The 15th Annual
NC State University
Undergraduate Research Symposium
Biological Sciences:
Zoology, Physiology,
Behavior, Neurobiology
Abstracts
Abstracts are listed in alphabetical order by the last name of the
corresponding author.
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Allmond, Jillian S. |
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Department(s): |
Zoology |
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Research |
John Godwin/Zoology Beth Hawkins/Zoology Gisele Passador-Gurgel/Zoology |
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Title of Presentation: |
Use of cDNA
Microarrays to Study Sexual Differentiation in Bluehead Wrasse |
Sexual differentiation is often controlled by
genetic expression and hormonal
regulation. Bluehead wrasses (Thalassoma bifasciatum)
make good models to study sexual differentiation because of their ability to
change sex over a relatively short period of time. When an aggressive
terminal phase male is lost, initial phase males or initial phase females may
undergo a role change or sex change respectively. In order to gain a
better understanding of the effects of altered gene expression on sexual differentiation, we will
be comparing RNAs from the three sexual phenotypes
and female-to-male sex changers using cDNA microarray technology. Microarrays
will be constructed using clones from a bluehead
wrasse cDNA library. Here we describe the steps
involved in the preparation of bluehead wrasse cDNA microarrays, RNA extraction,
hybridization procedures and statistical analyses. Completion of this
experiment will lead to a better understanding what genes are being expressed
in certain sexual phenotypes and during different stages of sex change.
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Bailey, Sean T. |
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Department(s): |
Zoology |
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Research |
Russell J. Borski/Zoology Christian K. Tipsmark/Zoology |
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Title of Presentation: |
Estrogen and Androgen Control
of Prolactin Release in a Teleost
Fish, the Tilapia (Oreochromis
mossambicus):
An Evaluation of Two Procedures for Analyses of Prolactin
Release In Vitro |
Prolactin has over 300 known functions in vertebrates, where
it plays prominent roles in controlling salt and water balance, reproduction
(parental behavior and lactation), immunity, development and growth. Discovering the factors that regulate its
activity is central to understanding how prolactin is
controlled under varied physiological states.
Although prolactin has known reproductive
actions in vertebrates, relatively little is known of the estrogenic and
androgenic control of prolactin secretion in teleosts. The
purpose of these studies was to assess the effects of two gonadal
steroids, estradiol-17B and testosterone, on prolactin
release from the rostral pars distalis
(RPD, prolactin cell region) portion of the pituitary
of the euryhaline teleost,
the tilapia (Oreochromis
mossambicus), in
vitro. We also compared two methods
for measures of prolactin release, radioimmunoassay
(RIA) and polyacrylamide gel electrophoresis (PAGE).
The RPDs were dissected from the pituitary and
incubated in a completely defined hyperosmotic media
(360mOsm, causes low baseline prolactin release) with
or without testosterone and estradiol-17B (10nM, 100nM, 1000nM) for 18
hours. We found that estradiol-17B
stimulates PRL release, at least at higher concentrations. The effects of
testosterone were more inconsistent, albeit a slight stimulation of prolactin release was observed in some cases. RIA and PAGE methods for measurement of prolactin release yielded similar results suggesting both
are valid for measures of prolactin secretion. It appears that gonadal
steroids influence prolactin release, suggesting they
may play a role in controlling prolactin cell
activity during reproduction in the tilapia.
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Caruth, Joseph E. |
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Department(s): |
Zoology |
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Research |
Harold Heatwole/Zoology |
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Title of Presentation: |
Myrmecological Behaviors
to Differing Food Source Sizes in the |
Ants are the great cleaners
and consumers of the natural environment. More so than any other animal, ants
are the dominant biomass of the majority of the world’s biomes. This study
attempts to discern the differences in the behaviors of naturally existing ant
species towards the different sizes of food found through foraging and feeding.
Different species of ants are of different sizes and have different foraging
strategies. Accordingly, within an
assemblage of many species, they may tap different resources. The present study was to investigate resource
partitioning among species by size of food item.
