The 6th
Annual
NC
Undergraduate
Summer Research Symposium
Undergraduate Research
Awards and
Undergraduate Summer
Enrichment Awards
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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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Zoology |
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Research |
John Godwin/Zoology Gisele Passador-Gurgel/Zoology |
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Title of Presentation: |
Use of cDNA
Microarray Technology to Study Sexual
Differentiation of the Brain in the Bluehead Wrasse |
Sexual differentiation is often controlled by genetic
expression and hormonal regulation. Bluehead wrasses
(Thalassoma bifasciatum)
made good models to study sexual differentiation because of their ability to
change sex over relatively short periods 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 altered gene expression patterns underlying this pattern of sexual
differentiation, we compared RNAs from two sexual
phenotypes using cDNA microarrays.
Experiments included 18 independent hybridizations comparisons of a TP male
with a female. Each comparison experiment included RNA extractions from each
brain (9 TP males and 9 females), RNA amplification and labeling, and then heterologous hybridizations on the arrays (heterologous because we are using arrays constructed from
the closely related Astatotilapia buroni).
Following hybridization, the arrays were scanned and the images were processed
using ScanAlyze. Data will be analyzed using two
sequential ANOVA models to rigorously identify differentially expressed genes.
The results obtained from this project will lead to a better understanding of
gene expression in the brain and the role those genes play in the sexual
differentiation of the bluehead wrasse. This project
also further validates the usefulness of heterologous
hybridizations.
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Brancato, Jessica |
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Home
Institution: |
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Program: |
Undergraduate Research Awards and Summer Enrichment
Awards |
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College: |
Textiles |
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Department(s): |
Textile Engineering Chemistry and Science |
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Research |
Richard Kotek/Textile Engineering Chemistry and Science Marjan Abassi/Textile
Engineering and Fiber Chemistry and Science |
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Title of
Presentation: |
Self-Crimped Eco-friendly
Fibers |
Companies desire to produce products more efficiently
at the lowest cost possible while still maintaining a quality product.
Many things can factor into the cost of making a product such as energy
consumption, cost of materials, and availability for these materials, just to
name a few. Plastic bottles or plastic food storage
containers, mainly made from polyethelene terephthalate, or better known as PET, are commonly
available. We are taking these everyday items that have been recycled and
making them into fibers that can be used in a variety of different
products. The properties of recycled PET are not sufficient to produce a
usable fiber; therefore the recycled PET must be combined with additional
fibers using a bicomponent machine. In this
process it was also discovered that the properties of the different PET fibers
made the fiber crimp under tension. This also helps keep the costs down
when manufacturing the fiber and keeps the degradation of the fiber to a
minimum.
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Cooke, Natalie K. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Biochemistry and Chemistry |
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Research |
Pat Estes/Genetics |
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Title of Presentation: |
Genetic Control of Glial Development in the Central Nervous System of Drosophila melanogaster |
We study development of midline cells within the
central nervous system (CNS) of the fruit fly, Drosophila melanogaster. Midline cells separate
the two symmetrical sides of the CNS and serve as a guidepost for developing
lateral CNS axons. Previous experiments in our lab led to the identification of
regulatory sequences of a gene, CG11206, expressed in the midline and lateral
CNS glia and located on the second chromosome in Drosophila. Currently, this is only a
computed gene in Drosophila and it
has not been characterized. Our goal is to identify and structurally define the
transcripts of CG11026, using Northern analysis. For this, total embryonic RNA
of wild type flies was run on an agarose gel and then
transferred to a positively charged nylon membrane by means of downward
Northern blot transfer. To detect the CG11206 transcript, probes were made that
span the region of the genome predicted to contain the gene. The probes were
generated using the polymerase chain reaction (PCR) with primers corresponding
to various CG11206 regions and then biotinylated. To
detect the transcripts, the biotinylated probe was
then denatured and hybridized to the Northern blot. Visualization of the
hybridized probe is made possible by a chemiluminescent
reaction between the binding of streptavidin-alkaline
phosphatase conjugate and biotin when exposed to
film. Results of the size and amount of RNA and conclusions made about the
characterization of the transcript will be shown. These experiments will
identify the structure of the CG11206 transcript. We can then use in situ
hybridization to compare its expression with the expression pattern of the
reporter gene. Ultimately, we will generate mutations in the gene to determine
its function in CNS glia. These experiments will lead
to a greater understanding of this gene and its role in the development of Drosophila CNS.
