cssi/SciSciGPT-SciSciNet huggingface dataset:
Alliance portfolio diversity and firm performance

In this paper, we offer a comprehensive alliance portfolio diversity construct that includes partner, functional, and governance diversity. Grounding our work primarily with the resource- and dynamic capabilities-based views, we argue that increased diversity in partners' industry, organizational, and national background will incur added complexity and coordination costs but will provide broadened resource and learning benefits. Increased functional diversity results in a more balanced portfolio of exploration and exploitation activities that expands the firm's knowledge base while increased governance diversity inhibits learning and routine building. Hypotheses were tested with alliance portfolio and performance data for 138 multinational firms in the global automobile industry during the twenty-year period from 1985 to 2005. We found alliance portfolios with greater organizational and functional diversity and lower governance diversity were related to higher firm performance while industry diversity had a U-shaped relationship with firm performance. We suggest firms manage their alliances with a portfolio perspective, seeking to maximize resource and learning benefits by collaborating with a variety of organizations in various value chain activities while minimizing managerial costs through a focused set of governance structures. Copyright © 2010 John Wiley & Sons, Ltd.
Neural Correlates of Value Are Intrinsically History Dependent

Abstract A central finding in decision neuroscience is that BOLD activity in several regions, including ventral striatum and ventromedial prefrontal cortex, is correlated with the subjective value of the option being considered, and that BOLD activity in these regions can predict choices out of sample, even at the population-level. Here we show, across two different decision making tasks in a large sample of subjects, that these BOLD value-correlates are intrinsically history dependent. If the subjective value of the previous offer was high, the signal on the current trial will be lower, and vice versa. This kind of history dependency is distinct from previously described adaptation or repetition suppression effects, but instead is of the form predicted by theories of efficient coding such as time-dependent cortical normalization. In terms of practical application, since value-based choice behavior does not exhibit the same history dependence, neural prediction studies may exhibit systematic errors without accounting for history effects. The data-driven, interpretable, whole-brain prediction approach we use to identify history effects also illustrates one way to adjust predictions for neural history dependency.
Determinants of Civil Rights Filings in Federal District Court by Jail and Prison Inmates

This article uses panel data estimation techniques to examine the relation between the number of federal court civil filings by inmates and jail and state prison populations (and, hence, the relation between jail and prison inmate filing rates) both before and after the effective date, in 1996, of the Prison Litigation Reform Act (PLRA). The research issue matters for several reasons. First, the amount of litigation by inmates is a crucial component of the regulatory regime governing jails and prisons and thus what factors drive filings, and by how much, deserves close attention and assessment. In addition, the PLRA was a major congressional attempt to control and ration litigation; understanding its effects in finer gauge seems itself worthwhile. Finally, we hope to show, methodologically, how research about litigation rates can be carried out sensitively, even if the litigation results from case filings by two separate populations. We make three major findings. (1) As expected, inmate filings vary positively with prison population. However, the relationship with jail population is less secure. (2) As the prison proportion of inmates in a particular state increases, so too does the number of filings. (3) The PLRA's passage has significantly lessened but not eliminated this prison proportion effect.
Driven from the Tribunal: Judicial Resolution of Internal Church Disputes

Any organization may experience internal dissension. If the dispute continues, one faction may seek a judicial resolution. If the organization is a church, however, concern over the propriety of state intervention may cause a court to refrain from deciding the dispute. If the court decides that the religion clauses of the Constitution call for complete autonomy for the religious organization, it will refuse to hear the dispute, granting the organization immunity from judicial dispute resolution. The price of immunity, however, is denying church members ordinarily available remedies, solely on account of the religious nature of the organization in which the corporation, contract, or trust dispute arose. When a court refuses to adjudicate church disputes, it may sacrifice members' contractual interests and religious freedom. There is thus a tension between autonomy for the church and some of the very values that such autonomy might at first be assumed to further.This article suggests a resolution to this tension. In so doing, the Article assumes that the goal is a religiously neutral adjudication: one that neither advances nor retards a church faction on the basis of its religious views. The alternative of a religiously-based adjudication one which favors a faction on the basis of its religious beliefs-is unlikely to meet constitutional requirements. The only other alternative is to refuse to decide church disputes, an approach that would satisfy the goal of avoiding entanglement at the price of members' rights and church organizing ability. This article shows why a religiously neutral adjudication is normally possible, making it unnecessary to pay the price of abstention.
Security analyst superiority relative to univariate time-series models in forecasting quarterly earnings

Abstract This paper provides evidence of security analyst (SA) superiority relative to univariate time-series (TS) models in predicting firms' quarterly earnings numbers and shows that SA forecast superiority in our sample is attributable to: (1) better utilization of information existing on the date that TS model forecasts can be initiated, a contemporaneous advantage; and (2) use of information acquired between the date of initiation of TS model forecasts and the date when SA forecasts are published, a timing advantage.
The Global Determinants of U.S. Foreign Affairs Law

