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Effects of Brain NAT8L Knockdown on Myelin
Neurological disorders such as multiple sclerosis and Alzheimer’s disease are a result of decreased levels of N-acetylaspartate (NAA) in the brain. NAA is a brain-specific mitochondrial metabolite that plays a role in lipogenesis and myelination within the central nervous system. NAA is synthesized by an N-acetyltransferase enzyme that is encoded by the gene N-acetyltransferase-8-like (NAT8L) and metabolized into acetate and aspartate by the enzyme aspartoacylase (ASPA) in oligodendrocytes. Oligodendrocytes are neuronal cells responsible for myelinating the central nervous system axons. This study is sought to examine the changes in myelin lipids using brains of postmortem NAT8L knockout mice, which were unable to synthesize NAA. Western blotting and immunohistochemistry will be performed to measure the effects of NAA deficiency on myelin.
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Working Backwards: Enhancing Forest Restoration by Reversing Effects of Reclamation on Soil Bulk Density
Cuyahoga Valley National Park is readily accessible and located only 15 miles from Kent State University. My study focuses on one of more than 40 legacy mines in the park. Before the 1970’s, these mines were used for gravel to build nearby highways. After mining, reclamation efforts were minimal. Industrial rollers were used to compress the soil to stop nutrient runoff and prevent further pollution. Although this brought life back to the sites, the compaction made it nearly impossible to grow woody plants due to inability to spread roots. Recently the National Park Service and Kent State has become interested in reintroducing hardwood trees to return these sites to their natural form. The national park adopted a soil ripping method to reduce the soil bulk density to allow roots to expand and grow. Large shanks were dug into the ground and “ripped” through the soil in a 2x2 meter grid pattern throughout the field site. To determine its effectiveness, we dug pits and took soil bulk densities at varying depths to 60cm. The bulk density of the soil was generally lower in the rips than in the non-rips at depths deeper than 20cm. This helped to reverse the previous compaction resulting from land remediation. The lower bulk densities lead us to believe that the roots of hardwood trees will penetrate soils easier in the rips than in the non-rips. We hope that this soil ripping technique will have a lasting positive effect on the root penetration of our trees.
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Full Spectrum Hemp Extracts and Black Tea Extract Inhibit Ovarian Cancer Cell Proliferation
Isolated cannabinoids, catechins and theaflavins exhibit cytotoxicity toward many cancer cells, including those derived from ovarian cancer. However, other phytochemicals in whole plant extracts may potentially modulate each other’s effects via the “entourage effect” as has been observed with Δ9-tetrahydrocannabinol (THC) versus whole plant extracts (Biochem Pharmacol 157:285-293, 2018). Therefore, we investigated if these extracts inhibit the proliferation and migration of ovarian cancer cells. All experiments were performed in serum-free DMEM:F12 medium in the presence or absence of broad and full spectrum hemp extracts and a standardized black tea extract. For cell survival studies, the extracts were tested on subconfluent cells. Cell migration assays were performed on confluent cells. The activity of matrix metalloprotease-2 (MMP-2) was assayed by zymography on gelatin gels. Data were analyzed by one-way ANOVA and Bonferroni post-hoc test. The results of our studies suggest that both full spectrum hemp extract, which contains multiple cannabinoids and terpenes, and the black tea extract with theaflavins are cytotoxic to SKOV3 ovarian cancer. Broad spectrum hemp extracts did not exhibit any antiproliferative activity, while the full spectrum and black tea extracts inhibited the proliferation of the cells. The cells rounded up, swelled, and detached from the substratum in the presence of the hemp extract alone, but remained attached and swollen when treated simultaneously with both extracts. The migration of cells was inhibited primarily by the black tea extract. The activity of MMP-2, a gelatinase associated with tumor cell migration and metastasis, was also markedly inhibited by the black tea extract.
