Abstracts

[A-G]   [H-N]  [O-U]  [V-Z]

 

The Role of Nitric Oxide in the Vascular Effect of Simulated Microgravity

Sukgu Han
Mentor: Dr. Ralph Purdy

The focus of this study was to investigate the effect of simulated microgravity on contractility to norepinephrine (NE) in the carotid and femoral arteries from Wistar rats. Microgravity was simulated using the hindlimb unweighting (HU) model for 20 days. Following the treatment, tissues were cut into 3 mm rings and used to measure isometric contraction. HU treatment reduced the maximum contractile response to NE in both carotid and femoral artery rings toward the control values. Aminoguanidine (AG), a selective inducible nitric oxide synthase (iNOS) inhibitor, was used to elucidate the role of iNOS in HU effect on the arteries. In the absence of L-Arginine, iNOS substrate, AG increased the contractile response to NE in both carotid and femoral HU-treated tissues. However, in the presence of L-arginine, AG had greater restoring effect in HU-treated femoral artery rings. In addition, AG had no effect on endothelium dependent relaxation induced by acetylcholine (Ach) in either carotid or femoral arteries. These results suggest that the reduced contractility to NE as a result of HU treatment involves altered endothelium constitutive nitric oxide synthase (ecNOS) and iNOS activity in the carotid artery; and altered iNOS activity in femoral artery.

 

Speech Perception

Melia Heredea
Mentor: Dr. Virginia Mann

The ability to effectively communicate with one another is prominently influenced by one's perception of the speech sounds found in his or her language. The investigation at hand examines the interaction involved in the processing of acoustic cues to speech. In the present study 20 undergraduate participants from the University of California, Irvine identified a range of four hybrid stimuli consisting of synthetic fricative noises, and naturally produced vocalic segments (from sa, sha, su, and shu) recorded by a male and a female voice. Specifically, this experiment looked at decision independence vs. decision dependence in participant's identification of consonants and vowels in syllables. Previous research suggests that listeners identify vowels and consonants in an independent fashion (Batchelder & Crowther, 1997). The speech sounds utilized in the present study have not been the subject of previous research into the question of dependence vs. independence, and on the contrary seem to demonstrate dependence between the consonants and vowels (Mann & Repp, 1980). A secondary goal was to examine the possibility that the vowel and sex of the speaker can separately affect the perceived way in which the participant processes the consonant. Data analysis is currently underway. Results will be analyzed by using mathematically based multinomial processing tree models (MPT), which attempt to measure latent cognitive capacities (Batchelder & Crowther, 1997).

 

The Role of Cultural Norms on UCI Chicana Sexual/Contraceptive Behavior

Irma Hernandez
Mentors: Dr. John Dombrink & Dr. Juan Francisco Lara

Sexual behavior has become a widely researched topic due to both the devastating consequences of HIV (Human Immunodeficiency Virus) that contemporary society has witnessed and the growing trend of teen pregnancies in our nation. Research studies continuously depict the severe effects of these health issues on the Latino population, particularly Latino women in the US (Darabi et al., 1986; DuRant, et. al, 1990; Villaruel, 1998). For teens and young adults, an unplanned pregnancy is often a motive to abandon their education. Thus, this present study focuses on the sexual behavior of undergraduate Chicanas, an uncommon population for such studies. Fifty UCI undergraduate Chicanas completed an anonymous survey designed to assess their sexual/contraceptive practices and beliefs, high-risk behavior patterns, and the relationship between these behaviors and cultural norms. The same questionnaire was administered to a control group composed of fifty-three non-Latino White undergraduate women. Data analysis is currently in progress and will analyze the following cultural factors in relation to sexual behavior: Gender roles and relations such as the power imbalance in heterosexual relationships, sexual silence, religiosity, and acculturation. It is hypothesized that the more traditional cultural norms among the Chicano community will have a greater impact in the sexual behavior and beliefs of Chicanas, ultimately exacerbating their risk of an unplanned pregnancy. The final results of this study will serve to better understand the sexual/contraceptive behavior of UCI undergraduate Chicanas and to describe the effects of cultural values on this behavior.

 

Critical Reflection Upon the Filipina American Experience of Identity

Melissa Honrado
Mentor: Dr. Nancy Naples

In this study, I compared and contrasted similar issues between queer women of color in the United States and in the Philippines. I utilized the interview methodology to draw upon personal instances that exemplify the intersectionality of the Queer Filipina Identity in both areas. Common histories of colonialism were analyzed to explore notions of neo-colonialism experienced at the present time. In addition, globalization and diasporic processes are also explored. Sexual orientation and gender identities are studied within the framework of colonialism, migration, and post-colonialism. In many cases, the boundaries between these identities are blurred and intersect to build an "authentic" self. What does it mean to be a queer Filipina American? I argue that the "Authentic" identity is fluid and dynamic over spatial and temporal settings. The only constant is change. Because of this postmodern notion of fluidity, we are constantly challenged with the struggle to construct and reconstruct, to evaluate and re-evaluate, to shape and reshape ourselves in an effort to form an "Authentic" identity over differing spatial and temporal parameters.

 

The Role of "Very Important" Nonparental Adults in the Lives of At-Risk Adolescents

Tara Hooker
Mentor: Dr. Ellen Greenberger

Nonparental adults play a significant role in the lives of adolescents. A relationship with an aunt, uncle, a teacher, neighbor, or friend’s parent can provide an adolescent with the benefit of emotional support, instrumental support, companionship, and guidance. In 1998, Greenberger, Chen, and Beam studied the role of "very important" nonparental adults (VIP) in the lives of 243 adolescents and found that VIP characteristics account for a significant amount of variance in adolescent behavior and depressive symptoms. The study is longitudinal and covers aspects of adolescent development including family and peer relationships, key psychosocial outcomes, and relationships with nonparental adults whom adolescent subjects considered to be "very important" in their lives. The current research utilizes the data of Greenberger, Chen, and Beam to conduct intensive case studies of the relationship between three "high-risk" and three "low-risk" adolescents and their VIPs. From among a relatively low risk sample, subjects were chosen from the upper and lower quartiles based on their mean scores on depression, problem behavior, negative life events, and family and peer relationships scales. Case studies utilize survey and interview data to investigate (1) how VIP influences on behavior and mood are transmitted to adolescents, and (2) how a relationship with a VIP may function to moderate negative psychosocial outcomes in "high-risk" adolescents. Case studies reflect the adolescent’s family and peer relationships, adolescent’s psychosocial position, adolescent and VIP’s perceptions of their relationship, and function and role of the relationship in the adolescent’s life. Data analysis is currently underway.

 

Influences of a Physical, Three-dimensional Model of the Vandenberg Task on Gender Differences in Mental Rotation

Kelly Hughes
Mentor: Dr. Mary Louise Kean

Gender difference in spatial ability is a widely studied topic, perhaps because of its very controversial nature. Social and political implications (e.g. possible correlation with SAT math score) have encouraged continuing studies to determine why there appears to be a male advantage. It has been found that the magnitude of the gender difference can vary, depending on the type of spatial task (Hamilton, 1995). Evidence has also been observed that a person’s gender role (as opposed to biological sex) might be an important component of performance (Hamilton, 1995). This research has been conducted to further investigate these findings, using a physical, three-dimensional version of the Vandenberg Mental Rotations Test (one which has yielded robust gender differences). The original Vandenberg Test is presented on paper and consists of 20 sets of block-like figures to be rotated into congruity. Both forms of the test will be administered to 30 participants, 15 female and 15 male. The Bem Sex Role Inventory will also be administered to determine the prominent gender traits of the participant. Analysis of results is currently underway. It is expected that there will be a difference in the performance on the two forms of the test, as each places a different type of demand on cognitive processes. A difference in prominent gender traits among high scorers is also expected for the two version of the test. Implications of these findings in relation to current theories will be discussed.

