cssi/SciSciGPT-SciSciNet huggingface dataset:
Seti and serendipity

Abstract The serendipitous detection of an ETI signal during the course of regularly scheduled radio astronomical observations has been an intriguing possibility for the past two decades. For some, this has been enough. For others, unsatisfied with such a passive approach, it has been enough to attempt detection through unconventional applications of radio astronomical instrumentation. Had detections occurred during such searches, they too would have been serendipitous to the development of the field of radio astronomy. For still others, use of equipment intended for the detection of weak, noise-like signals from astrophysical sources has not been enough. SETI-specific instrumentation having unique capabilities for the efficient detection of a moderately broad range of artificial signals has been designed and partially constructed. As a result, it is now possible to consider what serendipitous discoveries of an astrophysical nature might result from the use of this equipment in regularly scheduled SETI observations. The SETI-specific instrumentation will view the Universe through a set of observational filters which have never before been systematically employed by astronomers. In this paper, a particular model of what constitutes a truly new and unique astrophysical phenomenon is used to predict the likelihood of an astrophysically serendipitous discovery during the course of the proposed SETI microwave observing program. Having considered what SETI may do for astronomy, we return to the more traditional approach to serendipity and discuss what a newly designed background software package for the Very Large Array of radiotelescopes can do for SETI. This project is the logical follow-on to the symbiotic use of data contained in stored radio maps from the Westerbork Synthesis Radio Telescope, which was described at the IAA CETI Review Symposium during the 1981 IAF Congress in Rome.
Critical Points and Supersymmetric Vacua, III: String/M Models

A fundamental problem in contemporary string/M theory is to count the number of inequivalent vacua satisfying constraints in a string theory model. This article contains the first rigorous results on the number and distribution of supersymmetric vacua of type IIb string theories compactified on a Calabi-Yau 3-fold X with flux. In particular, complete proofs of the counting formulas in Ashok-Douglas [AD] and Denef-Douglas [DD1] are given, together with van der Corput style remainder estimates. Supersymmetric vacua are critical points of certain holomorphic sections (flux superpotentials) of a line bundle $$\mathcal{L} \to \mathcal{C}$$ over the moduli space of complex structures on X × T 2 with respect to the Weil-Petersson connection. Flux superpotentials form a lattice of full rank in a 2 b 3(X)-dimensional real subspace $$\mathcal{S} \subset H^0(\mathcal{C}, \mathcal{L})$$ . We show that the density of critical points in $$\mathcal{C}$$ for this lattice of sections is well approximated by Gaussian measures of the kind studied in [DSZ1,DSZ2,AD,DD1].
The Properties of High Redshift Galaxies

In recent years, a variety of techniques at optical, near-infrared, sub-mm, and radio wavelengths have opened complementary windows on the high-redshift Universe. Here we review the current understanding of the general properties of the z≳2 galaxies detected in the optical (Lyman-break galaxies) and in the sub-mm (SCUBA sources). We list some of the key questions that need to be answered in order to understand the nature and evolution of the high-redshift galaxies. Wherever possible, we present tentative answers given so far to those questions, in particular on the low-redshift couterparts of the high-redshift galaxies, on the impact of dust obscuration on the observed quantities, and on physical characteristics of the high-z systems as inferred from observations.
TRANSIT PROBABILITIES FOR STARS WITH STELLAR INCLINATION CONSTRAINTS

The probability that an exoplanet transits its host star is high for planets in close orbits, but drops off rapidly for increasing semimajor axes. This makes transit surveys for planets with large semimajor axes orbiting bright stars impractical, since one would need to continuously observe hundreds of stars that are spread out over the entire sky. One way to make such a survey tractable is to constrain the inclination of the stellar rotation axes in advance, and thereby enhance the transit probabilities. We derive transit probabilities for stars with stellar inclination constraints, considering a reasonable range of planetary system inclinations. We find that stellar inclination constraints can improve the transit probability by almost an order of magnitude for habitable-zone planets. When applied to an ensemble of stars, such constraints dramatically lower the number of stars that need to be observed in a targeted transit survey. We also consider multiplanet systems where only one planet has an identified transit and derive the transit probabilities for the second planet assuming a range of mutual planetary inclinations.
Divestment laws, fiduciary duty, and pension fund management: an empirical examination

Purpose – This paper aims to conduct an empirical analysis of subnational laws of the USA that require public pension funds to divest from companies that are in business with Cuba, Iran, Syria, and Sudan and explores whether public fund officials may be in violation of their fiduciary duty responsibilities toward pension system beneficiaries as they execute state-mandated divestment schemes. Design/methodology/approach – A database search was conducted for specific federal laws, presidential executive orders, and departments, offices, and terminology relevant to the topic of the research to explore the extent by which states employ public pension divestment regimes inspired by the federal governments designation of the four countries labeled as state sponsors of terrorism. Quantitative and financial calculations were used to conduct the cost analysis of divestment laws. Findings – Divestment laws are costly for the beneficiaries. In the majority of the states that have divestment laws, the public funds, r...
Dynamical Moving Mirrors and Black Holes

