incubated with adenine. Therefore, such G-FET devices are effective in detecting aptamer binding to small, electrically-neutral molecules, which will allow for rapid screening of potential therapeutic ligands. Further, different electrical observations of n-doping upon aptamer functionalization and p-doping upon ligand binding reveal unique interactions at the graphene surface. Molecular dynamics simulations were carried out to interpret experimental results and to determine if another well characterized aptamer (FMN) is a suitable candidate for G-FET studies. Trajectory data from the Xpt aptamer domain complexed with hypoxanthine (PDBID: 4FE5) and guanine (PDBID: 1Y27) showed significant differences in root mean square deviation (RMSD) and radius of gyration (Rg) from their respective non-binding mutants. These findings provide evidence that compaction of the RNA phosphodiester backbone is responsible for graphene detection. RMSD and Rg differences from FMN (PDBID: 3F4E) indicate that this aptamer may not show a significant change in G-FET signal. These findings suggest that G-FET biosensors can provide an avenue for the discovery of novel antibiotics for aptamer targets to combat burgeoning antibiotic resistance.Thesis (BS) — Boston College, 2021.Submitted to: Boston College. College of Arts and Sciences.Discipline: Departmental Honors.Discipline: Biochemistry
Physician Assisted Suicide in Massachusetts: Vote "No" on 2012 Ballot Question 2
Get PDFThesis advisor: Marc LandyThe “Death with Dignity Act,” if passed in November 2012 in Massachusetts by means of a ballot initiative, would have allowed doctors to prescribe lethal drugs to patients with fewer than six months to live. Introduced by two pro-assisted suicide organizations from the Pacific Northwest, the initiative was expected to take advantage of a political “perfect storm” brewing in the Bay State. A blue state in a presidential election year, with President Obama at the top of the Democratic ticket, Massachusetts was expected to produce an electoral outcome favorable to assisted suicide. Oregon and Washington State had legalized physician-assisted suicide in 1998 and 2008, respectively. Polling in 2011 showed a 2-1 majority among Massachusetts voters in favor of assisted suicide. Nonetheless, the Archbishop of Boston and the Bishops of Worcester, Fall River and Springfield, organized as the Massachusetts Catholic Conference, took up the challenge to oppose the initiative. Relying on the expertise of paid political consultants, they mounted a two-tiered campaign. An internal component, directed at Catholics, included the dissemination of over 2 million pieces of in-print and electronic materials urging a “no” vote on the measure. An external component, directed at the wider public, relied on a coalition of organizations representing the three major religions, health and hospice organizations, disabilities rights activists, and pharmacists. Using “flaws” in the bill identified through strategic polling, they appealed to voters even sympathetic to assisted suicide to reject the bill. When the votes were counted 2.7 million Massachusetts citizens voted on the physician-assisted suicide initiative and it was defeated by 67,891 votes, 51.1% to 48.9%. One key to the defeat was the split in the vote in the city of Boston, where Question 2 was defeated 50.9% to 49.1% . Twelve of Boston’s 22 wards voted against the measure. Leading the way among the twelve were Dorchester, Roxbury, and Hyde Park, traditionally black, liberal Democratic strongholds. This study shows that even the most effective, well-funded, Church-initiated campaign in Massachusetts in 2012 might well have foundered on the 2-1 majority in favor of assisted suicide at the polls, not for the strategic identification of “flaws in the bill,” the broad-based coalition campaign based on them, and the “split in the vote in the black community in Boston.”
.Thesis (PhD) — Boston College, 2021.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Political Science
TheRole of the Nucleus Accumbens Core in Scaling Fear to Degree of Threat:
Get PDFThesis advisor: Michael A. McDannaldIdentifying the neural circuits underlying adaptive fear is fundamental to understanding and developing more effective treatments for anxiety disorders. Adaptive behavior requires fear to scale to the level of threat and dysfunction in this capacity is a hallmark of fear-related anxiety disorders. Identifying the neural circuits underlying adaptive fear is fundamental to understanding anxiety disorders and propelling more effective treatments for patients. Fear is adaptive when the level of the response rapidly scales to degree of threat. Using a discrimination procedure consisting of danger, uncertainty, and safety cues, our laboratory has found rapid fear scaling (within 2 s of cue presentation). However, the neural underpinnings of this behavior are unknown. The overarching goal of this dissertation is to examine a role for the nucleus accumbens core (NAcc) in scaling fear to degree of threat. In three experiments I used neurotoxic lesions, optogenetic inhibition, and in vivo electrophysiology combined with an intricate fear learning procedure to elucidate a role for the NAcc in both general and rapid scaling of fear. Permanent NAcc dysfunction, via neurotoxic lesion, generally disrupted the ability to scale fear to degree of threat and specifically impaired one component of scaling: rapid discrimination of uncertain threat and safety. Reversible NAcc dysfunction, via optogenetic inhibition, specifically impaired rapid discrimination of uncertain threat and safety. Further, I demonstrated that NAcc activity is threat responsive and exhibits heterogeneity in the timing and specific nature of threat firing. The results reveal that the NAcc is essential to scale fear to degree of threat and responds to threat cues across both rapid and general timescales. Taken together, the results reveal a novel role for the NAcc in scaling fear and identify it as a plausible source of dysfunction in stress and anxiety disorders. Identifying the brain regions underlying adaptive fear is fundamental to understanding and developing more effective treatments for anxiety disorders.Thesis (PhD) — Boston College, 2021.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Psychology
