6TH ANNUAL POSTER SESSION
Bannow Science Center MacDonnell Atrium and Second Floor
Wednesday, April 26, 2006
3:00 p.m. to 5:00 p.m.
Rachel Abenavoli ’07, Andrea McCarthy ’06,
Marion Schimpf ’07, Sophia Velez ’06, and Chrissy Young ’07
Advisor: Elizabeth Gardner, Ph.D., Fairfield University
The cross-race effect
Previous research on the cross-race effect (also known as the same-race
bias) has shown that individuals are able to recognize faces of people
belonging to their own race much better than they are able to recognize
faces of people belonging to other races. While the cross-race effect
may be influenced by the frequency with which a person comes into contact
with faces of a certain race or by differences in the underlying perceptual
processes used to code same and other-race faces, our study examined the
possible relationship between prejudicial attitudes and the ability to
recognize faces. Thirty Caucasian undergraduates from Fairfield University
were presented with 20 faces belonging to Black individuals and 20 faces
belonging to White individuals. Following this first presentation and
a filler task, participants were presented with another 40 faces, half
of which were taken from the first phase, and were instructed to determine
whether or not the faces had been presented during the first presentation
of faces. Each participant then completed a Race Implicit Associations
Test in order to gauge any automatic preferences for White versus Black
faces. People accurately recognized significantly more White faces (75.35%
accurate) than Black faces (65.83% accurate). However, the Implicit Associations
Test was not an accurate predictor of the cross-race effect. The findings
have applications to the eyewitness testimony debate, as well as to daily
patterns of interaction with members of other races.
Caroline Agin ’06 and Lauren Blanchette
Faculty Advisor: Shannon Harding, Ph.D., Fairfield University
Using a one day morris water maze test for memory
and visual acuity in middle aged and old aged enriched mice
The current study was part of a collaborative effort with the Biology
Department to investigate the role of peroxiredoxins in the memory decline
in mice. Female mice were housed in an enriched environment upon arrival
to the lab until reaching 10 months (middle age) or 22 months (old age).
A one-day Morris water maze test was developed by the students for the
purpose of this study. Mice were initially trained to reach a submerged
platform, and spatial memory was assessed by measuring the time to reach
the platform when animals were dropped from multiple locations. To confirm
that the differences in swim time were due to spatial memory decline and
not visual impairments, a visual acuity test was performed at the end
of the data collection. Based on previous research, it was hypothesized
that middle-aged mice would learn to reach the hidden platform sooner
than old-aged animals. However, no significant differences were observed
between groups in terms of swim time. This suggests that the groups were
not dramatically different in terms of spatial memory ability, yet we
did observe considerable variability between animals. After sacrifice,
brains were removed and examined by the biology department for changes
in peroxiredoxin, a protein that is reported to have protective effects
Caitlin Bickhart ’06
Faculty Advisor: Glenn R. Sauer, Ph.D.
The effect of metallothionein-inducing agents on
cell viability and detection of apoptosis in human articular chondrocytes
Articular chondrocytes, cells that maintain the matrix of joint cartilage,
have been found to undergo apoptosis when exposed to some cytotoxins.
It has been found that exposure to metallothioneins prior to treatment
with cytotoxins leads to a lower percentage of cell death (Sauer et al.,
1998). Detection of cell death can be achieved with the lactate dehydrogenase(LDH)-release
assay, while the detection of apoptotic cells requires the caspase-3 fluorimetric
assay. In this study, human articular chondrocytes were treated with varied
concentrations of the cytotoxins etoposide, staurosporine, cycloheximide,
actinomycin, dexamethasone, sodium nitroprusside, hydrogen peroxide, and
glucose oxidase. A control LDH-release assay was performed; an additional
trial tested for metallothionein activity by treating cells with dexamethasone,
cadmium, or zinc, allowing the metallothionein inducing treatments a 24
hour induction period, then adding the cytotoxins. The caspase-3 assay
showed staurosporine and glucose oxide-treated cells resulting in slightly
elevated levels of caspase-3 activity after 3 hours. In contrast, most
reagents resulted in cytotoxicity at the concentrations tested as indicated
by the LDH-release assay. Pre-treatment of cells with metallothionein
inducing agents resulted in lower levels of cytotoxicity. It was concluded
that there were only slight levels of apoptotic chondrocytes with exposure
to cytotoxins, and that there is a possible linkage between metallothionein
activity and cell viability.
