Collection Description

Collection of student theses and dissertations from as early as 1939, but mainly from 2010 to present.

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A bee staggers out of the peony
A bee staggers out of the peony., is a curation of fragments, an assembly of moments whose temporal roots have been dug up and grafted. The results of this process present themselves as decontextualized familiarity, the details of which, concrete and known, become obscured when considered in the overall presentation. From this obfuscation, like the bee, meaning emerges, staggering. The title of this thesis, a haiku by 17th century poet Matsuo Basho, exemplifies the formal simplicity, vivid imagery, and emotional depth possible when one becomes a master of their craft. This body of work nods to the history of craft, its dedication to material, design and the discipline required to be a lifelong student of the practice. A dear friend once told me that in order to find happiness, one must ‘first get a grip, then let go.’ While this work is steeped in an awareness of craft history and material sensitivities, its primary exploration lives within the moment after skilled hands let go. Each piece presented in this body of work finds itself in freefall, an amalgam of social histories, personal memories, Platonic abstraction and the present. Now equally weighted, these fragments engage plainly in an honest dialogue between past and present, mind and matter. By breaking these delineations, we can begin to investigate what it means to experience, not as unidirectional linear beings, but ones whose memories and histories are constantly being filtered through the objects and people that surround us. Through this, we learn how those imbued objects are used to derive and communicate meaning internally and interpersonally. The purpose of this project is to follow the bee-to attempt to tie a thread between its staggers, dips, drops and flutters-to glean meaning when and wherever possible-to follow its drunken freefall as it attempts to discover what lies beyond the peony., San Diego State University
A biogeographic approach to understanding burrowing crab impacts on an ecologically important salt marsh plant
Burrowing animals, such as earthworms, crabs, prairie dogs, ground squirrels, ghost shrimps, and rodents, are often considered ecosystem engineers because of their influence on plant communities. For example, in coastal salt marshes, burrowing crabs can influence plant communities by modifying plant zonation, plant production, plant colonization, nutrient cycling, and erosion. Their effects on vegetation can vary across spatial and temporal gradients. In particular, the direction of burrower impacts (positive or negative) can depend on variation in the surrounding animal and plant community, as well as external abiotic conditions. Given that global climate change can alter such environmental conditions, such as salinity and nutrient availability, there is a need to predict when, where, and how burrowers will influence vegetation. Unfortunately, this ability is impeded because few studies have used comparative-experimental approaches to examine animal impacts on plants across space and time. In this dissertation, I explore the effects of burrowing crabs on California salt marsh plant communities using field manipulations and laboratory feeding assays. In my first chapter, I conducted a multi-site, multi-year field manipulation to examine burrowing crab impacts on plant communities in southern California salt marshes. I focused on the effects of burrowing crabs (Pachygrapsus crassipes [lined shore crab] and Uca crenulata [fiddler crab]) on the abundance of the two dominant marsh plants (Spartina foliosa [cordgrass] and Sarcocornia pacifica [pickleweed]), and I explored mechanisms underlying these effects by monitoring plant characteristics and sediment biogeochemistry. Crab impacts on plant community structure differed between each of our three sites. In contrast to our predictions, 1) plant-grazing crabs (lined shore crabs) had positive effects on cordgrass cover at one site and no effect on cordgrass production at a nearby site in the same marsh (Kendall-Frost marsh), and 2) detritivorous crabs (fiddler crabs) did not stimulate cordgrass production at another marsh (San Dieguito Lagoon). In fact, burrowing crabs suppressed cordgrass abundance at San Dieguito Lagoon, the site with the greatest detritivorous crab density (~10x the density of all other sites). Because crabs affected assemblage characteristics of cordgrass in the direction consistent with changes in cordgrass cover, we propose that marsh-specific crab effects on community structure were largely mediated through changes in cordgrass, as opposed to pickleweed. Importantly, crabs facilitated cordgrass during marsh-wide cordgrass loss, suggesting that crabs may mitigate environmental stress for this ecologically important plant. Cordgrass abundance can be a critical measure of marsh functioning and is often a restoration target, and thus maintaining healthy salt marsh functions should require monitoring and management of crab and cordgrass populations. In my second chapter, I combined these results with a similar field manipulation (e.g. multi-site and multi-year) in northern California to create a framework that could more broadly predict burrowing crab effects. While many studies have addressed burrowing crab impacts, few have sought to observe and predict these effects across multiple sites, multiple years, or both. This is especially true for salt marshes along the Pacific coast, where burrowing crab effects on plants have gone untested. In conjunction with our field experiments, we estimated total consumption of marsh plants by the dominant, herbivorous burrowing crab (the lined shore crab) by conducting laboratory feeding assays. Then, we used statistical models to predict crab effects using factors related to the crab community and soil conditions. By combining field, laboratory, and statistical modeling, my comparative-experimental approach allowed me to examine crab impacts across all site-year combinations. Crab effects