cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and evaluation of 17α-E-20-(heteroaryl)norpregn-1,3,5(10),20 tetraene-3,17β-diols [17α-(heteroaryl)vinyl estradiols] as ligands for the estrogen receptor-α ligand binding domain (ERα-LBD).

Abstract A series of 17α-(heteroaryl)vinyl estradiols was prepared to evaluate the influence of heteroatom on the affinity and efficacy of estrogenic ligands for the estrogen receptor-alpha ligand binding domain (ERα-LBD). The products demonstrated reduced binding affinity compared to the parent 17α-E-phenylvinyl estradiol, but the binding was relatively independent of the heteroatom. The greatest influence of the heteroatom was evident in the efficacy of the compounds as the thienyl derivatives 2f , g were more potent than either the pyridyl 2b – d or pyrimidinyl 2e analogs. The results suggest that a subtle interplay of interactions between the ligands and the receptor influences the biological response.
Transport properties between quantum Hall plateaus

We propose a unified transport theory for the two-dimensional electron gas (2DEG) in the dissipative quantum Hall regime in the presence of a long-range disorder. We find that the evolution of the longitudinal conductivity peaks as a function of the disorder can be described by a single parameter β−1 which is determined by the typical gradient of the electron density fluctuations. In the case of relatively strong disorder we utilize the edge states network model to describe transport in a half-filled Landau level. In the fractional quantum Hall regime we apply the network model to the system of composite fermions finding universal values of the resistivity at even-denominator filling fractions. The breakdown of the network model takes place at weak disorder because the edge channels develop into wide compressible strips and at strong disorder because of the destruction of the incompressible strips, isolating the edge channels. We find the limits of the applicability of the network model in terms of β. In the limit of very weak disorder the system is effectively a Fermi-liquid of composite fermions. We calculate the conductivity in this regime by considering the motion of non-interacting fermions in a spatially varying magnetic field arising from the density fluctuations. The resistivity is found to scale linearly with the magnetic field with the slope given by β−1. Although the presence of the non-local transport makes measurements of the resistivity difficult, we find qualitative and in some cases quantitative agreement with experiment.
COMPUTATIONAL STUDY OF KNI-272, A POTENT INHIBITOR OF HIV-1 PROTEASE : ON THE MECHANISM OF PREORGANIZATION

The compound KNI-272 is a potent, peptide-like inhibitor of HIV protease. Its conformation when complexed with the protease is close to that which it assumes in its single-molecule crystal. This observation led to the suggestion that KNI-272 gains affinity by being preorganized for binding. On the other hand, one might well expect KNI-272 to be flexible because it possesses 15 rotatable bonds. Moreover, a recent ab initio study of KNI-272 suggests that it is not preorganized because its bound conformation is strained. Here, we use a novel algorithm to study the conformational distribution of this inhibitor. The results show good agreement with a recent NMR analysis of KNI-272 in solution. The calculations indicate that KNI-272 in solution occupies three major conformations, one of which matches the bound conformation and the NMR structure. In addition, the thioproline amide bond tends to be in the trans conformation found in the complex of KNI-272 with HIV protease. Further calculations on hypothetical an...
Angular diameters as a probe of a cosmological constant and Omega

The lensing effect of curved space, which can cause the angular diameter of a fixed reference length seen on the sky to reach a minimum and then increase with redshift, has recently been claimed to provide evidence, using compact radio sources, for a q sub 0 = 1/2 expansion. We show here that this relation, in particular the position of the observed minimum, depends sensitively on the value of the cosmological constant, Lambda, in a flat universe. The sensitivity to a nonzero Lambda in a flat universe is compared to the sensitivity to q sub 0 in an open universe without a cosmological constant. The reported results could provide the strongest available limit on the cosmological constant in a flat universe (and on Omega in an open universe) and so we explore how uncertainties in distance measures and evolution of the sources can affect the results. Evolution of less than 30 percent in source size for z of less than 2 can completely alter the results, and so must be convincingly ruled out if this technique is to provide a new tool for cosmology.
Prognosis with abnormal thallium images in the absence of significant coronary artery disease.

Abstract In the presence of coronary artery disease (CAD), thallium imaging has been reported to add prognostic information that is independent of coronary anatomy. To investigate the prognostic importance of thallium imaging in the absence of significant CAD, 87 patients (65 men, 22 women) with abnormal thallium images without significant CAD were followed for a median duration of 22 months (range 11 to 50). Tomographic thallium images obtained immediately and 4 hours after exercise were interpreted by 2 experienced observers who graded thallium uptake in 24 segments in 3 views (short axis, horizontal long axis, vertical long axis) on a 5-point scale (normal; mildly, moderately, or severely reduced; absent). All patients had an abnormal thallium study, defined as a reversible defect of at least mild severity or a fixed defect of at least moderate severity seen in ≥ 2 views, or a combination of these, and a coronary angiogram with stenosis not ≥ 70% in diameter narrowing. Eighty-two patients had at least 1 reversible segment, and 26 patients had defects in ≥ 2 coronary artery distributions. During follow-up there were no deaths or myocardial infarctions. Coronary angioplasty and bypass surgery were performed in 2 patients. Three-year survival without myocardial infarction or revascularization was 97%. Patients with abnormal thallium images in the absence of significant CAD have an excellent short-term prognosis.
Spontaneous CP nonconservation and natural flavor conservation: A minimal model

