Digital Commons @ the Georgia Academy of Science
Not a member yet
1290 research outputs found
Sort by
DMSO, BUT NOT WATER, CAN EXTRACT COMPOUNDS FROM TURF FIELD INFILL THAT ACTIVATE THE ARYL HYDROCARBON RECEPTOR
No full textThe use of infill beads made of ground rubber for turf athletic fields has raised concerns that prolonged exposure may increase cancer risk, especially for athletes who play frequently on these fields. Vulcanized rubber, such as that found in tires, is known to contain polycyclic aromatic hydrocarbons (e.g., B[a]P) that promote DNA mutations. Exposure to aryl hydrocarbon receptor (AhR) ligands activates CYP1A1 expression and the subsequent metabolism of B[a]P to its highly-mutagenic diol-epoxide form. Previous studies indicate increased AhR activity with DMSO extracts of ground tire infill. This study compares the components of different field infills, one using only black ground tire rubber and another using a mixture of black ground tire rubber and green rubber beads. Mouse hepatocytes were treated with infill extracts made with water or DMSO. AhR activity was determined using a CYP1A1-promoter luciferase reporter assay. Some samples were co-treated with the bioflavonoid, quercetin, an inhibitor of the AhR. DMSO extracts made from black-rubber-only infill expressed a 14.1-fold increase (p \u3c0.001) in AhR activity. The DMSO extracts made from black tire-rubber in the mixed infill increased AhR activity 17.3-fold (p \u3c0.001), while the DMSO extracts made from the green rubber beads from the mixed infill increased 19.5-fold (p \u3c0.001). Quercetin treatments decreased AhR activation in all DMSO infill samples (74%, 75%, and 85%, respectively). None of the bead extracts made with water activated AhR activity. These data suggest that, while AhR agonists are present in the turf infill tested, water is less likely than DMSO to extract these compounds as a delivery pathway to people using these fields
HOW DOES WATER QUALITY, PHYSICAL SETTING, AND COASTAL DEVELOPMENT AFFECT OYSTER SPAT SETTLEMENT IN SOUTHERN GEORGIA SALT MARSHES?
No full textMuch of the United States\u27 East Coast has experienced a decline in eastern oyster (Crassostrea virginica) landings since the early 1900s. In Georgia, this decline has been linked to overharvesting, disease, storms, and alterations in both water quality and natural flow regimes. Although past research has provided important information about the distribution of Georgia oyster reefs, microsite differences of spat settlement in relation to water quality, sediment composition, and coastal development have not been adequately addressed. A study was begun in March 2020 to determine if oyster spat settlement is correlated with these parameters. Three sites were chosen on Sapelo Island and three sites on Jekyll Island based upon proximity to development and location along the upland-estuary-sound gradient. Oyster spat settlement racks were established at each site. Tiles were collected every six weeks and number of oyster spat along with other biofouling organisms such as barnacles (Chthamalus fragilis) were determined. Additionally, water quality and sediment composition were measured during each collection period. The highest oyster spat settlement occurred in open sites with relatively high salinity, low turbidity, and high nitrogen levels. The highest barnacle settlement occurred in upper tidal creeks with relatively low salinity, high turbidity, and low nitrogen levels. Implications of this correlational analysis are discussed as well as future in-field manipulation experiments. This study is a preliminary attempt to develop a model for identification of potential oyster reef restoration sites
Effect of Bridges on Low Order Stream Fish Assemblages, South Georgia, USA
Get PDFAnthropogenic impacts such as bridge sites can greatly alter established streambed morphology, associated ecology and flora and fauna. At bridge sites, streams are often channelized approaching the site and deep pools are created at the bridge site causing ecological alterations of faunal assemblages. However, restoring channels and reducing negative construction practices allows the return of natural habitats that are likely to include more sensitive species. Recent conservation studies have suggested that anthropogenic sites may serve as potential habitats for reestablishment of populations following a drought event. This study examined the impact of bridges on fish assemblages at first through fourth order streams in the Suwannee River Basin of South Georgia. Collections were made at bridge, upstream and downstream sites via seining and setting of gill nets. Assemblage structure at bridge sites was compared to bridge structure, biological and physiochemical factors at fourteen bridge sites. Fish assemblages were least diverse upstream of bridge sites, most diverse at bridge sites, and intermediate in diversity downstream of bridge sites. The results suggest that bridge sites, if properly engineered, can serve as valuable refuges for reestablishing fish assemblages up and down stream after events such as the severe drought that impacted South Georgia in 2011
MICROBIAL FERMENTATION OF KUDZU (PUERARIA MONTANA): FROM INVASIVE PEST TO BIOFUEL FEEDSTOCK**
