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Explorations In Novel Photochemical Modes Of Radical-Alkene Reactivity: My Piece Of The Pi
Full text linkThe formation of Csp3-Csp3 bonds is arguably the most critical yet challenging transformation in organicsynthesis. For many years the Michael addition, which utilizes highly reactivity organometallic carbon nucleophiles which are “poised to react”, was used to achieve hydroalkylation of activated alkenes. Furthermore, this mode of reactivity also offered the potential to use other electrophiles to perform vicinal (1,2) alkene difunctionalization. Though effective in many contexts, this reaction is often plagued by functional group incompatibilities, poor 1,2 vs 1,4 addition selectivity and unstable precursors. In contrast to organometallic carbanions, carbon-centered radicals display markedly higher regioselectivly in additions to alkenes and demonstrate much improved chemoselectivity. The Giese addition utilizes carbon radicals, typically generated from alkyl halides via halogen atom abstraction, to engage in radical addition with activated alkenes. Unfortunately, the harsh conditions and reagents required for the radical chain mechanisms employed in Giese reactions restrict the transformation to alkene hydroalkylations with minimal functional group compatibility. However, several modes of photochemical catalysis can be used for radical generation which are significantly milder and more tolerant than typical radical initiation used in classical Giese addition protocols. These catalytic mechanisms offer the potential for further functionalization of radical addition intermediates opening the door a wide variety of alkene difunctionalizations with dramatically improve functional group compatibility compared to classical vicinal difunctionalizations. Herein are reported personal explorations in novel radical alkene reactions facilitated via photochemical modes of catalysis
Reorienting Sonic Creativity Amid Ecological Disorientation
Full text linkThis dissertation offers ecological disorientation as an analytic for making sense of affective experiences of the climate crisis and the epistemological shifts that attend it. It focuses this analytic on a range of thinkers and makers whose reckonings with the climate crisis appeal to sonic creativity. It contributes to the difficult labor of reorienting music studies, the humanities, and higher education institutions to better contend with the climate crisis, for which there is no panacea. Chapter one analyzes the discourse of theorists, critics, scientists, and public officials who deploy sonic figures to make sense of ecological disorientation. The chapter opens this project’s overriding concern—namely, that sonic figures and practices of embodied sense-making can spur action and mobilize affects. Chapter two constellates and analyzes music studies practitioners’ reckonings with ecological disorientation to argue that such reckonings may perpetuate anthropocentric, identitarian epistemologies. Chapter three theorizes parahuman sonic creativity and compiles an archive of practitioners whose creative work in sound contends with, figures, or otherwise relates with the climate crisis and its disorienting effects; it argues that such works aestheticize the climatic, ecological conditions of possibility for their own existence. Chapter four offers a suite of the author’s creative and pedagogical models for reorientation: a breath-controlled instrument linking users’ breath to the real-time air quality of three user-defined cities around the world; a short film demonstrating the instrument; a film about the afterlives of industrial asbestos waste and environmental racism in Ambler, Pennsylvania; a video experiment in “pneumatography”; and two syllabi, available as supplementary files
Penn Library\u27s LJS 411 - Sharḥ-i Zīj-i Ulugh Bēg. = شرح زيج الغ بيگ. (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1164/thumbnail.jp
Patterns Of Accumulation: Capital, Form, And The Spatial Composition Of The Mexican Novel (1962-2017)
Full text linkThis dissertation lies at the intersection of Marxist literary criticism, spatial literary analysis or geocriticism, and Mexican literary studies. Throughout the dissertation I interrogate the plausible concatenations of these fields for the study of the spatiality of the Mexican modernist novel of the second half of the twentieth century, a period marked by Mexico’s transition from an industrial to a new-export oriented pattern of capital accumulation. I use the notion ‘spatial composition’ to theorize the conceptual relation between the novel’s formal ordinations and the patterns that model the reproduction of capital under specific historical and geospatial conditions. I show that the formal solutions offered by the Mexican novel to the changing dynamics of capital accumulation provide a systematic account of how unevenness comes to be produced and reproduced within the world order of late multinational capital. The periodization advanced corresponds to literary modernism’s consolidation as a cultural dominant in Mexico, a process that can be traced back to the long sixties. I argue that in the context of this long decade, Mexican literary modernism came to operate as a form of symbolic compensation for the exhaustion of the developmental program of the national-popular state. Each chapter studies modernist form against the backdrop of a momentous turning point in the consolidation of a new export-oriented pattern of capital reproduction in Mexico. Thus, each chapter considers how the modernist novel absorbed the antinomies produced by transition, displacement, and economic adjustment, and how self-consciousness and experimentation became imaginary lifelines in the face of socioeconomic decimation. While modernism’s paradigmatic ascendancy continued to hold sway throughout the second half of the twentieth century, a series of narrative impetuses began to challenge modernism’s literary predominance toward the turn of the century. These apertures would continue to develop as modernism transitioned into a cultural residual. I conclude by showing how the historicization of modernism provides formal codifications to apprehend the structural couplings of subjective and objective violence at the end of accumulation
