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Welcome to the 18th Annual Scientific Research Poster Session
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You may want to browse the author or discipline list to find the abstract number.
See the Poster Location Map to find its location by number.
Christopher M. Brown, Steven C. Jaume and Sarah L. Cooper, Department of Geology and Environmental Geosciences
During the summer of 2005 we recorded ambient seismic noise at 21 sites in the greater Charleston, SC area to determine shear wave velocities. Data was collected using 24 vertical and horizontal (SV configuration) 4.5 Hz geophones spaced 4 to 8 meters apart. In addition to spiking the geophones into the ground surface, at some sites we also set the geophones upon bricks on sidewalks and roads. We recorded six ambient noise windows of 30 seconds at each site. Sites were picked based on locations where SCPT tests have been conducted. The ambient noise data was processed into slowness-frequency space following Louie (2001) and Rayleigh dispersion values were estimated from this data. The dispersion picks were then used to determine a shear wave velocity model at each site. We also modeled the shear wave velocity structure using a refraction P velocity structure determined as part of the same experiment. Preliminary results show that surficial sediment layers have velocities ranging from 125 to 250 m/sec. Velocities generally increase to 300-600 m/sec within 5-15 meters of the surface and up to 700 m/sec at depths of 40-60 meters or more. Some sites show low velocity layers within the upper 30 meters. We find VS30 falls in the range 260-420 m/sec (NEHRP C-D boundary) when determining the shear wave velocity structure without a P velocity structure constraint, but all sites are NEHRP Class D (230-350 m/sec) when the P velocity structure is used as a constraint in the dispersion modeling. We will compare these results with the SCPT tests and some shear wave refraction results at the same site.
Michelle Mac Brooks, Catherine P. Jung, Elodie Rolando, and Jean Rockford, Department of Chemistry and Biochemistry
In the recent decade, a plethora of high resolution techniques for EPR spectroscopy have been developed. These techniques have allowed the study of the electronic structure of radical species that have heretofore been unattainable. The measurement of the nitrogen hyperfine coupling constants in the chlorophyll a cation radical has been hampered in the past by the presence of overlapping peaks caused by contributions from multiple nuclei. Pulsed EPR spectroscopy permitted an estimation of these couplings, but no definitive values have been measured. By using a combination of pulsed EPR, hyperfine sublevel correlation spectroscopy (HYSCORE), and spectral simulations, we have determined these coupling constants and present here the electronic structure of the radical. The electronic structure of the radical species in vitro can provide insight into the role of the cofactor in vivo.
Cate Foster and Gary Harrison, Department of Mathematics
Using a three-stage model programmed in Matlab, a simulated occupancy matrix for the number of beds occupied in a hospital is generated. The simulated data is used to estimate model parameters and test how well the estimated parameters match the parameters used to generate the data, and to test the bias and variance of the estimated parameters. The simulated parameters are close to the actual parameters; however there is some bias in the estimates from the least squares method for some of the parameters.
Gary Harrison and Bonny Riemer, Department of Mathematics
Three, two, and one compartment models for length of stay of patients in a hospital and flow of patients through a hospital were compared. Programs were created using Matlab to determine whether or not there is a significant difference in the number of overflows in a one compartment model, a two compartment model, and a three compartment model. Moreover, for each year of simulated data obtained by the Matlab programs, basic statistics such as mean, median, and standard deviation were calculated, which aided in determining the differences between the three models. Another question addressed was whether the models could be improved by utilizing parameters for both the day of the week and monthly cycles.
Dena R. Hodges and Gorka Sancho, Department of Biology
During spawning, male Atlantic spotted seatrout, Cynoscion nebulosus, make loud courtship calls, forming sonic fish aggregations. We studied the possible effects that increased dolphin presence may have on seatrout spawning, since bottlenose dolphins are known predators of sciaenid fishes. Throughout the summer of 2005, during peak seatrout spawning, dolphin activity was monitored through hour-long observations carried out twice a day, once in the morning and once in the evening, while seatrout activity was monitored by an acoustic recording device deployed near the fish aggregation site, recording male callings. Dolphin presence and activity levels were identical during morning and evening surveys. Tides seemed to have no effect on either dolphin presence or seatrout spawning activities. Daily male seatrout sound production was extremely regular in time, seemingly unaffected by dolphin presence or tidal cycles. Bottlenose dolphins seem to not selectively feed on spotted seatrout while forming spawning aggregations.
Josh Fuller and Linda Jones, Department of Physics and Astronomy
Merocyanine 540 (MC540) is a photosensitizer that has been used experimentally to purge leukemia cells from bone marrow. MC540 is taken up in leukemia cells and is excluded from normal bone marrow cells. However the mechanism of selective MC540 uptake has not been established. Human A549 lung cancer cells are also known to be resistant to MC540 photosensitization. A549 cells have membrane transport proteins including MRP1 and p-glycoprotein that exclude certain drugs associated with multidrug resistance (MDR). The goal of this project is to investigate the role of MDR in A549 resistance to MC540. The effect of specific inhibitors of MRP1 and p-glycoprotein-mediated efflux was determined quantitatively with fluorescence spectroscopy. Preliminary results indicate that inhibition of any one membrane protein is insufficient to prevent the efflux of MC-540.
Sam Crickenberger, Department of Biology, and Leslie Sautter and Ross Martin, Department of Geology
Benthic foraminifera fossil assemblage distributions can serve as proxies for paleoecological and paleooceanographic conditions. Sediments in the Gulf of Mexico, as well as along the Charleston Transect, are most accurately dated to the early Pleistocene, providing an environmental record during that time period. Thirteen grab samples were collected along the Charleston Transect, ranging in depth from 9.9 to 100.4 m, and were analyzed for benthic foraminifera distributions. General dominance distributions were found similar to that of Poag (1981) in the Gulf of Mexico with the exception of Textularia, Eponides, and Elphidium. Textularia was dominant at the hardgrounds of the outer shelf with Eponides and Elphidium having somewhat of a role reversal in their depth related distributions.
Sam Ready Department of Biology and Shelli Graham, Linda Jenkins, and Martine LaBerge Clemson University Bioengineering Department
Metallic and polymeric wear debris from implanted devices such as total joint replacements are known to cause reactions leading to failure of prostheses, but little is known about system-wide effects of debris. Speculation is that particles released from devices such as total joint replacements might cause conditions in the cardiovascular system to become favorable to atherosclerosis. This study completed a step in the process of identifying the effects of wear debris, having the intent of verifying that it travels through the vasculature. Several rats were injected with a solution of simulated wear particles of either stainless steel or titanium in saline. Organs and vascular tissue were then harvested and analyzed for the presence of foreign particles. Evidence of foreign particles was observed in the livers of most stainless steel injected subjects and was rarely found in other samples.
Jason Messervy and Courtney J. Murren, Department of Biology
Phenotypic integration describes the strength of correlations among traits within functional modules. Additionally, weak or absent correlations among modules may allow for the independent evolutionary trajectories of the modules. These patterns of integration may evolve to maximize fitness of an organism (Klingenberg, 2004). Our experiment examined phenotypic integration in three species of the monkey flower (Mimulus) through ontogeny. We hypothesize that among trait relationships may change through the lifecycle of a plant (based on work by Preston and Ackerly, 2004). We hypothesized that we would observe three modules: 1) leaf characteristics, 2) root characteristics, and 3) floral characteristics. Preliminary results reveal that all species are highly integrated within and between leaf and root modules at the rosette stage, with M. guttatus having the greatest number of correlations. Our work is ongoing, and we hypothesize that the observed high levels of integration between functional modules will decrease through ontogeny.
Charles K. Rathburn, Brett M. Macey, Louis E. Burnett, and Karen G. Burnett, Grice Marine Laboratory, Department of Biology
We hypothesized that crabs with bacterial infections, as observed in natural populations, may be more susceptible to infection on subsequent exposure to pathogenic bacteria. Blue crabs were injected with saline or Vibrio campbellii (105/g crab). When a second injection containing bacteria was administered 2 h after the first injection of saline or Vibrio, crabs having received two doses of bacteria had significantly fewer culturable bacteria (CFU)/ml in hemolymph at 10, 20, 40 and 120 min after the second injection, compared to crabs first injected with saline (P=0.043). When the second injection containing bacteria was administered 24 h after a first injection of either saline or Vibrio, there was no difference in CFU/ml in hemolymph between the treatment groups at any subsequent timepoint tested. These results suggest that recent exposure to a sub-lethal bacterial infection may improve the short-term immune response of crustaceans to additional infections when environmental conditions are optimal.
