Mathematics and Natural Sciences

Ricky Granger, Nick Elder, Lauren Redfern

Faculty Sponsor: Dr. El Bejjani

Brendan Fries

Faculty Sponsor: John Yukich

When the average person thinks about rubber bands, they imagine firing it at a friend. That’s not the case for physicists though. When we think of rubber bands we also think of their thermodynamic properties. This project will be using rubber bands to investigate two relations involving the temperature of a rubber band. The first relation is Force vs. Temperature. Most materials exhibit a positive coefficient of thermal expansion, but this is not the case for rubber bands. The second relation is Adiabatic Stretching vs. Temperature. When rapidly stretching a rubber band, its temperature drastically increases. My first objective of this project is to prove the relation between Force vs. Temperature. The second objective is to investigate Adiabatic Stretching vs. Temperature. Upon completion one should be able to confirm the negative coefficient of thermal expansion of rubber bands. Additionally, draw a relation between some physical property of a rubber band and how its temperature changes as a result of Adiabatic Stretching.

Noah Batke

Faculty Sponsor: Dr. Kristi Multhaup, Dr. Greta Munger

Music has been shown to evoke vivid and specific autobiographical memories. Two experiments examine music’s ability to activate two different kinds of memory recall: direct retrieval and generative reconstruction. Direct memories come to mind quickly and with little effort, while generative memories come to mind slowly and require effort to recall. Experiment 1 included 58 Davidson College students (ages 18-22, M = 19.24, SD = 0.98) who received both word-based and musical memory cues. Experiment 2 included 56 members of the Choral Arts Society of Davidson (ages 23-79, M = 56.51, SD = 16.71) who received both familiar and unfamiliar musical memory cues. After data was collected in both experiments, memories were categorized as either direct or generative based on the amount of effort participants indicated was associated with recall. Results demonstrate that participants’ direct memories were more frequent and vivid than their generative memories (Experiment 1 and Experiment 2). This difference in vividness was more pronounced in music-evoked memories compared to word-evoked memories (Experiment 1). Words evoked more vivid memories than music (Experiment 1) and familiar music evoked more vivid memories than unfamiliar music (Experiment 2). There was a marginally significant positive correlation between musical experience and the prevalence of direct memories.

Cole Reynolds

Faculty Sponsor: Shaw Smith and Naila Mamoon

Medicine has been practiced for thousands of years, evolving to what it is today, and the relationship between doctor and patient has evolved with it. This presentation briefly covers the evolution of the doctor-patient relationship through historical ages, focusing on the recent development of patient-centered medicine. Various works of art illustrating historical medical practices provide insight to past interactions between doctor and patient. More modern paintings and photography depict the recent ideals of the doctor-patient relationship and the desire to understand the patient as a whole to enhance treatment.

Itzayana Cuellar, Branden Becham

Faculty Sponsor: Dr. Malcolm Campbell

Although humans naturally synthesize full-length glycogen and many plants synthesize cellulose, chemically producing short glycogen and cellulose polymers in the laboratory is complex and often takes months. The goal of our research is to efficiently synthesize glycogen primers using the primer enzyme glycogenin and cellulose polymers with the enzyme cellulose synthase. Glycogen is large polymer of glucose that requires two protein enzymes. The first enzyme, glycogenin, assembles up to 10 glucose molecules to form a glycogen “primer” molecule. Glycogen synthase then uses the primer to synthesize the much larger glycogen molecule. Cellulose synthase does not require a primer enzyme and can synthesize polymers composed of hundreds of glucose molecules. In our study, we aimed to clone the human glycogenin gene and bacterial cellulose synthase and independently produce the enzymes in E. coli. We have confirmed the production of glycogenin. The focus of current work is visualizing glycogen primers on LC-MS and producing bacterial cellulose synthase. Our method to produce glycogen primers and cellulose will serve as the basis for better understanding the role of glucose-based polymers in various metabolic and biological processes.

Jonah Mische, Jack Shumway

Faculty Sponsor: Professor Wadgymar

Plants are sessile, meaning that they cannot relocate in response to changes in their environment. Consequently, many plant species have evolved the ability to alter their development or appearance in response to unfavorable conditions. These non-genetic alterations are called phenotypic plasticity, and these changes may benefit plants by allowing them to avoid or tolerate environmental stress. One of the most well known examples of phenotypic plasticity in plants is Shade Avoidance Syndrome (SAS). Plants that employ SAS undergo a suite of developmental changes upon perceiving reduced red light levels relative to far-red light levels due to shading from other plants. These phenotypic changes cumulatively enhance light acquisition and accelerate development to increase reproductive success. Here, we characterize the extent to which the annual plant Arabidopsis thaliana (Brassicaceae) responds plastically to simulated shade and the extent of variation in responses among distinct genotypes.

Cameron Dove

Faculty Sponsor: Dr. Wessner

Sour ales are produced through introducing one or a combination of fermenting agents such as lactic acid producing bacteria. We isolated these microorganisms from four different foeder tanks that make sour ales at D9 Brewery, a local microbrewery in Cornelius, and grew them both on general media plates (tryptic soy agar) as well as plates containing a selective medium, MRS (De Man, Rogosa, and Sharpe) agar. MRS is a selective medium that is designed to favor the growth of Lactobacilli (lactic acid bacteria). The growth of microorganisms on both these plates were compared. The pH of tryptic soy broth (TSB) was manipulated to three different pHs and the growth of the microorganisms from each of the four different foeders was measured over a 48 hour period to determine growth curves. These growth curves allowed us to further classify the microorganisms that are present in the foeder tanks as well as to determine pHs the microorganism were able to grow the best. We also did a sequence analysis of the bacteria to further characterize them.

Jonah Mische

Faculty Sponsor: Susana Wadgymar

An organism’s phenotype is a set of observable characteristics. Phenotypic plasticity describes an organisms ability to alter its phenotype in response to changes in the environment. These environmental effects can influence organisms directly or may be passed on to individuals by their parents. In this poster, I explore how can we visualize these different types of environmental effects, and how we may conduct experiments to find these effects in organisms such as Arabidopsis thaliana in response to environmental stress.