Category: Poster Presentation

The Study on Global AGEing and Adult Health (SAGE): Body Composition Measurements among Aging Populations

Presenter: Austin Wong

Mentors: Josh Snodgrass and Melissa Liebert, Anthropology

Poster: 65

Major: Biology

Frequently used as a predictor of obesity-related health risks, body mass index (BMI) estimates general adiposity instead of abdominal obesity, and does not distinguish between fat and lean mass. Further, previous research has found it is possible for adults to maintain a normal BMI, yet increase their waist circumference (WC) over time.

This makes BMI a less accurate predictor of cardiometabolic risk in older adults (/50 years old). While measures of central obesity have been found to be better indicators of cardiovascular disease than BMI, debate continues over the optimal measure of central adiposity. The current study uses data from the World Health Organization Study on global AGEing and adult health (SAGE), a longitudinal study of nationally representative samples from older adults
in six middle income countries (China, Ghana, Mexico, India, Russian Federation, and South Africa). We examine associations among body composition measures (BMI, WC, waist-to-stature ratio, and body adiposity index) across age groups, sex, and country. Furthermore, this study investigates associations between body composition measures and hypertension. We hypothesize that: 1)abdominal obesity measures will increase with age groups but decrease in those over 80 years old, 2) stronger associations will be found between abdominal adiposity measurements and blood pressure, and 3) diverse associations will be found in the populations examined due to a variety of factors including diet, urbanization, and health care access.

Where the Wild Things Grow: A Case Study of Ventilation in Bathrooms

Presenter: Hannah Ward

Co-presenters: Alex Collins and Julia Frost

Mentors: Alison Kwok and Tom Collins, Architecture

Poster: 64

Major: Architecture

According to the City of Eugene’s website, newly constructed bathrooms must either have an operable window or “a venting system capable of 50 cubic feet per minute” controlled by “a dehumidistat, timer, or similar means of automatic control.”1 Spaces that do not provide enough ventilation can often be susceptible to damage such as mold growth and dry rot if humidity levels reach a certain point and stay there consistently. As Eugene is a mild and humid climate, many buildings have issues with mold growth because of high humidity levels. This study will assess which ventilation strategies are supportive in reducing humidity levels and ultimately preventing mold growth in a damp climate, such as Eugene. Specifically, this study will test the hypothesis that apartments with continuous bathroom ventilation systems are more capable of maintaining 50% RH [relative humidity] than apartments with non-continuous bathroom ventilation systems. To test the hypothesis, the study used a two-phase approach, which included four HOBO data loggers2 to record the relative humidity of three different apartment bathrooms using three different styles of ventilation, before testing the capacity of airflow from the two bath fans. Our results show that active ventilation techniques are not the only effective way to ventilate a space and, in fact, one of the bathrooms using an active fan actually performed worse than a comparable, passively ventilated bathroom.

How Smartphone Use during Walking Affects Ability to React to an Unexpected Event in Young Adults

Presenter: Deborah Wang

Mentors: Li-Shan Chou and On-Yee Lo, Human Physiology

Poster: C8

Major: Human Physiology

College students often engage in risky mobile phone behaviors. Though texting while driving has been an extensively studied, the issue of texting or other smartphone usage while walking has only been recently examined as a daily hazard. This project focused on how smartphone usage affected a person’s response to an unexpected event when the subject was looking intently at the screen. This study examined the failure rate as the subject stopped in front of a projected line, and associated gait characteristics including stride length, center of mass (COM) velocity and COM medial-lateral sway. In this experiment, whole body motion was collected with 29 reflective bony landmark markers and a 10-camera system. Subjects first stopped in front of a projected line at the same location, and with the same timing for 5 trials (expected condition, EX). Subjects were then asked to stop in front of the line projected at different times or locations for 10 trials (unexpected condition, UN), and then simultaneously completing a Stroop test on an iPod touch under the same unexpected condition for another 10 trials (UN_Stroop). A Stroop test has subjects pick the ink color a word of a color (IE green, blue or red) is written in (IE green, blue or red). This made the UN_Stroop condition the most challenging. UN and UN_Stroop had a higher failure rate than the 0% of EX (33% and 17% respectively). Furthermore, with smartphone usage, gait velocity and stride length decreased while medial-lateral sway increased, which could negatively impact pedestrian safety.

Influences on U.S. Mammal Diversity over the 20th Century: Implications for Future Response to Climate Change

Presenter: Kendra Walters

Mentor: Edward Davis, Geology

Poster: 63

Majors: Geology and Biology

Biodiversity loss is recognized as a global crisis. Current research strives to quantify and predict the change in biodiversity throughout the world, focusing on a wide range of taxa. However, current predictive models of mammal diversity in the United States suffer from low precision. They are not scaled with adequate spatial or temporal resolution because richness has not been evaluated at a broad spatiotemporal scale. Our research is a high- resolution analysis of the changes in mammal diversity in the continental United States through the last 110 years.