A simple quantum mechanical model of N free scalar fields interacting with a dynamical moving mirror is formulated and shown to be equivalent to two-dimensional dilaton gravity. We derive the semi-classical dynamics of this system, by including the back reaction due to the quantum radiation. We develop a hamiltonian formalism that describes the time evolution as seen by an asymptotic observer, and write a scattering equation that relates the in-falling and out-going modes at low energies. At higher incoming energy flux, however, the semi-classical model appears to become unstable and the mirror seems to accelerate forever along a trajectory that runs off to infinity. This instability provides a useful paradigm for black hole formation and introduces an analogous information paradox. Finally, we indicate a possible mechanism that may restore the stability of the system at the quantum level without destroying quantum coherence.
Academic research and industrial innovation

The purpose of this study is to estimate the extent to which technological innovations in various industries have been based on recent academic research, and the time lags between the investment in recent academic research projects and the industrial utilization of their findings. Because no attempt (to my knowledge) has been made to estimate the social rate of return from academic research, ’ we also make some rough and tentative estimates of this sort. While the results are subject to many limitations discussed below, they should be of interest to public policy-makers concerned with science and technology, as well as to
Electronic Properties of ZnO Varistors: A New Model

Much of the research on ZnO varistors has concentrated on the explanation of their dc current-voltage characteristics. However, varistors also have unusual ac properties which can be technologically important, and must be described by any comprehensive model. In an ideal varistor with identical grain boundaries throughout, there should be no dispersive capacitance at zero bias. In real varistors this capacitance varies considerably with frequency. This dispersion has two causes, charge trapping in the depletion regions and differing grain boundary barriers. Calculations for each process are given. For voltages well below the varistor breakdown value, the low frequency capacitance increases with applied voltage. At even higher voltages the capacitance turns over and becomes negative. All of these effects can be described with a double depletion layer/thermionic emission model. The anomalous capacitance behavior with bias is due to the modulation of the potential barriers by charge trapping at the grain boundaries. In the varistor breakdown regime minority carriers created by impact ionization are important.
Palladium-Catalyzed C3-Benzylation of Indoles

A general method for regioselective C3-benzylation of indoles has been developed. Various 3-substituted indoles and benzyl methyl carbonates with different electronic properties react under mild conditions to afford a diverse range of 3-benzylindolenine products in good yields.
Molecular Breeding of Genes, Pathways and Genomes by Dna Shuffling

Existing methods for optimization of sequences by random mutagenesis generate libraries with a small number of mostly deleterious mutations, resulting in libraries containing a large fraction of non-functional clones that explore only a small part of squence space. Large numbers of clones need to be screened to find the rare mutants with improvements. Library display formats are useful to screen very large libraries but impose screening limitations that limit the value of this approach for most commercial applications. By contrast, in both classical breeding and in DNA shuffling, natural diversity is permutated by homologous recombination, generating libraries of very high quality, from which improved clones can be identified with a small number of complex screens. Given that this small number of screens can be performed under the conditions of actual use of the product, commercially relevant improvements can be reliably obtained.
Taboo Topics Structural Barriers to the Study of Organizational Stigma

Studies of organization stigma have become increasing prominent. Yet these studies are not uncontroversial; structural barriers to the study of organization stigma still exist within the profession...
Uniform convergence in the mapping class group

We characterize convex cocompact subgroups of the mapping class group of a surface in terms of uniform convergence actions on the zero locus of the limit set. We also construct subgroups that act as uniform convergence groups on their limit sets, but are not convex cocompact.
Alternate path routing for multicast

Current network-layer multicast routing protocols build multicast trees based only on hop count and policy. If a tree cannot meet application requirements, the receivers have no alternative. In this paper, we propose a general and modular architecture that integrates alternate path routing with the network's multicast services. This enables individual multicast receivers to reroute a multicast tree according to their needs, subject to policy restrictions. Our design focuses on the two primary components of this architecture - a loop-free path installation protocol and a scalable, distributed path computation algorithm. Based on a simulation study, we demonstrate that using alternate path routing enables receivers to find acceptable paths nearly as well as a link-state protocol, with much lower overhead. We also show that our approach scales to large networks and that performance improves as a multicast group grows in size.
Measurements of discharge coefficients in film cooling

Measurements of discharge coefficients for several film cooling configurations having hole length-to-diameter ratios of 2.3, 4.6, 6.6, and 7.0 are presented. Recently, it was documented that the velocity distributions over the hole exit plane vary significantly with changes in hole length-to-diameter ratio. This paper documents the effects of such variations on coolant discharge coefficients. Due to the short holes, injection in engines is with a substantial amount of coolant departing the upstream portions of the hole exit plane. This results in a higher rate of momentum exchange with the free stream at that location than for longer holes, which permits more uniform exit flows. Discharge coefficient measurements are discussed in terms of this distribution of velocity. This paper also documents the effects of the hole supply plenum geometry on discharge coefficients. When the coolant flow is delivered to the holes with significant momentum either in the direction of the free stream or opposite to that direction, significant changes in discharge coefficient values are observed.
Efficient trading mechanisms with pre-play communication