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Corbitt, Alexis C. |
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Department(s): |
Food Science |
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Research |
Jonathan Allen/Food
Science |
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Title of Presentation: |
Determination of Insulin
and Glucose Response to Sweet Potato and White Potato Cultivars Using ELIZA C-Peptide
Analysis |
Diabetes mellitus is one of
the most common chronic diseases. Characteristics of this disease occur
when the body’s cells cannot effectively respond to insulin. Through diet management,
exercise, self-testing of glucose and medication, diabetics can keep blood
glucose near normal. Many foods that have a low glycemic
index, like sweet potato, can help control blood glucose. An extract of a
Japanese sweet potato called Caiapo is sold as a
dietary supplement to control diabetes. C-peptides are released from the
pancreas along with insulin in response to glucose concentrations in the
blood. C-peptide level reveals the amount of insulin recently secreted by
the pancreas. The objective of our study was to measure the hormonal
response associated with glycemic index measurement
of sweet potato and Caiapo in comparison with the
more commonly consumed white potato. Our focus was on glucose, insulin and
C-peptide analysis in blood collected from subjects at 0, 60, and 120 minutes
after consumption of 50 g of carbohydrate from whole, flesh, or skin of sweet
potato, whole white potato, or white potato + Caiapo.
Comparing C-peptide quantities to the glucose standard illustrated the extent
to which the active ingredients of the sweet potato affects the glucose and
insulin response. Changes in blood C-peptide in response to each potato
sample were similar to the changes in blood glucose and insulin, suggesting
that the hypoglycemic mechanism is not increased glucose uptake by target
cells, or improved insulin binding to receptors, as previously proposed. The
variable C-peptide levels after consumption of sweet potato follows the change
in blood glucose, and lower glucose uptake may be the result of reduced
breakdown of sweet potato starch into glucose. This information will lead
to further understanding of preferred foods for diabetics to assist in keeping
blood glucose stable.
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Cunningham, Sarah S. |
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Department(s): |
Zoology |
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Research |
S.E. Dobrin/Zoology J.E. Hampton/Zoology J.L. Lubischer/Zoology Robert M. Grossfeld/Zoology |
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Title of Presentation: |
NAAG
Peptidase (Glutamate Carboxypeptidase) Activity of
Rat Optic Nerve Increases after Crush Injury |
N-acetylaspartylglutamate
(NAAG) is a neurotransmitter or neuromodulator
peptide in mammalian nervous system that can regulate the excitatory activity
of the amino acid glutamate at synapses. NAAG peptidase, aka glutamate carboxypeptidase (GCP), terminates NAAG’s
activity extracellularly by forming glutamate and N-acetylaspartate. Its inhibition protects nervous
tissue against neurodegenerative conditions generally attributed to excessive extracellular glutamate. Berger et al. suggested that
axonal release of NAAG and its hydrolysis might influence peripheral nerve
regeneration through an action on glial cells that
form the insulating myelin sheath. Indeed, we found that GCP activity
varies as predicted during degeneration and regeneration of mouse peripheral
(sciatic) nerve. Optic nerve is a central nerve that degenerates when
injured but that normally does not regenerate. We asked whether GCP
activity would be up-regulated after crush injury, as it is in sciatic nerve,
or would decrease as the nerve fibers progressively degenerated. To test
this, the left optic nerve of rats was crushed near the orbit and, one month
later, both optic nerves were isolated for assay of GCP activity or to examine
histological changes. Unilateral loss of the pupillary
constriction reflex indicated the effectiveness of nerve crush. As the crushed
optic nerve fibers degenerated histologically and the
girth of the nerve decreased, the nerve lost protein but not the ability to
hydrolyze NAAG; consequently GCP “activity” increased. Persistence of GCP
activity probably reflects survival of glial cells,
where the enzyme is localized, as the density of (glial)
cell nuclei was unchanged. If NAAG is an axon-glia
signaling agent in optic nerve fibers, then the loss of a source of NAAG as the
axons degenerate may compromise oligodendroglial cell
function, e.g. formation of myelin, and may contribute to the inability of
central nerve fibers to regenerate.
