cssi/SciSciGPT-SciSciNet huggingface dataset:
Conservative Economics and Optimal Consumer Bankruptcy Policy

In this paper, Professor Wiggins explores the relationship between conservative economic theories and major bankruptcy reforms recently enacted by the United States Congress. First, she describes three key components of conservative economic theory as advanced by the Bush Administration and conservative scholars. These include: (1) a strong preference for private ordering over public ordering, (2) the promotion of private property as a means to expand personal freedom and liberty, and (3) the encouragement of individual risk internalization. Next, she describes two theoretical components of the new bankruptcy reforms. These include: (1) a preference for creditor collection over debt relief and (2) the promotion of individual risk internalization. Then Professor Wiggins examines two questions: First, is there meaningful theoretical symmetry between conservative economics and the new bankruptcy law? Second, is there significant operational symmetry between the two? The paper suggests theoretical convergence for two reasons: First, both conservative economics and the new bankruptcy law aim to promote private bargains over administratively adjusted ones. Second, both seek to force individuals to absorb more of the risks of financial decision-making. The paper suggests, however, that at the operational level there exists significant divergence between the aims of conservative economics and the predicted consequences of the new law. Professor Wiggins concludes, among other things, that economic conservatives should pay more rigorous attention to personal bankruptcy policy because operational asymmetry between their theories and the new legislation could blunt their ambitious economic agenda for American consumers.
Properties of the evolution of scientific fields: An inductive study in applied sciences

Abstract. The evolution of science is made possible when experimental results are compared with expectations from theory and are consistent. In this context, experimental physics, as applied science, plays a vital role for the progress of science in society. The experimental physics is a discipline where physics scholars have an intensive laboratory experience that concentrates on experiments for substantiating and/or challenging established and/or new theories in physics. No studies to date allows us to explain the endogenous processes that support the evolution of scientific disciplines and emergence of new scientific fields in applied sciences of physics. In fact, one of the fundamental questions in science is how scientific disciplines evolve and sustain progress in society. This study confronts this question here by investigating the evolution of experimental physics to explain and generalize, whenever possible, some characteristics of the dynamics of applied sciences. Empirical analysis suggests a number of properties about the evolution of experimental physics and in general of applied sciences, such as: a)scientific fission, the evolution of scientific disciplines generates a process of division into two or more research fields that evolve as autonomous entities over time; b)ambidextrous drivers of science , the evolution of science via scientific fission is due to scientific discoveries or new technologies; c)new driving research fields , the drivers of scientific disciplines are new research fields rather than old ones (e.g., three scientific fields with a high scientific production in experimental physics are emerged after 1950s); d)science driven by development of general purpose technologies, the evolution of experimental physics and applied sciences is due to the convergence of experimental and theoretical branches of physics associated with the development of computer, information systems and applied computational science (e.g., computer simulation). Results also reveal that average duration of the up wave of scientific production in scientific fields supporting experimental physics is about 80 years. Overall, then, this study begins the process of clarifying and generalizing, as far as possible, some characteristics of the evolutionary dynamics of scientific disciplines that can lay a foundation for the development of comprehensive properties explaining the evolution of science as a whole for supporting fruitful research policy implications directed to advancement of science and technological progress in society. Keywords. Research Fields; Scientific Disciplines; Scientific Fields; Evolution of Science; Dynamics of Science; Applied Sciences; Basic Sciences; Experimental Physics; Scientific Fission; Scientific Development; Scientific Paradigm; Branching in Science; Sociology of Knowledge; Scientific Knowledge; Philosophy of Science. JEL. A19; C00; I23; L30.
THE SHARPE RATIO EFFICIENT FRONTIER

ABSTRACT We evaluate the probability that an estimated Sharpe ratio exceeds a given threshold in presence of non-Normal returns. We show that this new uncertainty-adjusted investment skill metric (called Probabilistic Sharpe ratio , or PSR) has a number of important applications: First, it allows us to establish the track record length needed for rejecting the hypothesis that a measured Sharpe ratio is below a certain threshold with a given confidence level. Second, it models the trade-off between track record length and undesirable statistical features (e.g., negative skewness with positive excess kurtosis). Third, it explains why track records with those undesirable traits would benefit from reporting performance with the highest sampling frequency such that the IID assumption is not violated. Fourth, it permits the computation of what we call the Sharpe ratio Efficient Frontier (SEF), which lets us optimize a portfolio under non-Normal, leveraged returns while incorporating the uncertainty derived from track record length. Results can be validated using the Python code in the Appendix. Keywords: Sharpe ratio, Efficient Frontier, IID, Normal distribution, Skewness, Excess Kurtosis, track record. JEL Classifications: C02, G11, G14, D53.
Contract Structure and Design in Identity-Preserved Soybean Production