Janelle Buckley ’06 and Patrick Dameron ’06
Faculty Advisor: Jerry Sergent, Ph.D.
When an individual’s heart rate becomes irregular
or unstable, there is a need to quicken the response of medical personnel
When an individual’s heart rate becomes irregular or unstable, there
is a need to quicken the response of medical personnel. In the case of
a person with heart disease, if their heart rate becomes irregular or
unstable due to a variety of conditions, for example a heart attack, the
heart monitor will alert the proper medical personnel. Minimal individual
involvement is necessary, when alerting medical personnel. Once the individual’s
the heart rate goes either above or below the preprogrammed parameters,
a signal will be sent to a device which will automatically contact medical
personnel. The medical personnel will receive a call which will inform
them of both the heart rate, and the individual’s location due to
an attached locator system.
This device is only meant to alert medical personnel, in an attempt to
quicken their response time. It is not intended to prevent a heart attack,
or administer treatment to the individual’s heart. Approximately
250,000 people die per year of a heart attack before reaching a hospital.
(Bianco, 10) Implementation of the device is intended to aid, and to quicken
the response of medical personnel.
We have chosen all the necessary components. We are using the Polar FS3
heart monitor and the Boost Mobile i415 cell phone with GPS capability.
We are currently in the integration phase of the project. Due to time
constraints, and unavailability of resources from the cell phone manufacturer,
the requirements of the design were slightly changed. The new proposed
design includes automatically placing a phone call to medical personnel
once the heart monitor detects a heart rate above or below the preprogrammed
Nicole Carlson ’06 and Maggie Wollschlager ’06
Faculty Advisor: Shelley Phelan, Ph.D.
Analysis of Peroxiredoxin Expression in Aging in
Peroxiredoxins are a family of antioxidant proteins which utilize cysteine
residues to reduce peroxides in the cell. There have been six peroxiredoxin
family members identified in mammals, which are differentially expressed
in a wide variety of tissues. Peroxiredoxin expression was recently detected
in brain tissue and found to be differentially distributed based on cell
type, suggesting a specific role for individual peroxiredoxins in neural
function. Many studies have also shown a close correlation between the
aging process, age-related disease and oxidation. Based on the differential
expression of peroxiredoxins in the brain, as well as other tissues, and
the known role of antioxidants in aging, we hypothesized that peroxiredoxins
would be differentially regulated in different aged mice. RNA was extracted
from brain and liver of middle and old aged mice, and gene expression
was analyzed for individual peroxiredoxins, specifically Prdx1, Prdx2,
and Prdx6. Expression was assayed using a one-step RT-PCR method. We successfully
purified intact RNA from all tissues. From our data, we have concluded
that there is no difference in expression levels of Prdx6 or Prdx2 in
the brain or liver at different ages. Expression of additional peroxiredoxins
is currently being measured. Changes in antioxidant expression in brain
tissue could indicate a potential role in neurodegenerative diseases.
Jessica Cataldo ’06
Faculty Advisor: Linda Henkel, Ph.D.
People can sometimes come to believe that they have performed actions
or made statements that they did not in fact do. This study looks at how
and why people take credit for ideas that are not their own (i..e., unintentional
plagiarism). Under what conditions is inadvertent plagiarism more likely
to occur? The study examines whether people are selective in the information
that they inadvertently use and claim to be their own, which would have
important implications for understanding the cognitive processes that
give rise to such memory failures. Specifically, the aims are to determine
if people are more likely to claim as their own ideas that they believe
are more attractive (e.g., more popular, more credible, or more desirable).