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Assessing Plant Species’ Diversity with the Whittaker Plot Method in Queen Elizabeth National Park, Uganda
Uganda’s Queen Elizabeth National Park (QENP) has historically contained diverse vegetation for wild animals. New prevalence of the invasive woody plant Dichrostachys cinerea has caused rapid biodiversity loss and forced these animals into private pastureland that worsens human-wildlife conflicts. Consequently, QENP staff have devoted countless hours relocating animals back into the park and assisting the community. As an intervention designed to mitigate woody plant encroachment, habitat patches within QENP have been clear cut to reset vegetation succession and remove invasive species. QENP’s long-term goal is to restore the grasslands, bring back the grazer populations, and reduce human-wildlife contact. Whittaker’s plant diversity sampling method consists of a pattern of taped off quadrats that are compounded to project the species richness. Kent State University students laid out Whittaker plots in QENP with the help of students and staff from the Uganda Wildlife Research and Training Institute. The purpose was to compare species richness in a cleared habitat patch with a patch of similar size that had not been cleared of the woody invasive plants. Results project that the cleared habitat patches had higher plant species abundance than the uncleared patches. There were numerous juvenile plants in the recently cleared area; high species competition can be inferred from this. This was preliminary research to assess the effectiveness of clear cutting as a conservation practice for native flora. Future monitoring should be done to conduct the Whittaker plot method on a larger scale and test the possibility of using alternative conservation methods that manipulate fire and grazing.
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Lichens of Two Kent State University Properties in Portage County, Ohio
Lichens are a diverse and speciose group of organisms that have colonized every continent on the planet. They occur on virtually all natural substrates, as well as numerous synthetic substrates, and play essential roles in healthy terrestrial ecosystem. Similar to other groups of inconspicuous organisms, lichens are underrepresented in almost every facet of biological research, and much about them, including diversity, ecology, distribution, medicinal uses, etc. remains hidden under a veil of obscurity. In this study, two comprehensive surveys of lichens were conducted at two different properties owned by Kent State University. A specimen of each species found was collected for each site in order to increase lichen representation in local herbaria. A total of 91 species were found, all of which were included in a dichotomous key in order to provide identification capability for a novel combination of lichen species.
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Generation of Tissue-specific Huwe1 Knockout Mice
Huwe1 is a ubiquitin E3 ligase that plays a role in regulating the DNA damage response, apoptosis, metabolism, and autophagy in various cell types. The objective of this study was to determine the impact of Huwe1 deletion in different tissues by generating transgenic mouse models. We crossed a tissue-specific Cre mouse line with the Huwe1flox/flox mouse line in which exon 11 of the Huwe1 gene is flanked by two loxP sites. When expressed in the same cells, Cre recombinase would excise exon 11, resulting in a frameshift that generates a premature stop codon. By choosing different tissue-specific Cre mouse lines, this method allowed us to create tissue-specific Huwe1 knockout mice. First, lymphocyte-specific Huwe1 knockout mice were generated using a mouse line that expressed Cre recombinase under the Rag-1 promoter. Second, liver-specific Huwe1 knockout mice were created utilizing an Alb-Cre mouse line that expressed Cre recombinase under the albumin promoter. Lastly, inducible whole-body knockout mice were generated through the Cre allele fused to the modified estrogen receptor (ER), which translocates from the cytoplasm to the nucleus upon binding to the estrogen antagonist, tamoxifen. In this Cre-ER model, injection of tamoxifen induced acute deletion of the Huwe1 gene. In all the knockout mouse models, we performed PCR to confirm their genotypes. We also carried out western blot to analyze the depletion of Huwe1 protein in the tissues. We will discuss phenotypes of each tissue-specific Huwe1 knockout mouse model.
