Abstracts of posters presented at the Second Annual Undergraduate Research Symposium held April 3, 1997 in the Keathley University Center on the Campus of Middle Tennessee State University. Sponsored by the College of Basic and Applied Sciences and the Counsel on Undergraduate Research.

The nine PGA putting greens at The Little Course were sampled. A 36" tube sampler was used. Four cores, 9" long by ¾" diameter, were taken from each putting green in March 1997. The rooting depth was recorded for each core. The cores from each green were divided into top and bottom portions. Media pH was measured on air-dried media using a 1:1 media to distilled water mix. The pH was measured with a glass electrode. A regression equation was used to test the significance of pH on rooting depth.

Dairy cows experience a negative energy balance during peripartum period that is attributable to feed intake that is insufficient to support high levels of milk production. Gradually increasing daily energy intake, commonly referred to as lead-feeding, decreases the incidence of metabolic disorders associated with parturition including ketosis, periparturient paresis, and displaced abomasum. In addition, the timing of negative energy balance nadir is correlated with onset of estrus activity. However, reproductive performance as a function of the extent of negative EB has not been quantified. The objective of the current study was to determine the effects of feeding incrementally increasing amounts of energy prior to parturition on reproductive function in mature Holstein cows. In this study, cows were randomly assigned to control (n = 16) or treatment (n = 17) dietary groups. Control animals were maintained during the prepartum period on diets containing 3.0 kg grain/d, with a total energy intake of 14.8 Mcal/d initially, and gradually increasing throughout the prepartum period due to increased hay intake until predicted energy intake reached 18.6 Mcal/d. Cows fed treatment diets received daily increases in energy intake starting at 14.6 Mcal/d at 21 d prior to predicted date of parturition and increasing incrementally until 3 d post calving (28.1 Mcal/d). Body condition scores were recorded for individual cows weekly and estrous activity was observed daily. Blood samples were collected weekly for endocrine and metabolite analysis. Increasing the energy intake decreased the rate of decline of body condition scores. However, the length of the post partum interval was not significantly decreased in treatment cows (56.0 + 19.0 d) compared with control cows (50.3 + 4.3 d) affected by diet (p<0.05). In summary, lead feeding is instrumental in maintaining adequate body condition score, but does not appear to increase the onset of estrus activity in dairy cows.

Tennessee claims a wide variety of agricultural ecosystems providing the opportunity to select from several crops in diversified farming operations. In addition to differences in prices for each product, producers must observe constraining conditions when considering various cropping scenarios. The objective of the current research was to develop a linear program that is flexible enough for farmers across the state to enter production values, and rigorous enough to determine the extent of resources that should be committed to selected production enterprises for optimum profit. The developed model incorporates 10 different crops including tobacco, cotton, soybeans, corn, hay and pumpkins. Constraining factors include management hours available (by month), available capital for investment, land (owned and rented) and equipment. In addition, the model determines the number of hours of labor that must be hired (by month) and the amount of capital that must be borrowed for maximum profit. The linear program is effective in determining the optimum acres that must be devoted to each crop for maximum profit within the constraining factors for maximum profit within a given farming situation. In addition to solving numbers of acres, shadow prices for nonbinding constraints and reduced costs for activities that are not included in the solution are calculated. These values can be incorporated into the decision-making algorithms for risk analysis. The model is currently being tested in case-studies throughout Tennessee for validation. In conclusion, the current research has resulted in a computer model that is useful for producers to use as a management tool in selecting diversification. In addition to prior experience, the model can be used in combination with futures prices and risk analysis for comprehensive decision-making.

We demonstrate that the use of the transmission line matrix modeling (TLM) method is an effective technique for calculating the time-dimensional structures to electromagnetic radiation. In particular, the tunneling of e-m radiation incident on finite thickness of dielectric media beyond the critical angle, frustrated total internal reflection. For such an event we define and measure a "phase time" to represent the tunneling time of an e-m pulse. The simulations show directly that the pulse tunnels with a superluminal velocity. The simulation also demonstrates that the phase times for these e-m pulses are constant, specifically zero, independent of the thickness of the dielectric gap through which it tunnels.