A minimal model based on the standard SU(2)\ifmmode\times\else\texttimes\fi{}U(1) gauge theory, with spontaneous $\mathrm{CP}$ violation and natural flavor conservation, is presented in some detail. In particular it is shown that one on the minima of the classical Higgs potential leads to spontaneous $\mathrm{CP}$ breaking. The generalized Cabibbo-type matrix is real and there is no $\mathrm{CP}$ violation in the manner of Kobayashi-Maskawa. The $\mathrm{CP}$ nonconservation is entirely due to Higgs-boson exchange, and can be characterized by a single phase for an arbitrary number of quark generations.
A Statistical Analysis of Editorial Influence and Author–Character Similarities in 1990s New Yorker Fiction

We present a quantitative analysis of 442 pieces of fiction published between 5 October 1992 and 17 September 2001 in the New Yorker magazine. We address two independent questions using the same data set. First, we examine whether changes in the Executive Editor or Fiction Editor are associated with significant changes in the type of fiction published at the New Yorker. Second, we examine whether New Yorker authors write fiction more often than not about characters with whom they share demographic traits. We find that changes in Fiction Editor at the New Yorker are associated with numerous significant, quantifiable changes in the magazine's fiction and that these effects are greater than those associated with a change in the New Yorker's Executive Editor. We also find that authors of New Yorker fiction write significantly more often than not about protagonists who share their race, gender, and country of origin and who are within or below their age range. The same is true of secondary characters except in the case of gender.
Tests for relative performance evaluation based on assumptions derived from proxy statement disclosures

The main purpose of this paper is to test for relative performance evaluation (RPE) using assumptions derived from an examination of firms’ disclosures about their RPE use. Prior empirical evidence supporting the use of RPE in executive compensation is mixed. This is puzzling since studies of firm disclosures indicate that firms claim to use RPE based on both accounting measures and stock returns. Those few studies that do find empirical support observe it with either an accounting performance measure or stock returns, but not both. The lack of strong consistent empirical support for RPE is due, in part, to the fact that the preponderance of tests for RPE incorporate unsubstantiated assumptions about the way firms apply RPE. This includes the compensation measure to which RPE is applied and the way in which firms use firm-own and peer group performance when determining compensation. Our test results provide support for the use of RPE among 1998 S&P 500 firms with both stock returns and return on equity. To our knowledge, this is the first study to find support for RPE with both stock returns and an accounting performance measure. Through a series of sensitivity analyses, we also provide insight into the amount of detail researchers need to build into their empirical tests in order to find support for RPE.
IRLbot: Scaling to 6 billion pages and beyond

This article shares our experience in designing a Web crawler that can download billions of pages using a single-server implementation and models its performance. We first show that current crawling algorithms cannot effectively cope with the sheer volume of URLs generated in large crawls, highly branching spam, legitimate multimillion-page blog sites, and infinite loops created by server-side scripts. We then offer a set of techniques for dealing with these issues and test their performance in an implementation we call IRLbot. In our recent experiment that lasted 41 days, IRLbot running on a single server successfully crawled 6.3 billion valid HTML pages (7.6 billion connection requests) and sustained an average download rate of 319 mb/s (1,789 pages/s). Unlike our prior experiments with algorithms proposed in related work, this version of IRLbot did not experience any bottlenecks and successfully handled content from over 117 million hosts, parsed out 394 billion links, and discovered a subset of the Web graph with 41 billion unique nodes.
Adaptive polarimetry design for a target in compound-Gaussian clutter

We develop optimal adaptive design of radar waveform polarizations for a target in compound-Gaussian clutter. We present maximum likelihood estimates of the target's scattering matrix and clutter parameters using a parameter-expanded expectation-maximization (PX-EM) algorithm. We compute the Cramer-Rao bound (CRB) on the target's scattering matrix. To design the polarization, we propose an algorithm that minimizes a CRB function. We propose also suboptimal versions of this algorithm and illustrate the performance as well as compare our algorithm with numerical examples.
CONSTRAINTS ON NATAL KICKS IN GALACTIC DOUBLE NEUTRON STAR SYSTEMS

