cssi/SciSciGPT-SciSciNet huggingface dataset:
Connections between linear systems and convolutional codes

The article reviews different definitions for a convolutional code which can be found in the literature. The algebraic differences between the definitions are worked out in detail. It is shown that bi-infinite support systems are dual to finite-support systems under Pontryagin duality. In this duality the dual of a controllable system is observable and vice versa. Uncontrollability can occur only if there are bi-infinite support trajectories in the behavior, so finite and half-infinite-support systems must be controllable. Unobservability can occur only if there are finite support trajectories in the behavior, so bi-infinite and half-infinite-support systems must be observable. It is shown that the different definitions for convolutional codes are equivalent if one restricts attention to controllable and observable codes.
The Discovery of an Anomalous X-Ray Pulsar in the Supernova Remnant Kes 73

We report the discovery of pulsed X-ray emission from the compact source 1E 1841-045, using data obtained with the Advanced Satellite for Cosmology and Astrophysics. The X-ray source is located in the center of the small-diameter supernova remnant (SNR) Kes 73 and is very likely to be the compact stellar remnant of the supernova that formed Kes 73. The X-rays are pulsed with a period of 11.8 s and a sinusoidal modulation of roughly 30%. We interpret this modulation to be the rotation period of an embedded neutron star, and as such it would be the longest spin period for an isolated neutron star to date. This is especially remarkable since the surrounding SNR is very young, ~2000 yr old. We suggest that the observed characteristics of this object are best understood within the framework of a neutron star with an enormous dipolar magnetic field, B 8 × 1014 G.
Learning arithmetic circuits

Graphical models are usually learned without regard to the cost of doing inference with them. As a result, even if a good model is learned, it may perform poorly at prediction, because it requires approximate inference. We propose an alternative: learning models with a score function that directly penalizes the cost of inference. Specifically, we learn arithmetic circuits with a penalty on the number of edges in the circuit (in which the cost of inference is linear). Our algorithm is equivalent to learning a Bayesian network with context-specific independence by greedily splitting conditional distributions, at each step scoring the candidates by compiling the resulting network into an arithmetic circuit, and using its size as the penalty. We show how this can be done efficiently, without compiling a circuit from scratch for each candidate. Experiments on several real-world domains show that our algorithm is able to learn tractable models with very large treewidth, and yields more accurate predictions than a standard context-specific Bayesian network learner, in far less time.
Baryon number transport in high-energy nuclear collisions

Recent SPS data on the rapidity distribution of protons inp+S,p+Au and S+S collisions at 200 AGeV and preliminary Pb+Pb collisions at 160 AGeV are compared to HIJING and VENUS calculations as well as to predictions based on the Multi-Chain Model (MCM). The preliminary Pb data suggest that a linear dependence of the proton rapidity shift as a function of the nuclear thicknes, as first observed inp+A reactions, may apply up to Pb+Pb reactions. The observed rapidity dependence of produced hyperons in bothp+A and A+A reactions however cannot be explained in terms of such models without introducing additional non-linear effects.
Coupling of alpha channeling to parallel wavenumber upshift in lower hybrid current drive

Although lower hybrid (LH) waves have been shown to be effective in driving plasma current in present-day tokamaks, they are predicted to strongly interact with the energetic α particles born from fusion reactions in eventual tokamak reactors. However, in the presence of the expected steep α particle birth gradient, this interaction can produce wave amplification rather than wave damping. Here, we identify the flexibilities and constraints in achieving this amplification effect through a consideration of symmetries in the channeling interaction, in the wave propagation, and in the tokamak field configuration. Interestingly, for standard LH current drive that supports the poloidal magnetic field, we find that wave amplification through α channeling is fundamentally coupled to the poorly understood |k∥| upshift. In so doing, we show that wave launch from the tokamak high-field side is favorable both for α-channeling and for achieving the |k∥| upshift.
GE high density interconnect: a solution to the system interconnect problem

It is noted that the General Electric high density interconnect (GE-HDI) is an excellent solution to the digital multichip packaging problem, and it offers solutions to other difficult system interconnect problems in analog power, microwave, display, and sensors. GE-HDI offers the closest hybrid solution to wafer scale integration, achieving the benefits of performance and density without the limitations and yield problems of the monolithic approach. Relative to other hybrid applications, it offers significant advantages in performance and anticipated reliability due to its sputtered metal interconnection and excellent thermal properties while not sacrificing density or cost. Maskless adaptive lithography allows for rapid prototyping and flexibility in design and debugging. With the complete absence of tooling for mask or tape bonding, NRE costs are the lowest of any multichip module technology. HDI also requires the fewest processing steps, because there is no need to mount die on tape or to do lead or die bumping. >
Dimensionally stable and bioactive membrane for guided bone regeneration: An in vitro study