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Dixon, Elizabeth M. |
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Department(s): |
Biological Life Sciences
with Nutrition Concentration |
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Research |
Jonathan C. Allen/Food
Science |
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Title of Presentation: |
Use of Calcium Chloride
and Vitamin D in an Aqueous Sports Drink |
Our purpose is to explore
the interaction of calcium chloride and vitamin D in an aqueous sports drink
solution. Four levels of calcium chloride and four levels of
water-soluble vitamin D were added to flavored drinking water which was
administered to vitamin D-depleted female rats. A water-soluble vitamin
D/beta-lactoglobulin complex was spray-dried for use
in the drink solution. Vitamin D content of the additive was measured by
HPLC. All treatment groups were fed a vitamin D-deficient diet, and 2
control groups were fed regular AIN 96-G purified diet. Water intake and
weight were monitored throughout the study. After a 6 week treatment
period, bone and blood samples were collected and analyzed for calcium, vitamin
D, and physical measurements. Serum calcium, protein, and vitamin D
concentrations were measured by atomic absorption spectrophotometry,
refractive index and ELISA, respectively. After completion of the study,
measurable amounts of vitamin D were found within the deficient diet that had
been administered to the treatment groups. Based on group means of
physical measurements, differences among treatments were not apparent for bone
weight, length, thickness, ash and calcium content. Differences between
treatment groups were shown with the ELISA for vitamin D, but no apparent Ca
differences were shown with atomic absorption. The vitamin D present
within the diet may have promoted calcium uptake for adequate bone growth to
make up for the low levels of calcium in some treatment groups. Extra
water-soluble vitamin D in the drink solution increased vitamin D status within
the rats, but extra calcium in the drink solution did not significantly alter
calcium metabolism among treatment groups. Therefore, this study suggests
vitamin D allows rats to compensate for low calcium intake.
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Dorsch, Andrea M. |
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Department(s): |
Zoology |
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Research |
Robert M. Grossfeld/Zoology |
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Title of Presentation: |
Plan for Western Blot and RT-PCR
Analyses of NAAG Peptidase (Glutamate Carboxypeptidase)
Protein Levels and Transcription in Mammalian Nerves |
Western blot immunoassay and
quantitative real time polymerase chain reaction (RT-PCR) are essential techniques
for quantitating the amount of a protein of interest
and its coding messenger RNA, respectively.
We are interested in adapting these procedures for investigation of the
effect of injury on glutamate carboxypeptidase (GCP)
of rodent nerves. This enzyme catalyzes
hydrolysis of the abundant neuropeptide N-acetyl-aspartylglutamate (NAAG).
In so doing, it inactivates the peptide and forms glutamate, an
excitatory amino acid neurotransmitter.
NAAG and GCP have been proposed as important links in neuron-glia signaling relevant to development and regeneration of myelinated nerve fibers and in the deterioration of nerve
cells in animal models of a variety of neurodegenerative disorders. Western blotting and RT-PCR can provide
insight about whether changes in enzyme activity represent modulation of
existing enzyme or synthesis of additional enzyme and about factors that
regulate expression of the relevant gene in response to nerve injury. In Western Blotting, proteins in a tissue
extract are separated by polyacrylamide gel
electrophoresis and transferred to a nitrocellulose membrane for probing with
specific (“primary”) antibody raised against the protein of interest, in our
case a rabbit anti-GCP antibody from Zymed
Laboratories. The location of GCP protein
on the blot is detected and the amount quantitated by
then probing the blot with a tagged (“secondary”) antibody that recognizes the
immunoglobulin of the host in which the primary antibody was generated. The goat anti-rabbit IgG
antibody used for this purpose will have horseradish peroxidase
(HRP) covalently coupled to it as a “tag”, as that enzyme can be detected on
film at high sensitivity by enhanced chemiluminescence
of an HRP reaction product. In
quantitative RT-PCR, RNA tissue extracts are processed through multiple rounds
of PCR using oligonucleotide probes designed with
reference to published sequences of mammalian GCP cDNA
(GenBank Accession Number NM 016770). As the transcripts become labeled with the
dye SYBR Green, the amount of GCP mRNA will be monitored.
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Harris, Michael J. |
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Department(s): |
Zoology |
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Research |
John R. Godwin/Zoology |
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Title of Presentation: |
Neuropeptide and Dopaminergic
Signaling in the Brain of a Sex Changing Coral Reef Fish |
Dopamine (DA) and Arginine Vasotocin (AVT) are
important neural signaling molecules produced in many vertebrate species. Dopamine is a monoamine neurotransmitter
involved in many functions including sexual behavior, neural reward pathways,
and movement,. Arginine
vasotocin (AVT) stimulates water reabsorbtion
in the kidney, the of blood vessel dilation , and regulates sexual and
aggressive behavior in teleost fish and other
vertebrates. AVT plays a key role in
socially-mediated sex change in the bluehead wrasse (Thalassoma bifasciatum),
increasing in expression as females change sex to become territorial males This
project investigated potential interactions between the dopamine and AVT
systems using a new method for assessing protein expression in brain tissue.
