Theses and Dissertations from UMD
Permanent URI for this communityhttp://hdl.handle.net/1903/2
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
More information is available at Theses and Dissertations at University of Maryland Libraries.
Browse
17 results
Search Results
Item SENSORY AND HORMONAL MECHANISMS OF EARLY LIFE BEHAVIOR IN A SOCIAL CICHLID FISH(2024) Westbrook, Molly; Juntti, Scott; Biology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Studying the ontogeny of animal behavior is fundamental to ethology and allows understanding how behaviors in early life may affect later life success. The social cichlid Astatotilapia burtoni is an excellent model for examining the mechanisms of early life aggression due to the robust social hierarchy enforced by stereotyped, measurable social behaviors. We examine how hormonal signaling affects early life aggression through pharmacology and CRISPR-Cas9 mutants. We test which sensory pathways convey aggression-eliciting stimuli through sensory deprivation experiments. And we identify kinematic features that predict aggression through machine-learning video tracking algorithms. We observe that aggressive behaviors emerge around 17 days post fertilization (dpf), correlating with when the animals transition to free swimming away from the mother. We find that sex steroids subtly organize behavioral circuits for aggression and suggest that unknown additional mechanisms play a leading role. We show that thyroid hormone is not necessary or sufficient for the transition to aggressive behavior. We show that visual signals are necessary for the full expression of aggression, but in the absence of visual signal, low levels of aggression remain. We show that ciliated olfactory receptor signaling maintains low levels of aggression, as mutant animals display higher levels of aggressive behavior between 17 and 24 dpf. Finally, we demonstrate that swimming velocity has potential to predict aggressive instances of behavior. Together, we find multiple levels of control for early life aggressive bouts from sensory input to hormonal organization of brain circuits.Item EFFECTS OF ENVIRONMENTAL ENRICHMENTS ON WELL-BEING MEASURES IN COLONY-CAGED JAPANESE QUAIL (COTURNIX JAPONICA)(2022) Mathkari, Chirantana Vikas; Dennis, Rachel L; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Breeding purpose Japanese quail (Coturnix japonica) are often maintained in barren cages with little environmental complexity. These conditions can lead to unwanted social interactions and stress-related behaviors that can cause serious injury, mortality, and reduce productivity. Use of environmental enrichments has shown to improve poultry well-being; however, the optimal enrichments for quail have not been widely studied. The aim of this project was to evaluate the effectiveness of various enrichments on the well-being and productivity of breeding quail colonies (1 male, 2 females/cage). The enrichments studied were designed to reduce unwanted interactions and stress-related behaviors by either providing a shelter (protective enrichments) or by providing mental stimulation (stimulatory enrichments). In Experiment 1, using an incomplete Latin square design, each cage received one protective enrichment (Hut, Plastic leaves, or Grass), or one stimulatory enrichment (Mirror, Feeder toy, or Mat), or no enrichment (control) (average n=17/treatment). In Experiment 2, using an incomplete Latin square design, each cage received one of the following enrichment combinations: Hut + Mirror, Hut + Feeder toy, Hut + Mat, or only Hut (average n=14/treatment). Parameters measured included behaviors, body weight, Hen Day Egg Production (HDEP), egg weight, physical scores, and fecal corticosterone metabolites (FCM) levels. Measures were analyzed using a one-way ANOVA or Chi-square test on SAS 9.4. The results indicate that exposure to a single enrichment reduced stress-related damaging behaviors and increased resting; while exposure to a combination of enrichments reduced a larger variety of stress-related damaging behaviors more efficiently. Two of the three protective enrichments (Hut, Grass) exerted a notable impact on production, while combinations of protective and stimulatory enrichments were more efficient in decreasing physical scores as compared to a single enrichment. The Hut + Mat combination notably reduced the FCM levels as compared to only Hut. Our study identified enrichments which are optimal for improving breeding quail well-being, and exhibit the potential to improve the economics of the quail industry.Item American Populism, Political Information, and Trade Opinion(2022) Campana, Robert David Louis; Gimpel, James G.; Government and Politics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Trade policy is a complex issue that involves economics and international politics. Traditionally, Americans have not often expressed opinions on trade policy due to its high issue complexity and because Democrats and Republican politicians since the later part of the 20th century have been inconsistent in their support for neoliberalism or protectionism. Despite this, populist candidates like Bernie Sanders and Donald Trump have repeatedly used their support for protectionist policies to differentiate themselves from more mainstream candidates. Using multiple public opinion surveys and survey experiments, this project