Natural Science Seminar Abstracts - Spring 2009

Note: All photos posted with the abstracts are photos made by the students who presented their work unless indicated.

Alex Linares
January 26, 2008
Behavioral Effects of Valerian (valeriana officinalis) on Kenneled Dogs (canis familiaris)

Mentor: Dr. Robert Eckstein

Abstract: Awareness of the psychological welfare of companion canines has increased dramatically with the growing animal industry. The stress related to confinement in an unknown environment can create destructive behaviors, leading to a search for an effective remedy for this anxiety. Herbal remedies, valerian in particular, have become increasingly popular as treatments for insomnia and anxiety, but there are very few trials conducted on species other than humans and rats. Therefore, my objective was to determine whether a valerian containing biscuit had an effect on the behaviors of kenneled dogs. Using 69 dogs in 3 separate trials, a two-hour pre-treatment observational study was performed, when the status of vocalization, posture, and movement was recorded for each dog. Afterwards, to maintain a double-blind study, an assistant randomly chose half of those dogs, and they received the amount of valerian product determined by their weight. The control group received a placebo biscuit. After one hour, a post-treatment observational session was performed. The number of positive vocalization, movement, and active behaviors changed significantly between the two observational sessions for both the control and treatment groups (p values all .0001 or less using a Wilcoxon matched-pairs signed-rank test) except for the vocalization in the control group (p value= .4961). The difference between the control and treatment groups was also significant (p value= .0086, .0227, and .0109 respectively, using a Mann-Whitney test). Post-prandial depression and influence of calmer dogs can explain the general decrease in active behaviors in both treatments. These results suggest, however, that the valerian product contributed to the greater decrease of vocalization, movement, and active behaviors.

Emily Axtman
Golf Course Runoff from a Tributary that Feeds Beaver Lake
January 26, 2009

Mentor: Dr. Mark Brenner

Abstract: Golf course runoff has become an on-going environmental issue. This is especially true for water bodies that are in close proximity to them. Beaver Lake in Asheville North Carolina is one of the many water bodies that affected by golf course runoff. This is because it is fed by a tributary stream that runs through the adjacent Country Club of Asheville. The objective of this study was to determine whether there is a difference in nutrient levels in the tributary upstream and downstream of the golf course. Three samples were collected from upstream and downstream. The samples were analyzed for ammonia, nitrate and phosphate using EPA approved colorometric procedures.  There was no significant difference between the upstream nutrient levels compared to downstream for the three parameters. However, the level of phosphates found the tributary were high enough to have an impact on the lake. 

Joe Giambruno
Oviposition and herbivory preference of the Painted Lady Butterfly, (Vanessa cardui), on two host-plants
February 2, 2009

Mentor: Dr. Robert Eckstein

Abstract: The oviposition site choice of a butterfly can determine the survival of her offspring.  Females of many butterfly species have demonstrated the ability to discriminate amongst a variety of host-plant factors.  Painted lady butterflies (Vanessa cardui) select from more than 100 compatible host-plants, each with particular costs and benefits.  The objective of my study was to determine the strength of preference in larval food choice and oviposition, and to establish whether development can be altered by larval hosts in Vanessa cardui.  Painted lady caterpillars were subjected to one of three treatments containing equal edible amounts of hollyhock (Alcea rosea) and common yarrow (Achillea millefolium). The first treatment contained fresh hollyhock and poor yarrow; the second treatment contained fresh yarrow and poor hollyhock; and the third contained both fresh yarrow and hollyhock.  Poor samples of hollyhock and yarrow were produced by allowing the fresh clippings to wilt for 12 hours.  Food preference was determined by observing the location of the larvae on either of the host plants.  The weight of all larvae and pupae were recorded, as were the larval and pupation durations.  The adult butterflies were placed in hanging hoop nets, grouped according to their treatment, and were allowed to lay eggs on fresh samples of hollyhock and yarrow. Results of this experiment demonstrate no clear larval food preference.  Larval weight (p=0.16), pupation duration (p=0.08), and oviposition preference (p=0.32) did not vary significantly between the treatments.  Larval duration (p=0.02) varied significantly amongst the treatments as did pupae weight (p<0.0001). All treatments demonstrated a clear ovipositional preference for common yarrow (p<0.0001). A comparison of the fresh hollyhock treatment and fresh yarrow treatment shows that the fresh yarrow treatment produces heavier pupae in a shorter amount of time.  Although the different host-plants had a demonstrated affect on larval development; no preference in host-plant selection was observed for the larvae.  In contrast, ovipositional preference for yarrow was significantly greater than preference for hollyhock.

