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Final fall semester Graduate Student Seminar scheduled for Dec. 5

The next Beckman Institute Graduate Student seminar will be held on Wednesday, December 5 at Noon in Room 1005 at the Beckman Institute. This is the final seminar of the Fall series and it will feature the following presentations: "4-Dimensional Intuition: Can We See In 4D?" by Mike Ambinder; "Limits on Learning Language Constraints from Speech Production Experience" by Jill Warker; and "Designing Nano Aggregate Probes for Surface Enhanced Vibrational Spectroscopy" by Anil Kodali. The hour-long seminar is open to the public and a pizza lunch will be served.

Published on Nov. 27, 2007

4-Dimensional Intuition: Can We See In 4D?
Mike Ambinder

The goal of this presentation is to examine spatial intuition in 4D space. While both mathematics and physics currently allow for the possibility of numerous spatial dimensions, most people only have direct experience with 3 spatial dimensions. The focus of the current research is to examine the possibility of quantifying 4-dimensional reasoning. That is, can people develop an idea of the spatial relationships existent in a 4D space without having direct experience with a 4D space? In a series of ongoing experiments, we are examining this possibility using the Beckman CUBE. We hope to determine whether or not people are able to make distance judgments or angle judgments about points belonging to a 4D object after viewing 3D slices of that object over time. In this vein, we hope to quantify 4-dimensional reasoning and to show that people are able to comprehend an object existing in 4 spatial dimensions in a practical manner beyond mathematical or theoretical abstractions.

Limits on Learning Language Constraints from Speech Production Experience
Jill Warker

Speech errors provide valuable insight into our speech production system. They adhere to phonotactic constraints in the language, which specify what phonemes may occur in a particular syllable position, such as [h] begins syllables in English but does not end them. Previous work indicates that adults can learn new constraints from speaking syllables that follow these constraints. In this talk, I will discuss a series of experiments investigating whether there are limits to learning phonotactic constraints from speech production experience. These experiments use speech errors as a measure of learning.

Designing Nano Aggregate Probes for Surface Enhanced Vibrational Spectroscopy
Anil Kodali

Detection of multiple molecular species is significant in a range of biomedical analyses from functional imaging to disease detection, prognosis and diagnosis. Vibrational (Infrared and Raman) spectroscopy provides highly specific information but its sensitivity is limited by the signal intensities. Surface enhanced vibrational spectroscopy (SEVS), using metal nanoparticle aggregates as probes to amplify the signal, offers an exciting new opportunity for ultra-sensitive and multiplexed imaging. However its experimental reliability is in question due to signal enhancement being a compounded contribution of several case-specific factors. The fundamental phenomena and signal enhancement can be described using a model based on surface plasmons arising from metal nanoparticles. Our research focuses on devising a rational design of optimal nanoparticle structures as probes for reproducible signal enhancement. We use classical electromagnetic theory to evaluate the signal enhancement and to design optimal probe configurations. Here, we present an electromagnetic model for signal enhancement in SEVS using nanostructural aggregates with tunable optical properties, providing a template for optimal design of SEVS probes for molecular imaging.