cssi/SciSciGPT-SciSciNet huggingface dataset:
EXTENDED X-RAY EMISSION FROM A QUASAR-DRIVEN SUPERBUBBLE

We present observations of extended, 20 kpc scale soft X-ray gas around a luminous obscured quasar hosted by an ultraluminous infrared galaxy caught in the midst of a major merger. The extended X-ray emission is well fit as a thermal gas with a temperature of kT ≈280 eV and a luminosity of L X ≈ 1042 erg s–1 and is spatially coincident with a known ionized gas outflow. Based on the X-ray luminosity, a factor of ~10 fainter than the [O III] emission, we conclude that the X-ray emission is either dominated by photoionization, or by shocked emission from cloud surfaces in a hot quasar-driven wind.
Nyx: A Massively Parallel AMR Code for Computational Cosmology

We present a new N-body and gas dynamics code, called Nyx, for large-scale cosmological simulations. Nyx follows the temporal evolution of a system of discrete dark matter particles gravitationally coupled to an inviscid ideal fluid in an expanding universe. The gas is advanced in an Eulerian framework with block-structured adaptive mesh refinement; a particle-mesh scheme using the same grid hierarchy is used to solve for self-gravity and advance the particles. Computational results demonstrating the validation of Nyx on standard cosmological test problems, and the scaling behavior of Nyx to 50,000 cores, are presented.
Sigma Models on Flags

We study (1+1)-dimensional non-linear sigma models whose target space is the flag manifold $U(N)\over U(N_1)\times U(N_2)\cdots U(N_m)$, with a specific focus on the special case $U(N)/U(1)^{N}$. These generalize the well-known $\mathbb{CP}^{N-1}$ model. The general flag model exhibits several new elements that are not present in the special case of the $\mathbb{CP}^{N-1}$ model. It depends on more parameters, its global symmetry can be larger, and its 't Hooft anomalies can be more subtle. Our discussion based on symmetry and anomaly suggests that for certain choices of the integers $N_I$ and for specific values of the parameters the model is gapless in the IR and is described by an $SU(N)_1$ WZW model. Some of the techniques we present can also be applied to other cases.
BugDoc: Algorithms to Debug Computational Processes

Data analysis for scientific experiments and enterprises, large-scale simulations, and machine learning tasks all entail the use of complex computational pipelines to reach quantitative and qualitative conclusions. If some of the activities in a pipeline produce erroneous outputs, the pipeline may fail to execute or produce incorrect results. Inferring the root cause(s) of such failures is challenging, usually requiring time and much human thought, while still being error-prone. We propose a new approach that makes use of iteration and provenance to automatically infer the root causes and derive succinct explanations of failures. Through a detailed experimental evaluation, we assess the cost, precision, and recall of our approach compared to the state of the art. Our experimental data and processing software is available for use, reproducibility, and enhancement.
Variation of Molecular Line Ratios and Cloud Properties in the Arp 299 Galaxy Merger

High-resolution observations of 12CO (23),13CO (39), and HCN (54) J = 1-0 in the galaxy merger Arp 299 (IC 694 and NGC 3690) show that the line ratios vary dramatically across the system. The 12CO/13CO ratio is unusually large, 60 ± 15, at the IC 694 nucleus, where 12CO emission is very strong, and much smaller, 10 ± 3, in the southern extended disk of that galaxy. Elsewhere, the 12CO/13CO line ratio is 5-20, typical of spiral galaxies. The line ratio variation in the overlap between the two galaxies is smaller, ranging from 10 ± 3 in the east to 20 ± 4 in the west. The 12CO/HCN line ratio also varies across Arp 299, although to a lesser degree. HCN emission is bright toward each galaxy nucleus and in the extranuclear region of active star formation; it was not detected in the IC 694 disk or the eastern part of the overlap region, leading to lower limits of 25 and 20, respectively. By contrast, at the nuclei of IC 694 and NGC 3690 the ratios are 9 ± 1 and 14 ± 3, respectively. In the western part of the overlap region it is 11 ± 3. The large 12CO/13CO 1-0 intensity ratio at the nucleus of IC 694 can primarily be attributed to a low-to-moderate optical depth (τ 1) in the 12CO 1-0 line. These data support the hypothesis that unusually high 12CO/13CO line ratios (>20) are associated with extremely compact molecular distributions in the nuclei of merging galaxies. Relative to 12CO,13CO 1-0 is brightest in quiescent regions of low 12CO surface brightness and weakest in starburst regions and the galactic nuclei. A medium consisting of dense (n = 104-105 cm-3) and warm (Tk > 50 K) gas will reproduce the extreme line ratios observed in the nucleus of IC 694, where the area filling factor must be at least 20%.
The Redshift Evolution of the Metagalactic Ionizing Flux Inferred from Metal Line Ratios in the Lyman Forest

