Digital Commons Network^™

A Vacuolar Proton Pump Controls The Post-Germinative Growth Of Rice (Oryza Sativa Ssp. Japonica), Peter James Icalia Gann, Soumen Nandy, Rodrigo Botelho, Kari Vinzant, Mariya Khodakovskaya, Vibha Srivastava

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Post-germinative growth in plants is controlled by sucrose mobilization from the endosperm. Regulation of this process, however, is not fully understood. Transcriptional suppression of the rice vacuolar H+ translocating pyrophosphatase (V-PPase) referred to as VPP5 led to enhanced starch content in mature grains. However, vpp5 suppressed lines displayed a slower post-germinative growth rescuable by sucrose, indicating inefficient sucrose mobilization from the endosperm. Biochemical and gene expression analyses showed a slower rate of starch to sucrose conversion and altered expression of the key starch utilization pathway genes. We hypothesized that the modulation of metabolic activities in the vpp5 lines was based …

Integrating Methods To Investigate Phytoplankton Dynamics Along Gradients Of A Major Urban River, Nicholas Sheldon

University Honors Theses

Waterways that support human society and life on Earth host superabundant microorganisms which support all ecosystems and food webs: phytoplankton. This study aimed to identify and quantify phytoplankton in the Willamette River in order to understand the dynamics between different phyla. Building on previous studies, which showed that communities of phytoplankton change with the river environment, this work determined how eukaryotic and prokaryotic phytoplankton vary with one another while inhabiting the same river conditions. The approach involved sampling the Willamette river over a weekly time series and combined analytical techniques of qPCR, flow cytometry, and image cytometry to assess population …

Exploring Natural Competence Of Escherichia Coli Through Biofilm Formation, Thulni Liyanaarachchi

University Honors Theses

Escherichia coli is a species not known for natural competence; however, specific growth conditions can induce the process in this bacterium due to the presence of homologous competence genes. These conditions could be met with biofilm formation through an active growth phase in the two-layer architecture. Therefore, my thesis examined whether natural competence is exhibited in E. coli during biofilm formation as determined by the genetic transfer of ampicillin and chloramphenicol-resistance genes between two separate strains. The experiments were broken into three aims to determine the morphology of the biofilm in inter-strain co-cultures and cell-DNA mixes, the effect of …

Investigating A Link Between Dna Repair And Dna Replication In Escherichia Coli Using A Bacterial Two-Hybrid System, Lo Cooper

University Honors Theses

Cells rely on nucleotide excision repair (NER) to remove bulky DNA lesions, such as those caused by UV light. In Escherichia coli, NER involves the UvrABC complex, and includes two main pathways, global genomic repair and transcription-coupled repair (TCR). While TCR, which preferentially removes lesions that block RNA polymerase on the transcribed strand of active genes, is well studied, less is known about whether a similar coupling between repair proteins and replisomes blocked by damaged DNA exists. Such a process has been suggested by a high throughput interactome study, using the replisome subunit HolC as bait and the damage …

Indigenous Science And The Legacy Of Fire: Resilience, Fuels, Mosaics, And Eco-Cultural Landscapes In Oregon’S Coastal And Cascade Range, Julia Alcalá

University Honors Theses

Most of Oregon's western Cascade and Coastal range is a landscape that has historically been considered devoid of mid to low-intensity fires by Western science. However, for time immemorial, Indigenous peoples have been stewarding the forests through the use of "good fire," creating diverse and heterogenous landscapes with mixed fire regimes, ranging from less than a decade to several centuries since the last fire, resulting in a mosaic of patchy forest, oak savannas, prairies, and wetlands. Yet centuries of Indigenous displacement, cultural assimilation, and suppression of cultural burning contributed to this prevailing belief. Despite that, in recent decades, Western scientists …

Kinetic Analysis Reveals T6a-Protein Specificity For T6a And Hn6a Trna Modifications, Cassandra Mae Harker

