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Collection Description

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

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Vertebrate paleontology and stratigraphy of the late Irvingtonian (Pleistocene) Coyote Badlands, Anza-Borrego Desert State Park, California
The Coyote Badlands in northwestern Anza-Borrego Desert State Park, San Diego County, California is among three of the most fossil rich areas in the park. Only Ash Wash, a canyon on the northwestern edge of the badlands, has previously been described in terms of its stratigraphy and paleontology. The central Coyote Badlands, which contain numerous fossil localities, remains unstudied. Four stratigraphic sections were measured and correlated based on the presence of sedimentologically unique calcareous mudstone beds. The northwestern most of these sections contains an ash lens which is believed to be part of 759 ka Bishop Ash series, exposed in ash wash. In addition to a 250 meter thick composite stratigraphic section, a structural map was also produced for the badlands. This map presents the exposures of the correlative mudstone beds, bed attitudes and observed faults. An Irvingtonian Land Mammal age vertebrate fauna was collected prior to this study. The taxa within the fauna is identified and described in this study. The assemblage is restricted to mammals and include typical carnivores and herbivores for other North American lrvingtonian aged faunal assemblages. More rare Irvingtonian taxa from the fauna include Canis sp. cf. C. armbrusteri, Homotherium sp. cf. H. crenatidens, Tapirus merriami, and Paleolama. An analysis of the temporal ranges of all the taxa identified from the assemblage shows an overlap within the middle Pleistocene or late Irvingtonian. This age assignment corroborates the correlated 759 ka age for the ash in the section. The Coyote Badlands assemblage was compared to other late Irvingtonian faunal assemblages from western North America using three comparison coefficients. These other faunal assemblages include from southern California Ash Wash, Borrego Badlands, Vallecito Badlands, Bautista Creek, and Pauba Formation. Other assemblages compared are: Irvington, California; El Golfo, Sonora, Mexico; Curtis Ranch, Arizona; and Porcupine Cave, Colorado. The fauna was most similar to the Borrego and Vallecito Badlands. Lastly, an analysis of the sedimentololgy of the deposits and paleoenvironments for the fauna indicate a savanna-type habitat on an alluvial fan and braided stream depositional system., San Diego State University
Vertical and lateral carbon flux in a desert shrubland near La Paz, Baja California Sur, Mexico
Includes bibliographical references (p. 26-32), Arid and semi-arid ecosystems comprise about 30% of terrestrial cover and are projected to increase by 17-20% in area during this century due to global climate change. Likewise, the dynamics of carbon sequestration under extreme water and temperature stress provides important information about carbon exchange in relation to water use efficiency in the context of rising atmospheric CO_ levels, global temperature increase, and precipitation shifts. The technique of Eddy Covariance has emerged as an important tool to measure fluxes of carbon dioxide between terrestrial ecosystems and the atmosphere over extended periods of time. Carbon loss through lateral transfer is missed by this method and may play an important role in regional carbon balance. The objective of this study is to quantify the lateral transport of carbon in aboveground litter fall in comparison to the annual net ecosystem exchange (NEE) measured by the Eddy Covariance tower in a desert shrub ecosystem on the reserve of the Centro de Investigaciones Biológicas del Noroeste (CIBNOR) near La Paz, Baja California Sur, Mexico. Using the tower based Eddy Covariance method and litter fall and lateral transport measurements, an accurate measure of lateral carbon transport can be made along with its importance to the overall ecosystem carbon cycle. By analyzing the Eddy Covariance data from 2004-2008, along with previously published data from 2001-2003, a 7.5-year data set of seasonal and annual carbon flux can be produced. These data show decreasing carbon sinks during the years 2001-2003, to increasing carbon sources to year 2006, after which the annual carbon source begins to decrease. Seasonally, fall and winter show general carbon sinks following large late summer hurricane events, switching to monthly carbon sources in early spring and increasing through summer. There is a strong control of annual NEE by the current and previous year's precipitation. The lack of a large precipitation pulse prevents an annual carbon sink in future years. Lateral carbon transport experiments show lateral transport of leaf litter during and after periods of increased litter fall and litter export during episodic storm events. The distance traveled of litter transported by wind is greater than an area of 2500 m_ during periods of increased litter fall. Carbon stored in litter fall is transported over large distances throughout the year and may be subject to respiration or storage outside of the measured footprint of the Eddy Covariance tower. Depending on the geographic and meteorological conditions of the ecosystem, this lateral transport of carbon may distort the annual NEE of the measured ecosystem
Vice Principals: Prescription for the Principalship
Includes bibliographical references (pages 117-122)., This dissertation aims to understand how leadership practices of early career and more seasoned principals are informed and influenced by their past experiences as vice principals. The overarching goal: increase understanding of how the work experiences of vice principals can be better leveraged as apprenticeship opportunities for future principals. A phenomenological research design was utilized. Interviewed participants were asked to indicate which vice principal experiences were directly transferable to current responsibilities as a principal and to describe how these duties inform their current work. Findings suggest leadership practices of early-career, and highly effective principals were influenced by past experiences as vice principals via pathways to the principalship and through relationships with lead principals. Further, work experiences of vice principals served as training ground for principals, both operationally and instructionally. Identified gaps in leadership training included budget, instructional leadership, special education, and human resources. Due to the lack of succession management systems, school districts might benefit from succession plans for aspiring leaders. Preadministrative opportunities for teacher leaders ensure positive socialization into administration. Former middle vice principals revealed gaps regarding instructional leadership training, yet elementary vice principals did not. Middle school principals would benefit from additional training, accordingly. This paper asks current principals to reflect on their former roles and responsibilities as vice principals and describe how those experiences inform their current work as instructional leaders.