?????Metal line ratios in a sample of 13 quasar spectra obtained with the HIRES spectrograph on the Keck I Telescope have been analyzed to characterize the evolution of the metagalactic ionizing flux near a redshift of 3. The evolution of Si IV/C IV has been determined using three different techniques: using total column densities of absorption-line complexes, as in the approach of Songaila & Cowie, using the column densities of individual Voigt profile components within complexes, and using direct optical depth ratios. All three methods show that Si IV/C IV changes abruptly at z ~ 3, requiring a jump in value of about a factor of 3.4 and indicating a significant change in the ionizing spectrum that occurs rapidly between z = 2.9 and z = 3, just above the redshift at which Reimers et al. detected patchy He II Ly? absorption. At lower redshifts, the ionization balance is consistent with a pure power-law ionizing spectrum, but at higher redshifts the spectrum must be very soft, with a large break at the He+ edge. An optical depth ratio technique is used to measure the abundances of ions whose transitions lie within the forest, and C III, Si III, and O VI are detected in this way. The presence of a significant amount of O VI at z > 3 suggests either a considerable volume of He III bubbles embedded in the more general region in which the ionizing flux is heavily broken or the addition of collisional ionization to the simple photoionization models.
Structure in a loitering universe.

We study the formation of structure for a universe that undergoes a recent loitering phase. We compare the nonlinear mass distribution to that in a standard, matter dominated cosmology. The statistical aspects of the clustered matter are found to be robust to changes in the expansion law, an exception being that the peculiar velocities are lower by a factor of ~3 in the loitering model. Further, in the loitering scenario, nonlinear growth of perturbation occurs more recently (z~3–5) than in the matter dominated case. Differences in the high redshift appearances of the two models will result but observable consequences depend critically on the chosen form, onset and duration of the loitering phase.
HST Imaging of Dust Structures and Stars in the Ram Pressure Stripped Virgo Spirals NGC 4402 and NGC 4522: Stripped from the Outside In with Dense Cloud Decoupling

We describe and constrain the origins of ISM structures likely created by ongoing ICM ram pressure stripping in two Virgo Cluster spirals, NGC 4522 and NGC 4402, using HST BVI images of dust extinction and stars, as well as supplementary HI, Halpha, and radio continuum images. This is the highest-resolution study to date of the physical processes that occur during an ICM-ISM ram pressure stripping interaction, ram pressure stripping's effects on the multi-phase, multi-density ISM, and the formation and evolution of ram-pressure-stripped tails. In dust extinction, we view the leading side of NGC 4402 and the trailing side of NGC 4522; we see distinct types of features in both galaxies. NGC 4522 has experienced stronger, more recent pressure and has the jellyfish morphology characteristic of some ram pressure stripped galaxies. Its stripped tail extends up from the disk plane in continuous upturns of dust and stars curving ~2 kpc above the disk plane. A kinematically and morphologically distinct extraplanar arm of young, blue stars and ISM extends above a mostly-stripped portion of the disk, and between it and the disk plane are decoupled dust clouds. NGC 4402 contains long dust ridges, suggesting that large parts of the ISM are being pushed out at once. Both galaxies contain long ridges of polarized radio continuum emission indicating the presence of large-scale ordered magnetic fields. We propose that magnetic fields could bind together gas of different densities, causing nearby gas of different densities to be stripped at the same rate and creating the large, coherent dust ridges and upturns. A number of factors that play roles in determining what types of structures form as a result of ram pressure: ram pressure strength and history, the location within the galaxy relative to the leading side, and pre-existing substructure in the ISM that may be bound together by magnetic fields.
Proton Synchrotron Gamma-Rays and the Energy Crisis in Blazars

The origin of high-energy emission in blazars jets (i.e., leptonic versus hadronic) has been a long-standing matter of debate. Here, we focus on one variant of hadronic models where proton synchrotron radiation accounts for the observed steady $\gamma$-ray blazar emission. Using analytical methods, we derive the minimum jet power ($P_{j,\min}$) for the largest blazar sample analyzed to date (145 sources), taking into account uncertainties of observables and jet's physical parameters. We compare $P_{j,\min}$ against three characteristic energy estimators for accreting systems, i.e., the Eddington luminosity, the accretion disk luminosity, and the power of the Blandford-Znajek process, and find that $P_{j,\min}$ is about 2 orders of magnitude higher than all energetic estimators for the majority of our sample. The derived magnetic field strengths in the emission region require either large amplification of the jet's magnetic field (factor of 30) or place the $\gamma$-ray production site at sub-pc scales. The expected neutrino emission peaks at $\sim 0.1-10$ EeV, with typical peak neutrino fluxes $\sim 10^{-4}$ times lower than the peak $\gamma$-ray fluxes. We conclude that if relativistic hadrons are present in blazar jets, they can only produce a radiatively subdominant component of the overall spectral energy distribution of the blazar's steady emission.
Photometric Variability in Kepler Target Stars. II. An Overview of Amplitude, Periodicity, and Rotation in First Quarter Data