We collected mammal occurrence data from the online database VertNet and individual museum collections, divided it into ten year increments, and used scripts in ArcGIS 10.2 to produce sampling-standardized patterns of mammal diversity in each decade. We then analyzed the geographic distribution of diversity change over the 20th century. Mammal diversity in the last century increased in two regions: one northern horizontal strip between 43° and 47° latitude and one southeast strip from Texas to North Carolina. Diversity decreased throughout the rest of the United States. Our study describes regions in the United States that are experiencing the most severe biodiversity changes which suggests that those regions should be focal areas for conservation efforts. Further directions include testing hypotheses about the role of climate and human population change to influence these patterns of mammal diversity shifts.

The Correlation of Prehistoric Wells, Groundwater Resources, and Statues on Easter Island Imply Greater Understanding of Natural Landscape by Prehistoric Rapanui People

Presenter: Sadie Trush

Mentors: Terry Hunt, Honors College Anthropology; Nick Dreher, Environmental Studies

Poster: C6

Major: Environmental Science

Commonly overlooked in the numerous narratives of Easter Island’s mystery, is the most critical resource to human beings: freshwater. Recent field research on the Island has focused on puna (archaeological well features) that may have allowed the prehistoric Rapanui people to obtain this essential element. An RC quadcopter, high resolution camera, and trimble unit were used on this research project to create 3-dimensional reconstructions of the puna, while the coastline was manually surveyed to find traces of freshwater at the marine interface. These two data sets were geographically compared with previously mapped locations of moai and ahu (great stone statues and platforms), since puna are always found within 50 meters of an ahu presentation. Additionally, in these areas notable amounts of fresh, potable, groundwater seeps into the sea. This correlation of puna, potable water, and
ahu with moai suggests a connection between resource use and moai placement, and challenges previous beliefs that moai were merely 70-ton manifestations of ancestor worship. In fact, the correlation may reflect the Rapanui’s connection to the natural landscape and understanding of limited resources. Given current freshwater shortages, these findings not only lend themselves to further knowledge of water resources on Easter Island in the context of Rapanui prehistory, but may also assist modern Rapanui people to utilize local water resources instead of shipping it thousands of kilometers from Chile.

Recycled Insulation for Resource Scarce Regions

Presenter: Katrina Tran

Co-Presenters: Kyle Plata and Alex Weaver

Mentors: Alison Kwok and Mathieu Deraspe, Architecture

Poster: C7

Major: Architecture

This experiment sought to assess the efficacy of using excess trash as a solution to resource scarcity in the developing world by testing the thermal efficiency of glass bottles as an insulating material. The glass bottles were packed densely with shredded paper and then laid on their sides into a rough wall assembly. The general thermal efficiency of this recycled insulation was tested inside a thermal hotbox using HOBO data loggers, which measured the temperatures inside the “hot” and “cold” sides of the hotbox for twelve hours. The hypothesis was that the recycled insulation could sustain a temperature difference greater than 5°F for at least three hours after applying heat to the “hot” side of the hotbox. The data collected showed a temperature difference greater than 5°F for four hours after the heating period. Once the original hypothesis held true, further testing was conducted using a heat flux transducer in order to calculate an exact R-value for the recycled insulation. The transducer data showed that the recycled insulation has an R-value of 15 hrft2°F/Btu. The results of this experiment indicate that this insulation may be suitable for mild to moderate climates.

Do Progenitor Subpopulations Contribute to Zebrafish Enteric Nervous System Development?

Presenter: Charlotte Taylor

Mentors: Judith Eisen and Julia Ganz, Biology

Poster: 62

Major: Biochemistry 

The enteric nervous system (ENS) provides intrinsic intestinal innervation and modulates intestinal function. The ENS forms a complex network of neuronal and glial subtypes. ENS progenitors that give rise to this network express different marker genes, e.g. phox2b, sox10, and ret. Using the zebrafish model, we investigated whether expression of these markers defines distinct ENS progenitor subpopulations. Gene expression revealed subpopulations, the most prominent of which are characterized by the following combinations: phox2b; phox2b/ret; phox2b/sox10; phox2b/ret/sox10. We will now determine whether these distinct progenitors have functional significance for ENS development. We will use the Cre/loxP lineage tracing system to track progeny of distinct progenitor subpopulations and determine if they give rise to different ENS cell types. Using BAC-recombineering, we will generate BAC- constructs that drive Cre recombinase expression under enteric progenitor specific promoters (e.g. ret). To test if BAC enteric progenitor promoter sequences drive expression faithfully, we are generating BAC-constructs that drive expression of green fluorescent proteins (GFP). We are currently analyzing ENS GFP expression of a modified ret BAC. After generating Cre-constructs, we will inject them into a reporter line and identify progeny of labeled progenitors at different times during ENS development. Our results will provide a comprehensive lineage analysis of ENS precursors in vivo and thus offer new insights into ENS development and the potential of individual ENS precursors.

