A-G H-N O-Z Groups
Optimization of Robotic Elements Using CAD, CAM,
and Rapid Prototyping
Marni Hager
Mentor: Behzad Bavarian
California State University, Northridge
Robots today perform a variety of work from space
exploration on Mars to Search & Rescue work. Exploration and Search & Rescue
robots work in situations that present unique challenges for engineers trying to optimize
robotic movement. These robots require enough torque to navigate over obstacles and
sufficient speed to cover a large area. Complicating matters is the attempt to produce an
ideal manufacturability and assembly design, which aids in repair and maintenance. Design
iterations have become easier to perform and less time consuming due to newer technologies
including computer-aided design (CAD), computer-aided manufacturing (CAM), and rapid
prototyping (RP). This research began with a robotic gearbox that needed to have its
design optimized for ease of manufacturing and assembly while maintaining a nice balance
between speed and torque. The removal of the motor from the integrated motor-gearbox
design was necessary to achieve the manufacturability and maintenance goals, as well as
achieving size and weight goals. Multiple design iterations were made using I-DEAS, a CAD
software package. The new gearbox was produced on a ThermoJet RP modeler, which
provided another perspective for continued optimization.
Steam Pyrolysis & Hydro-Gasification of
Biomass
Eden Haile
Mentor: Colin Hackett
University of California, Riverside
Carbonaceous waste materials, such as raw sewage
and products of wastewater treatment, were converted to energetic gases using a
combination of steam pyrolysis and hydro-gasification. The objective of this study was to
produce gases with high calorific values such as CH4, CO, and C2-C3
hydrocarbon gases, while minimizing production of CO2. This was accomplished
using a batch micro-reactor system. The reactor containing the waste material was heated
by immersion in a molten salt bath maintained at a selected temperature. The reactor
effluent was then measured using a Residual Gas Analyzer (RGA), which provided continuous
measurements of the resulting gas species and their partial pressures. The systems
temperature (600 ºC to 700 ºC), water-to-carbon mole ratio, and peak reactant gas
pressure (6-21 atm) were varied independently to learn how the reactions were affected.
The recorded data indicated that as reactor temperature was increased, the total carbon
converted from biomass to product gases increased. In addition, as the peak pressure of
the gas reactant was increased, the total carbon conversion increased. Also, as the water
to carbon mole ratio was increased, the production of energetic gases and CO2
increased. Using the continuous record of chemical speciation measurements from the RGA,
reaction kinetics, rate constants, and activation energies were calculated. The highest
calorific value of the product gases was measured at 82% of the calorific value of the
biomass feed. The steam pyrolysis and hydro-gasification of sewage biomass has been shown
to be a feasible technology for the disposal of these waste materials and their conversion
to useful fuels.
Do MaxiK Channels, c-Src, and caveolin-1 Form a
Macromolecular Complex in Vascular Smooth Muscle of Aorta?
Seunggu Han
Mentor: Ligia Toro
University of California, Los Angeles
Vascular smooth muscle cells (VSMC) control blood
vessel diameter by their ability to contract and relax. The activity of VSMC is under the
control of various bioactive agents, such as peptides and neurotransmitters. These
agonists activate multiple cellular signaling pathways that, in turn, control
vasoconstriction or vasorelaxation. Recent studies in Dr. Ligia Toros lab have
described that several vasoconstrictors use MaxiK channels and c-Src tyrosine kinase, two
abundant proteins in VSMC. In this project, I hypothesized that MaxiK and c-Src coassemble
in specialized areas of the smooth muscle plasma membrane, known as caveolae, whose marker
protein is caveolin. In preliminary data collection, I was able to detect MaxiK, c-Src,
and caveolin-1 in aortic tissues using Western blots, specific antibodies, and infrared
fluorescence. Bands at the expected sizes were labeled, ~130 kDa (MaxiK), ~65 kDa (c-Src),
~25 kDa (caveolin-1). Also, I was able to successfully express MaxiK channels and c-Src
tyrosine kinase in HEK 293T for protein-protein interaction studies. My immediate goals
are to determine if MaxiK, c-Src, and caveolin-1 co-assemble in VSMC and if MaxiK channels
physically interact with caveolin and c-Src. Co-immunoprecipitation, immunoblotting, and
molecular approaches will be used. I will also examine c-Src and caveolin interaction with
MaxiK using MaxiK wild-type and MaxiK without c-Src and caveolin-binding motifs. The
results show that antibodies can readily recognize the three proteins in a specific
manner, and that sufficient amount of proteins can be recovered for protein-protein
interaction studies.
Determination of Activation Energy of Transitional
Metal EDTA Complexes
Steven Han
Mentor: Yong Ba
California State University, Los Angeles
In previous experiments, analyzation of the
behavior of metal-EDTA complexes has been thoroughly investigated by VT-NMR and
simulation. Depending on the type of metal binding to EDTA to form the metal-EDTA complex,
different splitting patterns arise. The results showed that depending on the Z/r2
of the metal cation, an AB pattern could be formed at room temperature if the ratio was
small. On the other hand, if the ratio was large, most likely a single line will arise
from the complex. This research investigated into more detail the three metals of EDTA
complexes, scandium, yttrium, and lanthanum. We examined these complexes to see if any
trends arose from using both VT-NMR and simulation methods. In analysis, with both
experimental and simulated spectra, linear correlation of all three metals arose and
physical characteristics can be summarized from these results, in particular, radii,
ionization energy, and electronegativity of the metal cations.
Development of a Generalized Transductional System
for the Bacterial Predator, Bdellovibrio bacteriovorus
Renee Hanlin
Mentor: Mark Martin
Occidental College
Bdellovibrio bacteriovorus is a relatively
uncharacterized bacterial predator of other Gram negative bacteria. Because there are few
genetic tools available to analyze this interesting but "undomesticated"
microbe, we have begun to develop a bacteriophage-driven system to move genes between
different strains of Bdellovibrio by generalized transduction. Phage Mombo was
originally isolated by Bentley Fane of the University of Arizona. We have demonstrated
that this Bdellovibrio specific bacteriophage can move genetic markers between
various host independent strains of this microbe, and even from host independent to
wild-type strains. We are currently working toward optimizing this process, and believe
that phage Mombo will be a useful tool for the genetic analysis of predation in Bdellovibrio.
Globalization and the Treaty Power of the United
States
Patrick Hardy
Mentor: Ronald Steiner
Chapman University
In the early 21st century,
globalizations momentum is having particular and unexamined effects on federal
systems. The most visible of these have come through the creation and implementation of
treaties to enforce the "law of nations," to ensure rule of law for nations that
engage in it. This paper argues, in the context of globalization, current legal
interpretations of the power to finalize treaties are a threat to the U.S.
Constitutions 10th Amendment definition of federalism. Part I examines
the enlargement of globalizations impact on citizenry in the 21st century
and the potential for even greater scope in years ahead. It assesses the impact that
globalization has had on the volume, negotiation, and content of treaties. It concludes by
observing that subjects previously considered domestic are now distinctly multi-national.
Part II highlights the position of treaties in U.S. and international law. It reviews case
law that suggests that any constraint on the negotiation or impact of domestic law can be
nullified by a treaty. By analyzing the approach that courts have taken on the supremacy
of treaties, this paper concludes that treaties will further impinge on domestic law.
Given this increasing encroachment, the principle of a limited central government promised
by the U.S. federal system of unified but sovereign states guaranteed by the 10th
Amendment is simply a technicality to be sidestepped whenever it presents itself as an
obstacle to the federal governments accommodation to globalization.
Effects of Histone Acetylation on
Glucocorticoid-Evoked Apoptosis
Elon Hartman
Mentor: Rheem Medh
California State University, Northridge
Apoptotic cell death is marked by changes in gene
expression that lead to organized cellular suicide. In lymphoid cell lines, glucocorticoid
(GC)-evoked apoptosis is associated with downregulation of c-Myc and cyclin D3, both of
which regulate the G1-to-S transition. The acetylation state of histones is
important to gene regulation, and histone hyperacetylation normally causes increased
levels of gene expression. The effects of inhibiting histone deacetylation on GC-evoked
apoptosis were tested in human leukemic T cells by co-treating cultures with dexamethasone
(Dex), a synthetic glucocorticoid, and trichostatin A (TSA), a histone deacetylase
inhibitor. Western blots were carried out to identify changes in gene expression, and cell
growth rates were measured to determine whether TSA would cause a decrease in sensitivity
to glucocorticoids. Results of the Western blots showed that, in cells treated with both
Dex and TSA, increased c-Myc levels were present relative to cells treated with Dex alone.
In contrast, cyclin D3 expression was notably reduced in co-treated cells compared to
those treated only with Dex. Low-concentration treatments with TSA alone showed no large
differences in either c-Myc or cyclin D3 expression compared to the untreated control. In
preliminary studies, low concentrations of TSA did not significantly alter cell growth
rate or GC-evoked cell death. These results indicate that changes in acetylation are
important for GC-associated reductions in c-Myc expression and that such changes may be
involved in the GC-evoked apoptotic response. Histone deacetylase inhibition appears to
have a secondary effect on cyclin D3 expression that must be pursued further.
Reforming Urban High Schools
Ali Hasan
Mentors: Mary Christianakis & Norm Olson
Occidental College
The focus of this research is to address the
question of how can we reform high school pedagogy to empower students. Currently, the No
Child Left Behind Act has established test score standards that are well beyond the
current performances of most inner-city high school students. This act depends upon a
behaviorist teaching method and pedagogy that encourages teachers to teach their students
through individualistic approaches, that reduce classroom interaction and socialization.
According to education scholars, such as Lisa Delpit, James Ogbu, and Gloria
Ladson-Billings, it is important that policies be written that will promote interactive
teaching methods and pedagogy that can empower students. Ogbus thesis, in
particular, is based upon the idea that many inner-city minorities feel that they are
involuntary minorities of America and that such a feeling causes them to distrust the
American educational system. Ogbu feels that the most effective way to gain the trust of
all inner-city students is to empower them, by giving them more freedom, choices, and
acceptanceideals that only interactive teaching methods could deliver, not
behaviorist ones. Through qualitative ethnographic observation, including interviews with
teachers, students, and experts of an inner-city high school of high minority
concentrations situated within an area of high poverty, in combination with the studies of
educational theories behind pedagogy, this study shows that interactive teaching methods
empower students, creating healthier learning environments for all types of learners,
regardless of race or socio-economic status, and most important to some legislators,
higher test scores. Ultimately, legislators ought to realize that the true solutions to
reforming the public education system do not lie solely within policies of increasing
budgets, introducing new standardized tests, or increasing score standards, but rather,
within addressing the pedagogy that is used inside the classroom itself.
Expression of Gossypol Biosynthetic Enzymes in E.
coli
Joy Marie Helou, University of La Verne
Mentor: Donald Pettigrew, Texas A&M University
The goal of this experiment was to construct a new
vector to allow expression of the enzyme d-cadinene synthase from cotton (DCS) in the DH5a
strain of Escherichia coli. It is well known that DCS catalyzes synthesis
of the sesquiterpene d-cadinene, which is the first committed intermediate in gossypol
synthesis in cotton. Gossypol is an important component of plant defense against pathogens
and insects. The DCS cDNA from plasmid pcdn1-C1 was amplified by using PCR with
primers designed to generate restriction endonuclease sites, which allow ligation of the
coding segment for DCS into a new expression vector, pTrc99A. To move the amplified DNA
insert into the new vector, both were cleaved with EcoR1 and Xba1, and the fragments were
joined by using T4 DNA ligase. The ligation reaction product was introduced into strain
DH5a via transformation of cells made competent by calcium chloride, and transformants
were selected by ampicillin resistance. Recombinants were screened for by (1) using
restriction endonuclease digestion of purified plasmid DNA and agarose gel electrophoresis
to detect the insert DNA, (2) SDS-PAGE on total cell extracts to detect DCS synthesis, and
(3) gas chromatography of ethyl acetate extracts of the cultures to detect enzymatic
synthesis of d-cadinene. The control plasmid pGEX CA1C-26 was observed to
contain an insert of the DCS cDNA. However, the DNA insert was not found in the pTrc99A
constructs, and the cell extracts did not contain DCS protein or synthesize detectable
levels of d-cadinene.
Influence of Discharge and Location on Debris Pile
Volume and Composition
Aaron Hopkins
Mentors: Darren Stoub & Cheryl Swift
Whittier College
Natural rivers have the ability to trap debris
floating downstream where it accumulates essentially forming a dam, channel bar, or new
bank. These debris piles slow current velocity reducing the waters capacity to
transport sediment and nutrients so that even more sediment is deposited in the debris
pile. We conducted a study on the East and West Forks of the San Gabriel River in July and
August of 2003 in order to determine the effect of stream discharge, and location of the
debris pile in the streambed cross section on the size and composition of debris piles.
Debris pile volume was related to discharge as well as location in the streambed cross
section. Reaches with higher stream discharge showed greater debris pile volumes on the
floodplain, but lower volumes in piles on the bank and in the stream. The number of stems
and the size of stems growing in debris piles were correlated with increased debris pile
volume. Increasing numbers of stems can increase the sediment trapping function of debris
piles as well as anchor the debris pile. These results suggest that increased amounts of
sediment can be trapped on floodplains during periods of increased stream discharge.