In addition, the study addresses whether certain aspects of personality
are related to occurrences of unintentional plagiarism, such as suggestibility,
compliance, and creativity. Participants were presented with a series
of ideas from other people that were possible solutions to the issue of
recycling on the Fairfield University campus. They were then asked to
generate their own ideas for the same problem. One week later, they were
asked again to generate new ideas regarding the same issue, and their
memory for the source of the ideas they read or generated a week ago was
also assessed. Standardized measures of suggestibility and compliance
were administered, as well a self-developed creativity scale. Data collection
is still underway, and completed analyses will be presented at the poster
session. It is hypothesized that participants will be more likely to claim
as their own ideas that were said to be more popular or frequent, ideas
that were from a more credible source, and ideas that were better or more
desirable than unpopular, noncredible, or undesirable ideas. In addition,
it is expected that more suggestible people, more compliant people, and
less creative people will plagiarize more often than other participants.
Jessica Curtis ’06
Faculty Advisor: Laura McSweeney, Ph.D.
Statistical Analysis and Survey Techniques
For my Honors thesis project, I have been working on an independent statistical
analysis project under the supervision of Dr. Laura McSweeney. I began
by generating an unbiased survey following the guidelines of how to create
a survey without inference or bias, and then conducted this survey independently
to collect raw data. In learning the techniques of generating a good survey,
I was able to analyze and critique the research, sampling, and analysis
techniques used by the popular college rank guide The Princeton Review.
My specific area of interest in creating this survey was to test the student
body on campus to analyze the views of the academic and/or social life
offered at Fairfield University based on their experience. Throughout
this independent study, I was able to learn and use new statistical software
programs such as SPSS to organize my data and conduct statistical analysis,
which I will then be discussing in a full report by the end of the term.
I intend to present my preliminary findings from my research today.
Bryant Duda ’06
Faculty Advisor: Dorothea Braginsky, Ph.D.
Protestant Ethic and Locus of Control in College
Students: A comparison from the 1970s to present
A comparison of college students over time (decades) of their perceptions
of Locus of Control and the importance of Protestant Ethic in their lives.
Analysis will be questionnaire data obtained from Fairfield University
and from two earlier cohorts.
Bryant Duda ’06, Kristina Chomick ’06,
Jamie Versace ’07, Cagney Rignaldi ’07
Faculty Advisor: Dorothea Braginsky, Ph.D.
The Protestant Ethic and Locus of Control in College
The research consists of surveys and interviews which were conducted to
determine the degree to which one’s gender and major (business vs.
non-business) affects their locus of control and Protestant Ethic.
Bridget Gallagher ’06
Faculty Advisor: Shelley Phelan, Ph.D.
Regulatory Elements of Prdx6 Transcription
Peroxiredoxin 6 (Prdx6) is a member of the peroxiredoxin family of antioxidant
molecules, which protect cells by reducing cellular peroxides produced
by normal cellular metabolism. It has been shown that peroxiredoxin 6
is widely expressed, with highest expression in the liver. Previous studies
from our lab have demonstrated that Prdx6 expression is down regulated
with serum deprivation, and up-regulated in a time-dependent manner in
response to various soluble ligands. In order to determine the regulatory
elements that mediate basal and induced expression, we generated reporter
constructs containing regions of the Prdx6 proximal promoter, and tested
them in transient transfection assays. We first tested and optimized the
lipofectamine method of transfection and a colorimetric assay for reporter
expression. We then analyzed the immediate proximal promoter for ability
to drive reporter expression in the absence and presence of inducers.
We hypothesized that this 160 base pair sequence would be necessary and
sufficient to mediate growth-regulated expression. We found that this
region mediates high expression in growing cells and down-regulation in
serum-deprived cells. Our data suggests that this region may also mediate
ligand-induced expression, however further studies are required. Future
studies aim to investigate additional upstream regulatory regions of Prdx6.
Further investigation of Prdx6 may have implications for age-related diseases,
as antioxidant molecules have been shown to play key roles in the prevention
of such diseases.
Tara Hansen ’06, Joe Griffin ’06, Scott
Davidson ’06, Trevor Kelly ’06
Faculty Advisor: Alan Dubrow and Clem Anekwe, Ph.D.