This paper provides a survey of contract design structures in identity-preserved soybean production. Drawing from economic theories of contract and organizational design, we document the allocation of value and decision rights associated with the transaction and the resulting allocation of risk associated with various sources of uncertainty for a sample of contracts for identity-preserved (or segregated) soybeans. We also list several hypotheses and avenues for future research suggested by the contract terms discussed in the paper.
Do Individuals Comply on Income Not Reported by Their Employer

Individuals with income not reported to the tax authority by a third party (e.g., the self-employed, those earning tips) may be less likely to be detected evading taxes relative to the case in which their income is subject to third-party reporting. However, their compliance responses—to changes in the proportion of income that is reported to the tax authority, to changes in audit and tax rates, etc.—are largely unknown, in part because of the difficulty in obtaining information on individual choices in these situations. The authors use experimental methods to examine individual income tax compliance in settings where individuals differ in the portion of their income that is ‘‘matched’’ (reported to the tax authority via third-party information) versus ‘‘non-matched’’ (not fully reported to the tax authority). The results indicate that individuals who have relatively more non-matched income exhibit significantly lower tax compliance rates than individuals who earn relatively less non-matched income.
Rare Disasters and Risk Sharing with Heterogeneous Beliefs

Risks of rare economic disasters can have a large impact on asset prices. At the same time, difficulties in inference regarding both the likelihood and severity of disasters, as well as agency problems, can lead to significant disagreements among investors about disaster risk. We show that such disagreements generate strong risk-sharing motives, such that just a small number of optimists in the economy will significantly reduce the disaster risk premium. Our model highlights the "latent" nature of disaster risk. The disaster risk premium will likely be low and smooth during normal times but increases dramatically when the risk-sharing capacity of the optimists is reduced, e.g., following a disaster. The model also helps reconcile the difference in the amount of disaster risk implied by financial markets and international macroeconomic data, and provides caution to the approach of extracting disaster probabilities from asset prices, which will disproportionately reflect the beliefs of a small group of optimists. Finally, our model predicts an inverse U-shaped relation between the equity premium and the size of the disaster insurance market. The Author 2012. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com., Oxford University Press.
Faster Binary Embeddings for Preserving Euclidean Distances

We propose a fast, distance-preserving, binary embedding algorithm to transform a high-dimensional dataset T⊆Rn into binary sequences in the cube {±1}m. When T consists of well-spread (i.e., non-sparse) vectors, our embedding method applies a stable noise-shaping quantization scheme to Ax where A∈Rm×n is a sparse Gaussian random matrix. This contrasts with most binary embedding methods, which usually use x↦sign(Ax) for the embedding. Moreover, we show that Euclidean distances among the elements of T are approximated by the l1 norm on the images of {±1}m under a fast linear transformation. This again contrasts with standard methods, where the Hamming distance is used instead. Our method is both fast and memory efficient, with time complexity O(m) and space complexity O(m) on well-spread data. When the data is not well-spread, we show that the approach still works provided that data is transformed via a Walsh-Hadamard matrix, but now the cost is O(nlog⁡n) per data point. Further, we prove that the method is accurate and its associated error is comparable to that of a continuous valued Johnson-Lindenstrauss embedding plus a quantization error that admits a polynomial decay as the embedding dimension m increases. Thus the length of the binary codes required to achieve a desired accuracy is quite small, and we show it can even be compressed further without compromising the accuracy. To illustrate our results, we test the proposed method on natural images and show that it achieves strong performance.
Mutant p53 suppresses innate immune signaling to promote tumorigenesis

Mutant p53 (mtp53) proteins can exert cancer-promoting gain-of-function activities. We report a mechanism by which mtp53 suppresses both cell-autonomous and non-cell-autonomous signaling to promote cancer cell survival and evasion of tumor immune surveillance. Mtp53 interferes with the function of the cytoplasmic DNA sensing machinery, cGAS-STING-TBK1-IRF3, that activates the innate immune response. Mtp53, but not wild-type p53, binds to TANK-binding protein kinase 1 (TBK1) and prevents the formation of a trimeric complex between TBK1, STING, and IRF3, which is required for activation, nuclear translocation, and transcriptional activity of IRF3. Inactivation of innate immune signaling by mtp53 alters cytokine production, resulting in immune evasion. Restoring TBK1 signaling is sufficient to bypass mtp53 and lead to restored immune cell function and cancer cell eradication. This work is of translational interest because therapeutic approaches that restore TBK1 function could potentially reactivate immune surveillance and eliminate mtp53 tumors.
Real-time observation of structure and dynamics during the liquid-to-solid transition of FUS LC