We present a CCD photometric survey of two relatively unstudied open clusters, IC 361 and NGC 6802, on the BVRI system. Color-magnitude diagrams of both clusters reveal fairly populous red giant clumps and well-defined main sequences, extending about 4 to 5 magnitudes below the main sequence turnoff to V 21. Comparison with evolutionary models allows us to estimate cluster properties such as metallicity, reddening, age, and distance. Using VandenBerg's (1985) theoretical isochrones, we find a best fit to the color-magnitude diagram sequences for IC 361 with parameters [Fe/H] = -0.23, E(B-V) = 0.64 + 0.05, distance modulus (m-M)₀ = 11.92 + 0.48, and an age of 1.25 < t < 1.50 Gyr. Likewise, for NGC 6802, we find a best fit with [Fe/H] = -0.45, distance modulus (m-M)₀ = 10.78 + 0.16, and an age of 1.00 Gyr. The reddening for NGC 6802 is calculated to be E(B-V) = 0.94 + 0.05, but the width of the main sequence relative to the expected observational errors suggests the influence of differential reddening to the cluster. Our improved photometry and revised ages for these clusters make them attractive targets for in-depth studies of both stellar evolution and the structure and chemical evolution of the Galactic disk.

We present BVRI photometry of several wide binaries which contain white dwarf (WD) components. In a test for random and systematic effects in the reductions of the co-added CCD data, we compare two independent ways of correcting for atmospheric extinction and for transforming to the standard photometric systems. The first is an interactive method that isolates the determination of the individual photometric variables. The second method uses routines included in the IRAF software provided by the NOAO. We show that the two methods give essentially identical results, within the uncertainties determined for each variable. The BVRI data reported here will contribute to our determination of the WD luminosity function, from which we hope to derive a firm lower limit on the age of the Galactic disk. Our photometric parallaxes will also be used to examine the distribution of projected semimajor axes among wide binaries.

An "intelligent tutor" is a software system that interacts with a user in a way that appears intelligent. In other words, the system seems to know the user and respond in an "individual" manner. This research is part of a prototype intelligent tutoring system for software testing. To "test" software means to determine if it contains errors. Testing skills are critical for computer professionals. This system tutors beginning computer science majors in techniques of software testing. The ultimate goal, which has not yet been realized, is to assist them in testing their own software.

Dissolved substances from chemical reactions and extraction procedures are often recovered through rotary evaporation at water aspirator pressure, a technique that allows solvents to be rapidly distilled at temperatures much lower than their normal boiling points. Safe application of this method requires that toxic solvents be retained in the receiver and not vented into the laboratory air or condensed in the water aspirator and, subsequently, flushed down the drain. An apparatus was built to monitor effluent vapor pressure during rotary evaporation and was used to measure the retention of the solvents commonly employed in the organic chemistry laboratory. The effect of various parameters on the operation of this apparatus was investigated for the purpose of obtaining reproducible results during these experiments, which also provided quantitative data for optimizing the performance of rotary evaporators in general. The type of water aspirator, the efficient stirring of the heating bath, and prior equilibration of the vacuum were found to be especially important variables.

Applications of organosiloxane films include coatings, chromatography, sensors, nonlinear optical devices, and microlithograpy. Uses can be expanded if chemical transformations of existing well characterized films are simple and proceed in high yield. Self-assembled films of 11-phenylundecyl trichlorosilane on fused silica and Si(111) surfaces are reproducible and the surface characteristics have been well measured. The films are photooxidized primarily to surface-bound alkylaldehydes. The aldehydes surfaces were chemically converted to new functional groups and the surfaces analyzed using contact angle goniometry, ultraviolet/visible spectroscopy, grazing angle infrared spectroscopy.

Polyelectrolytes have been used extensively in biomedical and environmentally benign applications. We have designed a new monomer for polymerization to polyspiroketals fo potential use as bio- or environmentally degradable materials. The first step was the development of a synthetic protocol to form 1,4-cyclohexanedione monomers with solubilizing and/or charged groups attached at the 2 and 5 positions. The synthesis of the monomer was accomplished in three steps from inexpensive commercial starting compounds. Polycondensations with pentaerythritol were performed under conditions analogous to those described for reaction of 1,4-cyclohexanedione with pentaerythritol. Here we present our synthetic approaches to this class of monomers and polymers.