Global Optimization for Molecular Systems
Gene Hsiao
Mentor: Gary Huber
University of California, San Diego
Understanding the structure of proteins is a
crucial step toward new drug development, preventative treatment, and improved care for
those already afflicted with disease. Unfortunately, according to the Levinthal Paradox,
it would take longer than the age of the universe to discover the correct folding state
through brute-force computational means; nature can solve this NP-complete problem and
correctly fold a protein in less than a minute. Simulated annealing may be a more
efficient approach for reaching the correct folding state. This research investigates the
effectiveness of several different simulated annealing approaches for finding the global
minimum of complicated energy functions that may describe proteins. We employ molecular
dynamics, a Monte Carlo Markov Chain heuristic, a hybrid of the aforementioned, and
finally the weighted-ensemble simulated annealing method. These methods are applied to the
Lennard-Jones function, which, despite having a trivial minimum for a single pair of
neutral atoms, becomes a complex energy landscape across a larger number of particles when
many of these curves are superimposed. Furthermore, energy minimization of atomic clusters
has very practical importance for physical scientists, particularly in the case of protein
structure prediction.
Investigating a Novel Lifespan Gene in Drosophila
melanogaster
Richard Hsu
Mentor: Brian Zid
California Institute of Technology
Aging is a universal process among living
organisms in which homeostasis decreases and chance of death increases with age. Trying to
understand aging in a simpler organism, such as Drosophila, is a possible
intermediate step in understanding aging in humans. A screen for lifespan extension was
performed using a driver line and a collection of EP lines. A driver line has a P-element
that expresses the yeast transcriptional activator, gal4, while an EP line has a
complimentary P-element that contains the DNA binding sequence of gal4. When a driver is
crossed to an EP, the region downstream of the EP will be overexpressed. The mutant EP3306
was identified and found to have a reproducible lifespan extension. The EP3306 insertion
site was found, and the putative gene overexpressed appeared to be an uncharacterized
gene, CG7900. A genomic transgenic was constructed to verify that overexpression of CG7900
extends lifespan in an independent line. A recombinant was made between EP3306 and the
daughterless-gal4 driver to look at interactions with other long-lived lines in the lab.
Results show that CG7900 is the cause of increased lifespan and the gene itself seems to
play a vital role in metabolism. In conclusion, the EP is located 300 base pairs upstream
of the CG7900 gene, which has a high sequence similarity to a human protein. Hence, the
understanding of how overexpression of CG7900 extends lifespan could be important to not
only the understanding of fly aging, but also the aging process in humans.
The Distribution and Binding Partners of the Motor
Protein Kinesin II in Resting and Carbachol Stimulated Lacrimal Acini
Jasmin Hu
Mentor: Sarah Hamm-Alvarez
University of Southern California
Kinesin II is a member of the kinesins, one of two
families of microtubule-based motor proteins, the other being the cytoplasmic dyneins. It
is a plus-end director of the movement and transport of organelles in the cell,
particularly secretory cells. Previous studies on melanophore transport in Xenopus
melanocytes suggest that kinesin II interacts and requires the dynactin complex, a
cofactor of cytoplasmic dynein, in transport activity. I decided to address if that would
be true in lacrimal acini, secretory epithelial cells responsible for production and
release of tear proteins. Further, I explored whether secretagogue stimulation, which
stimulates exocytosis that utilizes cytoplasmic dynein and dynactin, would cause changes
in the interaction of kinesin II and dynactin. I used immunofluorescence staining to
determine the distribution of kinesin II and its association with the p150Glued
subunit of dynactin. I found that kinesin II and p150Glued strongly
co-localized after stimulation, showing that kinesin II and dynactin interact at secretion
sites. To further test this, I used co-immunoprecipitation, and found that after
stimulation, antibodies against kinesin II pulled out p150Glued, and in the
reverse experiment, antibodies to p150Glued pulled out kinesin II. This led to
the question whether kinesin II would be associated with dynein, since both utilize
dynactin in their functions. Further immunoprecipitation revealed that kinesin II also
pulled down the intermediate chain of dynein. These results indicate that kinesin II and
dynactin interact in lacrimal acini, and dynactin bind to dynein and kinesin II
simultaneously.
Exposure of the Hyperthermophilic Anaerobe Pyrococcus
furiosus to Oxygen
Charles Hummel
Mentor: E.J. Crane
Pomona College
Pyrococcus furiosus is a hyperthermophilic
archaeon found in hydrothermal vents. These strict anaerobes require a strongly reducing
environment in order to grow. Extensive preliminary studies were undertaken in order to
determine the proper growth conditions for Pyrococcus prior to exposing it to
stress conditions. It was determined that despite their anaerobic nature, it is necessary
to shake liquid cultures of Pyrococcus, especially during growth with insoluble
elemental sulfur. This greatly reduces both the variability and length of the lag phase of
growth. Previous studies have shown that Pyrococcus is able to survive exposure to
oxygen at lower temperatures. We are interested in whether this survival is due to the
organism actively removing oxygen from its environment, or whether the organism is simply
protected by decreased rates of oxidation of cellular components at lower temperatures. Pyrococcus
cells at a defined temperature are exposed to oxygen, and oxygen consumption is measured
using a heat-stable oxygen electrode, which can be inserted through a septum into the
sealed media bottle. Through these results, we hope to determine whether the survival of Pyrococcus
cells exposed to oxygen at lower temperatures is due to the action of an oxidative stress
response system or whether it is due to reduced susceptibility of Pyrococcus in
oxygen at lower temperatures.
VEGF-mediated Response to Acute Cerebral Ischemia
Andrew Hurder
Mentors: Dave Bourgaize & Cheryl Swift
Whittier College
Following an acute ischemic stroke, hypoxia occurs
in nearby cerebral tissue. Hypoxia induces the expression of vascular endothelial growth
factor (VEGF), which in turn increases vascular permeability and edema in the brain,
leading to tissue damage. This study is aimed at understanding how endothelial
cell-signaling pathways facilitate this response, specifically to identify the role of
focal adhesion kinase (FAK) in the VEGF-induced physiological response to acute ischemic
stroke. FAK mutants have dramatically reduced volumes of damaged tissue following a
stroke. FAK phosphorylates through several integrins and kinases in this cell-signaling
pathway, such as Src and Erk1/2. My study is localized on the signaling of FAK expression
through endothelial cell barriers within murine and cell culture models. My data shows
that FAK is expressed through growth factors in mouse embryonic fibroblast cells,
visualized in SDS-PAGE experiments.
JnK: A Genetic Framework for Distributed Discovery
Mechanisms
Khanh Huynh
Mentors: Tatsuya Suda & Junichi Suzuki
University of California, Irvine
In todays technology, peer-to-peer (P2P)
systems offer a simple and efficient way to store and access large amounts of data. P2P is
a type of network that takes advantage of distributed resources available by sharing. The
explosive growth of P2P applications in recent years is due to the fact that these systems
provide low cost, high availability of large number of computing and storage resources,
and high network connectivity. Many existing P2P protocols have different capabilities,
transportation, and needs
thataasfdsthat required by a variety of network
applications. Due to the different needs of network objects, an extensive survey was
conducted to develop a generic framework to improve the chances of locating and storing
network resources. Selectively, P2P systems, such as Gnutella, Freenet, Chord, NeuroGrid,
and Tapestry, and genetic frameworks, such as Microsoft .Net, Unified Peer-to-Peer
Database, JXTA, Structured Peer-to-Peer Overlays, and Anthill, were chosen to identify
common and genetic interfaces and data structures. Well-known lookup mechanisms, such as
Distributed Hash Tables (DHT), Decentralized Object Location and Routing (DOLR), and Group
Anycast and Multicast (CAST), that provide a foundation to develop a genetic framework are
carefully analyzed. As a result of the survey, I implemented a new P2P protocol called
GnutellaUNI that provides a more complicated and enhanced search criteria called
compound-search. My stimulation of genetic framework called JnK implemented Gnutella,
Freenet, NeuroGrid, and GnutellaUNI protocols. The implementation of the JnK framework is
written in JAVA and CORBA as a middleware to develop and deploy distributed applications
The Oxidation of L- and D-Dopa by Synthetic Mimics
of Metal-ion Containing Enzymes, such as Tyrosinase and Alkaline Phosphatase
Robert Iafe
Mentor: James Roe
Loyola Marymount University
The interest in enzymes is due to several factors:
their dynamic and essential role in the cell, their extraordinary catalytic power, and
their selectivity. In this experiment, two characteristics will be evaluated: enzyme
activity as a function of structure and molecular selectivity. I propose to determine
whether the copper and zinc ion derivatives of tris[2-(3,5-dimethyl-1-pyrazoyl)methyl]
amine and that of tris[2-(3,5-dimethyl-1-pyrazoyl)ethyl] amine serve as reasonable models
of the active sites of metalloproteins, such as tyrosinase, which contains copper, and
alkaline phosphatase, which contains zinc. The activity of the mimics to catalyze the
oxidation of L- and D- dopa (3,4-dihydroxyphenylalanine; a precursor to the
neurotransmitter, dopamine) in aqueous solution will be compared with that of the native
enzymes. It has been shown that the copper complex of TPM successfully mimics the
reactivity of the enzyme tyrosinase in the catalysis of the oxidation of catechol in
methanol solution (Malachowski et al., 1992). It was speculated in this article that the
difference in reactivity between the two complexes depends on the differences in geometry.
Another speculation is that the TPE complex completely surrounds the copper ion and due to
steric hindrance the substrate is unable to approach the metal ion directly in order to be
oxidized. In addition to monitoring the activity due to the different geometries of
the model compounds, different metal ions will be substituted in order to determine which
serves as the most effective catalysts. By experimental analysis of changes in geometry
and metal ion substitution on the oxidation of dopa, insights should be gained on the
mechanism of tyrosinase.
In Situ Hybridization of Melk in Embryonic,
Newborn, and Adult Mice Brains
Sylvie Inkindi
Mentor: Harley Kornblum
University of California, Los Angeles
Maternal embryonic leucine zipper kinase (Melk) is
a gene in the Snf1/AMPK serine/threonine kinase family. Members of this family contribute
to cell survival in response to nutrition starvation. Melk has a leucine-zipper motif
within the N-terminal catalytic domain. This motif allows for protein-DNA and potentially
protein-protein interactions (Seong et al., 2002). Melk is differentially expressed during
mouse embryogenesis. In germ cells, an intense signal is detected in mitotically active
stem cells called spermatogonia (Heyer et al., 1999). This suggests that Melk is expressed
in highly proliferating cells. The identity of the Melk gene as a neural progenitor gene
was assessed using microarrys comparing neural stem/progenitor cells against
differentiated cells derived from a representational difference analysis (RDA)
subtraction. In situ hybridization demonstrated that Melk is expressed in the
germinal zones of the developing mouse brain. This is consistent with Melk playing a
specific role in neural progenitor or stem cells (Geschwind et al., 2001; Easterday et
al., submitted). The present study focuses on the expression of Melk in whole brain
sections of embryonic, newborn, and adult mice using in situ hybridization.
Taming the Elusive 310-helix: Synthesis
and Conformational Analysis of Olefinic Heptapeptides
Wendy Iskenderian
Mentor: Daniel OLeary
Pomona College
Although not as widely recognized as the a-helix,
the 310-helix is becoming increasingly recognized as an important structural
motif in smaller, hydrophobic and biologically active peptides. Previous NMR studies from
these laboratories have shown that 310-helix stabilization can be achieved in
heptapeptide model compounds (modeled after Karles peptide) using serine allyl
ether-derived RCM crosslinks connecting the i,i+4 amino acid side chains. We have
demonstrated that the ring-closing metathesis reaction can be used to install a chemical
crosslink between the i,i+3 serine side chains in a related heptapeptide. Current research
is focusing on the synthesis and conformational analysis of the related homoserine
heptapeptide. Computational studies suggest that the size of the RCM-derived macrocycle
(as determined by the use of serine vs. homoserine allyl ether) can profoundly influence
the preferred helix type in the i,i+3 tethered heptapeptide. It is expected that both the
i, i+3 tethered serine and i, i+3 tethered homoserine cyclic heptapeptides will form
stable 310-helices in the solution phase, which will be investigated by
circular dichroism studies this winter (which we will perform at the University of
Wisconsin). Additionally, NMR temperature dependence studies are being performed to
compare the solvation of the amides in both the cyclic and the acyclic serine
heptapeptides.
Reaction of 2-Alkyl-3-Bromo-1,4 Naphthoquinone
with Amines; A Novel Demethylation Reaction
Cameron Iverson
Mentor: Tetsuo Otsuki
Occidental College
Derivatives of 1,4-naphthoquinone are utilized as
anti-fungal, antibacterial, and potential anticancer pharmaceuticals, which often show
unexpected reactivities. Here we study the reactivity of
2-bromo-3-methyl-1,4-naphthoquinone toward primary and secondary amines. In the reaction
with primary amines in methanol, contrary to our expectations, demethylation of
2-bromo-3-methyl-1,4-naphthoquinone generates 2-alkylamino-3-bromo-1,4-naphthoquinone as
the major product. Furthermore, secondary amines such as N-ethylmethylamine gave
2-methylamino-3-bromo-1,4-naphthoquinone, presumably as the secondary reaction product.
Unexpectedly, the reaction of 2-bromo-3-ethyl-1,4-naphthoquinone with primary, secondary,
and tertiary amines yields very different results. In the reaction
2-bromo-3-ethyl-1,4-naphthoquinone with propylamine, for example, substitution occurs for
the bromine. We believe this is due to the varying acidity between the two
2-alkyl-3-bromo-1,4-naphthoquinones. The scope and limitations of the reaction and
reaction mechanism are studied.