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Davis, Rachel L.T. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
Textiles |
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Department(s): |
Textile
Engineering, Chemistry, and Sciences |
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Research |
Hyun S. Whang/Textile
Engineering, Chemistry, and Sciences |
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Title of Presentation: |
Surface
Modification of Poly(vinyl alcohol) with onochlorotriazynyl-β-cyclodextrin
for the Controlled Release of Fragrance |
The purpose of this research is surface modification
of poly(vinyl alcohol) (PVA) film with Monochlorotriazynyl-
β-CD (MCT-β-CD). The MCT-surface
modified PVA film has applications for controlled release of additives such as
fragrance or antimicrobial agents. Cyclodextrins
(CDs) are cyclic oligosaccharides having a truncated conical shape with a
hollow interior. CDs have polar, hydrophilic exteriors and hydrophobic
interiors, making them soluble in water and able to form non-covalently
inclusion complexes (ICs) with a variety of guest molecules in their interiors.
MCT-β-CD
is the first reactive CD derivative for modification onto polymer surfaces such
as natural and synthetic fibers. PVA was cast as a film and then treated with
MCT solution via a modified pad-dry-cure process. The fixation of MCT onto the
PVA film surface was verified from a peak at about 1574 cm-1 as a
characteristic of conjugated cyclic >C=N using Attenuated Total Reflectance
(ATR). Four parameters (curing temperature, curing time, pH, and concentration
of MCT) influencing the amount of MCT-β-CD bonded to the PVA film surface were
investigated and the fixed concentration of the MCT was measured using an
elemental analysis. The results show that curing temperature and pH have the
significant influence on the fixation yield of MCT onto the PVA film. The MCT
bonded PVA film was immersed in a solution containing lemon oil as a fragrance
for the formation of inclusion complex between the lemon oil and the MCT. We
then used a UV reflectance spectrophotometer to confirm that lemon oil is
included as a guest inside the host MCT cavities. Controlled release
characteristics of lemon oil from the PVA film surface were examined using Thermogravimetric analysis (TGA).
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Downen, Lori N. Kong, Michelle H. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
Engineering
and Technology |
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Department(s): |
Nuclear
Engineering |
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Research |
Mohamed Bourham/
Nuclear Engineering |
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Title of Presentation: |
Application
of a Capacitive Model to an Atmospherically-Generated Plasma During Treatment
of Polydimethylsiloxane |
Polydimethylsiloxane (PDMS) is becoming a widely
used, silicone-based material for various applications due to its unique
chemical and mechanical properties. These applications include use in microfluid devices, tissue engineering, and artificial
replacements. In previous work, researchers crosslinked
PDMS to spin-coated specimens and then exposed the samples to radio-frequency
and microwave, oxygen vacuum plasmas. This research showed that the oxygen
plasma helped form smooth oxidized surface layers on the samples. In this
research, atmospherically-generated plasmas replace vacuum plasmas for higher
productivity and elimination of vacuum systems. Plasma is generated in a helium
atmosphere, oxidized with up to 2% oxygen, and samples of PDMS are exposed to
the plasma for different time intervals. Exposed samples are weighed, pre- and
post-plasma exposure, to determine weight changes. Various analytical
techniques are used to investigate the surface morphology, surface composition,
and elemental structure of the samples as well as the effect of plasma species
on the substrate, and contact angle measurements to determine the sample’s hydrophobicity. The electron number density and electron
temperature characterize plasma, and these parameters can change when a
substrate is inserted into the plasma. A mathematical model was devised for the
plasma device in which measured voltage, current, and gas temperature are used
to solve for electron number density with a variety of gas mixtures, as well as
with and without substrates. Data analysis using the measurements and the
developed mathematical model indicates changes in electron number density when
changing plasma gas mixture or when changing the substrate. Analysis of the
plasma gas temperature inside the test cell indicates slight temperature
distribution from the center of the cell towards the cell walls.
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Fuchs, Stephen M. Lowder, Casey D. Pan, Diana Lomax, Aaron W. Galvăo, Rafaelo M. |
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Home Institution: |
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Program: |
Undergraduate Research Awards
and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Biological
Sciences Biological
Sciences Microbiology Biological
Sciences Plant
Biology |
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Research |
Wendy Boss/Plant Biology |
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Title of Presentation: |
Transgenic
Arabidopsis thaliana Overexpressing UbDKγ4 Displays an Altered Unfolded
Protein Response |
Ubiquitin-like domain kinase γ4 (UbDKγ4) is one of many genes
up-regulated during the unfolded protein response (UPR) in Arabidopsis thaliana. UPR is a signaling mechanism activated to
protect eukaryotic cells against the accumulation of unfolded proteins, which
can be caused by environmental stresses and chemical agents. UbDKγ4 encodes a protein kinase that interacts in
vitro with proteins involved in controlled protein degradation. In order to
investigate the role of UbDKγ4 in
vivo, we generated transgenic Arabdopsis thaliana
plants that over-express UbDKγ4-derived peptides. Homozygous transgenic
plants were selected, mRNA encoded by the transgene
was detected using RT-PCR, and protein production was confirmed using immunoblotting. Our hypothesis was that these plants would
have altered UPR and therefore would be more susceptible to the accumulation of
unfolded proteins. To test our hypothesis we exposed control and transgenic
plants to Tunicamycin (Tm), an antibiotic that
promotes buildup of unfolded proteins. Control and transgenic seeds were
germinated in Tm-containing medium and then transferred to Tm-free medium.
