cssi/SciSciGPT-SciSciNet huggingface dataset:
Technology and Big Data Are Changing Economics: Mining Text to Track Methods

The last 40 years have seen huge innovations in computing technology and data availability. Data derived from millions of administrative records or by using (as we do) new methods of data generation such as text mining are now common. New data often requires new methods, which in turn can inspire new data collection. If history is any guide, some methods will stick and others will prove to be a flash in the pan. However, the larger trends towards demanding greater credibility and transparency from researchers in applied economics and a “collage” approach to assembling evidence will likely continue.
On Privacy of Socially Contagious Attributes

A common approach to protect user's privacy in data collection is to perform random perturbations on user's sensitive data before collection in a way that aggregated statistics can still be inferred without endangering individual secrets. In this paper, we take a closer look at the validity of Differential Privacy guarantees, when sensitive attributes are subject to social contagion. We first show that in the absence of any knowledge about the contagion network, an adversary that tries to predict the real values from perturbed ones, cannot train a classifier that achieves an area under the ROC curve (AUC) above 1-(1-δ)/(1+e^e), if the dataset is perturbed using an (e,δ)-differentially private mechanism. Then, we show that with the knowledge of the contagion network and model, one can do substantially better. We demonstrate that our method passes the performance limit imposed by differential privacy. Our experiments also reveal that nodes with high influence on others are at more risk of revealing their secrets than others. Our method's superior performance is demonstrated through extensive experiments on synthetic and real-world networks.
Neuropeptide regulation of secretion and inflammation in human airway gland serous cells.

Airway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways. To elucidate how neuropeptides regulate serous cells, we tested if human nasal turbinate serous cells secrete bicarbonate (HCO3−), important for mucus polymerisation and antimicrobial peptide function, during stimulation with cAMP-elevating vasoactive intestinal peptide (VIP) and if this requires CFTR. Serous cells stimulated with VIP exhibited a ∼15–20% cAMP-dependent decrease in cell volume and a ∼0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl− and HCO3− secretion, respectively. HCO3− secretion was directly dependent on CFTR and was absent in cells from CF patients. In contrast, neuropeptide Y (NPY) reduced VIP-evoked cAMP increases, CFTR activation, and Cl−/HCO3− secretion. Culture of primary serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3− secretion. Moreover, VIP enhanced antimicrobial peptide secretion and antimicrobial efficacy of secretions while NPY reduced antimicrobial efficacy. In contrast, NPY enhanced cytokine release while VIP reduced cytokine release through a mechanism requiring CFTR. As levels of VIP and NPY are up-regulated in diseases like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control mucus rheology and inflammatory responses in serous cells. Furthermore, the loss of CFTR conductance in serous cells may contribute to CF pathophysiology by increasing serous cells inflammatory responses in addition to directly impairing Cl− and HCO3− secretion.
Centrioles control the capacity, but not the specificity, of cytotoxic T cell killing

Immunological synapse formation between cytotoxic T lymphocytes (CTLs) and the target cells they aim to destroy is accompanied by reorientation of the CTL centrosome to a position beneath the synaptic membrane. Centrosome polarization is thought to enhance the potency and specificity of killing by driving lytic granule fusion at the synapse and thereby the release of perforin and granzymes toward the target cell. To test this model, we employed a genetic strategy to delete centrioles, the core structural components of the centrosome. Centriole deletion altered microtubule architecture as expected but surprisingly had no effect on lytic granule polarization and directional secretion. Nevertheless, CTLs lacking centrioles did display substantially reduced killing potential, which was associated with defects in both lytic granule biogenesis and synaptic actin remodeling. These results reveal an unexpected role for the intact centrosome in controlling the capacity but not the specificity of cytotoxic killing.
The colored symmetric and exterior algebras

In this extended abstract we present colored generalizations of the symmetric algebra and its Koszul dual, the exterior algebra. The symmetric group Sn acts on the multilinear components of these algebras. While Sn acts trivially on the multilinear components of the colored symmetric algebra, we use poset topology techniques to describe the representation on its Koszul dual. We introduce an Sn-poset of weighted subsets that we call the weighted boolean algebra and we prove that the multilinear components of the colored exterior algebra are Sn- isomorphic to the top cohomology modules of its maximal intervals. We show that the two colored Koszul dual algebras are Koszul in the sense of Priddy et al.
Smart Phone Based Mobile Code Dissemination for Heterogeneous Wireless Sensor Networks

