cssi/SciSciGPT-SciSciNet huggingface dataset:
Social Media Insights Into US Mental Health During the COVID-19 Pandemic: Longitudinal Analysis of Twitter Data

Background: The COVID-19 pandemic led to unprecedented mitigation efforts that disrupted the daily lives of millions. Beyond the general health repercussions of the pandemic itself, these measures also present a challenge to the world’s mental health and health care systems. Considering that traditional survey methods are time-consuming and expensive, we need timely and proactive data sources to respond to the rapidly evolving effects of health policy on our population’s mental health. Many people in the United States now use social media platforms such as Twitter to express the most minute details of their daily lives and social relations. This behavior is expected to increase during the COVID-19 pandemic, rendering social media data a rich field to understand personal well-being. Objective: This study aims to answer three research questions: (1) What themes emerge from a corpus of US tweets about COVID-19? (2) To what extent did social media use increase during the onset of the COVID-19 pandemic? and (3) Does sentiment change in response to the COVID-19 pandemic? Methods: We analyzed 86,581,237 public domain English language US tweets collected from an open-access public repository in three steps. First, we characterized the evolution of hashtags over time using latent Dirichlet allocation (LDA) topic modeling. Second, we increased the granularity of this analysis by downloading Twitter timelines of a large cohort of individuals (n=354,738) in 20 major US cities to assess changes in social media use. Finally, using this timeline data, we examined collective shifts in public mood in relation to evolving pandemic news cycles by analyzing the average daily sentiment of all timeline tweets with the Valence Aware Dictionary and Sentiment Reasoner (VADER) tool. Results: LDA topics generated in the early months of the data set corresponded to major COVID-19–specific events. However, as state and municipal governments began issuing stay-at-home orders, latent themes shifted toward US-related lifestyle changes rather than global pandemic-related events. Social media volume also increased significantly, peaking during stay-at-home mandates. Finally, VADER sentiment analysis scores of user timelines were initially high and stable but decreased significantly, and continuously, by late March. Conclusions: Our findings underscore the negative effects of the pandemic on overall population sentiment. Increased use rates suggest that, for some, social media may be a coping mechanism to combat feelings of isolation related to long-term social distancing. However, in light of the documented negative effect of heavy social media use on mental health, social media may further exacerbate negative feelings in the long-term for many individuals. Thus, considering the overburdened US mental health care structure, these findings have important implications for ongoing mitigation efforts.
Tracking the Mysterious Loz in the Secrets of Natural History

Abstract The loz is a bovid that in medieval folklore was believed to live in Bohemia. It defended itself against hunters by spraying them with boiling and corrosive water stored in a dewlap beneath its neck. First appearing in the learned tradition with Bartholomaeus Anglicus’ De proprietatibus rerum, it then shows up in a richly illustrated geographical and wonders treatise, the Secrets of Natural History (SNH) of about 1380. This work is a Middle French translation of a small portion (on wonders of various regions of the world) of Pierre Bersuire’s exempla collection Reductorium Morale. The only visual representations of the loz are to be found in the SNH. I argue that both in its written and in its visual existence, the loz is the offspring of two different animals, also more or less imaginary, the bonnacon of the Bestiary and the other, the onager, or wild ass, though a very unusual form of that animal.
RNA Biogenesis Instructs Functional Inter-Chromosomal Genome Architecture.

Three-dimensional genome organization has emerged as an important layer of gene regulation in development and disease. The functional properties of chromatin folding within individual chromosomes (i.e., intra-chromosomal or in cis) have been studied extensively. On the other hand, interactions across different chromosomes (i.e., inter-chromosomal or in trans) have received less attention, being often regarded as background noise or technical artifacts. This viewpoint has been challenged by emerging evidence of functional relationships between specific trans chromatin interactions and epigenetic control, transcription, and splicing. Therefore, it is an intriguing possibility that the key processes involved in the biogenesis of RNAs may both shape and be in turn influenced by inter-chromosomal genome architecture. Here I present the rationale behind this hypothesis, and discuss a potential experimental framework aimed at its formal testing. I present a specific example in the cardiac myocyte, a well-studied post-mitotic cell whose development and response to stress are associated with marked rearrangements of chromatin topology both in cis and in trans. I argue that RNA polymerase II clusters (i.e., transcription factories) and foci of the cardiac-specific splicing regulator RBM20 (i.e., splicing factories) exemplify the existence of trans-interacting chromatin domains (TIDs) with important roles in cellular homeostasis. Overall, I propose that inter-molecular three-dimensional proximity between co-regulated nucleic acids may be a pervasive functional mechanism in biology.
Studying the Effect of Gravel Roads Geometric Features on Corrugation Behavior