Ashley Conley
Arsenic Determination in Soils from the Apple Orchard on Warren Wilson Campus
Feb 9, 2009

Mentor: Dr. John Brock

Abstract: Arsenic is a naturally occurring heavy metal often associated with non ferrous ores such as, lead, zinc, copper, gold and uranium.  Arsenic is a constituent of many minerals, and can be released into the environment through weathering, erosion, biologic activity and volcanic emissions. However anthropogenic processes such as mining and smelting of ores, the combustion of fossil fuels and application of herbicides, pesticides, and wood preservatives has had direct impact on environmental and human health. Arsenical insecticides, such as lead arsenate were the largest sources of soil Arsenic contamination in the 20th century, due to their effectiveness as against orchard pests. The objective of my study was to determine soil arsenic levels from the warren Wilson college apple orchard, and examine possible mobilization through the soil column. These levels were compared with known contaminated levels from Barber Orchard, in Haywood County.  Sampling locations were randomly selected using GIS and GPS coordinates assigned for ten locations. Samples were collected with a soil auger and a Ziploc bag. Three depths of 0-10, 10-20 and 20-30 cm were analyzed at all ten locations giving me 30 samples. Replicates of 0.5 g were weighed out for each depth and an acid digestion was conducted.  Analysis of all blanks, standards, and unknowns was performed with an inductively coupled plasma atomic emission spectrophotometer (ICP-AES). An external calibration curve was created and the linear operating range used to determine the concentration of arsenic in each sample.  Results showed that the total soil arsenic concentration found from wwc soils was between 160 and 207 ppb. The average concentration found from 0-10 cm was 184 ppb, from 10-20 cm 200 ppb, and from 20-30 cm 167 ppb. My data met all assumptions and passed all normality tests, therefore an ANOVA was conducted resulting in a P-value of 0.6367. Individual differences between soil depths were compared for each location, resulting in a P-value of 0.1104. The total soil arsenic concentration from Barber Orchard was between 160,000 and 320,000 ppb due to lead arsenate applications. The levels of arsenic found from the Warren Wilson college apple orchard soils was between 160 and 207 ppb. The levels found are most likely due to the composition of the geologic material in this region.

Franklin Stone
Analysis of Imidacloprid in Hemlock Trees
9 February 2009

Mentor: Dr. Dean C. Kahl

Abstract: Hemlock trees are an important part of the ecosystem providing shade and habitat for numerous animals.  The trees are currently in danger from a pest called the hemlock wooly adelgid (Adelges tsugae).  The adelgid is a pest native to Asia.  The Eastern Hemlock and Carolina Hemlock have no natural defense.  Imidacloprid is a pesticide that is highly effective against sucking insects such as the hemlock wooly adelgid.  Imidacloprid blocks the acetylcholine receptors causing paralysis and death.  The objective of this research was to develop a method of analysis for imidacloprid using gas chromatography coupled with mass spectrometry.  Because imidacloprid is a solid derivatization was used to convert the pesticide into a volatile molecule.  Two derivatization processes were tested. Trifluoro acetic acid anhydride failed to produce a derivative in every trial. The reaction with heptafluoro butyric acid anhydride was successful at relatively high concentrations of the anhydride and imidacloprid, but at low concentrations of imidacloprid the reaction failed.  The most likely reason for failure of the reaction is the effect of water on the derivatizing agent, causing the acid anhydride to  form  heptafluoro butyric acid.

Hank Hambright
Allelopathy and crown competition for growing space in Black Walnut (Juglans nigra) stands
February 16th, 2009

Mentor: Dr. David Ellum

Abstract: Allelopathy is defined as a competitive strategy where one plant negatively affects another plant through the production of chemicals, known as allelochemicals, that escape into the environment. This study will focus on the principle allelochemical present in Black Walnut trees (Juglans nigra), juglone. Allelochemicals are released into the rhizosphere through decomposition, volatilization, and root exudation. Allelopathy affects many plant processes such as regulation of growth, respiratory metabolism, photosynthesis, and nutrient uptake. Black Walnut trees contain non-toxic hydrojuglone in the leaves, fruit hulls, inner bark, and roots. Hydrojuglone is oxidized into the toxic allelochemical juglone when exposed to air. Allelopathy gives allelopathic plants a competitive advantage because allelopathy restricts growing space. Growing space is the sum of all factors necessary to tree growth. Trees will continue to grow until one or more factor is either limited at the site or, as in the case of this study, taken up by another tree. When two trees compete, one will end up dominating or killing the other. The purposes of this study are to use black walnut to study the allelopathic differences between dominant and suppressed trees and to determine if superior crown competitors relate to superior ground competitors through allelopathy. A controlled germination study of allelopathy was conducted using white pine (Pinus strobus) and red maple (Acer rubrum) seeds. Black Walnut trees were selected from Warren Wilson College stand CT6 and identified as either dominant or suppressed. Cambium was extracted from six dominant trees and six suppressed trees. The tissue was dried, ground, and sonicated into 100 mL of solution. Dominant, suppressed and control solutions were used to water seeds and germination success, radical length, and dry weight were recorded after ten days. This experiment shows significant difference among the treatments for germination success (p<0.0001) with germination significantly reduced by dominant trees. There was a significant difference between the control (DI water) and suppressed treatments for radical length (p=0.003) although the dominant treatment was not included in the statistics due to low N. There was no significant difference in dry weights among the three treatments (p=0.138). The reason that dominant trees restrict growing space through allelopathy more than suppressed trees may be due to limited photosynthate production in suppressed trees and limited secondary compound production, such as allelochemicals. The results of this study may help us understand the relationship between dominant crown competitors and dominant ground story competitors through allelopathy.

