Tag: Poster 67

Acute Hemodynamic Adjustments to Hot Water Immersion

Presenter: Sarianna Harris

Faculty Mentor: Christopher Minson, Brett Ely

Presentation Type: Poster 67

Primary Research Area: Science

Major: Human Physiology

Funding Source: Clark Honor’s College Thesis Research Grant, $1,000; Undergraduate Research Opportunity Program’s Mini Grant Recipient, $1,000

Passive heat therapy (regular hot tub or sauna use) has gained attention for its potential to improve cardiovascular health, and recent evidence suggests that it produces beneficial vascular adaptations. However, the cardiovascular responses to a single bout of hot water immersion have not yet been characterized; therefore the mechanisms that produce long-term adaptations are not yet fully known. PURPOSE: To examine the acute cardiovascular hemodynamic effects of a 60min bout of hot water immersion. METHODS: Thirteen healthy, young (26±4 yrs) subjects were immersed to heart level in 40.5°C water for 60minutes. Measurements, including heart rate, cardiac output, and skin blood flow, as well as diameter and blood velocity of carotid and brachial arteries, were taken at baseline prior to and during immersion. Peak changes were compared to baseline. RESULTS: Heart rate increased significantly from 60±3 at baseline to a peak of 121±5 bpm during immersion. Cardiac output increased significantly from baseline to peak, as did blood flow in both carotid and brachial arteries, total shear (4*velocity/diameter) in both brachial and carotid arteries, and skin blood flow. CONCLUSION: Hot water immersion caused substantial increases in cardiac output, arterial blood flow, skin blood flow, and shear rates. These changes are similar to those seen during a single bout of exercise, suggesting that repeated hot water immersion may cause beneficial vascular adaptations through similar mechanisms.

A Sedimentary Analysis of the Eugene Millrace

Presenter(s): Ethan Niyangoda − Geology

Faculty Mentor(s): Josh Roering

Poster 67

Research Area: Natural Science

The Eugene Millrace, a slowly-flowing 1.5 mile channel which is connected to the Willamette River and flows through East Eugene, has once again become a matter of public interest. Originally designed by Hillyard Shaw and constructed in 1851 to create a millrace for the quickly-industrializing city. Approximately half of the channel is a former side-channel of the Willamette River, and the other half was constructed by man. With the advent of the highly-publicized Knight Campus, which will be built around and possibly atop the Millrace, there has been great speculation into the future of this small but culturally-significant channel. One helpful means of understanding the nature and movement of a river system is to examine its bathymetry (the topography of its channel) and sediment accumulation pattern. In order to do this, we used six- to twelve- foot steel rods, a canoe, a GPS unit, and a tape measure to gauge sediment depth at a given location. To do this, we launched the canoe at several locations and took measurements from the center of the channel and around drainage pipes. This was done once in May 2017 and once in November 2017. We hypothesized that the channel would have mostly uniform, shallow (less than one foot) levels of sediment throughout. This hypothesis was completely wrong, as we discovered that the Millrace in fact has sediment ranging from less than a foot to meters in depth depending on the location measured. This finding could potentially have significant implications for channel dredging during the building and design associated with the Knight Campus.

Investigating Gp32 Binding Behavior on Single-Stranded DNA With Different Polarity And Length Using Microsecond Resolution smFRET Measurements

Presenter(s): Anson Dang

Faculty Mentor(s): Andrew Marcus & Peter von Hippel

Poster 67

Session: Sciences

The single-stranded (ss)DNA binding protein (gp32) of bacteriophage T4 plays a central role in regulating the functions and integration of the helicase, polymerase and primase components of the T4 DNA replication system. The T4 replication system serves as an excellent model for higher organisms as it contains all the essential components for DNA replication. This project aims to investigate how polarity and length of the ssDNA affect gp32 DNA binding. We perform microseconds resolution single-molecule FRET (smFRET) measurements on four primer templates of 14-15 base pairs and different polarities. Data are analyzed using both second- and fourth- order time correlation functions. At the current stage of this project, our results indicate at least three different conformational stages for gp32 binding. Further analysis is required to compare if and how gp32 dimer bind differently on the different constructs.