varied from strongly positive to strongly negative, and depended upon our estimate of the total consumption pressure exerted by crabs an environmental conditions (i.e. salinity and ammonium). Crabs facilitated cordgrass at low total consumption pressure, extreme salinities, and intermediate levels of ammonium. Additionally, my models provided estimates of the threshold values of these environmental factors where the magnitude and direction of crab effects changed. Moving forward, we must seek to mechanistically understand how these key factors (grazing, salinity, and ammonium) drive inter- site variation in crab effects on cordgrass— as such information may be critical to the restoration and management of Pacific coast salt marshes. In my third chapter, I focused on the trophic mechanism by which burrowing crabs influence plants. Herbivores can have important impacts on plant communities, and palatability is among the important factors influencing herbivore consumption and herbivore impacts on plant communities. Here, I assessed the relative palatability of dominant marsh plants among three northern California salt marsh sites— all within one degree of latitude of each other. Although biogeographic approaches reveal that plant palatability to herbivores can vary across broad geographic scales, less is known about how the relative palatability of multiple plant species can vary across small scales. Such variation could be common given the species-specific responses of plants and herbivores to environmental conditions. To address this gap, I conducted multi-choice feeding assays with the lined shore crab - a consumer that has access to the leaves and roots of both cordgrass and pickleweed plants. I assessed the influence of plant species and tissue-types (roots and leaves) on crab feeding preference and the mechanisms underlying them. Surprisingly, the relative palatability of cordgrass and pickleweed switched between marshes within the study region. This shift may have been related to an increase in the palatability of pickleweed leaves at one of our sites. Because cordgrass palatability did not differ among these sites, the change in relative palatability did not appear related to changes in cordgrass. These patterns may be related to nutrient availability at our sites because plants at sites with high pickleweed palatability had lower C:N ratios than the other sites. However, the shift in the palatability of these two dominant plants does not appear to drive shifts in crab impacts on northern salt marsh plant communities, suggesting that crab impacts on plant communities is multi-faceted. The impact of the burrowing activity by crabs on plants may outweigh the consumptive effects of crabs on plants. We encourage future studies examining plant palatability to consider within-region variability in order to understand how such small-scale differences in plant palatability can alter local community structure and ecosystem function. Salt marshes filter water, buffer coastlines, bury atmospheric carbon, protect critical fisheries, and provide habitat for endangered and endemic species. These salt marshes, and the services they provide, are being critically impacted by human development and face a myriad of additional threats due to anthropogenic climate change. However, it will be impossible to predict how these threats will impact marshes if we lack an understanding of the basic species interactions that control the abundance of the foundation species (e.g. cordgrass) within these critical ecosystems. My dissertation highlights that burrowing animals can strongly control plant community composition and the production of cordgrass, and that these plant-animal interactions are highly variable across space and time. By taking a comparative-experimental approach, I was able to delve into this variation to identify possible biotic and abiotic drivers (e.g. grazing rates and soil conditions) that may help predict the magnitude and direction of burrowing crab effects on cordgrass in California marshes. Additionally, recognizing how these drivers may change with environmental stress, especially the effects of severe climate events (e.g. drought, storms, and heat spells), may help develop adaptive management strategies to buffer salt marshes from climate change— preserving the critical ecosystems services which they provide., University of California Davis; San Diego State University
A bioinformatics approach for dengue and Zika virus substrate discovery within the human proteome
Dengue (DenV) and Zika (ZIKV) Viruses are two of the most important human viral pathogens around today with no vaccines or antivirals. Understanding these viral interactions with the host is critical. Part of their life cycle involves well-classified proteolytic cleavage events that process their viral proteome before maturation. Consequently, viral proteases have been targeted for research and development of antivirals. Activity of these proteases is relatively well understood but little is known about their substrate recognition beyond the viral proteome. These proteases are able to cleave host substrates during the viral life cycle. Therefore, we have undertaken an in-silico approach utilizing the field of bioinformatics. We created a practical search using Regular Expressions (Regex) and a statistical search using a Position Weight Matrix (WM) that allowed analysis and retrieval of possible host substrates that met specified parameters. Substrates found in-silico are potential true viral protease substrates later to be tested using biological assays. To reveal novel host substrates of DenV and ZIKV proteases, substrates known to be cleaved by the viral proteases will serve as controls. The long-term goal of identifying novel host substrate cleavage events is to gain a better understanding of how the virus interacts with the host at the molecular level. With a better understanding of viral/host interactions, the potential for elucidating novel target sites could lead to the development of novel therapeutics targets against DenV and ZIKV. The Regex search revealed a large number of hits, ranging from tens to thousands, after varying parameters such as the offset and total number of amino acids. The WM search revealed thousands of potential target sites by scoring and summing a series of twelve amino acid sites. Results from Regex and WM were then compared following a filtering method that led to a list of hits found through both bioinformatics approaches. Among those, we focused on an initial list of most probably biologically significant hits that included five hits for the NS4A/2K site and ten for the CAPSID, NS2A/B, NS2B/3, NS34/A, and NS4B/5 sites. These lists will provide the basis for biological analysis in the context of viral infection., San Diego State University
