Summer Research Celebration 2011
Thursday, September 8, 2011
4-6 p.m. Winter Hall - Poster Display and Reception in the Rotunda
4:30 Talks to be held in Darling Foundation Lecture Hall
Featured Speaker - Dr. Brian Novy, DDS. '02
Researchers have worked over the summer in the fields of Biology, Chemistry, History, Math, Music, Physics, Psychology and Religious Studies. The following abstracts detail their work and collaboration with faculty members. Faculty, students, parents, alumni and prospective students are invited to attend. Please RSVP to Barb Kennedy in the Provost's Office at bkennedy@westmont.edu
SYNTHESIS OF WITTIG REAGENTS FROM A CYCLIC CARBAMATE
Useful organic compounds can be stereoselectively synthesized from Wittig reagents with chiral auxiliaries. Wittig reagents are used in a reaction with aldehydes or ketones to form a carbon-carbon double bond. These alkenes with chiral auxiliaries can then be transformed in stereoselective ways to produce useful organic compounds. Cyclic carbamates with different N-protecting groups were used to produce Wittig reagents with an ester linkage to the chiral auxiliary. With the t-butoxycarbonyl as an N-protecting group, a side reaction prevented the formation of the desired ester Wittig reagent. When the N-tosyl group was used, the expected reaction occurred to eventually produce a chiral alkene. However, the olefination reaction was not highly E-selective, yielding the alkene with an 85:15 E/Z ratio. Additionally, a side product resulting from nucleophilic substitution of the chiral auxiliary by a butoxide ion was observed. Elijah Tylski ‘12, Dr. David Marten, Professor of Chemistry
EFFECT OF DESORPTION OF CHLORINATED HEXANES ON THE FLUORESCENCE OF 1-METHYLNAPHTHALENE AND 2-ETHYLNAPTHALENE ON AL203
Bilayers of 1-methylnaphthalene and 2-ethylnapthalene with 1-chlorohexane were deposited on the surface of a single aluminum oxide crystal in the center of a high vacuum chamber. When optically pumped, the 1-chlorohexane was non-emissive while the naphthalene derivatives were fluorescent. The surface of the crystal was heated using temperature programmed desorption (TPD) and the emissions were viewed optically. The 1-methylnaphthalene was found to desorb at 260 K, 2-ethylnaphthalene desorbed at 275 K, and the 1-chlorohexane desorbed at 200 K. During this procedure, the excimer intensity of the 1-methylnaphthalene and 2-ethylnaphthalene decreased around 20-30 degrees prior to desorption of 1-chlorohexane and a trap was formed at this temperature. Excimer was then formed at a higher temperature along with the expected trap characteristic of the naphthalene derivative by itself. This change in intensity is most likely attributed to the transfer of energy between the 1-chlorohexane and the naphthalenes. Samantha R. Gardner*, ’13, Seth W. Simonds‡*, ’12, A.M. Nishimura, K.A. Martin‡Department of Chemistry, Westmont College, Santa Barbara, CA 93108
‡Department of Chemistry, Point Loma Nazarene University, San Diego, CA 92106
ODMR LINEWIDTH OF 2-INDANONE
Optically detected magnetic resonance, ODMR, can be used to determine the arrangement of molecules in individual 2-indanone crystals. Two microwave sources were used in the experimental setup to supply continuous wave energy and to sweep the zero-field transition. As the cw power was increased, the spectral linewidth of 2-indanone decreased asymmetrically. This supports the uneven and inequivalent arrangement of unit pairs in the triclinic 2-indanone crystal. The unsymmetrical sets of molecules result in inhomogeneous broadening of the ODMR line, which is evidenced by the deconvolution of the lineshapes. Rachel Teranishi ’12, Dr. Allan Nishimura, Professor of Chemistry
SEQUENCE REQUIREMENTS FOR THE SELF-ASSEMBLY OF α-HELICAL FIBRILS
Apolipoprotein A-I (apo A-I) comprises the main protein in high-density lipoprotein (HDL) and is integral in the reverse transport of cholesterol. Peptides modeled after apo A-I have been found to mimic the action of apo A-I in the reverse transport of cholesterol and may prove useful in the treatment of atherosclerosis. Previously, Peptide 3, a helix-turn-helix peptide with two identical 18-residue, amphiphilic, α-helical segments joined by a turn from apo A-I, was synthesized. This peptide readily formed α-helical fibrils in solution. To investigate the driving forces behind fibril formation, modifications were made to the sequence of Peptide 3. In Peptide 1, the central Pro residue of Peptide 3 was replaced with a Gly residue:
Ac-DWLKAFYDKVAEKLKEAFKVEGLRADWLKAFYDKVAEKLKEAF-NH2.