Functional Enzyme Microarrays
Aaron Jacobs, Harvey Mudd College
Mentor: Angelika Niemz, Keck Graduate Institute
Biochemical activities for gene products of newly
sequenced genomes are generally obtained via functional annotation based on sequence
homology to known proteins, an approach that is often incomplete and at times misguiding.
To analyze entire proteomes, a high throughput method must be available to determine
functionality of each expressed protein. Due to the fragile nature of proteins, most
assays are performed in a homogeneous format using microtiter well plates, which limits
the miniaturization possibilities. By immobilizing the protein in micron-scale surface
bound hydrogel pads, a protein microchip can be developed, leading to drastically
increased integration density. During this project, we optimized techniques for obtaining
reproducible microarrays as a function of several variables. Then we developed an
alternate procedure for modifying proteins with acrylamide functional groups, which
enables copolymerization of the proteins into the hydrogel matrix. Multiple assays using
the fluorogenic substrates Amplex Red and Quanta Blu were employed in an attempt to
analyze the activity and kinetics of Horseradish Peroxidase microarrays. To develop a
practically useful screening system, functional protein microarrays were fabricated
through a combination of affinity capture and copolymerization. This method is applicable
to protein A fusion proteins, relying on the Fc fragments affinity for protein A. Fc
fragments were acrylamide modified and immobilized in the hydrogel matrix, which provides
an affinity support for future enzyme microarray studies.
Expression of Markers of Microglial Activation in
Alzheimer Disease (AD) in Relation to Severity of Cerebral Amyloid Angiopathy (CAA)
Syed Jaffery
Mentor: Harry Vinters
University of California, Los Angeles
Tissue microarray (TMA) is a procedure by which
autopsied brain tissues from similar regions of multiple cases can be studied on one
slide. A TMA was created from Alzheimer Disease (AD) patients having severe cerebral
amyloid angiopathy (SCAA) vs. minimal cerebral amyloid angiopathy (MCAA). A TMA, including
samples of cortical and subcortical regions from the brains of 29 autopsied AD patients,
was analyzed. The TMA was stained with an antibody directed against MHC-II, an indicator
of microglial activation. We hypothesize that there are differences in microglial number
and/or distribution, which may result from differing degrees of CAA in the two groups of
AD (SCAA and MCAA). Microglial counts were performed using the Olympus BX-40 compound
microscope at 400 magnification. The cell counts of immunoreactive microglia were
correlated with the degree of CAA. The data obtained was analyzed using students
t-test. The t-test showed no statistically significant difference in microglial MHC-II
expression between the two groups examined. The subcortical region contained significantly
greater numbers of immunoreactive microglia in each group (SCAA p = 0.0242 and MCAA p =
0.0396). Further studies are planned using lymphocyte function associated antibody-1
(LFA-1) as well as markers of glial proliferation.
Processing and Characterizing Bulk Metallic
Glasses (BMGs) and BMG Composites
Tracy Janov
Mentor: Ersan Ustundag
California Institute of Technology
Bulk Metallic Glasses (BMGs) are metal alloys that
are stronger than steel and also are fracture-resistant and highly ductile because of
their high elastic strain limit. Their potential uses range from golf clubs to cell phone
casings to aircraft frame components. To develop BMGs, a sample is produced in a vacuum
chamber and cooled very rapidly. Then x-ray diffraction analysis identifies its phase, a
detailed microscopic study reveals how the dendrites form inside the glass matrix, and
tensile and compression trials test its strength. It is important to understand how the
shear bands that form in the matrix interact with their metallic reinforcements at the
microstructural scale so that we can understand why certain composite mixtures have more
desirable properties than others. Although BMG samples are limited to being small so that
their cooling rate is high enough, they are easily produced and represent a breakthrough
material that is already being used in various industries.
Rootless Matrices
Camden Jansen
Mentor: Scott Annin
California State University, Fullerton
Given a square matrix, we ask: Does it have a
square root? If the matrix is diagonalizable, you may know that the answer is always
"yes." But what about in general? And what about cubed roots, such as 4th
roots, 5th roots, and so on? This project describes my research on the
classification of rootless matrices. A rootless matrix is a square matrix that fails to
have a square root, cubed root, 4th root, and so on. This work generalizes
results published by B. Yood in Mathematics Magazine (June 2002) by using the
machinery of Jordan Canonical Forms. After reviewing this important tool, I will use it to
present the solution to the classification problem described above. That is, we describe
precisely which square matrices possess roots. The results may surprise you, and they lead
to a host of other intriguing questions as well.
Power Structures and Empire
Doug Jensen
Mentor: Nikhil Singh
University of Washington
Official discourse, particularly in matters of
foreign policy, is saturated by politically expedient exhortations in the United States.
While this may seem to be a relatively new phenomenon in the midst of what the Bush
Administration calls the "War on Terror," the ideas presented by political
officials, and the actions that result from these ideas are not spontaneous creations.
Indeed, the current ideology of those in power has much in common with the ideals and
logic of liberalism as it emerged in the 19th century. Hence, if we are to gain
some kind of understanding of this present moment, it is necessary to view similar periods
of international aggression in the past. The United States invasion of the
Philippines is such an example. Upon examining a wide variety of sources including news
accounts from the period, speeches made by political figures, letters to the editor, and
personal accounts, three methods of control and dominance that lie within the
"language of freedom" emerge. First, factual events were deliberately
misrepresented by authorities. Secondly, assumptions not subject to the burden of proof
were widely espoused. Finally, the logic of officials such as Theodore Roosevelt or John
Hay centered on extremely authoritarian conceptions of "freedom." The results of
these methods in practice make it immediately clear that if peoples of the world are to
ever discover what democracy or freedom mean, then the actions of the powerful have
extremely little to offer them in their search.
Optical Sensor for Non-Invasive Detection of Oral
Cancer
Goldwyn Jequinto, University of California, Irvine
Mentor: Petra Wilder-Smith, University of
California, Irvine & Loma Linda University
Using existing techniques, non-invasive diagnosis
or monitoring of oral pathologies is not possible. The object of this investigation is to
identify in vivo fluorescence excitation/emission spectral characteristics of
healthy and pathological oral tissues using a non-invasive fiber-optic diagnosis system.
In patients referred to UCI Medical Center Department of Otolaryngology and/or UCI Cancer
Center for inspection of existing leukoplakias and erythroplakias, in vivo
multi-wavelength excitation/detection spectra from normal and pathological sites were
acquired using a flexible fiber-optic system prior to conventional biopsy. Spectral
characteristics of dysplastic, malignant, and other pathological sites were identified and
characterized. Detailed diagnostic status of each lesion mapped was obtained from
histopathological sections of the biopsy tissues. Considerable differences were
consistently observed between spectral emissions of the different pathologies
investigated, based mainly on changes in tissue extracellular matrix, vasculature, and
tissue metabolic state. Characteristic in vivo spectral signatures were identified
for a wide range of oral histopathological diagnoses.
Sex Differences in Mating Preferences for Humor
Jennifer Joeyen-Waldorf
Mentor: David Rakison
Carnegie Mellon University
Evolutionary psychology makes predictions about
human behavior based on what behaviors would have been adaptive in the environment of
evolutionary adaptation (EEA). The aim of these studies was to examine sense of humor in
the context of evolutionary psychology. Buss found that sense of humor in potential mates
was highly and equally important to males and females (1988). We have recently determined,
by examining online personal advertisements (n = 2,640), that in a mating context, females
seek out males with an "active" sense of humor (saying or doing something
funny), while males seek out females with a "responsive" sense of humor
(laughing at or appreciating something funny). We identified this effect in countries in
Europe, North America, South America, Africa, and Asia. We have also used self-report to
examine the possibility that "active" and "responsive" senses of humor
are predictors of other traits already known to be valued by females or males in a mating
situation (for example, fidelity, dominance, or generosity), which may have caused
selective pressure for these mating preferences during human evolution.
Constructing Social Difference in the Everyday
Lives of Children
Nastassia Isis Johnson
Mentor: Marjorie Goodwin
University of California, Los Angeles
The reality of everyday life in the United States
is laden with discrimination based on differences ranging from ethnicity, socioeconomic
status, physical features, and disability. Likewise, knowledge of these social differences
greatly influence the thoughts and actions through which people construct their everyday
lives and such notions of difference are readily available to children simply through the
direct observation of the world around them. However, it has been held that young children
are incapable of critically understanding the implications of ethnic or class matter.
Through my research I investigate when, where, and how children as young as four
understand concepts of social difference. Moreover, my research has focused on the
relationship between this knowledge and the tendency to use this information in the
construction of meaning, expression, and conduct in childrens own social milieu.
Through naturalistic observations of two groups of 20 four-year-old children at a school
environment and daycare setting, I have found that children are aware of concepts about
difference through the behaviors and verbal discourse demonstrated. I suggest that ideas
of difference, such as ethnicity, correlate with ideas about social class differences and
both are used by children in their peer interactions. Through analysis of the data
(extensive field notes) of my observations, I have assessed that childrens behaviors
and expressed beliefs differed based on location and were heavily influenced by
teacher/adult expressed beliefs and behaviors and their involvement with the children
during peer interaction. As a result, the construction of social difference by children is
important because such behavior is not only harmful to its target, but over time this
behavior contributes to the continuation of discrimination and victimization.
Competence of Escherichia coli in the
Transformation of Plasmid PBR322
Kelly Kawashiri
Mentor: Steven Goodman
University of Southern California
Escherrichia coli (E. coli) is mainly found
in the intestines of animal and humans. It is helpful in the aid of breaking down food. In
my lab, this bacteria, however, is commonly used to make copies of plasmid DNA. E. coli
does this is through transformation, which is the extracellular uptake of DNA. Although in
previous research it was discovered that the range in competence varied with temperature.
In my project I had to find the specific range of temperature in which the E.coli
was most competent and then find out the reason for its competency. I first ran
preparatory tests for the DNA plasmid PBR322. I had to be sure that I was growing the pure
plasmid DNA before finding the E. colis competency. I isolated the DNA by
using an antibiotic. Then I grew the E-coli and the DNA plasmid in different
temperatures ranging from body temperature to 20 ºC.
Curcumin in Curry Powders: Quantitation by High
Performance Liquid Chromatography
Fatima Khwaja
Mentor: Cheryl Rock
University of California, San Diego
Curcumin, derived from the rhizome, Curcuma longa
L., is one of the principal ingredients in turmeric and curry powders used as a spice in
Asian Indian cuisine. More recently, laboratory and clinical research has shown that
curcumin has the potential to contribute to the prevention of cancer and other chronic
diseases. Specifically, studies have demonstrated that dietary curcumin significantly
inhibits colon tumorgenesis and tumor size in animal models. While the manufacturers of
the various spices and curry powders list the ingredients in a relatively quantitative
manner, they do not give exact amounts. In order to determine and compare the quantitative
amounts of the curcumin that is present in various curry powders, a high performance
liquid chromatography (HPLC) technique was used. It was found that pure turmeric had the
highest curcumin concentration, averaging 1.25% curcumin. The curry powder samples, with
one exception, had large differences in curcumin content and relatively small amounts
present. Considering bioavailability of the compound, these differences could possibly
have significance in terms of its influence in chemoprevention.
Rational Polygons: Construction and Properties
Radoslav Kirov
Mentor: Ramin Naimi
Occidental College
The majority of geometric constructions do not
produce rational "parts." For example a triangle with rational sides seldom has
rational area. This research was on the existence of so-called rational polygons, namely
polygons with rational sides, diagonals, and area. We found a construction method for
producing rational polygons with an arbitrary number of sides. Moreover we proved certain
properties of those polygons. For any rational polygon, all segments of the lines formed
by extending the sides and diagonals are rational and so are all areas bounded by those
lines.
Dendritic Growth Cones and Recurrent Basal
Dendrites are Typical Features of Newly Generated Dentate Granule Cells in the Adult
Hippocampus
Matthew Korn
Mentor: Charles Ribak
University of California, Irvine
Granule cells in the hippocampal dentate gyrus are
generated throughout the adult life of mammals, and recent studies indicate that they are
incorporated into neural circuitry and mature into functional neurons. To determine
whether newly generated granule cells form dendritic growth cones during this process of
synaptogenesis, we used the immunocytochemical method to label within these neurons
doublecortin, a protein associated with microtubules found in neuronal growth cones of
newly generated granule cells. Here we show that both dendritic growth cones and recurrent
basal dendrites are common features of newly generated dentate granule cells. As
previously described, these cells appeared along the hilar border of the granule cell
layer as well as in the subgranular zone of the dentate gyrus. These observations for
growth cones suggest that dendrites of newborn neurons in the adult nervous system grow in
a similar way as those found in the immature brain. This study is significant because it
is the first to show dendritic growth cones in the dentate gyrus of the adult nervous
system.
Zinc Oxide Growth as Thin Film Transducer
Haroon Lais
Mentor: William Tang
University of California, Irvine
The high quality of the zinc oxide piezoelectric
thin film transducer is used on the micro-scale resonator application. Using the radio
frequency (RF) sputtering technique, there are several parameters including pressure,
temperature, Ar/O2 ratio, and RF power that will influence the quality of the
thin film. These parameters will determine the crystal orientation, grain size, surface
roughness, and the deposition rate of the piezoelectric thin film. To characterize the
thin film, scanning electron microscopy (SEM) is used to investigate the grain size,
surface roughness and the cross-section of the crystal orientation. X-ray diffraction
technique will also be used to determine its crystal orientation.
Microarray Analysis of Longevity in Drosophila
melanogaster Mutants
Anna Lam
Mentor: Horng-Dar Wang
California Institute of Technology
Aging is the biological process of deterioration.