Recovery of growth and development was monitored over time and recorded. We
found that the transgenic plants recovered slower compared to the control
plants. Our observation indicates that the over-expression of
UbDKγ4-derived peptides in transgenic plants decreased their ability to
degrade misfolded proteins which resulted in
hypersensitivity to the accumulation of unfolded protein.
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Hill, E. Nicole |
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Home Institution: |
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Program: |
Undergraduate Research Awards
and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Biological
and Agricultural Engineering |
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Research |
Mari S. Chinn/Biological and Agricultural
Engineering |
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Title of Presentation: |
Sweet
Sorghum as an Alternative Farm-Produced Biomass for |
The rising need for biofuels
and other biobased products in our country has
provided farmers with a great opportunity to benefit from farm-produced biomass.
For the southeast region, particularly North Carolina, a crop other than corn
needs to be established that is 1) is well suited to the region’s soils and
climate; 2) provides relatively high production of easy to process, directly
fermentable aqueous sugar; 3) unlike corn and other cellulosic
crops does not require complex conversion of starch, lignin, cellulose, and/or hemicellulose; and 4) can be a feedstock for production of
high priority building block chemicals.
Thus, sweet sorghum is being investigated because of its reduced steps
and inputs required for complete conversion to ethanol, adaptability to
temperate regions, high drought tolerance, and high photosynthetic efficiency
making it easier to grow and sustain in NC. The objective of this project was
to examine the fermentation process during conversion of fresh, frozen and
previously concentrated sweet sorghum juice. The effects of pH level (natural,
5.0 and 4.5), yeast type (Ethanol Red and Dry Alcohol), incubation time and
sterilization were investigated on the fresh sorghum juice. Brix
readings, ethanol and individual sugar concentrations (sucrose, fructose and
glucose) were measured over time. The
main and interaction effects of yeast type and pH were not statistically
different under lab conditions. Experiments using sterilized fresh sorghum
juice stocks contained initial sugar concentrations of 50% w/w sucrose, 24% w/w
glucose, 26% w/w fructose, which decreased over time with yeast input. Ethanol
concentration increased over time resulting in 7.85% v/v ethanol and 81% of
theoretical maximum ethanol production within 3 days. Cultures grown on diluted syrup did not
demonstrate any signs of metabolic activity over a 5 day period. Overall, sweet sorghum juice is capable of
supporting yeast fermentation with minimal input, making it a suitable
substrate for development of on-farm ethanol conversion.
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Hoffman, Torissa J. Ohja, Saytajeet Stevens, Derrick |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
PAMS |
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Department(s): |
Mathematical
and Physical Science Textile
Engineering |
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Research |
Laura Clarke/Physics Russell Gorga/Physics |
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Title of Presentation: |
Construction
and Characterization of Fibrous Mats of Chitosan |
Chitosan is highly biocompatible
polymer that is made from the processing of chitin, a naturally formed material
that is found in crustacean shells. Recently, much interest has been generated
in the use of chitosan as tissue scaffolds. One
strategy to make artificial tissue scaffolds that have comparable porosity and
fiber size as mammalian extracellular matrices (ECM)
is to electrospin chitosan
into fibrous mats. Morophology is important, but
other physical parameters such as electrical properties may also be imperative.
The natural materials of the ECM have some innate conductivity, as does chitosan. Electrical properties are also important for
functional tissue engineering, where mechanical or electrical signals are used
to manipulate the cells. The proposed mechanism of conduction in chitosan is the protonation of
amine groups in the backbone to form mobile hydroxyl ions when exposed to
water. This increase in conductivity occurs as the polymer swells. We use chitosan with a lower molecular weight, electrospun
into fibrous mats, than the films previously measured. We observe that the
conductivity increase upon wetting is smaller than previously reported. This
may occur if the fibers have a higher crystallinity
than films, which would therefore lower the conductivity by decreasing their
ability to swell. Another explanation could be that our samples were a lower
molecular weight then the ones previously measured. We observed that the
morphology of mat changes after swelling has occurred. In particular, we
observed changes in the porosity and a disassociation of the mats. More
research needs to be done to find the exact reason for the smaller increase in
conductivity.