This paper studies the problem of designing efficient trading mechanisms that are immune to pre-play communication. It is well known that equilibrium behavior can be affected, sometimes drastically, if players have the opportunity to exchange messages prior to playing some particular game. We investigate the relationship between efficiency, pre-play communication, and unique implementation in Bayesian environments with independent types and private values. We identify a class of simple mechanisms which are immune to pre-play communication and show that any incentive efficient allocation can be uniquely implemented by such a mechanism.
Multirate and composite control of two-time-scale discrete-time systems

The design of stabilizing feedback control of singularly perturbed diserete-time systems is decomposed into the design of slow and fast controllers which are combined to form the composite control. Composite control strategies are developed for the case of single rate measurements (all variables are measured at the same rate) as well as for the case of multirate measurements (slow variables are measured at a rate slower than that of fast variables).
Chiral rings, vacua and gaugino condensation of supersymmetric gauge theories

We find the complete chiral ring relations of the supersymmetric U(N) gauge theories with matter in adjoint representation. We demonstrate exact correspondence between the solutions of the chiral ring and the supersymmetric vacua of the gauge theory. The chiral ring determines the expectation values of chiral operators and the low energy gauge group. All the vacua have nonzero gaugino condensation. We study the chiral ring relations obeyed by the gaugino condensate. These relations are generalizations of the formula SN = Λ3N of the pure = 1 gauge theory.
Time resolved measurement of electron temperatures of exploding foil x-ray laser plasmas

Abstract We present results of recent experiments to measure the plasma conditions present in a neon-like x-ray laser plasma. We measure the time-resolved K -shell emission spectra of low Z tracer material doped into a yttrium exploding foil target. We determine the plasma conditions by analysing the K -shell emission spectra assuming a quasi-steady state approximation. Two dimensional LASNEX hydrodynamics simulations are in reasonable agreement with these time-resolved electron temperatures.
Wavelet-based protocols for ion channel electrophysiology

Fluctuation-induced phenomena caused by both random and deterministic stimuli have been previously studied in a variety of contexts. They are based on the interplay between the spectro-temporal patterns of the signal and the kinetics of the system it is applied to. The aim of this study was to develop a method for designing fluctuating inputs into nonlinear system which would elicit the most desired system output and to implement the method to studies of ion channels. We describe an algorithm based on constructing the input as a superposition of wavelets and optimizing it according to a selected cost functional. The algorithm is applied to ion channel electrophysiology where the input is the fluctuating voltage delivered through a patch-clamp experimental apparatus and the output is the whole-cell ionic current. The algorithm is optimized to aid selection of Markov models of the gating kinetics of the voltage-gated Shaker K+ channel and tested by comparison of numerically obtained ionic currents predicted by different models with experimental data obtained from the Shaker K+ channels. Other applications and optimization criteria are also suggested. The method described in this paper can be useful in development and testing of models of ion channel gating kinetics, developing voltage inputs that optimize certain nonequilibrium phenomena in ion channels, such as the kinetic focusing, and potentially has applications to other fields.
Computations of Jet Impingement on a Flat Surface

Abstract : An incompressible, inviscid rotational flow model is used to represent the normal impingement of axisymmetric jets and the oblique impingement of two-dimensional jets upon a flat surface. The Poisson-type equation that results from this formulation is cast into suitable finite difference form and solved by relaxation techniques. Results, in terms of the ground plane pressure distribution, centerline velocity decay, and oblique impingement flow field structure, compare well with observations. (Author)
Growth, Inequality and Simulated Poverty Paths for Tanzania, 1992–2002

Although Tanzania experienced relatively rapid growth in per capita GDP in the 19952001 period, household budget survey (HBS) data show only a modest and statistically insignificant decline in poverty between 1992 and 2001. To assess the likely trajectory of poverty rates over the course of the period, changes in poverty are simulated using unit-record HBS data and national accounts growth rates under varying assumptions for growth rates and inequality changes. To this end the projection approach of Datt and Walker (2002) is used along with an extension that is better suited to taking into account distributional changes observed between the two household surveys. The simulations suggest that following increases in poverty during the economic slowdown of the early 1990s, recent growth in Tanzania has brought a decline in poverty, particularly in urban areas. Unless recent growth is sustained, the country will not meet its 2015 Millennium Development Goal (MDG). Poverty reduction is on track in urban areas, but reaching the MDG target for bringing down poverty in rural areas, where most Tanzanians live, requires sustaining high growth in rural output per capita.
Twisted tachyon condensation in closed string field theory

