Mentor: Dr. Sharon Stern
During the summer of 1999, the majority of Huntington Beach's coastline was closed to the public. Shortly after the implementation of Assembly Bill 411, unsafe levels of enterococci and other fecal bacteria were found in the ocean. The Orange County Sanitation District (OCSD) conducted extensive tests of the water and determined urban runoff to be the most likely cause of the contamination. The goal of the current research is to determine the public's perceptions of the contamination. A survey was conducted on the beach at both Huntington and Newport Beaches. Fifty-two subjects were asked questions about their knowledge and perceptions of the contamination. Data analysis is currently in progress. Planned analyses will determine how educated the public was regarding the contamination. In addition, the analyses will address whether or not beach goers changed the frequency with which they came to Huntington Beach. Results will be compared among subjects from the two beaches as well as among subjects who did and did not know about the contamination. The findings from the perception half of the study should increase our understanding of the public's reaction to the closure of Huntington Beach as well as their perceptions of contamination in general. In addition, articles regarding beach contamination in various parts of the world will be analyzed and compared with OCSD's final report on Huntington. By examining solutions to urban runoff that have been implemented elsewhere, we might be able to construct a plan that will control urban runoff in Southern California.
Bridging Realities and Breaking Stereotypes: The Women in Juan Rulfo's Pedro Páramo
Mentor: Dr. Ivette Hernandez-Torres
In the novel Pedro Páramo, by Juan Rulfo, the character Juan Preciado goes in search of his father, a number of years after the Mexican Revolution, and instead meets many women in the forms of ghosts, through whom he learns more about his father. In the novel, using relatively few words and fragments, Rulfo creates a world in which every character struggles with guilt, pain, and isolation, the women in addition struggling under the strongly patriarchal society. This study examines how the women are all oppressed and marginalized in the town controlled by Pedro Páramo. In such a masculine-dominated world, many of them only find hope and meaning through motherhood, as it allows them to live through their children and have an identity that goes beyond their bodies. While there are many maternal figures, Dolores is the only one who accomplishes that goal through her son Juan Preciado, some of the others merely ending with frustrated hopes based in illusion. Though the women have a place of articulation for their voices in death, emotions such as jealousy, loneliness, and loss continue, as does the weight of sterility and guilt. The main female character who is not preoccupied with motherhood, yet who achieves an escape from the boundaries the culture places on women and their bodies, is Susana. She effects it through madness, exiting into a world where she can live again and again a specific erotic experience. But even her madness proves to be an illusion and a "living death." In this study I build upon the complicated struggles of the women in the novel, focusing on how Rulfo gives them a voice and breaks down stereotypes, but still withholds ultimate hope, which he himself may not believe exists.
Evaluation of Cellular Uptake of Synthetic DNA Binding Ligands
Mentor: Dr. Barbara Hamkalo
Polyamides are synthetic analogues of the classical DNA minor-groove binding drug Distamycin. This class of small molecules has the exciting capability of targeting DNA with the specificity and affinity of endogenous DNA binding proteins, such as transcription factors. Recently, breakthrough experiments have demonstrated the striking in vivo efficacy of polyamides by assaying gene expression of targeted genes in cell culture. However, these studies assumed the uptake ability of polyamides without directly monitoring cellular uptake/localization. We have determined from laser-scanning confocal microscopy of living mammalian cells incubated in naturally fluorescent polyamides, that, although polyamides are cell permeable, they localize perinuclearly in cells. The gene modulating concentration of 1 m M polyamide and 24-hour exposure was sufficient for labeling. In cell lines where exposure is continuous throughout the cell cycle, the polyamide only appears to have access to the DNA when the nuclear envelope is disassembled during mitosis. Such access appears to be insufficient for nuclear retention in vivo. We conclude that despite the small molecular mass of polyamides, its cellular permeability does not necessarily include nuclear localization/retention at concentrations sufficient to detect by fluorescence microscopy.
Mentor: Dr. Doug Smith
In recent years, instrumented indentation has become a useful technique for determining material mechanical properties, such as the elastic modulus and the hardness. In this technique, an indenter is loaded into the surface and then unloaded while continuously recording the load and depth. Instrumented indentation is advantageous for samples of minute volume, particularly for thin film properties. In thin film coated systems it is difficult to determine the mechanical properties at depths that are shallow enough as to allow only the properties of the film to be measured while having minimal contribution from the substrate. At such shallow depths (10-20 nanometers), determining the contact area is the basis for accurate analysis; therefore, the unknown and/or variable tip shape of the indenter must be experimentally determined. However, due to the lack of standard methods, practices, and reference materials, the technique and analysis are not uniform throughout industry and research institutions. To accurately establish standards, an international round-robin experiment was implemented in 1997. Analysis was conducted on data gathered for a 1-micrometer film of Al2O3 coated on an Al (polycrystalline) substrate. The unloading data for thin film systems are unlike homogenous materials and traditional models can not be used to determine mechanical properties. New models were developed and tested to calculate both thin film and substrate properties.
Determination of Antibiotic Resistant Vibrio cholerae Isolated from the Newport Bay Watershed
Mentor: Dr. Sunny Jiang
Vibrio cholera is the causative agent for the diarrheal disease cholera. Cholera is a serious epidemic that claims the lives of millions of people each year. An increasing number of Vibrio cholerae strains have been found to be resistant to multiple antibiotics. To determine the presence of antibiotic resistant Vibrio cholerae strains in the Newport Bay Watershed, a total of 48 strains were isolated from 6 aquatic sites along the San Diego Creek, Newport Bay and Pacific Ocean at Balboa Pier, California between June 1999 and February 2000. Antimicrobial susceptibility tests were performed by the disk diffusion method for chlortetracycline (30 mcg), erythromycin (15 mcg) penicillin (10 units), rifampin (5 mcg) and streptomycin (10 mcg). Strains exhibiting zones smaller than the intermediate value were considered resistant. Two of the five antibiotics used were found to be ineffective against samples from 2 or more sites indicating the presence of antibiotic resistant strains of Vibrio cholerae.
Construction of a Robotic Interface Platform for Testing Computational Models of Mammalian Brain Circuits
Mentor: Dr. Richard Granger
Brains encode, organize and retrieve information about their environments and then use this information to perform goal-directed behavior, and they do so in ways that significantly outperform engineering approaches to these same problems. Despite decades of research, computers and robotic systems still do not approach the locomotive capabilities of even relatively simple animals (e.g., insects), let alone the visual processing capabilities of, say, a cat. A strong need exists for real world testing of computational models of the mammalian brain. Such models are usually tested using only computer simulations; yet, regardless of how accurate the physics are within these simulators, they can never fully replicate a real world environment. The objective of the current project is to construct a robotic interface platform for a set of existing brain circuit models, in order to more realistically test the hypotheses they raise. More specifically, these models are based on the striatal complex which controls higher motor functions. These higher motor functions consist of sequences of actions which the system is also responsible for learning. The models that use this interface are concerned with spatial navigation in a complex visual environment. As a result, a primary focus of the robotic interface is to capture particular visual stimuli and interpret them into a form that is understood by the respective models, and then implement the actions dictated by those models.
Fear of Gang Crime: A Content Analysis of Two Metropolitan Newspapers
Mentor: Dr. James Meeker
The majority of people attribute their knowledge of crime to information obtained from the mass media (Dominick, 1978; Jacobson, 1989). Although studies have found that television and radio are sometimes more important transmitters of news than are newspapers, newspapers do contribute greatly. The focus of this research is to study the influence of newspaper coverage of gang crime on peoples fear of gang crime in Orange County. This project is threefold. First, a content analysis of two metropolitan newspapers (LA Times and the Orange County Register) for a three-month period was used to measure several variables that influence fear. In addition, secondary analysis of survey data conducted in September of 1997 by James Meeker, Ph.D., was used to compare the newspaper findings with reported levels of fear by Orange County residents. Lastly, the Gang Activity in Orange County Database (gang crime database) will be used to track the actual level of gang crime in Orange County. In an attempt to reduce peoples fear of gang crime, this research can identify possible factors in newspapers that may increase peoples fear of gang crime. Considering the policy and behavior implications that peoples fear of crime influences, it becomes important to study the impact that newspaper readership has on peoples perceived levels of fear and gang crime.
