Tag: Science

Synthesis of Diindenoanthracene Derivatives for use in Organic Field-Effect Transistors

Presenter: Victoria Stanfill

Faculty Mentor: Michael Haley, Geri Richmond

Presentation Type: Poster 39

Primary Research Area: Science

Major: Chemistry

Funding Source: Presidential Undergraduate Research Scholars Program, $5000

Organic field-effect transistors (OFETs) are a type of organic electronic device that determine how and where charge flows throughout a system. They are important to the electronic industry because they are longer lasting and cheaper to synthesize than traditional silicon field-effect transistors. OFETs are ranked on their charge mobility, the speed and quality of the charge transfer. Diindenoanthracenes are a type of organic small molecule with potential to be used in OFETs because of their biradical character, giving them the ability to transport charge. Our research focuses on synthesizing a variety of diindenoanthracene derivatives so we have a large range of molecules with different electronic properties to test in devices. The ultimate goal is to increase the charge mobility of these molecules so that these electronic devices are comparable to traditional inorganic electronics. So far we have created one new diindenoanthracene which has yet to be tested in devices, but we are working towards creating a more generalized synthesis method to make it possible to add a variety of substituents to the general diindenoanthracene scaffold.

Missing Transverse Momentum Trigger Performance Studies for the ATLAS Calorimeter Trigger Upgrades

Presenter: Brianna Stamas

Faculty Mentor: Stephanie Majewski, Geraldine Richmond

Presentation Type: Oral

Primary Research Area: Science

Major: Physics

Funding Source: Presidential Undergraduate Research Scholars Program, UO Undergraduate Research Opportunity Program, $5,000

A basic question about our universe remains unanswered: what is everything fundamentally made of? Everything we know of only makes up 4% of the universe; a significant fraction of the remaining 96% is made of an unknown fundamental particle referred to as dark matter. In an attempt to identify the dark particle, the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland is recreating the conditions of the Big Bang. The ATLAS Experiment is one of two general purpose detectors at the LHC. In anticipation of discovering new physics, the ATLAS detector will undergo numerous hardware upgrades in the coming years, one of which will be an improvement to the existing trigger system which is a 3-level hardware and software based system. This study focuses on the upgrades to the level-1 trigger. The LHC collides bunches of protons every 25 ns, which amounts to a lot of data in an extremely short period of time. Specifically, the missing transverse energy (ETmiss) trigger is crucial in being able to detect a previously undetectable particle. Therefore, we propose implementing a topological clustering inspired algorithm on the level-1 ETmiss trigger. The algorithm will be employed on the gFEX (global feature extractor) with 0.2×0.2 eta-phi granularity to be installed in 2019. This study analyzes the performance the algorithm for future implementation.

Investigating Iron Oxide Nanoparticle Growth via Slow Injection Synthesis

Presenter: Alexia Smith

Co-Presenters: Susan Cooper, Jim Hutchison, Darren Johnson

Faculty Mentor: Darren Johnson, Susan Cooper

Presentation Type: Oral

Primary Research Area: Science

Major: Chemistry

Funding Source: Presidential Undergraduate Research Scholarship, University of Oregon, $5000

Nanoparticles have been studied for decades due to their optical, chemical, and magnetic properties, leading to a vast array of applications from nanocatalysts to contrast agents in magnetic resonance imaging. Nanoparticles are simply small-scale particles ranging from 1-100 nm in size, roughly the size of the tip of a sewing needle. The given size of nanoparticle plays an important role in their application, as many nanoparticles have size-dependent properties. In particular, magnetic iron oxide nanoparticles offer promise in technological applications such as magnetic inks or precursors for magnetic media devices. In order to effectively synthesize selectively-sized, monodisperse iron oxide nanoparticles, an understanding of their growth mechanisms is necessary. Currently, the parameters to produce selective iron oxide nanoparticles are extensive and each approach has its complications. The synthesis of nanoparticles has been studied extensively in the Hutchison lab in order to understand how to optimize their chemistry, size, and structure. Recent work has shown that a slow-injection synthesis versus a hot injection synthesis produces more monodisperse particles and is a greener method of synthesis. Additionally, particle size is directly related to synthesis temperature, and increases linearly as temperature increases. Many other conditions have been tested to see how the growth of particles is affected: air flow, environment, glassware, precursor used, and volume. Understanding these specific parameters enables synthesis selectivity in order to optimize the nanoparticle size desired for a given application.