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Perilipin 3 Binding to Model Lipid Droplets Using Pendant Drop Tensiometry
Lipid droplets (LDs) are dynamic organelles that are critical for cellular energy regulation. LDs consist of a neutral lipid core and a phospholipid monolayer, which allows for protein localization and binding. The mechanism of protein-lipid interactions at this monolayer remains less understood compared to those at biological membranes. These LD-associated proteins are essential to the development and functionality of LDs. One of the most abundant families of mammalian LD-binding proteins is the perilipin family, consisting of five proteins, named perilipin 1-5. Perilipins 1 and 2 are found bound to LDs, while perilipins 3-5 exchange between the surface of LDs and the cell cytosol. We are interested in the mechanism by which these exchangeable, or cytosolic, proteins bind to LDs. Here, we study the protein perilipin 3. Langmuir monolayer data from our lab suggest that the α-helix bundle located on the C-terminus of perilipin 3 has strong interactions with the lipid interfaces. To obtain a more comprehensive picture of the function of this C-terminal domain, we compare the full-length perilipin 3 to a truncated sequence that contains only this domain. Pendant drop tensiometry is used to examine protein binding to simulated LD monolayers with lipids that have the same headgroup structure but varying acyl chain saturation, and with lipids with the same acyl chain saturation but varying headgroup size and charge.
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Variation in Muscle Thermogenic Response to Predator Threat Stimuli in Mice
With the growing obesity epidemic, there is a drive to determine a better route for weight reduction. We are interested in mechanisms to increase caloric expenditure in mice and rats, including muscle thermogenesis. We discovered that muscle thermogenesis can be acutely induced by predator threat, specifically predator odor, in rats and mice. In mice, other stimuli may more potently activate this sympathetically- driven muscle thermogenesis. Here, we investigated the potential multimodal activation of muscle thermogenesis in the mice. We hypothesize that the mice will show a greater thermogenic activation when exposed to the multimodal predator stimulus (mobile robotic stimulus) compared to the predator odor because of the increased threat perceived. First, mice were habituated to the conditions of the study. Then, mice were presented with three stimuli in randomized order: control, ferret odor, and the multimodal robotic bug. There was a trend observed toward a significant effect of the multimodal predator threat on muscle thermogenesis with control inducing the lowest thermogenesis, then ferret odor and multimodal predator stimuli with higher activation of thermogenesis. This suggests that the multimodal approach may more potently activate muscle thermogenesis; however, more statistical power is needed. Additional combinations of stimuli can be examined in combination with the multimodal approach.
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Tight Junction Proteins in Mice
The purpose of this study was to evaluate tight junction protein changes during different time points of cuprizone treatment in the corpus callosum and cortex of mice. Cuprizone is a copper chelator that causes demyelination and is used as an animal model of multiple sclerosis. Demyelination is the result of breakdown of the myelin sheath that insulates neurons and can cause nerve impulses to slow down or even fail. It is important to study demyelination because it causes neurological problems associated with multiple sclerosis and current treatments are lacking. Studies in our lab have shown early breakdown of the blood brain barrier during cuprizone treatment. Tight junction proteins are molecules that maintain the integrity of the blood brain barrier that protects cells in the brain. TJ proteins have barrier functions that hold cells together and facilitate signaling in the central and peripheral nervous system. Mice were given 0.3% cuprizone as a diet for two different time periods, three days and one week. The brains were extracted and sliced and the tight junction proteins were immunolabeled and imaged using a confocal microscope. Cuprizone fed and control mice staining patterns were quantified and compared in the corpus callosum and cortex at three days and one-week of treatment.
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The Search For Happy Chromatin: An Analysis of the Relationship Between Neurodegeneration and Serotonylation
Multiple sclerosis (MS) is an autoimmune disorder characterized by demyelination of the central nervous system (CNS) and neurodegeneration. Serotonin is a neurotransmitter that plays a role in numerous pathways throughout the body including sleep, happiness, and epigenetic modifications. Recent studies have found that serotonin levels are decreased in MS for reasons that are currently unknown. This is significant because serotonin plays a role in the post-translational modification of histone 3. Because serotonin is decreased, we have hypothesized that serotonylation is decreased which leads to subsequent aberrant gene expression in MS. The purpose of this experiment is to explore a new epigenetic mark and its role in neurodegeneration and MS. Using the cuprizone mouse model of MS, we isolated brain tissue and looked at changes in serotonylation. Because Alzheimer’s disease (AD) is also characterized by neurodegeneration, brain tissue from mice treated with APP (AD mouse model) was also analyzed. Analysis was conducted on nuclear fractions via Western Blotting, confocal imaging, and densitometry.
