Student Abstracts


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Julie Yang Faculty Mentor: Dr. Robert E. Steele

Identification of the Mouse Region Homologous to the Human Cri du chat Region

The Cri du chat (CDC) syndrome is a mental and developmental retardation syndrome associated with deletions of the short (p) arm of human chromosome 5. A critical region of 2.5 Mb from the human chromosome 5p15.2 have been associated with the typical facial characteristics and severe mental retardation of CDC. The amount of homology mapping in this region in limited by the paucity of genes that have been localized to distal 5p. To date, there are four genes distal to the CDC region that map to mouse chromosome 13. In addition, there are several other genes proximal to the CDC region that localize to mouse chromosome 15. Therefore, it is possible that a synteny breakpoint could lie within the CDC region. It would be useful to know if the entire CDC region is contiguous in the mouse, especially for the generation of a mouse model for CDC. At this point, human exons from the CDC region have been used to hybridize and identify polymorphism in mouse genomic DNA. Using the strains C57BL/6J and Mus spretus, 9 out of a total of 26 exons hybridized have identified polymorphism. One of these exons, from the distal part of the CDC region, has been hybridized to southern blots of DNA from (C57BL/6J X SPRET/Ei) X SPRET/Ei (BSS panel 2) backcross panel generated at the Jackson Laboratory. This exon maps to mouse chromosome 15. Thus, it seems likely that the entire CDC region is contiguous in the mouse. However this result must be confirmed by analyzing more exons throughout the CDC region.

Janet Yazdi Faculty Mentor: Dr. Sujata Tewari

Effects of Prior Ethanol Exposure on 3(H)-Thymidine Uptake by M-MuLV Infected Fibroblasts

Ethanol, a neuroteratogen and immunosuppressant, has been shown to decrease the proliferation of astrocytes, a specific glial cell population of the Central Nervous System (CNS). Preliminary studies from this laboratory show that neonatal brain astrocytes and C6 glioma cells (transformed astrocytes) can be infected by Moloney-Murine Leukemia Virus (M-MuLV), a neuromagenic retrovirus similar to the AIDS retrovirus. Under these conditions, prior ethanol exposure of retrovirally infected astrocytes/C6 cells did not have any inhibitory effects on the proliferation activities, as measured by 3[H]-thymidine incorporation. No such studies are available on whether the infectibility of M-MuLV can be affected following ethanol exposure. For the present studies, NIH/3T3 mouse fibroblast cell lines productively infected with M-MuLV were initially grown in the presence or absence of 0.46% ethanol for 72 hours, followed by the addition of 3[H]-thymidine into the cell culture media for 24 hours. Cells were harvested and processed immediately for labeled thymidine uptake. In addition, effects of ethanol exposure on M-MuLV infection was determined by Syncitia formation using the XC Plaque Assay. Data showed that ethanol significantly inhibited (by 70%) 3[H]-thymidine incorporation by the NIH/3T3 M-MuLV infected cells when compared to the non ethanol exposed controls. However, Syncitia formation appeared to be either increased or not affected by ethanol exposure. Data suggest that ethanol adversely affects fibroblast metabolism which was already compromised by infection with M-MuLV. Experiments are now in progress to test if M-MuLV infection of astrocytes can be facilitated due to prior ethanol exposure of the retrovirus.

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Rui Zhao Faculty Mentor: Dr. Hao Liu

Studies of Hyphal Growth in Candida albicans

Human fungal pathogen Candida albicans is dimorphic and able to switch from yeast form growth to filamentous form of hyphal growth. The baker's yeast Saccharomyces cerevisiae can also similarly grow in a yeast form and a filamentous pseudohyphal form. The activation of Cln/Cdc28 has been shown to promote polarized cell growth in S. cerevisiae (Lew and Reed, 1995). Recent results from our lab show that Cln/Cdc28 kinase activity is important for filamentous growth in both S. cerevisiae and C. albicans. Here we are interested to use S. cerevisiae to identify potential target of Cln/Cdc28 kinase from Candida. We have isolated three Candida genes that can complement the inability of S. cerevisiae cln1 mutant strains to form filaments. Further characterization of these genes are in progress.



