DRUM - Digital Repository at the University of Maryland

DRUM collects, preserves, and provides public access to the scholarly output of the university. Faculty and researchers can upload research products for rapid dissemination, global visibility and impact, and long-term preservation.

 
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Submit to DRUM

To submit an item to DRUM, login using your UMD credentials. Then select the "Submit Item to DRUM" link in the navigation bar. View DRUM policies and submission guidelines.
Equitable Access Policy

Equitable Access Policy

The University of Maryland Equitable Access Policy provides equitable, open access to the University's research and scholarship. Faculty can learn more about what is covered by the policy and how to deposit on the policy website.
Theses and Dissertations

Theses and Dissertations

DRUM includes all UMD theses and dissertations from 2003 forward.

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Recent Submissions

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CONSTRUYENDO GUATEMALA Tradition & Technology: Living in a 21st Century Latin American City
(2024) Velasquez, Deisy Noemi; Bell, Matthew MB; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
In Guatemala, 21.5% of the population is living in extreme poverty. Poverty is a leading factor in poor-conditioned housing and a high percentage of children not attending primary school. This thesis focuses on constructing communities in Guatemala using innovative solutions and sustainable materials. Mass timber construction is an energy-efficient alternative material that is changing the built environment due to its sustainability, biophilic design, construction process, and economic development. This thesis focuses on exploring timber technology in an earthquake-prone region by learning, understanding, and embracing place with new technology that can sustain the future.
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Sustainable Living: Integrating Climate Adaptation in Bangkok's Informal Settlements
(2024) Pipatpongsa, Ploy; Kim, Taejun; Architecture; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
This thesis intends to demonstrate how the largest urban vulnerable communities in Thailand, using the case of At Narong in Khlong Toei, an informal settlement of over 30,000 residents who rent lands adjacent to the Port Authority of Thailand (PAT) in Bangkok. The PAT plans to evict the slum dwellers and develop the land, posing a severe threat to their lives and livelihoods. The thesis a multifaceted design framework that leverages social assets to enhance community resilience and inclusivity, particularly among vulnerable populations. The site location in PAT presents an opportunity to relocate informal settlements in the Lock 1-2-3 and 70 Rai communities, proposing multipurpose wetlands that serve as flood control, recreation areas and a market plaza that encourage social interaction and community cohesion.
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TREE GENETICS AND GREENSPACE MANAGEMENT INTENSITY INFLUENCE URBAN TREE INSECT COMMUNITIES, DAMAGE, AND FOLIAR TRAITS
(2024) Perry, Eva Emma; Burghardt, Karin T; Entomology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Trees are essential to well-functioning urban systems, providing services that benefit humans and wildlife. For example, arthropods that use trees in cities perform key roles in the urban food web as both prey and predators, but they can also be vulnerable to environmental stressors associated with cities. Previous work documents broad patterns in arthropod communities associated with management practice gradients in urban areas. How these patterns relate to changes in tree genetic background across management types remains a largely unexplored topic. To disentangle the genetic and management associated effects on arboreal insect abundance, communities, and foliar damage, I repeatedly sampled trees of known genetic relatedness for two commonly planted tree species: Acer rubrum (n = 65), and its non-native congener Acer platanoides (n = 71), in June and August of 2023 and 2024. I systematically selected about 3 individual trees growing in four human management intensity categories (street trees, parks and residential yards, urban forest patches, or rural forests) for each of 5 genetic lineages per tree species. I used vacuum sampling to collect mobile arthropods from the lower canopy of each focal tree in June and August of 2023 and 2024, and identified samples to order. I also assessed insect and systemic foliar damage, gall abundance, and select physiological traits in August 2024. I found the general trend of increasing total arthropod abundance with increasing management intensity. However, management effects differed across genetic background with almost ubiquitous interactions between management type and genetic lineage. The most dominant group of insects found on study trees belonged to the order Hemiptera. This group of primarily herbivorous piercing/sucking insects were the primary drivers of these overarching abundance patterns. Spiders, which were the most abundant primarily predatory arthropod order, exhibited the opposite pattern, increasing in overall abundance in the later season, decreasing with increasing management intensity, and generally not responding to tree genetic lineage. In 2024, increasing management intensity negatively affected cumulative insect herbivore damage and gall abundance, and did not vary by genetic lineage. Gall formers were found only on native Acer rubrum, with no galls sampled from the non-native A. platanoides. In contrast, systemic foliar damage did not change with management, and only varied by tree genetic lineage for Acer platanoides. Foliar photosynthetic traits’ variance by management intensity or tree genetic lineage was species dependent; A. rubrum traits varied by tree genetic lineage, while A. platanoides traits varied by management intensity. Overall, my results suggest that tree genetic background plays an important role in mediating management effects on insect populations, particularly for piercing-sucking herbivorous species, but genetic background’s effect on other metrics such as foliar damage and traits may be species-specific. Further studies should be sure to consider the structure of genetic populations when describing patterns of insect use. Results of this thesis will serve to inform best practices for urban tree management and pest mitigation, as cities work to maintain and increase urban canopy cover.
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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.
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Examining Associations between Neural Sensitivity to Social Feedback with Trait and State Loneliness in Adolescents
(2024) Alleluia Shenge, Victoire; Redcay, Elizabeth; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Loneliness can be defined as the negative emotional response to an experience of discrepancy between the desired and actual quality or quantity of one’s relationships. Loneliness is associated with many negative outcomes, including depression and self-harm. This phenomenon tends to increase in adolescence and adolescents with autism spectrum disorder (ASD) are at even greater risk for developing loneliness during this time than their neurotypical peers. The present study examined how neural sensitivity to both positive and negative feedback from peers is related to loneliness and social experiences among adolescents with and without autism. In a sample of 94 adolescents (22 autistic and 72 non-autistic) ages 11-14, we used an innovative ecologically valid paradigm for fMRI task along with real-world experience sampling to assess self-reported interaction quality and state loneliness, as well as surveys to examine reports of “trait” (or stable levels of) loneliness.The results indicated group differences in both state and trait loneliness, with the autistic group showing high levels of loneliness. In addition, the autistic group had lower interaction quality compared to their non-autistic peers. However, we did not find support for associations between neural sensitivity to feedback and interaction quality or loneliness across our full group. This work provides an important first step in understanding the relation between loneliness, neural sensitivity to social feedback and social experiences and can further inform intervention for adolescents at risk for negative mental health outcomes depending on which mechanism shows an association effect on social experiences and loneliness