 

Activation of Alternative Pathway of Complement During Ventricular Assist

Thanh Huynh
Mentor: Dr. John Chen

By providing mechanical support to a patient’s failing heart, ventricular assist devices (VADs) have improved survival rates in selected patients. Unfortunately, VAD use continues to be complicated by problems such as thromboembolism, prolonged bleeding, infection, and end-organ failure. The activation of the complement system may contribute to these problems. Previous studies have found that the complement common terminal pathway is activated during VAD circulation. The common terminal pathway of complement can be activated by either of two pathways, the alternative or the classical. The purpose of this study was to determine the relative contribution of the alternative versus the classical pathway in complement activation during in vitro VAD circulation. To perform this experiment, we simulated six in vitro VAD circuits with human blood under physiological conditions for 3 days. After withdrawing samples at regular intervals, we used enzyme immunoassays to measure concentrations of fragments that were specific to either pathway: increases in fragment Bb indicated alternative pathway activation and increases in fragment C4d indicated classical pathway activation. Fragment Bb levels quickly rise from 1.92 m g/mL to 10.77 m g/mL during the first 6 hours of circulation. Thereafter, Bb levels plateau. C4d levels slowly rise from 1.49 m g/mL to 6.84 m g/mL in 72 hours. These results suggest that both the alternative and classical pathways of complement are activated during VAD circulation. The alternative pathway is activated earlier and may be of greater importance in clinical VAD circulation.

 

Permeability Coefficient of Nitric Oxide in a Monolayer of Bronchial and Alveolar Epithelial Cells

Suk-On Ip
Mentor: Dr. Steven George

Nitric Oxide (NO) is a pervasive and physiological active molecule in mammalian. Intensive care patients can be treated by inhalation of exogenous NO gas. This has improved patient outcomes in diseases such as adult respiratory distress syndrome (ARDS) and other inflammatory diseases of the lung. The dosage of NO is critical since it can be toxic at high concentrations. The permeability coefficient of NO in a human lung tissue is a necessary physiological parameter that can enhance our understanding of NO as a therapy for various lung diseases. NO (43 ppm) was placed in the upper compartment of a two-compartment chamber. The compartments are separated by a polycarbonate membrane and a layer of pulmonary epithelial cells. The concentrations as a function of time of both compartments are measured and used to determine the permeability of the polycarbonate membrane (Pm) and the epithelial monolayer (Pmm). Preliminary analysis of the top compartments demonstrated an exponential decay of concentration as a function of time. Further data analysis is currently underway. The findings of this study will increase our knowledge of NO transport dynamics in the lungs.

 

Intraoperative Cardiac Output and PA Pressure Measurements to Determine Optimal LVRS Techniques in a Rabbit Model of Emphysema

Rayhan Jalal
Mentors: Dr. John Chen & Dr. Matthew Brenner

Lung volume reduction surgery, a procedure being evaluated as a treatment for emphysema, may improve spirometry but may decrease diffusing capacity with high resection volumes. Optimal lung resection amounts may be limited by the functional pulmonary capillary surfaces. Right ventricular performance and pulmonary artery (PA) pressure may serve as useful intraoperative indicators for determining the optimal lung volume to resect during LVRS. The purpose of the investigation was to compare PA pressure and cardiac output (CO) before and after LVRS in a rabbit model of emphysema to further define limits of lung volume resection. These variables and compliance were measured in 12 New Zealand White rabbits with emphysema before and after LVRS. The mean compliance for the rabbits decreased from 5.5 to 4.5 ml/cm H2O. The mean CO dropped from 284 to 254 ml/min post surgery. The systolic PA pressure increased to 15.7 from 13.6 cm H2O before LVRS. With lung reduction surgery for emphysema, CO declines and PA pressure increases. In contrast, LVRS also produces an overall improvement in spirometry as demonstrated by the decrease in compliance after surgery. However, despite spirometric improvements, other variables such as the decline in pulmonary surface area and CO or the increase in the PA pressure, may diminish the benefits of LVRS. Further investigation is necessary to delineate potential PA pressure and cardiac output measurement limitations of LVRS.

 

The European Policy Against Terrorism: Between National and Supranational Solutions

Rebecca Kanter
Mentor: Dr. Emanuel Richter

Terrorism is alive and well in Europe and around the world. Globalization, often hailed as advantageous to our growing world society, has complicated attempts to combat terrorism. One scholar noted that "the terrorist has become truly international and takes no account of frontiers." With the opening of the internal market and elimination of border controls in Europe after the Single European Act, terrorists have a further advantage over agencies, nations, or organizations who would wish to stop them. The focus of my research is policy responses to terrorism in Europe. Somewhere between national policies, bilateral and international cooperation, and supranational methods is the solution to the terrorist threat in Europe. The most recent activity in the EU demonstrates a slight trend towards supranationalism as the arena for agenda setting in this area, but the member states continue to struggle to achieve a unified policy and approach to curbing terrorism in Europe and around the world.

 

The Stages of Exercise Adoption and Self-Efficacy in a Worksite Sample

Anisa Kassim
Mentor: Dr. Daniel Stokols

This study examined whether the implementation of a worksite walking club would increase employees’ levels of physical activity and their sense of self-efficacy. Questionnaires designed to measure employees’ stage of exercise change, in light of Prochaska’s stages of change model, and their subjective reports of self-efficacy, were administered to 20 workers at a large pharmaceutical firm. A pre- and post-test were administered to determine whether individuals engaged in more advanced stages of exercise reported higher levels of self-efficacy and readiness for physical activity change than those who were characterized by less advanced stages of exercise. Results suggest that individuals in the latter stages of change were more likely to have a greater self-efficacy rating than those in the earlier stages of exercise. Also, individuals in the earlier stages of exercise adoption began to engage in exercise more frequently upon the conclusion of the study. Understanding the stages of change in exercise adoption will aid program implementers in targeting their physical activity promotion programs to individuals at different stages of exercise adoption.

 

Antibody Induced Apoptosis of Bystander Cells

Gabriel Katz
Mentor: Dr. Donald Forthal

Apoptosis is thought to be involved in the depletion of CD4 positive t-helper cells in Human Immuno Deficiency Virus Positive patients. My research project is looking at induction of apoptosis and cytotoxicity by lysis in human CD4+ cell lines induced by peripheral blood mononuclear cells (PBMC). I am using cell death detection kit ELISA, which simultaneously measures apoptosis as well as lysis of HIV-transfected cells. The principle of this assay is that cells of the immune system such as CTLs , NKs, or LAKs (lymphokine-activated killer cells) can recognize and destroy damaged, infected, and mutated target cells. Two possible cytocidal mechanisms are involved: apoptosis and lytic molecules by which lytic molecules (e.q. perforin) are secreted by the effector cell and polymerize to form lytic pores in the target cell membrane. These mechanisms are not mutually exclusive, but complementary. The main characteristic is that the fragmented DNA is released from the cytoplasm into the culture supernatant due to pore formation in the target cell plasma membrane. The main idea for my study is to investigate whether HIV-induced apoptosis occurs via direct or indirect mechanism. I am looking for evidence that CD4 cells which do not express HIV antigen (bystander cells) will be killed when NK cells or monocytes are killing HIV-envelope transfected cell. This study is a window into deeper understanding of HIV and perhaps raise more questions in the scientific community, which can potentially lead to other studies alike.