No full textThe challenge of replacing petroleum-based fuels with something less environmentally damaging has been worked on extensively in recent decades. One of the first and most cost-effective steps toward a greener carbon footprint involves replacing light petroleum distillates used in gasoline with a bio-based fuel, such as ethanol. Production of ethanol from sustainable sources is directly dependent on their carbohydrate content. Cultivated crops such as maize, beets and sugarcane are currently used, but these rely heavily on unsustainable land use practices to produce the required fermentable compounds. Kudzu (Pueraria montana) is a fast-growing invasive in the United States, that often contains similar amounts of carbohydrates as today’s biofuel crops. Our research is focused on directly and qualitatively producing ethanol from kudzu by microbial fermentation. We used leaves and roots as our carbohydrate source, both of which contain significant amounts of carbohydrates. We tested several common strains of Saccharomyces cervisiae yeast, in combination with alpha-amylase and amyloglucosidase enzymes to break the starches into fermentable sugars. We also tested various pre-fermentation treatments of the plant material. Ethanol content was measured by 1H NMR spectroscopy. If possible, the production of ethanol from kudzu will not only make a more sustainable fuel but help to eliminate an invasive species in the process
DEVELOPING AN EXPERIENTIAL LEARNING TECHNIQUE FOR TEACHING GENETIC PARENTAGE ANALYSIS IN THE LABORATORY**
No full textLaboratory experiences are a critical component of how universities equip students in the sciences for the job market, yet there can be several challenges when adapting difficult molecular techniques into interactive learning activities for the classroom. Providing experiential learning approaches in the laboratory enables students with diverse learning styles to grasp difficult lecture concepts. Through collaborative learning, students will engage in genetic parentage analysis of the dwarf seahorse, Hippocampus zosterae, who has a unique mating system with monogamy and male pregnancy. This multi-week experiment provides undergraduate students with the opportunity to learn common molecular techniques for identifying parent-progeny relationships and analyze the genetic component of mate selection. The project will allow for peer teaching during the group work conducted in teams, which reinforces the concepts as students learn. Nine male and 11 female H. zosterae were allowed to freely mate and offspring were collected after male seahorses gave birth. Each student group will extract DNA from sixteen offspring to compare their results with the unique genetic identities for each of the potential parents from the experimental mating tank. Using the results from the parentage assignments, students will be able to determine if seahorses preferred mates of a specific size and learn more about mate selection patterns. During the experiment, students will gain valuable hands-on experiences while learning common molecular techniques, such as PCR, gel electrophoresis to separate the DNA bands by size, and fragment analysis to identify the genetic differences for identification. The experiential learning activity will reinforce the lecture concepts for students with all learning styles and introduce students to molecular techniques that are transferable for jobs in various scientific careers. Understanding how we can teach genetic concepts through experiential learning is key for training well-rounded biology undergraduates as they prepare for their career choices after college
BIOLOGICAL EFFECTS OF BENZOTHIAZOLE DERIVATIVES: ALS CELLS AND THE EFFECTS OF THE TDP-43 PROTEIN**
No full textALS (amyotrophic lateral sclerosis) is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. Motor neurons run from the brain to the muscles by going through the spinal cord. When the motor neurons stop functioning, the ability of the brain to initiate and control muscle movement is lost. With voluntary muscle action progressively affected, patients may lose the ability to speak, eat, move, and breathe. Few drugs are known to treat against ALS. Presently, Riluzole is the only FDA-approved drug for ALS, and. this drug has been shown to have little to no effects on the treatment. Riluzole is derived from a class of compounds known as benzothiazoles. Benzothiazoles are heterocyclic compounds that contain a benzene ring and a sulfur and nitrogen within a cyclopentane group referred to as thiazoles. Benzothiazoles are ubiquitously found in clinical setting, specifically as fungicide to a cancer targeting agent. TDP-43 protein (TDP-43) is a transactive response DNA binding protein. TDP-43 is protein found in the nucleus of cells and it normally participates in several mechanisms of mRNA metabolism. Certain amino acids of the C-terminus in the protein can become phosphorylated and the protein folds onto itself in a conformation that renders it inactive with prion-like characteristics. Thus causing buildup of the proteins in the cell and delaying cytosolic degradation of the proteins which causes cellular damage and death. Benzothiazole-derivatives have been synthesized and will be tested on HEK-293T cells, wild-type TDP-43 protein, and HEK293T cells transfected with TDP43 protein in order to discern what substituents are the most effective on the treatment of ALS
Can the synergistic relationship between elemental sulfur and synthetic fungicides observed in the field be explained by their effect on the fungal growth of Northopassalaora personata?**