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Soil Salinity: How Much Road Salt Do Stormwater Wetland Soils Retain?
Road salt is commonly used to remove ice from the roads by lowering the freezing point of the water. During the winter, the roads are often treated with the salt before there is significant precipitation and cold weather to prevent dangerous accidents on the road and ultimately, create a way to make transportation safer. However, the road salt is contributing to a problem within the aquatic ecosystems. The road salt has ultimately increased the salt concentrations in freshwater ecosystems. Such examples of these ecosystems are wetlands, streams, and lakes. With increasing salt concentrations, both the plants and animals in these ecosystems, adapted to live in freshwater, can be seriously affected and harmed. Wetlands, have been commonly known to filter pollutants from water. As the preliminary work shows in the Kinsman-Costello lab, wetlands can remove salt from the water. Ultimately, wetlands reduce the transport of the harmful concentrations of both salt and pollutants. Although there is knowledge that wetlands can remove salt, it is unknown where the salt goes within the wetland. The project will assess how much salt is stored within the soil and sediments of wetlands impacted by stormwater runoff, carrying high salt concentrations as due to the deposits of salt trucks. In the project, soil salinity and extractable concentrations of specific salt ions will be measured such as chloride and sodium.
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Invasive Plants Fight Back: The Battle of Managing Invasive PlantsLantana camara is an invasive plant species that is bird-dispersed and has spread across South Africa, perhaps because of its allelopathic properties. I examined the dispersal of L. camara under and away from tree canopies in a communal and conserved area near Acornhoek, South Africa as a follow-up study to that of Rodger and Twine (2002). These authors found that L. camara was more common in the communal area than in the conserved area. In the 20 years between studies, herbicide was sprayed in the conserved area to control L. camara. As found in the earlier study, I found more L. camara in the subcanopy than in the intercanopy. There was a large increase in the number of L. camara plants in the conserved area relative to the earlier study, although the individuals were far smaller, and virtually no L. camara in the communal area. I tested the allelopathy hypothesis by examining the suppression of the germination rate of two plant species, Raphanus sativus and Cynodon dactylon seeds in soil collected from under L. camara bushes and in open areas. I found that R. sativus seeds had a higher average germination rate in open-area soils (95%) than in L. camara soils (84%), while the opposite was true for C. dactylon seeds (84% vs. 90%). These results suggest that birds are important dispersers of L. camara seeds and that allelopathic effects vary between plant species. Most concerning was that regrowth in the conserved area has occurred despite herbicide application. |
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Feeling Salty-Road Salt Does not Cause the Decline of Dominant Swamp Forest Species in Mentor Marsh
The changing ecosystem of the Mentor Marsh, in northeastern Ohio, is an important topic of discussion among ecologists. Over decades, the diverse native swamp forest in this marsh has declined and has been replaced by a single species, the common reed Phragmites australis, that is salt-tolerant. Many experts believe this is due to the large amount of road salt dumped adjacent to the marsh. Using a greenhouse experiment, we tested the effect of road salt on five dominant swamp-forest species that are representative of those in decline at the Mentor Marsh. We hypothesized that trees exposed to high levels of salt would be less healthy than those exposed to low levels of salt. Experimentally, this can be tested by comparing the growth rates and levels of nutrients, specifically nitrogen and nonstructural carbohydrates, in the plants. Surprisingly, we found that there was no significant difference in the amount of nutrients between trees exposed to high salinity and trees exposed to low salinity. In conclusion, the increasing amount of road salt at the Mentor Marsh alone has not influenced the ecology of the marsh. However, further research is being conducted to determine if the combination of road salt and agricultural run-off has negative effects on the tree species.
