cssi/SciSciGPT-SciSciNet huggingface dataset:
Political parties as a commitment technology: effects of term limits on vote share

Building on models of electoral competition with reputational mechanisms, I show that term limits decrease the vote share of candidates from parties less able to reward or punish candidates. Candidates suffer by not being able to credibly commit to policies far from their own preferences. Assuming that the major parties can provide better discipline of their members than third parties, the implication of the model is that third party candidates will be worse off, in terms of vote share garnered, in elections for offices with term limits. The hypothesis that third parties do worse under term limits is tested using state gubernatorial elections. Data from 1977–2008 show the vote share of third party candidates is approximately six percent lower in elections for a term-limited office when controlling for other election characteristics and regional and temporal trends in party popularity
Rheology of concentrated solutions of poly(γ‐benzyl‐glutamate)

Steady shear viscosity, dynamic viscosity, dynamic modulus, and normal force were measured via rotational rheometry for concentrated solutions of racemic mixtures of poly(benzyl-L-glutamate) and poly(benzyl-D-glutamate) in m-cresol. A transition from the isotropic state to liquid–crystalline order with increase in concentration was indicated by optical anisotropy and maxima in all four material functions. This occurred at a critical concentration higher than the Flory prediction. Over a well-defined range of concentrations and shear stresses, some of the liquid–crystalline solutions exhibited negative first normal-stress differences that were not due to inertial effects.
Anomaly of film porosity dependence on deposition rate

This letter reports an anomaly of film porosity dependence on deposition rate during physical vapor deposition – the porosity increases as deposition rate decreases. Using glancing angle deposition of Cu on SiO2 substrate, the authors show that the Cu film consists of well separated nanorods when the deposition rate is 1 nm/s, and that the Cu films consists of a more uniform film when the deposition rate is 6 nm/s; all other deposition conditions remain the same. This anomaly is the result of interplay among substrate non-wetting, density of Cu nuclei on the substrate, and the minimum diameter of nanorods.
Novel, rapid DNA-based on-chip bacterial identification system combining dielectrophoresis and amplification-free fluorescent resonance energy transfer assisted in-situ hybridization (FRET-ISH)

Although real-time PCR (RT-PCR) has become a diagnostic standard for rapid identification of bacterial species, typical methods remain time-intensive due to sample preparation and amplification cycle times. The assay described in this work incorporates on-chip dielectrophoretic capture and concentration of bacterial cells, thermal lysis, cell permeabilization, and nucleic acid denaturation and fluorescence resonance energy transfer assisted in-situ hybridization (FRET-ISH) species identification. Identification is achieved completely on chip in less than thirty minutes from receipt of sample compared to multiple hours required by traditional RT-PCR and its requisite sample preparation.
Tunneling images of a 2D electron system in a quantizing magnetic field

Abstract We have applied a scanning probe method, subsurface charge accumulation imaging, to resolve the local structure of the interior of a semiconductor two-dimensional electron system (2DES) in a tunneling geometry. Near magnetic fields corresponding to integer Landau level filling, submicron scale spatial structure in the out-of-phase component of the tunneling signal becomes visible. In the images presented here, the structure repeats itself when the filling factor is changed from ν =6 to 7. Therefore, we believe the images reflect small modulations in the 2DES density caused by the disorder in the sample.
String theory and quintessence

We discuss the obstacles for defining a set of observable quantities analogous to an S-matrix which are needed to formulate string theory in an accelerating universe. We show that the quintessence models with the equations of state −1 < w < −1/3 have future horizons and may be no better suited to an S-matrix or S-vector description. We also show that in a class of theories with a stable supersymmetric vacuum, a system cannot relax into a zero-energy supersymmetric vacuum while accelerating if the evolution is dominated by a single scalar field with a stable potential. Thus describing an eternally accelerating universe may be a challenge for string theory as presently defined.
The uniqueness of the Practical Salinity Scale (1978): testing the scale with natural seawaters

The scale provides a precisely defined, unambiguous method that is universally applicable to all waters for determining the practical salinity from measurements of conductivity, temperature, and pressure. In the terminology of standards, it is highly desirable to have a scale that is also unique. The authors questioned whether measurements performed on a particular water sample at different temperatures would lead to the same value of practical salinity. They have investigated this problem by examining the behavior of natural seawaters from several oceans and conclude that the PSS provides a unique scale for salinity measurements for these waters within the bounds +or-0.001 in salinity. >
Reconstructions for some coupled-physics inverse problems

Abstract This letter announces and summarizes results obtained in Bal and Uhlmann (2011) [1] and considers several natural extensions. The aforementioned paper proposes a procedure for reconstructing coefficients in a second-order, scalar, elliptic equation from knowledge of a sufficiently large number of its solutions. We present this derivation and extend it to show which parameters may or may not be reconstructed for several hybrid (also called coupled-physics) imaging modalities including photo-acoustic tomography, thermo-acoustic tomography, transient elastography, and magnetic resonance elastography. Stability estimates are also proposed.
Cross-cultural Psychology

