cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of Local Dissipation Profiles on Magnetized Accretion Disk Spectra

We present spectral calculations of non-LTE accretion disk models appropriate for high-luminosity stellar mass black hole X-ray binary systems. We first use a dissipation profile based on scaling the results of shearing box simulations of Hirose et al. to a range of annuli parameters. We simultaneously scale the effective temperature, orbital frequency, and surface density with luminosity and radius according to the standard α-model. This naturally brings increased dissipation to the disk surface layers (around the photospheres) at small radii and high luminosities. We find that the local spectrum transitions directly from a modified blackbody to a saturated Compton scattering spectrum as we increase the effective temperature and orbital frequency while decreasing midplane surface density. Next, we construct annuli models based on the parameters of a L/L Edd = 0.8 disk orbiting a 6.62 solar mass black hole using two modified dissipation profiles that explicitly put more dissipation per unit mass near the disk surface. The new dissipation profiles are qualitatively similar to the one found by Hirose et al., but produce strong near power-law spectral tails. Our models also include physically motivated magnetic acceleration support based once again on scaling the Hirose et al. results. We present three full-disk spectra, each based on one of the dissipation prescriptions. Our most aggressive dissipation profile results in a disk spectrum that is in approximate quantitative agreement with certain observations of the steep power-law spectral states from some black hole X-ray binaries.
A Shift Selection Strategy for Parallel Shift-invert Spectrum Slicing in Symmetric Self-consistent Eigenvalue Computation

The central importance of large-scale eigenvalue problems in scientific computation necessitates the development of massively parallel algorithms for their solution. Recent advances in dense numerical linear algebra have enabled the routine treatment of eigenvalue problems with dimensions on the order of hundreds of thousands on the world’s largest supercomputers. In cases where dense treatments are not feasible, Krylov subspace methods offer an attractive alternative due to the fact that they do not require storage of the problem matrices. However, demonstration of scalability of either of these classes of eigenvalue algorithms on computing architectures capable of expressing massive parallelism is non-trivial due to communication requirements and serial bottlenecks, respectively. In this work, we introduce the SISLICE method: a parallel shift-invert algorithm for the solution of the symmetric self-consistent field (SCF) eigenvalue problem. The SISLICE method drastically reduces the communication requirement of current parallel shift-invert eigenvalue algorithms through various shift selection and migration techniques based on density of states estimation and k-means clustering, respectively. This work demonstrates the robustness and parallel performance of the SISLICE method on a representative set of SCF eigenvalue problems and outlines research directions that will be explored in future work.
THE CARBON CONTENT OF INTERGALACTIC GAS AT z = 4.25 AND ITS EVOLUTION TOWARD z = 2.4

This paper presents ionization-corrected measurements of the carbon abundance in intergalactic gas at 4.0 < z < 4.5, using spectra of three bright quasars obtained with the MIKE spectrograph on Magellan. By measuring the C iv strength in a sample of 131 discrete H i-selected quasar absorbers with �/¯ � ≥ 1.6, we derive a median carbon abundance of [C/H]= −3.55, with lognormal scatter of approximately � ≈ 0.8 dex. This median value is a factor of two to three lower than similar measurements made at z ∼ 2.4 using C iv and O vi. The strength of evolution is modestly dependent on the choice of UV background spectrum used to make ionization corrections, although our detection of an abundance evolution is generally robust with respect to this model uncertainty. We present a framework for analyzing the effects of spatial fluctuations in the UV ionizing background at frequencies relevant for C iv production. We also explore the effects of reduced flux between 3-4 Rydbergs (as from He ii Lyman series absorption) on our abundance estimates. At He ii line absorption levels similar to published estimates the effects are very small, although a larger optical depth could reduce the strength of the abundance evolution. Our results imply that ∼ 50% of the heavy elements seen in the IGM at z ∼ 2.4 were deposited in the 1.3 Gyr between z ∼ 4.3 and z ∼ 2.4. The total implied mass flux of carbon into the Ly-� forest would constitute ∼ 30% of the IMF-weighted carbon yield from known star forming populations over this period. Subject headings: quasars : absorption lines; intergalactic medium
Supersymmetry Breaking by Fluxes

Type II string theory and M-theory admit flux configurations that break supersymmetry below the Kaluza-Klein scale. These backgrounds play a central role in most models of the string landscape. I argue that the behavior of such backgrounds at weak coupling is generically a rolling solution, not a static space-time. Quantum corrections to the space-time potential are computed around this classical time-dependent background. This is particularly important for non-perturbative corrections. This change in perspective offers an explanation for why there appear to be many effective field theory models that seemingly evade the known no-go theorems forbidding de Sitter space-times. This has interesting implications for type IIB string landscape models.
Renormalization group flows from gravity in anti-de Sitter space versus black hole no-hair theorems

