Category: Poster Presentation

Fabrication of Diffraction Gratings Using Electron Beam Lithography

Presenter: Carly Wright

Mentor: Ben McMorran

Poster: 36

Major: Physics/Math 

Studying electron diffraction using transmission electron microscopy allows us to better understand many different phenomena in physics, particularly conservation of forces and wave-particle duality. To be able to make these observations, we require diffraction gratings on the nanoscale. This can be done with a variety of techniques, but our particular focus is electron beam lithography. EBL is a dynamic method for fabrication and can be used from the micro-scale down to the nanoscale, but for our particular purposes and scale it is somewhat difficult to achieve nicely resolved lines. This technique involves coating a sample with a photosensitive resist that breaks down at the molecular level from the bombardment of electrons and then developing the resist to create physical features. Using this process, we were able to create straight and forked gratings ranging from 100nm pitch to 50nm pitch that can be used to study the behavior of electrons inside of a transmission electron microscope. With some revisions to our technique, we hope to decrease this pitch down to 20nm while maintaining efficiency, which will provide clearer diffraction data.

Brain Training and Cognitive Aging: A Meta-analytic Review

Presenter: Lauren Williams

Co-Presenters: Selina Robson

Mentor: Ulrich Mayr

Poster: 35

Major: Psychology

Cognitive decline is an unfortunate hallmark of aging. Deficits can interfere with daily activities and often come at the cost of living independently. In recent years, “brain training” programs and games have become a popular option for older adults who are looking to sharpen their cognitive skills. However, despite their commercial success, it is not clear to what degree these programs produce generalized effects beyond improvement on the trained skills. To determine the size of generalized training effects, we conducted a meta-analysis of existing training studies that used plasticity-focused practice regimes. Studies were included if they sampled adults aged 50 and older, participants had no cognitive impairment, and they had a control group. This led to a final sample of 32 studies. Preliminary results suggest a small-to-moderate overall effect size. In addition, we found that the effect size declined along the near-to-far transfer continuum as assessments become more dissimilar to training type, and with the sample size of the study. Particularly surprising is the fact that the effect size is negatively correlated with duration of the practice regimen. For far-transfer outcome measures with large sample sizes and long durations of practice, the effect size approaches zero. These results raise doubts about the promise that plasticity-related training regimes effectively counter the broad effects of cognitive aging.

Humanizing the Houseless: Warming a Tent Through Homemade Insulation

Presenter: Stefanie Wibiasa

Co-Presenters: Amber Bass, Marisa Daluro

Mentor: Alison Kwok

Poster: 34

Major: Architecture

The Pacific Northwest’s climate-mild, but with occasional extremes-greatly affects a resident’s satisfaction with his or her particular thermal environment. The primary goal of this study was to help the tent communities of Eugene, Oregon stay significantly warmer during the harsh winter months. To this end, we investigated whether adding a layer of homemade insulation to the floor of a tent would significantly reduce heat loss and better regulate the interior temperature. Group members selected a neutral, unsheltered outdoor venue and set up a small tent similar to one that would be found in a houseless community. Over the course of a 24-hour period (divided into three eight-hour segment), hourly temperature readings both inside and outside the tent were measured and recorded. The first eight- hour assessment functioned as a control period—data taken without supplementary insulation. The second and third eight-hour assessments measured temperature data after various layers of homemade insulation had been added to the interior base of the tent. The study goals were addressed primarily through data logging, quantitative inquiry, and analyzing ideas of thermal comfort.

Tooth Eruption Sequence of Eporeodon occidentalis

Presenter: Kendra Walters

Co-Presenters: Meaghan Emery

Mentor: Edward Davis

Poster: 33

Major: Geology/Biology

Oreodonts lived in North America during the Cenozoic Era and were especially abundant from the Eocene to Miocene Epochs. Despite their abundance, they have no modern descendants. The dentition of fossil oreodonts is often well preserved, including deciduous or “baby” teeth. In order to understand more about oreodont behavior and development, our research examines the tooth eruption sequence for juvenile Eporeodon occidentalis. Tooth eruption sequences differ among groups of animals and reflect their specific life history patterns, including time of weaning and overall lifespan. We created 3D models of the crania of juvenile Eporeodon occidentalis individuals using Agisoft PhotoScan, and examined these models to stitch together the eruption sequence. Interestingly, the eruption sequence showed only the permanent first premolar which means the deciduous first premolar either did not exist or fell out extremely early, possibly before birth. This is a unique feature shared with pigs which may be evidence of a close relationship, similar behaviors, or similar life histories. By comparing the tooth eruption sequences of Eporeodon occidentalis and modern species such as pigs, camels, and sheep, I was able to infer possible life history patterns of Eporeodon occidentalis from known life history patterns of the modern species. In the future, this tooth eruption sequence will be compared to that of other oreodonts to evaluate differences and similarities in behavior, phylogeny, and life histories.

