Bulletin of the American Physical Society
Joint Fall 2017 Meeting of the Texas Section of the APS, Texas Section of the AAPT, and Zone 13 of the Society of Physics Students
Volume 62, Number 16
Friday–Saturday, October 20–21, 2017; The University of Texas at Dallas, Richardson, Texas
Session B3: SPS I |
Hide Abstracts |
Chair: Bob Glosser, University of Texas at Dallas Room: DGAC 1.102C |
Friday, October 20, 2017 2:45PM - 3:09PM |
B3.00001: Tracking Reactive Oxygen Species Activated Drug Activity on DNA Chips Invited Speaker: Monica Lou Anticancer treatments that induce cancer-selective DNA damage represent a promising strategy for therapy. The drugs RAC1 and RAP are activated by elevated levels of hydrogen peroxide in certain cancer cells~and presumably function by forming phenol adducts on DNA bases. It is hypothesized that these adducts interfere with hydrogen bonding, thus lowering the stability of DNA,~showing a potential link to anticancer activity. Using electrochemical chips to establish changes in duplex stability, this correlation is observed. Chip signals are highly sensitive to structural alteration of DNA and enable study of real-time activity of DNA damaging drugs that disrupt DNA double helix stability, such as RAC1 and RAP. Duplex stability changes in response to drug treatment were tracked by room temperature current-voltage characteristics on DNA chips under biologically relevant conditions, particularly with square wave voltammetry peak heights. Concentration dependence of both drugs and the hydrogen peroxide that activates the drugs were determined as well as the optimum pH and the kinetics of drug-adduct formation were followed. This work supports the notion of DNA destabilization by reactive oxygen species-activated drugs and clarifies the timescales of activity. [Preview Abstract] |
Friday, October 20, 2017 3:09PM - 3:21PM |
B3.00002: Maintaining ProtoDUNE Dual Phase's Uniform Electric Field with Divider Board Douglas Zenger The ProtoDUNE project of the dual-phase Liquid Argon (LAr) Time Projection Chapter (TPC) is a prototype experiment for the Deep Under Ground Neutrino Experiment (DUNE) at Fermilab. The protoDUNE field cage (FC) consists of 98 extruded aluminum profiles, supported by fiber reinforced plastic I-beams. A neutrino will interact with LAr, and the resulting secondary particles ionize LAr, whose electrons are detected in the gaseous argon. A strong, uniform electric field of 500V/cm generated by the FC will cause the electron to drift upwards, requiring a voltage potential of -300kV at the cathode at the bottom. To connect profiles electrically and to protect the power supply, four 2G$\Omega $ resistors, reducing the current flowing, and two groups of four varistors in series, protecting the resistors from potential electrical surges, will be placed in parallel between each profile placed on a divider board. Testing will ensure the quality of the parts using liquid nitrogen. The resistors used will have only 1.5{\%} difference from the mean of its resistance compared to other resistors, causing about a 40{\%} rejection rate. Varistors will be tested to show if a high resistance at 1.5kV is present, showing about a 15{\%} rejection rate. [Preview Abstract] |
Friday, October 20, 2017 3:21PM - 3:33PM |
B3.00003: Using Arduino to Train Rats Through Weave Poles Armando Gutierrez, Calvin Berggren, Scott Bailey Animal trainers teach tricks to animals by giving them feedback on whether or not they are following the task correctly, in which the animals hear a sound from a clicker to convey they are either following or not following the correct task, depending on the technique. However, this type of tactic for training animals has not been scientifically analyzed. An experiment about training rats through weave poles was organized to test whether feedback improved their learning. The apparatus used was a wooden box equipped with PVC pipes that had photodiodes and IR LEDs to create beams for the rats to break. The electronic sensors for each beam are connected to an Arduino microprocessor which will keep track of the path that the rats take and provide feedback with tones based on whether or not they follow the correct path through the poles. The presentation will focus on the design and construction of the apparatus. [Preview Abstract] |
Friday, October 20, 2017 3:33PM - 3:45PM |
B3.00004: Fraunhofer Diffraction of Laguerre-Gaussian Vortex (LGV) Beams Carrying Equal and Opposite Angular Momentum Sophia Andaloro Lasers ordinarily produce Hermite-Gaussian (HG) beams. These beams can be transformed to LGV beams using an astigmatic mode converter. LGV beams carry an intrinsic orbital angular momentum of $l\hbar $ per photon, where $ l$ is an integer. On reflection, the beam retains the magnitude of angular momentum but reverses its sense of rotation. Like plane waves (PW), LGV beams can be diffracted through different apertures. The results of Fraunhofer diffraction of LGV beams diffracted through equilateral triangle, square and regular pentagonal apertures are expected to reveal features not encountered in the diffraction of PW. The experiment studied the relation between diffraction of LGV beams of opposite angular momentum indices. LGV beams with $l=$1-3 were diffracted by triangular, square and pentagonal apertures. Experimental results confirm the theory of Fraunhofer diffraction for LGV beams. For apertures without a center of inversion, the Fraunhofer diffraction pattern does not have a center of inversion. Diffraction patterns of LGV beams of equal and opposite angular momentum indices are related by a rotation of 180\textdegree . [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700