Abstract: Our goal today is to explore a small corner of the world of abstract mathematics. Thus in this presentation, we shall consider the Natural Numbers as an introduction to commutative, totally--ordered monoids, which we shall call tomonoids. We will explore a tomonoid - in this case a subset of the Natural Numbers with addition - with an odd order. We shall note that monoids that admit these odd orders require 3 or more generators and 9 or more elements.
Abstract: Environmental groups and industrial associations
often give conflicting views concerning the dangers of exposure to various
chemicals in the environment. Debates rage over the consequences of human
exposure to lead, dioxin, PCBs, DDT, and arsenic. Further, millions of
dollars have been and are spent to remove these chemicals from soil, water,
air, and even the bottom of the Hudson river.
Scientists have begun to ask a series of questions about pollution and efforts to protect human health. First, what chemicals can be found in humans? Second, what is the level of this exposure in the general population? Third, what are the possible health effects of these exposures? Fourth, are these effects found in the general human population?
For the better part of the last decade, I led a research laboratory with 8 scientist at the Centers for Disease Control (CDC) examining these questions. Further, I have collaborated with researchers from all around the world to design and implement epidemiologic studies of breast cancer, non-Hodgkins lymphoma, pancreatic cancer, male birth efects, early intelligence development. I will present an overview of this work with an emphasis on the importance of analytical chemistry in these studies.
Menror: Dr. Victoria P. Collins
Abstract: Allelopathy is a function of biochemical interactions
between plants which interferes with several physiological processes of
the receiving plant. Some major agronomic crops produce allelochemicals
which effect weed growth, influence the success of the following crops,
and sometimes result in autotoxicity. The purpose of this experiment
was to study the persistence of the allelochemicals released from the rye
residue in the Landscaping plot. Six soil samples were taken sixty
days after the rye was tilled under. Another set of soil samples
were taken from the field Big Berea, which has never been planted in rye.
The soil was placed in a funnel and washed with spring water to make an
aqueous extract of the allelochemicals. The solutions were used to
dampen paper towels and ten lettuce seeds in each petri dish, which were
then left for approximately five days before success of seed germination
could be observed. Two controls were used: one of water and one of
Isotoic Anhydride. The means of the number of seeds germinated per
petri dish are as follows: Landscaping plot 9.72, Big Berea 9.63,
Water 9.1, and I. A. 7.7. Because the standard error of the I. A. control was large, the natural log of the data was taken and a one-way Analysis of Variance was run. This test showed that the p-value was 0.0989, which is considered to be not significant. The treatment using soil from the Landscaping plot therefore had no effect on the lettuce seed germination. This indicates that, in this field, the rye residue was no longer toxic towards lettuce after sixty days of decomposition.
Mentor: Dr. Lou Weber
Abstract: Only five percent of the original habitat that ocelots use is left in South Texas, and this habitat is fragmented. I used a Geographic Information Systems (GIS) program, Arcview to examine the total area of the fragments left. Then I used a population viability analysis (PVA), Vortex, to examine how the populations in the fragmented habitat would react if they contained corridors compared to those populations in fragmented habitat without corridors. I used an unpaired t-test, and found there was no significant difference between treatments (p= 0.82). This meant, according to the PVA, that the ocelot population would become extinct in approximately fifty-five years even if fragments were connected. Not being able to accept this, I ran another test. This one changed the mortality rate of kittens from 50% to 25%. After using an unpaired t-test, I found there was a significant difference between treatments (p=0.0002), but the populations still went extinct in 83 years. With this information, I concluded that adding corridors would not keep ocelot populations from going extinct. Protecting kittens between the ages of 0-2yrs is a benefit, but other management techniques should be considered.
Mentor: Dr. Victoria Collins
Abstract: Fumonisins are mycotoxins that are found in corn and many corn-based products (Trucksess and Pholand 2001). Mycotoxins are metabolites produced by molds or filamentous fungi such as Aspergillus, Fusarium, and Penicillum. Mycotoxins cause many health and economic problems (Sweeney and Dobson 1999). This project investigated the most common fumonisin, B1, sometimes produced by Fusarium moniliforme and Fusarium proliferatum fungi which are commonly found in corn. Because corn is one of the major food staples for humans and animals, it is important to control and prevent this fumonisin health threat (Marasas 1995). My objective was to isolate and quantify fumonisin B1 from various corn products including corn grown at Warren Wilson College. The method was sensitive to fumonisin levels as low as 0.0000400 ppm. Fumonisin concentrations were highly variable ranging from 0.0000400 ppm to 0.500ppm. Fumonisin concentrations in all corn products analyzed were below FDA guidance limits.
Oct. 15, 2001
The Effects of Selenium and Vitamin E on the Reproductive Performance of Dairy Cattle
Mentors: Dr. Robert Eckstein and Dr. Victoria Collins
Mentor: Dr. Mark Boudreau
Abstract: Lespedeza cuneata is a perennial legume from
southeast Asia. It has spread throughout the southeastern United
States after its introduction by European settlers. The plant was
used for erosion control and wildlife habitat by the state of Missouri
until the early 90’s. L. cuneata invades open spaces, including
fields, prairies, meadows, and borders of ponds and wetlands. This
invasive plant encroaches even on high quality sites and develops an extensive
Shaw’s Nature Reserve (SNR), owned by the Missouri Botanical Garden, is located 40 miles west of St. Louis, MO. The prairie reconstruction project at this reserve is infested with L. cuneata. SNR uses Garlon and Roundup, applied by hand to the stems of the plant, to curb the invader. This process is labor and chemical intensive. Morrison (2001) proposed a study to investigate the effectiveness of non-chemical control methods—combinations of mowing and overseeding with natives—at SNR.
