Browsing Bachelor's Essays (Embargoed) by Issue Date "2013-05"
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- ItemA Test of the Effects of Covert Marketing: Should Marketers Proceed With Caution?(2013-11-04) Gordon, Sarah B.; Blose, Julia E.
- ItemChoice among Equally Priced Food Alternatives in Rats(2013-11-04) Gonto (Burnette), Kelsey Leigh; Galuska, ChadStudies investigating unit price predictions of choice in humans and monkeys have indicated that – at relatively cheap prices – most subjects prefer a large reward for more work than a small reward for less work; however, the opposite pattern has been reported in pigeons. Our study further explored this issue by examining rats’ demand and choice between alternatives equal in price but comprised of different response requirements and reinforcer magnitudes. Five food-restricted adult male Long Evans rats lever pressed for food pellets. Demand curves were first obtained by manipulating the fixed-ratio (FR) response requirement across sessions using 1-pellet and 4-pellet reinforcers. In the choice phase of the study, two levers were available simultaneously. In most conditions, the alternatives were equally priced but comprised of FR and reinforcer sizes of differing magnitudes. Two patterns of results were exhibited: rats either displayed a clear preference for one of the alternatives or they showed a lever bias. The rats with lever biases demonstrated a clear preference for the cheaper alternative during conditions in which the alternatives were unequally priced. Rats demonstrating preference under equally priced choice comparisons tended to prefer the larger magnitude alternative over the smaller one until the overall price became expensive. These results provide mixed support for unit-price predictions of choice, which state that, when two alternatives of equal unit price are available, there should be no discernable preference between them. This study demonstrates that some rats do, in fact, exhibit a preference between equally priced alternatives comprised of different response requirements and reinforcer amounts.
- ItemEvaluating Cortical Stimulation as a Therapeutic Adjunct to Motor Skills Rehabilitation Training in a Rodent Model of Traumatic Brain Injury(2013-11-04) McCarthy, Jordan J.; Milliken, GarrettVarious studies in animal models of stroke have found that motor impairments caused by stroke can be greatly reduced if the injured area of the motor cortex is electrically stimulated while the animal performs motor skills rehabilitation tasks. This rehabilitation and stimulation combination therapy is very effective, as animals receiving combination therapy are significantly less impaired than animals receiving only rehabilitation after stroke. This study evaluated the behavioral effects of combining cortical stimulation to the affected motor cortex with motor skills rehabilitation training after traumatic brain injury (TBI) to determine if cortical stimulation holds the same benefits for TBI as it does for stroke in reducing motor impairments after injury. In this study, rats were initially trained to a criterion level of proficiency on a skilled single-pellet reaching task. Rats then received a controlled cortical impact (CCI) to the area of the motor cortex corresponding to their preferred reaching limb, and electrodes were implanted over the perilesional tissues near the injury site. Nine days after surgery, rats began a seven-week rehabilitation training program in one of four conditions: 100 Hz anodal stimulation during training, 100 Hz cathodal stimulation during training, 100 Hz bipolar stimulation during training, or no stimulation during training. The behavioral effects of rehabilitation and stimulation were assessed throughout the study with weekly single-pellet reaching test probes that evaluated qualitative aspects of 12 distinct motor movements in the reaching task. Overall, no significant differences in reaching performance were found between any of the four groups. These results suggest that 100 Hz anodal, cathodal, and bipolar stimulation are not effective adjuncts to motor skills rehabilitation training in the rodent CCI model of TBI. However, future studies should test different combinations of frequency, intensity, and polarity parameters, because it is possible that a different combination of stimulation parameters could be an effective therapeutic adjunct to motor skills rehabilitation training after TBI.
- ItemFacebook Knows You: An Analysis of Facebook, Social Anxiety, and Narcissism in Young Adults(2013-06-05) Cifaldi, Olivia; Gutshall, Anne; Kolak, Amy$Participants were recruited via Facebook and administered a brief survey exploring Facebook use, social anxiety, and narcissism. Several significant relationships were found including results supporting prior research on social anxiety, friend selection and activity of use; as well as with narcissism and self-promotion. Overall, an individual's persona on Facebook is related to their real life persona. In addition, those with socially anxious and narcissistic qualities also reflect those qualities online. Recommendations and ideas for future research and practice are discussed.
- ItemFinancial Industry Diversification: An Empirical Analysis(2013-11-05) von der Lieth, James P; Neesham, BethThis paper uses a quantitative approach to determine whether or not diversified financial institutions perform better than specialized financial institutions for shareholders. It aims to identify whether or not economies of scope benefits of financial conglomerates outweigh the negative implications of providing a wide variety of services. Other academic work has identified economies of scope benefits in the financial sector, including the ability to market diversified services to existing customers, sharing of fixed costs, and ability to take advantage of the moral hazard of the FDIC. (Laeven and Levine) Possible diseconomies of scope effects include exacerbating agency problems between managers and investors, more precarious risk management and invoking inner-company conflicts of interest due to offering both investment services and banking services. This paper will identify which financial institutions business model has historically provided the best returns to shareholders since the repeal of the Glass-Steagall, when United States financial institutions were permitted to diversify their services to the greatest extent since the 1920’s.