Group Presentations

Group Project 
Stewart O. Aragon, Jill Chandler, Julia Dane, Keely Orlando, Kristina Pipkin, Jeannine Taylor, Timothy Titus Faculty Mentor: Dr. Raymond Novaco

On Conflict Resolution, Anger Provocation, and Acceptability of Abuse; An Examination of Cultural Barriers to Cooperation

On our culturally and ethnically diverse campus, there arises the possibility that cooperation can be impeded by differences in cultural values, ethics and norms. The focus of this study is to examine relationships between culture, ethnicity,and various measures of conflict and aggression which could stand in the way of mutual cooperation. These measures included methods of dealing with conflict ("Conflict Tactic Scale," Straus, 1979), reaction to anger provocation ("Novaco Anger Scale," Novaco, 1994), and acceptability of various forms of domestic violence. The latter of these is a scale developed specifically for this study. A sample of approximately 300 undergraduate subjects were recruited through the Social Science Subject Pool. These subjects were asked to complete a 30-minute survey consisting of these scales and demographic information. By comparing the responses between ethnic groups across these three scales, it was anticipated that we could identify where cultures differ, thus highlighting an opportunity to strengthen the cooperation in our research community.

Group Project
Jason Artof, Linda Brennen , Jonathan Demeter, Preben Nielsen, Joseph Penitsch, Douglas W. Profitt, Ory Selzer Faculty Mentor: Dr. John C. LaRue
UCI Cargo Plane Team

Throughout history, mechanical and aerospace engineers pushed the limits of aircraft flight performance. The quest continues. Maximizing cargo load is currently a concern in today's economic world. The Society of Aerospace Engineers (SAE) is holding its annual "Heavy Lift Cargo Plane Competition" in June. A team of seven undergraduate students from the University of California at Irvine has been assembled to compete in this contest. Together, the team must design and construct a remote controlled aircraft able to lift a desired cargo load into flight. Judging is based on the weight of the cargo successfully lifted. Our goal, therefore, is to lift a cargo weighing 30 pounds. In perspective, the aircraft itself is expected to weigh merely six pounds. To attain this goal, challenges must be met both in the design and construction phases. Theoretical and experimental methods are being incorporated to develop a successful design. Course work from aerodynamics, structures, and controls has provided the foundation for design. In addition, wind tunnels have been extensively utilized to experimentally determine optimum airfoil shape. Construction techniques require research and experimentation to create stiff-light weight components. The areas of importance in the design of the aircraft are extensive. Therefore, distinct challenges have been assigned within our team to discrete sub-teams. The final result will be a conglomeration of each sub-teams work to form the UCI syndicate for the 1997 Heavy Lift Cargo Plane Competition.

Group Project
Alberto Eugene Boleda, Dawn Dilbeck, Kevin Williams Faculty Mentor: Dr. John C. LaRue

Permeable Exchange Membrane Fuel Cell

Fuel cells are a type galvanic cell that continuously convert chemical energy into direct-current electricity through electrochemical reactions. The maximum theoretical efficiency of fuel cells is much higher than that of modern heat engines. Under load, a typical hydrogen-oxygen fuel cell may expect an actual efficiency about 16 percent greater than a typical heat engine. Hydrogen-oxygen fuel cells (HOFCs) have other advantages over heat engines. One of the most important is that they are an environmentally friendly technology. Based on the advantages over heat engines, fuel cells are likely to become an eclipsing technology, replacing the load of small to medium sized power plants. For our senior design project we have designed and built a working permeable exchange membrane hydrogen-oxygen fuel cell. Our cell consists of a stack of five cells which operate at room temperature and pressures slightly higher than atmospheric. Our membrane electrode assemblies incorporate a production method which uses a relatively low quantity of platinum catalyst and require no complicated electrodeposition techniques. We hope to achieve a cell potential of 0.5 volts (out of an ideal 1.23 volts) per cell and assuming we are able to achieve a current density of 400 mA/cm2 we could expect a maximum of 14 Amps from our stack. We expect an overall efficiency of 31% for our fuel cell stack.

Group Project
Sandy Shuai-Ju Chuan, Lyudmila (Lucy) Povoroznyuk Faculty Mentor: Dr. Harold Biessmann

DNA Organization at the 2L Chromosome End of the Mosquito Anopheles gambiae
We have mapped the telomere at the end of the left arm of the second chromosome in the mosquito Anopheles gambiae. Previous studies demonstrated length polymorphism of the 2L chromosome and revealed the presence of a shorter chromosome that was more accessible for analysis. This shorter chromosome appeared to represent a true chromosome end, thus, making it possible to examine the telomeric region as well as the end of the chromosome. A phage library of the wild type mosquito Anopheles.gambiae was established, and screened with the subterminal satellite probe. Several recombinant phages from the 2L telomere were isolated and characterized. One of the phages, PE-15, represented a novel A. gambiae LTR-retrotransposable element with homologies to the D. melanogaster element BEL. Other phages extended into the region proximal to the subterminal satellite and provided a single copy probe for screening a second genomic library of EcoRI fragments. Two classes of phages were isolated that represented the fragments previously mapped by field inversion gel electrophoresis. Further analysis revealed the presence of either an unknown sequence or of 28S ribosomal DNA distal to the satellite, indicating that the fragments do not represent the true chromosome ends.