A prominent factor for the span of longevity in organisms is their physiological ability
to resist different stresses. In previous studies, a forward genetic screening for
multiple stress resistance has led to the discovery of several long-lived Drosophila
mutants. Among them, 1101, 1130, and 2456 have been able to resist stresses
of paraquat poisoning and starvation while having life spans up to 35% longer than the
control w1118. The genetic factors of these three mutants longevity are not
clear. The "reverse genetics" method is particularly useful in addressing this
problem. Because all three mutants are long-lived, the genes co-regulated among them may
provide a clue to the biological pathway of longevity. To narrow the genes for longevity,
I used the relatively new Affymetrix GeneChip microarray technology to analyze the
genome-wide expression of the 13,976 genes in the three mutants. Analysis of this data
allows me to find genes that are either over or under-expressed in all three mutants
compared to genes of the control. Investigation of the particular function of all these
common genes may lead to the identification of the biological processes for longevity.
Better understood, the candidate genes found from this analysis might prompt solutions to
human aging in the future.
Detection of Small Molecular Weight Thiols in Pyrococcus
furiosus
Kyle Lancaster
Mentor: Edward Crane
Pomona College
Oxygen, so necessary to terrestrial life, spells
death for many deep-sea thermophilic microorganisms. Such organisms do, however, possess
mechanisms to counter the ill-effects of oxidative stress. Genomic and biochemical data
gathered for the hyperthermophile Pyrococcus furiosus suggests that one method of
coping with oxidative stress is through the activity of the enzyme Coenzyme A disulfide
reductase (CoADR), an enzyme that keeps the low-molecular weight thiol coenzyme A (CoA) in
a form that can be used to reduce oxygen or other reactive oxygen species. The presence of
this enzyme suggests the presence of high concentrations of CoA within Pyrococcus.
However, as of now it is not known whether CoA is present at high levels within the cells
or rather if the CoADR uses another thiol as its substrate. Using fluorescence labeling,
we sought to determine what thiols were present within the cells. Pyrococcus cells
were labeled with monobromobimane (MBBr), a reagent that produces fluorescent adducts upon
reaction with thiols. Following extraction, the labeled thiols were separated
chromatographically via HPLC and compared to standards. Cellular thiols present in
disulfide linkages were also analyzed by assaying in the presence of dithiothreitol, a
disulfide reducing agent. We found strong evidence for the presence of high concentrations
of CoA in Pyrococcus.
Studies in the Purification and Structure
Characterization of a Helical Heptapeptide
Erica Lanni
Mentor: Daniel OLeary
Pomona College
The importance of helical peptides for applied
chemistry and biochemistry has inspired much research into stabilizing and manipulating
their structures. We have been exploring the properties of a family of such helical
peptides for a number of years. Currently, research is focused on the tethered and
non-tethered variations of the heptapeptide
Boc-Val-Ser(O-Allyl)-Leu-Aib-Ser(O-Allyl)-Val-Leu-OMe. In this instance a tether can be
formed using the Grubbs ruthenium olefin metathesis catalyst between the two O-allyl
serine residues located in the i and i+3 positions. In this study, we report methods for
purifying the acyclic heptapeptide and the cyclic isomers using high performance liquid
chromatography. We also used NMR spectroscopy to study the degree of intramolecular
hydrogen bonding within the peptide helices. Finally, we looked at differences in the
cis/trans selectivity using two versions of the Grubbs catalyst, where we found the
"second generation" Grubbs catalyst to be far more trans-selective when
tethering the serine O-allyl functional groups.
An Analysis of Hamptonese Using Hidden Markov
Models
Ethan Le
Mentor: Mark Stamp
San Jose State University
The mysterious writing system known as Hamptonese
has baffled cryptologists for the past 40 years. Hamptonese was developed by James
Hampton, a Washington, DC, janitor who also created an amazing work of visionary art
entitled "The Throne of the Third Heaven of the Nations Millennium General
Assembly." While the Hamptonese text clearly has some religious significance, nothing
specific is known of its content or meaning. In our research, we analyzed Hamptonese using
Hidden Markov Models (HMMs). HMMs provide probabilistic information about the underlying
state of a model, given a set of observations of the system. In our model, the Hamptonese
text is the set of observations and the underlying (and unknown) language is the hidden
part of the HMM. This approach was used as a tool to help determine whether Hamptonese was
composed as a simple substitution of English or any other known language. To this end, we
also cross-referenced Hamptonese symbols with 232 languages. In addition, we examined
Hamptonese in connection to its biblical references, writing patterns, and organizational
patterns. Although our results did not decipher the text, we have clearly established that
Hamptonese is not a simple substitution of characters for letters in English text.
Furthermore, our analysis did not reveal any significant similarities to other languages.
However, organizational patterns and biblical passages found in Hamptonese do suggest
possible interpretations of the text. Our work has yielded the first substantive results
in the analysis of Hamptonese and will prove valuable to future researchers studying this
language.
Method of Constructing Distributed Parallel
Threads Using Templates
Michael Le
Mentors: Lubomir Bic & Michael Dillencourt
University of California, Irvine
The process of generating distributed parallel
code from sequential code is a complex task. Such conversion requires sequential code to
be mapped into some form dependency graph. Any sequential code to dependency graph
transformation requires the analysis of loops. Most loops from modern programs have
lengths that are dynamic in nature. A static dependency graph representation of loops of
variable length is unacceptable. We propose using meta-graphs, or templates, to represent
these loops. Templates capture the overall dependency of a loop and not its actual
dimensions, thus templates lead to a more natural representation of loops with variable
lengths. Because dependencies of a loop are represented in these templates, it is possible
to construct threads, specifically distributed parallel threads, for a loop without having
to know the loops actual dimension. The method of constructing threads is made
concrete by comparing the thread layout between two methods of loop representation, static
dependency graphs and templates. It can be shown that the thread layout using templates
accurately matches the thread from the static dependency graph with the important addition
of being generalizable to a loop of variable length. It is expected that the template
representation of loops and the method of constructing distributed parallel threads using
templates will greatly assist in the future goal of automating the transformation of
sequential to distributed parallel code.
The Evolution of Rhodopsin in Nymphalidae
Lawrence Lee
Mentor: Adriana Briscoe
University of California, Irvine
Rhodopsin is a G-protein coupled receptor in
photoreceptor cells that is light sensitive. In butterflies, it is composed of an opsin
protein covalently attached to the chromophore, 11-cis-3-hydroxyretinal. The
chromophore alone absorbs light in the ultraviolet regions of the spectrum; however,
certain amino acids in the chromophore binding pocket of the opsin protein can increase
the peak absorbance (l max) of the visual pigment to the longer wavelength
region. Furthermore, previous studies in butterflies have shown that amino acid changes in
the opsin protein have led to red-shifted sensitivities (Briscoe 2001, 2002). This
research studies the amino acid composition of the opsins in butterfly species with
independently evolved red-shifted pigments to determine what evolutionary events have
taken place that may be responsible for the physiological shift in sensitivity. We chose
two species with red-shifted sensitivities, Danaus plexippus and Anartia
jatrophae, and one species with the ancestral, green-sensitivity, Inachis io.
For each of the species, I performed polymerase chain reactions (PCR) using two or more
sets of primers and cloned the PCR products. After extracting the plasmids from selected
clones with the DNA insert, I sequenced the plasmid DNAs. I obtained partial opsin gene
sequences for all three species. These data were compared with previously published green-
and red-sensitive pigments and examined for amino acid substitutions that are correlated
with known spectral tuning sites in vertebrates and insects.
Studies of Critical Micelle Concentration Using
Capillary Electrophoresis
Michael Lee
Mentor: Phoebe Dea
Occidental College
The formation of sodium dodecyl sulfate (SDS) and
chlorpromazine hydrochloride (CPZ) micelles was studied using capillary electrophoresis.
The elution time of a neutral marker was used to determine when the surfactant had changed
from its monomer to micelle form. The markers interactions with the surfactant
changed as the monomer formed micelles, and caused the markers elution time to
change as well. The elution times of a range of surfactant concentrations were graphed,
and from this data the critical micelle concentration (CMC) was determined. This method
worked well for SDS using 2-naphthalenemethanol as the marker; the CMC was determined to
be 3.4 millimolar. This method, however, did not work as well for CPZ because of
CPZs absorbance of ultraviolet (UV) light. This character caused a poor baseline for
the electropherogram and made finding a suitable marker difficult. Possible markers were
tested using UV spectroscopy to determine if their absorbance was strong enough to be seen
through CPZs absorbance. Preliminary tests with benzyl alcohol showed that it may be
a usable marker
Research on Propulsion Mechanism of Underwater
GnatsFishtels
Vinh Lee
Mentor: Marc Madou
University of California, Irvine
We are developing a small underwater
self-propelled autonomous vehicle, which will use a mechanism similar to fish swimming,
that could open up new applications, such as clandestine operations and surveillance. The
propulsion part is essential to the whole device. Artificial muscle material could be used
to make biomimetic fins to generate propelling forces. In order to determine the input
power from the battery, the drag force of the vehicle needs to be estimated theoretically
or numerically, and energy efficiency of the propulsion needs to be addressed. Optimal
design factors such as shape of the body, number, and shape of the fins will give this
fishtel faster speed and more efficient control.
3D Lithography
Young Lee
Mentor: Marc Madou
University of California, Irvine
Lithography is the use of light to create patterns
on a surface. The light-sensitive medium used, called photoresist, changes solubility when
exposed to light. During exposure, a mask selectively allows light to pass through, and
the photoresist is developed to create the desired 2D patterns. With the advent of MEMS
(Micro ElectroMechanical Systems), there has been an interest in creating micro or
nanoscale 3D structures. Much of the fabrication of todays MEMS devices is limited
because the processes used are inherited from conventional integrated circuit technology,
which is two-dimensional. For example, very small precision lenses cannot be created using
standard lithography techniques because the curvature of the lens cannot be produced. I
have experimented with the many parameters involved in conventional lithography to create
3D structures. For example, exposure and development time can be varied to change the
vertical profile of the edges of the patterns. With a thick photoresist layer, truly 3D
structures were created. I learned how to fabricate 3D microstructures by working in the
clean room (Integrated Nanosystems Research Facility). Increasing exposure dose and
adjusting development time allows fabrication of conical structures. Grey-Tone Masks with
multiple levels of transparency can also be used to form multi-level structures.
Molecular Dynamics Simulation Studies of the
Structure and Function of Mutant Surfactant Protein B Peptides
Jenny Lester
Mentor: Douglas Tobias
University of California, Irvine
Lung Surfactant is a mixture of phospholipids and
apoproteins that line the surface of the alveoli and maintains respiratory stabilization
during the breathing process. Deficiency or dysfunction of lung surfactant has resulted in
respiratory diseases, particularly Neonatal Respiratory Distress Syndrome. As a result,
the roles of its components are being studied in order to synthesize a mixture as a
therapy for lung disease. In order to closely analyze the interaction between the protein
and lipid components at the atomic level, molecular dynamics simulations were carried out
on a model system containing a Palmitic Acid monolayer (as a substitute for the actual
lipid monolayer) and surfactant protein-B (SP-B). The model system appears to maintain its
stability through electrostatic interactions between the charged residues of the peptide
and the hydrophilic head groups of the lipid, and also through interactions between the
aromatic groups of the peptide and the hydrophobic tail region of the lipids. In order to
determine the specific role of the charged residues, the four cationic residues were
removed from the peptide in a mutant SP-B, which was also simulated in the model system.
When the simulations of the mutant and the native were compared, it appeared that the
presence of the charged residues affect the orientation and secondary structure of the
peptide as well as the order of the lipids in the monolayer.
Holocaust Revisionism and its Underlying
Discrepancies
Michelle Levian
Mentor: Chaim Seidler-Feller
University of California, Los Angeles
Holocaust revisionism is the theory that the
Holocaust, the utter annihilation of six million Jews during the years of 1933 and 1945,
was nothing more than a hoax. Revisionists attempt to downplay the figure of six million
deaths by claiming that only one million fatalities occurred. Furthermore, they discount
the evidence that extermination camps and gas chambers were built to systematically
eradicate Jewish civilians. The objective of this study is to closely examine and analyze
the evidence and motives behind the audacious claims of revisionist thinkers. In an
attempt to comprehend the provocations of such potent assertions against historical facts
that contain substantiated evidence, various analyses were performed. Upon examination it
becomes conclusive that revisionists are individuals who are in complete denial that the
Holocaust occurred. Additionally, revisionists, most of whom are of German decent, are
greatly humiliated by the horrific wrongdoings of their ancestors. In an attempt to
justify the actions of their ancestors, they refute the phenomenon as a whole. The topic
of holocaust revisionism is of great academic relevance today. Prejudice and
discrimination on the basis of race and gender is still rampant all over college campuses.
Therefore, learning about the motivations of deniers is an essential component in
combating further perversion of the truth.
Induction of a Hepatic Antioxidant Gene Following
Dietary Administration of a Chinese Herbal Product
Huihui Li
Mentors: Stephen Bondy, Edward Sharman, &
Kaizhi Sharman
University of California, Irvine
Several flavonoids found within Scutellaria
baicalensisan herb long used in Chinese traditional medicine for its
anti-inflammatory, antibacterial and hepatoprotective propertieshave been identified
as potent antioxidants and inflammatory enzyme inhibitors. The current study was performed
in order to evaluate the potential of this herb for restoration of liver functionality in
older animals. The herb constituted 0.25% of the diet, which was fed for eight weeks to
both young (8-week-old) and aged (25-month-old) C57BL/6 mice. Following administration of Scutellaria,
RNA was prepared from the liver, and Northern blot analysis of an antioxidant gene,
glutathione peroxidase, (GPX) and an immune-related gene, Complement B (C1B), were
performed. The dietary supplementation significantly elevated levels of GPX over basal
values in young but not old mice. Furthermore, such herbal treatment had no significant
effect on C1B in animals of either age. It is concluded that this herb has limited utility
in enhancing antioxidant or immune defenses of elderly animals, but in younger animals, Scutellari
may be able to elevate levels of a key enzyme involved in detoxification of free radicals.