Black hole no-hair theorems are proven using inequalities that govern the radial dependence of spherically symmetric configurations of matter fields. In this paper, we analyze the analogous inequalities for geometries dual to renormalization group flows via the AdS/CFT correspondence. These inequalities give much useful information about the qualitative properties of such flows. For Poincare invariant flows, we show that generic flows of relevant or irrelevant operators lead to singular geometries. For the case of irrelevant operators, this leads to an apparent conflict with Polchinski's decoupling theorem, and we offer two possible resolutions to this problem.
Angular Power Spectra of the COBE DIRBE Maps

The angular power spectra of the infrared maps obtained by the Diffuse Infrared Background Experiment (DIRBE) instrument on the COBE satellite have been obtained by two methods: (1) the Hauser-Peebles method previously applied to the Differential Microwave Radiometer experiment maps, and (2) by Fourier transforming portions of the all-sky maps projected onto a plane. The two methods give consistent results, and the power spectrum of the high-latitude dust emission is Cl l-3 in the range 2 < l < 300.
Quarkonium from the fifth dimension

Adding fundamental matter of mass mQ to = 4 Yang Mills theory, we study quarkonium, and ``generalized quarkonium'' containing light adjoint particles. At large 't Hooft coupling the states of spin ≤ 1 are anomalously light [10]. We examine their form factors, and show these hadrons are unlike any known in QCD. By a traditional yardstick they appear infinite in size (as with strings in flat space) but we show that this is a failure of the yardstick. All of the hadrons are actually of finite size ~ (g2N)1/2/mQ, regardless of their radial excitation level and of how many valence adjoint particles they contain. Certain form factors for spin-1 quarkonia vanish in the large-g2N limit; thus these hadrons resemble neither the observed J/Ψ quarkonium states nor ρ mesons.
Minimal surfaces bounded by elastic lines

￻￻ ￻ In mathematics, the classical Plateau problem consists of finding the surface of least area that spans a given rigid boundary curve. A physical realization of the problem is obtained by dipping a stiff wire frame of some given shape in soapy water and then removing it; the shape of the spanning soap film is a solution to the Plateau problem. But what happens if a soap film spans a loop of inextensible but flexible wire? We consider this simple query that couples Plateau’s problem to Euler’s Elastica: a special class of twist-free curves of given length that minimize their total squared curvature energy. The natural marriage of two of the oldest geometrical problems linking physics and mathematics leads to a quest for the shape of a minimal surface bounded by an elastic line: the Euler–Plateau problem. We use a combination of simple physical experiments with soap films that span soft filaments and asymptotic analysis combined with numerical simulations to explore some of the richness of the shapes that result. Our study raises questions of intrinsic interest in geometry and its natural links to a range of disciplines, including materials science, polymer physics, architecture and even art.
BI-HAMILTONIAN STRUCTURE OF THE SUPERSYMMETRIC NONLINEAR SCHRÖDINGER EQUATION

We show that the supersymmetric nonlinear Schrodinger equation is a bi-Hamiltonian integrable system. We obtain the two Hamiltonian structures of the theory from the ones of the supersymmetric two-boson hierarchy through a field redefinition. We also show how the two Hamiltonian structures of the supersymmetric KdV equation can also be derived from a Hamiltonian reduction of the supersymmetric two-boson hierarchy.
Turbulent Mixing in Stars: Theoretical Hurdles

A program is outlined, and first results described, in which fully three-dimensional, time dependent simulations of hydrodynamic turbulence are used as a basis for theoretical investigation of the physics of turbulence. The inadequacy of the treatment of turbulent convection as a diffusive process is indicated. A generalization to rotation and magnetohydrodynamics is indicated, as are connections to simulations of 3D stellar atmospheres.
Contact inequality: first contact will likely be with an older civilization

First contact with another civilization, or simply another intelligence of some kind, will likely be quite different depending on whether that intelligence is more or less advanced than ourselves. If we assume that the lifetime distribution of intelligences follows an approximately exponential distribution, one might naively assume that the pile-up of short-lived entities dominates any detection or contact scenario. However, it is argued here that the probability of contact is proportional to the age of said intelligence (or possibly stronger), which introduces a selection effect. We demonstrate that detected intelligences will have a mean age twice that of the underlying (detected + undetected) population, using the exponential model. We find that our first contact will most likely be with an older intelligence, provided that the maximum allowed mean lifetime of the intelligence population, τmax, is ≥ e times larger than our own. Older intelligences may be rare but they disproportionately contribute to first contacts, introducing what we call a ‘contact inequality’, analogous to wealth inequality. This reasoning formalizes intuitional arguments and highlights that first contact would likely be one-sided, with ramifications for how we approach SETI.
Anisotropic thermal conductivity of 4H and 6H silicon carbide measured using time-domain thermoreflectance

