UNCG
11/17/07

Last modified 10/31/07

Abstracts of the talks

Timothy Brown: Can an autoregressive error model be used to determine whether or not nitrogen oxide reductions from utilities have improved ground level ozone Levels in the Nitrogen Oxides State Implementation Plan (NOx SIP) Call States?
Anne Castelaz: Equal Circle Packing
Meghan Fitzgerald: Kleptoparasitism: Time is of the essence for Onthophagus taurus
Yair Goldberg: When Mathematics Attacks: A brief look into the Riemann Zeta Function
Kristen Gore: Can meteorologically adjusted ozone air quality trends identify the impact of the nitrogen oxides utility reductions?
Robert Gove: Colony Fitness as a Function of Division of Labor and Multiple Mating in Honeybee Queens
Stacy Jones: Resolving the Ambient Air Quality/Emissions Inventory Discrepancy
Wilma Jackson: Improving Public Health Advisories for Forecasting Fine Particulate Matter for the Air Quality Index
Adam Montjoy: The Clinic Surge Planning Model: Performance Estimates and Validation Results
Sarah Post: Coding of Ethnographic Data for Quantitative Analysis
Ashley Roberts: Application of Nanometer Scale Technology Used in Aerospace Engineering
Steven Somers: Can Blood Lead Levels in Children be Reduced?
Brian Stadler: Dynamics of Small Order Combinatorial Graphs
Beth White: Obese Children and Adults Walk with Similar Gait Kinetics
Matthew Wilhelm: The Mating Game: Evolutionary Stable Strategies of the Mating Sign Behavior in Honeybees


Can an autoregressive error model be used to determine whether or not nitrogen oxide reductions from utilities have improved ground level ozone Levels in the Nitrogen Oxides State Implementation Plan (NOx SIP) Call States?

Timothy Brown, NC State University, Raleigh, NC
mentored by
Dr. William Hunt

Abstract: My focus will be on analyzing NOx emissions data from NOx SIP call states and finding significant variables that affect the output from stations. These stations are mainly based in utilities.


Equal Circle Packing

Anne Castelaz, UNC Asheville, NC
mentored by
Dr. Patrick Bahls

Abstract: The study of maximally dense packings of small numbers of disjoint equal circles into various containers has developed over the past forty years. The optimal densities and arrangements are known for many packings of small numbers of equal circles into containers including squares, equilateral triangles and circles. Previous studies have focused only upon hard boundary containers. In this presentation, we will explore packings of small numbers of equal circles on a torus. First we will outline the underlying concepts of equal circle packing. Next we will discuss several mathematical tools developed to analyze the densities of arrangements on a torus. Finally, we will describe proofs of all locally and globally maximally dense arrangements of n=1 through n=5 circles on a standard triangular torus completed at the Summer 2007 Research Experience for Undergraduates at Grand Valley State University. This work was partially supported by National Science Foundation grant DMS-0451254 which funds the REU.


Kleptoparasitism: Time is of the essence for Onthophagus taurus

Meghan Fitzgerald, UNCG, Greensboro, NC
mentored by
Dr. Mary Crowe, Dr. David Remington, and Dr. Jan Rychtář

Abstract: Kleptoparasitism is the act of stealing food or resources that another organism has found, killed, or otherwise prepared for its own use. The dung beetle Onthophagus taurus is known to find brood masses already created, dispose of the egg, and use the prepared brood chamber for it’s own offspring. We have adapted previously-developed models of kleptoparasitism to model the dung beetle system. In testing this, we have collected empirical data in order to estimate the parameters of the model we have developed. This incorporates the search and handling times, as well as the time or fitness gains in following a kleptoparasitic behavior. Typically the occurrence rate is based on either the density of organisms compared to the availability of resources, the quality of the prepared brood resource, or the ability of the beetles to find previously prepared resources. Using statistical analysis of our field data, we will refine our model based on the true biological behavior.


When Mathematics Attacks: A brief look into the Riemann Zeta Function

Yair Goldberg, UNCG, Greensboro, NC
mentored by
Dr. Filip Saidak and Dr. Sebastian Pauli

Abstract: There are many questions that could be asked regarding the Riemann Zeta Function. Some of them are: What is the Riemann Zeta Function? Where did it come from? Why do we care? There are also many much deeper questions which can be asked, some of which are involved in what is probably the most famous open problem in Analytic Number Theory, and perhaps even in all of Mathematics, the Riemann Hypothesis.