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Metzler, Tria M. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Animal
Science |
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Research |
Chris M. Ashwell/Poultry
Science |
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Title of Presentation: |
Differences
in Aorta Tissue Gene Expression between Atherosclerosis-susceptible and
Atherosclerotic-resistant Pigeon Lines |
Atherosclerosis, a chronic inflammatory response in
arterial walls to the deposition of lipoproteins, is one of the leading causes
of death in the
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Overton, Matthew H. Sepulveda, Jennifer |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Biochemistry
Microbiology
Chemistry |
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Research |
Stefan
Franzen/Chemistry Richard
Guenther/Plant Pathology Steve
Lommel/Plant Pathology |
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Title of Presentation: |
Uptake
of RCNMV-Peptide Conjugates in Cancer Cells |
Selective and specific delivery of cytotoxic compounds to cancerous cells is the goal for next
generation cancer treatment. One way to selectively deliver cytotoxic
compounds is to load them in a nanoparticle that has
been engineered to target only cancererous cells.
This research seeks to investigate the interactions between human cancer cells
and a novel plant virus nanoparticle that has been
modified to bind to specific cell types. These nanoparticles
are constructed by chemically attaching to Red Clover Necrotic Mosaic Virus
multiple copies of fluoroscein-labeled peptides that
bind to surface receptors on the cancer cell. Different lines of cancer cells
are known to over express certain receptors on their outer membranes that
healthy cells do not. This over expression acts as a potentially useful target
when developing methods of cancer treatment. Because certain peptides are able
to attach to these membrane receptors, they are easily taken into the cell. In
this study two localization signal peptides, one that binds to the CD46
receptor and the other that binds to the HER-2 receptor, were tested on how
well they were internalized into HeLa and MCF-7 cell
lines. The cellular uptake of the viral nanoparticles
is monitored using fluorescence activated cell sorting (FACS) flow cytometry. The HER-2 peptide labeled virus was found to
internalize effectively into the MCF-7 breast cancer cells but were poorly
internalized by HeLa cells. In contrast the CD-46
peptide labeled virus was poorly internalized by the MCF-7 cells and
effectively internalized to HeLa cells. The
difference in the internalization rates is believed to be related to the
difference in surface expression of the target receptors in the two cell lines.
Thus, these results appear to show the peptide-dependant manner of viral uptake
in two different lines of cancer cells.
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Roberts, Wesley A. Hoffman, Torissa J. Stevens, Derrick R. McCullen, Seth D. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
PAMS |
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Department(s): |
Mechanical
and Aerospace Engineering Physics
and Mathematical Sciences Textiles |
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Research |
Laura
I. Clarke/Physics Russell
E. Gorga/Fiber and Polymer Science |
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Title of Presentation: |
Effects
of Sample Size on Nanotube/Polymer Matrix |
Nanocomposites containing conducting
particles (e.g., carbon nanotubes, metal nanoparticles) embedded within an insulating matrix
(generally polymer) become conductive when the density of particle is sufficient
to create a connected particle cluster than spans the sample. This mechanism is
known as percolation. Conductance measurements determine this critical particle
volume fraction where the composite conductivity generally increases by ten
orders of magnitude. The effect of sample size on the critical density where
this dramatic transition occurs has not been carefully studied. By utilizing
planar interdigitated electrodes onto which a highly
porous mats of multiwalled carbon nanotubes:poly(ethylene
oxide) nanofibers have been electrospun,
percolation at different length scales can be measured. Current data suggests
that as the distance between the fingers of the interdigitated
electrodes (the effective length of the sample) increases, with the MWNT volume
percentage held constant, conductance decreases. This may be associated with
theoretical predictions that sample size is important near the percolation
threshold.