explores how populism, anti-expert sentiment, anti-capitalism, diversity anxiety, and ethnonationalism influence American’s views on free trade policy and shows that all these factors are associated with greater support for protectionist policies. Additionally, this project examines and adjusts for the unusually high level of non-response regarding questions about trade policy.This project also analyzes what causes Americans to think trade policy (specifically, the withdrawal from the Trans-Pacific Partnership) is more important. This project finds that Americans who believe themselves to be strangers in their own country are more likely to believe the withdrawal from the Trans-Pacific partnership is important. Meanwhile, Americans who believe the United States is less respected than in the past are less likely to believe the Trans-Pacific Partnership is important. Two survey experiments are conducted to see how the presence of “don’t know” responses in trade opinion questions and patriotic framing shift attitudes on trade policy. In both cases, issue framing does not significantly shift opinion on trade policy. This project carries out a longitudinal study to see how the same group of Americans shift their attitudes on trade policy over a multi-year time frame. Generally, these shifts are very small; however, Americans with differing views on regulation displayed the greatest attitudinal shift. Initially, Americans who wanted more government regulation were the most protectionist while Americans who wanted less government regulation were the least protectionist. Over the multi-year period, this association became significantly less visible. Finally, this project analyzes how economic attitudes, immigration attitudes, economic identity, immigrant identity, local immigrant populations, and local economic data influence views on trade policy. The study finds that immigration attitudes are closely aligned with views of trade policy.Item Effect of grazing muzzles on grazing miniature horse behavior and physiological stress(2019) Davis, Kristina; Burk, Amy O; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Grazing muzzles are highly effective at reducing forage intake in horses and are a popular tool to control horse weight. However, grazing muzzle design may cause horses stress. The objective of these studies was to determine how grazing muzzles impact behavior and physiological stress in grazing horses. Two groups of 6 miniature horses, housed individually or in a herd, wore grazing muzzles for 0, 10, and 24 h/d. Over 9 weeks, body weight, heart rate parameters, salivary cortisol concentrations, and observations of behavior were collected. Results indicate muzzling did not seem to cause physiological stress as measured by cardiac and salivary cortisol parameters but did alter grazing and locomotive patterns. Muzzling for 24 h/d was necessary for weight loss and was associated with lower heart rate and higher heart rate variability. These findings suggest that muzzles do not cause stress in horses, even if left on for 24 h/d.Item USING ENGINEERING DESIGN PROJECT JOURNALS TO INFER INDIVIDUAL ACTIVITY AND ASSESS TEAM BEHAVIOR(2018) Born, Werner Christian; Schmidt, Linda C; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Design is critical to our society and yet we still do not understand a great deal about the underlying processes which occur as the engineering designer solves a problem. Analyzing such information could provide a wealth of insight on not only how design works but also how individuals work design. Concurrently maintained design journals kept by mechanical engineering students enrolled in capstone design courses offer a rich avenue to explore this phenomena. By applying a classification scheme to design journals, the entries of design activity of both individuals and teams were analyzed to determine relative time on each activity. These proportions were then examined across multiple project intervals defined by key deliverable dates in addition to across the project as a whole. Recurring sequences within these activities were also identified. Beyond the use of the classification scheme, other aspects of design journal analysis were explored. Specific concepts were tracked across a team, which were also used to calculate ratios of how often a member of a team references concepts by their teammates, themselves, and the final concept. With the addition of entry dates this information will also be used to map the exchange of ideas across a team and to chart the life of each concept. Journal content was codified and tested. Discoveries were made not only about the activity frequencies but how much those frequencies varied from person to person and team to team. The most common activity recorded in journals was Analysis, which averaged 23.13% of journal segments. Students were moderately accurate at identifying the frequency of Analysis and Reflection work. The most common sequences of unique activity were Idea Generation and Analysis along with its reverse. There were 3 distinct patterns of how individual behavior related to team members. 