Invasive exotic plants decrease species diversity (Swanson 1995, Reid and Miller 1989, Risser 1988). Miller et. al. (1999) used diversity indices to investigate if a habitat’s diversity decreased after an L. cuneata population was eradicated with a chemical control; though the control was successful they did not see a change in diversity.
Two transects were erected and 24 samples were taken from the transect in a high density L. cuneata site; 8 samples were taken from the low density transect. Species were identified and percent cover was estimated for all the plots,. An analysis of this pre-treatment data was conducted using two diversity indices, Shannon-Weiner’s and Simpson’s. The means of the low and high plots were compared using an unpaired t-test. The t-test for the Shannon-Weiner index did not show a significant difference with a p-value of 0.1919. However, the Simpson’s index did show a significant difference with a p-value of 0.0074. The methods of calculation differ; Shannon-Weiner’s index does not take into consideration that there are a finite number of species, while the Simpson’s index takes this into account. Further research needs to be done to quantify the effects of exotic species on plant communities.
Mentor: Dr. Victoria P. Collins.
Abstract The Oriental Fruit Moth (OFM) was introduced to the
United States from Japan around the year 1913 on infested nursery stock
(Metcalf and Flint 1962). The OFM has infested most regions of the
United States where pome and stone fruits are grown. Conventional
controls of OFM have been insecticides, mainly organophosphates and chlorinated
hydrocarbons. An alternative to insecticides is pheromone-mediated
mating disruption, the controlled release of a synthetic sex pheromone
that disrupts mating (Pree et al 1994). In this study two paraffin
emulsions were compared containing the same synthetic sex pheromones in
the same concentrations. 7.5 acres of orchard in Fairview, NC was
divided into nine 0.15-acre plots with 0.1-acre buffer between. There
were 3 replicates of each treatment. There were three treatments
the control, Confuseâ-OFM a commercial formulation, and an experimental
paraffin emulsion. Population traps were placed in the center of
each plot and were monitored weekly for twenty weeks. The cumulative
trap counts were compared by 2-way ANOVA, with main effects of treatment
and replicate as the variables. The mean trap counts were 6, 20,
and 27 for experimental, Confuse, and control, respectively. The
experimental formulation consistently had fewer insects, but the effect
of treatment was not significant (p=0.48) probably due to the small number
of replicates. Further studies are warranted because pheromone mating
disruption is an environmentally benign method of insect control.
Mentor: Dr. Dean C. Kahl
Abstract: Comfrey (Symphytum officinale) is an herb used for its medicinal properties. Comfrey produces pyrrolizidine alkaloids, probably for defense. Pyrrolizidine alkaloids are harmful to the body when digested by the liver. The objective of this research was to develop a method for the separation and identification of pyrrolizidine alkaloids from comfrey. Comfrey samples were obtained from Natural Foods store in Black Mountain, NC as well as the WWC Garden. The alkaloids were extracted from the comfrey, and then analyzed on the gas chromatograph/mass spectrometer. The spectra of the samples suggested the presence of butylated hydroxytoluene(BHT,) and stopcock grease. BHT is synthetic preservative, that should not be in organic comfrey, and the stopcock grease probably dissolved into the sample during the extraction. The Total Ion Chromatogram (TIC) for a sample from the Natural Foods store suggested the presence of echimidine, a hepatoxic pyrrolizidine alkaloid. The method proved to be unreliable as the results did not show alkaloids in all samples. Based on this information, the method needs to be further developed.
Mentors: Dr. Lou Weber and Ms. Dawn Nelson
Abstract: Fire is an important tool for ecosystem management in many biomes throughout the world. The Natural Resources Crew (NRC) does prescribed burning in campus forests to combat many invasive species. Every species reacts differently to disturbances; some benefit and some do not. Prescribed burning in WWC forest has been determined to have a devastating effect on tree species with a smaller diameter breast height (Shaper, 1998). Invertebrate assemblages are often useful indicators for monitoring effects of land management practices on biodiversity (Eyre, 1989). In this study populations of 29 different invertebrates were counted and compared before and after prescribed burning on Jones Mountain, Swannanoa Valley, NC. Ground dwelling invertebrates were sampled using pit-fall traps. There were two control treatments, named A and C, where no burning took place, and there was one treatment, named B, that was burned by the NRC on March 14, 2001. Each treatment had ten pit-fall traps within the area. The pitfall taps were placed in 2-3 lines, and each trap had a 2.5 m buffer surrounding it. Invertebrates were collected four times before burning, and then weekly for nine weeks after burning. All found species were then counted and identified to Order or lower, if practical. A total of 6,745 specimens were collected and identified. To analyze the data, Community Similarity Indices were used to express relative similarities between communities. The first two indices used, looked at all three plots together. The Jaccard and Sorenson Coefficients (Quotients of similarity) were 0.44 and 0.61 respectively. The proportional similarity was 72%. Due to inadequate numbers because of weather before the burn, the last two indices look at numbers after the burn only. Using the Bray and Curtis Index the totals for plots A versus B, and B versus C were 0.68 and 0.82 respectively. Horns Information-Theoretic Index values for A versus B, and for B versus C were 0.83 and 0.93 respectively. All values for indices used range from 0 (no similarity) to 1.0 (identical). All indices suggest that burning does not alter population densities. Further studies are warranted to sample populations for full seasons and to perform prescribed burning in the middle of a growing season.
