|Dik Pacheco||Faculty Mentor: Dr. Henry Lee|
Numerical Simulation of Optical Transmission and Reflection in Multilayer Semiconductor Structures
The project is focused on the study of Diffuse Reflectance Spectroscopy (DRS) for temperature measurement during semiconductor epitaxial growth. DRS measures the spectral intensity of light which has undergone a scattering process inside the semiconductor. The light first passes through the sample. After that, it is scattered at the back of the sample and then it returns toward the detector. We can relate the detected spectral light intensity to the sample temperature. Experimental DRS temperature readings show oscillations as different epitaxial layers are deposited on top of the sample. It is possible that those oscillations are due to optical interference, a real temperature change, or a combination of both. The object of this project is determine the effect of optical interference on those temperature readings. This is done through computer calculations of electromagnetic wave propagation through sample structures. The results provide insights that might lead to improvements in the manufacture of optoelectronic semiconductor layered structures.
|Sejal Patel||Faculty Mentor: Dr. Allen Gibbs|
Physical Properties of Insect Cuticular Lipids
Cuticular lipids contain complex mixtures of long-chain hydrophobic compounds which play an important role in the water balance of terrestrial arthropods. Their water-proofing abilities primarily depend on their physical properties, but due to the complex composition of the cuticular lipids, it is difficult to predict the biophysical properties of the total lipid mixtures. Therefore, I analyzed biophysical properties of individual lipid components and simple model mixtures. The melting temperature (Tm) of alkenes increased with an increase in total number of carbon atoms. Moreover, the Tm of alkenes did not depend on the position of the double bond, unless the double bond resided near the end of the molecule. The Tm of pure wax esters increased linearly with an increase in either alcohol or fatty acid chain length. When mixtures of n-alkanes and wax esters were made from n-alkanes and wax esters having different Tm values, their Tm values were equal to the weighted average of the Tms of the component lipids. However, if the Tms of alkanes and wax esters were the same, then mixtures melted at temperatures up to 7oC lower than the temperature predicted from the component Tm values. All of the mixtures melted over a broader temperature range than their individual lipid components. I conclude that physical properties of natural lipid mixtures can not be predicted from the properties of the individual components.
|Olegario Perales||Faculty Mentor: Dr. Bruce G. Berg|
Relationships between DPOAE Audiograms and Spectral Weights
The spectral decomposition of sounds by the cochlea has been theorized as being a passive mechanism. However, there is evidence now to support the belief that the cochlea is actually an active processor which functions as a bio-mechanical feedback system. Initial findings by Kemp (1978) using a physiological measurement of otoacoustic emissions of the cochlea, has provided evidence that the basilar membrane is not a homogenous structure as one conceived. The objective of the current study is to investigate through psychoacoustic methods how behavior of the cochlear transduction mechanism can provide insight into the perception of sounds. Specifically, the current study investigates the problem using a profile discrimination task. Listeners are presented computer-generated sounds monaurally over headphones and are asked to discriminate two sounds (signal vs. nonsignal). A weighting procedure, developed by Berg (1989), is then employed to analyze how each component of the sound contributed to a listener’s decision. Previous research using spectral weights for profile discrimination tasks has shown large differences in performances across-subjects and has proven to be stable over long periods of time. The current research is investigating whether spectral weights will show behavioral differences between left and right ears of the peripheral auditory system. If the spectral weights show a difference between left and right ears, the data would warrant an investigation for relationships between spectral weights and a physiological measurement of the basilar membrane using otoacoustic emissions. Data collection is currently in progress.