University Honors Theses

Transfer RNA (tRNA) is essential for accurate translation of genetic information and plays a role in cellular processes such as lipid aminoacylation and bacterial conjugation. Base modifications help tRNA fold correctly and function properly. An important base modification, N6-threonylcarbamoyladenosine (t6A) occurs at position A37 in the anticodon-stem-loop of tRNA. This modification is crucial for decoding ANN codons. Interestingly, an Archeal organism, Methanocaldococcus jannaschii, can have either t6A and hydroxynorvalylcarbamoyl-6- adenosine (hn6A) modification at the same position on tRNAs. As Tsa proteins catalyze the formation of both t6A and hn6A modifications, this raises the question of whether discrimination between these …

Exploring Vaccine Efficacy And Safety For Ms Patients On Immunosuppressant Treatment In Light Of The Covid-19 Pandemic, Rain Pross

University Honors Theses

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disorder affecting approximately 2.8 million people worldwide. Despite decades of research to understand the molecular mechanisms of MS pathology, little is known about why the neurodegeneration caused by this illness occurs. For this reason, current treatments for MS target two broader aspects of the disease: relapse management and prevention via disease-modifying therapies. These treatments often involve immunosuppressive mechanisms, creating vulnerability to infectious diseases that became particularly concerning during the COVID-19 pandemic. This literature review examines the safety and efficacy of vaccination for MS patients on immunosuppressant therapies, highlighting the novel mRNA vaccines …

Assessing Illegal Take Of Sea Turtle In Bocas Del Toro, Panamanian Caribbean, Daniela Carolina Rojas-Cañizales

Theses and Dissertations

In Bocas del Toro, Panama, sea turtles were exploited for generations to supply local, national, and international markets. Today, sea turtle species are globally protected by different laws, and Panama is no exception. However, the use of sea turtles in Bocas del Toro and local perceptions regarding the consumption of these reptiles are unknown. Accordingly, during May of 2024, I conducted twenty-five semi-structured interviews with key informants selected by targeted and snowball sampling. Sea turtle consumption persists, and there is a clandestine network to sell turtle meat and derived products in Bocas del Toro. This study provides the first assessment …

Digesting The Details: How Cooking Shapes The Microbiome And Influences Obesity, Tracy Lieu

University Honors Theses

Obesity is a growing global health concern linked to chronic diseases and changes in the gut microbiome. While diet is known to affect gut microbes, less attention has been given to how food processing methods, such as heating, fermentation, and cold processing, change food in ways that influence the gut microbiome and health. This thesis reviews research on how different cooking and preparation techniques affect the availability of nutrients for microbial fermentation and the resulting effects on microbial diversity and metabolism. The findings show that fermentation and cold processing are the most supportive of gut health. These methods help preserve …

Woofs And Warbles: The Influence Of Urban Dog Walking On Birdsong, Grace Phillips

University Honors Theses

Recreational activity in natural areas can disrupt songbird singing during critical learning or courtship periods, increasing the risk of fitness and population declines in sensitive species. Local data on birdsong disturbance caused by recreation can guide management efforts protecting wildlife, such as signage, leash laws, and dog walking bans. This study assessed bird vocalization responses to groups with and without dogs in urban greenspaces. Surveys were conducted in Fall 2024 at three parks in Portland, Oregon, with varying rates of dog and human presence. Throughout two-hour observation periods, bird vocalization activity of seven songbirds was recorded at five-minute intervals and …

Correlations Between Social Media, Body Image Perceptions, And Disordered Eating Prevalence In Postpartum Women: A Pilot Cross-Sectional Study, Hannah Smith

Master's Theses

Postpartum women are a high-risk population for body dissatisfaction and disordered eating behavior due in part to the plethora of hormonal and physiological changes. Despite this, research examining this issue among postpartum women remains limited.