Mentors: Dr. Louise Weber and Dr. William C. Davis
Abstract: The Natural Resources Crew has had
an active burn program to control exotic species for nearly six years now.
To this point there has been no system to quantify the results of these
prescribed burns, this is the motivation behind this seminar. The
objectives are to develop a system to quantify fire effects on exotic species
and to test the effect of prescribed burning on Japanese spiraea (Spiraea
japonica) and oriental bittersweet (Celastrus orbiculatus) after one growing
season. A BACI (Before, After, Impact, Assessment) design was used,
and the impact was prescribed burning. Three control and three impact
belt transects 20 m long by 40 cm wide were used to take percent cover
both pre- and post burn. The data was represented graphically for
analyses, specifically for oriental bittersweet and Japanese spiraea.
Results found that the percent cover of both oriental bittersweet and Japanese
spiraea was reduced by more than half. The data was taken in late
February, the burn occurred in mid March, and the data was remeasured in
mid November. If this monitoring is continued on an appropriate timeline
(i.e. monitoring in early September, burning in Feb., and monitoring again
the following September,) results may be more accurately displayed.
This method effectively illustrates the effects of prescribed burning on
Mentor: Dr. Louise Weber
Abstract: The Nature Conservancy considers Sarracenia flava (the
yellow trumpet pitcher plant), a carnivorous plant to be rare.
Authorities estimate that less than 5% of the original Sarracenia
stands remain in the southeast. Sarracenia flava stands normally
occur in the coastal regions of North Carolina. Carnivorous
plants generally grow in nutrient poor soils. The plant compensates
by breaking down the soft part of the insect in order to absorb nutrients
such as phosphorous, nitrogen, and potassium from the insect.
My objective was to test a variety of horticultural methods in hopes
of bringing stands to western North Carolina by introducing them
into the future outdoor science laboratory. Seventy-two plants
were donated. The tallest 25% of the pitchers of each plant
were measured in centimeters once in May, June, July, and August.
The average percent growth was calculated for each month relative
to the height in May. They were divided into soil treatments, fertilizer
treatments and food treatments. The food treatments seemed
to cause harm to the plants so that treatment was ended.
Using the Mann-Whitney test there was significantly greater growth
in the peat moss/perlite compared to the clay (p-value of 0.0030).
The mean for fertilizer was not considered significantly different
from the no fertilizer with a p-value of 0.1521. The clay soil
found in the area behind the library did not have the ability to
hold water or to bring water up from the bottom of the pots.
It compacted easily and was very clumpy. The pitchers tore
and were dying off after feeding them their supplements. Some
were exuding a liquid from their mouth. The plants could have
been getting to much protein because they were already feeding
on their own. I believe that the plants were overly secreting
the digestive acids and enzymes and therefore causing harm to themselves.
Mentor: Dr. Louise Weber
Abstract: Rainbow Lake is a wilderness area within Prentice
Cooper State Forest in Tennessee. The area has two streams flowing through
it on which I conducted my study, Middle Creek and Bee Branch Creek. Using
benthic macroinvertebrates as indicators to water quality is an effective
way to qualify the health of streams and rivers. Benthic macroinvertebrates
are animal groups of various taxa that live in the “benthos” or bottom
sediment of the aquatic environment (Klem et al. 1990). Different types
of stress will often produce different types of invertebrate communities
(Klem et al. 1990). To qualify these invertebrates tolerance for stress,
several “biotic indices” that give tolerance values for certain taxa have
been developed. My objectives were to compare the water quality of Middle
Creek to that of Bee Branch Creek using a simple t-test, and to compare
the results of four different water quality assessments. Samples were collected
throughout the summer of 2000. The invertebrates were then identified and
the data was analyzed and given qualitative values to each sample site
using EPT taxa richness, the Hilsenhoff Family Biotic Index (FBI) (Hilsenhoff
1977), the North Carolina Biotic Index (NCBI) (Lenat 1993), and the Alabama
Water Watch Stream Assessment Form (AWW) (Deutsch 1993). The results of
the stream comparison from all of the data had an average p-value of less
than 0.89, considered not significant. Hilsenhoff’s (FBI) proved inappropriate
for studies in the southeast. A drought summer had serious effects on the
benthic fauna. This is a good reason why so few taxa were found and that
overall numbers in the samples were low. Lenat stated that in order for
the indices (biotic index) to be more valid, a higher number of individuals
and taxa are needed in the samples (Lenat 1993). Therefore, the most accurate
assessment of water quality was the EPT taxa richness assessment, which
designated poor water quality for every sample site along Middle Creek
and Bee Branch Creek.
Abstract: Nutrient levels within low order mountainous streams
are typically low, and phosphorous is usually the limiting nutrient for
primary production. However, allocthonous sources, especially the autumn
leaf fall, provide most of the energy for the stream ecosystem. These streams
typically have cool water temperatures and high levels of dissolved oxygen
making them ideal locations for commercial trout production. The effluent
from trout farms contains high levels of nutrients and organic matter from
fish waste and excess feed. The objective of this study was to look at
the effects of effluent from one trout farm on leaf decomposition and periphyton
growth. Leaf packs and artificial substrate were placed upstream and downstream
of a trout farm on Shope Creek in Buncombe Co. North Carolina. Nutrient
levels at both sites were measured throughout the study. Phosphorous and
ammonia levels were both significantly higher downstream (P = 0.0200 and
P = 0.0004). Nitrate-N levels were not significantly different (P = 0.2303).