"Phonemic Perception" in Aphasia and the Isolated Right Hemisphere
Laura Barde (Co-authors: Kathleen Baynes & Nicole Gage)
Mentor: Dr. Gregory Hickok
Research in the late 1970s and early 1980s suggested that phonemic perception problems arising from certain left hemisphere lesions make only a relatively small contribution to the auditory comprehension deficits observed in Wernickes aphasia. Further, because substantial phonemic perception problems do not arise from damage anywhere in the left hemisphere, but are associated with bilateral superior temporal lesions, it is reasonable to hypothesize that phonemic perception is supported by superior temporal regions bilaterally. Despite this evidence, the view persists that phonemic perception is strongly left lateralized. We present data that replicates earlier work on phonemic perception in aphasia and extends it by examining the phonemic perception abilities of the isolated hemispheres of a split-brain patient (JW). Nine aphasics with unilateral left hemisphere lesions performed an auditory word-to-picture matching task that contained along with the target, a phonological, semantic and unrelated foil. JW listened to auditory words and then made a match/no-match decision on individual pictures that were lateralized to one or the other visual field. Replicating previous work, aphasics committed more semantic than phonological errors. JW performed well overall (LVF = 92%, RVF = 94% correct), and was able to accurately discriminate matching items from phonological foils in both hemispheres (A-prime: LVF = .96, RVF = .995). These data suggest that both the left and right hemispheres can construct a sound-based representation of speech sufficiently well to support auditory comprehension at the word level. We conclude that speech perception systems are largely bilaterally organized.
Langmuir Monolayer Studies of Membrane Proteins
Mentor: Dr. Michael Dennin
Langmuir monolayers are single layers of lipid molecules which have one hydrophilic and one hydrophobic end that are confined to an air-water interface. This is an effective model for biological systems such as cell membranes. This system has a number of advantages: conditions such as pH and temperature are easy to control, and optical microscopy can be performed with much less difficulty than with a system in solution. Our research focuses on pressure-area isotherms and fluorescence microscopy. In the isotherms, we compressed the insoluble lipid monolayer with a movable barrier. The changing pressure provides information on how the molecules pack together as a function of area. With proteins present, this packing depends upon whether the protein inserts between the lipids, binds to them, or remains in solution. In addition, fluorescence microscopy is used to observe the domains formed by the phospholipids as they interact with the protein. I will report on the changes in domain caused by the use of different lipids or combinations, and the presence of protein and its interaction with the lipids. The next step in the experiments is adding fluorescence probes to the protein, so that it and the monolayer fluoresce with different colors, allowing us to determine the position of the protein relative to the phospholipid components. I will report on our discoveries from these experiments as well.
Formal Policies and Informal Practices in Managing Family and Work Responsibilities
Mentor: Dr. Matt Huffman
The labor market has increased greatly with the growth in womens participation in the work force. The spur of family benefits policies have been implemented in large organizations to render these changes. More working mothers and fathers are struggling with role conflicts in an attempt to balance their work and childcare responsibilities. Research conducted in 1997 by Glass and Estes, found that the lack of flexible scheduling creates marital problems, personal distress and tardiness. Other research done by Christensen and Staines in 1990 found flextime the best possible solution. Flextime enabled employees to utilize part-time work, job sharing, work-at-home, compressed work-weeks and v-time (employees work out an annual agreement for the number of hours to be done per week). This study focuses on public institutions, in particular the University of California, Irvine (UCI). This institution is unable to offer its employees the flexibility to alter their schedule from day to evening shifts primarily because offices operate from 8am-5pm. Therefore, the current study determines what methods UCI employees use to manage their work and childcare responsibilities. Approximately two hundred surveys were distributed among different offices on the UCI campus. Data analysis is currently underway. A statistical program called SPSS is being used to create cross-tabulations, regression tables and univariate/bivariate analyses of the data. These tables will address questions regarding how UCI employees manage their childcare and work responsibilities, how satisfactory the Universitys policies are and what other methods employees utilize. These findings are expected to increase the understanding of the effectiveness of the Universitys current workplace family benefits.
Estrogen Increases Levels of Endothelial Nitric Oxide Synthase (eNOS) Protein in Isolated Rat Cerebral Microvessels
Mentor: Dr. Diana Krause
Stroke results from decreased blood flow to the brain. The body has mechanisms to regulate blood flow in the cardiovascular system and one of these is through the utilization of neuroprotective substances such as nitric oxide (NO). Nitric Oxide causes vasodilation and inhibits platelet aggregation. These two roles of NO may be key in protecting against stroke. Some studies indicate that estrogen plays an important role in protecting against stroke (Alkayed et al., 1998). We previously demonstrated that chronic (in vivo) treatment with estrogen increases endothelial nitric oxide synthase (eNOS) protein levels in cerebral microvessels of gonadectomized male and female rats. The increase in levels of eNOS protein afforded by estrogen may be a result of changes in hemodynamics that, in turn, have a secondary effect on eNOS. On the other hand, the increase in eNOS protein levels may be a direct effect of estrogen on cerebral microvessels. The objective of this study is to determine if estrogen increases NO production in rat cerebral microvessels by directly increasing the levels of eNOS protein. Using Western blot analysis, eNOS protein levels were measured in cerebral microvessels that were isolated from ovariectomized female rats and then treated with varying concentrations of estrogen (10-12 10-8M). We found that incubation with estrogen increased levels of eNOS protein in all cerebral microvessels isolated. Furthermore, it was found that estrogen receptor antagonists blocked the increase in eNOS levels afforded by estrogen. These results suggest that estrogen directly increases eNOS protein levels through a receptor-mediated mechanism.
Does Distance Matter? How the Location of Hazardous Facilities Affect Personal Relevance and Risk Perception
Mentor: Dr. Elaine Vaughan
Modern technological advances, such as oil refining, chemical and pesticide production, and nuclear energy involve a number of social and environmental risks. The risks people experience from living near hazardous facilities and the daily reminder of it are ever-present. Does the location of the hazardous facility impact peoples perception of risk and their belief in fairness? This study examines how people are affected by living near hazardous facilities, particularly oil refineries. The respondents, over 90% African American, reside in Richmond, California. Richmond is an economically depressed city, adjacent to large oil refineries. The sample (n=76) was divided into four groups, based upon respondents residential distance from the refinery: less than one mile, between one and two miles, between two and three miles, and beyond three miles. Respondents were questioned concerning their beliefs about exposure to hazardous substances, worry over possible negative environmental and health consequences, and beliefs about future negative health consequences from the refinery. Respondents rated their perception of the importance of considering fairness and justice in policy decisions about environmental risks. Data analysis is underway. Preliminary results indicate proximity to the refinery influences perceptions of worry, views about exposure and future negative consequences, and beliefs about justice. How distance affects peoples risk judgements may have implications for the individuals response to hazards, as well as the enactment of policies concerning environmental and health risks.
Creating in Space
Mentors: Dr. Lisa Naugle, Dr. Deidre Sklar & Mr. Alan Terricciano
Culture conditions how individuals perceive such issues as the body and Metaphysical Energy. In Chinese philosophy this metaphysical energy, which affects body and space, is called Ch'i. Our objective in this research was to come to an understanding of how this energy can affect humans in everyday life. Our research includes interviews with people aware of this energy, abstracts taken from literature on this topic, and philosophical discussions of our personal experiences. Next, we applied our research and current understanding of this philosophy to our own studies of Dance and Environmental Design. We came to the conclusion that it wasn't necessarily important what field or medium you were working with, but that the importance lied in the creative process and the use of this energy. The end product is a collaborative event that will be presented live in UCI's Studio Theatre on May 26th and May 27th beginning at 7:30pm. The event incorporates the principles of Ch'i and how it relates to, or affects the body and space, while also attempting to seek out the similarities between these two art forms.
NYU/UCI International Arts Collaboration
Mentor: Dr. Lisa Naugle
The purpose of the NYU/UCI International Arts Collaboration was to acquaint European artists, specifically Polish and German, with new and inspirational performance works by North American artists and to build collaborations that inspire further development of artistic ideas. The New York University Composers Ensemble was invited to perform an evening long event titled "Travels with Cassandra," at the Krakow, 2000 Music Festival. Professor Dinu Ghezzo directs the ensemble, and this tour, and included composers Ron Mazurek, Lucas Marquardt, John Gilbert and flautist Cindy Shiung. Professor Ghezzo also included improvisational dance by Professor Lisa Naugle and Dancer Jennifer Brown from the University of California, Irvine. The final pieces of the collaboration were: software designer-video/theatre artist John Crawford, Polish musicians and actors, and German musicians. This event demanded of the artist perfect technique and precision, while also imploring vast imagination and flexibility from the performers. The "live" collaboration included instrumentals, computer processing of pre-recorded choreography, dance and theatre. The music combined modern melodies with unconventional sounds, while projected computer images highlighted todays cutting edge technical influences of the arts. The actors punctuated and intensified the mood with words in English, Polish, and German, while structured improvisational dance was woven over and through the melodic pieces. This project posed several questions to the artists involved: What extent can particular media affect each other, what is created as a result of those influences, and what can collaborating give to composer, director, and choreographer? This type of collaboration evokes the imagination of not only the creators, but also the audience with unconventional results that take place between metaphor and realism, fantasy and seriousness.