A bioinformatics approach to developing an EMAST mouse model
Colorectal Cancer (CRC) is a global health issue. Recent studies into Sporadic CRC have shown certain tumors exhibit Elevated Microsatellite Alterations at Selected Tetranucleotide repeats, EMAST. EMAST is a biomarker of aggressive CRC and is characterized by insertions/deletions of tetranucleotides in repetitive non-coding DNA. The exact molecular mechanisms of EMAST are unknown, but a potential pathway involves the reduced function of MSH3 (a DNA mismatch repair protein) under conditions of oxidative stress/inflammation. Studies into EMAST have been restricted to clinical samples due to the lack of an appropriate animal model. A major difficulty in finding an animal model of EMAST is in finding repeat sequences that are characteristic of EMAST. Thus, our aim was to use bioinformatic tools to establish a potential panel of mouse specific EMAST sequences that could be tested in a mouse model of colon cancer. Published human EMAST sequences were analyzed and a set of requirements was gathered, including repeat length and type, to design a Python program. Flanking sequences taken from the human EMAST loci were also analyzed using the Multiple Em for Motif Elicitation (MEME) tool to identify conserved elements. These motifs were included in our program parameters and sequences found in the mouse genome using our program were then checked for homology to human EMAST loci using ClustalW. Those that showed >89% homology were analyzed further using the ENSEMBL database. ENSEMBL allowed us to prioritize the potential mouse EMAST sequences, in terms of previous evidence of instability. Murine sequences found using our program have been confirmed in mouse tissue using PCR. A panel of 8 mouse sequences were tested in tumor and adjacent normal tissue and instability in 2 of these sequences has been observed. In conclusion, novel motifs that are significant in human EMAST loci were identified and used in designing a unique Python program to discover potential species-specific EMAST sequences. Our program has produced a list of mouse repeat sequences that have the potential to display EMAST. Our results show that 2 out of 8 sequences have identified EMAST in tumor samples from our mouse model.
A blended pedagogy: Synthesizing best practices of opera and musical theatre programs to promote a holistic approach to training the singing actor
Includes bibliographical references (p. 26-27), This project report identifies the historical progression of pedagogy in the fields of opera performance and musical theatre, with regard to training the contemporary singing actor. Subsequently, it proposes a creative and exciting blend of the two techniques, which includes breathing, alignment, relaxation, movement, music theory, acting, and singing. My research produced a clear view of the shortcomings in each of the aforementioned academic programs; thus, blending the pedagogies to support the current "crossover market" is suitable and necessary for the success of the contemporary student.
A blended summer school experience for English learners
This study analyzes Achieve3000, Lexia Core 5, and Imagine Learning software programs designed to increase student literacy levels in a six-week summer school program. The Brainology program was also used with 4th to 6th grade students to determine if there was an increase in growth mindset. Three elementary schools with the highest percentages of English learners and students eligible for free and reduced lunch were selected from Bonita Valley Unified. Each school received a different digital curriculum. Second through sixth grade English learners (n = 241) not making one level of growth on the CELDT between the 2013-14 and 2014-15 school years were invited to attend. The summer school program took place from June to July of 2015. The instruments used to measure pre- and post-growth were the STAR Reading Enterprise, CELDT results, AMAO targets, reclassification rates from the 2014-15 and 2015-16 school years, and the Mind Assessment Profile (MAP) survey that measures growth mindset. Student surveys, focus groups, and classroom observations were also part of this study. Students that attended EL summer school showed Lexile gains of M = 92.40 for Achieve3000, M = 60.57 for Lexia Core 5, and M = 90.69 for Imagine Learning. A multiple regression analysis shows an R2 = .50 of variance in the Lexile reading score that is explained by Grade (p < .01), Pre CELDT levels in Writing (p < .01), Reading (p < .05), and Listening (p < .05), and special education status (p < .05). Gains were made in AMAOs in two of the three schools, along with increased reclassification rates at all three sites. As a result of using the Brainology program, students increased their growth mindset as evidenced by MAP scores and qualitative data. CELDT overall scores for Fall 2015 indicate an R2 = .31, which is explained by Lexile post scores (p < .001) and special education status (p < .005). Students identified as special education and English Learner benefited from the summer program., San Diego State University
A breath from the fluttering edge
The Thesis Exhibition, A Breath from the Fluttering Edge, was held in the University Art Gallery in the School of Art and Design at San Diego State University between April 11th and April 21st, 2016. This writing project is a reflection of the processes, influences and philosophies that affected my development as a graduate student, artist and human being.
