cssi/SciSciGPT-SciSciNet huggingface dataset:
RAPID RECOVERY PROTOCOL FOR PRIMARY TOTAL KNEE ARTHROPLASTY REDUCES LENGTH OF STAY AND DECREASES HOSPITAL READMISSIONS IN A COMMUNITY SETTING

Introduction Rapid recovery protocols (RRP) for joint replacements have been shown to improve efficiency, reduce costs, and minimize adverse outcomes in academic health systems. The purpose of this study is to evaluate if RRP can be safely implemented in a community health system for total knee arthroplasty. Methods This study used a retrospective cohort of 3,608 patients who underwent primary unilateral total knee arthroplasty from January 1, 2013 to December 31, 2014. 60 Patients were excluded because data or surgery could not be verified: BMI less than 18.5 or greater than 60 kg/m∘2 or if the surgical time was less than 45 seconds or greater than 180 minutes, and bilateral surgery. Data was obtained from querying the health system9s inpatient database containing information for all joint replacements within the system. Patients were compared in two groups: those who received a RRP after surgery versus those who received traditional post-op care. The main outcome measure was all-cause 30-day readmissions. Multivariate logistic regression was used to calculate the odds for all-cause 30-day readmission for patients who received RRP versus traditional care when controlling for age, gender, race, insurance status (Medicare versus no Medicare), obesity, diabetes, renal disease, tobacco use, and ASA score (less than 3 versus 3 or greater). Results Patients receiving RRP were readmitted less than those who received traditional care (1.6% versus 3.6%, p Conclusions Rapid recovery protocols are an effective means of reducing 30-day readmissions and length of stay in patients undergoing primary unilateral total knee arthroplasty in a community setting.
Bistable compliant mechanism using magneto active elastomer actuation

One of the challenges in the emerging field of origami engineering is achieving large deformations to enable significant shape transformations. Bistable compliant mechanisms provide a means to achi...
Surviving an "Eternal September": How an Online Community Managed a Surge of Newcomers

We present a qualitative analysis of interviews with participants in the NoSleep community within Reddit where millions of fans and writers of horror fiction congregate. We explore how the community handled a massive, sudden, and sustained increase in new members. Although existing theory and stories like Usenet's infamous "Eternal September" suggest that large influxes of newcomers can hurt online communities, our interviews suggest that NoSleep survived without major incident. We propose that three features of NoSleep allowed it to manage the rapid influx of newcomers gracefully: (1) an active and well-coordinated group of administrators, (2) a shared sense of community which facilitated community moderation, and (3) technological systems that mitigated norm violations. We also point to several important trade-offs and limitations.
Association of missing paternal demographics on infant birth certificates with perinatal risk factors for childhood obesity.

The role of fathers in the development of obesity in their offspring remains poorly understood. We evaluated associations of missing paternal demographic information on birth certificates with perinatal risk factors for childhood obesity. Data were from the Linked CENTURY Study, a database linking birth certificate and well-child visit data for 200,258 Massachusetts children from 1980–2008. We categorized participants based on the availability of paternal age, education, or race/ethnicity and maternal marital status on the birth certificate: (1) pregnancies missing paternal data; (2) pregnancies involving unmarried women with paternal data; and (3) pregnancies involving married women with paternal data. Using linear and logistic regression, we compared differences in smoking during pregnancy, gestational diabetes, birthweight, breastfeeding initiation, and ever recording a weight for length (WFL) ≥ the 95th percentile or crossing upwards ≥2 WFL percentiles between 0–24 months among the study groups. 11,989 (6.0 %) birth certificates were missing paternal data; 31,323 (15.6 %) mothers were unmarried. In adjusted analyses, missing paternal data was associated with lower birthweight (β -0.07 kg; 95 % CI: −0.08, −0.05), smoking during pregnancy (AOR 4.40; 95 % CI: 3.97, 4.87), non-initiation of breastfeeding (AOR 0.39; 95 % CI: 0.36, 0.42), and with ever having a WFL ≥ 95th percentile (AOR 1.10; 95 % CI: 1.01, 1.20). Similar associations were noted for pregnancies involving unmarried women with paternal data, but differences were less pronounced. Missing paternal data on the birth certificate is associated with perinatal risk factors for childhood obesity. Efforts to understand and reduce obesity risk factors in early life may need to consider paternal factors.
An Integrated Environment Blending Dynamic and Geometry Models

Modeling techniques tend to be found in isolated communities: geometry models in CAD and Computer Graphics and dynamic models in Computer Simulation. When models are included within the same digital environment, the ways of connecting them together seamlessly and visually are not well known even though elements from each model have many commonalities. We attempt to address this deficiency by studying specific ways in which models can be interconnected within the same 3D space through effective ontology construction and human interaction techniques. Our work to date has resulted in an environment built using the open source 3D Blender package, where we include a Python-based interface, as well as scene, geometry, and dynamics models.
Under-Constrained Symbolic Execution: Correctness Checking for Real Code