Composite fibrous electrospun membranes based on poly(dl-lactide) (PLA) and poly(e-caprolactone) (PCL) were engineered to include borate bioactive glass (BBG) for the potential purposes of guided bone regeneration (GBR). The fibers were characterized using scanning and transmission electron microscopies, which respectively confirmed the submicron fibrous arrangement of the membranes and the successful incorporation of BBG particles. Selected mechanical properties of the membranes were evaluated using the suture pullout test. The addition of BBG at 10 wt % led to similar stiffness, but more importantly, it led to a significantly stronger (2.37 ± 0.51 N mm) membrane when compared with the commercially available Epiguide® (1.06 ± 0.24 N mm) under hydrated conditions. Stability (shrinkage) was determined after incubation in a phosphate buffer solution from 24 h up to 9 days. The dimensional stability of the PLA:PCL-based membranes with or without BBG incorporation (10.07-16.08%) was similar to that of Epiguide (14.28%). Cell proliferation assays demonstrated a higher rate of preosteoblasts proliferation on BBG-containing membranes (6.4-fold) over BBG-free membranes (4- to 5.8-fold) and EpiGuide (4.5-fold), following 7 days of in vitro culture. Collectively, our results demonstrated the ability to synthesize, via electrospinning, stable, polymer-based submicron fibrous BBG-containing membranes capable of sustaining osteoblastic attachment and proliferation-a promising attribute in GBR.
Ab initio study of BaTiO 3 surfaces

We have carried out first-principles total-energy calculations of (001) surfaces of the tetragonal and cubic phases of BaTiO${}_{3}$. Both BaO-terminated (type I) and TiO${}_{2}$-terminated (type II) surfaces are considered, and the atomic configurations have been fully relaxed. We found no deep-gap surface states for any of the surfaces, in agreement with previous theoretical studies. However, the gap is reduced for the type-II surface, especially in the cubic phase. The surface relaxation energies are found to be substantial, i.e., many times larger than the bulk ferroelectric well depth. Nevertheless, the influence of the surface upon the ferroelectric order parameter is modest; we find only a small enhancement of the ferroelectricity near the surface.
Crossed products by spectrally free actions

Abstract We define spectral freeness for actions of discrete groups on C*-algebras. We relate spectral freeness to other freeness conditions; an example result is that for an action α of a finite group G, spectral freeness is equivalent to strong pointwise outerness, and also to the condition that Γ ˜ ( α g ) ≠ { 1 } for every g ∈ G ∖ { 1 } . We then prove permanence results for reduced crossed products by exact spectrally free actions, for crossed products by arbitrary actions of Z / 2 Z , and for extensions, direct limits, stable isomorphism, and several related constructions, for the following properties: • The combination of pure infiniteness and the ideal property. • Residual hereditary infiniteness (closely related to pure infiniteness). • Residual (SP) (a strengthening of Property (SP) suitable for nonsimple C*-algebras). • The weak ideal property (closely related to the ideal property). For the weak ideal property, we can allow arbitrary crossed products by any finite abelian group. These properties of C*-algebras are shown to have formulations of the same general type, allowing them all to be handled using a common set of theorems.
Carrier dynamics in self-assembled ErAs nanoislands measured by optical-pump THz-probe spectroscopy

We use optical-pump THz-probe spectroscopy to study carrier dynamics in self-assembled ErAs:GaAs nanoislands. Sub-picosecond carrier capture times are measured, indicating the potential of these devices as THz detectors comparable to low temperature grown GaAs.
The Legal and Policy Implications of the “Flexibility Stigma”

American workplace law prohibits employment decisions based on gender stereotypes and forbids retaliation against employees who take certain job-protected family leaves. Yet the studies in this Issue documenting the “flexibility stigma” indicate popular perceptions and attitudes that run counter to these legal proscriptions. Three key aspects of the flexibility stigma as documented suggest legal and policy implications. First, because the flexibility stigma is rooted in gender stereotypes, its effects may be litigable under federal law prohibiting sex discrimination in employment. Second, workplace policies that provide leave or flexible scheduling must also recognize and address bias against those who use them or the policies risk being undermined by workers engaging in bias avoidance. Third, the flexibility stigma operates in workplaces across the class spectrum, indicating a greater urgency for public policy to counteract its effects.
Estimating continuous distributions in Bayesian classifiers

When modeling a probability distribution with a Bayesian network, we are faced with the problem of how to handle continuous variables. Most previous work has either solved the problem by discretizing, or assumed that the data are generated by a single Gaussian. In this paper we abandon the normality assumption and instead use statistical methods for nonparametric density estimation. For a naive Bayesian classifier, we present experimental results on a variety of natural and artificial domains, comparing two methods of density estimation: assuming normality and modeling each conditional distribution with a single Gaussian; and using nonparametric kernel density estimation. We observe large reductions in error on several natural and artificial data sets, which suggests that kernel estimation is a useful tool for learning Bayesian models.
A Short Proof of the Zeilberger-Bressoud $q$-Dyson Theorem

