cssi/SciSciGPT-SciSciNet huggingface dataset:
The high-resolution X-ray spectrum of MR 2251-178 obtained with the Chandra HETGS

The QSO MR 2251-178 was observed with the Chandra High Energy Transmission Grating Spectrometer (HETGS) at a 2-10 keV luminosity of 2.41 ? 1044 ergs s-1 (using H0 = 72 km s-1 Mpc-1). We observe the source in a relatively low state. The light curve shows no evidence of variability. We present the zero-order image of MR 2251-178 and compare it to previous observations. We find evidence of a highly ionized, high-velocity outflow, which we detect in a resolved Fe XXVI Ly? absorption line. The outflow appears to have a large mass and kinetic energy flux compared to the estimated nuclear accretion rate and luminosity. We examine the possibility that other absorption features in the spectrum are associated with the high-velocity outflow. We detect a narrow Fe K? line and resolved forbidden line emission from Ne IX and O VII. Modeling the emitting material enables us to constrain its properties and conclude that it is not along our line of sight.
Homogeneous hydrogenation of nitroaliphatic compounds catalyzed by group VIII transition metal phosphine complexes

Abstract A variety of Group VIII transition metal phosphine complexes were shown to be active catalysts for hydrogenation of nitroaliphatic compounds. The catalysis was determined to be homogeneous based on results of selective catalyst poisoning experiments using dibenzo[a,e]cyclooctatetraene and Hg. A deuterium labeling study showed that in the absence of added base the primary hydrogenation pathway does not involve intermediates containing C=N bonds.
Difference-Form Contests and the Robustness of All-Pay Auctions

Abstract In much of the existing literature on rent-seeking games, the outcome of the contest is either infinitely sensitive or relatively insensitive to contestants' efforts. The current paper presents a family of contest games that permit characterization of equilibrium for all levels of sensitivity of the outcome to contestants' efforts. Specifically, the outcome of the contest depends on the difference between efforts, which encompass the lottery and the all-pay auction as polar cases. The equilibrium converges to that of the all-pay auction as the probability of winning the prize grows infinitely sensitive to one's effort, and the main qualitative features of equilibrium persist over a large parameter region. Journal of Economic Literature Classification Numbers: D44, D72.
Universal dynamics of spontaneous Lorentz violation and a new spin-dependent inverse-square law force

We study the universal low-energy dynamics associated with the spontaneous breaking of Lorentz invariance down to spatial rotations. The effective lagrangian for the associated Goldstone field can be uniquely determined by the non-linear realization of a broken time diffeomorphism symmetry, up to some overall mass scales. It has previously been shown that this symmetry breaking pattern gives rise to a Higgs phase of gravity, in which gravity is modified in the infrared. In this paper, we study the effects of direct couplings between the Goldstone boson and standard model fermions, which necessarily accompany Lorentz-violating terms in the theory. The leading interaction is the coupling to the axial vector current, which reduces to spin in the non-relativistic limit. A spin moving relative to the ``ether rest frame will emit Goldstone Cerenkov radiation. The Goldstone also induces a long-range inverse-square law force between spin sources with a striking angular dependence, reflecting the underlying Goldstone shockwaves and providing a smoking gun for this theory. We discuss the regime of validity of the effective theory describing these phenomena, and the possibility of probing Lorentz violations through Goldstone boson signals in a way that is complementary to direct tests in some regions of parameter space.
Pyramid Power: Searching for an Error in Test Scoring with 830,000 Helpers

Abstract A mathematics question that was asked on the Preliminary Scholastic Aptitude Test was scored incorrectly. This subsequently was discovered and became the subject of national attention. In this article we examine the data generated by this item from almost 830,000 examinees and find that detailed statistical analysis with even this enormous sample size would not have yielded clues to the blunder. The epistemological and practical consequences of this are also discussed.
Rapid synthesis of β-hydroxy-α-amino acids, such as L-threonine, β-hydroxyphenylalanine, and β-hydroxyleucine, via an application of the sharpless asymmetric epoxidation☆

