cssi/SciSciGPT-SciSciNet huggingface dataset:
Data-Driven Approaches for Computation in Intelligent Biomedical Devices: A Case Study of EEG Monitoring for Chronic Seizure Detection

Intelligent biomedical devices implies systems that are able to detect specific physiological processes in patients so that particular responses can be generated. This closed-loop capability can have enormous clinical value when we consider the unprecedented modalities that are beginning to emerge for sensing and stimulating patient physiology. Both delivering therapy (e.g., deep-brain stimulation, vagus nerve stimulation, etc.) and treating impairments (e.g., neural prosthesis) requires computational devices that can make clinically relevant inferences, especially using minimally-intrusive patient signals. The key to such devices is algorithms that are based on data-driven signal modeling as well as hardware structures that are specialized to these. This paper discusses the primary application-domain challenges that must be overcome and analyzes the most promising methods for this that are emerging. We then look at how these methods are being incorporated in ultra-low-energy computational platforms and systems. The case study for this is a seizure-detection SoC that includes instrumentation and computation blocks in support of a system that exploits patient-specific modeling to achieve accurate performance for chronic detection. The SoC samples each EEG channel at a rate of 600 Hz and performs processing to derive signal features on every two second epoch, consuming 9 μJ/epoch/channel. Signal feature extraction reduces the data rate by a factor of over 40×, permitting wireless communication from the patient’s head while reducing the total power on the head by 14×.
Thermal conductivities of quantum well structures

This work analyzes the size and the boundary effects of a gallium arsenide- (GaAs) based quantum well (QW) structure on the thermal conductivity of the well material. Calculations show that the order of phonon mean free path (MFP) is equal to or even longer than the typical dimension of the well (-200 A or less). Holland's model is applied to match the thermal conductivity data of bulk GaAs from 2 to above 600 K. The equation of phonon radiative transfer (EPRT) developed from the Boltzmann transport equation is then introduced for the heat transport in the QW structure. Boundary conditions are built from the diffuse phonon mismatch theory, and approximate solutions are obtained for the cases of heat flow perpendicular and parallel to the well. Results show that the thermal conductivity of the quantum well can be one order-of-magnitude lower than that of its corresponding bulk form at room temperature. The size and boundary effects also cause anisotropy of the thermal conductivity, even though the unit cell of GaAs is cubic.
Heavy ion inertial fusion: Initial survey of target gain versus ion-beam parameters

Inertial-fusion targets have been designed for use with heavy-ion accelerators as drivers in fusion energy power plants. We have made an initial survey of target gain versus beam energy, power, focal radius, and ion range. This provides input for understanding the trade-offs among accelerator designs.
Simulation: a tool for performance evaluation in network computers

The success or failure of network computers in today's highly competitive market will be determined by system performance. Consequently, existing network computer configurations are constantly being modified, extended, and hopefully, improved. The key question pertaining to the implementation of proposed changes is "Does the proposed change improve the existing system performance?" Unless techniques are developed for measuring system performance, network computers will remain expensive toys for researchers, instead of becoming cost effective tools for progress.
Masers and millimeter waves

The characteristics of a number of different kinds of masers are reviewed to estimate their usefulness in the region between one and a tenth millimeter. An estimate of the maximum power output for these systems is made and compared with the output to be expected from mixing two optical signals in a nonlinear dielectric and on a photocathode. Additionally, the noise characteristics of maser amplifiers are briefly reviewed for this region of the spectrum.
Broad versus regional integration: what matters more for economic development?

In this paper, we examine the impacts of broad and regional integration on long-run economic development.We construct cross-country measures of regional integration that account for both the magnitude and the endogeneity of individual regional integration agreements. We then include our regional integration measures along with the broad trade share, institutions and geography in a deep determinants regression. Our results show that regional integration, unlike broad trade, can raise the long-run level of real gross domestic product (GDP) per capita.
Leave-one-out cross-validation is risk consistent for lasso

The lasso procedure pervades the statistical and signal processing literature, and as such, is the target of substantial theoretical and applied research. While much of this research focuses on the desirable properties that lasso possesses--predictive risk consistency, sign consistency, correct model selection--these results assume that the tuning parameter is chosen in an oracle fashion. Yet, this is impossible in practice. Instead, data analysts must use the data twice, once to choose the tuning parameter and again to estimate the model. But only heuristics have ever justified such a procedure. To this end, we give the first definitive answer about the risk consistency of lasso when the smoothing parameter is chosen via cross-validation. We show that under some restrictions on the design matrix, the lasso estimator is still risk consistent with an empirically chosen tuning parameter.
Predictions of long-term behavior of a large-volume pilot test for CO2 geological storage in a saline formation in the Central Valley, California