Manipulations of the dopamine system can affect the occurrence of sex change in
a congener of the bluehead wrasse. Using immunocytochemistry, we treated brain samples with specific
antibodies for AVT or tyrosine hydroxylase (the
rate-limiting enzyme in dopamine synthesis ), then secondary antibodies
conjugated to near-infrared emitting dyes.
We detected and quantified labeling using a two-wavelength confocal laser scanner. We localized and quantified AVT and
tyrosine hydroxylase (TH) in key regions of the
hypothalamus and optical processing areas.
The data will be used to test for variations in tyrosine hydroxylase expression in the vicinity of AVT neurons, in
key sites of catecholamine synthesis, and in visual processing areas across
sexual phenotypes in this species.
Differences in tyrosine hydroxylase expression
across phenotypes, especially in the vicinity of AVT neurons, would be
consistent with the hypothesis that dopaminergic
signaling may influence sex change by directly or indirectly affecting AVT
neurons.
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Heinz, Heather M. |
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Department(s): |
Zoology |
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Research |
John R. Godwin/Zoology |
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Title of Presentation: |
Territorial Aggression in Bluehead Wrasse Social Hierarchies |
Field research is inherently
expensive and often limited to certain seasons of the year. By understanding the
degree of fidelity to wild behaviors in the laboratory, scientists may better
understand the utility of laboratory simulations of wild social structures. In
the wild, the coral reef fish Thalassoma bifasciatum displays
complex, clearly defined social dominance hierarchies based on sex and size. We
conducted laboratory studies aimed at testing the effects of different neural
signaling systems on aggressive behavior and comparing interactions in the
laboratory setting to those in the wild. Neurochemical
manipulations predicted to alter typical aggressive behavioral responses to
social stimuli did not produce consistent and statististically
significant changes in behavior.
Treatments included manipulating nitric oxide production via injection
of inhibitors and substrates and dopamine signaling via a receptor agonist and
antagonist. To compare social
interactions in laboratory and wild settings, we constructed social groups of
4-5 same-sex fish along a size gradient.
While the largest fish were dominant to smaller fish, we did not find
statistically significant differences in aggressive behavior between the
largest and second largest fish. Further, aggressive behaviors by the second
largest fish did not significantly increase when the largest fish was removed.
However, aggressive behaviors “received” by this newly-dominant fish showed a
decreasing trend as these fish became
dominant, consistent with Shapiro’s model of “received behavior” as a strong
cue in regulating sex change. Newly dominant fish also spent more time under
cover. There was some evidence that the diel cycle of
behavior seen in nature is maintained. Time of day affected chase frequency and this varied significantly
by sex. No courtship behavior was observed. Small sample sizes may have influenced
results and these will be increased. Field studies will be conducted for
comparison during May-June at the Glover's Reef Marine Research Station in
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Kim, Okwha |
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Department(s): |
Biological Sciences |
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Research |
Harold F. Heatwole/Zoology |
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Title of Presentation: |
Foraging Behavior of Ants
at Different Elevation |
Foraging behavior of
different ant species was observed in the forest surrounding Yates Mill
Pond. Sardine baits were placed at each station with numbered ribbon at
10m intervals – continuing through 100m. At each interval, the baits were
placed on the ground in the open, at the base of the tree near the ribbon, and
up on the trunk of that tree. Observation was made for approximately 30
minutes after placing baits. Observed ants around the bait were then
categorized into five different groups, according to foraging behavior:
foraging in the area, feeding, feeding and carrying, attempting, or mobilizing. Finally,
one ant of each species from each location was collected for
identification. From these data, comparison was made of the foraging
strategy of the various species. There were two separate assemblages, one
foraging on the ground and the other in trees. They met at the base of
trees and species with equivalent strategies fought over food.
Within an assemblage species engaged in combat over food
and the species were ranked according to which won or lost these
engagements. The assemblage was described into the numbers and kinds of
strategies exhibited.
