• A MATLAB GUI to Study Ising Model Phase Transition

      Thornton, CurtisLee; Department of Chemistry and Physics (2016-03)
      We have created a MATLAB based graphical user interface (GUI) that simulates the single spin flip Metropolis Monte Carlo algorithm. The GUI has the capability to study temperature and external magnetic field dependence of magnetization, susceptibility, and equilibration behavior of the nearest-neighbor square lattice Ising model. Since the Ising model is a canonical system to study phase transition, the GUI can be used both for teaching and research purposes. The presence of a Monte Carlo code in a GUI format allows easy visualization of the simulation in real time and provides an attractive way to teach the concept of thermal phase transition and critical phenomena. We will also discuss the GUI implementation to study phase transition in a classical spin ice model on the pyrochlore lattice. Funding Source: Center for Undergraduate Research and Scholarship and Department of Chemistry and Physics
    • The Presence of Coliforms and Fecal Coliforms in a Sports Environment

      Caballer-Hernani, Teresa; Covington, Katherine; Chen, Lin; Department of Psychological Sciences (2016-03)
      Golf is relatively unique compared to other sports, with large nature landscapes providing the area of play. Golf courses are often home to wildlife and provide rest stops for migratory birds. Animal inhabitants, as well as natural streams and ponds, provide an ideal environment for the proliferation of coliforms and fecal coliforms. Unlike other sports, golfers may engage in several hand to mouth behaviors (e.g. licking their fingers to clean mud off a ball, eating food during play). Furthermore, the research team hypothesizes that golfers may not clean some of their equipment frequently (e.g. gloves, bags). To assess golfers’ potential exposure to coliforms and fecal coliforms during a round of golf, swabs were taken from a pilot sample of ten golfers’ hands and equipment prior to and following their round of golf. A brief survey assessed golfers’ hand washing, eating and golf equipment cleaning behaviors. While none of the golfers’ hands tested positive for fecal coliforms prior to the round of golf, 55% of the golfers’ equipment and/or hands tested positive after the round. No golfers reported cleaning their gloves or bags, and most reported they would likely lick their fingers and/or eat while golfing.
    • A Prospective Dominant Negative Mutant of Wnt Signaling In Zebrafish Causes Craniofacial Asymmetry with Low Penetrance

      Ravilla, Dheeraj; Neiswender, Hannah; Department of Biological Sciences; Department of Cellular Biology and Anatomy (2016-03)
      Wnt gene signaling pathways have been implicated in development, cell behavior, and diseases, including craniofacial abnormalities. We created mutant complementary DNA constructs using QuikChange mutagenesis and then compared them to wild-type cDNA for effects on zebrafish development following injection into one-cell embryos. We hypothesized that disrupting a putative Wnt-binding lipocalin motif would allow mutant tinagl1 mRNAs to induce a dominant negative phenotype, similar to tinagl1 gene knockdown. Mutant LCN-W2 but not WT mRNA preferentially gave small eyes and ventral body curvature similar to the gene knockdown. Our main focus was on craniofacial development using Alcian blue staining of cartilage elements in 5 day old zebrafish. Abnormalities were seen at low penetrance in high-survival (high-quality) clutches with the highest injected dose of TIN LCN-W2,150 pg. These included smaller head and asymmetric head skeleton with one smaller eye on side of variable cartilage defects. Craniofacial defects, especially asymmetry, were more prevalent in clutches with lower survival rates. These asymmetric defects had not been seen in the gene knockdown. In summary, the phenotypes of LCN-W2 partially support similarity to a dominant negative phenotype with cartilage defects, small eyes, and ventrally curved body, but the craniofacial asymmetry appears novel. More research is needed for further understanding.
    • Psychological Variables Associated with Health Behavior

      Gaffney, Jasmine; Rogers, Rebecca L.; Department of Psychological Sciences (2016-03)
      Forty percent of deaths from heart disease, cancer, respiratory diseases, and stroke are preventable. Altering compromising health behavior would significantly reduce premature death; thus, investigating variables associated with health behavior is important. We examined whether health locus of control (HLOC), hypochondriasis (Hs), and social introversion (Si) would predict perceived physical fitness (PPF) and health behavior (e.g., tobacco use). HLOC is the extent to which people believe that their health is controlled by internal or external factors. Individuals who score high on scales of Hs tend to be preoccupied with their health whereas those who score high on Si tend to be shy and submissive. Participants were 108 undergraduate students. Separate hierarchical multiple regressions were conducted with PPF and health behavior as the dependent variables. Factors of HLOC were entered at stage one of the analyses. Hs and Si were entered at stage two. HLOC did not predict PPF. However, introducing the Hs and Si variables explained 20% of the variation in PPF (p = .001). Likewise, HLOC did not predict health behavior but adding Hs and Si explained 14% of the variation in health behavior (p = .01). Higher Hs and Si were related to lower PPF and health behavior.
    • Spin Wave Feynman Diagram Vertex Computation Package

      Datta, Trinanjan; Price, Alexander; Javernick, Philip; Department of Chemistry and Physics; Department of Physics and Astronomy (2016-03)
      Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group’s effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.
    • Studying the Interplay between Superconductivity and Anti-Ferromag-Netism through Bose-Fermi Mixtures on Optical Lattices

      Brackett, Jeremy; Department of Chemistry and Physics (2016-03)
      Motivated by the recent experimental progress with ultra-cold atoms, we investigate the physics of a Bose-Fermi mixture on a two dimensional optical lattice. We treat the system parameters such that 2-component fermions are in a deep external trap and weakly interacting bosons are in a shallow external trap, however both of these atoms are subjected to the same optical lattice. In this parameter regime, the bosons form a Bose-Einstein condensate and mediate an attractive interaction between fermions through low energy Bose excitations. As a result, the dynamics of the fermions can be described by the single band Hubbard model that involves on-site repulsive interaction and elementary excitation mediated attractive interactions. Using a mean field theory, we derive an effective action up to the quartic order in both d-wave superconducting and anti-ferromagnetic order parameters. Using this Landau energy functional, we then discuss the phase transition and study the competition and/or cooperation of anti-ferromagnetism and d-wave superconductivity in the system.
    • Ufmylation Maintains the Proper Er Homeostasis of Pancreas from Alcoholic Rodents

      Miller, Camille; Department of Biological Sciences (2016-03)
      The accumulation of misfolded pancreatic enzymes in the rough ER causes an activation of unfolded protein response (UPR). Ufmylation (Ufm1) is a novel post-translational ubiquitin-like modification system involved in UPR. Ufm1 modifies its target proteins through a biochemical pathway that involves E3 ligase. RCAD is an E3 ligase that forms a complex with DDRGK1. Be- cause of the synthesis, folding/sorting of pancreatic enzymes takes place in the rough ER and Ufm1 is involved in ER homeostasis. The first objective was to study the importance of RCAD and DDRGK1 in both proper sorting and secretion of digestive enzymes. We found that the lack of RCAD or DDRGK1 causes an increase in the expression of pancreatic amylase and trypsin activation. Because Ufmylation is involved in rough ER homeostasis and alcoholism causes changes in the expression of multiple rough ER proteins involved in the UPR, the next objective was to compare the relative expression of RCAD and DDRGK1 in alcohol-treated rats with non-treated rats. We found that both RCAD and DDRGK1 are highly expressed in alcohol-treated pancreas. In conclusion, alcoholism could increase the level of these proteins in the exocrine pancreas to protect it from ER stress and inflammation. Funding Source: Center for Undergraduate Research and Scholarship, Department of Biological Sciences and Scholarly Activity Award