Bootstrap Confidence Intervals of Fit Indexes: A Comprehensive Study
Get PDFThesis advisor: Hao WuThesis advisor: Ehri RyuIn SEM, fit indexes provide useful information about how well a hypothesized model fits the population. Bootstrap has been applied to construct confidence internals for fit indexes. We proposed the most recent method for constructing confidence intervals (CIs) of fit indexes (Cheng & Wu, 2017): the bootstrap-test-based method. This dissertation includes the most popular bootstrap CI methods and the bootstrap-test-based method. In addition to the percentile bootstrap CI method used in Zhang and Savalei (2016), we also included other popular bootstrap CI methods. For all bootstrap CI methods, we explored their performances with and without the transformation proposed by Yuan, Hayashi, and Yanagihara (2007). In this process, we also solved computation difficulty for Studentized CI. The bootstrap-test-based method is improved by using alternative search statistics. As the previous approaches were not extended to nonnormal conditions, the CI estimation for fit indexes with nonnormal data are investigated for both bootstrap CI and bootstrap-test-based methods, using adjusted definitions of fit indexes for nonnormal data. Different nonnormal data generation techniques are applied. This dissertation presents a comprehensive comparison of bootstrap CI methods and the bootstrap-test-based method under various conditions. From the simulation results, the CIs for fit indexes under the bootstrap-test-based method are more accurate than most bootstrap CI methods. The results also show that the bootstrap-test-based method can be generalized well to non-normal data. The confidence bounds coverage by bootstrap-test-based method are closer to their nominal levels.Thesis (PhD) — Boston College, 2021.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Psychology
Citizenship, society and international higher education: A qualitative study of international students perspectives
Get PDFThesis advisor: Rebecca C. SchendelIncreased student mobility has been one of the most significant developments observed in the global landscape of higher education. Yet, research on student mobility often takes an individualized perspective on the benefits learners possess through internationalization. Meanwhile, the last two years were marked by the emergence of a new direction in internationalization - the Internationalization of Higher Education for Society (IHES). The surge in studies on how institutions can contribute to society through their internationalization strategies and efforts has proven that the phenomenon which for a long time was focused on individual gains and institutional branding, can evolve and address the larger purpose it serves. However, while many of these works highlight the directions IHES should follow and present good practices, still little is known about international students' perspectives of these dimensions. As a group that was identified as one of the vivid actors of IHES, it is not only reasonable but crucial to gain insight into their understandings, experience, and valorization of this topic. The primary objective of the study is to investigate how students understand the sense of global identity and community engagement through education abroad. By listening to their voices, it makes a methodological contribution in terms of extending the understanding of student mobility as an inherent part of the internationalization discourse in the globalized world. Furthermore, analyzing these voices and deducting their meanings serves towards the materialization of ill-defined concepts of global citizenship and International Higher Education for Society. Finally, the study aims at building a more complex understanding of the current state of international higher education phenomena by exploring connections between internationalization and its missions to society.Thesis (MA) — Boston College, 2021.Submitted to: Boston College. Lynch School of Education.Discipline: Educational Leadership and Higher Education
Using Elements of a Screenplay to Promote Visualization and Increase Reading Comprehension in Students With Disabilities and Striving Readers:
Get PDFThesis advisor: David ScanlonImproving reading comprehension for middle school students with disabilities and others who struggle with reading, referred to here as striving readers, is challenging. Formal reading instruction typically shifts from skills acquisition to application in middle and high school, providing inadequate support in the skills for comprehension (Chall, 1983; Klingner et al., 2007). Further, both students with disabilities and striving readers can have negative school experiences which impact their reader identities and cause them to become disengaged from learning. It is increasingly challenging for secondary teachers to provide interventions which explicitly teach and reinforce critical comprehension skills while sustaining student engagement. An experimental screenplay intervention designed by the researcher to increase visualization and promote reading comprehension was used. The intervention was based on research by Snyder (2005) identifying elements of a screenplay, similar to story grammar. Movies were used first as a novel way to engage learners; visual supports were gradually reduced as students transferred visualizing skills to texts of increasing complexity. The readers used plot diagrams to organize the elements graphically in support of their comprehension.
Seven middle school students with high incidence disabilities and striving readers learned to identify seven elements of a screenplay in a 3-week online researcher-developed intervention. A mixed-methods case study design was used to identify reading-related outcomes and students’ experiences (attitudes and behaviors) of reading as they learned the intervention. Data were collected for reading comprehension, recognition of screenplay elements, and visualization skills. Reading behaviors, attitudes, identities, and motivation for reading were also assessed.