3 of 13 teams examined had uniform proportions of activity, while at the other extreme another 7 teams had little to no uniformity. The three activity classes found to be most affected by a project's time line were Problem Understanding, Idea Generation, and Decision Making, which each were found to have a statistically significant change in recorded activity over time.Item FOUR ESSAYS ON HOW PRESIDENTIAL POLICY REPRESENTATION ON THE ISSUE OF IMMIGRATION AFFECTS LATINO POLITICAL BEHAVIOR(2018) Rodriguez, Antonoi; Rouse, Stella M.; Government and Politics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)I bridge the presidency literature and priming literature to develop a new model for understanding how the executive office can prime the public's attitudes. The Executing Priming Theory (EPT) hypothesizes that the president can subtly alter the public's views toward him by responding to the public’s policy demands through the use of his executive powers. These actions will often draw news coverage from the media, taking the president's policy actions directly to the public and raising the salience of these issues. In turn, this affects the criteria that will be used to evaluate the president's performance and influence political behavior. In four essays, based on data from the Pew Research Center, I find an association between Latino approval of President Obama’s policies on immigration and their political behavior. These findings present a new way of thinking about the president's policy responsiveness. Previous presidents have been found to respond to policy demands with symbolic actions (Cohen 1997) rather than substantive policies or motivated primarily by partisan factors (Wood 2009). I demonstrate here that President Obama utilized unilateral actions to provide Latinos with substantive policy representation to improve his standing within this community. Overall, I find that substantive presidential policy representation influences not only Latino but also non-Latino political behavior. The findings presented in these four essays demonstrate that substantive policy representation by the president matters.Item The effects of embryonic norepinephrine on Japanese quail behavior and neurophysiology(2018) Mengers, Jasmine Nisha Parikh; Dennis, Rachel L; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Stress in poultry breeding flocks results in elevated in ovo monoamines affecting behavior and physiology. We injected Japanese quail (Coturnix japonica) eggs with 10 μl of 0.05M (n = 111) or 0.01M (n = 113) concentrations of norepinephrine (NE) or saline (n = 112) at ED1 and incubated with intact controls (n = 78) to observe the influences of elevated embryonic NE on behavior and productivity. We tested developmental memory, tonic immobility, open field isolation behaviors, home cage aggression, and novel conspecific responses. We also measured body weights, egg lay and survival-related behaviors before and after rehoming at sexual maturity. Results indicated dose and age differences between treatments. Norepinephrine birds exhibited variations in stress-coping strategies, decreased productivity, increased consumption frequencies, decreased activity levels, and changes in survival-related behaviors following rehoming. Our data suggest that elevated embryonic NE plays a role in behavioral programming with impacts on poultry well-being.Item Generating and Using Evidence for Program Design: Lessons from Evaluations in Pakistan and Peru(2015) Picon, Mario Giuseppe; Graham, Carol; Public Policy; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The design and implementation of development programs is driven by a set of assumptions on development interventions that typically overlook the role of context; particularly social norms and institutions. Moreover, evaluation is still focused in understanding if an intervention works, instead on how to make it work better. This dissertation discusses the evaluation of a marketing intervention in Pakistan, and the evaluation of a participatory development strategy in Peru. Neither intervention produced the expected results. Rather than stopping there, I discuss the reasons behind their lack of effectiveness, specifically looking at elements for program re-design. The first essay discusses the randomized evaluation of a marketing intervention in Pakistan. The hypothesis was that given the positive role models featured in brochures promoting a microfinance product, women would increase their demand for loans. The brochure, however, had a negative effect in program take up among the poorest women. The likely reason behind this: prevailing social norms regarding role of women. The second essay stresses that the randomized evaluation experiment should not be taken as indicating that marketing is ineffective to improve the impact of microfinance in rural Pakistan, and that the role of social norms in microfinance can be internalized and used in the re-design of the brochure along several dimensions. Using theory of change and realistic evaluation approaches, I propose a framework that combines formative and process evaluation to design and pilot alternative marketing intervention in Pakistan. The third essay features the evaluation of the participatory strategy of El Alto, in Peru. This was a study with very limited data and virtually no control of the research team over the intervention. A mix of quantitative and qualitative techniques is used for outcome and intervention evaluation, and the framework presented on the second essay is used to understand why the participatory strategy has not been successful in sustaining participation. Originally