cssi/SciSciGPT-SciSciNet huggingface dataset:
Behavior based learning in identifying High Frequency Trading strategies

Electronic markets have emerged as popular venues for the trading of a wide variety of financial assets, and computer based algorithmic trading has also asserted itself as a dominant force in financial markets across the world. Identifying and understanding the impact of algorithmic trading on financial markets has become a critical issue for market operators and regulators. We propose to characterize traders' behavior in terms of the reward functions most likely to have given rise to the observed trading actions. Our approach is to model trading decisions as a Markov Decision Process (MDP), and use observations of an optimal decision policy to find the reward function. This is known as Inverse Reinforcement Learning (IRL), and a variety of approaches for this problem are known. Our IRL-based approach to characterizing trader behavior strikes a balance between two desirable features in that it captures key empirical properties of order book dynamics and yet remains computationally tractable. Using an IRL algorithm based on linear programming, we are able to achieve more than 90% classification accuracy in distinguishing High Frequency Trading from other trading strategies in experiments on a simulated E-Mini S&P 500 futures market. The results of these empirical tests suggest that High Frequency Trading strategies can be accurately identified and profiled based on observations of individual trading actions.
Default Risk in Equity Returns

This is the first study that uses Merton’s (1974) option pricing model to compute default measures for individual firms and assess the effect of default risk on equity returns. The size effect is a default effect, and this is also largely true for the bookto-market (BM) effect. Both exist only in segments of the market with high default risk. Default risk is systematic risk. The Fama‐French (FF) factors SMB and HML contain some default-related information, but this is not the main reason that the FF model can explain the cross section of equity returns. A FIRM DEFAULTS WHEN IT FAILS to service its debt obligations. Therefore, default risk induces lenders to require from borrowers a spread over the risk-free rate of interest. This spread is an increasing function of the probability of default of the individual firm. Although considerable research effort has been put toward modeling default risk for the purpose of valuing corporate debt and derivative products written on it, little attention has been paid to the effects of default risk on equity returns. 1 The effect that default risk may have on equity returns is not obvious, since equity holders are the residual claimants on a firm’s cash flows and there is no promised nominal return in equities. Previous studies that examine the effect of default risk on equities focus on the ability of the default spread to explain or predict returns. The default spread is usually defined as the yield or return differential between long-term
Law and emotion: a proposed taxonomy of an emerging field.

Scholars from diverse fields have begun to study the intersection of emotion and law. The notion that reason and emotion are cleanly separable—and that law rightly privileges and admits only of the former—is deeply engrained. Law and emotion scholarship proceeds instead from the belief that the legal relevance of emotion is both significant and deserving of (and amenable to) close scrutiny. It is organized around six approaches, each of which is defined and discussed: emotion-centered, emotional phenomenon, emotion theory, legal doctrine, theory of law; and legal actor.
Single-Choice, Repeated-Choice, and Best-Worst Scaling Elicitation Formats: Do Results Differ and by How Much?

This paper presents what we believe to be the most comprehensive suite of comparison criteria regarding multinomial discrete-choice experiment elicitation formats to date. We administer a choice experiment focused on ecosystem-service valuation to three independent samples: single-choice, repeated-choice, and best-worst scaling elicitation. We test whether results differ by parameter estimates, scale factors, preference heterogeneity, status-quo effects, attribute non-attendance, and magnitude and precision of welfare measures. Overall, we find limited evidence of differences in attribute parameter estimates, scale factors, and attribute increment values across elicitation treatments. However, we find significant differences in status-quo effects across elicitation treatments, with repeated-choice resulting in greater proportions of “action” votes, and consequently, higher program-level welfare estimates. Also, we find that single-choice yields drastically less-precise welfare estimates. Finally, we find some differences in attribute non-attendance behavior across elicitation formats, although there appears to be little consistency in class shares even within a given elicitation treatment.
Good Cop, Bad Cop: Using Civilian Allegations to Predict Police Misconduct

Preventing police officer misconduct, while giving police officers the incentives and flexibility to fight crime, is a notoriously difficult challenge. We explore whether civilian complaints can help identify and reduce police officer misconduct. Using data on over 50,000 civilian allegations against police officers in Chicago over a 13-year period, we find that civilian allegations are strongly associated with (1) non-civilian allegations of misconduct, such as allegations from supervisors, and (2) the likelihood of and outcomes in civil rights litigation. We conclude that civilian allegations contain a strong signal of police officer misconduct. In particular, lawsuits against police officers are external and quantifiable measures of officer misconduct and typically arise from serious incidents. We further find that, if an administrative body sustains an allegation against an officer, that officer’s civilian allegation rate decreases and the probability that he or she exits the force increases. We conclude that civilian allegations against police officers in Chicago can be better utilized to prevent misconduct.
Why do Criminals Obey the Law? The Influence of Legitimacy and Social Networks on Active Gun Offenders