This pilot cross-sectional study investigated the relationship between social media use, body dissatisfaction, and disordered eating behavior among women up to 13 months postpartum. For this study, the following research questions were asked: Is high social media usage associated with higher levels of disordered eating among women up to 13 months postpartum? Is the association between social media usage and disordered eating mediated by a …

Impact Of Harvest Date And Year On The Volatile And Physicochemical Properties Of Fresh-Market Blackberry Cultivars, Rahul Sen, Andrea Myers, Alyssa Finocchiaro, Gracie Howard, Luke Norman, Renee Threlfall, Amanda Mcwhirt, Margaret Worthington, Scott Robert Lafontaine

Food Science Faculty Publications and Presentations

Fresh-market blackberries face challenges with inconsistent flavor, limiting consumer demand. This study examines how harvest date and environmental conditions impact the physicochemical and volatile profiles of three cultivars (Sweet-Ark (R) Ponca, Sweet-Ark (R) Caddo, and Ouachita) grown in Fayetteville, AR, during the 2022-2023 seasons. Using targeted and untargeted GC-MS/MS approach, 262 volatile compounds across 12 classes were identified. Increased rainfall and cooler temperatures in 2023 positively affected Ouachita and Sweet-Ark (R) Caddo's physical attributes but reduced Sweet-Ark (R) Ponca's firmness and weight. Sweet-Ark (R) Caddo exhibited the highest volatile content in 2022 (2991 mu g/kg), driven by terpenes (1018.03 mu …

Cll Cell-Derived Exosomes Alter The Immune And Hematopoietic Systems, Ivo Veletic, David M Harris, Uri Rozovski, Maria Teresa S Bertilaccio, George A Calin, Koichi Takahashi, Ping Li, Zhiming Liu, Taghi Manshouri, Rares-Constantin Drula, Ken Furudate, Muharrem Muftuoglu, Anwar Hossain, William G Wierda, Michael J Keating, Zeev Estrov

Faculty, Staff and Student Publications

The origins of immunosuppression, neutropenia, and anemia in patients with chronic lymphocytic leukemia (CLL) are not fully understood. Because in patients with CLL, circulating exosomes, which participate in cell-to-cell interactions, are CLL cell-derived, we examined whether those exosomes contribute to abnormal features of this disease. Our data revealed that CLL cell-derived exosomes engulfed by healthy donors’ monocytes, fibrocytes, and lymphocytes altered target-cell gene and protein expression and suppressed normal hematopoiesis. CLL cell-derived exosomes increased normal monocytes’ CD14 and CD16 expression such that it mimicked the accessory cell profile and upregulated T cells’ checkpoint PD-1 and CD160 protein levels, potentially reducing …

Genetic Control Of Prickles In Tetraploid Blackberry, Carmen Johns, Alexander Silva, Thomas Mason Chizk, Lacy Nelson, John R. Clark, Rishi Aryal, H. Ashrafi, Ellen Thompson, Michael Hardigan, Margaret Worthington

Horticulture Faculty Publications and Presentations

Prickle-free blackberry (Rubus subgenus Rubus) canes are strongly preferred by growers due to food and worker safety concerns and damage to fruit from mechanical injury by prickles. This project was conducted to identify the genetic region responsible for prickle-free canes derived from the recessive "Merton Thornless" source in autotetraploid blackberry using a genome-wide association study, develop diagnostic Kompetitive Allele-Specific PCR markers for prickle-free canes, and determine the effects of allele dosage at the prickle-free locus on prickle density in 2 biparental populations. The prickle locus was located on chromosome Ra04 from 30.48 to 36.04 Mb in an extensive LD block, …

The Ethnobotany And Pharmacology Of Medicinal Plants For Caribbean Women’S Health, Ella Thomas Vardeman

Dissertations, Theses, and Capstone Projects

Approximately 55% of the world’s population lives in cities, and the United Nations estimates that this number will rise to 68% by 2050. Urban ethnobotany, the study of people’s traditional knowledge and use of plants in cities, is increasingly important as people adapt their cultural traditions to changing environments. In New York City (NYC), there have been several urban ethnobotany investigations in collaboration with Caribbean immigrant groups. However, there has yet to be an ethnobotanical survey that documents and botanically authenticates the medicinal plants used in the Haitian community. Previous collaborative research with women from the Caribbean in NYC has …

The Sub-Syllabic Symphonies Of Self-Learning: How Do Zebra Finches Sing Them?, Abiesha Abiola Budiman