We give a formal Laurent series proof of Andrews's q-Dyson Conjecture, first proved by Zeilberger and Bressoud.
Safety of a Higher Loading Dose of Phenobarbital in the Term Newborn

The conventional loading dose of phenobarbital for newborn infants with hypoxic-ischemic seizures, 20 mg/kg, often fails to control convulsive activity. To determine the safety of a higher loading dose and to establish the pharmacokinetic parameters of a higher loading dose, ten severely asphyxiated term newborns were given 30 mg/kg of phenobarbital intravenously over 15 minutes. The mean serum concentration of phenobarbital two hours after loading was 30.0 +/- 3.2 micrograms/mL, the apparent volume of distribution was 0.97 +/- 0.18 L/kg, total clearance was 0.08 +/- 0.03 mL/min/kg, and mean serum half-life was 148 +/- 55 hours. The higher loading dose was not associated with any short-term adverse effects on cardiorespiratory function, even in spontaneously breathing infants.
Supersymmetry: Aspirations and Prospects

The realization in the early 1980s that weak scale supersymmetry stabilizes the Higgs sector of the spectacularly successful Standard Model led several authors to explore whether low energy supersymmetry could play a role in particle physics. Among these were Richard Arnowitt, Ali Chamseddine and Pran Nath who constructed a viable locally supersymmetric Grand Unified Theory (GUT), laying down the foundation for supergravity GUT models of particle physics. Supergravity models continue to be explored as one of the most promising extensions of the Standard Model. After a quick overview of some of the issues and aspirations of early researchers working to bring supersymmetry into the mainstream of particle physics, we re-examine early arguments that seemed to imply that superpartners would be revealed in experiments at LEP2 or at the Tevatron. Our purpose is to assess whether the absence of any superpartners in searches at LHC8 presents a crisis for supersymmetry. Toward this end, we re-evaluate fine-tuning arguments that lead to upper bounds on (some) superpartner masses. We conclude that phenomenologically viable superpartner spectra that could arise within a high scale model tuned no worse than a few percent are perfectly possible. While no viable underlying model of particle physics that leads to such spectra has yet emerged, we show that the (supergravity-based) Radiatively-driven Natural Supersymmetry (RNS) framework serves as a surrogate for a phenomenological analysis of an underlying theory with modest fine-tuning. We outline the phenomenological implications of this framework, with emphasis on those LHC and electron-positron collider signatures that might point to the underlying natural origin of gauge and Higgs boson masses. We conclude that the supergravity GUT paradigm laid down in 1982 by Arnowitt, Chamseddine and Nath, and others, remains a vibrant possibility.
Detecting range expansions from genetic data.

We propose a method that uses genetic data to test for the occurrence of a recent range expansion and to infer the location of the origin of the expansion. We introduce a statistic ψ (the directionality index) that detects asymmetries in the two-dimensional allele frequency spectrum of pairs of population. These asymmetries are caused by the series of founder events that happen during an expansion and they arise because low frequency alleles tend to be lost during founder events, thus creating clines in the frequencies of surviving low-frequency alleles. Using simulations, we show that ψ is more powerful for detecting range expansions than both FST and clines in heterozygosity. We also show how we can adapt our approach to more complicated scenarios such as expansions with multiple origins or barriers to migration and we illustrate the utility of ψ by applying it to a data set from modern humans.
Microinsurance: A Case Study of the Indian Rainfall Index Insurance Market

Rainfall index insurance provides a payout based on measured local rainfall during key phases of the agricultural season, and in principle can help rural households diversify a key source of idiosyncratic risk. This paper describes basic features of rainfall insurance contracts offered in India since 2003, and documents stylized facts about market demand and the distribution of payouts. The authors summarize the results of previous research on this market, which provides evidence that price, liquidity constraints, and trust all present significant barriers to increased take-up. They also discuss potential future prospects for rainfall insurance and other index insurance products.
An Efficient Implementation of a Scaling Minimum-Cost Flow Algorithm

The scaling push-relabel method is an important theoretical development in the area of minimum-cost flow algorithms. We study practical implementations of this method. We are especially interested in heuristics which improve real-life performance of the method. Our implementation works very well over a wide range of problem classes. Some heuristics we develop may apply to other network algorithms. Our experimental work on the minimum-cost flow problem motivated theoretical work on related problems.
Decomposition of geometric-shaped structuring elements using morphological transformations on binary images

A unified technique to simplify the decomposition of various types of big geometric-shaped structuring elements into dilations of smaller structuring components by the use of a mathematical transformation is presented. The method can be applied to all types of ID gray-scale structuring elements to decompose them into dilations of smaller structuring components. The desired morphological erosion and dilation are equivalent to a simple inverse transformation over the result of operations on the transformed decomposable structuring elements. A strategy to decompose a large cyclic cosine structuring element is described. A technique for decomposing a two-dimensional convex structuring element into one-dimensional elements is also developed. >
Bimodal electronic structure of isolated Co atoms on Pt(111)