Abstract The optically active epoxy alcohols 6abc , prepared by a Sharpless kinetic resolution-epoxidation process, were converted to the optically pure β-hydroxy-α-amino acids 1abc in four steps and high overall yield.
Endotoxin exposure and eczema in the first year of life

Abstract Rationale Early life exposure to endotoxin may protect against the development of allergic diseases. Our objective was to examine the relation between endotoxin exposure and eczema in the first year of life in children with parental history of asthma or allergies. Methods Prospective birth cohort study. Results In multivariate analyses adjusting for sex, household income, and season of birth, endotoxin level in the household at age 2 to 3 months was inversely associated with physician or nurse diagnosed eczema in the first year of life (odds ratio [OR] for each quartile increment=0.76; 95% confidence interval [CI]: 0.61–0.96: P=0.02). Exposure to a dog in the home at age 2–3 months was also inversely associated with eczema in the first year of life, but the confidence interval for the estimate of the association between dog exposure and eczema became wider when endotoxin was included in the multivariate model (OR=0.54, 95% CI=0.27–1.09: P=0.09). Other variables associated with eczema in the first year of life included paternal history of eczema (OR=1.91, 95% CI=1.03–3.55, P=0.04) and maternal specific IgE positive to =1 allergen (OR=1.61, 95% CI=1.01–2.56, P=0.05). Conclusions Among children with parental history of asthma or allergies, exposure to high levels of endotoxin in early life may be protective against eczema in the first year of life. In these children, paternal history of eczema and maternal sensitization to at least one allergen are associated with an increased risk of eczema in the first year of life.
Depolarization of diffusing spins by paramagnetic impurities

The depolarization of diffusing spins (muons) interacting with dilute paramagnetic impurities in a solid was studied using a simple computational model which properly treats the muon motion and preserves correct muon-impurity distances. Long-range (dipolar) and nearest-neighbor (contact) interactions are treated together. Diffusion parameters are deduced and model comparisons made for AuGd (300 ppM).
X-Ray Binaries and the Current Dynamical States of Galactic Globular Clusters

It has been known for over 30 years that Galactic globular clusters (GCs) are overabundant by orders of magnitude in bright X-ray sources per unit mass relative to the disk population. Recently a quantitative understanding of this phenomenon has developed, with a clear correlation between the number of X-ray sources in a cluster, NX, and the cluster's encounter frequency, Γ, becoming apparent. We derive a refined version of Γ that incorporates the finite lifetime of X-ray sources and the dynamical evolution of clusters. With it we find we are able to explain the few clusters that lie off the NX-Γ correlation, and resolve the discrepancy between observed GC core radii and the values predicted by theory. Our results suggest that most GCs are still in the process of core contraction and have not yet reached the thermal equilibrium phase driven by binary scattering interactions.
Review of physics results from the Tevatron: QCD physics

We present a summary of results from studies of quantum chromodynamics at the Fermilab Tevatron collider by the CDF and the D0 experiments. These include Run II results for the time period up to the end of Summer 2014. A brief description of Run I results is also given. This review covers a wide spectrum of topics, and includes measurements with jet and vector boson final states in the hard (perturbative) energy regime, as well as studies of soft physics such as diffractive and elastic scatterings, underlying and minimum bias events, hadron fragmentation, and multiple parton interactions.
Connections with Skew-Symmetric Ricci Tensor on Surfaces

Some known results on torsionfree connections with skew-symmetric Ricci tensor on surfaces are extended to connections with torsion, and Wong’s canonical coordinate form of such connections is simplified.
Calculations of liquid helium and neon VUV emission spectra, self-absorption and scattering for a neutrino detector

To evaluate the feasibility of the recently proposed detection scheme of low energy neutrinos released from the Sun and supernovae, which relies on the transparency of noble-gas cryogenic liquids to VUV radiation, we analyze theoretically VUV emission, self-absorption, and scattering of liquid helium and neon, primary candidates for CLEAN. The emission spectrum is substantially shifted from the absorption spectrum, and the absorption is expected very small, allowing building large detectors. Our analysis, however, shows that the self-absorption and Rayleigh scattering are comparable to the size of the proposed detector.
Universal approximation depth and errors of narrow belief networks with discrete units