Since the discovery of the first double neutron star (DNS) system in 1975 by Hulse and Taylor, there are currently eight confirmed DNS in our galaxy. For every system, the masses of both neutron stars, the orbital semimajor axis, and eccentricity are measured, and proper motion is known for half of the systems. Using the orbital parameters and kinematic information, if available, as constraints for all systems, we investigate the immediate progenitor mass of the second-born neutron star (NS2) and the magnitude of the supernova kick it received at birth, with the primary goal to understand the core-collapse mechanism leading to neutron star formation. Compared to earlier studies, we use a novel method to address the uncertainty related to the unknown radial velocity of the observed systems. For PSR?B1534+12 and PSR?B1913+16, the kick magnitudes are 150-270?km?s?1 and 190-450?km?s?1 (with 95% confidence), respectively, and the progenitor masses of the NS2 are 1.3-3.4 M ? and 1.4-5.0 M ? (95%), respectively. These suggest that the NS2 was formed by an iron core-collapse supernova in both systems. For PSR?J0737 ? 3039, on the other hand, the kick magnitude is only 5-120?km?s?1 (95%), and the progenitor mass of the NS2 is 1.3-1.9 M ? (95%). Because of the relatively low progenitor mass and kick magnitude, the formation of the NS2 in PSR?J0737 ? 3039 is potentially connected to an electron capture supernova of a massive O-Ne-Mg white dwarf. For the remaining five Galactic DNS, the kick magnitude ranges from several tens to several hundreds of?km?s?1, and the progenitor mass of the NS2 can be as low as ~1.5 M ? or as high as ~8 M ?. Therefore, in these systems it is not clear which type of supernova is more likely to form the NS2.
Non-linear dynamics and leadership emergence

Abstract The process by which leaders emerge from leaderless groups is well-documented, but not nearly as well understood. This article describes how non-linear dynamical systems concepts of attractors, bifurcations, and self-organization culminate in a swallowtail catastrophe model for the leadership emergence process, and presents the experimental results that the model has produced thus far for creative problem solving, production, and coordination-intensive groups. Several control variables have been identified that vary in their function depending on what type of group is involved, e.g. creative problem solving, production, and coordination-intensive groups. The exposition includes the relevant statistical strategies that are based on non-linear regression along with some directions for new research questions that can be explored through this non-linear model.
Inverting Phase Functions to Map Exoplanets

We describe how to generate a longitudinal brightness map for a tidally locked exoplanet from its phase function light curve. We operate under a number of simplifying assumptions, neglecting limb darkening/brightening, star spots, detector ramps, as well as time variability over a single planetary rotation. We develop the transformation from a planetary brightness map to a phase function light curve and simplify the expression for the case of an edge-on system. We introduce two models—composed of longitudinal slices of uniform brightness, and sinusoidally varying maps—which greatly simplify the transformation from map to light curve. We discuss numerical approaches to extracting a longitudinal map from a phase function light curve, explaining how to estimate the uncertainty in a computed map and how to choose an appropriate number of fit parameters. We demonstrate these techniques on a simulated map and discuss the uses and limitations of longitudinal maps. The sinusoidal model provides a better fit to the planet's underlying brightness map, although the slice model is more appropriate for light curves which only span a fraction of the planet's orbit. Regardless of which model is used, we find that there is a maximum of ~5 free parameters which can be meaningfully fit based on a full phase function light curve, due to the insensitivity of the latter to certain modes of the map. This is sufficient to determine the longitudes of primary equatorial hot spots and cold spots, as well as the presence of secondary maxima/minima.
Double K-shell photoionization of neon

Double K-shell photoionization of Ne at 5000 eV was observed by recording the KK-KLL Auger-electron hypersatellite spectrum. The measured Auger spectrum is compared with the results of multiconfiguration Dirac-Fock calculations. Shake calculations are used to identify likely multivacancy states produced by photoexcitation or ionization in addition to double-K vacancies, and their calculated Auger spectra are compared with the measured spectrum. The measured relative intensities of hypersatellite and diagram Auger lines are combined with experimental and theoretical determinations of branching ratios from single- and double-K vacancies into final states to determine the ratio of double-to-single K-shell photoionization cross sections to be 0.32(4)%. This ratio is much larger than the calculated high-energy-limit ratio and indicates a large contribution of dynamic electron correlation.
A critical evaluation of exchange rate policy in Turkey

Abstract This paper reviews and critically evaluates the exchange rate policy followed in Turkey in the post-1980 period during which a far-reaching program of liberalization has been launched. We conclude that the new exchange rate policy has been essential for Turkey's regaining its creditworthiness. Furthermore, it has positively contributed to growth of output and exports, and to expansion of tradables production relative to nontradables. Persistence of inflation and weakness of private investment in tradables overshadow the successes recorded in other areas, and cast doubt over the sustainability of Turkey's outward orientation. We argue that the root cause of these problems has been inconsistencies between overall economic policies, rather than the exchange rate policy itself. We compare the period of real appreciations since late 1998 with the earlier period of real depreciations, and draw policy implications.
The UV Continuum of Quasars: Models and SDSS Spectral Slopes