Low-power Wireless Sensor Networks (WSNs) are being widely used in various outdoor applications including environmental monitoring, precision agriculture, and smart cities. WSN is a distributed network of sensor devices where the software running on the sensor devices defines how the devices should operate. In real-world WSN deployments, sensor node's software update is required to fix bugs and maintain optimal operation. In this paper, we present a novel mobile code dissemination tool based on smart phone running on Android Operating System for heterogeneous WSN reprogramming. Our implementation builds upon Mobile Deluge with new enhancements and more convenient mobile code dissemination tool in practice. We have evaluated our application performance on Android platform, and validated our mobile tool with a real-world outdoor low-power heterogeneous WSN deployment, demonstrating its practical merit.
The effect of autopolyploidy on population genetic signals of hard sweeps

Searching for population genomic signals left behind by positive selection is a major focus of evolutionary biology, particularly as sequencing technologies develop and costs decline. The effect of the number of chromosome copies (i.e. ploidy) on the manifestation of these signals remains an outstanding question, despite a wide appreciation of ploidy being a fundamental parameter governing numerous biological processes. We clarify the principal forces governing the differential manifestation and persistence of the selection signal by separating the effects of polyploidy on the rates of fixation versus rates of diversity (i.e. mutation and recombination) using coalescent simulations. We explore the major consequences of polyploidy, finding a more localized signal, greater dependence on dominance and longer persistence of the signal following fixation, and discuss what this means for within- and across ploidy inference on the strength and prevalence of selective sweeps. As genomic advances continue to open doors for interrogating natural systems, simulations such as this aid our ability to interpret and compare data across ploidy levels.
Insights for developing effective decision support tools for environmental sustainability

Despite the increasing number of decision support tools (DSTs) intended to inform sustainability decision-making, recent evidence suggests they may not be reaching stakeholders who need them most and are of varying content and quality. One way to enhance their use and quality is to evaluate tools during their development and deployment in order to improve DSTs and their relevance and usability within decision-making processes. Here we identify key characteristics of successful DSTs that enhance decision quality through a review of the literature, and then consider some ways that the ecosystem of decision support activities—coastal plan process and planning tool—used to develop Louisiana’s Coastal Master Plan embody these characteristics. We conclude with thoughts on the transferability of effective DST ecosystems to other situations in the context of environmental decision-making, and we offer key considerations for DST developers to best support meaningful integration of relevant science into planning and policy realms.
Wellposedness of the two-sided variable coefficient Caputo flux fractional diffusion equation and error estimate of its spectral approximation

Abstract In this article a two-sided variable coefficient fractional diffusion equation (FDE) is investigated, where the variable coefficient occurs outside of the fractional integral operator. Under a suitable transformation the variable coefficient equation is transformed to a constant coefficient equation. Then, using the spectral decomposition approach with Jacobi polynomials, we proved the wellposedness of the model and the regularity of its solution. A spectral approximation scheme is proposed and the accuracy of its approximation studied. Three numerical experiments are presented to demonstrate the derived error estimates.
Toward an Engineering Faculty Development Initiative for Associate Professors: Results from Focus Groups at an R1 Institution

The purpose of this full research paper is to explore faculty perceptions on how departments and colleges can continue to support faculty through the associate professor level. Little research exists that discusses best practices or even possible formats for mentoring and faculty development programs at the associate professor level. This study begins to fill this gap for one institutional type, eliciting suggestions from faculty on desired characteristics and attributes of a mid-career (associate) faculty development program. To elicit feedback, five focus groups of between 5-9 tenured or tenure-track mechanical engineering faculty each were conducted to elicit information on what faculty at various levels knew about career development post tenure, and what their ideas of an “ideal” mid-career faculty development initiative would look like. Audio recordings and jottings were collected as data and analyzed through constant comparative methods and content analysis methods, using landscapes of practice theory to highlight areas where faculty noted the need for explicit professional development. Results indicate that perceptions on career advancement post-tenure differed between faculty at different levels, and indicate several potential structures, characteristics, and attributes that a successful potential midcareer faculty development model might have.
The Early Years: Lyman Spitzer, Jr. and the Physics of Star Formation

The discovery of the interstellar medium and the early work of Lyman Spitzer, Jr. are reviewed here in the context of the remarkable observation in the early 1950's that star formation continues in the present age. Prior to this observation, stars were thought to have formed only at the beginning of the universe. The main debate in the 1930's was whether stars had the young age of ~3 Gyr suggested by the expansion of the universe and the meteorites, or the old age of 10^{13} yr suggested by thermalized stellar motions. The adoption of Ambartsumian's claim of modern-day star formation was slow and mixed in the early 1950's. While some astronomers like Adriaan Blaauw immediately followed, adding more from their own data, others were slow to change. By the end of the 1950's, Lyman had deduced the basic theory for star formation that we would recognize today.
Attack Trees for Security and Privacy in Social Virtual Reality Learning Environments

