Terwilliger, Ender (Ender Terwilliger) (author), (Su Zheng) (Thesis advisor), Wesleyan University Ethnomusicology (Degree grantor)
The aim of this dissertation is to portray the complex story of the kuajie music scene in Taipei, the capital of Taiwan, with each chapter playing a role in the telling. Chapter one places the kuajie music scene in the context and tension of Taipei and Taiwan. Chapter two introduces the Chinese orchestra and its instruments and how they found their way to Taiwan. Chapter three presents the current political motivations and precedence for the development of the kuajie music scene in Taipei. Chapter four uses biographical accounts and thick description to paint a clearer picture of the individuals in the music scene. Chapter five unites all of the previous chapters¿ work to present a case study of an ambitious kuajie band¿s collaborations. Finally, chapter six widens the scope of this dissertation by portraying other performers who utilize uniquely Taiwanese sounds to produce political meaning in their efforts to fortify their identities. This chapter, and the dissertation as a whole, concludes that the efforts of kuajie musicians in Taipei to sound out their identities are part of a larger phenomenon, wherein artists sonically construct their Taiwanese identities through performance., In Copyright – Non-Commercial Use Permitted (InC-NC)
Li, Freda (Freda Li) (author), (Wai Kiu Chan) (Thesis advisor), Wesleyan University Mathematics (Degree grantor)
Let E be an imaginary quadratic field. A Hermitian lattice L is said to be regular if L globally represents all elements that are locally represented by L. It is n- regular if L globally represents all Hermitian lattices of rank n that are locally represented by L. In 2005 Rokicki proved that, for a fixed imaginary quadratic field, there exist only finitely many isometry classes of nondegenerate normalized positive definite n-regular Hermitian lattices of rank n + 1.
The notion of n-regularity can be strengthened to strict n-regularity. A sub- lattice, N, of a Hermitian lattice, L, is primitive in L if N is a direct summand of L. We say that L is strictly n-regular if L primitively represents all Hermitian lattices of rank n that are locally primitively represented by L. In this thesis, we prove an analogous result to Rokicki's for strictly n-regular Hermitian lattices, for n ≥ 2.
Another notion of regularity is almost n-regularity. A Hermitian lattice L is almost n-regular if L globally represents all but finitely many Hermitian lattices of rank n that are locally represented by L. In this thesis, we also consider almost n-regular lattices, and prove a finiteness result for almost n-regular lattices of rank n+1., In Copyright – Non-Commercial Use Permitted (InC-NC)
The marked length spectrum of a metric on a compact Riemannian manifold records the length of the shortest closed curve in each free homotopy class.
It is known that a negatively curved Riemannian metric on a compact surface is uniquely determined by its marked length spectrum up to isometry. My results show that under certain conditions on the excluded homotopy classes, a partial marked length spectrum also uniquely determines such a metric.
It is also known that an inequality between the marked length spectra of two negatively curved Riemannian metrics on a compact surface implies a corresponding inequality between the area with respect to the metrics. I will show that an inequality between the partial marked length spectra is enough to imply the same conclusion., In Copyright – Non-Commercial Use Permitted (InC-NC)
King, Melissa Elizabeth (Melissa Elizabeth King) (author), (Michelle Personick) (Thesis advisor), (Irina Russu) (Thesis advisor), (Brian Northrop) (Thesis advisor), Wesleyan University Chemistry (Degree grantor)
Bimetallic nanoparticles with dilute alloyed surfaces are promising materials for many applications, especially catalysis. However, the preparation of nanoparticles composed of catalytically advantageous metal pairs is complicated by challenges, such as lattice mismatch and dissimilar reduction potentials. Herein we outline several particle systems that produce unique mono and bimetallic structures that are catalytically relevant. Moreover, the work outlined in the final chapter describes a novel application for halide ions within bimetallic systems. Indeed, low concentrations of halide ions provide a knob by which metal ion reduction may be differentially tuned in one-pot syntheses at mild temperatures. Additionally, this differential control has been shown effective in multiple metal systems including gold and palladium, palladium and copper, and gold and silver suggesting that these findings have the potential to be generally applicable. Differential metal ion reduction provides an avenue for the deliberate design of tunable bimetallic catalysts., In Copyright – Non-Commercial Use Permitted (InC-NC)
This thesis describes the application of novel and existing cinchona-alkaloid catalyzed Interrupted Feist Bènary (IFB) reactions towards the total synthesis of two biologically active targets: the anticancer compound (-)-rocaglamide and the benzo[b]indeno[2,1-d]furanone Picornavirus inhibitor tetracyclic antiviral-1 (TA-1).