After 47 days, leaf decomposition was significantly higher at the upstream
site (P< 0.0001). After 67 days, periphyton growth, measured as
total organic matter accumulated on the artificial substrate (ash free
dry mass), was significantly higher at the downstream site (P = 0.0250).
Paired t-tests were used to compare phosphorous, nitrate-nitrogen, and
ammonia levels at the two sites. Previous research has found phosphorous
to be a limiting factor in the growth of algae and fungi. Therefore, the
increased organic matter growth at the downstream site can be explained
by the higher nutrient levels. Leaf decomposition appears to be inhibited
by the addition of trout farm effluent to the stream. Bacteria and fungi
both participate in leaf break down and their increased levels downstream
suggest that leaf decomposition should also be greater at this site. One
possible explanation for why this was not found is that macro-invertebrate
shredders such as Plecoptera, which feed on leaves, were more abundant
at the upstream site. Macroinvertebrate populations were not quantified
in this study, but the leaves at the upstream site showed skeletonization
typical of shredder consumption, while the downstream leaves were still
December 10, 2001
Molecular Evolution in Parasitic Finches
Mentors: Dr. Michael Sorenson (Boston Univ.), and Dr. Jeff Holmes
Abstract: Avian brood parasites are opportunistic species with
adaptations that enable them to obtain parental care, for their young,
from a host species. One interesting, and less studied, group of brood
parasites is the genus Vidua. The genus Vidua contains ten species of indigobird
and nine species of long-tailed whydah. These species are host-specific
parasites and each tends to parasitize a single species of estrildid finch.
The genus has a long history of brood parasitism, and that history has
been characterized by cycles of host colonization, speciation, extinction,
and subsequent recolonization. This dynamic process of repeated bottlenecks
may produce an increased rate of sequence evolution and a mutational bias
within the lineage. This increased rate is predicted by the nearly neutral
theory of molecular evolution. This theory proposes that lineages with
a smaller effective population size will have a faster rate of sequence
evolution than equivalent lineages with a larger effective population size.
This occurs because slightly deleterious mutations are more likely to become
fixed in small populations due to genetic drift. Thus, the increase will
be concentrated at nucleotide sites subject to selection, creating a mutational
bias. Hypotheses about the process of molecular evolution in Vidua were
tested using the complete mitochondrial genome of eight different taxa.
This group represented the parasitic finch lineage, its closest non-parasitic
relatives, and an outgroup. Analyses indicated that the parasitic finch
lineage exhibited a relatively faster rate of sequence evolution than that
of estrildid hosts and other passerines. The rate of sequence evolution
in the parasitic finch lineage was 30% greater than that in other lineages.
In addition, Vidua accumulated a greater amount of slightly deleterious
mutations than other clades. The lineage had a greater ratio of nonsynonymous
to synonymous substitutions. These results are consistent with the nearly
neutral theory of molecular evolution, as described by Ohta, and the evolutionary
history of Vidua as a brood parasite.
Mentor: Dr. Victoria P. Collins
Abstract: Shiitake mushrooms, Lentinus edodes, are a delicious
and healthy food. Shiitake are native to East Asia, but are now cultivated
all over the world. Shiitake are grown on hardwoods, but primarily
white oak logs.
Mushroom science is young, but studies on Shiitake have shown that it can boost the immune system, lower blood cholesterol levels, shrink tumors in lab studies, and act as an antibacterial agent (Manzi, 315). The sulfur lenthionine is the principal antibacterial compound found in Shiitake.
Lenthionine, C2H4S5, which is responsible for the strong sulfur aroma of shiitake is also the principal antibacterial component. Lenthionine has been isolated and synthesized (Morita et al), the enzymic formation of lenthionine has been studied (Yasumoto et al), and lenthionine has also been used in studies on natural substances which prevent dental caries (Hirasawa et al).
This study investigated the effect of a non-polar shiitake extract. 200 g (wet weight) shiitake yielded 1.5 g of oil. The minimum inhibitory concentration of oil against Esherichia coli, Salmonella typhimurium, and Streptococcus lactis was 0.8 mg oil/ml nutrient broth and >1.12 mg oil / ml broth for Enterobacter cloacae. The determination of a bactericidal effect vs. a bacteriostatic effect of the oil against Streptococcus lactis was inconclusive.
Mentor: Dr. Mark A. Boudreau
Abstract: Late blight is a disease caused by the pathogenic protist Phytophthora infestans. Commercial fungicides are used to manage the spread of late blight disease, which is “the cause of the largest uses of agrochemicals” according to the Global Initiative on Late Blight. As an alternative to commercial fungicides, several plant volatile oils were identified that have shown signs of being anti-fungal: Allium sativum, Allium cepa, Origanum majorana, or Thymus vulgaris. The objective of this study was to determine whether volatile oils of garlic, onion, sweet marjoram, or thyme would inhibit the growth of P. infestans in vitro. Also, one of four oils was to be selected for a field trial with tomato against late blight. Two in vitro trials measured how P. infestans growth would be inhibited by each essential oil as a separate treatment. Copper sulfate was used as a positive control and water was used as a negative control. The first in vitro trial studied the effects of the four oils at one concentration level of 1.0ml ml-1. The second in vitro trial studied the effects of the four oils at four concentration levels: 1.6ml ml-1, 1.2ml ml-1, 0.8ml ml-1, 0.4ml ml-1. The volatile oils were purchased from Gritman Oil Co. and were added as individual treatments to rye-b media post autoclave sterilization. The results for trial one were that P. infestans did not grow among the four treatment plates or the positive copper sulfate control plates. Growth did occur on the negative control plates, which also had contamination. The results for trial two were that garlic inhibited the growth of P. infestans most successfully among treatments. Garlic was chosen to be used in a field trial to combat the disease on tomato. However, before the treatment applications could be given, the tomato plants contracted the disease naturally in the field. No results were obtained. In conclusion, in vitro trial one suggests inhibition by all treatments excluding the water control. However, a longer growth time was needed for a more accurate assessment. In trial two of the in vitro study, evidence suggests that garlic inhibited the growth of P. infestans. The field study was inconclusive.