DNA-Protein Crosslinking from Guanine Oxidation:
Sensitivity of Crosslinking to the Presence of Guanine Multiplets
Catrissa Lightfoot
Mentor: Eric Stemp
Mount St. Marys College
The 1-electron oxidation of guanine via the
Flash-Quench Technique results in DNA-Protein crosslinks (Journal of the American Chemical
Society, 2000, 122, 3585). It is known that the oxidation potential of guanine in DNA
decreases in the order -GT- < -GC- << -GA- < -GG- < -GGG- (Journal of the
American Chemical Society, 1996, 118, 7063). This study examines how DNA is affected in
its ability to form crosslinks with protein by local DNA sequence. Three different
oligonucleotides that contain -GGG-, -GGC-, and -GCG- sequences were synthesized. The DNA
was modified by the addition of an amino group and conjugated to Alexa Fluor 350, a
fluorescent dye, then purified by HPLC. Uv-vis and mass spectrometry indicated that the
Alexa Fluor dye was successfully conjugated to the DNA strands. Crosslinking was observed
for all of the sequences studied here and is not a simple function of guanine oxidation
potential
Universal Multimedia Access With JPEG2000 And
MPEG-7
Jongyu Lin
Mentor: Mehran Moshfeghi
University of California, Irvine
Universal Multimedia Access (UMA) allows scalable
and adaptive delivery of multimedia to client devices with capabilities, such as display
size and bandwidth. This is important for multimedia applications in consumer electronics,
pervasive computing and mobiles applications. Conventional systems typically use a
transcoding proxy to dynamically adapt the content for different clients, or pre-compute
and store multiple representations of content on a content server. The former requires an
additional server and is computationally expensive, while the latter wastes storage space.
We have used some of the features of the JPEG2000 image compression standard to overcome
these problems. JPEG2000 offers flexible decoding of images, where an image can be
compressed once and decompressed different ways to provide resolution scalability, quality
scalability, region of interest coding, spatial random access, and efficient lossless or
lossy compression. MPEG-7 addresses the requirements of UMA by providing Description
Schemes that support the adaptation of multimedia according to the capabilities of client
devices. MPEG-7 Importance Hints are used to annotate the importance of different regions
in an image and Spatial Resolution Hints are used to specify the maximum allowable spatial
resolution reduction factor for perceptibility. We have developed a UMA system where the
JPEG2000 Internet Protocol (JPIP) is used in a client/server architecture. With this
system JPIP and XML-7 enable the client to make intelligent requests and download selected
portions of the JPEG2000 code-stream from the server, thereby producing an optimal image.
New Dromomerycids (Mammalia: Artiodactyla) From
the Middle Miocene
Matthew Liter
Mentor: Donald Prothero
Occidental College
The Sharktooth Hill Bonebed in the Round Mountain
Silt, northeast of Bakersfield, California, is famous for its rich fauna of marine mammals
and fish, but yields few identifiable terrestrial mammals. Recent discoveries have
recovered several dromomerycid skulls and jaw fragments that were originally misidentified
as "Palaeomeryx". Although the best skull is from a juvenile (possibly female)
and does not have characteristic orbital horns of adult male dromomerycids, it can be
identified by its short occipital horn, dentition, and size based on comparison with the
dromomerycids in the Frick Collection of the American Museum of Natural History. The new
specimen is most similar to Bouromeryx americanus, a typical late
Hemingfordian-Barstovian taxon. This new material prompted a review of the species-level
taxonomy of the Dromomerycidae, which has not been updated since Fricks 1937
monograph. Most of Fricks genera are valid, but the species are grossly oversplit.
Using statistical techniques, we significantly reduced the number of species in each
genus. All the primitive Hemingfordian species (marslandensis, sweeti) and subgenera (Probarbouromeryx,
Protobarbouromeryx) are synonymized with Barbouromeryx trigonocorneus (Barbour
and Schultz, 1934). Bouromeryx submilleri from the late Hemingfordian is still
distinct based on size, but all the remaining late Hemingfordian-Barstovian species (milleri,
parvus, madisonius, pawniensis, supernebrascensis, pseudonebrascensis) are
indistinguishable, and synonymized with Bouromeryx americanus (Douglass, 1909).
Likewise, the number of species of Cranioceras and Procranioceras recognized
by Frick has been greatly reduced.
Systematics of the Middle Eocene (Uintan)
Protoceratid Leptoreodon
Joshua Ludtke
Mentor: Donald Prothero
Occidental College
A recent re-evaluation of the primitive
protoceratid Leptoreodon was undertaken to see if a large number of new finds from
San Diego County improves the systematics work previously done. This artiodactyl, found in
middle Eocene deposits from Texas, Utah, Saskatchewan, and Southern California, was
formally divided into five species in the last published review of the genus. Being able
to identify which of these species occurred when and where in the stratigraphic record is
valuable to correlating the age of rocks across a wide expanse of western North America.
Dozens of lower jaws and teeth from the Los Angeles County Museum, San Diego Natural
History Museum, and University of California, Riverside, were measured with standard dial
calipers and evaluated in light of characteristics used in the last review of the genus as
it appears in Southern California. Measurements were compared to see if species could be
distinguished via measurable characteristics instead of less quantifiable characteristics.
Of the species previously recognized, five appear to remain valid. L. pusillus
remains distinct through its small size. L. marshi and L. major differ due
to the overall larger size of L. major, which also has a longer lower molar row. L.
leptolophus and L. edwardsi differ little in their teeth sizes, but show a
geographical trend and also have distinct looking fourth lower premolars. The most
recently described species, L. stocki, does not appear to be distinct from L.
edwardsi, and the two species should be combined.
Intercalation-Induced Changes in DNA Tertiary
Structure Studied by Atomic Force Microscopy
Elaine Ly, Occidental College
Mentors: Megan Nunez, Mt. Holyoke University;
Eileen Spain, Occidental College
Development of new drugs relies in part on
understanding how a particular molecule interacts with DNA. To address this challenge,
atomic force microscopy (AFM) is applied to three DNA molecule-systems. AFM can image DNA
shape, condensation, and protein binding at the nanometer scale. Intercalators, such as
ethidium bromide and octahedral ruthenium complexes, induce changes in the superhelical
shape of DNA, producing an extension, unwinding and stiffening of the DNA helix. A few
groups have demonstrated supercoiled characteristics using air and liquid AFM studies of
pBR322 with ethidium bromide, but no one has yet studied the effect of intercalating
octahedral metal complexes on DNA by AFM. Studies of the plasmid DNA, pBR322, will be
conducted using TappingMode AFM in both air and liquid to observe these transformations,
which are caused by the untwisting of base pairs and helical backbone needed to
accommodate the intercalator between the DNA base pairs. We will investigate the
structural transitions in the plasmid DNA in response to Ru2+ intercalation.
Currently, studies are in progress to collect a diverse set of images with and without the
Ru2+ intercalator, to determine what tertiary structures are formed, and
whether this complex does indeed intercalate into DNA.
LC-MS-MS Analysis of the Nucleoside Reverse
Transcriptase Inhibitor Lamivudine (3TC) in Human Hair
Larissa Madrid, University of California, Irvine
Mentors: Francesca Aweeka, University of
California, Irvine; Anura Jayawardene, University of California, San Francisco
Techniques such as measuring drug concentrations
in plasma and urine have been evaluated for the determination of adherence to
antiretroviral therapies; however, these methods are limited to short term (1-2 day)
behavior assessment. Unlike the aforementioned methods, hair analysis shows potential for
less invasive therapeutic monitoring and assessing long-term adherence because the level
of drugs in hair reflects uptake from the systemic circulation over an extended period of
time (weeks to months). The focus of this study was to develop and validate a method of
quantitating antiretroviral drug concentrations in hair samples from HIV-positive
subjects. This detection method was developed using liquid chromatography-tandem mass
spectrometry to measure drug concentrations in hair, specifically targeting the nucleoside
reverse transcriptase inhibitor (NRTI) drug 3TC, which is used to treat HIV infection.
Calibration standards and quality control samples were prepared and used during validation
to assess accuracy and precision of the method. Azidodideoxyuridine was chosen as an
internal standard for this assay. The 3TC hair extraction and quantitation method will be
validated according to AIDS Clinical Trails Group guidelines. HIV-positive subject hair
samples will then be analyzed using this validated method with quality control samples to
further substantiate the method. This form of hair analysis will have future implications
in therapeutic monitoring of NRTI effectiveness in HIV patients.
Byzantium and Russia: The Orthodox Church as a
Venue for Progress
Michael Marakhovsky
Mentor: Barisa Krekic
University of California, Los Angeles
When one studies history, it is often presented in
blocks, broken up according to some national or chronological principle. However coherent
such divisions might be, they fail to highlight the fact that throughout history,
connections between nations and regions were of primary importance in pushing the progress
of these areas. This consideration becomes of supreme importance when we examine the
history of Russia. Russia is a state that played a huge role in forming the world that we
live in, both politically, with the Cold War just the latest major influence, and
culturally. The history and the role of Russia nevertheless cannot be properly understood
until we examine its connections with the Byzantine Empire and the enormous influence that
it had in forming the Russian state. Through religion, through culture, and through direct
political connections the Byzantine Empire helped define the Russian character and state,
and, through this inheritance, continues to influence the world today. This presentation
will follow the unfolding story of this exchange focusing on key points in the
relationship those moments where this connection proved to be a crucial factor in
determining the future of Russia.
The Murals of Diego Rivera: Political Expression
and Propaganda Through Art
Claire Markgraf
Mentor: Linda Stark
Occidental College
Throughout history, artistic expression has served
as a means to better understand the human experience. Poets, musicians, authors, and
painters retain the unique ability to fuse dissimilar and seemingly opposed ideas,
revealing complexities and dimensions of an issue that could not be realized through any
other medium. Often, turmoil and great social disruption give rise to a torrent of
expression through art as people and societies grapple with their changing surroundings.
Mexicos famed painter Diego Rivera (1886-1957) lived through the most significant
and explosive period of the 20th century socialist/communist movement. Using
his distinct fresco style, Rivera created hundreds pieces of art through which he
expressed his support of the movement and its Marxist ideals. Riveras art came as
revolutionary, providing the world with a visual commentary on the status of the
proletariat in a market-driven society. As an acclaimed muralist, Rivera captured
considerable media attention and was able to propagate the social messages of his work to
the masses. While this elicited strong support in some places, Riveras works brought
impassioned refutation from many, influencing public policy in the United States and
abroad. It is this highly expressive and influential art that I have researched in order
to understand better the intricacies of incorporating artistic expression with political
thought.
The Staples Center: Urban Regeneration In Downtown
Los Angeles
Chris Martin
Mentor: Stephen Koletty
University of Southern California
From 2000 to 2002, the Staples Center in Los
Angeles held the national spotlight as it hosted three consecutive NBA championships. The
Los Angeles Arena Company just completed construction of this new downtown events center
in 1998. The new arena plays host to several of Los Angeles well-known professional
sports teams, and also serves as a meeting place for conventions. Staples Center was
designed to be the anchor, and the stimulus for a large-scale urban renewal process taking
place south of downtown Los Angeles. As a result of the arenas success and
popularity, new development is taking place and is transforming its neighborhood.
Investors have undertaken several multi-million dollar residential and commercial
developments. The Staples Center is an example of a larger trend in American cities, as
arenas and stadiums are constructed in downtown landscapes to encourage the renewal of the
inner city. By constructing "a large draw," cities hope to create a jumping-off
point for further development. This paper examines the success of the Staples Center in
stimulating urban renewal in Los Angeles and contrasts this with the mixed results
experienced in other cities that have employed this strategy.
Long-Term Study of the Effects of Dietary Jojoba
Oil on Plasma Lipoprotein Concentrations in New Zealand White Rabbits
Christopher Martinez
Mentor: Raymond Garcia
California State University, Los Angeles
High levels of high-density lipoproteins (HDL) and
low levels of low-density lipoproteins (LDL) are indicators of a low risk for the
development of atherosclerosis, while the inverse is indicative of a high risk. Previous
studies in our laboratory have shown that female New Zealand White rabbits fed a 2% jojoba
oil diet for seven days results in a significant increase in HDL-C concentration. Our
objective is to determine whether or not this effect of dietary jojoba oil on HDL-C
concentration persists beyond the seven-day bleeding period. This objective was achieved
by feeding female New Zealand White rabbits a rabbit chow supplemented with a 2% (w/w)
jojoba oil for 0, 14, 28, and 39 days. Blood was collected from an ear vein and serum was
obtained by centrifugation. The HDL fraction was separated from the VLDL+LDL fraction by
polyanion precipitation of the serum, and total cholesterol (free cholesterol +
cholesteryl ester) concentration was measured enzymatically. The results show an increase
in the HDL-C concentration from 0 to 14 days, but a steady decline thereafter. Unlike
HDL-C concentration, however, VLDL + LDL-C concentration exhibits a continuous increase
throughout the entire feeding period. This suggests that dietary jojoba oil has an optimum
period for increasing HDL-C concentration that is between 7 and 14 days. The reason for
the inverse relationship in the level of HDL-C and VLDL+LDL-C after 14 days is unknown.