A recurring debate in foreign affairs law focuses on the appropriate level of congressional and judicial deference to the President. In answering that question, most scholars focus on the Constitution, Supreme Court precedent, and historical practice for guidance, or evaluate the expertise and strategic incentives of Congress, the President, and the courts. For these scholars, the inquiry exclusively centers on domestic, internal constraints on the President. But this analysis is incomplete. Determination of the appropriate level of deference has consequences for how the President can pursue U.S. interests abroad. If the United States wants to be successful in achieving its foreign policy goals, it requires some consideration of the external world in which the President acts. This Article challenges the conventional wisdom by arguing that the appropriate level of constraint on the President requires an evaluation of both internal constraints from domestic sources and external constraints from international politics. It provides a framework to integrate both sets of constraints, develops a theory of external constraints, and describes the normative implications of this approach for foreign affairs law. The Article argues that the failure to account for both internal and external constraints and to recognize their relationship might yield a deference regime that either does not provide the President with sufficient freedom to pursue U.S. interests (over-constrained), or leaves the President free to act without sufficient congressional and judicial oversight (under-constrained). It further explains the conditions under which higher and lower levels of constraints are preferable and moves us closer to determining the appropriate level of deference to the President in foreign affairs.
Should the Mortgage Follow the Note

SHOULD THE MORTGAGE FOLLOW THE NOTE? John Patrick Hunt 1 Abstract The law of mortgage assignment has taken center stage amidst foreclosure crisis, robosigning scandal, and controversy over the Mortgage Electronic Registration System. Yet a concept crucially important to mortgage assignment law, the idea that “the mortgage follows the note,” apparently has never been subjected to a critical analysis in a law review. This Article makes two claims about that proposition, one positive and one normative. The positive claim is that it has been much less clear than typically assumed that the mortgage follows the note, in the sense that note transfer formalities trump mortgage transfer formalities. “The mortgage follows the note” is often described as a well-established principle of law, when in fact considerable doubt has attended the proposition at least since the middle of the last century. The normative claim is that it is not clear that the mortgage should follow the note. The Article draws on the theoretical literature of filing and recording to show that there is a case that mortgage assignments should be subject to a filing rule and that “the mortgage follows the note,” to the extent it implies that transferee interests should be protected without filing, should be abandoned. Whether mortgage recording should in fact be abandoned in favor of the principle “the mortgage follows the note” turns on the resolution of a number of empirical questions. This Article identifies key empirical questions that emerge from its application of principles from the theoretical literature on filing and recording to the specific case of mortgages. 1 Assistant Professor of Law, University of California, Davis School of Law (King Hall), jphunt@ucdavis.edu. A.B. Harvard College, J.D. Yale Law School, M.F.E. (Master’s in Financial Engineering) University of California, Berkeley Haas School of Business. The author thanks Jack Ayer, Andrea Bjorklund, Anupam Chander, Wendy Gerwick Couture, Diane Lourdes Dick, Joel Dobris, Katherine Florey, David Friedman, Robert W. Hillman, Mohsen Manesh, Elizabeth Pollman, and Kevin Tu for helpful comments, and Tammy Weng and Ted Tao for excellent research assistance. Thanks to King Hall Dean Kevin Johnson and Associate Dean for Academic Affairs Vikram Amar for financial support of this work. All opinions and errors are the author’s own.
Minimally acceptable altruism and the ultimatum game

Abstract I suppose that people react with anger when others show themselves not to be minimally altruistic. With heterogeneous agents, this can account for the experimental results of ultimatum and dictator games. Moreover, it can account for the surprisingly large fraction of individuals who offer an even split with parameter values that are more plausible than those that are required to explain outcomes in these experiments with the models of Levine [Levine, D.K., 1998. Modeling altruism and spitefulness in experiments. Review of Economic Dynamics 1, 593–622], Fehr and Schmidt [Fehr, E., Schmidt, K.M., 1999. A theory of fairness, competition and cooperation. Quarterly Journal of Economics 114, 817–868], Dickinson [Dickinson, D.L., 2000. Ultimatum decision making: a test of reciprocal kindness. Theory and Decision 48, 151–177] and Bolton and Ockenfels [Bolton, G.E., Ockenfels, A., 2000. ERC: a theory of equity, reciprocity, and competition. American Economic Review 90, 166–193].
The minimum variability time-scale and its relation to pulse profiles of Fermi GRBs