Gravel and unpaved roads make up nearly 50% of the United States roads network. This explains the need to have a sophisticated and advanced Gravel Roads Management System (GRMS). Thus, the Wyoming Technology Transfer Center (WYT2C) is in the process of developing a holistic GRMS. One of the most important factors in developing a GRMS is understanding the deterioration behavior of the roads. In this study, the effect of gravel roads geometric features on surface distresses in terms of corrugation was investigated. Factorial design method was used to study the relation between the existence of horizontal curve and vertical grade and the corrugation severity. The study found that there is a significant relation between corrugation severity and the existence of horizontal curve and vertical grades. Therefore, a model was developed to provide an accurate prediction for the corrugation at these special locations. The developed model has a coefficient of determination (R2) of 88% which means that this model represents 88% of the studied data. The findings of this study provide the pavement engineers with a better understanding about the deterioration behavior of gravel roads. Employing the results of this study in GRMS will enhance the maintenance budget optimization process significantly.
Salvaging Merkle-Damgård for Practical Applications

Many cryptographic applications of hash functions are analyzed in the random oracle model. Unfortunately, most concrete hash functions, including the SHA family, use the iterative (strengthened) Merkle-Damgard transform applied to a corresponding compression function. Moreover, it is well known that the resulting "structured" hash function cannot be generically used as a random oracle, even if the compression function is assumed to be ideal. This leaves a large disconnect between theory and practice: although no attack is known for many concrete applications utilizing existing (Merkle-Damgard based) hash functions, there is no security guarantee either, even by idealizing the compression function. Motivated by this question, we initiate a rigorous and modular study of developing new notions of (still idealized) hash functions which would be (a) natural and elegant; (b) sufficient for arguing security of important applications; and (c) provably met by the (strengthened) Merkle-Damgard transform, applied to a "strong enough" compression function. In particular, we develop two such notions satisfying (a)-(c): a preimage aware function ensures that the attacker cannot produce a "useful" output of the function without already "knowing" the corresponding preimage, and a public-use random oracle , which is a random oracle that reveals to attackers messages queried by honest parties.
Does Social Capital in Social Media Equate to Revenue

The primary audience for this case study is business students who are taking classes in e-commerce, Web 2.0, social media, online business, business strategy, and internet marketing. Due to the fact that many Americans today are having problems with employment and income, but still have time to spend on Facebook or other social media, it may be the right moment in internet marketing history to utilize a social medium they are already wedded to as a platform to make some revenue. The objective is to find out whether utilizing Facebook “friends” on a daily basis can actually be an efficient way to increase Google AdSense revenue rather than relying on search engines to bring customers or clickers to their websites without asking their social capital (Facebook friends) to intentionally click on AdSense advertisements. This case is about the effect of Facebook on Google AdSense revenue based on web content search.
Identifying Remnants of Evidence in the Cloud

With the advent of cloud computing, law enforcement investigators are facing the challenge that instead of the evidence being on a device that they can seize, the evidence is likely located in remote data centers operated by a service provider; and may even be in multiple locations (and jurisdictions) across the world. The most practical approach for an investigator when cloud computing has been used is to execute a warrant that requires the service provider to deliver the evidence. However, to do this, the investigator must be able to determine that a cloud application was used, and then must issue a warrant with reasonable scope (e.g. the subject’s username at the cloud provider, the name of the documents, the dates accessed, etc). Fortunately, most cloud applications leave remnants (e.g. cached web sites, cookies, registry entries, installed files, etc) on the client devices. This paper describes the process for identifying those remnants and parsing them to generate the data required by law enforcement to form warrants to cloud service providers. It illustrates the process by obtaining remnants from: Google Docs accessed by Internet Explorer, Dropbox, and Windows Live Mesh.
Pressure Profile in Annulus: Solids Play a Significant Role

This paper looks into the effects of solids on the wellbore pressure profile under different conditions. An extensive number of experiments were conducted on a 90-ft-long, 4.5 in. 8 in. full-scale flow loop to simulate field conditions. The flow configurations are analyzed. A solid–liquid two-phase flow configuration map is proposed. Significant difference is found between the pressure profile with solids and without solids in the wellbore. The results of this study show how the pressure profile in the wellbore varies when solids present in the annulus, which may have important applications in drilling operations. [DOI: 10.1115/1.4030845]
A note on the computable categoricity of l^p spaces

Suppose that \(p\) is a computable real and that \(p \ge 1\). We show that in both the real and complex case, \(\ell ^p\) is computably categorical if and only if \(p = 2\). The proof uses Lamperti’s characterization of the isometries of Lebesgue spaces of \(\sigma \)-finite measure spaces.
Business environment, clustering, and industry location : evidence from Indian cities