We provide an overview of stellar variability in the first quarter data from the Kepler mission. The intent of this paper is to examine the entire sample of over 150,000 target stars for periodic behavior in their light curves and relate this to stellar characteristics. This data set constitutes an unprecedented study of stellar variability given its great precision and complete time coverage (with a half hour cadence). Because the full Kepler pipeline is not currently suitable for a study of stellar variability of this sort, we describe our procedures for treating the raw pipeline data. About half of the total sample exhibits convincing periodic variability up to two weeks, with amplitudes ranging from differential intensity changes of less than 10?4 up to more than 10%. K and M dwarfs have a greater fraction of period behavior than G dwarfs. The giants in the sample have distinctive quasi-periodic behavior, but are not periodic in the way we define it. Not all periodicities are due to rotation, and the most significant period is not necessarily the rotation period. We discuss properties of the light curves, and in particular look at a sample of very clearly periodic G dwarfs. It is clear that a large number of them do vary because of rotation and starspots, but it will take further analysis to fully exploit this.
NEIGHBORLINESS OF THE SYMMETRIC MOMENT CURVE

We consider the convex hull ℬ k of the symmetric moment curve U k ( t )=(cos t ,sin t ,cos 3 t ,sin 3 t ,…,cos (2 k −1) t ,sin (2 k −1) t ) in ℝ 2 k , where t ranges over the unit circle 𝕊=ℝ/2 π ℤ. The curve U k ( t ) is locally neighborly: as long as t 1 ,…, t k lie in an open arc of 𝕊 of a certain length ϕ k >0 , the convex hull of the points U k ( t 1 ),…, U k ( t k ) is a face of ℬ k . We characterize the maximum possible length ϕ k , proving, in particular, that ϕ k > π /2 for all k and that the limit of ϕ k is π /2 as k grows. This allows us to construct centrally symmetric polytopes with a record number of faces.
AN X-RAY SEARCH FOR COMPACT CENTRAL SOURCES IN SUPERNOVA REMNANTS. II. SIX LARGE-DIAMETER SNRs

We present the second in a series of studies in which we have searched for undiscovered neutron stars in supernova remnants (SNRs). This paper deals with the six largest SNRs in our sample, too large for Chandra or XMM-Newton to cover in a single pointing. These SNRs are nearby, with typical distances of <1 kpc. We therefore used the ROSAT Bright Source Catalog and past observations in the literature to identify X-ray point sources in and near the SNRs. Out of 54 sources, we were immediately able to identify optical/IR counterparts to 41 from existing data. We obtained Chandra snapshot images of the remaining 13 sources. Of these, 10 were point sources with readily identified counterparts, two were extended, and one was not detected in the Chandra observation but is likely a flare star. One of the extended sources may be a pulsar wind nebula, but if so it is probably not associated with the nearby SNR. We are then left with no identified neutron stars in these six SNRs down to luminosity limits of ~10^(32) ergs s^(-1). These limits are generally less than the luminosities of typical neutron stars of the same ages, but are compatible with some lower luminosity sources such as the neutron stars in the SNRs CTA 1 and IC 443.
Postponing the dynamical transition density using competing interactions

Systems of dense spheres interacting through very short-ranged attraction are known from theory, simulations and colloidal experiments to exhibit dynamical reentrance. Their liquid state can thus be fluidized at higher densities than possible in systems with pure repulsion or with long-ranged attraction. A recent mean-field, infinite-dimensional calculation predicts that the dynamical arrest of the fluid can be further delayed by adding a longer-ranged repulsive contribution to the short-ranged attraction. We examine this proposal by performing extensive numerical simulations in a three-dimensional system. We first find the short-ranged attraction parameters necessary to achieve the densest liquid state, and then explore the parameter space for an additional longer-ranged repulsion that could further enhance reentrance. In the family of systems studied, no significant (within numerical accuracy) delay of the dynamical arrest is observed beyond what is already achieved by the short-ranged attraction. Possible explanations are discussed.
Transport dynamics of ultracold atoms in a triple-well transistor-like potential

The transport of atoms is experimentally studied in a transistor-like triple-well potential consisting of a narrow gate well surrounded by source and drain wells. Atoms are initially loaded into the source well with pre-determined temperature and chemical potential. Energetic atoms flow from the source, across the gate, and into the drain where they are removed using a resonant light beam. The manifestation of atom–atom interactions and dissipation is evidenced by a rapid population growth in the initially vacant gate well. The transport dynamics are shown to depend strongly on a feedback parameter determined by the relative heights of the two barriers forming the gate region. For a range of feedback parameter values, experiments establish that the gate atoms develop a larger chemical potential and lower temperature than those in the source.
Effect of magnetic perturbations on turbulence-flow dynamics at the L-H transition on DIII-D

Detailed 2D turbulence measurements from the DIII-D tokamak provide an explanation for how resonant magnetic perturbations (RMPs) raise the L-H power threshold P LH [P. Gohil et al., Nucl. Fusion 51, 103020 (2011)] in ITER-relevant, low rotation, ITER-similar-shape plasmas with favorable ion ∇ B direction. RMPs simultaneously raise the turbulence decorrelation rate Δ ω D and reduce the flow shear rate ω shear in the stationary L-mode state preceding the L-H transition, thereby disrupting the turbulence shear suppression mechanism. RMPs also reduce the Reynolds stress drive for poloidal flow, contributing to the reduction of ω shear. On the ∼100 μs timescale of the L-H transition, RMPs reduce Reynolds-stress-driven energy transfer from turbulence to flows by an order of magnitude, challenging the energy depletion theory for the L-H trigger mechanism. In contrast, non-resonant magnetic perturbations, which do not significantly affect P LH, do not affect Δ ω D and only slightly reduce ω shear and Reynolds-stress-driven energy transfer.
"Low" Energy GUTs