We measure long (2200-4000 A) and short (1450-2200 A) wavelength spectral slopes α (Fν να) for quasar spectra from the Sloan Digital Sky Survey. The long- and short-wavelength slopes are computed from 3646 and 2706 quasars with redshifts in the z = 0.76-1.26 and 1.67-2.07 ranges, respectively. We calculate mean slopes after binning the data by monochromatic luminosity at 2200 A and virial mass estimates based on measurements of the Mg II line width and 3000 A continuum luminosity. We find little evidence for mass-dependent variations in the mean slopes, but a significant luminosity-dependent trend in the near-UV spectral slopes is observed with larger (bluer) slopes at higher luminosities. The far-UV slopes show no clear variation with luminosity and are generally lower (redder) than the near-UV slopes at comparable luminosities, suggesting a slightly concave quasar continuum shape. We compare these results with Monte Carlo distributions of slopes computed from models of thin accretion disks, accounting for uncertainties in the mass estimates. The model slopes produce mass-dependent trends which are larger than observed, although this conclusion is sensitive to the assumed uncertainties in the mass estimates. The model slopes are also generally bluer than observed, and we argue that reddening by dust intrinsic to the source or host galaxy may account for much of the discrepancy.
Giambelli formulae for the equivariant quantum cohomology of the Grassmannian

We find presentations by generators and relations for the equivariant quantum cohomology of the Grassmannian. For these presentations, we also find determinantal formulae for the equivariant quantum Schubert classes. To prove this, we use the theory of factorial Schur functions and a characterization of the equivariant quantum cohomology ring.
Campus-wide asynchronous lecture distribution using wireless laptops

This work explored mechanisms to asynchronously distribute video objects to intranet users. The primary application driver was to disseminate lecture videos created by the instructor as well as annotated videos from students. The storage requirements made remote storage mechanisms as well as local infrastructure storage impractical. Hence, we investigated the feasibility of distributing video contents from user devices. Based on the recent trend of devices going wireless, we analyzed the viability of using laptop devices. We envision a variant of RSS feed mechanism that searched for the lectures among currently available replicas. The effectiveness of this distribution mechanism depended on the total number of voluntary replicas and availability patterns of wireless devices. Using extensive analysis of the observed node behavior, we showed that though laptop users were online for shorter durations, their temporal consistency can provide reasonable availability, especially at the times of the day when students were typically active.
Nietzschean Health and the Inherent Pathology of Christianity

Listen rather, my brothers, to the voice of the healthy body: that is a more honest and purer voice. More honestly and purely speaks the healthy body that is perfect and perpendicular: and it speak...
MFS: a modular text formatting system

This paper presents the design goals and architecture of the Modular Formatting System, currently being developed at West Virginia University. MFS applies to formatters the principles of separation of function used in many successful program systems. A small central kernel forms the basis for a family of formatting systems, tailored to specific applications and environments.MFS is intended to support a wide spectrum of applications drawn from the experience of commercial composition, word processing, and research systems. It does not rely on any specialized terminal or input source characteristics. Output devices from line printers through high resolution typesetters are handled in a uniform manner. Users can exercise detailed control over document appearance, or work exclusively with styles predefined through macros.
A Hydraulic Analogy of Radiating Bodies for Illustrating the Luminosity of the Welsbach Mantle

A Hydraulic Analogy of Radiating Bodies for Illustrating the Luminosity of the Welsbach Mantle
Bifurcation of Pulsating and Spinning Reaction Fronts in Condensed Two-Phase Combustion

Abstract We employ a nonlinear stability analysis to describe the bifurcation of pulsating and spinning modes of combustion in condensed media. We adopt the two-phase model of Margolis (1983) in which the modified nondimensional activation energy Δ of the reaction is large, but finite, and in which the limiting component of the mixture melts during the reaction process, as characterized by a nondimensional melting parameter M. We identify several types of non-steady solution branches which bifurcate from the steady palanar solution and show that they are supercritical and stable only for certain realistic ranges of M. For example, the spinning modes, though supercritical and stable for a range of M > 0, are subcritical and unstable for M = 0.
Stock index futures and index arbitrage in a rational expectations model

This article analyzes the role of stock index futures and index arbitrage in a rational expectations model with competitive stock and futures markets. Index arbitrage is a trading strategy designed to exploit price differentials between the spot market and the futures market. By buying the lower-priced instrument (stocks or futures) and selling the other, an arbitrage profit can be made.' The stock market part of this transaction is executed with the use of automated systems, which allow for the rapid and simultaneous buying or selling of large amounts of stocks. This is referred to as "program trading" or "basket trading."'2 In this article, I restrict myself to the study of index arbitrage and its impact on prices, price volatilities, and welfare.
Intramolecular cyclopropanation reactions en route to novel P-heterocycles

Abstract The first examples of intramolecular cyclopropanation reactions on a phosphonate template catalyzed by Rh 2 (OAc) 4 are described. These reactions proceed in excellent yield and give mixtures of the P-heterocycles cis - 2a-d and trans - 2a-d with moderate levels of diastereoselectivity. The diastereoselectivity of this tranformation is dependent upon the size of the alkyl group R contained in the alkyl α-diazodiallylphosphonoacetate starting materials 1a-d .
A Survey for New Members of Taurus with the Spitzer Space Telescope