Variability Selection Hypothesis, Weed Macaques, and Body Size Variance

Presenter: Harry Sullivan

Mentors: Andrea Eller and Frances White, Biology

Poster: 61

Major: Biology 

Variability Selection Hypothesis (VSH) proposes that early Homo gained adaptive benefit from being flexible in novel or unpredictable climates. Increased intra-taxon variation in body size and the expansion of geographic ranges in early Homo populations suggests greater phenotypic and developmental plasticity. Similar levels of ecological flexibility have been documented in some species of macaques, earning them the moniker of “weed species”. We compare body size variance between weed and non-weed macaques to determine whether intrataxon variation in body size positively correlates with ecological flexibility, as proposed by the VSH. We used two sources of body size data for all available taxa: original data on postcranial osteological body size estimators (seven species, n=49), and published body masses for nineteen species. Fourteen osteometric body size estimators on the humerus, radius, ulna, femur, and tibia were included. All estimators show a tight correlation with body mass: R2 values range from 0.79 to 0.95 with a mean of 0.9. Variance per estimator per species was calculated, as proxies for body mass variance. Averaged estimator variances in non-weed species range from 1.71-11.34, but only 2.26-4.36 within weed species. This data analysis indicates that weed macaques do not exhibit more intrataxon body size variance than non-weeds. Macaques are under-utilized ecological referents for human evolution, and this genus’ diversity is informative for understanding the role of adaptive flexibility in primate evolution generally.

Age-Related Differences in Healthy Male Runners

Presenter: Justine Silberberg

Mentors: JJ Hannigan and Li-Shan Chou, Human Physiology

Poster: 60

Major: Human Physiology

Previous research suggests that older males display less ankle plantar flexion and greater hip flexion during gait compared to younger individuals. Differences in running gait between younger and older individuals, however, are largely unknown. This study investigated differences in strength, flexibility, and range of motion between younger runners (n = 15; age range = 18-21) and older runners (n = 10; age range = 40-51). All subjects were males who ran at least 20 miles per week. For testing, subjects ran continuous laps of approximately 40-meters in the Motion Analysis Laboratory. Running kinematics were collected using a 10-camera motion capture system, strength was measured using a Biodex System 3 dynamometer, and flexibility was measured statically by a trained clinician. Independent sample t-tests were used to examine group differences. Older individuals were found to have increased hamstring flexibility, increased first metatarsal-phalangeal joint range of motion, decreased quadriceps flexibility, and decreased trunk flexion compared to younger runners (p < 0.01). Limitations include the relatively small sample size and cross-sectional nature of this study. Understanding age-related differences in running gait may help clinicians better treat injuries in older runners. Future studies exploring age-related differences in running should recruit a wider age range and follow these individuals over time.

The Effect of Different Light Wavelengths on the Dust Microbiome

Presenter: Andy Siemens

Mentors: Jessica Green and Erica Hartmann, Biology

Poster: 59

Major: Biology 

Different light treatments affect the growth of certain bacterial strains in the built environment, however little is known about the effect of light on an entire bacterial community. The goal of this study is to investigate the impact of UV vs. visible light on the viability of the dust microbiome. We developed a method to quantify viable dust by treating samples with the DNA-binding agent propidium monoazide (PMA), which prevents the amplification of DNA from non-viable cells during polymerase chain reaction (PCR). This technique was used to determine the amount of DNA from live vs. dead cells by comparing amplified 16S gene copy numbers with and without PMA treatment using quantitative PCR (qPCR). As a pilot study, dust samples were treated with broad-spectrum light to determine the appropriate dosage for killing dust microbes. The built environment was simulated using light boxes designed by the Energy Studies in Buildings Laboratory. Experiments were performed in triplicate using identical box setups for each trial. In future experiments, the relationship between different wavelengths of light and bacterial viability will be tested by subjecting dust samples to sunlight with UV wavelengths removed, sunlight with visible and infrared wavelengths removed, and dark conditions. The results from these studies will influence the choice of light filtering in windows for buildings such as hospitals where the elimination of pathogens is extremely important.