Part I presents our progress towards both targets via the classic highly enantioselective and diastereoselective IFB reaction. Towards rocaglamide, we activated the relatively unreactive ester moiety of the IFB product and perform side chain extension, required to close the cyclopentanone ring of the natural product. We also accomplished the activation of the IFB¿s benzylic C-H bond by Hartwig¿s mild C-H azidation. Towards TA-1, we constructed the tetracyclic core of the target via a required tertiary alcohol protection followed by tin-mediated cyclization.
Part II describes the discovery and optimization of the asymmetric IFB-like reaction between 1,2,3-indanetriones and substituted phenols. We found that the introduction of a substituted aryl ester at the ortho position of the 1,2,3-indanetriones leads to moderate enantioselectivities (up to 79% ee). The introduction of stoichiometric benzoic acid additive was key for obtaining excellent enantioselectivity (up to 93% ee). This new acid-assisted asymmetric IFB-like reaction was used to prepare a number of chiral cyclic hemiacetals, which are useful precursors towards TA-1 and its analogs., In Copyright – Non-Commercial Use Permitted (InC-NC)
Lanno, Stephen Michael (Stephen Michael Lanno) (author), (Joseph Coolon, Ph.D.) (Thesis advisor), Wesleyan University Biology (Degree grantor)
Our understanding of the genetic basis of adaptation is still evolving. A significant example of natural selection at work resulting in adaptive phenotypic changes is the evolution of insecticide resistance. The work presented in this thesis takes advantage of an interesting case study investigating the genetic basis of a recently acquired adaptive trait in Drosophila sechellia, a dietary specialist fruit fly that has evolved to overcome the toxic secondary defense compounds produced by the fruit of its host plant, Morinda citrifolia. I begin by examining the potential roles of common detoxification gene families routinely involved in evolved toxin resistance: cytochrome P450s, glutathione-S-transferases, and esterases. In order to further identify candidate resistance genes, I employ a functional genomics approach to measure genome-wide gene expression in D. sechellia and closely related sister species D. melanogaster and D. simulans upon exposure to toxins and chemicals found in Morinda fruit. Taking advantage of genetic and genomic tools in D. melanogaster, I use RNA interference to functionally test candidate resistance genes with bioassays to measure differences in survival upon toxin exposure. This work led to the discovery of specific genes underlying loci implicated in this resistance trait as well as a family of genes representing a novel route to evolve toxin resistance. Esterases were found to specifically alter toxin resistance in D. sechellia and the Esterase-6 gene was identified as both significantly differentially expressed and shown to functionally alter resistance phenotypes. Additionally, this work identified genes from the enigmatic Osiris family as important mediators of toxin resistance. Osiris 6 (Osi6), Osi7, and Osi8 were observed to alter sensitivity not only in the pairwise relationship between D. sechellia and its host plant toxins, but subsequent research using metagenomic analyses and functional genetics indicates these genes can also influence resistance to commercial insecticides. The findings presented in this thesis have potential to address global problems concerning insect pest management affecting both crop protection and disease vector control., In Copyright – Non-Commercial Use Permitted (InC-NC)
the impermanence of OR selection and destabilization of OSN identity in OP cells
Noble, Joyce Carol (Joyce Carol Noble) (author), (Robert Lane) (Thesis advisor), Wesleyan University Molecular Biology & Biochemistry (Degree grantor)
The olfactory system is necessary for environmental perception in animals, where olfactory sensory neurons (OSNs) can detect volatile molecules in the air. For OSNs, terminal maturation is temporally coordinated with, and dependent on, the expression and function of olfactory receptors (ORs) that directly bind to odorants. In mouse, an OR is stochastically selected in a monogenic and monoallelic fashion from 1000 potential ORs, granting each neuron its own unique identity. Though the exact mechanism underlying OR expression regulation is not fully understood, research in this field has provided evidence that it is likely a coordinated process of cis and trans factors and nuclear organization that ensures singular OR expression.