Abstract Silicon carbide (SiC) is a wide bandgap (WBG) semiconductor with promising applications in high-power and high-frequency electronics. Among its many useful properties, the high thermal conductivity is crucial. In this letter, the anisotropic thermal conductivity of three SiC samples, n-type 4H-SiC (N-doped 1 × 1019 cm−3), unintentionally doped (UID) semi-insulating (SI) 4H-SiC, and SI 6H-SiC (V-doped 1 × 1017 cm−3), is measured using femtosecond laser based time-domain thermoreflectance (TDTR) over a temperature range from 250 K to 450 K. We simultaneously measure the thermal conductivity parallel to ( k r ) and across the hexagonal plane ( k z ) for SiC by choosing the appropriate laser spot radius and the modulation frequency for the TDTR measurements. For both k r and k z , the following decreasing order of thermal conductivity value is observed: SI 4H-SiC > n-type 4H-SiC > SI 6H-SiC. This work serves as an important benchmark for understanding thermal transport in WBG semiconductors.
Learning Contextual Bandits in a Non-stationary Environment

Multi-armed bandit algorithms have become a reference solution for handling the explore/exploit dilemma in recommender systems, and many other important real-world problems, such as display advertisement. However, such algorithms usually assume a stationary reward distribution, which hardly holds in practice as users' preferences are dynamic. This inevitably costs a recommender system consistent suboptimal performance. In this paper, we consider the situation where the underlying distribution of reward remains unchanged over (possibly short) epochs and shifts at unknown time instants. In accordance, we propose a contextual bandit algorithm that detects possible changes of environment based on its reward estimation confidence and updates its arm selection strategy respectively. Rigorous upper regret bound analysis of the proposed algorithm demonstrates its learning effectiveness in such a non-trivial environment. Extensive empirical evaluations on both synthetic and real-world datasets for recommendation confirm its practical utility in a changing environment.
Toward a Conformal Field Theory for the Quantum Hall Effect

An effective Hamiltonian for the study of the quantum Hall effect is proposed. This Hamiltonian, which includes a "current-current" interaction has the form of a Hamiltonian for a conformal field theory in the large N limit. An order parameter is constructed from which the Hamiltonian may be derived. This order parameter may be viewed as either a collective coordinate for a system of N charged particles in a strong magnetic field; or as a field of spins associated with the cyclotron motion of these particles.
Bispectrality of Multivariable Racah–Wilson Polynomials

We construct a commutative algebra ${\mathcal{A}}_{x}$ of difference operators in ℝ p , depending on p+3 parameters, which is diagonalized by the multivariable Racah polynomials R p (n;x) considered by Tratnik (J. Math. Phys. 32(9):2337–2342, 1991). It is shown that for specific values of the variables x=(x 1,x 2,…,x p ) there is a hidden duality between n and x. Analytic continuation allows us to construct another commutative algebra ${\mathcal{A}}_{n}$ in the variables n=(n 1,n 2,…,n p ) which is also diagonalized by R p (n;x). Thus, R p (n;x) solve a multivariable discrete bispectral problem in the sense of Duistermaat and Grunbaum (Commun. Math. Phys. 103(2):177–240, 1986). Since a change of the variables and the parameters in the Racah polynomials gives the multivariable Wilson polynomials (Tratnik in J. Math. Phys. 32(8):2065–2073, 1991), this change of variables and parameters in ${\mathcal{A}}_{x}$ and ${\mathcal{A}}_{n}$ leads to bispectral commutative algebras for the multivariable Wilson polynomials.
CONJUGATE GENERATORS OF KNOT AND LINK GROUPS

This note establishes a stronger version of a conjecture of Reid and others in the arithmetic case: if two elements of equal trace (e.g. conjugate elements) generate an arithmetic two-bridge knot or link group, then the elements are parabolic (and hence peripheral). This includes the figure-eight knot and Whitehead link groups. Similarly, if two conjugate elements generate the trefoil knot group, then the elements are peripheral.
Obtaining presentations from group actions without making choices

Consider a group G acting nicely on a simply-connected simplicial complex X . Numerous classical methods exist for using this group action to produce a presentation for G. For the case that X/G is 2-connected, we give a new method that has the novelty that one does not have to identify a fundamental domain for the action. Indeed, the resulting presentation is canonical in the sense that no arbitrary choices need to be made. It can be viewed as a nonabelian analogue of a simple result in the study of equivariant homology.
Garbage in, garbage out?: do machine learning application papers in social computing report where human-labeled training data comes from?