Research on procedural justice and legitimacy suggests that compliance with the law is best secured not by mere threat of force, but by fostering beliefs in the fairness of the legal systems and in the legitimacy of legal actors. To date, however, this research has been based on general population surveys and more banal types of law violating behavior (such as unpaid parking tickets, excessive noise, etc.). Thus, while we know why the average citizen obeys the law, we do not have similar knowledge as it pertains to the population most likely to commit serious violent crimes. This study fills this void by using a unique survey of active offenders called the Chicago Gun Project (CGP). The CGP was designed to understand how the perceptions of the law and social networks of offenders influence their understanding of the law and subsequent law violating behavior. The findings suggest that while criminals as a whole have negative opinions of the law and legal authority, the sample of offenders are more likely to comply with the law when they believe in (a) the substance of the law, and (b) the legitimacy of legal actors, especially the police. Moreover, we find that opinions of compliance to the law are not uniformly distributed across the sample population. In other words, not all criminals are alike in their opinions of the law. Gang members but especially gang members with social networks saturated with criminal associates are significantly less likely to view the law and its agents as a legitimate form of authority. However, those individuals (including gang member) with less saturated criminal networks actually tend to have more positive opinions of the law.
Economic Openness and Great Power Competition: Lessons for China and the United States

The U.S.-China relationship is more likely than not to slide into economic and military competition, despite the perhaps best intentions of both states. This new bipolar competition is not inevitable. The key question is whether both governments have the self-restraint to limit domestic rent-seeking interests who will undoubtedly demand protection at home and exclusivity in their spheres of influence abroad. If not, the new superpowers will, like great powers in the past, “race” for economic privileges that can quickly divide the world up into exclusive blocs. Like the security dilemma, great powers need not actually exclude one another from their economic zones; the fear of exclusion alone is enough to ignite the process of division. There was always some likelihood of a competitive economic spiral given China’s close business-government relations in a “state-capitalist” economy. Now, for the first time in seven decades, there is a chance that the United States, in the grips of economic nationalism, might abandon its historic policy of free trade and ignite a new race for economic privilege as well.
EVOLUTIONARILY INDUCED ALTERNATIVE STATES AND COEXISTENCE IN SYSTEMS WITH APPARENT COMPETITION

Predators often consume multiple prey and by mutually subsidizing a shared predator, the prey may reciprocally harm each other. When predation levels are high, this apparent competition can culminate in a prey species being displaced. Coupling quantitative genetics and Lotka- Volterra models, we study how predator evolution alters this and other eco- logical outcomes. These models account for a trade-off between the predator's attack rates on two prey species. We provide a mathematical characteriza- tion of a strong form of persistence-permanence—for which there is a global attractor bounded away from extinction. When the evolutionary dynamics occur at a sufficiently slower time scale than the ecological dynamics, we also characterize attractors and their basins of attraction using singular pertur- bation theory and a graphical approach to the eco-evolutionary dynamics. Our results show that eco-evolutionary feedbacks can mediate permanence at intermediate trade-offs in the attack rates. However, at strong trade-offs, per- manence is lost. Despite this loss of permanence, there can be attractors sup- porting coexistence. These attractors, however, may coincide with attractors at which the predator is excluded. Our results highlight that eco-evolutionary feedbacks can alter community structure by mediating coexistence or leading to trait-dependent alternative stable states.
Healing Medicare hospital recidivism: causes and cures.

The role of Medicare in our national market for acute care hospital services is that of a power buyer. Medicare beneficiaries in 2008 included some 45.2 million people. Total benefits paid in 2008 were $462 billion, including 29% of all hospital spending. Medicare's dominance in the buyer's market for acute care hospital beds renders the program particularly wellsuited to scrutinize the role of acute care hospital services in producing effective and efficient outcomes for Medicare beneficiaries. “[I]f there are to be far-reaching changes in the way medicine is practiced in this country, Medicare will have to drive them.” It is a historical irony that a program, a scaled-down version of national health insurance, could have grown to this power buyer status; but the history of Medicare is full of ironies—the greatest of which may prove to be that Medicare reforms now sit at the very center of the funding mechanisms for the 2010 Patient Protection and Affordable Care Act (PPACA).
Credit rationing and crowding out during the industrial revolution: evidence from Hoare’s Bank, 1702–1862

Abstract Crowding out during the British Industrial Revolution has long been one of the leading explanations for slow growth during the Industrial Revolution, but little empirical evidence exists to support it. We argue that examinations of interest rates are fundamentally misguided, and that the 18th- and early 19th-century private loan market balanced through quantity rationing. Using a unique set of observations on lending volume at a London goldsmith bank, Hoare’s Bank, we document the impact of wartime financing on private credit markets. We conclude that there is considerable evidence that government borrowing, especially during wartime, crowded out private credit.
Macroeconomic policies and project performance in the social sectors: A model of human capital production and evidence from LDCs

Abstract This paper investigates the relationship between economy-wide policies and the performance of investment projects in education and health sectors. The model highlights the fact that the production of human capital requires an interaction of the demand for and supply of social services, both are related to labor market conditions and macroeconomic policies. A Probit analysis shows that the probability of project failure is positively and significantly associated with indicators of macroeconomic instability and distortion; and negatively associated with the overall dynamism of the economy. Economy-wide policies therefore are crucial for the success of social projects, which underscores the need of linking the lending in the social sectors to the overall policies and reforms.
Adoption Laws and Practices in 2000: Serving Whose Interests?