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Loftin, Patrick G. Shepard, Nathan A. |
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Department(s): |
Zoology |
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Research |
Harold F. Heatwole/Zoology |
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Title of Presentation: |
Coevolution of Toxicity of Venom in Venomous Snakes and the
Resistance to Venom by Prey |
Effects of venom from two
vipers, the cottonmouth (Agkistrodon piscivorus piscivorus)
and the copperhead (Agkistrodon contortix contortix),
were studied to determine their effects, in varying concentrations, on
different ages and tissues in bullfrogs (Rana catesbeiana). The preparation of the study
tissues provided a means to learn many laboratory techniques, such as mounting,
sectioning, and staining tissues for microscopic observation. A chance to
learn the histology of envenomated and control
tissues was also afforded. The envenomated
bullfrog tissues were compared in order to assess the relative toxicity of the
vipers’ venom and the bullfrogs’ resistance to that venom. Since
cottonmouths and copperheads feed on bullfrogs in different intensities, it is
believed that coevolution will be shown in this
relationship as well. Tadpoles were the most sensitive to venom, with
resistance rising drastically during metamorphosis. Adult frogs showed a
decrease in venom resistance, but it was still at a higher level than the
tadpole resistance. Cottonmouth venom proved most lethal, with all test
juvenile and adult bullfrogs dying at all concentrations of injected venom, while
copperhead venom showed lethality only in some adults in concentrations of 200
mg/g body wt) or higher.
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Mayer, Matthew K. |
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Department(s): |
Entomology |
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Research |
David R. Tarpy/Entomology |
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Title of Presentation: |
The Effect of Weight on
the Outcomes of Queen Bee Fights |
In a honey bee colony Apis mellifera, a
single reproductive female, the queen bee, is the mother to all nestmates within the hive.
When a queen is removed from a hive, usually by the process of swarming,
the workers raise a dozen daughter queens from the existing larvae. When the virgin queens emerge, a series of
fights ensues, ending ultimately with one queen as the heiress to the throne. The purpose of this study was to determine
whether or not queen weight has any bearing upon the outcomes of queen
fights. Queens were paired in such a
manner so as to maximize weight differences between them, and then each pair
was observed within individual queen fighting arenas. No evidence was found to suggest that weight
strongly influenced the outcomes of queen fights. As a result, it is likely that other factors
such as worker-queen interactions play a more influential role in deciding which
daughter queen will become the heiress to a colony.
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Messenger, Kevin R. |
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Department(s): |
Zoology |
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Research |
Harold F. Heatwole/Zoology |
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Title of Presentation: |
The Biodiversity and
Movement Patterns of Snakes in the |
The Carolina Sandhills National Wildlife Refuge in
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O'Donoghue, Caitlin A. |
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Department(s): |
Zoology |
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Research |
Harold Heatwole/Zoology
Betty Black/Zoology |
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Title of Presentation: |
Physiological Changes in
the Tissue of Envenomated Tadpoles |
Coevolution occurs between predator and prey. At different life stages, different methods are necessary to defend against the predators present during that life stage. For example, a tadpole would have to have defense mechanisms to deal with aquatic predators, while an adult frog would have to defend against terrestrial predators. I wanted to examine whether tadpoles would change in their resistance to specific as they shifted from an aquatic to a terrestrial environment during metamorphosis. I used histology to examine tissues from various organs of envenomated tadpoles to see what changes occurred as a result, if any, upon envenomation.
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Rankin, Susanna K. |
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Department(s): |
Zoology |
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Research |
John Godwin/Zoology James Gilliam/Zoology |
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Title of Presentation: |
Domestication and Genetic
Contributions to Anxiety-related Behaviors in Danio
rerio (Zebrafish) |
In recent years the zebrafish (Danio rerio) has become an important biomedical research model. Because
of this focus and the genetic tools that are being developed for this species,
we are using this zebrafish to assess genetic and
environmental contributions to the display of anxiety-related behaviors and
differences between wild- and domestic-derived stocks. Research in this model
organism could lead to a better understanding of mood disorders in humans and
advances in aquaculture where stress-responsiveness impacts growth and disease
resistance. In this study, we tested lab-reared zebrafish
derived from two stocks (a wild stock from