Dissertations, Theses, and Capstone Projects

Learning is a lifelong journey, where the mind and muscle dance to a tune of memory and motion. It begins at infancy and continues throughout life, encompassing everything from singing to achieving peak performance in sports. Complex motor skills involve multiple components and require coordination of several muscles. Humans and animals are extremely adept at learning complex motor skills on their own. However, we do not completely understand how self-directed learning works. One group of animals used to observe self-directed learning are songbirds. Zebra finches, Taeniopygia guttata, are one of the most studied songbird species due to their well-defined …

Environmental Enrichment Reduces Cue-Induced Reinstatement Of Heroin-Seeking Following Prolonged Use And Reverses Region-Specific Heroin-Induced Neuroadaptations, Apoorva Vashisht

Dissertations, Theses, and Capstone Projects

Background: Relapse remains the greatest barrier to long-term recovery and the consequential rising overdose-related mortality in heroin use disorder (HUD). Currently available behavioral and pharmacological interventions fail to extend their benefits beyond the duration of the treatment. Additionally, opioid agonist-based medications accompany harmful neurobiological risks and propensity to promote further drug-seeking post-treatment. We have shown that environmental enrichment (EE), as a therapeutic strategy applied after drug intravenous-self administration (IVSA), can effectively facilitate abstinence and reduce reinstatement of drug-seeking in animal models of drug abuse. Moreover, dopamine receptors like D1 and D3, and mu-opioid (MO) receptors are well known for their …

Disturbance And Diversity: Lichens In Changing Landscapes, Laura Boggess

Dissertations, Theses, and Capstone Projects

Disturbance is a fundamental ecological force that shapes biodiversity, community composition, and ecosystem function. Human-driven disturbances—such as habitat fragmentation, deforestation, and air pollution—are increasing worldwide, altering ecosystems at unprecedented rates. While ecological research has illuminated many effects of disturbance, significant knowledge gaps remain for underappreciated but ecologically vital organisms, such as lichens. Lichens are obligate symbioses between at least one fungus and one alga or cyanobacterium. As such, they are sensitive bioindicators of environmental change, offering unique insights into ecosystem health due to their responses to stressors such as poor air quality, habitat fragmentation, and deforestation. Yet, their responses to …

When Avatars Go To School: The Effect Of Virtual Reality On Learning And Error Correction, Lauren Barack

Dissertations, Theses, and Capstone Projects

The pandemic in 2020 led to an increasing dependency on technology particularly in learning environments. National educational assessments in the proceeding years have indicated steep, measurable learning loss. While a fully virtual learning environment is not the norm today, we chose to investigate how virtual reality (VR) environments influence learning in college students.

Our primary research goal was to look at how students learn and remember information gathered in virtual spaces. In particular, we examined whether sensory inputs in the VR environment, including spatial audio and haptic feedback, such as vibrations felt in a handheld controller, would help to better …

Neural Mechanisms Of Context-Sensitive Behavior In The Adult Male Zebra Finch, Katherine L. Anderson

Dissertations, Theses, and Capstone Projects

Adapting behaviors to the perceived external environment is key to the success and survival of individuals in social species. This context-sensitive modulation of behavior is critical for informative interactions with conspecifics, like alerting a neighbor to a nearing predator or capturing the attention of a potential mate. For the adult male zebra finch (Taeniopygia guttata), a vocal-learning songbird, context-sensitive adaptions to a learned song are key for developing and maintaining pair-bonds with females who are extremely attentive to subtle modulations of song structure. In this thesis, I explore the hypothesis that the influence of a social behavior network …

Understanding How Genetic Mutations Induce Oligodendrocyte Progenitors To Become Cancer Cells, Dennis Huang

Dissertations, Theses, and Capstone Projects

Gliomas are the most devastating adult brain tumors characterized by poor survival rate and limited options for treatment. Previous studies have shown that they are very heterogeneous and can be further sub-classified based on their transcriptional signature and the presence of specific mutations. One such subtype, is the “proneural glioma”, which is characterized by the enrichment in oligodendrocyte progenitor cell (OPC) transcripts and mutations in genes encoding for the tumor suppressor P53 (Trp53) and for Platelet Derived Grow Factor (PDGF) signaling. Since OPCs are the most abundant proliferative population in the adult brain, in this …

Biophysical Analysis Of S100a12 And The Nucleosome Core Particle, Christopher Diforte Jr.