Perhaps cholesteryl ester transfer protein is involved since it is a metabolic link
between these two lipoprotein fractions.
Identification of Phosphorylation Sites in
Fibrinogen by Combination of Affinity Chromatography and Mass Spectrometry
Daisy Martinon
Mentor: Agnes Henschen-Edman
University of California, Irvine
The intent of this study is to test if the Fe+3-chelate-Sepharose
column affinity chromatography in combination with mass spectrometry can be utilized to
selectively identify phosphorylation sites in fibrinogen. Fibrinogen is a central protein
in blood coagulation. The increase in fibrinogen phosphorylation after elective surgery
may be linked with the increased risk of thrombosis in these patients. An in depth study
has not been made whether conformational and/or functional changes occur in fibrinogen as
a result of phosphorylation. So far the complete set of phosphorylation sites in
fibrinogen is only known for the human protein. It is important to isolate fibrinogen
phosphopeptides with the most efficient method to analyze the functional relevance of
phosphorylation. To test the methods efficiency, horse and sheep fibrinogen tryptic
digests were fractionated on an Fe+3-chelate-Sepharose column. All samples of
peptides that showed affinity for the column were partially treated with phosphatase. A
mass spectrometer was used to observe a subsequent phosphate group loss of 80 Da mass
units in order to verify the presence of these groups. The analysis confirmed the 80 Da
shift in the phosphatase treated peptides, thus proving that the Fe+3-chelate-Sepharose
column affinity chromatography is an efficient method for isolating fibrinogen
phosphopeptides. In horse and sheep species, eight and 10 phosphopeptides were observed,
respectively. The peptides will be further identified by amino acid sequence analysis to
determine positions of phosphorylation, which will be helpful for the understanding of the
contribution to conformation and function in fibrinogen.
Activation of PI-3/Akt Pathway by Estrogen and
Testosterone in Male Cerebral Blood Vessels
Kevin Marx
Mentor: Diana Krause
University of California, Irvine
It has been shown in brain blood vessels that
estrogen increases vasodilation whereas testosterone enhances contraction of the vessel. A
key regulator of vascular reactivity is nitric oxide (NO), a vasodilator produced by
vascular endothelium. Phosphorylation of the kinase Akt (p-Akt) via PI-3 kinase is an
important pathway for activating endothelial NO synthase (eNOS) to produce NO. We tested
that hypothesis that estrogen and/or testosterone would affect Akt phosphorylation in male
rat cerebral blood vessels. For acute treatment studies, blood vessels were isolated from
orchiectomized (ORX) males and incubated (30 min) with estrogen (1 nM, 10 nM) or
testosterone (10 nM, 100 nM or 1m M). In the chronic study, rats were divided into three
groups with two groups treated with hormone for four weeks: ORX (control), ORX with 17b
-estradiol (ORX+E), and ORX with testosterone (ORX+T). Blood vessels were isolated from
the brains, and levels of p-Akt were determined using Western blot analysis. Both chronic
and acute estrogen treatment increased p-Akt protein levels compared to ORX controls.
Unlike estrogen, chronic testosterone treatment did not alter p-Akt protein levels in male
cerebral blood vessels. However, acute treatment with testosterone did increase p-Akt.
Because testosterone can be converted to estrogen via vascular aromatase, further studies
are needed to determine if this hormone acts through androgen or estrogen receptors.
Together, however, these results show that both steroid hormones, estrogen and
testosterone, acutely regulate Akt phosphorylation. Activation of this kinase would be
expected to increase production of NO in cerebral blood vessels.
Solving an Engineering Problem Utilizing a Beowulf
Cluster
William Maxwell
Mentor: Meng-Lai Yin
California State Polytechnic University, Pomona
In the complex world of business and engineering
the need to come up with solutions quickly is growing rapidly. In the information age
modeling has become a critical part in the business product development cycle. With the
increasing modeling complexity, obtaining modeling and/or simulation results can be very
time-consuming. The need to produce time-efficient solutions is a driving force of this
project. The purpose of this project is to develop low-cost high-performance computing
solutions. In particular, the problem was checking the availability of a Global
Positioning System across the United States. The entire area of the continental United
States is divided into 500 grid points, and each point has its availability calculated
over a 24-hr period. The solution developed was the implementation of a 12-node Beowulf
cluster running both the Message Passing Interfacing and Parallel Virtual Machine
environments. This presentation addresses the nature of the problem and the implementation
of the best cluster solution.
"This Haunted Grove": Liminality,
Ireland, and Authority in A Midsummer Nights Dream
Corey McEleney
Mentor: Arthur Little
University of California, Los Angeles
Many critics have addressed the structural
opposition between Athens and the woodland in A Midsummer Nights Dream,
arguing that the woods subvert the authority of Athens rigidly hierarchical court.
Taking these interpretations as departure points, this paper places the relationship
between Athens and the woodland in conversation with English relations with and
representations of Ireland. While several studies have examined the references to Ireland
in Shakespeares history plays, few have pointed out how Shakespeares
construction of the wood in A Midsummer Nights Dream symbolically and
thematically draws on deep-rooted English conceptions of Ireland. Using Victor
Turners model of liminality to set up my argument, I begin with close readings of
both Shakespeares play and Gerald of Wales History and Topography of
Ireland (1185) to investigate the relationship between the threatening liminality of
Ireland and the threatening liminality of the early modern theatera relationship
with added gravity in this context, given Andrew Hadfields suggestion that the
repression of Ireland in Shakespeares plays was effected by the regulation and
censorship of the theater. A Midsummer Nights Dream is an ideal text to
analyze, then, since it metatheatrically directs criticism against an authority that
(dis)regards the theatrical as mere trifle. The woodland of A Midsummer Nights
Dream thus emerges not only as an indicator of how Ireland might be read into the
liminal spaces of Shakespeares plays, but also as the site of Shakespeares
interrogation of Englands cultural authority (to regulate the theater) and imperial
authority (to oppress and repress Ireland).
Directed Single-Walled Carbon Nanotubes on HSQ
Patterned Surfaces
James McFarland
Mentor: David Tanenbaum
Pomona College
The interesting and unique properties of carbon
nanotubes suggest a wide range of possibly revolutionary applications. From semiconductor
manufacturing to materials science, the functionality of carbon nanotubes has remained
mostly theoretical to this point largely because of our inability to position and
manipulate individual nanotubes. One possible approach to such control is to use hydrogen
silsesquioxane (HSQ), a negative tone glass resist, to pattern structures on top of
catalyst pads, forcing directional growth of the nanotubes. Before obtaining directional
growth using HSQ structures, however, it is important to understand and characterize the
general process of growing nanotubes on these structures. We present such an investigation
using CVD growth of carbon nanotubes on various patterned HSQ structures. Our results show
a wide range of tube densities, often with predictable growth patterns. We were also able
to successfully manipulate nanotubes suspended on the HSQ structures with an AFM probe,
suggesting possible future techniques to further control the position of the tubes.
Testing a Model to Explain the Different
Phenotypes of Lines Derived from the Same P-Element Insertion
Angela McGuire
Mentor: Catherine McElwain
Loyola Marymount University
We have established more than 100 lines of flies
derived by P-element transposition from a single line of flies carrying a white-bearing
P-element on the right arm of the third chromosome. In this original line the red
pigmentation associated with the expression of the white gene in the eye is limited
to a stripe across the middle of the eye. Some of these derivative lines have white eyes
and probably represent the excision of the original P element. Some of the lines have red
eyes and probably represent insertion of the original white-bearing P into a
different location on the third chromosome. Some of the lines retain the striped pattern,
although the phenotype of the stripe is quite different from the original line. These
stripes vary in width, intensity, pigmentation in the flanking regions dorsal and ventral
to the stripe and the continuity of the stripe. We are testing a model that predicts that
these derivative lines, which still retain a striping pattern, result from the excision
and reinsertion of the original P-element into sites close to the original site (local
hopping). Furthermore, we predict that at least one of these stripe characteristics will
correlate to the position of the insertions along the chromosome. We will present evidence
to support the assertion that the derivative lines represent local hopping, and that the
phenotypes can be classified along at least one continuum.
Salinas Valley Water Table Elevations: A
Visualization Using GIS
April McMillian
Mentor: Douglas Smith
California State University, Monterey Bay
Solving Californias significant water crisis
requires water management plans that take into account historic trends in local
groundwater systems. By understanding how groundwater elevations have changed over time,
predictions and water management policies can be made to ensure the quality and longevity
of groundwater resources in California. Animations of historic water table elevations can
effectively communicate water table behavior to many people through the visualization of
problems and identify possible causes. Calibrated model water table data for the Salinas
Valley were obtained form the Monterey County Water Resources Agency. These elevations
were color contoured and mapped for consecutive years from 1949 through 1994. These maps
were animated to show the changes the Salinas Valley water table has undergone from 1949
through 1994. Water table elevations declined in the lower Salinas Valley and coastal
areas during the period of 1949 to 1957, and from 1983 to 1994. Water table elevations in
the upper Salinas Valley, fed by two reservoirs, remained relatively stable through time,
with minor changes due to precipitation. Increases in water table elevations are shown in
all areas when the Nacimiento and San Antonio reservoirs began operation. Comparing these
animations with previously published land use maps can identify possible links between
land use practices and changes in water table elevations. Land use maps overlaid upon the
contoured water table maps indicate that the City of Salinas lies at the center of a large
zone of regional drawdown, suggesting municipal development may have large impacts on
groundwater elevations.
Sequencing and Mapping Chromosome Breakage
Junctions of Tetrahymena thermophila
Andrea Medina
Mentor: Eduardo Orias
University of California, Santa Barbara
The ciliate Tetrahymena thermophila is an
excellent model organism for studying eukaryotic biology. Tetrahymena contains two
genomes, the germline or micronuclear genome (MIC) and the expressed or macronuclear
genome (MAC). The germline consists of five pairs of chromosomes. During macronuclear
differentiation about 300 macronuclear chromosomes are generated by site-specific
fragmentation of the germline chromosomes at chromosome breakage sites (Cbs). Using the
15bp Cbs sequence, the Orias lab has isolated and sequenced a fourth of the Cbs junctions.
I have been mapping these junctions. Site specific primers are designed that flank each
Cbs. Polymerase chain reaction (PCR) is used to amplify these junctions from MIC DNA.
Nullisomic strains of Tetrahymena lack both copies of a chromosome or chromosome
arm in their MIC. I use DNA from these strains and PCR to map each junction to a
chromosome arm. When a junction contains a polymorphism, I am also able to map it to a MIC
linkage group. The Tetrahymena genome is currently being sequenced, and this
research will help relate the genetic and physical maps to the sequence.
Precision Photometry of the Microvariable Quasar
3C 66A
Erik Mendoza
Mentor: Stephen Gillam
California State University, Los Angeles
This paper describes the results of a short
observing run of 3C 66A on January 13, 2003 at Table Mountain Observatory with the 0.6 m
telescope and 2K CCD camera. The purpose of the observation was to contribute data to the
characterization of the variability of 3C 66A. The reduction procedure is described in
great detail, as well as all of the analysis procedures. We employed two standard stars in
the same field for differential magnitudes. Furthermore, results from the reduction
process provide information on the precision of the new 2K CCD camera used.
For the Dream: An Artistic Exploration of Unity
Angela Miller
Mentor: Maxine White
University of Wisconsin, Whitewater
This 55" X 72" visual art piece is a
hybrid between painting, illustration and sewing. The first layer of the canvas (the back
layer) was influenced by the work of Jackson Pollock, which suggests a style of
"action" painting to represent hectic energy. This layer utilized several colors
and throwing techniques. The second (or top) layer was cut into various pieces, which were
sewn together with a "dead" area between the pieces. This "dead" area
allows one to view parts of the back layer once the canvas layers are placed on top of
each other. The conceptual material on the top layer has charcoaled anatomical studies
with different perspectives. In each of the top layers section backgrounds is an
excerpt, written in different languages, from Martin Luther King Jrs "I Have a
Dream" speech. The conceptual message that this piece creates relates to the idea of
equality. It conveys the message that we all are human and the same because we share many
similar thoughts, feelings, and experiences. Our differences are the result of our
different positions in lifes journey. These differences are all temporary, however,
and we are one people in the final analysis.
Viologens Capture by Polymer-Supported Crown
Ethers
Kent Miller
Mentor: Fraser Stoddart
University of California, Los Angeles
Paraquat, a viologen, is one of many pesticide
poisons. It acts as an executioner on many vital organs of the human body. Paraquat is a
commonly used pesticide in agriculture and often its levels become too concentrated in
places in the environment. However, nanotechnology allows us to solve this problem. It is
theorized that, through supramolecular chemistry, Merifield resin beads can be
functionalized with crown ethers that complex with the viologens, making pseudorotaxanes.
The complexation of the two components will make the viologen more recognizable and easier
to gather from the environment. This hypothesis was tested first using a protocol, and the
result was a glowing success. Of great significance was the ability of using
environmentally safe chemical synthesis as a way to solve an environmental problem.
