2019 High School Winner
Anya Razmi, Hathaway Brown School, Shaker Heights, OH
CWRU Faculty Advisor: Dr. Jessica Fox, Department of Biology
Title: Impact of Haltere Removal on Gravitational Perception
Found on dipteran insects, halteres are mechanosensory organs known to aid flies in detecting shifts in gravity. Certain flies oscillate halteres during walking, such as Sarcophagidae, while in others, including Dolichopodidae, halteres do not oscillate. In Sarcophaga bullata subjected to a free fall while stationary, halteres are necessary to respond to the sudden gravitational shifts. However, the utility of these organs in flies that do not oscillate halteres during walking, or in flies responding to sudden changes in gravity while walking, has yet to be explored. In this study, wild-caught, stationary Dolichopodidae (varying species) and walking Sarcophaga bullata were observed. Each intact or haltereless (removal via forceps) fly was placed in a clear, plastic container hung 2 cm above a surface and filmed using a high-speed video camera as the container fell. It was hypothesized that there would be no difference in median velocity during the fall between intact and haltereless Dolichopodidae. This was proven correct (n=9; 5 trials intact, 5 trials ablated per fly; p>0.05), suggesting that flies that oscillate halteres while walking are more adept at reacting to shifts in gravity. Secondly, it was hypothesized that haltereless (as opposed to intact) Sarcophaga bullata would have a lower mean velocity during the fall; however, the difference in mean velocity of intact and haltereless Sarcophaga bullata (n=10) was not significantly different (p>0.05). A possible explanation for these results is that flies are inherently unstable while walking, and this instability overrides the benefits of halteres when subjected to shifts in gravity.
2018 High School Winners
Somya Sharma, DuPont Manual High School, Louisville, KY
CWRU Faculty Advisor: Dr. Faramarz Ismail-Beigi, Department of Medicine
Title: Glucose-Lowering Effect of a Novel Insulin (SCI-1) and its Thermal Stability Compared to Insulin Lispro (Humalog)
Insulin is a hormone that is secreted by the beta cells of the pancreas. The hormone is essential for survival and it functions to control blood glucose levels. Insulin consists of two chains, A and B chains, which are connected by disulfide bonds. Lispro insulin (Humalog) is a fast-acting, two chain insulin that is clinically prescribed for patients. Single Chain Insulin connects the A chain and B chains together by adding an amino acid linker. In preliminary experiments, Single Chain Insulin-1 (SCI-1) was shown to be active in lowering blood glucose and, unlike Lispro insulin, it exhibited thermal stability when heated above 45C. The focus of this study is to compare glucose-lowering effects of Lispro insulin and SCI-1. In addition, the thermal stability of Lispro insulin and SCI-1 will be compared at higher temperatures. Streptozocin-induced diabetic rats were injected subcutaneously with Lispro insulin or SCI-1. The tip of the tail was snipped with a sharp razor blade to obtain blood samples. During the first hour, blood glucose was measured at ten-minute intervals using a standard glucometer. Subsequent measurements were made less frequently for the 5-6 hour duration of the experiment. The data obtained from the experiment were then graphed and analyzed. In studies discussed below, SCI-1 had a more prolonged glucose-lowering effect than Lispro insulin. SCI-1 was found to be a biphasic insulin, being fast-acting in the first stage and long-acting in the second. Compared to Lispro insulin, SCI-1 showed more heat stability. SCI-1, heated for 110 hours at 75C, retained most of its activity. In contrast, the glucose-lowering effect of Lispro insulin was decreased by approximately 50% when heated for only 5 hours at 75C. In conclusion, SCI-1 appears to function in a biphasic manner and is much more heat stable in comparison to Lispro insulin. Thermal stability of insulin may be of great importance during its shipping and storage.
