Category: 2013

Variation Through Tooth Wear Obscures the Differential Diagnoses of the Fossil Beavers Dipoides stirtoni and Dipoides smithi

Presenter : Savannah Olroyd

Mentor : Sam Hopkins

Major : Biology

Poster 30

Diagnostic features that show variation can be problematic when their variation interferes with clear distinction between species. Fossil identification can be further confounded when highly variable supposedly diagnostic dental characters change with tooth wear. The fossil beavers Dipoides stirtoni and Dipoides smithi are distinguished from one another by the presence or absence of striations on the fourth premolars. D. stirtoni has a parastria running down the cheek side of the upper P4 and a parastriid on the tongue side of the lower p4 in all wear stages. D. smithi lacks the parastria and only occasionally has a parastriid in later wear stages.

We have reviewed this diagnosis by examining over 200 cheek teeth of both species. No well-worn upper P4s of D. smithi have a para- stria, but the parastria is present in the earlier wear stages of all upper cheek teeth. Approximately 25% of the lower p4s of D. smithi studied have a parastriid in later wear stages, and one D. stirtoni lower p4 had no parastriid. We investigated other dental characters to see if other features were diagnostic to these species. The two are indistinguishable in tooth size, molar shape, and wear stages. The cur- rent diagnosis makes confident identification of new specimens difficult unless the specimen includes a well-worn upper P4. Complex series of tooth wear can produce a large amount of apparent dental variation in mammals with high-crowned teeth. Caution should be taken when using dental characters to assign diagnoses to such taxa.

Evaluating 2D and 3D Methods of Measuring Fluctuating Asymmetry of Primate Skulls

Presenters : Colin Oliveira, Lauren Moore

Mentor : Frances White

Major : Anthropology

Poster 36

Morphological fluctuating asymmetry (FA), particularly cranial FA, can be used as an indicator of past developmental instability or environmental stress. Primate FA has been measured using a variety of two and three dimensional methods either directly from speci- mens or from images. We compared the effectiveness of three methods of calculating FA: Microscribe readings of three dimensional landmarks on the specimen, two dimensional landmarks measured from photographic superimposition using tpsDig, and linear distances using digital calipers on the specimen. Three observers used each of the three methods on two Macaca fuscata skulls, one that appeared asymmetrical and one that appeared symmetrical, using 5 midline points and 7 bilateral points for 5 replicates. Measure- ments taken by each method were compared between the two specimens. Measurement in 3D space via Microscribe exhibited no sig- nificant interaction term, no significant difference between observers (F=1.22, df 2,24, p=0.3119), and significant difference between specimens (F=5.56, df 1,24, p<0.05). Measurement of 2D distances from photographs via tpsDIG exhibited no significant interaction term, significant difference between observers (F=9.78, df 2,24, p<0.001), and significant difference between specimens (F=10.80, df 1,24, p<0.01). Measurement of linear distances via digital calipers exhibited no significant interaction term, no significant difference between observers, and no significant difference between specimens.

Synthesis of a Water-Soluble Macrocyclic Iron-Phosphine Complex

Presenter : Aditya Nathan

Mentor : Bryan Nell

Major : Biochemistry

Poster 7

Although society is progressing towards increased dependency on alternative sources of energy, natural gas remains as the one of the most relied upon sources of energy. A major contaminant of natural gas is dinitrogen. Our research focuses on the synthesis and characterization of a water-soluble macrocyclic iron-phosphine complex that is capable of reversibly binding dinitrogen. Our intended method for developing such a complex involves a multistep process beginning with a template synthesis, which involves the coordina- tion of open-chain phosphine ligands to a transition metal atom (specifically Ni(II), Pd(II), or Pt(II) for the sake of square planar geom- etry). Subsequently, the components would be linked/bridged together using base and an alpha/omega dihalide to form the macrocycle. The complex would then be demetallated using cyanide ion or a sulfide source and subsequently coordinated to Fe(II). In order to confer the complex with water-solubility, we plan on adding water-soluble functional groups to the side chains of the macrocycle. Thus far, we have been able to synthesize and characterize key intermediate complexes that serve as the precursor for the macrocycles. In addition, we have investigated methods for macrocyclizing the intermediate complexes.