This article examines some of the limitations of social psychology and shows how they can be remedied by increased attention to cross‐cultural studies. For example, many of the key constructs of the discipline, such as self, conformity, control, intelligence, and well being, are culture bound. The author proposes directions in theory development and methodology that will incorporate cultural syndromes in social psychological theories. Also, the author gives examples of methodologies that can consider simultaneously attributes of the participants (including their culture), attributes of the actors and targets of action (including their culture), attributes of the setting and context of the study, the prior relationships of the actor and target, and the attributes of the behaviors under examination.
Efficient C−B Bond Formation Promoted by N-Heterocyclic Carbenes: Synthesis of Tertiary and Quaternary B-Substituted Carbons through Metal-Free Catalytic Boron Conjugate Additions to Cyclic and Acyclic α,β-Unsaturated Carbonyls

Metal-free nucleophilic activation of a B−B bond has been exploited in the development of a highly efficient method for conjugate additions of commercially available bis(pinacolato)diboron to cyclic or acyclic α,β-unsaturated carbonyls. The reactions are readily catalyzed by a simple N-heterocyclic carbene (NHC) present at 2.5−10 mol %. A variety of cyclic and acyclic unsaturated ketones and esters can serve as substrates. The transformations deliver β-boryl carbonyls bearing tertiary or quaternary B-substituted carbons in up to >98% yield. Preliminary studies indicate that although related Cu−NHC-catalyzed reactions are equally efficient, the metal-free variant is more functional-group-tolerant; in contrast to the Cu-catalyzed reactions, the metal-free processes proceed readily in the presence of a terminal alkyne and do not promote concomitant diboration of an aldehyde. Representative functionalization of the resulting boron enolates demonstrates the strong influence of the Lewis acidic B atom of the β-...
Synthetic analogues of cysteinate-ligated non-heme iron and non-corrinoid cobalt enzymes

2.7.2. Models Containing Oxygenated Sulfurs 834 2.8. Reactivity Models 835 2.8.1. Models That Bind Inhibitors 836 2.8.2. Models That Bind Hydroxide 837 2.8.3. Models That Bind Nitriles 838 2.8.4. Models That Hydrolyze Nitriles 838 2.8.5. Making Low-Spin Co(III) More Reactive 840 3. Superoxide Reductase (SOR) 840 3.1. Enzyme Function 840 3.2. Active Site Structure and Mechanism 840 3.3. Exogenous Ligand Binding 842 3.4. Biomimetic Models of SOR 843 4. Perspective 845 5. References 846
Algebraic aspects of the fractional quantum Hall effect

Abstract Some algebraic issues of the FQHE are presented. First, it is shown that on the space of Laughlin wavefunctions describing the ν = 1 m FQHE, there is an underlying W∞ algebra, which plays the role of a spectrum generating algebra and expresses the symmetry of the ground state. Its generators are expressed in a second quantized language in terms of fermion and vortex operators. Second, we present the naturally emerging algebraic structure once a general two-body interaction is introduced and discuss some of its properties.
Bilinear quantum Monte Carlo : expectations and energy differences

We propose a bilinear sampling algorithm in the Green's function Monte Carlo for expectation values of operators that do not commute with the Hamiltonian and for differences between eigenvalues of different Hamiltonians. The integral representations of the Schrodinger equations are transformed into two equations whose solution has the formψa(x) t(x, y)ψb(y), where ψa and ψb are the wavefunctions for the two related systems andt(x, y) is a kernel chosen to couplex andy. The Monte Carlo process, with random walkers on the enlarged configuration spacex ⊗y, solves these equations by generating densities whose asymptotic form is the above bilinear distribution. With such a distribution, exact Monte Carlo estimators can be obtained for the expectation values of quantum operators and for energy differences. We present results of these methods applied to several test problems, including a model integral equation, and the hydrogen atom.
Localization and causality for a free particle

Abstract Theorems (most notably by Hegerfeldt) prove that an initially localized particle whose time evolution is determined by a positive Hamiltonian will violate causality. We argue that this apparent paradox is resolved for a positive energy free particle described by either the Dirac equation or the Klein–Gordon equation because such a particle cannot be localized in the sense required by the theorems.
Development of hyperspectral image projectors

We present design concepts for calibrated hyperspectral image projectors (HIP) and related sources intended for system-level testing of instruments ranging from complex hyperspectral or multispectral imagers to simple filter radiometers. HIP, based on the same digital mirror arrays used in commercial digital light processing (DLP) displays, is capable of projecting any combination of many different arbitrarily programmable basis spectra into each pixel of the unit under test (UUT) at video frame rates. The resulting spectral and spatial content of the image entering the UUT can simulate, at typical video frame rates and integration times, realistic scenes to which the UUT will be exposed during use. Also, its spectral radiance can be measured with a calibrated spectroradiometer, such that the hyperspectral photon field entering the UUT is well known. Use of such generated scenes in a controlled laboratory setting would alleviate expensive field testing, allow better separation of environmental effects from instrument effects, and enable system-level performance testing and validation. Example potential applications include system-level testing of complex hyperspectral imaging instruments as implemented with data reduction algorithms when viewing realistic scenes, testing the performance of simple fighter-fighter infrared cameras under simulated adverse conditions, and hardware-in-the-loop testing of multispectral and hyperspectral systems.
The Investment Incentive Effects of Land Use Regulations

