SRI 2002 - Participant Abstracts
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Georgina Bermudez
Stony Brook University
Junior
Biomedical Engineering
Faculty Mentor:
Dr. Janet Andersen, Assistant Professor of Biomedical Engineering
Laboratory of Dr. Nancy Reich
Department of Pathology
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The Response of Cells to Viral Infection
The focus of our study is to investigate
the role of Interferon Regulatory Factor 3 (IRF3) and a select set
of Interferon Stimulated Genes (ISGs) in apoptosis or cell death.
IRF3 is a transcription factor that increases the production of interferon
after viral infection. Interferon is produced by the body's immune
system in response to viral infections and it induces the expression
of a different set of ISGs in nearby cells that produces antiviral
products. In addition, IRF3 can induce the transcription of a select
set of ISGs independent of interferon by forming the transcription
factor complex called double-stranded RNA activated factor 1 (DRAF1).
To study the effects of IRF3 and this set of ISGs in the absence of
viral infection, we are generating an Inducible Mammalian Expression
System, using the human cell line HEC 1B. Using the Inducible Expression
System may enable us to manipulate the specific genes involved to
combat viral diseases.
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Willie Caraballo
City College
Junior
Electrical Engineering
Faculty Mentor:
Dr. Thomas Robertazzi,
Assistant Professor
Department of Electrical Engineering
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The Equilibrium State Transition Flow Patterns
Statistical performance evaluations have become our primary tool for designing multifaceted communication
and information processing systems. One important aspect of this field is "Queuing Theory"−mainly the study
of queues. Typically, a queue is defined as a form of a waiting line that exists due to the difference between
the arrival rate and the service rate of a system. This branch of mathematics is mainly concerned with
flows of probability flux within a system of queues. In this research, the main goal to is to discover
certain patterns within a system of queues, of non-product form solution, that will help facilitate
the obtainment of an alternative computational algorithm for equilibrium state probability in the near future.
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Jamilla Dick
Medgar Evers College
Junior
Environmental Science
Faculty Mentor:
Dr. Sultan Hameed, Professor
Marine Science Research Center
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Criteria Pollutant Trends in New York City
Criteria pollutants are those for which the United States Environmental Protection Agency (USEPA) has
established National Ambient Air Quality Standards (NAAQS). These include standards for Carbon Monoxide
(CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM) and sulfur dioxide (SO2).
Over the past twenty years the Department of Environmental Conservation (DEC) and the EPA have
continuously monitored these six criteria pollutants, especially after many programs designed to reduce
their ambient concentrations have been put into place. This research uses air concentrations of the
criteria pollutants that are collected at various monitoring sites in New York City to show how the
pollutant trends have changed. The air quality trends compiled based on the information collected over
the ten-year period from 1988 to1998 are of great importance. Significant changes in the pollutant
concentrations can be determined and measured to correct and understand their sources. Thus pollution
levels could be reduced and maintained at acceptable standards. In this work we will try to determine:
(i) how and why do pollutant concentrations and type vary (ii) why changes for pollutants in certain
locations are similar or different, and (iii) the statistical properties of these trends.
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Lakesha Farmer
Grambling State University
Junior
Biology
Faculty Mentor:
Dr. James Konopka, Associate Professor
Research Mentor:
Dr. Amy Warenda, Post Doc
Department of Microbiology
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Factors that Promote True Hyphal Growth in Candida Albicans
The budding yeast Candida albicans is an opportunistic human pathogen capable of growing in a variety of forms.
The polymorphic fungus can grow in a round yeast form, called a blastospore, or in two filamentous forms: true
hyphae and pseudohyphae. Microscopically, cells with true hyphal growth and pseudohyphal growth have very
similar phenotypes. To distinguish the difference two, GFP (green fluorescent protein) is used to tag Cdc 10,
one of the four septin proteins (Cdc 3, 10, 11, 12) found in yeast cells. Septin proteins are highly homologus,
filament forming proteins that organize other proteins in all eukaryotes. The septin-GFP proteins localize as a
ring at the neck of pseudohyphal cells and on the tip or towards the middle of the germ tube of true hyphae
allowing easy classification of the two filamentous morphs.