We present a direct link between the minimum variability time-scales extracted through a wavelet decomposition and the rise times of the shortest pulses extracted via fits of 34 Fermi Gamma-ray Burst Monitor (GBM) Gamma-Ray Burst (GRB) light curves comprised of 379 pulses. Pulses used in this study were fitted with lognormal functions, whereas the wavelet technique used employs a multiresolution analysis that does not rely on identifying distinct pulses. By applying a corrective filter to published data fitted with pulses, we demonstrate agreement between these two independent techniques and offer a method for distinguishing signal from noise.
The Life Cycle of Hedge Funds: Fund Flows, Size, Competition, and Performance

This paper analyzes the life cycles of hedge funds. Using the Lipper TASS database it provides category and fund specific factors that affect the survival probability of hedge funds. The findings show that in general, investors chasing individual fund performance, thus increasing fund flows, decrease probabilities of hedge funds liquidating. However, if investors chase a category of hedge funds that has performed well (favorably positioned), then the probability of hedge funds liquidating in this category increases. We interpret this finding as a result of competition among hedge funds in a category. As competition increases, marginal funds are more likely to be liquidated than funds that deliver superior risk-adjusted returns. We also find that there is a concave relationship between performance and lagged assets under management. The implication of this study is that an optimal asset size can be obtained by balancing out the effects of past returns, fund flows, competition, market impact, and favorable category positioning that are modeled in the paper. Hedge funds in capacity constrained and illiquid categories are subject to high market impact, have limited investment opportunities, and are likely to exhibit an optimal size behavior.
Bolsa or NYSE: price discovery for Mexican shares

Abstract Is price discovery and the calibration of news through American (A) or global (G) depositary receipts (DR) or depositary shares (DS), traded in central markets, superseding local discovery in peripheral markets? This question remains very much open as the evidence we present on the durability of price innovations in two major Mexican stocks provides little support for the view that the demise of local markets is inevitable. Rather it appears that such markets may have some advantage in information efficiency that may compensate for their extra costs.
Dyads, triads, and the theory of exchange: Between liberty and coercion

Economists commonly use the Edgeworth box to illustrate the ability of exchange to generate gains from trade. In contrast to this framework of dyadic exchange, we explore triadic forms of exchange where margins of coercion are also present. In the presence of triadic exchange, market transactions are no longer wholly voluntary and instead reflect an admixture of liberty and coercion. We illustrate triadic exchange in the context of credit markets, showing how continual turbulence is a sign of neither market failure nor government failure but is rather a systemic quality of triadic exchange as a system of societal governance.
Bond yields in emerging economies: It matters what state you are in ☆

Abstract While many studies have looked into the determinants of yields on externally issued sovereign bonds of emerging economies, analysis of domestically issued bonds has hitherto been limited, despite their growing relevance. This paper finds that the extent to which fiscal variables affect domestic bond yields in emerging economies depends on the level of global risk aversion. During tranquil times in global markets, fiscal variables do not seem to be a significant determinant of domestic bond yields in emerging economies. However, when market participants are on edge, they pay more attention to country-specific fiscal fundamentals, revealing greater alertness about default risk.
State Immunity Waivers for Suits by the United States

INTRODUCTION 93 I. THE BACKGROUND PRINCIPLE OF STATE SOVEREIGN IMMUNITY 96 II. QUI TAM ACTIONS UNDER THE FALSE CLAIMS ACT 98 III. THE WAIVER IN THE CONSTITUTIONAL PLAN FOR SUITS BY THE U NITED STATES 101
Management of Financial Information in Charitable Organizations: The Case of Joint‐Cost Allocations

Charities that use direct mailings or other activities that combine a public education effort with fundraising appeals must allocate the joint costs related to these activities to programs, fundraising, and administration. This study investigates whether charities use joint‐cost allocations to manage the program ratio—a widely used measure of spending efficiency. Using a hand‐collected dataset of 708 organization‐year observations from 1992 to 2000, we find evidence that charities use joint costs to mitigate changes in the program ratio.
Clinical Legal Education in China: In Pursuit of a Culture of Law and a Mission of Social Justice

Seeking to play a greater role in an evolving world order, China faces pressure to conform to international legal norms and the rule of law. Strengthening the legal culture in China includes exploring new ways to train Chinese law students. Against this background of cultural and pedagogical change, clinical legal education has begun to take root in Chinese law schools. This Note from the Field explores the potential for clinical legal education to motivate students and scholars in China to push the boundaries of law, making it a tool of social justice for the average Chinese citizen. Drawing on her experiences as a clinical instructor in Chinese law schools, Pamela Phan argues that the American model of clinical legal education and its social justice tradition can play a significant role in the development of Chinese legal education, in turn strengthening legal culture and reform in China.
Do Migrants Improve Their Hometowns? Remittances and Access to Public Services in Mexico, 1995-2000