This paper provides an overview and synthesis of the results from recent studies of how different types of land use regulations affect land development incentives. The presentation is nontechnical and focuses on uncovering general principles for the dynamic effects of such policies. It explains why the risk of regulation leads to faster development of unregulated land and how the effect on structural densities reflects the underlying pattern of growth in the demand for land by competing uses. It also discusses how the general pattern of timing and density responses for regulated property reflect the same growth patterns in demand.
Gasoline-Like Fuel Effects on High-Load, Boosted HCCI Combustion Employing Negative Valve Overlap Strategy

In recent years a number of studies have demonstrated that boosted operation combined with external EGR is a path forward for expanding the high load limit of homogeneous charge compression ignition (HCCI) operation with the negative valve overlap (NVO) valve strategy. However, the effects of fuel composition with this strategy have not been fully explored. In this study boosted HCCI combustion is investigated in a single-cylinder research engine equipped with direct injection (DI) fueling, cooled external exhaust gas recirculation (EGR), laboratory pressurized intake air, and a fully-variable hydraulic valve actuation (HVA) valve train. Three fuels with significant compositional differences are investigated: regular grade gasoline (RON = 90.2), 30% ethanol-gasoline blend (E30, RON = 100.3), and 24% iso-butanol-gasoline blend (IB24, RON = 96.6). Results include engine loads from 350 to 800 kPa IMEPg for all fuels at three engine speeds 1600, 2000, and 2500 rpm. All operating conditions achieved thermal efficiency (gross indicated efficiency) between 38 and 47%, low NOX emissions ( 0.1 g/kWh), and high combustion efficiency ( 96.5%). Detailed sweeps of intake manifold pressure (atmospheric to 250 kPaa), EGR (0 25% EGR), and injection timing are conducted to identify fuel-specific effects. The major finding of this study is thatmore » while significant fuel compositional differences exist, in boosted HCCI operation only minor changes in operational conditions are required to achieve comparable operation for all fuels. In boosted HCCI operation all fuels were able to achieve matched load-speed operation, whereas in conventional SI operation the fuel-specific knock differences resulted in significant differences in the operable load-speed space. Although all fuels were operable in boosted HCCI, the respective air handling requirements are also discussed, including an analysis of the demanded turbocharger efficiency.« less
Highly Z/E stereoselective approach to β-iodo aza Morita–Baylis–Hillman adducts

A multicomponent reaction between sulfonyl-protected imines, magnesium iodide, and acetylenic esters or ketones is described. The resulting β-iodo aza Morita–Baylis–Hillman adducts were obtained in good yields and excellent Z/E stereoselectivities. The reaction showed good tolerance for sulfonyl protecting groups, as well as for acetylenic ketones and esters. This work presents the first synthetic approach to β-iodo aza Morita–Baylis–Hillman adducts.
Searching for high speed long-lived charged massive particles at the LHC

The conventional way to search for long-lived CHArged Massive Particles (CHAMPs) is to identify slow (small β) tracks using delayed time of flight and high ionization energy loss. But at the 7–14 TeV center of mass energy of the LHC, a CHAMP may be highly boosted (high β) and therefore look more like a minimum ionizing particle, while for high momentum muons (≳500 GeV/c) the radiative effect dominates energy deposition. This suggests a new strategy to search for CHAMPs at the LHC. Using energy deposition from different detector components, we construct a boosted decision tree discriminant to separate high momentum CHAMPs from high momentum muons. This method increases substantially the CHAMP discovery potential and it can be used to distinguish possible di-CHAMP or CHAMP–muon resonance models from di-muon resonance models. We illustrate the new method using a mGMSB model and a recently proposed di-CHAMP model and we give updated CHAMP mass limits for these two models using the results from a recent CDF CHAMP search.
On notions of harmonicity

In this paper we address the equivalence of the analytic and probabilistic notions of harmonicity in the context of general symmetric Hunt processes on locally compact separable metric spaces. Extensions to general symmetric right processes on Lusin spaces, including infinite dimensional spaces, are mentioned at the end of this paper.
Effects of renin-angiotensin system inhibitors on the occurrence of acute kidney injury following off-pump coronary artery bypass grafting