Video upload tool with subtitling feature
The Language Acquisition Resource Center (LARC) at San Diego State University has developed various projects to facilitate the process of language learning. The focus of my research is on making a bridge between teachers and students to communicate more effectively on the language learning process. It basically helps teachers to easily upload the language learning videos and add subtitles to them for better understanding. It emphasizes on better language learning and lesser navigation clusters. Beauty of this application is that it's a very handy tool to simply upload videos and add subtitles to it. Once added it would not be directly accessible by the general users. Once approved will allow the general users, in this case, students, to experience the video learning process. Also users can add comments to a particular video, in a way opening up a new area to connect and share knowledge. Apart from this it also has the ease of navigation, simple to use flow that will not create problems in between for users to navigate through the system. Fairly simple, easy to navigate, upload and add subtitles, and eventually teach students with ease. This tool is in sync with the LARC's goal to reach teachers and students with tools that will simplify their language learning experience process to be smooth and wealthy.
Violations Of Early Motherhood: The Darkside Of Social Support And Postpartum Mental Illness
Subsequent to the birth of a child, over half of all mothers are adversely affected by feelings of depression, stress, exhaustion, and anxiety that often result in a more serious mental disorder known as postpartum mental illness. Especially in regard to distressed individuals, social support is not always beneficial and positive; it not only represents a method of ameliorating postpartum mental illness, but also a process that can complicate or exacerbate such illness. Social support, when incompetently expressed and managed, can have deleterious impacts on an already distressed mother, and has the ability to catalyze a range of dysfunctional internal perceptions. This study investigated how the perceived social support processes are associated with outcome valence, and who mothers prefer to be supported by in the time of their distress (i.e., up to one year after giving birth). An online survey was completed by 146 females via snowball sampling. Findings yielded a promising set of initial results. In general, mothers preferred support most from their husband/partner and parents/siblings/immediate family. In the case of informational support, however, mothers preferred support from medical professionals and peers. For all four categories of social support (i.e., tangible, companionship, emotional, informational), mothers strongly disliked support from in-laws. In the way of major findings, results indicated that informational support provided by medical professionals is satisfactory only when the information is framed with emotional tactics. Additionally, medical professionals were proven to be a source of additional support when mothers lacked support in general. However, when mothers did no lack support, they did not feel the need to be supported by their healthcare providers. Other major findings were present for emotional-identity support. Moreover, appropriate identity support contributed to overall satisfaction, while support that did not make mothers feel like a "good mom" was the least satisfying overall. This proposes identity support to be a powerful contributor of overall satisfaction. Last, results suggested that appropriate social support may be more influential than inappropriate support. Following results and discussion, limitations and directions for future research are reviewed.