There are several factors that contribute to true hyphal growth: temperature, pH, cell density, nutrients, and
serum concentration. In lab, factors that mimic a mammalian host such as growth at 37°C, neutral pH, and the
presence of blood serum, tends to promote true hyphal growth. Reports vary of the amount of serum necessary to
promote true hyphal growth.
This study attempts to investigate the relationship between the amount of serum in the media and the percentage
of true hyphal cells generated. It also investigates if the amount of serum affects the overall hyphal lengths.
Additionally, cells are being tested to see how the absence of sugar (dextrose) affects true hyphal growth.
Overall, it appears that higher percentages of serum in the media increase the percent of true hyphal cells and
germ tube length. Results also show that the absence of sugar in the media increases the percent of true hyphae
and filamentous growth.
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Frances Fernandez
Hunter College
Junior
Biochemistry
Faculty Mentor:
Dr. James Bliska, Associate Professor
Department of Microbiology, Centers for Molecular Medicine
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Purification of Translocator Proteins from Yersinia
Yersinia pseudotuberculosis is a bacterium that causes an infectious disease characterized by mesenteric
lymphoadenitis. Yersinia uses the type III secretion system to inject bacterial effectors (Yops) into the
host cell through the use of a small needle like projection extended from its surface. Three Yop proteins,
YopB, YopD, and LcrV, are required for the translocation of the other Yops across the membrane. They are
thought to form a pore in the target cell membrane that allows effectors to enter and disturb the target
cell. This work involves the purification of YopB, YopD, and LcrV to determine the effect of each individual
protein on the target cell. In order to purify the proteins, genes coding for these proteins are cloned in
plasmids under the control of bacteriophage T7 RNA polymerase transcription, which is induced by the use of
IPTG. The pET 28a plasmid allows the cloning of a gene next to a sequence that codes for a poly-histidine tag.
When T7 RNA polymerase is induced, the majority of the cell´s resources are diverted to the transcription of
the His-tagged fusion proteins. Conditions for growth, temperature and induction time are analyzed to obtain
the maximum amount of soluble protein.
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Zoe Gibson
Fort Valley State University
Junior
Biology
Faculty Mentor:
Dr. Daniel Bogenhagen, Professor
Department of Molecular Pharmacology
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Purification of Mitochondrial DNA; Protein Complexes from the Fission Yeast S. Pombe
Schizosaccharomyces pombe is a fission yeast having characteristics similar to those of other, more complex
eukaryotes. In our lab mtDNA (mitochondrial DNA) nucleoids, consisting of mtDNA and all other proteins
associated with it, including the DNA binding protein, mtTFA (mitochondrial transcription factor A) have
been purified from Xenopus oocytes. These studies will determine whether or not this nucleoid can be
purified from S. pombe. This may be possible because S. pombe´s mtDNA is similar in size to human and
Xenopus mtDNA and it undergoes the normal eukaryotic cell cycle. Although no protein equivalent to the
Xenopus DNA binding protein mtTFA has been identified in S. pombe, two HMG Box proteins have been found
to be possible homologs to mtTFA. We will determine if either of these proteins is associated with mtDNA.
S. pombe has recently had its genome sequenced. It has been discovered that its genome is much smaller
than that of any other eukaryote whose genome has been sequenced, containing only 4,824 protein-coding
genes. This is advantageous because it makes it much simpler to study all of the proteins that bind to mtDNA.