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Rueda, Caroline M. |
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Department(s): |
Food Science |
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Research |
Jonathan Allen/Food
Science Gary Matsey/Food
Science |
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Title of Presentation: |
The Determination of
Under-reporting and Over-reporting and Focus Group Evaluation of an Internet-Based
Diet Analysis Program by Middle School Students |
Objective: To identify the
incidence of under-reporting and over-reporting of diet by middle school
students using a proprietary internet-based diet analysis program and determine
its potential for recording their diet and physical activity. Design:
Fifty-three students (ages 11-17) were recruited for focus group analysis
regarding the design, effectiveness, and usefulness of an online diet analysis
program. Eleven of the students (ages 12-14) recorded a 3-day diet record and
completed a physical activity survey using the program. The resulting data
included analysis of under-reporting (
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Selgrade, Brian |
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Department(s): |
Biological Sciences |
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Research |
Peter L. Mente/Biomedical Engineering |
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Title of Presentation: |
The Relationship between Surface
Cracking in Impacted Cartilage and Impact Direction |
More than 20 million
Americans currently have osteoarthritis, and that number will rise greatly as
the majority of the population ages. One major risk factor for osteoarthritis
is a previous impact injury to the arthritic joint. An important part of the mechanism that leads
from injurious impact to the damaged cartilage associated with osteoarthritis
is the degradation of type II collagen, which forms much of the extracellular matrix in cartilage. While orientation of
collagen strands in most of the matrix tend to be random, collagen strands at
the cartilage surface run in relatively the same direction. In this study, porcine cartilage explants
were impacted and surface cracking – an indicator of collagen damage – was
measured. Impact forces were applied in
three different directions: normal to the cartilage surface, in longitudinal
shear across the length of the surface, and as radial shear force across the
width of the surface. While longitudinal shear impactions produced the most
cracking, they also had the largest area of contact and, thus, caused fewer
cracks relative to the area of the damaged
surface than normal
impactions did. These results suggest
that normal impacts may cause more damage to collagen on the cartilage surface
than longitudinal shear impacts if applied over equal areas. Radial shear
produced low levels of cracking, but one of the radial impactions was applied
with a very low force compared to the others, likely skewing results. If the
radial impact results are correct, they would suggest that cartilage has more
strength in the radial direction than longitudinally. However, a study with
larger sample size is necessary to confirm these findings.
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Sherman, J.A. |
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Department(s): |
Zoology |
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Research |
Robert M.Grossfeld/Zoology S.E. Dobrin/Zoology J.L. Lubischer/Zoology A.K. Murashov/Physiology,
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Title of Presentation: |
NAAG Peptidase (Glutamate Carboxypeptidase) Activity is Developmentally Regulated
in Rat Optic and Sciatic Nerves and Increases after Crush
Injury of Sciatic Nerve |
N-acetylaspartylglutamate
(NAAG) is the most abundant neurotransmitter peptide in mammalian central nervous
system. It is present throughout brain and spinal cord, and in peripheral
nerves, e.g. sciatic nerve, and in central nerves, e.g. optic nerve, from which
it is released by physiological stimulation. It can activate neuronal
receptors for the amino acid glutamate, the major excitatory chemical
transmitter in mammalian brain. In low doses, NAAG protects neurons from
excessive stimulation by glutamate, but in high doses it is a source of
excessive glutamate that may contribute to neurodegenerative disorders.
The enzyme responsible for the hydrolysis of NAAG is known as glutamate carboxypeptidase (GCP), or more generally as NAAG
peptidase. This membrane-bound glial ectoenzyme forms glutamate and N-acetylaspartate
in the extracellular space. Since NAAG appears
to be a primary chemical signaling agent between axons and glia
in crayfish nerve, we are interested to determine whether it has a similar
function in mammalian nerve. As a first step, we investigated whether GCP
is present in rodent sciatic and optic nerves and if its activity is modulated
during development or after nerve injury. We measured GCP activity as the
formation of radioactive glutamate from radiolabeled
NAAG. We found that GCP activity in rat sciatic and optic nerves is
developmentally regulated, with the greatest activity during the first 2
postnatal weeks. Crush injury of adult mouse sciatic nerves results in an
up-regulation of GCP activity during the ensuing 2 weeks post-crush and then a
down-regulation, corresponding roughly in time with morphological and
behavioral measures of nerve degeneration and regeneration, respectively.
These results are consistent with the possible role of NAAG and GCP in axon-glia signaling relevant to glial
cell myelination and remyelination
of mammalian peripheral nerve fibers.
