Physical Sciences and Mathematics Commons^™

Exploring Indicator Displacement Assays For Phosphate Detection In Seawater, Francis Radics

Chemistry & Biochemistry Student Scholarship

Francis Radics ’22
Major: Biochemistry
Faculty Mentor: Dr. John Breen, Chemistry and Biochemistry

Indicator displacement assays are based on the optical signal modulation of a noncovalently bound indicator upon dissociation by an analyte species. Our work has focused on exploring the lower detection limits for luminescent displacement assays for inorganic phosphate in seawater using complex ions containing two di(2-picolyl)amine ligands (also called DPA or bis(2-pyridylmethyl)amine), each coordinating a zinc cation. Following the work of B.D. Smith and coworkers, we have prepared three ligands by covalently attaching two DPA moieties, 2,6-bis(chloromethyl) benzene, and 2,6-bis(chloromethyl)-4-methylphenol, and 1,2-phenylenedimethylamine, for assays with 6,7-dihydroxy-4-methanesulfonic acid …

Towards The Development Of Low-Cost And Easily-Deployable Sensing Platforms For Phosphate, Maureen Pontarelli, Thomas Koch

Chemistry & Biochemistry Student Scholarship

Maureen Pontarelli ’20
Major: Chemistry

Thomas Koch '20
Major: Biochemistry

Faculty Mentor: Dr. John Breen, Chemistry and Biochemistry

Periodic Table Club, Makayla Gill, Kailynn Jensen

Honors Expanded Learning Clubs

This club is dedicated to teaching the generation of future scientists the periodic table. This is designed to be a unique take on a STEM club that uses the periodic table as a backbone for a solid foundation in chemistry.

Comparative Analysis Of The Human Serine Hydrolase Ovca2 To The Model Serine Hydrolase Homolog Fsh1 From S. Cerevisiae, Jessica S. Bun, Michael D. Slack, Daniel E. Schemenauer, R. Jeremy Johnson

Scholarship and Professional Work - LAS

Over 100 metabolic serine hydrolases are present in humans with confirmed functions in metabolism, immune response, and neurotransmission. Among potentially clinically relevant but uncharacterized human serine hydrolases is OVCA2, a serine hydrolase that has been linked with a variety of cancer-related processes. Herein, we developed a heterologous expression system for OVCA2 and determined the comprehensive substrate specificity of OVCA2 against two ester substrate libraries. Based on this analysis, OVCA2 was confirmed as a serine hydrolase with a strong preference for long-chain alkyl ester substrates (>10-carbons) and high selectivity against a variety of short, branched, and substituted esters. Substitutional analysis …

Trophic Upgrading And Mobilization Of Wax Esters In Microzooplankton, Keyana Roohani, Brad A. Haubrich, Kai-Lou Yue, Nigel D'Souza, Amanda Mantalbano, Tatiana Rynearson, Susanne Menden-Deuer, Christopher Reid

Science and Technology Department Faculty Journal Articles

Heterotrophic protists play pivotal roles in aquatic ecosystems by transferring matter and energy, including lipids, from primary producers to higher trophic predators. Using Oxyrrhis marina as a model organism, changes to the non-saponifiable protist lipids were investigated under satiation and starvation conditions. During active feeding on the alga Cryptomonas sp., the O. marina hexane soluble non-saponifiable fraction lipid profile reflected its food source with the observed presence of long chain mono-unsaturated fatty alcohols up to C25:1. Evidence of trophic upgrading in O. marina was observed with long chain mono-unsaturated fatty alcohol accumulation of up to C35:1. To the best of …

Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté

Science and Technology Department Faculty Journal Articles

Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we …

Decreasing Phosphatidylcholine On The Surface Of The Lipid Droplet Correlates With Altered Protein Binding And Steatosis, Laura Listenberger, Elizabeth Townsend, Cassandra Rickertsen, Anastasia Hains, Elizabeth Brown, Emily G. Inwards, Angela K. Stoeckman

Chemistry Faculty Publications

Alcoholic fatty liver disease (AFLD) is characterized by an abnormal accumulation of lipid droplets (LDs) in the liver. Here, we explore the composition of hepatic LDs in a rat model of AFLD. Five to seven weeks of alcohol consumption led to significant increases in hepatic triglyceride mass, along with increases in LD number and size. Additionally, hepatic LDs from rats with early alcoholic liver injury show a decreased ratio of surface phosphatidylcholine (PC) to phosphatidylethanolamine (PE). This occurred in parallel with an increase in the LD association of perilipin 2, a prominent LD protein. To determine if changes to the …

