Poster Presentation – Page 3 – Undergraduate Research Symposium Abstracts

Obstacle Crossing Toe Clearance Following Concussion in Adolescents

Presenter: Maisie Rapp

Faculty Mentor: Quinn Peterson, Li-Shan Chou

Presentation Type: Poster 81

Primary Research Area: Science

Major: Human Physiology

Sustaining a mild traumatic brain injury (mTBI) can lead to physical and cognitive deficits; however, it has not been determined how long these deficits last. Previous research concluded that after a month post-concussion young adults still have deficiencies with toe-clearance during split attention obstacle crossing. Another study found that adolescents have greater gait balance control deficits two months post-injury compared to young adults. To determine how these deficiencies affect obstacle crossing during gait after two month, obstacle toe clearance was measured in adolescents following concussion and healthy matched controls. Data was collected using a 10-camera motion capture system which recorded the positions of twenty-nine retroflective markers that were placed on bony landmarks of the each subject. Concussion subjects came to the lab 72 hours, one week, two weeks, one month, and two months after the date of their injury. The purpose of this study is to determine the effect of navigating obstacles during gait in adolescents following concussion.

Water Flux in a Mangrove Forest

Presenter: Katalin Plummer

Co-Presenters: Alyssa Bjorkquist

Faculty Mentor: Richard Emlet, Jan Hodder

Presentation Type: Poster 48

Primary Research Area: Science

Major: Marine Biology, Spanish

Water flux plays an important role in structuring and maintaining biodiversity in aquatic environments, such as tropical mangrove forests where lower water flux could reduce organic carbon outflow so that critical nutrients are more available for regulating organismal trophic processes. In the present study, we used two dissolution methods to estimate water flux at two mangrove sites within Bocas del Toro, Panama. We investigated how water flux differs with respect to mobility of a substratum (mobile versus stationary) as well as its position within a mangrove forest (exterior versus interior). We also examined organic carbon content of the sediment of each site in relation to water flux activity to ascertain the existence of a correlation between water flux and nutrient cycling in these environments.

Water flux differed significantly between sites for both the long-term and short-term (p < 0.001, both) dissolution trials. Additionally, we found a significant difference in sediment carbon content between sites (p < 0.01). While the two sites differed significantly from one another overall, these results do not suggest that water flux alone significantly affects marine community composition within a mangrove forest. We speculate that outside abiotic or geographic factors also influence physical conditions of these communities. Studying the intersection of biological and physical factors within mangrove forests may inform future research and conservation efforts pertaining to these environmentally sensitive habitats.

Anthropogenic Effects on Procyon lotor: Detecting a Secular Trend

Presenter: Carly M. Pate

Faculty Mentor: Frances J. White, Andrea R. Eller

Presentation Type: Poster 32

Primary Research Area: Science

Major: Anthropology, General Science

The Common Raccoon (Procyon lotor) is an ecologically flexible mammal that occupies many N. American suburban environments. Their dietary range, dexterous hands, and plastic phenotype allows them to navigate human landscapes. Due to the food availability of human N. American areas, we hypothesize that raccoons will experience increased body size through time. We compiled body masses over a 70 year period, and report results on the use of cranial data to predict body size.

To document body size in Procyon lotor, we include published body masses, museum data (records and new metrics; n=26), whole body measures (n=2), and cranial measures (n=21). Whole body measures were retrieved through museum records, or obtained in necropsy. Cranial measures (n=24) were based on published protocols. We used cranial and external measurements as a proxy for body weight. Of 25 measurements, 36% (n=9) had less than a 20% error (2.47-17.71); four of these measures had an R2 above 0.40. Combining data to chart size over time, we plotted the masses by year collected. Our results show a slight negative slope between log-transformed body weight and time, (m=-0.0023, n=51) between 1940 and 2016; we believe this result is influenced by small sample size. Procyon lotor provides a model for understanding anthropogenic ecologies, and potentially other areas of population and health.