We generalize recent theoretical work on the minimal number of layers of narrow deep belief networks that can approximate any probability distribution on the states of their visible units arbitrarily well. We relax the setting of binary units Sutskever & Hinton, 2008; Le Roux & Bengio, 2008, 2010; Montufar & Ay, 2011 to units with arbitrary finite state spaces and the vanishing approximation error to an arbitrary approximation error tolerance. For example, we show that a q-ary deep belief network with layers of width for some can approximate any probability distribution on without exceeding a Kullback-Leibler divergence of . Our analysis covers discrete restricted Boltzmann machines and naive Bayes models as special cases.
8-Endo versus 5-exo cyclization of unsaturated acrylate esters upon reaction with t-BuHgI/KI

Free radical addition of t-BuHgI/KI to 1-vinyl-4-pentenyl acrylates in DMSO followed by a photostimulated reaction with Ph2S2 leads to the formation of free radical cyclization products 3 by the 8-endo mode and/or 5 by the 5-exo mode.
Partially-revealing rational expectations equilibrium in a competitive economy

Abstract A class of pure exchange economies is considered in which some agents are informed of private information and others are uninformed. Existence of a partially-revealing rational expectations equilibrium (REE) is proved—without restricting attention to particular functional forms for utility functions and probability distributions, without introducing “noise” into the model, and without departing from the standard definition of REE. The equilibrium is robust in the sense that if the primitives of the economy are slightly perturbed, the economy continues to have a qualitatively-similar REE. With somewhat stronger assumptions placed on the economy, the equilibrium is also the unique measurable REE.
Quantum "solitons" which are SU ( N ) fermions

In two dimensions, we find a construction for an SU(N) quark field in terms of N real Bose fields. Hence, equivalence is shown between certain massive SU(N) Thirring models and systems of quantum sine-Gordon-like equations. From the point of view of the bosons, the ''soliton-quark'' SU(N) is topological. To minimize guesswork in the development of such correspondences, we employ a systematic blend of Mandelstam's operator approach with the interaction picture. (AIP)
Earth’s carbon cycle: A mathematical perspective

The carbon cycle represents metabolism at a global scale. When viewed through a mathematical lens, observational data suggest that the cycle exhibits an underlying mathematical structure. This review focuses on two types of emerging results: evidence of global dynamical coupling between life and the environment, and an understanding of the ways in which smaller-scale processes determine the strength of that coupling. Such insights are relevant not only to predicting future climate but also to understanding the long-term co-evolution of life and the environment.
A brief review of air transport noise

Abstract Flight vehicles are characterized according to their manner of operation and type of propulsion system; and their associated sources of noise are identified. Available noise reduction technology as it relates to engine cycle design and to power plant component design is summarized. Such components as exhaust jets, fans, propellers, rotors, airflow-surface interactions and reciprocating engine exhausts are discussed, along with their noise reduction potentials. Significant aircraft noise reductions are noted to have been accomplished by the application of available technology in support of noise certification rules. Further noise reductions to meet more stringent future noise regulations will require substantial additional technology developments. Improved analytical prediction methods, and well controlled validation experiments supported by advanced design aeroacoustic facilities, are required as a basis for an effective integrated systems approach to aircraft noise control.
Chiral duals of non-chiral SUSY gauge theories

Abstract We study N = 1 SUSY gauge theories in four dimensions with gauge group Spin (7) and N f flavors of quarks in the spinorial representation. We find that in the range 6 N f SU ( N f - 4) gauge theory with a symmetric tensor and N f antifundamentals. As a spin-off, we obtain by deforming along a flat direction a dual description of the theories based on the exceptional gauge group G 2 with N f fundamental flavors of quarks.
On Arithmetic Branching Programs