|Karen J. Placencia (Chapman University)||Faculty Mentor: Dr. Roberta Lessor|
Medical Dominance, Social Control and Competing Ideologies in the Practice of Licensed and Lay Midwifery
In looking at the history of professional medicine in the U.S., one must examine the history of the medicalization of midwifery. In order to assure dominance, medicine needed to eliminate midwifery as a viable choice and practice. However, one can find that midwifery was never eliminated. Instead, midwives continued to practice outside the sphere of medical science. Without the ability to abolish midwifery, medicine then subsumed nurse midwifery, keeping control and ultimate dominance over the practice. Even through this medical paradigm of midwifery, lay midwifery continues to serve a need for a non-medically based practice. Through a small field study I have looked at the varying ideologies that surround the practice of midwifery. Using interviews with both nurse-certified and lay midwives, I have conducted an analysis of the motivating beliefs and values of this divided field. The practice of midwifery still remains in tension with the accepted medical model. Through my interviews I have found that in this common struggle, nurse midwifery strives to professionalize while lay midwifery works to preserve the traditional role of the midwife. This has separated the field into two sides, one striving for acceptance in the domain of medical practice, and the other holding to the original, spiritual and natural processes.
|David Emil Posin||Faculty Mentor: Dr. Rhona Berenstein|
Here Comes the Good Part...
Spectacle in narrative cinema is a concept that has often been mentioned, but rarely defined. The focus of this research is to discuss the spectacle as a common component of American narrative. Spectacles are designed to offer unique sights to the audience while eliciting emotional reactions from the audience. Spectacle is not constrained by genre definitions, and the similarity in spectacle construction across genres allows for many of the comparisons that occur in modern critical theory. However, the specific visual imagery and auditory components of a spectacle will be unique for each genre. My thesis will focus on two genres: the pornographic film and the slasher film. The work being presented on this topic is based on a survey of the critical literature on these two specific genres, genre theory in general, and spectacle theory, as well as a survey of applicable films.
|Gregory Qushair||Faculty Mentor: Dr. Patrick Farmer|
Reconstitution of Modified Hemes into Myoglobin
The use of enzymatic models is an invaluable tool in the study of the mechanistic details of the catalytic activity of heme proteins such as the oxidoreductases. We are using models based on an unlikely protein, myoglobin, whose primary natural function is the storage of oxygen in muscle tissue. Although myoglobin does not perform catalytic functions in vivo, its structural similarities to the oxidoreductases, as well as the degree to which it can be readily modified, make it an ideal candidate. Our general strategy lies in reconstituting modified hemins with native apomyoglobin. These altered heme sites are produced by affixing electron conducting organic substituents, denoted pendant arms, to various porphyrin scaffolds by an amide linkage. A major focus of this presentation is maximizing this peptide linkage reaction through the use of various coupling reagents. Pendant arms are selected for electrochemical and photochemical applications. The subsequent metallation of the modified porphyrins is the final step before reconstitution. Preliminary results of reconstitutions and electrochemical response of modified porphyrins will be discussed.
|Sheela Rao||Faculty Mentor: Dr. James T. Chiampi|
The Reflection of the Changing Political Climate in Italy in the Protagonists of Post World War II Films
Changing political climates make their mark on all forms of expression including cinema. Italian cinema was especially vulnerable to the drifts in political interest in the postwar years. Several different movements emerged in those years which influenced film directors' conviction to bring the audience to reflect upon reality precisely as it was. From the beginning to the end of the postwar period, Italian films shifted their focus from the scrutiny of the external world to the dissection of the interior state of the individual. Directors employed techniques ranging from camera angle to shot composition to heighten these contrasts. While the films of 1945 to 1948 underscore societal ills, the films of the 50s and 60s explore the psyche of the individual. This pattern corresponded with the changing political climate of post-war Italy. At the beginning of the post-war period, the Italian people were unified in their condemnation of the collapsed Fascist regime, yet later they had trouble in identifying one political party as the new leader of democratic reforms in Italy. The films illustrated this dissipation of unity in their portrayal of the protagonists. The earliest postwar films depicted protagonists as heroes to a certain extent, but the later ones at best refrain from condemning their protagonists. A chronological examination of the most prominent films produced by Italian directors from the 1940s to the 1960s will provide further proof of these trends.