Background: Despite several studies that evaluated the effects of renin-angiotensin system (RAS) inhibitors on postoperative renal function in cardiac surgery patients, no final conclusions are available. The aim of the present study was to determine the effect of RAS inhibitors on renal function following off-pump coronary artery bypass grafting (OPCAB). Methods and Results: Among patients who underwent OPCAB, perioperative characteristics, postoperative renal function and incidence of acute kidney injury (AKI) were compared between those who received RAS inhibitors for at least 2 weeks (RASI group, n=296) and those not treated with RAS inhibitors (Control group, n=176). AKI was defined as an increase in serum creatinine >0.3 mg/dl or >50% from baseline. Preoperative comorbidities were more frequent in the RASI group. Operative data were similar. Incidence of postoperative AKI (19.9% vs 20.9%, P=0.815) and of postoperative renal function was comparable between groups. In the adjusted multivariate logistic regression model for propensity scores between groups, diabetes mellitus, preoperative creatinine level and perioperative transfusion were significant risk factors for postoperative AKI, whereas preoperative treatment with RAS inhibitors did not increase the risk. Conclusions: Chronic preoperative use of RAS inhibitors did not affect postoperative renal function or increase the risk of postoperative AKI in patients undergoing OPCAB. (Circ J 2010; 74: 1852 - 1858)
Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Analysis of a Metal-Poor Stellar Stream

We present the results of a detailed abundance analysis of one of the confirmed building blocks of the Milky Way stellar halo, a kinematically coherent metal-poor stellar stream. We have obtained high-resolution and high signal-to-noise spectra of 12 probable stream members using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory and the 2dCoude spectrograph on the Smith Telescope at McDonald Observatory. We have derived abundances or upper limits for 51 species of 46 elements in each of these stars. The stream members show a range of metallicity (–3.4 < [Fe/H] <–1.5) but are otherwise chemically homogeneous, with the same star-to-star dispersion in [X/Fe] as the rest of the halo. This implies that, in principle, a significant fraction of the Milky Way stellar halo could have formed from accreted systems like the stream. The stream stars show minimal evolution in the α or Fe-group elements over the range of metallicity. This stream is enriched with material produced by the main and weak components of the rapid neutron-capture process and shows no evidence for enrichment by the slow neutron-capture process.
Rearrangements of Cyclobutanes

1 Introduction 2 Thermal Rearrangements of Cyclobutanes 3 Rearrangements of Cyclobutyl-Containing Reactive Intermediates 4 Closing Remarks 5 Acknowledgment Keywords: cyclobutane thermal rearrangements; activation energies for stereomutation; cyclobutane (and related) carbocation chemistry; cyclobutylcarbinyl (and related) systems; rate of ring opening; resonance stabilization; rearrangement and radical-stabilizing substituents on cyclobutane ring; ‘hole catalyzed’ (radical cation) Diels–Alder reaction
Measurement and Model Correlation of Specific Heat Capacity of Water-Based Nanofluids With Silica, Alumina and Copper Oxide Nanoparticles

Nanofluids are being considered for heat transfer applications. However, their thermo-physical properties are poorly known. Here we focus on nanofluid specific heat capacity. Currently, there exist two models to predict a nanofluid’s specific heat capacity as a function of nanoparticle concentration and material. Model I is a straight volume-weighted average; Model II is based on the assumption of thermal equilibrium between the particles and the surrounding fluid. These two models give significantly different predictions for a given system. Using differential scanning calorimetry, the specific heat capacities of water based silica, alumina, and copper oxide nanofluids were measured. Nanoparticle concentrations were varied between 5wt% and 50wt%. Test results were found to be in excellent agreement with Model II, while the predictions of Model I deviate very significantly from the data.
The M.I.T. Blowdown Compressor Facility

A blowdown compressor test facility has been developed which allows time-resolved aerodynamic testing of full-scale transonic compressor rotors at low cost. The rotor is brought to speed in vacuum, a diaphragm is opened, and the test gas is allowed to flow for a time of the order of 0.1 sec, during which the rotor is driven by its own inertia. Both 'steady-state' performance evaluation and detailed time resolution of the flow on the blade-passing time scale have been demonstrated for a two-ft-diam transonic rotor with a tangential Mach number of 1.2 and a nominal pressure ratio of 1.6. The steady-state performance as determined in the experiments includes an efficiency of 0.92 and a pressure ratio of 1.55 at design speed. The time-resolved measurements include the combination tone structure in the upstream flow field, resolved both axially and radially, and the wake structure downstream of the rotor, also resolved both radially and axially.
Wind-driven gas networks and star formation in galaxies: Reaction-advection hydrodynamic simulations