Group Project
Sibyl M. Collao, Shirley Georgia Levy, Claire Ann Menez, Luke A. Thelen Faculty Mentor: Dr. Daniel Stokols

The Ecology of Situation Selection: Some Traits Predict Situations Better than Others
Craik's (1976) tri-partite typology of personality traits describes three different domains of traits: interpersonal, intrapsychic, and environmental. The interpersonal domain encompasses traits that characterize how people interact with one another. The intrapsychic domain reflects how people relate to themselves. The environmental domain entails the way in which people relate to the environment. It has been shown in previous studies that personality traits are predictive of the types of situations in which people are likely to select themselves. However these studies have failed to examine the effects of the environmental domain on situation selection. This study expands on previous studies by including the environmental domain. The current study used the Experience Sampling Technique in which 92 subjects were paged randomly twice a day in order to capture their daily experiences. In addition, subjects also filled out several personality tests to assess the three domains of personality. While current data analysis is in progress, it is expected that intrapsychic traits will have the least effect on situation selection. Interpersonal traits will predict what types of social situations subjects experience while environmental traits will predict the types of environments in which subjects choose (though these may prove to be supportive of their social inclinations). This study will demonstrate that the environmental domain is an important facet of personality and needs to be studied further.

Group Project
Charles Galaviz, Natalie Quanquin Faculty Mentor: Dr. Jerry Manning

The Isolation, Characterization, and Expression of the Gene that Encodes Surface Antigen 20H1 in the Infective Form of the Parasite Trypanosoma cruzi

The goal of this project is to isolate and characterize the gene that encodes antigen 20H1, a surface antigen restricted to the flagellar region of the infective form of the parasite Trypanosoma cruzi, so that its effectiveness as a vaccine can be studied. We prepared a l cDNA library from total Trypanosoma cruzi mRNA. We screened the library with a 32P labeled oligonucleotide probe that was prepared from a DNA sequence that encodes for a protein recognized by monoclonal antibody 20H1. 14 phage were selected, and the general organization of the DNA of each phage was derived from restriction mapping with enzymes Eco R1, Xho 1, and Bam H1. One phage was selected, and the Trypanosoma cruzi DNA insert in the phage was sequenced using the dideoxy chain termination method. From the DNA sequence and the known molecular weight of the antigen, the probable coding region of the gene was surmised, as well as the protein sequence. The DNA was ligated into the pTrcHis plasmid expression vector and expressed in Escherichia coli. Bacterial lysates were reacted with the monoclonal antibody 20H1, and a single protein with the expected molecular weight reacted. This shows that this fusion protein is antigen 20H1 and that the gene we isolated from the cDNA library codes for the 20H1 proteins. Other flagellar proteins have been shown to be viable vaccine candidates, and now that the gene for 20H1 has been isolated, we can make enough protein to study 20H1's effectiveness as a vaccine.

Group Project
Kiarash Golshani, Mohammad Helmy, Joe David Ma Faculty Mentor: Dr. James D. Belluzzi

Self-Administration of a Dopamine Agonist is Attenuated by D1 and D2 Antagonists

The reinforcing properties of cocaine are related to its inhibition of presynaptic dopamine re-uptake and the resulting increased concentration of dopamine in the synaptic cleft. However, it is not clear which of the five subtypes (D1-D5) of dopamine receptors is responsible for reinforcement. In this study, the effects of the selective D2 agonist, (+)-PHNO, in combination with either a D2 selective or a D1 selective antagonist, were measured during self-administration by rats. Male Sprague-Dawley rats (initially 250-300g) were trained to press a lever reinforced by food, then surgically implanted with an intravenous catheter into their external jugular vein. During each three-hour experimental session lever presses for cocaine self-administration were recorded. After establishing a baseline (+10% for two consecutive days), a drug was substituted for cocaine during the next session. Self-administration of (+)-PHNO (0.3, 1, and 3 µg/kg/inj.) in combination with a dose of eticlopride (0.1, 0.3, 1 or 3 µg/kg/inj.) was measured. These were compared to self-administration of (+)-PHNO alone. Self-administration of (+)-PHNO decreased with increasing doses of eticlopride, higher doses of eticlopride being needed to antagonize higher doses of (+)-PHNO. Self-administration of the (+)-PHNO (1 and 3 µg/kg/inj.), in combination with D1 antagonist SCH23390 (0.03, 0.1, 0.3, and 1 µg/kg/inj.) was also measured. Self-administration of (+)-PHNO decreased with increasing doses of SCH23390, independent of the dose of (+)-PHNO. The results indicate that D2 receptors play a role in the reinforcing actions of cocaine, and that D2 reinforcement may be attenuated by blocking of either D1 or D2 receptors.