Pileup Suppression in the ATLAS Detector

Presenter: Elliot Parrish

Faculty Mentor: Stephanie Majewski

Presentation Type: Poster 31

Primary Research Area: Science

Major: Physics

The ATLAS experiment at the Large Hadron Collider at CERN is looking to improve on their previous discovery of the Higgs boson in 2012 with the discovery of new particles. To ensure the continued success of ATLAS, there are a series of planned upgrades to the detector. After the Phase II upgrade, scheduled for 2026, the ATLAS detector will receive collisions of proton bunches every 25 ns with an average of 140 interactions per collision. Most of these interactions are not energetic enough to produce interesting physics (high energy events). The uninteresting interactions are referred to as pileup. These pileup interactions happen simultaneously with the interesting events, leading to a masking of the signal beneath the pileup. In order to sift through the large amounts of data, a firm understanding of pileup is needed. The focus of this study is to measure the energy deposited in the detector due to pileup and use it as a discriminating factor in reducing the data flow to a rate that can be written out in the time allotted.

Vascular Endothelial Growth Factor (VEGF) Signaling Contributions to Heart Ventricle Development

Presenter: Justine Nguyen

Faculty Mentor: Kryn Stankunas, Kate Karfilis

Presentation Type: Poster 79

Primary Research Area: Science

Major: Human Physiology

Cardiomyopathies are congenital heart diseases that affect the heart musculature, which could cause the heart to become weaker and pump less blood efficiently. The purpose of my research is to study the developmental programs that underlie ventricular trabeculation and the role vascular endothelial growth factor (VEGF) plays in regulating this process. VEGF plays a distinct role in direct signaling of angiogenesis along with the cardiac muscle formation and trabeculation in the ventricles. If the gene pathways for the development of trabeculation in the heart are understood, then in a disease state, appropriate remedies could be determined based on where the genes are expressed incorrectly. Currently, two possible hypotheses could explain VEGF signaling and its role in trabecular development. One hypothesis is that VEGF signaling is directly turning on a gene that directs VEGF signaling while the other hypothesis is that the two cell types (endocardial and myocardial cells) are directly interacting with each other due to VEGF signaling. In order to study trabecular development, pregnant mice are dissected when the embryos are developing the trabeculations. Embryos are processed so that their hearts are examined through various cellular biology techniques. A specific small molecule inhibitor, Cabozantinib is used in order to inhibit VEGF signaling, disrupting the formation of the trabeculae. A VEGF inhibited sample can be compared to an untreated wildtype sample to compare the differences in the trabeculation development.

A Diversity of Endophytic Fungi Can Transfer from Host-Leaf Tissue Directly into Woody Substrates

Presenter: Aaron Nelson

Faculty Mentor: Roo Vandergrift, Bitty Roy

Presentation Type: Poster 78

Primary Research Area: Science

Major: Biology

Funding Source: UROP mini-grant $1000; UnderGrEBES award, GrEBES (Graduate Evolutionary Biology and Ecology Students) $500

Endophytes are defined as fungi that grow within plant tissues without causing disease symptoms. Virtually all terrestrial plants on earth possess endophytic fungi, and while some benefits for the plant hosts have been observed, the benefits for many of the fungal partners are still unknown. One hypothesis is that endophytic fungi within leaves gain enhanced dispersal abilities to other substrates when the leaves fall. This would require that endophytes have the ability to transfer from leaf-tissues into other substrates such as woody litter. We set out to test the presence of this ability and to gain an initial glimpse of how widespread this ability may be among fungal endophytes. We accomplished this by surface-sterilizing leaves from an evergreen tree (Nectandra lineatifolia) and placing leaf fragments onto pieces of sterilized birch wood, giving endophytes an opportunity to colonize the wood. Fungal cultures were then grown out of the wood onto agar plates and isolated, resulting in 477 fungal isolates, 64 of which we determined to be morphologically distinct from one another. The DNA from each morphotype was extracted and amplified and is currently being analyzed. Our finding that a multitude of fungal endophytes can readily transfer to a woody substrates suggests that endophytism may play a major roles both in the dispersal of fungi and in the ecology of decomposition in forests in general.