No full textSulfur is one of the oldest known fungicides used in peanut production to control late leaf spot disease (LLS) caused by the fungus Northopassalaora personata. Sulfur also exhibits properties that aid in making peanut plants greener, potentially increasing tolerance of peanut to LLS. In some situations, there is a synergistic reduction in LLS disease when synthetic fungicides are mixed with sulfur compared to these fungicides and sulfur alone. It is not clear whether the synergistic effect is due to sulfur’s activity on the host or the pathogen. A lab study is in progress to investigate how the fungicide-sulfur mixtures influence pathogen growth. Six treatments 1) nonfungicide control, 2) elemental sulfur, 3) Tebuconazole 4) sulfur mixed with Tebuconazole, 5) Azoxystrobin and 6) sulfur mixed with Azoxystrobin will be applied to the surface of Potato Dextrose Agar. Spores of N. personata will be placed on top of the treatments. Germination and hyphal growth will be quantified after 48 and 96 hours for at least 30 spores. If the hypothesis is true, spores exposed to the DMI sulfur mixtures will exhibit a greater than expected decline in hyphal growth based on how DMI’s target the pathogen, and spores exposed to the QoI sulfur mixtures will exhibit a greater than expected decline in germination based on how QoI’s target the pathogen. The experiment will include 3 replications and will be repeated twice
THE EFFECTIVENESS OF INDIGENOUS CONFLICT MANAGEMENT STRATEGIES IN LOCALIZED CONTEXTS
No full textThe professionalization of addressing conflict creates a field filled with specialists highly trained to apply modularized and manualized, often evidence-based solutions. But how effective are these professionalized conflict management strategies in Indigenous and localized cultural contexts compared to homegrown Indigenous approaches? While instances of these Indigenous peacebuilding and conflict management strategies are routine throughout the world, to date, no one has attempted to test which conflict management approaches are most effective empirically, nor has the literature sufficiently addressed the contexts in which strategies are most helpful. Using multi-dimensional scaling and chi-square tests of independence applied to a similarity matrix of co-occurrences from select Outline of Cultural Materials subjects from the Human Relations Area Files cultural database, this study tests the hypothesis: Indigenous conflict management strategies are more effective (i.e., less associated conflict) than non-Indigenous conflict management strategies in Indigenous contexts. We show that Indigenous conflict management approaches co-occur with conflict less often than non-Indigenous strategies. From an applied perspective, when we break conflict into four discreet types - sociocultural/interpersonal, political, legal/judicial, and economic—Indigenous conflict management strategies co-occur most often with socio-cultural types of conflicts. The results suggest that Indigenous approaches are more effective in Indigenous contexts overall, while they are most often applied to socio-cultural and interpersonal conflicts. Based on our findings, homegrown solutions effectively manage, resolve, and transform localized conflicts
W. Peter Hambright: From Chicago to Howard University Chemistry
No full textBorn in Chicago, Illinois on December 15, 1939, to Winford Peter Hambright and Theda Hambright, Dr. W. Peter Hambright1 was reared in Chicago; graduated from high school there. He earned the B.S. degree in chemistry at Antioch College in 1962. He returned to Chicago in 1962 and earned the Ph.D. in Inorganic Chemistry at the University of Chicago in 1966. Dr. Hambright joined the faculty at Howard University in 1966 and he immediately established a highly recognized research program which he sustained until his retirement in 2005 after nearly a forty-year tenure there5. Dr. Hambright’s specialization was in inorganic and bioinorganic chemistry, focusing his research on the coordination chemistry of metalloporphyrin molecules. He became the “Master” of water soluble tetraphenylporphyrin chemistry, synthesis, characterization, and kinetics – that will forever be linked with the name of Hambright. In one noted article he was not only cited several times, but he was described as “the father of water-soluble porphyrins. Over the course of Dr. Hambright’s career, he became increasingly interested in photodynamic therapy and radiopharmaceutical therapy and MRI contrast agents8,9,10
ANTIMICROBIAL EFFECTS OF EUCALYPTUS AND LAVENDER ESSENTIAL OILS ON COMMON EPIDERMAL BACTERIAL AND FUNGAL STRAINS
No full textPathogenic microorganisms, like bacteria and fungi, are always evolving to become more resistant to antimicrobial agents, necessitating a search for new agents. The results from this experiment show that lavender and eucalyptus essential oils have antimicrobial effects against Candida albicans, Corynebacterium xerosis, Staphylococcus aureus, and Staphylococcus epidermidis. Disk diffusion assays using 2 μl of the oil or DMSO control were done on Mueller Hinton agar (bacteria) or Sabouraud agar (fungus). Minimum Inhibitory Concentration (MIC) assays were performed using the oil and the corresponding broth media. The MIC was the lowest concentration of oil that significantly inhibited growth compared to the no oil control. Minimum bacteriocidal concentration (MBC) assays were performed by plating microbes from the broth containing the potential MIC on an agar plate, growing overnight and checking for growth. One-way ANOVA and post hoc Tukey test were used to determine the statistical significance of all results obtained. Neither oil significantly inhibited microbial growth on the disk diffusion assay compared to the DMSO control. Lavender had a MIC of 6.25% for S. aureus and S. epidermidis (p\u3c0.05) and 3.125% for C. albicans (p\u3c0.01). Eucalyptus had a MIC of 1.56% for S. aureus (p\u3c0.05) and C. albicans (p\u3c0.01), 6.25% for S. epidermidis (p\u3c0.05), and 0.391% for C. xerosis (p\u3c0.05). Preliminary data indicate that lavender may have a MBC of 12.5% for S.aureus and S. epidermidis and 6.25% for C. albicans. Eucalyptus may have a MBC of 1.56% for C. xerosis. Using essential oils as an alternative traditional antimicrobials can create a safe and sustainable way to kill bacteria and fungi cultures commonly found on skin