Abstract The long-term behavior of a CO 2 plume injected into a deep saline formation is investigated, focusing on mechanisms that lead to plume stabilization. Key measures are plume migration distance and the time evolution of CO 2 phase-partitioning, which are examined by developing a numerical model of the subsurface at a proposed power plant with CO 2 capture in the San Joaquin Valley, California, where a large-volume pilot test of CO 2 injection will be conducted. The numerical model simulates a fouryear CO 2 injection period and the subsequent evolution of the CO 2 plume until it stabilizes. Sensitivity studies are carried out to investigate the effect of poorly constrained model parameters permeability, permeability anisotropy, and residual gas saturation.
Born-Infeld strings tunneling to D-branes

Abstract Recent work on solutions to the Born-Infeld theory used to describe D-branes suggests that fundamental strings can be viewed, in a certain limit, as D-branes whose worldvolumes have collapsed to string-like configurations. Here we address the possibility of undoing this collapse, by inducing the string to tunnel to an extended brane configuration. Using semiclassical methods we argue that, by putting one of these Born-Infeld strings in the background of a uniform 4-form RR field strength, the string can nucleate a spheroidal bulge of D2-brane, or, if the string is wrapped around a small enough circle, it can tunnel to a toroidal D2-brane. This process can also be interpreted in terms of the M2-brane. We also address the extension to other D p -branes, and discuss the range of validity of the approximations involved.
NEUTRINO PHYSICS: AN EXPERIMENTAL OVERVIEW

The field of neutrino physics is currently very exciting, with several recent results pointing to new physics. I will give an overview of the current experimental situation, focusing primarily on neutrino oscillation results. The data are not entirely consistent however, and puzzles remain. I will then review the new experiments which are poised to solve the outstanding puzzles.
Diagnosis of natural rubber latex allergy.

The accurate diagnosis of a latex-allergic individual begins with a comprehensive clinical history. Atopy, food allergies, hand dermatitis, and temporal relationships between allergic symptoms and natural rubber product exposure are risk factors that increase the suspicion of latex allergy. If symptoms are temporally delayed (hours-days) and confined to skin-latex product contact areas, Type IV hypersensitivity should be suspected and patch testing may be performed to identify activated T cells that are specific for selected rubber chemical additives. If ocular, upper and lower airway, and/or systemic allergic symptoms are observed with rapid onset (minutes) following a definable latex exposure, Type I hypersensitivity should be suspected. One or several confirmatory tests for latex-specific IgE antibody in the skin or blood may next be performed to verify a sensitized (IgE antibody positive) state. If the clinical history remains discordant with a skin test or blood test result, in vivo provocation tests may be cautiously considered for adjudication. Diagnostic methods for latex-specific IgE antibody detection in skin and blood are overviewed, with a focus on their performance, advantages, and limitations.
Costly Arbitrage: Evidence from Closed-End Funds

Arbitrage costs lead to large deviations of prices from fundamentals. Using a sample of closed-end funds, I find that the market value of a fund is more likely to deviate from the value of its assets (1) for funds with portfolios that are difficult to replicate, (2) for funds that pay out smaller dividends, (3) for funds with lower market values, and (4) when interest rates are high. These factors are related to the magnitude of the deviation, as opposed to the direction (i.e., whether discount or premium), and explain a quarter of cross-sectional mispricing variation. These findings are consistent with noise trader models of asset pricing.
Explicit Calculation of the Renormalized Singlet Axial Anomaly

Abstract A careful and complete discussion is given of the renormalization of the singlet axial anomaly equation in a vector-like nonabelian gauge theory such as QCD regularized by ordinary dimensional regularization. Pseudotensorial structures are treated with the 't Hooft-Veltman prescription. A general framework for calculations is developed, and subsequently verified by explicit computations through two loops. This is followed by a discussion of the matrix elements obtained.
Composition of mappings given by embedded dependencies

Composition of mappings between schemas is essential to support schema evolution, data exchange, data integration, and other data management tasks. In many applications, mappings are given by embedded dependencies. In this article, we study the issues involved in composing such mappings.Our algorithms and results extend those of Fagin et al. [2004], who studied the composition of mappings given by several kinds of constraints. In particular, they proved that full source-to-target tuple-generating dependencies (tgds) are closed under composition, but embedded source-to-target tgds are not. They introduced a class of second-order constraints, SO tgds, that is closed under composition and has desirable properties for data exchange.We study constraints that need not be source-to-target and we concentrate on obtaining (first-order) embedded dependencies. As part of this study, we also consider full dependencies and second-order constraints that arise from Skolemizing embedded dependencies. For each of the three classes of mappings that we study, we provide: (a) an algorithm that attempts to compute the composition; and (b) sufficient conditions on the input mappings which guarantee that the algorithm will succeed.In addition, we give several negative results. In particular, we show that full and second-order dependencies that are not limited to be source-to-target are not closed under composition (for the latter, under the additional restriction that no new function symbols are introduced). Furthermore, we show that determining whether the composition can be given by these kinds of dependencies is undecidable.
The Stimulating Effects of Ethanol on Ventral Tegmental Area Dopamine Neurons Projecting to the Ventral Pallidum and Medial Prefrontal Cortex in Female Wistar Rats: Regional Difference and Involvement of serotonin-3 Receptors