I utilized an immature olfactory neuron cell line clonally derived from the developing olfactory placode (OP6) as a model system to study OR regulation and OSN development. I investigated OR re-selection frequencies and selection biases within OP6 colonies and cell populations. I found that OR re-selection occurs as frequently as at least once every cell cycle, and although OR selection is not stable, expression biases persist even with prolonged culturing. Overall, these findings suggest that though the chromatin environment to maintain OR selection is not stable in mitotic OP cells, epigenetic states that dictate OR selection probability are persistent.
I also investigated if a candidate chromatin modifier, G9a, may be involved in OSN lineage maintenance. Histone methyltransferase G9a is involved in the expression of olfactory-specific genes, and acts as a barrier in the reprogramming of neuronal precursor cells. To investigate the role of H3K9 methylation in OSN development, I developed a G9a drug inhibition protocol on OP cell populations. Surprisingly, drug-treated OP6 cells appeared to lose neuronal characteristics, exhibiting embryoid body-like colony formation, which was not evident in untreated OP6 cells or in treated GD25 (fibroblast) cells. Several stem cell markers were also upregulated within these OP6 colonies relative to untreated cells. Interestingly, initial colony formation and maintenance appears to be dependent on the cell cycle-promoting large T-antigen. These results suggest that epigenetic and mitotic barriers may prevent lineage regression towards stem-like states and provides evidence for G9a's direct involvement in neuronal identity maintenance in OP cells.
Lastly, I investigated the function of several known factors of robust OR expression - transcription factor Lhx2, locus control regions, and the unfolded protein response - in the OP cell where selection, but not commitment, is occurring. I observe little evidence of Lhx2 functioning on OR expression as ChIP reveals no enrichment of Lhx2 at OR promoters or LCRs. LCRs do not contain canonical chromatin states such as H3 acetylation and DNase hypersensitivity that normally would classify them as functional. LCRs also do not aggregate to interact in trans. However, preliminary data suggests that they may interact in cis. Finally, I provided evidence that ER stress alone is not sufficient to upregulate the downstream factors associated with the OR-specific UPR pathway, a necessary event in vivo for OR commitment. This data suggests that these factors (Lhx2, LCR) or pathways (UPR) that appear to be a requirement for commitment are likely not necessary for OR expression in the pre-commitment neuron.
The de-repression of previously selected ORs in the mitotic olfactory neuron and the destabilization of neuronal identity through G9a perturbation imply a unique characteristic of cell state malleability in immature olfactory neuronal cells. These studies provide evidence to suggest that olfactory neurons may have a greater developmental plasticity than other cell types, a hypothesis that is consistent with the need to meet the highly regenerative capacity of this system., In Copyright – Non-Commercial Use Permitted (InC-NC)
In the Peking opera ensemble, qinshi is the lead accompanist who plays the instrument jinghu. Historically, in addition to offering jinghu accompaniment, qinshi also served as Peking opera composers and Peking opera music teachers, contributing significantly to the artistry of Peking opera music. Since the 1980s, China has experienced tremendous social change, including economic and cultural reforms. Many traditional performance genres, including Peking opera, have encountered a survival crisis. Meanwhile, intracultural communications among different performance genres and art forms have become frequent and more intense, which have brought contemporary qinshi performance challenges as well as opportunities. In this context, many contemporary qinshi are no longer content to only play the traditional role as a lead accompanist in a Peking opera troupe. Although contemporary female qinshi¿s performances have attracted much attention in and outside of Peking opera circles, their musicality has been devalued by many Peking opera performers. In my dissertation, I will analyze the transformation of qinshi¿s performance tradition in the People¿s Republic of China (1949-present) from four perspectives: traditional jinghu accompaniment and accompaniment changes brought about by modernized Peking opera music, the institutionalization of qinshi¿s traditional training, contemporary qinshi¿s performance activities, and the impact of the all-male performance tradition on contemporary female qinshi¿s solo jinghu performance. These discussions will elaborate on how qinshi¿s performance tradition
and their musical lives have been shaped by political intervention, the market economy, mass media, and gender politics., In Copyright – Non-Commercial Use Permitted (InC-NC)
