Open Access Kent State (OAKS)

Ongoing climate change and urbanization will continue to put pressure on diminishing freshwater resources. To combat these effects, water management policies need to be continually updated with the most current scientific information to reflect changes in types and amounts of pollutants and new knowledge about toxicity. For this analysis, we compared two metals: a well-studied pollutant (copper [Cu]) and emerging contaminant of concern (silver [Ag]). We assessed water quality criteria for these two metals from the United States, Australia and New Zealand, South Africa, Canada, and the European Union to determine the intent of these criteria and implementation strategies used in adoption practices. Additionally, we conducted standard chronic toxicology tests for silver and copper on the freshwater pond snail Lymnaea stagnalis to assess the level of effectiveness offered by each regulation in protecting ecological integrity. L. stagnalis were individually placed in 100 mL beakers of test solution (0–32 µg/L for both Cu and Ag) for a 28-day period with water changes every 4 days. Ten replicates were used per treatment to measure mortality and growth rates. Preliminary results suggest that Ag is more toxic than Cu. However, because Ag is a poorly studied contaminant, water quality criteria for Ag are typically older, more variable, or absent and thus may not offer protection in some jurisdictions.

An increasing number of feral and free-ranging cats roam the United States; the repercussions of which have become apparent to both the scientific community and caretaker community alike. Due to the steadily increasing population of feral and free-ranging cats in the United States and globally, research and caretaker interest about this issue is also increasing. However, the most effective control methods for these non-native predators is debated. Management decisions do not always rely on the best available science, partly because the science is inadequate for many issues related to feral and free-ranging cats. For example, estimates of immigration and emigration rates into and out of feral cat colonies is limited in the scientific literature. In a previous pilot study conducted in 2015, an attempt was made to add important empirical data to this debate through the investigation of immigration and emigration rates into and out of local feral and free-ranging cat colonies. Although the results of this small study were inconclusive, it became clear that these data were important and an expansion of the pilot study was warranted. As a follow-up to the previous study, a larger scale study will be conducted to add the data that is lacking to the discussion. In addition, education of the public is also critical; without it, we cannot create a collaborative environment within which we can identify common solutions and develop best strategies focused on reducing cat overpopulation.

Background: The reaction of NO with superoxide anion to form peroxynitrite has been implicated as a potential mechanism contributing to the limited NO bioavailability observed in diabetes. Furthermore, there is little evidence outlining the effects of intravenous anesthetic, propofol, on NO bioavailability in cardiomyocytes (CMs) isolated from diabetic mice. We hypothesized that propofol would act as a superoxide scavenger, thereby increasing NO bioavailability.

Methods: For NO, superoxide and peroxynitrite measurements, freshly isolated control and diabetic CMs were incubated in the presence or absence of propofol with NO, superoxide (DHE) or peroxynitrite (HKG) fluorescent probes. Fluorescence was measured using either fluorescence microscopy or a fluorescent microplate reader.

Results: NO fluorescence was decreased 34 ± 8% in diabetic CMs as compared to control. Superoxide-dismutase polyethylene-glycol (catalyzes superoxide; PEG-SOD) increased fluorescence 33 ± 6% in diabetic CMs while it had no effect on the control. Intra-nuclear DHE fluorescence was increased 41 ± 9% in diabetic CMs compared to controls. Propofol increased NO bioavailability 25 ± 7%, 32 ± 5% and 41 ± 6%, respectively, in diabetic CMs while having no effect in controls. Moreover, propofol decreased superoxide 24 ± 8% and peroxynitrite 27 ± 3% in diabetic CMs while having no effect in controls.

Conclusions: Our results indicate that NO levels are decreased in diabetic CMs due to its reaction with elevated superoxide levels, producing excessive amounts of peroxynitrite. Clinically relevant concentrations of propofol increased NO bioavailability and this is, in part, mediated by the propofol-induced decrease in superoxide in diabetic CMs.

Alzheimer’s disease (AD) is one of the most prevalent neurodegenerative diseases, affecting over 5 million people in the United States. Previous work in our laboratory demonstrates the importance of luteinizing hormone (LH) signaling in learning and memory and AD. Though we have also previously demonstrated that LH is present in the brain, the neuroanatomical and cellular localization of LH has not been determined. To address this, we carried out immunofluorescence of free floating coronal sections to determine in which regions of the brain and cellular types LH are located. Immunoreactivity of LH is observed in limbic system areas associated with emotion as well as learning and memory and several midbrain motor nuclei. Importantly, high expression of LH is visualized in the retrosplenial cingulate cortex and other areas of critical importance in AD. Furthermore, we have also identified the expression of LH and GAD67 to be neuronally co-localized and the expression of LH to be localized to inhibitory neurons. Together our findings demonstrate that LH localization and the co-localization of LH and GAD67 are in areas and cell types important in regulating cognitive and emotional circuits. Thus, our data further supports a direct role of this hormone in cognition.

Moth Species Diversity and Abundance Across Different Habitat Types in South Africa Savanna

Ruthann Antolik, Brettney Lamp

We recorded moth species richness and diversity at the Wits Rural Facility in the Limpopo province, South Africa. It was conducted from January 5th to January 10th. The purpose of this study was to observe whether moth community composition changed across three different habitats within the South African savanna biome. Those habitats were the ecotone, our campsite, which represented a disturbed habitat, and woodland. We compared these three habitats because each one is different enough to foster different morphotypes, but they are also close enough to have an overlap in morphotypes. We expected the disturbed habitat to have the highest abundance and richness because it is very well lit, attracting many moths. Moth traps were set within each habitat by hanging white sheets and placing a lantern in their proximity to attract moths. We set three replicates in each habitat. The moths were collected the following morning between 4:30 AM and 5:30 AM. The collection was done for four days. Collected moths were placed in a “kill jar”, a container with acetone in the lid's compartment to collect moths without damaging their wings. We categorized 37 moth morphotypes and counted their relative abundance. Overall, there were more morphotypes collected in the disturbed habitat, as well as more moths collected overall. Our results suggest a very limited overlap in morphotypes across different habitats.