Abstract A subset of the proteins found in pathological protein fibrils also exhibit tendencies for liquid-liquid phase separation (LLPS) both in vitro and in cells. The mechanisms underlying the connection between these phase transitions have been challenging to study due to the heterogeneous and dynamic nature of the states formed during the maturation of LLPS protein droplets into gels and solid aggregates. Here, we interrogate the liquid-to-solid transition of the low-complexity domain of the RNA-binding protein FUS (FUS LC), which has been shown to adopt LLPS, gel-like, and amyloid states. We employ magic-angle-spinning NMR spectroscopy, which has allowed us to follow these transitions in real time and with residue-specific resolution. We observe the development of β-sheet structure through the maturation process and show that the final state of FUS LC fibrils produced after LLPS is distinct from that grown from fibrillar seeds. We also apply our methodology to FUS LC G156E, a clinically relevant FUS mutant that exhibits accelerated fibrillization rates. We observe significant changes in dynamics during the transformation of the FUS LC G156E construct and begin to unravel the sequence specific contributions to this phenomenon with computational studies of the phase-separated state of FUS LC and FUS LC G156E.
Acousto-optic modulation of a wavelength-scale waveguide

Since the advent of the laser, acousto-optic modulators have been an important tool for controlling light. Recent advances in on-chip lithium niobate waveguide technology present new opportunities for these devices. We demonstrate a collinear acousto-optic modulator in a suspended film of lithium niobate employing a high-confinement, wavelength-scale waveguide. By strongly confining the optical and mechanical waves, this modulator improves a figure-of-merit that accounts for both acousto-optic and electro-mechanical efficiency by orders of magnitude. Our device demonstration marks a significant technological advance in acousto-optics that promises a novel class of compact and low-power frequency shifters, tunable filters, non-magnetic isolators, and beam deflectors.
Extra base hits: Widespread empirical support for instantaneous multiple-nucleotide changes

Despite many attempts to introduce evolutionary models that permit substitutions to instantly alter more than one nucleotide in a codon, the prevailing wisdom remains that such changes are rare and generally negligible or are reflective of non-biological artifacts, such as alignment errors. Codon models continue to posit that only single nucleotide change have non-zero rates. Here, we develop and test a simple hierarchy of codon-substitution models with non-zero evolutionary rates for only one-nucleotide (1H), one- and two-nucleotide (2H), or any (3H) codon substitutions. Using over 42, 000 empirical alignments, we find widespread statistical support for multiple hits: 61% of alignments prefer models with 2H allowed, and 23%-with 3H allowed. Analyses of simulated data suggest that these results are not likely to be due to simple artifacts such as model misspecification or alignment errors. Further modeling reveals that synonymous codon island jumping among codons encoding serine, especially along short branches, contributes significantly to this 3H signal. While serine codons were prominently involved in multiple-hit substitutions, there were other common exchanges contributing to better model fit. It appears that a small subset of sites in most alignments have unusual evolutionary dynamics not well explained by existing model formalisms, and that commonly estimated quantities, such as dN/dS ratios may be biased by model misspecification. Our findings highlight the need for continued evaluation of assumptions underlying workhorse evolutionary models and subsequent evolutionary inference techniques. We provide a software implementation for evolutionary biologists to assess the potential impact of extra base hits in their data in the HyPhy package and in the Datamonkey.org server.
Matrix Completion Methods for Causal Panel Data Models

In this paper we study methods for estimating causal effects in settings with panel data, where some units are exposed to a treatment during some periods and the goal is estimating counterfactual (untreated) outcomes for the treated unit/period combinations. We propose a class of matrix completion estimators that uses the observed elements of the matrix of control outcomes corresponding to untreated unit/periods to impute the "missing" elements of the control outcome matrix, corresponding to treated units/periods. This leads to a matrix that well-approximates the original (incomplete) matrix, but has lower complexity according to the nuclear norm for matrices. We generalize results from the matrix completion literature by allowing the patterns of missing data to have a time series dependency structure that is common in social science applications. We present novel insights concerning the connections between the matrix completion literature, the literature on interactive fixed effects models and the literatures on program evaluation under unconfoundedness and synthetic control methods. We show that all these estimators can be viewed as focusing on the same objective function. They differ solely in the way they deal with identification, in some cases solely through regularization (our proposed nuclear norm matrix completion estimator) and in other cases primarily through imposing hard restrictions (the unconfoundedness and synthetic control approaches). The proposed method outperforms unconfoundedness-based or synthetic control estimators in simulations based on real data.
Infinite norm of the derivative of the solution operator of Euler equations

Through a simple and elegant argument, we prove that the norm of the derivative of the solution operator of Euler equations posed in the Sobolev space Hn, along any base solution that is in Hn but not in H n + 1, is infinite. We also review the counterpart of this result for Navier–Stokes equations at a high Reynolds number from the perspective of fully developed turbulence. Finally, we present a few examples and numerical simulations to show a more complete picture of the so-called rough dependence upon initial data.
The Anti-Republican Origins of the At-Will Doctrine