Renewable Hydrogen Energy
The system takes water and breaks it down into hydrogen and oxygen. The
oxygen is vented out of the system while hydrogen is stored in tanks which
ultimately go into the fuel cell. This system is solar powered. We helped
fix a plumbing problem by raising a KOH separator. Also, we designed a
new pumping system that is powered by a hydraulic/pneumatic system that
would replace the existing pump if the budget would allow. We are fixing
the efficiency of the system by heating the cells to its optimum temperature,
which will be determined with testing. This is being done by converting
a heater that is sparkless with a platinum catalytic heater to run off
of hydrogen produced by the system.
Stephanie Hohler ’06
Faculty Advisor: Linda Henkel, Ph.D.
Older and Younger Adults’ Memories for Pictures
Prior research has shown that older adults often tend to remember more
positive events and information, whereas younger adults tend to remember
more of the negative. Carstensen’s (1987, 1991, 1993) socioemotional
selectivity theory postulates that older adults pay attention to and selectively
remember more positive information because it is more important for people
closer to the ends of their lives to maximize positive experiences. The
present experiment examines whether older adults systematically bias their
memories in favor of positive information when they are asked to repeatedly
remember as much as they can. Older (65 and up) and younger (18 –
23) adults were shown a series of positive, negative, and neutral pictures
and then were asked to recall the pictures on three separate occasions.
The context and motivation for the repeated recall tests were manipulated
by using a standard recall procedure that simply asked the participants
to recall the pictures and an assisted recall procedure that gave the
participants an incentive, such as their family or friends wanting a list
of the pictures. Data collection is still underway. Results are expected
to show that older adults will remember more positive pictures on the
final recall test, whereas younger adults will remember more negative
pictures on the final recall test. Futhermore, results from a later old/new
recognition test are also expected to show this age-related positivity
bias. Additional analyses will determine whether individual differences
in participants’ future time perspective mediate this positivity
Hien T. Le ’06
Faculty Advisor: Jen Klug, Ph.D
Effects of variation in nitrogen and phosphorus
ratios and concentrations on cyanobacteria heterocysts frequency
Nitrogen fixation is a process used to convert nitrogen gas, an unusable
form to a useable form, ammonium. Cyanobacteria are known for this capability.
Aphanizomenon and Anabaena are examples of these cyanobacteria species.
Nitrogen fixation takes place in a specialized cell on each filament known
as the heterocyst. Under circumstances when nitrogen is low, Aphanizomenon
and Anabaena have a competitive advantage over other phytoplankton species
because they can fix nitrogen on their own. In this project, I have been
looking at water samples from Lake Lillinonah for year 2003, 2004, and
2005. The method used to prepare the sample for enumeration under an inverted
microscope is Utermohl. This project looks at the relationship between
heterocyst frequency versus the nutrient chemistry and how heterocyst
frequency changes over the course of the summer.
Daniel Levesque ’06
Faculty Advisor: Phyllis Braun, Ph.D.
Effect of ECGC and ECG on the formation and destruction
of biofilms produced by Candida albicans
Previous experiments have shown that crude green tea extract (GTE) effectively
destroys biofilms produced by the yeast C. albicans. Two different strains,
10231 and 4918, were separately tested in this experiment. Two catechins
found in GTE that could be responsible for its antifungal properties were
examined. Those two chemicals were epigallocatechin-gallate (ECGC) and
epicatechin-gallate (ECG). Polyphenol extract that contains ECG and ECGC
was also used. These chemicals were added at various concentrations to
a microtiter plate containing C. albicans in order to prevent the formation
of biofilms. Further experiments determined whether the two chemicals
destroyed preformed biofilms as well. The density of the biofilms was
measured using calorimetric assay based on the metabolic activities of
the biofilm formation. ECGC, ECG, and polyphenol was hypothesized to both
prevent the growth of biofilms and destroy preformed biofilms. Both strains
of C. albicans showed an average decrease of 66% in biofilm formation
when these chemicals were added to the growing form of C. albicans. Treating
preformed biofilms with these polyphenols for 6 hours unexpectedly appeared
to allow continued growth of these biofilms. This should be retested to
confirm these unexpected results.
Samantha Lipinsky ’06
Faculty Advisor: Jen Klug, Ph.D.