Can meteorologically adjusted ozone air quality trends identify the impact of the nitrogen oxides utility reductions?

Kristen Gore, NC State University, Raleigh, NC
mentored by
Dr. William Hunt

Abstract: Inhalation of ground-level or tropospheric ozone can trigger a variety of health ailments, including chest pain, coughing, throat irritation, and congestion. Additionally, tropospheric ozone creates an increased risk of bronchitis, emphysema, and asthma. The ability to determine the impact of ozone precursor emission controls on ground-level ozone trends is complicated by the presence of meteorological and biogenic factors, which can enhance or hinder ozone formation. How does one know if emission controls are effective? The major precursors to ground-level ozone formation are volatile organic compounds (VOCs) and nitrogen oxides (NOx). The EPA Nitrogen Oxides State Implementation Plan Call (NOx SIP Call) was implemented in 2001 in an effort to mitigate the formation of ground-level ozone. Did it reduce ground level ozone? There have been many different approaches to determining possible trends in ozone concentration to account for the impact of meteorological variables. The purpose of this project was to build a regressive time series model that removes the effects of meteorology, autocorrelation, and seasonal trends. Our dataset included ozone and meteorological data from the North Carolina Department of the Environment and Natural Resources, Maryland Departments of the Environment and the New Jersey Department of Environmental Protection, as well as the North Carolina State Climate Office. This data spans April through October of 1997 through 2006 for Maryland and Washington, D.C.; 1997 and 2005 for New Jersey; and January 1997 through October 2007 for North Carolina. As the result of our analysis, a series of models were combined with a filtered time series model, autoregressive, and back trajectory modeling to estimate the reduction in ground-level ozone over this ten-year period. These results suggest an improving trend in ozone concentrations over this time period in New Jersey, Maryland, and North Carolina.


Colony Fitness as a Function of Division of Labor and Multiple Mating in Honeybee Queens

Robert Gove, UNCG, Greensboro, NC
mentored by
Dr. Maya Chhetri and Dr. Olav Rueppell

Abstract: The honeybee, Apis mellifera, exhibits extreme polyandry—queens will mate with approximately 10-12 drones (male bees) at the beginning of their life and then never mate again. As a consequence of multiple mating, genetic variability of the colony is increased. One hypothesis on why this mating behavior is adaptive for honeybees is that the colony will benefit from a more efficient division of labor. In this study we focus on this hypothesis and how colony fitness is influenced by mating number under this hypothesis. The first model that was produced involved a decision making process by the worker bees based on their genotype and the current colony conditions compared with the optimal colony conditions. To check our results from the first model, we created a second model which used a similar decision making process. By approaching solutions of the two models by way of a simulation, we produced two similar sets of results which show that colony fitness improves inverse exponentially as the queen’s mating number increases. The results suggest an optimal number of matings slightly below actual mating levels; however, this could be explained because bees have difficulty counting.


Improving Public Health Advisories for Forecasting Fine Particulate Matter for the Air Quality Index

Wilma Jackson, NC State University, Raleigh, NC
mentored by
Dr. William Hunt

Abstract: Fine particulate matter is a significant pollutant that endangers human health. Small particles, 2.5 micrometers in diameter or less, penetrate further into the lungs of humans than larger particulates leading to increased cases of respiratory diseases and eventual death. Both annual mean and 24 hour National Ambient Air Quality Standards have been set for fine particulate matter (PM2.5). PM2.5 is one of five pollutants reported in the USEPA's Air Quality Index. It is critically important that the current PM2.5 value can be accurately forecasted so it can be reported to the public with an appropriate health advisory. My objective is to develop reliable forecasting regression models to serve as tools for predicting PM2.5. The regression models will take into account various meteorological parameters such as temperature, wind speed, wind direction, and yesterdays PM2.5 measurements. My client, the Maryland Department of Environment, provided all meteorological and fine particulate matter data. Analyses of selected particulate matter monitoring stations and meteorological sites in the state of Maryland have lead to discoveries of certain PM2.5 patterns. Trends show PM2.5 variations between winter and summer seasons as well as weekday and weekend periods. Various patterns, interaction terms, nonlinear curvature, and other possible confounders will be taken into account. The focus of this effort is to develop a model which predicts the midnight to midnight PM2.5 value by 10:00 a.m. in the morning. The prediction is made14 hours before the midnight to midnight measurement is available. This approach is significantly more accurate than the prediction prepared the day before. It is necessary for this model to make use of the newest conditions in order to give the public the most reliable and current prediction possible.