After enactment of the first "modern" state adoption statute in 1851,1 adoption in the United States evolved as both a state judicial process and a specialized child welfare service to promote the "best interests" of children in need of permanent homes. During the last quarter of the century, however, developments have occurred which force us to ask whether U.S. adoption is meeting the needs of children, its original child welfare intent, or serving the interests of adults? The most significant developments are: (1) the increased involvement of the federal government in promoting adoption for children in our child protection system; (2) the federally mandated elimination of race from all adoption or foster care placement decision-making; (3) the opening up of the adoption process, allowing adult adopted persons access to their records and according birth parents post-adoption visi tation rights; and (4) the growth of private adoptions as a business to place infants. This essay shall focus on developments (1), (2) and (4). Various congressional enactments,2 other developments such as Pres ident Clinton's heralded Adoption 2002 Initiative,3 and the 1993 Hague
Revisiting the Foundations of Organizational Distrust

Parallel to the very large scholarly interest in trust, scholars in management and related disciplines have made the case for the importance of distrust as a related but distinct construct. This paper critically assesses current literature on distrust in organizational settings. We first take stock of the extant research on organizational distrust and suggest an integrative framework. Second, to underpin research on organizational distrust, we examine the different scholarly perspectives on the conceptual relationship between trust and distrust. In turn, we discuss key issues to position research on trust and distrust. Third, we highlight empirical evidence on the role of distrust as opposed to that of trust. We specifically discuss alternative approaches and implications about how distrust and trust can be empirically distinguished. Fourth, we make suggestions to integrate distrust research into relationship repair literature. Fifth, we summarize our review and point to specific areas for new theoretical and empirical research on distrust, particularly at the organizational level. Finally, we discuss specific empirical challenges in this growing literature. Based on our systematic discussion of the organizational distrust literature, we believe that we have opened up prospective avenues to advance distrust research in strategic management.
Rogue Debtors and Unanticipated Risk

Commercial actors are becoming increasingly concerned about the effect that various types of political risk, including the risk of sovereign default, has on their investments. This Essay considers the problem of rogue debtors (i.e., states that intentionally ignore their legal and financial obligations) as a type of unanticipated risk and analyzes how well various responses, including domestic litigation, interstate negotiation and investment arbitration, address investors’ needs. In particular, the discussion focuses on how effective investment arbitration is in overcoming a number of difficulties traditionally associated with rogue debtors and the various means by which states are attempting to bypass the threat of investment arbitration, including the use of exclusionary treaty provisions, contractual waivers of investment arbitration and collective action clauses.
The Third Death of Federalism

Federal drug laws proved a stumbling block to the Rehnquist Court's attempted federalism revival. In its final year, the Court's fragile federalism coalition splintered in a pair of cases arising under the Controlled Substances Act (CSA). Missing from the emerging legal literature concerning those two decisions is any substantive discussion of the Supreme Court's much earlier, ill-fated efforts to preserve both judicial enforcement of the enumerated powers doctrine and federal narcotics laws. This article fills that gap. Ninety-odd years ago the Court arrived at the same jurisprudential juncture it now confronts. In the early decades of the twentieth century, the White and Taft Courts similarly faltered when the Justices professed dedication to federalism was tested by congressional overreaching in the name of guarding the people from narcotics and other temptations to perceived moral vices. In sustaining what the Justices no doubt believed to be laudatory federal morals regulations, they sowed the seeds of federalism's first death twenty years later. For during the constitutional crisis of the 1930s, the Court's critics pointed to this earlier compromise of federalism principles in their efforts to expose as pre-textual the Court's invalidation of New Deal legislation on the ground that it exceeded Congress's enumerated powers. This article explores the parallels between the neglected history of federal narcotics laws and the Court's recent rulings in Gonzales v. Raich and Gonzales v. Oregon. The full significance of those decisions can be perceived only when they are viewed in the light cast by the turbulent history offederal narcotics regulation. Then and now, drug abuse provokes intense reactions, both physical and emotional. The history suggests that now, as then, the Court's decisions may prove more * Professor, University of Cincinnati College of Law. This article has benefited greatly from the helpful and encouraging comments and suggestions from Jay Bybee, Betsy Malloy, Thomas McAffee, and Michael Solimine. I thank them, as well as all the participants in scholarly workshops held at Chase College of Law, Northern Kentucky University, and the University of Cincinnati College of Law. Thanks also to Chris Laver, Lynsay Gott, and Brennan Grayson for excellent research assistance, and the University of Cincinnati College of Law and the Harold C. Schott Foundation for financial support. This article grows out of my research for a book, POWERS RESERVED FOR THE PEOPLE AND THE STATES: A HISTORY OF THE NINTH AND TENTH AMENDMENTS (2006), which I co-authored with Thomas McAffee and Jay Bybee. Of course the claims made herein, as well as any remaining errors, are mine alone. HeinOnline -17 Cornell J. L. & Pub. Pol'y 101 2007-2008 102 CORNELL JOURNAL OF LAW AND PUBLIC POLICY [Vol. 17:101 portentous than they might at first appear. In addition, this parallel also begs more general questions about the feasibility of judicial efforts to enforce federalism. The final part of this article identifies and ventures some preliminary reflections on these issues. A B STR A C T 10
Reviving a Natural Right: The Freedom of Autonomy