Social Virtual Reality Learning Environment (VRLE) is a novel edge computing platform for collaboration amongst distributed users. Given that VRLEs are used for critical applications (e.g., special education, public safety training), it is important to ensure security and privacy issues. In this paper, we present a novel framework to obtain quantitative assessments of threats and vulnerabilities for VRLEs. Based on the use cases from an actual social VRLE viz., vSocial, we first model the security and privacy using the attack trees. Subsequently, these attack trees are converted into stochastic timed automata representations that allow for rigorous statistical model checking. Such an analysis helps us adopt pertinent design principles such as hardening, diversity and principle of least privilege to enhance the resilience of social VRLEs. Through experiments in a vSocial case study, we demonstrate the effectiveness of our attack tree modeling with a reduction of 26% in probability of loss of integrity (security) and 80% in privacy leakage (privacy) in before and after scenarios pertaining to the adoption of the design principles.
Determinants of cyclization-decyclization kinetics of short DNA with sticky ends.

Cyclization of DNA with sticky ends is commonly used to measure DNA bendability as a function of length and sequence, but how its kinetics depend on the rotational positioning of the sticky ends around the helical axis is less clear. Here, we measured cyclization (looping) and decyclization (unlooping) rates (kloop and kunloop) of DNA with sticky ends over three helical periods (100-130 bp) using single-molecule fluorescence resonance energy transfer (FRET). kloop showed a nontrivial undulation as a function of DNA length whereas kunloop showed a clear oscillation with a period close to the helical turn of DNA (∼10.5 bp). The oscillation of kunloop was almost completely suppressed in the presence of gaps around the sticky ends. We explain these findings by modeling double-helical DNA as a twisted wormlike chain with a finite width, intrinsic curvature, and stacking interaction between the end base pairs. We also discuss technical issues for converting the FRET-based cyclization/decyclization rates to an equilibrium quantity known as the J factor that is widely used to characterize DNA bending mechanics.
Continuous Cocycle Superrigidity for the Full Shift Over a Finitely Generated Torsion Group

Chung and Jiang showed that, if a one ended group contains an infinite order element, then every continuous cocycle over the full shift on that group, taking values in a discrete group, must be cohomologous to a homomorphism. We show that their conclusion holds for all one ended groups, so that the hypothesis of admitting an infinite order element may be omitted.
Detecting hidden webcams with delay-tolerant similarity of simultaneous observation

Abstract Small, low-cost, wireless cameras are becoming increasingly commonplace making surreptitious observation of people more difficult to detect. Previous work in detecting hidden cameras has only addressed limited environments in small spaces where the user has significant control of the environment. To address this problem in a less constrained scope of environments, we introduce the concept of similarity of simultaneous observation where the user utilizes a camera (Wi-Fi camera, camera on a mobile phone or laptop) to compare timing patterns of data transmitted by potentially hidden cameras and the timing patterns that are expected from the scene that the known camera is recording. To analyze the patterns, we applied several similarity measures and demonstrated an accuracy of over 87% and F1 score of 0.88 using an efficient threshold-based classification. We used our data set to train a neural network and saw improved results with accuracy as high as 97% and an F1 score over 0.95 for both indoors and outdoors settings. We further extend this work against an attacker who is capable of delaying when the video is sent. With the new approach, we see increased F1 scores above .98 for the original data and delayed data. From these results, we conclude that similarity of simultaneous observation is a feasible method for detecting hidden wireless cameras that are streaming video of a user. Our work removes significant limitations that have been put on previous detection methods.
BREM-SC: a bayesian random effects mixture model for joint clustering single cell multi-omics data.

Droplet-based single cell transcriptome sequencing (scRNA-seq) technology, largely represented by the 10× Genomics Chromium system, is able to measure the gene expression from tens of thousands of single cells simultaneously. More recently, coupled with the cutting-edge Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq), the droplet-based system has allowed for immunophenotyping of single cells based on cell surface expression of specific proteins together with simultaneous transcriptome profiling in the same cell. Despite the rapid advances in technologies, novel statistical methods and computational tools for analyzing multi-modal CITE-Seq data are lacking. In this study, we developed BREM-SC, a novel Bayesian Random Effects Mixture model that jointly clusters paired single cell transcriptomic and proteomic data. Through simulation studies and analysis of public and in-house real data sets, we successfully demonstrated the validity and advantages of this method in fully utilizing both types of data to accurately identify cell clusters. In addition, as a probabilistic model-based approach, BREM-SC is able to quantify the clustering uncertainty for each single cell. This new method will greatly facilitate researchers to jointly study transcriptome and surface proteins at the single cell level to make new biological discoveries, particularly in the area of immunology.
Computer-Adaptive Testing†

This entry presents an overview of computer-adaptive testing (CAT). The basic CAT algorithm is introduced, followed by a discussion of item response theory (IRT) test information functions and their role in adaptive testing. Issues such as test efficiency and security risks under CAT are also discussed. The entry concludes with a description of four promising CAT variants, including CAT shadow tests, a-stratified CAT, testlet-based CAT, and computer-adaptive multistage testing. Keywords: computer-adaptive testing; computerized adaptive testing; test delivery; maximum information
5 – Job costing

