• Investigating the Role of Hob1 in Translesion Synthesis in Schizosaccharomyces Pombe

      Walton, Breana R.; Department of Biological Sciences (2016-03)
      DNA replication is essential for an organism’s survival since the organism will die if the DNA is not replicated. The damage that DNA incurs may impede the progression of the replication process. The translesion synthesis (TLS) pathway bypasses damage, allowing replication to continue. Research conducted by our collaborator at the Augusta University Cancer Center indicates that the protein Rev1 physically interacts with Bin1, a protein involved in cancer progression in mammalian cells. We hypothesize that the two genes operate in the same pathway in yeast as they do in mammalian cells, and we intend to test this genetically. We conducted a mutation assay looking for an epistatic relationship between the two genes REV1 and HOB1, the homolog of Bin1 in Schizosaccharomyces pombe. These data suggest that Hob1 functions with Rev1 to allow for TLS, relieving stress caused by DNA damage during replication. Funding Source: Center for Undergraduate Research & Scholarship, Department of Biological Sciences
    • Led Type and Composite Photoinitiator Effects on Toothbrush Wear Resistance

      Chyan, David; Mettenberg, Donald; Department of Oral Rehabilitation (2016-03)
      Purpose: This research studied the effects of matching or mismatching dental light curing unit output color (blue or blue/vio- let, aka “multi-wave”) with the known photoinitiator content of dental restorative composites using toothbrush wear resistance. Methods: Combinations of lights and composites tested were a blue-only LED used to photocure a camphorquinone-only lay- ered composite, or a multi-wave LED used to activate composite containing Camphorquinone and Lucirin TPO photoinitiators. A ten-second exposure was provided to composite specimens utilizing all combinations of light curing units. Cured specimens were placed in a toothbrush-testing machine, simulating durations of 0, 4, 8, and 12 months of brushing. Surface profiles of composite surfaces were performed prior to as well as during tooth brushing. The average vertical loss of each specimen was measured within a 2.5-mm wide location. Regression analysis determined composite wear rates. Results: Using the blue-only LED on the Camphorquinone-containing composite resulted in a significantly lower wear rate than when using the multi-wave light on the same material. The opposite effect was found when using the blue-only LED on the Camphorquinone/TPO composite. SIGNIFICANCE: Optimal wear resistance of dental restorative composite surfaces is obtained by matching of LED spectral output with composite photoinitiator spectral needs. Funding Source: Frederick Rueggerberg
    • Macroinvertebrates and Water Quality in Oxbow Lakes along the Savannah River

      Wolff, Liam; Department of Biological Sciences (2016-03)
      Oxbow lakes are the remains of original channels that were cut off from the main river. Being more stagnant than the river, these lakes often differ in many physical, chemical, and biological parameters from the adjacent river. The goal was to compare four Savannah River oxbow lakes – Conyers, Miller, Possum Eddy, and Whirligig – to determine similarities and differences between oxbows with and without existing surface connections during non-flood flows. The comparison focused on water quality parameters and macroinvertebrate abundance and diversity. It is hypothesized that oxbow lakes with an existing surface water connection to the river have greater macroinvertebrate abundance and diversity than disconnected oxbows. Macroinvertebrates were sampled from sediment and other substrates using a petit ponar dredge and d-ring dip-nets, sorted according to EPA protocols, and identified to order or family. The resulting data showed that the most common organism at all sites were insects in the family Chironomidae, followed closely by members of the orders Cladocera, Anostraca, and Hemiptera. Among lakes, Conyer’s Lake (disconnected lake) was dominated by Bivalvia organisms, and Miller Lake (connected lake) was dominated by Hemiptera organisms whereas Chironomidae was the most common macroinvertebrate found in Possum Eddy (disconnected
    • Mercury Accumulation and Endocrine Disruption in Largemouth Bass in the Rae’s Creek Watershed, Augusta, GA