In Peptide 2, salt bridges within the turn sequence were abolished:
Ac-DWLKAFYDKVAEKLKEAFKVQPLRANWLKAFYDKVAEKLKEAF-NH2.
The effects of these modifications, along with the techniques used to purify and analyze the peptides, will be discussed. Aaron Barnes ’12, Dr. Kristi Lazar, Assistant Professor of Chemistry
STRUCTURAL ASPECTS INVOLVED IN THE SELF-ASSEMBLY OF α-HELICAL FIBRILS
Apolipoprotein A-I (apo A-I) is the main protein of high-density lipoprotein (HDL) and has several important functions in the reverse transport of cholesterol. Peptide models of apo A-I have been shown to mimic the properties of apo A-I. Previous work involved the characterization of a helix-turn-helix peptide model of apo A-I, Peptide 1, with two identical 18-residue, α-helical segments connected by a turn sequence from apo A-I:
Ac-DWLKAFYDKVAEKLKEAFKVEPLRADWLKAFYDKVAEKLKEAF-NH2. The peptide was shown to form α-helical fibrils. To investigate the role of the α-helix in fibril formation, a truncated derivative of Peptide 1, Peptide 2, was studied for its ability to generate fibrils:
Ac-DKVAEKLKEAFKVEPLRADKVAEKLKEAF-NH2. The optimal conditions for the purification of Peptides 1 and 2 will be discussed as well as the effect of the helix truncation. FTIR experiments are also ongoing in the laboratory to explore the α-helical structure of Peptide 1 fibrils. Dayna Chang ’12, Dr.Kristi Lazar, Assistant Professor of Chemistry
SYNTHESIS OF A WITTIG REAGENT CONTAINING HYDROXYL GROUPS FROM A CYCLIC CARBONATE
Wittig reagents are common compounds used in the formation of alkenes in organic synthesis. Chiral auxiliaries are components of molecules which direct the selective formation of one enantiomer in a chemical reaction. Wittig reagents which contain chiral auxiliaries are valuable tools for synthesizing organic molecules stereoselectively without the formation of undesired side products and isomers, a practice which can be very valuable in the pharmeceutical industry. In these experiments we used a simple, novel method to prepare a Wittig reagent containing a chiral auxiliary group attached to an ester from a cyclic carbonate and a phosphonium ylide. After isolation of the Wittig reagent, it was reacted with benzaldehyde. A conjugate addition reaction using an organocopper reagent was preformed with this product to determine how the chiral auxiliary group in the Wittig reagent affected the steroselectivity of the addition. Kelsey Cannon ‘12; David Marten, Professor of Chemistry
PEDAGOGICAL ANALYSIS OF VIOLIN ETUDES BY WOHLFAHRT, BENDA ET AL
Etudes are a critical part of any musician’s studies. For violinists, there is a vast repertoire of etudes available covering a variety of important techniques. No resources exist at this time, however, to find and compare etudes for various levels of players and according to the various techniques which they focus on. Such a resource would especially be useful for violin teachers. This project focuses on creating a database whereby teachers can easily search for etudes by composer, level, and/or technique in order to find a brief description of each book and individual etude, and therefore better address their students’ needs. This database includes some of the most common etude composers such as Benda, Hofmann, Kreutzer, Mazas, Trott, Wohlfahrt and Whistler. The future goal is to continue adding both common and unfamiliar names, and etudes to this database in order to help teachers effectively utilize the etude repertoire. Sarah Shasberger ’12, Dr. Philip Ficsor, Assistant Professor of Music
INFLUENCE OF PERSONALITY ON DIAGNOSIS OF COGNITIVE IMPAIRMENT IN OLDER ADULTS
The current study explored differences in personality among older adults whose cognitive diagnosis improved, declined, or remained stable over time. Longitudinal data were collected for 73 older adults who completed a neuropsychological battery and the NEO-Five Factor Inventory to assess personality. Participants were classified into four aging-related diagnostic groups. The results suggest that those with lower levels of Openness to Experience and Agreeableness appear to be more likely to experience a change in diagnosis than those with higher levels of Openness and Agreeableness. When considering the specific type of diagnostic change, those with lower levels of Openness at first assessment seem to be more likely to experience a decline in their diagnosis over time. These results suggest that older adults with lower levels of Openness and Agreeableness are at greater risk of experiencing cognitive decline over time than older adults with higher levels of these personality factors. Kelsey Wolff, ’12; Deborah Lowe, Neuropsychology Research Coordinator; Dr. Steve Rogers, Assistant Professor of Psychology