To achieve a GUT scale that is small, � 200TeV, so that it is within the reach of conceivable earth-based accelerated colliding beam devices, we introduce a new approach to the subject of grand unification. Central to the approach is the abstraction of the heterotic string symmetry group physics ideas in a novel way which allows us to control baryon number violating effects to be consistent with current experimental limits.
Possible Stellar Metallicity Enhancements from the Accretion of Planets

A number of recently discovered extrasolar planet candidates have surprisingly small orbits, which may indicate that considerable orbital migration takes place in protoplanetary systems. A natural consequence of orbital migration is for a series of planets to be accreted, destroyed, and then thoroughly mixed into the convective envelope of the central star. We study the ramifications of planet accretion for the final main-sequence metallicity of the star. If maximum disk lifetimes are on the order of ~10 Myr, stars with masses near 1.0 M are predicted to have virtually no metallicity enhancement. On the other hand, early F- and late A-type stars with masses M* ≈ 1.5-2.0 M can experience significant metallicity enhancements due to their considerably smaller convection zones during the first 10 Myr of pre-main-sequence evolution. We show that the metallicities of an aggregate of unevolved F stars are consistent with an average star accreting ~2 Jupiter-mass planets from a protoplanetary disk having a 10 Myr dispersal time.
Noisy Bayesian active learning

Consider the problem of noisy Bayesian active learning given a sample space, a finite label set, and a finite set of label generating functions from the sample space to the label set, also known as the function class. The objective is to identify the function in the function class that generates the labels using as few label queries as possible and with low probability of error despite possible corruption by independent noise. The key to achieving this objective relies on the selection of queries in a strategic and adaptive manner. The problem generalizes the problem of noisy generalized binary search [1]. This paper explores the connection between the above Bayesian active learning problem and the problem of information acquisition in which a Bayesian decision maker is responsible for dynamically collecting noisy observations so as to enhance her/his information in a speedy manner about an underlying phenomena of interest with a constraint on the probability of error. This view of the problem allows for developing a general lower bound on the expected number of queries to identify the function that generates the labels in terms of the observation noise statistics, the desired probability of error, and the cardinality of the function class. Furthermore, viewing the problem as an information acquisition problem enables a deterministic and Markov heuristic policy based on greedy maximization of Extrinsic Jensen-Shannon divergence [2]. The performance of this heuristic is compared with the state of the art strategies for noisy generalized binary search. In the case where the function class is sample-rich, it is shown that this heuristic is better than previous results and, in particular, matches the earlier proposed lower bound asymptotically.
Type Iax Supernovae

Type Iax supernovae (SN Iax), also called SN 2002cx-like supernovae, are the largest class of peculiar white dwarf (thermonuclear) supernovae, with over fifty members known. SN Iax have lower ejecta velocity and lower luminosities, and these parameters span a much wider range, than normal type Ia supernovae (SN Ia). SN Iax are spectroscopically similar to some SN Ia near maximum light, but are unique among all supernovae in their late-time spectra, which never become fully nebular. SN Iax overwhelmingly occur in late-type host galaxies, implying a relatively young population. The SN Iax 2012Z is the only white dwarf supernova for which a pre-explosion progenitor system has been detected. A variety of models have been proposed, but one leading scenario has emerged: a type Iax supernova may be a pure-deflagration explosion of a carbon-oxygen (or hybrid carbon-oxygen-neon) white dwarf, triggered by helium accretion to the Chandrasekhar mass, that does not necessarily fully disrupt the star.
Topological properties of spaces admitting a coaxial homeomorphism

Wright (1992) showed that, if a 1–ended, simply connected, locally compact ANR Y with pro-monomorphic fundamental group at infinity (ie representable by an inverse sequence of monomorphisms) admits a ℤ–action by covering transformations, then that fundamental group at infinity can be represented by an inverse sequence of finitely generated free groups. Geoghegan and Guilbault (2012) strengthened that result, proving that Y also satisfies the crucial semistability condition (ie representable by an inverse sequence of epimorphisms). Here we get a stronger theorem with weaker hypotheses. We drop the “pro-monomorphic hypothesis” and simply assume that the ℤ–action is generated by what we call a “coaxial” homeomorphism. In the pro-monomorphic case every ℤ–action by covering transformations is generated by a coaxial homeomorphism, but coaxials occur in far greater generality (often embedded in a cocompact action). When the generator is coaxial, we obtain the sharp conclusion: Y is proper 2–equivalent to the product of a locally finite tree with ℝ. Even in the pro-monomorphic case this is new: it says that, from the viewpoint of the fundamental group at infinity, the “end” of Y looks like the suspension of a totally disconnected compact set.
Compton Scattering of Polarized Radiation in Two-Phase Accretion Disks in Active Galactic Nuclei