Hospice Care vs. Hospital Care 2000: What is the Future in Care for the Terminally Ill in America?
Mentor: Dr. Chelsea Starr
Care for the terminally ill in America has been a subject of great debate over the last quarter century. The two most common types of care for the dying are known as curative care and palliative care. Curative care medically treats dying patients for their physical symptoms in a hospital setting, whereas palliative care patients are given the tools to deal with their death through the combination of emotional, spiritual, social, and physical supports, usually within the home setting. This research used nine hospital and hospice nurse interviews, including supplementary data from two social workers. This study shows a distinct difference of training, care attitudes, pain control and knowledge of palliative care for nurses and social workers dealing with dying patients. Data analysis suggests that dying patients within the hospital setting are receiving limited emotional, social and spiritual support. Further, the lack of mandatory training for hospital nurses hinders their ability to cope with their patients in a more holistic manner, especially within the curative setting. The results demonstrate the need to educate and train hospital nurses to holistically help the growing number of dying persons within U.S. hospitals.
Prevalence and Distribution of Human Papillomavirus (HPV) Types Infecting a Population in Oaxaca, Mexico
Mentor: Dr. Victor DeFillipis
Cervical cancer is the third most common cancer of female reproductive organs, making this disease the leading cause of female cancer morbidity and mortality in developing areas such as Mexico, South America, and Central America. Past studies have shown that the human papillomavirus (HPV) is a major risk factor for the development of cervical cancer. Because of the high percentage of cervical cancer cases reported in Oaxaca, Mexico and the involvement of HPV with it, a molecular study on HPV was conducted upon cervical smears taken from the indigenous women of Oaxaca. HPV determination was done using PCR assays and sequencing procedures. Analysis of the cervical smears revealed a distribution of HPV types in the following manner: 16% HPV 16, 1% HPV 18, 16% unclassified HPV types, and 67% all other types. Results suggest a low rate of high risk HPV types in Oaxaca and a high rate of the prevalence of unclassified or new HPV types compared to literature. Because of the high percentage of cervical cancer and HPV infection among the women of Oaxaca, research should be continued on HPV and its expression among high-risk women as predictors of the development of cervical cancer.
Mentor: Dr. Joseph DiMento
Concern about anthropogenic degradation of the global environment has become a priority issue for many nations. As a result, the international community has conducted a number of conferences dedicated to the preservation, conservation, and protection of the natural environment. In December 1997, the Third Conference of the Parties to the United Nations Framework Convention on Climate Change was held in Kyoto, Japan and produced the Kyoto Protocol. The most significant outcome of the Protocol was the establishment of binding limitations on the emissions of six greenhouse gases for developed nations. While the Protocol has been regarded as a successful tool in advancing the discussions about climate change, several important issues remain unresolved which have contributed to its lack of success as an international environmental management strategy. The primary purpose of this research is to review the effectiveness of the Kyoto Protocol and to discuss its shortcomings so that future international climate change negotiations can be adapted to ensure greater effectiveness. This research is based on the secondary analysis of policy, law, and environmental scholars. It includes an overview of the greenhouse effect and its potentially disastrous consequences, the emergence of international environmental management strategies, and the history of climate change negotiations. In particular, the non-participation of developing nations and the utilization of different market mechanisms are examined. Finally, this research presents conclusions about the effectiveness of the Kyoto Protocol as well as suggestions for modifications to the Protocol to improve its implementation.
Effects of Acculturation on Attitudes Regarding Mental Health Care Utilization by Individuals of Mexican Ancestry in Santa Ana, California
Mentor: Dr. Caesar Sereseres
The purpose of this research project is to determine if acculturation affects Mexicans use of mental health services. The research focus is Mexicans attitudes regarding utilization of mental health services. The method used in this study will consist of a survey of thirty questions. The sample will consist of 100 individuals, fifty males and fifty females. To analyze data, cross-tabulations will be made and gamma will be used to measure direction and strength of association. Once the analysis is completed, it is expected that high acculturation of an individual will result in positive attitudes regarding mental health services. Due to the growing population of Latinos in the United States, it is important to understand their perspectives in mental health in order to provide appropriate care to meet their needs.
When Flesh Becomes Word: The Politics of Language Adoption
Mentor: Dr. Ann Jessie Van Sant
Language has long maintained its role as an accessible extension of the writers self and the integration between the writer and language remain fused. Ultimately, language assumes a natural and amoral role and the writer remains unconscious. Enters, then, the conscious writer. In the pause, the hesitation and the struggle with language presented in their texts, the ex-slave, the non-native/immigrant and the transgendered writers represent an "other" who reveal language not as a natural or an immediately accessible form of expression, but as an "other" itself, a biased construction to which they must adopt, invade or reject. Particularly in these texts, the rigid boundaries of language confirm its legitimacy by aligning itself with a seemingly fixed and natural image of the body. It is this specific image of the body, perceived by language, that obstructs these writers from language. As these texts reveal, language defines the body along a series of binary constructions: black/white, non-native/native speaker or writer and female/male. These "narratives of inequality" reveal that movement between these paired spaces is prohibited because the identities are placed on a hierarchical scale. Consequently, the theme of transition complicates the role of language in these narratives. The insistence of these writers "movement" (enslaved to free, non- to native speaker/writer and female to male) weakens/loosens the rigid and confining definitions traced by language through the body and consequently exposes the boundaries as insufficient and unnatural. These conscious writers stretch language out of its boundaries by placing their own "authorized" bodies within language. When, indeed, flesh becomes word, we find the word bulging and overflowing with ideas and identities uncontainable within rigid, unyielding definitions.
The Validity of Assumptions Concerning the Relationships of First and Second Generation Female Jewish Immigrants, 1880-1920
Mentor: Dr. Alice Fahs
Upon arriving in the United States between 1880 and 1920, female Jewish immigrants from Europe faced a completely foreign world compared to what they were accustomed to in the Old World. This culture shock prompted many different reactions from the immigrant generations. Frictions usually centered on the choice between adhering to Jewish traditions or thoroughly embracing Americanization. This pitted mothers against daughters, the latter of whom were raised and often born in America. Many scholars have summed up the relationships between first and second generation female Jewish immigrants as often confrontational at best, concluding that all Jewish mothers and daughters disagreed. However, while historians have eagerly examined the evidence of frictions between mothers and daughters, they have failed to delve further and observe the complexities and patterns present in these relationships. Generational frictions only tell part of the Jewish female immigrants story. For example, Americanization was often the root of friction, but it was often a common goal for mothers and daughters alike. Some daughters disagreed with their families about the observance of Jewish traditions, but it must be noted that these same young women became traditional Jewish mothers when they married. Probing research into primary sources has brought to light the many differing levels of Jewish mother-daughter, first and second generation immigrant relationships. These finds must be considered in order to portray the most accurate picture possible of the different generations of Jewish female immigrants
Mechanism of Nickel Nanoparticle Growth
William Charette, Jr.
Mentor: Dr. Reginald Penner
The mechanism for electrochemical growth of nickel nanoparticles on HOPG (highly oriented pyrolytic graphite) with hydrogen coevolution, is being investigated. The result of electrodeposition at potentials far negative of the standard potential for nickel reduction is size monodispersed populations of hemispherical particles ranging in diameter from a few nanometers to 500 nanometers. These large particles are comprised of smaller 2 nm particles. Work is being done to determine how these 2 nm particles self assemble to form the larger hemispheres. Using chronoamperometry, the particles are grown for different time intervals, from 5 ms to 16 s, and atomic force microscopy (AFM) is then used to analyze the particles.