Mentor: Dr. Lou Weber
Abstract: This study was initiated due to the increase of black
bear sightings on Warren Wilson Campus College over the past couple of
years. The first objective of the study was to determine the causes
of this recent increase in bear sightings on campus. The second objective
was to determine whether a corridor exists between the top of Suicide Ridge
and Jones Mountain. The fourth was to determine the important aspects
of habitat with in the corridor and lastly to determine if bears are found
foraging in the forest or if trash is their only source of food on Warren
Wilson Campus. Black bear history and distribution are important
to the understanding human bear interactions on Warren Wilson campus.
According to a study done by Mark Jones in 1998 a population of 1 bear
per km2 was found which is in close proximity to Warren Wilson campus,
one of the most dense bear populations in the region and country.
I used a black bear sighting interview form which I sent as an All-l, email
attachment. Interviews were also conducted personally, through the
campus mail, and via phone. This data was organized into a Microsoft
word database. A Global Positioning Satellite (GPS) unit was then
used to collect all bear sighting points, and other important aspects of
habitat. I performed a qualitative analysis of the black bear corridor
and a qualitative analysis of two important areas of bear sightings with
in the corridor. With this data I created a Geographical Information
Systems, Arcview map of all the important data. The results show
that there is a diversity of vegetative cover with in the possible black
bear corridor, but rhododendron thickets are the dominant coverage type.
Important sources of soft and hard masting species were found through out
the possible corridor as well as important water sources. Signs of
bear such as scat, claw scratchings, and diggings were found through out
the corridor. There was an abundance of hard masting trees as well
as soft masting species with in the John Casey and Bill Davis study sites.
The reasons for bears coming onto Warren Wilson Campus are yet to be determined.
Although, I have shown there is a substantial corridor from Suicide ridge
to Jones Mountain with an abundance of important food sources to bears.
There are also a few bears that used Warren Wilson property for foraging.
This leads me to suggest that this corridor be protected and managed to
keep bears safe on Warren Wilson’s property as long as no human bear conflict
occurs. To reduce the risk of human bear conflict I would suggest
that a community wide effort to obtain bear proof trash containers be undertaken.
For further study I would suggest creating a GIS model to assess the quality
of habitat for black bears on Warren Wilson Campus including Dam Pasture.
Another study would be to measure the weight of acorn mast in oaks on Warren
Wilson campus. I also suggest setting up a series of bait triggered
camera stations to determine the number frequency of bears coming onto
Warren Wilson property. As a last resort to pest bears I would suggest
using a taste aversion conditioning experiment on pest bears to trash.
February 25, 2002
Mentor: Dr. Paul Bartels
Abstract: Tardigrades are invertebrates and are the sole
members the phylum Tardigrada. For many years the systematics surrounding
tardigrades has been debated and was often ignored, as this phylum’s relationship
to other phyla was, and continues to be unclear (Kinchin 1994). The
phylum Tardigrada has however been classified as a sister group of the
arthropods (Nelson and Marley 2000). Tardigrades are hydrophilous,
requiring a layer of water in which to swim and perform gas exchange.
They are considered meiofauna, benthic animals 40-50mm in size (Hauer and
Lamberti 1996). Not much has been known with regards to tardigrade
representation in the Great Smoky Mountain National Park, and it is through
the All Taxa Biodiversity Inventory that scientists have been able to focus
on studying tardigrades in the Smokies. By using samples collected
for the Inventory, I was able to do a separate study. The object
of the study was to determine if there is a correlation between the number
of tardigrades to rotifers or nematodes in a sample, and to hypothesize
reasons of the correlation using other available data such as species diversity
and the number of predator species present. The Pearson’s product-moment
correlation was used on Excel for the statistical analysis, and the r2
value was used to measure the percentage of variance accounted for by a
correlation (Dytham 1999). The Ho being tested is that there is no
correlation in either of the three The Pearson product-moment correlation
indicates an insignificant positive association between nematodes and tardigrades
(r=0.111, d.f.=21, P>0.05) with r2=0.0123, a significant positive association
between rotifers and tardigrades (r=0.610, d.f.=21, P<0.05) with r2=0.372,
and a significant positive association between nematodes+ rotifers and
tardigrades (r=0.473, d.f.=21, P<0.05) with r2=0.224. A positive
significant correlation was found between tardigrades and rotifers, and
tardigrades and nematodes+rotifers.
Mentor: Dr. William C. Davis
Abstract: Warren Wilson College has been closely tied to its
land since its inception in 1894. Until the late 1950?s and 1960?s,
the farm was the major producer of food for the school. Also, lumber from
the forest is still used for building and heating purposes. In my
study, I pursued two research questions. One was to ascertain if
the seeds of environmentalism were present at the school before the national
environmental movement of the late 1960?s, and two if attempts at self-sufficiency
represented precursors for the school?s present environmentalism.