This article highlights the origin of the employment at-will doctrine by providing the contextual contrast of Reconstruction free labor republicanism. To date, no work has situated the doctrine’s emergence in the heady Reconstruction discussions of labor reform that immediately preceded it. This article briefly summarizes how the at-will rule functions to subordinate employees. The article then elaborates upon the pervasive, overarching anti-subordination themes of the Radical Republican debates in Congress as well as their specific initiatives targeted at equalizing power disparities. Further, the article examines the paradox that the Thirteenth Amendment’s minimum constitutional guarantee that workers have a right to quit became doctrinally embedded in the at-will rule’s justification. Third, the article explores the contemporary post-bellum republican alternatives, both in treatises and in the dissent’s critique in the seminal case of Payne v. Western and Atlantic Railroad. While one treatise writer, Horace Wood, advanced the at-will rule, another, James Schouler, imbued with a sense of republicanism, advanced a different rule of duration based upon custom and pay period. Finally, the article examines an early critique that at-will circumstances were so unsubstantial as to fail to amount to any contract at all. Overall, this article provides a different perspective from which to view the doctrine’s emergence, that is, as a retrenchment of railroads’ authority over their day workers at the very time that Reconstruction’s egalitarian reform efforts were fading. Utilizing contract terminology, the constitutionally guaranteed right to quit was bootstrapped into the prerogative for employers – right to fire employees at will eventually becoming the predominant employment doctrine today.
Limit Shapes of Local Minimizers for the Alt–Caffarelli Energy Functional in Inhomogeneous Media

This paper considers the Alt–Caffarelli free boundary problem in a periodic medium. This is a convenient model for several interesting phenomena appearing in the study of contact lines on rough surfaces, pinning, hysteresis and the formation of facets. We show the existence of an interval of effective pinned slopes at each direction $$e \in S^{d-1}$$ . In $$d=2$$ we characterize the regularity properties of the pinning interval in terms of the normal direction, including possible discontinuities at rational directions. These results require a careful study of the families of plane-like solutions available with a given slope. Using the same techniques we also obtain strong, in some cases optimal, bounds on the class of limit shapes of local minimizers in $$d=2$$ , and preliminary results in $$d \geqq 3$$ .
A generalization of permanent inequalities and applications in counting and optimization

Abstract A polynomial p ∈ R [ z 1 , … , z n ] is real stable if it has no roots in the upper-half complex plane. Gurvits's permanent inequality gives a lower bound on the coefficient of the z 1 z 2 … z n monomial of a real stable polynomial p with nonnegative coefficients. This fundamental inequality has been used to attack several counting and optimization problems. Here, we study a more general question: Given a stable multilinear polynomial p with nonnegative coefficients and a set of monomials S, we show that if the polynomial obtained by summing up all monomials in S is real stable, then we can lowerbound the sum of coefficients of monomials of p that are in S. We also prove generalizations of this theorem to (real stable) polynomials that are not multilinear. We use our theorem to give a new proof of Schrijver's inequality on the number of perfect matchings of a regular bipartite graph, generalize a recent result of Nikolov and Singh [23] , and give deterministic polynomial time approximation algorithms for several counting problems.
Crystal orientation and detector distance effects on resolving pseudosymmetry by electron backscatter diffraction

Accurately indexing pseudosymmetric materials has long proven challenging for electron backscatter diffraction. The recent emergence of intensity-based indexing approaches promises an enhanced ability to resolve pseudosymmetry compared with traditional Hough-based indexing approaches. However, little work has been done to understand the effects of sample position and orientation on the ability to resolve pseudosymmetry, especially for intensity-based indexing approaches. Thus, in this work the effects of crystal orientation and detector distance in a model tetragonal ZrO2 (c/a = 1.0185) material are quantitatively investigated. The orientations that are easiest and most difficult to correctly index are identified, the effect of detector distance on indexing confidence is characterized, and these trends are analyzed on the basis of the appearance of specific zone axes in the diffraction patterns. The findings also point to the clear benefit of shorter detector distances for resolving pseudosymmetry using intensity-based indexing approaches.
Single-molecule micromanipulation studies of methylated DNA

Cytosine methylated at the five-carbon position is the most widely studied reversible DNA modification. Prior findings indicate that methylation can alter mechanical properties. However, those findings were qualitative and sometimes contradictory, leaving many aspects unclear. By applying single-molecule magnetic force spectroscopy techniques allowing for direct manipulation and dynamic observation of DNA mechanics and mechanically driven strand separation, we investigated how CpG and non-CpG cytosine methylation affects DNA micromechanical properties. We quantitatively characterized DNA stiffness using persistence length measurements from force-extension curves in the nanoscale length regime and demonstrated that cytosine methylation results in longer contour length and increased DNA flexibility (i.e., decreased persistence length). In addition, we observed the preferential formation of plectonemes over unwound single-stranded "bubbles" of DNA under physiologically relevant stretching forces and supercoiling densities. The flexibility and high structural stability of methylated DNA is likely to have significant consequences on the recruitment of proteins recognizing cytosine methylation and DNA packaging.
Angled Crested Like Water Waves with Surface Tension: Wellposedness of the Problem