Group Project
David Jaffe, James Raymond Wedge Faculty Mentor: Dr. Larry D. Jamner

Nicotine Products Use and Abuse in a College Population

Historically, drug and alcohol abuse among teens has increased over time. Teens and young adults have experimented with various nicotine containing products such as cigarettes and chewing tobacco, which deliver "drug like" effects. With nicotine alternatives such as the patch and gum now sold without a prescription, the potential for abuse among teens and young adults is now a major concern. Over 500 UCI students (220 men, 305 women; X = 21 years) completed a survey designed to investigate potential abuse of nicotine replacement products. Although nicotine replacement use was not very common among the survey participants, 1.1% reported using the patch themselves for reasons other than smoking cessation. The reasons endorsed by the participants included: (1) to help study, (2) to be social, (3) to boost energy, (4) to relieve pain, and (5) to control appetite. In addition, 17.5% indicated that their family or friends used the patch for reasons other than smoking cessation. Interestingly, 3.2% of the survey participants indicated that they wanted to try the patch but had not because it is too expensive. Preliminary findings also indicate that 53% of the survey participants drink alcohol and 39% have tried illicit substances such as marijuana and mushrooms. Although data collection and analyses are ongoing for this study, present findings indicate that the abuse of over-the-counter nicotine products is a realistic possibility especially among today's youth.

Group Project
Susie Hue Knoski, Pendleton Trong Than, Chap Hey Yam Faculty Mentor: Dr. James D. Belluzzi

The Roles of Dopamine D1 and D2 Receptors in Cocaine Self-Administration

Previous studies have shown cocaine to have strong reinforcing actions. Cocaine blocks the presynaptic re-uptake of dopamine, thereby increasing its concentration in the synapse and enhancing stimulation of the postsynaptic dopamine receptors. Five structurally different dopamine receptor subtypes (D1-D5) have been identified and classified. This experiment examines the roles of the D1 and D2 dopamine receptors in cocaine self-administration in rats. Male Sprague-Dawley rats (initially 250-300 g) were trained to lever press for food and then surgically implanted with an intravenous catheter into their external jugular vein. Self-administration rates were collected at the end of daily three-hour sessions in which a lever press delivered 0.1 ml of cocaine (750 µg/kg/inj.) solution. After stable baseline were established (+10% for two consecutive days), dopamine agonists were substituted for cocaine. In addition to the dopamine agonists, saline and different doses of cocaine were also tested. Both the D1 receptor agonist SKF 82958 (1, 3, 10, and 30 µg/kg/inj.) and D2 receptor agonist (+)-PHNO (0.1, 0.3, 1, and 3 µg/kg/inj.) were tested alone and in combination. The descending limb of a cocaine (250, 375, 750, and 1500 µg/kg/inj.) dose response curve was also obtained. When the agonists were presented in a mixture, but not alone, the animals' response mimicked those seen with cocaine and the response rates were comparable to a high dose of cocaine. These results suggest that both D1 and D2 dopamine receptor subtypes play a role in cocaine reinforcement.

Group Project
Debbie Lin, Donna Fay Woo Faculty Mentor: Dr. Roxane Silver

Spontaneous Comments Made By Vietnam Veterans on a Questionnaire

Decades after the occurrence of the Vietnam War, the psychological effects on the veterans of that war are ongoing. This presentation will report the results of a survey recently completed by researchers at UCI of over 1300 Vietnam veterans who completed a 32-page questionnaire. A large number of these veterans added spontaneous comments to their questionnaire concerning their feelings in response to completing the questionnaire. The comments were categorized into two groups: positive and negative. For example, a positive comment consisted of such statements as "Thank you for caring about Vietnam Veterans" and "This survey gave me an opportunity to express feelings kept in for over 20 years. " Negative comments made by the veterans included a statement such as "This is a bunch of bull..." The psychological health of the Vietnam veterans was inferred from the comments. It is hypothesized that those veterans who express positive comments have little natural opportunity to discuss their feelings about the war. Veterans who made negative comments, on the other hand, would be expected to have higher levels of anger and hostility. These spontaneous comments give insight into the current psychological health of the veterans who participated in the survey.