How do differences in the local business environment influence location of industry within countries? How do the benefits of a good business environment compare with those from good market access and agglomeration economies from industry clustering? The authors examine these questions by analyzing location decisions of individual firms. Using data from a recently completed survey of manufacturing firms in India, they find that both the local business environment and agglomeration economies significantly influence business location choices across cities. In particular, excessive regulation of labor and of other industrial activities reduces the probability of a business locating in a city. The authors' findings imply that in order to attract industrial activity, smaller or remoter cities need to offer even more attractive policy concessions or reforms to offset the effects of their relatively adverse (economic) geography. Their methodology pays special attention to the identification of agglomeration economies in the presence of unobserved sources of natural advantage.
Invariant representations of GSp(2) under tensor product with a quadratic character

Let $F$ be a number field or a $p$-adic field. The author introduces in Chapter 2 of this work two reductive rank one $F$-groups, $\mathbf{H_1}$, $\mathbf{H_2}$, which are twisted endoscopic groups of $\textup{GSp}(2)$ with respect to a fixed quadratic character $\varepsilon$ of the idele class group of $F$ if $F$ is global, $F^\times$ if $F$ is local. When $F$ is global, Langlands functoriality predicts that there exists a canonical lifting of the automorphic representations of $\mathbf{H_1}$, $\mathbf{H_2}$ to those of $\textup{GSp}(2)$. In Chapter 4, the author establishes this lifting in terms of the Satake parameters which parameterize the automorphic representations. By means of this lifting he provides a classification of the discrete spectrum automorphic representations of $\textup{GSp}(2)$ which are invariant under tensor product with $\varepsilon$. Table of Contents: Introduction; $\varepsilon$-endoscopy for $\textup{GSp}(2)$; The trace formula; Global lifting; The local picture; Appendix A. Summary of global lifting; Appendix B. Fundamental lemma; Bibliography; List of symbols; Index. (MEMO/204/957)
New Control Laws for the Attitude Stabilization of Rigid Bodies

Abstract This paper introduces a new class of globally asymptotically stabilizing feedback control laws for the complete (i.e., dynamics and kinematics) attitude motion of a rotating rigid body. Control laws are given in terms of two new parameterizations of the rotation group derived using stereographic projection. The stabilizing properties of the proposed controllers are proved using Lyapunov functions which involve a quadratic plus a logarithmic term. An Interesting feature of the proposed Lyapunov functions is that they often lead to controllers that are linear with respect to the kinematic parameters.
The end of slow networks: it's time for a redesign

The next generation of high-performance networks with remote direct memory access (RDMA) capabilities requires a fundamental rethinking of the design of distributed in-memory DBMSs. These systems are commonly built under the assumption that the network is the primary bottleneck and should be avoided at all costs, but this assumption no longer holds. For instance, with InfiniBand FDR 4×, the bandwidth available to transfer data across the network is in the same ballpark as the bandwidth of one memory channel. Moreover, RDMA transfer latencies continue to rapidly improve as well. In this paper, we first argue that traditional distributed DBMS architectures cannot take full advantage of high-performance networks and suggest a new architecture to address this problem. Then, we discuss initial results from a prototype implementation of our proposed architecture for OLTP and OLAP, showing remarkable performance improvements over existing designs.
A tool for inference detection and knowledge discovery in databases

Latent dependencies and relationships between groups of attributes in databases can produce inference channels that pose serious security threats. This paper uses a powerful knowledge discovery formalism for modeling and identifying latent inference channels in relational databases. The inference discovery methodology supports the analysis of precise and imprecise inference in database schemes and extensions. An interactive graphical tool for aiding inference discovery in Oracle databases is described. This tool is useful for identifying compromising inference channels in databases with many hidden dependencies.
How far to the hospital?: The effect of hospital closures on access to care

Do urban hospital closures affect health care access or health outcomes? We study closures in Los Angeles County between 1997 and 2003, through their effect on distance to the nearest hospital. We find that increased distance to the closest hospital increases deaths from heart attacks and unintentional injuries. This finding is robust to several sensitivity checks. We also find that, for residents with health insurance, increased distance shifts regular care towards doctor's offices. While most residents are otherwise unaffected, we find some evidence that seniors perceive more difficulty accessing care.
Exclusion and moral hazard: The case of identical demand

Abstract This paper examines the problem of costly exclusion of individuals from a public good. Previous analyses of exclusion have treated it as solely a question of technologies; in our analysis exclusion depends on technology and incentives. In this paper providers of the good design a mechanism to provide an optimal level of deterrence to free riders. If individuals are heterogeneous optimal deterrence may allow some free riders. We examine the effect of costs of exclusion on the Samuelson condition for optimal provision, and see that the desire to deter free riding leads to underprovision of the good irrespective of the degree of rivalry of the good.
Children of incest