Software bugs are a well-known source of security vulnerabilities. One technique for finding bugs, symbolic execution, considers all possible inputs to a program but suffers from scalability limitations. This paper uses a variant, under-constrained symbolic execution, that improves scalability by directly checking individual functions, rather than whole programs. We present UC-KLEE, a novel, scalable framework for checking C/C++ systems code, along with two use cases. First, we use UC-KLEE to check whether patches introduce crashes. We check over 800 patches from BIND and OpenSSL and find 12 bugs, including two OpenSSL denial-of-service vulnerabilities. We also verify (with caveats) that 115 patches do not introduce crashes. Second, we use UC-KLEE as a generalized checking framework and implement checkers to find memory leaks, uninitialized data, and unsafe user input. We evaluate the checkers on over 20,000 functions from BIND, OpenSSL, and the Linux kernel, find 67 bugs, and verify that hundreds of functions are leak free and that thousands of functions do not access uninitialized data.
A spectral method for nonlinear elliptic equations

Let Ω be an open, simply connected, and bounded region in ?d$\mathbb {R}^{d}$, d ? 2, and assume its boundary ?Ω is smooth and homeomorphic to Sd?1$\mathbb {S}^{d-1}$. Consider solving an elliptic partial differential equation Lu = f(?, u) over Ω with zero Dirichlet boundary value. The function f is a nonlinear function of the solution u. The problem is converted to an equivalent elliptic problem over the open unit ball Bd$\mathbb {B}^{d}$ in ?d$\mathbb {R}^{d}$, say L~u~=f~(?,u~)$\widetilde {L}\widetilde {u} =\widetilde {f}(\cdot ,\widetilde {u})$. Then a spectral Galerkin method is used to create a convergent sequence of multivariate polynomials u~n$\widetilde {u} _{n}$ of degree ≤ n that is convergent to u~$\widetilde {u}$. The transformation from Ω to Bd$\mathbb {B}^{d}$ requires a special analytical calculation for its implementation. With sufficiently smooth problem parameters, the method is shown to be rapidly convergent. For u?C?Ω¯$u\in C^{\infty } \left (\overline {\Omega }\right ) $ and assuming ?Ω is a C? boundary, the convergence of u~?u~nH1$\left \Vert \widetilde {u} -\widetilde {u}_{n}\right \Vert _{H^{1}}$ to zero is faster than any power of 1/n. The error analysis uses a reformulation of the boundary value problem as an integral equation, and then it uses tools from nonlinear integral equations to analyze the numerical method. Numerical examples illustrate experimentally an exponential rate of convergence. A generalization to ?Δu + ?u = f(u) with a zero Neumann boundary condition is also presented.
Dye-Vector Flow Visualization—Cooling Water Model

An extensive hydraulic scale model (densimetric Froude law) of the intake and discharge flows of the cooling water system of an ocean coast power plant with coastal currents, made use of flow visualization techniques to obtain details of patterns near the discharge and intake. This was important to develop insights to the characteristics of the mixing and induced bottom flows. One technique was to drop dye crystals to the bottom, and photograph (in color) the growth of the dye vectors. This was so useful that a thorough quantitative study was made of the growth rate of these vectors, U d , relating the growth rate to the friction velocity, U*. The results were interpreted using boundary layer theory and numerical and physical model studies of low Reynolds number flow around objects. For a range of values of U* of practical importance in hydraulic model studies over hydraulic smooth bottoms, a linear relationship between U* and U d was established. This appears to be a new quantitative technique.
Radioactive atoms: Auger-Electron, α-, β, γ-, and X-Ray Data

Decay schemes and decay characteristics are presented for 105 radioactive atoms of special importance in nuclear medicine, health physics, and industrial applications. Listed in tabular form are “best” values for half-lives, energies, intensities, equilibrium absorbed-dose constants, and 90% absorbed-dose ranges (in water) for each of the atomic and nuclear radiations emitted by these radioactive atoms. Data basic to the adopted values are also given with appropriate literature references.
Compositional and Structural Versatility in an Unusual Family of anti-Perovskite Fluorides: [Cu(H2O)4]3[(MF6)(M'F6)].

A series of six anti-perovskite fluorides of the type [Cu(H2O)4]3(M1–xM′xF6)2 (where M and M′ = V, Cr, Mn, Fe as well as M = Fe and M′ = V and Cr) was synthesized as high-quality single crystals via a mild hydrothermal route. These materials belong to a class of perovskite-based structures in which the anions and cations of the regular ABX3 perovskite structure have exchanged positions. Two complex anions, MF63– and M′F63–, occupy the normal A and B cation positions, while three complex cations, [Cu(H2O)4]2+, occupy the normally anionic X positions. As in the ABX3 compositions, the A and B positions can be occupied by different complex anions, allowing for the preparation of a wide range of compositions. Magnetic property measurements were performed on all six phases, and complex magnetic behavior was observed at low temperatures in the Mn, Fe, and bimetallic Fe/V and Fe/Cr phases.
An interconnect-centric design flow for nanometer technologies