America in the early twenty-first century is a place where oppressive state constitutional amendments discriminate against millions of gay Americans; where compassionate end-of-life choice is illegal in 49 states and where the one state where it is legal is being sued by the U.S. government; where hundreds of thousands are arrested yearly and tens of thousands are in prison for private possession or use of marijuana and the federal government successfully sues to prevent a state from allowing the use of medical marijuana; where a woman’s right to maintain control over her own reproductive decisions hangs by a thread; and where religious freedom is under relentless attack.
Industry dynamics: Foundations for models with an infinite number of firms☆

This paper explores the connection between three important threads of economic research offering different approaches to studying the dynamics of an industry with heterogeneous firms. Finite models of the form pioneered by Ericson and Pakes (1995) capture the dynamics of a finite number of heterogeneous firms as they compete in an industry, and are typically analyzed using the concept of Markov perfect equilibrium (MPE). Infinite models of the form pioneered by Hopenhayn (1992), on the other hand, consider an infinite number of infinitesimal firms, and are typically analyzed using the concept of stationary equilibrium (SE). A third approach uses oblivious equilibrium (OE), which maintains the simplifying benefits of an infinite model but within the more realistic setting of a finite model. The paper relates these three approaches. The main result of the paper provides conditions under which SE of infinite models approximate MPE of finite models arbitrarily well in asymptotically large markets. Our conditions require that the distribution of firm states in SE obeys a certain “light-tail” condition. In a second set of results, we show that the set of OE of a finite model approaches the set of SE of the infinite model in large markets under a similar light-tail condition.
Agricultural Productivity, Comparative Advantage and Economic Growth

The role of agricultural productivity in economic development is addressed in a two-sector model of endogenous growth in which (a) preferences are non-homothetic and the income elasticity of demand for the agricultural good is less than unitary, and (b) the engine of growth is learning-by-doing in the manufacturing sector. For the closed economy case, the model predicts a positive link between agricultural productivity and economic growth, while, for the small open economy case, it predicts a negative link. This suggests that the openness of an economy should be an important factor when planning development strategy and predicting growth performance.
Genome-wide signatures of plastid-nuclear coevolution point to repeated perturbations of plastid proteostasis systems across angiosperms

Nuclear and plastid (chloroplast) genomes experience different mutation rates, levels of selection, and transmission modes, yet key cellular functions depend on their coordinated interactions. Functionally related proteins often show correlated changes in rates of sequence evolution across a phylogeny [evolutionary rate covariation (ERC)], offering a means to detect previously unidentified suites of coevolving and cofunctional genes. We performed phylogenomic analyses across angiosperm diversity, scanning the nuclear genome for genes that exhibit ERC with plastid genes. As expected, the strongest hits were highly enriched for genes encoding plastid-targeted proteins, providing evidence that cytonuclear interactions affect rates of molecular evolution at genome-wide scales. Many identified nuclear genes functioned in post-transcriptional regulation and the maintenance of protein homeostasis (proteostasis), including protein translation (in both the plastid and cytosol), import, quality control, and turnover. We also identified nuclear genes that exhibit strong signatures of coevolution with the plastid genome, but their encoded proteins lack organellar-targeting annotations, making them candidates for having previously undescribed roles in plastids. In sum, our genome-wide analyses reveal that plastid-nuclear coevolution extends beyond the intimate molecular interactions within chloroplast enzyme complexes and may be driven by frequent rewiring of the machinery responsible for maintenance of plastid proteostasis in angiosperms.
Toward Model Parallelism for Deep Neural Network based on Gradient-free ADMM Framework