Center of Mass Displacement with a Rigid Ankle-Foot Orthotic in Healthy Individuals

Presenter: Spencer Smith

Co-Presenters: Therese Wichmann, Shannon Pomeroy, Michael Hahn,

Faculty Mentor: Shannon Pomeroy, Michael Hahn

Presentation Type: Poster 83

Primary Research Area: Science

Major: Human Physiology

Ankle arthritis is inflammation of the articular cartilage, resulting in pain, stiffness and diminished quality of life. Ankle arthritis is often treated with a complete artificial fusion of the affected bones and removal of the damaged cartilage, which can lead to significantly altered gait and further long-term complications. Rigid ankle-foot orthotics (AFOs) have been used in similar clinical populations to stabilize the joint; however, they have been shown to retain many gait characteristics and improve stability despite limiting ankle range of motion (ROM). In order to better understand how the body adapts to such a sudden and severe limitation of ankle ROM, we performed a gait analysis on 16 healthy individuals within the lab. Each subject went through a normal baseline walking trial on the treadmill followed by a 30 minute walking trial in which they were equipped with a rigid AFO. We used motion capture cameras to collect the 3D motion of strategically placed reflective markers. Subsequently, whole-body marker position data was used to calculate and observe the subjects’ center of mass between walking without an AFO and with an AFO over time. Preliminary data analysis indicates that a rigid AFO may result in increased COM displacement with a range less than baseline following 30 minutes of AFO acclimation, suggesting that an AFO leads to return to more normal gait given an acclimation period.

Dust Microbial Communities Have Dosage-Dependent Responses to Daylight

Presenter: Andrew Siemens

Faculty Mentor: Jessica Green, Erica Hartmann

Presentation Type: Oral

Primary Research Area: Science

Major: Biology

Funding Source: UO UnderGrEBES Research Grant, University of Oregon Institute of Ecology and Evolution, $500; UO Undergraduate Research Opportunity Grant, UO Undergraduate Research Opportunity Program, $1000

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 daylighting, specifically UV vs. visible light, on the viability of the dust microbiome. We collected dust samples and treated them with varying doses of broad-spectrum light. Using a method we developed to quantify the viability of microbes in dust, we determined the amount of DNA from live vs. dead cells by comparing 16S ribosomal gene copy numbers in each sample. The results from broad-spectrum light exposure revealed a decrease in dust viability as the amount of total light exposure increases. Subsequently, the relationship between different wavelengths of light and bacterial viability was tested by subjecting dust samples to sunlight with UV wavelengths removed, sunlight with visible and infrared wavelengths removed, and dark conditions. We achieved a gradient of lighting conditions that will help us determine whether the effect of daylighting on viability is impacted by UV light as compared to visible light. The results from this research could influence the choice of light filtering in windows for buildings such as hospitals where the elimination of pathogens is extremely important.

Rpb1 Mutations and Interactions with Backtracked RNA in RNA Polymerase II in Yeast

Presenter: Mandi Severson

Faculty Mentor: Diane Hawley

Presentation Type: Poster 82

Primary Research Area: Science

Major: Biology, Human Physiology

Funding Source: NICHD Summer Research Program, National Institutes of Health, $3800

RNA Polymerase II (RNAP II) is an enzyme that catalyzes the synthesis of all mRNA in eukaryotic cells. The Rpb1 subunit participates in RNA elongation in the active site of the enzyme. However, residues in Rpb1 have also been identified as having a potential role in backtracking and arrest. Backtracking occurs when RNAP II moves backward along the DNA, causing the 3’ end of the RNA to dislodge from the active site and bind to nearby RNAP II residues. If the polymerase has not backtracked extensively, RNAP II can spontaneously resume transcription; however, if the polymerase has backtracked too much, elongation stops and RNAP II arrests. This study focuses on creating mutations in Rpb1 residues that interact with backtracked RNA. The point mutations being investigated change nucleophilic amino acid residues into residues that theoretically should have reduced ability to bind to backtracked RNA. If RNAP II residues and backtracked RNA are interacting this way, it may induce less extensive backtracking and decreased incidence of arrest. Currently we are using site-directed mutagenesis to create and isolate mutants, which are then tested in transcription assays to observe the effects on speed and incidence of arrest of RNAP II. Mutants are still being isolated and tested at this time. Results from this study will contribute to our knowledge about backtracking and its function in the transcription cycle, which could help us combat viral proliferation and genetic disease.