Jonathan Sticca, Julie Woolworth, and Tien Hsu, Department of Biology, and Department of Pathology and Lab Medicine, MUSC
The metastatic capabilities of malignant tumors are the primary cause of death in patients diagnosed with cancer. The nm23 gene is a tumor metastasis suppressor that has been found to be down regulated in many forms of cancer. We are conducting an siRNA knockdown of the nm23 gene in human ovarian cancer cells (ovcar3) and observing cell migration in vitro. We are using an adenovirus based siRNA to obtain a stable knockdown delivery system. Our goal is to make a recombinant plasmid encoding an adenovirus from which siRNA corresponding to regions of human nm23 mRNA will be generated. If successful, this strategy would provide a method to artificially down regulate the nm23 gene, possibly inducing cancer metastasis in vitro. Collectively, this type of research may extend the knowledge of how the nm23 tumor suppressor gene affects cancer metastasis and ultimately may provide insights into the feasibility of RNAi based approaches in studying genes associated with human cancers.
Christina Skalit and Leslie Sautter, Department of Geology
Benthic foraminifera were picked from surface sediments collected across the continental shelf off Charleston, SC, along the Charleston Transect. Relative abundances of genera -- defined as any genus greater than 5% in one or more sample -- were calculated, and the distributions of Generic Predominance Facies were mapped. The inner shelf (0-20m water depth) was dominated by Quinqueloculina, and the mid-shelf (20-50m), was dominated by Cibicides and Quinqueloculina. The outer shelf (50-100m), which is strongly influenced by the Gulf Stream, was dominated by Cibicides and Hanzawaia; however, one station located near a rocky outcrop (50m) was dominated by Textularia. These strong variations in predominance of foraminifera genera are due to (1) depth variations across the shelf; (2) proximity to the Gulf Stream; and (3) substrate differences. Substrates range from coarse sand mega-ripples, to hardground areas surrounded by sediment, to incised ancient river channels.
Sarah Sonnett and Robert J. Dukes, Jr., Department of Physics and Astronomy
One of the most common ways of determining frequencies of variation in time series is the use of a variation on Fourier analysis known as the periodogram. The most common way to validate a frequency is to calculate a signal-to-noise ratio (SNR), defined as the amplitude of a signal divided by the average of all points in a defined range (called the box size) of the periodogram after the signal has been removed. Empirically, workers have found that signals with SNR greater than 4.0 are usually real signals. However, little work has been done exploring various box sizes. In this paper, we attempt to determine this appropriate box size for standard (SNR) calculations for frequencies typical of Gamma Doradus and Slowly Pulsating B (SPB) stars. To do this, we will use artificial data that mimics observations for these classes of stars.
Robert Nusbaum and McKean Smith, Department of Geology and Enviormental Geosciences
The Charleston Bump is a bathometric shallowing from about 2000 feet to 1200 feet over which the Gulf Stream flows. Returned samples from the Charleston Bump are rare and offer insight into phosphorite precipitation processes during the Neogene. We studied eleven samples using transmitted and reflected light, along with Scanning Electron Microscope EDAX data to determine composition. This was supplemented with limited XRD data and microprobe WDE mapping of selected elements. Megascopically the samples consist of phosphate-coated vesicular conglomerate composed of carbonate clasts and ooze, angular layered phosphorite clasts, and minor chert. Texturally, the phosphorite has complex intergrowths of at least two phosphate minerals. Some of the samples also contain mullite, a high temperature alumino-silicate that is a common byproduct of coal powered furnaces. The furnace slag is a likely remnant of the shipping industry dating somewhere from the mid-to-late 1800s to the twentieth century when diesel ships began traversing the Atlantic.
Erin Smith and Robert Nusbaum, Department of Geology and Environmental Geosciences
The purpose of this study was to apply satellite remote sensing imagery and digital elevation data to map geologic units and structures exposed in the Toquima and Monitor ranges near Kingston, Nevada. The abundance of phyllosilicate-bearing rock, carbonates, and volcanic units makes this area suitable for analysis through remote sensing. Two types of remote sensing data sets were used: imagery from the ASTER (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) operating on the Earth Observation System Terra satellite; and data from the EO-1 (Earth Observer 1) ALI (Advanced Land Imager) satellite. Prior to image analysis, layer stacking of the VNIR (visible near-infrared) and SWIR (short wave infrared) bands and masking of snow and vegetation were necessary to facilitate use of spectral profiling. Band math ratios and analysis of spectral profiles were utilized to differentiate geologic units. Structures were mapped by applying shaded relief topography to a DEM (digital elevation model).
John Rosen, Briget Doyle, and Michael Johnson, Department of Geology
Coastal Louisiana may currently be subsiding at a rate of < 3mm/yr. It has been suggested that this subsidence is due to the reactivation of listric normal growth faults initiated by hydrocarbon withdrawal. The fault system of interest, the Lappey Rouse fault, runs through coastal Louisiana, roughly parallel to the shoreline. It is important to determine how active this system is, and, if it is currently active, what influences that activity. This is relevant from the point of view of both short-term wetlands conservation and long term scientific evaluation of growth fault systems in general. These faults have been studied extensively by the petroleum industry as they occur on heavily sediment loaded margins and can create hydrocarbon traps in both the footwall and in the "rollover" of the hanging wall. However, my interpretation of the 3-D seismic and GIS data of Southeastern Louisiana suggests the faults are not currently active.
Hayley S. Messich & Mark D. Lazzaro, Department of Biology
Our research conducted over the past year has investigated organelle motility and distribution within Picea abies pollen tubes (Norway Spruce). Previous studies have shown that both microfilaments and microtubules are responsible for the growth and elongation of P. abies. Within the tip of the tube, cytoskeleton streaming is seen as a fountain pattern. Both the microfilaments and the microtubules work together to organize this fountain pattern. This was supported by applications of latrunculin B (a microfilament inhibitor) and oryzalin (a microtubule inhibitor). Latrunculin B totally stops streaming, whereas oryzalin reverses the streaming pattern. With this previous knowledge, mitochondria were the chosen organelles of interest, due to the necessity of these organelles for energy and growth. By using a fluorescent mito-tracker dye, we examined mitochondria distribution and movement within the tip of the tube. We found mitochondria distribution to be uniformly distributed throughout the tip of the tube, with no particular area of concentration. Applications of oryzalin and latrunculin B found that mitochondria motility is dependent on microfilament and microtubule organization in the tube.
Rhea Matsuura and Jaap Hillenius, Department of Biology
The partial skull of a fossil toothed whale was brought to the CofC Biology Department for identification by Susan Bailey, who found the fossil near Cainhoy, SC. The specimen most likely originates from the Ashley Formation (Early Oligocene, 30 mya). After cleaning and preparation, the specimen was compared to other whale fossils at the Charleston Museum: comparative taxa principally included Agorophius, Xenorophus, Patriocetus, and an undescribed Eosqualodontoid. Only the basal portion of the rostrum is preserved, including the antorbital notch and the posterior section of the snout and palate. However, this is enough to demonstrate that the new specimen differs significantly from all four reference taxa. The new specimen appears to be a small squalodontid (a shark-toothed dolphin), but it is shorter and proportionately wider than the four reference taxa. Although more comparative work is necessary for further determination, this specimen appears to be a new genus and species.
Carson Grimes and James Neff, Physics and Astronomy
We are examining a large database of wind speed and direction measurements obtained in a local coastal environment in attempt to find the potential of this wind for energy production. The data comes from an on-line database provide by NOAA. They include many years of measurements made at a site on Folly Beach. The wind is being analyzed using the time of day, day of year, wind speed, wind direction, and other relevant parameters. From this, we are determining the instantaneous power available in the coastal wind at various times of day and over the course of the year, and then integrating this to yield the total available power of the coastal wind (per square meter). We are then analyzing several different commercial wind turbine models to estimate their energy production potential in Folly Beach.
Catherine A. House, Department of Biology, Timothy E. Targett, Graduate College of Marine Studies, University of Delaware and Barney B. Rees, Department of Biological Sciences, University of New Orleans
This study was designed to investigate physiological effects of several dissolved oxygen levels on the estuarine fish Fundulus heteroclitus, and to determine the time-course of adaptation. Fish were held at 5 different dissolved oxygen treatments for 28 days. Fish were measured for length and weight and specific growth rates were calculated for time intervals 0-8, 0-14, 14-28, and 0-28. Growth rates of fish in the severe hypoxia treatment were able to acclimate to 1.18 mgO2/l over the 28 day period. In fact, whereas fish lost weight over the first two weeks at 1.18 mgO2/l, during the second two weeks their growth rate approached that of fish in normoxia. No significant growth related effects of dissolved oxygen were seen in any of the other treatments. Analyses of white muscle tissue showed no major changes in hydration or organic content accompanying long-term adaptation to severe hypoxia.
F. Scot Fitzgerald, Norman Levine, Lara Jelenevsky, Briget Doyle, and Robert Nusbaum Geology and Environmental Geosciences
A Geographic Information Systems (GIS) of geologic data was used to assess future block slide failure locations along the Pigeon River Gorge section of Interstate 40 in Haywood County, North Carolina. This section of interstate has experienced block slides and attempts to stabilize steep slopes. This study hypothesizes that the steep slopes and bedding or foliation dipping in the same direction could indicate potential problem areas. The assessment incorporates data from Digital Elevation Models, along with strike and dip information digitized from a geologic map of the area. Geologic information and soils data were also compiled in a database so that it was possible to query strike and dip, bedding and foliation, and slope of the rock to produce maps that demonstrate possible areas of block slides along this segment of Interstate 40. Preliminary results suggest that this method has potential as a first-order assessment.
