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The Role Of Information Disclosure In Corporate Bankruptcy
No full textThe bankruptcy system plays an important role in resolving financial distress and reallocating resources in the economy. While many believe that transparency is central to an efficient bankruptcy system, the Bankruptcy Code lacks clear standards for disclosure and financial reporting. In this paper, I study the effects of information disclosure on bankruptcy outcomes by exploiting two sources of plausibly exogenous variation in disclosure during a bankruptcy: the random assignment of bankruptcy judges who may differ in interpreting the disclosure requirements of the law, and a significant change in regulation that increased disclosure by certain creditors but not others. I find evidence that disclosure can both improve asset allocation choices and facilitate more efficient bargaining between creditors. I also highlight two frictions—compliance costs and proprietary costs—that may inhibit transparency and make mandatory disclosure undesirable. My findings provide some of the first evidence on the role of information disclosure in corporate bankruptcy, and I discuss their implications for policy and for the broader corporate disclosure literature
Job Flexibility And Household Labor Supply: Understanding Gender Gaps And The Child Wage Penalty
Get PDFThis dissertation investigates how occupational flexibility affects married couples\u27 labor supply and the gender pay gap around childbirth. Using the NLSY79 data and Goldin\u27s (2014) measure of occupational flexibility, I show that flexibility is a significant determinant of married couples\u27 labor supply adjustments. When a husband\u27s job exhibits low flexibility, couples are more likely to specialize with the wife dropping out of the labor market and the husband increasing hours worked. In contrast, couples with greater flexibility show less labor supply adjustment to childbirth. To analyze the relationship between occupational flexibility and family-friendly labor market policies, I develop and estimate a dynamic discrete choice model of couples\u27 decision-making about labor supply and occupations. In the model, occupations are characterized by wage-hours schedules and flexibility levels. I find that increasing women\u27s and men\u27s own occupational flexibility increases labor force participation by 4 percentage points in the childbirth year. Interestingly, increasing husband\u27s flexibility has a greater impact on the wife\u27s labor adjustment than her own flexibility, augmenting her participation rate and working hours by 10 and 7 percentage points. Finally, I evaluate the effects of family-friendly policies providing temporary flexibility for couples experiencing a birth in the last two years. Policies that target women increase female labor supply and reduce the gender pay gap by 8% in the long run. However, when the benefits are offered to both spouses, the positive effects on the wife\u27s labor supply are weakened, and the gender pay gap expands in the long run
Sodium Hydrogen Exchanger 1 Enhances Antitumor Activity Of Nk-92 Natural Killer Cells
Get PDFAdoptive cell transfer immunotherapy has remarkable efficacy against some hematological malignancies. However, its efficacy in solid tumors is limited by the adverse tumor microenvironment (TME) conditions, most notably that acidity inhibits T and NK cell mTORC1 activity and impairs cytotoxicity. In several reported studies, systemic buffering of tumor acidity enhanced the efficacy of immune checkpoint inhibitors. Paradoxically, we found in a Myc-inducible hepatocellular carcinoma model that buffering increased tumor mTORC1 activity, negating inhibition of tumor growth by anti-PD1 treatment. To avoid such adverse effects of systemic buffering favoring tumor growth, we overexpressed activated RHEB in the human NK-92 cell line, thereby rescuing acid-blunted mTORC1 activity and enhancing cytotoxicity. To mitigate the effect of acidity, we sought to metabolically engineer NK-92 cells with ectopically expressed acid extruder proteins. Whereas ectopic expression of carbonic anhydrase IX (CA9) moderately increased mTORC1 activity, it did not enhance effector function. In contrast, overexpressing a constitutively active Na+/H+-exchanger 1 (NHE1; SLC9A1) in NK-92 did not elevate mTORC1 but enhanced degranulation, target engagement, in vitro cytotoxicity, and in vivo antitumor activity. Our findings provide proof-of-concept that metabolic engineering of NK cells can enhance ACT for better efficacy against solid tumors without increasing mTORC1 activity
Hans Scharoun, Neues Bauen, And The Chinese Werkbund: The Search For Post-Perspectival Space
No full textArchitectural historians know Hans Scharoun (1893-1972) as a key proponent of “Expressionist” architecture based on his contribution to the “Crystal Chain” correspondence, his visionary drawings, and his magnum opus, the Berlin Philharmonic Concert Hall. It is, however, the insufficiency of systematic studies of Scharoun’s spatial construction and his interest in and research of Chinese architecture and urban culture that have prompted me to undertake the present research.