Eighteen prospectively ascertained cases of brother x sister and father x daughter matings are described. A series of illegitimate children whose mothers were as nearly matched as possible to the incest mothers for intelligence, age, height, weight, and socioeconomic conditions were used as controls. Six of the children of incest had died or were found to have major defects on follow-up 6 months after birth date, whereas one of the comparison children was so classified. This is a larger inbreeding effect than would be predicted on the basis of published findings from marriages of first cousins. The series is published at this time to encourage others to collect these important, but rare and elusive data, in a prospective, controlled manner.
Strategies for zeolite synthesis by design

Publisher Summary This chapter presents the thermodynamics, kinetics and a proposed synthesis mechanism for the crystallization of a prototypical high-silica zeolite, namely ZSM-5. This information is used to develop strategies for the design of zeolite syntheses and a few of these strategies are outlined. Two aspects of the design process are described below: (i) The design of pore architectures and (ii) the design of framework atom positioning. In order to develop zeolite pore architecture by design, the proper choice of organic structure-directing agent and inorganic composition must be made. Next, the size and rigidity of the molecule must be controlled. It is clear that as the size of the organic molecule is increased, the specificity for producing zeolite pore architectures also increases. Very recently, Zones has shown that there is a good correlation between structure direction and the rigidity of the organic structure-directing agent as measured by the number of tertiary and quaternary connectivities in the molecule for a series of organics with C/N. Thus, size, rigidity, and hydrophobicity, simultaneously, must be correctly specified in order to prepare a good structure-directing agent by design. For the inorganic compositions, it is clear that for pure-silica preparations a small amount of alkali-metal cations is necessary for practical kinetics; however, large amounts will lead to layered compounds.
Truncated Product Methods for Panel Unit Root Tests.

This paper proposes two new panel unit root tests based on Zaykin et al. (2002)’s truncated product method. The first one assumes constant correlation between P-values and the second one uses sieve bootstrap to allow for general forms of cross-section dependence in the panel units. Monte Carlo simulation shows that both tests have reasonably good size and are powerful in cases of some very large P-values. The proposed tests are applied to a panel of real GDP and inflation density forecasts, resulting in evidence that professional forecasters may not update their forecast precision in an optimal Bayesian way.
Estrogen Receptors Are Present in the Epididymis of the Rooster

Our recent discovery that testicular genn cells and epi­ didymal spenn ClOI11U't active P450 aroma1ase suggests that the repro­ ductive tract may be a target for estrogen. Therefore, the objective of this study was to detennine if estrogen receptors (ER) are present in the avian epididymis using immunocytochemistry, northern blot analysis, and in situ hybridization. lmrnunoperoxidase staining for ER was found principally In nuclei of nonclliated epithelial cells of proximal and distal efferent ductules and the epididymis c1Jct. The ciliated cells also 8Jr peared to be slightly positive In the efferent ductules. Weak immuno­ stalnlng was also obaerYed in the connecllve tissue of the epididymis duel lmmunostaining was more intense In epithelial cells of the efferent T he avian epididymis, consisting of the efferent ducts (ductuli efferentes), connecting ducts (ductuli conjugen­ tes), and the epididymis duct (ductus epididymidis), plays an important role in the resorption of lwninal fluids from the testis (Qulow and Jones, 1988). Although spenn tra­ verse this region of the male reproductive tract rapidly, these ducts resorb nearly 90% of the testicular plasma output be­ fore the spenn are stored for an extended period in the duc­ tus deferens. Androgens are considered the major hormones involved in the regulation of epididymal functions in mammals (Ro­ baire and Henno, 1988). However, there is considerable ev­ idence that structure and function of the efferent ductules and the initial segment of the epididymis are also dependent on other lwninal factors derived from the testis (Fawcett and Hoff, 1979; Douglass et al, 1991 ). The avian species con­ tains homologous structures to the mammalian epididymis, i.e., a fluid-resorbing epithelium with ciliated cells (Tmgari, 1972; Qulow and Jones, 1988); therefore, it is possible that some regions of the avian epididymis are less responsive to androgens and are regulated by other testicular factors. One of these nonandrogen factors may be estrogen. In
High-technology-industry trade and investment: The role of factor endowments

Abstract This paper develops a dynamic general equilibrium model of international research and development (R&D) competition based on the Heckscher-Ohlin structure of production. We analyze the model's unique steady-state equilibrium in which both R&D expenditures and the rate at which firms discover new superior products are constant over time. The model generates intraindustry trade, inteerindustry trade, product cycles and multinational corporations even when factor price equalization prevails across countries. These phenomena on the factor endowments. In the absence of r&D incentives the model reduces to the familiar Heckscher–Ohlin model at each point in time.
Quantum and Semiclassical Theories of Chemical Reaction Rates