Alternating Direction Method of Multipliers (ADMM) has recently been proposed as a potential alternative optimizer to the Stochastic Gradient Descent(SGD) for deep learning problems. This is because ADMM can solve gradient vanishing and poor conditioning problems. Moreover, it has shown good scalability in many large-scale deep learning applications. However, there still lacks a parallel ADMM computational framework for deep neural networks because of layer dependency among variables. In this paper, we propose a novel parallel deep learning ADMM framework (pdADMM) to achieve layer parallelism: parameters in each layer of neural networks can be updated independently in parallel. The convergence of the proposed pdADMM to a critical point is theoretically proven under mild conditions. The convergence rate of the pdADMM is proven to be $o(1/k)$ where $k$ is the number of iterations. Extensive experiments on six benchmark datasets demonstrated that our proposed pdADMM can lead to more than 10 times speedup for training large-scale deep neural networks, and outperformed most of the comparison methods. Our code is available at: https://github.com/xianggebenben/pdADMM.
Elliptic curves and Thompson's sporadic simple group

Abstract We characterize all infinite-dimensional graded virtual modules for Thompson's sporadic simple group whose graded traces are weight 3 2 weakly holomorphic modular forms satisfying certain special properties. We then use these modules to detect the non-triviality of Mordell–Weil, Selmer, and Tate-Shafarevich groups of quadratic twists of certain elliptic curves.
Resonances as viscosity limits for exponentially decaying potentials

We show that the complex absorbing potential method for computing scattering resonances applies to the case of exponentially decaying potentials. This means that the eigenvalues of −Δ + V − iɛx2 and |V(x)| ≤ Ce−2γ|x| converge, as ɛ → 0+, to the poles of the meromorphic continuation of (−Δ+V−λ2)−1 uniformly on compact subsets of Re λ > 0, Im λ > − γ, and arg λ > −π/8.
Robust Safety-Critical Control for Dynamic Robotics

We present a novel method of optimal robust control through quadratic programs that offers tracking stability while subject to input and state-based constraints as well as safety-critical constraints for nonlinear dynamical robotic systems in the presence of model uncertainty. The proposed method formulates robust control Lyapunov and barrier functions to provide guarantees of stability and safety in the presence of model uncertainty. We evaluate our proposed control design on dynamic walking of a five-link planar bipedal robot subject to contact force constraints as well as safety-critical precise foot placements on stepping stones, all while subject to model uncertainty. We conduct preliminary experimental validation of the proposed controller on a rectilinear spring-cart system under different types of model uncertainty and perturbations.
A GLOBAL PANOPTICON? THE CHANGING ROLE OF INTERNATIONAL ORGANIZATIONS IN THE INFORMATION AGE

Introduction 160 I. The Compliance Challenge 162 A. Why Do States Obey International Law? 163 B. International Organizations and Compliance Monitoring ..... 165 1. Self-Reporting 167 2. Information Produced by Nongovernmental Entities ...... 168 II. Compliance Monitoring in Action: Health, Environment, and Human Rights 168 A. Health 169 B. Environment 173 C. Human Rights 175 III. The Promise of Information Technologies 180 A. Access to Information 181 1. Health 182 2. Environment 182 3. Human Rights 184 4. Policy Proposals 185 B. Online Compliance Monitoring 186 1. Health 187 2. Environment 196 3. Human Rights 199 IV. A Global Panopticon? 201 A. The Panopticon Effect: Empowering IOs 203 B. States’ Counterreactions 205 1. Disrupting Access 205 2. Hindering the Production of Information 207 C. Normative Proposals 209 1. Setting Procedures for Online Compliance Monitoring .. 209 2. Encouraging Fragmentation 212 Conclusion 214
Young adults with recurrent low back pain demonstrate altered trunk coordination during gait independent of pain status and attentional demands

Pain influences both attention and motor behavior. We used a dual-task interference paradigm to investigate (1) alterations in attentional performance, (2) the ability to switch task prioritization, and (3) the effect of attentional demand on trunk coordination during narrow-based walking in and out of a painful episode in individuals with recurrent low back pain (LBP). We tested twenty young adults with LBP both in and out of a painful episode and compared them to twenty matched back-healthy individuals. Participants simultaneously performed a narrow step width matching task and an arithmetic task, with and without instructions to prioritize either task. A motion capture system was used to record kinematic data, and frontal plane trunk coordination was analyzed using vector coding on the thorax and pelvis angles. Single-task performance, dual-task effect, dual-task performance variability, task prioritization switch, and trunk coordination were analyzed using paired t tests or repeated measures two-way ANOVAs. Results indicated that active pain has a detrimental effect on attentional processes, indicated by poorer single-task performance and increased dual-task performance variability for individuals with recurrent LBP. Individuals with LBP, regardless of pain status, were able to switch task prioritization to a similar degree as their back-healthy counterparts. Compared to the control group, individuals with recurrent LBP exhibited a less in-phase, more pelvis-dominated trunk coordination during narrow-based walking, independent of pain status and regardless of attentional manipulations. Thus, altered trunk coordination in persons with LBP appears to be habitual, automatic, and persists beyond symptom duration.
From VOAs to Short Star Products in SCFT

