Master's Theses (Fall 2009 to Present)
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New submissions to the University of Delaware Master's Theses collection are added as they are released by the Office of Graduate & Professional Education. The Office of Graduate & Professional Education deposits all master's theses from a given semester after the official graduation date.
University of Delaware master’s theses submitted between 1980 - Summer 2009 are available online through Dissertations & Theses @ University of Delaware. Use the library catalog, DELCAT Discovery, to search for all print or microform copies of master's theses 1980 - 2009 that are NOT available in Dissertations & Theses @ University of Delaware because Dissertations & Theses @ University of Delaware does NOT contain the complete collection of University of Delaware master's theses.
Master’s theses in the Longwood Graduate Program in Public Horticulture submitted between 1970 - 2004 are available online.
More information is available at Dissertations & Theses.
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Recent Submissions
- ItemCharacterizing the egg-3(as40) phenotype to elucidate the role of EGG-3 during egg activation in Caenorhabditis elegans(University of Delaware, 2023) Strouse, Ariel MarieEgg activation is the process where the mature oocyte transitions into a cell that can support embryogenesis and includes a multitude of changes to the newly fertilized egg. Some of the proteins involved in C. elegans egg activation have been identified, including MBK-2, CHS-1, EGG-3, EGG-4, and EGG-5. The aforementioned proteins form the egg activation complex and the pseudophosphatase EGG-3 is hypothesized to act as a molecular scaffold for MBK-2 until the initiation of the egg activation process. ☐ My research goal is to utilize the temperature sensitive allele egg-3(as40) to offer more insight on the role of EGG-3. Brood sizing data shows that egg-3(as40) worms lay more oocytes and dead embryos as well as produce significantly less progeny than the wild-type. I also documented a developmental delay in the progeny produced by egg-3(as40) mutants as compared to wild-type worms. I used fluorescent imaging to examine whether egg-3(as40) affects the stability or localization of EGG-3 and to study the localization of the other egg activation proteins in the egg-3(as40) background. My research findings indicate that EGG-3, MBK-2, and CHS-1 localize normally in the egg-3(as40) mutant. Additionally, live imaging showed defects in meiosis in the mutant and formation of only a single polar body in eggs produced by egg-3(as40) worms. Taken together my data indicate that some, but not all, functions of EGG-3 are impaired by the egg-3(as40) mutation.
- ItemFear of cancer recurrence, anxiety, and depression among patients with head and neck cancer: a latent change score analysis(University of Delaware, 2023) Fenech, Alyssa L.Patients with head and neck cancer frequently report some of the highest levels of psychological distress amid managing their disease as well as debilitating and disfiguring treatment side effects. Symptoms of anxiety and depression are common among patients with cancer, but chronic symptoms may lead to impairments in quality of life and emotional health. Fear of cancer recurrence (FCR) is a top unmet need and concern of patients with head and neck cancer. Prior research suggests symptoms of anxiety and depression are potential antecedents to FCR, but findings have been limited to mostly cross-sectional studies in small samples. Utilizing data collected through the Head and Neck 5000 Study in the United Kingdom, the objective of the present study was to examine early level and change in symptoms of anxiety and depression in relation to later change in FCR among patients with head and neck cancer during the first year after diagnosis. A sample of 4891 patients from the parent study completed self-report longitudinal assessments of anxiety, depression, and FCR around the time of diagnosis and 4 and 12 months later. Utilizing a multiple indicator latent change score model, results revealed baseline anxiety level and increases in anxiety from baseline to 4 months were positively associated with change in FCR from 4 to 12 months. Neither baseline depression nor change in depression from baseline to 4 months were significantly associated with later FCR change. Findings suggest that early level and increases in symptoms of anxiety may be a marker of later FCR development. Future research should consider anxiety as a unique antecedent and maintaining factor of FCR and interventions targeting anxiety early in the cancer trajectory may have downstream effects on FCR development.