As integrated circuits (ICs) are scaled into nanometer dimensions and operate in giga-hertz frequencies, interconnect design and optimization have become critical in determining system performance and reliability. This paper presents the ongoing research effort at UCLA to develop an interconnect-centric design flow, including interconnect planning, interconnect synthesis, and interconnect layout, which allows interconnect design and optimization to be properly considered at every level of the design process. Efficient interconnect performance estimation models and tools at various levels are also being developed to support such an interconnect-centric design flow.
Catalysis Involving Phosphinite-Based Metallacycles

Phosphinite-based metallacycles are important intermediates, catalyst precursors, or catalysts for a variety of chemical transformations. Facile, reversible formation of P–O bonds allows phosphinites to act as catalytic directing groups that lead to more efficient and selective metal-catalyzed processes. Relatively low costs and convenient syntheses make metallacyclic phosphinite complexes attractive compounds for catalytic studies. Given the high interest in developing the related phosphine- and phosphite-based catalysts, this Perspective focuses specifically on the comparisons between these different metallacyclic complexes in catalytic reactions. In a number of examples, phosphinite-based metallacycles are more efficient catalysts due to better-matched ligand properties for rate-limiting steps or faster conversion of the complexes to catalytically active species.
Intraday Market Effects in Electronic Soybean Futures Market during Non-Trading and Trading Hour Announcements

This article investigates market reactions to major United States Department of Agriculture announcements during non-trading and trading hours in the soybean futures market using microstructure dat...
Numerical solution of gravitational dynamics in asymptotically anti-de Sitter spacetimes

A variety of gravitational dynamics problems in asymptotically anti-de Sitter (AdS) spacetime are amenable to efficient numerical solution using a common approach involving a null slicing of spacetime based on infalling geodesics, convenient exploitation of the residual diffeomorphism freedom, and use of spectral methods for discretizing and solving the resulting differential equations. Relevant issues and choices leading to this approach are discussed in detail. Three examples, motivated by applications to non-equilibrium dynamics in strongly coupled gauge theories, are discussed as instructive test cases. These are gravitational descriptions of homogeneous isotropization, collisions of planar shocks, and turbulent fluid flows in two spatial dimensions.
Full-waveform inversion with extrapolated low-frequency data

ABSTRACTThe availability of low-frequency data is an important factor in the success of full-waveform inversion (FWI) in the acoustic regime. The low frequencies help determine the kinematically relevant, low-wavenumber components of the velocity model, which are in turn needed to avoid convergence of FWI to spurious local minima. However, acquiring data less than 2 or 3 Hz from the field is a challenging and expensive task. We have explored the possibility of synthesizing the low frequencies computationally from high-frequency data and used the resulting prediction of the missing data to seed the frequency sweep of FWI. As a signal-processing problem, bandwidth extension is a very nonlinear and delicate operation. In all but the simplest of scenarios, it can only be expected to lead to plausible recovery of the low frequencies, rather than their accurate reconstruction. Even so, it still requires a high-level interpretation of band-limited seismic records into individual events, each of which can be extr...
Collaborative Academic Library Digital Collections Post-Cambridge University Press, HathiTrust and Google Decisions on Fair Use

Academic libraries face numerous stressors as they seek to meet the needs of their users through technological advances while adhering to copyright laws. This paper seeks to explore one specific proposal to balance these interests, the impact of recent decisions on its viability, and the copyright challenges that remain after these decisions
Mortgage Payment Problem Development and Recovery: A Joint Probability Model Approach

The existing literature on mortgage default and foreclosure largely examines the development of mortgage problems (the first stage) and the possibility of recovery from such problems (the second stage) separately. Such studies may provide an incomplete picture of the development and possible resolution of mortgage problems. This paper uses the proprietary geo-coded version of the Panel Study of Income Dynamics from 2009 through 2013 to implement a different type of probability model. Three transitional probability equations are estimated: the likelihood of homeowners developing mortgage payment problems, the likelihood that those who develop such problems move to resolve their problems, and the conditional probability that those who develop such problems and don’t move will recover from them by other means. The coefficients from all three are combined to calculate the joint (state) probability of households having mortgage problems from which they will not recover. The analysis contains a number of unique results: changes in the mortgage front-end ratio are shown to have a substantial influence on both developing a mortgage problem and its resolution for those who do not move, 2) prior foreclosures are determined to affect the development of current mortgage problems, and 3) out-of-pocket medical expenses are found to influence both mortgage problem development and recovery. Also, the impact of policy actions are considered across several at-risk demographic groups. This experiment demonstrates that by improving the financial and mortgage characteristics, and the education level of households that actually develop mortgage problems, their predicted probability of developing mortgage problems that cannot be resolved could be reduced substantially.
Domain walls and ferroelectric reversal in corundum derivatives