Architecture-Focused Case Study on the Erb Memorial Union Atrium’s Environmental Performance

Presenter: Mauricio Underwood

Co-Presenters: Jiawei Mai

Mentor: Alison Kwok

Poster: 32

Major: Architecture

The Erb Memorial Union acts today as the center of the University of Oregon Campus and is subjected to the most diverse and frequent student traffic. Yet it is one of the oldest, largest, and most poorly insulated buildings on the University of Oregon campus. This research studies the southeast atrium, where many students tend to congregate. The space is well lit due to the expanse of windows covering the entire southeast side of the building and most of the roof. While this allows for plenty of natural light, the single-paned windows also cause enormous amounts of heat loss in the atrium. But does the amount of heat gain through solar-oriented windows compensate for the heat loss during winter months? The result of the temperature data analysis shows that the solar gains in Btu/Hour through the atrium windows is about twelve times greater than the heat loss to the exterior. However, the steam profile of the building indicates that the atrium is still being heated. Our finding suggests infiltration to be the primary source of heat loss, which was initially overlooked in the study. This further indicates the importance of airtightness in the passive cooling/heating of architecture.

Saturating the Neurospora Genome for Mutants Defective in Methylation

Presenter: Calvin Summers

Mentor: Eric Selker

Poster: 31

Major: Biology

Cytosine methylation, a fundamental form of epigenetic regulation, is found in many eukaryotes and plays a significant role in cancer and other diseases. Using the genetically tractable model organism Neurospora crassa, the Selker laboratory has identified genes that when mutated, cause the strains to be defective in methylation (dim). The process of DNA methylation in Neurospora has been shown to be dependent on DCDC, a five member complex that directs the histone methyltransferase DIM-5 to trimethylate Lysine 9 on histone H3 (H3K9me3). This mark is recognized by HP1, which directs DIM-2 to methylate DNA. Another silencing complex, HCHC, employs HDA-1, CDP-2, HP1, and CHAP to deacetylate lysines on the histone. While we know a good deal about DNA methylation, it is still unclear whether we have identified all genes involved in the process. Thus this research focuses on our search for dim mutants, and asks whether our current model for DNA methylation is saturated. Using a selection for reactivation of resistance genes silenced by DNA methylation we aimed to answer this question. Interestingly, we predominantly identified known dim genes, including dim-5, dim-7, dim-8, dim-9, chap, cdp-2, and hda-1, suggesting our model may be saturated. We localized mutations in these known dim genes by DNA sequencing. The dim mutant collection generated should be a useful resource for further investigation into the roles of these genes and their protein products in DNA methylation. Understanding epigenetic pathways in Neurospora is an auspicious first step in elucidating mechanisms of complex genetic regulation in our own cells.

University of Oregon’s Environmental Leadership Program: Critters and Currents Environmental Education Team

Presenter: Makenzie Shepherd

Mentor: Katie Lynch

Poster: 30

Major: Environmental Studies

The prominence of technology and urbanization in the 21st century has established a concrete distinction between the urban and natural worlds. Younger generations, increasingly disengaged and separated from their local natural environments, are exhibiting symptoms of what is colloquially called “nature-deficit disorder.” Marked by rising levels of ADD/ADHD, obesity, depression, and muted creativity, nature-deficit disorder reflects a concerning trend that will accelerate if not immediately and holistically addressed. As the 2014 Critters and Currents team of the Environmental Leadership Program at the University of Oregon, it is our mission to bridge the gap between youth in Eugene, OR and their environment by inspiring them to form connections with the McKenzie River Watershed. Our place-based environmental education curriculum emphasizes hands-on learning by providing creative, collaborative, and physically active lessons that challenge our students to engage the senses and think critically about the local environment and our interdependence with it. Scavenger hunts, field journaling, and storytelling are all activities that empower our students with the attitudes, skills, knowledge, and confidence to create and maintain a strong bond with nature. It is crucial that younger generations restore this connection because our youth have the potential to transform the ways in which our society views and interacts with nature. The Critters & Currents curriculum promotes environmental awareness, inspires respect and compassion for the natural world, and encourages positive environmental action now and in the future.

Women and Glaciers: Perspectives on Climate Change Vulnerability, Identity, and the Professional Sphere