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Szwagiel, Jaclynn Possiel, Erin |
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Department(s): |
Entomology |
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Research |
Fred Gould/Entomology |
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Title of Presentation: |
A Genetic Basis for Differences
in Larval Coloration Patterns between Heliothis virescens and Heliothis subflexa |
Heliothis virescens and Heliothis subflexa are closely related moth species which, as
adults, look almost identical. As larvae, however, they can be distinguished by
the trained eye. This study examines the genetic basis for differences in
larval coloration patterns between H. virescens and H. subflexa. To
differentiate between the two species, a scaling rubric was created to grade
the following specific traits: Midline, Midline Strength, Dorsal Band, Lateral
Line, Deepness of Red, and Overall Color. An F1 cross of the 2 species was
followed by a backcross to H. virescens and 88 offspring from the backcross were
photographed, graded phenotypically, and then
analyzed genotypically using AFLP markers. It was
found that three chromosomes (C15, C22, and C27) out of the moths’ 31 are
responsible for Midline coloration. Chromosome C16 is responsible for the
Midline Strength trait, while C03, C08, and C22 are responsible for the Dorsal
Band trait. C11, C15, C17, and C23 were found to control the intensity of the
Lateral Line, and C10, C11, and C14, control the Deepness of Red. A BC3 was
later examined to confirm findings in BC1. Though similarities were found,
small sample size of 50
individuals proved to be a
disadvantage.
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Welsh, Laura E. |
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Department(s): |
Zoology |
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Research |
Marianne Niedzlek-Feaver/Zoology |
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Title of Presentation: |
A Non-Invasive Technique
for Administering Endocrine-Disrupting Chemicals (EDCs)
to American Bird Grasshoppers |
There is a growing body of
evidence suggesting that leakage of certain synthetic chemical compounds into
the environment disrupts normal endocrine function in animals and humans.
Invertebrates have been shown to be useful for studying the effects of
endocrine-disrupting chemicals (EDCs). However, there
have been few studies where EDCs were administered
orally to terrestrial invertebrates. The current experiment is a preliminary
attempt to develop a reproducible yet non-invasive technique for administering EDCs to grasshoppers throughout their life span so that the
suitability of these animals as bioassay organisms for such compounds can be
determined.
A starting population of 30 male and 37 female nymph and
adult (4th to 7th instar) Schistocerca americana were fed 16 micro liters of a
progesterone solution (5 mg/mL in 95% ethanol) per
0.04g of grass leaf, once a week for 4 weeks. Grasshoppers were fasted on bran
and/or alfalfa at least 48 hrs prior to administering hormone. A control group
consisting of 22 grasshoppers (mixed male and female) were fed a solution of
95% ethanol. Both solutions were micropippetted onto
the leaf and left to dry. The average percentage of grasshoppers who ate at
least 1 leaf versus those who did not eat anything was 0.40 for experimental
males, 0.43 for experimental females and 0.37 for controls. The number of
deaths for the experimental group consisted of 3 males and 1 female. In the
control group there were 2 male and 2 female deaths. Deaths appeared to occur
during or right after molting for experimental males.
While it has been shown that Schistocerca
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Willis. Rebekah
S. |
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Department(s): |
Animal Science |
|
Research |
Sarah L. Ash/Food Science |
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Title of Presentation: |
Nutrition Students and
Changes in Their Health Habits |
Secondary education is
geared toward improving the lives of the individuals enrolled. It would be expected that someone in an
introductory nutrition course would apply the knowledge gained to his/her own
situation because such nutrition courses are meant to instruct on how “a better
lifestyle improves your health and well-being”.
The purpose of the research was: to see if education in nutrition
changed the daily habits and nutrition-related attitudes of students enrolled
in an introductory level nutrition course (NTR 301). Two anonymous surveys were designed. The first survey consisted of eighteen
questions pertaining to eating habits, exercising, and views on dieting. The second survey asked the same eighteen
questions as well as a few more in-depth questions about the change in
consumption frequency for specific nutrients and food groups. Exemption from the IRB council to use a human
model was applied for and received. These
surveys were then examined together to determine if a change in frequency
occurred and in what areas. No surveys
were excluded on the basis of any criteria.
There were a limited number of significant changes in daily dietary
habits, so that it can be assumed that such classes have little or no
effect. Some of the interesting findings
were an increase in the percentage of people who said that they did not
exercise at all and an increase in the number of people who considered a food
label before deciding on a product was found.
Other results as well as potential sources of error and limitation in
survey and questionnaire design will be presented.
- Biological Sciences abstracts
Applied Sciences (Crop, Poultry, Animal, and Horticultural Sciences)
Ecology, Environmental, Conservation, Botanical
Molecular, Biochemical, Genetics, Cell Biology
Zoology, Physiology, Behavior, Neurobiology
- Engineering
& Technology abstracts
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Social Sciences, Psychology abstracts
- Physical and Mathematical Sciences
abstracts
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