The Price of Crossing Lines: Illegal Immigrants and Their Confrontations with Coyotes, the Border Patrol and Hate Organizations
Mentor: Dr. Alejandro Morales
Ever since the first fence was erected between Mexico and the United States, tension and violence have plagued the area. In 1987, Anzaldua defined the United States-Mexico border as "una herida abierta where the Third World grates against the first and bleeds." In the same study, Anzaldua proposed that "the only legitimate inhabitants [of the U.S.-Mexico border] are those in power, the whites and those who align themselves with whites." Her view is partially correct. After careful analysis of three border "hotzones," Tijuana-San Diego, Mexicali-Calexico, and Ciudad Juarez-El Paso, it was found that a certain type of "illegitimate inhabitant," in this case illegal immigrants, are common victims of people "in power." But unlike Anzalduas proposal, the victimizers are not necessarily white. The investigation concluded that Mexican illegal immigrants have three common enemies: (1) coyotes, (2) the Border Patrol, and (3) hate organizations. The data indicates that violent attacks directed by all three victimizers against Mexican illegal immigrants were damaging, both physically and psychologically. Yet, the danger that illegal immigrants face by crossing the border was revealed not to be a deterrent for crossing it.
Response of Rat Gastrocnemius Muscle to Tibial Distraction and Lengthening
Mentor: Dr. Vince Caiozzo
The Ilizarov technique of tibial distraction using external fixation is used orthopaedically to correct discrepancies in limb length. This technique, however, has a high complication rate that is thought to be due to the failure of skeletal muscle to add sarcomeres in a series at a rate equivalent to bone lengthening. The purpose of this study was to utilize tibial distraction to investigate mechanisms of longitudinal skeletal muscle growth, specifically the regulation of muscle length (ML), muscle fiber length (FL), and sarcomere length (SL). Female Sprague-Dawley rats were assigned to one of four groups: normal control (NC, n=5); frame control (FC, n=5); 0.25mm/day distraction (.25mm DIS, n=5); or 0.5mm/day distraction (.5mm DIS, n=5). Animals in the FC group had fixators applied but were not distracted, while .25mm DIS or .5mm DIS animals were distracted for a period of 28 days. Following distraction, the gastrocnemius muscles of the lower limb were removed, fixed in formaldehyde, and analyzed. No significant changes in ML, FL, or SL occurred between the NC group and FC group (P<0.05). Compared to NC and FC groups, significant increases in ML, FL, and SL were found in .25mm DIS and .5mm DIS groups (P<0.01). While NC and FC muscles had a SL » 2.3 m m, SLs were significantly different (» 2.7 m m), yet surprisingly similar, in both the .25mm DIS and .5mm DIS muscles. This data suggests that a sarcomere length » 2.7 m m may represent a set point initiating sarcomerogenesis in response to further muscle lengthening.
Bioactive VEGF Expression in Pancreatic Cancer Cells
Mentors: Dr. Murray Korc, Dr. Jian-ying Luo
Vascular endothelial growth factor (VEGF) is an angiogenic polypeptide that is produced by many cancer cells. In this study, both the expression of vascular endothelial growth factor in seven human pancreatic cell lines and the effect of this growth factor on the proliferation of human endothelial cells are investigated. Results from an enzyme linked immuno sorbent assays (ELISA assay) indicate that vascular endothelial growth factor is released by all seven tested human pancreatic cancer cell lines (ASPC-1, BXPC-3, PANC-1, CAPAN-1, COLO-357, MIA-PaCa-2, and T3M4). Results from an endothelial cell proliferation assay suggest conditioned media from human pancreatic cancer cells contain growth factors, which stimulated the proliferation of human endothelial cells. The presence of vascular endothelial growth factor in the media of human pancreatic cancer cell lines coupled with positive stimulation of human endothelial cell proliferation. Together, this data suggest that human pancreatic cancer cells secrete bioactive vascular endothelial growth factor.
An Analytic Approach for the Determination of Therapeutic Electron Beams Output Factors from a Medical Linear Accelerator
Mentor: Dr. Matthew Al-Ghazi
Electron beams in the energy range 6-20 MeV are used to treat superficially located tumors. These beams are generated using medical electron linear accelerators. The output of the accelerator is dependent on the beam energy and the details of the collimation system used. In order to deliver the correct radiation dose to the treatment site, the output of the accelerator has to be measured for the field being treated. This is what is currently being practiced. The purpose of this project is to conduct measurements as a function of electron beam energy and field size. The data obtained are used as the basis for a mathematical formalism aimed at predicting the output factor for clinically used treatment fields with sufficient accuracy. This will eliminate the need for individual measurements. The mathematical model uses the work of Khan and Higgins (Physics in Medicine & Biology 44, N77 - N80, 1999) and Khan et al (Physics in Medicine & Biology 43, 2741 2754, 1998).
Parasitic Protozoa Contamination of San Diego Creek by Cliff Swallow Population
Mentor: Dr. Betty Olson
The parasitic protozoa, Cyclospora cayetanensis is an emerging water and food borne pathogen. From 1996 to 1999, Cyclospora cayetanensis was transmitted via contaminated raspberries and lettuce. Of the several species of Cyclospora, only C. cayetanensis has been shown to be a human pathogen. Since protozoa are resistant to the chlorine disinfection used in water treatment systems, it is important to determine their presence in water. The San Diego Creek site was the focus of this research. In earlier research, the presence of C. cayetanensis was detected by PCR in summer months. During the summer, Cliff Swallows nest above the San Diego Creek site. Cliff Swallows are migratory birds. During the winter months, they reside in South America (much of the food borne cases of C. cayetanensis infection originated from South American produce). The primary method of this research project was to analyze water and fecal samples for a period of a year. Fecal samples were only collected for three months of the year because the Swallows returned to South America. The main goal of the project is to determine the presence of Cyclospora in the fecal material and in the water samples. If contamination by Cyclospora in not present during the winter months while the birds are away, and then reappears when the Swallows arrive at the site, an association as to the source of contamination can be made. PCR was the method used for detection of Cyclospora in fecal and water samples. Preliminary results show that the Cliff Swallows are possible carriers of a protozoa pathogen similar to Cyclospora. The band visualized in gel electrophoresis is slightly different from that of C. cayetanensis. Genetic sequencing is being performed in order to identify the organism of infection.
Myoglobin Reconstituted with Unnatural Heme Cofactors: Functional Models for Nitrate Reductases
Mentor: Dr. Patrick Farmer
A variety of metalloenzymes, such as the sulfite and nitrite reductases, utilize reduced-heme prosthetic chlorin groups. While the molecular structures of many of these chlorins are now known, correlation between their structure and reactivity has yet to be determined. Synthesis and characterization of related iron oxochlorin derivatives and their subsequent myoglobin reconstituted products will be presented. Initial investigations into the electrocatalysis of these reductase model systems is also discussed. By following the redox chemistry at the active site, we hope to understand how these unique chlorin prosthetic groups influence the activity in the native proteins.
An Examination of Gravitational Lensing
Mentor: Dr. Steven Ruden
Einsteins General Theory of Relativity predicts that massive objects will gravitationally "bend" electromagnetic radiation that passes close to them. The effect, known as "gravitational lensing," occurs when a massive object intervenes between a viewer and source of radiation, and can be observed in the sky as multiple images of a single source, or as arcs and rings rather than a point source, and has been observed in such systems as Abell 370, PKS1830-211, and MG1654+1346. Since these images are due to well-understood and well-defined equations, qualitative analysis can aid in understanding the intervening masses responsible for the images. This is of interest for massive objects such as black holes, which are difficult to detect by other means. In order to better understand the images which appear in the sky, a computer program is being developed to create data sets which may correspond to images seen in the sky. These are based on such parameters as the amount of lensing (a function of the mass of the intervening object) and the relative positions of the image and the object. The program is designed as a base upon which more complex analysis may be built through further programming, but is an important first step in the basic understanding of and prediction of images resultant from gravitational lensing, and through comparison of data to images actually observed, a better estimate of intervening masses.
Investigations of the Prins-Pinacol Reaction Applied to the Synthesis of Attached Rings and Studies Toward the Total Synthesis of Cuprenenol
Mentor: Dr. Larry Overman
Studies toward the enantioselective total synthesis of cuprenenol are reported. Progress toward synthesis of a model substrate to investigate the diastereoselectivity of the Prins-Pinacol reaction, the key transformation of the proposed synthesis, is described. The first generation route toward the model substrate involved Suzuki coupling of a vinyl triflate with a boronic acid. Progress is also described on an improved second generation route towards the substrate, which utilizes a Wittig coupling of a phosphonium salt and a ketone.