Resolving the Ambient Air Quality/Emissions Inventory Discrepancy

Stacey Jones, NC State University, Raleigh, NC
mentored by
Dr. William Hunt

Abstract:Can exploratory data analysis identify patterns in measured crustal particulate matter that would help explain the discrepancy between emission inventories of naturally occurring crustal matter and the actual measured concentrations of crustal matter? The discrepancy between emission inventories of naturally occurring crustal matter, based upon engineering estimates, will be compared with the total estimated emissions of fine particulate matter and the actual measured concentrations of crustal matter as a fraction of the total measured fine particulate matter? Why does the emission inventory say that crustal emissions are 30 percent of the total inventory, while measured crustal matter are 5 to 10 percent of the measured fine particulate matter? This is a very significant problem that affects the entire air quality management process. An exploratory analysis of many factors – regional, seasonal, weekly, various meteorological conditions, etc. - will be undertaken to try and determine the reason or reasons for this discrepancy. This will be discussed during the presentation.


The Clinic Surge Planning Model: Performance Estimates and Validation Results

Adam Montjoy, Clemson university, Clemson, SC
mentored by
Dr. Jeffrey Herrmann

Abstract: In case of a terrorist attack or natural outbreak of a contagious disease, it may be necessary to vaccinate patients in mass quantities. This project focuses on the creation and implementation of a mathematical model that gives an estimate of the performance of a clinic with a modeled number of stations and staffing, given that there is a large number of patients waiting before the clinic opens. The model was created in Microsoft Excel so that it can be easily accessed by any clinic. Simulation for the purpose of validation was done in Rockwell Arena. Two separate simulations with different cases were compared to estimates made by the planning model to determine its accuracy.


Coding of Ethnographic Data for Quantitative Analysis

Sarah Post, UNCG, Greensboro, NC
mentored by
Dr. Eric Jones

Abstract:n Anthropology the majority of the data that gets collected is qualitative data, pertaining to the reasons behind the actions of individuals and societies. This method poses a problem with cross culture comparisons. It’s nearly impossible to take the findings of a culture in Africa and compare and contrast them to the findings of a culture in the South Pacific. For our cross-culture analysis we have created a coding system to attempt to solve this problem. I begin by choosing a culture in the Human Relations Area Files and going through the ethnographies searching for evidence of a corporate or network religious/political/and economic arrangement. I try to find evidence in all three categories, after the concrete details are found I assign a number code identifying it as a network culture, a corporate culture, or a mixed system where the evidence is neither definitely one nor the other. This coding allows us to compare a cultures code with other societies around the world. We are doing this in an effort to dissect the correlation between the frequencies of disaster and a group’s response to disaster with the set-up of the elite system.


Application of Nanometer Scale Technology Used in Aerospace Engineering

Ashley Roberts, Appalachian State university, Boone, NC
mentored by
Dr. Phillip Russell and Dr. Donovan Leonard

Abstract: This research project will present data on the function and operation of scanning electron microscopy (SEM), focused ion-beam (FIB), and/or x-ray microanalysis (EDS) technology to evaluate several materials commonly used in aerospace engineering and of great importance to NASA projects. Through the operation of scanning electron microscopes and focused ion-beam microfabrication, nanometer scale procedures essential for atomic scale imaging, micromachining, and/or microdeposition methods will be implemented. These techniques are of growing importance to the aerospace and other advanced technology industries. Essential features of micromechanical devices and systems will be studied through definition of small geometries, dimensional control, design flexibility, and interfacing which are all used to evaluate the reliability, yield, and cost for these devices. Case studies prepared for presentation may include an optoelectronic device and a power semiconductor device.