We build a bridge between two algebraic structures in superconformal field theories (SCFT): a vertex operator algebra (VOA) in the Schur sector of 4d $$\mathcal {N}=2$$ theories and an associative algebra in the Higgs sector of 3d $$\mathcal {N}=4$$ . The natural setting is a 4d $$\mathcal {N}=2$$ SCFT placed on $$S^3\times S^1$$ : by sending the radius of $$S^1$$ to zero, we recover the 3d $$\mathcal {N}=4$$ theory, and the corresponding VOA on the torus degenerates to the associative algebra on the circle. We prove that: (1) the Higgs branch operators remain in the cohomology; (2) all the Schur operators of the non-Higgs type are lifted by line operators wrapped on the $$S^1$$ ; (3) no new cohomology classes are added. We show that the algebra in 3d is given by the quotient $$\mathcal {A}_H = \mathrm{Zhu}_{s}(V)/N$$ , where $$\mathrm{Zhu}_{s}(V)$$ is the non-commutative Zhu algebra of the VOA V (for $${s}\in \mathrm{Aut}(V)$$ ), and N is a certain ideal. This ideal is the null space of the (s-twisted) trace map $$T_{s}: \mathrm{Zhu}_{s}(V) \rightarrow \mathbb {C}$$ determined by the torus 1-point function in the high temperature (or small complex structure) limit. It therefore equips $$\mathcal {A}_H$$ with a non-degenerate (twisted) trace, leading to a short star-product according to the recent results of Etingof and Stryker. The map $$T_{s}$$ is easy to determine for unitary VOAs, but has a much subtler structure for non-unitary and non- $$C_2$$ -cofinite VOAs of our interest. We comment on relation to the Beem-Rastelli conjecture on the Higgs branch and the associated variety. A companion paper will explore further details, examples, and some applications of these ideas.
Learning Robustness with Bounded Failure: An Iterative MPC Approach

Abstract We propose an approach to design a Model Predictive Controller (MPC) for constrained Linear Time Invariant systems performing an iterative task. The system is subject to an additive disturbance, and the goal is to learn to satisfy state and input constraints robustly. Using disturbance measurements after each iteration, we construct Confidence Support sets, which contain the true support of the disturbance distribution with a given probability. As more data is collected, the Confidence Supports converge to the true support of the disturbance. This enables design of an MPC controller that avoids conservative estimate of the disturbance support, while simultaneously bounding the probability of constraint violation. The efficacy of the proposed approach is then demonstrated with a detailed numerical example.
A fast and efficient smoothing approach to Lasso regression and an application in statistical genetics: polygenic risk scores for chronic obstructive pulmonary disease (COPD)

High dimensional linear regression problems are often fitted using Lasso approaches. Although the Lasso objective function is convex, it is not differentiable everywhere, making the use of gradient descent methods for minimization not straightforward. To avoid this technical issue, we apply Nesterov smoothing to the original (unsmoothed) Lasso objective function. We introduce a closed-form smoothed Lasso which preserves the convexity of the Lasso function, is uniformly close to the unsmoothed Lasso, and allows us to obtain closed-form derivatives everywhere for efficient and fast minimization via gradient descent. Our simulation studies are focused on polygenic risk scores using genetic data from a genome-wide association study (GWAS) for chronic obstructive pulmonary disease (COPD). We compare accuracy and runtime of our approach to the current gold standard in the literature, the FISTA algorithm. Our results suggest that the proposed methodology provides estimates with equal or higher accuracy than the FISTA algorithm while having the same asymptotic runtime scaling. The proposed methodology is implemented in the R-package smoothedLasso, available on the Comprehensive R Archive Network (CRAN).
Community College Pathways for Disadvantaged Students

Objective: We estimated the correlations between the “pathways” chosen by community college students—in terms of desired credentials and fields of study, as well as other choices and outcomes along...
Intercalated disk nanoscale structure regulates cardiac conduction