 

The Evolution of Encapsulation in Drosophila melanogaster

Brian Keefer
Mentor: Dr. Bradford Hawkins

This project has explored the possibility of coevolution between insect parasitiods, which parasitize their hosts by depositing their own eggs within them, and the hosts they utilize, which can defend themselves against parasitization by encapsulating the parasitoid’s egg. I have specifically manipulated and examined colonies of the pomace fly, Drosophila melanogaster, that have been cultured in the absence of parasitoids for over ten years (at least 200 generations) to determine whether they possess the genetic variability to evolve higher encapsulation rates. It is possible that they have lost some of the genetic variability to evolve higher encapsulation rates as a result of the lack of selective pressure for this trait for so many generations. I have investigated this question by maintaining colonies of these flies and providing specific interactions between these colonies and one species of parasitoid wasp, Leptopolina boulardi. The D. melanogaster colony has been maintained under strong selective pressure from parasitoids in an attempt to affect higher encapsulation rates. I have run trials to determine whether a higher proportion of flies survive parasitization from one generation to the next, which would indicate acquisition of an increased resistance against the parasitoids. I have examined seven generations of flies, and have exposed each generation to strong selective pressure to develop resistance to parasitization. Thus far, there has been no evidence of the evolution of such a trait, and the proportion of flies surviving parasitization in the trials has remained consistently low. Possible reasons for the lack of the development of the expected results are discussed.

 

Effects of Corticosterone Administered After Pre-Exposure on Memory of Inhibitory Avoidance Training

My Kha
Mentors: Dr. James L. Mc Gaugh & Dr. Benno Roozendaal

Previously we have found that glucocorticoids given immediately after inhibitory avoidance training enhances memory. However these studies did not discriminate between memory for the environment (inhibitory avoidance box) and the stressor (footshock). This study examined the effect of corticosterone administration immediately after pre-exposure on memory for inhibitory avoidance training. Here we show a non-significant impairing effect of pre-exposure to the later shock environment on memory for the inhibitory avoidance test. Systemic (sc) injections of either vehicle or corticosterone (1.0 mg/kg and 3.0 mg/kg) were administered immediately after a 1 min pre-exposure to the inhibitory avoidance box. Twenty four hours later, the rats were given an inescapable footshock (0.35 mA, 1 s). Retention testing 24 h after the training showed that rats that were pre-exposed to the inhibitory avoidance box showed shorter retention latencies than rats that did not receive the pre-exposure. Both doses of corticosterone blocked the shortening effects of pre-exposure on retention latencies. These results suggest that memory for the inhibitory avoidance training involves both memory for the environment and the stressor. We will run more tests to obtain significant results.

 

The Effects of Exogenous ACTH on CRH Gene Expression in the Amygdala

Najeeb Khan
Mentor: Dr. Tallie Z. Baram

Adrenocorticotrophic hormone (ACTH) is used as a therapeutic agent for numerous neurological disorders. However, the mechanism of ACTH effects in treating these disorders remains unknown. An established action of ACTH is induction of glucocorticoid (GC) release from the adrenals. GCs can cross the blood-brain barrier and influence the CNS. Whether ACTH also acts directly on the CNS, independent of GC, constituted the focus of this study. Specifically, we tested the hypothesis that ACTH downregulates expression of the neuropeptide corticotropin releasing hormone (CRH) in the amygdaloid central nucleus (ACE) independent of GC. In order to distinguish the direct effects of ACTH on CRH expression in ACE from the effects mediated by GC, intact rats were compared to those in which GC were eliminated by adrenalectomy. ACTH (80u/kg) was given to intact or adrenalectomized rats and both were compared to na´ve controls. Animals were sacrificed four hours later. CRH expression was measured by in situ hybridization. Plasma GC and ACTH levels were measured by radioimmunoassay. ACTH administration resulted in 25% decrease in CRH mRNA expression in ACE that appeared to be independent of GC levels: ACTH effects were similar in both intact (where ACTH led to very high GC levels) and in adrenalectomized animals (where GC levels were zero). Expected hormonal effects of ACTH were verified. ACTH acts directly on the CNS to downregulate CRH expression in ACE.

 

A Synthetic Search for AMPA Receptor Desensitization Modulators

Peter Krutzik
Mentor: Dr. A. Richard Chamberlin

Released at approximately half of all brain neural synapses, L-glutamate binds to ionotropic receptors and elicits excitatory post-synaptic potentials (EPSPs). These potentials play a role in long term potentiation (LTP), a process crucial to learning and memory. However, since overactivation of glutamate receptors (GluRs) and their ion channels can lead to excitotoxic influxes of small ions, the GluRs (AMPA, KA, and NMDA) become "desensitized" to glutamate after only a few milliseconds. Drugs such as IDRA-21, CTZ, and D1 have been proven to inhibit desensitization and promote GluR excitation, showing promising effects in in vivo learning and memory studies on various mammals, including humans. Yet, some of these drugs also cause excitotoxicity and therefore, their activity must be limited. Thus, various analogs of D1 were synthesized. The goals of the syntheses were as follows: 1) to find compounds that more readily passed through the blood-brain barrier, 2) to discover analogs that were active at typical drug concentrations, 3) to understand the structure-activity relationships (SAR) of these compounds, and 4) to help elicit the nature of the drug binding site. Although no compounds were found that were much more effective than D1, various synthetic strategies pertaining to the benzothiadiazine ring were discovered, including regioselective reduction and amino acid coupling methods. Also, the structure of these analogs has helped to elucidate the binding site and mechanism of the benzothiadiazine class of AMPA receptor drugs.

 

The Effects of Low-Intensity Electromagnetic Fields (EMF) on the Immune System and on Melatonin Production

Jennifer LaFemina
Mentors: Dr. Edward DeMet & Dr. Aleksandra DeMet

Animal studies have reported that low-intensity electromagnetic fields (EMF) can suppress pineal activity and melatonin synthesis. Melatonin has immuno-enhancing properties and decreases in this hormone could diminish disease resistance. Epidemiological studies in humans have produced conflicting results on the effects of EMF. This study examines EMF effects on melatonin and immune function in 12 normal volunteers using a double-blind design. No significant effect of EMF was found in the overall sample. Over 40% of the subjects, however, had melatonin suppressions over 50%. The results suggest that while most people are not sensitive to EMF, others are susceptible to the acute stress of earth-strength EMFs. These findings provide possible explanations for discrepant reports that have appeared on the effects of EMF.

 

The Role of Fraud in the Japanese Financial Crisis

Jason Lam
Mentor: Dr. Henry Pontell

The Savings and Loan debacle plundered the nation’s financial resources and effectively served notice that white collar crime is inevitably linked to profit-orientated atmospheres. With an estimated total cost of $500 billion, the crisis was an incredibly destructive financial disaster. The causes of that disaster were not faulty business decisions but rather the work of deliberate insider fraud combined with systematic political collusion. This same pattern of fraud and political collusion has now brought upon an even more devastating crisis, which has been deemed by the popular media as the "Asian Financial Crisis." Questionable investments, underfunded banks, and political misconduct has sent currencies in Thailand, Malaysia, Indonesia, and Korea tumbling to record lows. The crisis that faced Japan’s banks, however, proved most shocking and troubling to the world’s economy. Dramatic suicides, arrests and resignations of high ranking officials in Japan’s Finance Ministry have accompanied the drastic fall of Japan’s benchmark Nikkei Stock Average. As the world’s largest creditor country and second largest economy, it’s economic woes could conceivably bring about economic chaos throughout Europe and America. As the drama unfolds and more information becomes readily available, a full and all-encompassing analysis can be made comparing the causes of the Savings and Loan debacle with the chaos facing Japan’s banking system.