We consider twisted tachyons on /N orbifolds of bosonic closed string theory. It has been conjectured that these tachyonic instabilities correspond to decays of the orbifolds into flat space or into orbifolds with smaller deficit angles. We examine this conjecture using closed string field theory, with the string field truncated to low-level tachyons. We compute the tachyon potentials for /2 and /3 orbifolds and find critical points at depths that generate about 70% of the expected change in the deficit angle. We find that both twisted fields and untwisted modes localized near the apex of the cone acquire vacuum expectation values and contribute to the potential.
Approaches to the preservation of human granulocytes by freezing

Because of its simplicity, the FDA assay can be used effectively as a screening test to eliminate procedures and treatments that are damaging to cells. In this context, a number of conclusions can be drawn from the data presented: (1) Exposure to 1 and 2 M glycerol at room temperature damages human granulocytes in a few minutes. Reducing the exposure temperature to 0/sup 0/C reduces the amount of injury substantially. (2) Human granulocytes respond to freezing and thawing in a manner typical of many mammalian cells in that they exhibit a maximum in survival at an optimum cooling rate slightly above 1/sup 0/C/min when combined with rapid warming. The use of rapid warming and a high (2 M) concentration of glycerol reduces the dependence of survival on cooling rate by broadening the range of rates over which survival is relatively high. (3) Human granulocytes show some sensitivity to dilution stresses since survival depends somewhat on the concentration of glycerol used and the severity of the dilution procedure. The reasons for the sharp decrease in cell viability following incubation of frozen-thawed granulocytes at 37/sup 0/C are not known. One possibility is that the phosphate buffered saline suspending medium used is notmore » suitable for incubation at 37/sup 0/C. A second possibility is that some cell injury is not expressed at 0/sup 0/C and remains undetected by the FDA assay until the cells are incubated at 37/sup 0/C. There is also the possibility that lysosomal enzymes released by a few damaged cells in a sample will cause additional damage in other cells at 37/sup 0/C.« less
Processing and characterization of multi-layered wear-resistant ceramic coatings

A new concept of a multi-layered ceramic coating consisting of a porcelain enamel bond interlayer with thermal expansion characteristics tailored to match those of a cast iron substrate and a plasma-sprayed wear-resistant surface layer of chromium oxide, chromium carbide, or partially stabilized zirconia was investigated. Flat substrates of grit-blasted and surface-treated cast iron were slurry sprayed with a finely ground glass frit mixed with isopropyl alcohol and water. Subsequently, the specimens were dried in an oven before firing at 1023 K to produce a smooth, dense, and strongly adherent enamel coating 75 to 100 μm thick. Wear-resistant coatings of oxides and carbides with varying particle sizes and powder densities were then thermally sprayed, by means of a plasma spray gun, at controlled power ratings and gas flow rates. The produced ceramic coatings were subsequently ground to a thickness of about 120 μm. Adherence testing by the tensile pull-off technique revealed high interfacial strength between the enamel coating and the substrate resulting from enhanced chemical interdiffusion and mechanical interlocking. Unlubricated sliding wear experiments using a ball-on-flat tribotester and tungsten carbide balls as sliders demonstrated low initial and moderately high steady-state friction coefficients. Optical and scanning electron microscopy and surface profilometry of the tested ceramic-coated specimens verified that surface damage and wear rate were negligibly small. The important role of the main process parameters on the interfacial adherence and uniformity of the enamel and ceramic layers and the potentiality of the developed processes in the deposition of relatively low-friction and wear-resistant multi-layered thick ceramic coatings are discussed in the context of the obtained results.
On block noncoherent communication with low-precision phase quantization at the receiver

We consider communication over the block noncoherent AWGN channel with low-precision Analog-to-Digital Converters (ADCs) at the receiver. For standard uniform Phase Shift Keying (PSK) modulation, we investigate the performance of a receiver architecture that quantizes only the phase of the received signal; this has the advantage of being implementable without automatic gain control, using multiple 1-bit ADCs preceded by analog multipliers. We study the structure of the transition density of the resulting channel model. Several results, based on the symmetry inherent in the channel, are provided to characterize this transition density. A low complexity procedure for computing the channel capacity is obtained using these results. Numerical capacity computations for QPSK show that 8-bin phase quantization of the received signal recovers more than 80–85% of the capacity attained with unquantized observations, while 12-bin phase quantization recovers above 90–95% of the unquantized capacity. Dithering the constellation is shown to improve the performance in the face of drastic quantization.
Synthesis of iodocubanes by decarboxylative iodination

Abstract An efficient method is described for the preparation of iodocubanes from the corresponding carboxylic acids utilizing thiohydroxamic ester methodology with 2,2,2-trifluoroiodoethane as the iodide source.
Clean intermittent catheterization : safe, cost-effective bladder management for male residents of VA nursing homes