The model of arithmetic branching programs is an algebraic model of computation generalizing the model of modular branching programs. We show that, up to a polynomial factor in size, arithmetic branching programs are equivalent to complements of dependency programs, a model introduced by Pudlak and Sgall. Using this equivalence we prove that dependency programs are closed under conjunction over every field, answering an open problem of theirs. Furthermore, we show that span programs, an algebraic model of computation introduced by Karchmer and Wigderson, are at least as strong as arithmetic programs; every arithmetic program can be simulated by a span program of size not more than twice the size of the arithmetic program. Using the above results we give a new proof that NL/poly??L/poly, first proved by Wigderson 25. Our simulation of NL/poly is more efficient, and it holds for logspace counting classes over every field.
Cross-National Indices with Gender-Differentiated Data: What Do They Measure? How Valid Are They?

The two cross-national indices with gender-differentiated data introduced by the UNDP in 1995, as well as several other such indices developed subsequently, are an important resource for researchers and policy makers interested in gender disparities. Yet questions remain regarding how these indices should be interpreted and how valid they are. Relying on a framework that synthesizes key guidelines concerning the methodology of measurement, this article offers an assessment of indices currently used to study gender disparities on a global scale and sheds light on these unresolved questions. We answer two questions—what do these indices with gender-differentiated data actually measure? and, how valid are these indices?—and discuss the implications of our assessment for users and producers of gender indices.
Multi-scale extensions to quantum cluster methods for strongly correlated electron systems

A numerically implementable multi-scale many-body approach to strongly correlated electron systems is introduced. An extension to quantum cluster methods, it approximates correlations on any given length-scale commensurate with the strength of the correlations on the respective scale. Short length-scales are treated explicitly, long ones are addressed at a dynamical mean-field level and intermediate length-regime correlations are assumed to be weak and are approximated diagrammatically. To illustrate and test this method, we apply it to the one-dimensional Hubbard model. The resulting multi-scale self-energy provides a very good quantitative agreement with substantially more numerically expensive, explicit quantum Monte Carlo calculations.
Why is GeV physics relevant in the age of the LHC

The contribution that Jefferson Lab has made, with its 6 GeV electron beam, and will make, with its 12 GeV upgrade, to our understanding of the way the fundamental interactions work, particularly strong coupling QCD, is outlined. This physics at the GeV scale is essential even in TeV collisions.
Preliminary Psychometric Properties of the BEST in CLASS Adherence and Competence Scale.

The measurement of treatment integrity is critical to evaluate the efficacy and effectiveness of evidence-based programs (EBPs) designed to improve the developmental outcomes of young children at risk of emotional/behavioral disorders. Unfortunately, the science of treatment integrity measurement lags behind the development and evaluation of EBP for young, high-risk children. This article describes the development and preliminary psychometric properties of the BEST in CLASS Adherence and Competence Scale (BiCACS), designed to measure the adherence and competence of delivery of the BEST in CLASS prevention program. Independent observers coded videotaped (n = 116) and live (n = 289) observations of teachers delivering the BEST in CLASS program. The BiCACS showed good interrater reliability and analyses provided some support for the validity of the measure. Implications for future research and integrity measurement work are discussed.
On the Rarity of X-Ray Binaries with Naked Helium Donors

The paucity of known high-mass X-ray binaries (HMXBs) with naked He donor stars (hereafter He star) in the Galaxy has been noted over the years as a surprising fact, given the significant number of Galactic HMXBs containing H-rich donors, which are expected to be their progenitors. This contrast has further sharpened in light of recent observations uncovering a preponderance of HMXBs hosting loosely bound Be donors orbiting neutron stars (NSs), which would be expected to naturally evolve into He-HMXBs through dynamical mass transfer onto the NS and a common-envelope (CE) phase. Hence, reconciling the large population of Be-HMXBs with the observation of only one He-HMXB can help constrain the dynamics of CE physics. Here, we use detailed stellar structure and evolution models and show that binary mergers of HMXBs during CE events must be common in order to resolve the tension between these observed populations. We find that, quantitatively, this scenario remains consistent with the typically adopted energy parameterization of CE evolution, yielding expected populations which are not at odds with current observations. However, future observations which better constrain the underlying population of loosely bound O/B-NS binaries are likely to place significant constraints on the efficiency of CE ejection.
Selective oxidation of 8,8'-hydroxylated binaphthols to bis-spironaphthalenones or binaphtho-para- and binaphtho-ortho-quinones.