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Seyam, Mohamed A. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
Engineering and Technology |
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Department(s): |
Chemical and Biomolecular Engineering |
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Research |
Rich Spontak/Chemical
and Biomolecular Engineering; Materials Science and
Engineering |
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Title of Presentation: |
Cross-Linked Polymer Nanocomposites for H2 Gas Separation from CO2 |
Gas separation is an important process in the chemical
industry, particularly in the separation of the products resulting from the
water-gas shift reaction during steam reformation of hydrocarbons. In this
process, hydrogen (H2) must be separated from a mixed gas stream
containing primarily carbon dioxide (CO2), but also potential trace
amounts of water (H2O) and carbon monoxide (CO). Hydrogen gas is
utilized in many different ways. For instance, in the growing demand for
alternative energy sources, hydrogen fuel cells have emerged as an important
consideration. It has become industrially important to reduce energy and
economic demands of current gas separation processes and polymer membranes
provide an attractive opportunity to achieve this goal. In this study, we have
examined the gas separation properties of a cross-linked polyimide containing
as-grown palladium (Pd) nanoparticles. Implementation
of Pd nanoparticles into these polymer membranes
decreases the free volume of the membrane as well as improves the affinity for
H2 over other gas species. Additionally, chemical cross-linking of
the membranes further reduces free volume and increases chain rigidity, aiding
in the prevention of CO2 plasticization and precluding relatively
larger gas molecules to penetrate.
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Smith, Ashley M. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Toxicology |
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Research |
Andrew D.
Wallace/Toxicology |
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Title of Presentation: |
Promoter Analysis of the
Human Pregnane X Receptor (PXR) Gene |
PXR
is a nuclear transcription factor, highly expressed in the liver, which is
activated by binding to pesticides, environmental contaminants, and many prescription
drugs. Activation of PXR has been shown to be responsible for the induction of
a growing number of key metabolizing enzymes such as cytochrome
P450 3A4 (CYP3A4). Expression of metabolizing enzymes is dependent on PXR
levels in the cell, but little is known about the mechanisms regulating PXR
expression. The hypothesis of this
research is that key regulatory elements in the human PXR promoter control the
constitutive and inducible expression of the human PXR gene. This project aims to identify promoter
regulatory elements important for the constitutive and inducible expression of
the human PXR. To study the PXR promoter
regulatory elements, a 2.3 kb portion of the PXR promoter was PCR generated
with primers containing restriction sites and cloned into a TA plasmid. By direction cloning, the 2.3 kb region of
the PXR promoter was ligated into the
pGL4.13-Luciferase reporter plasmid. The HepG2 human liver cell line was
transiently transfected with the PXR-Luciferase reporter plasmid and promoter activity was
measured. Once these measurements were
obtained, it was shown that the pGL4.13-Luciferase plasmid was creating high
background activity which did not allow assessment of reliable PXR promoter
activity levels. Steps are being taken
to remove the PXR insert from this vector and place it into the
pGL410-Luciferase reporter plasmid. Understanding what controls PXR expression
is important, because a number of studies have indicated that the magnitude of
the CYP3A4 induction, and other metabolizing enzymes, is dependent on PXR
expression levels. The regulation of these key pathways by PXR can lessen the
effectiveness of therapies or increase drug toxicity. Also inappropriate
metabolism of endogenous steroids such as testosterone or estradiol
may lead to disruption of normal endocrine pathways.
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Whisnant, Adam W. |
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Home Institution: |
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Program: |
Undergraduate Research
Awards and Summer Enrichment Awards |
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College: |
CALS |
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Department(s): |
Animal Science |
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Research |
H.C. Sunny Liu/Animal
Science |
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Title of Presentation: |
Interaction Identification
of Host Proteins and Marek's Disease Virus UL49.5
Protein |
Marek’s
disease (MD) is a highly contagious neoplastic
disease in chickens. The cause of MD is the Marek’s
disease virus (MDV), an oncogenic herpesvirus
that is able to down regulate MHC class 1 molecules on the cellular surface. It
has been found that similar herpesviruses such as
bovine herpesvirus 1 (BHV1), pseudorabies
virus (PRV), and equine herpesvirus 1 (EHV1) also
avoid immunodetection through blocking the
Transporter associated with Antigen Processing (TAP). TAP is part of a complex
that loads MHC class 1 molecules from the endoplasmic reticulum with viral
peptides which are then recognized at the surface of the infected cell by cytotoxic T lymphocytes (CTLs).
In BHV1, PRV, and EHV1, the viruses encode UL49.5 protein to deactivate TAP.
MDV UL49.5 gene is similar to the other viral UL49.5 genes and it is possible
that MDV UL49.5 protein plays a part in the down regulation of MHC class 1
surface expression. It is worth investigating which proteins from the host cell
interact with MDV UL49.5 to determine if it plays a part in the evasion of the
immune system. A common method of determining protein interactions is the
yeast-two hybrid approach. This approach was used with MDV UL49.5 as the bait
protein for the gene sequence that would code for beta-galactosidase,
adenine, and histinine. Testing for these three
compounds yielded thirteen positive colonies. The prey plasmids from these
inserts will be sequenced.
[ 2007 Undergraduate Summer
Research Symposium Main Page ]
Last modified June 2007 by Sharon E. Hunt