Violence against women in India: Three essays on its offline and online forms
Despite significant increase in research efforts on violence against women (VAW) in the past two decades, key gaps remain, particularly for emerging issues such as climate and VAW, and online VAW. This dissertation attempts to fill these gaps in literature by examining two separate and lesser studied areas of inquiry related to VAW in India- a) the relationship between droughts, an extreme weather event, and married women’s experience of intimate partner violence (IPV) (Study 1), and b) online misogyny or online hate speech against women- its temporal prevalence on Twitter before and during COVID-19 (Study 2), and its relationship with offline normative attitudes and behavior (Study 3). Integrating remote sensing data on drought status with information on women’s experience of IPV from two rounds of a nationally representative survey (National Family Health Survey or NFHS; 2015-16 and 2019-2021; N=122,696 women), Study 1 found that droughts increase the risk of married women experiencing physical and emotional IPV in India. Study 2 used supervised machine learning methods to predict the status of misogyny across a large corpus of over 30 million tweets posted from India between 2018 and 2021. Interrupted Time Series Analysis showed that the absolute volume as well as proportion of these misogynistic tweets posted from India increased significantly after the onset of COVID-19, relative to trends prior to the pandemic. Study 3 is an ecological study that merged information on offline normative attitudes and behaviors from NFHS (2019-2021) with data on online misogyny prevalence at a sub-regional level. Results showed that gender-related offline normative behavior was significantly associated with online misogyny on Twitter. Findings support the growing body of evidence regarding the relationship between climate and VAW, highlighting the need for gender responsive strategies for disaster management and preparedness. With regards to online forms of VAW, results emphasize that online misogynistic rhetoric is prevalent and increasing on Twitter; it often occurs in tandem with offline contexts where control of and violence against women is normative. Online violence prevention efforts need to be part of the overall agenda of VAW, given the strong links between offline norms and online misogyny., San Diego State University; University of California, San Diego
Viral community function across microbial ecosystems
Viruses manipulate bacterial community function through lytic and lysogenic infections and the horizontal transfer of metabolic genes affecting biochemical cycling in their environment. Viral effects on microbial communities has been mostly characterized in the marine biome. However, as research on virus functions continues to expand, less studied biomes, like sediment and snow, become invaluable sources for studying alternate virus-microbe dynamics. Microbes in the sediment and snow biomes, in general, are subjected to resource limitations and environmental stress that are not present in the marine biome. In the sediment biome viral auxiliary metabolic genes influence the microbial functions differently at specific depths. Abundance of lysogenic phages increases with sediment depth, implying increased survivability of lysogens in the deep sediment biome. In the snow biome, the microbial community structure and functional capacity during an algal bloom were analyzed to determine how viruses manipulate snow microbes. The algal bloom brings about a shift in the microbial community structure due to additional energy provided by the algal photosynthate. The microbial functional capacity, however, is more influenced by the location and the auxiliary metabolic genes present in the neighboring viral community. Viruses in snow encode auxiliary metabolic genes involved in cellular respiration, protein synthesis, and de novo purine synthesis, suggesting that viruses provide microbial functions to exploit energy sources specific to the local environment. Together, these studies show a higher importance of lysogenic lifestyles and horizontal gene transfer of metabolic genes by viruses in extreme environments than previously recognized., San Diego State University
Viral metagenomics in host-associated systems
Viruses are the most abundant and diverse entities on earth. Exploration of viral diversity has traditionally been limited by the lack of common marker genes, however, the advent of viral metagenomics has made it possible to characterize global viral communities. Viruses in host-associated systems, such as human and animal tissues, are of special interest as they may be causative agents of disease. Additionally, changes in the total viral consortium may be indicative of host health status, with opportunists and pathogens replacing normal viral flora in the disease state. This dissertation presents an introduction to viral metagenomics and explores use in both human and animal associated systems. Methods in viral metagenomics, including both molecular biology and bioinformatics are reviewed as well as viral metagenomic studies to date. The metagenomic signature technique is explored as a method to characterize metagenomes and to screen for contaminating host genomic DNA sequences in viral metagenomes. Three experimental studies are presented to demonstrate the utility of metagenomics in healthy and diseased individuals. A case study of oropharyngeal viruses revealed the presence of phage-encoded virulence genes in healthy individuals, and also provided the first ever characterization of oropharyngeal viral communities. In the second study, viral communities from the airways of individuals with and without cystic fibrosis (CF) were compared. There was a striking difference in metabolic functions encoded by phage in CF versus Non-CF individuals. Regardless of which taxa were present, CF-associated phage shared a common core metabolism that reflected the disease state and aberrant airway physiology. Viral communities in healthy and diseased fish were compared in the third study. In contrast to the airway viromes, fish-associated viromes were found to differ taxonomically but not in metabolic function in the disease state. Together these studies demonstrate the power of viral metagenomics for discovery and for deciphering how viral communities change in the face of disease., San Diego State University
Virtual reality integration into geography education: A case study of physical geography