The intercalated disk (ID) is a specialized subcellular region that provides electrical and mechanical connections between myocytes in the heart. The ID has a clearly defined passive role in cardiac tissue, transmitting mechanical forces and electrical currents between cells. Recent studies have shown that Na+ channels, the primary current responsible for cardiac excitation, are preferentially localized at the ID, particularly within nanodomains such as the gap junction-adjacent perinexus and mechanical junction-associated adhesion-excitability nodes, and that perturbations of ID structure alter cardiac conduction. This suggests that the ID may play an important, active role in regulating conduction. However, the structures of the ID and intercellular cleft are not well characterized and, to date, no models have incorporated the influence of ID structure on conduction in cardiac tissue. In this study, we developed an approach to generate realistic finite element model (FEM) meshes replicating nanoscale of the ID structure, based on experimental measurements from transmission electron microscopy images. We then integrated measurements of the intercellular cleft electrical conductivity, derived from the FEM meshes, into a novel cardiac tissue model formulation. FEM-based calculations predict that the distribution of cleft conductances is sensitive to regional changes in ID structure, specifically the intermembrane separation and gap junction distribution. Tissue-scale simulations predict that ID structural heterogeneity leads to significant spatial variation in electrical polarization within the intercellular cleft. Importantly, we found that this heterogeneous cleft polarization regulates conduction by desynchronizing the activation of postjunctional Na+ currents. Additionally, these heterogeneities lead to a weaker dependence of conduction velocity on gap junctional coupling, compared with prior modeling formulations that neglect or simplify ID structure. Further, we found that disruption of local ID nanodomains can either slow or enhance conduction, depending on gap junctional coupling strength. Our study therefore suggests that ID nanoscale structure can play a significant role in regulating cardiac conduction.
Reverse engineering imperceptible backdoor attacks on deep neural networks for detection and training set cleansing

Abstract Backdoor data poisoning (a.k.a. Trojan attack) is an emerging form of adversarial attack usually against deep neural network image classifiers. The attacker poisons the training set with a relatively small set of images from one (or several) source class(es), embedded with a backdoor pattern and labeled to a target class. For a successful attack, during operation, the trained classifier will: 1) misclassify a test image from the source class(es) to the target class whenever the backdoor pattern is present; 2) maintain high classification accuracy for backdoor-free test images. In this paper, we make a breakthrough in defending backdoor attacks with imperceptible backdoor patterns (e.g. watermarks) before/during the classifier training phase. This is a challenging problem because it is a priori unknown which subset (if any) of the training set has been poisoned. We propose an optimization-based reverse engineering defense that jointly: 1) detects whether the training set is poisoned; 2) if so, accurately identifies the target class and the training images with the backdoor pattern embedded; and 3) additionally, reverse engineers an estimate of the backdoor pattern used by the attacker. In benchmark experiments on CIFAR-10 (as well as four other data sets), considering a variety of attacks, our defense achieves a new state-of-the-art by reducing the attack success rate to no more than 4.9% after removing detected suspicious training images.
Stability analysis for a class of linear controllers under control constraints

This paper presents a method of analyzing a system for stability when control magnitude constraints are introduced. Given a linear full state feedback controller (of a certain form) which stabilizes the system in the absence of control constraints, we then determine sufficient conditions under which the system with constrained control remains stable. To guarantee stability, there is a tradeoff between the size of the initial condition set and the size of the control constraints. Results are extended to systems with time varying uncertainty in the system matrix and input matrix.
Functional architecture of neural circuits for leg proprioception in Drosophila.

Summary To effectively control their bodies, animals rely on feedback from proprioceptive mechanosensory neurons. In the Drosophila leg, different proprioceptor subtypes monitor joint position, movement direction, and vibration. Here, we investigate how these diverse sensory signals are integrated by central proprioceptive circuits. We find that signals for leg joint position and directional movement converge in second-order neurons, revealing pathways for local feedback control of leg posture. Distinct populations of second-order neurons integrate tibia vibration signals across pairs of legs, suggesting a role in detecting external substrate vibration. In each pathway, the flow of sensory information is dynamically gated and sculpted by inhibition. Overall, our results reveal parallel pathways for processing of internal and external mechanosensory signals, which we propose mediate feedback control of leg movement and vibration sensing, respectively. The existence of a functional connectivity map also provides a resource for interpreting connectomic reconstruction of neural circuits for leg proprioception.
Diagrammatic expansion of non-perturbative little string free energies

In [1] we have studied the single-particle free energy of a class of Little String Theories of A-type, which are engineered by N parallel M5-branes on a circle. To leading instanton order (from the perspective of the low energy U(N) gauge theory) and partially also to higher order, a decomposition was observed, which resembles a Feynman diagrammatic expansion: external states are given by expansion coefficients of the N = 1 BPS free energy and a quasi-Jacobi form that governs the BPS-counting of an M5-brane coupling to two M2-branes. The effective coupling functions were written as infinite series and similarities to modular graph functions were remarked. In the current work we continue and extend this study: working with the full non-perturbative BPS free energy, we analyse in detail the cases N = 2, 3 and 4. We argue that in these cases to leading instanton order all coupling functions can be written as a simple combination of two-point functions of a single free scalar field on the torus. We provide closed form expressions, which we conjecture to hold for generic N. To higher instanton order, we observe that a decomposition of the free energy in terms of higher point functions with the same external states is still possible but a priori not unique. We nevertheless provide evidence that tentative coupling functions are still combinations of scalar Greens functions, which are decorated with derivatives or multiplied with holomorphic Eisenstein series. We interpret these decorations as corrections of the leading order effective couplings and in particular link the latter to dihedral graph functions with bivalent vertices, which suggests an interpretation in terms of disconnected graphs.
Evaluation of confocal laser endomicroscopy for detection of occult gastric carcinoma in CDH1 variant carriers