Rationale The ventral tegmental area (VTA) mediates the local stimulating effects of ethanol (EtOH) in a region-dependent manner, with EtOH administration in the posterior but not anterior VTA stimulating the mesolimbic system. The serotonin-3 (5-HT3) receptor has been involved in the effects of EtOH on the mesolimbic system.
Novel chromophoric heterocycles based on maleimide and naphthoquinone

1-Phenyl-3,4-dichloromaleimide, 1-n-propyl-3-bromomaleimide, and 2,3-dichloro-1,4-naphthoquinone have been condensed with various mono- and bis-nucleophiles to yield a range of novel dyes and pigments. Their visible absorption spectra are discussed.
Heat transport in silicon from first-principles calculations

Using harmonic and anharmonic force constants extracted from density functional calculations within a supercell, we have developed a relatively simple but general method to compute thermodynamic and thermal properties of any crystal. First, from the harmonic, cubic, and quartic force constants, we construct a force field for molecular dynamics. It is exact in the limit of small atomic displacements and thus does not suffer from inaccuracies inherent in semiempirical potentials such as Stillinger-Weber's. By using the Green-Kubo formula and molecular dynamics simulations, we extract the bulk thermal conductivity. This method is accurate at high temperatures where three-phonon processes need to be included to higher orders, but may suffer from size scaling issues. Next, we use perturbation theory (Fermi golden rule) to extract the phonon lifetimes and compute the thermal conductivity $\ensuremath{\kappa}$ from the relaxation-time approximation. This method is valid at most temperatures, but will overestimate $\ensuremath{\kappa}$ at very high temperatures, where higher-order processes neglected in our calculations also contribute. As a test, these methods are applied to bulk crystalline silicon, and the results are compared and differences are discussed in more detail. The presented methodology paves the way for a systematic approach to model heat transport in solids using multiscale modeling, in which the relaxation time due to anharmonic three-phonon processes is calculated quantitatively, in addition to the usual harmonic properties such as phonon frequencies and group velocities. It also allows the construction of an accurate bulk interatomic potentials database.
Leptoquark explanation of HERA anomaly in the context of gauge unification

Abstract We examine the consequences of leptoquark explanation of HERA anomaly in the context of R parity conserving supersymmetric gauge unified theory with the gauge unification scale at ∼10 16 GeV. We pointed out the difficulty of constructing a grandunified theory. However gauge coupling unification is still possible at ∼10 16 GeV when additional multiplets are introduced. We determine the mass spectrum of these additional fields (fermions and scalars) in gauge mediated and supergravity scenarios. Unique signatures and mass bounds are discussed.
Stereocontrolled Preparation of Fully Substituted Cyclopentanes: Relevance to Total Synthesis

This Microreview aims to identify important advances in the asymmetric synthesis of fully substituted five-membered carbocyclic ring systems. Recent efforts directed towards the intricate and densely functionalized core substructures of three distinct classes of cyclopentane-based natural products will be examined. Strategies featuring high levels of stereocontrol and/or conciseness in the total number of synthetic steps required to access complex natural product ring fragments are highlighted. Stereoselective Diels–Alder cycloaddition approaches to access functionalized norbornene intermediates as latent chiral cyclopentanes in the tradition of Corey's elegant prostaglandin studies are a recurring theme. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Systolic architectures for radar CFAR detectors

The authors discuss several advances in the evolution of radar CFAR (constant false alarm rate) detectors, from the classical mean-level detector to more recent designs using order statistics, or sorted data values. These algorithms can be implemented by modifying the existing running window order statistic filtering techniques used in signal/image processing. Although the signal processing theory of CFAR detection is well advanced, practical applications lag because of the high throughput required in radar. This intensive computational requirement is unlikely to be met by further advances in VLSI technology alone; it must result from parallel processing techniques. Systolic array architectures are proposed for several important CFAR detectors. Techniques for improving the processor utilization efficiency of the proposed array architectures are also discussed. >
N-Sulfinyl β-Amino Weinreb Amides: Synthesis of Enantiopure β-Amino Carbonyl Compounds. Asymmetric Synthesis of (+)-Sedridine and (−)-Allosedridine

N-Sulfinyl β-amino Weinreb amides are prepared by condensation of sulfinimines with the potassium enolate of N-methoxy-N-methylacetamide. These new chiral building blocks are useful for the asymmetric synthesis of β-amino carbonyl compounds, as illustrated here by the concise enantioselective syntheses of sedum alkaloids (+)-sedridine and (−)-allosedridine.
Optimal State-Space Control of a Gas Turbine Engine