Many machine learning projects for new application areas involve teams of humans who label data for a particular purpose, from hiring crowdworkers to the paper's authors labeling the data themselves. Such a task is quite similar to (or a form of) structured content analysis, which is a longstanding methodology in the social sciences and humanities, with many established best practices. In this paper, we investigate to what extent a sample of machine learning application papers in social computing --- specifically papers from ArXiv and traditional publications performing an ML classification task on Twitter data --- give specific details about whether such best practices were followed. Our team conducted multiple rounds of structured content analysis of each paper, making determinations such as: Does the paper report who the labelers were, what their qualifications were, whether they independently labeled the same items, whether inter-rater reliability metrics were disclosed, what level of training and/or instructions were given to labelers, whether compensation for crowdworkers is disclosed, and if the training data is publicly available. We find a wide divergence in whether such practices were followed and documented. Much of machine learning research and education focuses on what is done once a "gold standard" of training data is available, but we discuss issues around the equally-important aspect of whether such data is reliable in the first place.
Spatially Resolved Properties of Galaxies from CANDELS+MUSE: Radial Extinction Profile and Insights on Quenching

Studying the internal processes of individual galaxies at kilo-parsec scales is crucial in enhancing our understanding of galaxy formation and evolution processes. In this work, we investigate the distribution of star formation rate (SFR), specific SFR (sSFR), and dust attenuation across individual galaxies for a sample of 32 galaxies selected from the MUSE-Wide Survey at 0.1 $< \textit{z} <$ 0.42 with a dynamic range in stellar masses between $10^{7.7}$ and $10^{10.3}$ M$_{\odot}$. We take advantage of the high spatial resolution of the MUSE integral-field spectrograph and measure reliable spatially resolved H$\alpha$ and H$\beta$ emission line maps for individual galaxies. We also derive resolved stellar mass, SFR and dust maps using pixel-by-pixel SED fitting on high resolution multi-band HST/ACS and HST/WFC3 data from the CANDELS survey. By combining these, we analyze the radial profile of various physical parameters across these galaxies. We observe a radial dependence in both stellar and nebular color excess profiles peaking at the inner regions of galaxies. We also find the color excess profiles to most strongly correlate with the integrated sSFRs of galaxies. The median sSFR$_{\mathrm{H}\alpha}$ radial profiles of galaxies in our sample show a 0.8 dex increase from the central regions outward. This increase compared to the almost flat median radial profile of sSFR$_{\mathrm{SED}}$, which traces longer timescales of star formation, is in favor of the inside-out quenching of star formation. We bring further evidence for this quenching scenario from the locus of different subregions of galaxies on the SFR-M$_{*}$ and sSFR-M$_{*}$ relations.
Offline Contextual Multi-armed Bandits for Mobile Health Interventions: A Case Study on Emotion Regulation

Delivering treatment recommendations via pervasive electronic devices such as mobile phones has the potential to be a viable and scalable treatment medium for long-term health behavior management. But active experimentation of treatment options can be time-consuming, expensive and altogether unethical in some cases. There is a growing interest in methodological approaches that allow an experimenter to learn and evaluate the usefulness of a new treatment strategy before deployment. We present the first development of a treatment recommender system for emotion regulation using real-world historical mobile digital data from n = 114 high socially anxious participants to test the usefulness of new emotion regulation strategies. We explore a number of offline contextual bandits estimators for learning and propose a general framework for learning algorithms. Our experimentation shows that the proposed doubly robust offline learning algorithms performed significantly better than baseline approaches, suggesting that this type of recommender algorithm could improve emotion regulation. Given that emotion regulation is impaired across many mental illnesses and such a recommender algorithm could be scaled up easily, this approach holds potential to increase access to treatment for many people. We also share some insights that allow us to translate contextual bandit models to this complex real-world data, including which contextual features appear to be most important for predicting emotion regulation strategy effectiveness.
Homotopy groups and twisted homology of arrangements

Now M is the complement of a real codimension two subset of R and so has numerous topological properties of interest. Here we focus on the homotopy theory of the complement. Since the fundamental group of the complement D 1.M /is fairly rich in structure, it makes sense to look at covers of the complement. Equivalently one may look at homology or homotopy with coefficients in RD ZŒ  modules or at local system homology. Two results motivate this study. The first is found in Randell [10]; the untwisted Hurewicz homomorphism hW k.M /! Hk.M IZ/ is trivial for k > 1. On the other hand, Yoshinaga [12] has shown that the twisted Hurewicz homomorphism maps onto certain twisted homology for nonresonant local systems, in the case that M is a generic section of another hyperplane arrangement. In this work we generalize both these results while giving a unified treatment.
A systematic study of chloride ion solvation in water using van der Waals inclusive hybrid density functional theory

In this work, the solvation and electronic structure of the aqueous chloride ion solution was investigated using density functional theory (DFT) based ab initio molecular dynamics (AIMD). From an analysis of radial distribution functions, coordination numbers, and solvation structures, we found that exact exchange (Exx) and non-local van der Waals (vdW) interactions effectively weaken the interactions between the Cl− ion and the first solvation shell. With a Cl–O coordination number in excellent agreement with experiment, we found that most configurations generated with vdW-inclusive hybrid DFT exhibit sixfold coordinated distorted trigonal prism structures, which is indicative of a significantly disordered first solvation shell. By performing a series of band structure calculations on configurations generated from AIMD simulations with varying DFT potentials, we found that the solvated ion orbital energy levels (unlike the band structure of liquid water) strongly depend on the underlying molecular struct...
Wang and Yau’s quasi-local energy for an extreme Kerr spacetime