Cytokinins are derivatives of adenosine that act as plant hormones. They are involved in the promotion of cell division and differentiation, and retardation of senescence. In addition they have been shown to have effects on animal tissues such as inhibition of tumor cells, and some immunosuppressive behaviors such as inducing remissions in leukemia patients. ¹H (200 MHz) NMR spectra have been obtained for four cytokinins including 6-benzylamino purine riboside, 6-(gamma, gamma-dimethylallylamino) purine riboside, kinetin riboside, and zeatin riboside. Chemical shift assignments have been made and the ¹H-¹H spin couplings measured and used to determine the preferred furanose conformation.

Protozoal infections are the causative agent in millions of disease cases world-wide. Diseases such as sleeping sickness and Chagas' disease are caused by protozoa called trypanosomes. These organisms are dependent upon the purine salvage pathway for nucleic acid synthesis. Humans have an alternative synthesis pathway and therefore, the specific enzymes of the trypanosomal pathway can be targets of drug therapy. An important enzyme in this biosynthetic pathway is inosine-uridine nucleoside hydrolase (IUNH). The bacterium, Escherichia coli, also has IUNH activity. The purpose of this study is to use the polymerase chain reaction (PCR) to amplify the DNA for the IUNH gene of E. coli, ligate the IUNH gene into a plasmid that will allow high levels of this protein to be produced in a bacterial expression system, and also facilitate the purification of that protein. Results from this study will allow the characterization of the purified enzyme which may lead to potential therapy strategies.

The interactions of viruses with pulmonary tissues is a long-standing concern of biomedical research. Reovirus has proven to be an excellent model of viral pathogenesis and reovirus serotype 3 (T3) has recently been shown to induce a prominent inflammatory response in the rat lung compared to serotype 1 (T1). Preliminary studies indicate that alveolar macrophages play an important role in this response through the production of inflammatory molecules called cytokines. The goal of this work is to begin to understand the mechanisms by which T1 and T3 mediate differential regulation of the inflammatory cytokines in alveolar macrophages by determining whether reovirus T1 and T3 replicates in an alveolar macrophage cell line, and if there is a serotype difference in the efficiency of replication. Previous studies indicate that reovirus T1 replicates to higher titers in the rat lung than reovirus T3. Preliminary studies suggest macrophages can be infected by reovirus T3 in vitro. These studies will test the hypothesis that macrophages can be productively infected with reovirus T1 as well as T3.

Cercariae of the trematode parasite Proterometra macrostoma emerge from snails to infect bluegill sunfish, Lepomis macrochirus. Because parasite reproduction hinges critically on the ability of cercariae to locate fish host, natural selection should favor traits that increase the likelihood of such contact. In this experiment, I tested the hypothesis that cercarial emergence is triggered by water-borne fish odors. Twelve hundred snails of the species Elimia livescens were collected from a local population known to be infected by P. macrostoma. Upon return to the laboratory, one hundred-fifty snails were placed in each of eight, ten gallon aquaria. Four of these aquaria were labeled as experimental, and received a daily treatment of 500 ml of water taken from an aquarium containing bluegill sunfish. The remaining aquaria were labeled as controls, and received daily treatments of water taken from aquariums containing no fish. To minimize the possibility of position bias, control and experimental aquaria were arranged to provide for maximum interspersion. All aquaria were monitored for cercarial emergence for a period of five days. During this time, a total of 10 cercariae emerged from snails in the control aquaria, and 14 from the experimental aquaria. Statistical analysis shows that the difference between the control and experimental treatments is not significant, hence the hypothesis that cercarial emergence is cued to fish odor is not supported.

The results of this experiment indicate that a traditional DNA isolation and precipitation protocol, such as a DNA "mini-prep," is more effective than a protocol requiring Guanidine Isothiocyanate in isolating Salmonella spp. DNA for polymerase chain reaction-based procedures. In addition, the experiment revealed that a selected Middle Tennessee farm pond did not have a high concentration of Salmonella spp. Gastroenteritis is a disease that effects thousands of individuals each year. One of the primary pathogens associated with gastroenteritis is Salmonella spp. Which can contaminate environmental water sources. Once into the water supply, Salmonella-induced gastroenteritis can rapidly be spread throughout a population, resulting in a possible epidemic. While health agencies have typically relied on culture methods for Salmonella spp. detection, polymerase chain reaction-based technologies provide a more sensitive and speedy tests. This project compares Samonella spp. DNA isolation and precipitation protocols and tests for the presence of Salmonella spp. in an environmental water source.