630 ka Lava Creek Tuff Exchange with Isotopically Labeled Water: Testing the Stability of D/H Paleoenvironmental Signals

Presenter: Abigail Ross

Faculty Mentor: Angela Seligman, Ilya Bindeman

Presentation Type: Poster 35

Primary Research Area: Science

Major: Geology

Funding Source: UROP Mini-Grant Recipient, $1000; Department of Geological Sciences

Studies focused on paleoenvironments are becoming increasingly popular and relevant as we begin to understand future climatic patterns through studying those of the past. Isotopic ratios of hydrogen and oxygen of volcanic glass that has been hydrated by surrounding environmental waters have been used as paleoclimate indicators through inferring the isotopic values of past meteoric waters. By testing the exchange of hydrogen and oxygen isotopes

of hydrated volcanic glass with surrounding water, we analyze the validity of this method. This project focuses specifically on the element of age, evaluating if a significant difference in deposition time makes a difference in the isotope’s ability to re-equilibrate, as was suggested by Cassel et al. (2014).

Nolan and Bindeman (2013) placed hydrated ash from the 7.7 ka eruption of Mt. Mazama in isotopically labeled water and observed that the H2O and d18O values remained constant, but the dD values of ash increased with the surrounding water, INDICATING THAT XXX. My research expands on this work by conducting the same experiment, but with ash from the 630 ka Lava Creek Tuff eruption of Yellowstone to see if significantly older glass produces similar results. Preliminary data show that exchange of hydrogen isotopes of hydrated glass is not limited by the age of the glass, and that the use of hydrogen isotopes of secondarily hydrated glass may not be a reliable paleoclimate indicator.

Hyenas through Space and Time: Using Teeth to Study Changing Ecological Niches

Presenter: Selina Robson

Faculty Mentor: Samantha Hopkins, Win McLaughling

Presentation Type: Oral

Primary Research Area: Science

Major: Geology, Psychology

Funding Source: Presidential Undergraduate Research Scholarship, University of Oregon $5,000; UROP Mini- grant, University of Oregon $1,000; Walter Youngquist Scholarship, Department of Geology at the University of Oregon, $1,500

The four modern hyena species are some of the most specialized carnivores on the planet. Three hyena species are bone-crushers—the only living mammals that are specialized for this—and one species is an insect eater, feeding on social insects such as termites. Hyenas are uniquely adapted for both of these diets. However, little is known about how hyenas evolved these capabilities. Unlike their modern relatives, the earliest hyenas were small omnivores that consumed plant material as well as meat. Some of these ancestral hyenas developed more carnivorous traits and eventually became the bone crushers we are familiar with today. We can study the evolution of hyena diets, and by extension hyena ecological niches, by examining the shape and proportions of their teeth. I have applied this method to a hyena species recently discovered in Kyrgyzstan. The new hyena, currently designated as Hyaenictitherium sp. nov., has transitional dentition indicating an omnivorous but meat-dominated diet. The hyena was alive approximately 7 million years ago, making it a relatively young species. I am examining the ecological niche of this new hyena and determining how the specimen enhances our understanding of hyena evolution. Then, I am looking at other hyena species to determine if hyenas are following previously hypothesized patterns of dietary and ecological change.

Design and Synthesis of a Nitrogen Binding Molecule for Natural Gas Purification

Presenter: Nicholas Rinehart

Faculty Mentor: Dave Tyler, Justin Barry

Presentation Type: Oral

Primary Research Area: Science

Major: Chemistry

Funding Source: Presidential Undergraduate Research Scholarship, UROP, 5000; SAACS Scholarship, SAACS, 500

Natural gas provided 28% of total energy consumption during 2014 in the United States. Nearly 20% of domestic natural gas wells are contaminated with nitrogen gas, making them unsuitable for use in natural gas burning equipment. Current methods of purification have a large cost, so they are often infeasible. A more feasible purification method is necessary to reduce the cost of purifying contaminated natural gas reserves and dependence on expensive imported natural gas. The Tyler Lab has demonstrated that a certain type of molecule called a coordination complex, which in this case contains phosphine ligands and a central iron atom, can serve as a nitrogen gas sorbent. Since the previous coordination complex bound nitrogen, but degraded too quickly to be applied in industry, current work is focused on creating a longer lived version of this molecule by redesigning the ligands bound to the central iron atom. Progress on the synthesis of this new coordination complex will be presented.

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.