There exist constant radial surfaces, $\mathcal{S}$, that may not be globally embeddable in $\mathbb{R}^3$ for Kerr spacetimes with $a>\sqrt{3}M/2$. To compute the Brown and York (B-Y) quasi-local energy (QLE), one must isometrically embed $\mathcal{S}$ into $\mathbb{R}^3$. On the other hand, the Wang and Yau (W-Y) QLE embeds $\mathcal{S}$ into Minkowski space. In this paper, we examine the W-Y QLE for surfaces that may or may not be globally embeddable in $\mathbb{R}^3$. We show that their energy functional, $E[\tau]$, has a critical point at $\tau=0$ for all constant radial surfaces in $t=constant$ hypersurfaces using Boyer-Lindquist coordinates. For $\tau=0$, the W-Y QLE reduces to the B-Y QLE. To examine the W-Y QLE in these cases, we write the functional explicitly in terms of $\tau$ under the assumption that $\tau$ is only a function of $\theta$. We then use a Fourier expansion of $\tau\left(\theta\right)$ to explore the values of $E[\tau\left(\theta\right)]$ in the space of coefficients. From our analysis, we discovered an open region of complex values for $E[\tau\left(\theta\right)]$. We also study the physical properties of the smallest real value of $E[\tau\left(\theta\right)]$, which lies on the boundary separating real and complex energies.
Coupling MOS quantum dot and phosphorous donor qubit systems

Si-MOS based QD qubits are attractive due to their similarity to the current semiconductor industry. We introduce a highly tunable MOS foundry compatible qubit design that couples an electrostatic quantum dot (QD) with an implanted donor. We show for the first time coherent two-axis control of a two-electron spin logical qubit that evolves under the QD-donor exchange interaction and the hyperfine interaction with the donor nucleus. The two interactions are tuned electrically with surface gate voltages to provide control of both qubit axes. Qubit decoherence is influenced by charge noise, which is of similar strength as epitaxial systems like GaAs and Si/SiGe.
Carbon Chain Molecules toward Embedded Low-mass Protostars

Carbon chain molecules may be an important reservoir of reactive organics during star and planet formation. Carbon chains have been observed toward several low-mass young stellar objects (YSOs), but their typical abundances and chemical relationships in such sources are largely unconstrained. We present a carbon chain survey toward 16 deeply embedded (Class 0/I) low-mass protostars made with the IRAM 30 m telescope. Carbon chains are found to be common at this stage of protostellar evolution. We detect CCS, CCCS, HC$_3$N, HC$_5$N, l-C$_3$H, and C$_4$H toward 88%, 38%, 75%, 31%, 81%, and 88% of sources, respectively. Derived column densities for each molecule vary by one to two orders of magnitude across the sample. As derived from survival analysis, median column densities range between 1.2$\times 10^{11}$ cm$^{-2}$ (CCCS) and 1.5$\times 10^{13}$ cm$^{-2}$ (C$_4$H) and estimated fractional abundances with respect to hydrogen range between 2$\times 10^{-13}$ (CCCS) and 5$\times 10^{-11}$ (C$_4$H), which are low compared to cold cloud cores, warm carbon chain chemistry (WCCC) sources, and protostellar model predictions. We find significant correlations between molecules of the same carbon chain families, as well as between the cyanpolyynes (HC$_{\rm n}$N) and the pure hydrocarbon chains (C$_{\rm n}$H). This latter correlation is explained by a closely-related production chemistry of C$_{\rm{n}}$H and cyanpolyynes during low-mass star formation.
Experimental study of consumer responses to different sources of information about prescription drugs

Abstract Consumers receive risk information about prescription drugs from many sources, including from largely unregulated attorney advertisements. This experiment measures subjective risk beliefs about prescription drugs and subjects’ drug-taking behavior in an incentivized setting. Results of the experiment are used to estimate a Bayesian learning model to ascertain the risk levels implied by different information sources and the informational weights subjects place on these sources. Even after people have received scientifically based drug risk information from a doctor and product label, attorney litigation advertising boosts risk beliefs about side effects by an average of 16 out of 100 cases, which is roughly a 50% increase over baseline risk beliefs. Risk beliefs have a significant effect on drug-taking behavior in an incentivized environment. Experience with taking the drug also feeds back into the learning process about risk beliefs. Our experimental results help formalize how consumers update risk beliefs and suggest ways to encourage a learning environment that avoids alarmist updating based on information sources like attorney advertising.
“Watch Me!” Training Increases Knowledge and Impacts Attitudes Related to Developmental Monitoring and Referral Among Childcare Providers

