Digital Commons Network^™

Fungal Iron Oxidation In Brazilian Iron Caves, Braxton L. Hornick

Williams Honors College, Honors Research Projects

The iron caves in Brazil are thought to form through a cycle of Fe(III)-reduction and Fe(II)-oxidation; the Fe(II) is washed out of the cave walls by rainwater, where it is oxidized to Fe(III) and deposited in iron-oxide crusts. Bacteria are known to reduce Fe(III) in the caves, but what species may be oxidizing Fe(II) is still unknown. Our hypotheses was another bacterial species was involved and our initial assays were aimed at isolating Fe(II)-oxidizing bacteria; however all our Fe(II)-oxidizing cultures were contaminated with fungi when Fe(II)-oxidation was seen. Antifungals were used to inhibit growth of fungal species, which inhibited both …

Measuring Bacterial Growth Using A 3d-Printable Spectrometer, Samuel R. Bunting

Williams Honors College, Honors Research Projects

Visible light spectroscopy is a commonly used technique for measuring the growth of bacterial cultures, and growth curves provide broadly important data. However, the equipment and resources required for these experiments has been restricted to higher education and industry due to high cost and sophistication. We have previously reported on an inexpensive, 3D-printable photospectrometer called the SpecPhone. This device utilizes an iPhone as the camera, along with several other, inexpensive additions to make a fully functional spectrometer. Here, the application of the SpecPhone is expanded to the quantification of actively dividing E. coli cultures. Two protocols have been developed; one …

Nanoparticle Targeting To The Central Nervous System, Emily Baker

Williams Honors College, Honors Research Projects

Drug delivery to the central nervous system is complicated by the blood-brain barrier, a vascular structure that prevents free diffusion of molecules into brain tissue. In this study, we examined the in vitro properties of a nanoparticle-based drug delivery system. We used several nanoparticle formulations, both LTP based and PLGA based, to test the cellular uptake and toxicity in microglial cells. Using immunofluorescence imaging, we show that LTP nanoparticles are taken up by microglia. We confirmed that our nanoparticle formulations are non-toxic by two cell viability assays. These results suggest that nanoparticle formulations may be a biocompatible method of delivering …

Biomarkers Of Sepsis: A Retrospective Approach, Jose M. Roberts

Williams Honors College, Honors Research Projects

Background: Biomarkers are taking the spotlight in becoming the norm for early diagnoses. Sepsis is an inflammatory disease that increases metabolic rate in children. The first biomarker is hyponatremia. Hyponatremia is a frequent electrolyte imbalance in clinical practice, often observed in children with inflammatory disease and infection. Presence of hyponatremia is associated with electrical signaling imbalances, inflammation and renal dysfunction. The clinical value of hyponatremia in pediatric patients is unknown. The C-reactive protein is a second biomarker. Its presence signifies that necrotic cells and inflammation are present.

Objectives: To evaluate the use of biomarkers in children seen in the Emergency …

Analysis Of Microbial Diversity In Disturbed Soil, Tyler G. Sanda

Williams Honors College, Honors Research Projects

This paper uses the composition and abundance of microbial species to analyze soil recovery in disturbed land. Surface mining disturbs ecological communities throughout the world. As organizations seek to reclaim these disturbed lands, a proper analysis of recovery is needed. In previous studies, recovery of disturbed land was limited to surface examinations, which do not characterize the possible unseen devastating effects of the subsoil. Soil microorganisms are extremely sensitive to environmental changes such as strip mining. It is proposed that these microorganisms may serve as better indicators of recovery post disturbance. Our analysis indicates microbial recovery, however it may not …

The Effects Of Polyunsaturated Aldehydes On Pelagic Microbial Food Webs In The Chesapeake Bay Area And Atlantic Coastal Waters, Chase Alfman