Thus, this dissertation investigates the role of Chinese architecture and town-planning tradition played in shaping Scharoun’s spatial concepts of what can be characterized as “post-perspectival.” Built upon his Neues Bauen conviction, Scharoun began to engage with the Chinese architecture tradition in the mid-1930s through his assistant Chen-kuan Lee. From October 1941 to May 1942, Scharoun, along with Lee, was involved in the Chinese Werkbund meetings initiated by Hugo Häring. Even though Häring’s and Lee’s encounter with East Asian architecture, especially the history of the Chinese Werkbund, has been partially explained, the significance of Chinese architecture and town planning to Scharoun has been neglected to date. Although he never visited China, Scharoun strove to employ the understandings that he obtained through the Chinese Werkbund meetings and his subsequent research to advance his spatial concepts, urbanist thinking, and organicist design approach. Further investigation is thus necessary to understand Scharoun’s work, his evolving “post-perspectival” spatial concepts, his urbanist strategy for rebuilding postwar Berlin, and the Asian-European exchange in early modern architecture in general.
This dissertation is structured in two parts. Part I first presents a chronological study of Scharoun’s career from the early 1910s to 1945, then introduces Häring’s organicists Neues Bauen principle, and lastly reviews the history of the Chinese Werkbund. The second part makes as solid a case as the evidence suggests for the direct impact of Chinese architecture and urban tradition upon Scharoun’s postwar practice. This section examines Scharoun’s spatial concepts such as “Stadtlandschaft,” “Wohnzelle,” “aperspectival” space, and “Raum der Mitte” in borrowing, adaption, or assimilation of Chinese architecture and town-planning principles
Essays In Housing And Urban Economics
Get PDFThis dissertation examines how housing and location choice decisions contribute to spatial and social inequality. The first chapter studies the financial burdens of property taxes on homeowners. Exploiting a reform in Philadelphia that generated changes in property taxes without changing the provision of public goods and services, I measure how sensitive homeowners are to increases in their property tax bills. I find that a $100 increase in property taxes increases property tax delinquency by 3.9% after one year and 7.7% after two years. Home sales also increase by 4.1% after two years. There is no effect on house prices. Further, the financial burdens of property taxes vary considerably by owner race and occupancy status. White owners are more likely to recover from delinquency and sell their homes than Black and minority owners. Owners who live in their houses are also more likely to sell than landlords. The second chapter studies how the time spent commuting to work have evolved over the last four decades for White and Black commuters. In 1980, Black commuters spent 50.3 more minutes commuting per week than White commuters; by 2019, that difference declined to 22.4 minutes. Two factors account for the majority of this decline: Black workers are more likely to commute by transit, and Black workers make up a larger share of the population in cities with long average commutes. Increases in car commuting by Black workers account for nearly one quarter of the decline in the racialized difference in commute times between 1980 and 2019. Today, commute times have mostly converged (conditional on observables) for car commuters in small- and mid-sized cities. However, persistent differences in commute times still remain today in large, segregated, congested, and---especially---expensive cities, revealing the limits of cars in overcoming entrenched racialization of other factors of commuting
Essays On Banking And Credit Markets
Get PDFThis dissertation focuses on two themes in the field of empirical banking. First, the importance of credit relationships for corporations experiencing financial distress; second, the relevance of credit market structure for the price and non-price terms associated with the provision of credit.
The first chapter investigates whether relationship lending helps firms experiencing idiosyncratic financial distress. By constructing a novel dataset on syndicated lending that tracks the availability and pricing of credit for US corporate borrowers over three decades, I conclude that relationship lending benefits borrowers in distress. Specifically, I find that relationship lenders provide a higher credit amount, charge lower interest rates, and require similar collateral and fees, relative to non-relationship lenders. Firms benefit from relationship lending irrespective of their access to outside financing options. Overall, my findings provide support to theories of implicit commitment and reputational capital in lending relationships.