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Maternal Huwe1 is Indispensable for Oocyte Maturation and Early Embryonic Development
Huwe1 is a ubiquitin E3 ligase and tags various proteins for degradation via the ubiquitin-proteasome pathway. The aim of our study is to elucidate a role of Huwe1 in female infertility. Utilizing the Zp3-Cre/loxP system, we generated an oocyte-specific Huwe1 knockout (KO) mouse line. When Huwe1 heterozygous females were bred with wild type males, the number of litters was significantly reduced and, more importantly, the Huwe1 knockout allele was not passed on to the litters. In Huwe1 heterozygous females, oocytes matured and fertilized in vitro normally. However, only 50% of eggs isolated from Huwe1 heterozygous females reached the blastocyst stage in vitro. This suggests that Huwe1 knockout eggs died at an earlier stage. Interestingly, the oocyte-specific homozygous deletion of the Huwe1 gene caused complete female infertility. In vitro oocyte maturation assays further revealed that almost all of the knockout oocytes died or remained arrested at the germinal vesicle (GV) stage, whereas the majority of Huwe1 wild type oocytes matured to meiosis II. These results suggest that the loss of Huwe1 negatively affects oocyte maturation and early embryonic development, resulting in female infertility. Importantly, knockout of one of the well-known substrates of Huwe1, tumor suppressor p53, did not rescue any of these phenotypes in Huwe1 KO female mice. Therefore, it is suggested that female infertility in Huwe1 KO mice is secondary to the accumulation of a substrate of Huwe1 other than p53. Together, our results indicate that maternal Huwe1 is indispensable for oocyte maturation and early embryonic development.
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Association Between Mosquito Spread and Neurodegenerative Diseases: A First Glance
Mosquitoes carrying important arboviruses, such as West Nile (WNV) and Zika (ZIKV) viruses, have expanded in range over the past few decades due to numerous factors, including climate change, international trade, and long-haul travel. Many arboviruses activate the host’s innate immune response,including interferon (IFN) pathway. On the other hand, the IFN pathway has been shown to be involved in neuroinflammation and neurodegeneration, such as that seen in Alzheimer’s and Parkinson’s diseases (PD). We hypothesized that viral-triggered IFN activation may contribute to neurodegenerative diseases. Here we examine relationships between changes in the mosquito distribution and PD incidence from 1990 to 2010, as well as any changes in rainfall, and average temperature worldwide. We also considered distribution of variants of IFN type III genes, IFN Lambda 3 and 4, in human populations, as these genes have been shown to play a role in immune response to flaviviral infections. Our results show similarly increasing trends in PD incidence and mosquito spread over time across different countries. For example, during this study period Italy, Russia, and the United States all experienced an increase in distribution and/or introduction of a new mosquito species capable of carrying arboviruses. At the same time these countries appeared to have an increase in incidences of flaviviral infections and PD. While multiple factors, including better diagnostic and surveillance of neurodegenerative diseases, may be responsible for the reported PD trends, the potential links between arboviral infections and neurodegenerative diseases should be explored further.
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Effects of Urbanization on Nutrient Cycling in Freshwater Ecosystems
The functioning of stream ecosystems can be influenced by many factors, both natural and anthropogenic. As urban sprawl becomes an increasing issue and the demand for freshwater increases, urban stream ecosystems are seeing an imbalance in nutrient supply, which may influence rates of key ecosystem processes. The cotton strip assay uses small strips of cotton as surrogates of leaf material to measure decomposition and determine environmental factors that influence carbon cycling. Cotton strips were placed in 19 sites across the Chatahoochee and Ocmulgee River basins in the Atlanta,GA Metropolitan Area. From these cotton strips, phosphorus, carbon, and nitrogen content were analyzed to see the effect urbanization had on nutrient content in streams and on the process of carbon cycling. We anticipate that there will be high N and P content in cotton strips in the most urban streams, which increased rates of decomposition. Overall, this technique can show us how nutrient imbalances affect the ecosystem processes that occur in urban environments and inform efforts to potentially reduce or fix nutrient imbalances.