How do citizens in developing countries access public services? Scholars study this question by emphasizing the role of government, measuring government performance as household access to public services, such as clean water and sanitation. However, the authors argue that the state does not hold a monopoly on provision of such utilities: Citizens in developing countries often turn to nonstate providers for basic utilities. In Mexico, the authors find that direct money transfers from migrants, known as remittances, are used to provide household access to public services. The statistical analysis across Mexico’s 2,438 municipalities demonstrates that citizens improve their own access. The results also contribute new evidence to the literature on remittances and development by offering a micro-level explanation for how remittances affect both the availability and the source of basic utilities. The findings suggest that the measures scholars typically associate with government performance may in fact capture ...
Profit maximization with bankruptcy and variable scale

Abstract In a diffusion model of an enterprise with variable scale, conditions are given for the maximization of ‘profit’ (expected total discounted withdrawals) to lead to bankruptcy almost surely. The optimal withdrawal policy is an ‘overflow policy’: the withdrawal rate is zero if the asset level is below a ‘barrier’, and equal to the maximum rate if the asset level is at least equal to the barrier. The optimal policy for the control of the drift (yield) and volatility (risk) of the earnings is the solution of an explicit differential equation, and a formula is given for the corresponding value function.
The Future of Securitization

Securitization, a process in which firms can raise low-cost financing by efficiently allocating asset risks with investor appetite for risk, has been one of the most dominant and fastest-growing means of capital formation in the United States and the world. The subprime financial crisis, however, has revealed certain defects with how securitization is sometimes utilized. This Article examines these defects and the extent they can, and should, be remedied going forward.
Bond tender offers in mergers and acquisitions

Abstract We explore the motives and consequences of bond tender offers announced in connection with mergers and acquisitions (M&A). We find merging firms use bond tender offers strategically to renegotiate with bondholders to gain financial flexibility by reducing leverage and eliminating covenants, and to curtail the coinsurance benefits associated with M&A. Moreover, we find bondholder wealth effects depend not only on the bond's own characteristics, but also on the characteristics of its sibling bonds. Finally, the use of bond tender offers in M&A is associated with increased likelihood of deal consummation and lower acquisition premiums.
Work ethic in formerly socialist economies

Abstract Do younger workers in transition economies have a different work ethic from those who were trained and employed in the former socialist economy? Is there a positive link between work ethic and earnings among workers in transition economies? We address these questions using data collected from employee surveys conducted in Armenia, Azerbaijan, Kazakhstan, Kyrgyzstan, Russia, and Serbia. Employing a composite measure, we find that younger workers tend to adhere more strongly, and older workers less strongly. This result is obtained in the majority of cases for the individual work ethic components, as well. We also find work ethic adherence is stronger among men than women, among supervisors, and among participants who exhibit an internal locus of control. The link between work ethic and earnings is positive: participants who scored highest on the work ethic measure earn 15% more than those who scored lowest. Commonalities across these six culturally and economically diverse countries provide a foundation for developing a more global perspective of work ethic and worker performance.
Filmmaking in the Precinct House and the Genre of Documentary Film

This Article explores side-by-side two contemporary and related film trends: the recent, popular enthusiasm for the previously arty, documentary film and the mandatory filming of custodial interrogations and confessions. The history and criticism of documentary film shows, and contemporary movie audiences understand, the documentary film as a tool of political and social advocacy, in which a story is told using the medium of film to convey a specific, usually not unbiased message (recent examples are Michael Moore’s Fahrenheit 9/11 and Errol Morris’s Fog of War). By contrast, judges, advocates and legislatures, assume that films of custodial interrogations and confessions, which also serve a “documentary” purpose, reveal truth and lack a distorting point of view. As this Article will explain, the trend at law, although aimed at furthering venerable criminal justice principles, holds a fairly naive view of film’s indexical relationship to the lived world and typically ignores consideration of the contemporary trend in cinema. Understanding the documentary as truth-revealing is a mistake, a mistake which can frustrate (if not undermine) the criminal justice goals of the legislative policies. Understanding the impulse to film custodial interrogations as an impulse born through documentary filmmaking transforms our understanding of the object of the film exercise from revealing a truth (of guilt or lack of coercion) into reconstituting (an image of) the world into one favored by the filmmaker. Whatever may explain the convergence of filmmaking in the precinct house and a penchant for mainstream documentary movie-going, the trends are shaping contemporary expectations about film in contradictory ways. Investigating these
Strategic Customer Behavior, Commitment, and Supply Chain Performance