Ann-Marie DuBois
Stage class life history analysis of the tardigrade Thulinius stephaniae
February 16, 2009

Mentor: Dr. Paul Bartels

Abstract: Tardigrades, an invertebrate phylum of microscopic animals are found in moist sediments throughout the world. Seventy-eight species of tardigrades have been described for a multi-habitat inventory in the Great Smokey Mountains National Park. Beyond taxonomic descriptions, we know very little about most of these species. The purpose of this study was to conduct a life history analysis of the tardigrade Thulinius stephaniae using stage class methodology to determine number of molts, age at first reproduction, and fecundity. Leslie matrix models were used to analyze stage structures as a tool for future predictions of population growth. Five random samples of tardigrades were obtained from Carolina Biological Supply. Measurements were taken, using photomicroscopy and i-solutions an imaging acquisition and measuring software, of body length, buccal tube length, and the number of eggs recorded. These measurements were plotted against frequency to determine the number of instars.  Instars and stage at reproduction were obtained using buccal tube length. Leslie matrix, with three assumptions, allowed the prediction of future population growth, plotting of survivorship curves, and calculates r and Ro. Both r and Ro indicate a declining population. The data suggest that reproduction starts with stage two individuals and that this species has at least four stage classes or three molts during its lifecycle. Leslie matrix can be used when age is not known to prediction population growth, age of first reproduction, and fecundity. The knowledge grained from Leslie matrix models makes it a valuable tool for population ecology and in determining conservation efforts.

Mandy Monroe
Disorientation effect of artificial amber lights on loggerhead sea turtle (Caretta caretta) hatchlings
23 February 2009

Mentors: Dr. Mark Brenner and Dr. DuBose Griffin

Abstract: The loggerhead sea turtle (Caretta caretta) is a reptile species with federally threatened status in the United States (US).  Adult female loggerheads use coastal beaches of the southeastern states of the US every year from May to August for nesting.  They crawl to the dunes at night to lay a clutch eggs then use visual light cues and the downward slope of the dunes to navigate back to the sea.  Beginning in July, hatchling loggerheads emerge from the nests at night and use the same cues to find the ocean.  Both adult females and hatchlings are attracted to artificial light sources.  Light pollution in coastal areas with heavy human population contributes to hatchling disorientation and resultant mortality.  In order to promote cost effective light bulbs that limit hatchling disorientation due to artificial lighting, this study compared the sea-finding ability of hatchlings under two light treatments: a “turtle friendly” light-emitting diode (LED), and a control with no artificial light source.  Though data are limited and subject to confounding variables, Watson’s U2 test showed no significant difference between the sea-finding ability of hatchlings under the two light treatments.  However, qualitative observations showed that hatchlings under the “turtle friendly” amber LED treatment crawled in circles and up the slope of the dunes before choosing a direction while hatchlings under no artificial light headed towards the sea without hesitation.  These observations suggest that the amber LED is not completely “turtle friendly.”  Further data collection in future nesting seasons is warranted to strengthen this study.