A rigorous quantum mechanical theory (and a semiclassical approximation thereto) is described for calculating chemical reaction rates ``directly``, i.e., without having to solve the complete state-to-state reactive scattering problem. The approach has many vestiges of transition state theory, for which it may be thought of as the rigorous generalization.
Agricultural Banking and Early Warning Models for the Bank Failures of the Late 2000s Great Recession

This paper is designed to validate if the agricultural sector can once again be labeled as an instigator of the late-2000s Great Recession using the early warning models technique. The empirical results indicate that exposure to agribusiness operations does not necessarily enhance a banks’ tendency to fail.
THE DOCTOR'S FEDERAL TAXES

Excerpt During the period of the first world war, the maximum amount which was raised by taxes in any one year was $5,400,000, 000. Our present tax laws are yielding more than five times that amoun...
The surprisingly low importance of income uncertainty for precaution

While it is common to use income uncertainty to explain household saving decisions, there is much disagreement about the importance of precautionary saving. This paper suggests that income uncertainty is not an important motive for saving, although households do have other precautionary reasons to save. Using a question from the Survey of Consumer Finances that asks how much households want for precautionary purposes, this paper shows that expressed household preferences, and liquid savings, are much lower than predicted by standard modeling assumptions. Households rarely list unemployment as a reason to save. Perceived income uncertainty does not affect liquid savings or precautionary preferences. Neither does being in an occupation with higher income volatility. Instead, households seem very concerned with expenditure shocks.
Four Parameters of Interest in the Evaluation of Social Programs

This paper reviews four treatment parameters that have become commonly used in the program evaluation literature: the average treatment effect, the effect of treatment on the treated, the local average treatment effect, and the marginal treatment effect. We derive simply computed closed-form expressions for these treatment parameters in a latent variable framework with Gaussian error terms. These parameters can be estimated using nothing more than output from a standard two-step procedure. We also briefly describe recent work that seeks to go beyond mean effects and estimate the distributions associated with various outcome gains. The techniques presented in the paper are applied to estimate the return to some form of college education for various populations using data from the National Longitudinal Survey of Youth.
Adults only: why don’t children belong to the clean-plate club?

What percentage of the food you serve do you eat? If we could provide estimates of how much food people took they actually ate, this would open the door for a huge number of studies in psychology, marketing, economics and consumer behavior that have been dismissed or overlooked by nutrition and public health because they measured how much subjects served, but not how much they ate. Providing this ‘percent eaten’ estimate was the objective of Wansink and Johnson.1 After aggregating results from a wide number of self-served meals and snacks, one conclusion was that most adults are members of the clean-plate club. Regardless of their sex or ethnicity, it was estimated the average adult in these studies ate ~92% (unweighted by sample size) of what they served.
Pareto efficiency in synthesizing shared autonomy policies with temporal logic constraints

For systems in which control authority is shared by an autonomous controller and a human operator, it is important to find solutions that achieve a desirable system performance with a reasonable workload for the human operator. We formulate a shared autonomy system capable of capturing the interaction and switching control between an autonomous controller and a human operator, as well as the evolution of the operator's cognitive state in the working environment. To trade-off human's effort and the performance level, e.g., measured by the probability of satisfying the underlying temporal logic specification, a two-stage policy synthesis algorithm is proposed for generating Pareto efficient coordination and control policies with respect to user specified weights.
Inflation in the universe, Circa 1986

The hot big bang cosmology, or the standard cosmology as it is appropriately known, is a highly successful model, providing a reliable and tested accounting of the Universe from 0.01 s after the bang until today, some 15 Gyr later. However, very special initial data seem to be required in order to account for the observed smoothness and flatness of our Hubble volume and for the existence of the small primeval density inhomogeneities required for the formation of structure in the Universe. Inflation offers a means of accounting for these special initial data which is based upon physics at sub-Planck energy scales (≪m pl ≃ 1019 GeV) and is motivated by contemporary ideas in particle theory. Here I review the status of the “Inflationary Paradigm,” Circa 1986. At present essentially all inflationary models involve a very weakly-coupled (quantified by the presence of a dimensionless parameter of order 10−12 or so) scalar field which is displaced from the minimum of its potential. Regions of the Universe where the scalar field is initially displaced from its minimum undergo inflation as the scalar field relaxes, resulting in a Universe today which resembles ours in regions much larger than our present Hubble volume (≃ 1028 cm), but which on very large scales (≫ 1028 cm) may be highly irregular. At present, the most conspicuous blemish on the paradigm is the lack of a compelling particle physics model to implement it. I also briefly review some other unresolved issues facing inflation, including the confrontation between the predictions of inflation and observational data.
The use of asset management companies in the resolution of banking crises - cross-country experience