- ItemGeographic distributions and vertebrate host specificity of genetic lineages of Borrelia burgdorferi(University of Delaware, 2023) Shifflett, ScarletCharacterizing the diversity of genes associated with virulence and transmission of a pathogen across the pathogen’s distribution can inform our understanding of host infection risk. Borrelia burgdorferi is a vector-borne bacterium that causes Lyme disease in humans and is common in the United States. The outer surface protein C (ospC) gene of B. burgdorferi exhibits substantial genetic variation across the pathogen’s distribution and plays a critical role in virulence and transmission in vertebrate hosts. In fact, B. burgdorferi infections that disseminate across host tissues in humans are associated with only a subset of ospC alleles. Delaware has a high incidence of Lyme disease, but the diversity of ospC in B. burgdorferi in the state has not been evaluated. We used PCR to amplify ospC in B. burgdorferi-infected blacklegged ticks (Ixodes scapularis) in sites statewide and used short-read sequencing to identify ospC alleles. B. burgdorferi prevalence in blacklegged ticks varied across sites, but not significantly so. We identified 15 previously characterized ospC alleles accounting for nearly all of the expected diversity of alleles across the sites as estimated using the Chao1 index. Nearly 40% of sequenced infections (23/58) had more than one ospC allele present suggesting mixed strain infections and the relative frequencies of alleles in single infections were positively correlated with their relative frequencies in mixed infections. Turnover of ospC alleles was positively related to distance between sites with closer sites having more similar allele compositions than more distant sites. This suggests a degree of B. burgdorferi dispersal limitation or habitat specialization. OspC alleles known to cause disseminated infections in humans were found at the highest frequencies across sites, corresponding to Delaware’s high incidence of Lyme disease. ☐ Negative interactions among pathogen genotypes during infection may affect overall transmission dynamics in multi-host systems. For example, specialist pathogens may limit the impact of generalists, which may become emerging infectious diseases. Borrelia burgdorferi, a bacterium that causes Lyme disease, is transmitted primarily among wildlife hosts and Ixodes ticks. Despite significant bacterial genetic diversity, most human infections are caused by bacteria with specific alleles of the outer surface protein C (ospC) gene (“human infectious alleles”; HIAs). We tested 272 individuals of 11 mammalian species for B. burgdorferi and sequenced ospC alleles. Multiple allele (“mixed”) infections were common in individuals of all species. HIAs were most common in mice (Peromyscus spp.) with only one HIA in a site with almost no mice. Chipmunks (Tamias striatus) were hosts of allele U, the only specialist. Surprisingly, while an unexpectedly large number of alleles were recovered from chipmunks, including HIAs, allele U was not found in mixed infections. These results are consistent with allele U excluding other alleles, perhaps through indirect host-immune mediated mechanisms, thereby reducing the capacity of chipmunks to act as reservoirs for HIAs. This suggests that specialized pathogens may be able to mitigate the infection risk of hosts they do not infect.
- ItemWar Crystals, Everlasting Metal, and Space-Time Annihilation: Excavating the Historical Geography of Early Digital ElectronicsBurrington, IngridUtilizing government archives, historical trade catalogues, and archival newspaper coverage, this research traces the origins of two key mineral supply chains for digital electronics: high purity quartz (used in semiconductor chips) and tantalum (used in capacitors, among other applications). Sourcing of both materials by United States firms were dramatically influenced by procurement initiatives during World War II developed for specialized communications technology demands, with massive investment and extraction occurring primarily in Brazil for high purity quartz and predominantly in Belgian Congo for tantalum. Both histories are situated within the broader context of the “critical mineral” as a political category and concept developed in the interwar period in the United States amidst the rise of political models like technocracy and the associative state. The ramifications of these supply chain histories on contemporary understanding of high purity quartz and tantalum are also discussed.
- ItemGender-Based Training and its Effects on Probation/Parole Officer-Client RelationshipsQuinci, SofiaUntil recent decades, men offenders have been the primary focus when developing criminal justice programs. This has also been the case for the training probation/parole officers complete. Since 2003, many states have introduced gender-based training for probation/parole officers who work with women. Using survey data collected from probation/parole officers and their women clients from 16 Michigan counties, this study aims to answer two questions: (1) how does gender-based training and experience of parole/probation officers affect their clients’ trust and feeling understood by their PO? (2) how do clients’ perceptions of being understood and trust in parole/probation officers differ from POs’ intended relationship with their clients? Findings show that gender-based training does not increase trust or understanding within a PO-client relationship from either side’s perspective. The only exception was that probation/parole officers who went through one day of gender-based training were less likely to perceive their clients as trusting them. This could reflect that while POs are aware of the unique issues that women involved in the criminal justice system, they do not have enough training to adopt that knowledge into their supervisory style. This lack of significant findings could be due to the relatively small sample size, making it so more robust findings do not emerge. This study reveals that there is a need for more effective gender-based training for probation/parole officers which would not only foster more positive PO-client relationships, but also lead to lower recidivism rates for clients re-entering the community.