Materials physicists are increasingly coming to understand that domain walls in complex materials often have a life of their own. Far from being unwanted ``defects'', they may have rich and interesting physics not available in the bulk material. Here, the authors use first-principles theoretical methods to consider ferroelectric domain walls in a promising family of corundum-derivative materials. Beyond studying issues of domain wall mobility and clarifying the factors that allow polarization reversal, the authors also identify an unusual set of domain-wall-specific couplings between polarization, magnetization, and chirality that they suggest may lead to new functionalities.
Dynamic Teams and Decentralized Control Problems With Substitutable Actions

This technical note considers two problems—a dynamic team problem and a decentralized control problem. The problems we consider do not belong to the known classes of “simpler” dynamic team/decentralized control problems such as partially nested or quadratically invariant problems. However, we show that our problems admit simple solutions under an assumption referred to as the substitutability assumption. Intuitively, substitutability in a team (resp. decentralized control) problem means that the effects of one team member's (resp. controller's) action on the cost function and the information (resp. state dynamics) can be achieved by an action of another member (resp. controller). For the non-partially-nested LQG dynamic team problem, it is shown that under certain conditions linear strategies are optimal. For the non-partially-nested decentralized LQG control problem, the state structure can be exploited to obtain optimal control strategies with recursively update-able sufficient statistics. These results suggest that substitutability can work as a counterpart of the information structure requirements that enable simplification of dynamic teams and decentralized control problems.
Planting landscape plants.

Editor's Note This paper has been published in the full knowledge that its contents have appeared in many publications in this country. The advisory services of both the United Kingdom and the United States of America commit public funds to encourage sound arboricultural practice and professional organisations likewise devote their resources to achieve a better understanding of tree care and maintenance. Despite this effort arboriculturists the world over are confronted by indifference to the dead tree by society that it is hoped the different techniques advocated in this paper by Drs Ray Maleike and Rita Hummel, will encourage arboricultursts and others to give more consideration to their attitudes towards tree planting.
Modeling Tangential Vector Fields on a Sphere

AbstractPhysical processes that manifest as tangential vector fields on a sphere are common in geophysical and environmental sciences. These naturally occurring vector fields are often subject to physical constraints, such as being curl-free or divergence-free. We start with constructing parametric models for curl-free and divergence-free vector fields that are tangential to the unit sphere through applying the surface gradient or the surface curl operator to a scalar random potential field on the unit sphere. Using the Helmholtz-Hodge decomposition, we then construct a class of simple but flexible parametric models for general tangential vector fields, which are represented as a sum of a curl-free and a divergence-free components. We propose a likelihood-based parameter estimation procedure, and show that fast computation is possible even for large data sets when the observations are on a regular latitude-longitude grid. Characteristics and practical utility of the proposed methodology are illustrated th...
Compression With Actions

We consider the setting where actions can be used to modify a state sequence before compression. The minimum rate needed to losslessly describe the optimal modified sequence is characterized when the state sequence is either noncausally or causally available at the action encoder. The achievability is closely related to the optimal channel coding strategy for channel with states. We also extend the analysis to the lossy case.
Constructing Evaluation Corpora for Automated Clinical Named Entity Recognition

We report on the construction of a gold-standard dataset consisting of annotated clinical notes suitable for evaluating our biomedical named entity recognition system. The dataset is the result of consensus between four human annotators and contains 1,556 annotations on 160 clinical notes using 658 unique concept codes from SNOMED-CT corresponding to human disorders. Inter-annotator agreement was calculated on annotations from 100 of the documents for span (90.9%), concept code (81.7%), context (84.8%), and status (86.0%) agreement. Complete agreement for span, concept code, context, and status was 74.6%. We found that creating a consensus set based on annotations from two independently-created annotation sets can reduce inter-annotator disagreement by 32.3%. We found little benefit to pre-annotating the corpus with a third-party named entity recognizer.
TIED: An Artificially Simulated Dataset with Multiple Markov Boundaries

We present an artificially simulated dataset (TIED) constructed so that there are many minimal sets of variables with maximal predictivity (i.e., Markov boundaries) and likewise many sets of variables that are statistically indistinguishable from the set of direct causes and direct effects of the response variable. This dataset was used in the Potluck Causality Challenge to determine all statistically indistinguishable sets of direct causes and direct effects and all Markov boundaries of the response variable and also to predict the response variable in the independent test data. We also present baseline results of application of several algorithms to this dataset.
An overview of pricing models for revenue management

In this paper we examine the research and results of dynamic pricing policies and their relation to Revenue Management. The survey is based on a generic Revenue Management problem in which a perishable and non-renewable set of resources satisfy stochastic price-sensitive demand processes over a finite period of time. In this class of problems, the owner (or the seller) of these resources uses them to produce and offer a menu of final products to the end customers. Within this context, we formulate the stochastic control problem of capacity that the seller faces: how to dynamically set the menu and the quantity of products and their corresponding prices in order to maximize the total revenue over the selling horizon.
A semi-classical treatment of channeling radiation reaction