An analog fuel control for a gas turbine engine was compared with several state space derived fuel controls. A single spool, simple cycle gas turbine engine was modeled using ACSL (high level simulation language based on FORTRAN). The model included an analog fuel control representative of existing commercial fuel controls. The ACSL model was stripped of non-essential states to produce an 8 state linear state space model of the engine. The A, B, and C matrices, derived from rated operating conditions, were used to obtain feedback control gains by the following methods: (1) state feedback; (2) LQR theory; (3) Bellman method; and (4) polygonal search. An off-load transient followed by an on-load transient was run for each of these fuel controls. The transient curves obtained were used to compare the state space fuel controls with the analog fuel control. The state space fuel controls did better than the analog control.Copyright © 1991 by ASME
Rollout strategies for sequential fault diagnosis

Test sequencing is a binary identification problem wherein one needs to develop a minimal expected cost testing procedure to determine which one of a finite number of possible failure sources, if any, is present. The problem can be solved optimally using dynamic programming or AND/OR graph search methods (AO/sup */, CF, and HS). However, for large systems, the associated computation with dynamic programming or AND/OR graph search methods is substantial, due to the rapidly increasing number of OR nodes (denoting ambiguity states) and AND nodes (denoting tests) in the search graph. In order to overcome the computational explosion, the one-step or multistep lookahead heuristic algorithms have been developed to solve the test sequencing problem. In this paper, we propose to apply rollout strategies, which can be combined with the one-step or multistep lookahead heuristic algorithms, in a computationally more efficient manner than the optimal strategies, to obtain solutions superior to those using the one-step or multistep lookahead heuristic algorithms. The rollout strategies are illustrated and tested using a range of real-world systems. We show computational results, which suggest that the information-heuristic based rollout policies are significantly better than other rollout policies based on Huffman coding and entropy.
Novel synthesis of phytosphingosine from levoglucosenone

Abstract Phytosphingosine, (2S,3S,4R)-2-amino-1,3,4-octadecanetriol was prepared in 8.6% overall yield in 17 steps from levoglucosenone (1,6-anhydro-3,4-dideoxy-β- d -glycero-hex-3-enopyranos-2-ulose) by reduction of the carbonyl group, selective cis-oxyamination of the carbon-carbon double bond, oxidation of the 2-hydroxyl group to the carbonyl group, regioselective Baeyer-Villiger oxidation, reduction of the afforded lactone to the linear amino alcohol, oxidation of the primary hydroxyl group to the aldehyde, introduction of the hydrocarbon chain using a Wittig reaction, hydrogenation of the resulting carbon-carbon double bond, and deprotection.
On a linearized problem arising in the Navier–Stokes flow of a free liquid jet

Abstract In this work, we analyze a Stokes problem arising in the study of the Navier–Stokes flow of a liquid jet. The analysis is accomplished by showing that the relevant Stokes operator accounting for a free surface gives rise to a sectorial operator which generates an analytic semigroup of contractions. Estimates on solutions are established using Fourier methods. The result presented is the key ingredient in a local existence and uniqueness proof for solutions of the full nonlinear problem.
Symmetry, Isotopy, and Irregular Covers

We say that a covering space of surfaces $$S\rightarrow X$$ has the Birman–Hilden property if the subgroup of the mapping class group of $$X$$ consisting of mapping classes that have representatives that lift to $$S$$ embeds in the mapping class group of $$S$$ modulo the group of deck transformations. We identify one necessary condition and one sufficient condition for when a covering space has this property. We give new explicit examples of irregular branched covering spaces that do not satisfy the necessary condition as well as explicit covers that satisfy the sufficient condition. Our criteria are conditions on simple closed curves, and our proofs use the combinatorial topology of curves on surfaces.
Impact of Admission and Cache Replacement Policies on Response Times of Jobs on Data Grids

Caching techniques have been used widely to improve the performance gaps of storage hierarchies in computing systems. Little is known about the impact of policies on the response times of jobs that access and process very large files in data grids, particularly when data and computations on the data have to be co-located on the same host. In data intensive applications that access large data files over wide area network environment, such as data-grids, the combination of policies for job servicing (or scheduling), caching and cache replacement can significantly impact the performance of grid jobs. We present preliminary results of a simulation study that combines an admission policy with a cache replacement policy when servicing jobs submitted to a storage resource manager.The results show that, in comparison to a first come first serve policy, the response times of jobs are significantly improved, for practical limits of disk cache sizes, when the jobs that are back-logged to access the same files are taken into consideration in scheduling the next file to be retrieved into the disk cache. Not only are the response times of jobs improved, but also the metric measures for caching policies, such as the hit ratio and the average cost per retrieval, are improved irrespective of the cache replacement policy used.
Labor supply and household meal production among working adults in the Health and Retirement Survey