The effects of wind-driven star formation feedback on the spatio-temporal organization of stars and gas in galaxies is studied using two-dimensional intermediate-representational quasi-hydrodynamical simulations. The model retains only a reduced subset of the physics, including mass and momentum conservation, fully non-linear fluid advection, inelastic macroscopic interactions, threshold star formation, and momentum forcing by winds from young star clusters on the surrounding gas. Expanding shells of swept-up gas evolve through the action of fluid advection to form a ‘turbulent’ network of interacting shell fragments which have the overall appearance of a web of filaments (in two dimensions). A new star cluster is formed whenever the column density through a filament exceeds a critical threshold based on the gravitational instability criterion for an expanding shell, which then generates a new expanding shell after some time delay. A filament-finding algorithm is developed to locate the potential sites of new star formation. The major result is the dominance of multiple interactions between advectively distorted shells in controlling the gas and star morphology, gas velocity distribution and mass spectrum of high mass density peaks, and the global star formation history. The gas morphology strongly resembles the model envisioned by Norman & Silk, and observations of gas in the Large Magellanic Cloud (LMC) and local molecular clouds. The dependence of the frequency distribution of present-to-past average global star formation rate on a number of parameters is investigated. Bursts of star formation only occur when the time-averaged star formation rate per unit area is low, or the system is small. Percolation does not play a role. The broad distribution observed in late-type galaxies can be understood as a result of either small size or small metallicity, resulting in larger shell column densities required for gravitational instability. The star formation rate increases with density, but dependences on gas velocity dispersion and average shell column density suggest that the dependence is multivariate. The distribution of gas velocities exhibits exponential tails over a broad range of parameter values and the velocity distribution for gas in filaments is nearly exponential. Decay simulations with no star formation suggest that the exponential tails are caused by multiple shell interactions, not individual stellar winds. The cloud mass spectra, estimated using a simplified version of the structure tree method, tend to be power laws at the higher-mass end, with an index that is nearly independent of the star formation activity or model parameters. Kinetic energy decay in simulations without star formation yields a t−1 dependence. We discuss how the simulations can be viewed in the context of various incomplete conceptual models, including collisional cloud coalescence, wind-driven turbulence, propagating star formation, forced mass-conserving Burgers turbulence, and granular fluids.
First-year maternal employment and child outcomes: Differences across racial and ethnic groups ☆

Abstract We use data from the Fragile Families and Child Wellbeing Study to examine associations between first-year maternal employment and child outcomes for 3-year-old White, Black, and Hispanic children ( N = 1483). Results from OLS regressions and propensity score matching models indicate that first-year maternal employment is associated with lower vocabulary scores for White, but not Black or Hispanic, children and with elevated levels of behavior problems for Hispanic, but not White or Black, children. Factors such as type of child care, maternal depressive symptoms and stress, and parenting behaviors (including measures of discipline, nurturance, and provision of cognitively stimulating materials) do not mediate these associations between first-year maternal employment and children's outcomes or explain the differential associations across racial and ethnic groups, suggesting the need to look at other explanations for these associations, as well as the need for better measurement of parenting, especially mother–child interaction.
DOPAMINE AND THE PHARMACOLOGY OF SCHIZOPHRENIA: THE STATE OF THE EVIDENCE

Publisher Summary This chapter discusses the connection between dopamine and schizophrenia. The evidence connecting dopamine transmission with schizophrenia comes primarily from three areas of research, namely, the blocking effects of antipsychotic drugs on amphetamine- and apomorphine-induced stereotyped behavior, the approximate equality of potency of d - and l -amphetaminein eliciting psychosis, and the ability of the antipsychotics to enhance brain dopamine turnover. It is true, in a general way, that tranquilizing drugs block amphetamine- and apomorphine-induced stereotyped behavior. Thiethylperazine is a phenothiazine used in the treatment of motion sickness but regarded as without antipsychotic effects the relative potency of d -amphetamine as compared with the l -form is 1–3 to 1. The similarity of the effects of the stereoisomers in man would constitute intriguing evidence for the involvement of a dopaminergic system, at least in amphetamine psychosis, and perhaps also in schizophrenia. Conceivably, there are regional differences in the effect of phenothiazines on dopamine receptors so that thioridazine might have a large effect on limbic dopamine endings but a small effect in the caudate.
Distributed convergence to Nash equilibria in two-network zero-sum games

This paper considers a class of strategic scenarios in which two networks of agents have opposing objectives with regard to the optimization of a common objective function. In the resulting zero-sum game, individual agents collaborate with neighbors in their respective network and have only partial knowledge of the state of the agents in the other network. For the case when the interaction topology of each network is undirected, we synthesize a distributed saddle-point strategy and establish its convergence to the Nash equilibrium for the class of strictly concave-convex and locally Lipschitz objective functions. We also show that this dynamics does not converge in general if the topologies are directed. This justifies the introduction, in the directed case, of a generalization of this distributed dynamics which we show converges to the Nash equilibrium for the class of strictly concave-convex differentiable functions with globally Lipschitz gradients. The technical approach combines tools from algebraic graph theory, nonsmooth analysis, set-valued dynamical systems, and game theory.
Generalized approach from sugars to enantiomerically pure tetra-C-substituted carbocycles

Abstract A set of cis -dienophiles ( 2, 6, 9 ) derived from D - or L -arabinose reacts with high yield and stereospecificity to give enantiomerically pure 5,6-disubstituted norbornenes.
Accurate Molecular and Soot Infrared Radiation Model for High-Temperature Flows