Abstract A semi-classical formalism is used to calculate the radiation reaction of a relativistic particle in a straight, continuous focusing system. Due to the absence of quantum excitation in such a focusing system, the radiation damping rate of the transverse action obtained using this formalism agrees exactly with the result from the classical Lorentz-Dirac radiation reaction equation. In the limit where the pitch angle of the particle is much smaller than the radiation opening angle, the transverse action damps exponentially with an energy-independent rate that is much faster than the energy decay rate. In the opposite limit, both the transverse action and the energy damp with power laws and their relative rates are comparable. The general time-dependence of the transverse action damping and the energy decay are obtained analytically from these rate equations.
Reordering Ranganathan: Shifting User Behaviors, Shifting Priorities

S.R. Ranganathan's Five Laws of Library Science provide a broad framework for designing and evaluating library programmes, activities and services. The laws continue to be extensively cited even today suggesting their continued relevance. This paper attempts to interpret the five laws in the present day context of information abundance, digital revolution, currently available resources and services, and user behaviours. The idea has been to suggest how libraries and librarians can better connect to those behaviours. After examining the changing roles of the Five Laws on the basis of findings of recent research, the paper suggests reordering and reframing of the Five Laws of Library Science. A number of recommendations for realizing the intent of the laws have also been made.
Inspection of periodic patterns with intensity spatial filters

This reports the application of spatial filtering to integrated circuit photomask inspection. Experiments were performed that used intensity filters and took advantage of the grating effect of the periodic array. A stop filter corresponding to the periodic distance was placed at the diffraction plane. The transmitted image showed tip the nonperiodic errors, i.e., contamination pinholes, scratches, missing or extra features and incorrectly registered patterns.
Deep Learning with Sets and Point Clouds

We introduce a simple permutation equivariant layer for deep learning with set structure.This type of layer, obtained by parameter-sharing, has a simple implementation and linear-time complexity in the size of each set. We use deep permutation-invariant networks to perform point-could classification and MNIST-digit summation, where in both cases the output is invariant to permutations of the input. In a semi-supervised setting, where the goal is make predictions for each instance within a set, we demonstrate the usefulness of this type of layer in set-outlier detection as well as semi-supervised learning with clustering side-information.
Successive synthesis of latent Gaussian trees

A new synthesis scheme is proposed to effectively generate a random vector with prescribed joint density that induces a (latent) Gaussian tree structure. The quality of synthesis is measured by total variation distance between the synthesized and desired statistics. The proposed layered and successive encoding scheme relies on the learned structure of tree to use minimal number of common random variables to synthesize the desired density. We characterize the achievable rate region for the rate tuples of multi-layer latent Gaussian tree, through which the number of bits needed to simulate such Gaussian joint density are determined. The random sources used in our algorithm are the latent variables at the top layer of tree, the additive independent Gaussian noises, and the Bernoulli sign inputs that capture the ambiguity of correlation signs between the variables.
Axioms for higher twisted torsion invariants of smooth bundles

This paper attempts to investigate the space of various characteristic classes for smooth manifold bundles with local system on the total space inducing a finite holonomy covering. These classes are known as twisted higher torsion classes. We will give a system of axioms that we require these cohomology classes to satisfy. Higher Franz–Reidemeister torsion and twisted versions of the higher Miller–Morita–Mumford classes will satisfy these axioms. We will show that the space of twisted torsion invariants is two-dimensional or one-dimensional depending on the torsion degree and is spanned by these two classes. The proof will greatly depend on results about the equivariant Hatcher constructions developed in Goodwillie, Igusa and Ohrt (2015).
Projected Semi-Stochastic Gradient Descent Method with Mini-Batch Scheme Under Weak Strong Convexity Assumption

We propose a projected semi-stochastic gradient descent method with mini-batch for improving both the theoretical complexity and practical performance of the general stochastic gradient descent method (SGD). We are able to prove linear convergence under weak strong convexity assumption. This requires no strong convexity assumption for minimizing the sum of smooth convex functions subject to a compact polyhedral set, which remains popular across machine learning community. Our PS2GD preserves the low-cost per iteration and high optimization accuracy via stochastic gradient variance-reduced technique, and admits a simple parallel implementation with mini-batches. Moreover, PS2GD is also applicable to dual problem of SVM with hinge loss.
Probabilistic inverse design for self-assembling materials

One emerging approach for the fabrication of complex architectures on the nanoscale is to utilize particles customized to intrinsically self-assemble into a desired structure. Inverse methods of statistical mechanics have proven particularly effective for the discovery of interparticle interactions suitable for this aim. Here we evaluate the generality and robustness of a recently introduced inverse design strategy [B. A. Lindquist et al., J. Chem. Phys. 145, 111101 (2016)] by applying this simulation-based machine learning method to optimize for interparticle interactions that self-assemble particles into a variety of complex microstructures as follows: cluster fluids, porous mesophases, and crystalline lattices. Using the method, we discover isotropic pair interactions that lead to the self-assembly of each of the desired morphologies, including several types of potentials that were not previously understood to be capable of stabilizing such systems. One such pair potential led to the assembly of the hi...
Splines on the Alfeld split of a simplex and type A root systems