In this paper, I consider how working adults near retirement age in the United States allocate time and monetary resources to meal production. Using the Consumption and Activities Mail Survey supplement to the Health and Retirement Survey, I use a fixed-effects tobit specification to estimate the effect of hours worked, labor income, non-labor income and assets on meal production decisions for respondents between 45 and 75 years of age who either live alone or with their spouse/partner. These relationships are estimated separately by gender and household structure (single-headed and dual-headed households). Among single males, increasing labor supply by 10 h per week was associated with 33.8 fewer minutes per week allocated to at-home meal preparation, 39.5 fewer minutes per month eating at restaurants, and $6.73 more per week spent on groceries. In contrast, the time and expenditure allocations of single females did not respond to changes in hours worked. Within dual-member households, increasing own-labor supply by 10 h per week was associated with a decrease in time allocated to preparing meals for both the male (30.4 min per week) and female member (30.5 min per week) with only weak evidence that the spouse/partner compensated by increasing their allocation of time.
Pillared smectite clay coatings for ceramic-matrix composites

This paper describes a novel route for the low-temperature formation of mullite, from pillared smectite clay precursors, for use as fiber coatings in ceramic-matrix composites. In particular, alumina-pillared bentonite converts in part to mullite at the unusually low temperature of about 800°C. The clay precursors display excellent film-forming capability and have been coated onto silicon carbide fibers. Mechanical tests on composites of the coated fibers and a borosilicate glass demonstrate their success as debond coatings, suggesting that this approach is a viable and simple route to oxide coatings for fibers.
The Siberian Curse: Does Russia's Geography Doom Its Chances for Market Reform?

(2006). The Siberian Curse: Does Russia's Geography Doom Its Chances for Market Reform? Problems of Economic Transition: Vol. 48, No. 11, pp. 7-29.
Strong environmental coupling in a Josephson parametric amplifier

We present a lumped-element Josephson parametric amplifier designed to operate with strong coupling to the environment. In this regime, we observe broadband frequency dependent amplification with multi-peaked gain profiles. We account for this behavior using the “pumpistor” model which allows for frequency dependent variation of the external impedance. Using this understanding, we demonstrate control over the complexity of gain profiles through added variation in the environment impedance at a given frequency. With strong coupling to a suitable external impedance, we observe a significant increase in dynamic range, and large amplification bandwidth up to 700 MHz giving near quantum-limited performance.
A new method for constructing invariant subspaces

The new idea that is used in this article for producing non-trivial (closed) invariant subspaces of (bounded linear) operators on reflexive Banach spaces, is the use of fixed points of set-valued functions. The advantage of this new method is that it is reasonable to expect that the famous method of Lomonosov for producing invariant subspaces using fixed points of functions, can be viewed as a special case of the use of fixed points of set-valued functions. Further uses of this new idea and open questions are suggested at the end of the article.
Finding alternatives to disability benefit receipt

This introduction offers a context for the articles in this thematic series by providing an overview of the programs that provide cash and in-kind supports to people with disabilities in the United States, summarizes the increasing reliance on these programs, and describes the challenges associated with reducing dependency on these programs. It then briefly discusses the articles in this thematic series in light of these issues. H5, I3, J2, J14
The silence of corruption : identifying underreporting of business corruption through randomized response techniques

Research on the economic consequences of corruption has been hampered by the inability to directly measure corruption. Using an innovative methodology that allows respondents to report individual experiences with corruption while minimizing self-incrimination and an objective diagnostic to evaluate lying (false responses), this paper explores the extent of business corruption in Bangladesh. The analysis shows that traditional measures of corruption underreport the extent of business corruption in Bangladesh and existing strategies to evaluate and elicit truthful responses have limited effectiveness. The authors identify the types of firms that are associated with false responses and nonresponses to survey questions on corruption.
Human Computer Interaction in Virtual Standardized Patient Systems

Interactive computer generated characters can be applied to the medical field as virtual patients for clinical training. The user interface for the virtual characters takes on the same appearance and behavior as a human. To assess if these virtual patients can be used to train skills such as interviewing and diagnosis they need to respond as a patient would. The primary goal of this study was to investigate if clinicians could elicit proper responses from questions relevant for an interview from a virtual patient. A secondary goal was to evaluate psychological variables such as openness and immersion on the question/response composites and the believability of the character as a patient.
Orthographic and morphological processing for English---Arabic statistical machine translation

