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The Effect of Cortisol on Sexual Differentiation in Zebrafish
Full text linkThe use of zebrafish has become a prevalent practice amongst researchers in a multitude of different scientific fields. However, previous research has established that the sexual determination in domesticated zebrafish lines, which are currently used in research, are not determined through a specific sex-linked locus but rather is polygenically determined. This differing method of sexual determination causes zebrafish to be susceptible to environmental factors that have been linked to masculinization of female zebrafish. It has been established that little is understood of the mechanism behind this masculinization apart from that it is induced through cortisol. Therefore, it is important for researchers to establish the levels of cortisol that trigger this shift, because shifts in sexual ratio are a confounding variable. In the study, measurements of the whole-body cortisol levels in adult zebrafish, both exogenously and internally produced, were taken to provide foundational techniques for future researchers. Hopefully, after establishing these techniques, future study on this project will allow researchers to determine the definite levels at which the sexual ratio in zebrafish begin to shift
The Analysis of BPA Leaching in Various Types of Athletic Wear using Fluorescence Spectrometry
Full text linkBisphenol A (BPA) is the most common endocrine-disrupting chemical that has been used in polycarbonate plastics and epoxy resins. BPA has been linked to several health issues due to binding to estrogen receptors. BPA is associated with an increase of ovarian, breast, prostate, and testicular cancer as well as low sperm count, motility and abnormal morphology of sperm, birth defects, early puberty, and Polycystic Ovary Syndrome.
The item of focus for this research project was athletic wear. BPA can be absorbed dermally which is concerning because clothes have prolonged dermal contact with various types of tissue. Prior research at Ouachita Baptist University had found the presence of BPA in several brands of leggings. BPA leaching from different types of athletic wear were tested in a 50:50 methanol/water mixture as well as in artificial sweat.
BPA leaching was observed and measured with a spectrofluorometer. BPA is a fluorescent compound, which means following excitation, it will emit radiation at a longer wavelength than the exciting wavelength. BPA is excited at 275 nm and emits at 306nm. This emitted light was measured and correlated to the concentration of BPA present in the sample. Fluorescence is a very sensitive and selective technique, which makes it possible to determine very low concentrations of BPA with few concerns about contamination.
To compare the BPA leaching behavior of different types of athletic wear, a calibration curve was first established to help correlate the concentration of BPA in a standard solution to fluorescence emission intensity. The BPA leaching was monitored over the course of six hours, and a leaching curve was prepared for each sample. BPA is found in very small concentrations in clothes; therefore, the standard addition method was used to calculate the unknown BPA concentration by the addition of a BPA standard solution to the testing solutions
Sacred Sovereignty Lost: The Georgian Orthodox Church, The Treaty of Georgievsk, and Russian Annexation
No full textDavidson Methodist Campground records
Full text linkMeeting minutes, land deeds and documents, and legal correspondence relating to the Davidson Methodist Campground in Clark County, Arkansas
Mathematics Speaker
No full textDr. Lorin Matthews was a speaker for the Mathematics presentations of the 2025 Arkansas Women in STEM conference
Scholars Day 2025 Program of Events
Full text linkThis is the program of events for the 2025 Scholars Day Conference, where undergraduates across disciplines present their scholarly and creative works