Project Advisor: Susan Quincy, Connecticut Department of Environmental
Protection – Kellogg Environmental Center
Eastern Bluebirds (Sialia sialis)
Eastern bluebirds suffered a population decline due to the depletion of
nesting space. The decrease in viable nesting space is due to many factors,
which include urbanization, pesticide use and competition with nonnative
species. Organizations such as the Connecticut Department of Environmental
Protection have developed a nest box program to provide possible nesting
space for the Eastern bluebirds. Many factors are considered when setting
up the nest boxes. For example, the distance of a nest box from wooded
areas and from other nest boxes must be carefully considered in order
to create the best nesting space. Once the nest boxes are set up they
are monitored regularly. When found, the nests and any eggs of nonnative
birds like the European starling and house sparrow are removed from the
boxes. Even with human intervention it is possible for the Eastern bluebirds
to lose the nesting space to other native birds. Approximately one third
of the nest boxes contain an old nest. These nests were left in the boxes
to see if birds prefer nest boxes that are empty or boxes that contain
a nest. Any observations and data that are collected are submitted to
the Connecticut Department of Environmental Protection and the Cornell
Ornithology Laboratory for further study.
Nora Lopez ’03
Faculty Advisor: Olivia Harriott, Ph.D.
Phylogenetic and microscopic studies by others have demonstrated that
marine sponges host a large diversity of transient and symbiotic microorganisms.
Several members of the sponge-symbiont communities may belong to a monophyletic
lineage of sponge specialists (e.g., Fieseler et al. 2004). In this study
a molecular approach was used to characterize 16S rDNA gene sequences
of Bacteria harbored by the Caribbean marine sponge Chondrilla nucula
collected in the Florida Keys. Using domain-specific primers, 16S rDNA
gene libraries of C. nucula were constructed and compared to a clone library
of bacterioplankton from the surrounding water. Diversity was estimated
using amplified ribosomal DNA restriction analysis (ARDRA) patterns of
clones that were generated with HpaII and HhaI. Rarefaction analysis was
used to estimate species richness in these communities based on combined,
unique ARDRA profiles. The results show that the majority of bacterial
clones in the C. nucula library (>95%) were not detected in the bacterioplankton
library. The symbiont community appears to be relatively stable because
several bacterial species were identified when ARDRA profiles generated
from two different C. nucula sponge libraries created in 2002 and 2004
were compared. Furthermore, as indicated by 16S rDNA sequences, our data
supports the hypothesis (Hentschel et al. 2002) that sponges living in
tropical oceans separated by 104 km harbor a subset of highly specific
Carolyn Manning ’06
Faculty Advisor: Elizabeth Gardner, Ph.D. and Sue MacAvoy, Ph.D.
Stereotypes and attitudes towards housed people
To test my hypothesis that people who are homeless have generally negative
or pessimistic stereotypes, attitudes and opinions about people who are
housed, 27 program participants from two homeless shelters in Connecticut
were given a questionnaire. This was comprised of 26 statements / questions.
Participants were asked to circle a number, one through seven, to indicate
degree of agreement where one was the strongest disagreement and seven
was the strongest agreement. These statements / questions themselves probed
opinions, attitudes and behaviors of the participants of the survey towards
housed people. There were generally positive and optimistic responses
from the participants as measured by their means and standard deviations.
My hypothesis was not supported here. In this work, a number of possible
reasons for the positive responses are given, as well as implications
and uses from the results of the survey.
Christopher Miller ’06
Faculty Advisor: Stephen Sawin, Ph.D
The mathematical theory of knots has numerous applications to many areas
of science. Knot theory is useful in the study of genetics, string theory,
and quantum computing. The seemingly disparate nature of these three areas
in which knot theory is useful is a testimony to the power of knot theory.
We will present an overview of some of these applications within the context
of introductory knot theory, as well as demonstrate some current research
on the Jones Polynomial, an important property of knots.
Anne Morris ’06
Faculty Advisor: Tod Osier, Ph.D.
Program Advisor: Colin Campbell, Ph.D. at the University of Minnesota
Deficient DNA repair in a cell culture model of
Fanconi anemia (FA) is a genetically heterogeneous fatal disease afflicting
mainly children. There is an emerging consensus that the bone marrow failure
and cancer predisposition associated with this disorder result from defective
DNA repair. Several lines of evidence suggest that this defect involves
the evolutionarily conserved Rad50-dependent DNA end-joining pathway.