We consider the capillary–gravity water wave equation in two dimensions. We assume that the fluid is inviscid, incompressible, irrotational and the air density is zero. We construct an energy functional and prove a local wellposedness result without assuming the Taylor sign condition. When the surface tension $$\sigma $$ is zero, the energy reduces to a lower order version of the energy obtained by Kinsey and Wu (Camb J Math 6(2):93–181, 2018) and allows angled crest interfaces. For positive surface tension, the energy does not allow angled crest interfaces but admits initial data with large curvature of the order of $$\sigma ^{-\frac{1}{3}+ \epsilon } $$ for any $$\epsilon >0$$ .
DomainNet: Homograph Detection for Data Lake Disambiguation.

Modern data lakes are deeply heterogeneous in the vocabulary that is used to describe data. We study a problem of disambiguation in data lakes: how can we determine if a data value occurring more than once in the lake has different meanings and is therefore a homograph? While word and entity disambiguation have been well studied in computational linguistics, data management and data science, we show that data lakes provide a new opportunity for disambiguation of data values since they represent a massive network of interconnected values. We investigate to what extent this network can be used to disambiguate values. DomainNet uses network-centrality measures on a bipartite graph whose nodes represent values and attributes to determine, without supervision, if a value is a homograph. A thorough experimental evaluation demonstrates that state-of-the-art techniques in domain discovery cannot be re-purposed to compete with our method. Specifically, using a domain discovery method to identify homographs has a precision and a recall of 38% versus 69% with our method on a synthetic benchmark. By applying a network-centrality measure to our graph representation, DomainNet achieves a good separation between homographs and data values with a unique meaning. On a real data lake our top-200 precision is 89%.
Avoiding a Confrontation?: How Courts Have Erred in Finding That Nontestimonial Hearsay Is Beyond the Scope of the Bruton Doctrine

The Bruton doctrine holds that the Confrontation Clause is violated by the admission at a joint jury trial of a nontestifying co-defendant’s confession that facially incriminates other defendants but is inadmissible against them under the rules of evidence. Under this doctrine, Co-Defendant’s confession to Police Officer that “Defendant and I killed Victim” could not be admitted unless Co-Defendant testified at trial. But what if Co-Defendant made his confession to his mother, his brother, his lover, or his friend? While the vast majority of courts before 2004 would have held that such “noncustodial” confessions violated the Bruton doctrine, the tables have turned in the wake of Crawford v. Washington, with most courts finding such “nontestimonial” confessions beyond the scope of the Bruton doctrine.This article argues that courts have erred in reaching this conclusion because the Bruton doctrine is a test of Constitutional harmfulness while Crawford, like its predecessor, Ohio v. Roberts, is a test of Constitutional (un)reliability. Moreover, even if Crawford deconstitutionalized the Bruton doctrine with regard to nontestimonial hearsay, courts should still find that the admission of nontestimonial co-defendant confessions violates the rules of evidence.
The long‐run effect of government ideology on economic freedom

According to popular attitudes in Western democracies, the choice between right‐wing and left‐wing parties is a choice between socialism and unbridled free markets. In contrast, the cold and staid research of academia has frequently concluded that particular political parties do not really matter, as whichever party is elected will be closely tethered to the will of the median voter. This article considers the effects of the ideology of parties in power over the long run (1928–95) on economic freedom in subsequent periods. Right‐wing governments are found to have modest, positive effects on economic freedom, but the effects are not particularly robust. The findings here are consistent with others elsewhere, which conclude that there is minor, uneven evidence of an effect. Nonetheless, historically small effects may not be indicative of the future, should these effects be poorly indicative of today's tumultuous political landscape.
Nowcasting the trajectory of the COVID-19 recovery

I develop a weekly coincident index of economic activity in the State of Hawaii. The purpose of the index is to nowcast the recovery from the COVID-19 induced downturn. The index is the first princ...
Observation of a potential-dependent switch of water-oxidation mechanism on Co-oxide-based catalysts

Summary O–O bond formation is a key elementary step of the water-oxidation reaction. However, it is still unclear how the mechanism of O–O coupling depends on the applied electrode potential. Herein, using water-in-salt electrolytes, we systematically altered the water activity, which enabled us to probe the O–O bond-forming mechanism on heterogeneous Co-based catalysts as a function of applied potential. We discovered that the water-oxidation mechanism is sensitive to the applied potential: At relatively low driving force, the reaction proceeds through an intramolecular oxygen coupling mechanism, whereas the water nucleophilic attack mechanism prevails at high driving force. The observed mechanistic switch has major implications for the understanding and control of the water-oxidation reaction on heterogeneous catalysts.
A non-volatile cryogenic random-access memory based on the quantum anomalous Hall effect