OBJECTIVES: To compare the safety and cost of clean versus sterile intermittent bladder catheterization in male nursing home residents. To provide evidence to support the hypothesis that intermittent catheterization is a valid, alternative method of bladder management in male residents of long-term care in whom urinary retention is a documented problem. DESIGN: Randomized clinical trial. SETTING: Three long-term care sites having predominantly male populations. PARTICIPANTS: Eighty male veterans, residents of three long-term care facilities, ranging in age from 36 to 96 years with a mean age of 72. INTERVENTIONS: Standardized procedures for clean and sterile intermittent catheterization (IC) were implemented by staff nurses at each site. Patients were randomized into clean and sterile IC groups. Nursing time and catheterization equipment usage were recorded using bar code readers. Clinical data were collected from the medical chart. Treatment of urinary tract infection was prescribed by the medical personnel responsible for each individual resident. MEASUREMENTS: We compared the number of treatment episodes for symptomatic bacteriuria between groups randomized to receive either clean or sterile intermittent catheterization. Laboratory analysis of blood and urine was done on predetermined days. Control variables were research site and patient history of urinary tract infection within the last 6 months. A cost comparison of nursing time and equipment usage for the two catheterization techniques was also performed. RESULTS: No significant differences were found between clean and sterile groups with regard to number of treatment episodes, time to first infection, type of organism cultured, or cost of antibiotic treatment. The cost of sterile technique was considerably higher both in terms of nursing time and supplies. CONCLUSIONS: Findings from this study demonstrate that clean technique intermittent catheterization is a safe and cost-effective bladder management technique with male, nursing home residents, despite the frailty of this high risk population. An annual savings of approximately $1460 per patient in nursing time and catheterization supplies could be anticipated if a patient were catheterized an average of four times per day substituting clean IC technique for sterile IC technique. J Am Geriatr Soc 43:865–870, 1995.
Large time and small noise asymptotic results for mean reverting diffusion processes with applications

Summary. We use the theory of large deviations to investigate the large time behavior and the small noise asymptotics of random economic processes whose evolutions are governed by mean-reverting stochastic differential equations with (i) constant and (ii) state dependent noise terms. We explicitly show that the probability is exponentially small that the time averages of these process will occupy regions distinct from their stable equilibrium position. We also demonstrate that as the noise parameter decreases, there is an exponential convergence to the stable position. Applications of large deviation techniques and public policy implications of our results for regulators are explored.
Advancing cognitive engineering methods to support user interface design for electronic health records.

Background Despite many decades of research on the effective development of clinical systems in medicine, the adoption of health information technology to improve patient care continues to be slow, especially in ambulatory settings. This applies to dentistry as well, a primary care discipline with approximately 137,000 practitioners in the United States. A critical reason for slow adoption is the poor usability of clinical systems, which makes it difficult for providers to navigate through the information and obtain an integrated view of patient data.
Piecewise uniform vector quantizers

The companding model for quantizer design and analysis has been widely applied in the scalar quantization case. However, if the signal to be quantized is a vector, then the optimum companding system can be designed for only a limited number of distributions. On the other hand, multidimensional piecewise linear companders can be designed for any signal density, generating quantizers that are uniform on each region of the compander. These systems, while not optimal, can have asymptotic performance arbitrarily close to the optimum. Their analysis and implementation can be simpler than those of optimal systems. Piecewise linear companders for asymptotic multidimensional quantization are analyzed, and a method for their design is suggested. >
Experimental investigation of supersonic laminar, two-dimensional boundary-layer separation in a compression corner with and without cooling.

An experimental investigation of the boundary layer separation associated with a compression corner was conducted in the GALCIT Mach 6 wind tunnel, and a supplementary study was performed in the JPL supersonic wind tunnel. Special emphasis was placed on the development of a wind tunnel model which approximated true two-dimensional flow, and which could be run in either a highly cooled or an adiabatic configuration. The basic measurements consist of the model surface pressure and temperature, and Pitot surveys of the boundary layer. The surface pressure distributions for the adiabatic wall configurations are compared with the theory of Lees and Reeves (modified by Klineberg and Lees). The surface pressure distribution for the cold wall was compared with the adiabatic configuration for a laminar interaction, and the dependence on Reynolds number for both laminar and transitional interactions are observed. The "free interaction" similarity suggested by Chapman is empirically tested and found to be a good approximation for the adiabatic configuration, but it fails to correlate the cooled with the adiabatic case. The scaling suggested by Curle was tested and found to eliminate this deficiency.
An efficient, general asymmetric synthesis of carbocyclic nucleosides: Application of an asymmetric aldol/ring-closing metathesis strategy