Jennifer K. Donovan
Monoterpenes in Peppermint (Mentha piperita) Co-planted with Wine-cap Stropharia (Stropharia rugoso-annulata)
March 9, 2009

Mentor: Dr. Dean Kahl

Abstract: The practical and commercial value of peppermint (Mentha piperita) is determined by monoterpene composition in the peppermint oil. The monoterpene composition can be affected by several factors including the presence of other organisms. Peppermint and wine-cap Stropharia (Stropharia rugoso-annulata) were grown in pots in a growth chamber from September through October of 2008 in order to study whether co-planting would affect the plants and mushroom production. How many survived? Eleven of the twelve plants in the experimental group died. Three of the twelve plants in the peppermint control group, one in a pot contaminated by the Stopharia, also died. The fungi and water stress may have contributed to the fatalities. Liquid extracts were prepared from six fresh leaf pairs collected from surviving control plants. Samples were analyzed using gas chromatography-mass spectrometry, focusing on the presence of limonene, menthol, menthone, menthofuran and pulegone. An external calibration curve was used to measure the monoterpene concentrations in the samples. A total of 187 mushrooms were collected from 11 pots: one fungi control pot, one peppermint control pot and nine experimental pots. Peppermint extracts varied in monoterpene composition and concentration, though limonene was present in all samples. Monoterpene concentrations were consistent with those noted in other papers. Variation in monoterpene composition between leaf pairs was also consistent with other literature.

Chelsea Rae Maier
The Effect of Restraint Stress on Glucose and Thyroid Hormone Levels in Plasma of Alligator mississippiensis.
March 23, 2009

Mentors:  Dr Victoria Collins and Ashley Boggs

Abstract: Endocrine disrupting chemicals (EDC) disrupt regulation of hormones such as thyroid hormones (TH).  TH are important in glucose regulation in which they increase glucose uptake from the blood.  Epinephrine (E) and norepinephrine (NE) also participate in glucose transport by causing the release of glucose to the blood.  The effects that TH, E and NE have on glucose accessibility are necessary for survival in an emergency.  This study is part of a larger project addressing the interplay of hormones and EDCs; the data collected will identify normal levels of TH, NE, E, and glucose from juvenile Alligator mississippiensis in a low EDC exposure site.   Nine juvenile Alligator mississippiensis were caught from Orange Lake in Florida and blood samples were taken from each specimen at 0, 2, 4, and 8 minutes after capture during restraint.  TH and glucose levels will be measured at the University of Florida; E and NE will be measured at WWC after alumina extraction by high performance liquid chromatography with electrochemical detection.  An EG&G Princeton Applied Research Electrochemical Detector Model 400 with a Bioanalytical Systems dual glassy carbon electrode has been setup for this analysis. Calibration curves for NE, E, and an internal standard have been made with linear regression lines having high R2 values with an average relative standard deviation less than 5%.  The alumina extraction method is being optimized using dog blood samples.  The method can detect at concentration in pg/mL range which is 1000 times lower than expected values in alligator samples.  The data collected from this study are to be compared with alligators known to be exposed to EDCs.  The overall goal of the project is to indicate the ability of an Alligator mississippiensis to react appropriately in an emergency.

Kyle Fuller
Root-Knot Nematode (Meloidogyne sp.) Survival and Reproduction in Tall Fescue (Festuca arundinacea) Infected with Type AR542 Fungal Endophyte (Neotyphodium coenophialum)
March 30, 2009

Mentor: Dr. Victoria Collins

Tall fescue (Festuca arundinacea) grass harbors a fungal endophyte, Neotyphodium coenophialum, which may benefit the plant by providing resistance to parasites such as root-knot nematodes (Meloidogyne sp.). However, this fungal endophyte also causes fescue toxicosis, a disease that results in decreased weight gain and reproductive efficiency in grazing animals. The major alkaloid produced by the fungal endophyte, ergovaline, is believed to cause fescue toxicosis. A strain of fungus, known as AR542 or Max-Q, has been developed without the ergovaline alkaloid; however, it is unknown if this strain has retained the ability to provide nematode resistance. The objective of this study was to compare the biomass and number of root-knot nematodes in endophyte-free (E-), wild type  (E+), and Max-Q tall fescue. Twenty plants were grown in each of three treatments and inoculated with nematode eggs. After three months, the nematodes were cleaned from the roots and the eggs were counted.  No significant difference was found among the treatments for the number of nematodes (p=0.113) or the aboveground dry biomass (p=0.193). These results indicate that the ergovaline-free Max-Q endophyte does not affect root-knot nematodes or above ground biomass in a way that is different to the E+ endophyte. However, neither the E+ nor Max-Q endophyte treatments exhibited better nematode resistance than the E- control group.