Lauren Matasar, Hathaway Brown School, Shaker Heights, OH
CWRU Faculty Advisor: Dr. Jeffrey Garvin, Department of Physiology and Biophysics
Title: The Role of the Kidney in Hypertension
Before 1970 the amount of fructose in widely processed foods and drinks was extremely low. However, recently in the food industry many fats were removed and fructose was used as a flavor substitute. Today, more than 16 million Americans consume over 20% of their daily calories in the form of fructose, both through food and drink. In the years following an insurgence of dietary fructose, the incidence of high blood pressure also known as hypertension has risen to nearly 42% of Americans, half of which develop salt-sensitive hypertension. What we eat has an impact on our kidneys and thus our blood pressure, therefore we hypothesized that the consumption of dietary fructose will lead to the development of salt-sensitive hypertension without causing changes in weight or to any metabolic parameters. To research this hypothesis, 6 groups of rats were fed 1 of 4 diets and their blood pressure, blood glucose, and blood insulin concentration were consequentially measured. The four diets tested were glucose low-salt, which served as the control, glucose high-salt, fructose low-salt, and fructose high-salt, the diet expected to cause the development of salt-sensitive hypertension. Rats were fed these diets for 8 days and throughout them their food and water consumption, weight, and blood pressure were measured daily. At the end of the 8 days their blood glucose was measured and blood plasma was collected for insulin analysis. The results showed that there was no significant change in food consumption between the groups, however, as expected the high salt rats drank much more water. There was no abnormal weight gain in any of the diets. As hypothesized, the fructose high salt rats experience elevated blood pressures (+20 mmHg) and blood glucose (+12 mgDl), and developed salt sensitive hypertension. The insulin concentrations are currently being examined and no conclusions can be made at this time.
2017 High School Winner
Alison Kennedy, Mentor High School, Mentor, OH
CWRU Faculty Advisor: Dr. Ica Manas-Zloczower, Department of Macromolecular Science and Engineering
Title: Evaluating the Effect of Plasma Functionalization on Carbon Nanofillers for a Possible Increase in Adhesion with Epoxy Resin
Carbon nanotubes are emerging as a viable material for reinforcing polycarbonate composites due to their excellent mechanical properties such as high specific strength, tensile strength, hardness and Young’s modulus. The applications for carbon nanotube reinforced composites span many industries though the focus of this research is for fabricating composites for wind turbine blades. The most significant challenge of fabricating composites is sufficient load transfer. The lack of ample load transfer is due to the hydrophobicity of the carbon nanotubes. One way to combat hydrophobicity is a process called plasma functionalization. Plasma functionalization uses oxygen plasma to add oxygen containing functional groups to the surface of carbon nanotubes by disrupting the bonds at the surface. One way to measure the effect of plasma functionalization is through contact angle measurements. Contact angles, the angles that form between a drop of testing liquid and the surface that is being tested, are used to quantify the properties of the solid surface. The contact angles of the plasma treated polycarbonate and buckypaper were smaller than those of the untreated samples. This shows that plasma functionalization reduces the contact angle of water, dimethyl sulfoxide, and epoxy. This reduction in contact angle correlates with an increase in wettability and a possible increase in adhesion. An increase in adhesion will make the composites stronger. Future research would include gathering contact angle data with other testing liquids so that the surface energy could be estimated. It would also include fabricating composites with plasma functionalized carbon nanotubes and experimentally testing their strengths.
2016 High School Winner
Juan Sanchez, John Hay High School, Cleveland, OH
CWRU Faculty Advisor: Dr. David Schiraldi, Department of Macromolecular Science and Engineering
Title: Multilayered Films For Gas Barrier Applications
The purpose of this project is to create a multilayered and biaxially oriented high glass barrier film containing high aspect ratio and low Tg°C -- temperature where the glass transitions from a solid to a molten state. The importance of this project is that the these films have good oxygen blocking capabilities due to its polymeric structure compared to other gas barrier films seen in the food packaging industry. The main ingredients in the films are Tin Flurophosphate Glass (Pglass) and Ethylene Vinyl Alcohol (EVOH). Pglass has a suitable Tg°C range allowing it to be paired with other organic polymers very easily, however, it doesn’t have good oxygen permeability. EVOH on the other hand is a great oxygen barrier film and pairing it with Pglass shows great potential. Permeability was tested between EVOH alone (control) and Pglass paired with EVOH. At 10% volume, 10% Pglass mixed with 90% EVOH, the film showed a higher permeability towards oxygen compared to EVOH alone. This shows that Pglass paired with EVOH has a lot of potential in being a high gas barrier film, which is important in the food packing industry because the better the film can block out oxygen, the longer the food can stay fresh. The manufacturing cost is also cheaper compared to other commercial methods making this film a viable option in the future.