Asset management companies have been used to address the overhang of bad debt in the financial system. There are two main types of asset management company: those set up to expedite corporate restructuring and those established for rapid disposal of assets. A review of seven asset management companies reveals a mixed record. In two of three cases, asset management companies for corporate restructuring did not achieve their narrow goal of expediting bank or corporate restructuring, suggesting that they are not good vehicles for expediting corporate restructuring. Only a Swedish asset management company successfully managed its portfolio, acting sometimes as lead agent in restructuring - and helped by the fact that the assets acquired had mostly to do with real estate, not manufacturing, which is harder to restructure, and represented a small fraction of the banking system's assets, which made it easier for the company to remain independent of political pressures and to sell assets back to the private sector. Asset management companies used to dispose of assets, rapidly fared somewhat better. Two of four agencies (in Spain and the United States) achieved their objectives, suggesting that asset management companies can be used effectively for narrowly defined purposes of resolving insolvent and inviable financial institutions, and selling off their assets. Achieving these objectives required an easily liquefiable asset - real estate - mostly professional management, political independence, adequate bankruptcy, and foreclosure laws, appropriate funding, skilled resources, good information and management systems, and transparent operations and processes. The other two agencies (in Mexico and the Philippines) were doomed from the start, as governments transferred to them politically motivated loans or fraudulent assets, which were difficult for a government agency susceptible to political pressure and lacking independence to resolve or sell off.
The Courts, Educational Policy, and Unintended Consequences

Recent school finance litigation illustrates yet again how law can generate unintended policy consequences. Seeking to improve student achievement and school accountability, more states now turn to educational standards and assessments. At the same time, a multi-decade school finance litigation effort develops and changes its theoretical base. Recently, educational standards and school finance litigation converged in a way that enables school districts to gain financially from their inability to meet desired achievement levels. Specifically, courts increasingly allow litigants and lawsuits to transform standards and assessments into constitutional entitlements to additional resources. As a consequence, increased legal and financial exposure for school districts follows from the implementation of what many consider a plausible educational policy. The judiciary's participation in this transformation uncovers old and new problems that arise when courts are asked to set educational policy.
Global Completability with Applications to Self-Consistent Quantum Tomography

Let \({{p}_{1},\ldots, {p}_{N} \in \mathbb{R}^D}\) be unknown vectors and let \({\Omega \subseteq \{1,\ldots,N\}^{2}}\). Assume that the inner products \({{p}_{i}^T {p}_{j}}\) are fixed for all \({(i,j) \in \Omega}\). Do these inner product constraints (up to simultaneous rotation of all vectors) determine \({{p}_{1}, \ldots, {p}_{N}}\) uniquely? Here we derive a necessary and sufficient condition for the uniqueness of \({{p}_{1}, \ldots,{p}_{N}}\) (i.e., global completability) which is applicable to a large class of practically relevant sets \({\Omega}\). Moreover, given \({\Omega}\), we show that the condition for global completability is universal in the sense that for almost all vectors \({{p}_{1}, \ldots,{p}_{N} \in \mathbb{R}^{D}}\) the completability of \({{p}_{1}, \ldots,{p}_{N}}\) only depends on \({\Omega}\) and not on the specific values of \({{p}_{i}^T {p}_{j}}\) for \({(i,j) \in \Omega}\). This work was motivated by practical considerations, namely, matrix factorization techniques and self-consistent quantum tomography.
Azimuthal anisotropies in p + Pb collisions from classical Yang–Mills dynamics

Abstract We compute single and double inclusive gluon distributions in classical Yang–Mills simulations of proton–lead collisions and extract the associated transverse momentum dependent Fourier harmonics v 2 ( p T ) and v 3 ( p T ) . Gluons have a large v 2 in the initial state, while odd harmonics such as v 3 vanish identically at the initial time τ = 0 + . By the time τ ≲ 0.4 fm / c final state effects in the classical Yang–Mills evolution generate a non-zero v 3 and only mildly modify the gluon v 2 . Unlike hydrodynamic flow, these momentum space anisotropies are uncorrelated with the global spatial anisotropy of the collision. A principal ingredient for the generation of v 2 and v 3 in this framework is the event-by-event breaking of rotational invariance in domains the size of the inverse of the saturation scale Q s . In contrast to our findings in p + Pb collisions Yang–Mills simulations of lead–lead collisions generate much smaller values of v 2 , 3 ( p T ) and additional collective flow effects are needed to explain experimental data. This is because the locally generated anisotropy due to the breaking of rotational invariance is depleted with the increase in the number of uncorrelated domains.
Skill-Biased Technical Change and the Cost of Higher Education

We document the growth in higher education costs and tuition over the past 50 years. To explain these trends, we develop a general equilibrium model with skill- and sector-biased technical change. Finding the model’s parameters through a combination of estimation and calibration, we show that it can explain the rise in college costs between 1961 and 2009, along with the increase in college attainment and the change in the relative earnings of college graduates. The model predicts that if college costs had ceased to grow after 1961, enrollment in 2010 would have been 3%–6% higher.
Pitch and spectral estimation of speech based on auditory synchrony model