Much of the work on statistical machine translation (SMT) from morphologically rich languages has shown that morphological tokenization and orthographic normalization help improve SMT quality because of the sparsity reduction they contribute. In this article, we study the effect of these processes on SMT when translating into a morphologically rich language, namely Arabic. We explore a space of tokenization schemes and normalization options. We also examine a set of six detokenization techniques and evaluate on detokenized and orthographically correct (enriched) output. Our results show that the best performing tokenization scheme is that of the Penn Arabic Treebank. Additionally, training on orthographically normalized (reduced) text then jointly enriching and detokenizing the output outperforms training on enriched text.
Stochastic bounds for parallel program execution times with processor constraints

A parallel program can be modeled as an acyclic directed graph, where a node represents a task, which is the smallest grain of computation to be assigned to a processor, and arcs stand for precedence (synchronization) constraints among the tasks. Due to different input data and unpredictable dynamic run time environments, the execution times of tasks as well as the entire program can be treated as random variables. In this paper, we develop some stochastic lower and upper bounds for parallel program execution times when there are limited processors. Such analysis can provide important information for job scheduling and resource allocation. For several typical classes of parallel programs, we derive very accurate closed form approximations for the bounds. Examples are also given to demonstrate the quality of the bounds derived.
Bayesian Inference for Logistic Models Using Pólya–Gamma Latent Variables

We propose a new data-augmentation strategy for fully Bayesian inference in models with binomial likelihoods. The approach appeals to a new class of Polya–Gamma distributions, which are constructed in detail. A variety of examples are presented to show the versatility of the method, including logistic regression, negative binomial regression, nonlinear mixed-effect models, and spatial models for count data. In each case, our data-augmentation strategy leads to simple, effective methods for posterior inference that (1) circumvent the need for analytic approximations, numerical integration, or Metropolis–Hastings; and (2) outperform other known data-augmentation strategies, both in ease of use and in computational efficiency. All methods, including an efficient sampler for the Polya–Gamma distribution, are implemented in the R package BayesLogit. Supplementary materials for this article are available online.
Florbetapir positron emission tomography and cerebrospinal fluid biomarkers

Abstract Background We evaluated the relationship between florbetapir-F18 positron emission tomography (FBP PET) and cerebrospinal fluid (CSF) biomarkers. Methods Alzheimer's Disease Neuroimaging Initiative-Grand Opportunity and Alzheimer's Disease Neuroimaging Initiative 2 (GO/2) healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) dementia subjects with clinical measures and CSF collected ±90 days of FBP PET data were analyzed using correlation and logistic regression. Results In HC and MCI subjects, FBP PET anterior and posterior cingulate and composite standard uptake value ratios correlated with CSF amyloid beta (Aβ 1–42 ) and tau/Aβ 1–42 ratios. Using logistic regression, Aβ 1–42 , total tau (t-tau), phosphorylated tau 181P (p-tau), and FBP PET composite each differentiated HC versus AD. Aβ 1–42 and t-tau distinguished MCI versus AD, without additional contribution by FBP PET. Total tau and p-tau added discriminative power to FBP PET when classifying HC versus AD. Conclusion Based on cross-sectional diagnostic groups, both amyloid and tau measures distinguish healthy from demented subjects. Longitudinal analyses are needed.
Experimental and Numerical Study of Swept Ramp Injection into a Supersonic Flowfield

Time-averaged measurements of pressure, temperature, velocity, and injectant mole fraction are presented using the planar laser-induced iodine fluorescence technique in the complex three-dimensional compressible flowfield around a swept ramp fuel injector. Within the range of thermodynamic conditions present in the test case studied, the technique's accuracy is estimated to be 4% for pressure, temperature, and velocity and 3% for injectant mole fraction. Comparisons with numerical simulations using the SPARK three-dimensional Navier-Stokes computer code with an algebraic turbulence model are made at the centerplane of the flowfield as well as on three crossflow planes downstream of the injector. Calculations and measurements are in good agreement throughout the flowfield, with deviations on the order of 5%; however, in specific regions, such as in the base of the ramp, deviations are larger. A weak asymmetry in the incoming flowfield appears to be amplified by boundary-layer separation occurring when the ramp-generated shock reflects off the tunnel walls. Ramp-generated vortices are weaker in the calculated results due to the effects of numerical viscosity in the vortex cores. This leads to less turning and mixing of the jet plume than observed in the experiments. The rate of decay of the maximum injectant mole fraction with streamwise distance is greater for the present ramp injection scheme than for previously measured transverse injection schemes. In this recirculation region at the base of the injector, laminar calculations show better agreement with the measurements than turbulent calculations.
On the geometric boundaries of hyperbolic 4{manifolds

We provide, for hyperbolic and flat 3{manifolds, obstructions to bounding hyperbolic 4{manifolds, thus resolving in the negative a question of Farrell and Zdravkovska.
Parallel rendering techniques for massively parallel visualization