We have used low-temperature scanning tunneling microscopy and spectroscopy to probe the local electronic structure of Co adatoms on the Pt(111) surface. Two varieties of Co adatoms that differ in their $dI∕dV(V)$ spectra are identified. We find that this contrast in spectral density is due to the adatom binding site on the surface. Atoms at different surface lattice sites (i.e., fcc versus hcp sites) exhibit different local densities of states (LDOS). Manipulation of a Co atom from one kind of lattice site to the other results in the expected change in its LDOS. $dI∕dV(V)$ spectra measured in this study were normalized using a method that compensates for differences in tunneling current that occur at different points on the surface. Such normalized spectra are shown to be useful in predicting the spatial contrast of $dI∕dV$ maps.
Interferometric study of concentration profiles in solutions near membrane surfaces

Abstract A new technique for the observation and interpretation of concentration profiles in diffusion layers at membrane-solution interfaces was developed. The concentration profiles in dilute (0·01N) KCl solutions near an ion-exchange membrane were observed in a modified O'Brien-type wedge laser interferometer while electric current (1·15 and 2·3 mA cm−2) passed through the solution (25°C). After current reversal, following prepolarization periods of 5–60 s, a concentration minimum develops. The image of this minimum in relation to the membrane surface is not subject to optical deflection and can therefore be accurately determined. From its trajectory, the salt concentration at the membrane surface at the time of current reversal was determined. It was found that as this concentration dropped to the order of 10−3–10−4M (“critical concentration”) significant deviations occurred between observed trajectories and those computed from a theory based on the Nernst-Planck equations. These deviations are believed to be caused by substantial migration of H+ and OH−. While these measurements indicate the order of magnitude of the critical concentration, additional measurements are necessary for quantitative determination of this concentration under different physicochemical and hydrodynamic conditions.
Construction of a Penrose diagram for an accreting black hole

A Penrose diagram is constructed for a spatially coherent black hole that accretes at stepwise steady rates as measured by a distant observer from an initial state described by a metric of Minkowski form. Coordinate lines are computationally derived, and radial lightlike trajectories verify the viability of the diagram. Coordinate dependences of significant features, such as the horizon and radial mass scale, are clearly demonstrated on the diagram. The onset of a singularity at the origin is shown to open a new region in space time that contains the interior of the black hole.
Comment on 'Exact results for survival probability in the multistate Landau-Zener model'

We correct the proof of the Brundobler–Elser formula (BEF) provided in Volkov and Ostrovsky (2004 J. Phys. B: At. Mol. Opt. Phys. 37 4069) and continued in the appendix of Volkov and Ostrovsky (2005 J. Phys. B: At. Mol. Opt. Phys. 38 907). After showing that some changes of variables employed in these articles are used erroneously, we propose an alternative change of variables which solves the problem. In our proof, we reveal the connection between the BEF for a general N-level Landau–Zener system and the exactly solvable bow-tie model. The special importance of the diabatic levels with maximum/minimum slope is emphasized throughout.
Mach number effects on transonic aeroelastic forces and flutter characteristics

Transonic aeroelastic stability analysis and flutter calculations are presented for a generic transport-type wing based on the use of the CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) finite-difference code. The CAP-TSD code was recently developed for transonic unsteady aerodynamic and aeroelastic analysis of complete aircraft configurations. A binary aeroelastic system consisting of simple bending and torsion modes was used to study aeroelastic behavior at transonic speeds. Generalized aerodynamic forces are presented for a wide range of Mach number and reduced frequency. Aeroelastic characteristics are presented for variations in freestream Mach number, mass ratio, and bending-torsion frequency ratio. Flutter boundaries are presented which have two transonic dips in flutter speed. The first dip is the usual transonic dip involving a bending-dominated flutter mode. The second dip is characterized by a single degree-of-freedom torsion oscillation. These aeroelastic results are physically interpreted and shown to be related to the steady state shock location and changes in generalized aerodynamic forces due to freestream Mach number.
Metaplectic formulation of linear mode conversion

The metaplectic formulation of linear mode conversion is presented. We begin by discussing the connection between wave operators in weakly inhomogeneous media, their symbols, and related pseudodifferential operators. A brief summary of WKB theory and Hamiltonian ray dynamics is given. In regions where mode conversion occurs, the WKB approximation breaks down and must be replaced by an appropriate local approximation. This is done by expanding in a Taylor series about the degenerate region and keeping only the leading-order terms. At leading order a linear canonical transformation on the ray phase space can be performed which brings the system into a simpler form. This linear canonical transformation induces a unitary transformation, called a [ital metaplectic] [ital transformation], in the wave function's Hilbert space. This is a generalization of the Fourier transformation. The advantage of metaplectic techniques over Fourier techniques lies in the wider range of transformations available to simplify the problem. We show how to construct the [ital S] matrix, relating incoming and outgoing waves, and the Wigner tensor. We examine the Wigner function in detail with particular attention to its asymptotic properties.
CRUISE LINES AND CONSUMERS: TROUBLED WATERS