IS THERE A CONNECTION BETWEEN QUALITY OF LIFE, PERSONALITY, AND FRONTAL/EXECUTIVE FUNCTIONING? IMPLICATIONS FOR COGNITIVE IMPAIRMENT AND PREVENTATIVE MEASURES
The current study examines the relationship and interaction between quality of life, mood, personality, and frontal/executive measures. Two-hundred and four older adults completed a neuropsychological battery assessing the cognitive and emotional functioning of older adults. The findings suggest that the frontal/executive functions of older adults are strongly related to their quality of life and personality. Older adults who are more susceptible to neuroticism, anxiety, and depression have more difficulty on tasks involving processing speed, divided attention, working memory, abstract reasoning, and filtering out distractions. In contrast, those who score higher on extroversion and openness, as well as partake in healthier lifestyle activities, process information more quickly and exhibit better divided attention and abstract reasoning. These results demonstrate the degree and importance to which lifestyle and personality impact cognition. This can assist the identification of those who are more prone to problems with frontal/executive functions, as well as aid in the diagnosis and treatment process. Sara Humes, ’12; Deborah Lowe, Neuropsychology Research Coordinator; Dr. Steve Rogers, Assistant Professor of Psychology
SYNTHESIS OF Ru(bpy)2-salen PRECURSORS AND COMPLEXES FOR HYDROCARBON OXYGENATION
We are developing Ruthenium-modified metal salens as photocatalysts for the oxygenation of organic substrates. This summer, we sought to conjugate photoredox active Ru-diimine complexes to salen ligands and their Cobalt(II) complexes. In the presence of axial ligands such as pyridine, [Co(II)salen] complexes reversibly add dioxygen to give η1-O2 complexes that can in principle be converted to highly oxidizing Co=O intermediates by photoreduction and subsequent protonation. In our initial work, we prepared (2-aminoethyl-1,10-phenanthroline) and the complex [Ru(bpy)2(2-aminoethyl-1,10-phenanthroline)](NO3)2 via a four step synthesis in ~10% overall yield. Due to the difficulty of this synthesis we later focused on preparing precursors of Ruthenium-containing salen ligands by conjugation of [Ru(bpy)2(5-NH2-phenanthroline)](NO3)2 to [(4,4’-dicarboxysalen)Co(II)]. EDC-HOBt coupling in nitromethane gave crude {4,4’-[Ru(bpy)2(phen-NHCO)]2-salen}Co(II) in 32% yield. In water, the salen hydrolyzed to give [Ru(bpy)2(phen-NHCO-C6H3(COH)(OH)](NO3)2. A more rational synthesis of the latter compound was attempted by reacting 5-aminophenanthroline with [Ru(bpy)2(5-NH2-phenanthroline)](NO3)2 Surprisingly, this gave phen-NHCO-C6H3(COH)(OH) in 71% yield. Ashley Greenawalt ‘12, Stephen Contakes, Assistant Professor of Chemistry
SYNTHESIS OF ARMINE-TERMINATED RUTHENIUM-MODIFIED PAMAM DENDRIMERS
We are developing Ruthenium modified dendrimers that bind wastewater contaminants and photooxidize or reduce them to harmless products. In this project we used HOBt/EDC coupling to attach [Ru(bpy)2(dcbpy)](NO3)2 (dcbpy = 4,4’-dicarboxybipyridine) to G2.0 PAMAM dendrimers containing amine surface groups. The coupling yield decreases from 72 to 29% as the Ru:dendrimer reactant ratio is increased from 1:1 to 16:1. The coupling reaction could be used to reliably produce conjugate mixtures with average Ru:dendrimer ratios in the range 0.72 – 2.94. The conjugates’ absorbance spectra are similar to those of other Ruthenium diimine complexes while their emission spectra exhibit maxima at unusually long wavelengths. The emission maxima decrease and emission quantum yields increase with Ru:dendrimer ratio, becoming closer to that for [Ru(bpy)2(phen)]2+. Potentiometric measurements indicate that the Ruthenium:dendrimer complexes bind multiple nitrate, nitrite, and perchlorate ions at all Ru:dendrimer ratios. Garrett Johnson, ‘12, Stephen Contakes, Assistant Professor of Chemistry
IMPROVED SYNTHESIS OF CARBOXYL-TERMINATED RUTHENIUM-MODIFIED PAMAM DENDRIMERS AND 2-PHTHALYNIMINOETHYL- & 2-AMINOETHYLPHENANTHROLINE DIIMINE LIGGANDS
We are developing Ruthenium modified dendrimers which can bind wastewater contaminants and photooxidize or reduce them to harmless products. To this end we have been investigating the preparation of Ru-dendrimer conjugates. We improved the two step synthesis of 4-(2-aminoethyl)-1,10-phenanthroline in order to prepare [RuII(bpy)2(4-(2-aminoethyl)phen)](NO3)2 which can be covalently attached G1.5 PAMAM dendrimers in 70-90% yield using an EDC-coupling procedure by increased the overall yield of the precursor 4-(2-aminoethyl)-1,10-phenanthroline from 10% to 30%. This was done by increasing the reaction time for deprotection of its precursor, 4-(2-phthalimino)-1,10-phenanthroline, with hydrazine hydrate from 4 hours to two days. We also utilized HOBt/EDC coupling to significantly improve the yield for covalent attachment of [Ru(bpy)2(5-amino-1,10-phenanthroline)]2+ to G1.5 PAMAM dendrimers. The coupling yield decreases from 62 to 18% as the Ru:dendrimer ratio used in the conjugation reaction is increased from 1:1 to 16:1, reliably giving conjugates with average Ru:dendrimer ratios in the range 0.62 – 2.82. Tamara Sparks, ‘13, Stephen Contakes, Assistant Professor of Chemistry