Extraction, Isolation and Characterization of
Rhizobia from Woody Legume Root Nodules
Heather Mitchell
Mentor: James Blauth
University of Redlands
Woody legumes, with their deep root systems and
mutualistic relationship with rhizobia, can serve to assist in the re-vegetation of
disturbed arid lands. Woody legumes are a part of the legume family that is characterized
by their ability to produce wood. Rhizobia are the nitrogen-fixing bacteria that dwell in
the root systems of legumes. By extracting, isolating, and characterizing rhizobia from
legume-dominated desert areas, it will be possible to determine the optimal combination of
rhizobia and legumes for restoration efforts. Through various tests such as culturing on
specific media, Gram staining, and carbon source testing, we found that the rhizobia
collected could be characterized into species-specific groups. Using nodulation assays and
cross-inoculation tests, we gathered information concerning the nodulation abilities of
the collected rhizobia. Further testing will allow for the determination of rhizobia
specificity to legume hosts. By using rhizobia and woody legumes it may be possible to
start a natural succession of desert life in disturbed arid lands at relatively low cost.
The Effect of Prostaglandin E2 on Human Dendritic
Cell Phenotype and Function
Kathleen Mitchell, Loyola Marymount University
Mentors: Russell Salter & Simon Watkins,
University of Pittsburgh
Dendritic cells (DCs) mature following antigen
uptake and travel to lymph nodes in order to stimulate naive T-cells and initiate immune
responses. Immunotherapy using mature tumor antigen-loaded DCs has been used effectively
to treat some cancers in clinical trials, but the inability to ensure that these DCs will
move to lymph nodes and initiate a proper and successful immune response limits their
utility. The standard method for maturing DCs for in vitro and in vivo
clinical trial use is monocyte conditioned media (MCM) with tumor necrosis factor alpha
(TNF-alpha) and prostaglandin E2 (PGE2). The use of PGE2
has recently been debated because of evidence that it decreases IL-12p70 and IFN-gamma
production, which leads to a Th2 biased response. We tested the effect of PGE2
in the MCM/PGE2/TNF-alpha maturation mixture on human peripheral blood monocyte
derived DCs. The DCs were then measured for T-cell stimulatory capacity (defined by T-cell
proliferation in MLR), immunophenotypic maturity (defined by upregulation of CD83, also
CD86, CD80, and MHC Class I and II), and motility (defined by movement along a
collagen-coated coverslip in live cell imaging analysis) in vitro. Our data
suggests that DCs matured in a media containing PGE2 had lower levels of CD83
expression, a lowered ability to induce T-cell proliferation, and a lowered percentage of
mobile cells. Our data suggest that DCs matured with MCM/TNF-alpha may be a more
functional option for in vitro study and most importantly for in vivo
clinical use.
A Comparison of Post-Injury Compensatory Fiber
Outgrowth in the Male and Female Rat Cholinergic System Under Varying Lengths of Estrogen
Treatment
Bibhu Mohanty
Mentor: Sonsoles de Lacalle
California State University, Los Angeles
Alzheimers disease is one of several
illnesses known to result in dementia, which is characterized by loss of memory,
behavioral impairments, and diminished ability to carry out simple daily functions.
Numerous studies have linked the prevalence of such symptoms in post-menopausal women to a
lack of estrogen. Estrogen is thought to be a key modulator in the function and
maintenance of cholinergic neurons in the basal forebrain. Our laboratory has described in
vitro estrogen induced increases in neurite size and number in cholinergic neurons.
Based on those findings, we hypothesize that such estrogen-induced changes could occur
post-injury at the axonal level, and that a compensatory sprouting effect could be
beneficial. To address this issue, we have started to study the effects of estrogen
treatment on males, in addition to females, which have traditionally been the focus of
many such studies. The immunotoxin 192 IgG-Saporin was used to make a lesion in the
horizontal limb of the diagonal band of Broca, a group of neurons in the basal forebrain
that project to the entorhinal cortex. Lesioned rats of both sexes were then treated with
either four or eight weeks of estrogen and subsequently, the brains were sectioned and
histochemically prepared to analyze the effect of hormonal treatment on compensatory fiber
outgrowth. Our results indicate that while sprouting occurs at similar levels in both
sexes when treated with four-weeks of estrogen, after eight weeks of estrogen, there are
significantly greater levels of sprouting in males than females.
Parent-Child Co-Sleeping: Where Do Fathers Fit In?
Marshall Moncrief
Mentor: Wendy Goldberg
University of California, Irvine
Parent-child co-sleeping (parents and children
sleeping together on a shared surface, typically the parents bed) is one of the
leading sources of contention today in the area of early childhood and familial well
being. Empirical data are beginning to emerge concerning variations in family sleep
arrangements, and the effects of co-sleeping on infant well being, early child
development, and family interactions (McKenna, 2000; Keller & Goldberg, in press).
However, very little information is available with regard to fathers views toward
family sleep practices, especially co-sleeping. In this study, which is the first phase of
a two-part investigation of the fathers role, data are reported from questionnaires
completed by more than 100 mothers of preschool-aged children. (The second phase will
focus on direct assessments of the fathers). The research question driving this study was
"To what extent are fathers involved in decisions about family sleep arrangements and
what are the correlates of their involvement?". The major objective of this first
phase was to examine the associations between fathers inclusion in and support of
the choice of family sleep practice and mothers reported satisfaction with that
practice as well as overall family wellbeing. Preliminary findings of this study indicate
that when fathers are perceived by mothers as being highly supportive of sleep
arrangements, mothers report being more satisfied with sleep arrangements. A preliminary
descriptive analysis of the findings indicate mothers reporting more support from fathers
for solitary sleeping than for co-sleeping. However, in cases where children are
displaying sleep problems, mothers report high support from fathers for co-sleeping
arrangements. Further analyses will address whether or not father support, father
satisfaction, and marital satisfaction will vary by the type of sleep arrangement
(solitary sleeping children, co-sleepers, and reactive sleepers).
Genome Stability within the Human Cancer Cell
Lines HeLa, MCF-7, and HL-60
Celina Montelongo
Mentor: Douglas Swartzendruber
Pepperdine University
With the advent of human cell culture came the
possibility of retaining human cells viably in continuous culture indefinitely. The
changes that might occur within the genome of these cells after they are removed from the
human body and passaged continuously in vitro raise the question of the genomic
stability of these cells in culture. This study quantified genomic differences existing
within the human cancer cell lines HeLa, MCF-7 and HL-60 collected from different
laboratories. Using flow cytometric analyses to determine DNA indices, it was found that
these three lines are consistently aneuploid. Within the HeLa and HL-60 cell line, no two
laboratories provided cells with the same DNA content. While two of the MCF-7 lines were
very similar, the third line contained almost 75% less DNA. The three lines HeLa, MCF-7
and HL-60 are not genomically similar within their respective cell lines across
laboratories, and are thus not genomically stable. These results may impact the validity
of the experimental research that has utilized these cell lines.
Zapatista Feminism: The Importance of Women within
a Movement
Ana Morales
Mentor: Maria Elena Martinez
University of Southern California
This research paper analyzes the gender roles that
women play within the EZLN (Zapatista Army for National Liberation) and Maya communities
of eastern Chiapas more generally. It also studies the changes Maya women experienced in
their communities, as the EZLN became a more dominant influence in their lives. The main
purpose of the paper is to understand the role women play in the EZLN community and the
social changes that have come out of Zapatista feminism. In order to explain those
changes, it begins with an historical overview of Maya indigenous struggles of eastern
Chiapas and of the relationship of indigenous communities in that region with the central
Mexican government and Zapatismo, the movement inspired by the peasant leader of one of
the main factions of the Mexican Revolution, Emiliano Zapata. The paper then covers
specifically how the EZLN has affected women in these Maya communities and what
significance has come from it. It ends with an analysis of the literature and discussion
of further research on this topic.
Use of an IVET System to Identify Periplasmic
Regulated Genes in the Bacterial Predator, Bdellovibrio bacteriovorus
Ryan Murphy
Mentor: Mark Martin
Occidental College
Bdellovibrio bacteriovorus is a relatively
uncharacterized bacterial predator of other Gram negative bacteria. In an effort to better
understand this "genetically undomesticated" organism, we have been developing
an in vivo expression technology) in order to identify Bdellovibrio genes expressed
in the periplasm of host cells. Sau3A cut Bdellovibrio genomic DNA was
cloned into pSVS101 (modified from pIVET8). Successful clones expressed different levels
of chloramphenicol resistance, depending on promoter strength of the Bdellovibrio
DNA inserted. A "bank" of such clones was mobilized into wild type Bdellovibrio,
and allowed to attack E. coli host cells. Chloramphenicol was then added. Clones
isolated following this procedure may be periplasmically expressed. We believe that this
approach, because it is non-directed, will provide insights into how Bdellovibrio
carries out its predatory lifestyle inside host cells.
DNA Sequence Matching Processor
Jane Nawilis
Mentors: Yi Cheng & Meng-Lai Yin
California State Polytechnic University, Pomona
The objective of this senior group project is to
design and implement a high-speed DNA sequence matching processor using Verilog HDL
programming language and a Xilinx Field Programmable Gate Array (FPGA) board. With the
exponential growth of the DNA research, searching an unknown DNA sequence in existing
database could be very time-consuming. Performance becomes a crucial factor in DNA
sequence searching, which motivates this project. Our approach is to utilize the parallel
processing capability available on the FPGA board, where multiple comparisons can be done
simultaneously. In particular, this processor looks for the exact-matched sequences from
an existing data bank, e.g., a portion of the GenBank (NIH genetic sequence database) in a
"pipeline" fashion. Theoretically, after the initial setup, this processor can
compare n DNA pairs at the same time, thus improving the performance by a factor of
n. The sequence-matching module written in Verilog HDL is downloaded into the FPGA board
using the Xilinx-provided software and the simulation tool ModelSim. Our initial result is
encouraging, which shows that, with the processing power of the FPGA, the search time is
significantly reduced. This project continues after the first years experience, and
more DNA searching algorithms are being studied and implemented using this parallel
processing approach.
The Rita Stories: Writing Life & Death
Alexis Nelson
Mentor: Robyn Bell
University of California, Santa Barbara
Since the 18th century, biography has
been a popular literary genre. However, our most celebrated biographies give accounts not
of ordinary peoples lives, but of the lives of famous historical figures.
Theres Boswells Life of Johnson, for example, or Twains biography
of Joan of Arc. Yet Johnson himself, when advising Boswell about his writing, said,
"There is nothing too little for so little a creature as Man. It is by studying the
little things that we attain the great knowledge of having as little misery and as much
happiness as possible." Although few of us are fortunate enough to know any
"famous historical figures" as well as Boswell did, most of us do know
people whose lives we celebrate privately. These people lead lives that an outsider would
deem little or ordinary, but that we who admire them look upon as heroic. My best
friends mother Rita is one such person for me. "The Rita Stories" began
four years ago, as a few scattered pieces about my relationship with her. I have since
collected and built upon these stories, creating a single work of substantial length that
covers the breadth of our relationship, beginning in my adolescence when I first became
friends with her daughter and was welcomed into her home, and ending one year ago, with
her death. My "Stories" paint a mosaic-like portrait of Rita as I knew
hera mother, a mentor, a friend; in short, an extraordinary woman whose life story
deserves to be told.
Which Form of Insulation is Most Effective?
Jessica Ng
Mentor: Wendy Cozen
University of Southern California
When the human body faces tough temperature
changes, our body has to adapt to it. We need to rely on more than our air heating system
to give a more tangible feeling of warmth. The objective of this project was to determine
which form of insulation would be best at keeping the human body at a stable temperature.
The testing variables are cotton, human hair, chicken feathers, wool, and a combination of
50% cotton and 50% polyester fabric. The controlled variable had no insulation. My
hypothesis is that wool will be the most effective, while chicken feathers will be the
least effective. To begin the project, I lined the inside of a plastic bag with one form
of insulation material equally. Then I heated one cup of boiling water and placed it in a
container. When the water temperature reached 183 °F in the container, it was sealed and
placed in one bag. The bag was stored in a 50 °F environment. The container was removed
from this environment, and the water was measured every 10 min. This process was continued
for 120 min. The recorded data revealed that human hair was 122 °F, thermal insulation
was 120 °F, cotton was 122 °F, chicken feathers were 128 °F, wool was 118 °F, and the
50% cotton/50% polyester was 114 °F (the controlled variable was 80 °F). In conclusion,
my hypothesis was wrong because it was found that chicken feathers kept in the most heat,
while the 50% cotton/50% polyester material kept in the least heat.
Neutrophil Migration in Overlapping
Chemoattractant Gradients
Connie Nguyen
Mentor: Noo Li Jeon
University of California, Irvine
Neutrophils are the polymorphonuclear leukocytes
that respond to foreign pathogens or tissue injury and are involved in the bodys
immune system. These mobile cells show chemotactic response to chemoattractant gradients,
such as IL-8 (interleukin 8) and LTB-4 (leukotriene B4). Multistep migration, in which the
neutrophil leaves local chemoattractant vicinity in response to a distant gradient, has
been shown to play an important role in neutrophil recruitment and defense response.
Previous studies have also shown that there is a hierarchy between bacteria-derived
chemoattractants such as fMLP (f-met-leu-phe), and host-derived chemoattractants,
such as IL-8 and LTB-4. The main purpose of this project is to verify the multistep
migration model and to investigate if there is also a hierarchy between two host-derived
chemoattractants, namely LTB-4 and IL8. We have developed a microfluidic device using soft
lithography and PDMS to create stable overlapping linear gradients of IL-8 and LTB-4.
Neutrophils were loaded to the chamber and time-lapse images of migrating cells were taken
for analysis. The migrating cells were divided into two populations. The initial position
of one population was closer to the IL-8 gradient and the other was closer to the LTB-4
gradient. A higher percentage of cells in both populations moved toward the distant
gradient, implying that the multistep migration model is valid. Neutrophils migrated more
effectively toward the LTB-4 gradient, suggesting that there may be a hierarchy between
two host-derived chemoattractants, and LTB-4 is higher in the hierarchy than IL-8.