Findings revealed whole-class mean score gains in passage and sentence level comprehension, pre-to-post. Students also learned the screenplay elements and were proficient in finding examples within a text. Further, the students reported greater details at post-test when reporting their visualizations and when describing elements. Case studies of three students representing three reading proficiency levels upon entrance to the study revealed distinct experiences for each. Implications for reading instruction are discussed.Thesis (PhD) — Boston College, 2021.Submitted to: Boston College. Lynch School of Education.Discipline: Teacher Education, Special Education, Curriculum and Instruction
The Development of Racial Understanding as Told by Black People in America : A Narrative Analysis Regarding Colorblindness, Blackness, and Identity
Get PDFThesis advisor: Sara MoormanThesis advisor: Eve SpanglerThis research project explores the narratives of how and when young Black people came to understand their race, as well as the implications of it. In order to expand upon the existing studies regarding racial realization and provide specific stories of such instances, qualitative interviews with nine Black people (ages 18-22) were conducted. The upbringings of these young Black people were analyzed in depth in order to provide insight to different types of racial socialization. It was found that both colorblind upbringings and non-colorblind upbringings that center individuals rather than systems of oppression are not helpful in the racial identity formation of young Black people. They both result in the perpetuation of the idea that racially marginalized people should modify their behavior. Additionally, this project exposes some of the reasons why racial realization is often a jarring experience for Black people in America, and in turn, expose some of the ways it can be less so.Thesis (BA) — Boston College, 2021.Submitted to: Boston College. College of Arts and Sciences.Discipline: Departmental Honors.Discipline: Sociology
Kurdish Insurgency in Iran : The Effects of Historical Mobilization on Subsequent Militant Recruitment
Get PDFThesis advisor: Ali KadivarDetermining the empirical causes of recruitment to nationalist militant organizations is a pertinent topic, given the global rise in neo-nationalist attitudes. In this article, I seek to explore one prospective cause through a case study of the Kurds in Iran. The Kurdish population within Iran has witnessed rising levels of insurgency into militant nationalist organizations. These organizations routinely conduct armed operations against Iranian forces in historically Kurdish regions within Iran, with the goal of reclaiming territory and halting perceived inequitable treatment of the Kurdish minority by the Iranian government. My research intends to explore the root causes of this rise in violence and whether historical political mobilization within Kurdish-dominated regions of Iran has resulted in the increased Kurdish insurgency efforts. I employ an original database and three models to test the relationship between an area's mobilization history and its subsequent insurgency recruitment levels. Ultimately, my results point to contextual variables as the driving factor behind insurgency recruitment compared to the aforementioned historical variables. My research provides a foundation for future exploration into the historical causes of Kurdish insurgency in Iran. A more sophisticated approach to data collection may generate a wider pool of data from which further analysis may be conducted.Thesis (BA) — Boston College, 2021.Submitted to: Boston College. College of Arts and Sciences.Discipline: Departmental Honors.Discipline: Sociology
"I Just Signed Your Death Warrant": A Content Analysis of News Media Coverage of Violent Crimes Against Women in the #MeToo Era
Get PDFThesis advisor: Alyssa GoldmanThis study analyzes the narratives that emerged in the news media’s coverage of violent crimes against women during the #MeToo Movement. Additionally, it seeks to uncover if and how news media crime coverage differed based on the race of defendants. I conduct a content analysis of the news media coverage of the criminal cases State of Michigan v. Lawrence Gerard Nassar and Commonwealth of Pennsylvania v. William Henry Cosby, Jr. during the #MeToo Movement. I find that news media coverage of violent crimes against women typically exhibits an inverse relationship in which supportive portrayals of victims predict unsupportive portrayals of defendants, and vice versa. I also find some evidence to suggest that Black male defendants receive more lenient news media coverage than white male defendants. The results of this study demonstrate the power of social movements in influencing criminal justice outcomes and the news media’s role in shaping public opinion on criminal cases.Thesis (BA) — Boston College, 2021.Submitted to: Boston College. College of Arts and Sciences.Discipline: Departmental Honors.Discipline: Sociology
Lake Sedimentation and Land Use Change in Medomak and Sennebec Watersheds, Coastal Maine:
Get PDFThesis advisor: Noah SnyderThe purpose of this study is to quantify land use change in two coastal New England watersheds using lake core analysis, orthorectified historic aerial imagery, and data from the National Land Cover Database (NCLD). The study covers Sennebec and Medomak ponds in coastal Maine, which lie between the Penobscot Bay and the southern stretch of the Kennebec River. With lake cores recording >800 years (Sennebec) and >1600 years (Medomak), the timeframe of this study spans from the era of Indigenous populations, through the period of EuroAmerican settlement, and into the modern day, to provide insight into the interactions between humans and watershed dynamics through time.Thesis (BS) — Boston College, 2021.Submitted to: Boston College. College of Arts and Sciences.Discipline: Departmental Honors.Discipline: Earth and Environmental Sciences