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Analyzing the Shark Paleoecology of Coastal Georgia From the Miocene and Pliocene Epochs
Get PDFThe field of shark paleoecology often yields indecisive conclusions based on the limited fossilization of their anatomical structures, with the exception of their teeth. The majority of the Atlantic coast has been studied regarding the presence of certain prehistoric shark species from the Miocene, Pliocene, and Pleistocene epochs. However, information pertaining to the Georgia coast and understanding its potential community structure is relatively understudied. This study was conducted in which thousands of fossil shark specimens and subsequent marine fauna were collected from dredge spoils created by the US Army Corps of Engineers (USACE): Savannah District. A total of 5,127 fossil shark teeth were collected, of which 4,981 were identified. Twenty-three potential species are believed to be included in this assemblage. Previous research conducted by the U.S. Geological Survey in 2001 shed light on the fossil formations beneath Brunswick, including their specific depths below sea level. Further communication with the USACE detailed their annual dredging depths of 36, 38, and 41 feet below the Mean Lower Low Water (MLLW). By combining this information with the known life histories of each of the 23 species of prehistoric sharks, it was determined that all species potentially coexisted from a time period spanning the late Miocene to early Pliocene (8.0-3.0 Ma) and were preserved in the Ebenezer Member 5 formation. Continued research regarding the ecological roles of all identified shark species will elucidate the community structure of coastal Georgia during the late Miocene and early Pliocene
APPLICATION OF A DIATOMIC MOLECULE MODEL POTENTIAL TO A SERIES OF HOMO- AND HETERODIATOMIC MOLECULES
Get PDFWe apply a one-dimensional classical model of a diatomic molecule model potential with modifications to H2, HF, LiF, N2, and CO. We obtain the unknown parameters of this model by digitizing plots of the potential curves for the molecules from a published, Hartree-Fock based theoretical electron correlation calculation (Piris 2017). We then apply the method of successive approximations to the model in order to calculate the wavenumber for each molecule in the series. The wavenumber depends on a parameter which in turn depends on the initial conditions. The value of this parameter for each individual molecule gives zero percent error for the corresponding molecule’s wavenumber, but an average is used in the final calculation of all molecules’ wavenumbers. The resulting wavenumbers are all within seven percent of the experimental values
FLUORESCENT AND COMPARATIVE ANALYSIS OF PROTEIN LOCALIZATION IN SACCHAROMYCES CEREVISIAE**
No full textA principal objective of cellular biology is to identify the function of proteins as they interact with their environment. Cellular localization provides context for the function and interactions of proteins. In this study, we seek to identify the localization of three proteins within Saccharomyces cerevisiae through C-terminal green fluorescent protein epitope tagging and subsequent fluorescent microscopy. As 75% of the yeast proteome has been classified, this project seeks to fill the remaining gap in unidentified cellular localization by investigating the proteins fsh3, gid10, and ade13. The analysis of high-resolution localization and comparative phylogenetic data reveals potential cellular environments and protein functions
SPATIAL AND TEMPORAL PATTERNS OF E. COLI DISTRIBUTION IN THE PIEDMONT UNIVERSITY WETLANDS, DEMOREST, GEORGIA
No full textPrevious Escherichia coli monitoring along Camp Creek in the Piedmont University Wetlands has shown overall low numbers with occasional spikes in colonies associated with rain events. Because those spikes were not detected above the wetlands, it was considered likely that they are attributable to beaver activity there. We wanted to know if there was spatial and/or temporal variation in E. coli colony production within that wetland system. Our hypothesis was that this variation exists, and we predicted that it would be revealed by more extensive surveys within the system. Water samples were collected from 5 locations from September 16th – November 14th 2022 and tested for E. coli colony concentration using the E.coli/Coliform count plate methodology administered by the Georgia Adopt a Stream Bacterial Monitoring Program. Four out of five sample locations had elevated E. coli counts during at least one sample. Two sample dates, associated with minor rain events, had elevated numbers across those four locations. From our results it is difficult to identify a specific source of E coli contamination, although we can eliminate one possible source, because of consistently low E. coli counts at that sample location. Our results support the role of rain events in triggering spikes of E. coli
THE APPLICATION OF MULTILOCUS GENOTYPING TO DETECT INVASIVE HYBRIDS IN THE GENUS CYPRINELLA**