My research methods were to first read the 3 major histories of the college,
then research the farm and forest in the school?s archives, rummage through
journals and files in the farm office, and finally to orally interview
the ?old timers? of the school. I found that by today?s standards
of environmentalism, most evidence pointed to a lack of environmentalism
prior to the late 1960?s and that the school?s early self-sufficiency did
not indicate environmental precursors. However, some environmental
measures were taken.
Mentor: Dr. Lou Weber
Abstract: Loggerhead sea turtles have been listed as a threatened species under the U.S. Endangered Species Act since 1978. There are many threats to Loggerhead sea turtles as a species. Some of these threats include habitat destruction, the shrimp industry, subsistence harvesting of sea turtles by developing countries and, of course, natural threats such as predation, drowning due to excess tidal inundation, and ?cooked? or melted nests during drought summers. The overall objectives for this project were to determine if it is a feasible conservation technique to avoid relocating nests laid between the mean and spring high tide lines during a drought summer. An additional objective was to determine whether hatch success for nests laid between the mean and spring high tide lines (that experienced tidal inundation) was higher than hatch success of nests laid above the spring high tide line. There have been two previous research projects conducted concerning the effect of tidal inundation on nests during drought years. One study resulted in inconclusive data with no visible trends, while the other study concluded that tidal inundation increased the hatch success of nests during a drought year.
In an attempt to prevent nests from heating up too much during the forecasted drought summer of 2000, I avoided relocating all nests laid between the mean and spring high tide lines and labeled these nests ?experimental.? The logic behind leaving nests laid between the mean and spring high tide lines in situ (not relocating these nests) is that the bi-monthly new and full moon tides would inundate the nests with water, and nest temperatures would then cool off, preventing the nests from cooking. The nests were monitored daily, and the instances of tidal inundation were recorded for each nest. To collect data, an inventory was conducted for each nest, and the nest contents were examined to calculate percent hatch success. The result of this study was that the mean hatch success for nests laid above the spring high tide line was significantly higher than the mean hatch success for experimental nests (Mann Whitney p< 0.0001).
Because the results of this experiment yielded significant results, it does not appear to be a valid conservation technique to avoid relocation of loggerhead sea turtle nests laid between the mean and spring high tide lines during drought years. Furthermore, experimental nests were more prone to predation and storm erosion. Even if it is a drought nesting season, nests laid below the spring high tide line should be relocated in all future loggerhead management projects.
Mentor: Dr. Lou Weber
Abstract: Loggerhead sea turtles have been a threatened species since 1978. There are many threats to Loggerhead turtles such as habitat loss, beach lighting, the shrimp and fishing industry, and natural threats such as predation. Conservation efforts must be evaluated to improve their status. There are many beach management strategies aimed at increasing hatch success. One of these strategies is nest relocation. Relocation is moving nests from below the spring high tide line to a higher location on the beach to prevent flooding of the nest. The incubation conditions of a nest are variable according to the placement on the beach. Different incubation environments could have great impacts on developing embryos. Incubation temperatures are the main factor in determining incubation duration. Warmer temperatures cause shorter incubation durations and cooler temperatures cause longer incubation durations. The main objective of my research was to determine if hatchling fitness is affected by different incubation durations. Knowing what incubation durations produce the greatest fitness in hatchlings would have many implications for management, especially in relocation efforts.
A speed test was used to compare hatchling performance as a measure of fitness. I used 20 randomly selected hatchlings from 12 different nests throughout the summer. I ran them on an 8-meter track split into two 4-meter sections. Three times were taken: orientation time (the first 4 meters), speed time (the second four meters), and overall time (the full 8 meters). Average clutch speeds were then compared. A significant correlation was found between incubation duration and all three times: incubation duration vs. orientation time (P=0.01), incubation duration vs. speed time (P=0.04), and incubation duration vs. overall time (P=0.005).
My results show that longer incubation durations produce faster hatchlings.
This indicates that cooler incubation temperatures produce faster hatchlings.
If being fast is a fitness advantage, then it is an important factor for
management to consider, especially in relocation efforts. When nests
are moved they could be moved to cooler incubation environments to increase
fitness. I am not suggesting this as a management strategy because
further research must be done to determine if speed is actually a fitness
advantage, and especially to assess the impacts of this strategy on sex
ratio. My research does not determine the best management strategy
for relocation, but simply adds an additional factor to consider in sea
turtle beach management.
Mentor: Dr. Dean Kahl
Abstract: Kudzu (Pueraria lobata) is a weed common to the Southeastern United States as a fast-growing and somewhat pesky plant. First imported to America in 1876, kudzu has been used for thousands of years in China for both food and medicinal purposes. The flower of Pueraria lobata resembles a pea flower and is very aromatic; the smell resembles grape soda.
A literature search revealed that no research has yet been published on the components of the kudzu flower fragrance. The objective of this experiment was to use a gas chromatograph/mass spectrophotometer (GC/MS) as well as a solid phase micro extractor (SPME) in order to analyze the components of the aromatic vapor of the flower.
A method was developed on the GC/MS that would give the most satisfactory chromatograms. This temperature program was then used during each kudzu experiment. The SPME was positioned above the kudzu flowers and allowed to extract the vapors of the flowers. The SPME was then injected into the GC/MS and chromatograms of the unknown substances were obtained. The GC/MS library, which contains 20,000 different chromatograms of known compounds, was used to identify some of the components in the unknown flower vapor.