Publisher Summary This chapter discusses job costing. The jobbing environment is characterized by the existence of departments through which the order travels, such as a machine shop, an assembly shop, and specialist functions—such as heat treatment or grinding. Contract costing is a form of specific order costing that applies where work is undertaken to customers' special requirements and each order is of long duration. Calculation of profit is an important part of contract cost accounting. The cost of operating the construction services department that provides technical advice to each of the contracts is apportioned over the contracts in proportion to wages incurred. The actual batch cost is the aggregated costs relative to a cost unit that consists of a group of similar articles, which maintains its identity throughout one or more stages of production. Batch costing can be found in the printing, packaging, clothing and building products industries, among others.
Thermodynamic inconsistency of the conventional theory of superconductivity

A type I superconductor expels a magnetic field from its interior to a surface layer of thickness λL, the London penetration depth. λL is a function of temperature, becoming smaller as the temperat...
A macroscopic finite element for a symmetric double lap joint subjected to mechanical and thermal loading

A thermo-mechanical analytical model and a corresponding macroscopic bonded joint finite element is presented for the analysis of orthotropic double lap joints subjected to combined thermal-mechanical loads. The analytical solution offers an improvement in accuracy over its predecessor, at the cost of increased solution complexity. However, to facilitate the use of this solution, it has been incorporated into a macroscopic bonded joint finite element. The single element reproduces the analytical solution with minimal analyst input, and therefore can be easily incorporated into early design studies. The macroscopic element provides a computationally efficient and mesh independent comparative stress result. To validate the element, the stress predictions of the single element are compared with a continuum finite element model.
Activation Energies of Polymer Degradation

Publisher Summary This chapter describes the activation energies of polymer degradation. The chapter illustrates the study of polymer degradation and durability. In this study, there is little reliable, predictive methodology that is universally valid over wide spans of temperature and time. Many of the high temperature “accelerated” oven tests have been deemed unrealistic for different mechanisms were prevalent. In the mean time, for practical reasons, experimental time spans of much longer than a year are extremely difficult to conduct. The chapter conducts a broad based study on the kinetics of polymer degradation. The Arrhenius activation energy has been used as the parameter to follow the rate dependence with temperature. The chapter explores the frequent observation that kinetic parameters obtained at high temperatures often lead to grossly optimistic results at ambient. When the activation energies from thermal processes are compared with the rate of surface embrittlement, a striking self similarity, or near identical activation energies at the same temperature is evident. Finally, this observation can lead to broader applications and further understandings on the polymer degradation.
CONSUMPTION COMMITMENTS AND EMPLOYMENT CONTRACTS

We examine an economy in which the cost of consuming some goods can be reduced by making commitments that reduce ∞exibility. We show that such consumption commitments can induce consumers with risk- neutral underlying utility functions to be risk averse over small variations in income, but sometimes to seek risk over large variations. As a result, optimal employment contracts will smooth wages conditional on being employed, but may incorporate a possibility of unemployment.
3 – Conversion costs

Publisher Summary This chapter discusses conversion costs. Conversion costs include direct wages, direct expenses, and absorbed production overhead. A departmental manager/supervisor/foreman can have an agreed predetermined workload and the requisite number of people under him/her to do the work. In a well-managed organization, all the work can be professionally timed and the manning levels agreed. As labor is very often a fixed cost, subject to a contractual daily or weekly rate, the control of lateness and/or absenteeism becomes difficult. Where there is effective control over the arrivals and departures of employees, this can be monitored easily. There are two essential ways that labor can be incorporated into the cost of an activity. If the labor is direct, an employee can be allocated directly to a task or job, then the hours worked, or hours produced, multiplied by the labor cost can give the figure.
Emerging equity markets and economic development

Abstract We provide an analysis of real economic growth prospects in emerging markets after financial liberalizations. We identify the financial liberalization dates and examine the influence of liberalizations while controlling for a number of other macroeconomic and financial variables. Our work also introduces an econometric methodology that allows us to use extensive time-series as well as cross-sectional information for our tests. We find across a number of different specifications that financial liberalizations are associated with significant increases in real economic growth. The effect is larger for countries with high education levels.
Voyager 1 Saturn Targeting Strategy

A trajectory targeting strategy for the Voyager 1 Saturn encounter has been designed to accomodate predicted uncertainties in Titan's ephemeris while maximizing spacecraft safety and science return. The encounter is characterized by a close Titan flyby 18 hours prior to Saturn periapse. Retargeting of the nominal trajectory to account for late updates in Titan's estimated position can disperse the ascending node location, which is nominally situated at a radius of low expected particle density in Saturn's ring plane. The strategy utilizes a floating Titan impact vector magnitude to minimize this dispersion. Encounter trajectory characteristics and optimal tradeoffs are presented.
Measuring fluorescence to track a quantum emitter's state: a theory review