No full textDue to anthropogenic pressures, freshwater ecosystems are being rapidly destroyed worldwide. Human impacts also have resulted in the loss of native aquatic biodiversity. In particular, the introduction of non-native species to aquatic habitats is of great concern. Historically, the introductions of many non-native freshwater fishes are the result of commercial baitfish aquaculture, food industries, or private aquarium release. The Red Shiner (Cyprinella lutrensis) is a small stream fish endemic to the central USA, with its natural range largely restricted to West of the Mississippi River. Since the 1950’s, Red Shiner have been commercially raised and transported across the globe as fishing bait and ornamental fish. During the early 1990’s populations of invasive Red Shiner were first observed in the Coosa River Basin of Northwest Georgia, USA. Originating from bait bucket releases, it quickly established within the Upper Coosa River Basin, and now hybridizes with at least one native Cyprinella, the Blacktail Shiner (C. venusta). Prior research suggests that hybrid shiners are intermediate to parental shiners in both swimming performance and morphology. Following previous studies that use swimming as a proxy for fitness, this may mean that hybrids have competitive levels of fitness when compared to parentals. Positive identification of hybrid shiners is critical to the conservation of native species in the Coosa, and previous work has largely relied on the use of morphological traits. To confirm the reliability of morphological traits used for hybrid identification, we collected twenty morphologically intermediate specimens identified by microsatellite genotyping. Seven previously developed nuclear loci will be used to detect the presence of genetic admixture from Red and Blacktail Shiner. PCR products will be scored with genotype analysis software. Individuals were then assigned to an admixture category according to the average assignment values to the first cluster which were developed by previous studies
QUANTIFYING FUNGI AND THE PRESENCE OF ASPERGILLUS IN HEMP AND GARDEN SOILS OF GEORGIA
No full textHemp production in the state of Georgia recently began with the passage of the Agriculture Improvement Act of 2018 which legalized its cultivation. Due to decades of prohibition, soil fungi that can possibly contaminate hemp products have not been widely investigated. Soil fungi belonging to the genus Aspergillus are known to produce mycotoxins, and human aspergillosis has been associated with cannabis use. There are currently no published studies that quantify fungi on hemp farms in Georgia, especially species belonging to the genus Aspergillus. Therefore, the goal of our study was to quantify the total amount of fungi and identify Aspergillus spp. in soil from hemp farms and vegetable gardens in Georgia. In addition, we sought to identify correlations between fungal populations and soil characteristics (water content, pH, ammonium (NH4+), and nitrate (NO3-)). Soils were collected in August of 2021 from five hemp farms, five vegetable gardens, and three non-agricultural sites. Total fungi and Aspergillus species were quantified using Dichloran-Rose Bengal-Chloramphenicol agar. There was not a significant difference in total fungi or Aspergillus among our three site types (p = 0.64). In addition, we did not observe a significant difference among our three site types for any of the measured soil parameters other than NO3-. Pearson correlation indicates a strong positive relationship between the total number of fungi and NO3- as well as total nitrogen (r = 0.87 and 0.94, respectively). Pathogenic Aspergillus (A. flavus, A. fumigatus, and A. terreus) were detected on hemp farms as well as in vegetable gardens. Aspergillus fumigatus is the most common cause of aspergillosis, and it was found on 40% of hemp farms and vegetable gardens surveyed. Our results indicate that there is not a significant difference between vegetable garden soils and hemp farm soils as it relates to total fungi and Aspergillus presence
HIGH-FREQUENCY ACCELEROMETER MONITORING OF FORAGING AND MOVEMENT BEHAVIOR IN A SECRETIVE PREDATOR (CENTRAL RAT SNAKES, PANTHEROPHIS ALLEGHENIENSIS)**
No full textAdvancements in bio-logging technology have transformed study of animals in nature. Among the many bio-loggers available, accelerometers (ACTs) are becoming increasingly common in studies of animal behavior. ACTs are small (\u3c1 g) piezo-electric (spring-like) sensors capable of measuring three-dimensional acceleration derived from subject-motion, and advanced machine learning techniques enable automated classification of distinct behavioral states from these data. While ACTs were previously utilized in the investigation of larger organisms and those most compliant to the temporary attachment of external devices, smaller dimensions have expanded the breadth of organisms amenable to these methods. The goal of this project is to expand a novel framework for ACT monitoring in snakes, a group of smaller vertebrates that have been previously absent in biologging applications. We will conduct comprehensive captive validation trials for robust machine learning model training and testing for accurate classification of key behaviors in Rat Snakes (Pantherophis allegheniensis), including full-body movement, immobility, predatory strikes, constriction, and ingestion of prey items. All classification model procedures will be conducted with open-source software specifically designed for acceleration data processing, demonstrating the increasing accessibility and feasibility of ACT studies. Following captive validation, this method will be applied to the field using a population of P. allegheniensis located in the lower Piedmont of middle Georgia to provide continuous and remote field-monitoring of activity patterns and key predatory behaviors. We envision validation of this technique carrying significant conservation and management implications. Real-time monitoring of foraging efficiency in the field facilitates improved interpretation of the causes and consequences of variation in individual behavior and performance, and its ultimate effects on population trajectories