The cruise industry represents the fastest growing segment of the leisure travel industry. This article will examine the legal obstacles faced by plaintiffs who try to litigate consumer complaints against cruise lines. First, the article will discuss the passenger contract and the enforceability of forum selection clauses and time limitation clauses under maritime law. Second, the article will address the issue of whether or not state deceptive trade practices acts are preempted by federal admiralty law. Last, the article will conclude that sound arguments may be made in favor of accommodating state consumer protection legislation in the context of general maritime law.
IUE observations of HL CMa and the winds of cataclysmic variables

As evidenced by the P Cygni profiles of their ultraviolet resonance lines, cataclysmic variables-like early-type stars-are known to have extensive, high velocity winds. Assisted by AAVSO visual data and IUE ultraviolet spectra, we present an observational and theoretical study of the P Cygni profiles of the dwarf nova HL CMa. As these profiles are dependent upon the ionization structure of the wind, we describe a model of a radiatively-driven shocked wind for cataclysmic variables, and present results for the temperature and ionization structure of the outflowing gas.
Existence of equilibria in atomless production economies with price dependent preferences

Abstract The existence of a competitive equilibrium for an economy with a measure space of agents is proved by reducing the economy to a three-person game and then applying Debreu's lemma (1952). In addition to the relative simplicity and shortness of the proof, we generalize known results [Aumann (1966), Hildenbrand (1970), Schmeidler (1969)] by allowing both price dependent preferences and satiation.
Evaluation of approaches to active compressor surge stabilization

Recent work has shown that compression systems can be actively stabilized against the instability known as surge, thereby realizing a significant gain in system mass flow range. Ideally, this surge stabilization requires only a single sensor and a single actuator connected by a suitable control law. Almost all research to date has been aimed at proof of concept studies of this technique, using various actuators and sensor combinaltons. In contrast, the work reported here can be regarded as a step toward developing active control into a practical technique. In this context, the paper presents the first systematic definition of the influence of sensor and actuator selection on increasing the range of stabilized compressor performance
Tidal perturbations on the satellite 1967-92A

The orbit of the 1967-92A satellite was studied to ascertain the extent to which tidal forces contribute to orbital perturbations. Parameters describing the ocean tide potential-in particular for the M2 and S2 constituents-were estimated. Since the ocean tide potential is less well known than the solid Earth tide, the ocean tide parameter estimation is based upon the use of a value of 0.3 for the solid Earth tide Love number in the orbit determination procedure. These tidal parameter values are in good agreement with those appearing in numerical models of the M2 and S2 tides derived from surface data.
Bifurcation and Chaos in Externally Excited Circular Cylindrical Shells

The nonlinear response of an infinitely long cylindrical shell to a primary excitation of one of its two orthogonal flexural modes is investigated. The method of multiple scales is used to derive four ordinary differential equations describing the amplitudes and phases of the two orthogonal modes by (a) attacking a two-mode discretization of the governing partial differential equations and (b) directly attacking the partial differential equations. The two-mode discretization results in erroneous solutions because it does not account for the effects of the quadratic nonlinearities. The resulting two sets of modulation equations are used to study the equilibrium and dynamic solutions and their stability and hence show the different bifurcations. The response could be a single-mode solution or a two-mode solution. The equilibrium solutions of the two orthogonal third flexural modes undergo a Hopf bifitrcation. A combination ofa shooting technique and Floquet theory is used to calculate limit cycles and their stability. The numerical results indicate the existence of a sequence of period-doubling bifurcations that culminates in chaos, multiple attractors, explosive bifurcations, and crises.
WISE Detections of Dust in the Habitable Zones of Planet-bearing Stars

We use data from the Wide-field Infrared Survey Explorer (WISE) all-sky release to explore the incidence of warm dust in the habitable zones around exoplanet-host stars. Dust emission at 12 and/or 22 microns (T(sub dust) approx.300 and/or approx.150 K) traces events in the terrestrial planet zones; its existence implies replenishment by evaporation of comets or collisions of asteroids, possibly stirred by larger planets. Of the 591 planetary systems (728 extrasolar planets) in the Exoplanet Encyclopedia as of 2012 January 31, 350 are robustly detected by WISE at > or = 5(sigma) level. We perform detailed photosphere subtraction using tools developed for Spitzer data and visually inspect all the WISE images to confirm bona fide point sources. We find nine planet-bearing stars show dust excess emission at 12 and/or 22 microns at > or = 3(sigma) level around young, main-sequence, or evolved giant stars. Overall, our results yield an excess incidence of approx.2.6% for stars of all evolutionary stages, but approx.1% for planetary debris disks around main-sequence stars. Besides recovering previously known warm systems, we identify one new excess candidate around the young star UScoCTIO 108.
A directional gamma-ray telescope using coded aperture techniques