We review the continuous monitoring of a qubit through its spontaneous emission, at an introductory level. Contemporary experiments have been able to collect the fluorescence of an artificial atom ...
The "New Judicial Federalism" Before its Time: A Comprehensive Review of Economic Substantive Due Process Under State Constitutional Law Since 1940 and the Reasons for its Recent Decline

The coming of the New Deal may have spelled the end of the Lochner era in the federal courts, but in the state courts Lochner's doctrine of economic substantive due process lives on. Since the New Deal, courts in almost every state have rebuffed the United States Supreme Court and have interpreted their own state constitutions' due process clauses to provide substantive protections to economic liberties. This Article presents a comprehensive survey of state court use of economic substantive due process since the New Deal. It includes an enumeration of every instance since 1940 of a state court of highest review protecting economic liberties through state constitutional economic substantive due process. Previous work on the subject has examined this post-New Deal rejection of the United States Supreme Court's jurisprudence, but this is the first study to comprehensively analyze the trends of that rejection. This comprehensive analysis reveals an intriguing, and potentially controversial, discovery. The discovery is that although state courts still to some degree apply state constitutional economic substantive due process in protecting economic liberties, the rate of that application declined dramatically in the 1970s and 1980s. The decline is surprising considering that through the 1940s, 1950s, and even 1960s, a full thirty years after the New Deal, state courts did not shy from invoking the long-past ghost of Lochner. This Article argues that the reason for this relatively sudden decline is that many state judges were comfortable applying economic substantive due process until the coming of Roe v. Wade and its related right to privacy cases. Because the right to privacy cases utilized substantive due process, but of the non-economic variety, a continued use of economic substantive due process provided legitimacy to their holdings. Faced with either legitimizing opinions legalizing abortion and other privacy rights, or rejecting substantive due process altogether, conservative state jurists chose the latter. These conservatives joined with progressive jurists who were already hostile toward the protection of economic liberties. Thus, with these strange bedfellows aligned, the use of economic substantive due process under state constitutional law quickly withered into the rare, but not quite extinct, doctrine that it is today.
Ciphers that Securely Encipher their own Keys.

In response to needs of disk encryption standardization bodies, we provide the first tweakable ciphers that are proven to securely encipher their own keys. We provide both a narrowblock design StE and a wideblock design EtE. Our proofs assume only standard PRP-CCA security of the underlying tweakable ciphers.
Oncogenic and Circadian Effects of Small Molecules Directly and Indirectly Targeting the Core Circadian Clock

Circadian rhythms are essential for controlling the cell cycle, cellular proliferation, and apoptosis, and hence are tightly linked to cell fate. Several recent studies have used small molecules to affect circadian oscillations; however, their concomitant cellular effects were not assessed, and they have not been compared under similar experimental conditions. In this work, we use five molecules, grouped into direct versus indirect effectors of the circadian clock, to modulate periods in a human osteosarcoma cell line (U2OS) and determine their influences on cellular behaviors, including motility and colony formation. Luciferase reporters, whose expression was driven via Bmal1- or Per2-promoters, were used to facilitate the visualization and quantitative analysis of circadian oscillations. We show that all molecules increase or decrease the circadian periods of Bmal1 and Per2 in a dose-dependent manner, but period length does not correlate with the extent of cell migration or proliferation. Nonetheless, molecules that affected circadian oscillations to a greater degree resulted in substantial influence on cellular behaviors (ie, motility and colony formation), which may also be attributable to noncircadian targets. Furthermore, we find that the ability and extent to which the molecules are able to affect oscillations is independent of whether they are direct or indirect modulators. Because of the numerous connections and feedback between the circadian clock and other pathways, it is important to consider the effects of both in assessing these and other compounds.
COVID-19: guaranteed Loans and Zombie Firms

Based on a survey (7-13 April 2020) we evaluate the reaction of Swiss firms towards the COVID-19 crisis. Firms show little pro-active reactions towards the crisis, but decrease their business activities. The firms in the survey report that the decline in foreign demand is the single most important reason for their deteriorating business situation. Firms that faced a more difficult business situation before the crisis are affected more severely during the crisis. Moreover, we investigate the impact of the Swiss federal loan program (Bundeshilfe) on the business activities. To this end, we develop a stylized theoretical model of financially constrained heterogeneous firms. We find that policy makers face a trade-off between immediate higher unemployment rates and long-term higher public spending. The former arises from a combination of a too strong economic impact of the COVID-19 lockdown (demand drop) and too low levels of loans provided. Nevertheless, providing (too) high levels of loans to firms creates zombie firms that are going to default in the future leading to an increase in public spending. (JEL codes: D22, D25, D84, and G33).
Numerical investigation of vortex onset in supersonic Taylor-Couette flow