The selective oxidation of a series of functionalized 8,8′-hydroxylated binaphthols to binaphtho-para- and binaphtho-ortho-quinones has been realized using either a Co-salen catalyst or ortho-iodoxybenzoic acid. A unique spirocyclic bis-spironaphthalenone was also obtained in good yield via a phenyliodonium diacetate promoted oxidative dearomatization.
Infrared spectrum of the silicon hydride cation SiH7

Silanium ions are an important class of hypervalent molecules, and the determination of their structure will yield insights into the nature of nonclassical bonding and provide a contrast to the bonding in carbonium ions. We report the infrared spectrum of the mass-selected silicon hydride cluster ion ^(28)SiH_7^+ detected by vibrational predissociation spectroscopy. Silanium ions were formed in a pulsed high pressure glow discharge and cooled by the subsequent supersonic expansion. Photodissociation spectra were obtained using a tandem time-of-flight mass spectrometer: (formula available in paper) ions were mass-selected and excited by a tunable infrared laser. The resulting photofragments were detected using a reflectron as a mass analyzer. We observed a vibrational band at 3865 cm^(-1), which was the only one observed from 3500 cm^(-1) to 4200 cm^(-1). This result suggests that the molecule might form a symmetric complex with the structure H_2⋅SiH_3^+⋅H_2, in contrast to the CH_7^+ which has the structure CH_5^+⋅H_2.
Preparation of Allyl and Vinyl Silanes by the Palladium‐Catalyzed Silylation of Terminal Olefins: A Silyl‐Heck Reaction

A high-yielding protocol for the palladium-catalyzed silylation of terminal alkenes using silyl halides is reported. This method allows facile conversion of styrenes to E-β-silyl styrenes using either TMSI or TMSCl/LiI. Terminal allyl silanes with good E:Z ratios are also readily accessed from α-olefins by this method. When combined with existing technology, this transformation provides a powerful strategy to selectively functionalize the vinyl or allylic position of terminal alkenes.
Doublet craters and the tidal disruption of binary asteroids

An evaluation is conducted of the possibility that the tidal disruption of a population of contact binary asteroids can account for terrestrial-impact 'doublet' craters. Detailed orbital integrations indicate that while such asteroids are often disrupted by tidal forces outside the Roche limit, the magnitude of the resulting separations is too small to account for the observed doublet craters. It is hypothesized that an initial population of km-scale earth-crossing objects encompassing 10-20 percent binaries must be responsible for doublet impacts, as may be verified by future observations of earth-approaching asteroids.
Are Causality Violations Undesirable

Causality violations are typically seen as unrealistic and undesirable features of a physical model. The following points out three reasons why causality violations, which Bonnor and Steadman identified even in solutions to the Einstein equation referring to ordinary laboratory situations, are not necessarily undesirable. First, a space-time in which every causal curve can be extended into a closed causal curve is singularity free—a necessary property of a globally applicable physical theory. Second, a causality-violating space-time exhibits a nontrivial topology—no closed timelike curve (CTC) can be homotopic among CTCs to a point, or that point would not be causally well behaved—and nontrivial topology has been explored as a model of particles. Finally, if every causal curve in a given space-time passes through an event horizon, a property which can be called “causal censorship”, then that space-time with event horizons excised would still be causally well behaved.
Line Search Techniques Based on Interpolating Polynomials using Function Values Only

In this study we derive the order of convergence of some line search techniques based on fitting polynomials; using function values only. It is shown that the order of convergence increases with the degree of the polynomial. If viewed as a sequence, the orders approach the Golden Section Ratio when the degree of the polynomial tends to infinity.
Reduced switching-frequency voltage-balancing strategies for modular multilevel HVDC converters