Gina Applebee and Robert Nusbaum, Department of Geology and Environmental Geosciences
Cenozoic-age bentonite in the Atlantic Coastal Plain is rare due the paucity of volcanism within the region. A rare occurrence of bentonite of demonstrable volcanic origin occurs in the 46 Ma Castle Hayne limestone in the Coastal Plain of North Carolina. Based on the anomalously high BaO content of unaltered biotite pyroclasts Nusbaum et al. (1988) proposed that the SIP is the source of the bentonite. The purpose of our research is to further explore this conclusion through analysis of biotite phenocrysts in two felsic samples from the SIP. We examined biotite compositions with an electron microprobe from two nearly identical hypabyssal intrusions collected in the SIP. When considered with age constraints, source distance and prevailing wind directions, anomalously BaO content of biotite from this study is consistent with a SIP source area for the Castle Hayne biotite.
Daniel Morrall, Narayanan Kuthirummal, and Alem Teklu, Department of Physics and Astronomy
Photoacoustic (PA) and resonant ultrasound investigations have been carried out on erbium-doped lithium niobate (Er3+:LiNbO3) and on pure (LiNbO3) crystals. The Photoacoustic spectrum revealed very weak absorptions corresponding to 4F7/2, 4F9/2 and 2H11/2 levels. When comparing the elastic constants for pure and doped LiNbO3 crystals, the bulk modulus was found to increase by 5.2% after doping. Also the Elastic constants were compared. C11 decreased by 4%, C12 increased by 18% and C44 increased by 16.6%. The surface-doping explains the decrease in only one direction.
Ransom C. White III and Leslie R. Sautter, Department of Geology and Environmental Geosciences
Research conducted on the continental shelf off Charleston, SC was designed to examine sediment grain size and composition. Continental shelves typically progress from coarse grained sediments nearshore to finer sediments offshore; passing over the inner-, mid-, and outer-shelf regions, to the shelf edge. Eleven stations across these shelf regions were sampled at least three times during four Transect Program cruises. Sediment size variations deviated from the classic shelf model in that mean grain sizes irregularly progressed from fine sand (2.5-3 Phi) on the inner-shelf to medium sand (1.5-2 Phi) on the middle and outer shelf regions. Samples collected on different cruises at the same location sometimes varied significantly, possibly due to migration of megaripples. Sediments were predominantly lithogenic sands, with a higher concentration of relict lithogenics on the outer shelf, most likely remnant from shoreline migrations since the Pleistocene. Conversely, shelf-edge sediments were fine biogenic sands deposited from the Gulf Stream.
Adam Dean and Narayanan Kuthirummal, Department of Physics & Astronomy
Photoformation of gold nanoparticles in the solid matrix of gold-chitosan-silica aerogels prepared with Au(III)/-NH2 (amine function from Chitosan) mole ratios of 1:5, 1:15, 1:25, and 1:50 has been investigated using photoacoustic (PA) spectroscopy. Photoreduction using 320 nm light revealed significant shift in the plasmon band (~ 213nm) of gold nanoparticles upon varying the concentration. This could probably be attributed to the difference in nanoparticle size in the matrix. The duration of UV exposure, however, doesn't really affect the peak absorption wavelength. Detailed SEM studies are currently under progress to get a more realistic depiction of the nanoparticle size.
Claire duPont, Department of Physics and Astronomy
Fractals or fractal-like structures (structures which are self-similiar under magnification) exist everywhere in nature. Flowering plants, trees, leaves, and branches are examples. There is a computer technique, which in some ways mimics living DNA, that can draw surprisingly convincing pictures of natural living plants. A structure made in this way is call a Lindenmayer system, after its inventor Aristid Lindenmayer. The technique, called "code replacement," consists of taking a basic code and iterating it into itself, repeatedly. A simple computer software called TrueBasic was used to iterate and plot the code as well as to color it to further depict nature as a fractal. This poster will show what such a code looks like, how it is implemented, and some examples of plant like structures drawn as Lindenmayer systems.
Lauren Halloran, Biology Dept. and Leslie R. Sautter, Geology Dept.
Echinoderm specimens were collected in November 2004 and May 2005 across the continental shelf off Charleston, SC aboard the R/V Savannah. Specimens were identified to the species level and separated into three taxonomic groups: asteroids, ophiuroids, and echinoids. Species density per 1000 m2 for all organisms collected was determined along with a seasonal comparisons and overall spatial distribution of key species. Greater than 10 specimens of a species per 1000 m2, collected in November or May, defined the key species. Overall, more echinoderms were collected in May than in November. Asteroids were found in greater numbers in May compared to November and were more numerous in the mid-shelf during May and November. Similarly, more ophiuroids were collected in May, however, one key species was dominant across the shelf in both seasons. Seasonal variations and a change in dominance of echinoids were observed across the shelf.
Walker Cobb and Anton Dumars, Department of Geology
One focus of this summer's work went into survey methodology. In surveying the beach we developed effective and efficient survey techniques for our purpose. Using the data we collected we were able to better understand how the inlet between Folly and Morris Island worked.
Jon Hansen and Narayanan Kuthirummal, Department of Physics and Astronomy
The investigation of Er3+-doped silicate and polymer optical materials was undertaken in an attempt to progress the development and usage of these materials in laser and optical amplification systems. The characterization was done using a photoacoustic (PA) spectrometer as well as a fiber-optic spectrometer. Prominent peaks could be explained based on the available ground (4I15/2) and various excited states (2G9/2, 2G11/2, 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2) of erbium ion. The nature of the spectra shows that the local site symmetry around erbium is homogeneous. The nonradiative efficiency of Er3+ in the polymer matrix is significantly less compared to that in the silicate matrix.
Robert J. Dukes, Jr. and Joseph Bramlett, Department of Physics and Astronomy
The slowly pulsating B star HD1976 has been observed since late 1999 by the Four College Consortium Automatic Photoelectric Telescope (FCAPT). After reducing the data we have analyzed it using the standard period analysis program Period04. We have confirmed the period of 1.06 days (0.939 cycles/day) found by Waelkens et. al. (1998, A&A, 330, 215) in their analysis of the Hipparcos data as well as the period of 2.51 days (0.399 c/d) found in the 2000 Andrews /&Dukes study (BAAS 32, #46.03). We have tentatively identified three additional periods at 1.07 days (0.930 c/d), 1.053 days (0.949 c/d), and 1.028 days (0.972 c/d). The signal-to-noise ratio observed in these frequencies is significantly higher than the lower threshold generally attributed to noise. Observation and analysis is still continuing on this star. This work has been supported by a College of Charleston Research Presentation Grant and NSF Grants AST95-28906 and AST05-07551.
Tara Cox, Department of Psychology
The difference in failing to comply with stop signs between male and female drivers was observed. The participants consisted of 2,723 male and 2,203 female drivers who failed to stop at a stop sign. Stopping was operationally defined as the vehicle coming to a complete stop. Four intersections in Charleston (all with four-way stop signs) were observed over an eight day period approximately eight hours per day. Only drivers who failed to stop at the stop signs were recorded. A Chi Square Goodness of Fit statistical test was used to conduct the analysis and rendered the following results, Χ2 (1, N = 4,926) = 54.9, p <.05. The results revealed that there were significantly more male drivers than female drivers who did not stop at stop signs. This may imply that male drivers tend to engage in more risk taking behavior than female drivers.
Alexis Suozzi, Department of Psychology
A stereotyping study was conducted to determine if individuals are more likely to give a positive rating to a speaker with a British accent or a speaker with a Spanish accent. Eighty nine Introductory to Psychological Science students were randomly assigned to listen to a tape recorded speaker with either a British or a Spanish accent (both speakers had recorded the same 9-minute speech). After listening to the speech, participants completed a survey where they evaluated the speaker on several characteristics using a scale of 1-5. After all sessions were complete, the data were combined, and an independent sample t-test yielded a result of t (87) = 3.71, p<.05, d = .14. The British accent speaker (M = 3.54, SD = .72) was rated significantly higher than the Spanish accent (M = 2.94, SD = .79). This finding suggests that stereotyping occurs even at the unconscious level.
Geoff Tucker and Brian G. Scholtens, Department of Biology
The superfamily Bombycoidea (Sphingidae, Saturniidae, Lasiocampidae, and Mimallonidae) has a strong presence in coastal South Carolina. Bucket trapping was performed for two months to see how recorded phenologies and weather conditions compared to data collected from trapping. A total of 16 species of Bombycoidea were recorded from trapping. The phenologies were confirmed by trapping. Temperature, relative humidity, wind speed, rainfall, and moon phase were compared to catches. Humidity seemed to be the only factor correlated to flight times.