Fluorescence Laparoscopic Detection of Metastatic Ovarian Cancer Using 5-Aminolevulinic Acid (ALA) in an Animal Model
Mentor: Dr. Bruce Tromberg
Our objective in this study is to determine the efficacy and sensitivity of using laparoscopic photodynamic diagnosis to detect ALA-induced fluorescent tumors in an epithelial ovarian cancer rat model. One million Nutu-19 syngeneic epithelial cancer cells were injected into the peritoneum of immuno-competent Fischer 344 rats to induce diffuse microscopic peritoneal carcinomatosis. After 4 weeks of tumor induction, ALA (100mg/kg) was injected intravenously to establish in vivo fluorescence in tumor nodules. All intraperitoneal surfaces including the diaphragm, peritoneal wall, bowel mesentery, omentum, and pelvis were inspected using both fluorescence and white-light laparascopy with a Wolf Photodynamic Diagnosis System. Both the fluorescence and white light distribution images were captured using a xenon lamp with a color CCD camera, coupled to a computer image acquisition system. Suspicious cancerous lesions were then biopsied in vivo under both fluorescence and white-light laparoscopic guidance by a single surgeon. All biopsied specimens were analyzed and measured by a pathologist blinded to our clinical impression. We determined the clinical utility of fluorescence laparoscopic-guided photodynamic diagnosis in detecting cancerous lesions at various regions of the peritoneum. Moreover, we compared the sensitivity of fluorescence and white light laparascopic-guided detection of metastatic ovarian cancer. Image processing was performed on the acquired images allowing for the quantification of individual tumor fluorescence.
Torture in Mexico: The Enigma of the Justice System
Mentor: Dr. Alison Brysk
Mexico is among the many countries in Latin America that fails to protect the basic human rights of its citizens. Impunity, the lack of punishment to perpetrators of abuse, as in other Latin American countries is prevalent in Mexico. There has been a series of reforms to the Mexican Justice System, which encompasses the courts, the Public Ministry (investigating prosecutor) and the police, beginning in 1990, yet a decade later monstrous human rights violations such as torture still occurs at an alarming rate. This project demonstrates the flaws within the Mexican Justice System and its effect on the practice of torture, the culture of impunity, the manner in which torture occurs, and why recent reforms have failed to make a difference in the protection of human rights. Included in this analysis of the Mexican Justice System and its relevance to the practice of torture are several interviews conducted in Puebla, Mexico during the summer of 1999. Interviews were conducted individually, and the sample interviewed includes human rights advocates such as local human rights commissioners, lawyers, law students and university professors. Special attention was given to the responses of law students because they are a valuable source in discovering what the future of human rights awareness holds for Mexico.
Mentor: Dr. Sabee Molloi
The focus of this study was to produce an accurate and easily implementable technique of measuring the vessel cross-sectional area using videodensitometry. A videodensitometric cross-sectional area measurement requires knowledge of the out-of-plane angle of a vessel, which is the angle that a vessel makes with the image plane. The technique was tested by taking x-ray images of the vessel using different projections and at known out-of-plane angles. Anatomical landmarks were used to define the vessel segment endpoints. The position of those endpoints in real space were determined using just two images taken at different projections. The real space coordinates of those endpoints were then used to calculate the out-of-plane angle. Cross-sectional area measurements were made by integrating the grey level along the vessel profile perpendicular to its centerline. The cross-sectional area measurements were then corrected for out-of-plane angle. An analysis of the reconstruction of the length of the vessel showed that for a high out-of-plane angle (60° ), the error in length reconstruction was less than 25%. Based on these values, a cross-sectional area measurement corrected for out-of-plane angle will have a predicted error of 13%. In contrast, a cross-sectional area measurement that does not take out-of-plane angle into account will have an error of 50%. Therefore, we expect our method of calculation the cross-sectional area by correcting for the out-of-plane angle will produce more accurate measurements than if the corrections were not used.
Study of the Sawtooth Instability in a Magnetic Fusion Experiment
Mentor: Dr. William Heidbrink
The idea behind fusion is to fuse two hydrogen atoms to produce a helium atom, some neutrons and excess energy in the order of MeVs. For this reaction to occur, we must have the hydrogen atoms close together and at reactive energies. Thus, there are two major problems in fusion devices 1) confinement which involves keeping the hydrogen atoms together and 2) heating the hydrogen to reactive temperature (about 1000 times our suns temperature). There are three methods of confinement: gravitational, inertial and electromagnetic. The heating methods available in magnetic confinement experiments are neutral beam heating, P = IV heating, and electromagnetic wave heating. The biggest tokamak in the nation, the DIII-D tokamak in San Diego uses deuterium (hydrogen-2) in a magnetically confined plasma heated by neutral beams, P=IV, and radio waves. There is an instability in the plasma, known as the sawtooth (ST). The signature of the ST is that the electron temperature of the plasma oscillates in a sawtooth fashion. There are periodic crashes during the ST instability that causes the tokamak to redistribute its energy. My work is to analyze data from DIII-D that would help us better understand the ST. Investigation of the ST shows that the ST period can sometimes be lengthened by ion cyclotron heating (ICH). ICH is done by coupling a radio frequency source to the plasma. The changes in the structure of the magnetic field associated with the ST cycle is analyzed.
Bimodal Speech Perception in Speakers of Chinese
Mentor: Dr. Virginia Mann
The McGurk effect (MacDonald & McGurk, 1978) was examined to determine the basis of a previous observation regarding a lower reliance on visual information during speech perception in Chinese speakers (Sekiyama, 1997). The independent variables were stimulus type (syllables read by native Chinese or native English speakers), and participant language background (American born non-Chinese, Chinese who arrive in the U.S. before the age of 12, or Chinese who arrived after the age of 15), and visual presentation type (labial vs. nonlabial). A pilot study revealed a significant interaction between language background and stimulus type resulting from a stronger McGurk effect for the Chinese who arrived after the age of 15 in the Chinese stimulus condition. In contrast, the Chinese who arrived before the age of 12 and native English speakers had a stronger McGurk Effect in the English stimuli condition than in the Chinese stimulus condition. This result suggests that linguistic factors, rather than cultural factors, are most influential in the inducement of the McGurk effect. The proposed study, in Experiment 1, will examine the McGurk effect with English and Chinese speakers using the same Chinese and English stimuli, in addition to Russian stimuli. The McGurk effect will also be examined using synthetic speech stimuli in Experiment 2. Low frequencies of the McGurk effect across groups in the Russian stimulus condition would further confirm the idea that the magnitude of McGurk effect is a function of whether the stimuli is presented in a tonal or non-tonal language (linguistic factors). Introduction of synthetic speech in a separate experiment will examine linguistic factors due to aspects of natural speech.
Heat Capacity Changes of Cartilage During Laser Irradiation
Mentor: Dr. Brian J.F. Wong
The mechanical properties of cartilage are unique and serve key roles such as cushioning impact and providing structural support. To avoid thermal damage during laser irradiation of cartilage, heat conduction must be understood. Previous investigations by our laboratory have determined that the heating curve for cartilage during laser irradiation was not linear. These findings neglected diffusion and alterations in the thermal properties of the cartilage specimen. In those studies, a laser spot approximately (5-6 mm diameter) was used to irradiate a much larger target specimen (20-30 mm). To effectively study the properties of cartilage, minimizing of axial and radial diffusion must occur. This current study proposes to minimize axial diffusion by using a thin specimen, with respect to the penetration depth of the laser. Imaging and magnifying the laser beam over the entire region of the specimen can minimize the effect of radial diffusion. This investigation will show the validity of a constant specific heat capacity of cartilage during laser irradiation.
Expression of the GABAr 1 Receptor in the Methylotrophic yeast, Pichia pastoris
Mentor: Dr. Ricardo Miledi
g -aminobutrate (GABA) is an inhibitory neurotransmitter in the central nervous system and acts through at least three different classes of receptors: GABAA, GABAB, and GABAC. It is known that GABA r 1 subunits can form homo-oligomeric GABAC receptors distinct from hetero-oligomeric GABAA receptors. In order to study the structural properties of the r 1 subunit in detail, it is necessary to express it in large amounts, to obtain sufficient protein to produce crystals. Therefore, as a first step to produce the receptor in a recombinant system, we chose the methylotrophic yeast, Pichia pastoris, which has the benefits of producing high yields of foreign proteins. The expression plasmid, pPIC-r 1, was constructed and characterized. It was then used to transform Pichia pastoris (GS115). Colonies were first screened on selective minimal media and PCR confirmed the integration of r 1 into the yeast genome. Following methanol-induced expression, protein production was analyzed via SDS-PAGE. However, as yet, the r 1 protein subunit has not been detected. More experiments are ongoing to determine if the receptor is being transcribed or if the receptor is being produced in minute amounts. Different cell culture conditions and testing of other recombinant plasmids will be necessary to improve the protein yields.