      Sayre, Joe; Department of Biological Sciences (2016-03)
      The Savannah River Basin in Augusta, Georgia, has a history of heavy metal contamination. Industrialization in the 19th century led to elevated concentrations of lead contamination. Notable examples of contributors to the problem included the Confederate powder works (1861-65) and the Augusta arsenal (1816-1955). Significant mercury contamination has become apparent in this century. Possible causes include industrial chlorine and paper production. In 2011 and 2015, we investigated two lakes in the Rae’s Creek watershed. Aumond Lake and Lake Olmstead are impoundments of Rae’s Creek and flow into the Augusta Canal and ultimately into the Savannah River. Our interest was in mercury contamination in Micropterus salmoides (largemouth bass) because these lakes are popular for anglers who provide fish for family consumption. We also examined endocrine disruption via assessment of vitellogenin. Mercury analysis in fish in this watershed has typically been reported as a composite sample and includes fish other than largemouth bass. Our data show that the mercury concentration in largemouth bass (since 2011) has decreased in both impoundments, but the concentration of mercury is significantly higher in Aumond Lake than Lake Olmstead. Our data indicate that endocrine disruption is occurring in male largemouth bass. Funding Source: Center for Undergraduate Research and Department of Biological Sciences
    • p65fl/fl/LysMCre Transgenic Mouse Model Shows Altered Nf-Kb Signaling In Macrophages

      Howard, Shelby; Talkad, Aditi; Oza, Eesha; Department of Biological Sciences (2016-03)
      We have produced and begun characterizing a transgenic mouse model, p65fl/fl/LysMCre, that lacks canonical nuclear factor-kappaB (NF-kB) signaling (p65) in cells of the myeloid lineage, which includes macrophages. NF-kB pathway activity is very important in normal immune function, synaptic plasticity, and memory, and aberrant NF-kB activity is associated with autoimmune disease, and importantly, cancer. Macrophages can be present in very large numbers in a variety of cancers, and can lead to tumor progression through promotion of tumor inflammation, angiogenesis, invasion, and metastasis. This animal model will allow our group to pursue experiments involved in better understanding how stromal macrophages communicate with cancer cells through the NF-kB pathway, and how loss of canonical NF-kB signaling in cells of the myeloid lineage might weaken the tumor and make it more susceptible to standard treatments. Characterization of the model thus far reveals that p65 protein is indeed absent in macrophages derived from bone marrow monocytes, and that NF-kB signaling is altered when stimulated with lipopolysaccharide. We have just begun co-culture experiments with p65 deleted macrophages and glioma cells, and anticipate altered communication when compared to culture with control macrophages. Funding Source: Cancer Center Collaboration Grant
    • Role of the Aryl Hydrocarbon Receptor (Ahr) in Skeletal Muscle

      Bowles, Jessica; Lambert, Andrea; Dukes, Amy; Mendhe, Bharati; Department of Biological Sciences (2016-03)
      The AhR is a ligand-activated transcription factor known to mediate the negative effects of environmental contaminants such as dioxin. Inactivation of AhR in skeletal muscle appears to be a response to both resistance exercise training and endurance exercise training, whereas activation of the receptor impairs tissue regeneration in zebrafish. AhR is also a receptor for kynurenine, an oxidized metabolite of the aromatic amino acid tryptophan. We have found that while tryptophan can preserve lean mass and stimulate muscle-derived IGF-1 in the setting of dietary protein deficiency, kynurenine decreases both muscle mass and IGF-1. Aside from these few studies, very little is known about the role of AhR in muscle wasting in catabolic settings such as aging or disease, or how it mediates the response to exercise. We have identified expression of the AhR in skeletal muscle using immunostaining and gene expression (PCR) of mouse hindlimb muscles (tibialis anterior). We are currently working to determine whether AhR expression levels change with age, or differ between males and females. The ultimate goal of this research is to develop novel therapeutic approaches, perhaps targeting AhR, to prevent muscle loss with aging and disuse. Funding Source: National Institute on Aging
    • Yell/!Grita! Techniques and Challenges When Translating Gender Related Issues

      Ortiz, Dana; Department of English and Foreign Languages (2016-03)
      For my undergraduate honors thesis, I translated selected articles from Yell!, which is a magazine based on women and gender studies. My translation included the cover page of the magazine, the About Yell! portion of the magazine, and the Letter from the editor. The articles that I translated varied in text type. The text types were expressive, operative, and informative. In order to complete the translation, I used some common translation techniques including but not limited to modulation, transposition, addition, and omission. I used a text written by Jack Child, titled Introduction to Spanish Translation, a Collins Spanish-English dictionary, and Wordreference.com as references during the completion of my project. In doing this translation, my aim was to examine some of the common issues faced by translators when translating a work with such sensitive topics. I wanted to under- stand the role semantics played in translating sensitive materials and be able to better recognize the importance of selecting appropriate words and or the correct phrasing of expressions in order not to offend my target audience. My second aim was to make the information in Yell! available to the Latino/a community in the CSRA. As I had seen in doing my research for this thesis, there are not many resources available to the Spanish-speaking community related to topics in women and gender studies that focus on gender or sexuality. I feel that this translation can serve as a valuable resource to the Latino/a community.