Stefanie Morris and David Gentry, Department of Psychology
A study investigating the relationship between impulsivity and sensation seeking was conducted using twenty three college students at the College of Charleston in South Carolina in the fall semester of 2005. Subject's degree of impulsivity was measured using a delay-discounting computer program looking at three monetary rewards ($20. $200, and $2000) available after one week, one month, six month, one year, or five year delays periods versus a smaller monetary reward available immediately. Their discounting values were then calculated using a hyperbolic equation for delay discounting, V=A/(1+kD). In addition, the subjects all completed the AISS, the Arnett Inventory of Sensation Seeking (Arnett 1994), to measure their degree of sensation seeking and a questionnaire designed by the experimenters with questions pertaining to the subject's lifestyle and personal finances. The types of behavior examined, scores on the AISS, and discounting values recorded were all correlated to find any significant relationships that may exist. It was found that students who are more stressed about money scored higher on the AISS and that those students who scored high on the novelty subscale of the AISS had a significant negative correlation with the number of hours the subject studies per day.
Chris Stubbs, Ray Creede, and Leslie Sautter, Department of Geology and Environmental Geosciences
In March 2006, the NOAA Ship Nancy Foster conducted a cruise on the continental shelf edge off South Carolina to calibrate a new Kongsberg Simrad multibeam sonar system. Students from the College of Charleston Geology Department assisted with bathymetric data collection and have begun preliminary processing and evaluation of identified seafloor features, using Caris HIPS/SIPS software. The data are being contextualized with previously quantified shelf-edge sidescan sonar data from the region collected during previous Transects Programs (Stubbs 2005, Giddens 2005) and Ocean Exploration submersible expeditions (Sedberry et al. 2002). The most prominent feature discovered is an outcropping hard-ground structure approximately 650 by 150m, with 10m vertical relief. It is oriented parallel to shore along the shelf edge in water depths of 60m. Possible geological and biological influences on the structure's origin and morphology are being explored.
George P Kablick III, Linda Jones, and B.L. Lindner, Department of Physics & Astronomy
It is well established that the interaction of infrared radiation with trace gases in the lower atmosphere (less than 100 km) is responsible for global warming. However, the extent to which each gas contributes is uncertain. Using the atmospheric model MODTRAN3, the absorption of two important trace gases CO2 and CH4 was simulated for different conditions. For three different scenarios: no clouds, low cumulus clouds ( 0.06 to 2.7 km) and slightly higher altostratus clouds (2.4 to 3 km), the transmission of energy from the surface was calculated for mid-latitude winter conditions (272.2 K). The data shows that transmission non-linearly decays with respect to concentration, which means that lower concentrations of these gases have higher potential for trapping heat per volume than higher concentrations. The temperature profile was also determined for each scenario. For a doubling of CO2 and CH4, the temperature increase is 1.193 K and 0.111 K, respectively.
George P Kablick III and Laney Mills, Department of Physics and Astronomy
The double pendulum is a classic example of a chaotic system which exhibits erratic motion. The archaic, and possibly first, weapon of mass destruction, the trebuchet, is a glorified double pendulum. In medieval times, the engineers of siege weapons had no idea that instruments they made for hurling projectiles at enemy castles would be analyzed for their lack of predictable behavior. But, then again, nobody knew what chaotic behavior meant back then. This project analyzed the chaotic motion of the trebuchet, and used a true BASIC program to model the behavior of the time series, phase plot and two-dimensional motion of the weapon as it fired. A model trebuchet was constructed to test the validity of the motion modeled by the program, and to launch a few random fruits and other objects. The motion of the model is chaotic with an attractor independent of initial conditions.
Danielle Adler and Agnes Ayme-Southgate, Department of Biology
Projectin is a giant sarcomeric protein with multiple possible functions. The complete sequence indicates that projectin is 1,000 kDa protein. Its amino-terminal region contains a PEVK-like domain which undergoes complex alternative splicing events, as well as two clusters of Ig domains. The PEVK domain and/or the Ig domains might confer elastic properties to the protein. We will present data indicating the presence of a stretchable domain and its characterization within the IFM-specific isoform. We will discuss the importance of the elastic domain(s) in the stretch-activation mechanism
William Hartley and Agnes Ayme-Southgate, Department of Biology
The Drosophila protein, projectin, is an essential component of myofibrils, the contractile units of muscles, and it is a long extended molecule with a predicted molecular weight of 1,000 kDa. In flight muscles, projectin is associated with the connecting filaments (C-filaments), which contribute to the myofibrils? elastic properties. The goal of this research project is to evaluate projectin?s contribution during both the assembly of myofibrils and during flight. We will take advantage of the RNAi protocol coupled with the Gal4-UAS regulatory system to inhibit the synthesis of the projectin protein in flight muscles. PCR was used to create the RNAi construct that was injected into Drosophila. We are currently using a Southern blot protocol to determine the number of genomic inserts per line. By crossing the fly lines with the most inserts, we will be able to better halt the production on projectin and study the effects.
Catherine Kramp and Agnes Ayme-Southgate Department of Biology
Projectin is a giant sarcomeric protein with multiple possible functions. The protein has been identified in several insect species including the bee (Apis mellifera). We used the Drosophila projectin sequence to retrieve genomic sequences corresponding to the bee projectin from the recently released Apis mellifera?s genome. The complete sequence indicates that bee projectin is very similar in its domain composition and pattern. However the elastic PEVK domain seems quite different in bee compared to Drosophila. We will present initial data on the structure of the bee projectin gene, its exon-intron splicing and the potential PEVK structure.
Thomas P. Smith and Leslie. R. Sautter, Department of Geology and Environmental Geosciences
Surface sediments from three different Transect Program research cruises were collected across the continental shelf off Charleston, SC. The Charleston Transect ranged from nearshore waters to the shelf edge where water depths were 100 m. Micro-gastropods were removed from sieved samples (<1mm) and specimens were identified to the species level. Assemblages were characterized based on relative abundances of predominant species. Different depth zones and cross-shelf geographic ranges were identified using these micro-gastropod assemblages. Four different micro-gastropod sediment facies can be identified by the abundance of two to three species found at each site within the inner shelf (0-20m water depth), mid-shelf (20-50m), outer shelf and shelf edge (50-100m). No seasonal variability was observed, despite the variations in sediment grain size analyses (White, 2006), indicating a well-homogenized fossil assemblage.
Thomas P. Smith and Brian G. Scholtens, Department of Biology
Insect bucket traps were placed at Dixie Plantation at two locations, a field and a forest, in order to sample both different habitat types. The traps were set every night and picked up every morning for a time span of two months. All the insects that were attracted to light were removed from the traps and sorted by family. The families: Limacodidae, Megalopygidae and Arctiidae were identified to the species level and were compared with different environmental factors including temperature, wind speed, relative humidity, and the phase of the moon. All of these factors proved to be insignificant with field activity although there were correlations between wind speed and humidity with forest activity.
Sam Covington, Laney Mills, Department of Physics and Astronomy
I want to find a way to write music using fractals to control the note frequencies and time values of the notes in the music. Since fractals repeat themselves on smaller scales, they can be recognized somewhat in music. In classical music, themes or musical ideas are commonly found throughout the entire piece in different time scales, meaning one idea may be repeated (or have variations of it repeated like iterations of the "randomized" Koch flake) throughout the piece over varying intervals of time. I would like to use multiple voices that are controlled separately by chaotic functions with similar periodicity. I find that the attractors of a fractal or a chaotic function are analogous to the method in which a composer can build up to a cadence or give the audience an idea as to where the piece is going and how it may change over time.
George Khouri and Linda Jones, Department of Physics & Astronomy
The long term goal of this project is to develop a non-invasive optical method to quantify the photosensitizer in human esophagus in order to optimize the light dose for esophageal photodynamic therapy (PDT). A rat model was used in this study. Rats were injected intravenously with Photofrin, the only photosensitizer that has been approved by the FDA for use in PDT. The Photofrin was allowed to localize in the rat esophagus for 24 hours, then rats were euthanized, and the esophagus was removed. Reflectance spectra were obtained with a fiber optic spectrometer for control and photosensitized rats in order to determine the effect of the Photofrin content on the spectra. The sensitizer was then extracted from the tissue with chemical tissue solubilizers, homogenization, and centrifugation. The extracted sensitizer was quantified with absorption and fluorescence spectra and compared to standard curves. The results of this study will be used to develop a method of determining Photofrin content with spectral data.
Johnny Apple, LaToria Bostick, Franklin Czwazka, Carmen Headrick, Darby Jarrett, PJ Mestres, Jeff Montgomery, Thomas Hutchinson, and Garrett Milliken, Department of Psychology
Experiment one evaluated the role of contextual cues in line length estimation and found that subjects performed poorly at estimating line length regardless of whether the lines had vertical or oblique oriented contextual cues. In Experiment 2, eye movement and the number of eye-fixations using the Mller-Lyer stimulus and a neutral context stimulus were measured using the ERIKA Eye Gaze Analysis System. Our results show that more eye-movement and more fixations were related to the variable line than the referent line to which estimates were directed. We also found no difference in eye-movement and fixations between stimuli with respect to contextual cues. These results could indicate a greater role for cognitive processes rather than oculomotor processes in making line length judgments.