Virtual Reality (VR) technology and software has developed to the point where high-fidelity headsets and programs are affordable to the public. This thesis focuses on virtual reality technology and its potential application and adoption in Geography, specifically education and the topic of Physical Geography. The topic of Physical Geography was chosen for its ability to be modeled using already gathered geography data which could be readily converted into virtual reality environments. The objectives of the study were to assess the suitability of VR for use in geographic education in comparison to a traditional mixed media/lecture format. This study conducted paired entry and exit usability and knowledge evaluation surveys with 26 students pulled from the San Diego State University (SDSU) Geography undergraduate student pool or those that have completed or have enrolled in Geography 101 (Earths’ Environmental Science) within the past year. Major findings were that while there was a significant test score increase in the virtual reality group, just utilizing virtual reality technology alone as the sole method of lecture did not work as an effective alternative to traditional media lecture methods. While no direct causes can be attributed, the traditional methods group ended with a higher exit survey average (assessing Physical Geography Knowledge) than the virtual reality group. Smartphone-based virtual reality is better for answering questions regarding glacial landforms, and good for the self-perception of students’ own learning progress. Traditional learning methods are better at educating simpler mapping concepts like isolines and remote imagery. When analyzing the feedback from the knowledge surveys and a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis from users of the virtual reality prototype, it was made clear that while virtual reality does provide unique educational situations, it lacks the immediate versatility that traditional media and web-based lectures have. In addition, certain negatives such as cost, disorientation, and development time investment currently keep virtual reality from being a ready and effective alternative to traditional mixed media lecture formats. While certain concepts translate well into virtual reality, development costs and difficulties of production suggest using virtual reality as a supplemental tool to lectures., San Diego State University
Virtual standardized patient (VSP) simulation: A Comparison of pedagogical methods to improve nursing knowledge and skill
Claremont Graduate University and San Diego State University: 2018 Nurses serve a valuable role in the healthcare industry. Nurses are trained to have knowledge and skills for a fast-paced, evolving environment. In order to meet the needs of complex and diverse patients, nurses must be able to assess patients and prioritize care to produce safe and quality outcomes. This quantitative study framed in Benner’s Novice to Expert Theory and the National League for Nursing Jeffries Simulation Theory involved undergraduate baccalaureate nursing students from a California State University. The study examined differences in teaching methodologies regarding a low-frequency, high risk patient scenario. Survey responses from 161 participants provided opportunities to identify relationships between various teaching methodologies and nursing student knowledge and skill after a virtual standardized patient (VSP) anaphylaxis simulation. Participating students represented three levels of undergraduate nursing classes. Level one nursing students (Nursing Fundamentals) were familiar with reading case studies but had no formal clinical experience (n = 65). Level two nursing students (Medical-Surgical I) consisted of students with basic clinical experience (n = 60). Level three nursing students (Medical-Surgical II) consisted of students with extensive clinical experience (n = 36). Each willing participant was randomly assigned to a VSP anaphylaxis simulation research group that was delivered by three different teaching methods. Research group one consisted of a video simulation via traditional two-dimensional video plus a written case study (n= 54). Research group two consisted of a three-dimensional, mixed reality VSP simulation via the Microsoft HoloLens® (n = 53). Research group three consisted of a written case study (n =54). Participating students from within the three levels of nursing courses were stratified and randomly assigned to a research group. All students participating in the study received written instructions and an unfolding case study regarding the life threatening disorder of anaphylaxis. Following three observation periods, students were asked a series of knowledge and skill measures. The study participants were largely 19 to 20 years of age, had no previous clinical experience (67.1%), no combined previous immersive simulation experience (60.9%), and varying hours of nursing simulation experience. Correlational statistics showed evidence of a relationship between student knowledge and differences in teaching modalities. A one-way Analysis of Covariance revealed that video instruction provided the most knowledge gained (M= .96) compared to written case study (M = .95), and Microsoft HoloLens. Correlational statistics showed evidence of a relationship between student skill and differences in teaching modalities. A one-way Analysis of Covariance revealed that video instruction provided the most skill (M = .78) compared to the Microsoft HoloLens (M = .69), and written case study (M = .61). Regarding the Microsoft HoloLens group, when looking at overall knowledge, Level 2 (Medical-Surgical I) is the only variable that entered the Stepwise regression model. Regarding the Microsoft HoloLens group, when looking at overall skill, Level 1 (Nursing Fundamentals) is the only variable that entered the Stepwise regression model. The study’s findings showcase the importance of considering which type of teaching modality will provide students an opportunity to gain knowledge and skill when presented with a life-threatening patient scenario. This study suggested video instruction plus a written case study was the teaching modality that provided the most knowledge and skill gained among undergraduate nursing students. These results have significant research, practice, and policy implications for nursing school faculty and administration. In addition, the findings have heuristic value for other healthcare profession educators wishing to use emerging technologies for low-frequency, high-risk scenarios through the use of a virtual standardized patient., San Diego State University