Group Project
Latarsha Lytle, Dawn Roe Faculty Mentor: Dr. Elaine Vaughn

Social Diversity in Response to Environmental Risks

Policy makers often struggle to make environmental risk decisions that are effective, just and practical. This is made more difficult because of the varying circumstances of exposure and differing responses to environmental hazards by various social groups. Persistent conflicts about how to manage situations such as the disposal of toxic waste, nuclear power plants, and chemical additives in foods often reflect fundamental disagreements about how to define the policy problem. Recently, many ethnically diverse and poorer communities particularly have been vocal in questioning the fairness and effectiveness of decisions to protect public health. Formal studies of public response to risk often have excluded communities characterized by extreme poverty and considerable ethnic diversity, even though they are likely to be at greater risk and are more vulnerable to negative effects of environmental hazards. The purpose of our research is twofold: First, we seek to provide information about the broader social and physical circumstances of exposure to toxic substances in several inner-city communities by constructing a "risk" profile of the sociophysical context of exposure. Second, we are measuring public response to health risks across diverse communities, with an emphasis on the variety of values and conceptualizations or risk problems that may exist across society. Multimethods will be used including experimental, survey, interview and systematic observational techniques, as well as an analysis of archival government records to map the hazards existing in these communities. Four hundred participants will be sampled from selected urban areas over the course of the project. Results may provide policy makers with information about how various lay populations assess environmental risks, and the most effective ways to engage diverse social groups in the process of risk management.

Group Project
Sepideh Najaran, Terri Rembuskos Faculty Mentor: Dr. Fadio Haddod

B-GPA: Running Wheel Study

The purpose of this experiment was to examine the changes in muscles of rats in response to change in the feeding regimen as well as daily exercise provided by a running wheel. B-GPA, an analogue of a well studied naturally occurring compound called creatine, was administered to twelve rats; six of these rats were merely fed the diet whereas the other six were also exposed to the running wheel in addition to the diet. We hypothesized that when fed a diet containing B-GPA, the muscle cells of rats would adapt as if they were being used in an endurance training program. The B-GPA displaces creatine, which is used as part of an energy storage system in muscle cells. The B-GPA, however, can not be used by the cells in the same way as the creatine. The muscle cells are able to "sense" that levels of the creatine containing energy storage compound are low and seem to "assume" that it is because the muscles are active for long periods, as with endurance training. The muscle cells respond to this by adapting (changing some of the proteins) as if they were being endurance trained. Controls were also used as a method of comparison. By measuring citrate synthase activity as well as the protein levels in the plantaris and the soleus leg muscles we were able to examine the effects of the B-GPA diet with and without the running wheel on the hind limb muscles of the rats.

Group Project
Adrienne Elayne Cooper, Huy Kim Pham Faculty Mentor: Dr. Joyce Keyak

Effect of Load Direction on Femoral Fracture Load

As bone density decreases due to osteoporosis or other diseases, the risk of hip fracture increases. An improved method of estimating bone strength and fracture risk may be achieved through the use of engineering structural analyses. Previous work established and validated an inexpensive method for automatically generating three dimensional finite element models from CT scan data. This previous work showed that these models can predict femoral fracture load for two loading conditions, one similar to single limb stance, and one simulating a fall. However, the question arises as to how small changes in loading condition affect femoral fracture load. In particular, are certain types of falls, (such as falls directly backward or directly to the side), more likely to result in fracture because fracture load is found to be lower? And, is fracture more likely to occur during stair climbing, rising from a seated position, walking, or abruptly stepping off a curb? This project required taking two finite element models from a previous study, and changing the direction of the load for two simulations. This was done by varying two angles which define the direction of the applied force for each loading condition. For the stance and fall loading conditions, a is defined as the angle between the force and the sagittal plane. b is defined as the angle between the force and the coronal plane. Data analysis is currently being conducted.

Group Project
Benjamin Craft, Mohammed Shaaban Faculty Mentors: Dr. Reginald Penner, Dr. Ralph Nyffenegger

Characterization of Electrochemically Deposited Zinc Oxide Particles Using Laser Spectroscopy and Non-Contact Atomic Force Microscopy

The laser-induced luminescence of electrochemically deposited zinc oxide on graphite has been investigated at low temperatures. ZnO films prepared by two different synthetic schemes were compared: "Direct" formation of zinc oxide in the electrolytic cell, and a two step procedure involving deposition of zinc metal and the subsequent oxidation in air. No bandgap emission was observed for direct deposited zinc oxide, however, a very bright yellow emission was observed which is typical of trap state emission from included chloride. In case of zinc oxide synthesized by the two step method, both emission at the band gap and a yellow/ green emission could be seen. The distribution and the size of zinc oxide nano-particles was also studied using Non-contact Atomic Force Microscopy (NC-AFM).


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