To evaluate the impact of “Watch Me!” developmental monitoring training on childcare providers’ knowledge and attitudes related to monitoring developmental milestones and making recommended referrals when there is a concern about a child’s development. A pretest–posttest design using web-based surveys was used to assess the impact of “Watch Me!” training on knowledge and attitudes related to conducting five key components of developmental monitoring (tracking development, recognizing delays, talking to parents about development, talking to parents about concerns, and making referrals). Variables included belief that developmental monitoring is important and is part of childcare provider role; perceived knowledge of, access to tools for, and prioritization of developmental monitoring; and ability to list recommended referrals when there is a concern. Childcare providers demonstrated a significant pre-post increase in perceived knowledge and access to the tools to engage in five core components of developmental monitoring after completing “Watch Me!” training. There was also a significant pre-post increase in childcare providers’ ability to list the child’s doctor as an appropriate referral (39 pre–63% post), but not in the ability to list Part C/Part B programs as an appropriate referral (56 pre–58% post). “Watch Me!” training may be effective at impacting targeted areas of knowledge and attitude about developmental monitoring among childcare providers in the short term.
The Economic Consequences of Sir Robert Peel: A Quantitative Assessment of the Repeal of the Corn Laws

Britain’s repeal of the Corn Laws in 1846 was the signature trade policy event of the nineteenth century. This paper provides a quantitative general equilibrium evaluation of the repeal on sectoral output and employment, factor prices and income distribution, international trade and the terms of trade, and economic welfare based on a detailed input-output matrix of the British economy in 1841. We find that the repeal left Britain’s overall welfare roughly unchanged, or perhaps negligibly (0.1 percent) lower, as the static efficiency gains are offset by the adverse terms-of-trade effects of the tariff reduction. Labor and capital gained a slight amount of income at the expense of landowners (whose income fell about 3-5 percent). Combining the changes in factor payments with different consumption patterns across income groups, we find that the top 10 percent of income earners lose while the bottom 90 percent of income earners, who spent a disproportionate amount of their income on food, gain. To assess whether the model yields reasonable results, we compare the model’s output, price, and trade predictions with the actual ex post outcomes.
Monitoring Retinal Responses to Acute Intraocular Pressure Elevation in Rats with Visible Light Optical Coherence Tomography

Elevated intraocular pressure (IOP) is an important risk factor for glaucoma. However, the role of IOP in glaucoma progression, as well as retinal physiology in general, remains incompletely understood. We demonstrate the use of visible light optical coherence tomography to measure retinal responses to acute IOP elevation in Brown Norway rats. We monitored retinal responses in reflectivity, angiography, blood flow, oxygen saturation (sO2), and oxygen metabolism over a range of IOP from 10 to 100 mmHg. As IOP was elevated, nerve fiber layer reflectivity was found to decrease. Vascular perfusion in the three retinal capillary plexuses remained steady until IOP exceeded 70 mmHg and arterial flow was noted to reverse periodically at high IOPs. However, a significant drop in total retinal blood flow was observed first at 40 mmHg. As IOP increased, the venous sO2 demonstrated a gradual decrease despite steady arterial sO2, which is consistent with increased arterial-venous oxygen extraction across the retinal capillary beds. Calculated total retinal oxygen metabolism was steady, reflecting balanced responses of blood flow and oxygen extraction, until IOP exceeded 40 mmHg, and fell to 0 at 70 and 80 mmHg. Above this, measurements were unattainable. All measurements reverted to baseline when the IOP was returned to 10 mmHg, indicating good recovery following acute pressure challenge. These results demonstrate the ability of this system to monitor retinal oxygen metabolism noninvasively and how it can help us understand retinal responses to elevated IOP.
Is the Stock Market Worried About Climate Change? Lessons from the 2010s

On Christmas Eve 2019, the MIT Technology Review published an article entitled “The 2010s Were Another Lost Decade on Climate Change.” On New Year’s Day, the Washington Post published a longer article with the same title. Both pieces told basically the same story, one repeated by many environmentalists and climate experts, the failure to take meaningful action on climate change in the 2010s had dramatically exacerbated the problem. This article investigates how the stock market reacted to the negative climate-related news that emerged during the 2010s. The results suggest that at an aggregate level the stock market was unconcerned about the climate news, implying that the market believed that climate change would not have a major impact on future macroeconomic growth. There is evidence, however, that the market concluded that climate issues would be a significant problem for fossil fuel companies. TOPICS:ESG investing, Tail risks, financial crises and financial market history Key Findings ▪ According to many environmental experts, the 2010s were a lost decade for climate change, which foretold large future economic damages. This suggests that the 2010s should have been a bad decade for the stock market as it discounted the prospect of future climate-related costs. ▪ In fact, the decade of the 2010s was the second best in US history, surpassed only by the 1950s. The largest stock market drops that did occur during the decade were totally unrelated to climate news. ▪ Although the aggregate stock market was apparently unconcerned about climate change, climate worries did affect certain sectors. For instance, fossil fuel companies dramatically underperformed the overall market.
Lagrangian particle model for 3D simulation of pellets and SPI fragments in tokamaks