Examination of Executive Function Measurements in Healthy Adolescents and Young Adults

Presenter : Madison Murray

Mentor : Li-Shan

Major : Biology

Poster 42

Executive function has been defined as the ability to utilize external stimuli in order to plan purposeful action. It is thought to be im- portant for tasks like problem solving and decision-making. As the adolescent brain has not yet reached full maturation and is under- going rapid development particularly in the frontal lobe, where executive function is considered to take place, it may be vulnerable to trauma during this time of life. Due to the continued development of the frontal lobe in the adolescent brain it was hypothesized that healthy adolescent individuals would have decreased executive function ability when compared to healthy young adults. The Attention- al Network Test and the Task Switching Test were administered to 14 healthy individuals (7 adolescents, 7 young adults) five times over a period of two months. Testing was carried out 1 week, 2 weeks, 1 month, and 2 months after the initial testing. Testing was performed in a computer lab to free from noise or visual distractions. Young adults displayed faster overall reaction times, however contrary to our hypothesis; preliminary data has shown that adolescents have increased executive function ability compared to young adults. Further research will examine the effects of concussion of the adolescent brain compared with an adult brain. In order to make an accurate comparison between concussed individuals we must first compare healthy individuals.

Investigating the Effect of Heat Shock on Lifespan and Gene Expression in C. remanei

Presenter : Sarah Mete

Mentor : Patrick Philips

Major : Human Physiology

Poster 3

Low doses of various stressors have been shown to slow the process of aging and increase tolerance to future stress in numerous organ- isms, a phenomenon known as hormesis. Previous studies conducted using C. elegans have examined heat-induced hormetic effects on lifespan; however, the presented data is conflicting and inconclusive. Studying the hormetic response to sub-lethal heat shock in C. remanei can help us understand the underlying mechanism of hormesis and its effect on lifespan in a new model organism. We pre- dicted that exposing an outbred population of C. remanei to either a mild heat stress, an acute heat shock or a combination of the two would produce a hormetic response in lifespan, observing the most beneficial response in those exposed to both treatments. The worms were raised either at 20°C, or exposed to a mild heat stress of 30°C during larval development. A subset of worms from each group were then subjected to a 36.8°C heat shock for 1 hour. We measured lifespan for each group in adult, virgin females maintained at 20°C. Surprisingly, no significant differences in lifespan were observed across the various conditions. These results stimulated the idea of us- ing RNA-sequencing to evaluate changes in gene expression to explain why no response in lifespan was observed. The sequencing data illustrated significant changes in gene expression associated with both the mild and acute heat treatments, indicating a large enough change to compensate for the heat stress but not enough to affect lifespan.

Reoccurring Goal Monitoring Display Design: Effects on Completion Rates, Motivation, and Emo- tional Affect

Presenter : Molly Martini

Mentor : Sara Hodges

Major : Psychology

Poster 24

Reoccurring goals, such as exercising every other day, are important for health and work-life balance, yet seem to be quickly disre- garded as soon as other deadlines and daily stressors enter our lives. Given that information presentation affects how one processes and acts upon the information, could a different display design other than a standard weekly planner increase an individual’s chances of completing his or her goals? Specifically, could a visual object display lead to increased motivation and more goal completions com- pared to a text based display? Three different goal monitoring tools were created to answer this question: an Android app that shows goals as squares that visually stretch out as goal deadlines approach, another Android app that lists the goals and their deadlines by text, and a paper planner consisting of two calendar weeks. Participants were randomly assigned one of these three tools and asked to monitor their own reoccurring goals for two weeks, completing nightly questionnaires asking about motivation level, goal completion, and affect. It is predicted that the visual app will lead to more goal completions, higher motivation, and higher levels of both positive and negative affect compared to the two text conditions. Data analysis has yet to take place, but will be completed by May 16, 2013. Importantly, the study may suggest new ways in which display design can be utilized to help people achieve personal reoccurring goals.

What’s in my Dust? Communicating Research Findings to Agricultural Families

Presenter : Rossmary Marquez

Major : Human Physiology

Poster 29

The collection of environmental samples represents a responsibility to return study findings to participants. However, developing appropriate and understandable messages can be challenging due to language differences and cultural differences. A previous study collected information from families living in an agricultural community about ways they may be exposed to pesticides and the impact of pesticides on the health and neurological development of their children. A total of 483 dust samples were collected over 4 years. The dust samples collected were analyzed for four organophosphate pesticides. The goal of this study was to evaluate different formats for presenting study findings to participants. Material presenting the results of pesticide concentration was developed along with materials describing methods to reduced exposure. A pilot study was designed to determine which format should be used and questions were designed to evaluate knowledge and reaction to the data. English speakers and Spanish speakers were recruited for the study. It was determined that education and language impacted people’s ability to read and understand the graphs. Higher education was associated with higher quiz scores. English speaking group scored higher. Finding the best ways to return results is still a challenge. Feedback received form the community members was utilized to design an effective and appropriate intervention material to reduce pesticide exposure and inform the families about the pesticides levels found in their homes.