COMPOSITES, PERSISTENCE, AND PERSONS: A STUDY IN MEREOLOGY AND HUMAN ONTOLOGY
This study in mereology (the philosophical study of parts and wholes) examines various contemporary accounts of the conditions for mereological composition (the conditions in which given objects make up a whole), and how they deal with various problems in mereology such as the Paradox of Increase and the Problem of the Many.The study concludes, using arguments from vagueness and the constraint of locality, that mereological extremism (viz.either mereological universalism or nihilism are true) is the best answer to these problems.The implication of this, however, is that ordinary material objects that gain or lose parts over time cannot serve as subjects of persisting identity.A human person, then, who persists through time and change, cannot be identical with his or her material body.This study suggests an immaterial human ontology, and yet with functional holism and relational teleology, using the analogy of an ecosystem to describe the interdependence between the immaterial person and the material body. Daniel Gee '13, Dr. David Vander Laan, Associate Professor of Philosophy
INTRODUCTION TO HISTORY: RESEARCHING THE HOLOCAUST
This summer we collaborated on a syllabus and reader for an introductory methods history course to be taught in the Spring of 2012 on the theme of the Holocaust. The goal of the class is to teach students the research process through interaction with primary and secondary sources. The course focuses on specific historiographical questions such as the history of antisemitism, definitions of victims, and rationales of rescuers. Creating a methods based course allows one to research a particular area more deeply, but can also prove to be complicated: along with the typical challenge of finding appropriate sources for first and second year students, this particular topic presented other possible difficulties, namely the emotional vulnerability often present when discussing the Holocaust. While one cannot deny the horrific nature of the Holocaust, in order to reflect on it the scope must be made manageable, thus the hope of this class is to show how the historian can bear a faithful witness to the past. Danielle Willard ’12, Marianne Robins, Professor of History
CALIBRATION OF THE MoNA AND LISA ARRAYS FOR THE LISA COMMISSIONING EXPERIMENT
The new LISA (the Large-area multi-Institutional Scintillator Array) neutron detector array, designed to be used in conjunction with MoNA (Modular Neutron Array) at the National Superconducting Cyclotron Laboratory was recently commissioned in an accelerator-based experiment designed to investigate excited states of neutron-rich Oxygen isotopes near the neutron drip-line. In order for the trajectories of neutrons arising from decay to be determined with sufficient precision to allow reconstruction of the invariant mass of the decaying system, all 288 scintillator bars must be precisely position-calibrated and time-synchronized to within a few tenths of a nanosecond, and the time origin for neutron time-of-flight determination must coincide precisely with the secondary beam particle/target interaction. The former was accomplished using cosmic muons passing through the array, and the latter using detection of gamma-rays produced at the target in each of the 18 layers of the MoNA-LISA array. Several Root C++ macros were developed in order to produce these calibrations. Results for the LISA commissioning run experiment will be presented.Work supported by NSF grant PHY-1101745 Amanda Grovom ‘11, Jackson Kwiatkowski ‘11, Warren Rogers, Professor of Physics, and the MoNA Collaboration –
CALIBRATION OF THE SWEPER CHAMBER CHARGED-PARTICLE DETECTORS FOR THE LISA COMMISSIONING EXPERIMENT
