Sarah A Olliges
Inhibition of weed growth by corn meal, corn gluten meal, wheat gluten meal, and sunflower seed meal
Sept. 25, 2000.  Mentor: Dr. Mark Boudreau

Abstract: Corn gluten meal, wheat gluten meal, and sunflower seed meal have all been found to inhibit germination of seeds. Evanari reviewed known germination inhibitors; included in his list are the seeds of Triticum sp.(wheat) and Helianthus sp.(sunflower). More recently Bingaman and Christians (1995) found that corn gluten meal inhibits germination of some grass species and Gough and Carlstrom (1999, HortScience 34:269-370) found that wheat gluten meal inhibits the germination of several weed species. With the growing concern over the effects of pesticides on human and environmental health, these may provide important alternatives to chemical herbicides. This study sought to further examine the ability of wheat gluten and sunflower seed meal to inhibit germination, since extensive studies have been done with corn gluten meal. Sunflower seed meal, wheat gluten meal, corn meal, and corn gluten meal were evaluated for their ability to inhibit germination of Chenopodium album L. seeds in petri dishes.

Concentrations of 100g/m2 and 200g/m2 were studied. Trifluralin, a pre-emergent herbicide was used as a control. Five replicates were used in a completely randomized design. In a separate field study, wheat gluten meal and corn gluten meal were evaluated for their effect on weed populations. They were studied at concentrations of 200g/m2 and 400g/m2. Six replicates were used in a completely randomized design. The number of weeds was counted after 22 days. Data were analyzed using a one-way ANOVA. Sufficient germination did not occur in the petri dishes to analyze data. There was no significant difference found between any of the treatments in the field. It is possible that the concentration of the corn and wheat gluten was not high enough. Also, wheat gluten may not have the same inhibitory effect as corn gluten. For further research, I would suggest repeating the laboratory study using a fungicide to prevent old growth, and repeating the field study using higher concentrations and more replicates.



Juliet Wood
Oxidized Fatty Acids in Cat Food
October 2, 2000.  Mentor: Dr. Victoria Collins

Abstract: Fats provide the most concentrated source of energy of any food and provide essential fatty acids (Chow, C.K. 2000. Fatty acids in foods and their health implications. Marcel Dekker, Inc., New York, NY, 427-435 p. and 687-710 p). However, oxidation is a problem when storing and using fats. Double bonds make unsaturated fatty acids vulnerable to oxidation. Oxidation is the major source of rancid food and malondialdehyde (MDA) which initiates tissue damage and contributes to diet-related degenerative diseases (Chow 2000). Malondialdehyde precipitates in free radical oxidation mechanisms (Guillen-Sans, R. and M. Guzman-Chozas. 1998. The thiobarbituric acid reaction in foods: a review. Critical reviews in food science and nutrition. 38: 315-330).

Oxidation of natural polyunsaturated fats produces malondialdehyde. The reagent, thiobarbituric acid (TBA), reacts with MDA to produce colored compounds which is measured spectrophotometrically (Guillen-Sans and M. Guzman-Choas 1998). These colored thiobarbituric acid reactive substances (TBARS) are well correlated with fat oxidation in animal food products and tissues. The TBA test accurately measures the amount of oxidation in mg/Kg of Malondialdehyde produced. TBARS were measured in fourteen samples of cat food with three replicates of each sample. The means of the TBARS were compared using a one-way ANOVA. There was no significant difference among the brands of cat food (p= 0.0581). There was a significant among between the types (dry, semi-moist, and wet) of cat food (p=0.0015). There was no significant difference among the base (non-fish and fish) of the cat foods (p=0.105). There was no correlation between the cost per serving of the food and the amount of oxidation (r2= 0.0339).