The modular multilevel converter (MMC) is a potential candidate for medium/high-power applications, specifically for high-voltage direct current (HVDC) transmission systems. One of the technical challenges associated with the control of an MMC is to carry out the submodule (SM) capacitor voltages balancing task without imposing any unnecessary switching transition among the SMs. This paper develops a general framework for the capacitor voltage balancing of an MMC. Based on the developed framework and with the objective of reducing the unnecessary switching transitions among the SMs, three capacitor voltage-balancing strategies are proposed and investigated: 1) a slow-rate balancing strategy based on the conventional sorting method; 2) a hybrid balancing strategy which combines a predictive method with the conventional sorting method; and 3) a fundamental-frequency balancing strategy. Performance of the proposed strategies for a point-to-point 21-level MMC-based HVDC system is evaluated based on time-domain simulation studies in the PSCAD/EMTDC software environment. The reported study results demonstrate the capability and tradeoffs of the proposed strategies to reduce the number of switching transitions and, consequently, the MMC losses, under various conditions.
Bank regulation in the United States: understanding the lessons of the 1980s and 1990s

Abstract Despite two decades of extensive deregulation, banks in the United States remain among the most heavily regulated entities in the US economy. Partly, banks remain a prominent target for American populism and its political manifestations; but also important is the general recognition that one specific category of bank regulation—safety-and-soundness (prudential) regulation—is a crucial element in preserving the stability of the banking system and contributing to the health of the US economy. This paper expands on that theme and discusses the important lessons and insights that can be gained from the experiences of the banking sector and of safety-and-soundness regulation during the past two decades.
Determinants of interest rates on tax-exempt hospital bonds.

Abstract The aim of this paper is to examine the determinants of interest rates on tax-exempt hospital bonds. The results highlight the potential and actual roles of Federal and state policy in the determination of these rates. The shift to a Prospective Payment System under Medicare has subsidized the borrowing costs of some hospitals at the expense of others. The selection of underwriters by negotiation rather than by competitive bidding results in higher interest rates. The Federal tax of 1986 raised the cost of hospital debt by encouraging bond issues to contain call features.
Testing Population Synthesis Models with Globular Cluster Colors.

We have measured an extensive set of UBVRIJHK colors for M31 globular clusters. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31 globular clusters. The best-fitting models fit the cluster colors very well: the weighted mean color offsets are all smaller than 0.05 mag. The most significant offsets between model and data are in the U and B passbands; these are not unexpected and are likely caused by problems with the spectral libraries used by the models. The metal-rich clusters ([Fe/H] -0.8) are best fit by young (8 Gyr) models, while the metal-poor clusters are best fit by older (12-16 Gyr) models. If this range of globular cluster ages is correct, it implies that conditions for cluster formation must have existed for a substantial fraction of the galaxies' lifetimes.
Applying chiral perturbation to twisted mass lattice QCD

We have explored twisted mass LQCD (tmLQCD) analytically using chiral perturbation theory, including discretization effects up to O ( a 2 ) , and working at next-to-leading (NLO) order in the chiral expansion. In particular we have studied the vacuum structure, and calculated the dependence of pion masses and decay constants on the quark mass, twisting angle and lattice spacing. We give explicit examples for quantities that both are and are not automatically improved at maximal twisting.
Polarization in hyperon photo- and electro-production

Multiple polarization observables must be measured to access the amplitude structure of pseudoscalar meson photoproduction off the proton. The hyperon-producing reactions are especially attractive to study, since the weak decays allow straightforward measurement of the induced and recoil polarization observables. In this paper we emphasize γ + p → K + + Λ, discussing recent measurements of C x , C z , P for this reaction. An empirical constraint on the helicity amplitudes is obtained. A simplified model involving spin-flip and spin-non-flip amplitudes is presented. Finally, a semi-classical model of how the polarization may arise is presented.
Absorption coefficient regression scheme for splitting radiative heat sources across phases in gas–particulate mixtures