|Sheela Rao||Faculty Mentor: Dr. Jan West|
Detection of Presence of Virus in the Rosid I Clade of Angiosperms from the Tropical Deciduous Forest of Sierra de Huautla, Morelos, Mexico
The evolution of virus has been the subject of considerable debate due to its bearing on human disease. Plants offer an interesting model for study of virus-host interactions. A random survey was conducted of the Rosid I clade of angiosperms in Sierra de Huautla, Morelos, Mexico. Fifty plant leaf samples were processed using the Morris and Dodds protocol for the isolation and analysis of double-stranded RNA (dsRNA) from virus-infected plants. Of these 50 samples, 6 displayed dsRNA bands for virus on an agarose gel resulting in 12% viral incidence in the sample population. These samples diagnosed with plant virus belonged to two different plant species: Dorstenia drakeana (Moraceae) and Gliricidia sepium (Fabaceae). The presence of virus did not correspond to presumed phylogenetic relationships between these plant species. The families which presented dsRNA bands, Fabaceae and Moraceae, are only distantly related. The samples with virus did not consistently display one type of symptom. While 4 of the 6 samples with virus exhibited necrotic lesions with chlorotic haloes or mild or intermediate mosaic patterns, only 2 exhibited chlorotic lesions. In the overall study of all the clades examined in Sierra de Huautla, herbaceous or annual life forms had a higher incidence of virus than woody or perennial life forms. Determining how plant viruses may effect events of speciation will require base sequence data and more detailed genetic analysis.
|Heather Lynn Revilee||Faculty Mentor: Dr. George L. Hunt, Jr.|
Small-Scale Convergences and Their Impact on Zooplankton Aggregation in a Tidal Body
Small surface slicks are present in shallow bays off San Juan Island in Puget Sound. They are often associated with lines of accumulated debris which suggest that they are convergence slicks, or areas where two water masses come together. I investigated the hypothesis that these slicks were strong enough to aggregate zooplankton, and thus increase the rate of trophic level transfer to predatory gelatinous zooplankton. For this investigation, the slick (a visible line of water approximately three meters in width) was defined as the convergence area, and the non-convergence area was defined as the area on either side of the slick. To test the hypothesis that (1) copepods would be more abundant inside slicks, (2) gelatinous zooplankton would be more abundant inside slicks, and (3) ctenophores would have greater foraging success inside slicks, I performed a series of vertical net tows at stations inside slicks and ten meters on either side. I found no significant aggregation of copepods or ctenophores inside the slicks. Also, there was no significant difference in the presence of food in the ctenophores found inside the slicks. An alternate hypothesis is that the actual area of convergence extends beyond the visible slick areas, and thus the sampling was taken at too small a scale to detect significant zooplankton aggregation. Time-series analysis of the data shows a significant increase in the number of copepods over time, regardless of station. This finding supports the alternate hypothesis. Future investigation of these slicks will involve sampling at larger spatial scales.
|Bonita Rhoads||Faculty Mentor: Dr. Julia Reinhard Lupton|
Imagining the Jew in Renaissance Europe
My research project was inspired by studying representations of Jews in Renaissance literature -- some famous examples would be Shylock in Shakespeare’s The Merchant of Venice, as well as Barabas in Christopher Marlowe’s play, The Jew of Malta. The UROP grant committee enabled me to go beyond the borders of the literary tradition (rich though it is) by funding a research trip to New York City, where I spent a week doing archival work at several institutions, looking for representations of Jews in the religious art of late medieval and Renaissance Europe. Because a great majority of people were illiterate in the 15th and 16th centuries, this investigation into the history of representation of Jews in the visual arts provided an invaluable opportunity to learn about popular perceptions of the Jews in the Renaissance.