A general and efficient synthesis of carbocyclic and hexenopyranosyl nucleosides has been developed. The strategy combines three key transformations: an asymmetric aldol addition to establish the relative and absolute configuration of the pseudosugar, a ring-closing metathesis to construct the pseudosugar ring, and a Trost-type palladium(0)-mediated substitution to assemble the pseudosugar and the aromatic base. Carbovir, abacavir, and their 2'-methyl derivatives as well as hexenopyranosyl nucleoside analogues have been prepared by this sequence.
Model of management learning styles as a predictor of export behavior and performance

Abstract This paper reports the findings of a preliminary investigation of the relationships between the export performance and behavior of firms and the search for market information by the principal international marketing executives of these firms. The first part of the study deals with acquiring objective market information, and the second part is concerned with the acquisition of experiential market knowledge. While the findings of the experiential portion are inconclusive, the use of learning theory in this aspect of the work provides direction for future research in this area.
Model studies for the synthesis of the marine hepatotoxin cylindrospermopsin. Preparation of a bicyclic guanidine with the hydroxymethyluracil side chain

Abstract Ketone 13 was prepared by coupling acetylene 7b with aldehyde 9 in a convergent six-step sequence. In the key step, hydrogenation of bromo ketone 14 afforded 81% of an 81:14:4.5:0.5 mixture of 15–18 . Hydrolysis of the major product 15 in concentrated hydrochloric acid at reflux afforded cylindrospermopsin model 5 in 95% yield.
Dependence Potential and Abuse Liability of Nicotine Replacement Therapies

Abstract Some abstinent smokers develop withdrawal symptoms when they stop using nicotine gum or when placebo is substituted; thus, physical dependence on nicotine gum does occur. Some smokers also use nicotine gum beyond the recommended period; thus, behavioral dependence on the gum occurs. Many (7–41 %) smokers misuse nicotine gum by smoking cigarettes and chewing the gum concurrently. Among smokers who stop using the gum, many (35–90 %) do not stop gum use by the recommended 3 months, and a substantial percentage (13–38 %) persist in gum use for 1 year. Among quitters, long-term use of nicotine gum appears to be greater than that of placebo gum. If rapidity of onset and frequency of use are determinants of dependence potential, then nasal sprays and aerosols but not nicotine patches should have dependence potential. There are no reports of misuse of the gum by non-smokers; thus, the gum appears to have little if any abuse liability.
Semidefinite relaxations for stochastic optimal control policies

Recent results in the study of the Hamilton Jacobi Bellman (HJB) equation have led to the discovery of a formulation of the value function as a linear Partial Differential Equation (PDE) for stochastic nonlinear systems with a mild constraint on their disturbances. This has yielded promising directions for research in the planning and control of nonlinear systems. This work proposes a new method obtaining approximate solutions to these linear stochastic optimal control (SOC) problems. A candidate polynomial with variable coefficients is proposed as the solution to the SOC problem. A Sum of Squares (SOS) relaxation is then taken to the partial differential constraints, leading to a hierarchy of semidefinite relaxations with improving sub-optimality gap. The resulting approximate solutions are shown to be guaranteed over- and under-approximations for the optimal value function.
Electronic liquid-crystal phases of a doped Mott insulator

The character of the ground state of an antiferromagnetic insulator is fundamentally altered following addition of even a small amount of charge1. The added charge is concentrated into domain walls across which a π phase shift in the spin correlations of the host material is induced. In two dimensions, these domain walls are ‘stripes’ which can be insulating2,3 or conducting4,5,6 — that is, metallic ‘rivers’ with their own low-energy degrees of freedom. However, in arrays of one-dimensional metals, which occur in materials such as organic conductors7, interactions between stripes typically drive a transition to an insulating ordered charge-density-wave (CDW) state at low temperatures. Here it is shown that such a transition is eliminated if the zero-point energy of transverse stripe fluctuations is sufficiently large compared tothe CDW coupling between stripes. As a consequence, there should exist electronic quantum liquid-crystal phases, which constitute new states of matter, and which can be either high-temperature superconductors or two-dimensional anisotropic ‘metallic’ non-Fermi liquids. Neutron scattering and other experiments in the copper oxide superconductor La1.6−xNd0.4SrxCuO4 already provide evidence for the existence of these phases in at least one class of materials.
Zone methods and the fermion sign problem

Abstract We review a recently proposed approach to the problem of alternating signs for fermionic many body Monte Carlo simulations in finite temperature simulations. We derive an estimate for fermion wandering lengths and introduce the notion of permutation zones, special regions of the lattice where identical fermions may interchange and outside of which they may not. Using successively larger permutation zones, one can extrapolate to obtain thermodynamic observables in regimes where direct simulation is impossible.
Laser bandwidth and other sources of focus blur in lithography