A directional detector for gamma-ray astronomy has been developed to image sources in the energy range 0.1 to 5 MeV. An array of 35 gain stabilized bismuth germanate detectors, together with a coded aperture mask based on a uniformly redundant array allows imaging in 4 deg square sky bins over a 16 x 24 deg field-of-view. The position of a strong point source, such as the Crab Nebula, can be determined to within not more than about 1 deg. A complementary 'anti-mask' greatly reduces systematic effects arising from nonuniform background rates amongst the detectors. The telescope has an effective area of 190 sq cm and an energy resolution of 19.5 percent FWHM at 662 keV. Results of laboratory tests of the imaging system, including the ability to image multiple sources, uniformity of response over the field-of-view, and the effect of the 'anti-mask', are in good agreement with computer simulations. Features of the flight detector system are described and results of laboratory tests and computer simulations are reviewed. A balloon flight of the telescope is planned for the fall of 1982.
Selective Fluorescence Detection of Polycyclic Aromatic Hydrocarbons in Environmental Tobacco Smoke and Other Airborne Particles

Abstract An analytical method is described for the simultaneous quantitation of polycyclic aromatic hydrocarbons [PAHs] and alkyl-derivatives [alkyl-PAHs] in “real world” samples using microbore reversed-phase high performance liquid chromatography in conjunction with two programmable fluorescence detectors. Sensitivity and selectivity were enhanced by analyzing PAHs under their optimum fluorescence wavelengths. The accuracy of the analytical method was evaluated by determination of PAHs in 5 mg of standard reference material SRM 1649. The method was also successfully employed to analyze major parent PAHs and some alkyl-PAHs from environmental tobacco smoke [ETS] with a sample size of 2 mg using class-selective fluorescence wavelengths. Some alkyl-PAHs were tentatively identified even in the absence of standard compounds. Coeluting pairs were identified and analyzed by careful selection of excitation and emission wavelengths for each compound. Identities of the signals were confirmed by comparing both the...
Geometrical Optics Approach to Markov‐Modulated Fluid Models

We analyze asymptotically a differential-difference equation, that arises in a Markov-modulated fluid model. Here, there are N identical sources that turn on and off, and when on they generate fluid at unit rate into a buffer, which processes the fluid at a rate c < N. In the steady-state limit, the joint probability distribution of the buffer content and the number of active sources satisfies a system of N + 1 ODEs, that can also be viewed as a differential-difference equation analogous to a backward/forward parabolic PDE. We use singular perturbation methods to analyze the problem for N → oo, with appropriate scalings of the two state variables. In particular, the ray method and asymptotic matching are used.
Statistical Power for School-Based RCTs With Binary Outcomes

Abstract This article develops a new approach for calculating appropriate sample sizes for school-based randomized control trials (RCTs) with binary outcomes using logit models with and without baseline covariates. The theoretical analysis develops sample size formulas for clustered designs where random assignment is at the school or teacher level using generalized estimating equation methods. The article focuses on the impact parameter pertaining to rates and proportions rather than to the log odds of response, which has been the focus of the previous literature. The article also compiles intraclass correlations (ICCs) for the clustered design for a range of binary outcomes using data from seven education RCTs. These ICCs and the power formulas are then used to conduct a power analysis using a provided SAS macro; the key finding is that sample sizes of 40 to 60 schools that are typically included in clustered RCTs for student test score or behavioral scale outcomes will often be insufficient for binary o...
Cost-efficient dragonfly topology for large-scale systems

Evolving technology and increasing pin-bandwidth motivate the use of high-radix routers to reduce the diameter, latency, and cost of interconnection networks. This migration from low-radix to high-radix routers is demonstrated with the recent introduction of high-radix routers and they are expected to impact networks used in large-scale systems such as multicomputers and data centers. As a result, a scalable and a cost-efficient topology is needed to properly exploit high-radix routers.
Phosphorus‐Carbon Bond Formation: Palladium‐Catalyzed Cross‐Coupling of H‐Phosphinates and Other P(O)H‐Containing Compounds

Two generally applicable systems have been developed for the cross-coupling of P(O)H compounds with Csp2X and related partners. Palladium catalysis using a ligand/additive combination, typically either xantphos/ethylene glycol or 1,1′-bis(diphenylphosphino)ferrocene/1,2-dimethoxyethane, with diisopropylethylamine as the base, proved to be generally useful for the synthesis of numerous PC containing compounds. Routinely, 2 mol% of catalyst are employed (less than half the amount typically employed in most other literature reports). In most cases, excellent results are obtained with a variety of electrophiles (RX, where R=alkenyl, allyl, alkynyl, etc.). The full account of our studies is disclosed, including tandem hydrophosphinylation/coupling and coupling/coupling for doubly catalytic phosphorus-carbon bond formation. The methodology compares favorably with any existing literature report. The use of an additive appears to be a generally useful strategy to control the reactivity of phosphinylidene compounds.
Information Production, Insider Trading, and the Role of Managerial Compensation

