Fairfield University Chapter
Sigma Xi, The Scientific Research Society
Annual Poster Session
April 25, 2002
Participants and Topic
Faculty Mentor: Robert Silver, REU
How cells make decisions: Laboratory of Robert Silver
Experiments have proposed that calcium is able to achieve specificity and selectively in its signaling through quantum emission domains (QEDs). The Silver Lab has proposed that QEDs are produced by microdomains, autonomous minimal space-time volume within which a signaled process can occur. We focused on Pre-NEB calcium signaling. It has identified proximally acting metabolic pathway elements in the mitotic apparatus that are essential to the generation of these QEDs prior to NEB. Intricate interactions of these pathways provide a mechanism which allows OEDs to be generated. By better understanding these metabolic pathways we will be able to reveal how the pathways interact and couple with one another to create a mechanism that generates and degrades the calcium QEDs necessary for NEB. Phosophofructokinase PFK is a possible key player in the metabolic pathways that work to create these calcium QEDS. As a compound of the glycolytic pathway, PFK is one of the most highly in the cell making it a good candidate for a highly specific signaling mechanism. Research I took part in was an experiment created by Dr. Silver to identify and characterize PFK activity in the mitotic apparatus from certain cell fractions of E.Parma.
Faculty Mentor: Diane Brousseau, Ph.D.
The population dynamics of the blue crab, Callinectes sapidus, in Holly Pond
This project consists of a catch and release method of estimating relative Blue Crab abundance of a tidal pond community located in Stamford, Connecticut. The objective was to quantify factors affecting the Blue Crab population levels and to identify and assimilate information necessary for the formation of Holly Pond management policy.
and Kimberly Young
Faculty Mentor: Malcolm Hill, Ph.D.
A comparison of antimicrobial compounds isolated from temperate and tropical species
Secondary metabolites from "Haliciona" sp. and "Microciona prolifera" were extracted using both methanol and a 1:1 dichloromethane: methanol solution. Bioassays were performed with five strains of marine bacteria isolated from Long Island "Haliciona" sp. was highly active against all five bacterial strains, while "Microciona prolifera" did not inhibit bacterial growth. We hypothesize that "Haliciona" sp. produces antimicrobial secondary metabolites to deal with greater threats from microbial pathogens in the Caribbean.
and Kimberly McDermott
Faculty Mentor: Glenn Sauer, Ph.D.
Isolation and purification of metallothionein from non-induced commercial liver tissue
Metallothionein (MT) is a small cysteine rich metal binding protein that is typically obtained from Zn or Cd induced animal tissues. Research was done to determine whether or not MT could be isolated from non-induced commercial calf and chicken liver. Gel filtration chromatography was used to separate MT from other proteins. A unique property of MT is that is has a higher absorbance at 245nm than at 280nm, and spectroscopic readings, therefore, were important in determining which fractions had MT. Antibody slot blotting was also done for all purified MT samples. Gel electrophoresis was another analytical method used. The stained gel showed a MT protein band for the purified liver samples, however, a few other faint bands were also observed.
and Catherine Moran
Faculty Mentor: Shelley Phelan, Ph.D.
Characterization of Aop2 gene regulation in murine cells using a Bgal reporter
There is evidence that the thiol-specific antioxidant protein Aop2 plays a role in atherosclerosis resistance in mice as a result of its antioxidant properties. We investigated how the gene is regulated. We hypothesized that basal expression of Aop2 is controlled by the proximal promoted while inducible expression in response to oxidative stress may require distal regulatory element. We tested the ability of the proximal Aop2 promoter to drive transcription of a downstream Bgal reporter gene in murine cells under normal and oxidative stress conditions. We sought to verify the correct orientation of the promoter in two previously isolated Bgal reporter constructs. The ability of these vectors to drive Bgal expression once transacted into murine epithelial cells was analyzed against the Bgal control vector. Results confirmed the correct orientation of the promoter in these clonoes. Several experiments were then performed to attempt to optimize transfection conditions and Bgal detection. Preliminary evidence suggests that basal expression is controlled by the proximal promoter.
Faculty Mentor: Woods Hole, REU
Barnacle population dynamics: Larval settlement and stability
used barnacle mortality, maternity and larval settlement rates to plot the size
of a barnacle population through time. Some of these rates were functions of
the total number of adults or the total number of larvae at a given time.
It is possible that changing these functions would alter dynamics - a population that over time once tended towards a fixed number of adult barnacles might tend towards extinction, or maybe oscillate around a value. In our investigation, we altered the larval settlement function. We examined the dynamics and also how a population responded to small disturbances. Our findings showed that although changing the larval settlement rate could produce different dynamics, this was only in rare cases.
and Christopher Szabo
Faculty Mentor: Matthew Kubasik, Ph.D.