The interplay between ferromagnetism and topological properties of electronic band structures leads to a precise quantization of Hall resistance without any external magnetic field. This so-called quantum anomalous Hall effect (QAHE) is born out of topological correlations, and is oblivious of low-sample quality. It was envisioned to lead towards dissipation-less and topologically protected electronics. However, no clear framework of how to design such an electronic device out of it exists. Here we construct an ultra-low power, non-volatile, cryogenic memory architecture leveraging the QAHE phenomenon. Our design promises orders of magnitude lower cell area compared with the state-of-the-art cryogenic memory technologies. We harness the fundamentally quantized Hall resistance levels in moire graphene heterostructures to store non-volatile binary bits (1, 0). We perform the memory write operation through controlled hysteretic switching between the quantized Hall states, using nano-ampere level currents with opposite polarities. The non-destructive read operation is performed by sensing the polarity of the transverse Hall voltage using a separate pair of terminals. We custom design the memory architecture with a novel sensing mechanism to avoid accidental data corruption, ensure highest memory density and minimize array leakage power. Our design provides a pathway towards realizing topologically protected memory devices.
Dynamic foot morphology explained through 4D scanning and shape modeling.

Abstract A detailed understanding of foot morphology can enable the design of more comfortable and better fitting footwear. However, foot morphology varies widely within the population, and changes dynamically as the foot is loaded during stance. This study presents a parametric statistical shape model from 4D foot scans to capture both the inter- and intra-individual variability in foot morphology. Thirty subjects walked on a treadmill while 4D scans of their right foot were taken at 90 frames-per second during stance phase. Each subject’s height, weight, foot length, foot width, arch length, and sex were also recorded. The 4D scans were all registered to a common high-quality foot scan, and a principal component analysis was done on all processed 4D scans. Elastic-net linear regression models were built to predict the principal component scores, which were then inverse transformed into 4D scans. The best performing model was selected with leave-one-out cross-validation. The chosen model predicts foot morphology across stance phase with a root-mean-square error of 5.2 ± 2.0 mm and a mean Hausdorff distance of 25.5 ± 13.4 mm. This study shows that statistical shape modeling can be used to predict dynamic changes in foot morphology across the population. The model can be used to investigate and improve foot-footwear interaction, allowing for better fitting and more comfortable footwear.
Hindsight Expectation Maximization for Goal-conditioned Reinforcement Learning

We propose a graphical model framework for goal-conditioned RL, with an EM algorithm that operates on the lower bound of the RL objective. The E-step provides a natural interpretation of how 'learning in hindsight' techniques, such as HER, to handle extremely sparse goal-conditioned rewards. The M-step reduces policy optimization to supervised learning updates, which greatly stabilizes end-to-end training on high-dimensional inputs such as images. We show that the combined algorithm, hEM significantly outperforms model-free baselines on a wide range of goal-conditioned benchmarks with sparse rewards.
A Finite Time Combinatorial Algorithm for Instantaneous Dynamic Equilibrium Flows

Instantaneous dynamic equilibrium (IDE) is a standard game-theoretic concept in dynamic traffic assignment in which individual flow particles myopically select en route currently shortest paths towards their destination. We analyze IDE within the Vickrey bottleneck model, where current travel times along a path consist of the physical travel times plus the sum of waiting times in all the queues along a path. Although IDE have been studied for decades, no exact finite time algorithm for equilibrium computation is known to date. As our main result we show that a natural extension algorithm needs only finitely many phases to converge leading to the first finite time combinatorial algorithm computing an IDE. We complement this result by several hardness results showing that computing IDE with natural properties is NP-hard.
Doomed Steamers and Merged Fires: The Problem of Preempted Innocent Threats in Torts

This article addresses a classic question of tort theory: When a court assesses damages in a negligence action, is it relevant that the defendant’s negligence prevented the plaintiff from suffering a later unrelated harm? For example, defendant Taxi Driver negligently crashes his taxi thereby injuring plaintiff Passenger. Is it relevant that because of the accident Passenger did not reach the ocean liner he had been planning to sail on and, as a result, his life was saved because the ocean liner sank, killing everyone aboard?Though this question has been recognized and addressed for almost a century, there is no consensus among either courts or commentators on its proper answer. Some take the position that because the defendant’s negligent conduct actually benefited the plaintiff, there should be no recovery. Others take the position that because the benefit provided – avoidance of drowning – was unforeseeable it should not reduce the plaintiff’s recovery. This article reviews and critiques the existing literature on the topic and provides a new, superior, answer: The preemption of an innocent threat, such as the threat of being drowned on an ocean liner, is relevant to the extent, and only the extent, that the harm preempted is identical to the harm that would have befallen the plaintiff if not for the negligence. Thus some, but not full, reduction in recovery is appropriate. The article defends this position as coherent, intuitively correct and supported by existing law.
The Power of D-hops in Matching Power-Law Graphs