Though two of the kudzu experiments resulted in poor chromatograms, four chromatograms were acceptable for library searches and fragmentation pattern analysis. Nonanal, decanal, and methyl anthranilate were identified as chemicals possibly responsible for the fragrance of kudzu. Due to poor library matches, contamination by foreign chemicals, and variations in temperature program, many compounds remain unknown.
The study proved successful in the development of a method for fragrance analysis as well as the identification of three chemicals in the vapor of the kudzu flower. Additional work will be required in order to determine more of the volatile flavor components.
Mentor: Dr. Mark Boudreau
Abstract: The term living mulch was first coined in 1979 by Robert
Sweet of Cornell University. A living mulch is a type of intercropping
that is attained by undersowing a low-growing, densely planted groundcover
underneath a market crop. Living mulches have been found to suppress
weeds, reduce pest populations, increase crop yields, enhance soil organic
matter, and reduce soil erosion. The main drawback of a living mulch
is that it can compete with the market crop for nutrients, water, light,
and space. The objective of my study was to determine the effects
of clover and arugala living mulches on broccoli yields. The commercial
viability of living mulches and the Land Equivalence Ratio (LER) were assessed
to see how applicable living mulches were to agriculture. In the
fall of 2001 broccoli was grown with a clover living mulch, an arugala
living mulch, by itself and hand weeded, and by itself with no weeding.
Fresh and dry weights of broccoli yields were measured and showed that
the arugala and clover living mulches had no effect on the fresh weight
broccoli yields. The arugala living mulch did significantly decrease
the broccoli head dry weight. The LER for broccoli
and clover was 1.64 and 1.29 for broccoli and arugala. Commercial
viability of living mulches was not assessed because there was no significant
difference in broccoli yields between the treatments. The results
of this research and prior research show promise for the application of
living mulches in commercial agriculture.
Mentor: Dr. Mark Brenner
Abstract: In 1997, the Swannanoa River received a Good-Fair classification for swimming and recreational waters by the Division of Water Quality in the North Carolina Department of Environment and Natural Resources. In response RiverLink, a nonprofit organization addressing water quality issues, created a nonpoint source pollution management plan with grant money from Section 319d of the Federal Clean Water Act. Part of RiverLink’s management plan involved a bioassessment of the Swannanoa River Watershed. This bioassessment involved me sampling for E. coli and determining water quality based on pollution tolerance of aquatic macroinvertebrates.
This study used the data collected for E. coli and the macroinvertebrates
to evaluate the relationship between E. coli levels and pollution tolerance
of macroinvertebrates using the Hilsenhoff Field Biotic Index, HFBI.
I sampled nine sites from the upper watershed, in Lower Black Mountain,
to the lower watershed in Biltmore Village. I counted E. coli samples
using an indicator dye method. I sampled, identified, and scored
the tolerance values for aquatic macroinvert-ebrates using the Hilsenhoff
Field Biotic Index with corrections for North Carolina. I correlated these
tolerance values with E. coli colony counts using a Pierson correlation
analysis. The range of E. coli colony counts were from 0.0 to 110.3
colonies per 100 mL, with a substantial number of sites having 0.0 colony
counts per 100 mL. The HFBI tolerance values ranged from 2.9, mainly
intolerant species, to 6.9, signifying more tolerant species. Results
for all three sample dates were not significant and correlation values
for r ranged from 0.46 to –0.66. I found no direct relationship between
the abundance of E. coli and HFBI tolerance levels for macroinvertebrates
in the Swannanoa River watershed. All E. coli samples contained less than
126 colonies per 100mL, the EPA safety standard for recreational use. Tolerance
values for the HFBI ranged from 2.9 to 6.9, indicating Excellent to Fairly
Poor water quality for the Swannanoa River watershed. With continuous
aeration in mountain streams, the impacts of organic pollution do not adversely
affect macroinvertebrates. Also, the possible impacts of non-source
pollution caused by organic pollution may be determined by other factors
not related to dissolved oxygen.
Mentor: Dr. Dean C. Kahl
Abstract: Ginkgo biloba extract is an herbal supplement that is reputed to be a natural antioxidant which has a scavenging effect on free radicals. Free radicals damage cell membranes through peroxidation of structurally important fatty acids. Antioxidants stop these free radical reactions. The objective of this study was to develop a method to analyze free radical trapping properties of various antioxidants. The ultimate objective of this study was to study the antioxidant properties of Ginkgo biloba and compare to known antioxidants.
A method was adapted from Valkonen and Kuusi (1997, Journal of Lipid
Research 38:823-833). Free radicals were produced by 2,2’-azobis(methylpropionamidine)
dihydrochloride. In the presence of phosphate buffered human serum,
the reaction of the radicals and 2,7-dichloroflourescein-diacetate was
facilitated by the esterases in the serum to produce a colored product.
The formation of this product was observed at 504 nm with a UV/VIS spectrophotometer.
According to our preliminary results the method appears promising, but
more work needs to be done (1) on the effects of concentrations of AAPH,
DCFH and human serum on the rate of the reaction (2) to determine the reproducibility
of the results and (3) to study the effect of various antioxidants, including
extracts of Ginkgo biloba.