We present results of radiative transfer calculations of Compton scattering of polarized radiation in a corona above an accretion disk. The corona has a plane-parallel geometry and is assumed to be homogeneous with a fixed temperature. We employ a Feautrier method to calculate the radiative transfer, incorporating the full relativistic, polarized Compton redistribution matrix. This allows us to explore a broad range of parameter space, in particular large optical depths and/or low corona temperatures, for which the iterative scattering method is very inefficient. Compared with Thomson scattering, Compton scattering generally produces smaller polarizations for featureless spectra. Distinct frequency-dependent patterns in polarization are produced near lines and edges, which can be used as diagnostics for the corona. We discuss the physics that gives rise to these results. Compton scattering can smear out Lyman edges in total flux and at the same time produce large increases in polarization. This might help explain the rises in polarization observed near the Lyman limit in some quasars, although in general Compton scattering does not appear able to produce polarization changes that are as steep as observed.
A streamlined proof of Goodwillie's $n$–excisive approximation

We give a shorter proof of Goodwillie’s, [Geom. Topol. 7 (2003) 645–711; Lemma 1.9], which is the key step in proving that the construction PnF gives an n–excisive functor.
Succinct blind Quantum computation using a random oracle

In the universal blind quantum computation problem, a client wants to make use of a single quantum server to evaluate C|0⟩ where C is an arbitrary quantum circuit while keeping C secret. The client’s goal is to use as few resources as possible. This problem, first raised by Broadbent, Fitzsimons and Kashefi [FOCS 2009], has become fundamental to the study of quantum cryptography, not only because of its own importance, but also because it provides a testbed for new techniques that can be later applied to related problems (for example, quantum computation verification). Known protocols on this problem are mainly either information-theoretically (IT) secure or based on trapdoor assumptions (public key encryptions). In this paper we study how the availability of symmetric-key primitives, modeled by a random oracle, changes the complexity of universal blind quantum computation. We give a new universal blind quantum computation protocol. Similar to previous works on IT-secure protocols (for example, Broadbent-Fitzsimons-Kashefi), our protocol can be divided into two phases. In the first phase the client prepares some quantum gadgets with relatively simple quantum gates and sends them to the server, and in the second phase the client is entirely classical — it does not even need quantum storage. Crucially, the protocol’s first phase is succinct, that is, its complexity is independent of the circuit size. Given the security parameter κ, its complexity is only a fixed polynomial of κ, and can be used to evaluate any circuit (or several circuits) of size up to a subexponential of κ. In contrast, known schemes either require the client to perform quantum computations that scale with the size of the circuit, or require trapdoor assumptions.
David Hume, economic rationality, and policy: Symposium introduction

Abstract This is an introduction to the symposium, "David Hume, Economic Rationality, and Policy." Topics treated in the symposium include the idea of true preferences; Hume's theory of preferences in relation to his economic philosophy; justice and markets as a joint coordination regime; the instability of general, inflexible rules; conservatism and liberalism; the ethics of policy innovation; Hume and classical economics; group analytics and contemporary political sociology.
Auxetic Two‐Dimensional Nanostructures from DNA

Architectured materials exhibit negative Poisson's ratios and enhanced mechanical properties compared with regular materials. Their auxetic behaviors emerge from periodic cellular structures regardless of the materials used. The majority of such metamaterials are constructed by top-down approaches and macroscopic with unit cells of microns or larger. There are also molecular auxetics including natural crystals which are not designable. There is a gap from few nanometers to microns, which may be filled by biomolecular self-assembly. Herein, we demonstrate two-dimensional auxetic nanostructures using DNA origami. Structural reconfigurations are performed by two-step DNA reactions and complemented by mechanical deformation studies using molecular dynamics simulations. We find that the auxetic behaviors are mostly defined by geometrical designs, yet the properties of the materials also play an important role. From elasticity theory, we introduce design principles for auxetic DNA metamaterials.
A Note on One-loop Cluster Adjacency in N = 4 SYM

We study cluster adjacency conjectures for amplitudes in maximally supersymmetric Yang-Mills theory. We show that the n-point one-loop NMHV ratio function satisfies Steinmann cluster adjacency. We also show that the one-loop BDS-like normalized NMHV amplitude satisfies cluster adjacency between Yangian invariants and final symbol entries up to 9-points. We present conjectures for cluster adjacency properties of Plucker coordinates, quadratic cluster variables, and NMHV Yangian invariants that generalize the notion of weak separation.
Digital Cell Sorter (DCS): a cell type identification, anomaly detection, and Hopfield landscapes toolkit for single-cell transcriptomics