Rhiannon R. Carter and Justin K. Wyatt, Department of Chemistry and Biochemistry
The synthesis of the antiobiotic Cytosporone E has been completed and the development of new, more potent derivatives must be accomplished. Working towards this goal we have had to figure out how to incorporate a vinyl group onto a highly hindered position of a substituted benzene derivative using the Suzuki cross-coupling reaction of vinyltrifluoroborate and the an aryl bromide.
Julianne McLaughlin, Jason S. Overby, and Justin K. Wyatt, Department of Chemistry and Biochemistry
The ortho-alkylation of an aromatic oxazoline is a strong synthetic reaction. There is only one application of this chemistry to alkylate in a chiral fashion utilizing a chiral aromatic oxazoline. We have developed and will present a synthetic target that will increase the chiral selectivity of this reaction.
Lester Proctor and Dana Hughlett and Gorka Sancho, Department of Biology
As part of the Transects project, in the Spring of 2005, we sampled small sized demersal fishes at seven sites across the Continental Shelf using a 1 m beam trawl. Symphurus minor (Largescale tonguefish) was found at all depths along the continental shelf, and the maximum recorded depth of 100 meters was 40 meters deeper than currently documented for this species. Both males and females were caught at the same depths, indicating a mixed sex adult habitat, although females were found to dominate the sex ratio. The only site where a juvenile was caught was located at the nearest site to shore, no mature individuals were sampled, possibly indicating its value as a recruitment site. Large captures of juvenile Etropus cyclosquamus (Shelf flounder) indicate possible recruitment events during winter months in near shore waters. We also conducted preliminary age-size analysis of juveniles E. cyclosquamus.
Robert J. Dukes, Jr., Sarah. M. Sonnett, and Laney. R. Mills, Department of Physics and Astronomy
Spica has long been known to be both a spectroscopic binary and an ellipsoidal variable. In 1969 it was found it to be a Beta Cephei variable. By 1972 the short period Beta Cephei variation had become undetectable. While there have been sporadic reports of detection of short period light variation, none of these have been confirmed. In order to monitor the presence or absence of the strong pulsation, we obtained approximately 1000 Stromgren four-color observations on 130 nights during the 1996, 1997, and 2005 seasons. We have good phase coverage of the 4.01-day orbital period, enabling us to both verify the apsidal period and to examine the variation in temperature due to ellipsoidal variation. After removing the ellipsoidal variation we examined the residuals for sign of a short period term. We can definitively state that there is no sign of the original 5.75 c/d pulsation.
Lester Proctor and Gorka Sancho, Department of Biology
Seasonal changes in relative abundance and size distribution of demersal fishes were examined from samples collected across the continental shelf off Charleston, SC, in May 2005 and November 2004. Fifteen sites were sampled with a 1 meter beam trawl, catching fifty four different fish species. Each physiographic region of the continental shelf (Inner, Middle and Outer Shelf) was dominated by a different fish species. The Inner and Middle shelf had the highest relative abundance of Etropus cyclosquamus (Shelf Flounder), while the Outer shelf was dominated by Synodus foetens (Inshore Lizardfish). Demersal fish abundances variedbetween seasons however; patterns were observed suggesting possible migration and recruitment events. Size analysis of E. cyclosquamus and Prionotus carolinus showed an increased abundance but lower average size, suggesting a recruitment event occurred between seasons. The other species analyzed for seasonal size differences were Symphurus minor, Serrinaculus pumilio, and S. foetens, all observedhad increased abundance and size.
Ben Stone and Gorka Sancho, Department of Biology
In May of 2005, the Transects program (LEG 04) collected benthic samples along a transect line across the continental shelf off the coast of Charleston, South Carolina. Samples were collected using a beam trawl with a 1.0 meter wide opening in order to describe shelf communities of small demersal fishes. A total of 41 different species of fish were caught. Fish density and diversity were compared with depth, sediment type, and presence of live bottom. Fish distribution patterns seemed to be species specific, and were commonly correlated with depth and/or the presence of live bottom. The presence of live bottom was positively correlated with biodiversity, with the outer shelf having the highest diversity compared to the inner and mid-shelf zones.
Ben Stone and Gorka Sancho, Department of Biology
Hydrothermal vent fishes are large mobile predators which can influence vent community structures both directly and indirectly. These fishes are difficult to catch and are most commonly observed in video recordings taken by submersibles. TowCam photographic surveys made for geological purposes at the 9N hydrothermal vent field at East Pacific Rise (EPR) were analyzed to explore their value for analyzing vent fish distribution patterns. Still photographs of the bottom were used to count and identify fishes plus characterize their habitat preferences. Habitats were classified based on their distance from active vent sites, sediment type, and benthic communities. Thermarces cerberus, the most abundant species found, was most abundant near the vent sites. Other species of fish were found to be more abundant further away from the vent sites.
Leah Crowe, Department of Biology
The philometrid nematode Philometroides paralichthydis is found in various microhabitats in the southern flounder, Paralichthys lethostigma. These microhabitats include muscles at the base of the dorsal and ventral fins, between bones in the buccal cavity, inside the tongue, and on the gill rakers and hyoid arches. It was hypothesized that the size of the worms may be affected by physical constraints encountered in each microhabitat. Gravid female worms were collected from the various microhabitats and measured. Worms from the bases of fins were found to be significantly larger than worms in any other microhabitat. The link between size of gravid females and number of larvae born from these worms warrants further investigation.
Stephen Hughes and Timothy Giblin, Department of Physics and Astronomy
Gamma-ray bursts (GRBs) are high energy optical transients that occur frequently in the cosmos. The Swift satellite in low-Earth orbit can detect sudden increases in the gamma-ray background signal and locate the GRB using its Burst Alert Telescope (BAT). Swift sends the burst coordinates to the Gamma-ray burst Coordinates Network (GCN) which in turn forwards the information to ground-based telescopes. When we receive these alerts we capture images of the GRB afterglows using our DFM 16-inch Cassegrain telescope and CCD camera. We then perform image reduction using the program IRAF (Image Reduction and Analysis Facility). Utilities such as imcombine and imalign are used to increase the signal-to-noise ratio (SNR) so we may increase the sharpness of the images. We are using these images to test the limiting magnitudes found last year and to further study the afterglows that GRBs leave behind.
Paul Goforth, Department of Biology
A crucial step in mate selection process among crickets involves the female locating a male by phonotaxis. The male produces a calling song that is then interpreted by a female to either be a dominant or subordinate signal. In this experiment, 17 crickets ranging from very small (<2 cm in length) to very large (>2.2 cm) were recorded in the presence of a compatible female. The callings songs were then organized into dominant/subordinate categories based on size. Three 10 second clips of both songs were then isolated and analyzed. The physical characteristics were determined of each, including amplitude, inter-chirp intervals and general clarity. The recorded songs were used in playback experiments to see the pattern of response of a female. Various recordings were also made of an isolated male who could hear another male interacting with a female to see if the mechanism of calling was strictly a genotypic property. A subordinate song was used in playback experiments but altered one characteristic at a time to see at what point a subordinate song becomes competitive with a dominant song. Finally, songs were played "on top" of one another in playback experiments to see if leading a song changes the female's response.
Alan Wilder*, Pamela Riggs-Gelasco*, and Andrew Gelasco** *Department of Chemistry and Biochemistry, College of Charleston **Department of Medicine, Medical University of South Carolina and Research Service, Ralph H. Johnson VA Medical Center
The enzyme NADPH Oxidase (NOX) reduces molecular oxygen generating superoxide. The prototype NOX enzyme is found in neutrophils, where it participates in "respiratory burst"-a process that generates superoxide, hydrogen peroxide and hydroxyl radicals functioning in the immune response. The role of NOX found in other tissues is not clear, including the renal form NOX4. We have been making plasmid constructs of the genes involved in the NADPH oxidase system in renal cells. The renal forms of NOX4, P22, and P47 genes were cloned, digested and inserted into each of four plasmids. The plasmids used attach a fluorescent fusion protein to the overexpressed proteins. The hope is that we will be able to observe these differently tagged proteins (red, yellow, green and luciferase) interacting with one another in vivo using microscopy and bioluminescent resonant energy transfer. Our progress in creating these clones will be described.
Paul Chandler, Department of Biology, and Lisa Martin, and Carol Eisenberg, MUSC, Department of Cell Biology & Anatomy
The concept of cardiomyocyte (CM) regeneration remains controversial despite evidence of adult stem cells differentiating into CMs and even improving cardiac infarct injuries in animal models. There is also growing, yet controversial evidence of CM progenitor cells located inside the adult heart. To identify and investigate the properties of adult, heart-resident CM progenitors we immunostained for traditional stem cell markers (e.g. Islet-1) and found them scattered throughout the heart. We also employed the use of donor hearts from transgenic mice (TG1852) whose myocardial-specific gene (GATA-6) was labeled with a β-galactosidase reporter. The β-galactosidase-positive cells were also observed to be scattered throughout the heart and interestingly, the only cluster observed was in the ventricular apex. Preliminary observations showed that since these cells have sarcomeres, but donit express mature myocyte or stem cell markers, they may be in the process of differentiating from CM progenitors to mature CMs.