This paper studies the impact of strategic customer behavior on supply chain performance. We start with a newsvendor seller facing forward-looking customers. The seller initially charges a regular price but may salvage the leftover inventory at a lower salvage price after random demand is realized. Customers anticipate future sales and choose purchase timing to maximize their expected surplus. We characterize the rational expectations equilibrium, where we find that the seller's stocking level is lower than that in the classic model without strategic customers. We show that the seller's profit can be improved by promising either that quantities available will be limited (quantity commitment) or that prices will be kept high (price commitment). In most cases, both forms of commitment are not credible in a centralized supply chain with a single seller. However, decentralized supply chains can use contractual arrangements as indirect commitment devices to attain the desired outcomes with commitment. Decentra...
Law, Economics, and the Skeleton of Value Fallacy

Experiments in the last decade or so have demonstrated persistent failures on the part of ordinary individuals rationally to pursue self-interest. The experiments pose serious challenges to economics, rational choice theory, and the law and economics school. Some experiments, for example, suggest an "endowment effect", that contradicts the Coase Theorem; the notion that, in the absence of transaction costs, goods will find their most efficient distribution regardless of their initial assignment. Cass Sunstein has collected a set of essays by economists and legal scholars exploring these challenges, in a volume entitled Behavioral Law and Economics. This review essay argues that the contributors to the volume have not worked out the full implications of these experiments, and that to do so gives one good reasons not to do economics or the economic analysis of law at all. The experiments indicate that value is context dependent. If value is context dependent, then it is also intransitive. But the transitivity of value is an essential assumption of economic analysis. Economists recognize, of course, that their method is reductive, and that it does not reflect human valuation and choice in all its actual richness. But economists and legal economists do suppose that they have captured at least the essentials of sound practical reasoning, so that their policy prescriptions are reliable. This assumption is unsustainable. I refer to this defect as the skeleton of value fallacy, and describe how it infects several of the essays collected in this volume.
The Political Fourth Amendment

The Political Fourth Amendment builds on Justice Ginsburg’s recent dissent in Herring v. United States to argue for a “more majestic conception” of the Fourth Amendment focused on protecting political liberty. To put the point dramatically, we misread the Fourth Amendment when we read it exclusively as a criminal procedure provision focused entirely on either regulating police or protecting privacy. In order to see the Fourth Amendment as contributing to the Constitution’s protections for political liberty, and not simply as an invitation to regulate police practice, we must take seriously the fact that the Fourth Amendment’s textual purpose is to secure a “right of the people,” which places it textually alongside the First, Second, and Ninth Amendments that similarly seek to protect the “right[s] of the people.” Narratives focused on regulating police or protecting privacy each risk blinding us to the Fourth Amendment’s broader constitutional setting. By looking at the historical origins of the Fourth Amendment in relation to substantive First Amendment concerns, and examining the textual significance of protecting a “right of the people,” this Article argues that the two dominant narratives overlook a central political purpose of the Fourth Amendment. The political Fourth Amendment seeks to protect the political liberties of  Associate Professor of Law, University of South Carolina School of Law, and Visiting Scholar, American Academy of Arts & Sciences. J.D. Yale Law School; Ph.D. Vanderbilt University. I would like to thank Tara Grove, Coleman Hutchison, Orin Kerr, Dan Markel, Helen Norton, Wadie Said, Daniel Solove, and Stephanie Stern for their generous feedback and insight. I also benefited greatly from presentation of this project to the faculty at Florida State University. I owe thanks to Chris Kenney and William McKinney for excellent research assistance. 304 WASHINGTON UNIVERSITY LAW REVIEW [VOL. 88:303 the sovereign “People.” Focused exclusively on protecting privacy by regulating police practice, current Fourth Amendment doctrine offers no protection to anything a person knowingly exposes to others, a hazard in an era of electronic social networking. Reading the Fourth Amendment back into the Constitution makes available new grounds for the Constitution’s relevance in an age of pervasive electronic surveillance.
To Drink the Cup of Fury: Funeral Picketing, Public Discourse and the First Amendment

In Snyder v. Phelps, the Supreme Court ruled that the Westboro Baptist Church had a First Amendment right to picket the funeral of a young soldier killed in Iraq. This decision reinforces a view that has become increasingly dominant in First Amendment jurisprudence — the view that the state may not regulate public discourse to protect individuals from emotional or dignitary injury. This Article contends that this view not only sacrifices the law’s protections for individual personality but also undermines the normative foundations of public discourse itself. The Article then presents an alternative theory of the First Amendment which holds that the same values of human dignity and autonomy that support free speech also give rise to other fundamental rights. Thus, speakers should have a duty to respect the personality and rights of others. Drawing extensively on the record in Snyder as well as on other materials, the Article argues that Westboro’s funeral picketing should not receive First Amendment protection, for the picketing is intended to condemn the deceased and to inflict severe distress on the mourners in violation of their rights to privacy, dignity, emotional well-being, and religious liberty. Finally, the Article shows that although Westboro prevailed in Snyder, this may prove to be a Pyrrhic victory, for the Court also suggested that states can protect mourners through carefully drawn buffer-zone laws.
International Cross-Listing and Visibility