To test this hypothesis, a transgenic FA cell culture system was created.
Human fibrosarcoma-derived HT1080 cells were transfected with a disease-causing
allele of the FA ‘C” gene, and a stable cell line called L554P
was isolated. Analysis revealed that nuclear protein extracts from the
transgenic L554P cells displayed reduced levels of DNA end-joining activity,
compared to extracts from un-modified HT1080 cells. In addition, extracts
from the L554P cells had significantly less DNA tethering activity than
did extracts from control cells. These results support the working hypothesis
that FA cells fail to activate the Rad50-dependent DNA repair pathway.
Our long term objective is to understand why this pathway of DNA repair
is inactive in FA cells in order to facilitate the development of a drug
to treat FA patients.
Stephanie Serpa ’06
Faculty Advisor: Shelley A. Phelan, Ph.D.
Analysis of Peroxide in Mouse Liver
Hydrogen peroxide (H2O2) is known as a reactive oxygen species (ROS).
ROSs form as a natural byproduct of the normal metabolism of oxygen but
can damage proteins, DNA, and cell membranes through oxidation. Interestingly,
H2O2 has been shown also to play a significant role in cellular signal
transduction. Peroxiredoxin 6 (PRDX6), is a member of the peroxidredoxin
antioxidant family of enzymes. This antioxidant family shares the ability
to reduce H2O2 to water, protecting the cell from oxidative damage. Since
PRDX6 is highly expressed in the liver, we sought to determine if hydrogen
peroxide levels in liver would vary under different oxidative-stress conditions
in mice. We first tested a peroxide-detection assay to determine quantitative
levels of aqueous and lipid peroxides. We then prepared liver lysates
from mice under different conditions. We compared the effects of high
fat diet, PRDX6 knockout, and age on aqueous peroxide levels. We hypothesized
that all three conditions would increase oxidative stress in the liver,
resulting in an increase in aqueous peroxide levels. Values from this
assay were recorded and compared. The Bio-RAD protein assay was then used
to quantify the amount of protein obtained in each mouse liver lysate,
in order to standardize samples. We found that both aqueous and lipid
peroxides can be accurately measured by this method, although a different
technique is required for extraction of lipid peroxides from tissue. We
are currently comparing H2O2 levels between samples. Further analysis
will be required to determine the relative amount of PRDX6 in each of
these tissues, and to investigate a correlation between H2O2 levels and
the amount of PRDX6.
Mike Shinall '07
Faculty Advisor: Matt Kubasik, Ph.D.
Hydrogen/Deuterium Exchange Studies on Two Short
Hydrogen/Deuterium Exchange (HDX) experiments are commonly used to investigate
the stability and conformational excursions of biomolecules such as proteins,
DNA, RNA and peptides. We have conducted an HDX study on two short peptides
in an effort to characterize the stability of their short helical structures
in solution. Intramolecular hydrogen bonds maintain the integrity of the
helical structure, and these hydrogen bonds exist in a bonded/non-bonded
equilibrium. Non-hydrogen-bonded amide protons are susceptible to exchange,
whereas hydrogen-bonded amdie protons are protected from exchange. By
measuring the rate of exchange, we can determine the relative stabilities
of specific hydrogen bonds in our peptides.
Maliha Siddiqui '06
Faculty Advisor: Edmond J. O'Connell, Ph.D.
Detection of Ketene Intermediates in the Phaotolysisof
c is-1,2-dibenzoylethylene is known to undergo a photochemically induced
rearrangement. It is strongly suspected that there are conjugated ketene
intermediates involved in this reaction. It is our goal to characterize
these ketenes using proton NMR.
Alison Sikora ’06
Faculty Advisor: Glenn Sauer, Ph.D.