We present the results of a search for new members of the Taurus star-forming region using the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope. With IRAC images of 29.7 deg2 of Taurus at 3.6, 4.5, 5.8, and 8.0 μm, we have identified sources with red mid-infrared colors indicative of disk-bearing objects and have obtained optical and infrared spectra of 23 of these candidate members. Through this work, we have discovered 13 new members of Taurus, two of which have spectral types later than M6 and thus are likely to be brown dwarfs, according to the theoretical evolutionary models of Chabrier & Baraffe. This survey indicates that the previous census of Taurus has a completeness of ~80% for members with disks. The new members that we have found do not significantly modify the previously measured distributions of Taurus members as a function of position, mass, and extinction. For instance, we find no evidence for a population of highly reddened brown dwarfs (AK ~ 2) that has been missed by previous optical and near-infrared surveys, which suggests that brown dwarf disks are not significantly more flared than disks around stars. In addition to the new members, we also present IRAC photometry for the 149 previously known members that appear within this survey, which includes 27 objects later than M6.
K -shell ionization cross sections in asymmetric heavy-ion-atom collisions

Experimental x-ray production cross sections for Ne projectiles impinging on thick Al foils and Ar projectiles on Si foils reveal that in asymmetric atom-atom collisions, $K$-shell vacancies are created in both collision partners. Only in the almost adiabatic collision regime at very low velocities, corresponding to projectile energies ${E}_{1}l20$ keV/amu, are all of the vacancies created in the collision partner with the lower atomic number, as predicted by the electron-promotion model of Pauli excitation. At higher energies, ${E}_{1}g25$ keV/amu, the ratio of the $K$-shell x-ray production cross section of the heavier collision partner to that of the lighter collision partner increases approximately as the square of the incident ion energy, and can exceed unity. It provides experimental evidence for Pauli excitation of both $K$ shells under nonadiabatic conditions.
THE EFFECT OF IN-GROUP FAVORITISM ON THE COLLECTIVE BEHAVIOR OF INDIVIDUALS' OPINIONS

Empirical findings from social psychology show that sometimes people show favoritism toward in-group members in order to reach a global consensus, even against individuals' own preferences (e.g., altruistically or deontically). Here we integrate ideas and findings on in-group favoritism, opinion dynamics, and radicalization using an agent-based model entitled cooperative bounded confidence (CBC). We investigate the interplay of homophily, rejection, and in-group cooperation drivers on the formation of opinion clusters and the emergence of extremist, radical opinions. Our model is the first to explicitly explore the effect of in-group favoritism on the macro-level, collective behavior of opinions. We compare our model against the two-dimentional bounded confidence model with rejection mechanism, proposed by Huet et al. [Adv. Complex Syst.13(3) (2010) 405–423], and find that the number of opinion clusters and extremists is reduced in our model. Moreover, results show that group influence can never dominate homophilous and rejecting encounters in the process of opinion cluster formation. We conclude by discussing implications of our model for research on collective behavior of opinions emerging from individuals' interaction.
21st Century extravehicular activities: Synergizing past and present training methods for future spacewalking success

Abstract Neil Armstrong’s understated words, “That’s one small step for man, one giant leap for mankind” were spoken from Tranquility Base forty years ago. Even today, those words resonate in the ears of millions, including many who had yet to be born when man first landed on the surface of the moon. By their very nature, and in the true spirit of exploration, extravehicular activities (EVAs) have generated much excitement throughout the history of manned spaceflight. From Ed White’s first spacewalk in the June of 1965, to the first steps on the moon in 1969, to the expected completion of the International Space Station (ISS), the ability to exist, live and work in the vacuum of space has stood as a beacon of what is possible. It was NASA’s first spacewalk that taught engineers on the ground the valuable lesson that successful spacewalking requires a unique set of learned skills. That lesson sparked extensive efforts to develop and define the training requirements necessary to ensure success. As focus shifted from orbital activities to lunar surface activities, the required skill set and subsequently the training methods changed. The requirements duly changed again when NASA left the moon for the last time in 1972 and have continued to evolve through the SkyLab, Space Shuttle, and ISS eras. Yet because the visits to the moon were so long ago, NASA’s expertise in the realm of extra-terrestrial EVAs has diminished. As manned spaceflight again shifts its focus beyond low earth orbit, EVA’s success will depend on the ability to synergize the knowledge gained over 40+ years of spacewalking to create a training method that allows a single crewmember to perform equally well, whether performing an EVA on the surface of the Moon, while in the vacuum of space, or heading for a rendezvous with Mars. This paper reviews NASA’s past and present EVA training methods and extrapolates techniques from both to construct the basis for future EVA astronaut training.
Boc-protected 1-(3-oxocycloalkyl)ureas via a one-step Curtius rearrangement: mechanism and scope

1-(3-Oxocyclobutyl) carboxylic acid (4a) was converted into N-Boc-protected 1-(3-oxocyclobutyl) urea (5a), a key intermediates for the preparation of agonists of metabotropic glutamate receptor 5, in one-step when treated with diphenyl phosphoryl azide and triethylamine in tert-butanol. The mechanism of the reaction involves a nucleophilic addition of the in situ generated tert-butyl carbamate to the isocyanate intermediate. This reaction is applicable to other 1-(3-oxocycloalkyl) carboxylic acids but not to linear γ-keto carboxylic acids.
Designing warning signs and warning labels: Part I – Guidelines for the practitioner