It is well known that the refractive optics used in today's exposure tools are highly chromatic, meaning that small wavelength shifts will cause large focus shifts. Even a line-narrowed excimer laser has a large enough range of wavelengths that we can no longer think of an infinitely thin image plane. The concept of "focus blur" can be generalized to encompass the effect of laser bandwidth chromatic aberrations, vertical stage vibrations, and stage tilts, which cause the focus to change during the scan. We introduce a new parameter called mean absolute defocus that can characterize the focus blur and is shown to correlate with the lithographic effects. Focus blur can be incorporated into simulation models, in a manner similar to the way that stage vibration is modeled. New simulation results illustrate the impact of focus blur on modern lithographic processes. Process stability and machine-to-machine matching issues are discussed.
Agricultural liberalization policy and commodity price volatility: a GARCH application

This study examines the effect of the recent radical agricultural liberalization policy, i.e. the 1996 FAIR Act, on agricultural commodity price volatility using Generalized Autoregressive Conditional Heteroscedasticity (GARCH) models. Results of the study indicate that the agricultural liberalization policy has caused an increase in the price volatility for three major grain commodities (corn, soybeans and wheat) and little change for oats, but a decrease for cotton. These findings stand in sharp contrast to Crain and Lee's observations in 1996 based on wheat markets that market-oriented measures in government farm policies tend to reduce agricultural price volatility.
Two-step solution-phase synthesis of novel quinoxalinones utilizing a UDC (Ugi/de-Boc/cyclize) strategy

Abstract The novel solution-phase synthesis of an array of biologically relevant quinoxalinones in a simple two-step procedure is revealed. Transformations are carried out in excellent yield by condensation of mono-Boc protected ortho-phenylene di-amine, glyoxylic acids and supporting Ugi reagents. Subsequent acid treatment and evaporation affords quinoxalinones in good to excellent yields.
Diffuse TeV emission at the Galactic Centre

ABSTRACT The High-Energy Stereoscopic System (HESS) has detected intense diﬀuse TeVemission correlated with the distribution of molecular gas along the galactic ridgeat the centre of our Galaxy. Earlier HESS observations of this region had alreadyrevealed the presence of several point sources at these energies, one of them (HESSJ1745-290) coincident with the supermassive black hole Sagittarius A*. It is still notentirely clear what the origin of the TeV emission is, nor even whether it is due tohadronic or leptonic interactions. It is reasonable to suppose, however, that at leastfor the diﬀuse emission, the tight correlation of the intensity distribution with themolecular gas indicates a pionic-decay process involving relativistic protons. In thispaper, we explore the possible source(s) of energetic hadrons at the galactic centre,and their propagation through a turbulent medium. We conclude that though Sagit-tarius A* itself may be the source of cosmic rays producing the emission in HESSJ1745-290, it cannot be responsible for the diﬀuse emission farther out. A distribu-tion of point sources, such as pulsar wind nebulae dispersed along the galactic plane,similarly do not produce a TeV emission proﬁle consistent wi th the HESS map. Weconclude that only a relativistic proton distribution accelerated throughout the inter-cloud medium can account for the TeV emission proﬁle measure d with HESS.Keywords: BlackHolePhysics,Cosmic Rays,MagneticFields,Turbulence,Galaxy:Centre
What norms trigger punishment

Many experiments have demonstrated the power of norm enforcement—peer monitoring and punishment—to maintain, or even increase, contributions in social dilemma settings, but little is known about the underlying norms that monitors use to make punishment decisions, either within or across groups. Using a large sample of experimental data, we empirically recover the set of norms used most often by monitors and show first that the decision to punish should be modeled separately from the decision of how much to punish. Second, we show that absolute norms often fit the data better than the group average norm often assumed in related work. Third, we find that different norms seem to influence the decisions about punishing violators inside and outside one’s own group.
Upscaling and Discretization Errors in Reservoir Simulation

Abstract Reservoir simulation models are used as an everyday tool for reservoir management. The number of grid blocks in a simulation model is generally much smaller than the number of the grid blocks in the geological model. The geological model is therefore regularly upscaled for building reasonably sized simulation models. Any upscaling causes a loss in detail and introduces errors. Understanding the nature of the errors that occur due to the upscaling step is important because it can provide a handle on the kind of upscaling to be performed and the optimum level of upscaling. Furthermore, understanding interaction of gridding and upscaling errors is essential for building reliable simulation models. In this article, we analyze errors introduced due to the upscaling step. First, the generality of the purely local single-phase upscaling is considered and the errors introduced due to its use in complex multiphase flows and investigated. Three kinds of errors, namely total upscaling errors, discretization...
Lack of effect of low [Ca2+], La3+, and pyrazinoate on urate transport by isolated, perfused snake renal tubules.