This paper studies seeded graph matching for power-law graphs. Assume that two edge-correlated graphs are independently edge-sampled from a common parent graph with a power-law degree distribution. A set of correctly matched vertex-pairs is chosen at random and revealed as initial seeds. Our goal is to use the seeds to recover the remaining latent vertex correspondence between the two graphs. Departing from the existing approaches that focus on the use of high-degree seeds in $1$-hop neighborhoods, we develop an efficient algorithm that exploits the low-degree seeds in suitably-defined D-hop neighborhoods. Specifically, we first match a set of vertex-pairs with appropriate degrees (which we refer to as the first slice) based on the number of low-degree seeds in their D-hop neighborhoods. This approach significantly reduces the number of initial seeds needed to trigger a cascading process to match the rest of graphs. Under the Chung-Lu random graph model with n vertices, max degree Θ(√n), and the power-law exponent 2 4-β/3-β, by optimally choosing the first slice, with high probability our algorithm can correctly match a constant fraction of the true pairs without any error, provided with only Ω((log n)4-β) initial seeds. Our result achieves an exponential reduction in the seed size requirement, as the best previously known result requires n1/2+e seeds (for any small constant e>0). Performance evaluation with synthetic and real data further corroborates the improved performance of our algorithm.
MetaXL: Meta Representation Transformation for Low-resource Cross-lingual Learning

The combination of multilingual pre-trained representations and cross-lingual transfer learning is one of the most effective methods for building functional NLP systems for low-resource languages. However, for extremely low-resource languages without large-scale monolingual corpora for pre-training or sufficient annotated data for fine-tuning, transfer learning remains an understudied and challenging task. Moreover, recent work shows that multilingual representations are surprisingly disjoint across languages, bringing additional challenges for transfer onto extremely low-resource languages. In this paper, we propose MetaXL, a meta-learning based framework that learns to transform representations judiciously from auxiliary languages to a target one and brings their representation spaces closer for effective transfer. Extensive experiments on real-world low-resource languages – without access to large-scale monolingual corpora or large amounts of labeled data – for tasks like cross-lingual sentiment analysis and named entity recognition show the effectiveness of our approach. Code for MetaXL is publicly available at github.com/microsoft/MetaXL.
A Cell Atlas of the Adult Drosophila Midgut

Studies on the adult Drosophila midgut have led many insights on our understanding of cell type diversity, stem cell regeneration, tissue homeostasis and cell fate decision. Advances in scRNA-seq provide opportunities to identify new cell types and molecular features. We used inDrop to characterize the transcriptome of midgut epithelial cells and identified 12 distinct clusters representing intestinal stem cells (ISCs), enteroblasts (EBs), enteroendocrine cells (EEs), and enterocytes (ECs). This unbiased approach recovered 90% of the known ISCs/EBs markers highlighting the high quality of the dataset and led to new insights on ISCs cell biology, the roles of new transcription factors, and EEs hormonal expression diversity. To facilitate, mining of the richness of the data set, we provide a web-based resource for visualization of gene expression in single cells. Altogether, our study provides a comprehensive resource for addressing novel functions of genes in the midgut epithelium.
The transmission problem in linear isotropic elasticity

We study the isotropic elastic wave equation in a bounded domain with boundary with coefficients having jumps at a nested set of interfaces satisfying the natural transmission conditions there. We analyze in detail the microlocal behavior of such solution like reflection, transmission and mode conversion of S and P waves, evanescent modes, Rayleigh and Stoneley waves. In particular, we recover Knott's equations in this setting. We show that knowledge of the Dirichlet-to-Neumann map determines uniquely the speed of the P and the S waves if there is a strictly convex foliation with respect to them, under an additional condition of lack of full internal reflection of some of the waves.
Combinatorial Blocking Bandits with Stochastic Delays

Recent work has considered natural variations of the multi-armed bandit problem, where the reward distribution of each arm is a special function of the time passed since its last pulling. In this direction, a simple (yet widely applicable) model is that of blocking bandits, where an arm becomes unavailable for a deterministic number of rounds after each play. In this work, we extend the above model in two directions: (i) We consider the general combinatorial setting where more than one arms can be played at each round, subject to feasibility constraints. (ii) We allow the blocking time of each arm to be stochastic. We first study the computational/unconditional hardness of the above setting and identify the necessary conditions for the problem to become tractable (even in an approximate sense). Based on these conditions, we provide a tight analysis of the approximation guarantee of a natural greedy heuristic that always plays the maximum expected reward feasible subset among the available (non-blocked) arms. When the arms' expected rewards are unknown, we adapt the above heuristic into a bandit algorithm, based on UCB, for which we provide sublinear (approximate) regret guarantees, matching the theoretical lower bounds in the limiting case of absence of delays.
Design of an aircraft vortex spacing system for airport capacity improvement