Nucleotide excision repair (NER) protects genomic DNA from a large number of chemically diverse lesions, including nucleotide adducts and cyclobutane pyrimidine dimers. In bacteria, NER is initiated by UvrA2 or the UvrA2-UvrB2 complex, which searches DNA for localized changes in structure and/or dynamics. Once the protein(s) encounter a potential site of damage, UvrA2 dissociates from the complex, leaving UvrB to verify the lesion and signal UvrC endonuclease to nick a segment of the damaged DNA strand for removal by UvrD helicase. Previous studies of UvrA2 have found that NER initiation is dependent on its ATPase and DNA binding activities. The mechanism by which these activities accomplish lesion recognition and set the repair process in motion remains speculative, especially due to a dearth of kinetic information. Our pre-steady state kinetic analysis of UvrA2 reveals new information on how the ATPase reaction is mechanochemically coupled to DNA binding and lesion recognition. Each monomer in the UvrA2 dimer has two ATPase sites (proximal and distal), both of which are required for NER and are implicated in lesion recognition and loading of UvrB at the damage site. We found that the two sites exhibit asymmetric ATP binding and hydrolysis that are modulated differentially by undamaged and damaged DNA. We also investigated formation of the UvrA2- lesion complex in the presence of different nucleotides to get a complementary view of how nucleotide-bound states of UvrA2 influence its conformation and interactions with DNA. We found that the UvrA2-lesion complex adopts a distinct conformation in the presence of ATP, which is not observed with other nucleotides. These findings provide an idea of key steps in the ATPase mechanism that are coupled to changes in UvrA2 interactions with DNA and drive initiation of NER. In addition, we began developing assays to detect conformational changes in UvrA2 related to lesion recognition and interaction with UvrB, in order to investigate its subsequent actions in NER. Finally, we also used pre-steady state kinetics methodology to deepen our understanding of how MutS protein uses ATP during initiation and signaling of DNA mismatch repair., In Copyright – Non-Commercial Use Permitted (InC-NC)
The overarching goal of this dissertation is to examine if transplantation of GABAergic interneuron progenitors derived from hESCs is a viable alternative for cell replacement therapy in the hippocampus, or other regions such as the ACC, in TLE patients to restore inhibition and control epileptogenesis. In this thesis, we first investigated the morphological and electrophysiological development of hESC-derived GABAergic progenitors transplanted into the mouse hippocampus. Secondly, we investigated the difference in seizure propagation in cingulate cortical slices prepared from SE and naïve mice and further investigate the role of GABAergic interneurons in seizure propagation., In Copyright – Non-Commercial Use Permitted (InC-NC)
Hesse, Katharine Marie (Katharine Marie Hesse) (author), (Seth Redfield) (Thesis advisor), Wesleyan University Astronomy (Degree grantor)
Very bright stars, despite being optimal atmospheric follow-up candidates, have been avoided by exoplanet missions since they saturate the CCD. A technique called Halophot (White et al., 2017) uses the unsaturated pixels in the surrounding ¿halo¿ of the star to extract a light curve. Unfortunately, bright stars require larger ¿postage stamps¿ to extract light curves using traditional methods, resulting in numerous background stars which must be removed before processing. These background stars have been modeled as 2-D gaussians but there may be a better approximation for the K2 PSF. We create a new PSF model to test this by stacking observations. We created this model for six channels across three campaigns to determine how the PSF varies with time and location. Each channel PSF was compared to the Kepler PRF for the respective channel as well as a 2-D gaussian., In Copyright – Non-Commercial Use Permitted (InC-NC)
Expressing 21st-Century Asian America Through Musical Theatre
Wang, Edward Zidong (Edward Zidong Wang) (author), (Su Zheng) (Thesis advisor), Wesleyan University Music (Degree grantor)
In my thesis, I claim that the Asian American musical theatre community in New York City uses modes of solidarity and subversion to resist historical portrayals of Asia/Asian America in Broadway musicals and other popular representational media. Through my fieldwork on Asian American composers/playwrights, performers, and audience members in New York City conducted from 2019-20, I show that stories told onstage are inextricably inflected by and interpreted through lenses of national and cultural identity, race and ethnicity, and relationality to an accumulative American musical-theatrical ethos. In addition, I interpret the Asian American musical theatre community as co-opting existing frameworks (such as American exceptionalism and the bildungsroman) to clarify rhetorical aims about first- and second-generation experiences. Although to perform musical theatre is still, in a sense, to `perform America,¿ those performers who undergo transnational journeys complicate definitions with the additional dimensions taken on by their work. Finally, through creating and performing musical theatre, I argue that Asian Americans combat insidious characterizations about lack of expressivity or individuality by imbuing their onstage stories with humor, pathos, and artistry. By telling stories, the individuals in my thesis embrace, present, and share their common humanity. They touch souls and laugh and learn and bring joy to others., In Copyright – Non-Commercial Use Permitted (InC-NC)