We analyze the information production decision of a manager who can trade on this information and whose compensation is increasing in the stock price. The amount of information produced increases with the stock's volatility and liquidity and decreases with the manager's pay-performance sensitivity. Insider trading regulations that symmetrically inhibit the manager's ability to buy and sell stock cause her to produce less information. But asymmetric insider trading regulations like the short sales prohibition have an ambiguous effect inducing her to produce more or less information depending on her pay-performance sensitivity. This contradicts the standard argument made by opponents of insider trading regulations that such regulations always reduce information production.
Visible light carrier generation in co-doped epitaxial titanate films

Perovskite titanates such as SrTiO3 (STO) exhibit a wide range of important functional properties, including ferroelectricity and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications; however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr, we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr3+ dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to 2.4–2.7 eV depending on doping levels. Transient reflectance spectroscopy measurements are in agreement with the observations from ellipsometry and confirm that optically generated carriers...
The Outcome of Patients with Nephrogenic Systemic Fibrosis after Successful Kidney Transplantation

Nephrogenic systemic fibrosis (NSF) is a debilitating disease in patients with severely diminished kidney function. Currently, no standard treatment exists but improvement has been reported after restoration of kidney function. We retrospectively studied 17 NSF patients with and without successful kidney transplantation (KTx) to evaluate the effects of KTx on NSF. Nine of the 11 KTx developed NSF pretransplant whereas two developed NSF immediately after KTx with delayed graft function. Two of the six dialysis patients had previous failed kidney transplants. Age and sex were well matched. All but one patient was dialysis dependent at the time of NSF. Median follow-up was 35 months for KTx patients and 9 months for dialysis patients. Kidney transplants achieved adequate renal function with median serum creatinine of 1.4 (0.9–2.8) mg/dL and a glomerular filtration rate of 42 (19–60) mL/min/1.73 m2. NSF improved in 54.6% of the transplanted patients and 50% of the nontransplanted patients (p = 0.86). Two KTx patients had complete resolution of their symptoms whereas four had partial improvement. Improvement in the dialysis patients was all partial. Successful KTx did not insure improvement in NSF and in fact appeared to have no significant benefit over dialysis.
Analysis of hydrogen depletion using a scaled passive autocatalytic recombiner

Hydrogen depletion tests of a scaled passive autocatalytic recombiner (PAR) were performed in the Surtsey test vessel Germany) at Sandia National Laboratories (SNL). The experiments were used to determine the hydrogen depletion rate of a PAR in the presence of steam and also to evaluate the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.
The use of sonochemistry in the asymmetric epoxidation of substituted chalcones with sodium perborate tetrahydrate

Abstract The synthesis of optically pure compounds in a safe and efficient manner is an increasingly important area of organic chemistry. Enantioselectivity in the oxidation of substituted chalcones is induced by the use of a polyamino acid catalyst. By employing sodium perborate tetrahydrate as an oxidizing agent and an ultrasonic reaction vessel, reaction times and conditions are improved from those obtained conventionally.
Application of the 2,3-sigmatropic rearrangement of β-sulfonyl acetylenic carbinols toward the synthesis of 1,4-bis(phenylsulfonyl)-1,3-butadienes

Abstract Sulfenic esters of β-sulfur substituted acetylenic carbinols undergo 2,3-sigmatropic rearrangement to produce allenylic sulfoxides which were converted to 1,4-bis(phenylsulfonyl)-1,3-dienes or α,β-unsaturated ketones.
Exceptional collections and D-branes probing toric singularities

We demonstrate that a strongly exceptional collection on a singular toric surface can be used to derive the gauge theory on a stack of D3-branes probing the Calabi-Yau singularity caused by the surface shrinking to zero size. A strongly exceptional collection, i.e., an ordered set of sheaves satisfying special mapping properties, gives a convenient basis of D-branes. We find such collections and analyze the gauge theories for weighted projective spaces, and many of the Yp,q and Lp,q,r spaces. In particular, we prove the strong exceptionality for all p in the Yp,p−1 case, and similarly for the Yp,p−2r case.
Electoral turnout and income redistribution by the state: A cross-national analysis of the developed democracies

. This article explores the sources of variation in state redistribution across 13 developed democracies over the period 1979–2000, drawing upon data from the International Institute for Democracy and Electoral Assistance, the Luxembourg Income Study and the Comparative Study of Electoral Systems. The discussion begins with the median voter hypothesis, which predicts that the extent of state redistribution in a country will be positively related to the degree of pre-government inequality. In seeking to extend the median voter approach, the article takes into account two additional variables: the level of electoral turnout and the degree to which turnout is skewed by income. The analysis confirms that pre-government inequality is indeed positively related to state redistribution. However, the predictive power of the median voter approach is significantly improved when account is taken of the level of electoral turnout and the extent to which the turnout rate reflects an income skew – variables that are themselves related. The link between turnout and redistribution is especially strong for social transfers as opposed to taxes, and for the lower and middle, as opposed to the upper, part of the income spectrum.
ESTIMATION OF A CHANGE POINT IN MULTIPLE REGRESSION MODELS