As the resolution of simulation models increases, scientific visualization algorithms which take advantage of the large memory and parallelism of massively parallel processors (MPPs) are becoming increasingly important. For large applications, rendering on an MPP tends to be preferable to rendering on a graphics workstation, due to the MPP's abundant resources: memory, disk and numerous processors. The challenge is developing algorithms that can exploit these resources while minimizing overheads, typically communication costs. This paper describes recent efforts in parallel rendering for polygonal primitives as well as parallel volumetric techniques. It presents rendering algorithms, developed for MPPs, for polygonal, spherical and volumetric data. The polygon algorithm uses a data-parallel approach, whereas the sphere and volume rendering use a MIMD approach. Implementations for these algorithms are presented for a Thinking Machines Corp. CM-5 and a Cray Research Inc. T3D.
Transformational and transactional presidents

During the 20th century, the United States went from being a second rate power to becoming the world’s sole superpower. Did leaders matter? In the cases I examined in Presidential Leadership and the Creation of the American Era, most presidents mattered, but not necessarily those that one might expect. Leadership experts distinguish transformational leaders with broad visions and an inspirational style (such as Woodrow Wilson or Ronald Reagan) from transactional leaders who have modest vision and a managerial style (such as Dwight Eisenhower or George H.W. Bush). Experts and editorialists generally prefer transformational leaders and consider them both more effective and more ethical. But the concepts have been poorly defined, and the normative preference for transformational leaders is not justified. Leadership theorists need to be more careful in their definitions and assessments.
BEST PRACTICES IN PREDICTION FOR DECISION‐MAKING: LESSONS FROM THE ATMOSPHERIC AND EARTH SCIENCES

Predictions that result from scientific research hold great appeal for decision-makers who are grappling with complex and controversial environmental issues, by promising to enhance their ability to determine a need for and outcomes of alternative decisions. A problem exists in that decision-makers and scientists in the public and private sectors solicit, produce, and use such predictions with little understanding of their accuracy or utility, and often without systematic evaluation or mechanisms of accountability. In order to contribute to a more effective role for ecological science in support of decision-making, this paper discusses three “best practices” for quantitative ecosystem modeling and prediction gleaned from research on modeling, prediction, and decision-making in the atmospheric and earth sciences. The lessons are distilled from a series of case studies and placed into the specific context of examples from ecological science. Corresponding Editor: J. S. Clark
The binprolog experience: Architecture and implementation choices for continuation passing prolog and first-class logic engines

We describe the BinProlog system's compilation technology, runtime system and its extensions supporting first-class Logic Engines while providing a short history of its development, details of some of its newer re-implementations as well as an overview of the most important architectural choices involved in their design. With focus on its differences with conventional Warren Abstract Machine (WAM) implementations, we explain key details of BinProlog's compilation technique, which replaces the WAM with a simplified continuation passing runtime system (the "BinWAM"), based on a mapping of full Prolog to binary logic programs. This is followed by a description of a term compression technique using a "tag-on-data" representation. Later derivatives, the Java-based Jinni Prolog compiler and the recently developed Lean Prolog system refine the BinProlog architecture with first-class Logic Engines, made generic through the use of an Interactor interface. An overview of their applications with focus on the ability to express at source level a wide variety of Prolog built-ins and extensions covers these newer developments.
SYNTACTIC AND SEMANTIC PARSABILITY

This paper surveys some issues that arise in the study of the syntax and semantics of natural languages (NL's) and have potential relevance to the automatic recognition, parsing, and translation of NL's. An attempt is made to take into account the fact that parsing is scarcely ever thought about with reference to syntax alone; semantic ulterior motives always underly the assignment of a syntactic structure to a sentence. First I consider the state of the art with respect to arguments about the language-theoretic complexity of NL's: whether NL's are regular sets, deterministic CFL's, CFL's, or whatever. While English still appears to be a CFL as far as I can tell, new arguments (some not yet published) appear to show for the first time that some languages are not CFL's. Next I consider the question of how semantic filtering affects the power of grammars. Then I turn to a brief consideration of some syntactic proposals that employ more or less modest extensions of the power of context-free grammars.
Dynamic Voluntary Contribution to a Public Project

We consider the dynamic private provision of funds to projects that generate public benefits. Participants have complete information about the environment, but imperfect information about individual actions: each period they observe only the aggregate contribution. Each player may contribute any amount in any period before the contributing horizon is reached. All Nash equilibrium outcomes are characterized. In many cases they are all also perfect Bayesian equilibrium outcomes. If the horizon is long, if the players' preferences are similar, and if they are patient or the period length is short, perfect Bayesian equilibria exist that essentially complete the project. In some of them the completion time shrinks to zero with the period length—efficiency is achieved in the limit.
The spillover effects of Medicare managed care: Medicare Advantage and hospital utilization.