|Monica Elizabeth Roby||Faculty Mentor: Dr. Roxane Silver|
Disaster Victims’ Emotions as Presented in Mass Media
Media coverage of disasters has been interpreted as dramatic and biased at best. In this study, emotional content in different forms of mass media was analyzed in order to assess the accuracy by which the media portrays victims’ emotions following a disaster such as the 1993 Laguna and Malibu fires. A content analysis of how victims’ emotions were portrayed in various types of mass media (e.g., print, television, etc.) up to one month following the 1993 Southern California fires was completed. The emotions reported in print media (e.g., magazines, newspapers) were compared to those reported in broadcast media (e.g., television, radio). Results indicated that the print media tended to portray the victims of these fires as experiencing a great deal of negative emotions, and these reports tended to be even more negative than the broadcast media. This presentation will also compare the results of this media analysis to results obtained by Holman and Silver (1994), who conducted structured interviews of the emotional responses of 85 residents of those communities in the immediate aftermath of the fire storms.
|Melanie Kay Rosa Vargas||Faculty Mentor: Dr. Stephen Barker|
Exploring the Aesthetics of a Traditional Healer in Mexico
The field of medical anthropology is currently involved in researching other systems of healing in an effort to understand the commonalties and differences between them. It is acknowledged that common to all systems of healing is the fact that all people experience illness. What differs is how the illness is dealt with and treated. This presentation explores, via video documentation, the aesthetics of a traditional healer in Mexico. Furthermore, this presentation reveals the aesthetics of the healing environment, as well as, the humanistic approach of a healer in another system of healing.
|Brian Evert Rowe||Faculty Mentor: Dr. John Sechrist|
Initial Cell-Cycle Termination and Differentiation in the Placodal Component of the Avian Trigeminal Ganglion
The lack of markers identifying undifferentiated cranial placodes has inhibited our understanding the development of such structures as the trigeminal ganglia. This study applies four techniques in novel combinations, providing new insights regarding the timing of trigeminal ganglion placode exit from mitosis and subsequent differentiation: 1) Whole embryo DiI labeling after neural tube closure reveals the precise distribution of placode-derived cells at specific time intervals; 2) Double staining with DiI and neurofilament antibody, a neural marker, indicates placode-derived cells are primarily neuroblasts; 3) Use of Pax3 genetic probe as a marker for placode-derived cells confirms the DiI labeled cells contribute to the trigeminal ophthalmic lobe; 4) Labeling placodal cells with BrdU or [3H]thymidine in conjunction with DiI, neurofilament antibody, or Pax3 expression indicates DNA synthesis ceases earlier than previously observed. In addition, we confirm prior observations regarding the timing of neural differentiation in the placode and localize the anlagen of ectoderm giving rise to the trigeminal placode. Furthermore, our experiments, performed on very young embryos, may reveal "pioneering" neurons which initially delineate a route by which future ophthalmic nerve cells will extend their axons.
|Cristin Gail Ryan||Faculty Mentor: Dr. Nancy M. Doherty|
In Search of Inorganic/Organic Hybrid Polymers: Synthesis and Study of Platinum 4,5-Dianilido-1,2-benzoquinone Coordination Complexes
Our modern and complex society depends heavily on materials which possess specialized properties. One major class of technologically important materials are polymers, the vast majority of which are organic (i.e. carbon-based) compounds such as plastics. At the other extreme, inorganic materials such as polysiloxanes, polyphosphazenes, and polysilanes have particularly useful chemical properties such as low temperature flexibility and high oxidative stability. It follows that research focused on producing inorganic/organic hybrid polymers could afford new polymeric compounds with an even broader range of potentially useful electrical, mechanical, thermal, optical, and magnetic properties. The goal of this research project is to prepare and characterize coordination compounds containing transition-metals bridged by organic molecules and to use these as models and building blocks for inorganic/organic hybrid oligomers and polymers. Specifically, my research project involves the synthesis and characterization of platinum 4,5-dianilido-1,2-benzoquinone coordination complexes. Principle investigation centers on the reactions of 4,5-di-N-methylanilino-1,2-benzoquinone and 4,5-di-p-toluidino-1,2-benzoquinone with zerovalent platinum compounds such as Pt(PEt3)4 and Pt2(dba)3, and the reactions of Na2[O2C6H2(N-p-tol)2] with divalent platinum compounds such as PtCl2py2.