Annual Summer Student Mini-Symposium

August 7th, 2007

Ewing Hall Room 436

Schedule

8:30-8:55 Refreshments

8:55-9:00 Welcome (John A. Pelesko)

9:00-9:25 Donald Knieriem

9:25-9:50 Lucero Carmona

9:50-10:15 Kyle Stern

10:15-10:30 Coffee Break

10:30-11:00 Paul Parsons and Peter Ucciferro

11:00-11:25 Van T. Lam

11:25-11:45 Haozhu Wang  

11:45-12:00 Coffee Break

12:00-12:15 Presentation of Sigma Xi Award and Closing Statements

Title: The Structure of Social Networks and Modeling the Spread of Infectious Disease

Student: Donald Knieriem,

Faculty advisor:  Dr. Richard Braun

The modeling of the spread of infectious disease in humans relies both on the properties of the disease in question and the interpersonal contact within the host population. This study focuses on the importance of the structure of the social network in which a disease spreads. Older models assume that the population is homogenous, and thus results depend only on the relative virulence of the disease. A novel model is used, which incorporates a social network. My results show that the behavior of diseases is as much dependent on the social structure of the population. Various social network types were used in simulating infectious disease outbreaks, and results confirm that social networks with different properties  exhibit different behavior for the same disease. Because the research is based on a new model for the spread of disease, the properties of the model itself were fully explored as well.

Title: An experimental and mathematical study of M. oryzae spore germination and dispersal in the presence of host and non-host volatiles

Student: Kyle Stern

Faculty advisor: Dr. John Pelesko

Each year, the fungus M. oryzae destroys enough of the world’s rice, barley, and wheat crops to feed more than sixty million people.  In this project we investigate whether or not there are volatiles in host plants that cause M. oryzae spores to react.  If true, these volatiles may cause the fungus to spread rapidly.  The first part of this project focuses on germ tube growth.  Spores and volatiles were strategically placed near each other in order to determine the angles the spores’ germ tubes made with the volatile.  The angles were measured using computer software and the data collated in a rose plot, which revealed the distribution of angles. The second part of this project focuses on spore dispersal in a controlled setting.  After placing either volatiles or actual leaves in a dish with the fungus and allowing ten days for the spores to be released from their stalks, the distance the spores traveled was measured using computer software.  Initial results from the germ tube experiment reveal that the spores tend to germinate in random orientations.  Data from our second experiment suggests that spores utilize an active dispersal process and that host volatiles may change the vigor with which spores disperse.  The results show that limonene, a volatile of the rice plant, is one such volatile that triggers vigorous active dispersal. Funded by Howard Hughes Medical Institute.

Title: Mathematical Model of Eye Lid Geometry and Motion

Students: Paul Parsons, and Peter Ucciferro

Faculty advisor: Dr. Richard Braun

There is little information concerning the mathematical description of eye lid shape and lid motion.  The overall goal of this project is to simulate an eye’s lid motion during a blink with polynomials. These polynomials will then be used as moving boundaries for partial differential equations that model the tear film distribution across the surface of the eye.  In this project, using a pre-existing algorithm, we first test its ability to accurately represent the eyelid’s motion and then use these results to develop its capturing accuracy.  By filming a variety of test subjects and recording their age, race and whether or not they were wearing contacts at the time of filming, it was clear that the algorithm had problems with most eye forms.  The algorithm starts by inputting the data of the high speed video and selecting regions requiring blurring, and then we proceed to find the points on the lid via Sobel edge detection.  Least squares fitting and smoothing splines are then applied to the points to create new polynomials to determine lid shape with minimal noise and unwanted fluctuation.   

Title: The Study of Self Assembly of Flexible Objects

Student: Van Lam

Faculty advisor:  Dr. John Pelesko

Self Assembly is one of the nature's most amazing phenomena, which can be easily found in every system, from the molecule to the formation of the galaxies. One example is the Cheerio Effect which is commonly known within the scientific world. This study focuses on the self assembly of the flexible bodies, hair, for example. First step is to understand the Cheerio Effect on a single bubble to a close-by wall. By ignoring the vertical forces acting on the system, we can calculate the attrative force between the bubble and the wall by solving the Euler-Lagrange Equation. Third step is to understand the case of two rigid bodies, this can be found in previous studies. Finally, we take a further step to examine the same force between one rigid and one flexible body. We conduct a rough experiment on how hair is attracted to the wall of a plastic contianer. This experiment fails due to the different characteristics of hair react in liquid water. Thus we test the same experiment to observe the attraction between a plastic straw and one other single straw of the same material. We then proceed with the case of multiple straws connected to each other using a thin thread. The data analysis is more difficult since we have to take many different variables into consideration, and to fit the data to the parametric differential equation of the distance at one end of the rod. All of this will gradually take us to reach our final goal: examine the case of multiple flexible bodies.

Student: Lucero Carmona

Faculty advisor: Dr. John Pelesko

Capillary surfaces are the surfaces that occur when a liquid makes contact with a surface. The sides of the liquid rise up slightly and then stops because of gravitational forces. These surfaces can cause some interesting results based on the liquid and shape of the container of water. In no-gravity areas, some of the sides of the surface can continue rising infinitely. Our goal is to see how these surfaces rise with respect to time. With an understanding of previous experiments that relate to capillary surfaces, we were able to conduct new experiments with different alterations to see how theory compares to differently prepared tubes. Then with the assistance of Matlab, we developed a numerical solution for the theoretical equation that produced the height in respect to time. We continued understanding these surfaces with different shapes of containers. In particular, we studied the behavior of certain liquids in wedges. Finally, some experimentation was done with water rising in porous sponges. These experiments contain some relation to the capillary tube which is of some interest for further research. 

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Title: Experiments and Mathematical Modeling of Intracellular Network Growth of Physarum Polycephalum 

Student: Haozhu Wang  

Faculty Advisor: Dr. Louis Rossi, Dr Chien-Chung Shen

Physarum Polycephalum, sometimes called True Slime mold or Mandy Headed Slime, is a unicellular multinuclei organism that inhabits in dark and moist areas. Its maximum diameter can be up to 20 meters. Its protist activity can be observed without a microscope. When food sources is distributed upon the cell's surface, efficient networks of tubes called pseudopodia are buildt between the food sources for intracellular nutrient distribution. Though the slime lacks a central nervous system, it demonstrates a form of primitive intelligence.  Over the summer I have conducted experiments on the vegetative phase of physarum polycephalum. I have explored the searching mechanism of the slime with single food source and the effects of boundary conditions on the growth of the slime. A singular potential model is a reasonable approximation to the searching mechanism. The efficient pattern of network construction can be applied to wireless sensor and actor networks that creates energy efficiency ad-hoc networks, road navigation mapping, contruction of logic gates in biological computers, and robotic control with biological cells.