Daniel McKenzie
Trait Perceptions of People with Disability as a Function of Participants Disability Status
March 30, 2009

Mentor: Dr. Martha Knight-Oakley

Abstract: People with disabilities suffer being labeled with a disability and the resulting stereotypes such as being dependent, incapable and deserving of pity. These stereotypes often lead people without disabilities to act in ways which are perceived as disrespectful or patronizing by people with disabilities. Based on research by Kleck and Strenta (1980), this research sought to determine how different are the perceptions between people with and without disabilities when viewing an interaction involving a person with a visible disability. Participants watched a short video interaction between a person with a disability and a person without a disability and rated the interactants on positive/negative traits, social activity preferences and friendship qualities. Multivariate analysis showed that the interactant without a disability was rated as more comfortable and cooperative than the interactant with a disability across all subjects (p<.05). The interactant with a disability was rated as more aggressive than the interactant without a disability across all participants (p<.01). A Chi-squared test.showed both groups said the interactant without a disability has more friends and an easier time making friends (p<.001). These results indicate that target’s disability status is more influential of the participant’s perceptions than the participants disability status.

Laura French
Analysis of Cis- and Trans- fatty acids by a combination of Silver Ion Thin Layer Chromatography and Gas Chromatography. 
April 6, 2009

Mentor: Dr. Victoria Collins

Abstract: Silver ion chromatography is a technique used to separate fatty acid mixtures. It is usually employed to separate mixtures of cis- double bonds, trans- double bonds, and saturated fatty acids. This project examined the effect of silver concentration on separation of these constituents.

Silica gel thin layer chromatography (TLC) plates were soaked in aqueous solutions of 5%, 10%, or 20% silver nitrate (w/v) with unsoaked blank plates. The plates were spotted with a 5:1 hexane:butter solution and developed in 90:10 ethyl acetate : methanol, and air dried. Triglycerides from the top and bottom halves of each plate  were then extracted with hexane, and derivatized into Fatty Acid Methyl Esters (FAMEs) for Gas Chromatography (GC) analysis.  Individual fatty acid components were identified using standards and their % areas compared between the top and bottom of each plate.

Palmitic acid (16:0) increased in the bottom relative to the top of plates as silver content increased. Arachidic acid (18:0), showed no effect of silver on the ratios of top and bottom % areas.  Linoleic acid (18:2 cis) acid increased in the bottom relative to the top of the plate as silver content increased.  A trans- fatty acid standard was also examined, but was not found in any of the butter samples.

This project showed successful results in the separation of cis- fatty acids from saturated fatty acids. However, it was a project fraught with issues including a difficult process to perfect and highly reduced sample sizes. Further examinations in this area are not recommended for the resources of Warren Wilson College.

Charles Bauman-Smith
Prevalence of Shiga-Like Toxin Producing Escherichia coli in Warren-Wilson Beef Cattle.
April 13, 2009

Mentor: Dr. Jeff Holmes

Abstract:  Escherichia coli is a pervasive microorganism found normally in humans and domesticated animals.  Some strains of E. coli contain genes that produce shiga toxins making them pathenogenic to humans.  Cattle have been shown to be a major reservoir for shiga toxin-producing E. coli (STEC). To test cow manure for the presence of STEC Polymerase Chain Reaction (PCR) can be employed.  The goals were to develop a positive control to test cow manure for Shiga toxin genes using PCR and to use PCR to detect a gene of known presence in Shigella flexneri.  Strains of Shigella were cultured overnight.  The cultures were diluted to various concentrations.  A sample of each dilution underwent DNA extraction.  Four different DNA extraction methods were used throughout the study.   Isolated DNA samples were run through 35 PCR cycles.  Gel Electrophoresis was used for DNA separation and identification.  All attempts to detect either the Shigella gene of known presence, or the positive control for Shiga toxin genes   yielded negative results.  Many variables involved in PCR can cause negative detection.  Further testing of variables is needed to optimize this study to produce detection of genes.    

Jackie Keating
A Potentiometric Evaluation of Groundwater and Surface Water from the Warren Wilson College Drainage Basin
April 13, 2009

Abstract: Potentiometric evaluations are used to compare the varying levels of water between two different hydrologic systems.  An evaluation such as this was used to compare the levels of surface water and groundwater from the Warren Wilson drainage basin.  The objective of this study was to use the compared data to define the specific hydrological relationship between the Warren Wilson surface water system and Warren Wilson groundwater system.
    Thirteen groundwater monitoring wells were installed along with four surface water stations along the Swannanoa River.  Data was collected from these sites over a continuous period of four months.  Surface water discharge measurements were also taken at each surface water station using a FlowTracker Acoustic Doppler Current Profiler.  Once the data collection period was complete a survey of all stations was conducted using a standard survey gun and rod.
    Elevation data was then used to create groundwater contour flow maps depicting the movement of water beneath the subsurface.  Groundwater hydrographs were also produced expressing the change of water level over time for each groundwater station.  Surface water discharge data was utilized in the production of rating curves for each surface water station.  The rating curve for each station was then used to produce individual rating tables and surface water hydrographs.
    The data presented by this research proves to be an important aspect of the Warren Wilson hydrologic cycle which should be continually studied.