Barba: A History Of Facial Hair As Cultural Symbol In The Roman World
No full textThis dissertation is a cultural study of male facial hair in the Roman world. It approaches facial hair as a cultural symbol and employs an historical anthropological approach to access the various cultural meanings of this bodily feature. Additionally, by understanding facial hair to be a natural symbol, this dissertation also shows how facial hair played a role in the mediation between nature and culture, as well as between the body and society. At the root level, facial hair symbolized “wildness” or uncontrolled nature in Roman culture. As such, it was subject to varying degrees of control through cultus. This dissertation begins with a diachronic account of facial hair and its cultus. This reveals the role that facial hair played in expressions of masculinity and how facial hair and its maintenance were exemplary of the debate around masculine cultus – a debate which changed over time. Additionally, facial hair was viewed as a disguise, which might be put on or off and viewers could “unbeard” those whom they held to have false beards. It then explores the depositio barbae – the ritual first shave – and the role of facial hair in the transition between adolescence and adulthood. The depositio was both a vow for a long life and a symbolic first act of cultus which reigned in the uncontrolled nature of youth, a life stage symbolized by lanugo or downy facial hair. Next, it explores the role of facial hair in the mediation between the paradigms of human and animal, urban and rustic, and Roman and non-Roman. It then discusses the “mourning beard” as a symbol of voluntary and temporary withdrawal from society. Following this is an analysis of facial hair as a symbol of the temporal otherness of Rome’s male ancestors. Lastly, it evaluates facial hair as a symbol of divine otherness. By exploring facial hair as a cultural trope, this dissertation accesses meanings, but also how these meanings changed over time and how facial hair was polysemous. It also contributes to the understanding of masculine self-fashioning, as facial hair was an embodied symbol
Essays On Mechanism And Information Design
Full text linkThis dissertation consists of two essays that examine issues related to data - how data is generated, used and monetized. In Chapter 1, I study how intermediaries such as Amazon and Google recommend products and services to consumers for which they receive compensation from the recommended sellers. Consumers will find these recommendations usefulonly if they are informative about the quality of the match between the sellers’ offerings and the consumer’s needs. The intermediary would like the consumer to purchase the product from the recommended seller, but is constrained because consumers need not follow the recommendation. I frame the intermediary’s problem as a mechanism design problem in which the mechanism designer cannot directly choose the outcome, but must encourage the consumer to choose the desired outcome. I show that in the optimal mechanism, the recommended seller has the largest non-negative virtual willingness to pay adjusted for the cost of persuasion. The optimal mechanism can be implemented via a handicap auction.
I use this model to provide insights for current policy debates. In Chapter 2, in the joint work with Mallesh Pai and Rakesh Vohra, we propose a statistical test for identifying whether a policy or an algorithm is designed by a principal with discriminatory tastes. The test can be used for identifying, for example, whether predictive policing algorithms are discriminatory against minority neighborhoods. We also argue that the marginal outcome test (Becker (1993)), the most popular test of taste-based discrimination, fails for policies. We consider a canonical setup where the principal designs a policy (algorithm) that maps signals (data) to decisions for each group, such as whether to patrol or not for each area. The principal commits to the policy, which in turn affects agents’ incentives to take action, such as whether to commit a crime. In this environment, the marginal outcome test fails because the principal not only cares about the marginal benefitof catching a criminal but how patrolling changes agents’ incentive to commit a crime. We propose a new statistical test that deviates from the marginal outcome test precisely as much as the incentive effect
Writing And Wronging: Prerogatives Of The Self-Translator