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Effectiveness of Fluorogold Bound Conjugate in Imaging Mice Neuroendocrine Circuits
The purpose of this study was to analyze the efficacy of a Fluorogold bound conjugate in labeling neuroendocrine circuits of the median eminence and paraventricular nucleus in the hypothalamus. Fluorogold is a retrograde tracer that is detectable by confocal microscopy and can be linked to gadolinium DOTA to be detectable by MRI. The Fluorogold bound conjugate labels neuroendocrine cells with axon terminals that extend beyond the blood-brain barrier following an intraperitoneal injection. 72 hours after injection, MR images were taken then mice were sacrificed and brains were extracted and sliced to be analyzed with confocal microscopy. Results show that the fluorogold bound nanoparticle was not as effective as fluorogold alone in labeling the hypothalamus. This study establishes a framework for future creation of more effective particles that can be detectable by both confocal microscopy and MRI. This data will be used to understand mechanisms and to identify potential techniques to image neuroendocrine cells in the hypothalamus noninvasively, as they are important for hormonal regulation of important functions within the body, and dysfunction can lead to issues such as neurodegenerative disease, cardiac and respiratory dysfunction, and blood pressure abnormalities.
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A Comparison of Rolled Leaf Beetles (Coleoptera: Chrysomelidae) in the Families Marantaceae and Heliconiaceae of Costa Rica
In the tropics, a group of tropical chrysomelid beetles live their lives within the immature, rolled leaves of Heliconia and Calathea plants. Within the rolled leaves, the beetles are able to obtain anything they’d need: shelter, food, and a breeding habitat. In this study, chrysomelid beetles were collected from within the rolled leaves of the Heliconiaceae and Marantaceae families of two field stations in Costa Rica. Two genera of beetles were present within the sampled plants, Cephaloleia and Chelobasis. Within these genera, there were a total of eight beetle species. Some of these beetle species showed plant-host specificity. The remaining beetle species were found to generalists in relation to their host plant. Overall, the beetle community dynamics differed between the beetles found in the two plant families.
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Golf Green to Green Stream: Does a Stream Restoration in an Ex-golf Course Impact Terrestrial Invertebrate Community?In recent years, human populations have grown at an astronomical rate. This has led to the loss, degradation, fragmentation, and homogenization of ecosystems across the globe. To try to combat this, restoration efforts are becoming more common throughout the United States as an effort to reclaim unused areas and return them to green space. One such example where restoration efforts are becoming more common are in old golf courses and country clubs throughout the state of Ohio. The purpose of this study was to assess the effect of stream restoration on the adjacent terrestrial invertebrate communities in former golf courses in Northeastern Ohio. This study was conducted in two reclaimed golf-courses: Acacia Reservation and Orchard Hills Park. In these parks, both restored and unrestored areas were of interest. Pitfall traps were used to sample the terrestrial insect communities. One was placed in the riparian zone, one in the upland, and one in the ecotone between these sites. A total of 18 traps were placed within each site and were collected after a week. This led to a total of 36 samples collected on one sampling date. It was hypothesized that invertebrate structure would differ between areas adjacent to streams that were restored vs unrestored. It was predicted that stream restoration efforts would increase invertebrate community dynamics such as Shannon’s diversity, richness, and abundance. We found that the insect communities have not truly recovered in the restored areas. The restoration status had no significance on species richness, biodiversity, or abundance. |
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Seasonal Fluctuations of Microbial Biomass Phosphorus and Nutrient Composition within a Vernal Pond System
Vernal ponds experience hydrologic changes throughout the year that cause heterogeneity in soil redox conditions which alter nutrient bioavailability in the soil. During flooded conditions, minerals such as iron (Fe) remain in a dissolved state, unable to sorb nutrients like phosphate (PO43-). As vernal ponds dry out, oxygen diffuses through the soil causing iron oxides to precipitate. These minerals can sorb PO43-, making it unavailable to organisms. Additionally, seasonal changes within temperate vernal pond soils can affect PO43- concentrations depending on precipitation, temperature and organic matter quality. Generally, as soils thaw, PO43- bioavailability increases due to microbial cell lysis in which nutrients are expelled from cells. Further, fresh leaf litter during autumn can also provide an input of PO43- to these soils. Therefore, I predict that there will be higher concentrations of PO43- in microbial biomass during the autumn and spring seasons. To assess changes in PO43- concentrations in microbial biomass as a function of seasonal variations, we obtained soil samples from lowland soils within a vernal pond and upland soils adjacent to the pond in Northeast Ohio during spring, summer, autumn and winter months. We measured microbial biomass P using traditional chloroform fumigation followed by a salt extraction. Preliminary results show that upland soils have a higher concentration of PO43- in microbial biomass compared to lowland soils. Additionally, upland soils have a higher percentage of organic matter than lowland soils. Further investigation of microbial biomass P will determine how significant seasonal events like thawing and leaf litter additions contribute to PO43- bioavailability in vernal pond soils.