This chapter presents several guidelines for designing warning signs and warning labels. These guidelines find their application in human factors engineering. Numerous approaches have been developed for evaluating the aspects of sign and label perception. Such approaches include the evaluation of reaction time, tachistoscopic procedures, measures of legibility distance, study of eye movements, and the evaluation of accuracy or errors. By applying such methods, insight can be obtained regarding both the perceptibility of signs and labels and the degree to which they attract attention. The format of a warning sign or label refers to the physical aspects such as size, the presence of signal words and symbols, methods of color coding, typography, and the arrangement of the sign or label's components. The two guidelines with the greatest relevance to specifying format are (1) making warning signs and labels conspicuous and each component legible and (8) conforming to standards and population stereotypes when possible. In specifying the content of a warning sign or label, several of the preceding guidelines become highly relevant. The message itself should match the warning to the level of performance at which critical errors occur for the relevant population.
Computational Interpretations of the Gricean Maxims in the Generation of Referring Expressions

We examine the problem of generating definite noun phrases that are appropriate referring expressions; that is, noun phrases that (a) successfully identify the intended referent to the hearer whilst (b) not conveying to him or her any false conversational implicatures (Grice, 1975). We review several possible computational interpretations of the conversational implicature maxims, with different computational costs, and argue that the simplest may be the best, because it seems to be closest to what human speakers do. We describe our recommended algorithm in detail, along with a specification of the resources a host system must provide in order to make use of the algorithm, and an implementation used in the natural language generation component of the IDAS system.
Spatial Competition with a Land Market: Hotelling and Von Thunen Unified

We introduce into the standard spatial competition model the consumption of land by households, and study the spatial competition under the influence of a land market. In contrast to the standard assumption of a fixed, given distribution of households, we introduce the possibility of households' relocation in reaction to firms' location decisions. Thus, the spatial distribution of households is treated as endogenous, and a land market is introduced on which households compete for land-use. Households consume simultaneously land and firms' output. Accordingly, the demand of each household becomes in turn endogenous as it depends on the income left after the land rent is paid. Not surprisingly, the results obtained within this more general framework prove to be very different from the standard results. For example, in the 2- and 3-firm cases, the optimal configuration of firms is a Nash equilibrium when transport costs are high enough or the amount of vacant land is large enough. The existence property is restored in the 3-firm case when the transport costs are high enough. The introduction of vacant land causes a discontinuous change in the set of equilibrium configurations.
A novel trisaccharide glycolipid biosurfactant containing trehalose bears ester-linked hexanoate, succinate, and acyloxyacyl moieties: NMR and MS characterization of the underivatized structure

A Gram-positive actinomycete growing on n-hexadecane secreted a family of anionic glycolipid surfactant homologs. The major homolog, with a molecular weight of 1210.6347, had the formula C58H98O26. Following mild alkaline saponification, 1H and 13C NMR spectroscopy were used to characterize the non-reducing trisaccharide backbone: β-Glcp-(1→3)-α-Glcp-(1↔1)-α-Glcp (‘laminaratrehalose’). Hexanoate, succinate, 3-hydroxyoctanoate, and 3-hydroxydecanoate were found in 3:1:1:1 molar ratio using GC–EIMS analysis of fatty acid methyl esters (FAME) prepared by transesterification. We found that the β-hydroxy acids bore secondary hexanoate chains in 3-O-ester linkage, giving acyloxyacyl anions of appropriate m/z in FABMS and FABMS/MS spectra. COSY, HETCOR, HMBC, and HMQC NMR experiments established the acylation pattern: succinate at C-2 of the terminal α-glucopyranose ring; hexanoate at C-3′′ of the β-glucopyranose ring; 3-hexanoyloxyoctanoate and 3-hexanoyloxydecanoate at the 2′- and 4-positions. In FABMS spectra, the homologs flanked the molecular ion by ±14 and ±28 amu, suggesting heterogeneity in acyl chain length.
Enthalpies of formation in the Al-Ni-Ru system by direct reaction synthesis calorimetry

Abstract The enthalpies of formation of ternary compounds in the Al–Ni–Ru system have been determined by high temperature reaction calorimetry. The composition dependence of the enthalpy of formation and lattice parameter of the compounds with B2 structure were determined in the region of 0.40 ≤ Al ≤ 0.5 mole fraction. Unusual behavior is observed for the composition dependence of the enthalpy of formation suggesting that formation of a miscibility gap in the B2 phase field occurs. For some compositions, the experimental enthalpy data therefore represent the formation enthalpy of the metastable B2 phase.
Children's altruism in public good and dictator experiments