No full textThe impetus for this dissertation comes from a straightforward question: how does the act, or even the expectation, of translating influence original composition? To study this I focus on authors who translate their own texts and I search out traces left by translation in unexpected places. I argue that the influences of translation—whether in theme, structure, style, or inspiration—are latent in first compositions, and point not necessarily to the coming translation, but to a mode of writing. Bringing together an author’s translation with the original allows for a kaleidoscopic reading: the overlay of lenses on the text allows for otherwise unobtainable vistas onto the texts. This project investigates aspects of four authors’ projects that are informed by and inextricable from their status as self-translators: Julien Green (selves-writings), Samuel Beckett (echo…Echo), Romain Gary (mythic autobiography), and Nancy Huston (translation as structure).Through close readings of the many versions of a text, I engage questions of self-translation with larger themes, structures, and even genres of the works. I build on recent work by translation scholars who demonstrate the fruitfulness of centering writers’ practice of self-translation in their oeuvre. This scholarship brings original and translation into dialogue, blurring the bounds between them. Echoing these earlier studies’ call for understanding translation’s fundamental role in these authors’ creations, I posit that the criticism of said creations can benefit from a similar movement. Taking up recurring topics from scholarship on these authors and reconsidering them in light of the act of self-translation brings original perspectives to author specific studies as well as the broader fields of translation studies and literary composition
Biglycan Regulation Of Regional Tendon Development Via The Pericellular Matrix
Full text linkTendons are a unique orthopaedic tissue that rely on a highly ordered tissue matrix for proper function. Tendon disease degrades this matrix order, causing deviations in resident cell behavior that result in decreased tissue function. Treatments for tendon disease remain ineffective due to a knowledge gap in the factors most vital for maintaining tendon health. Many matrix molecules help regulate tendon growth and maintenance, including biglycan and collagen VI. These molecules are attributed to the pericellular matrix, a critical matrix structure that preserves cellular health across multiple contexts. The role of the PCM, and how interactions between biglycan and collagen VI govern tendon health, however, remain unknown. This dissertation defined the coordinate roles of biglycan and collagen VI and determined that while both molecules are key for tendon health, collagen VI is a more robust regulator, and that biglycan and collagen VI do not play additive roles in tendon. This work sought to further refine biglycan’s regulatory mechanism in tendon by leveraging a unique model system of distinct tendon matrix environments – “wrap-around” tendons. In addition to the characteristic, aligned tendon matrix, wrap-around tendons contain a matrix that more closely mimics fibrocartilage. This work analyzed the effect of biglycan knockout across these distinct tissue contexts to determine the molecular mechanism by which biglycan regulates tendon function. In doing so, we mapped the postnatal development of regional tendon properties for the first time in mice. Results from this work demonstrate that while biglycan may regulated tendon function through the PCM, this mechanism is likely independent of collagen VI interactions. Instead, biglycan may regulate tendon properties by directly organizing the collagen matrix. Overall, this work provides unique insight into the role of biglycan across distinct tendon matrix environments and lays the foundation for future work that may identify the factors most essential for preserving tendon health. Such knowledge is critical for the prevention and treatment of tendon disease
Understanding The Trade-Offs In Scaling Back Sentencing Practices
No full textRoughly three out of one hundred adults in the United States are under some form of correctional control. Scaling back sentencing practices could save resources, mitigate collateral consequences, and reduce racial disparities. However, these practices could also reduce deterrence and weaken incapacitation effects. Using quasi-experimental designs and statistical methods, I examine three types of policy interventions that seek to manage the scope of the criminal justice system: prosecutor guidelines, judicial sentencing feedback systems, and prosecutor-led diversion for misdemeanor offenses. I gauge the extent to which these interventions can reduce the footprint of the criminal justice system and consider their trade-offs. I find that prosecutor guidelines can regulate line prosecutors into seeking short sentences and non-custodial sanctions, but curbing prosecutorial discretion incentivizes shopping for favorable judges which creates inefficiencies. Sentencing feedback systems can identify outlier judges that contribute to sentencing disparities. Providing judges with information on their sentencing practices and expanding the capacity for alternative sanctions could help nudge outlier judges closer to their colleagues. Adult diversion for misdemeanor offenses can reduce long-term recidivism rates and the use of criminal justice resources, but their efficacy depends on the degree to which a net-widening effect, the diversion program’s tendency to draw in defendants that previously would have been dismissed, is balanced out by a net-narrowing effect, the diversion program’s capacity to facilitate exiting the justice system with a clean slate. Understanding these trade-offs is critical for practitioners and policymakers who manage the scope of the criminal justice system
Topics In Differentially Private Statistical Inference
No full textThis dissertation studies the trade-off between differential privacy and statistical accuracy in parameter estimation problems. We understand the privacy-accuracy trade-off by finding the best achievable accuracy of any differentially private algorithm, also known as the privacy-constrained minimax risk , in a series of statistical problems: Gaussian mean estimation and linear regression, estimation in general parametric models, and non-parametric function estimation. The increasing difficulty and generality of this series is matched by the development of differentially private algorithms such as noisy iterative hard thresholding, and of minimax lower bound techniques such as the score attack