Can Blood Lead Levels in Children be Reduced?

Steven Somers, NC State University, Raleigh, NC
mentored by
Dr. William Hunt

Abstract: Lead pollution is a particularly serious problem as there are many health hazards associated with the element. Prolonged exposure causes seizures, retardation, and other behavior disorders. Exposure can be classified as either acute or chronic. Acute lead poisoning is a large amount of lead intake in a short amount of time. Chronic lead poisoning is a small amount of lead intake in a long amount of time and is more common among children. Our objective is to investigate elevated blood lead level (EBLL) rates per 1000 children. We will compare the 2003 California EBLL data to the 2006 California EBLL data to determine the integrity of the 2003 data. We expect the 2003 data to be incorrect and thus will rerun previous EBLL data sets with the 2006 California EBLL data. Using regression analysis, we hope to better inform the USEPA of areas with high EBLL so that the USEPA will be more knowledgeable as to which areas should be focused on for further research. We will be looking at other states such as NC, FL, TX, etc. to determine the quality of the data. This research may be able to determine a major contributor to high EBLL in children.


Dynamics of Small Order Combinatorial Graphs

Brian Stadler, UNCG, Greensboro, NC
mentored by
Dr. Jan Rychtář

Abstract: A graph can capture spatial, social and/or other structures of the population. Every vertex of a graph represents an individual. Individuals can place offspring into adjacent vertices, which is done proportionally to the individuals' fitness. We study the evolutionary dynamics on the graphs, mainly the probability a mutant will dominate a population that originally consisted of homogeneous residents. Through numerous simulations, graph characteristics analysis and known theoretical results we were able to find very strong correlations between the graph structure and the simulation results. A formula based on a certain graph characteristic was found to be able to predict the results for small graphs, forgoing any computationally intensive processes. Other results give potential to a possible general formula which would predict the results for all connected graphs.


Obese Children and Adults Walk with Similar Gait Kinetics

Beth White, East Carolina University, Greenville, NC
mentored by
Dr. Tibor Hortobagyi

Abstract: Obesity is reaching epidemic proportions around the world. It is thus important to understand the mechanical consequences of this condition especially in children who may be exposed to increased body mass for their lifetime. Our previous work demonstrated that obese compared with lean adults walk with a mechanical output from the leg muscles so that they produce similar hip and knee work but increased ankle work. The purpose of the present study was to test the hypothesis whether children compared with adults adopt a similar strategy in gait. Healthy lean and obese children ages 10-18 signed an informed consent and performed 5 level walking trials at 1.5 m/s and 5 stair ascent trials. Inverse dynamics analysis showed that obese children (n = 5, BMI 34.6 ± SD 2.8 kg/m2) walked with less work at the hip (0.073 ±0.054 W/m) and knee (0.011 ±0.008 W/m) when normalized to body mass and stride length than their lean counterparts (n = 5, BMI 17.5 ±2.0 kg/m2). Obese (1.34 ±0.041 W/m) versus lean (0.150 ±0.060 W/m) children also generated more work at the ankle. These data support the hypothesis that children, as adults, redistribute joint work in a proximal to distal shift during gait.


The Mating Game: Evolutionary Stable Strategies of the Mating Sign Behavior in Honeybees

Matthew Wilhelm, UNCG, Greensboro, NC
mentored by
Dr. Maya Chhetri, Dr. Olav Rueppell and Dr. Jan Rychtář

Abstract: The honeybee, Apis mellifera, exhibits extreme polyandry. After insemination, the male (drone) plugs the queen’s genital opening with his endophallus, known as the mating sign. This leads to his immediate death and has been shown to promote additional mating of the queen, casting doubt on the adaptiveness of this behavior: the drone forgoes the chance of future mating and effectively dilutes his genetic contribution to the next generation. On the other hand, the mating sign may be beneficial because it increases the genetic variability of the queen’s offspring and greater genetic variability increases colony fitness: Colonies with greater genetic variability are less susceptible to disease and benefit from a more efficient division of labor. Genetic variability also decreases the effects of sterile drone production. With these functions in mind, we investigated the evolutionary stability of the drone behavior ‘to plug’ or ‘not to plug’.