No More Plastic Water Bottles: A Inquiry into Sustainable Packaging Design

Presenter: Cara Murray

Faculty Mentor: Jessica Swanson

Presentation Type: Poster 29

Primary Research Area: Design

Major: Product Design, Clark Honors College

Packaging design is the discipline of creating the container, graphics and visible exterior of a product. While extensive time, energy, and billions of dollars are devoted to this field each year, virtually all packaging ends up in the trash. While the field of packaging design has traditionally maintained a “throwaway” mindset, the past decades have introduced a more sustainable trend. Given the extreme waste associated with packaging it is important to consider how it can be made more environmentally friendly.

Beyond the fundamental functions of product protection, transport, and identification, I examine the greater purpose of packaging design: who does it serve, what purpose does it serve, and who/what does it impact? Using these questions as a initial framework, this research explores the related materials, processes and applications, as well as the cultural relevance, of sustainable packaging design.

After investigating the past, present and future trends related to sustainable packaging, my research then touches on some more theoretical examinations of how packaging design can be used to encourage sustainable consumer habits. I address here how packaging can remain attractive, functional, and cost-effective, but also incorporate increased environmental consciousness.

Research methods include examination of primary and secondary sources from expert designers in the packaging design field, as well as personal exploration of existing packaging, user interviews, and survey based data collection. Ultimately, my research aims to provide a comprehensive examination of the current field of sustainable packaging, identify cultural relevance of these products, and raise theoretical questions regarding the ethics of our existing consumption habits and waste cycles.

Are Allometric Growth Patterns Consistent Throughout Development in Lower Jaw Bones of Chinook Salmon (Oncorhynchus tshawytscha)?

Presenter: Natasha Mckibben

Faculty Mentor: Charles Kimmel, Saywer Watson

Presentation Type: Poster 77

Primary Research Area: Science

Major: Human Physiology

In vertebrate species, bone morphology directly affects the function of the individual bone and the way it works within the skeletal system as a whole. Over the course of development, a variety of growth patterns are crucial in coordinating changes in bone morphology. Studying these changes in Chinook salmon, we hypothesized that the lower jaw bones, dentary and angular articular, grow allometrically, meaning that shape changes as a function of size. This study characterizes the growth pattern by quantitatively comparing bone shape of juvenile salmon using geometric morphometrics. We used two groups of juveniles at different ages, the first with an average length (fork length) of 48.5 mm and 85 mm for the second. We found that as the fish grows in length, the dentary becomes broader, while the posterior aspect of the angular articular rotates in a clockwise direction. These results show that growth between the two stages is allometric, supporting our hypothesis. We now can inquire whether the same allometric rules dictate the shape changes during other life history stages. To address this question we are examining both earlier and later time points of Chinook development. Studying such growth patterns across development can be used to evaluate how early growth patterns can impact the overall development of the individual and influence functionality, together resulting in constraints on evolution.

Genetic Architecture of Local Adaptation and Reproductive Isolation in Mimulus aurantiacus

Presenter: Hanna McIntosh

Faculty Mentor: Matt Streisfeld, Sean Stankowski

Presentation Type: Poster 76

Primary Research Area: Science

Major: Environmental Science

Funding Source: UROP Mini-Grant, University of Oregon, $1000

A major goal of speciation research is to understand the genetic architecture of isolating barriers. Theoretical studies predict that isolating barriers are most effective if they have a simple genetic basis and are controlled by loci in
the same genomic regions. To test this hypothesis, we used Quantitative Trait Locus (QTL) mapping to determine the genetic architecture of floral trait divergence between red and yellow ecotypes of the monkeyflower Mimulus aurantiacus. These ecotypes are closely related, but partially isolated due to preferences of different pollinators for contrasting floral traits. We phenotyped an F2 mapping population (n=226) and used RADseq to generate a high- density genetic map to investigate two floral traits—color and size—thought to underlie preference. Using a multi- QTL model, we identified 2 QTLs for flower color and 3 QTLs for flower size. For size, the total phenotypic variation explained by the 3 QTLs was 36%, indicating that this trait is controlled by many genes of small effect. In contrast, a single QTL explained over 65% of variation in flower color. While recent studies have shown that multiple isolating traits are controlled by the same genomic region, we observed no QTL overlap for color and size. In addition to revealing the genetic basis of adaptation in M. aurantiacus, our results show that complex, simple, and genetically- independent traits can contribute to reproductive isolation early in speciation.

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