INVESTIGATING THE EFFECTS OF ALGAL TURBIDITY ON MATING SYSTEM OF THE DWARF SEAHORSE (HIPPOCAMPUS ZOSTERAE)**
No full textDwarf seahorses (Hippocampus zosterae) are an excellent environmental indicator species because they spend their entire lives in coastal communities that are threatened by human-induced eutrophication. The goal of this study was to quantify laboratory reproductive success and identify the mate preferences in clear vs turbid treatments. The experimental design included paired (1F:1M), female-biased (2F:1M), and male-biased (1F:2M) treatments, in clear and turbid waters with a total of 128 seahorses across 8 replications. Of the 48 potential matings, the study yielded 40 males with reproductive success, 7 with brood reductions, and 1 non-mating. Mating latency was shorter for turbid treatments compared to their respective treatments in clear water. There was no detectable effect of algal turbidity on reproductive success, but differences were seen among the three treatments of varying sex ratios, with brood sizes being the highest in the female biased treatment (28 ± 4.56), followed by the male-biased treatment (25.31 ± 4.94), and lastly, the paired treatment (17.94 ± 4.90). For paired treatments, size matched mates’ body weights were correlated with the brood size in the clear water but not in the turbid water. In sex-biased treatments, fish’s weights best predicted the brood sizes when females were given a preference in mates. For sex-biased treatments, 75% of matings in clear water were size assortative, whereas mate preference was random in turbid treatments. Preliminary analyses (n=3) report greater levels of courtship behaviors for turbid treatments than clear treatments. On-going behavioral and statistical analyses will further elucidate the relationship between mate choice and reproductive success and will enable better predictions of reproductive patterns in the wild populations with varied sex-ratios. This study’s results highlight the critical need for interpreting the results of behavioral studies conducted in pristine lab conditions when investigating mating systems of coastal fishes adapted to eutrophic waters
EMERGING VIBRIO HARVEYI AND VIBRIO CAMPBELLII PATHOGENS IN GEORGIA’S CRASSOSTREA VIRGINICA OYSTERS AND MERCENARIA MERCENARIA CLAMS: PRESENCE, DISTRIBUTION, AND CONCENTRATIONS*
No full textIn the face of global warming and ocean acidification, Vibrio pathogens are geographically expanding and rapidly evolving. V. harveyi and V. campbellii belong to the Harveyi clade and are similar upon their genetic make-up. Natively found in warm waters of Asia and South America, these species are well-established pathogens that infect fish, shrimp, and mollusks. Neither strain is pathogenic to humans, however farmed oysters and clams are a valuable commodity in Georgia. Due to the climate change, the Southeastern United States is potentially becoming an accommodating environment for these pathogens, however this has never been previously explored. It is crucial for Georgia waters to be tested and monitored for both strains because if present in high concentration it would significantly impact the aquaculture industry. Using reference strains of V. harveyi ATCC 14126 and V. campbellii ATCC BAA-1116 / BB120, seven previously described primers for species-specific detection of V. harveyi virulence genes (toxR, luxR, vhh, vhh(a), srp, vhp, and rpoA) were tested with both strains. All the seven genes were reliable detected in both reference strains. These signature genes were used for qPCR detection and quantitation of V. harveyi and V. campbellii in wild oysters and farmed clams collected at random from three sites around Townsend, GA. In summer 2022 monitoring, vhh(a) and vhp genes were consistently detected in both oysters and clams in the range of 102 to 1010 copy numbers per gram of tissue, and no vhh gene was ever detected. Distribution and concentrations of the other genes varied between three sites. These results evidenced high abundance of V. harveyi and V. campbellii in wild and farmed mollusks. They also evidenced that not all previously published target genes are reliable for detection of these pathogens, and suggested vhh(a) and vhp genes as best targets. Data obtained in a complimentary study evidenced their presence in water and sediments
WHOLE DISK j- AND h-FILTER BRIGHTNESS MEASUREMENTS OF THE MOON
No full textAn SSP-4 photometer along with a small lens (diameter = 0.01 m, focal length = 0.06 m) was used in measuring the brightness of the Moon in near-infrared wavelengths. A small lens was needed to reduce the size of the Moon so that it would fit inside the photometer’s 1.0 mm field of view. These measurements appear to be the first whole-disk measurements of the Moon in the standard J and H filters. These filters are sensitive to wavelengths of 1150-1350 and 1500-1800 nanometers, respectively. The results are consistent with a J – H value of 0.60 magnitudes at a phase angle of 120° (waning crescent phase). The full Moon (with opposition surge) is estimated to be magnitude –14.75 (0.15) and –15.51 (0.15) magnitudes for the J and H filters, respectively. Uncertainties are in parentheses