The compressible flow between concentric cylinders, in the case where the inner cylinder rotates and the outer one is at rest, has been computed using a pseudospectral/finite difference method. The onset of turbulence in rarefied supersonic gap flows for flywheel applications, and particularly the impact of surface roughness on the development of Taylor vortices, has been explored. An immersed boundary method using an external force field was employed to model the surface roughness. The Navier-Stokes code was validated against results from the literature for a supersonic wide-gap flow. To validate the immersed boundary method, the rotor wall was replaced by a smooth offset wall modeled with an external force field. Very good agreement with the analytical solution for steady Couette flow was achieved. The growth of Taylor vortices in a narrow gap with smooth walls was studied first. Then, the external force field was used to create a riblet on the rotor to investigate the influence of the roughness of the rotor on the flow and, more particularly, on the onset of the instability. The most interesting feature is the early appearance of vortices for Taylor numbers where the flow with smooth walls is in the subcritical regime.
Global Existence for some Cross Diffusion Systems with Equal Cross Diffusion/Reaction Rates

We consider some cross diffusion systems which is inspired by models in mathematical biology/ecology, in particular the Shigesada-Kawasaki-Teramoto (SKT) model in population biology. We establish the global existence of strong solutions to systems for multiple species having equal either diffusion or reaction rates. The systems are given on bounded domains of arbitrary dimension.
Treasury inconvenience yields during the COVID-19 crisis

In sharp contrast to most previous crisis episodes, the Treasury market experienced severe stress and illiquidity during the COVID-19 crisis, raising concerns that the safe-haven status of U.S. Treasuries may be eroding. We document large shifts in Treasury ownership and temporary accumulation of Treasury and reverse repo positions on dealer balance sheets during this period. We build a dynamic equilibrium asset pricing model in which dealers subject to regulatory balance sheet constraints intermediate demand/supply shocks from habitat agents and provide repo financing to levered investors. The model predicts that Treasury inconvenience yields, measured as the spread between Treasuries and overnight-index swap rates (OIS), as well as spreads between dealers’ reverse repo and repo rates, should be highly positive during the COVID-19 crisis, which are confirmed in the data. The same model framework, adapted to the institutional setting in 2007-2009, also helps explain the negative Treasury-OIS spread observed during the Great Recession.
An Open Boundary Condition for High-order Solutions of Magnetohydrodynamics on Unstructured Grids

In this paper a characteristics-based open boundary condition (CBC) is proposed for the magnetohydrodynamic (MHD) system of equations. The algorithm is carefully designed and implemented in the con...
Distance indexing and seed clustering in sequence graphs

Motivation Graph representations of genomes are capable of expressing more genetic variation and can therefore better represent a population than standard linear genomes. However, due to the greater complexity of genome graphs relative to linear genomes, some functions that are trivial on linear genomes become much more difficult in genome graphs. Calculating distance is one such function that is simple in a linear genome but complicated in a graph context. In read mapping algorithms such distance calculations are fundamental to determining if seed alignments could belong to the same mapping. Results We have developed an algorithm for quickly calculating the minimum distance between positions on a sequence graph using a minimum distance index. We have also developed an algorithm that uses the distance index to cluster seeds on a graph. We demonstrate that our implementations of these algorithms are efficient and practical to use for a new generation of mapping algorithms based upon genome graphs. Availability and implementation Our algorithms have been implemented as part of the vg toolkit and are available at https://github.com/vgteam/vg.
Generative Adversarial Network Rooms in Generative Graph Grammar Dungeons for The Legend of Zelda

Generative Adversarial Networks (GANs) have demonstrated their ability to learn patterns in data and produce new exemplars similar to, but different from, their training set in several domains, including video games. However, GANs have a fixed output size, so creating levels of arbitrary size for a dungeon crawling game is difficult. GANs also have trouble encoding semantic requirements that make levels interesting and playable. This paper combines a GAN approach to generating individual rooms with a graph grammar approach to combining rooms into a dungeon. The GAN captures design principles of individual rooms, but the graph grammar organizes rooms into a global layout with a sequence of obstacles determined by a designer. Room data from The Legend of Zelda is used to train the GAN. This approach is validated by a user study, showing that GAN dungeons are as enjoyable to play as a level from the original game, and levels generated with a graph grammar alone. However, GAN dungeons have rooms considered more complex, and plain graph grammar’s dungeons are considered least complex and challenging. Only the GAN approach creates an extensive supply of both layouts and rooms, where rooms span across the spectrum of those seen in the training set to new creations merging design principles from multiple rooms.
REV-ERB agonism improves liver pathology in a mouse model of NASH