This study shows that international firms listing their shares on the New York Stock Exchange (NYSE) or the London Stock Exchange (LSE) experience a significant increase in visibility, as proxied by analyst coverage and print media attention (The Wall Street Journal or Financial Times). The increase in analyst following is also associated with a decrease in the cost of equity capital after the listing event in a way consistent with Merton's (1987) investor recognition hypothesis. Our results are stronger for NYSE listing firms than for LSE listing firms. This may partially compensate firms for the higher costs associated with NYSE listing (compared to LSE listing).
SODA: Multi-locus species delimitation using quartet frequencies.

MOTIVATION Species delimitation, the process of deciding how to group a set of organisms into units called species, is one of the most challenging problems in evolutionary computational biology. While many methods exist for species delimitation, most based on the coalescent theory, few are scalable to very large datasets, and methods that scale tend to be not accurate. Species delimitation is closely related to species tree inference from discordant gene trees, a problem that has enjoyed rapid advances in recent years. RESULTS In this paper, we build on the accuracy and scalability of recent quartet-based methods for species tree estimation and propose a new method called SODA for species delimitation. SODA relies heavily on a recently developed method for testing zero branch length in species trees. In extensive simulations, we show that SODA can easily scale to very large datasets while maintaining high accuracy. AVAILABILITY The code and data presented here are available on https://github.com/maryamrabiee/SODA. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Space-Charge Aberrations in Single-Shot Time-Resolved Transmission Electron Microscopy

In this paper, we discuss effects of space-charge fields on imaging performance in a single-shot time-resolved transmission electron microscope. Using a Green's function perturbation method, we derive analytical estimates for the effects of space-charge nonlinearity on the image formation process and the associated aberration coefficients. The dependence of these coefficients on the initial beam phase space distribution is elucidated. The results are validated by particle tracking simulations and provide fundamental scaling laws for the trade-off between temporal and spatial resolutions in single-shot time-resolved transmission electron microscopy.
Quantum State Complexity in Computationally Tractable Quantum Circuits

Using an approach based on the synergy between the techniques of quantum information and many-body physics, a study of quantum circuits indicates that the quality of being classically simulated can coexist with having high complexity.
Profiting from connections: Do politicians receive stock tips from brokerage houses?

Abstract This study investigates whether brokerage houses appear to provide stock tips to politicians. Our results indicate that trades by politicians who are politically connected to the brokerage house where the trade is executed are more profitable. Our estimates suggest that these connected trades earn an incremental 0.3% over a five-day window relative to the politician's average profitability. Given the average number of trades our sample politicians execute in a year, the 0.3% return per trade translates to an incremental $3,411 in trading profits each year. We provide additional support by investigating the frequency and differential profitability of politicians' trades immediately before the brokerage house issues a revised recommendation, as well as during a period when Goldman, Sachs & Co. was sanctioned for providing stock tips to high priority clients. Additional tests suggest that brokerages may provide stock tips to politicians in exchange for favorable legislative outcomes or political information.
Learning to predict with supporting evidence: applications to clinical risk prediction

The impact of machine learning models on healthcare will depend on the degree of trust that healthcare professionals place in the predictions made by these models. In this paper, we present a method to provide individuals with clinical expertise with domain-relevant evidence about why a prediction should be trusted. We first design a probabilistic model that relates meaningful latent concepts to prediction targets and observed data. Inference of latent variables in this model corresponds to both making a prediction and providing supporting evidence for that prediction. We present a two-step process to efficiently approximate inference: (i) estimating model parameters using variational learning, and (ii) approximating maximum a posteriori estimation of latent variables in the model using a neural network, trained with an objective derived from the probabilistic model. We demonstrate the method on the task of predicting mortality risk for patients with cardiovascular disease. Specifically, using electrocardiogram and tabular data as input, we show that our approach provides appropriate domain-relevant supporting evidence for accurate predictions.
Attention reinforces human corticofugal system to aid speech perception in noise