Logan Jensen
Circadian pattern of response to UV radiation in sexually reproducing Chlamydomonas reinhardtii
April 20, 2009

Mentor: Dr. Michael Torres

Abstract: A circadian clock has been demonstrated to regulate a number of biological activities in the green algae, Chlamydomonas reinhartii, including a daily rhythm of sensitivity to ultraviolet radiation. Amongst asexually reproducing Chlamydomonas reinhartii populations, a daily oscillation in UV sensitivity of physiological activities has been shown to correlate with the G1/S phase of cell division. . In this species, sexual reproduction is triggered by unfavorable environmental conditions to produce a highly resilient zygospore that is more resistant to UV radiation.  This experiment tested whether a similar circadian pattern of sensitivity to ultraviolet radiation is characteristic of C. reinhardtii during its sexual life cycle.  C. reinhartii grown on a 12:12 light-dark cycle were exposed to five seconds of ultraviolet radiation at different intervals within a 24-hour period.  This period occurred during gametogenesis, when C. reinhartii cells transform from vegetative to sexually competent gametes.  Consecutive removal of nitrogen from the growth media and exposure of cultures to light were prerequisites for gametogenesis. The results of this study indicate that neither gametogenesis nor synchronous cell growth were achieved, both of which are essential for determining whether there is a circadian rhythm regulating response to UV radiation during the sexual life cycle Experimental evidence suggests that failure to produce gametes resulted from insufficient nitrogen removal from the media.  Additionally, use of TAP Media for synchronous cell growth was demonstrated to be ineffective.  

Amy Peddie
Nitrogen and Phosphorous Removal from Swine Effluent with Pleurotus ostreatus
April 20, 2009

Mentor: Dr. Mark Brenner

Abstract: Mycoremediation is the use of fungi in the decomposition of waste products or removal of harmful chemicals from the environment.  In this study mycofilters, fungi grown on a fibrous substrate, were used to verify the viability of Pleurotus ostreatus in the removal of nitrogen and phosphorous, in the form of ammonia and phosphate, from water collected from the Warren Wilson College pig pond.  Factory pig farms produce a large amount of animal waste which is treated, anaerobically, in lagoons.  Lagoon failure, as leaking or flooding my result in the contamination of aquifers and waterways by pig waste.

Two groups of filters were created, the treatment filter with Pleurotus ostreatus and the control group filters without.  Each group was treated with pond water which was then analyzed by UV/Vis. for ammonia using Nessler's reagent and phosphate using the Ascorbic Acid Method.  A Beer's law plot was used to determine the concentration of each nutrient in the water, after being exposed to the treatment or control filters.

Results from this study showed a significant difference between the amount of ammonia removed by the treatment and control filters.  No significant difference was observed for phosphate between the treatment filters and the control filters.  Many variables could be altered to increase the effectiveness of the treatment filters, such as using a more appropriate fungi, adding the pond water at a point of high nutrient uptake, or sterilizing the pond water.

Despite the success of the treatment filters in removing ammonia from the pond water, further research into the swine industry is necessary to determine the economic viability of this method in wastewater treatment.  Mycoremediation is a growing field which requires additional research into the specific uses of different species of fungi; this research would greatly aid the further success of this study.

Erica Howe
Evaluating Winter Cover Crops for use in the Warren Wilson College Garden, Swannanoa, North Carolina
April 27, 2009

Mentor: Karen Joslin

Abstract: One of the main focuses of sustainable agriculture is soil fertility.  One way to increase soil fertility is to plant cover crops. Cover crops are crops planted and grown but not harvested for human consumption; they act as living mulch.  Cover crops improve the soil by adding organic matter, increasing the water holding capacity, preventing soil erosion, adding nitrogen, suppressing weeds, and soil moisture conservation.  Other benefits of cover crops include reducing use of fertilizer costs, reducing the use of pesticides or herbicides, and protecting water quality.  To develop an effective cover crop system, it is necessary to find a species that is adapted to the local climate and latitude, can easily be killed, and does not compete with the cash crop.  The objective of this study was to investigate the biomass production, winterkill date, and effectiveness of weed suppression of three legumes, two grain, and one broadleaf cover crop for minimal tillage production in the Warren Wilson College Garden. Six winter crop and weed biomasses were collected on 3 November 2008, 13 October 2008, 1 December 2008, and 5 April 2009.  Average weights were calculated and graphed.  The results indicated that rapeseed oil radish produced the greatest amount of biomass and suppressed the most weeds, but decomposed quickly. The legumes produced the smallest amount of biomass and suppressed the least weeds in the fall. The grains acted similarly, resulting in the second greatest biomass production and weed suppression in the fall.  In order to accurately determine which crop to plant, more research is needed to look at growing patters over a number of winter seasons. A mixture of barley, oats, and spring field pea would meet the goals a substantial biomass, effective weed suppression, a late winterkill date, nitrogen fixation, and residual dead biomass in the spring.