A 3D numerical model for the ablation of pellets and shattered pellet injection (SPI) fragments in tokamaks in the plasma disruption mitigation and fueling parameter space has been developed based on the Lagrangian particle code [R. Samulyak, X. Wang, H.-S. Chen, Lagrangian Particle Method for Compressible Fluid Dynamics, J. Comput. Phys., 362 (2018), 1-19]. The pellet code implements the low magnetic Reynolds number MHD equations, kinetic models for the electronic heating, a pellet surface ablation model, an equation of state that supports multiple ionization states, radiation, and a model for grad-B drift of the ablated material across the magnetic field. The Lagrangian particle algorithm is highly adaptive, capable of simulating a large number of fragments in 3D while eliminating numerical difficulties of dealing with the tokamak background plasma. The code has achieved good agreement with theory for spherically symmetric ablation flows. Axisymmetric simulations of neon and deuterium pellets in magnetic fields ranging from 1 to 6 Tesla have been compared with previous simulations using the FronTier code, and very good agreement has also been obtained. The main physics contribution of the paper is a detailed study of the influence of 3D effects, in particular grad-B drift, on pellet ablation rates and properties of ablation clouds. Smaller reductions of ablation rates in magnetic fields compared to axially symmetric simulations have been demonstrated because the ablated material is not confined to narrowing channels in the presence of grad-B drift. Contribution of various factors in the grad-B drift model has also been quantified.
Leveraging Social Media to Predict Continuation and Reversal in Asset Prices

Using features extracted from StockTwits messages between July 2009 and September 2012, we show through simulations that: (1) message volume and sentiment can be used as a risk factor in an asset pricing model framework; (2) message volume and sentiment help explain the diffusion of price information over several days, and (3) message volume and sentiment can be used as features to predict asset price directional moves. Our findings suggest statistics derived from message volume and sentiment can improve asset price forecasts and leads to a profitable trading strategy.
Are momentum profits driven by the cross-sectional dispersion in expected stock returns?☆

Abstract Consistent with the hypothesis that momentum profits are attributable to the cross-sectional dispersion in expected returns, Bulkley and Nawosah (2009) report that momentum is nonexistent in demeaned returns. Motivated by their work, I examine whether absence of momentum in demeaned returns is robust to methodological adjustments that mitigate microstructure biases. I find that with commonly employed techniques including skipping a month between the formation and holding periods and excluding firms priced less than $5 (penny stocks) from the sample, the mean monthly momentum profit in demeaned returns increases from −0.37% to 1.02% over the 1963 to 2006 sample period. The results highlight the critical importance of using microstructure screens in empirical momentum studies.
Founder-CEO Succession and the Paradox of Entrepreneurial Success

In the last few decades, we have developed a substantial body of knowledge about CEO succession. However, except for some studies of family businesses that lack direct applicability to nonfamily CEO succession, the past studies of succession have not examined the very first succession event in a firm, when the Founder-CEO is replaced, on a large-scale basis. The critical differences between later-stage succession and Founder-CEO succession include the higher level of attachment between Founder-CEOs and the firms they create, the much larger equity holdings of Founder-CEOs (which give them much more control of the firm), the fact that many Founder-CEOs remain in the firm (even though it is being run by their successors), and the fact that nearly all early-stage succession events involve outside successors (in contrast to later-stage succession research, which has focused on the insider-outsider distinction). These differences make it hard to extrapolate from later-stage succession findings to Founder-CEO succession. Therefore, in order to examine Founder-CEO succession, I used field research and grounded theory building to study the factors that should affect Founder-CEO succession in Internet start-ups. I find that there are two central intertemporal events that may affect Founder-CEO succession: The completion of product development and the raising of each round of financing from outside investors. I develop testable hypotheses about how each of these events affect the rate of succession, and then test these hypotheses using an event-history analysis of a unique dataset containing the succession histories of 202 Internet firms. My findings point to multiple "paradoxes of success" in which the Founder-CEO's success at achieving critical milestones actually causes the chance of Founder-CEO succession to rise dramatically.
How Well Do Social Ratings Actually Measure Corporate Social Responsibility

Ratings of corporations’ environmental activities and capabilities influence billions of dollars of “socially responsible” investments as well as some consumers, activists, and potential employees. In one of the first studies to assess these ratings, we examine how well the most widely used ratings— those of Kinder, Lydenberg, Domini Research & Analytics (KLD)—provide transparency about past and likely future environmental performance. We find KLD “concern” ratings to be fairly good summaries of past environmental performance. In addition, firms with more KLD concerns have slightly, but statistically significantly, more pollution and regulatory compliance violations in later years. KLD environmental strengths, in contrast, do not accurately predict pollution levels or compliance violations. Moreover, we find evidence that KLD’s ratings are not optimally using publicly available data. We discuss the implications of our findings for advocates and skeptics of corporate social
Predicting Land Use Change: How Much Does Transportation Matter?