Eri Takai
VISITORS' PERCEPTIONS AND ATTITUDES TOWARD THE FORESTS -COMPARATIVE STUDIES IN THE U.S. AND JAPAN
October 30, 2000.  Mentors: Dr. Lou Weber and Dr. William C. Davis

Abstract:  Recently, it has been recognized that the human dimensions information in natural resource management is as important biophysical and ecological information. I challenged this relatively new field focusing on three different forests, the Warren Wilson College forest, the Great Smoky Mountains National Park, and the Chichibu-Tama National Park in Japan. The objective of this research was to determine how visitors' perceptions and attitudes toward the forests are different in these three forests.

I used a self-administrated questionnaire to obtain the data form visitors. The analysis was conducted using ANOVA and Chi-square with some corrections of the data and variances when needed. As a result, I obtained 129 respondents at Warren Wilson College, 143 in the Great Smokies, and 140 in Chichibu-Tama National Park.

Overall, the responses to most of the questions were significantly different among three sites. This result revealed a fundamental difference in visitors' perceptions and attitudes toward the forests. There were significant differences in visitors' value on the forests. Agreement for the values was significantly different among three samples (p=0.0001). At the Warren Wilson College forest, the visitors named more values than the sample in other parks. The Great Smokies' sample came next, and The Sample in Chichibu-Tama National Park had the least agreement for each value.

There were similarities, however, within the results. Most visitors of all three sites expressed a willingness to compromise their life quality for the forest protection and an interest getting involved in decision-making process.

In some questions, I found similar responses in WWC and Chichibu-Tama National Park. This could be because they have better accessibility to the forests.

The Japanese sample, expressed fewer named values in the forests and less interest in participating in environmental activities than samples in the U.S. Differences in forest abundance, education, and political issues in forestry could explain these results.

One clear response shared by visitors at Chichibu-Tama National Park and Warren Wilson College forest was a desire for more and better information about the forests. These visitors also believed that the forests could be better managed. I assume if better information about forest management policy and practice were available, the communication would be improved between the public and the managers. This could increase visitors' impact sensitivity while insuring managers' social responsibility.



Kyla Marie Frohlich
The Effect of Dandelion Root Extracts on Crown Gall Tumors
Mentor: Dr. Dean Kahl
November 6, 2000

Abstract: Taraxacum officinal (dandelion) is a hearty, widespread plant that is often used as an herbal remedy (Availa, Juan and Charles Fetrow. 1989. Complimentary and Alternative Medicines. Springhouse Corporation, New York, NY, U.S.A. 216-217).  The dandelion is native to Asia and Europe but has been naturalized around the world. The dandelion is most widely viewed as a weed or a nuisance. According to both Fetrow and Availa (1989) and Williams, Goldstone, and Greenham (1996 Greenham, Jenny, Fiona Goldstone, and Cristina Williams.. Flavonoids, Cinnamic Acids and Coumarins from the Different Tissues and Medicinal Preparations of Taraxacum officinale. Phytochemistry. 42:121-127.), an aqueous extract of the root may have anti-tumor properties.

The crown gall tumor bioassay was used to test for anti-tumor activity. A gram negative bacteria, Agrobacterium tumefaciens, is the plant pathogen which causes crown gall tumors. It is possible that if a substance inhibits the crown gall tumor, it may also work as an inhibitor for human tumors (Galsky, Alan, James Wisely, and Richard Powell. 1980. Crown Gall Disc Bioassay: A Possible Aid in the Detection of Compounds with Anti Tumor Activity. Plant Physiol 65:184-185.).  The purpose of this experiment was to determine if extracts of the dandelion root inhibit the growth of crown gall tumors.

Five treatments were used in this experiment. The first treatment was an aqueous root extract, and the second treatment was an ethanol root extract (tincture). The other three treatments were controls. They were a water control, an ethanol control, and a DMSO control. The water control and the ethanol control were both expected to show no inhibition of the crown gall tumors, and the DMSO control was expected to show full inhibition of the tumors. It was found using a one way ANOVA that there was a significant difference in the amount of tumor inhibition between the different treatments. It was also found that both the aqueous root extract and the ethanol root extract showed statistical inhibition of the tumors in comparison to the controls. This was determined using a t-test which assumed unequal variance. Although these results are encouraging, it is important to remember that the crown gall tumor bioassay is a preliminary anti-tumor test and much further research is warranted.



