Abstracts for Tuesday, February 18


Robin Crigler, When George Washington's Ghost Turned Handsprings: South African Conflict and American Identity, 1895-1902
Americans have, for the most part, completely forgotten their interest in the South African War of 1899-1902 (also known as the Second Anglo-Boer War), notwithstanding their heated rhetoric and vigorous activism at the time.  But how could such a unique historical moment be forgotten?  What about the conflict between British imperial might and the Dutch-speaking farmers of the Transvaal and Orange Free State resonated with the Americans who wrote, debated, organised, fought, and even died for their side of choice?  Why was opinion so divided, anyway?  In exploring these questions we come to a deeper understanding of American self-identity at the dawn of "the American century."  Could the United States be both a land of liberty, and an empire?  Could a land of liberty exist on a foundation of oppression and discrimination?  By 1902, many were sure they had found their answers in southern Africa.


Rachel Taverner, Track Reconstruction and Simulation of Kinematic Parameters for the Qweak Experiment
The Qweak Experiment, being run at Jefferson Lab, is making a high-precision measurement of the weak charge of the proton by examining the asymmetry in the scattering rate of left-handed and right-handed electrons off of a proton target. The weak charge of the proton, Q_weak, is related to the scattering asymmetry and to the momentum transfer, Q^2. To measure Q_weak to low uncertainty, one must find the value of Q^2, also to low uncertainty. Monte Carlo simulations of the experiment are run to determine the values of various kinematic parameters, such as Q^2, the scattering angle, θ, and the scattered energy, E'. We generate plots comparing kinematic parameters from simulation and data to determine whether the simulation accurately describes the experiment. At present, there are major discrepancies between simulation and data, especially for the scattered energy distribution; we are in the process of finding the sources of the anomalies.

Jesse Evans, Implementation of Fast Light and Four Wave Mixing Schemes in Optical Gyroscopes
In our experiment we constructed an optical gyroscope containing a Rubidium cell. The optical gyroscope measures angular velocity explained by the Sagnac Principle, and our Rb cell will allow us to apply slow and fast light to our set up. We will also be using a Four-Wave Mixing scheme to enhance the performance of the gyroscope.


Erin Gregory, Context and Narrative Choice: The Commission and Execution of the Three Doors of the San Giovanni Baptistery
In this paper, I analyze the physical context, historical associations, and the artistic approaches to the commissions of the three bronze doors for the San Giovanni Baptistery in Florence.  In order to understand the special significance of the commissions, I explore both the religious and civic role which the Baptistery played in Florentine daily life, as well as the sacred, liminal meanings associated with the doors themselves. I evaluate the various stylistic and narrative methods employed in each of the doors by Andrea Pisano and Lorenzo Ghiberti to illustrate how the two artists approached the same commissions differently resulting in three distinctive, successful doors. In this talk, I will focus on the evolution of the presentation of narrative in each of the doors as a key element for accomplishing the glorification of not only the Baptistery, but also the city of Florence itself.


Christina Moore, The Effect of Methylmercury Exposure on Corticosterone and the Glucocorticoid Receptor in Australian Zebra Finches
Mercury is a naturally occurring element that, when released in excess anthropogenically, can have toxic effects on organisms of all types. Much research has been done on the toxic effects of mercury in mammals and fish, but fewer studies have focused on birds. Mercury is known to be an endocrine disruptor in mammals and fish, but the results from studies on the endocrine disrupting effects of mercury in birds have been equivocal. The endocrine system regulates many important processes throughout the body. One important function of the endocrine system is to regulate the release of corticosterone, a hormone vital to an organism’s response to stress. If mercury disrupts the release or regulation of corticosterone, or affects the glucocorticoid receptor in the brain that responds to levels of corticosterone in birds, these birds may be unable to properly respond to stress and may have trouble surviving in the wild.

Wendy Herbst, The Role of Voltage-Gated Calcium Channels and Spontaneous Calcium Activity in the Developing Nervous System
Changes in intracellular calcium concentration are implicated in a wide array of neuro-developmental events, including neural induction, the growth of axons and dendrites, and the specification of excitatory and inhibitory neural phenotypes. Given that voltage-gated calcium channels (VGCCs) allow for rapid influx of calcium ions and that VGCCs are expressed at the earliest stages of neural development, we hypothesize that VGCCs mediate spontaneous calcium activity and subsequent neural phenotype specification. To test this hypothesis, antisense morpholinos were used to knockdown a VGCC subunit, Cav2.1, and changes in calcium activity and neural gene expression were assessed. To further elucidate the role of calcium activity in vivo, a genetically encoded calcium indicator (GCaMP6) was used to visualize calcium activity in the developing neural plate. Calcium activity was perturbed –by means of pharmacologically manipulation or by targeting cells via laser ablation– and changes in activity and gene expression were analyzed.