Jesse Duff-Woodruff
Intraseasonal changes in breeding success of Piping Plovers on Long Island, New York beaches
April 27, 2009

Mentor: Dr. Louise Weber

Abstract: The beaches of Long Island, New York act as important breeding grounds for the Piping Plover(Charadrius melodus), yet human development of these beaches poses a considerable threat to the conservation of this listed species. Conservation management efforts must take into account the reproductive ecology of the species. We investigate how reproductive success and fecundity of the breeding population changes over the course of the breeding season. Data collected during breeding seasons starting from 1999 through 2008 by The Nature Conservancy on Long Island provide evidence that initial nesting attempts (first nests) exhibit the same fecundity and likelihood of success as attempts to replace a lost nest (renests); there were no significant differences between the two in terms of average clutch size (P = 0.55), hatching success (P = 0.58), or fledging success (P = 0.46). The data also suggest that nests that hatch earlier tend to feature a larger clutch size (P < 0.001) and hatch more eggs (P < 0.001). However, the number of chicks fledged from a nest was not associated with hatch date (P = 0.07). Research on other sites has suggested that more young fledge from nests that are laid earlier in the season. If so, we suggest that this may be more attributable to higher hatching success than to higher fledging success from amongst the chick population. Because of this intraseasonal decline in breeding capacity, likely due to greater challenges from human development and life history demands, the early part of the season is critical for breeding success and should be a priority for conservation management.
Nora Purcell

Eric Herrera
Shortnose Sturgeon: Development of a body weight estimate for conservation
May 4, 2009
Mentors: Dr. Louise M. Weber and James P. Henne (USFWS)

Abstract: The shortnose sturgeon is a federally endangered anadromous fish that inhabits waters along the eastern coast of North America. Declining populations of shortnose sturgeon in southeastern rivers are likely due to anthropogenic impacts. With little sign of recovery in many of these rivers, more information is needed concerning the biology of this species in its southern range. Sampling wild fish in the field often precludes the use of an accurate balance to measure fish weight.  Characterizing the general length-weight relationship of a fish species enables biologists to estimate fish size, condition, and sometimes other attributes of population dynamics from a single size measurement. Therefore the National Marine Fisheries Service (NMFS) has recently requested that morphological data be collected from a captive population of shortnose sturgeon held at the Bears Bluff National Fish Hatchery (Wadmalaw Island, SC), to acquire these length- weight relationships.  My objective was to develop an equation capable of predicting shortnose sturgeon weight from a single measurement of length and/or girth. In the spring of 2008, length, weight, and girth measurements were taken on 877 shortnose sturgeon from the Bears Bluff facility.  Least squares regression of log10 (Wt) vs. log10 (FL) produced the overall weight equation log10 (WT) = -6.2006 + (3.3927 × log10 (FL)).  Fulton’s condition factor (K) was calculated as K=W/FL3 for Bears Bluff shortnose sturgeon as well as wild populations of shortnose sturgeon from South Carolina and Hudson River, NY.  Dunn’s multiple comparisons test  found no significant difference between two groups; the Bears Bluff “middle” group and the wild population of South Carolina (P>0.05), providing the equation log10 (Wt) =  - 5.6154 + (3.1738 * log10 (FL)) that researchers can now use to determine weight for wild populations of South Carolina shortnose sturgeon.  This new equation could provide biologists with a faster and more accurate way to collect weight data in the field.  Given their endangered status, new information gained from this equation could aid in the conservation and survival of the shortnose sturgeon in South Carolina.   

Amy Rowlatt
Electrophoretic Variation of Malate Dehydrogenase in Lysimachia fraseri.
May 4, 2009

Mentor: Dr. Jeff Holmes

Abstract: Lysimachia fraseri (Fraser’s Yellow Loosestife) is a rare plant belonging to the Primulaceae (Primrose) family, endemic to the central and southeastern United States. North Carolina is home to the majority of the 86 confirmed extant populations nationwide. The cause of this species imperilment is unknown, but an understanding of the genetic variation among and between subpopulations of L.fraseri is essential for conservation. Using starch gel electrophoresis, the metabolic enzyme malate dehydrogenase (MDH), was analyzed for polymorphism among and between individuals from two groups of L. fraseri residing on the Warren Wilson College Campus. The enzymatic activity in leaf tissue from eighteen individuals from each of the potential sub populations was assayed. Results indicate that MDH is expressed from a minimum of two loci, one of which is polymorphic. Additionally, one of the two plots sampled expressed a unique phenotype, indicating the presence of greater genetic diversity within that plot. This suggests that the two groups of L. fraseri may have emerged as separate subpopulations of a larger metapopulation and may have been reproductively isolated for some time.

