Faculty and Student Publications
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- ItemPoly(methyl methacrylate) composites of copper-4,4′-trimethylenedipyridine(New Journal of Chemistry, 2012-07) Liu, Shisi; Ananthoji, Ramakanth; Han, Sungyub; Knudsen, Bernard; Li, Xiao; Wojtas, Lukasz; Massing, Justin; Gauthier, Carmen Valdez; Harmon, Julie P.A series of poly(methyl methacrylate) (PMMA) composites were prepared with a novel one dimensional coordination polymer copper-4,4′-trimethylenedipyridine (CU-TMDP). The CU-TMDP was sonicated in a methyl methacrylate monomer and polymerized in situ. Thermal, mechanical and optical properties of CU-TMDP–PMMA composites were probed via optical microscopy, Raman spectroscopy, differential scanning calorimetry (DSC), microhardness, and dynamic mechanical analysis (DMA). The CU-TMDP was characterized by X-ray crystallography. The functionality of the CU-TMDP interacted with the polymer matrix such that mechanical properties are tuned by varying CU-TMDP loadings. The data point to the fact that interactions are primarily due to London dispersion forces or dipole–dipole interactions. This initial study forms the basis for future applications requiring tailored mechanical properties.
- ItemDeterminants of Student Demand at Florida Southern College(Journal of Case Research in Business and Economics, 2012-07) Brown, Carl C.; McClary, Andrea; Bellingar, JaredDetermining the factors impacting student demand for higher education at Florida Southern College enables calculation of the effect that tuition levels and other variables have on enrollment and revenue. A times series study utilizing data on published tuition, net tuition and fees, and other potential explanatory factors is conducted to determine their impact on both freshman and total enrollment levels at Florida Southern. Separate analyses of students hailing from Florida and from out-of-state are conducted to determine if there are significant differences in the factors impacting the decisions by these groups to enroll at Florida Southern. In addition, estimates of price elasticities of demand are calculated based on the available data. This study finds that price-adjusted net tuition (including fees) is a statistically significant determinant of freshman enrollment, as is real per capita income, the annual number of high school graduates, and the US unemployment rate. The net tuition elasticity of demand among Florida freshman students is -1.8, while net tuition is statistically insignificant as a determinant of enrollment by non-Florida freshman students. The study also finds that the price elasticity of demand for the aggregate freshman student population has increased over time as net tuition has risen in real terms. When tuition +fees and financial aid are entered as separate variables (as opposed to being combined as net tuition) into the regressions, the explanatory value of the regression equations increase.
- ItemPhenotypic Plasticity in the Relative Hind-Limb Growth of Lab-Reared Anolis sagrei: Replication of Experimental Results and a Test of Perch Diameter Preference(2014-06) Langford, Gabriel J.; Macedonia, Joseph M.; Bessette, Christopher W.; Matey, Jennifer L.; Raboin, Brittany A.; Schiffmacher, Ashley E.; Reynolds, Brett J.Several observational and experimental studies have shown that perch diameter has an impact on the development of hind-limb length (HL) in Anolis species. This 'phenotypic plasticity' in relative hind-limb growth (RHG) has implications for short-term and long-term adaptation to different structural habitats. Our study is the first to replicate research in which hatchling/juvenile Anolis sagrei were reared on narrow-diameter or broad-diameter dowels in a laboratory setting. Although subjects reared on different dowel diameters did not differ significantly in RHG at 5 weeks into the experiment, results at 15 weeks revealed a significant effect of treatment but not of sex: subjects in the broad ( N = 69) treatment group exhibited significantly greater RHG than did subjects in the narrow ( N = 61) treatment group. We extended this research with a novel follow-up study: we placed our lab-reared subjects into outdoor enclosures where they had a choice of narrow- or broad-diameter dowels on which to perch. Results showed that subjects in both treatment groups chose broad-diameter dowels as perches more often than narrow-diameter dowels. We offer several potential explanations for the strong preference of our subjects for broad-diameter dowels irrespective of the dowel diameter on which they were reared.
- ItemElucidating the life cycle and life history of Dero hylae (Naididae), a rare parasitic oligochaete from Florida tree frogs.(Journal of Parasitology, 2015-03) Andrews, Jessee M.; Childress, Jasmine N.; Iakovidis, Triantafilos J.; Langford, Gabriel J.Given their ubiquitous nature, it is surprising that more oligochaete annelid worms (Annelida: Clitellata) have not adopted an endoparasitic lifestyle. Exceptions, however, are the understudied members of the genus Dero (Allodero) that parasitize the ureters of tree frogs and toads. This study experimentally explores the life cycle and host specificity of Allodero hylae, the worm’s use of chemical cues in host searching, and its seasonal prevalence and abundance over a year-long collection period on the Florida Southern College campus. A total of 2,005 A. hylae was collected from the ureter, urinary bladder, or expressed urine of wild Osteopilus septentrionalis; a significant positive correlation was found between host snout–vent length and parasite intensity for female but not male hosts. Monthly prevalence of A. hylae reached a peak of 58% in April, but never dropped below 20% in any month; mean abundance peaked March–May, whereas few worms were recovered in December and January. Confirming a parasitic lifestyle, wildcollected hosts with intense infections, typically .40 worms, showed obvious dilatation of the ureter wall, and some young-of-the-year O. septentrionalis exposed to A. hylae in the laboratory were killed by the apparent rupture of the host’s ureter. The worm has a direct life cycle: worms expelled in the host’s urine are capable of locating and re-infecting other hosts within aquatic microhabitats such as bromeliad tanks, and worms can survive for weeks in a free-living environment, even undergoing a morphological change. Further, chemotaxis assays found a positive response to a tree frog attractant for worms recently removed from hosts. Overall, this study provides the first multifaceted investigation on the life history and ecology of any Allodero spp., which offers new insights into an understudied endoparasitic oligochaete.
- ItemThere’s an App for That: Reliability of an iPhone App to Assess Upper Extremity Proprioception and Stability(International Olympic Committee World Conference on Injury and Illness Prevention, 2017-03) Lynch, James M.; Smith, Keeley; Patel, Vrund; Luchan, KaylaBackground: The ability to maintain joint stability and motion control of the extremities is important in injury prevention/recovery. Quantitative measurement of proprioception, especially the upper extremity, is difficult. Objective: We investigated the reliability of a custom iPhone app to compile accelerometer data and calculate a path length of movement over 20 seconds. Design: This study used a prospective test-retest design. Subjects completed three trials on each upper extremity (RA and LA) 48 hours apart (MWF). A convenience sample of subjects was used. Results: The mean path length for RA was 2669 with a standard error of 149, with LA being 2774 and 124. The intraclass correlation coefficient was 0.86 for the right arm and 0.74 for the left arm across three trials. Conclusions: The accelerometer in an iPhone 6 is a moderately reliable instrument for assessing motion control stability in the upper extremity. We plan to add additional data filtering to the app and repeat.