Background Hereditary diffuse gastric cancer syndrome, attributed to inactivating germline CDH1 variants, is associated with an elevated lifetime risk of gastric cancer. We sought to evaluate cancer detection using probe-based confocal laser endomicroscopy (pCLE) during endoscopic surveillance. Methods A prospective, single-institution study was conducted in asymptomatic adults with pathogenic or likely pathogenic (P/LP) CDH1 variants. Subjects received endoscopic gastric surveillance using pCLE in conjunction with the Cambridge method (CM). Abnormalities visualized by pCLE were biopsied, followed by non-targeted mucosal biopsies according to the CM. Primary endpoint was to determine pCLE sensitivity for detection of occult SRC carcinoma compared to CM. Results Thirty-six patients with P/LP CDH1 variants underwent endoscopy using pCLE and CM. Majority were female (75%) with median age 47 years. Targeted biopsies of focal abnormalities on WLE were negative for carcinoma. Overall, 19.4% (7/36) patients had SRC detected on ≥1 biopsy. Non-targeted CM biopsies revealed SRC in 11.1% (4/36), whereas pCLE revealed SRC in 16.7% (6/36). Fifteen patients underwent total gastrectomy; all 15 explants contained occult carcinoma. In those 15 patients, the false-negative SRC detection rates for pCLE and CM were 67% and 87%, respectively. Conclusions Confocal endomicroscopy alone has low sensitivity for occult cancer detection in CDH1 variant carriers, although it appeared no worse than the current recommended method and required fewer biopsies per patient. A more reliable endoscopic surveillance is needed as a viable alternative to surgery in this high-risk population (ClinicalTrials.gov, Number: NCT03648879).
Marine Community Metabolomes Carry Fingerprints of Phytoplankton Community Composition.

ABSTRACT Phytoplankton transform inorganic carbon into thousands of biomolecules that represent an important pool of fixed carbon, nitrogen, and sulfur in the surface ocean. Metabolite production differs between phytoplankton, and the flux of these molecules through the microbial food web depends on compound-specific bioavailability to members of a wider microbial community. Yet relatively little is known about the diversity or concentration of metabolites within marine plankton. Here, we compare 313 polar metabolites in 21 cultured phytoplankton species and in natural planktonic communities across environmental gradients to show that bulk community metabolomes reflect the chemical composition of the phytoplankton community. We also show that groups of compounds have similar patterns across space and taxonomy, suggesting that the concentrations of these compounds in the environment are controlled by similar sources and sinks. We quantify several compounds in the surface ocean that represent substantial understudied pools of labile carbon. For example, the N-containing metabolite homarine was up to 3% of particulate carbon and is produced in high concentrations by cultured Synechococcus, and S-containing gonyol accumulated up to 2.5 nM in surface particles and likely originates from dinoflagellates or haptophytes. Our results show that phytoplankton composition directly shapes the carbon composition of the surface ocean. Our findings suggest that in order to access these pools of bioavailable carbon, the wider microbial community must be adapted to phytoplankton community composition. IMPORTANCE Microscopic phytoplankton transform 100 million tons of inorganic carbon into thousands of different organic compounds each day. The structure of each chemical is critical to its biological and ecosystem function, yet the diversity of biomolecules produced by marine microbial communities remained mainly unexplored, especially small polar molecules which are often considered the currency of the microbial loop. Here, we explore the abundance and diversity of small biomolecules in planktonic communities across ecological gradients in the North Pacific and within 21 cultured phytoplankton species. Our work demonstrates that phytoplankton diversity is an important determinant of the chemical composition of the highly bioavailable pool of organic carbon in the ocean, and we highlight understudied yet abundant compounds in both the environment and cultured organisms. These findings add to understanding of how the chemical makeup of phytoplankton shapes marine microbial communities where the ability to sense and use biomolecules depends on the chemical structure.
Teams, Firms and the Evolution of Profit Seeking Behavior

Even as advances in information theory over the last quarter century have cast increasing doubt on the proposition that firms successfully maximize profits, the objective of profit maximization continues to be an axiomatic feature of the neoclassical theory of the firm. This paper attempts to improve our understanding firms by treating the objective function as an open question. Specifically, an ontogenetic thought experiment is undertaken to address the question of what differentiates production teams from firms by asking why team members would sell their control rights to a principal, thereby transforming the team into a firm. What results is an account of the emergence of the objective of profit seeking. Profit seeking emerges endogenously as a more fit alternative than the objective of value maximization, which is less capable of coping with uncertainty through purposive adaptation.