 

Resolution and Desymmeterization Using Binaphythyl-Azepine Compounds

Roger Lannon
Mentor: Dr. Scott Rychnovsky

Rychnovsky and co-workers have previously synthesized (▒ )-3,5-dihydro-3,3,5,5-tetramethyl-4H-dinaphth[2,1-c:1’,2’-e]azepine-N-oxyl, a chiral binaphthyl-based nitroxide. This compound has been demonstrated to be an effective catalyst in the kinetic resolution of chiral alcohols via enantioselective oxidation mediated by the corresponding N-oxo ammonium ion. The chiral nitroxide’s effectiveness as a chiral catalyst has sparked a need for suitable, large-scale synthesis of the nitroxide for potential industrial and research-oriented interests. Necessary improvements in the synthesis have been made, while further modifications are being explored. In addition, the ability of the binaphthyl nitroxide to react enantioselectively has also led to research exploring other prospective asymmetric applications of its amine-based precursors. This includes the desymmeterization of both meso-epoxides and prochiral ketones using chiral amide base chemistry, a relatively undeveloped field in organic chemistry.

 

Towards a Model for the Stereoselectivity of Nucleophilic Addition to Five-Membered Ring Oxonium Ions

Catharine Larsen
Mentor: Dr. Keith Woerpel

Synthetic chemistry is the lifeblood of the medical industry. Approximately ninety percent of the therapeutic drugs in use today are either synthesized de novo or by chemically enhancing the medicinal properties of a pre-existing natural product. For example, compounds derived from the sugar ribose have shown significant potential as cancer and AIDS therapies; AZT for the treatment of AIDS is the best-known example. The stereochemistry, the positioning of the substituents above or below the ring, at carbon-1 often determines the biological activity of these compounds. Nucleophilic addition to the five-membered ring oxonium ions of sugar derivatives provides access to this position. Five-membered ring oxonium ions currently lack a predictive model for the effects of structure and conformation on the stereoselectivity of nucleophilic addition. The stereochemical outcome of nucleophilic addition of substrates bearing only one substituent are easily predicted, but substrates with more than one substituent often yield unpredictable, yet highly selective, results. This stands in marked contrast to the understanding of stereoelectronic effects on six-membered ring oxonium ions. Analysis of the carbon-1 stereochemistry of the products of nucleophilic addition to substrates with varying substituents contributes to the development of a model for the stereoselectivity of nucleophilic addition to five-membered ring oxonium ions. A stereochemical model will save time and money that would otherwise be lost pursuing less selective synthetic pathways because chemists can then plan syntheses with the knowledge that certain substituents at specified positions on the ring will give the desired stereochemistry.

 

Temperature Profiles in a Diffusion Flame

Catherine Le
Mentor: Dr. Derek Dunn-Rankin

Combustion provides 90 percent of the energy we use to support the luxuries of our daily life: from electricity to powering our various modes of transportation, as well as keeping us warm in the winter and cool in the summer. Unfortunately, however, combustion is also responsible for 90 percent of air pollution. Understanding flame structure can help us realize the benefits of combustion while reducing the emitted pollutants. This project uses thermocouple and schlerien techniques to examine the temperature profile of diffusion flame issuing from a Wolfhard-Paker slot burner. The temperature profile is measured horizontally at one-millimeter increment across the flame at three different vertical positions using type R thermocouples. The data is recorded manually and by computer using LABView. The schlerien technique is a photographic method that correlates the deflection of light as it passes through a medium with the density gradient (the diffusion flame) and the temperature profile. The obtained temperature profile can be used to derive relationships with other characteristics of the combustion process such as soot formation.

 

A Profile of California's Latino Electorate in 2010

Loan Le
Mentor: Dr. Manuel Garcia y Greigo

Civic participation through voting has historically been more characteristic of individuals who are white and who have higher levels of income and education. In recent California elections, the Latino population has accounted for only a small proportion of the voting electorate with estimates ranging from 8-12%. Because the Latino electorate currently constitutes a small proportion of all California voters, this ethnic population has not determined the outcomes of past statewide elections. This study will examine the potential impact of the Latino population on future state elections through an analysis of demographic trends in conjunction with past voting rates and issue salience (Propositions 187, 209 and 227). It simulates future elections by rerunning past statewide elections with the potential ethnic voting electorate of 2010 in California. With the 1994 elections, for example, the Latino electorate exhibited a high degree of unity when voting as compared to other ethnic populations. By applying 2010 demographics to the Wilson/Brown race for the governor’s seat, we see that the Latino electorate of the future has the potential to considerably narrow the margin of victory in state elections if not alter future electoral outcomes. This potential will afford Latinos greater say in California’s political agenda as it exhibits that the Latino population may have great influence upon statewide electoral outcomes.

 

Evaluation of the Polymerase Chain Reaction for the Detection of Chlamydia trachomatis

Vu Le
Mentor: Dr. Ellena Peterson

The purpose of this study was to compare the performance of the polymerase chain reaction (PCR) with tissue culture for the detection of Chlamydia trachomatis, which is a leading cause of sexually transmitted disease in the United States. Culture has been the gold standard for the laboratory diagnosis of chlamydial infections but has several drawbacks including labor, expense, and sensitivity and thus is being challenged by newer, more sensitive molecular methods. Included in the evaluation were 887 cervical and urethral specimens submitted to the Medical Microbiology Laboratory at UCIMC. Specimens were collected in Bartel’s transport media and were tested in parallel by a standard tissue culture assay using McCoy cells and the semi-automated COBAS PCR assay. Discrepant results between assays were resolved by repeating the culture and the PCR in duplicate. There were 16 (1.8%) specimens that contained inhibitors of the PCR and therefore were not included in the data analysis. Overall, there were 44 specimens (5.2 %) positive by one or both methods with 35 and 42 detected by culture and PCR, respectively. There were 2 false positive PCR results on initial testing that were repeatedly negative. Culture had a sensitivity of 78.6% compared to 94.3% by PCR. The specificity of culture and PCR was 99.8% and 98.9%, respectively. In summary, the PCR was more sensitive but less specific than culture for the detection of C. trachomatis and therefore is an acceptable alternative method for the laboratory diagnosis of genital chlamydial infections.

 

German Reunification and European Integration

Carrie Lee
Mentor: Dr. Russell Dalton

The reunification of Germany in 1990 is one of the most significant events of the 20th century. The existence of two German states had been considered the foundation for peace in Europe following the two disastrous World Wars. Therefore, the reunification of Germany was to have profound effects throughout both Europe and the changing international order. The scope of the potential consequences of reunification was a cause of much fear and debate, as concerns surfaced regarding the possibility of Germany taking an aggressor role and attempting to dominate Europe. European Community members were especially concerned that the cause of European integration would be undermined through the unification of Germany. This thesis examines the outcomes and effects of German unification on the European Community/Union and the process of European integration. The thesis focuses on the areas of economics, balance of power, and foreign policy in the near decade following unification. The objective of this thesis is to explore the multifaceted repercussions of unification on the interrelationship between Germany and the process of European integration.

 

Differential Effects of NT-4 and BDNF Mediated by Localization of trkB and p75 LNTR

Jennifer Lee
Mentor: Dr. Ron Frostig

The goal of this project is to clarify the mechanisms by which the neurotrophins NT-4 and BDNF alter cortical plasticity in the rat barrel cortex. Though both neurotrophins bind the same receptors, we have seen previously through intrinsic signal imaging that BDNF induces a rapid change in plasticity, whereas NT-4 does not. It has been suggested that BDNF will bind to trkB receptors with or without the presence of p75 LNTR, and that NT-4 will bind to trkB only in the presence of p75 LNTR (Ryden et al 1995). This suggestion compelled me to characterize the distributions of p75 LNTR and trkB in the rat barrel cortex in order to discern the locations of the potential cells that may mediate the differential effects of NT-4 and BDNF. Immunocytochemical double staining of trkB and p75 LNTR receptors supports the above proposal by showing that the two receptors do not colocalize in the cells of the rat barrel cortex.