Williams Honors College, Honors Research Projects

Diatoms, one of the most common classes of phytoplankton, are autotrophic plankton, and are the primary food source for many organisms. Diatoms play a key role in nearly all oceanic food webs. Under stressful conditions, diatoms can undergo biological changes that produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA’s). This process is a form of allelopathy, utilized by many algae as a defense mechanism against predation, as well as to inhibit competitors. Microzooplankton are an essential part of these aquatic food webs as well, as they are a key herbivore in many oceanic environments. A set of experiments was …

Quantification And Analysis Of Carbon-13 And Nitrogen-15 Stable Isotope Variation In Brood V Cicada Nymph Exoskeletons, Eric Aho

Williams Honors College, Honors Research Projects

Endemic to eastern North America, the periodical cicada of the genus Magicicada is an insect that has captured people’s curiosity for centuries. Feeding on root xylem for 13 or 17 years, these insects emerge from the earth by the millions and shed their exoskeletons before maturing into reproductive adults. The short 2-3 month window in which periodical cicadas are active provides a short yet large resource pulse to both consumers and soil. Capitalizing on the 2016 emergence of Brood V, this study examined the d¹³C and d¹⁵N values of cicada nymph exoskeletons, seeking to identify patterns …

Effects Of Novel Fragment-Warhead Adducts In Situ And In Vitro With Glutaredoxin Orthologs., Andrew J. Caras

Williams Honors College, Honors Research Projects

Fragment-based drug design (FBDD) is a method of pharmaceutical research involving characterization of small “fragment” molecule interactions with a target protein. These fragments are optimized with the addition of a nucleophilic “warhead” moiety. Several novel fragment-warhead adducts have been synthesized in house by group member Ram Khattri Ph.D. The experiment investigates reactivity of these adducts with glutaredoxin protein (Grx) orthologs from Homo sapiens, Pseudomonas aeruginosa and Brucella melitensis. Three novel fragment-warhead adducts have been identified to cause weakly bacteriostatic and bacteriocidal effects, most with minimum inhibitory concentration values near 1.28 mg/mL. Discussed herein are molecular effects of these fragment-warhead …

Chocolate Bar Wrapping Machine, Austin M. Hoff, Daniel R. Trepke, Caleb B. Krichbuam

Williams Honors College, Honors Research Projects

Gilbert Chocolates has proposed to manufacture a machine to wrap chocolate bars. This machine is intended to replace two people wrapping the chocolate bars by hand, which is a time consuming method. This is especially apparent between October and January when the workers are working long hours in preparation for the Christmas rush of customers. Currently wrapping a bar takes about a minute and Gilbert Chocolates wants this time reduced down to 20-30 seconds. The budget for this project is set at $1000, and is being funded by the company. This machine needs to fit in a cubic foot of …

The Effects Of Methamphetamine Exposure On Cardiovascular Development In Combination With Hypoxia In Danio Rerio, Sarah Donaldson

Williams Honors College, Honors Research Projects

The purpose of this study was to determine the effects of methamphetamine combined with hypoxia on the development and function of the cardiovascular system in Danio rerio embryos. It was hypothesized that the combined effect of the drug and decreased oxygen concentration would result in decreased cardiac parameters due to underdevelopment of the ventricle and vessels resulting from cardiomyopathy and lack of blood flow to tissues. It was found that methamphetamine exposure correlated to an increase in stroke volume, caudal artery and vein diameters and RBC velocities alone, while having a multiplicative effect of increasing arterial RBC velocity when combined …

Wetland Connectivity And Macroinvertebrate Diversity, Samantha M. Hodgson, Jacob Pollock, Dr. Anne E. Wiley

Williams Honors College, Honors Research Projects

Wetlands are important in filtering pollutants from aquatic ecosystems and also serve as habitats for a diverse array of organisms. However, wetland-river networks are often subject to human disturbances such as dyke construction. These decreases in connectivity have the potential to impede movement of organisms and nutrients between habitats.

This study examined how the food web structure and diversity of macroinvertebrate communities differ between wetland sites connected and disconnected to nearby rivers. According to macroinvertebrate surveys in wetlands connected to nearby rivers and dyked wetlands (not connected to nearby rivers), there is an increase in average species richness and diversity …