Abstract Alfeld (1984) introduced a tetrahedral analog A S ( Δ 3 ) of the Clough–Tocher split of a triangle. A formula for the dimension of the spline space C k r ( A S ( Δ n ) ) is conjectured in Foucart and Sorokina (2013). We prove that the graded module of C r -splines on the cone over A S ( Δ n ) is isomorphic to the module D r + 1 ( A n ) of multiderivations on the type A n Coxeter arrangement. A theorem of Terao shows that the module of multiderivations of a Coxeter arrangement is free and gives an explicit basis. As a consequence the conjectured formula holds.
Covering and separation of Chebyshev points for non-integrable Riesz potentials

Abstract For Riesz s -potentials K ( x , y ) = | x − y | − s , s > 0 , we investigate separation and covering properties of N -point configurations ω N ∗ = { x 1 , … , x N } on a d -dimensional compact set A ⊂ R l for which the minimum of ∑ j = 1 N K ( x , x j ) is maximal. Such configurations are called N -point optimal Riesz s -polarization (or Chebyshev) configurations. For a large class of d -dimensional sets A we show that for s > d the configurations ω N ∗ have the optimal order of covering. Furthermore, for these sets we investigate the asymptotics as N → ∞ of the best covering constant. For these purposes we compare best-covering configurations with optimal Riesz s -polarization configurations and determine the s th root asymptotic behavior (as s → ∞ ) of the maximal s -polarization constants. In addition, we introduce the notion of “weak separation” for point configurations and prove this property for optimal Riesz s -polarization configurations on A for s > dim ( A ) , and for d − 1 ⩽ s d on the sphere S d .
A Restaurant Process Mixture Model for Connectivity Based Parcellation of the Cortex

One of the primary objectives of human brain mapping is the division of the cortical surface into functionally distinct regions, i.e. parcellation. While it is generally agreed that at macro-scale different regions of the cortex have different functions, the exact number and configuration of these regions is not known. Methods for the discovery of these regions are thus important, particularly as the volume of available information grows. Towards this end, we present a parcellation method based on a Bayesian non-parametric mixture model of cortical connectivity.
Counting maps from a surface to a graph

Let F be a non-abelian finite rank free group, and let H_g be the fundamental group of a surface of genus g with one boundary component represented by D_g in H_g. So, H_g is the free group and D_g is the product of commutators [a_1,b_1]...[a_g,b_g]. Given x in F, we are interested in the number num(x) of primitive, i.e. root-free, images of monomorphisms (H_g,D_g) -> (F,x). Our main result is that f(g) >= 2^g where f(g)=sup num(x), where sup is taken over all elements x in F. This answers a question of Zlil Sela that is related to his work on the Tarski problem. We also show that f is independent of F and go on to obtain similar results where the monomorphisms considered are additionally required to have minimal genus.
NONCOMMUTATIVE SYMMETRIC FUNCTIONS AND THE INVERSION PROBLEM

Let K be any unital commutative ℚ-algebra and z = (z1, z2, …, zn) commutative or noncommutative variables. Let t be a formal central parameter and K[[t]]〈〈z〉〉 the formal power series algebra of z over K[[t]]. In [29], for each automorphism Ft(z) = z - Ht(z) of K[[t]]〈〈z〉〉 with Ht=0(z) = 0 and o(H(z)) ≥ 1, a $\mathcal{N}{\rm CS}$ (noncommutative symmetric) system [28] ΩFt has been constructed. Consequently, we get a Hopf algebra homomorphism $\mathcal{S}_{{F_{t}}\,:\, \mathcal{N}{\rm Sym} \to \mathcal{D} \langle \langle z \rangle\rangle$ from the Hopf algebra $\mathcal{N}{\rm Sym}$ [9] of NCSFs (noncommutative symmetric functions). In this paper, we first give a list for the identities between any two sequences of differential operators in the $\mathcal{N}{\rm CS}$ system ΩFt by using some identities of NCSFs derived in [9] and the homomorphism $\mathcal{S}_{F_{t}}$. Secondly, we apply these identities to derive some formulas in terms of differential operator in the system ΩFt for the Taylor series expansi...
Stabilizing and destabilizing Heegaard splittings of sufficiently complicated 3-manifolds

Let M 1 and M 2 be compact, orientable 3-manifolds with incompressible boundary, and M the manifold obtained by gluing with a homeomorphism $${\phi : {\partial}M_1 \to {\partial}M_2}$$ . We analyze the relationship between the sets of low genus Heegaard splittings of M 1, M 2, and M, assuming the map $${\phi}$$ is “sufficiently complicated”. This analysis yields counter-examples to the Stabilization Conjecture, a resolution of the higher genus analogue of a conjecture of Gordon, and a result about the uniqueness of expressions of Heegaard splittings as amalgamations.
The Illustration of Oceanic Data II : Vectors