Abstract Perceiving speech-in-noise (SIN) demands precise neural coding between brainstem and cortical levels of the hearing system. Attentional processes can then select and prioritize task-relevant cues over competing background noise for successful speech perception. In animal models, brainstem-cortical interplay is achieved via descending corticofugal projections from cortex that shape midbrain responses to behaviorally-relevant sounds. Attentional engagement of corticofugal feedback may assist SIN understanding but has never been confirmed and remains highly controversial in humans. To resolve these issues, we recorded source-level, anatomically constrained brainstem frequency-following responses (FFRs) and cortical event-related potentials (ERPs) to speech via high-density EEG while listeners performed rapid SIN identification tasks. We varied attention with active vs. passive listening scenarios whereas task difficulty was manipulated with additive noise interference. Active listening (but not arousal-control tasks) exaggerated both ERPs and FFRs, confirming attentional gain extends to lower subcortical levels of speech processing. We used functional connectivity to measure the directed strength of coupling between levels and characterize “bottom-up” vs. “top-down” (corticofugal) signaling within the auditory brainstem-cortical pathway. While attention strengthened connectivity bidirectionally, corticofugal transmission disengaged under passive (but not active) SIN listening. Our findings (i) show attention enhances the brain's transcription of speech even prior to cortex and (ii) establish a direct role of the human corticofugal feedback system as an aid to cocktail party speech perception.
Stay on Topic, Please: Aligning User Comments to the Content of a News Article.

Social scientists have shown that up to \(50\%\) of the comments posted to a news article have no relation to its journalistic content. In this study we propose a classification algorithm to categorize user comments posted to a news article based on their alignment to its content. The alignment seeks to match user comments to an article based on similarity of content, entities in discussion, and topics. We propose a BERTAC, BERT-based approach that learns jointly article-comment embeddings and infers the relevance class of comments. We introduce an ordinal classification loss that penalizes the difference between the predicted and true labels. We conduct a thorough study to show influence of the proposed loss on the learning process. The results on five representative news outlets show that our approach can learn the comment class with up to \(36\%\) average accuracy improvement comparing to the baselines, and up to \(25\%\) comparing to the BA-BC. BA-BC is our approach that consists of two models aimed to capture dis-jointly the formal language of news articles and the informal language of comments. We also conduct a user study to evaluate human labeling performance to understand the difficulty of the classification task. The user agreement on comment-article alignment is “moderate” per Krippendorff’s alpha score, which suggests that the classification task is difficult.
COVID-19 economic impacts in perspective: A comparison to recent U.S. disasters

Abstract This paper places the COVID-19 pandemic into perspective by comparing it to other recent disasters in terms of impacts on the macroeconomy of the U.S. We present a short summary of advances in the state-of-the-art of economic consequence analysis, as well as estimates this approach yields on economic impacts of 9/11, a variety of natural disasters, the Great Recession, and COVID-19. The prevention of these negative impacts represents the benefits of various types of risk management tactics and strategies. In light of the enormously greater economic impact of COVID-19 as compared to natural and man-made disasters, it is reasonable to question whether adequate investments are being made to prevent future pandemics.
The Torelli map restricted to the hyperelliptic locus

Let $g \geq 2$ and let the Torelli map denote the map sending a genus $g$ curve to its principally polarized Jacobian. We show that the restriction of the Torelli map to the hyperelliptic locus is an immersion in characteristic not $2$. In characteristic $2$, we show the Torelli map restricted to the hyperelliptic locus fails to be an immersion because it is generically inseparable; moreover, the induced map on tangent spaces has kernel of dimension $g-2$ at every point.
A Multi-Agent Off-Policy Actor-Critic Algorithm for Distributed Reinforcement Learning

Abstract This paper extends off-policy reinforcement learning to the multi-agent case in which a set of networked agents communicating with their neighbors according to a time-varying graph collaboratively evaluates and improves a target policy while following a distinct behavior policy. To this end, the paper develops a multi-agent version of emphatic temporal difference learning for off-policy policy evaluation, and proves convergence under linear function approximation. The paper then leverages this result, in conjunction with a novel multi-agent off-policy policy gradient theorem and recent work in both multi-agent on-policy and single-agent off-policy actor-critic methods, to develop and give convergence guarantees for a new multi-agent off-policy actor-critic algorithm. An empirical validation of these theoretical results is given.
Contextual Blocking Bandits

We study a novel variant of the multi-armed bandit problem, where at each time step, the player observes an independently sampled context that determines the arms' mean rewards. However, playing an arm blocks it (across all contexts) for a fixed and known number of future time steps. The above contextual setting, which captures important scenarios such as recommendation systems or ad placement with diverse users, invalidates greedy solution techniques that are effective for its non-contextual counterpart (Basu et al., NeurIPS19). Assuming knowledge of the context distribution and the mean reward of each arm-context pair, we cast the problem as an online bipartite matching problem, where the right-vertices (contexts) arrive stochastically and the left-vertices (arms) are blocked for a finite number of rounds each time they are matched. This problem has been recently studied in the full-information case, where competitive ratio bounds have been derived. We focus on the bandit setting, where the reward distributions are initially unknown; we propose a UCB-based variant of the full-information algorithm that guarantees a $\mathcal{O}(\log T)$-regret w.r.t. an $\alpha$-optimal strategy in $T$ time steps, matching the $\Omega(\log(T))$ regret lower bound in this setting. Due to the time correlations caused by blocking, existing techniques for upper bounding regret fail. For proving our regret bounds, we introduce the novel concepts of delayed exploitation and opportunistic subsampling and combine them with ideas from combinatorial bandits and non-stationary Markov chains coupling.
Which group algebras cannot be made zero by imposing a single non-monomial relation?

