Category: 2013

Ducks Quacking – UO Network Characterization with NetFlows

Presenter : Ricky Kerndt

Major : Computer Science

Poster 35

“Intra/Inter-network traffic has become an important part of our daily lives. Its become a primary means of communication through email, messaging, and social networks (e.g. Facebook, Twitter). The University of Oregon represents a small community environment encompassing student housing and the daily activity of classes, staff and professors carrying out research, administration and services to keep the campus functioning. The University’s network backbone thus provides a potential data source for studying how society uses internet applications in their daily activities. This project evaluates the potential of using anonymized netflows obtained from the UO Network and Telecom Services (NTS) to characterize network activity. Netflow records are provided with local addresses anonymized from UO border routers to preserve confidentiality. The records are aggreagated and stored in a database for later characterization of network activity. The characterization includes packet rate!

s, bandwith utilization, applications (unique ports), and distribution of destination IP address. We can then look at how this charac- terization differs with different areas of campus (dorms, offices, wifi) and temporal patterns. The results show that netflow records will provide a valuable data source for studying how a community setting uses internet applications in carrying out their daily activities.

Biomechanical Changes in Obstacle Crossing During Walking Following Concussion in High School Athletes

Presenter : Michael Kado

Mentor : Li-Shan Chou

Major : Human Physiology

Poster 20

Approximately 136,000 sports related concussions are diagnosed within the high school athletic population annually with little known about the longitudinal impairments that follow. The objective of this study was to investigate the longitudinal effects of concussion on gait during an obstacle-crossing task. Concussed subjects (n=20) were diagnosed by a physician or certified athletic trainer. Control subjects (n=20) were matched by height, weight, age, and sport participation and examined in similar time increments. Gait variables examined were average walking speed, step length, step width, cadence, and obstacle clearance height during an obstacle-crossing task. Subjects were tested at 72 hours, 1 week, 2 weeks, 1 month, and 2 months post-concussion. We hypothesized that concussed subjects would have decreased average walking speed, step length, cadence, obstacle clearance height, and increased step width compared to control subjects. Motion data was collected using 29 reflective markers and a 10-camera motion analysis setup. Subjects were instructed to walk over an obstacle set at approximately 10% of their height. Of the five variables investigated, step length and width showed the greatest differences between groups. Step length of concussed subjects was less than control subjects over the two months. Additionally, step width of concussed subjects was greater over the two months following injury. These results suggest altered walking performance while crossing obstacles in concussed individuals while recovering.

Tracing the Endocardial Cell Lineage of Developing Heart Valves Using MADMMatter Pools?

Presenter : Amy Jones

Mentor : Kryn Stankunas

Major : Biology, Human Physiology

Poster 15

Heart valve development is a complex, multi-step process. During development, endocardial cushions form at specific locations in
the early heart tube. These cushions are populated by endocardial cells that delaminate in a process known as epithelial-mesenchymal transformation (EMT). In the mouse, EMT takes place between embryonic day 9.5-10.5. It is a vital process to understand since the heart valves are derived from this cardiac cushion tissue. Current models of cushion EMT suggest that a large number of endocardial cells undergo EMT. An alternative hypothesis is that only a few individual cells initially populate the cushions that then proliferate to expand cushion mesenchyme.To better understand how endocardial-derived cells contribute to heart valves, I am using a novel mouse genetic system termed MADM (mosaic analysis with double markers). MADM uses the Cre-lox system to permanently label specified cells by fluorescent protein expression. For my studies, I use the Tie2 promoter to direct Cre expression and instruct the MADM system to specifically trace the endocardial cell lineage. The low frequency by which labeled cells are generated allows me to exquisitely moni- tor contributions of clonally-related endocardial cells to developing valves. By gaining a complete understanding of the contribution of endothelial-lineage cells to developing valves, we can identify when embryonic heart malformations originate, supporting the development of therapeutics to prevent defective valves from progressing to a diseased state.

AICAR Administration Promotes a Cytoprotective and Pro-Angiogenic Stimulation in an Ex Vivo Model of Placental Ischemia

Presenter : Sarah Johnson

Mentor : Jeffrey Gilbert

Major : Biology/Human Physiology

Poster 28

The pregnancy-specific hypertension known as preeclampsia (PE) is widely observed worldwide and is recognized as a leading contributor to sickness and death of a mother and her baby. This pervasive condition is yet to be fully characterized, as is an effective therapy of symptom relief outside of inducing early delivery. We have recently reported treatment with an adenosine-mimetic, AICA-riboside (AICAR), in an experimental model of PE reduces the onset of PE-like characteristics; however, the underlying mechanisms are poorly understood. Therefore, our hypothesis was AICAR would initiate cytoprotective and pro-angiogenic stimulation in cultured placental tissue explants, and this effect would be mediated by the adenosine (ENT1/2) transporter. Tissues were cultured at 37°C for 12 hours in physiologic normoxic (8% O2) or hypoxic (1.5% O2) conditions, and treated with AICAR (2mM) and an adenosine transporter blocker (dipyridamole, DPM) (100μM). Explants treated with AICAR exhibited a decreased (P<0.05) secreted sFlt-1 in both O2 conditions, and DPM blocked this effect. The energy regulatory protein AMPKα phosphorylation was elevated in the tissues treated with AICAR, but was not statistically significant (0.1>P>0.05). Through modeling placental ischemia ex vivo, we have demonstrated AICAR decreas- es placental secretion of sFlt-1, mediated by adenosine transport activity. In concert with our previous in vivo studies with AICAR, this study further supports a placental specific mechanism of AICAR’s actions in vivo.