Helix handedness interconversion kinetics in an octamericpeptide
Faculty Mentor: Diane Brousseau, Ph.D.
A field study of fiddler crab burrow usage by the Asian crab, Hemigrapsus sanguineus
The physical features from larvae of the marine sponge species "Microciona prolifera" were observed from enlarged microscopic images. Differential staining and fluorescence microscopy were used to visualize bacteria symbiotic with a marine sponge of the genera "Microciona prolifera." Larval samples were stained with the fluorescent dyes 4'6- diamidino- 2- phenylindole, and SYTOX Green, and viable and compromised microbial symbionts were imaged using digital equipment. Among the imaged symbionts, over 58% of which were viable cells present in the larval samples from "Microciona."
Faculty Mentor: Katherine Marsland, Ph.D., Yale University
Maternal sensitivity as a mediator of the relationship between maternal and emotional intelligence and child's emotional awareness attunement and expressivity
Faculty Mentor: Laura McSweeney, Ph.D.
Does the 2000 census data for Connecticut follow Benford's Law?
With Dr. McSweeney, I studied Benford's Law and its properties. Then using Excel, I analyzed the 2000 census data for Connecticut and performed the Chi-Squared statistical test on the data to prove that the census data did follow Benford's Law.
Faculty Mentor: Dr. Dawson Hedges, Ph.D., Brigham Young University
Duration of Transcranial Afagnotic Stimulation (TMS) effects on neuroendocrine stress response and depressive behavior in rats
Transcranial Magnetic Stimulation is a relatively new, non-invasive procedure for altering neuronal activity in the brain. TMS has been shown to have antidepressant properties. In addition, TMS may alter hypothalamic-pituitary-adrenal function, resulting in better coping in stressful situations. This research was done to investigate the duration of the behavior and neuroendocrine effects in rats using a forced swim test to measure these effects.
and Elizabeth Vancza
Faculty Mentor: Phyllis Braun, Ph.D.
Candida albicans: The effects of farnesol on amino acid transport by wildtype + cell wall mutant strains
and Caitlin M. Feeney
Faculty Mentor: Shelley Phelan, Ph.D.
Searching for atherosclerosis-related genes in mice
is the leading cause of death in the Western world. Previous findings show there
is a difference in genetic susceptibility to heart disease among different strains
of mice under varied dietary conditions. The strain of mouse denoted B6 was
determined to exhibit symptoms of atherosclerosis after being fed a high fat/high
cholesterol diet. The Balb strain when fed the high fat/high cholesterol diet
did not exhibit atherogenic symptoms.
These findings has led us to hypothesize that a certain set of genes may be differentially expressed between these strains, leading to the atherosclerosis resistance phenotype of the Balb strain. In previous studies we have identified several sequences of unknown identity that are differentially expressed in these mice. We have cloned and sequenced these genes revealing matches with various known mouse genes including arginase-1 and mitochondrial gene species, most not linked to atherosclerosis.
Faculty Mentor: Nancy M. Haegel, Ph.D. & A.M. White, White Numeric Consulting, Ltd., Malvern, E.
Modeling of growth parameter effects for far infrared blocked impurity band detectors
Numerical modeling has been performed as a function of compensation in the absorbing layer, net doping in the blocking layer and the extent of interface doping gradient at the absorber/blocker interface. Space charge effects cause field variations in the blocking layer at the net doping levels currently obtainable in development efforts for Ge and GaAs based BIBS. Increased space charge at the absorber/blocker interface creates a field gradient, leading to reduced net field in the blocker layer and an extension of the depletion region in the absorber.
Faculty Mentor: L. Kraig Steffen, Ph.D.
Investigating tire dissolution of benzoin by atomic force microscopy
Atomic Force Microscopy (AFM) was used to determine that the dissolution of crystalline benzoin in hydroxylic solvents is asymmetric. Although the crystal packing structure of benzoin is known, featuring regular arrays of benzoin molecules with interconnecting hydrogen bonds, the various edges and sides of the crystal are not equivalent to each other with respect to the underlying molecular structure. The data collected by AFM shows that the dissolution of benzoin occurs at highly variable rates along individual edges as a complex function of the solvent(s) used and particular surface features present.
and Matthew Smylie
Faculty Mentor: Nancy M. Haegel, Ph.D.
Transient modeling and measurements for Ge:Ga photoconductors
Numerical modeling of the transient response of Ge:Ga photoconductors has provided insight into the cause of the hook behavior and the importance of the time scale of modulation in determining detector current output. In this poster, we will present comparisons of theoretical predictions with experimental transient behavior. Specific examples will include 1. the effect of signal size on the extent and time constant for the hook effect, 2. the direct determination of gain values based on the transient response, and 3. direct comparisons of experimental and simulated transient response.
and Christine McDonagh
Faculty Mentor: Malcolm Hill, Ph.D.