Motivation Analysis of singe cell RNA sequencing (scRNA-seq) typically consists of different steps including quality control, batch correction, clustering, cell identification and characterization, and visualization. The amount of scRNA-seq data is growing extremely fast, and novel algorithmic approaches improving these steps are key to extract more biological information. Here, we introduce: (i) two methods for automatic cell type identification (i.e., without expert curator) based on a voting algorithm and a Hopfield classifier, (ii) a method for cell anomaly quantification based on isolation forest, and (iii) a tool for the visualization of cell phenotypic landscapes based on Hopfield energy-like functions. These new approaches are integrated in a software platform that includes many other state-of-the-art methodologies and provides a self-contained toolkit for scRNA-seq analysis. Results We present a suite of software elements for the analysis of scRNA-seq data. This Python-based open source software, Digital Cell Sorter (DCS), consists in an extensive toolkit of methods for scRNA-seq analysis. We illustrate the capability of the software using data from large datasets of peripheral blood mononuclear cells (PBMC), as well as plasma cells of bone marrow samples from healthy donors and multiple myeloma patients. We test the novel algorithms by evaluating their ability to deconvolve cell mixtures and detect small numbers of anomalous cells in PBMC data. Availability The DCS toolkit is available for download and installation through the Python Package Index (PyPI). The software can be deployed using the Python import function following installation. Source code is also available for download on Zenodo: DOI 10.5281/zenodo.2533377. Supplementary information Supplemental Materials are available at PeerJ online.
Correcting for Cross‐Sectional and Time‐Series Dependence in Accounting Research

ABSTRACT: We review and evaluate the methods commonly used in the accounting literature to correct for cross‐sectional and time‐series dependence. While much of the accounting literature studies settings in which variables are cross‐sectionally and serially correlated, we find that the extant methods are not robust to both forms of dependence. Contrary to claims in the literature, we find that the Z2 statistic and Newey‐West corrected Fama‐MacBeth standard errors do not correct for both cross‐sectional and time‐series dependence. We show that extant methods produce misspecified test statistics in common accounting research settings, and that correcting for both forms of dependence substantially alters inferences reported in the literature. Specifically, several findings in the implied cost of equity capital literature, the cost of debt literature, and the conservatism literature appear not to be robust to the use of well‐specified test statistics.
The effect of drug vintage on survival: micro evidence from Puerto Rico's Medicaid program.

Using micro data on virtually all of the drugs and diseases of over 500,000 people enrolled in Puerto Rico's Medicaid program, the impact of the vintage (original FDA approval year) of drugs used to treat a patient on the patient's three-year probability of survival, controlling for demographic characteristics (age, sex, and region), utilization of medical services, and the nature and complexity of illness are examined. It is found that people using newer drugs during January–June, 2000, were less likely to die by the end of 2002, conditional on the covariates. The estimated mortality rates are strictly declining with respect to drug vintage. For pre-1970 drugs, the estimated mortality rate is 4.4%. The mortality rates for 1970s, 1980s, and 1990s drugs are 3.6%, 3.0%, and 2.5%, respectively. The actual mortality rate is about 16% (3.7% vs. 4.4%) lower than it would have been if all of the drugs utilized in 2000 had been pre-1970 drugs. Estimates for subgroups of people with specific diseases display the same general pattern.
New Technology, Old Defenses: Internet Sting Operations and Attempt Liability

Internet sting operations to catch adults preying on children have grown as exponentially as the public's use of the Internet. These operations typically involve an adult law enforcement officer posing as a child for Internet contact with a would-be defendant. Defendants caught in a sting are charged with attempt because by use of the sting operation, law enforcement has prevented the commission of the underlying offense against a child. These cases provide a contemporary opportunity to revisit some classic attempt liability issues. Part II of this article addresses the general principles of attempt liability, including a description of the doctrines of factual and legal impossibility and the rationale behind the historical treatment of these defenses. Part III describes recent Internet attempt cases, and Part IV analyzes issues raised by such cases. This article suggests that the new Internet cases provide further rationale for rejecting a distinction between factual and legal impossibility that would allow the latter to be a defense. This article also discusses issues surrounding the appropriate mens rea for attempt, and its applicability to Internet cases, where the defendants claim ignorance or indifference as to the age of the target of his advances. It suggests that attempt liability is appropriate only where there is proof the defendant believed that he was dealing with a child.
Phenomenological neutron star equations of state: 3-window modeling of QCD matter

We discuss the 3-window modeling of cold, dense QCD matter equations of state at density relevant to neutron star properties. At low baryon density, $n_{B}\lesssim 2n_{s}$ ( $n_{s}$ : nuclear saturation density), we utilize purely hadronic equations of state that are constrained by empirical observations at density $ n_B\sim n_s$ and neutron star radii. At high density, $n_{B}\gtrsim 5n_{s}$ , we use the percolated quark matter equations of state which must be very stiff to pass the two-solar mass constraints. The intermediate domain at $2\lesssim n_{B}/n_{s} \lesssim 5$ is described as neither purely hadronic nor percolated quark matter, and the equations of state are inferred by interpolating hadronic and percolated quark matter equations of state. Possible forms of the interpolation are severely restricted by the condition on the (square of) speed of sound, $ 0\le c_{s}^{2} \le 1$ . The characteristics of the 3-window equation of state are compared with those of conventional hybrid and self-bound quark matters. Using a schematic quark model for the percolated domain, it is argued that the two-solar mass constraint requires the model parameters to be as large as their vacuum values, indicating that the gluon dynamics remains strongly non-perturbative to $ n_{B}\sim 10n_{s}$ . The hyperon puzzle is also briefly discussed in light of quark descriptions.
Prospect Theory and Asset Prices