This paper proposes to measure the extent of the influence of transportation systems on land use change. With a set of high-resolution land use data for the Twin Cities, Minnesota, metropolitan region, logistic regression models of land use change are estimated for a 10-year period from 1990 to 2000. The models account for existing land use types, neighboring land uses, and transportation network variables that measure the physical proximity of highway networks, as well as the level of accessibility associated with a specific location. The models are estimated with and without the transportation variables and compared to assess the extent of their influence. Transportation-related variables exert some influence on changes to land use patterns, though not as much as variables representing existing and neighboring land uses.
Against Endowment Theory: Experimental Economics and Legal Scholarship

Endowment theory holds the mere ownership of a thing causes people to assign greater value to it than they otherwise would. The theory entered legal scholarship in the early 1990s and quickly eclipsed other accounts of how ownership affects valuation. Today, one finds appeals to a generic “endowment effect” throughout the legal literature. Recent experimental results, however, suggest that the empirical evidence for endowment theory is weak at best. When the procedures used in laboratory experiments are altered to rule out alternative explanations, the “endowment effect” disappears. This and other recent evidence suggest that mere ownership does not affect willingness to trade or exchange. Many experimental economists no longer ascribe to endowment theory. Legal scholars, however, continue to rely on endowment theory to predict legal entitlements’ probable effects on expressed valuations. That reliance is no longer warranted. Endowment theory’s influence in legal scholarship provides important lessons about how legal scholars and policymakers should, and should not, use results from experimental economics.
Do Birds of a Feather Vote Together, or Is It Peer Influence?

Why and when do legislators vote together on policy? Do legislators decide to vote similarly mainly because of social influence or similarity? I contribute to the literature by offering a social ne...
Stock returns, aggregate earnings surprises, and behavioral finance

Abstract We study the stock market's reaction to aggregate earnings news. Prior research shows that, for individual firms, stock prices react positively to earnings news but require several quarters to fully reflect the information in earnings. We find a substantially different pattern in aggregate data. First, returns are unrelated to past earnings, suggesting that prices neither underreact nor overreact to aggregate earnings news. Second, aggregate returns correlate negatively with concurrent earnings; over the last 30 years, for example, stock prices increased 5.7% in quarters with negative earnings growth and only 2.1% otherwise. This finding suggests that earnings and discount rates move together over time and provides new evidence that discount-rate shocks explain a significant fraction of aggregate stock returns.
Design Incentives Under Collective Extended Producer Responsibility: A Network Perspective

A key goal of Extended Producer Responsibility (EPR) legislation is to provide incentives for producers to design their products for recyclability. EPR is typically implemented in a collective system, where a network of recycling resources are coordinated to fulfill the EPR obligations of a set of producers, and the resulting system cost is allocated among these producers. Collective EPR is prevalent because of its cost efficiency advantages. However, it is considered to provide inferior design incentives compared to an individual implementation (where producers fulfill their EPR obligations individually). In this paper, we revisit this assertion and investigate its fundamental underpinnings in a network setting. To this end, we develop a new biform game framework that captures producers’ independent design choices (noncooperative stage) and recognizes the need to maintain the voluntary participation of producers for the collective system to be stable (cooperative stage). This biform game subsumes the net...
Indian Water Rights: Litigation and Settlements

This paper provides a brief review of modern federal Indian water right settlements, with a focus on the Snake River Basin Adjudication Water Rights Settlement Act of 2004 (Nez Perce Tribe). It critiques the Federal Administration's use of the Criteria and Procedures for Indian Water Settlements, which have been in place since 1990. It offers some suggestions for improvement in federal policies regarding financial contributions to Indian water rights settlements.
Reputation and International Law

Among the reasons that states comply with international law in the absence of coercive enforcement mechanisms is a concern for their reputation for compliance with international legal rules. Such a reputation is valuable because it allows states to make credible commitments to one another in an effort to overcome problems of cooperation. To date neither the international relations nor the international law literature has developed a theory of reputation that explains in detail how states acquire a reputation for compliance, how they lose it, and how it affects behavior. This paper seeks to provide such a theory. It examines how states' reputation for compliance can be gained or lost and how reputational concerns interact with other payoffs. It considers strategic decisions states must make to manage reputation over time as well as the connection between better information and more effective reputational sanctions. Finally, the paper discusses the question of whether states have a single reputation for compliance with international law or, instead, several such reputations corresponding to different issue areas. The way in which this compartmentalization of reputation influences the ability of states to solve international problems is explained.