Dissertations, Theses, and Capstone Projects

Calcium signaling and chromatin remodeling are fundamental regulatory processes that control protein activity and gene expression, respectively. This thesis investigates the molecular mechanisms by which local ligand binding and structural perturbations propagate allosteric effects across larger protein systems, using two distinct yet mechanistically analogous models: the calcium binding protein S100A12 and the nucleosome core particle. These studies are unified by a shared emphasis on how physical forces govern biological function.

In the first part, we explore calcium mediated allostery in S100A12, focusing on the distinct roles of its two EF-hand calcium binding loops (EF-I and EF-II). Through a combination of …

Memory Interference In The Lateral Entorhinal Cortex, Omar Ghazy

Dissertations, Theses, and Capstone Projects

Memory interference occurs when previously formed memories disrupt the acquisition or retrieval of new information. A prominent example of proactive interference is latent inhibition (LI), defined as a reduced ability to form or express Pavlovian associations with a stimulus following non-reinforced exposure. The interference-based model suggests that LI arises because the memory that the pre-exposed stimulus is inconsequential interferes with the memory that it predicts a reinforcer.

Because interference increases with age, identifying its neural basis may help prevent or slow cognitive decline. Prior studies using the LI paradigm implicate the entorhinal cortex (EC) in retrieving the memory that a …

Individual, Social, And Environmental Factors Associated With Patterns Of Parasitic Infection In Capuchin Monkeys (Cebus Imitator), Megan C. Henriquez

Dissertations, Theses, and Capstone Projects

Parasites, and the infectious diseases they carry, are thought to have significantly impacted our evolutionary trajectory for millennia. Exploring how parasites are acquired and transmitted by their hosts in wild, natural populations is integral to understanding how similar processes may have shaped host-parasite co-evolutionary relationships over time. However, parasitological studies in humans and in non-human primates have produced inconsistent results, highlighting the dynamic, nuanced, and unique relationships individual parasites have with their hosts. These relationships are largely regulated by variation in factors at host, social, and environmental levels. Characteristics unique to the host (e.g., age and sex), factors pertaining to …

Structural Studies Towards The Mechanism Of Scanning And Initiator Trna Recruitment During Eukaryotic Translation Initiation, Da Cui

Dissertations, Theses, and Capstone Projects

The central dogma, proposed by Francis Crick in 1958, marks the direction of the flow of genetic information: from DNA to DNA (DNA replication), DNA to RNA (transcription), and RNA to protein (translation). Each of these is tightly regulated and important for cells and organisms to function correctly, grow, and reproduce.

In the eukaryotic system, the initiation stage of translation is the first, the rate-limiting, and the most regulated stage. It involves direct regulation of multiple eukaryotic initiation factors (eIFs), scanning factors such as DHX29, and other factors such as Poly-A binding protein (PABP). It starts with the small subunit …

Re-Evaluating The Host Specificity Of Thirteen Eimeria Species That Infect Galliform Birds: Cross-Infection Experiments In Chukar Partridges (Alectoris Chukar), Northern Bobwhites (Colinus Virginianus) And Turkeys (Meleagris Gallopavo), Jessica L. Rotolo, A. Leveille, Rachel K. Imai, Elizabeth G. Zeldenrust, Billy M. Hargis, Elijah G. Kiarie, John R. Barta

Poultry Science Faculty Publications and Presentations

The commercial poultry industry has expanded and profited from intensively rearing birds, but it is not without consequences. Coccidiosis is an intestinal disease caused by Eimeria species that is well recognized by poultry producers because of the resulting health implications that often contribute to reduced welfare of birds, meat production and profitability. Strict host specificity of these parasites (infection of one host species only) is often assumed; however, examples of Eimeria spp. capable of infecting multiple galliform hosts have been described. Despite the relevance of coccidiosis in commercial poultry production, the number and extent of such crossinfections remain poorly understood, …