Molecular Evolution of Indian Hedgehog Following the Teleost Genome Duplication

Presenter : Ryan Loker

Mentor : Ingo Braasch

Major : Biology

Poster 26

Indian Hedgehog(IHH) is a signaling molecule that acts in several important developmental processes in vertebrates including gut, vascular, and skeletal development. Duplicated(paralogous) copies of the ihh gene have been retained in the teleost fish lineage, ihha and ihhb, following the teleost genome duplication(TGD). The mechanisms of evolution following a whole genome duplication are not completely understood, but one possible reason that ihh and many other duplicates remain in the teleost genomes is
that each paralog carries out essential sub-functions of the ancestral pre-duplication gene, following the Duplication-Degeneration-Complementation(DDC) model. Investigation of this mechanism requires characterization of the regulatory elements controlling expression of ihh genes in teleosts as well as the ancestral state, which can be represented using spotted gar(Lepisosteus oculatus), a member of a sister group to teleosts with an unduplicated genome. Here, we use a comparative genomics approach to compare the ge- nomes of several teleosts and gar in order to identify ancestral conserved non-coding elements(CNE) representing possible regulatory elements, and test their functionality in vivo using transgenic reporter constructs in zebrafish(Danio rerio). In addition to the insight of the evolutionary mechanisms, characterizing enhancers of ihha and ihhb will provide an opportunity to further characterize the role of these genes in developmental pathways, which are commonly conserved throughout vertebrates including humans.

Tour de Fans: An Exercise in Comfort

Presenters : Erik Larson, Kyle Stuart-Willis, Robert Nicholls

Mentor : Alison Kwok

Major : Architecture

Poster 23

We are architecture students at the University of Oregon investigating into the Environmental Control Systems of an architectural space and the level of success for their implementation. This study analyzed the UO Rec Center’s spinning (stationary bike) exercise room and how human activity affects environmental conditions. By studying the temperature and relative humidity during a class we were able to understand human-generated heat in a room and apply more ventilation equipment in order for the room to remain in the architecturally-defined “comfort zone” (defined by ASHRAE standard 55) for a longer period of time. We hypothesized that a third fan added during a spin class would increase the time spent in the comfort zone by 20%. The study took place over 2 weeks to gather data with multiple controlled variables. Devices known as HOBO data loggers took intermittent measurements of the classroom’s temperature and relative humidity We concluded that the implementation of a third fan dramatically increased the classroom’s circulation, resulting in highs up to 46% lower in temperature and 35% lower in relative humidity. Our investigation shows that proper research of the ventilation/air circulation of an architecturally-designed space results in a more pleasant environment for users and a greater contribution to society for the architects involved. We also learned that participating in multiple spin classes leads to great glutes.

Alkaline Synthesis of Amidines – A New Approach to Preparing Medicinally Relevant Small Molecules

Presenter : Muhammad Khalifa

Mentor : Michael Haley

Major : Biochemistry

Poster 16

Myotonic dystrophy (DM) is the most common adult form of muscular dystrophy. Recently, the small molecule pentamidine has been shown to relieve symptoms of DM in cell models; however, pentamidine is an inadequate drug for DM because of toxicity and bioavailability problems. Analogs of pentamidine, generically termed amidines, have proven to be significant candidates in the search for an effective cure for DM. It is therefore important to have access to the widest possible range of amidine structures for study against symptoms of DM. Existing methods of synthesizing amidines have largely depended upon reactions with acidic con- ditions; features of these reactions have limited the accessible range of amidines, especially substituted amidines. Here we outline a new method of preparing substituted amidines using alkaline conditions that features shorter reaction times, better yields, and better compatibility with many of our compounds of interest. Through synthesis and NMR characterization, we explore the range of usable starting materials, test the method’s selectivity in the presence of competing reactions, and demonstrate its application to the synthesis of several novel compounds. This method makes possible a host of new substituted amidine compounds that could prove useful in the search for a cure for DM, and provides a new, potentially more efficient, synthetic path to unsubstituted amidines for the same purpose.