The vectors most commonly considered in oceanic cartography are ocean currents, which can be represented in a variety of ways, according to the nature of the currents themselves, the manner in which these currents were observed, and the concepts which the illustrator wishes to display. Within the limits of a two-dimensional page there are the requirements of portraying the three-dimensional space in which the vectors were observed, the three-dimensional space of the vectors themselves and the dimension of time. Some solutions to this problem are provided from the literature.
Chemical warfare simulant‐responsive polymer nanocomposites: Synthesis and evaluation

Nanomaterials that undergo a physical change upon chemical warfare agent (CWA) exposure can potentially be used in detectors to warn soldiers of their presence or in fabrics to provide on-demand protection. In this study, hybrid nanoparticles (NPs) were prepared by grafting a CWA-responsive polymer from a silicon dioxide (SiO2) surface using ring opening metathesis polymerization; the covalent functionalization of the polymers on the NP surface was confirmed by gel permeation chromatography, dynamic light scattering, and transmission electron microscopy analysis. The polymer-grafted SiO2 NPs were found to undergo a pronounced decrease (approximately 200 nm) in their hydrodynamic radius upon exposure to CWA simulants trifluoroacetic acid and diethyl chlorophosphate in toluene. This decrease in hydrodynamic radius is attributed to the electrophile-mediated ionization of the triarylmethanol responsive unit and represents a rare example of polycation formation leading to polymer chain collapse. We have ascribed this ionization-induced collapse to the formation of a favorable stacking interaction between the planar triarylcations. These studies have important implications for the development of breathable fabrics that can provide on-demand protection for soldiers in combat situations. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3034–3040
Unique equilibrium states for geodesic flows in nonpositive curvature

We study geodesic flows over compact rank 1 manifolds and prove that sufficiently regular potential functions have unique equilibrium states if the singular set does not carry full pressure. In dimension 2, this proves uniqueness for scalar multiples of the geometric potential on the interval $${(-\infty,1)}$$ , which is optimal. In higher dimensions, we obtain the same result on a neighborhood of 0, and give examples where uniqueness holds on all of $${\mathbb{R}}$$ . For general potential functions $${\varphi}$$ , we prove that the pressure gap holds whenever $${\varphi}$$ is locally constant on a neighborhood of the singular set, which allows us to give examples for which uniqueness holds on a C0-open and dense set of Holder potentials.
Use of Contextual Information and Prediction by Struggling Adult Readers: Evidence From Reading Times and Event-Related Potentials

ABSTRACTWe employed self-paced reading and event-related potential measures to investigate how adults of varying literacy levels use sentence context information when reading. Community-dwelling participants read strongly and weakly constraining sentences that ended with expected or unexpected target words. Skilled readers showed N400s that were graded by the cloze probability of the targets, with larger N400s for more unexpected words. Moreover, it took these participants longer to read unexpected targets in strongly than weakly constraining sentences, suggesting a processing cost for revising predictions. Among less skilled readers, a reliable N400 difference was found between expected and unexpected targets only for the strongly constraining sentences. They also took longer when targets were unexpected, regardless of the context. These findings suggest that lower literacy readers could only immediately take advantage of strongly constraining context information to facilitate word processing and that th...
“Essentially, All Models Are Wrong, but Some Are Useful”: A Preliminary Conceptual Model of Co-occurring E-cig and Alcohol Use

As prevalence rates of electronic cigarette (e-cig) use increase, researchers and clinicians should not only be paying careful attention to the direct health effects of e-cigs, but also the potential impact e-cigs may have on alcohol use behaviors. We review the current state of the literature and propose a conceptual model for the relationship between e-cig and alcohol use, including important consequences, mechanisms, and moderators of this relationship. The model is based in emerging literature examining the direct relationship between e-cig and alcohol use, as well as indirect evidence concerning potential mechanisms from research on cigarette and alcohol use. Overall, research indicates a robust relationship between e-cig and alcohol use. We suggest that a relationship between e-cig use and alcohol use could be particularly problematic, especially for adolescents and for those with or at risk for alcohol use disorders. We hope the presented conceptual model can stimulate research in this area. We make research recommendations, including the need for more methodological rigor, including improved measurement of e-cig use, and expanding research to longitudinal and experimental designs.
A fast parallel algorithm to compute the rank of a matrix over an arbitrary field

It is shown that the rank of a matrix over an arbitrary field can be computed inO(log2 n) time using a polynomial number of processors.
Rules versus discretion in monetary policy historically contemplated

Abstract Monetary policy rules are attempts to cope with the implications of having a medium of exchange whose value exceeds its cost of production. Two classes of monetary rules can be identified: (1) price rules that target the value of money in terms of a real commodity, e.g., gold, or in terms of some index of prices, and (2) quantity rules that target the quantity of money in circulation. Historically, price rules, e.g. the gold standard, have predominated, but the Bank Charter Act of 1844 imposed a quantity rule as an adjunct to the gold standard, because the gold standard had performed unsatisfactorily after being restored in Britain at the close of the Napoleonic Wars. A quantity rule was not proposed independently of a price rule until Henry Simons proposed a constant money supply consisting of government-issued fiat currency and deposits issued by banks operating on a 100% reserve basis. Simons argued that such a plan would be ideal if it could be implemented because it would deprive the monetary authority of any discretionary decision-making power. Nevertheless, Simons concluded that such a plan was impractical and supported a price rule to stabilize the price level. Simons's student Milton Friedman revived Simons's argument against discretion and modified Simons's plan for 100% reserve banking and a constant money supply into his k% rule for monetary growth. This paper examines the doctrinal and ideological origins and background that lay behind the rules versus discretion distinction.
Ideological Extremists in the U.S. Congress: Out of Step but Still in Office