Non-alcoholic fatty liver disease (NAFLD) affects a significant number of people worldwide and currently there are no pharmacological treatments. NAFLD often presents with obesity, insulin resistance, and in some cases cardiovascular diseases. There is a clear need for treatment options to alleviate this disease since it often progresses to much more the much more severe non-alcoholic steatohepatitis (NASH). The REV-ERB nuclear receptor is a transcriptional repressor that regulates physiological processes involved in the development of NAFLD including lipogenesis and inflammation. We hypothesized that pharmacologically activating REV-ERB would suppress the progression of fatty liver in a mouse model of NASH. Using REV-ERB agonist SR9009 in a mouse NASH model, we demonstrate the beneficial effects of REV-ERB activation that led to an overall improvement of hepatic health by suppressing hepatic fibrosis and inflammatory response.
A reduced-order model of the spine to study pediatric scoliosis

The S-shaped curvature of the spine has been hypothesized as the underlying mechanical cause of adolescent idiopathic scoliosis. In earlier work, we proposed a reduced-order model in which the spine was viewed as an S-shaped elastic rod under torsion and bending. Here, we simulate the deformation of S-shaped rods of a wide range of curvatures and inflection points under a fixed mechanical loading. Our analysis determines three distinct axial projection patterns of these S-shaped rods: two loop (in opposite directions) patterns and one Lemniscate pattern. We further identify the curve characteristics associated with each deformation pattern, showing that for rods deforming in a Loop1 shape the position of the inflection point is the highest and the curvature of the rod is smaller compared to the other two types. For rods deforming in the Loop2 shape, the position of the inflection point is the lowest (closer to the fixed base) and the curvatures are higher than the other two types. These patterns matched the common clinically observed scoliotic curves-Lenke 1 and Lenke 5. Our S-shaped elastic rod model generates deformations that are similar to those of a pediatric spine with the same sagittal curvature characteristics and it can differentiate between the clinically observed deformation patterns.
Quantification of model uncertainty on path-space via goal-oriented relative entropy

Quantifying the impact of parametric and model-form uncertainty on the predictions of stochastic models is a key challenge in many applications. Previous work has shown that the relative entropy rate is an effective tool for deriving path-space uncertainty quantification (UQ) bounds on ergodic averages. In this work we identify appropriate information-theoretic objects for a wider range of quantities of interest on path-space, such as hitting times and exponentially discounted observables, and develop the corresponding UQ bounds. In addition, our method yields tighter UQ bounds, even in cases where previous relative-entropy-based methods also apply, e.g. , for ergodic averages. We illustrate these results with examples from option pricing, non-reversible diffusion processes, stochastic control, semi-Markov queueing models, and expectations and distributions of hitting times.
A Self-powered Analog Sensor-data-logging Device based on Fowler-Nordheim Dynamical Systems

Continuous, battery-free operation of sensor nodes requires ultra-low-power sensing and data-logging techniques. Here we report that by directly coupling a sensor/transducer signal into globally asymptotically stable monotonic dynamical systems based on Fowler-Nordheim quantum tunneling, one can achieve self-powered sensing at an energy budget that is currently unachievable using conventional energy harvesting methods. The proposed device uses a differential architecture to compensate for environmental variations and the device can retain sensed information for durations ranging from hours to days. With a theoretical operating energy budget less than 10 attojoules, we demonstrate that when integrated with a miniature piezoelectric transducer the proposed sensor-data-logger can measure cumulative “action” due to ambient mechanical acceleration without any additional external power. Designing ultra-low-power sensing and data-logging techniques with battery-free operation of sensor nodes remains a challenge. Here, the authors present a self-powered sensor-data-logger device that records a cumulative measure of the sensor signal intensity over its entire duration.
Reliance on Science by Inventors: Hybrid Extraction of In-text Patent-to-Article Citations

We curate and characterize a complete set of citations from patents to scientific articles, including nearly 16 million from the full text of USPTO and EPO patents. Combining heuristics and machine learning, we achieve 25% higher performance than machine learning alone. At 99.4% accuracy, coverage of 87.6% is achieved, and coverage above 90% with accuracy above 93%. Performance is evaluated with a set of 5,939 randomly-sampled, cross-verified “known good” citations, which the authors have never seen. We compare these “in-text” citations with the “official” citations on the front page of patents. In-text citations are more diverse temporally, geographically, and topically. They are less self-referential and less likely to be recycled from one patent to the next. That said, in-text citations have been overshadowed by front-page in the past few decades, dropping from 80% of all paper-to-patent citations to less than 40%. In replicating two published articles that use only citations on the front page of patents, we show that failing to capture those in the body text leads to understating the relationship between academic science and commercial invention. All patent-to-article citations, as well as the known-good test set, are available at http://relianceonscience.org.
Post, Robert C., The Social Foundations of Defamation Law: Reputation and the Constitution, 74 Calif. L. Rev. 691 (1986)