The accurate computation of infrared spectral radiation from high-temperature, nonequilibrium flows remains a challenging problem, particularly for polyatomic species and particulates. A versatile computer model for calculating the infrared radiation of water and carbon dioxide and soot in generic flowfields is proposed and examined. Molecular radiation is calculated using the high-resolution transmission absorption molecular database/ high-temperature spectroscopic absorption parameters and carbon dioxide spectroscopic databank-1000 line-by-line databases to provide high-resolution, accurate spectra between 200 and 8200 cm -1 . Soot particulate radiation is modeled using the first-term approximation of Mie scattering theory, and the pseudogas approximation is used. The program was parallelized in spectral increments to run efficiently on a message-passing interface equipped cluster. Validation was performed against well-documented radiation models such as ATHENA and nonequilibrium air radiation-infrared. Soot radiative properties were validated against measurements made on a sooting diffuse laminar flame, and carbon dioxide spectra were validated against experimental data. The computer radiation model is applied to two situations: a nonequilibrium bow shock and an Atlas-like sooting plume.
The impact of legislative change on the behavior of telecommunications carriers

Abstract This article examines the effect of the behavior of carriers on the legal arrangements that regulate them. Using James Buchanan's theory of constitutional contract, the paper shows that weaknesses in US telecommunications law have led carriers to engage in unproductive activities that move them closer to the “state of nature” instead of toward a superior outcome for all parties. This paper focuses on the period before and after the Telecommunications Act of 1996, a law with such a broad scope that there were many ambiguities and contradictions. Affected parties attempted to take advantage of these to design a constitutional contract that would favor them over their rivals. The paper focuses on the interconnection aspects of the law and presents recommendations for reducing unproductive activities.
Automatic recovery of invisible image watermarks from geometrically distorted images

One method of attacking an imbedded invisible watermark is to create a derivative image that is geometrically distorted relative to the original. One attack, developed at Cambridge University, is called 'StirMark.' Image-distorting methods modify images so subtly that the changes are essentially unnoticeable to a viewer. However, their effect on invisible watermarks can be devastating, rendering them unextractable. In this paper, an automated countermeasure to image-distorting attacks will be described. Employing an unmarked copy of the original image as a reference, the possible distortion in a suspect image is first detected by the method, then measured, and finally reversed, producing a restored image approximately geometrically aligned with the original. Using a robust invisible watermarking method presented previously by one of the authors to produce a watermarked image, 'StirMark' to distort the watermarked image, and a copy of the original unmarked image for reference, the restoration method is demonstrated to be sufficient by showing successful extraction of the imbedded watermark from a restored image.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Superplasticity of ceramics

Superplastic elongation of fine-grained ceramics can be observed when some mechanical and microstructural requirements are satisfied at appropriate test conditions, temperature and strain rate. The phenomenon can be utilized in superplastic forming, solid-state bonding, sinter-forging, hot press, and hot-isostatic pressing. Recent advances in ceramic processing brought about superplastic ZrO2 composites, covalent polycrystals, bioceramics, and nanocrystalline materials. Numerous works on superplasticity of ZrO2 ceramics revealed some characteristics, microstructural features, and possible mechanisms. Attempts to achieve high-strain rate superplasticity were performed by modifying the nature of the grain boundary.
Juvenile crime and punishment: evidence from Japan

Over the last decade, juvenile crime has become a serious social problem in Japan. The Juvenile Law was revised in 2001 to impose harsher punishment on juvenile offenders. This revision makes it possible to impose criminal punishment on 14- and 15-year-old criminal offenders, while those offenders aged 16–19 have always faced criminal punishment, both before and after the revision. Using this revision as a natural experiment, this study conducts a difference-in-differences estimation to examine the effect of punishment on juvenile crime. The analysis provides evidence that punishment can deter juvenile crime. In addition, this research examines the criminal behaviour of 13-year-olds, who face no change in punishment, but who soon will in the near future. The results suggest that the revision also had a negative impact on the criminal behaviour of these younger offenders.
A fully parallel algorithm for the symmetric eigenvalue problem

In this paper we present a parallel algorithm for the symmetric algebraic eigenvalue problem. The algorithm is based upon a divide and conquer scheme suggested by Cuppen for computing the eigensystem of a symmetric tridiagonal matrix. We extend this idea to obtain a parallel algorithm that retains a number of active parallel processes that is greater than or equal to the initial number throughout the course of the computation. We give a new deflation technique which together with a robust root finding technique will assure computation of an eigensystem to full accuracy in the residuals and in the orthogonality of eigenvectors. A brief analysis of the numerical properties and sensitivity to round off error is presented to indicate where numerical difficulties may occur. The algorithm is able to exploit parallelism at all levels of the computation and is well suited to a variety of architectures.Computational results are presented for several machines. These results are very encouraging with respect to both...
Approximation Algorithms for Fragmenting a Graph Against a Stochastically-Located Threat