Carbon and Nitrogen Mineralization in a Manipulated Northern Hardwood Forest Soil: Do Plants’ Allocation Strategies Help Set the Size and Responsiveness of Soil Organic Matter Pools?

Presenter : Geoffrey Johnson

Mentor : Scott Bridgham

Major : Environmental Science

Poster 31

Plant litter from aboveground and belowground production constitutes a major carbon (C) and nutrient input to forest soils worldwide. Uncertainty in the relative effects of these two biomass allocations on ecosystem structure and function is the impetus for the Detritus Input Removal and Transfer (DIRT) experiment, which incorporates root trenching and leaf litter removal and addition. In this study, we sampled mineral soils from DIRT plots at a temperate hardwood forest in Northwestern Pennsylvania in the 0-10 cm depth for all treatments and additional organic horizon and 10-20 cm profile depths for control (CO) and double litter (DL). This DIRT site was established in 1991. By incubating samples at 35°C and near-optimal moisture content for 56 weeks, we estimated maximum potential respiration and net nitrogen (N) mineralization and used the resulting cumulative values to compare rate constants and pool sizes for 1 and 2 pool exponential models among treatments. Net N mineralization in DL plots was significantly greater than CO (α=0.05) at 10- 20 cm, while the no input (NI) treatment was significantly less than CO and DL (α=0.05) at 0-10 cm. We also provide evidence that the treatment effects will continue to become more significant on longer time-frames. From these results, we suggest soil C and N pools are affected by plant litter allocation ratios on decadal time scales, and the most rapid effects may be outside of the pools in the uppermost mineral soil horizons.

Spatiotemporal Patterns of Inversion Allele Frequencies in Threespine Stickleback

Presenter :Erika Jackson

Mentor : William Cresko

Major : Biology

Poster 21

Chromosomal inversions have been linked to complex traits that facilitate adaptation in new environments in a small number of stud- ies. However, the generality of this pattern is still unclear. Studying the frequency of chromosomal inversions in threespine stickleback (Gasterosteus aculeatus) could provide an important case study to help us understand the role of chromosomal inversions in adaptive evolution. We focused on Alaskan and Oregon marine and freshwater stickleback populations to determine inversion frequencies between distant locations as well as between salinities in different bodies of water. We predicted that inversion allele frequency diver- gence between ocean and freshwater populations would occur if the inverted region contained genes important for adaptation to the alternative environments. We genotyped a large number of individuals for an inversion on Linkage Group XXI using polymerase chain reaction (PCR) designed to indicate alternate forms of the inversion. Our results showed that the inversion allele frequencies are highly divergent between Alaskan oceanic and freshwater populations. In addition, while Alaskan populations are geographically distant from Oregon populations, we found a similar pattern of divergence between Oregon populations in the two habitats. Our study provides ad- ditional evidence that chromosomal inversions may play an important role in adaptation to novel environments.

A Comparison of Hip Joint Extension, Thigh Segment Extension, and Pelvic Tilt Between Individu- als Who Exhibit Poor Hip Extension and Individuals With Good Hip Extension

Presenter : Richard Howey

Mentor : Li-Shan Chou

Major : Human Physiology

Poster 11

Full 3D kinematic analysis is often used for biomechanical assessment of running mechanics and corresponding injury risk. However, conclusions drawn from these analyses are highly dependent on data analysis methods. For example, poor hip joint extension (HJE) at toe-off is often interpreted clinically as resulting from weakness in extensor muscles. However, because joint angles are often calculated as movement of the distal segment relative to the proximal, two absolute orientations may result in the same calculated joint angle. Therefore, poor HJE could result in movements of the thigh or the pelvis. The purpose of this study is to compare hip joint, thigh seg- ment and pelvic tilt angles in runners with good and poor HJE. Data from this study were drawn from a database of 100 runners who had been analyzed in the motion analysis laboratory. Ten individuals with HJE 1.5 standard deviations above and below the database mean comprised the good and poor groups, respectively. While the two groups were different in HJE (good: M = -15.28° ± 1.34°; poor: M = 3.51° ± 4.94°; p < .001) the angle of the thigh segment relative to vertical was not different between groups (good: M = 3.52° ± 8.38°; poor: M = 3.41° ± 4.94°; p = .991). The pelvis angles also were significantly different between groups (good: M = -4.88° ± 8.76°; poor: 7.17° ± 8.03°; p = .005). These findings suggest that pelvic instability should be considered in addition to weakness in hip exten- sors when reduced HJE is observed.