 

Proposition 5

Larry Lee
Mentor: Dr. John Dombrink

In November 1998, California voters passed what was considered the costliest proposition in United States history. Proposition 5, the California Indian Self Reliance initiative, was a political battle between the California Native American tribes and a conglomerate of Nevada casinos, with $90 million, aimed at defining the legal scope of Indian gaming. This research will focus on the dynamics and strategies the California Indian tribes used to push this "unwinnable" campaign into a great success. The presentation will discuss key issues of coalition building, fundraising, framing of issues for debate, and the execution of a strategy for the campaign. Key players from the proponent side describe in detail how they were able to unify 88 California Indian tribes to face the opposition, which not only included the Nevada casinos but also labor unions, law enforcement, anti-gaming groups, and local California card clubs. Analysis of how the California Indian tribes raised enough money to outspend the opposition by nearly a margin of 3 to 1 will also be discussed. This research will show how the formulation of campaign issues became an integral part of the winning strategy.

 

The Ideal Female Form

Lisa Lee
Mentor: Dr. Mara Lonner

The physical appearance of a woman is a controversial subject. The pressures put on women to look like popular models are enormous. Fostered by mass media imagery, women have resorted to diets, surgery, and even drugs to achieve this "ideal" image. Further evidence of the scope of this problem can be found in the dangerous mental state of women who are seduced by it. Eating disorders such as anorexia and bulimia are two popular examples of this suffering. But, is society to hold all the responsibility for these troubles? The fact is --not all eating disorders result from society’s twisted image of the female body. Some women must fight internal battles, whether they are mental or physical. This project exposes the fallacy of these "ideal" images.

 

Effect of Estrogen on Nitric Oxide Synthase Activity in Rat Cerebral Microvessels

Anne Lieu
Mentor: Dr. Diana Krause

Estrogen has been implicated in imparting cardiovascular protection against disorders such as stroke, migraine and coronary heart disease. A proposed mechanism of action is estrogen’s enhancement of endothelial function by stimulating endothelial nitric oxide synthase (eNOS) to produce the vasodilatory molecule nitric oxide (NO). The objective of this study is to investigate the effects of estrogen on the eNOS activity of rat cerebral microvessels. Three groups of rats - female (F), ovariectomized female (O), and ovariectomized female with estrogen treatment (OE) were studied. Based on our finding that estrogen exposure increases expression of eNOS protein, we hypothesized that eNOS activity would be increased in the F and OE groups as compared to the O group. Microvessels were isolated from brain tissue taken from the 3 animal groups by homogenization and centrifugation. We measured eNOS activity by measuring L-[14C]citrulline produced from the L-[14C]arginine substrate (with concomitant release of NO); and performed a protein assay to determine the protein content of each animal group. eNOS activity was found to be linear with increasing time and protein concentration, and was inhibited by either the specific blocker, N -nitro-L-arginine methyl ester (L-NAME), or removal of calcium. We discovered that eNOS activity was greatest for O, followed by OE, with the lowest activity in F - results that are contrary to expectation. eNOS is tightly regulated by protein-protein interactions in endothelial caveolae. Thus, estrogen may influence the regulation of eNOS activity in addition to increasing enzyme levels.

 

Potable Reuse as a Solution to Water Shortage

Erin Lillibridge
Mentor: Dr. Sharon Stern

Water is one of the most valuable and limited resources on the planet. Although water covers over half of the planet, communities struggle to provide residents with quality water for drinking, agricultural, industrial and commercial needs. Water is especially scarce in arid regions like Southern California and Orange County in particular. Different strategies have been considered to solve the water shortage problem in Orange County and have included desalinization, conservation, regulation and currently potable reuse. With increasing demands for water at the same time groundwater supplies are diminishing, Orange County is developing a regional water replenishment project, which will recharge local water basins with highly treated wastewater. This project is expected to reduce the need for imported water from Northern California and the Colorado River and will reduce ocean discharges. This study evaluates the feasibility of the replenishment project and investigates the chemical and microbial concerns associated with potable water reuse. Questions concerning the health effects of the reuse project will be addressed through the analysis of the chemical and microbial data. The option of potable reuse should be considered a viable method of augmentation only if health issues, as well as environmental, economic and social concerns are adequately addressed. The findings of this study will assess the feasibility and success of the Orange County Water Replenishment Project for the problem of water shortage in Orange County.

 

Effects of Basal Forebrain Cholinergic Neurons on SMI-32 Positive Cortical Cells

Dayra Lopez
Mentor: Dr. Richard Robertson

The focus of this laboratory is the study of axonal afferents and differentiation of neurons. The model system used in the present study is cholinergic innervation to the cerebral cortex. Previous studies in the laboratory have shown that pyramidal cells, a subset of cortical neurons, exhibit changes in their morphology when grown in tissue culture in the presence of basal forebrain cholinergic neurons (Ha et al, 1998). The purpose of the present study is to determine whether the same cortical neurons are dependent on basal forebrain cholinergic innervation in vivo. In order to address this question we lesioned the left cingulate cortex by aspiration or knife cut to sever the cingulate bundle and cut the basal forebrain projections to the cerebral cortex. After one to two weeks following surgery, the animals were sacrificed by perfusion, brains were sectioned and stained by immunocytochemistry for SMI-32 to look at changes in cortical cells; and acetylcholinesterase histochemistry was performed for lesion verification in the basal forebrain. Furthermore, the preliminary results from this study indicate that there is no difference in pyramidal cell morphology. This may be due to the fact that there are many inputs that might influence SMI positive cells in vivo that are not present in vitro.

 

Civil War in El Salvador: Influence of Gender on Female Guerillas

Arlene Lozano
Mentor: Dr. Allison Brysk

From 1979 to January 1992, El Salvador was engaged in a fierce civil war between an U.S. supported military regime and the guerrillas of the FMLN (Farabundo MartÝ National Liberation Front, a coalition of guerrilla organizations). Although the civil war ended at a stalemate, it brought attention to the issue of gender. Much of the literature on women in revolutionary movements states that women are drawn into the struggle both as mothers responsible for families and as women seeking greater equality with men. The experience creates women who challenge gender roles, but inevitably remain at a disadvantage in terms of gender division of power and resources when the revolution is over. In El Salvador women made up 40% of the FMLN membership, including 30% of the combatants. Despite the unprecedented number of women guerrillas and collaboradoras (collaborators), gender equality and women’s rights were not a priority of the immediate revolution. During the war both men and women shared certain gender expectations that helped reinforce the gender discrimination within the guerrilla camps and FMLN leadership. My research focuses on ten women who took up arms and were not only combatants but mothers, girlfriends, and feminists as well. I explored their lives before, during, and after their involvement as guerrilla combatants. Data was obtained through personal interviews conducted in El Salvador.

 

Development of the Cholinergic System in the Dentate Gyrus of the Hippocampus

Roxana Makuch
Mentor: Dr. Richard Robertson

Studying the relationship between the development of axons and target cells is essential to understanding the complexity of the brain. An appropriate model system to study this is the cholinergic input from the basal forebrain to the dentate gyrus in the hippocampus. Although mature dentate granule cells in the external blade of the dentate gyrus can be observed in the adult brain, very little if any development could be seen prior to birth. As a result, the present study is being performed as an attempt to answer the following two questions: 1) whether the cholinergic axons coming from the basal forebrain into the external blade of the dentate gyrus innervate the maturation of the dentate granule cells or 2) the maturation of the dentate granule cells in the external blade attract the growing axons in that direction. In addition, the post-natal time at which these cholinergic neural axons reach the external blade of the dentate gyrus is investigated. Rat pups, post-natal day 2 (P-2) to day 12 (P-12) are used in this study. Fixation of the brain tissue followed by AchE histochemistry staining of the cholinergic neuron cells are the methods followed in order to observe under the microscope the noticeable axonal progression in the dentate gyrus after each day of existence. The granule cells were hypothesized to mature subsequent to axonal projections caused by external stimuli, which induces the cell development.