Motivated by issues in allocating limited preventative resources to protect a landscape against the spread of a wildfire from a stochastic ignition point, we give approximation algorithms for a new family of stochastic optimization problems. We study several models in which we are given a graph with edge costs and node values, a budget, and a probabilistic distribution over ignition nodes: the goal is to find a budget-limited set of edges whose removal protects the largest expected value from being reachable from a stochastic ignition node. In particular, 2-stage stochastic models capture the tradeoffs between preventative treatment and real-time response. The resulting stochastic cut problems are interesting in their own right, and capture a number of related interdiction problems, both in the domain of computational sustainability, and beyond. In trees, even the deterministic problem is (weakly) NP hard: we give a Polynomial-time approximation scheme for the single-stage stochastic case in trees when the number of scenarios is constant. For the 2-stage stochastic model in trees we give a ( 1 ? 1 e ) < ( 1 ? ( 1 ? 1 / 2 ? ) 2 ? ) $(1-\frac {1}{e})<(1-(1-1/2\delta )^{2\delta })$ -approximation in trees which violates the budget by a factor of at most 2 (? is the tree diameter), and a 0.387-approximation that is budget-balanced. For the single-stage stochastic case in trees we can save (1? (1 ? 1/?) ?) OPT without violating the budget. Single-stage results extend to general graphs with an additional O(log n) loss in budget-balancedness. Multistage results have a similar extension when the number of scenarios is constant. In an extension of the single-stage model where both ignition and spread are stochastic we give a ( 1 ? 1 e ) $(1-\frac {1}{e})$ -approximation in trees. Our approximation guarantees in trees also hold for multistage and probabilistic-element-failure generalizations of the Maximum Coverage with Knapsack Constraint problem (MCKP).
Synthetic efforts toward cyathane diterpenoid natural products

Covering: 2000 to 2008. Previous review: D. L. Wright and C. R. Whitehead, Org. Prep. Proced. Int., 2000, 32, 309–330
Terrorism and fertility: evidence for a causal influence of terrorism on fertility

Using a panel data set of 170 countries and terrorism data from 1970 to 2007, we 10 find that terrorist attacks decrease fertility as measured by both total fertility rates and crude birth rates. Furthermore, by using a novel instrumental variable approach, we identify a causal link and address endogeneity concerns related to the possibility of stress, caused by rising birth rates or transitioning demographics, affecting terrorism. We find that on average, terrorist attacks decrease fertility, 15 reducing both the expected number of children a woman has over her lifetime and the number of live births occurring during each year. The results are statistically significant and robust across a multitude of model specifications, varying measures of fertility, and differing measures of terrorism.
Convenient preparations of t-butyl esters and ethers from t-butanol

Abstract A one-pot preparation of t-butyl esters and ethers is described that proceeds from the carboxylic acid or alcohol and t-butanol using only anhydrous magnesium sulfate and catalytic sulfuric acid as additional reagents. The method affords t-butyl esters and ethers in good yields and is applicable to a variety of substrates.
Demosaicking as a bilateral filtering process

Digital Still Color Cameras sample the visible spectrum using an array of color filters overlaid on a CCD such that each pixel samples only one color band. The resulting mosaic of color samples is processed to produce a high resolution color image such that a value of a color band not sampled at a certain location is estimated from its neighbors. This is often referred to as 'demosaicking.' In this paper, we approach the process of demosaicking as a bilateral filtering process which is a combination of spatial domain filtering and filtering based on similarity measures. Bilateral filtering smooths images while preserving edges by means of nonlinear combinations of neighboring image pixel values. A bilateral filter can enforce similarity metrics (such as squared error or error in the CIELAB space) between neighbors while performing the typical filtering operations. We have implemented a variety of kernel combinations while performing demosaicking. This approach provides us with a means to denoise, sharpen and demosaic the image simultaneously. We thus have the ability to represent demosaicking algorithms as spatial convolutions. The proposed method along with a variety of existing demosaicking strategies are run on synthetic images and real-world images for comparative purposes.
The first Dirichlet eigenvalue of a compact manifold and the Yang conjecture

We give a new estimate on the lower bound of the first Dirichlet eigenvalue of a compact Riemannian manifold with negative lower bound of Ricci curvature and provide a solution for a conjecture of H. C. Yang. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Intrinsic Absorption Properties in Active Galaxies Observed with the Far Ultraviolet Spectroscopic Explorer

In a continuing survey of active galactic nuclei observed by the Far Ultraviolet Spectroscopic Explorer, we provide a deeper analysis of intrinsic absorption features found in 35 objects. Our survey is for low-redshift and moderate-luminosity objects, mostly Seyfert galaxies. We find a strong correlation between maximum radial velocity and luminosity. We also examine the relationships between equivalent width (EW), full width at half maximum, velocity, and continuum flux. The correlation between velocity and luminosity has been explored previously by Laor & Brandt, but at a significantly higher redshift and heavily weighted by broad absorption line quasars. We also have examined each object with multiple observations for variability in each of the aforementioned quantities, and have characterized the variation of EW with the continuum flux. In our survey, we find that variability of O VI λλ1032, 1038 is less common than of the UV doublets of C IV and N V seen at longer wavelengths, because the O VI absorption is usually saturated. Lyman β absorption variability is more frequent. In a target-by-target examination we find that broad absorption line and narrow absorption line absorbers are related in terms of maximum outflow velocity and luminosity, and both can be exhibited in similar luminosity objects. We also find one object that shows radial velocity change, seven objects that show equivalent width variability, and two objects that show either transverse velocity changes or a change in ionization.
Multifrequency Studies of Bright Radio Supernova Remnants. III. X-Ray and Radio Observations of 3C 397