an evaluation of small pretensions, it was used as an opportunity to revisit the objectives of the strategy, improve intervention design, and establishing a monitoring system based on administrative data. A case is made for complementary, context-based interventions.Item Assessing Knowledge, Attitudes, and Behaviors Toward West Nile Virus Prevention Among Adults ≥ 60 Years Old in Maryland: An Application of the Health Belief Model(2014) Mitchell, Kimberly C.; Howard, Donna E.; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)West Nile Virus (WNV) is a mosquito-borne virus and the leading cause of arboviral (arthropod-borne) disease in the U.S. While most WNV cases are asymptomatic, 20% of infected people develop WNV fever and < 1% develop severe neurologic disease. Individuals over 50 years old are at greatest risk of severe disease and death. Dramatic increases in WNV activity in 2012 underscored its unpredictable nature and highlighted concerns for adverse effects on older adults. It is important to understand factors that influence this population's engagement in WNV prevention. This study analyzed data collected by the Maryland Department of Health and Mental Hygiene (DHMH) via cross-sectional survey to identify barriers to WNV prevention among adults ≥60 years of age. Subjects were recruited via stratified random sample of 1,700 households from counties with ≥ two WNV cases, enrolling 211 Maryland adults ≥ 60 years old. Six constructs of the Health Belief Model (HBM)--perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy--were examined to assess how they predicted attitudes and behaviors toward WNV prevention. Univariate, bivariate and multivariate analyses examined the utility of the HBM for explaining WNV preventive behaviors in Maryland adults. Multivariate logistic regression models tested 36 hypotheses examining associations between HBM constructs and six outcomes: (1) avoiding the outdoors at dusk and dawn, (2) dressing in long-sleeved shirts and long pants when outdoors, (3) using insect repellent on exposed skin, (4) draining standing water from objects around one's property, (5) acceptance of a WNV vaccine, and (6) support for community mosquito control programs. Findings showed high WNV knowledge and awareness but low perceptions of personal risk for WNV infection. Perceived susceptibility to WNV predicted use of insect repellent, draining of standing water from objects around the home, and acceptance of a WNV vaccine; perceived benefits were associated with draining standing water and support for mosquito control programs. Feelings of worry about WNV may inform future WNV interventions and risk communication to older adults. Findings have implications for theory-based research, which could probe applications of the HBM and other theories in understanding WNV attitudes and behaviors.Item VIOLENCE AND DISORDER, SCHOOL CLIMATE, AND PBIS: THE RELATIONSHIP AMONG SCHOOL CLIMATE, STUDENT OUTCOMES, AND THE USE OF POSITIVE BEHAVIORAL INTERVENTIONS AND SUPPORTS.(2013) Eacho, Thomas Christopher; Leone, Peter E; Special Education; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The primary purpose of this study was to examine the relationship between school climate and student outcome variables. The secondary purpose was to examine the relationship between the use of Positive Behavioral Interventions and Supports (PBIS) and the same student outcome variables. Variables depicting student perceptions of school climate, self-reported student academic achievement, student perceptions of physical safety in school, and school use of PBIS were drawn from the baseline data collection of the Maryland Safe and Supportive Schools (MDS3) Initiative. Descriptive statistics, bivariate correlations, and multilevel modeling were used to analyze the MDS3 data and to answer four research questions. Descriptive results showed that greater risk factors including feelings of being unsafe, involvement in violence, and poor academic achievement were associated with being male, nonwhite, and in the ninth grade. Bivariate correlations showed statistically significant relationships between student academic achievement and perceptions of school climate, race, gender, and grade level. Average academic achievement at the school level was statistically significantly associated with average school climate, school minority rate, high free and reduced meals (FARM) rate, and use of PBIS. Student perceived physical safety had statistically significant associations with perceptions of school climate, race, gender, and grade level. Average physical safety at the school level was statistically significantly associated with average school climate, school minority rate, high FARM rate, and use of PBIS. Multilevel models of academic achievement showed disparities based on race, gender, grade level, perceptions of school climate, and enrollment in schools with high FARM rate. Multilevel models of physical safety showed disparities based on gender, grade level, perceptions of school climate, enrollment in schools with high FARM rate, and average school level perceptions of school climate. The use of PBIS in schools had little impact on either multilevel model. Recommendations include examining school climate carefully and implementing practices that aim to improve school climate, particularly for those students with the most risk factors.