Kenneth Robison, Jay Elliott, Jason Rogers and Ron See, Department of Biology, College of Charleston and Department of Neurosciences, Medical University of South Carolina
Histological techniques serve an important purpose in neurophysiological research. In behavioral pharmacology studies, histology has confirmed that stereotaxically placed cannulae delivered drug infusions to the targeted brain region. After behavioral testing, laboratory animals' brains were fixed in formaldehyde through perfusion. Preserved brains were sectioned into 75 um sections and stained with cresyl violet to be examined under low power microscopy. Inspection of these sections verified the accuracy of canulae placement, confirmed the validity of the data from each animal, and also illuminated novel neuroanatomical function when correlated with behavioral data. This was exemplified in a study in which the bed nucleus of the stria terminalis (BNST) was inactivated prior to a test of heroin relapse in addicted rats. Contrary to a prior hypothesis, histological analyses revealed that inactivation of the medioposterior BNST (BNSTmp) prevented heroin relapse; whereas inactivation of the ventral BNST (BNSTv) did not.
Travis Jenkins, Barbra Bannan and Elizabeth Meyer-Bernstein, Department of Biology
In mammals, a daily, or circadian, clock is located in the hypothalamic suprachiasmatic nucleus (SCN) which regulates an organism's rhythms. In other body tissues, peripheral clocks are responsible for local rhythms. While progress has been made in understanding clock cell function, much remains to be elucidated regarding specific intracellular signaling pathways used to communicate timing information throughout the body. The signal transduction enzyme, phospholipase Cβ4 (PLCβ4), has been implicated in the circadian system and is the focus of our research. Earlier studies showed that in LD housed mice, PLCβ4 oscillates in the mouse SCN and liver. The present study addressed whether this rhythm is generated by the internal clock or by the external photoperiod by assaying the PLCβ4 abundance in mice housed in constant darkness. Preliminary data indicate that PLCβ4 is rhythmic in the liver, but not in the SCN, suggesting differential regulation of this protein in these two tissues.
Sarah Belden, Travis Jenkins, Michael Gorman and Elizabeth Meyer-Bernstein Department of Biology, College of Charleston and Department of Psychology, University of California at San Diego
The suprachiasmatic nucleus (SCN) of the mammalian brain houses a clock which regulates daily biological rhythms. The protein components of the clock mechanism undergo a daily rhythm of abundance. The clock protein, Period1, peaks at dusk and is correlated with the animal's activity onset. In constant light, hamsters display a phenomenon called "splitting" which is characterized by two activity bouts per day. Based on this phenomenon, it has been theorized that the clock is comprised of two independent oscillators coupled together. In order to understand the molecular basis of "splitting,"we assayed the levels of Period1 protein in the SCN from "split" and "unsplit" hamsters. Preliminary data indicate that in "split" hamsters there are two peaks of Period1 protein which correlate with each activity bout. These data suggest that each independent oscillator is represented by a subset of cells within each SCN.
Travis Jenkins, Richard Wooldridge, Mary Harrington and Elizabeth Meyer-Bernstein Department of Biology, College of Charleston and Department of Psychology, Smith College
The mammalian biological clock is located in the suprachiasmatic nucleus (SCN), and is synchronized to the environment by light. In order to understand the intracellular pathways mediating photic input in the SCN, we have been investigating a potential role for the enzyme phospholipase C β4 (PLCβ4) in the mammalian circadian system. To determine if PLCβ4 is a component of the light input pathway, we blocked the activity of PLCβ in the SCN and completely inhibited the ability of a retinal neuropeptide to reset the clock. In order to identify the particular PLCβ isoform underlying this response, we assayed the levels of PLCβ1, 2, 3 and 4 in the SCN in response to a nighttime light pulse. While the current data clearly indicate the clock is reset in a PLCβ-dependent manner, and that PLCβ4 may be a primary constituent of that pathway, the extent to which the other PLCβ isoforms are contributing to this response has not been determined.
A.C. Smith, H. Buff, and C.A. Korey, Department of Biology
Infantile Neuronal Ceroid Lipofuscinosis is caused by mutations in the cln1 gene which encodes palmitoyl-protein thioesterase 1 (Ppt1), suggesting that there is an important role for the regulation of palmitoylation in normal neuronal function. Loss of Ppt1 function in patients produces granular osmiophilic deposits (GRODS) in all cells and massive neurodegeneration. What remains unclear is why the loss of Ppt1 results in the observed disease pathophysiology in neuronal cells and resulting neurodegeneration. We have performed a gain-of-function modifier screen in which we have used ~2000 EP and EY transgenic overexpression lines to suppress or enhance the degeneration produced by DmPpt1 overexpression. Several of the modifier genes we have identified have been previously shown to be important for neuronal function confirming an important role for DmPpt1 in neuronal signaling and synaptic development. Further analysis of the genes identified in our gain-of-function approach will facilitate the identification of in vivo substrates and signaling pathways that DmPpt1 may modulate thus shedding light on the molecular etiology of INCL.
Kathleen Mackie and Timothy J. Callahan, Department of Geology and Environmental Geosciences
Global sea level is rising; one effect is disruption of coastal processes (such as natural filtering systems by fringe wetlands and flood control) and bird and fishery habitats as human development restricts natural migration of coastal wetlands. This study focuses on two South Carolina tidal wetlands by inspecting nitrogen concentrations in the tidal salt marshes at North Inlet and Dixie Plantation near Charleston, SC. Nitrogen is important in tidal salt marshes because as sea level increases nitrogen levels also increase within these wetlands - supporting an increase in primary production - yet potentially leading to eutrophication. Twenty years of data are available from North Inlet, near Georgetown, SC; there the salt marsh is migrating southwest due to sea level rise. We plan to compare trends in the nitrogen budget at the two sites to help predict if similar migration will occur at a new site, Dixie Plantation, leading to wetland loss.
Georgette Hachem and Jeffrey L. Wragg, Department of Physics and Astronomy
We investigate optimization of flight time and fuel consumption for aircraft. Using the program Mathematica as a computational tool, we seek to optimize successively more realistic flight models. Initially, the flight is divided into three stages: climb, cruise and descent. Aircraft speed and fuel consumption are functions of altitude. The functions are modeled and the flight path is optimized.
Margaret A. Malone, Kelly M. Buck, and Gorka Sancho, Department of Biology
The trophic ecology of aggregated predatory fishes at fish aggregating devices (FADs) in the Indian Ocean, was investigated through two consecutive years of data collection and FAD observation periods. The major predators studied were the yellowfin tuna, (Thunnus albacares), wahoo, (Acanthocybium solandri), and dolphinfish, (Coryphaena hippurus). Diets were examined through stomach content analyses to determine approximate daily feeding time, as well as to determine if aggregated piscivores feed on the fauna observed at the drifting FADs. Seasonal and inter-annual changes in feeding times as well as diet composition were seen. These changes in dietary patterns were mainly the consequence of a large stomatopod (Natosquilla investigatoris) bloom. Lastly, FAD-associated prey were found to be of little significance in the diets of these predatory fishes.
John D. Knight, Bonnie J. Grant, Catherine R. Kramp, Clyde R. Metz, Jason S. Overby, and Charles F. Beam, Department of Chemistry and Biochemistry
C(alpha)-ketone carbomethoxyhydrazones, such as those from 1- or 2-tetralone, substituted acetophenones, and all aliphatic cyclonones were dilithiated with lithium diisopropylamide and condensed with aromatic esters to give C-acylated intermediates that were cyclized directly with acid to N-carbomethoxypyrazoles or N-carbomethoxydihydrobenzindazoles. The latter materials were saponified with potassium hydroxide, followed by decarboxylation to the targeted N-H dihydrobenzindazole or N-H pyrazole. Proton NMR spectra for the N-carbomethoxybenzindazoles displayed two triplets, as expected for the C-4 and C-5 protons. The same protons were displayed as a broad singlet in the H-1 NMR for their N-H pyrazole saponification products. X-ray crystal analysis of several products, confirmed the structure, with some of the crystalline samples being partially solvated. Also, a single isomer and not two isomers was present, with nitrogen two (N-2) bonded to a hydrogen atom. When several N-H dihydrobenzindazoles were dialkylated with methylene bromide, high melting point products were isolated and are being characterized.