Katie McCullough
The effect of zinc acetate injection on the average daily gain and final weaning weight of newborn piglets.
Mentor: Dr. Robert Eckstein
November 13, 2000

Abstract: Zinc is known to be related to many functions involving the overall health of swine including immunity, production and mechanisms of multiple enzymes, pancreatic function, and skin and connective tissue metabolism. Multiple studies have been performed involving the effect of zinc supplementation on the weight gain of weaned pigs. The object of this study was to determine whether administering supplemental zinc in the form of a zinc acetate injection had an effect on average daily gain or final weaning weight of neonatal pigs. In order to test the effect of zinc supplementation on weight gain, the piglets were divided within each litter into a test and control group. The test group received a zinc acetate injection (3 mg Zn acetate/kg body weight) while the other group received an equivalent amount of saline solution. The litters were weighed at 1,10, and 35 days to determine weight gain. A two way analysis of variance with the piglets blocked by litter was used to control for both the effect of sow and treatment. There was no significant difference between the weights of the zinc and saline treatments at 10 or 35 days of age. There was a significant difference between the weights of sow two as compared to sows one and three with respect to mean 10 day and mean 35 day weights 



Heather Lounsbury
Use Of Bird Boxes By The Eastern Bluebird (Sialia sialis) At Warren Wilson College
Mentor: Dr. Lou Weber
November 20, 2000

Abstract: Population numbers of the Eastern Bluebird, Sialia sialis throughout all of their North American territory have fluctuated substantially over the years. Destruction of their natural habitat and increasing numbers of nonindigenous species such as the House Sparrow (Passer domesticus ) and the European Starling (Sturnus vulgaris) have played a considerable part in bluebird decline. These circumstances have created limited availability of cavities suitable for breeding. Where nest boxes have been available bluebird numbers increased. The Biology and Environmental Studies Departments seeing the need to help, not to mention the opportunity to learn more about the species, have recently placed approximately 50 bird boxes throughout the property. My objective was to research the nesting preferences of box-dwelling Eastern Bluebirds and to make management suggestions for the future. Information was collected starting in March 2000 and continued through the summer. From the data I collected I found that all of the boxes were mounted on fence posts, trees, or phone poles. Of the 31 boxes I observed, only six were used by bluebirds. Of the boxes that were used, all were located in large open spaces rather than wooded areas. Most were subjected to predation. I also found the boxes to be in poor condition. Better management and further monitoring studies on college property need to be done so that we can be sure the boxes are beneficial to the growth and proliferation of the bluebirds. 


Bryan Petit
Mathematical Modeling of Tree Growth to Determine the Consistency of Annual Volume Formation
Mentors: Dr. William C. Davis and Dr. Mark Brenner.
December 4, 2000

Abstract: This study was undertaken to lay a foundation onto which a mathematical model to predict tree growth rates could be produced.  An exhaustive list of variables affecting tree growth rates was attempted to be formed.  Also, an equation explaining the relationship among several of the variables was attempted to be constructed.  This study was conducted in the fall of 2000 on a research plot (5.6 acres) in Dam Pasture at Warren Wilson College.  Eleven variables were analyzed to determine their affect on relative growth rate.  While most of the variables were negated (for which an ANOVA revealed p-values over  0.05), crown surface area, closure, canopy status, and species were compared to the volume of xylem added to the sample tree in the year 2000.  The resulting equation yielded an R2 value of 0.54.  This equation is not very conclusive probably because of a flaw in the crown surface area calculation.  Therefore, the list of 44 proposed variables cannot be concluded to be exhaustive.