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Assessing Biofilm Diatom Community Response to Nutrients
Anthropogenic changes to the environment impact aquatic ecosystems by modifying resource availability, which could influence community composition and function. Studies suggest a positive relationship between diversity and ecosystem functioning, with more diverse systems being more resilient. Some individuals are particularly sensitive to nutrient shifts in the environment. Organisms that indicate change in the environment are valuable because they shed light on humans’ impact on the ecosystem. Diatoms are useful bioindicators of water quality, as they respond to environmental conditions like nutrient inputs.To test the effect of nutrient availability on diatom community composition, we deployed nutrient diffusing substrate at four stream sites before and after nutrient rich tributaries. We used seven nutrient treatments including macronutrients phosphorus and nitrogen, along with micronutrients molybdenum and zinc with a control at each of the four sites. We expect the phosphorus treatments to select for fast growing taxa, and for the magnitude of this effect to be less at sites with higher background nutrient concentrations. Preliminary results indicate that tributaries upstream and downstream of nutrient rich tributaries have unique algal communities. Results from this experiment will provide insight into how stream communities respond to anthropogenic influences.
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Aboveground Biomass Tissue Chemistry in Old Woman Creek Estuary (Huron, OH)
Runoff containing excess nutrients from agricultural land use causes eutrophic conditions in freshwater systems, including harmful algal blooms. The nutrient storage capacity of wetlands may help mitigate recurring annual harmful algal blooms that the Western Basin of Lake Erie experiences due to excess phosphorus (P) loads. Wetlands are hot spots of carbon (C), nitrogen (N), and P cycling, and wetland plants temporarily store C, N, and P. We investigate how plant tissue chemistry (total P, total organic C, and total organic N) varies by plant taxa and tissue type (leaf vs. stem) within a well preserved Lake Erie coastal wetland. In the summer of 2019, we sampled aboveground plant tissues of two plant types in the Old Woman Creek estuary wetland: emergent plants (Phragmites and Typha), and floating leaf plants (Nelumbo and Nymphaea) to measure total C, N, and P concentrations of plant biomass as an index of plant nutrient storage. We predict that the emergent plant types (Phragmites, Typha) will have higher C and N concentrations than the floating leaf plant types (Nelumbo, Nymphaea) due to their higher allocation to structural tissues like rigid stems. We also predict that there will be higher P concentrations in the leaf tissues than in the stem tissues of all plant types. Plant tissue chemistry improves understanding of nutrient storage capacity of different plant types, thus informing wetlands preservation and management decisions.