The Correlation Between Epilepsy and b -Amyloid Plaque Formation
Mentor: Dr. Elizabeth Head
Alzheimers disease is the most common form of dementia. Dogs are one of the animal models currently in use for research into Alzheimers disease because dogs exhibit age-related changes in their brains similar to that of humans. One of the pathological hallmarks in the brains of human Alzheimers patients is the presence of senile plaques in the extracellular matrix which are composed of the protein b -amyloid (Ab ). Dogs also exhibit these senile plaques with age, but never develop Alzheimers dementia. These plaques are thought to be a possible cause of Alzheimers disease, and as such, increased deposition of Ab in the extracellular matrix is a risk factor for development of the disease. The Ab protein is produced by cleavage from a much larger integral membrane protein known as b -amyloid precursor protein (b APP or APP). An increase in the amount of APP should thus result in an increase in the amount of Ab deposition and an increase in senile plaques. Recently it has been found that seizure activity increases the production of APP. This study will investigate the effect of seizure activity on the deposition of Ab in the brains of epileptic dogs. It is hypothesized that seizure activity will cause either the development of Ab plaques at a younger age in epileptic dogs when compared with non-epileptic dogs or an increase in the overall amount of Ab plaques in epileptic dogs or both. The results of this study may lead to the identification of epilepsy as a risk factor for the development of Alzheimers disease.
A Novel Characterization Strategy Providing Evidence for the Exclusive Presence of Homodimers in Three Fibrinogens with Mutations at the Aminoterminus of the Aa Chain
Mentor: Dr. Agnes Henschen-Edman
Fibrinogen has a covalently dimeric structure made up of two sets of three non-identical peptide chains, Aa , Bb , and g . In individuals heterozygous for a genetic variant, the two peptide chain variants, e.g. X and Y, are present in similar amounts. If the peptide chains combined at random during biosynthesis, it is expected that ¼ of the molecules would be of the XX type, ¼ of the YY type and ½ of the XY type. However, in several cases of genetically abnormal, dysfunctional variants only symmetrical molecules were detected in some laboratories, but symmetrical as well as asymmetrical molecules in other laboratories. In an attempt to resolve the controversy a novel analytical strategy was developed and tested on three different abnormal fibrinogens with heterozygously expressed mutations. Fibrinogen Leogan contains an Aa 16 Arg® Cys mutation, fibrinogen Louisville an Aa 16 Arg® His mutation and fibrinogen Canterbury an Aa 20 Val® Asp mutation and Aa chains that start in position 20. Samples were digested first with thrombin or batroxobin to remove normal fibrinopeptides and then with CNBr. The mixture of N-terminal disulfide knots (NDSKs) was isolated by RP HPLC and then fractionated by affinity chromatography on fibrin(ogen)-agarose that only will bind normal N-terminal polymerization sites. The unretained and the retained portions were analyzed for their N-terminal amino acid sequences. In all three cases the unretained material contained exclusively the Aa chain component corresponding to the mutation and the retained material exclusively the a chain component corresponding to the normal structure. Thus, in all three types of mutation only symmetrical molecules were formed during biosynthesis, i.e. the Aa chains encoded by the paternal and the maternal genes had not combined at random.
Molecular Interactions of Glypican-1, A Cell-surface Heparan Sulfate Proteoglycan
Mentor: Dr. Arthur Lander
A unique feature that defines complex biological systems is cellular communication. At the heart of these cellular dialogues are signaling cascades mediated by interactions between numerous molecules. A definitive understanding of cellular language thus requires characterization of many molecular interactions. The aim of this project is to contribute to better understanding of rat glypican-1, a cell-surface heparan sulfate proteoglycan (HSPG) important during development, by investigating its interactions with molecules in the cell. Current evidence indicates that the glycosaminoglycan (GAG) chains of HSPGs interact with growth factors. However, recent studies suggest that the core proteins do not merely serve as anchors for GAG chains. For example, glypican-3 engineered to lack GAGs induces apoptosis in vitro, whereas glypican-1 core protein influences GAG synthesis and composition. Collectively, these studies strongly suggest that the core proteins of proteoglycans interact, or at least are involved in the interactions of HSPGs, with proteins in the cell. To search for proteins that directly interact with glypican-1 in these molecular interactions, a robotically controlled, high-throughput protein screening system that employs the Scintillation Proximity Assay (SPA) will be carried out. The glutamine synthetase gene-expression system is used to generate the significant amount of glypican-1 protein required by the SPA. Current experiments are directed towards constructing a glypican-1 fusion protein; modifying it (via site-directed mutagenesis) by adding a thrombin cleavage site and a histidine tag for purification purposes; and mass-producing the final, modified fusion protein. The findings of this study will improve understanding of HSPGs as important developmental molecules.
Mentor: Dr. Caesar Sereseres
Egyptian education has undergone many changes throughout the countrys turbulent political history. Since the revolution of 1952, the Egyptian government has funded every level of education, including the university level, in an attempt to manifest the ideal that all citizens, regardless of their socioeconomic status, have a right to be educated. Today, however, citizens acknowledge a pervasive problem in the system that seems to undermine the balance of Egypts egalitarian policy: the abundance of private lessons. The present study sought to determine if in fact a large percentage of Egyptian students take private lessons, as well as what the reasons for taking private lessons are. The study was conducted in Egypt and consisted of both formal interviews with school administrators and questionnaires for students. Nearly all the administrators interviewed gave very high percentages of students taking private lessons as their personal estimations. Out of the 31 students who completed the questionnaires, 21 of them reported that they were currently taking private lessons. Analysis of the data regarding the reasons for private lessons, given by administrators and students, is currently in progress. Hypotheses include that the main reasons given will relate to the overwhelming curriculum and to the lack of individual attention in regular classes. The findings from this study are expected to better define the shortcomings of the current educational system that is causing students to seek alternative resources, in order to help direct efforts for improvement.
Growth Comparison of Meningitis Pathogens on Human versus Sheep Blood Agar
Mentor: Dr. Gail Chapman
Studies of certain fastidious bacterial pathogens require the use of blood agar media, which is now typically prepared using sheep blood. However, laboratories and hospitals in developing countries often lack access to sterile defibrinated sheep blood, and therefore continue to use human blood, usually obtained from expired units of human whole blood. Bacteria growth may be negatively effected by use of human blood in blood agar media, which lack any standard of age, ABO type, or donor history. This study sought to compare the growth of the meningeal pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, on both sheep (SB) and human blood (HB) agars to evaluate any differences or inhibition related to the use of HB media. Clinical isolates and ATCC strains were tested in a standardized inoculum of 104 and 105 cfu/ml, and plates were incubated overnight at 35° C in 5-10 % CO2. Streptococcus pneumoniae showed strong morphological difference when grown on HB agars compared to SB, where hemolysis pattern, size, and colony morphology varied distinctly on the HB plates. Haemophilus influenzae demonstrated inhibition in growth in both size and number on the HB plates. Neisseria meningitidis showed no distinguishing changes. There was also significant variation between the HB plates themselves, which often differed in color and consistency. These results indicate that human blood agar is not the best media for growth of meningeal pathogens, and it is recommended that these developing countries take measures to upgrade laboratory facilities to shift to the use of sheep blood for blood agar media.
Topical Bactericides: Wetting Agents
Anna Jane Eliseo
Mentor: Dr. Jerry McCullough
Polyethylene glycol (PEG) and fatty acids linked with a novel amide structure have previously been shown to affect the viability of cultured human lymphocytes. These amphipathic molecules (both hydrophilic and lipophilic) may also disrupt or weaken bacterial cells by altering the structure of the bacterial cell membrane. The antimicrobial potential of eight novel polymeric compounds against common skin bacteria was assessed using select PEGbased polymers of varying molecular weights. Synthesized test materials were comprised of fatty acid chains linked to a given weight of PEG, producing this unique amide structure: polymers were linked to a chain of linoleic acid, lauric acid, or oleic acid using a PEG component of molecular weight 400-1450. Susceptibility testing was performed to evaluate the potential antimicrobial effectiveness using two gram-negative and two gram-positive bacterial strains in culture. Linoleic acid-based polymers at saturated concentrations were most effective against both gram-positive strains, and virtually ineffective against gram-negative strains. At concentrations of 75% and 50%, effectiveness against gram-positive strains decreased. No bacterial susceptibility was observed using 25% polymer. The increased susceptibility in the gram-positive cultures may be due to interaction with the unsaturated bonds of linoleic acid. This class of synthetic polymers shows potential for use as a topical antiseptic wash.