We study asset prices in an economy where investors derive direct utility not only from consumption but also from fluctuations in the value of their financial wealth. They are loss averse over these fluctuations, and the degree of loss aversion depends on their prior investment performance. We find that our framework can help explain the high mean, excess volatility, and predictability of stock returns, as well as their low correlation with consumption growth. The design of our model is influenced by prospect theory and by experimental evidence on how prior outcomes affect risky choice.
Assessing the relative informativeness and permanence of pro forma earnings and GAAP operating earnings

Abstract This study investigates whether market participants perceive pro forma earnings to be more informative and more persistent than GAAP operating income by analyzing a sample of 1,149 actual pro forma press releases. We find that pro forma announcers report frequent GAAP losses and are mostly concentrated in the service and high-tech industries. Our analyses of short-window abnormal returns and revisions in analysts’ one-quarter-ahead earnings forecasts indicate that pro forma earnings are more informative and more permanent than GAAP operating earnings. Our evidence suggests that market participants believe pro forma earnings are more representative of “core earnings” than GAAP operating income.
Social phobia with and without avoidant personality disorder: Preliminary behavior therapy outcome findings

The present study is the first psychotherapy outcome study comparing social phobia with and without avoidant personality disorder (APD). Eight social phobic subjects with APD and eight phobic subjects without APD received 8 sessions of behaviorally oriented group therapy for their public speaking anxiety. Before and after treatment, severity measures were taken and subjects were asked to give a talk in front of a small audience. Treatment resulted in the same degree of improved social anxiety and fear of public speaking for both groups. These results add to the literature that questions the validity of distinguishing between avoidant personality disorder and social phobia.
Firing Costs, Employment Fluctuations and Average Employment: An Examination of Germany

West Germany's Employment Promotion Act of 1985 facilitated the use of fixed-term contracts and increased the number of dismissals above which the employer is required to establish a ‘social plan’ (involving severance payments). I assess the effect of this reduction in ‘firing costs’ on movements in employment, using monthly data on a panel of detailed manufacturing industries for 1977-92. I also examine the effect of introducing flexible hours of work in certain industries beginning in 1985. I find that employment adjustment was unaffected by the lower firing costs, but slowed by the greater working hours flexibility.
Moving up the Residential Hierarchy: A New Remedy for an Old Injury Arising from Housing Discrimination

Ma ri lyn wa nt ed to mo ve out o f t he da nge rou s Chi cag o ne ig hbo rho od in wh ic h s he li ved . S he fo und a n a par tment in a su bur b, Be rwyn, th at su ite d her ne ed s i n t er ms of lo cat ion , pri ce, a nd siz e. Wh en th e l an dlo rd re fus ed to de al wi th her o r r ent h er the a par tme nt , Ma ri lyn be ca me dis co ura ged a nd dec id ed to sa ve mon ey , b uy a hou se, an d avo id en cou nte ri ng mor e dis cri mi nat ion i n t he re nta l mar ket .
Radial basis function (RBF)‐based parametric models for closed and open curves within the method of regularized stokeslets

Summary The method of regularized Stokeslets (MRS) is a numerical approach using regularized fundamental solutions to compute the flow due to an object in a viscous fluid where inertial effects can be neglected. The elastic object is represented as a Lagrangian structure, exerting point forces on the fluid. The forces on the structure are often determined by a bending or tension model, previously calculated using finite difference approximations. In this paper, we study spherical basis function (SBF), radial basis function (RBF), and Lagrange–Chebyshev parametric models to represent and calculate forces on elastic structures that can be represented by an open curve, motivated by the study of cilia and flagella. The evaluation error for static open curves for the different interpolants, as well as errors for calculating normals and second derivatives using different types of clustered parametric nodes, is given for the case of an open planar curve. We determine that SBF and RBF interpolants built on clustered nodes are competitive with Lagrange–Chebyshev interpolants for modeling twice-differentiable open planar curves. We propose using SBF and RBF parametric models within the MRS for evaluating and updating the elastic structure. Results for open and closed elastic structures immersed in a 2D fluid are presented, showing the efficacy of the RBF–Stokeslets method. Copyright © 2015 John Wiley & Sons, Ltd.
Denoising Diffusion Implicit Models

Denoising diffusion probabilistic models (DDPMs) have achieved high quality image generation without adversarial training, yet they require simulating a Markov chain for many steps in order to produce a sample. To accelerate sampling, we present denoising diffusion implicit models (DDIMs), a more efficient class of iterative implicit probabilistic models with the same training procedure as DDPMs. In DDPMs, the generative process is defined as the reverse of a particular Markovian diffusion process. We generalize DDPMs via a class of non-Markovian diffusion processes that lead to the same training objective. These non-Markovian processes can correspond to generative processes that are deterministic, giving rise to implicit models that produce high quality samples much faster. We empirically demonstrate that DDIMs can produce high quality samples 10× to 50× faster in terms of wall-clock time compared to DDPMs, allow us to trade off computation for sample quality, perform semantically meaningful image interpolation directly in the latent space, and reconstruct observations with very low error.
Content-Neutral and Content-Based Regulations of Speech: A Distinction That is No Longer Worth the Fuss