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Phosphorus Sorption Capacity of Sediments in Constructed Urban Wetlands of Northeast Ohio
Excess phosphorus (P) can lead to eutrophication of aquatic ecosystems and dead zones as recently seen in Lake Erie and the Gulf of Mexico. The potential for wetlands to remove phosphorus (P) from the water column varies based on the mineral composition of the sediments, herbaceous cover, age of the wetland, surrounding land usage, as well as many other variables. Total iron concentration has been found to be a good predictor of P sorption capacity in best management practice urbanized wetlands. In the summer of 2019, I collected sediment samples from open water areas, Typha stands, and mud-flats in three constructed, urbanized wetlands on Kent State University’s campus. To better understand P sorption capacity in the three wetlands, I assessed the phosphate sorption, or “stickiness” of the sediment, with a phosphate sorption index assay. To determine the primary mechanisms of phosphorus retention in each wetland, I measured percent organic matter, total iron oxides, and the proportion of poorly-crystalline iron oxides. Preliminary analysis of PSI results shows the mud-flats and the Typha stands of the youngest wetland sorb the least amount of phosphate. Upon further analysis, I expect to find lower concentrations of total iron oxides and/or a lower proportion of poorly-crystalline iron oxides in these sediments. This information could help guide future construction of wetlands in urbanized areas to maximize phosphorus retention to prevent downstream pollution events.
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Opioids Affect Intrinsic Ca2+ Spiking Behavior in Individual Cultured Nodose Ganglion Sensory Neurons
Introduction: Opioid overdose with synthetic opiates such as fentanyl are known to result in opioid-induced respiratory depression (OIRD). The effect of opioids has been shown well in the Central nervous system but, it’s effects on the Peripheral nervous system have not been well characterized. Sensory neurons within the Nodose Ganglion (NG) are important for regulating respiratory and cardiac behavior. NG neurons use changes in intracellular Ca2+ concentration ([Ca2+]i) to regulate neuronal communication important for regulating and modulating ventilatory dynamics. Objective: To examine the effect of fentanyl on the intrinsic Ca2+ spiking behavior in individually cultured rat NG sensory neurons. Methods: NG neurons were isolated from rat pups. “Real-time” Ca2+ imaging was used to assess intrinsic Ca2+ spiking behavior in the presence or absence of fentanyl. Results: Intrinsic Ca2+ spiking behavior varied amongst the population of NG neurons. Exposure to fentanyl decreased intrinsic firing frequency and amplitude of NG neurons that were exhibiting excitatory behavior. In contrast, exposure to fentanyl stimulated intrinsic firing of neurons that were initially quiescent. Also, removal of Ca2+ from the perfusate completely eliminated intrinsic Ca2+ spiking behavior in the presence or absence of fentanyl. Conclusion: This new approach to use intrinsically firing neurons as a model to test the effect of opioids has opened new avenues and our data provides evidence that fentanyl differentially modulates intrinsic activity of the NG sensory neurons and may be important in OIRD at the cellular level.
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Identifying Tree Species from Unknown Roots Samples Via Restriction Fragment Length Polymorphism
In order for researchers to understand temperate hardwood forest ecosystems, aboveground processes such as succession and net primary productivity are often the focus of experiments. However, belowground processes, such as interactions between tree roots and fungi, warrant further investigation. All trees in forests of the northern hemisphere have a root network that interacts with a specific fungal community called mycorrhizae. These two groups form an obligate symbiotic relationship which means that they require each other’s presence to survive. As the mycorrhizae break down organic nutrients for tree roots to more readily take up, the tree in turn releases carbon that feed the fungi. The strength and dependence of these interactions are dictated by the broad category in which the interaction falls: arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM). Our lab has set up a field experiment that studies these important belowground interactions and their effects on tree root neighborhoods. We placed root ingrowth cores in Jennings woods, a nearby hardwood forest owned by Kent State University. One key element of this experiment is developing a method to identify tree roots collected from these cores. This poster presents a way to identify roots from unknown tree species using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) digestion to amplify root DNA and create a unique molecular fingerprint for each species. This library of known profiles can then be used to identify samples of unknown roots collected from the ingrowth cores in our experiment, as well as hardwood forests worldwide.
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