For which groups G is it true that for all fields k, every non-monomial element of the group algebra k G generates a proper 2-sided ideal? The only groups for which we know this to be true are the ...
Temporal patterns of synchrony in a pyramidal-interneuron gamma (PING) network

Synchronization in neural systems plays an important role in many brain functions. Synchronization in the gamma frequency band (30–100 Hz) is involved in a variety of cognitive phenomena; abnormalities of the gamma synchronization are found in schizophrenia and autism spectrum disorder. Frequently, the strength of synchronization is not high, and synchronization is intermittent even on short time scales (few cycles of oscillations). That is, the network exhibits intervals of synchronization followed by intervals of desynchronization. Neural circuit dynamics may show different distributions of desynchronization durations even if the synchronization strength is fixed. We use a conductance-based neural network exhibiting pyramidal-interneuron gamma rhythm to study the temporal patterning of synchronized neural oscillations. We found that changes in the synaptic strength (as well as changes in the membrane kinetics) can alter the temporal patterning of synchrony. Moreover, we found that the changes in the temporal pattern of synchrony may be independent of the changes in the average synchrony strength. Even though the temporal patterning may vary, there is a tendency for dynamics with short (although potentially numerous) desynchronizations, similar to what was observed in experimental studies of neural synchronization in the brain. Recent studies suggested that the short desynchronizations dynamics may facilitate the formation and the breakup of transient neural assemblies. Thus, the results of this study suggest that changes of synaptic strength may alter the temporal patterning of the gamma synchronization as to make the neural networks more efficient in the formation of neural assemblies and the facilitation of cognitive phenomena.
Speed-related but not detrended gait variability increases with more sensitive self-paced treadmill controllers at multiple slopes

Self-paced treadmills are being used more frequently to study humans walking with their self-selected gaits on a range of slopes. There are multiple options to purchase a treadmill with a built-in controller, or implement a custom written self-paced controller, which raises questions about how self-paced controller affect treadmill speed and gait biomechanics on multiple slopes. This study investigated how different self-paced treadmill controller sensitivities affected gait parameters and variability on decline, level, and incline slopes. We hypothesized that increasing self-paced controller sensitivity would increase gait variability on each slope. We also hypothesized that detrended variability could help mitigate differences in variability that arise from differences in speed fluctuations created by the self-paced controllers. Ten young adults walked on a self-paced treadmill using three controller sensitivities (low, medium, and high) and fixed speeds at three slopes (decline, -10°; level, 0°; incline, +10°). Within each slope, average walking speeds and spatiotemporal gait parameters were similar regardless of self-paced controller sensitivity. With higher controller sensitivities on each slope, speed fluctuations, speed variance, and step length variance increased whereas step frequency variance and step width variance were unaffected. Detrended variance was not affected by controller sensitivity suggesting that detrending variability helps mitigate differences associated with treadmill speed fluctuations. Speed-trend step length variances, however, increased with more sensitive controllers. Further, detrended step length variances were similar for self-paced and fixed speed walking, whereas self-paced walking included substantial speed-trend step length variance not present in fixed speed walking. In addition, regardless of the self-paced controller, subjects walked fastest on the level slope with the longest steps, narrowest steps, and least variance. Overall, our findings suggest that separating gait variability into speed-trend and detrended variability could be beneficial for interpreting gait variability among multiple self-paced treadmill studies and when comparing self-paced walking with fixed speed walking.
Efficient, Positive, and Energy Stable Schemes for Multi-D Poisson–Nernst–Planck Systems

In this paper, we design, analyze, and numerically validate positive and energy-dissipating schemes for solving the time-dependent multi-dimensional system of Poisson–Nernst–Planck equations, which has found much use in the modeling of biological membrane channels and semiconductor devices. The semi-implicit time discretization based on a reformulation of the system gives a well-posed elliptic system, which is shown to preserve solution positivity for arbitrary time steps. The first order (in time) fully-discrete scheme is shown to preserve solution positivity and mass conservation unconditionally, and energy dissipation with only a mild O(1) time step restriction. The scheme is also shown to preserve the steady-states. For the fully second order (in both time and space) scheme with large time steps, solution positivity is restored by a local scaling limiter, which is shown to maintain the spatial accuracy. These schemes are easy to implement. Several three-dimensional numerical examples verify our theoretical findings and demonstrate the accuracy, efficiency, and robustness of the proposed schemes, as well as the fast approach to steady-states.