Bonnie J. Grant, John D. Knight, Catherine R. Kramp, Clyde R. Metz, Charles F. Beam, Department of Chemistry and Biochemistry
Methyl 2-(aminosulfonyl)benzoate has been condensed-cyclized with a variety of lithiated intermediates to afford new heterocyclic products: 3-substituted benzisothiazole dioxides; benzisothiazolo-isoquinolinone dioxides; pyrazol-benzenesulfonamides; and spiro[benzisothiazole-isoxazole]dioxides. Three-substituted benzisothiazole dioxides (3-BIDs) have been prepared by condensation-cyclization of this ester-sulfonamide with several types of polylithiated intermediates. For example, their condensation with dilithiated b-ketoesters, followed by cyclization gave a single tautomer product, a 3 BIDs-beta-ketoester, whose structure was confirmed by X-ray crystal analysis. The condensation-cyclization of dilithiated ortho-toluic acids and methyl 2-(aminosulfonyl)benzoate gave benzisothiazolo-isoquinolinone dioxides, a new fused-ring heterocyclic system, whose structure was also confirmed by X-ray crystal analysis. Pyrazol-benzenesulfonamides resulted from condensation-cyclization of dilithiated acetophenone phenylhydrazones and methyl 2-(aminosulfonyl)benzoate. When dilithiated acetophenone or cyclododecanone oximes were condensed-cyclized with this ester-sulfonamide, the originally anticipated products, isoxazol-benzenesulfonamides were not isolated; spiro[benzisothiazole-isoxazole]dioxides, a new heterocyclic system, were isolated instead. X-ray analysis was necessary for structure confirmation with both projects.
Catherine R. Kramp, Bonnie J. Grant, John D. Knight, Clyde R. Metz, Charles F. Beam, Department of Chemistry and Biochemistry
One- or 2-tetralone oximes were dilithiated with lithium diisopropylamide and condensed with a variety of aromatic esters to C-acylated intermediates that were acid cyclized directly to dihydronaphthisoxazoles. The yields of products from dilithiated 2-tetralone oxime condensations were less than those obtained from dilithiated 1-tetralone oxime. Dilithiated 1- and 2-tetralone oximes were also prepared from respective oximes with either n-butyllithium, or LDA. The dilithiated oximes underwent aldol-type condensations with electron enriched aldehydes, such as 3,4-dimethoxybenzaldehyde, or lithiated vanillin. The condensations were followed by direct acid cyclization of the beta-hydroxyoximes. The preparation of tetrahydronaphthisoxazoles from 1-tetralone oxime has recently been completed, and the preparation of isomeric tetrahydronaphthisoxazoles from 2-tetralone oxime is under investigation. Spectral characterization included HMQC, DEPT in addition to C-13 and H-1 NMR spectra. An X-ray crystal structure analysis of a representative tetrahydronaphthisoxazole from dilithiated 1-tetralone oxime revealed the 3, 3a geometry is trans, and not cis cited by others.
Eliza Reock, Department of Biology
We caused an overexpression of the protien Homer1c in the nucleus accumbens, a section of the brain, in Sprague-Dawley rats. Homer1c is known to regulate cocaine addiction. Through self-administration sessions, facilitated by catheterization, we found these Homer1c rats aquired cocaine faster at a high dosage and slower at a low dosage in comparison to GFB control rats. Also at a lower dose Homer1c rats had a lower maintenance levels of cocaine intake.
Kit Peters and Laney Mills, Department of Physics and Astronomy
The Lorenzian waterwheel is a physical system, first envisioned by Willem Malkus at MIT, that demonstrates chaotic behaviour such that its equations of motion are, through a change of variables, equivalent to the Lorenz equations. These equations were first proposed by E.N. Lorenz in 1963 to model atmospheric convection rolls, but are applicable to fluid dynamics, dynamoes, and lasers. The waterwheel is a useful tool for investigating the behaviour of the Lorenz equations. These equations, although simple, describe a behaviour that is extremely complex, to the point of apparent randomness although they are in fact deterministic. The poster will show how the waterwheel's equations of motion are developed and modeled using the Python programming language, and a running animation will also be provided.
Richard Smith and Laney Mills, Department of Physics and Astronomy
This poster describes and explains the operation of a van der Pol circuit. The van der Pol circuit is a variation of a simple resistor-inductor-capacitor series circuit ("RLC circuit") that demonstrates what is known as chaotic behavior. The term chaotic behavior refers to the fact that although this circuit is simple and is described by simple equations, its patterns of oscillation can appear exceedingly complex. Variations of this circuit have been used in many applications over a long period of time. The poster will explain the difference between the regular RLC circuit and the van der Pol circuit and will show computer plots of its behavior generated from the equations themselves.
George Peter Kablick and Laney Mills, Department of Physics and Astronomy
The double pendulum consists of a massless bar suspended from a horizontal axis. On the other end of the bar is a point mass and a second horizontal axis from which is suspended a second identical bar, on the far end of which is an identical point mass. There is assumed to be no friction in the system. The entire motion takes place in a vertical plane. The device is an example of a system that is simply constructed but which is capable of amazingly complex and even beautiful motion. It is also an example of what is known as a Hamiltonian chaotic system. Unlike many chaotic systems, this one conserves energy. The poster will show the development of the descriptive equations as well as a computer animation of its interesting motion.
Scotty Keith, Department of Physics and Astronomy
The term Brownian motion, originally used to describe the random motion of particles, has grown to encompass any phenomenon in which the various component motions involved are independent of each other. An even broader set of Brownian motion, called fractional Brownian motion, is characterized by a parameter (called the Hurst exponent, denoted by H) which has a value between 0 and 1 with H=0.5 being regular Brownian motion. A Hurst exponent between 0 and 0.5 describes motions which tend to move opposite to previous movements. Thus the system never deviates far from its original position (antipersistence). Correspondingly, a Hurst exponent between 0.5 and 1 describes motions tending away from its original position (persistence). This poster will show how such motions are generated on a computer as well as resulting examples. It will also show a computation of its so-called fractal dimension.
Lauren Diamant, Department of Biology
Over the past 100 years, the general climate of the earth has warmed by approximately 0.6 degrees C. Effects of global climate change on regional weather patterns will vary with increasing temperatures, precipitation, and CO2 levels. Climatic changes have already influenced the population dynamics and phenology of many taxa of organisms. Birds are particularly good indicators of environmental change because of their diversity and abundance. Data indicate earlier arrival, breeding, and migratory events in a significant number of birds in response to global warming trends. A less studied but equally pertinent affect of climate change is the rise of infectious diseases. As temperature and precipitation increase, disease pressure may intensify--causing bird and other animal populations to suffer. Further research should examine the implications of climate for bird disease in avian populations as well as other species put into contact with them.
Javier Orman, Department of Mathematics
In his First Incompleteness Theorem, Godel found that in any consistent recursive formal arithmetic there are undecidable sentences, that is, that any such arithmetic is simply incomplete. In the Second Incompleteness Theorem we find one such undecidable sentence, one that intuitively means: "This theory is consistent." The theorem states: "No consistent extension of Peano Arithmetic can prove its own consistency." Guided by George Tourlakis' Lectures in Logic and Set Theory, we study a way to prove the theorem through the development of tools that allow a formal arithmetic to make statements about itself.
Christian Boutan, Sorinel Oprisan and Laney Mills, Department of Physics and Astronomy
Phase Resetting treats neurons as black-box oscillators whose outputs are a function of the phase (j) of their inputs. Depending upon the phase at which a perturbation is received, a neuronis next firing will either be advanced or delayed. The amount by which the firing of a neuron is offset is given by a Phase Resetting Curve (PRC) function which we approximated with F(j) = -msin(pj), where m is the control parameter related to the connectivity strength between the two neurons. A simple network of two reciprocally coupled neurons can be formed where the firing of each neuron perturbs the other. This system can be solved analytically and put into a recursion form that can be mapped to find its steady states. Our primary concern will be to find the bifurcation points that mark the transitions between entrainment modes leading to the eventual transition to chaotic behavior.
Emily A. Simons, and Andrei Straumanis, Dept. of Chemistry and Biochemistry
POGIL is a lecture-less teaching method that models the way scientists function in the research laboratory. Among other things, the method claims to increase student engagement, develop content knowledge, and foster growth in process skills such as critical thinking, problem solving, self-assessment, information processing, management, communication, and teamwork. It is difficult to directly study engagement or growth in process skills. To get some measure of this we collected students' perceptions of their own growth using the Student Assessment of Learning Gains (SALG) instrument. SALG and common exam data were collected at a range of institutions in both POGIL and traditional sections of organic chemistry. Faculty adoption of POGIL is supported by NSF via the POGIL Project in the form of faculty development workshops, consultancies, and local networks of POGIL users. There will be a POGIL workshop for faculty here at the College of Charleston during May. More information can be found at www.pogil.org.
Kit Peters and Jerry Boetje, Department of Computer Science
CLforJava is a pure Java implementation of ANSI standard Common Lisp version 2 that aims for full Unicode support. We are creating an extensible architechture supporting the parsing and printing of any numeral supported by Unicode. For example, CLforJava can parse and print floating-point numerals in Thai, or a ratio in ancient Aegean numerals. Currently, we are concentrating on the characters in the Unicode Standard other than Han (Chinese) and Hangul (Korean), but our ultimate goal is to allow CLforJava to parse a string of characters that represents a number in any numbering system in the world, past or present, into a machine-storable number. We know of no other Common Lisp implementation that does this.