The new LISA (Large-area multi-Institutional Scintillator Array) neutron detector array, designed to be used in conjunction with MoNA (Modular Neutron Array) was recently commissioned at the National Superconducting Cyclotron Laboratory in an accelerator-based experiment designed to investigate excited states of neutron-rich Oxygen isotopes near the neutron drip-line. Charged fragments resulting from the neutron decays were swept out of the beam direction by the Sweeper Magnet after which they passed through a series of charged-particle detectors for fragment trajectory and energy determination. In order to achieve isotope separation and identification at the focal plane, which is then used to reconstruct the invariant mass of the unbound states, precise determinations of the fragment and neutron energies and trajectories are required. To correct for time-drifts in the charge-particle detectors that develop over the entire length of the experiment, Root C++ macros were developed to analyze and precisely correct for these detector drifts to within few tenths of a nanosecond. Root macros were also developed to position calibrate the ion chamber and CRDC’s. Results for the LISA commissioning run will be presented. Work supported by NSF grant PHY-1101745 Jackson Kwiatkowski ‘11, Amanda Grovom ‘11, Warren Rogers, Professor of Physics, and the MoNA Collaboration
EVALUATING THE ROLE OF THE SENSOR KINASE PlrS from B. bronchiseptica IN RESPONSE TO INNATE AND ADAPTIVE IMMUNITY
The host’s innate and adaptive immune responses provide critical defenses against bacterial infection, and the sensor kinase PlrS is required for B. bronchiseptica to resist innate immune functions in a mouse infection model. In this study, using B. bronchiseptica wild type and plrS mutant strains, we characterized the role of PlrS in B. bronchiseptica’s interaction with both innate and adaptive immune responses. When comparing the antibody response to infection from wild type- and and plrS- infected rats, there did not appear to be a significant difference. This would suggest that the adaptive immune responses might not be remarkably different between these two types of infection. Next, we used hydrogen peroxide assays and in vitro infection of macrophages to characterize bacterial responses to innate immunity. There was no significant difference in survival between wild type B. bronchiseptica and plrS mutants in the presence of hydrogen peroxide, suggesting that the PlrS gene doesn’t play a role in bacterial survival against oxidative stress. However, the amount of bacteria inside RAW 264 macrophages after 3 hours was significantly different between the two strains, indicating PlrS may play a role in how the bacteria interact with macrophages during infection. Further studies are necessary to demonstrate whether the plrS mutant is being engulfed more easily or is simply better at surviving macrophage killing mechanisms than wild type RB50. Amanda Burks ‘12, Samantha Kleen ‘11, Jose Ramirez ‘12 , Steve Julio, Assistant Professor of Biology
RESPONSE OF THE SENSOR KINASE PlrS TO NITROGEN LEVELS IN B. bronchiseptica
Two-component regulators change gene expression in response to environmental stimuli. In B. bronchiseptica, we have bee characterizing a novel two-component sensor kinase called PlrS, which we have previously shown to be necessary for bacterial virulence. PlrS has sequence homology to other sensor kinases that appear to control gene expression in response to nitrogen availability. We hypothesized that PlrS might play a similar role in Bordetella. Interestingly, however, there is another two-component system in Bordetella named ntrBC that is known to regulate genes in response to nitrogen levels. In order to determine whether PlrS senses nitrogen levels, we first created a B. bronchiseptica strain with an ntrB mutation. Wild type B. bronchiseptica, along with plrS and ntrB mutant strains, were grown in a modified SS media with varying amounts of ammonium sulfate as a nitrogen source. To qualitatively determine each strain’s ability to respond to nitrogen stress, total cell protein from these strains was run on an SDS PAGE gel. We observed at least one difference in protein expression between the wild type and ntrB mutant. However, no differences in protein expression were observed between the wild type and plrS mutant, suggesting PlrS does not respond to nitrogen levels under these experimental conditions. We have isolated total RNA from wild type and plrS mutant strains to evaluate total gene expression differences between these strains using microarray analyses. Amanda Burks ‘12, Samantha Kleen ‘11, Jose Ramirez ‘12 , Steve Julio, Assistant Professor of Biology
Participation in Christ: What Does It Mean
One way Christian theology has interpreted New Testament talk of believers’ being “in” Christ is in terms of participation or union. It is said that we truly participate, that we share, in Christ, in who and what he is. But what really does this mean, and to the extent that we are a “part” of Christ, do we still have agency, freedom, and responsibility? In conversation with recent theological work, we explore the multifaceted meaning of participation in Christ and of agency for those who are “in” Christ. Andrew Sutherland '12, Maurice Lee, Assistant Professor of Religious Studies.