We examine the deelopment of altruistic and free-riding behaior in 612-year-old children. We find that the leel of altruistic behaior in children is similar to that of adults but that repetition has a different effect. Younger children’s contributions tend to increase in later rounds of the experiments, whereas the contributions of older children, like those of adults, tend to decline. Group attachment is associated with higher contributions. Contributions in a subsequent dictator experiment are correlated with first-round contributions in the public good experiment, but are not Ž. strongly correlated with last-round contributions. JEL H41
McLaren's improved snub cube and other new spherical designs in three dimensions

Evidence is presented to suggest that, in three dimensions, spherical 6-designs withN points exist forN=24, 26,ź28; 7-designs forN=24, 30, 32, 34,ź36; 8-designs forN=36, 40, 42,ź44; 9-designs forN=48, 50, 52,ź54; 10-designs forN=60, 62, ź64; 11-designs forN=70, 72,ź74; and 12-designs forN=84,ź86. The existence of some of these designs is established analytically, while others are given by very accurate numerical coordinates. The 24-point 7-design was first found by McLaren in 1963, and--although not identified as such by McLaren--consists of the vertices of an "improved" snub cube, obtained from Archimedes' regular snub cube (which is only a 3-design) by slightly shrinking each square face and expanding each triangular face. 5-designs with 23 and 25 points are presented which, taken together with earlier work of Reznick, show that 5 designs exist forN=12, 16, 18, 20,ź22. It is conjectured, albeit with decreasing confidence fortź9, that these lists oft-designs are complete and that no other exist. One of the constructions gives a sequence of putative sphericalt-designs withN=12m points (mź2) whereN=1/2t2(1+o(1)) astźź.
FORMATION OF RELATIVISTIC OUTFLOWS IN SHEARING BLACK HOLE ACCRETION CORONAE

We examine the possibility that the relativistic jets observed in many active galactic nuclei may be powered by the Fermi acceleration of protons in a tenuous corona above a two-temperature accretion disk. In this picture the acceleration arises as a consequence of the shearing motion of the magnetic —eld in the corona, which is anchored in the underlying Keplerian disk. The protons in the corona have a power-law distribution because the density there is too low for proton-proton collisions to thermalize the energy supplied via Fermi acceleration. The same shear acceleration mechanism also operates in the disk itself; however, there the density is high enough for thermalization to occur and consequently the disk protons have a Maxwellian distribution. Particle acceleration in the corona leads to the development of a pressure-driven wind that passes through a critical point and subsequently transforms into a relativistic jet at large distances from the black hole. We combine the critical conditions for the wind with the structure equations for the disk and the corona to obtain a coupled disk-corona-wind model. Using the coupled model, we compute the asymptotic Lorentz factor of the jet as a function of the cylindrical starting radius at the base of the ! = out—ow, in the corona. Our results suggest that which is consistent with observations of super- ! = ( 10, luminal motion in blazars. We show that collisions between the jet and broad-line emission clouds can produce high-energy radiation with a luminosity sufficient to power the c-rays observed from blazars. Subject headings: acceleration of particlesaccretion, accretion disksgamma rays: theory ¨ radiation mechanisms: nonthermal
Fast estimation for range identification in the presence of unknown motion parameters

A fast estimator is proposed and applied to the problem of range identification in the presence of unknown motion parameters. Assuming a rigid-body motion with unknown constant rotational parameters but known translational parameters, estimation of the unknown parameters is achieved by a fast estimator, followed by recursive least square extraction. The results are also extended to the case of an affine motion. Simulations demonstrate the superior performance of fast estimation in comparison to an identifier-based observer.
A model of protogalactic cloud collapse

The present analytical model describes the collapse of a protogalactic cloud under the influence of gravitational and viscous forces. The model provides a discriminating mechanism that dictates what type of galaxy will eventually form.
High-Resolution Mid-Infrared Observations of Very Young Stellar Objects in NGC 1333

We observed 22 young stellar objects in the region of NGC 1333 by using the mid-infrared camera MIRLIN. NGC 1333 (in the Perseus OB2 molecular cloud complex) is a relatively well studied region, but not at high spatial resolution in the mid-infrared. MIRLIN's 05 spatial resolution allows us to look for source extension and multiplicity and to place new constraints on spectral energy distributions. We report here new detections of eight objects at mid-IR wavelengths. We find one object, SVS 12, that may be extended or multiple, and we confirm multiplicity in SVS 16. We find a new companion to ASR 107. We are able to classify six objects as Class I, flat spectrum, or II, place strong classification constraints on two objects, and more loosely restrict the classification of eight more objects. These observations will aid in interpretation of planned SIRTF observations of this cluster.
A FLUXGATE MAGNETOMETER FOR SPACE APPLICATION

Basic principles and characteristics of a fluxgate magnetometer used for space applications
Sampling strategies for mining in data-scarce domains

A novel framework leverages physical properties for mining in data-scarce domains. It interleaves bottom-up data mining with top-down data collection, leading to effective and explainable sampling strategies. This article describes focused sampling strategies for mining scientific data. Our approach is based on the spatial aggregation language, which supports construction of data interpretation and control design applications for spatially distributed physical systems in a bottom-up manner. Used as a basis for describing data mining algorithms, SAL programs also help exploit knowledge of physical properties such as continuity and locality in data fields. We also introduce a top-down sampling strategy that focuses data collection in only those regions that are deemed most important to support a data mining objective.
Comparison of dayside magnetic separatrix signatures in HF and incoherent scatter radar data