The National Aeronautics and Space Administration (NASA) is addressing airport capacity enhancements through the Terminal Area Productivity (TAP) program. Within TAP, the Reduced Spacing Operations element at the NASA Langley Research Center is developing an Aircraft VOrtex Spacing System (AVOSS). AVOSS will integrate the output of several systems to produce weather dependent, dynamic wake vortex spacing criteria. These systems provide current and predicted weather conditions, models of wake vortex transport and decay in these weather conditions, and real-time feedback of wake vortex behavior from sensors. The goal of the NASA program is to provide the research and development to demonstrate an engineering model AVOSS, in real-time operation, at a major airport. A wake vortex system test facility was established at the Dallas-Fort Worth International Airport (DFW) in 1997 and tested in 1998. Results from operation of the initial AVOSS system, plus advances in wake vortex prediction and near-term weather forecast models, "nowcast", have been integrated into a second-generation system. This AVOSS version is undergoing final checkout in preparation for a system demonstration in 2000. This paper describes the revised AVOSS system architecture, subsystem enhancements, and initial results with AVOSS version 2 from a deployment at DFW in the fall of 1999.
Are NLP Models really able to Solve Simple Math Word Problems

The problem of designing NLP solvers for math word problems (MWP) has seen sustained research activity and steady gains in the test accuracy. Since existing solvers achieve high performance on the benchmark datasets for elementary level MWPs containing one-unknown arithmetic word problems, such problems are often considered “solved” with the bulk of research attention moving to more complex MWPs. In this paper, we restrict our attention to English MWPs taught in grades four and lower. We provide strong evidence that the existing MWP solvers rely on shallow heuristics to achieve high performance on the benchmark datasets. To this end, we show that MWP solvers that do not have access to the question asked in the MWP can still solve a large fraction of MWPs. Similarly, models that treat MWPs as bag-of-words can also achieve surprisingly high accuracy. Further, we introduce a challenge dataset, SVAMP, created by applying carefully chosen variations over examples sampled from existing datasets. The best accuracy achieved by state-of-the-art models is substantially lower on SVAMP, thus showing that much remains to be done even for the simplest of the MWPs.
The Unseen Track of Erie Railroad: Why History and Jurisprudence Suggest a More Straightforward Form of Erie Analysis

Since announcing Erie Railroad v. Tompkins in 1938, the Court has developed, discussed and applied Erie’s doctrine by attempting to decide whether the state and federal rules potentially governing the issue in question are substantive or procedural. That is often not an easy characterization to make, and it depends greatly on context. Statutes of limitation, for example, are substantive for Erie purposes but procedural for most other choice-of-law purposes. The result has been uncertainty and confusion in applying the Erie doctrine. This article suggests that there is a better way to understand the doctrine and to predict how the Court will decide vertical choice-of-law questions in future. If one uses the lens of interest balancing, the most common horizontal choice-of-law technique today, to understand the Court’s decisions, they make a lot more sense and, in fact, display a coherence long thought to be lacking in Erie jurisprudence. The doctrine becomes easier to understand and to apply, and the interest-balancing analysis dispenses with the centrality of the question of whether a particular rule or issue is substantive or procedural.
Centrosomal P4.1-associated protein (CPAP) positively regulates endocytic vesicular transport and lysosome targeting of EGFR

Centrosomal P4.1-associated protein (CPAP) plays a critical role in restricting the centriole length in human cells. Here, we report a novel, positive regulatory influence for CPAP on endocytic vesicular transport (EVT) and lysosome targeting of internalized-cell surface receptor EGFR. We observed that higher CPAP levels cause an increase in the abundance of multi-vesicular body (MVB) and EGFR is detectable in CPAP-overexpression induced puncta. The surface and cellular levels of EGFR are higher under CPAP deficiency and lower under CPAP overexpression. While ligand-engagement induced internalization or routing of EGFR into early endosomes is not influenced by cellular levels of CPAP, we found that targeting of ligand-activated, internalized EGFR to lysosome is impacted by CPAP levels. Transport of ligand-bound EGFR from early endosome to late endosome/MVB and lysosome is diminished in CPAP-depleted cells. Moreover, CPAP depleted cells appear to show a diminished ability to form MVB structures upon EGFR activation. These observations suggest a positive regulatory effect of CPAP on EVT of ligand-bound EGFR-like cell surface receptors to MVB and lysosome. Overall, identification of a non-centriolar function of CPAP in endocytic trafficking provides new insights in understanding the non-canonical cellular functions of CPAP.