A case study of California Hispanic-serving institutions: Providing service through education-based therapy
In this dissertation project I explored the Hispanic-Serving Institution (HSI) construct at San Diego City College (SDCC) and San Diego State University (SDSU), and as a result of the research I took action to train at SDSU as a marriage and family therapist specialized in serving San Diego regional K-16 public education systems. The in-depth critical case study of SDCC and SDSU showed that the HSI construct has shifted from a federal higher education policy to an indicator for the need for instructors, counselors, and education-based therapists prepared to address the cultural-historical trauma that underpins Latina/o education at all levels. This research represents the first exploration of the HSI construct within the SDCC and SDSU campus communities that moved beyond the federal higher education policy perspective, and that underscored the construct's relationship to the history of the Chicana/o studies, bilingual education, and education counseling disciplines, and the local trauma-informed (TI) education movement. This discussion about HSI construct research at SDCC and SDSU offers a conceptual framework that provides guidance for further service and research in local K-16 public education systems. This case study progressed and finished differently than initially planned, but it positively influenced and affected my experience as an HSI campus community member, and compelled my personal transformation as an instructor, counselor, education-based therapist, and researcher of Latina/o education. Keywords: Chicana/o Studies, Hispanic-Serving Institution, Latina/o Higher Education, San Diego State University
A case study of discipline practices: Perceptions of administrators, teachers, and foster parents in Tibetan Children’s Village (TCV) schools in India
School discipline is considered important worldwide, and volumes of books and journal articles have addressed school disciplinary problems and strategies. However, no research scholars have addressed Tibetan refugee schools’ disciplinary practices. This research study attempted to fill that gap. This paper investigated the values and assumptions of school discipline practices in primary, middle, and senior levels of the Tibetan Children’s Village (TCV) schools in India. The major findings of this study include (1) a specification of schoolwide and classroom discipline problems, (2) barriers to maintaining effective school disciplines, and (3) discipline practices and strategies that were employed in schools. One of the striking findings has been the treatment of the Dalai Lama by the vast majority of Tibetan people (including my interview participants) who see him as a beacon of hope for seeking happiness in their daily lives, and for their dreams and struggles of returning home. Findings also include the researcher’s observations of the influence and impact of the Tibetan Buddhist culture and refugee status in India and the challenges in eliminating corporal punishment in schools. This study will provide information to Tibetan educators and policy makers on which to base more effective disciplinary policies and practices. This study also contributes new knowledge in the field of refugee and immigrant studies., San Diego State University; Claremont Graduate University
A case study of six immigrant instructors teaching their native languages and cultures to military students
Includes bibliographical references (pages 133-146)., The purpose of this case study was to examine the experiences of six civilian immigrant instructors teaching their native language and culture to military students. The participants were recent immigrants who spent 5 years or less in the United States. Previous research on foreign language education focused on learners' characteristics. The literature has a wealth of quantitative studies examining students' scores and efficiency of language and culture programs. The dearth of qualitative research about the experience of instructors was a motivation for this research. This qualitative case study also focused on describing the experiences of these instructors and how they used their native knowledge of language and culture to teach their students. The research questions that guided this case study explored the different instructional strategies used by the instructors and how their content knowledge influenced their teaching. The findings indicated lack of professional development led the instructors to fall back on their own experiences as former students. That consequently translated into a preference for a teacher-centered style of instruction. There was evidence the instructors lacked knowledge of the principles of adult learning and Knowles' assumptions of Andragogy. The instructors did not see that their students were capable of self-directed learning. They did not understand the relevance of the instruction to the mission of their military students. Therefore, they were unable to involve their students in the learning process. The overall recommendation of this study is to provide culturally appropriate pedagogical training for immigrant instructors on Andragogy and second language acquisition theories. The findings of the study reflected the need for intercultural communication training prior to language and culture classes—for instructors and students—to facilitate a more effective learning environment.