Mentor: Dr. Mark V. Brenner
Abstract: The Wildlife and Swim ponds here at Warren Wilson College have different ecology and history. The Wildlife pond is between Charlie?s Pasture and S-field which both receive added fertilizers every one to three years. The cows also spend considerable amount of time near, but not in, the Wildlife pond. It was made in fall 1999 because it was a naturally wet area due to groundwater and runoff from the fields. The Swim pond was built approximately 1945, is far from the fields and receives most of its water from a forested watershed, Kittredge parking lot and Warren Wilson Road. The objective of this study was to test for total nitrogen, total phosphorus and phytoplankton in order to determine the ponds current trophic status and hypothesize about future conditions. A random number generator was used to select three collection sites from each pond. Three samples from different areas in the pond were collected on six different days. The nutrients were tested using HACH Test in Tube Method. The technique involves digestion of the sample the reading the wavelength from a spectrophotometer. The phytoplankton was measured by concentration of chlorophyll-a using Monochromatic Method. This was also measured on the spectrophotometer. A paired t-test showed there was no significant difference between the ponds for the three parameters measured Chl-a p=0.44, total nitrogen p=0.096, total phosphorus p=0.36. According to trophic standards both ponds classified as having hypertrophic amounts of nitrogen and phosphorus and mesotrophic levels of phytoplankton. There was large variation in my results, including some negative numbers and some that were ?over range? which means they were too high for the spectrophotometer to read. Visually the ponds appear to be in good condition; both contain fish and there is low turbidity. The Wildlife pond does have a considerably large amount of macrophytes, which can use up phosphorus and nitrogen, and the Swim pond does not. While the ponds seem to have higher concentration in nutrients than lakes, they may be at high risk of volume loss by the fill in of sediments from algae and macrophytes.
Mentor: Dr. Lou Weber
Abstract: In the summer of 2000 Warren Wilson College cut a 1 ha stand of white pine (Pinus strubus) on North Lane because of a southern pine beetle (Dendroctonus frontalis) outbreak. It was a total overstory removal. This created heated controversy among the student body. I wanted to see if there was a difference in winter bird diversity in this opening than in an unthinned pine forest. Most of the research I could find was in hardwood forests and on neo-tropical and breeding bird populations. In the months of November and December I observed the species of birds that used the North Lane beetle kill area versus the species that were present in an unthinned white pine stand behind the pump house. I counted a total of 13 bird species in all. Eleven of these species were present at North Lane and three were in the Pump House stand. I found that North Lane had a higher average cover board index (355.75), lower forest canopy density (2.86%), and a lower average height (not including residuals) (2 meters). The Pump House stand had an average cover board index of 136, a full overstory canopy (63.18%), and an average tree height of 26 meters. This suggests that winter bird populations at Warren Wilson prefer forest openings to pure pine stands. These data suggest that even-aged management is beneficial to some birds.
Mentor: Dr. Robert A. Eckstein
Abstract: With the goal of enhancing psychological well-being, I developed an environmental enrichment program for four red wolves at the Western North Carolina Nature Center. I hypothesized that the environmental enrichment would illicit a change in the behavioral time budget of the wolves. I used four different enrichment items: smashed heads of garlic; peppermint oil emulsion; rosemary tea; and chopped rawhide. The subjects were exposed to each of the four enrichments on three occasions, for a total of 12 enrichment sessions over the course of a two month study period. These sessions were preceded by 12 control sessions in which no enrichment was present. The wolves spent a significantly larger percentage of time in sight when enrichment was present. I did not find a statistically significant reduction in the percentage of time engaged in the performance of stereotypic behavior for individual wolves or time spent inactive vs. active for all wolves. Environmental enrichment promoted increased time in sight in the sample group. This may indicate an interest in the enrichment which is important for determining effective enrichment techniques. The small sample size, lack of stereotypies, and timing of enrichment may have negatively impacted the results. Future studies should assess whether stereotypies are more like to occur at different times of day and determine the efficacy of specific enrichment techniques.
Mentor: Dr. Robert A. Eckstein
Abstract: Fields that are grazed only by horses tend to develop
an overall pattern in their appearances after an undisturbed time period
consisting of little pasture management (Odberg and Francis-Smith,
1976, Equine Veterinary Journal 8:147-149). My objective was
to compare the distribution of fecal piles in two different sized fields
to a random distribution, as well as to look at the trends in the distributions
between the two fields. The distribution of fecal piles was studied
in a field measuring 72 x 36 meters, and a field measuring 30 x 50 meters.
Four horses were used in this study, with two horses being housed in the
large field and two horses being housed in the small field. The study
was conducted for a total of ten days. The statistical analysis involved
usage of the Poisson distribution to analyze the dispersion of the fecal
piles in each sized field. Upon completion of the study it was determined
that both the large and the small sized field showed clustered distribution
of fecal piles. The chi-square statistic supported these conclusions.
May 06, 2002
Moss Height and Tardigrade Species Diversity
Mentor: Dr. Paul J. Bartels
Abstract: Tardigrades are a phylum of microinvertebrates that
were discovered in 1773. My study was about terrestrial tardigrades
that live on mosses. According to a previous study different species
of tardigrades prefer to live in different parts of the moss. My hypothesis
was that as the moss height increases the tradigrade diversity also increase.
I did my research as an extension of my mentor’s ATBI research project.
Moss samples from the Great Smoky Mountain National Park were collected
and tardigrdes were separated from those samples. Then 50 microscope slides
from each sample was made from tardigrades living on short and tall mosses.
Then these slides were identified with the help of Dr. Diane Nelson
at East Tennessee University. I compared the species richness and the Shannon-Wiener
Diversity Index on short moss vs. tall mosses. When I performed a
Mann-Whitney U test on my results I found that the P value was not
significant, so I was unable to reject my null hypothesis. In my experiment
the number of replicates were too small and it affected my significance
level. For future research I would do this experiment with a greater sample