- ItemFood Deserts in Context: A Look at South Carolina and Charleston(2013-06-05) Conwell, Elizabeth; Knotts, GibbsFor the history of its study, the concept of “food deserts” has been a difficult one to pinpoint. Various definitional challenges suggest a variety of potential ways to study food (in)accessibility in a spatial context. Because this research aims to lay a foundation in the study of food deserts in South Carolina and the Charleston area, the focus of this paper will use statistical analysis to present a preliminary look at where food deserts are located using data from the US Department of Agriculture’s Food Access Research Atlas. Are there any patterns as to where these areas of low access occur? Next, this paper will examine the demographic features of these areas, pairing the 2000 US Census demographic data to the accessibility data. Can we detect any trends in terms of the defining characteristics of these affected communities? Are there “indicators” of potentially low access? Finally, after calculating results for the various levels of analysis, a comparison between local, state, and national conditions of food accessibility will be discussed. How does South Carolina compare to national trends? How does Charleston stack up to other counties in the state? The answers to these questions represent a first step in better understanding food access in South Carolina and the Charleston area. Findings show that South Carolina and Charleston are consistent with national trends as well as previous localized studies.
- ItemGlutamate Kinetics in a Middle Aged Mouse Model of Parkinson's Disease(2013-11-05) Quattlebaum, Ariana; Korey, Christopher; Boger, Heather$GDNF, a known growth factor, is important for maintaining the health of dopamine (DA) neurons. Parkinson’s (PD) patients have a greatly decreased number of DA neurons in the substantia nigra (SN) while existing nigral neurons have a down regulation of GDNF. Animal models with partial GDNF reduction show an accelerated decline in the SN DA system and motor function similar to PD. Increased glutamate release in the subthalamic nucleus also occurs in PD patients. The purpose of the current study is to help determine the role of glutamate in a GDNF+/- model of PD. Potassium-stimulated glutamate release and uptake in the SN was assessed in anesthetized 12-month-old wild type (WT) and GDNF+/- mice (partial gene knockouts with decreased GDNF levels) by electrochemical detection. After this procedure, western blots helped determine how much glutamate transporter was in each tissue sample, and tissue staining allowed determination of phospho-mTOR levels in the SN (a measure of cellular stress). Initial data indicates high levels of glutamate are released in GDNF+/- tissue, as well as low levels of the transporter GLT-1. Staining results showed an upregulation of phospho-mTOR expression in the SN pars reticulata (SNpr). These results support the idea that glutamate excitotoxicity may play a role in cell death of PD patients, and that cell death leads to additional stress on nearby cells, potentially as an injury response.
- ItemInvestigation of the threshold photodynamic dose for HPPH-sensitized PDT of Panc-1 pancreatic cancer cells(2013-11-05) Patel, Pooja M; Jones, LindaOur research group at the College of Charleston has been working in collaboration with physicians at Mayo Clinic to develop a method of drug and light dosimetry for photodynamic therapy (PDT). We are studying Panc-1 pancreatic cancer cells with the photosensitizer 2-[1-Hexyloxyethyl]-2-devinyl Pyrophenophorbide-a (HPPH) and 670-nm light. Our aim is to improve the result of photodynamic therapy (PDT) for the treatment of pancreatic cancer. The first part of the project involved quantifying the photosensitizer using an optical dosimetry method. A “ratio method” was used in which the ratio of the integrated dye fluroesence was divided by the autofluorescence for various amounts of HPPH in a tissue phantom. While dye extraction is likely to overestimate the amount of dye that is therapeutically available in vivo, the ratio method reports optically active photosensitizer content. The second goal of this project was to determine whether there is a threshold of absorbed light for irreversible destruction of photosensitized Panc-1 pancreatic cancer cells. A preliminary experiment compared red and green light sources at an energy dose of 1 Joules/cm2. For the remainder of this project red light was used as it would not limit the depth of the treatment thus, it can penetrate deeper into the tissue to kill the pancreatic cancer cells. The cells were loaded with 1 mg/kg of HPPH and 670-nm light was applied at the range of 0.025-3.0 J/cm2. Clonal assays were used to determine the cell viability, accounting for cell death by both necrosis and apoptosis. After plotting the light absorption dose against cell viability, the LD-50 light dose (light dose that kills 50% of the cells) for HPPH-mediated PDT was determined. The LD50 light dose for panc-1 cells incubated with 1mg/m2 HPPH was 0.15 J/cm2. The dosimetry calculations gave a result of 3.5 x 1010 per cell, yielding an LD-50 dose in terms of photons of 1.11 x 1019 photons per gram of tissue.