Emily Long and Craig Plante, Department of Biology
Benthic microalgae (BMA), such as diatoms, migrate vertically through mud and sandy sediments in response to tidal variations. BMA are also known to excrete extracellular polymeric secretions (EPS), which can be used for nutrients by heterotrophic bacteria. The aims of this study were to determine if sedimentary bacteria also migrate, and test whether they 'follow' the diatoms. Replicate sediment cores from a semi-sheltered beach were taken at 3 time points (just after tidal exposure, at low slack tide, and after inundation). Cores were sliced horizontally for vertical analysis of diatom biomass (using fluorometry) and bacterial abundance (via microscopy). We found 1) high inter-site variability in vertical distribution patterns of both diatoms and bacteria, but also 2) a strong positive correlation between BMA and bacteria regardless of distribution pattern. This finding has important implications for understanding the ecology of sedimentary bacteria and their role in benthic food webs and decomposition processes.
Willie Moultrie and Fred Watts, Department of Physics and Astronomy
Holographic interferometry is a technique in which very small movements can be detected through creating double exposure holograms. When an object is under stress, strain will show up on the hologram as a pattern of light and dark lines indicating the areas affected. Using weights of known masses, objects such as an aluminum can and different type of metal bars were strained and double exposure holograms of each were taken under stress and with the stress removed. The interference pattern of these were then analyzed and compared with similar tests and a measure of stress and overall structural integrity was found. This will allow us to accurately predetermine the strain on common metal structures under known weight (stress), or determine the stress that was applied to a structure. Studies like this are very beneficial in determining structural weaknesses in objects and may have great impact in industry.
Austin Younger1,2, Bethany Smith2, Shereen Amria2, Agnes Ayme-Southgate1, and Azizul Haque2,
1Department of Biology, College of Charleston
2Department of Microbiology and Immunology, Center for Cell, Gene, and Vaccine Therapy, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC
The purpose of this research was to investigate the prospect of immunotherapy for the treatment of prostate cancer in the context of HLA Class II antigen presentation. Prostate epithelial cells express prostate specific membrane antigen (PSMA). PSMA contains both HLA Class I and II restricted antigenic peptides, required for T cell stimulation. Study suggests that reduced expression of target protein antigens is one of the possible immune escape mechanisms for malignant tumors. Higher levels of PSMA expression occur in most malignant prostate cells making them a potential target for immunotherapy. Prostate cancer cell lines (Dupro, Du145, LnCap, PC-3 and CWR-22) were analyzed using western blotting techniques to determine whether or not they express HLA Class II molecule as well as other components of the class II pathway. This course of research has demonstrated that select prostate cancer cells endogenously express the HLA Class II molecule and that higher levels of expression can be achieved by stimulating cells in vitro with cytokine interferon-γ. It is believed that genetically manipulated prostate cancer cells can present HLA class II-restricted PSMA peptides to stimulate CD4+ T cells.
Meghan K. Patton and John J. Widholm, Department of Psychology
Rats perinatally-exposed to 0 or 30 mg/kg/day of ammonium perchlorate (AP) were trained to press levers using an operant autoshaping task and then tested on a spatial discrimination / reversal learning (RL) task to assess the ability of AP to disrupt learning. For autoshaping, the periodic illumination of a cuelight located above a response lever was followed by a food pellet to develop an association between the cuelight (and the nearby lever) and reinforcement. Presses to the lever were immediately reinforced and the number of presses was recorded. For spatial RL, pressing the lever associated with the correct spatial location (left or right) was reinforced and the reinforced lever was periodically switched upon meeting a performance criterion of 85% correct. Although none of the between-groups comparisons were significant, a trend toward a sex-specific effect of AP exposure was observed on these tasks with AP-exposed males exhibiting impairments and AP-exposed females exhibiting facilitation.
John R. Casey1, Michael W. Lomas2, Joanna Mandecki3, Donald E. Walker2,
Gorka Sancho1
1 Department of Biology, College of Charleston
2 Bermuda Biological Station for Research, Inc, St. George’s, Bermuda
3 Princeton University, Princeton, New Jersey
In this study 15NO3- uptake rates specific to populations of the photoautotrophic marine cyanobacteria Prochlorococcus marinus were monitored throughout the fall bloom at Hydrostation "S" and the Bermuda Atlantic Time-series Study spatial stations southeast of Bermuda. Here, we present data supporting the observation of Prochlorococcus cell density maxima coincident with the nitracline. We use a novel field study approach coupling flow cytometric sorting techniques with stable isotope 15N tracers and isotope ratio mass spectrometry to yield a "pure" population specific NO3- uptake rate. Surface populations of Prochlorococcus were sorted but showed no net uptake of NO3- at any point during the bloom. However, the natural Prochlorococcus population at the deep chlorophyll maximum (DCM) showed significant NO3- uptake rates. NO3- uptake rates averaged over the fall bloom translated to a daily growth rate of 0.0091d-1, strikingly similar to the calculated average growth rate of 0.00734d-1 determined by the near five-fold population increase.
John R. Casey and Gorka Sancho, Department of Biology
Neuston net tows were made during both the day and night across the continental shelf off Charleston, SC during June 2004. Zooplankton biomass estimates were used to describe zooplankton distribution patterns; they were also correlated to a suite of environmental and biological factors to determine their influence in explaining these distributions. Potential biological proxies analyzed included surface chlorophyll a concentrations and the presence of floating Sargassum spp. clumps, a planktonic macroalgae which provides a unique habitat for fish, marine insects, and other natural predators of zooplankton. Sargassum is also a convenient biomarker for convergent surface currents. Our findings show that total zooplankton biomass at the surface were more than twice as high in samples containing significant (>170mL) amounts of Sargassum. Biomass was also nearly doubled during nighttime tows due to DVM. No direct correlations were observed between biomass and salinity, SST and, interestingly, chlorophyll.
Melissa Sims and Robert Dukes, Jr., Department of Physics & Astronomy
This project is the continuation of a study of the variable star HD21071, which has been on the observing program of the Four College Consortium Automatic Photoelectric Telescope, since 1998. HD21071 was previously determined to be a Slowly Pulsating B star by Waelkens, et. al. (Astron. Astrophys. 330, 215-221, 1998) with a suggested period of .841 day (1.19 c/d). Mills, L. R., et. al. (BAAS 31, 1482, 1999). confirmed the proposed period and suggested a .870 day (1.15 c/d) period. This project incorporates one more season of data and uses the Period04 program to ascertain frequencies in Stromgren uvby filters. During study of the new data, additional periods of .704 day (1.42 c/d), .775 day (1.29 c/d), and 1.14 day (.878 c/d) are suggested. The reality of the determined frequencies was tested using least squares analysis and a check of the signal to noise ratio. This project was made possible by the SCAMP and SURF programs at the College of Charleston.
* Supported by NSF Grant AST-0071260 & AST-050755
Joseph Hambright and Laney Mills, Department of Physics & Astronomy
Consider a regular kitchen faucet dripping slowly. If the flow rate is slow enough, but still to allow dripping, it drips constantly in steady time intervals. If the flow rate is increased even more, it follows a more complex but still a predictable pattern. This pattern becomes more complex with each critical value that is reached. When the flow rate reaches a certain value, it loses the complexity and becomes chaotic. This project focuses on observing this chaos. This particular example is a chaotic model of period doubling which will be explained along with a brief description of non-linear dynamics (chaos).
Cyrus Buffum1, Laney Mills1, and Chris Mack2
1Department of Physics and Astronomy, College of Charleston
2Applied Technology and Management, Mt. Pleasant, SC
This poster describes the construction and operation of a wave tank for the purpose of analyzing the movement of particles beneath propagating ocean waves. The tank is 3.05 m long, 25 cm wide and 61 cm deep. At one end is a device for generating waves and manually altering their frequency and amplitude. The objective is to gain insight regarding the detailed affect of ocean waves on beach morphology. Specifically, this tank allows for the analysis of the quantifiable relationship between ocean waves and bar migration. This project is conceived as a stepping stone to a larger study of the direct relationship between ocean waves and beach erosion. Chris Mack, Senior Engineer, from Applied Technology and Management, is assisting in the construction and analysis.
John Wallace and Phillip Dustan, Department of Biology
Protein skimmers may potentially be used as integrating sampling devices for marine/estuarine environments. These devices, used in salt water aquaria for waste removal, concentrate various inherent materials through a process known as foam fractionation. The foam fraction contains numerous dissolved organic compounds (DOCs), inorganics and various microorganisms and thus may aid in characterizing certain components of water quality. Differences among certain DOCs, inorganics, or organisms may be exhibited by collecting foam fraction samples at different locations. However, protein skimmers are stationary; they are fixed to aquarium walls. Thus, we describe the development of free-floating, self-sufficient portable protein skimmers for field use. Samples were collected across a range of local marine/estuarine environments. Our portable skimmers collect approximately 15mL/h for up to 15 hours, but we found that 1 hour yields are sufficient for water quality analyses. We plan to examine differences in Polycyclic Aromatic Hydrocarbons (PAHs).