Salicylamide Derivative Jmx0312 Protects Immunosuppressed Syrian Hamsters Against Adenovirus Lethal Challenge, Marta Carretero-Ledesma, Jun Li, Javier Martín-Escolano, Soraya Herrera-Espejo, Jimin Xu, Haiying Chen, Caridad Díaz-Navarro, Jerónimo Pachón, Javier Sánchez-Céspedes, Jia Zhou, María Eugenia Pachón-Ibáñez

Faculty, Staff and Student Publications

Despite the fact that human adenovirus (HAdV) causes severe infections in immunosuppressed and immunocompetent individuals, especially in children, there is currently no specific treatment for these infections. Previously we reported a new salicylamide analogue, JMX0312, as a potent inhibitor of HAdV infection with low cytotoxicity in vitro. Here we evaluate the in vivo efficacy and safety of this molecule in the immunosuppressed Syrian hamster model of HAdV infection. JMX0312 administration at a dose of 6.25 mg/kg did not affect the body weight of the animals, and reduced the viral load in liver and blood in a similar way than cidofovir. …

Comparing Stroke Risk Factors Among Sexual Minority Groups In Texas, Brittany Krenek, Samuel Tundealao, Jennifer E S Beauchamp, Sean I Savitz, Irene Tamí-Maury

Faculty, Staff and Student Publications

Background: Knowledge gaps remain on stroke risk and disparities between sexual minority (SM) subgroups. In this study, stroke risk between SM subgroups, specifically gay/bisexual men and lesbian/bisexual women (G/BM and L/BW), was assessed.

Method: Data were collected in June 2022 using a bilingual (English and Spanish) cross-sectional paper-and-pen survey distributed among 183 SM individuals attending the 2022 Houston Pride Parade and Festival, as well as across Texas via phone call or online format. Relevant sociodemographic and stroke risk factors were compared between G/BM and L/BW using chi-square (or Fisher's exact, when appropriate) and two-sample t-tests. Sexual orientation was used to …

A Virtual Wellness Program To Enhance Well-Being For Pediatric Oncology Staff During The Covid-19 Pandemic, Karen M Moody, Maria Chang Swartz, Zachary Gresham, Martha Askins, Laura Cahalan, Christine Geistkemper, Amy Heaton, Ruitao Lin, Melissa Melo, Alakh Rajan, Madeline Smith, Priti Tewari, Keyana Williams, Cheng-Han Yang, Rhonda Robert

Faculty, Staff and Student Publications

In response to the COVID-19 global health crisis and mandated social isolation, Pediatric leadership at MD Anderson Children's Cancer Hospital was concerned for the psychological impact on its workforce and encouraged wellness programming. A grassroots wellness taskforce was assembled for the Division of Pediatrics. The task force's primary mission was to promote the well-being of clinicians and non-clinical staff members through a broadly accessible, sustainable, and effective virtual wellness program. Guided by the Stanford Model for Professional Fulfillment, a virtual program entitled, "Weekly Wellness Webex" for Pediatrics staff was launched. Weekly Wellness Webex is a 1-hour live-streamed program with varied …

Decoding The Plant Metabolome: A Metabolomics Approach To Guereza (Colobus Guereza) Feeding Ecology In Kibale National Park, Uganda, Emma Grace Thurau

Dissertations, Theses, and Capstone Projects

Plant metabolites, an elusive and diverse group of plant chemicals, represent a complex chemical interplay between plants and herbivores. Plants contain essential nutrients necessary for herbivore survival, yet herbivore consumption results in negative fitness consequences to a plant. This relationship has triggered a coevolutionary arms race in which plants have evolved chemical defenses to prevent herbivore consumption and herbivores, in response, have evolved their own counter-adaptations. This arms race has led to the diverse numbers of herbivores and plants observed today; therefore, these plant metabolites act as a signature of evolution through their influence on herbivore adaptations. Plant metabolites are …