 

 

An Analysis of Academic Programs for Underrepresented Students

Jennifer Manongdo
Mentor: Dr. James Smith

Since the decline of affirmative action in education, programs geared towards underrepresented undergraduates have become increasingly important in retaining students and encouraging their pursuit of graduate education. The purpose of the current study is to determine if students who participate in academic programs for minorities are more likely to pursue graduate education than minority students who do not. If so, what aspects make these programs effective? Three possible explanations will be considered. First, the academic rigor of such programs may encourage students to enter graduate studies by demonstrating that they are capable of graduate level work. Second, students may form strong social support networks by interacting with peers of similar economic and cultural backgrounds. Finally, the students who chose to apply and are accepted to such programs may already be high achievers who would go on to graduate education regardless of their participation of these programs. The current study will be a case study on an academic program geared towards underrepresented students in the Social Sciences at the University of California, Irvine. Data will be collected from past and present participants regarding their experiences during and after the program and its effect on their career and educational goals. Faculty and staff members will also be interviewed on the goals of the program and their perceptions of its participants. This study may offer some insight to the specific needs of minority students in higher education.

 

Recombinant Mouse Adenovirus (MAV): Construction of a Chimeric MAV Green Fluorescent Protein (GFP) Plasmid

JosÚ Mayorga
Mentor: Dr. Luis Villarreal

Although the use of human adenovirus (types 2 and 5) in gene therapy has been shown to deliver the dystrophin gene in muscle cells (Kochanek et al. 1996), it can cause a secondary immune response in patients (Gall et al. 1996; Bao et al. 1996). The use of a mouse adenovirus (MAV) has been proposed as an alternative since it is capable of delivering genes to cells and not elicit a secondary immune response in humans (Ball et al. 1989; Larsen et al. 1979; Harltey et al. 1960). This paper describes the construction of the bacterial plasmid pBAMF, which contains the green fluorescent protein (GFP) gene (Chalfie et al. 1994) inserted in the early region of the MAV genome. The plasmid pBAMF has actively expressed the GFP in mouse cell culture. The plasmid pBAMF will be used to transfer the recombinant structure into the MAV genome by homologous recombination. The use of the resulting full-length MAV with the reporter gene GFP will be used to further study the use of the mouse adenovirus as a biological vector for gene therapy, especially in Duchenne Muscular Dystrophy.

 

 

Development and Characterization of Stable Expression Vectors in Kluyveromyces lactis

Sean McDermott
Mentor: Dr. Nancy DaSilva

Genetic engineering has been employed to create yeast strains which are beneficial to society (e.g., strains which produce pharmaceuticals, eucaryotic proteins, and other compounds for biological studies). The advantage of yeast over other recombinant systems for chemical production include its rapid growth rates, ability to be cultivated under various growth conditions, and past success in use on an industrial scale. In order to maximize the production of a desired chemical, the vectors inserted by genetic engineering techniques must be both structurally and segregationally stable. The host used in this set of experiments is the yeast Kluyveromyces lactis; this species was chosen for its ability to secrete a number of complex eucaryotic proteins more efficiently than S. cerevisiae, the most common yeast host. Four K. lactis-pKD1 vector systems have been constructed consisting of partial or full pKD1 plasmid vectors inserted into either a pKD1 or pKD1 host (in all possible combinations). In the current set of experiments, a wide range of conditions will be examined for these various recombinant yeast systems. The goal is to obtain solid background data that will help determine the best system for the specific case. Current tests (sequential batch culture) will determine the system that maximizes stability for both long-term and short-term cultivation. In addition, promoters of varying strength will be employed to determine the effect of expression level on stability in these systems.

 

Attitudes, Preparation, and Post-College Expectations: A Case Study of the Montebello Unified School District

Annel Medina
Mentors: Dr. Caesar Sereseres & Dr. Scott Simpson

Various studies demonstrate that low socioeconomic status, generational status, and decreased school standards result in low levels of educational attainment for Latinos. Variations within a school district will be examined to display the inequality of education. Some researchers contend that differences within school districts do not impact the student’s education. While both the same number of students complete the college eligibility curriculum (A-F requirements), schools within the Montebello Unified School Districts display differences in SAT scores, and UC attendance. This study will investigate the attitudes, preparation, and post-college expectations between two high schools within the Montebello Unified School District.

 

Motivational Myopia: The Influence of Visceral Factors on Decision Making

Sharla Meeks
Mentor: Dr. Peter Ditto

Individuals experiencing intense motivational arousal (e.g., sexual arousal or anger) often behave in ways that they later regret. A rich literature exists in social psychology on motivated reasoning, although little research has been done on how strong states of motivational arousal may affect cognitive processes and decision making. Lowenstein (1996) uses the term "visceral factor" to describe desires and impulses that result from drive states (e.g., hunger and sexual desire). This study builds upon his work and tests the hypothesis that decision makers experiencing a visceral factor do not evenhandedly deliberate between the pros and cons of a desire fulfilling behavior. Instead, they give disproportionate weight to the pros of fulfilling their desire than to the cons. In this study 78 UCI undergraduate students completed questionnaires concerning two different experiences from their own life. They were asked to describe in detail a time when they felt a strong desire and acted on it and a time when they felt a strong desire and did not act on it. Data analysis is currently underway. Planned analysis will assess how the pros and cons of a decision to act on a desire are weighted differently than the pros and cons of a decision not to act on a desire, as well as how the pros and cons of both decisions are weighted differently before versus after the decision is made and behavior completed. The findings of this study are expected to increase our understanding of how desire influences behavior through affecting cognitive processes and decision making.

 

Energy Dissipation in Natural Teeth and Implants

Catherine Mescher
Mentor: Dr. James Earthman

Many researchers have studied the effects of static loading on both dental implants and natural teeth, but the effects of dynamic loading leave much more room for investigation. Due to the differences in dental implant interfaces and natural tooth peridontal ligament interfaces, the two structures respond differently to both static and dynamic loads. This study addresses the nature of energy dissipation for both of these structures. It was motivated by the need to study the forces leading to clinical problems such as tooth intrusion and temporomandibular disorder (TMD). Thirty-five patients from a wide age group of over sixty years were given comprehensive oral examinations which included four main components. Each patient underwent qualitative measurements of energy dissipation, study cast evaluation to judge each site’s level of wear, an assessment of cracks and microfractures, and a complete temporomandibular joint and occlusal examination for any signs of TMD. Custom instrumentation was developed to measure the energy dissipation qualitatively by an engineering parameter known as the loss coefficient. Data analysis was performed for these four forms of testing for each subject, drawing correlations between numerical values of energy dissipation and clinically observed symptoms. The results offer better understanding of the effect dynamic loading has on both teeth and implant structures. The findings of this study offer critical knowledge for the future of implant and prosthetic design. Through increasing the energy dissipation of the structures, development of these dental components will achieve optimum longevity and biocompatibility.