Molecular evolution in Anthosigmelia varians: Evidence for a recent speciation event
We examined the evolutionary significance of discontinuous morphological variation of the common Caribbean sponge Anthosigmelia varians, which occurs in three distinct, habitat specific, morphotypes. We used DNA sequence analysis to three morphs are cryptic species. Forma "incrustians" and forma "varians" shared identical ITS2 sequences whereas forma "rigida" individuals had a single, fixed, nucleotide difference compared to the other morphs. We also surveyed the A.varians genome for fixed genetic differences using two techniques that generate anonymous, dominant genetic markers. Both the RAPD and ISSR techniques generated a large number of polymorphic markers, and provided evidence of genetic differences among morphs. These morphs appear to represent distinct species.
Isabelle Lemasson and Jennifer Nyborg
Faculty Mentor: R.EU
Targeted acetylation of HTLV-I promoter histories in vitro mediated by the ATF/CREB family
Through a one-step procedure, we have acetylated a 7-aminoccumarin dye, Coumarin 339. Acetylation has dramatically changed the UV-Vis and other properties of this dye. As a first step in the characterization of the molecule, we are determining the the barrier to rotation about the newly formed amide bond. The kinetics of rotation has been monitored through the coalescence behavior of three distinct protons. The three independent proton sites provide an opportunity to check the self-consistency of our lineshape methods. Kinetics measurements will be compared to computational results for the barrier to rotation.
Faculty Mentor. Glenn Sauer, Ph.D.
Influence of media formulations on growth and development of human articular chondrocytes
Articular chondrocytes are the predominant cell type involved in the growth and maintenance of joint cartilage. Disruption of normal chondrocyte growth can lead to joint disuse's such as arthritis. In this study, human articular chondrocytes were cultured to evaluate their growth in various media types. The results suggest that adding Dexamethasone to the growth media causes an increase in protein synthesis and a decrease in DNA replication. The results also indicate that vitamin C alone increases cell growth by increasing both cell division and protein synthesis. Decreased levels of DNA in cells treated with Dex suggests that Dex alone is not enough to cause rapid cell growth.
Faculty Mentor: Shelley Phelan, Ph.D. I
Expression of an antioxidant gene family in mouse and human cells: Potential role in atherosclerosis
The thiol specific antioxidant gene Aop2 codes for an antioxidant protein, which protects the cell from oxidative damage. Under conditions of extreme oxidative stress the cell adapts by regulating either transcription or post transcription to increase the concentration of antioxidant proteins. Using two different strains of cells, murine H2.35 and human K562, oxidative stress was induced for varying intervals of time by the addition of glucose oxidase, which causes an accumulation of hydrogen peroxide in the cell. Levels of Aop2 mRNA and protein were assessed by Northern blotting and Western blotting, respectively. Since this gene has been implicated in atherosclerosis in mice, understanding its regulation and role in the oxidative stress response will be critical in elucidating its anti-atherogenic effects.
Antennapedia-class Homeobox genes have found to be responsible for body plan development in many animals. The homeobox sequences code for DNA binding proteins, which act as transcription factors during the early stages of development. These Antennapedia-class homeobox genes are highly conserved in the metazoan lineage, which allows them to be examined and compared across many different species of animals. A fifty base-pair "guessmer" probe was designed to bind with the homeobox coding region and a cDNA library isolated from embryonic, larval and adult stages of Halichondria was screened. A novel homeobox gene of the Antennapedia-class BarH1 family was isolated from a marine sponge. These genes have been shown to perform regulatory functions in embryonic external sensory organs. It is interesting to see them present in an organism that has only a cellular grade of organization and lacks a discrete organ system.
Faculty Mentor: April Hill, Ph.D.
Hox and parahox genes from an anthozoan: Additional evidence for the ancient origin of the Hox gene cluster
We employed a
basal cnidarian (anthozoan) Parazoanthus parasiticus as a positive control to
facilitate our survey of poriferan genomes for Hox sequences. The work presented
focuses on our cnidarian sequences, which provide additional evidence for an
ancient origin of the Hox gene cluster. We have determined that three of the
Hox/paraHox genes are expressed in budding and/or stationary polyps while two
of the genes are not expressed at either stage. Results indicate that the enidarian
genome is likely to contain currently unknown Hox genes. Findings also lend
support to the hypothesis that the duplication of the hypothetical protohox
gene or gene cluster, occurred before the cnidarians diverged from the lineage
that gave rise to bilaterians.
This increases the probability that a protohox gene or gene cluster will be found in the Porifera, a hypothesis that has been supported by our isolation of a Hox sequence from two different poriferan groups.
Adam Sheehy and Tim Garelick
Faculty Mentor: Susan Brandon, Ph.D. & Allen Wagner, Ph. D., Yale University
A within-subject comparison of avoidance with yoked contingency effects on conditioned eyelid closures in the rabbit