Robert Post published “The Social Foundations of Defamation Law” 1 the month I graduated from high school in a remote and dusty West Texas oil field town. I encountered the article six years later ...
State-Dependent Cortical Unit Activity Reflects Dynamic Brain State Transitions in Anesthesia

Understanding the effects of anesthesia on cortical neuronal spiking and information transfer could help illuminate the neuronal basis of the conscious state. Recent investigations suggest that the brain state identified by local field potential spectrum is not stationary but changes spontaneously at a fixed level of anesthetic concentration. How cortical unit activity changes with dynamically transitioning brain states under anesthesia is unclear. Extracellular unit activity was measured with 64-channel silicon microelectrode arrays in cortical layers 5/6 of the primary visual cortex of chronically instrumented, freely moving male rats (n = 7) during stepwise reduction of the anesthetic desflurane (6%, 4%, 2%, and 0%). Unsupervised machine learning applied to multiunit spike patterns revealed five distinct brain states. A novel desynchronized brain state with increased spike rate variability, sample entropy, and EMG activity occurred in 6% desflurane with 40.0% frequency. The other four brain states reflected graded levels of anesthesia. As anesthesia deepened the spike rate of neurons decreased regardless of their spike rate profile at baseline conscious state. Actively firing neurons with wide-spiking pattern showed increased bursting activity along with increased spike timing variability, unit-to-population correlation, and unit-to-unit transfer entropy, despite the overall decrease in transfer entropy. The narrow-spiking neurons showed similar changes but to a lesser degree. These results suggest that (1) anesthetic effect on spike rate is distinct from sleep, (2) synchronously fragmented spiking pattern is a signature of anesthetic-induced unconsciousness, and (3) the paradoxical, desynchronized brain state in deep anesthesia contends the generally presumed monotonic, dose-dependent anesthetic effect on the brain.SIGNIFICANCE STATEMENT Recent studies suggest that spontaneous changes in brain state occur under anesthesia. However, the spiking behavior of cortical neurons associated with such state changes has not been investigated. We found that local brain states defined by multiunit activity had a nonunitary relationship with the current anesthetic level. A paradoxical brain state displaying asynchronous firing pattern and high EMG activity was found unexpectedly in deep anesthesia. In contrast, the synchronous fragmentation of neuronal spiking appeared to be a robust signature of the state of anesthesia. The findings challenge the assumption of monotonic, anesthetic dose-dependent behavior of cortical neuron populations. They enhance the interpretation of neuroscientific data obtained under anesthesia and the understanding of the neuronal basis of anesthetic-induced state of unconsciousness.
On momentum conservation and thermionic emission cooling

The possibility of increasing the performance of thermionic cooling devices by relaxing lateral momentum conservation is examined. Upper limits for the ballistic emission current are established. It is then shown that for most cases, nonconserved lateral momentum model produces a current that exceeds this upper limit. For the case of heterojunctions with a much heavier effective mass in the barrier and with a low barrier height, however, relaxing lateral momentum may increase the current. These results can be simply understood from the general principle that the current is limited by the location, well or barrier, with the smallest number of conducting channels. They also show that within a thermionic emission framework, relaxing lateral momentum conservation does not increase the upper limit performance in most cases, and when it does, the increase is modest. More generally, however, especially when the connection to the carrier reservoir is poor and performance is well below the upper limit, relaxing lateral momentum conservation could prove beneficial.
The missing magnetic morphology term in stellar rotation evolution

Aims. This study examines the relationship between magnetic field complexity and mass and angular momentum losses. Observations of open clusters have revealed a bimodal distribution of the rotation periods of solar-like stars that has proven difficult to explain under the existing rubric of magnetic braking. Recent studies suggest that magnetic complexity can play an important role in controlling stellar spin-down rates. However, magnetic morphology is still neglected in most rotation evolution models due to the difficulty of properly accounting for its effects on wind driving and angular momentum loss.Methods. Using state-of-the-art magnetohydrodynamical magnetized wind simulations we study the effect that different distributions of the magnetic flux at different levels of geometrical complexity have on mass and angular momentum loss rates. Results. Angular momentum loss rates depend strongly on the level of complexity of the field but are independent of the way this complexity is distributed. We deduce the analytical terms representing the magnetic field morphology dependence of mass and angular momentum loss rates. We also define a parameter that best represents complexity for real stars. As a test, we use these analytical methods to estimate mass and angular momentum loss rates for 8 stars with observed magnetograms and compare them to the simulated results.Conclusions. Magnetic field complexity provides a natural physical basis for stellar rotation evolution models requiring a rapid transition between weak and strong spin-down modes.