The second chapter focuses on the importance of bank specialization in monitoring specific projects for the design of loan contracts. Using detailed information on credit relationships in the US syndicated loan market, I first document that banks specialize in lending to specific industries. Specialization is common across industries and persistent over time. Then, I provide evidence that specialized banks provide credit with looser restrictions (covenants) and at lower cost (interest rates) when arranging loans in their sector of specialization. This is consistent with an explanation of bank specialization based on monitoring advantages. Overall, the laxer contract terms offered by specialized banks could provide an explanation for recent evidence that firms cannot easily substitute credit granted by specialized banks
The Role Of Clot Structure And Mechanics On Hemodynamics And Pharmacology
Get PDFHemostatic clots have a core/shell hierarchy comprised of a P-selectin positive core surrounded by a P-selectin negative shell. A new human blood microfluidic assay utilizing a 2-stage assay was developed to interrogate core/shell mechanics. By first perfusing whole blood over a collagen/TF surface and then swapping out the blood for buffer, we were able to pause thrombus growth at a specific point in time. The shear rate was then drastically increased to interrogate platelet-platelet interactions. We found that thrombin inhibition, but not fibrin, led to greater erosion of the thrombus, and that the core region of the thrombus was stable with or without the presence of fibrin. Next, we tested the effects of ADP or TxA2 inhibitors on thrombus growth and stability. We found that inhibiting TxA2 production did not affect platelet deposition, but the platelets that did attach to the clot were more likely to erode after being subjected to shear. Both P2Y1 and P2Y12 antagonism led to decreased initial platelet deposition and more platelet erosion. P2Y12 signaling had the most significant effect on deposition and stability suggesting that it might have an amplification effect on other signaling pathways. We demonstrated a new method to examine thrombus strength and stability and showed the effect of thrombin on core size along with the importance of secondary agonists on stability in the shell region. We used an 8-channel microfluidic device to examine the efficacy of ex vivo apixaban on platelet and fibrin deposition in neonates with CHD. This patient population was shown to have significantly more activity blood after surgery. We found that apixaban drastically lowers coagulation activity in neonatal blood before and after surgery and significantly prolongs occlusion time to a greater extent than adults. We also demonstrated that andexanet alfa reverses the inhibitory effect of apixaban in both neonates and adults. These results demonstrated that microfluidics is a useful way to examine pharmacological effects, especially in a population where only small quantities of blood can be drawn
Penn Library\u27s LJS 421 - [Letter from Hippocrates to Caesar]. (Video Orientation)
No full texthttps://repository.upenn.edu/sims_video/1169/thumbnail.jp
Polymer Dynamics in Disordered Nanoparticle Packings: Effect of Confinement, Interfaces, and Humidity
No full textInfiltration of polymers into disordered nanoparticle packings has shown to be a powerful method of fabricating highly loaded nanocomposites with superb mechanical properties. Polymer-infiltrated nanoparticle packings provide a unique platform to study the dynamics of macromolecules under extreme nanoconfinement. The degree of confinement can be tuned by appropriate choice of particle size and polymer molecular weight. The presence of large interfacial area between the polymer and the particle, high degree of nanoconfinement, and environmental triggers like atmospheric humidity can impact the dynamics of polymers at the segmental and the chain level. By using tools like microscopy, ellipsometry and molecular dynamic simulations, we investigate the dynamics of polymers at unprecedented levels of confinement. In solvent-driven infiltration of polymers (SIP) system, polymer chains are plasticized by capillary condensed solvent leading to capillary motion of the solvated polymer into the pores of the nanoparticle packing. We detail our investigations on the mechanism of infiltration with increasing polymer-nanoparticle interactions. In capillary rise infiltration(CaRI), the polymer film-nanoparticle packing bilayer is annealed above the glass transition temperature of the polymer leading to the polymer wicking into the pores of the packing. The dynamics of rise of the polymer into the nanoparticle packing can be studied by ellipsometric front-tracking giving a measure of the chain dynamics of polymer – effective viscosity – based on the Lucas-Washburn equation. Our investigations into the dynamics of high Tg, glassy polymers is complemented by studies of low Tg, mobile chains in disordered nanoparticle packings. Once infiltrated into a region of nanoparticle packings, these mobile chains spread out into adjoining unfilled regions. This room temperature, spontaneous lateral motion of polymer can be tracked to understand interfacial polymer diffusion under confinement. Higher humidity, unexpectedly, leads to faster spreading of the polymers within the packings possibly due to reduced particle-polymer friction with water coverage on particle surface. Thus, this work presents the effects of confinement, interfacial interactions, and atmospheric humidity on the chain and segmental dynamics of polymers in pores of disordered nanoparticle packings
Executable Denotational Semantics with Interaction Trees
No full textInteraction trees are a representation of effectful and reactive systemsdesigned to be implemented in a proof assistant such as Coq.They are equipped with a rich algebra of combinators to construct recursiveand effectful computations and to reason about them equationally.Interaction trees are also an executable structure, notably via extraction,which enables testing and directly developing executable programs in Coq.To demonstrate the usefulness of interaction trees, two applications arepresented. First, I develop a novel approach to verify a compiler from a simpleimperative language to assembly, by proving a semantic preservation theoremwhich is termination-sensitive, using an equational proof. Second, I present aframework of concurrent objects, inheriting the modularity, compositionality,and executability of interaction trees. Leveraging that framework,I formally prove the correctness of a transactionally predicated map, using anovel approach to reason about objects combining the notions of linearizabilityand strict serializability, two well-known correctness conditions forconcurrent objects