More than a quarter of Medicare beneficiaries are enrolled in Medicare Advantage, which was created in large part to improve the efficiency of health care delivery by promoting competition among private managed care plans. This paper explores the spillover effects of the Medicare Advantage program on the traditional Medicare program and other patients, taking advantage of changes in Medicare Advantage payment policy to isolate exogenous increases in Medicare Advantage enrollment and trace out the effects of greater managed care penetration on hospital utilization and spending throughout the health care system. We find that when more seniors enroll in Medicare managed care, hospital costs decline for all seniors and for commercially insured younger populations. Greater managed care penetration is not associated with fewer hospitalizations, but is associated with lower costs and shorter stays per hospitalization. These spillovers are substantial – offsetting more than 10% of increased payments to Medicare Advantage plans.
Statistical decision making for optimal budget allocation in crowd labeling

It has become increasingly popular to obtain machine learning labels through commercial crowdsourcing services. The crowdsourcing workers or annotators are paid for each label they provide, but the task requester usually has only a limited amount of the budget. Since the data instances have different levels of labeling difficulty and the workers have different reliability for the labeling task, it is desirable to wisely allocate the budget among all the instances and workers such that the overall labeling quality is maximized. In this paper, we formulate the budget allocation problem as a Bayesian Markov decision process (MDP), which simultaneously conducts learning and decision making. The optimal allocation policy can be obtained by using the dynamic programming (DP) recurrence. However, DP quickly becomes computationally intractable when the size of the problem increases. To solve this challenge, we propose a computationally eficient approximate policy which is called optimistic knowledge gradient. Our method applies to both pull crowdsourcing marketplaces with homogeneous workers and push marketplaces with heterogeneous workers. It can also incorporate the contextual information of instances when they are available. The experiments on both simulated and real data show that our policy achieves a higher labeling quality than other existing policies at the same budget level.
What Do We Learn from the Weather? The New Climate-Economy Literature

A rapidly growing body of research applies panel methods to examine how temperature, precipitation, and windstorms influence economic outcomes. These studies focus on changes in weather realizations over time within a given spatial area and demonstrate impacts on agricultural output, industrial output, labor productivity, energy demand, health, conflict, and economic growth, among other outcomes. By harnessing exogenous variation over time within a given spatial unit, these studies help credibly identify (i) the breadth of channels linking weather and the economy, (ii) heterogeneous treatment effects across different types of locations, and (iii) nonlinear effects of weather variables. This paper reviews the new literature with two purposes. First, we summarize recent work, providing a guide to its methodologies, datasets, and findings. Second, we consider applications of the new literature, including insights for the "damage function" within models that seek to assess the potential economic effects of future climate change. ( JEL C51, D72, O13, Q51, Q54)
The Neural Ring: An Algebraic Tool for Analyzing the Intrinsic Structure of Neural Codes

Neurons in the brain represent external stimuli via neural codes. These codes often arise from stereotyped stimulus-response maps, associating to each neuron a convex receptive field. An important problem confronted by the brain is to infer properties of a represented stimulus space without knowledge of the receptive fields, using only the intrinsic structure of the neural code. How does the brain do this? To address this question, it is important to determine what stimulus space features can—in principle—be extracted from neural codes. This motivates us to define the neural ring and a related neural ideal, algebraic objects that encode the full combinatorial data of a neural code. Our main finding is that these objects can be expressed in a “canonical form” that directly translates to a minimal description of the receptive field structure intrinsic to the code. We also find connections to Stanley–Reisner rings, and use ideas similar to those in the theory of monomial ideals to obtain an algorithm for computing the primary decomposition of pseudo-monomial ideals. This allows us to algorithmically extract the canonical form associated to any neural code, providing the groundwork for inferring stimulus space features from neural activity alone.
One dimensional models for relativistic electron beam diode design

ABSTRACT Most gyrolron electron gun designs are based on the use of electron trajectory codes; however, the complexity of the problem is such that a design procedure using only a simulation code can be very tedious and expensive. For these reasons one dimensional approximations to the flow are extremely useful. Such one dimensional flows can be used to synthesize first approximations to the electrode shapes. The purpose of this paper is to show how previous work on this technique for non-relativistic beams can be extended to the relativistic intense electron beam regime. The analysis is based on four one-dimensional planar or conical models for electron flow in diodes. The planar models are relativistic and can be used to obtain electrode shapes for space charge limited flow. The conical models shed light on important geometric effects. Principally, it is shown that the space charge limited current is larger in realistic geometries than in the corresponding planar configuration. A design procedure based o...
Geometric dual and matrix theory for SO/Sp gauge theories

Abstract In this paper, we give a proof of the equivalence of N =1 SO / Sp gauge theories deformed from N =2 by the superpotential of adjoint field Φ and the dual type IIB superstring theory on CY threefold geometries with fluxes and orientifold action after geometric transition. Furthermore, by relating the geometric picture to the matrix model, we show the equivalence between the field theory and the corresponding matrix model.