A Loose Domain Swapping Organization Confers A Remarkable Stability To The Dimeric Structure Of The Arginine Binding Protein From Thermotoga Maritima, Alessia Ruggiero, Jonathan D. Dattelbaum, Maria Staiano, Rita Berisio, Sabato D'Auria, Luigi Vitagliano

Chemistry Faculty Publications

The arginine binding protein from Thermatoga maritima (TmArgBP), a substrate binding protein (SBP) involved in the ABC system of solute transport, presents a number of remarkable properties. These include an extraordinary stability to temperature and chemical denaturants and the tendency to form multimeric structures, an uncommon feature among SBPs involved in solute transport. Here we report a biophysical and structural characterization of the TmArgBP dimer. Our data indicate that the dimer of the protein is endowed with a remarkable stability since its full dissociation requires high temperature as well as SDS and urea at high concentrations. In order to elucidate …

Integrating Art And Science In Undergraduate Education, Daniel Gurnon

Chemistry & Biochemistry Faculty Publications

The prevailing vision for undergraduate science education includes increased collaboration among teachers of science, technology, engineering and math (STEM) and an overhaul of introductory courses [1]–[4]. But by staying within the borders of STEM, are we overlooking connections between the arts and innovative science? Likewise, are we missing an important opportunity to inspire and inform nonscientists? Here we explore how weaving the visual arts into a science curriculum can both help develop scientific imagination and engage nonscientists. As an example, we describe a recent collaboration between artists and scientists to create a series of science-inspired sculptures.

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results. In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks. Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …

Her2 Targeted Molecular Mr Imaging Using A De Novo Designed Protein Contrast Agent, Jingjuan Qiao, Shunyi Li, Lixia Wei, Jie Jiang, Robert Long, Hui Mao, Ling Wei, Liya Wang, Hua Yang, Hans E. Grossniklaus, Zhi-Ren Liu, Jenny J. Yang

Chemistry Faculty Publications

The application of magnetic resonance imaging (MRI) to non-invasively assess disease biomarkers has been hampered by the lack of desired contrast agents with high relaxivity, targeting capability, and optimized pharmacokinetics. We have developed a novel MR imaging probe targeting to HER2, a biomarker for various cancer types and a drug target for anti-cancer therapies. This multimodal HER20targeted MR imaging probe integrates a de novo designed protein contrast agent with a high affinity HER2 affibody and a near IR fluorescent dye. Our probe can differentially monitor tumors with different expression levels of HER2 in both human cell lines and xenograft mice …

Photoreductive Dissolution Of Ferrihydrite By Methanesulfinic Acid: Evidence Of A Direct Link Between Dimethylsulfide And Iron-Bioavailability, Anne M. Johansen, Jennifer M. Key

All Faculty Scholarship for the College of the Sciences

Within open‐ocean regions where excess macronutrients are present, phytoplankton growth is limited by the bioavailability of iron supplied to these areas primarily within atmospheric aerosols of crustal origin. However, processes that control the abundance of biologically accessible iron in these aerosols are largely unknown. Here we show that dissolution of ferrihydrite, a surrogate iron(oxy)hydroxide phase found in atmospheric waters, is enhanced in the presence of methanesulfinic acid (MSIA, CH₃SO₂H, a dimethylsulfide (DMS) oxidation intermediate) in laboratory irradiation experiments with aqueous suspensions that simulate marine aerosol particles. The increased release of soluble Fe(II) is attributed to a …

Examination Of Technologies For Student-Generated Work In A Peer-Led, Peer-Review Instructional Environment, Brian P. Coppola, Alan L. Kiste

Chemistry and Biochemistry

There is a growing literature demonstrating the effectiveness of using computer environments to assist students’ in visualizing science and mathematics concepts. However, with many of these computerized learning environments, students do not have the option of manipulating the environment. Instead, they are presented with pre-made visualizations. Enabling students to display their understanding through multiple representational forms is more interesting. In our peer-led, peer-review environment, students generate a complex, literature-based, multimedia text on which their final examination is based. However, there are great time and personnel costs in this design. Collaborating with SRI Inc., we are addressing these demands via the …