Sample Abstracts

Title: Migration and Mixing between Populations in Disease Models
Presenter: David Burger
Advisor(s): Lora Billings
Abstract: In the field of epidemiology, models depend on how a population can be broken down into groups of people that carry similar traits that are important to the disease. These break downs occur at both the intra-population level as well as the inter-population level. Modeling how these groups interact is fundamental to capturing how a disease spreads in and between populations. We will only concern ourselves with the interactions that lead to differences in disease behavior. Within a single population, this would be the interactions between susceptibles and infectives. Between populations, this becomes the migration of susceptibles or infectives from one population into the susceptible or infective class of the other population. We study how migration and other mixing effects in an SIR model can induce an epidemic or how these can be controlled to curb an oncoming outbreak. In particular, we will consider single populations and two population models with a forcing on the contact rate. We use this to look for behavioral changes in the overall disease dynamics for different given initial conditions.

Title: Particle Size Results of the Andrill Southern Mcmurdo Sound Project
Presenter: Candice Falk
Advisor(s): Sandra Passchier
Abstract: The ANDRILL Southern McMurdo Sound (SMS) Project was carried out in December of 2007 by an international interdisciplinary team that recovered the most complete Neogene (23.03-2.59 Ma) stratigraphic record from Antarctica. Analyzing particle size distributions of samples throughout the core can determine environmental conditions of the past; such as the advancement or retreat of glaciers and the rise and fall of sea level. Over 300 samples were taken at approximately 3 m intervals from the 1100 m AND-2A core. Samples were processed and analyzed using a Malvern Instruments Mastersizer 2000 laser diffractometer which has the capability to measure sediments from 0.02 μm to 2000 μm. Statistical measures; such as the mean particle size; percent grain size; and distribution are analyzed to characterize the lithology. The changes in the percentage of clay; silt and sand will give a better understanding of the hydrological processes and climate changes in Antarctica through the Neogene which will help predict future global environmental changes.

Title: Fluorescent Sensors for Zinc Ions
Presenter(s): Agnieszka Zieba, Christopher Chu, Robert Cuellari, Agnieszka Chojnowski
Co-author(s): Christopher Chu, Robert Cuellari, Agnieszka Chojnowski
Advisor(s): Saliya de Silva
Abstract: Many fluorescent sensors for cations that use photoinduced electron transfer (PET) as the signaling mechanism have been reported over the past three decades. These sensors are based on a chromophore-spacer-receptor architecture and have a tertiary nitrogen as a part of the receptor. Since the tertiary nitrogen is also a receptor for protons; these sensors generate fluorescent signals for various metal ions as well as protons. The goal of this project is to design a new fluorescent sensors that contain common nitrogen based receptors and are not sensitive to protons. These sensors is based on a second generation sensor developed in our labs that is sensitive to zinc(II) ions as well as protons. The new sensors have an additional dimethoxyphenyl group that is expected to generate an additional PET process that would quench a signal due to protons. The synthesis of the new sensors and preliminary fluorescent studies will be presented.

Title: Mitochondrial genome sequence of Epidalea calamita
Presenter(s): Janeth Solorzano
Advisor(s): Jack J. Gaynor
Abstract: Mitochondrial DNA is the genomic information that is maternally inherited. Like nuclear DNA; mitochondrial DNA contain mutations. Recent studies have confirmed that mitochondrial DNA is a powerful tool for tracking ancestry through females and has been used in this role to track the ancestry of many species back hundreds of generations. Similarity of mtDNA for any two toads could provide a rough estimate of how closely related are organisms through their maternal ancestors. The purpose of this study is to detect how closely related is the Natterjack toad (Epidalea calamita) to other toads. In this study; Polymerase Chain Reaction (PCR) technique was used to amplify and extract short strands of mtDNA from the Bufo Natterjack sample. A 288 base sequence was generated at the 7200 - 8700 mid ND2; 5 tRNA's; 1 ori; mid COX1 regions of the Natterjack mitochondria. Then the sequence was aligned to other Bufo mitochondrial DNA sequences to compare them. The organism produced significant alignments with the maximum identity of 92% closely related to the Bufo melanostictus mitochondrion. This suggests that Bufo calamita and Bufo melanostictus share a common female ancestor.