River Stories: Preserving and Sharing Oral Histories and Traditions of the McKenzie River Valley Using Video and Audio Media

Presenters : Starr Hathway, Adrian Robins, Jacob Sembler

Mentor : Kathryn Lynch

Major : Environmental Studies, Cinema Studies

Poster 39

The McKenzie River Valley sustains a unique heritage that is in danger of being lost. The purpose of River Stories is to preserve the oral histories and traditions of the area before they are forgotten. Our goal is to share the stories we collect with the Eugene/Springfield community, as well as the residents of the McKenzie Valley and their families. The River Stories team is collecting these accounts from McKenzie River area residents that run the spectrum from river guides to local artisans. While conducting weekly interviews, the team employs an anthropological approach to capture the endangered community knowledge, specifically using audio and video formats. River Stories then uses transcription, audio logging, and video editing to create a product that is ready for community-wide dissemination. Thus far, 13 weeks of fieldwork have yielded findings that help piece together the McKenzie’s grander story. The team has inter- viewed 20 individuals from over a dozen pursuits including boat building, fly fishing, and sustainable agriculture. This term, the team is developing a mini-documentary series which aims to communicate findings to the Eugene/Springfield community. This project will encourage further documentation and appreciation of the McKenzie River Valley, setting a foundation for the connection of genera- tions and neighboring communities.

Determining the Effects of Essential Amino Acid Supplementation for Total Knee Arthroplasty Patients

Presenter : Caitlin Gibson

Mentor : Hans Dreyer

Major : Human Physiology

Poster 18

Osteoarthritis affects 60% of the US population over 65 years of age. Total Knee Arthroscopy (TKA), used to mitigate osteoarthritis knee pain, is the leading cause of hospitalization for adults, ages 45-84 years old. The most significant clinical barrier following TKA surgery is persistent muscle atrophy and weakness. Previous research has shown that essential amino acid (EAA) ingestion is a potent means to stimulate muscle protein synthesis in older adults. PURPOSE: To determine the effects of twice-daily ingestion of 20g of EAA for 1 week prior to, and for 2 weeks post-TKA, on muscle mass, strength, and functional mobility. METHODS: Magnetic resonance imaging (MRI), isometric quadriceps strength and functional mobility were obtained at baseline, 2 and 6 weeks post-TKA from older adults supplemented with EAA or placebo. RESULTS: Quadriceps muscle atrophy was greater in the placebo group at 2 and 6 weeks post-surgery. The intervention group had significantly less loss in quadriceps strength and performed significantly better at 2 and 6 weeks post-surgery on functional mobility tests. CONCLUSIONS: Our results show that TKA surgery is associated with significant muscle atrophy, declines in muscle strength and reductions in functional mobility. Our findings will help us to better understand the potential for EAA supplementation in order to attenuate muscle loss and boost recovery of muscle mass, strength and function follow- ing TKA in older adults.

N/A

Presenter : Michaeli Francisco

Poster 9

Tetraethylammonium (TEA) abolishes a large portion of the vasodilation observed with both cutaneous thermal and reactive hyper- emia by blocking calcium-sensitive potassium (KCa) channels. Some studies have shown effects of TEA on other potassium channels such as inward-rectifying potassium (KIR) channels, which are activated by increases in extracellular K+ and blocked by barium (Ba2+). Our primary goal was to test the specificity of TEA to KCa channels by ensuring TEA had no effect on KIR-mediated vaso- dilation to KCl. Furthermore, the effects of KIR channels in the skin has not previously been explored. Recent research suggests KIR channel activation to be the predominant contributor to ATP-mediated dilation in the forearm. Therefore, our secondary goal was to assess KIR-mediated vasodilation in response to ATP. The following drugs were continuously infused via microdialysis: 1) Control; 2) 50mM TEA; 3) 0.1mM barium chloride (BaCl2; KIR channel blocker). KCl was infused for 2 min at each site at 1mM and 10mM doses. Following KCl infusions, a single dose of 30mM ATP was infused for 1 min at each site. Dilation was characterized as Δ peak from baseline, and presented as % maximal cutaneous vascular conductance (CVC). KCl mediated vasodilation at the control site (1mM: 11.0±2.7%, 10mM: 10.4±2.3%) indicated 1mM KCl is sufficient to achieve complete activation of KIR channels, which is only ~ 10% of max. TEA had little effect on KCl-mediated vasodilation (1mM: 7.2.0±2.2%, 10mM: 9.2±3.1%) suggesting TEA does not affect KIR and/or Na+/K+ATPase pumps. Dilation to KCl was attenuated but not blocked by 0.1mM BaCl2 (1mM KCl: 6.0±1.7%, 10mM KCl: 4.9±2.0%). This indicates Na+/K+ATPase could also be responsible for a large portion of KCl-mediated vasodilation in the skin. ATP-mediated vasodilation was largely independent of KIR channel activation (Control: 43.7±14.0%, BaCl2: 41.0±11.4%). However, TEA blocked a large portion of ATP-mediated dilation (TEA: 11.6±4.5%) implicating KCa channels as a primary mechanism in ATP- mediated vasodilation in the skin.