 

Examining the Parental Involvement/Educational Success Connection in Early Adolescence

Mark Meyer
Mentor: Dr. Wendy Goldberg

Recent studies have shown that students have better attitudes about school, behave in a manner more conducive to school, and ultimately perform better in school when their parents are involved in school (Henderson, 1998). Grolnick and Slowiaczeck (1994) broadly defined this parental involvement as "the dedication of resources by the parent to the child" within an educational context. However, for the involvement to effect change in a child’s performance, "the child must experience these resources". This "experience" of parental involvement for pre-adolescent children is probably favorable, but with puberty, the parent/child relationship changes. The adolescents’ desire for autonomy often conflicts with parental oversight (Paikoff and Brooks-Gunn, 1991). Therefore, how the adolescents construct parental involvement in education may also have changed. This study examines the relationship between parental involvement, autonomy, and early adolescents’ academic success in forty children in the sixth grade. Each student and their teacher completed a questionnaire. Students reported on their preferences for parental involvement, as well as their feelings of control over their own education. Teachers reported on the type and frequency of the parental involvement, as well as the grades of the student. In addition, Steinberg and Silverberg’s (1986) Emotional Autonomy Scale, in combination with a scale of parental detachment, was utilized to assess each adolescent’s level of developmentally appropriate autonomy. Data analysis of the level of parental involvement, student achievement, emotional autonomy, and student preferences for parental involvement is ongoing. These analyses will address whether or not autonomy mediates the relationship between parental involvement and adolescent success, and will ultimately add to our understanding of the educational processes which are best for students at this important stage in their development.

 

A Comparison of Histology and Fluorescence Intensity to Determine the Ability of Laser-Induced Fluorescence to Detect Oral Cancer

Nicolle Miller
Mentor: Dr. Petra Wilder-Smith

Traditional techniques for diagnosing oral cancer, such as regular surveillance in conjunction with biopsies, detect malignant changes too late. Therefore, at diagnosis advanced lesions outnumber localized lesions by more than two to one. The purpose of this study is to detect malignant changes in the oral cavity early and non-invasively using laser-induced fluorescence. The results of a recent investigation suggest that the intensity of fluorescence from cancerous cells differs from that of normal cells. The main focus of this investigation was to determine whether the changes in fluorescence observed were indeed due to the epithelial cells becoming cancerous, and not related to other non-cancerous histological factors. Leukoplakia progressing into squamous cell carcinoma was induced in one cheek pouch in each of twenty Golden Syrian Hamsters. The hamsters were sacrificed at different stages of cancer development, at which point fluorescence measurements of the epithelium were taken. Their cheek pouches were then evaluated histologically. Significant changes in the fluorescence signature of the pathological cheek tissues were first seen 4-6 weeks after the commencement of carcinogenesis, paralleling histological evidence of very early dysplastic changes. Primary determinant was fluorescence intensity, although the wavelengths of the fluorescence emissions also changed over time. The fluorescence signature continued to change during the progressive development of squamous cell carcinoma. Thus, laser-induced fluorescence provides a novel, non-invasive tool for the early detection and diagnosis of oral cancer.

 

Genotyping Corticotropin-Releasing Hormone Knockout Mice: A PCR-Based System

Erene Mina
Mentor: Dr. Tallie Z. Baram

Recent data suggests that corticotropin-releasing hormone (CRH) is an excitatory neuropeptide in the immature nervous system. CRH activation in the hippocampus and amygdala may mediate certain types of seizures in the developing brain. This has tremendous clinical relevance in that most seizures in the human occur early in life and are provoked by injurious or stressful stimuli. CRH knockout (KO) mice will be utilized in this laboratory in a multifaceted approach to investigate the role of this neuropeptide in activation of the immature central nervous system. Essential to this investigation, we need to determine the genotypes and establish a colony of CRH KO transgenic mice. The polymerase chain reaction (PCR) is a simple, yet very powerful, technique for making unlimited copies of DNA fragments in the laboratory. We will use PCR as a method of genotyping these CRH KO mice. The goal of this project includes optimizing the conditions for accurate, reproducible and rapid DNA isolation and PCR analysis as well as determination of the three genotypes that exist among the CRH KO transgenic mice.

 

Purification of MGPA from Mouse Bone Marrow

Erick Miranda
Mentor: Dr. Michael Selsted

Mouse Granulocyte Peptide-A (MGP-A) is thought to have antimicrobial properties and was identified based on its sequence homology to Bovine Granulocyte Peptide-A, a bovine antimicrobial peptide (Selsted et al, 1998). It is also homologous to PGRP, a peptidoglycan recognition protein, isolated from Bombyx mori (Yoshida et al, 1996) and Trichoplusia ni (Kang et al, 1998). Furthermore, it has been characterized as a cytokine that triggers apoptosis in mouse L929 cell line (Kiselev et al, 1998). Based on cDNA cloning, MGP-A is predicted to be expressed as a 21 kD precursor, but the mature MGP-A peptide has not been characterized and the cellular origin of MGP-A also is unknown. Using an antibody raised to the deduced C-terminal 12 amino acids, we have begun to purify MGP-A from acid extractions of mouse bone marrow. Extracts dissolved in 30% acetic acid were fractionated using BioGel P-60 (gel purification chromatography) and analyzed with the anti-MGP-A antibody on western blots. Further purification of MGP-A containing fractions followed by western blotting will result in the isolation of natural MGP-A. Its characterization and isolation are important in further elucidating its role in innate immunity.

 

Social Identity, the Double Bind, and Feminism Among Black Women

LaToya Morgan
Mentor: Dr. Kristen Monroe

How do we know who we are as individuals and how do others identify us? Social identity theory and the examination of individual and group behavior is critical to understanding this concept. Prominent social identity theorists Henri Tajfel, John C. Turner, and Hogg and Abrams contend that identity is derived in part through individual self-awareness and from group membership as well. While some group memberships are more salient than others are, these groups allow the self to be examined in terms of social behavior in a cohesive setting. Two integral aspects of identity that are cemented during the socialization process are race and gender. Both provide a consistent, external (i.e. physical) as well as internal (i.e. social roles and values) forum for comparing and analyzing identity. Race and gender are two key indicators that affect self-perception and social group identification. As two fundamental attributes of identity, what are the tensions of race and gender in the social identity of Black professional women? Through interviews with Black women from the Orange County and Los Angeles areas, analysis of the narratives will address questions of race and gender conflict in the workplace, in everyday life experiences, and examine the importance of feminism to the lives of these women. This study is expected to increase knowledge of the social identity of Black women, their professional roles, and the manner in which race and gender tensions effect involvement and acceptance of feminism and feminist ideals.

 

Near-Infrared Study of the Central Driving Sources of Young Stellar Jets

Kurtis Nakamura
Mentor: Dr. Rognvald Garden

By analysis of images collected from the Near-Infrared Camera (NIRC) at the W. M. Keck 10-meter observatory in the spring of 1998, we are testing current theoretical models of young stellar jets with the highest sensitivity observations yet made of this stage of newly forming stars. A fundamentally important stage in protostellar evolution is the bipolar ejection of large amounts of molecular gas from the central young stellar object in the form of supersonic, highly-collimated jets. This complex process of mass ejection may in large part determine where a star will ultimately fall on the main sequence (i.e. how massive a star will be for most of its lifetime). The physical mechanisms which drive these jets will give us insights into an important stage of stellar development. We analyzed data for a selected source (HH 1-2) in the emission line of the forbidden transition of ionized iron, the Br gamma recombination line of hydrogen, and the vibrational line of hot shock-excited molecular hydrogen (H2) in order to selectively probe the spatial distribution of each associated type of gas. These emission lines in the near-infrared region of the electromagnetic spectrum provide a unique view of the morphology and excitation conditions in the immediate environment of the central driving engine (i.e. protostar/disk system). This set of data is of fundamental importance as it represents one of the highest angular resolution studies of young stellar objects conducted to date.