Analysis of Gene Defects Which Can Lead to Ethylmalonic Aciduria and Leigh Syndrome
Mentor: Dr. Moyra Smith
The objective of this study is to find the gene defects that may lead to Ethylmalonic Aciduria (EMA). EMA is an inborn error of metabolism characterized by acidosis, petichiae, encephalopathy and an increased excretion of ethylmalonic acid. A cell line was established on a blood sample obtained postmortem from an infant with ethylmalonic aciduria and Leigh's syndrome. This cell line was used for analysis of the ETFA, COX7a, SDH and PDH. These genes were chosen based on the biochemical analysis of the patient. Mutational analysis was carried out using SSCP. Additional analysis of COX7a was completed using FISH on chromosome spreads derived from the cell line. Exon 11 of PDH was sequenced in order to analyze ambiguous SSCP findings. No mutations were found by SSCP in either ETFA, COX 7A, and exon 10 of PDH. Sequencing showed no mutation in exon 11 of PDH. Based on a previously reported study on another patient, one exon of SHD was studied by SSCP and no mutations were found. Additional studies on SDH are being carried out using long PCR. Also the ATPase 6 gene is being investigated. Previous studies have found patients with Leighs syndrome to have mutations in this gene. This project is important in order to define the spectrum of genetic defects that can give rise to this fatal disorder and the mode of inheritance of these defects.
From Conception to Completion: How to Make an Audio CD of Original Music
Mentor: Dr. Christopher Dobrian
Who is the modern composer of today? What rigors must he/she go through to produce a finished product, that is, an audio CD? Todays composer is not Beethoven, who may have sat at a piano tirelessly with reams of blank score paper. Likewise, todays composer is hopefully not a techno-junkie, creating and recording unusual sounds in a recording studio (laboratory) "on-the-fly" for immediate mass-market consumption. Todays composer is not a complete electrical engineer and/or computer scientist, although these skills help. Rather, todays composer is a serious combination of the three aforementioned people. A composer today must possess the combined skills of the three aforementioned technicians. This presentation/talk and performance will focus on the procedure required to make an audio CD of original musical works. From initial designs of compositions from piano and MIDI, through the process of studio recording, multi-tracking, editing, and digital conversion, to final mastering and output production of a recorded, marketable, audio CD. There are (exclusive) facilities here on the UCI campus to do such things, and such research needs to be presented to the UCI community.
Mentor: Dr. Ralph Purdy
Mechanisms that regulate blood pressure include vasodilator substances released from the endothelial lining the vasculature. Nitric Oxide (NO) is one such substance. A second endothelium derived substance mediates dilation by opening Ca2+ dependent K+ channels. Through the use of drugs that inhibit each of these pathways, the present study intended to assess endothelium-mediated vasodilation mechanisms. The effects of simulated microgravity were also explored. Microgravity was simulated in rats for 20 days by attachment of the tail to a harness, thereby lifting the hindlimbs 0.5 cm off the cage floor (HU). These rats and their controls (C) were euthanized and carotid arteries were removed. Each artery was cut into 3 mm segments and mounted in organ baths to sustain function and measure isometric tension. Vessel segments were pre-contracted with phenylephrine and acetylcholine was added incrementally to induce endotheluim-dependent relaxation. L-NAME, which blocks the NO synthase , was present in all the baths. TEA, which blocks Ca2+ dependent K+ channels, was placed in half of the baths. Relaxation was abolished in tissues treated with L-NAME. Tissues treated with L-NAME and TEA showed no further effect. The results indicate that endothelium dependent relaxation was mediated entirely by the release of NO.
Ingestion and Degradation of Alzheimer's Amyloid b -Peptide by Microglial Cells
Mentor: Dr. Andrea Tenner
Microglia are phagocytic cells that are the resident inflammatory response cells of the central nervous system. Internalization of the amyloid b -peptide (Ab ) by microglia has been viewed as a therapeutic target in Alzheimers disease (AD), in that approaches that enhance clearance of Ab relative to production are predicted to result in decreased senile plaque formation. Interest in Ab uptake has been further heightened by a recent study showing that cerebral deposition of Ab in a transgenic mouse model of AD is diminished by prior inoculation with synthetic Ab peptide (Schenk et al., 1999), possibly due to generation of anti Ab antibodies and subsequent Fc-receptor (FcR) mediated phagocytosis of the peptide. The goal of this project is to obtain an analysis of Ab phagocytosis through two different pathways: FcR mediated and MSR (macrophage scavenger receptor) mediated. Current research is focused on determining whether or not these two pathways result in localization of the ingested peptide in the same lysosomal compartments in microglial cells. Scavenger receptor-mediated uptake is observed by the use of a fluorescein-conjugated Ab peptide. FcR mediated uptake is monitored through the use of immune complexes formed with non-fluorescent Ab peptide bound to antiAb antibody, followed by detection with a Cy3 anti-IgG conjugate. This allows both pathways to be examined in the same cell. Initial microscopy results suggest that the peptide ingested through the different pathways localizes in different lysosomal compartments. Future projects will focus on determining which pathway results in more degradation of digested peptide.
Mentor: Dr. James McGaugh
The effects of memory modulatory drugs appear to be centrally mediated through influences in the basolateral amygdala (BLA). The goal of the present study was to determine the relative contributions of the cholinergic projections of the nucleus basalis magnocellularis (NBM) to the mediation of memory enhancement dependent on the BLA. Unilateral amygdalopetal projections from NBM to the BLA were selectively lesioned in rats using the neurotoxin phthalic acid (PhtA). Mnemonic deficits were compared to sham (Sh) operated controls. Intra-BLA infusions of cholinergic agents ipsilateral to the lesion were administered immediately after inhibitory avoidance (IA) training and retention was tested 48 hours later. Behavioral assessment of sensory, motor and acquisition versus consolidation or retrieval deficits were performed. As the amygdala is involved in fear behavior, unconditional fear behavior of lesioned rats was also assessed. Lesioned animals (Les) showed selective impairment of the IA task. Sensory and motor control experiments revealed no nonspecific deficits. Ls also expressed a much lower level of freezing to an unconditioned fear stimulus (cat hair). These data support the view that cholinergic activation in the BLA is critically involved in consolidation of the aversive IA task and suggest that this critical cholinergic activation in the BLA is from (at least in part) the NBM. Furthermore, these data suggest that cholinergic afferents from the NBM to the BLA are also critically involved in expression of species-specific fear behavior.
Reducing Friction and Air Leakage in a Pneumatic Robot Arm
Mentor: Dr. James Bobrow
Most modern machines and robots use electric servos and motors as their actuators. These servos and motors are usually inefficient, heavy, and costly. Other fluid actuated robots use hydraulic fluid that can pose safety and environmental problems with fluid leakage. A robot arm having pneumatically powered actuators requires minimal friction in the piston cylinder and gland seals to properly function. The goal of this project is to reduce the static, Coulomb and viscous friction while maintaining tolerable air leakage as compensated by the computer control program. Various combinations of seal configurations are implemented on the robot arm. Under these various states the arm undergoes transient response testing. Results show reduction in all types of friction. Air leakage reduction is shown through pressure and submerging tests, as well as transient response testing. Reduced friction and air leakage allows for improved accuracy on position and time taken for arm movement. Fluid powered actuators can be made to meet or surpass the performance of electric motors with safer conditions, less weight and lower costs.
Latino Advocacy Groups: The "Voices" Behind Latino National Political Empowerment
Mentor: Dr. Caesar Sereseres
National Latino advocacy groups serve as representatives to the growing Latino communities in the United States. Such organizations like National Association of Latino Elected Officials (NALEO), Mexican-American Legal Defense and Educational Fund (MALDEF), National Council of La Raza (NCLR), League of United Latin American Citizens (LULAC), and Congressional Hispanic Caucus (CHC) dedicate their efforts to ensuring the economic, political, social, and cultural improvement of the Latino communities. Despite this commonality, the dynamics behind each organization present a clear distinction of the effectiveness within each advocacy group. This research study explores the possibility of various determinants: including organizational structure, political strategies, leadership, grassroots constituency, geographical base, and the efficacy of each advocacy group to formulate and implement a strong Latino agenda. Through interviews with the leadership and staff of several national organizations in Washington D.C. and Los Angeles, this research data illustrates all Latino advocacy groups clearly contributing significantly to Latino empowerment. Current data analysis also indicates various external factors, such as financial matters, that substantially affect the efficiency of each organization. Further research analysis addresses the ambiguity of formulating a single national Latino agenda. In attempting to address these various questions, the composition of each organization is being explored, as well as the possibility that coalitions among these Latino organizations can present a more influential method of advocating for the Latino community. This research study is expected to acknowledge the importance of Latino advocacy groups, as well as formulate a clear method in which Latino organizations can effectively represent the public policy concerns of the Latino communities.