Using NuSTAR data on a local sample of 55 Seyfert galaxies, we created a composite spectrum that represents the local luminosity density. Integrating the luminosity function, along with an evolution term over redshift, we are then able to determine the contribution of Seyfert galaxies to the Cosmic X-ray Background. We find that Seyfert galaxies alone are responsible for the bulk of the Cosmic X-ray Background in the 3-13.5 keV energy range., In Copyright – Non-Commercial Use Permitted (InC-NC)
We are looking at the following problem: given a graph and a number of nodes to be removed, what is the best way to choose these nodes to remove such that the largest connected component of the the remaining graph has the smallest size. We show that this problem is NP-complete by equating it to finding the C-dismantling number of a graph, that is the smallest set of nodes that must be removed to have a graph with connected components of size at most C. We propose a greedy algorithm that takes out shells from local balls around nodes. We compare our algorithm with other node removal algorithms on both synthetic and real networks, and find that it performs better when the number of nodes to be removed is small. Hence, it could be useful in cases where we have limited resources, e.g. a limited number of vaccines available to remove nodes from a contact network where disease is spreading., In Copyright – Non-Commercial Use Permitted (InC-NC)
The ability of DNA to bind proteins and other molecules makes it an ideal candidate for its use as a scaffold to which biomolecules can be attached. In this study circular DNA scaffolds of varying sizes have been designed. Curvature in the DNA ring is induced by the bacterial DNA binding protein Integration Host Factor (IHF). It is a heterodimer with an alpha helical body and two protruding beta sheet arms. These arms interact within the minor groove of DNA, and proline residues within the arms stabilize the DNA bending. Molecular dynamic simulations were run to determine the mechanics and stability of the DNA ring itself, as well as the mechanics and stability of IHF protein binding. Wet lab experiments are also being conducted to create the physical construct. Applications for this scaffold include its use in cryo-electron microscopy (CryoEM), a new molecular imaging technique that enables researchers to determine the structure of biomolecules. CryoEM requires biomolecules to be at least 200 kDa and maintain an axis of symmetry in order to obtain an accurate image of the structure. Thus, attaching biomolecules less than 200 kDa will enable them to be readily visualized by CryoEM. Additional functionality of this scaffold includes the facilitation and subsequent imaging of weak binding interactions., In Copyright – Non-Commercial Use Permitted (InC-NC)
Arlia, Christina Arnet (Christina Arnet Arlia) (author), (Dr. Matthew Kurtz) (Thesis advisor), Wesleyan University Psychology (Degree grantor)
Schizophrenia is known for its multitude of symptoms that impair every-day functioning, such as interpersonal relationships and vocational life. Symptoms and features include positive (i.e., hallucinations, delusions, etc.), negative (i.e., anhedonia, alogia, etc.), and cognitive (i.e., poor memory/concentration, etc.). Cognitive features manifest independently of positive and negative symptoms, while also not being well-treated by antipsychotic medications. Thus, alternative treatment methods for schizophrenia that specifically target cognitive deficits are needed. Cognitive remediation (CR) is a growing field in schizophrenia. Prior research shows the efficacy of two therapeutic models: a computerized drill-and-practice approach (PSSCogRehab) and practice strategy-based compensatory cognitive training approach (CCT). The present study aims to compare the efficacy of these two therapeutic models on social cognition in psychosis-spectrum disorders. It was hypothesized that participants in both conditions will demonstrate improvements in social cognition in comparison to the control group; however, participants in the CCT condition will show larger improvements compared to the PSSCogRehab condition. Given that the structure of CCT focuses on improving everyday functional skills and encourages more social interaction compared to the individualistic approach of PSSCogRehab, larger improvements are expected to be seen in social cognition within CCT. Thirty-four participants were recruited from River Valley Services in Middletown, CT and randomly assigned to either one of two CR groups or treatment as usual (control). Efficacy of the CR approaches was assessed through a multimodal battery of measures administered at baseline, immediately after the intervention, and after 3-months. The results demonstrate no significant differences across the treatment groups relative to the control group on social cognitive measures. Furthermore, statistical analyses also revealed no significant differences between social cognitive and neurocognitive measures., In Copyright – Non-Commercial Use Permitted (InC-NC)