This paper describes a system for processing sonorant regions of speech, motivated by knowledge of the human auditory system. The spectral representation is intended to reflect a proposed model for human auditory processing of speech, which takes advantage of synchrony in the nerve firing patterns to enhance formant peaks. The auditory model is also applied to pitch extraction, and thus a temporal pitch processor is envisioned. The spectrum is derived from the outputs of a set of linear fillers with critical bandwidths. Saturation and adaptation are incorporated for each filter independently. Each "spectral" coefficient is determined by weighting the amplitude response at that frequency by a measure of synchrony to the center frequency of the filter. Pitch is derived front a waveform generated by adding the rectified filter outputs across the frequency dimension. The spectral estimator and the pitch estimator are illustrated by processing pure tones and natural speech.
Signal-Locality and Subquantum Information in Deterministic Hidden-Variables Theories

It is proven that any deterministic hidden-variables theory, that reproduces quantum theory for a ‘quantum equilibrium’ distribution of hidden variables, must predict the existence of instantaneous signals at the statistical level for hypothetical ‘nonequilibrium ensembles’ . This ‘ signal-locality theorem’ generalises yet another feature of the pilot-wave theory of de Broglie and Bohm, for which it is already known that signal- locality is true only in equilibrium. Assuming certain symmetries, lower bounds are derived on the ‘ degree of nonlocality’ of the singlet state, defined as the (equilibrium) fraction of outcomes at one wing of an EPR- experiment that change in response to a shift in the distant angular setting. It is shown by explicit calculation that these bounds are satisfied by pilot-wave theory. The degree of nonlocality is interpreted as the average number of bits of ‘subquantum information’ transmitted superluminally, for an equilibrium ensemble. It is proposed that this quantity might provide a novel measure of the entanglement of a quantum state, and that the field of quantum information would benefit from a more explicit hidden-variables approach. It is argued that the signal-locality theorem supports the hypothesis, made elsewhere, that in the remote past the universe relaxed to a state of statistical equilibrium at the hidden-variable level, a state in which nonlocality happens to be masked by quantum noise.
Distribution-based Image Similarity

Image similarity measures are at the core of every image retrieval system. In this contribution, we provide a systematic overview of distribution based measures for image similarity. We then empirically compare nine families of color and texture similarity measures summarizing over 1,000 CPU hours of computational experiments. Quantitative performance evaluations are given for classification and image retrieval.
De-industrialization of the Riches and the Rise of China

This paper tries to understand the structural transformation in a global world. While employment and output have shifted out of the industrial sector and into services in the G7 countries, the majority of world manufacturing employment is now located in the developing countries of Asia, especially in China. China’s manufacturing industry is the largest in the world in terms of employment, employing more manufacturing workers than do all of the G7 countries combined. In addition, the merchandise exports of China account for more than 10 percent of the world merchandise exports. First, I analyze the relationship between productivity change and industrial employment in a closed economy general economy model for each of the G7 economies. The model has non-homothetic preferences incorporating Engel’s law to capture the declining role of agriculture in all of the G7 nations. On the other hand, the central feature of the model is uneven technological progress between industry and services to create the movement of labor from industry to services. I find that an explanation of de-industrialization due to increased productivity in industry relative to services in a closed economy setting is not compelling. After showing the failure of a closed economy model I investigate the effect of openness to understand the de-industrialization of the G7 economies in the context of the recent emergence of China in the world economy following the idea of Coleman (2007), who argues that the emergence of giant economies sets in motion a structural transformation in other countries around the world. I ask, To what extent is de-industrialization in the world’s richest nations the result of the emergence of China in world product markets, and to what extent would this de-industrialization have occurred anyway as the result of secular shifts in sectoral productivity in the G7 countries? I present a simple open economy framework to illustrate the effects of China on the de-industrialization of the G7 nations studying a two-country, three-sector model with no international labor mobility, in which countries trade industrial goods due to the (Armington) assumption that production of different goods is country specific. This feature of the model, and the degree of substitutability in preferences between home and foreign produced units of each good, endogenously determine each country’s equilibrium pattern of employment, production, and trade. I compare the de-industrialization predictions of the closed economy and open economy models between 1978 and 2006. I calibrate to sectoral data from China and the G7, and conduct numerical experiments to quantify the effect of the emergence of China on the de-industrialization of the economic activities in the G7 countries. I find that the sectoral labor productivity differences in the industrial sector in China and the rest of the world affect the sectoral distribution of employment in the G7. I argue that the results are promising for the future research.
Managing risks of capital mobility