Genetics of Male Sterility in Schiedea menziesii
Mentors: Dr. Ann K. Sakai & Dr. Stephen Weller
Most plants are hermaphroditic but in some species gynodioecy has evolved, a breeding system with both hermaphrodites and females in a population. In most plant species, the genetics of male sterility (females) is not well understood and male sterility can be under nuclear, cytoplasmic, or nuclear-cytoplasmic control. Schiedea menziesii provides an ideal opportunity to examine the genetics of male sterility before it becomes well established. S. menziesii is hermaphroditic in the field, but production of a few females in the greenhouse suggests a possible transition from hermaphroditism to gynodioecy. A controlled crossing program within and between species was used to decipher whether mutations for male sterility are allelic within S. menziesii, and at the same locus with S. salicaria and S. sarmentosa. By the end of April 2000 approximately 50% of the 4753 progeny had flowered. The low frequency of females in the progeny suggested that more than one mutation maybe involved. Some of these male sterility mutations are not allelic within the species. Both intraspecific and interspecific crosses suggest than one male sterility mutation. Based on interspecfic crosses, one of these mutations may be similar to that in S. salicaria and S. menziesii. Further crosses will be needed to determine in greater detail the genetics of male sterility in S. menziesii and its impact on the evolution of gynodioecy.
Generation of a Recombinant Mouse Polyoma Virus
Mentor: Dr. Luis Villarreal
The goal of this research is to generate a recombinant mouse polyoma virus containing a green fluorescent protein (GFP) marker gene. The development of this recombinant virus and its subsequent use will significantly improve current understanding of the in vivo functions of the early genes of the mouse polyoma virus. Two deletion mutants of the mouse polyoma virus in a P AN7 plasmid vector have been generated. These deletion mutants, pCW4D T1 and pCW4D T2, are essential to the development of the desired recombinant mouse polyoma virus. pCW4D T1 contains a 147 nucleotide basepair deletion in the large T antigen gene of the polyoma virus, while pCW4D T2 contains a 960 nucleotide basepair deletion in the same gene (large T antigen is a protein required for the replication of polyoma virus). pCW4D T1 is being used to test the ability of a large T antigen transformed 3T6 (mouse fibroblast) cell line to complement a large T deficient polyoma virus. pCW4D T2 is being used as an intermediate reagent for the generation of the recombinant virus. Attempts are currently underway to insert the GFP gene in frame with the large T region of plasmid pCW4D T2. This pCW4D T2-GFP plasmid will be used to produce a recombinant GFP polyoma virus.
Miranda: An Early Angel
Mentor: Dr. Julia Lupton
In Victorian times, a character type known as "the angel in the house" was employed in novels, poems and other forms of media as an example of the perfect woman. The "angel in the house" was quiet, sympathetic, unselfish, pure, and subservient to all male authority, though there are various additions to this definition according to different authors and interpreters. Another important point to the "angel in the house" definition is that she is objectified, a person to be seen and admired, not someone who leaves the house or partakes of any important activity. After reading The Tempest by William Shakespeare, I was struck by the similarities to what I knew as "the angel in the house" model for women to the character of Miranda. This project is an examination of the similarities and differences between Miranda and the common "angel in the house" model, as well as an examination of how these two characters from two very different time periods and social situations came to be so alike. The differences in these two characters' motivations, social standing and the historical reality for women of the respective time periods will be examined, as well as texts that were likely influences on the creation of these characters.
The Effects of the "Promise Keepers" Movement on Marital Relations
Mentor: Dr. Judith Stepan-Norris
Advocates claim that the main purpose of the Promise Keeper movement is to bring back male responsibility and re-establish male leadership. Because the Promise Keeper doctrine is based on conservative political, religious, and patriarchal beliefs, there is skepticism and opposition from liberal and feminist groups. Feminist have claimed that the PK movement is setting women back in the sense that it is forcing them to take a more subordinate role in the home and society in general. In a study done by Michael Walcheski, the influence of the Promise Keepers on fathers involvement with their children is explored. He concluded that husbands participation in the Promise Keeper conferences increased their communication and the amount of quality time that they spent with their children. This study will focus on the effect of the effect of Promise Keeper involvement on marital relations. In-depth interviewing will be the sole means of data collection. Approximately ten individuals will be interviewed (7 husbands and 3 wives). The variables used to measure the degree of change in the marital relationships will be attitudes and condition of their marriage and household. Data collection is still in progress. I will attempt to the address whether or not the Promise Keepers are helping in areas that feminists claim they are a detriment to.
Optical Characterizations of Biomedical Microfluidic Devices
Mentor: Dr. Guann-pyng Li
Microfluidic devices consisting of fluidic channels 50-100 microns in size manufactured on a single chip, are generating great interest in the research community. These microdevices have the potential to revolutionize the fields of medicine, chemistry, pharmacology, and biology, allowing chemical laboratories to be shrunk down to the size of a postage stamp. The technology to build these microsystems is currently being developed at UCI and other institutions. An important problem in the development of this technology is the characterization methodology of their physical, chemical and optical properties. This research will focus on the optical characterization methodology of some prototype microfluidic chips. Properties such as indexes of diffraction and reflection can be characterized by focusing lasers through different materials and components at the microscopic scale. Of interest, is to whether the chips can offer the ability to use optical elements built into the chip for diagnostic purposes.
Assessing the Academic and Psychological Preparedness of Latino and White High School Students in Advanced Placement Courses
Mentor: Dr. Caesar Sereseres
Studies in the area of education have shown that European-American students are more academically prepared for college attendance than Latinos. This study will examine the academic and psychological preparedness of Latino and European-American high school students currently enrolled in Advanced Placement (AP) courses. The study will be conducted at two Southern California high schools and will consist of surveys distributed to high school students of both ethnicities. Given the low enrollment of Latino students in four-year universities, it is necessary to address the factors affecting their high school and college performance. In this study, I expect to find that the psychological and academic performance of Latino students will be lower than that of European-American students due that many come from low-income families. Another issue that will be taken into account when conducting this study will be the lack of school resources that Latino students experience even when they are enrolled in Advanced Placement Courses.
The Role of Activin in Olfactory Epithelium Neurogenesis
Mentor: Dr. Anne Calof
Early in development, the nervous system attains its appropriate size via an orchestrated production of nerve cells (neurons). The finely tuned genesis of these neurons in precise numbers and locations, neurogenesis, occurs during a transient developmental window. Many attribute the absence of neuronal regeneration, following injury or disease, to a loss of neurogenesis in adults. Recent studies, however, have detected low levels of neurogenesis in some regions of the adult nervous system. This suggests the presence of cells capable of producing new neurons (neuronal progenitor cells). Thus, the inability to regenerate neurons may be due to inhibitory molecular signals rather than a lack of neuronal progenitor cells. Understanding the mechanism(s) by which such inhibitory signals act should help reveal what keeps the regenerative capacity quiescent during adulthood. Nevertheless, such a molecular approach becomes a formidable task due to the nervous systems enormous complexity. This is why our laboratory utilizes the mouse olfactory epithelium (OE) to approach this issue. The OE is used as a model system because, unlike the rest of the nervous system, the OE retains its capacity to regenerate neurons into adulthood. Recent studies performed in our lab using mouse OE indicate that Activin, which is a member of the TGFb growth factor superfamily, may play a role in regulating neurogenesis. Specifically, in tissue cultures Activin works to decrease the level of MASH1, a transcription factor essential for neuronal progenitor cell survival and development. Hence, Activins role in the ongoing production of new neurons within the OE may be to inhibit neuronal progenitor cell proliferation.
Studies Toward Enantiselective Total Synthesis of (+)-Aldosterone
Mentor: Dr. Kenneth Shea
Aldosterone is a mineralocorticoid steroid hormone produced by the adrenal cortex which is vital in reabsorption of Na+ and water in the kidney. Aldosterone has been synthesized several times since its isolation and structure elucidation in 1953. We believe that the type 2 intramolecular Diels-Alder (T2IMDA) reaction will prove to be a powerful method to exercise regio- and stereoselective control in the synthesis of aldosterone. The type 2 intramolecular Diels-Alder reaction is distinguished from the type 1 intramolecular Diels-Alder reaction by the placement of the tether connecting the diene and the dienophile. Use of a chiral tether provides a very powerful method for controlling the stereochemistry of the resultant bridged bicycle. This methodology is being applied to stereoselective closure of the steroid core of aldosterone at the C-ring. Progress toward the T2IMDA precursor will be presented.