Effects of low medium calcium concentration, of lanthanum, and of pyrazinoate on urate transport by isolated, perfused snake (Thamnophis spp.) distal-proximal renal tubules were studied. Removal of calcium from perfusate with 0.18 mmol/l calcium in bathing medium had no effect on net urate secretion (Juratenet) or on net fluid absorption (Jv). In the presence of calcium (1.8 mmol/l), lanthanum (2.0 mmol/l) in perfusate alone, in bathing medium alone, or in both perfusate and bathing medium had no effect onJuratenet. These findings suggest that urate transport, in contrast to para-aminohippurate (PAH) transport, is not sensitive to calcium entry into the cells and support the concept that urate and PAH are transported by separate mechanisms in these renal tubules. Pyrazinoate (1.0 mmol/l) in the bathing medium had no effect onJuratenet orJv. These findings do not support the idea of a primary urate secretory process uniquely sensitive to pyrazinoate among the vertebrates.
Magnetic properties of the R2Fe12 − xMnxCo2B systems (R ≡ Pr, Nd, Gd)

Abstract Magnetic properties (saturation magnetizations, anisotropy fields and Curie temperatures) of alloys of the composition R2Fe12 − xMnxCo2B with R ≡ Pr, Gd are presented. Both compounds crystallize in the tetragonal Nd2Fe14B structure. On substitution of iron by manganese, the Curie temperatures and saturation moments decrease. The anisotropy field HA is found to increase significantly. Thus a small amount of manganese incorporated into Pr2Fe12Co2B may beneficiate this material for permanent magnet fabrication.
Greenhouse gas abatement: How much? and Who pays?

Two basic questions that arise in international policy debates over greenhouse gas emission reduction are: (1) How much to control? and (2) Who pays? In this paper, we investigate the interdependence between these two issues. We characterize general conditions under which the Pareto-optimal environmental control will depend on the distribution of the cost burden among nations and provide a sufficient condition under which a Pareto optimum can be implemented by a market mechanism with tradable emission permits. However, numerical results suggest that the interdependence may be weak in a hypothetical negotiation between the OECD and the ROW (the rest of the world). The approach can be applied to more realistic cases with multiple regions.
Moments and root-mean-square error of the Bayesian MMSE estimator of classification error in the Gaussian model

The most important aspect of any classifier is its error rate, because this quantifies its predictive capacity. Thus, the accuracy of error estimation is critical. Error estimation is problematic in small-sample classifier design because the error must be estimated using the same data from which the classifier has been designed. Use of prior knowledge, in the form of a prior distribution on an uncertainty class of feature-label distributions to which the true, but unknown, feature-distribution belongs, can facilitate accurate error estimation (in the mean-square sense) in circumstances where accurate completely model-free error estimation is impossible. This paper provides analytic asymptotically exact finite-sample approximations for various performance metrics of the resulting Bayesian Minimum Mean-Square-Error (MMSE) error estimator in the case of linear discriminant analysis (LDA) in the multivariate Gaussian model. These performance metrics include the first, second, and cross moments of the Bayesian MMSE error estimator with the true error of LDA, and therefore, the root-mean-square (RMS) error of the estimator. We lay down the theoretical groundwork for Kolmogorov double-asymptotics in a Bayesian setting, which enables us to derive asymptotic expressions of the desired performance metrics. From these we produce analytic finite-sample approximations and demonstrate their accuracy via numerical examples. Various examples illustrate the behavior of these approximations and their use in determining the necessary sample size to achieve a desired RMS. The Supplementary Material contains derivations for some equations and added figures. HighlightsThe Bayesian Minimum Mean-Square-Error (BMMSE) error estimator of LDA is studied.The first, second, and cross moments of the BMMSE estimator with true error are considered.Both conditional and unconditional performance metrics are analyzed.For the first time, the Kolmogorov double-asymptotic is used in a Bayesian setting.Asymptotically exact finite-sample approximations of performance metrics are derived.
Adding style and behaviour to Web pages with a dash of spice

Abstract Extensions to HTML become simple to handle with a new language from HP that blends style sheets and scripting. Spice is an amalgam of CSS and JavaScript. HP is developing a free browser as a proof of concept for Spice and will be demonstrating this at WWW7 on Developer's Day. HP has submitted Spice to the World Wide Web Consortium, see http://www.w3.org/TR/1998/NOTE-spice-19980123.html
Ethical Web agents

As the Web continues to evolve, the sophistication of the programs that are employed in interacting with it will also increase in sophistication. Web agents, programs acting autonomously on some task, are already present in the form of spiders. Agents offer substantial benefits and hazards, and because of this, their development must involve not only attention to technical details, but also the ethical concerns relating to their resulting impact. These ethical concerns will differ for agents employed in the creation of a service and agents acting on behalf of a specific individual. An ethic is proposed that addresses both of these perspectives. The proposal is predicated on the assumption that agents are a reality on the Web, and that there are no reasonable means of preventing their proliferation.
Far infrared optical properties of selenium and cadmium telluride.

The optical constants of Se and CdTe have been measured in the far ir from 10 cm−1 to 100 cm−1 using Fourier transform spectroscopy. An oscillator model has been fit to the available data for both materials over the entire ir range from 10 cm−1 to 10,000 cm−1. Several three-phonon absorption peaks have been observed and identified in the absorption spectra of Se. The linear optical properties of these important ir materials have been summarized throughout the ir region.