This paper studies the least squares estimation of a change point in multiple regressions. Consistency, rate of convergence, and asymptotic distributions are obtained. The model allows for lagged dependent variables and trending regressors. The error process can be dependent and heteroskedastic. For nonstationary regressors or disturbances, the asymptotic distribution is shown to be skewed. The analytical density function and the cumulative distribution function for the general skewed distribution are derived. The analysis applies to both pure and partial changes. The method is used to analyze the response of market interest rates to discount rate changes.
Recursive Robust PCA or Recursive Sparse Recovery in Large but Structured Noise

This paper studies the recursive robust principal components analysis problem. If the outlier is the signal-of-interest, this problem can be interpreted as one of recursively recovering a time sequence of sparse vectors, St, in the presence of large but structured noise, Lt. The structure that we assume on Lt is that Lt is dense and lies in a low-dimensional subspace that is either fixed or changes slowly enough. A key application where this problem occurs is in video surveillance where the goal is to separate a slowly changing background (Lt) from moving foreground objects (St) on-the-fly. To solve the above problem, in recent work, we introduced a novel solution called recursive projected CS (ReProCS). In this paper, we develop a simple modification of the original ReProCS idea and analyze it. This modification assumes knowledge of a subspace change model on the Lt's. Under mild assumptions and a denseness assumption on the unestimated part of the subspace of Lt at various times, we show that, with high probability, the proposed approach can exactly recover the support set of St at all times, and the reconstruction errors of both St and Lt are upper bounded by a time-invariant and small value. In simulation experiments, we observe that the last assumption holds as long as there is some support change of St every few frames.
Dysphagia in systemic disease

Dysphagia, difficulty in swallowing sometimes accompanied by a sensation of food sticking, is a common symptom resulting from structural and/or motility disorders of the oropharynx and esophagus which may result from local factors or occur as one of the manifestations of a systemic disease process. In this review, “systemic disease” will include diseases that affect more than one organ or organ system in the body such as scleroderma or Crohn's disease; skin disorders such as epidermolysis bullosa dystrophica and benign mucosal pemphigoid; hematological disorders such as amyloid and iron-deficiency anemia; connective tissue disorders such as rheumatoid arthritis, dermatomyositis, polymyositis, and mixed connective tissue disorder; metabolic and endocrine disorders such as diabetes mellitus, sarcoidosis, and the Eaton-Lambert syndrome; and the immune-compromised host, and finally medications will all be addressed. The discussion will specificallyexclude diseases that produce dysphagia by local inflammation (such as erosive esophagitis due to gastroesophageal reflux) or local infiltration (such as pharyngeal or esophageal carcinoma). Similarly, diseases which affect specific areas of the brain (such as a cerebrovascular accident or brain tumor) will be excluded as will neuromuscular diseases such as myasthenia gravis and amyotrophic lateral sclerosis.
Use of random copolymers to determine the helix-coil stability constants of the naturally occurring amino acids

Abstract Short-range interactions dominate in determining the conformational preferences of the amino acid residues in proteins, and a variety of procedures (based on this concept) have been developed to predict the conformational states of the residues of a protein molecule. This paper is concerned with two such conformational states, helical and non-helical (or coil) states; the relative preferences of each of the twenty naturally occurring amino acids for these two states can be expressed in terms of the Zimm-Bragg parameters s and σ. In principle, these parameters can be determined from experimental studies of the thermally-induced helix-coil transition in homopolymers of amino acids in water. However, since most homopolyamino acids are insoluble in water, or are not helical, or (if helical) do not melt between 0 and 100°C in water, resort is had to the host-guest technique in which a random copolymer of a water-soluble host residue and a small amount of a guest residue is prepared. Using the helix-coil transition curves of such a copolymer, and the values of s and σ for the host homopolymer, it is possible to compute the values of s and σ over the temperature range of 0 – 70°C for the guest residue which is, in turn, each of the twenty naturally occurring amino acids. In most cases, the random copolymers are prepared from their N-carboxyan-hydrides, using suitable blocking groups to protect otherwise-reactive side-chain functional groups. The water-soluble copolymers are checked for the absence of racemization, α → β shifts, etc., and for the required degree of randomness. For example, for methionine as a guest residue, cyanogen bromide cleavage of the polymer chain yields a series of oligopeptides which indicates that the methionine was incorporated randomly in the chain. When the resulting values of s and σ are compared to the frequencies of occurrence of helical and non-helical conformations in proteins, a good correlation is obtained in most cases. In those cases where the correlation breaks down, the discrepancy provides information about the influence of specific long-range (e.g., electrostatic) interactions on the helical preferences of the given amino acid residues. The statistical weights deduced from the one-dimensional short-range interaction model are then incorporated with medium- and long-range interactions into a model to try to predict the three-dimensional structures of globular proteins.