Helen Yurchenco
Influenza and cold contagion factors on the Warren Wilson campus
May 11, 2009

Mentor: Dr. John Brock

Abstract: Influenza and the common cold (upper respiratory infections, or URI’s) pose a significant economic burden on society as well as a physical and emotional burden on those who suffer from the illnesses.  Since influenza and the common cold are viral and thus cannot be cured by medication, a substantial need exists to understand the underlying causes of the spread of influenza and the common cold.  The objective of the study was the contagion factors that are associated with the risk of contracting a URI on the Warren Wilson campus.  The identification of contagion factors is a way to understand how URI’s spread.  A cross-sectional epidemiological survey was administered to the student body of Warren Wilson College on two days in February of 2009 during lunchtime.  The survey contained questions pertaining to general health, hygiene, residency, and perceived stress.  The results of the survey were tabulated.  Significance of each exposure was determined using 2-proportion z-tests or chi-square tests, depending on the number of possible responses to each question.  Age was found to be correlated with the risk of contraction of URI’s (p-value: <0.05).  Age grouped to compare ages 18-20 with ages 21-24+ was also significant (p-value: <0.01).  Also, cafeteria preference (p-value: <0.05), whether or not the respondent’s roommate was sick (p-value: <0.0001), as well as 4 perceived stress questions (p-values of all four: <0.05) were found to be correlated with risk of infection.  In contrast to previous studies, hand washing in association with bathroom use was found to increase the risk of contracting a viral URI (p-value: <0.05).  From this study, it appears that being a younger age is associated with an increased risk of contracting a URI.  This could be because younger students are more likely to have roommates than older students and are more likely to live in the more crowded dorms.  Also, cafeteria preference was associated, specifically, attending both cafeterias was associated with an increased risk, which could be because these students come into more contact with a greater number of students than those students who only use one cafeteria or neither.  Four of the nine perceived stress questions were linked to the risk of contracting a URI; each question was correlated with an almost doubled risk of contracting a URI, as evidenced by the risk ratios, which were all between 1.81 and 1.85.  Having a roommate who was sick was correlated with a greatly increased risk of contracting a URI; however, since not all respondents answered both questions pertaining to this result, the risk found may have been greater than would have been found if all respondents had answered both questions (1. Have you had a URI since September and 2. Has your roommate had a URI since September?).  

Lyn Rutherford
The Effectiveness of Baits Used in Minnow Traps for Crayfish Capture on the Warren Wilson College Campus
May 11, 2009

Mentor: Dr. Mark Brenner

Abstract: Crayfish, also called crawfish, crawdads, or mudbugs, are freshwater crustaceans closely related to lobsters. Despite their ecological importance as decomposers, predator, and prey, many issues threaten their rich diversity. Threats include: habitat destruction, pollution, and nonnative invasive crayfish, which threaten native crayfish by either out competing or hybridizing with them. To my knowledge, it seems that there is no consensus on which technique for crayfish capture is most effective. In this study I sought to test the effectiveness of four different baits as used in minnow traps. Twelve sites along Bull Creek and the Swannanoa River on the Warren Wilson College campus, NC, were set with minnow traps, which were baited randomly either with sardines and other fish pieces, catfood, a live crayfish, or no bait. After checking these traps every two days from February to April 2009, the mean numbers of crayfish caught by each treatment were compared using an ANOVA test. With a p-value of .0254 it was found that the sardine treatment differed significantly form the crayfish treatment. When comparing just the treatments as tested at the Bull Creek sites, a p-value of .0103 suggests that there was a significant difference between not only the sardine and crayfish treatment, but the sardine and control treatments as well. A comparison of the mean number of crayfish caught at the different sites was inconclusive despite the fact that the Swannanoa river sites caught no crayfish. This study thus concludes that dead fish is most likely the most effective bait of the four treatments. Due to the fact that so many crayfish could be caught in one trap at the same time it would seem also that they have little aversion to a baited trap that is already occupied. Choosing a reliable site greatly influences the effectiveness of the minnow trap no matter the bait used. Hopefully this knowledge can aid crayfish research in the future. Since threats posed to crayfish biodiversity are in urgent need of attention, researching and understanding species ranges and the nature of hybridization is essential.