The popular binary distinction between content-based and content-neutral regulations of speech is widely assumed to be reasonably clear. The respective constitutional tests of content-based and content-neutral regulations of speech are also assumed to be hierarchical in their degrees of stringency. Thus constitutional tests of content-based regulations of speech are assumed to be more stringent, rigorous, demanding, or “strict” than tests of content-neutral regulations of speech. This Article, however, rejects both of these important and popular assumptions. Most crucially, the typical requirement that there remain ample alternative speech channels in the case of content-neutral, but not content-based, restrictions of speech decisively upsets any hierarchy of stringency as between the two tests. The effects of the alternative speech channels requirement, along with several other phenomena, undermine the meaningfulness of the distinction between content-based and content-neutral regulations of speech.
SEC Rule 10b5-1 and Insiders' Strategic Trade

The U.S. Securities and Exchange Commission enacted Rule 10b5-1 to deter insiders from trading with private information, yet also protect insiders' preplanned, non-information-based trades from litigation. Despite its requirement that insiders plan trades when not privately informed, the rule appears to enable strategic trade. Participating insiders' sales systematically follow positive and precede negative firm performance, generating abnormal forward-looking returns larger than those earned by nonparticipating colleagues. The observed association does not appear to be explained by market transaction disclosure response, “predictable” reversion following positive performance, or general periodic price declines. There is evidence, however, that a substantive proportion of randomly drawn plan initiations are associated with pending adverse news disclosures. There is also evidence that early sales plan terminations are associated with pending positive performance shifts, reducing the likelihood that insiders' sales execute at low prices. Collectively, this suggests that, on average, trading within the rule does not solely reflect uninformed diversification.
Why Do (Some) Households Trade So Much

When agents can learn about their abilities as active investors, they rationally "trade to learn" even if they expect to lose from active investing. The model used to develop this insight draws conclusions that are consistent with empirical study of household trading behavior: Households' portfolios underperform passive investments; their trading intensity depends on past performance; and they begin by trading small sums of money. Using household data from Finland, the article estimates a structural model of learning and trading. The estimated model shows that investors trade to learn even if they are pessimistic about their abilities as traders. It also demonstrates that realized returns are significantly downward-biased measures of investors' true abilities. The Author 2011. 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.
A Prospectus on the Anthropology of Entrepreneurship

This paper discusses the possible payoffs from investing scholarly attention in the anthropology of entrepreneurship, and considers the central topics, themes, and methods of this research. Ways in...
Portfolio diversification and value at risk under thick-tailedness†

This paper focuses on the study of portfolio diversification and value at risk analysis under heavy-tailedness. We use a notion of diversification based on majorization theory that will be explained in the text. The paper shows that the stylized fact that portfolio diversification is preferable is reversed for extremely heavy-tailed risks or returns. However, the stylized facts on diversification are robust to heavy-tailedness of risks or returns as long as their distributions are moderately heavy-tailed. Extensions of the results to the case of dependence, including convolutions of α-symmetric distributions and models with common shocks are provided. †The results in this paper constitute a part of the author's dissertation ‘New majorization theory in economics and martingale convergence results in econometrics’ presented to the faculty of the Graduate School of Yale University in candidacy for the degree of Doctor of Philosophy in Economics in March, 2005. The results were originally contained in the wor...
Waiting is the Hardest Part: Why the Supreme Court Should Adopt the Third Circuit's Analysis of Pay-for-delay Settlement Agreements

INTRODUCTION 1094 I. BACKGROUND 1098 A. Regulation of the Pharmaceutical Industry prior to Hatch-Waxman 1098 B. Hatch-Waxman’s Mechanisms to Promote Competition and Innovation 1100 C. Relevant Principles of Antitrust and Patent Law 1104 D. The Cardizem CD Cases 1108 II. DISCUSSION 1111 A. Valley Drug Co.: Creating the Scope of the Patent Test ..... 1112 B. Schering-Plough v. FTC: Expanding the Scope of the Patent Test 1115 C. In re Tamoxifen Citrate: Making the Scope of the Patent Test More Deferential 1119 D. In re Ciprofloxacin Hydrochloride: Entrenching the Scope of the Patent Test as a Toothless Test 1121 E. In re K-Dur: Rejecting the Scope of the Patent Test 1123 III. ANALYSIS 1127
Terrorism and Universal Jurisdiction: Opening a Pandora’s Box?

The relationship between terrorism and international criminal law has provoked a good deal of discussion in the wake of the terrorist attacks of September 11, 2001 in New York City and at the Pentagon in Washington, D.C. A particularly challenging issue pertains to whether terrorism is an international crime or a transnational crime, and if and in what context offenders and offenses, to which we affix the label of terrorist and terrorism, should or can be subject to the limited jurisdiction of the International Criminal Court (ICC) and other international and national criminal tribunals.