Radio-bright, presumably young supernova remnants offer the opportunity of studying strong-shock physics and the nature of the interaction of ejected material with the surrounding medium. The relation between radio and X-ray morphology varies considerably among supernova remnants, with important implications for the physics of the emission processes at different wavelengths. We use Very Large Array (VLA) and Roentgen Satellite (ROSAT) images of the radio-bright supernova remnant 3C 397 (G41.1-0.3) to examine the shock structure in both thermal X-ray emission and nonthermal radio emission. The unusual rectangular morphology can be seen in VLA maps at 20 and 6 cm wavelength at a resolution of 6'' and in ROSAT HRI images. The X-ray images resemble the radio strongly, except for a small, possibly unresolved X-ray hot spot near the center. There is no variation in the X-ray hardness ratio from ROSAT Position Sensitive Proportional Counter data across the remnant, suggesting that at least between 0.4 and 2 keV the interior emission is not different in character from that in the bright shell regions. The remnant is unpolarized at 20 cm and has a mean fractional polarization of 1.5% ± 0.1% at 6 cm. The polarized flux, and polarized fraction, peak inside the remnant at a location not coincident with either an internal maximum in total-intensity radio emission or with the X-ray hot spot. Spectral index maps between 6 and 20 cm do not show any systematic differences associated with interior emission; there appears to be no "plerionic" or pulsar-driven component in 3C 397, at least as normally characterized by high polarization and a flat radio spectrum. Spectral index values spread about the mean by about Δα ~ 0.2, a result consistent with previous work. The steep total-intensity profile off the southwest edge of 3C 397 allows an inference of the upstream electron diffusion coefficient and implies a mean free path for electron scattering shorter than in the general interstellar medium but longer than that similarly inferred for Tycho and SN 1006. A simple analysis based on the observed X-ray flux gives an estimate of the mean density in 3C 397 of about 4 cm-3, which would also be enough to depolarize the 20 cm emission completely, as observed. The remnant age is then of order 103 yr, and the current shock velocity is about 1600 km s-1. Finally, we speculate on possible mechanisms producing the X-ray hot spot.
Breakdown of dimensional regularization in the Sudakov problem

Abstract An explicit example is presented (a one-loop triangle graph) where dimensional regularization fails to regulate the infra-red singularities that emerge at intermediate steps of studying large- Q 2 Sudakov factorization. The mathematical nature of the phenomenon is explained within the framework of the theory of the As-operation.
Hydrocarbon Separations in Metal–Organic Frameworks

New materials capable of separating mixtures of saturated, unsaturated, and aromatic hydrocarbons can enable more efficient industrial processes and cleaner energy. Outstanding challenges in hydrocarbon separations stem from the similar structures, properties, and reactivities of the molecules comprising many of these mixtures. With high surface areas, tunable pore geometries, and adjustable surface functionality, metal–organic frameworks hold tremendous promise for effecting previously difficult or impossible separations. In this review, we provide a comprehensive account of the metal–organic frameworks that have been investigated for hydrocarbon separations within the context of their potential relevance for separating various industrial alkane-, alkene-, and aromatic-containing mixtures.
Masking-level differences and the form of the psychometric function

Functions showing the relation between-the detectability and the energy of a signal were determined for various interaural phase conditions. The empirical relation between d′ and signal energy E is approximately d′=m(E/N0)k where m and k are constants for a particular function. The data show that k is fairly constant for a particular O and that m depends upon the interaural condition. That is, the various psychometrie functions for a given O all had the same form, independent of location. Therefore, the magnitude of the MLD=(10/k)log(mi/mr), where mi is the constant for condition i, and mr corresponds to a reference condition. Consequently, an MLD is relatively independent of the level of performance that is chosen for the determination of that MLD.
LARGE TRUCKS IN THE UNITED STATES: SIZE AND WEIGHT REGULATIONS

This paper reviews the major changes which have occurred in the trucking industry in the United States, particularly in relation to truck size and weight. It briefly reviews the regulatory environment prior to the establishment of new Federal size and weight limits in 1982. It then outlines current length, width and weight restrictions related to the operation of large trucks, and discusses some of the effects of these regulations. Unresolved issues and on‐going or planned studies aimed at resolving some of these issues are addressed. A set of principles for idealized truck size and weight regulations are postulated.
A Major Discovery of Malthus Manuscripts

A substantial collection of Malthus manuscripts has recently been discovered at Ryde (Isle of Wight), in the home of Robert Malthus (1881–1972), the great-grandson of Malthus' brother. Discoveries of other Malthus documents, notably his travel diaries, had been made at Ryde in the early 1960s in response to the enquiries of G.F. McCleary and Patricia James, but this new material was apparently overlooked by Robert Malthus at that time.