Presenter: Jaclyn Rushing

Mentor: Mark Carey

Poster: 29

Major: Environmental Studies/Romance Languages

Women and glaciers appear to be disparate subjects and academic literature has yet to investigate the relationships between them. However, women’s relationships with glaciers can inform many important intersections of gender inequality in sport, science, culture, and environmental climate change. Historically women’s global interactions with glaciers helped them connect to place and self through spirituality, culture, mountaineering, and glaciology. Women have recorded their strong emotional and spiritual connection with glaciers in poems, oral traditions, religious stories, and autobiographical essays. But in recent decades, climate change has altered and complicated women’s interactions with glaciers. On the one hand, studies show that rapid glacier retreat has marginalized and disempowered women, because of increased natural disasters like glacial lake outburst floods, unpredictable water availability, and ecological loss. These hazards pose major threats to Himalayan and Andean mountain communities, especially for already culturally marginalized and impoverished women in those regions. On the other hand, climate- triggered ice loss has created unique opportunities for women to increase their participation in science, conservation, and politics. Historically marginalized women in the Himalayas and Andes are leading their own forums on climate change and disaster mitigation. More international aid agencies are reaching out to women and seeking women’s input in disaster mitigation and relief. Women in science are increasing their presence in the male-dominated field of glaciology largely because of growing academic gender tolerance, but also because climate change provides the occasion to study glacier retreat. Recent rapid glacier retreat thus complicates women’s experience by increasing their climate vulnerability while simultaneously providing them with opportunities to assert themselves in their communities.

Effects of the Aquatic Contaminant Perchlorate on Expression of NIS Clade Genes in Divergent Populations of Threespine Stickleback

Presenter: Amanda Redmond

Mentor: William Cresko

Poster: 28

Major: Biology

Perchlorate is a known endocrine disruptor and a wide spread environmental contaminant that causes hypothyroidism in humans. Our previous work demonstrated that perchlorate results in a masculinizing effect in anadromous threespine stickleback (Gasterosteus aculeatus), but it is not known whether ecotypes of stickleback respond differently to this contaminant. Perchlorate has a known effect of suppressing thyroid hormone synthesis by competitively inhibiting the sodium-iodide symporter (slc5a5). The large slc5 gene family is associated with thyroid function and vitamin/mineral transport in all vertebrates. Using bioinformatic approaches we have identified that
there are several closely related genes to slc5a5 in stickleback including slc5a6a, slc5a6b, slc5a8a, and slc5a8b.
We investigate the effect of perchlorate on developmental gene expression in three genetically diverged populations of stickleback from Rabbit Slough (oceanic), Boot Lake (freshwater), and Riverbend (freshwater) ecosystems. We have developed RNA anti-sense probes for the NIS genes that we will be using for gene expression analysis using in situ hybridization to document the spatio-temporal expression of slc5a6a, slc5a6b, slc5a8a, and slc5a8b genes in each ecotype in response to perchlorate exposure. Because evolutionarily diverged populations of stickleback living in different habitats have different osmoregulatory and developmental nutrient needs, we hypothesize that a single chemical that affects solute transporters may have variable developmental effects among populations. In a preliminary study, we have mapped the temporal and spatial distribution of these genes in Rabbit slough (oceanic) fishes, and have found that they are expressed starting at 8-10 days in numerous tissues including the thyroid and the gonad. Our goal next is to identify gene expression patterns of the slc5 genes in the thyroid and gonad at 8, 14, and 30 days post fertilization (dpf) in the diverged populations, and to test for changes in spatial or temporal expression of the genes based on population, perchlorate treatement, and/or an interaction of both. We hypothesize that a gene by environment interaction (G-by-E) will lead to unique patterns of slc5a5 clade gene expression response to perchlorate in each of the three populations. Using cryosections of both control and 100ppm perchlorate treated fish we will determine the expression of these genes at 8, 14, and 30dpf. Our study will be relevant to understanding more about effects of toxin exposure between very genetically divergent populations of fish and other vertebrates, including humans.

CO2 Got Me Feeling So Blue?

Presenter: Lindsay Rasmussen

Co-Presenters: Katie Bushman, Parisa Motahari-asl

Mentor: Alison Kwok

Poster: 27

Major: Architecture 

This case study measures the carbon dioxide levels in the Architectural Design Studios of Pacific Hall, focusing on room 223. The current number of occupants in this room exceeds the original design intent; nevertheless, the original variable-air-volume ventilation system continues to be used. This case study investigates whether a larger occupancy number raises the carbon dioxide levels past the ventilation system’s capacity to function at ASHRAE Standards. For a contextual comparison a control room in a newly renovated building was also studied. The principal hypothesis for this case study is that the amount of CO2 in Room 223 of Pacific Hall exceeds the maximum levels as defined by ASHRAE Standard 62.1-2010. Three CO2 monitors were placed directly at the primary vent, at desk level, and outside at the air-intake system. CO2 levels were recorded at the same time for 30 minutes in 30-second increments. This experiment was repeated twice per room, once with high-occupancy and once with low-occupancy. Our results show that CO2 levels did not exceed maximum levels in either room. Instead of being an air quality issue, we found there to be a thermal comfort issue in Pacific Hall. However, due to the state of the building and its prior use as a chemical lab, we still believe there to be an air quality issue that we could not account for in this experiment. Carbon dioxide is measured as an indicator of building air quality; however, the results of our experiment lead us to question whether or not CO2 is an accurate representative of overall indoor air quality. This experiment serves as a strong foundation for further research into indoor air quality.