Induced metallothionein gene expression in human
chondrocytes by metal exposure
Previous studies have suggested that metallothionein expression in human
cells can be induced by metal exposure. Expression of the metallothionein
gene in human chondrocytes has been observed to delay the onset of apoptosis
in such cells. Metallothionein is a cysteine-rich, low molecular weight
intracellular zinc binding protein. Production of this protein, due to
metallothionein gene expression, provides resistance to cellular oxidants
by scavenging free radicals. Therefore, by buffering the amount of reactive
oxygen species, the onset of apoptosis can be delayed. Apoptosis of human
adult chondrocytes can ultimately lead to cartilage degeneration, thus
resulting in debilitating conditions such as osteoarthritis and osteoporosis.
The present study seeks to determine which metals, and in which optimal
concentrations, can best induce the expression of metallothionein in human
chondrocytes. Human chondrocyte cell lines were maintained in both adhesion
and suspension cultures, treated with various metals, and then harvested
48 hours later. Extraction of cellular RNA, followed by RT-PCR, allowed
for metallothionein expression to be observed via gel electrophoresis.
Qualitative comparative analysis permitted the observation of metallothionein
expression depending on the various metals that were previously exposed
to the cells. Consistent with results from similar studies, both high
and low concentrations of cadmium metal induce gene expression of metallothionein,
thus suggesting that diets high in this metal may delay the onset of apoptosis
in human chondrocytes. Furthermore, high concentrations of zinc also appear
to induce metallothionein expression. The results from this study suggest
that cadmium and zinc metals may play an essential role in the integrity
of adult chondrocytes by inducing metallothionein gene expression and
thus preventing the rapid degeneration of cartilage tissue in aging human
Danielle Spears '06
Faculty Advisor: Olivia Harriott, Ph.D.
Analyzing Microorganisms that live
in the Marine Sponge, Chondrilla nucula
Previous studies have shown that marine sponges are home to many different
microorganisms. The microorganisms present in the sponge may protect the
sponge from disease. The microorganisms may also provide nutrients to
the sponge. The research I conducted focused on characterizing the microorganisms
that live symbiotically within the marine sponge Chondrilla nucula. Polymerase
chain reaction (PCR) was performed on total sponge community DNA using
bacterial rRNA primers to selectively amplify 16S rRNA genes of bacterial
representatives in the community DNA sample. Six rRNA gene fragments derived
from PCR were subjected to DNA fingerprinting and the DNA sequences of
two rRNA gene fragments. Based on the phylogenetic analysis of bacterial
rRNA gene fragments derived from Chondrilla nucula community DNA (this
study) and other marine sponges it appears that bacteria related to the
Acidobateria and Proteobacteria are commonly found in diverse marine sponges.
Michael Talmadge ’07
Faculty Advisor: Jack Beal, Ph.D.
Project Sponsor: National Science Foundation
Solid State Physics
Modeling electron diffusion in semiconductor materials and developing
methods for determining material parameters from experimental data through
use of numerical methods.
Melissa M. Wright ’06
Faculty Advisor: Linda A. Henkel, Ph.D.
Emotional Bias in Source Attributions for Young
and Older Adults
Older adults often exhibit a positivity bias – a tendency to attend
to and remember more positive than negative information. The present study
examined whether older adults would systematically remember more positive
than negative information over a series of successive recall tests and
would be more accurate at remembering the source of positive information.
While using full or divided attention, young and older adults encountered
positive, negative, and neutral words said by two different people. Shortly
after, they recalled the words 3 separate times and then indicated the
speaker of each remembered word on a recognition test. Results showed
higher recall rates for young than for older adults, though overall levels
of recall were relatively low for both groups and favored negative over
positive words. Older adults did not show any systematic increase in recall
across the successive tests, and this was true for those who encoded the
words under full attention as well as those who encoded words under divided
attention. Young adults under full attention at encoding recalled more
words on the 3rd test than on the 1st test, whereas young adults under
divided attention showed the same lack of an increase as did older adults.
Older adults under full attention and young adults under divided attention
showed a positivity bias in their source attributions, with fewer source
errors in claiming one person said the word when the other person did
for positive words than for negative words. In contrast, young adults
under full attention and older adults under divided attention showed the
opposite pattern: more source errors for positive than for negative items.
The role of attentional and memory processes in regulating emotional well
being are discussed in light of these findings.