In the last generation, congressional moderates have become ideologically more extreme over the course of their careers. We explain this "ideological migration" of moderates as a side effect of close partisan competition for control of the US House since 1994. Competition for the House caused activists, donors and, indirectly, voters to focus on the battle for majority status. Increased attention to partisan competition reduced individual members' ability to escape blame for their parties' actions. Equivalently, it meant that members could deviate from their district preferences and pay a lower electoral penalty; they would be blamed in any event. Our empirical analysis shows that party-centeredness abruptly and dramatically increased after 1994, with the electoral penalty members paid for being out of step with their constituents correspondingly declining. This contributed to an important, albeit complicated, shift from local/personal to national/party representation.
The number of fiberings of a surface bundle over a surface

For a closed manifold M , let SFib ( M ) be the number of ways that M can be realized as a surface bundle, up to π 1 –fiberwise diffeomorphism. We consider the case when dim ( M ) = 4 . We give the first computation of SFib ( M ) where 1 < SFib ( M ) < ∞ but M is not a product. In particular, we prove SFib ( M ) = 2 for the Atiyah–Kodaira manifold and any finite cover of a trivial surface bundle. We also give an example where SFib ( M ) = 4 .
Overlap junctions for high coherence superconducting qubits

Fabrication of sub-micron Josephson junctions is demonstrated using standard processing techniques for high-coherence, superconducting qubits. These junctions are made in two separate lithography steps with normal-angle evaporation. Most significantly, this work demonstrates that it is possible to achieve high coherence with junctions formed on aluminum surfaces cleaned in situ by Ar plasma before junction oxidation. This method eliminates the angle-dependent shadow masks typically used for small junctions. Therefore, this is conducive to the implementation of typical methods for improving margins and yield using conventional CMOS processing. The current method uses electron-beam lithography and an additive process to define the top and bottom electrodes. Extension of this work to optical lithography and subtractive processes is discussed.
Patent examiner specialization

Abstract We study the matching of patent applications to examiners at the U.S. Patent and Trademark Office. The distribution of technology classes is more concentrated than would occur under random matching and F-tests reject the hypothesis that family size and claim scope are randomly distributed across examiners. Using the application text, we show that examiner specialization persists even after conditioning on technology sub-classes. Specialization is less pronounced in computers and software than other technology fields. More specialized examiners have a lower grant rate. These findings undermine the idea that random matching justifies instrumental variables based on examiner behaviors or characteristics.
DenseAlert: Incremental Dense-Subtensor Detection in Tensor Streams

Consider a stream of retweet events - how can we spot fraudulent lock-step behavior in such multi-aspect data (i.e., tensors) evolving over time? Can we detect it in real time, with an accuracy guarantee? Past studies have shown that dense subtensors tend to indicate anomalous or even fraudulent behavior in many tensor data, including social media, Wikipedia, and TCP dumps. Thus, several algorithms have been proposed for detecting dense subtensors rapidly and accurately. However, existing algorithms assume that tensors are static, while many real-world tensors, including those mentioned above, evolve over time. We propose DENSESTREAM, an incremental algorithm that maintains and updates a dense subtensor in a tensor stream (i.e., a sequence of changes in a tensor), and DENSESALERT, an incremental algorithm spotting the sudden appearances of dense subtensors. Our algorithms are: (1) Fast and "any time": updates by our algorithms are up to a million times faster than the fastest batch algorithms, (2) Provably accurate: our algorithms guarantee a lower bound on the density of the subtensor they maintain, and (3) Effective: our DENSESALERT successfully spots anomalies in real-world tensors, especially those overlooked by existing algorithms.
BIOLOGICALLY INSPIRED ROBOT CONTROL

Abstract Limitations of conventional control methods for robots operating in unstructured environments are discussed, and contrasted with control techniques used by living systems. Three specific examples of robot systems designed with inspiration from biology are discussed: (1) multifingered robot hands with shape-adaptive grasping, (2) a walking machine which uses genetic algorithms to evolve a gait pattern, and (3) a behavior-based control system for a robot flying machine.
Using visualization for architectural localization and extraction

Abstract Understanding the architecture of a program requires determining both the major components into which the system is broken and the ways in which the components interact to accomplish the program's goals. Both static and dynamic analyses of the software can aid in obtaining this understanding. This paper describes an analysis technique for gaining such understanding and a visualization tool, called ISVis, that supports it. The technique is applied to the problem of enhancing the Mosaic web browser by both visualizing its architecture and finding the components of the browser into which an enhancement should be inserted.