Diabetes and Macrosomia: The Effect of Maintaining
Normal Blood Glucose Levels During Pregnancy and the Effectiveness of the Sweet Success
Program
Donna Nguyen
Mentor: Sibylle Reinsch
University of California, Irvine
Macrosomia, the medical term for newborn infant
weight greater than 4,000 grams, is a frequent outcome of diabetic pregnancies. Heavy
newborns are at risk for injury during the birthing process and for developing diabetes
later in life. Based on studies that demonstrated a reduction in macrosomia rates if blood
glucose values were maintained within a normal range during gestational diabetes, the
Sweet Success Program in Orange County, California, teaches pregnant women with diabetes
balanced nutrition, exercise, and stress management so that their newborn will have a
normal birth weight, which is between 2,500-4,000 grams. Other studies have shown, though,
that despite intense glucose control during pregnancy, women with pre-existing diabetes
had macrosomic infants at a rate six times greater than normal. This would suggest that
the Sweet Success Program might only be effective with women who developed diabetes in the
3rd trimester of their pregnancy. To address this issue, I used a data set obtained with
645 Hispanic women in Orange County, and divided the women into three groups, depending on
the trimester they were referred to the Sweet Success Program, with the reasoning that
early referrals had to be due to pre-existing diabetes, and 3rd trimester referrals had to
be gestational diabetes. Results, based on t-tests, showed no significant differences in
the mean birth weight among the different groups. Those who entered during the 1st
trimester had a mean birth weight of 3,483 grams, while those who entered during the 2nd
and 3rd trimester had mean birth weights of 3,484 grams and 3,494 grams,
respectively. The t-test also showed that the difference in mean birth weight among those
who had pre-existing diabetes and those who had gestational diabetes, 3,606 grams and
3,472 grams respectively, would have occurred by chance only 5% of the time. This agrees
with previous studies that claim that despite intense glucose control, women with
pre-existing diabetes were still more likely to have macrosomic infants. More than 80% of
the women had newborns of normal weight. Thus, the Sweet Success program seems to be an
effective program for many pregnant women who have diabetes, pre-existing as well as
gestational.
Application Mobility in Bio-Networking
Architecture
Kevin Nguyen
Mentors: Tatsuya Suda & Junichi Suzuki
University of California, Irvine
The Bio-Networking Architecture (BioNet) is a
decentralized network architecture that applies biological concepts to operate on large
scale, highly distributed, and dynamic environments. This project builds the migration
service part of BioNet that allows network applications (cyber-entities) to move from one
place to another. In BioNet, network applications are mobile agents and are analogous to
biological species that have behaviors, states, locations, and mobility. The migration
service is responsible for sending and receiving cyber-entities between BioNet platforms.
The migration service is composed of two components: ceSender and ceReceiver. When a
cyber-entity has enough energy to migrate, the ceSender serializes and sends the
entitys state, class definition (entitys source code), and name to the
destination platform. Upon receiving a migrating cyber-entity, the ceReciever uses class
loader mechanism (Java programming language) to load the class definition and
de-serializes the state of the cyber-entity. Then, the migration service initializes the
cyber-entity and registers it to the current platform. The migration service acts as a
bridge that allows cyber-entities to utilize their mobile capability. More importantly,
this service allows Bionet platforms to scale in large systems by spreading cyber-entities
around so the platforms do not collapse. This poster presentation overviews several common
design strategies for mobile objects, shows the detailed design and implementation of the
BioNet migration service, and demonstrates several results of its performance measurement.
Targeted Mutagenesis of the Genes flin-7
and flin-10 by Homologous Recombination in Drosophila melanogaster
Sheila Nguyen
Mentor: Peter Bryant
University of California, Irvine
The fruit fly Drosophila is a powerful
model system to identify the genetic mechanisms that are perturbed in cancer cells, and it
is especially useful for the identification of novel tumor suppressor genes. One of the
best studied of these genes is lethal(1)discs large-1, encoding the Discs large
(Dlg) protein, which functions in the larval brain and imaginal discs. Preliminary
evidence indicates that Dlg may exert its tumor suppressive function by regulating the
localization and/or function of DER (the Drosophila Epidermal Growth Factor
Receptor) either directly or through its interaction with the putative cytoskeletal
proteins Flin-7 and/or Flin-10. To test these ideas, I am producing genetic mutations of flin-7
and flin-10 using homologous recombination, a new technique that uses DNA repair
and recombination mechanisms to replace normal DNA with exogenous mutant DNA at a target
locus, mediated by sequence homology. In order to create the necessary DNA constructs, I
have developed a strategy using pGEM-T as an intermediate cloning vector, which enabled me
to increase the efficiency of the subcloning into pW25, the final vector, and to
successfully engineer the flin-7 construct. Using a similar approach, I am
in the process of subcloning flin-10 into pW25. In parallel to this second
subcloning procedure, I am injecting the flin-7 construct into fly embryos and
screening for both transformant flies and flin-7 mutants. The study of the
phenotypic defects of the flin-7 and flin-10 mutants should show whether the
gene products have the suggested functions in controlling cell proliferation.
Auditory Cortical Potential (N100, P200) to Gaps
in Noise in Normal Hearing and Auditory Neuropathy Subjects
Tin Nguyen
Mentor: Arnold Starr
University of California, Irvine
The objective of this project is to use
electrophysiological methods to study cortical potentials to gaps of different durations.
Auditory potentials to gaps were recorded from 12 normal subjects. Gaps of 2, 5, 10, 20,
and 50 ms in noise (60 dBnHL) were randomly presented every 2 sec. Subjects were tested in
two conditions: (1) press a reaction time (RT) button to a detected gap and (2) listen
without behavior. Trials to gaps were averaged and measures of peak latency and amplitude
of components N100/P200 were computed. Accuracy was ~99% for 50, 20, and 10 ms gaps, 73%
for 5 ms, and 17% for 2 ms gaps. RTs averaged ~292 ms to 50, 20, and 10 ms gaps, 352 ms
for the 5 ms gap, and 421 ms for the 2 ms gap. N100 and P200 were identified to gaps
between 50 and 5 ms. N100 and P200 amplitudes were significantly decreased when gap
durations were less than 20 ms; peak latency differences among gap durations were not
significant. Accuracy, RT, and N100 and P200 correlated with gap duration. These methods
provide a tool to study temporal processes in hearing disorders and mechanisms of central
auditory processing.
Conflict Detection on the Activation of the
Attachment System
Tryston Nguyen
Mentor: Shelly Gable
University of California, Los Angeles
This study examined the effect of conflict
detection on the activation of the attachment system, the system that monitors for
psychological distance from others. Attachment theory posits that when infants face
threatening situations, the attachment system is activated in order to lessen the distance
between the child and caregiver to promote safety. This study hypothesized that one major
form of threat is conflict, the indication that something is wrong. Once
conflict has been detected, the activity of the attachment system should be heightened,
such that individuals become more sensitive to indicators of psychological distance from
others and more motivated to reduce this distance. In this study, participants completed a
Stroop task (conflict) or a color-naming task (no conflict) and then decided whether
several types of words (psychological closeness: support; psychological
distance: rejection; neutral words: computer) were real or not. We
predicted that the conflict condition would heighten the sensitivity of the attachment
system and thus the accessibility of psychological distance words. Though we found no main
effect of conflict on reaction times to distance words, we found that individuals higher
in neuroticism or trait anxiety, associated with a more sensitive conflict detection
system, showed quicker recognition times to distance words in the conflict condition. We
discuss the relationship between anxious temperament and the sensitivity of the attachment
system.
Titin-Mimicking Multi-Domain Polymer Synthesis
Vivian Nguyen
Mentor: Zhibin Guan
University of California, Irvine
There are three important properties for material
performance: strength, toughness and elasticity. Naturally occurring materials, such as
the muscle protein titin, have combined these three properties. In my pursuit of
synthesizing an organic compound with optimum material performance, I have strived to
mimick the properties of titin consisting of multiple domains held together by strong,
specific hydrogen bonds. Creating such a synthetic material would be very useful to
commercial industry. Not only can such materials experience high force, but they can also
be extended, proving to be strong, tough, and somewhat elastic all at the same time. In
attempting to make a synthetic polymer that exhibits these qualities, I have been working
on making the monomers that will link together and form a repeating polymer. In doing so,
I have learned that the concepts taught in a chemistry lecture hall are not absolute
truths. The chemicals do not always behave the way the books say they will behave. Many of
the reactions did not work as I had planned, giving unexpected results. A minor change in
the setup, such as a different solvent, has made all of the difference. I have greatly
broadened my skills and chemical techniques in the laboratory, but most importantly, I
have realized that chemistry is not as exact a science as I thought it would be. Concepts
presented on the blackboard many times fail in practice, and it requires creative thinking
to come up with new systems that are applicable to each organic synthesis.
Radiative Transfer Model Fitting to Describe the
Properties of Class 1 Protostars
Kevin Nielson
Mentor: Susan Terebey
California State University, Los Angeles
When describing the formation of stars, it is
difficult to make direct correlations between observations and the properties of the
objects in question. While direct interpretation of astronomical data may not lead to good
stellar characterizations, an alternative exists in the realm of stellar modeling. By
creating a library of models of varying characteristics, including age, cavity angle,
cloud density, and inclination, we can match model profiles to observed objects and infer
similar characteristics for the observed object as were used to generate the model. Here
we compare the profile of Monte-Carlo radiative-transfer (RT) models to Hubble Space
Telescope data obtained for the class 1 protostar TMC-1 in the Taurus star-forming region.
We find that the angular intensity profile can be fit well using RT models, with only a
small discrepancy in background levels and some asymmetry not accounted for in the model.
We therefore infer that TMC-1 has an outflow cavity width of ~80-90 degrees and is
inclined toward us at ~50-60 degrees.
Mechanistic Investigation of Substituent Effects
on Oxime Radical Cations
Olena Norris
Mentor: Peter de Lijser
California State University, Fullerton
Photochemistry of oximes and its use as a method
for regeneration of carbonyl compounds has been of a growing interest; we focused our
studies on various ortho-substituted acetophenone oximes. Studies were done to investigate
the photochemical deprotection of acetophenone oximes to their corresponding carbonyl
compounds through the use of photosensitized electron-transfer reactions. With existing
knowledge of the reactions initial steps, our goal was to determine the
reactions mechanism and its assosiated intermediates. The method of investigation
involved the effects of the substituents on the reactivity of the oximes. The studies have
shown that substituents have steric, electronic and radical effects. It was hypothesized
that in order for electron transfer to be able to occur, the oxime moiety has to become
coplanar with the aromatic ring upon ionization. Certain ortho-substituents seem to
prohibit this alignment, as confirmed by semi-empirical calculations (AM1, DFT).
Ortho-substituted acetophenone oximes were studied by X-ray crystallography,
electrochemistry and fluorescence spectroscopy, data from these studies were compared to
those from the photosensitized electron-transfer reactions.
The LHX2 Gene in Schizencephaly and Septo-Optic
Dysplasia
Kelechi Nwede
Mentor: Edwin S. Monuki
University of California, Irvine
Schizencephaly and Septo-Optic Dysplasia (SOD) are
two rare but related malformations of the human brain. In most patients with
schizencephaly and SOD, the underlying cause remains unknown, although genetic defects
have been implicated in a subset of cases. The LHX2 gene emerged as a candidate gene based
on the brain phenotype of LHX2 knockout mice, which strongly resembles both human
disorders. Our goal is to determine if mutations in the human LHX2 gene can cause
schizencephaly or SOD. We are currently analyzing the LHX2 gene in a cohort of 25
patients. The experimental approach involves amplification of the LHX2 protein-coding
sequences using polymerase chain reaction (PCR), followed by direct sequencing and
computer-based sequence analysis. We have optimized the PCR and sequencing reactions for
all five LHX2 exons and have almost completed the analysis of exons 2-4. Thus far, we have
detected one potential mutation, which predicts a non-conservative amino acid change in a
potential functional domain of the LHX2 protein. In addition, we have confirmed a
single nucleotide polymorphism (SNP) known to exist in exon 4. A complete analysis of this
patient cohort should determine whether LHX2 plays a significant role in these two human
brain malformations.
What Does it Mean to be an African Feminist?
Understanding African Feminism Through the Works of Contemporary Nigerian Women Writers
Nmachika Nwokeabia
Mentor: Tara Lake
University of California, Los Angeles
The Sharia Law cases involving Amina Lawal and
Saffiya Hussaini in Nigeria, and the threat of women in the Delta region to strip in
rebellion against the powerful oil companies presented two diametrically opposite views of
the status of women in Nigeria. In literature, Buchi Emecheta, arguably Nigerias
most widely read female author, may sometimes be seen as representing, in her characters,
strong women that are nevertheless in conflict with Western ideas about feminism. She
calls her brand of feminism, "feminism with a small f." African
feminism is different from Western feminism in many ways, and critics have argued against
trying to understand African feminism, especially as presented in literature, from the
Western feminist perspective. "African feminist practice
reflects diverse
historical and personal experiences that are outside of Western experiences. As a result,
African feminism has constructed an alternative grid of values and priorities that cannot
be conflated with those of Western feminism, even if some concerns are similar"
(Petty, 1996). In analyzing some short stories from the collection "Inside My
Sisters Eyes," I try to analyze African feminism from a traditional perspective
and show how its flaws and strengths are derived from the African experience and its
multilayered history.
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