- ItemMKP‐1 LPS-Driven Osteoclastogenesis More Prevalent in Dusp‐1‐/‐ Females Than Males(2013-06-05) Browne, Courtney G; Valerio, Michael S; Kirkwood, Keith L; Morrison, Susan$Periodontal disease is the result of chronic inflammatory bone loss due to a sustained immune system response to pathogenic invasion. Osteoclasts (OC) are multinucleated, bone resorbing cells that play a vital role in bone turnover. Receptor activator of nuclear factor kappa B ligand (RANKL) is the physiological regulator of osteoclastogenesis (OCgen) in naïve progenitor populations. Gram-negative bacteria involved in pathogenesis of periodontal disease contain the endotoxin, lipopolysaccharide (LPS), which increases RANKL expression by activating innate immune inflammatory cascades including mitogen activated protein kinase (MAPK). MAPK activity is negatively regulated by MAPK phosphatase (MKP)-1 which is encoded by the gene Dusp-1. The current study aims to investigate the role of Dusp-1 when driven by LPS and primed with RANKL OC progenitors (OCP). Based on the role of MKP-1 as a negative regulator of activated MAPK, we hypothesize that Dusp-1 deficient OCP will form more OCs in response to LPS stimuli. OCPs were isolated from male and female hematopoietic stem cells via magnet-activated cell sorting (MACS) and plated (5x104/well) based on expression of CD11b (CD11bhigh, low and neg), from Dusp-1+/+ and Dusp-1-/- mice. Cells were primed with macrophage colony stimulating factor (M-CSF) and RANKL for 48 hours and were then stimulated with 10ng/ml of A. actinomycetemcomitans LPS for up to 4 days. A tartrate resistant acid phosphatase (TRAP) assay was used to visualize formation of OCs at day 0 (M-CSF +RANKL only) and days 2 and 4 post-LPS. Images generated from TRAP were used to determine the number of OCs, number of nuclei per OC, and area per OC. Day 0 cells lacked any exposure to LPS, resulting in minimal variation between Dusp-1+/+ and Dusp-1-/- for all CD11b populations. By Day 2 there was a significant trend of increased female Dusp-1-/- OCgen, with CD11bhigh having the greatest difference (p<0.05). Male data followed an opposite trend, with Dusp-1-/- having less OCgen for all CD11b sorted populations. By Day 4, female CD11bhigh (p<0.0001) and CD11blow (p<0.05) had significantly more OCs for Dusp-1-/-. Day 4 of the males showed a large decrease in Dusp-1+/+ cells, specifically in CD11blow. The data show that LPS induced more osteoclast formation in female Dusp-1-/- mice than Dusp-1+/+ mice. The male Dusp-1+/+ populations show a preliminary increase in OCgen. However, by day 4 there are substantially more Dusp-1-/- cells that are larger than their Dusp1+/+ counterparts. Therefore, these studies indicate that MKP-1 is key negative regulator of MAPK and the subsequent increased OC differentiation promotes inflammatory bone resorption.
- ItemQueering Femme: An Examination of Contemporary Femme Identity(2013-11-05) Reed, Hannah Clary; O'Dowd, Ornaith; Hladky, Katie$
- ItemThe Effect of Forgiveness on Anger in Autobiographical Narratives: The Moderating Role of Age(2013-11-04) Lee, Maria Eleanor; Robertson, Sarah M
- ItemThe effects of pesticide and salinity on early life stages of the green tree frog (<i>Hyla cinerea</i>)(2013-11-05) Wilder, Anneke E; Welch, AllisonIncreased salinity in freshwater habitats can result from anthropogenic factors such as climate change and sea level rise, use of road salts, over-irrigation and groundwater depletion. This emerging threat can affect freshwater species in both coastal and inland environments. Pesticides have also been found in freshwater environments around the globe, and can be harmful to many different aquatic organisms. Amphibians are highly sensitive to changes in their surroundings, making them good indicators of environmental quality, especially in freshwater habitats. This study examined the effects of increased salinity and a common insecticide, carbaryl, on early life history stages of the green tree frog (<i>Hyla cinerea</i>). To test effects of salinity on sperm activity, we subjected <i>H. cinerea</i> sperm to levels of salinity ranging from freshwater to moderately brackish and analyzed activity using computer assisted sperm analysis (CASA). Effects of carbaryl on sperm activity were measured in a similar fashion, using concentrations ranging from zero to a dose that is beyond the expected field concentration. We also examined female oviposition site selection in response to salinity and the presence of carbaryl in artificial pools. Mean sperm motility and velocity were both found to decrease as salinity concentration increased, butcarbaryl had no significant effect on sperm activity. Females tended to avoid ovipositing in pools with increased salinity. Although no significant difference was observed in oviposition between pools with and without carbaryl, pools received no oviposition when freshly dosed with carbaryl. These findings suggest that increased salinity may negatively affect reproductive success in <i>H. cinerea</i>, but that females may be able to avoid these effects through depositing eggs in freshwater sites. Selective oviposition may increase the ability of amphibian populations to persist in degraded habitats.