[1] Both high-frequency (HF) and incoherent scatter (IS) radar have previously been used to identify the open-closed magnetic field separatrix and to measure the magnetospheric reconnection rate. The HF radar signature of open magnetic field on the dayside is a high spectral width in the backscatter Doppler spectrum. The IS radar signature of closed field lines is the presence of ionization indicating boundary plasma sheet precipitation. We investigate the consistency of these different signatures of the separatrix and show that the consistency depends on the local reconnection electric field. The two signatures yield a consistent identification of the separatrix at local times where the reconnection electric field is low. In the merging gap, however, where the reconnection electric field is high, the signature in the HF radar signature moves several degrees equatorward of the signature in the IS radar. These observations are backed up by DMSP precipitating particle observations, which indicate that the IS radar technique is properly identifying the poleward edge of the dayside BPS precipitation but also that the trapping boundary of magnetospheric ions and the electron edge occur at a latitude consistent with the HF radar signature of the separatrix. These observations are consistent with the theory that a portion of the dayside BPS is on open magnetic field lines. The latitudinal width of the dayside BPS on open field lines is given by ΔΛ = 0.14°Erec[mV/m]. We conclude that the HF radar signature is the more accurate identifier of the magnetic separatrix in the region of active reconnection.
Time-consistent fiscal policy and heterogeneous agents

Abstract This paper characterizes the time-consistency properties of the set of Pareto efficient (or second best) fiscal policies, in a two-class, stochastic economy similar to that in [Judd, K.L., 1985, Redistributive taxation in a simple perfect foresight model, Journal of Public Economics 28, 59–83]. The key finding is that the continuation of any Pareto efficient policy is always Pareto efficient. Hence, to require any policy revision to be approved by unanimity safeguards the time consistency of efficient fiscal policy. I also show that any Pareto efficient policy from a timeless perspective can be rendered time consistent by a policymaker whose objective function is given by a utilitarian social welfare function with precise welfare weights. These results link the policymaker's equity considerations with the credibility of efficient fiscal policy.
Integrating and presenting clinical and treatment outcome data for cost-effective case management

The broad objective was to develop an information system which integrates various sources of clinical data and facilitates outcome assessment for patients evaluated in a lumbar spine service. During a patient encounter, the physician formulates a hypothesis regarding appropriate forms of treatment and he or she may then use this system to explore previous treatment outcomes for similar cases. The availability of a clinical tool that presents information in an outcome-oriented format may be highly relevant to the delivery of cost-efficient, high-quality health care and also create a formal mechanism for detecting practice variability.
Tobit at fifty: a brief history of Tobin's remarkable estimator, of related empirical methods, and of limited dependent variable econometrics in health economics.

Practitioners of empirical health economics might be forgiven for paying little heed to the recent 50th anniversary of the publication of one of the most important papers in its methodological heritage: James Tobin's widely-cited 1958 Econometrica paper that developed what later became known as the Tobit estimator. This golden anniversary milestone provides a fitting opportunity to reflect on Tobin's contribution and to assess the role that econometric limited dependent variable modeling has played in empirical health economics. Of primary focus here is how Tobin's estimator came to be and came to take root in empirical health economics. The paper provides a brief history of Tobin's estimator and related methods up through about 1971, discusses the early applications of Tobit and related estimators in health economics, i.e. the "technology diffusion" of Tobit in health economics, and offers some concluding remarks.
Instanton effects in hadron spectroscopy in SU(2) (lattice) gauge theory

Abstract We describe quenched spectroscopy in SU (2) gauge theory using smoothed gauge field configurations. We investigate the properties of quarks moving in instanton background field configurations, where the sizes and locations of the instantons are taken from simulations of the full gauge theory. By themselves, these multi-instanton configurations do not confine quarks, but they induce chiral symmetry breaking.
Instituting a conservative management protocol for pediatric blunt renal trauma: evaluation of a prospectively maintained patient registry.

Purpose: Retrospective studies show that even high grade pediatric renal trauma can be safely managed conservatively. We evaluated a prospective patient registry at our level 1 pediatric trauma center, where patients with renal trauma were treated with an institutional review board approved conservative blunt renal trauma protocol. Standardized treatment included a trial of expectant management for all stable cases.Materials and Methods: We identified 39 children with blunt renal trauma treated between 2003 and 2008. A strict conservative approach was used, ie nonoperative management in cases that were hemodynamically stable or had a favorable response with up to 2 units of blood transfused and no operative renal lesion on imaging. Adult imaging protocols were followed and exploratory laparotomy for nonrenal causes did not alter course of expectant renal management. Outcomes evaluated were injury grade, hematuria, operative management, length of stay and associated injuries.Results: Based on the American ...