 

Societal Perceptions of Political/Social Movements by People of Color

Karlene Marie Navarro
Mentor: Dr. Claire Jean Kim

In the mid-sixties civil rights activists strived for legal and political achievements, but witnessed the decline of movement moral, as Blacks in the United States were disillusioned by civil rights gains that did not alter racist social norms. At this point in the movement Black Americans were inspired by the philosophy of Malcolm X and a new ideology that transitioned the struggle from one of civil rights to a demand for human rights. In 1970, political scientists, Aberbach and Walker conducted an experiment entitled, The Meanings of Black Power. The outcome revealed a serious dichotomy between Black and White Americans in their opinion of the expression. It is significant to continue to study the varying perceptions of Blacks and Whites, and increasingly important to consider the viewpoints of Asian Americans and Chicano/Latinos, the fastest growing minority communities in the United States. This current study examines varying societal perceptions of social/political movements by people of color using the Aberbach and Walker research model. The theories associated with political conceptualization and how this may differ within and between these four racial/ethnic groups will be explored. Data analysis is currently being conducted including: respondents’ perceptions of the term Black Power, if/how they relate it to the respective movements [associated with their race/ethnicities] to which they may or may not identify, and their evaluation of the apparent differences in perception between racial/ethnic groups.

 

Performance of Channel Equalization of Channels with Colored Noise

Samuel Ng
Mentor: Dr. Wei Kang Tsai

A promising technology for high-speed modem transmission is ADSL (Asymmetric Digital Subscriber Line). The discrete multitone (DMT) modulation has recently been selected as the transmission choice in ADSL. DMT is a simple scheme using conventional fast Fourier transforms (FFT) and inverse FFT to generate parallel and orthogonal sub-channels that transmit data bits collectively at a much higher rate. These sub-channels are orthogonal because the input data block is appended by a cyclic prefix "guard band" which makes the input appear periodic. DMT works on the condition that standardized length-32 cyclic prefix is longer than the channel for the purpose of orthogonalizing the sub-bands. Time-domain equalizers (TEQ) have been designed for the DMT receiver to shorten the physical channel response. A TEQ design exists using the inverse power method, which deals with simulated systems with white noise. However, in real twisted-pair copper cables, near-end cross talk (NEXT) and far-end cross talk (FEXT) cause transmission noise to be colored. This project studies the effect of colored noise upon the performance of channel shortening.

 

Non-Invasive, Early Detection of Malignant Changes in the Oral Cavity

Linh Nguy
Mentor: Dr. Petra Wilder-Smith

As the incidences of oral cancer related to increases in tobacco and alcohol abuse and greater longevity rise, the need for early detection methods becomes more urgent. Fluorescence induced by a photosensitizer called ALA has been experimentally shown to differ in healthy versus dysplastic (pre-malignant) or malignant tissues. We proposed to investigate the use of this modality for the non-invasive diagnosis of oral leukoplakias (pre-malignant lesions) and early detection of squamous cell carcinomas. Conditions in the human oral cavity were stimulated most closely by the routinely used Golden Syrian Hamster Cheek Pouch Model. Each of the 10 hamsters’ right cheek pouch was treated with DMBA (a cancerous agent) three times a week. The left cheek was untreated and served as control. Fluorescence induced by topical application of ALA was measured in vivo in treated and untreated cheek pouch tissues every two weeks. Biopsies of cheek pouches were taken to provide tissue pathology status. Based upon our fluorescence analysis, there was a noticeable change in the fluorescence signatures as the cancer developed and progressed. The findings of this study provide the basis for clinical studies, leading to the development of inexpensive direct, non-invasive diagnostic capability for dentists and possibly physicians.

 

Gender Differences & The Effects of Videogame Practice on Mental Rotation Tasks

Mary Nguyen
Mentors: Dr. Barbara Dosher & Dr. Virginia Mann

This experiment has three purposes: 1) to examine the stereotype that men outperform women on mental rotation tasks 2) to examine the effects of prior video-game exposure on mental rotation tasks and 3) to determine whether or not skills developed during video-game practice can be transferred to a different type of task. Sixty participants took a pre-test and post-test of the Digit Symbols Test (DST) and the Differential Aptitude Test (DAT), a test that requires the use of three-dimensional mental rotation. All participants answered a questionnaire regarding their past and current exposure to video games. The participants played either the video game "Tetris" or "Solitaire" for 30 minutes. I hypothesize that 1) participants should show a significant level of improvement from pre-test to post-test of the DAT after playing "Tetris" 2) there would be a significantly large gender difference on the DAT, with males performing significantly better than females in both the pre-test and post-test of the DAT and 3) the expected gender difference is related to the amount of video game practice a participant has had in the past as well as current facilitation with video games. The results confirm hypothesis 2 but not hypothesis 1. Tests of hypothesis 3 will be discussed at the presentation.

 

The Myth of the Middle-Class Housewife: The Forgotten Figure of 1950's American Literature

Uyen (Nikki) Nguyen
Mentor: Dr. Lamar Hill

When we think of American literature from the 1950s, certain images always come to mind: brooding Beatniks, rebellious teenagers . . . and doting wives who vacuum in high heels. The Beatniks and teenagers definitely stand out in the literature of this period through such examples as Jack Kerouac's On the Road and J.D. Salinger's Catcher in the Rye, but the middle-class housewives are often forgotten in the shadows of the male-focused stories. The housewife lived a physically and mentally oppressed life; as Betty Friedan wrote in The Feminine Mystique, it was an arduous task for the housewife to continue hiding her frustrations when she was gnawed away by the knowledge that her "career" as a suburban housewife denied her the full use of her intellectual gifts. She is constantly seen merely as a result of her being the wife or mother of a character; she does not have a central place in 1950s American literature. My thesis explores the complex role of the housewife--not just as a historical figure, but also as a significant figure in literary works of the era. The complicated battles that rage within her reflect the subconscious instability of the decade, such as the simultaneous desire for and fear of containment and the commodification of daily life. Thus, although we tend to conjure up images of male figures when we think of the 1950s, the middle-class housewife of that decade still manages to influence the way we view domestic life today.

 

Mapping of Fos Protein and c-fos mRNA Expression Following IL-1 b-induced Seizures Indicate Activation of Hippocampal Neurons and Limbic Pathways

Agnes Nika
Mentor: Dr. Charles Ribak

Febrile seizures occur exclusively in infancy and early childhood (prevalence of 3-5% in population), and they are an important clinical problem. The link between interleukin-1, IL-1, elevation of body temperature in infants, and the induction of febrile seizures is of great interest. Recent studies showed that IL-1 induces seizures in rat pups. Previous studies showed that the expression of the proto-oncogene c-fos and its Fos protein is a useful marker for elevated levels of neuronal activity in the brain such as seizures. To determine what specific brain regions may be activated with IL-1-induced seizures, 10-day old rat pups were analyzed with Fos immunochemistry. Pups that were examined 24 hr after IL-1 induced seizures showed moderate numbers of Fos-immunolabeled cells in the pyramidal cell layer of CA3a and CA3b hippocampal regions, in the hilus and in the neocortex. The level of c-fos mRNA was elevated in the paraventricular nucleus of the thalamus and cingulate cortex 4 hr after seizures. A significant expression of c-fos mRNA also was observed in the CA3 region of hippocampus and central nucleus of amygdala. These data indicate that seizures following IL-1 administration activate telencephalic and diencephalic structures that are involved in limbic system connectivity such as the hippocampus, amygdala and midline thalamic nuclei. The activated cells following IL-1-induced seizures have a similar distribution to that found after limbic seizures.

 

Effects of Misinformation on Eyewitness Testimony

Nykya Nixon
Mentor: Dr. Barbara Dosher

The misinformation effect occurs when exposing an eyewitness to misleading information after an event has occurred; this effect can impair later memory reports of the original target event. The original target event is the first event witnessed by the subject. One hundred and twenty-one participants were included in the study to compare the number of errors on either a recognition test or a source monitoring test. The items were presented in the slide only condition, the slide and narrative condition, the narrative only condition, or neither condition. Results showed that the source monitoring test led to less suggestibility than the recognition test and there was no difference found between the audio narrative and the written narrative.

 

Top    Back to Program