Inherent in pursuing openness to international capital flows is an awareness that it brings both benefits and risks. Much of the current debate is about how best to balance them. Major benefits for developing countries include access to a broader menu of investment sources, options, and instruments, as well as enhanced efficiency of domestic financial institutions and the discipline of capital markets in conducting domestic macroeconomic policy. By easing financing constraints, the greater availability of international finance can extend the period for implementing needed adjustments. From the perspective of emerging market economies, the author highlights two sources of risk: the host governments' policy of liberalizing capital controls before having established the macroeconomic, regulatory, and institutional foundations required for capital openness. A shift in foreign leaders' and investors' sentiments and confidence, not necessarily related to a particular country's long-term creditworthiness. Risk management demands judicious strategies for both corporate and financial institutions and national policy. At the institutional level, with the advances in technology and communications, financial risk management practice has improved significantly in recent years through the use of statistical models, such as value at risk, computer simulation, and stress testing. At the national level, with the worldwide trend toward democracy, the author argues that managing the risks of financial openness will require developing national mechanisms through which to provide insurance to citizens-through the marketplace or through redistributive policy-and thus to avert political pressure for capital controls. To succeed, open democratic societies have to balance the threat of capital exit, made easier by the opening of capital markets, with the political voice of citizens-demanding protection through redistribution, social safety nets, and other insurance-like measures. These insurance measures have been critical increasing the tension between politics and financial openness in OECD countries. Indeed, cross-country empirical analysis confirms that countries that spend a large share of their GDP on social needs (education, health, and transfer payments) are more open to free international capital flows, and also score high on measures of political and civil liberty.
Laser beam self-focusing in gases

A new mechanism which may cause self-focusing in gases is proposed. We consider the case of a one-hundred picosecond pulse interacting with a monoatomic gas. Under these conditions of short time, low density and spherical atomic symmetry, the usual self-focusing mechanisms such as the Kerr effect may not be applicable. Since there are indications that self-focusing does occur under these conditions, one is led to seek new sources of nonlinearity in the wave equation. The one suggested here is multiphoton Raman scattering. For a sufficiently intense beam this should be a very rapid process and produce observable effects even under the afore-mentioned conditions. Our initial calculations indicate that this indeed may be the cause of self-focusing in gases.
Supernova II Neutrino Bursts and Neutrino Massive Mixing

The issue ofwhether or not neutrinos have masses is important for astrophysics and cosmology. Astrophysical considerations may represent the besthope fordetermining neutrino masses and mixings. In this paper, we examine how proposed neutral-currentbased, supernova neutrino-burst detectors, in conjunction with the next generation waterCerenkov detectors, could use a galactic supernova event to either measure or place constraints on the vμ,t masses in excess of 5 eV1.2. Such measurements would have important implications for our understanding of particle physics, cosmology, and the solar neutrino problem and would be complementarytoproposed laboratory vacuum-oscillation experiments. A light neutrino mass between 1 eV and 100 eV would be highly significant for cosmology. In fact, if a neutrino contributes a fraction v of the closure density of the Universe, it must have a mass mv ≈ 92 v, h eV, where h is the Hubble parameter in units of 100 km s-1 Mpc-1. Reasonable ranges for v, and h then give 1 eV to 30 eV as a cosmologically significant range. A neutrino with a mass in the higher end ofthis range (i.e., 10 mv 30 eV) could contribute significantly to the closure density of the Universe. The cosmic background explorer (COBE) observation of anistropy in the microwave background, combined with observations at smaller scales, and the distribution of galaxy streaming velocities, have been interpreted as implying that there are two components of dark matter: hot (ΩHDM ~ 0.3) and cold (ΩCDM ~ 0.6).
TIME-DEPENDENT CALCULATIONS OF EQUILIBRIUM AND STABILITY PROBLEMS IN SCYLLAC AND TOKAMAK GEOMETRIES

In preparation for a study of the equilibrium and stability properties of Scyllac, a sequence of problems has been studied by numerically solving the MHD equations in three dimensions. Among these are computations of the dynamics of nonequilibrium plasmas in toroidal theta pinches and high beta tokamaks, which illustrate what happens when there is no equilibrium as well as the approach to equilibrium when one exists. The evolution of Kruskal--Shafranov modes in a diffuse screw pinch was also computed from small amplitude to its final nonlinear state. The application of the same method to Scyllac is shown. (auth)
Intelligence without reason

Computers and Thought are the two categories that together define Artificial Intelligence as a discipline. It is generally accepted that work in Artificial Intelligence over the last thirty years has had a strong influence on aspects of computer architectures. In this paper we also make the converse claim; that the state of computer architecture has been a strong influence on our models of thought. The Von Neumann model of computation has lead Artificial Intelligence in particular directions. Intelligence in biological systems is completely different. Recent work in behavior-based Artificial Intelligence has produced new models of intelligence that are much closer in spirit to biological systems. The non-Von Neumann computational models they use share many characteristics with biological computation.