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Timothy Nwobosi
St. John´s University
Junior
Biology
Research Mentor:
Dr. Daniel Bogenhagen, Professor
Department of Molecular Pharmacology
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An Investigation into Whether the Ethanol Metabolite Acetaldehyde Cross-Links Mitoshondrial DNA to Proteins as
Mitoshondrial Trasncription Factor a (MTTFA)
Previous experimental work has shown that mitochondrial DNA in mouse liver is selectively degraded after acute
intoxication with ethanol. The mechanism involves detoxification of ethanol to acetaldehyde, an intermediate in
the conversion to ethyl acetate. The central hypothesis here is that N2-ethylidene-dG, a Schiff base and the most
abundant intermediate of acetaldehyde adduction, may react with adjacent proteins such as mtTFA (mitochondrial
transcription factor A) also called TFAM in mammals or abf2 in yeast. The mtTFA protein is an HMG (high mobility
group) box protein that binds to the minor groove of mtDNA where it is accessible to the N2 adduct. The
DNA-protein complex formation was monitored, using an electrophoretic mobility shift assay. SDS polyacrylamide
gel electrophoresis was used to observe cross-linking of protein to DNA. The covalent cross-linking of protein
to DNA would explain the negative effect of acetaldehyde on mtDNA transcription and replication. In replication
of DNA via DNA polymerase, the protein (e.g. mtTFA) interferes with the replication and transcription by
influencing the access of DNA damaging agents to mtDNA or by directly cross-linking to sites of DNA damaged residues.
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Mary Osisami
Stony Brook University
Senior
Biology
Faculty Mentor:
Dr. Dafna Bar-Sagi, Professor
Department of Microbiology
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The Regulation of HSPRY2 Subcellular Localization
Receptor tyrosine kinase (RTK) signaling is involved in cell migration, growth and differentiation.
However, high levels of RTK activity can lead to oncogenic transformation. Sprouty, a protein first
identified in a genetic screen in Drosophila, is an inhibitor of the RTK /RAS/ MAP kinase pathway.
Four mammalian homologues of Sprouty have been identified, hSpry1-4; among these hSprouty2 has the
highest homology to Drosophila Sprouty. Recent studies in our lab have shown hSpry2 localizes to the
endosome, however, the mechanism that regulates this sub cellular localization and function has yet
to be identified. We are interested in characterizing the region(s) responsible for hSpry2 targeting
to the endosome, since this would give insight into how it is regulated and how it functions. HA-tagged
hSpry2 and a series of truncation mutants were expressed in COS-1 cell and analyzed by immunofluorescence
microscopy. In this study we have identified two regions responsible for hSpry2 localization to the endosome.
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Chanda Louis Oton
City College
Freshman
Civil Engineering
Faculty Mentor:
Dr. Perena Gouma, Assistant Professor
Department of Materials Science
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The Development of Biosensors
Generally the concentration of organic compounds and inorganic ions in the body represent the efficiency of the
metabolic functions of the organs. Thus in clinical diagnosis, it is imperative to know and be able to detect
what these compounds are, and their concentration levels. Our primary concern is to be able to easily and
effectively detect urea. Urea is a nitrogenous ((NH 4) 2 CO 3 ) substance found in excess in perspiration and
urine. It undergoes a process called the urea cycle, a five-enzyme cycle, which works to detoxify ammonia.
The first four enzymes are comprised from arginine biosynthesis; the fifth enzyme is argininosuccinate. In the
urea cycle disorder there is a deficiency in any of the five enzymes, which allows for the accumulation of ammonia.
An overabundance of ammonia can lead to irreversible brain damage. Because of its irreversibility, preventive
techniques have become favorable. Currently we are developing a new technique that will allow for us to detect
urea, by measuring the concentration of ammonia, using resistor biosensors, which are comprised of a ceramic
matrix and biological components that react with enzymes. When the analyte reacts with the enzyme it releases
ammonia, allowing for measurement of the ammonia.
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Stanley Pyram
Bronx, New York
Stony Brook University
Junior
Mechanical Engineering
Research Mentor:
Dr. Hui Zhang, Assistant Professor
Department of Mechanical Engineering
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Polyethylene
The purpose of this research is to determine the effects of spray parameters on surface roughness and
"splat" morphologies. The roughness analysis of spray polyethylene (spray at different
conditions for example air fuel ratio, standoff distance, speed, etc.) was done using an instrument
called Newview 200. Newview 200 is a three-dimensional Surface Profilers (Zygo) that characterizes
and quantifies surface texture, step heights and critical conditions. With this instrument
three-dimensional surface topography was obtained and used to determine which spray parameters have
the greatest influence on surface roughness. In addition the analysis of single splats of polyethylene
onto aluminum was done using a microscope to find how the morphology (i.e. shapes and sizes) of single
splats of polyethylene are affected by processing conditions.
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