Abstract In a gas–particle mixture particles of different makes and sizes may have different local temperatures and are, therefore, modeled with separate energy equations. If the important radiative heat transfer contributions are determined with sophisticated spectral models such as k -distributions, spectral information is lost during the reordering process, making it difficult to separate the resulting radiative heat source across the various energy equations. It is shown here how radiative sources can be determined accurately with the full-spectrum k -distribution assembled from a narrowband database and combined with particle properties on a narrowband level. Proper distribution of the radiative source across the various phases is achieved using regression analysis. Numerical examples demonstrate the accuracy of the model.
MACROECONOMIC NEWS, STOCK TURNOVER, AND VOLATILITY CLUSTERING IN DAILY STOCK RETURNS

We study volatility clustering in daily stock returns at both the index and firm levels from 1985 to 2000. We find that the relation between today's index return shock and the next period's volatility decreases when important macroeconomic news is released today and increases with the shock in today's stock market turnover. Collectively, our results suggest that volatility clustering tends to be stronger when there is more uncertainty and disperse beliefs about the market's information signal. Our findings also contribute to a better understanding of the joint dynamics of stock returns and trading volume.
Status of light gaugino scenarios

Abstract I summarize recent developments in supersymmetry scenarios which leave some or all gauginos light. The emphasis is on experimental and phenomenological progress in the past year.
Competition in Transactions Mechanisms: The Emergence of Price Competition

Abstract This paper models competition between firm/market-makers. There are two goods, a divisible numeraire and an indivisible good, produced by firms. The set of active consumers is random; all consumers are identical, conditional on arriving at the market. First, firms produce output (equivalently, install capacity) and commit to a transactions mechanism. Next, nature chooses the set of consumers at the market, and each active consumer commits to visit a single firm. All equilibria involve all firms choosing a fixed price. Thus, price competition is derived, not assumed. Journal of Economic Literature Classification Numbers: D43, D83, L13.
Automated Optimal Stiffener Pattern Design

ABSTRACT An automated topology optimization based approach is proposed to generate the optimal stiffener pattern of 3D shell structures with the objective of maximizing a band of eigenfrequencies. The methodology is based on a fiber-reinforced composite model in which the stiffeners and base structure are modeled as Fibers and matrix, respectively. Solutions to the optimization problem are obtained by means of an iterative, two-level procedure based on an optimally criterion approach and a method of mathematical programming using analytical sensitivity analysis. Two numerical examples are presented to demonstrate the effectiveness of the proposed approach.
Self-consistent Thermal Accretion Disk Corona Models for Compact Objects. I. Properties of the Corona and the Spectrum of Escaping Radiation

We present the properties of accretion disk corona (ADC) models in which the radiation field, the temperature, and the total opacity of the corona are determined self-consistently. We use a nonlinear Monte Carlo code to perform the calculations. As an example, we discuss models in which the corona is situated above and below a cold accretion disk with a plane-parallel (slab) geometry, similar to the model of Haardt & Maraschi. By Comptonizing the soft radiation emitted by the accretion disk, the corona is responsible for producing the high-energy component of the escaping radiation. Our models include the reprocessing of radiation in the accretion disk. Here the photons either are Compton-reflected or photoabsorbed, giving rise to fluorescent line emission and thermal emission. The self- consistent coronal temperature is determined by balancing heating (due to viscous energy dissipation) with Compton cooling, determined using the fully relativistic, angle-dependent cross sections. The total opacity is found by balancing pair productions with annihilations. We find that, for a disk temperature kT(sub BB) approx. less than 200 eV, these coronae are unable to have a self-consistent temperature higher than approx. 140 keV if the total optical depth is approx. less than 0.2, regardless of the compactness parameter of the corona and the seed opacity. This limitation corresponds to the angle-averaged spectrum of escaping radiation having a photon index approx. greater than 1.8 within the 5-30 keV band. Finally, all models that have reprocessing features also predict a large thermal excess at lower energies. These constraints make explaining the X-ray spectra of persistent black hole candidates with ADC models very problematic.
Fourier spectrum analysis of the new solar neutrino capture rate data for the Homestake experiment

Abstract The paper provides results of the Fourier spectrum analysis of the new Ar-37 production rate data of the Homestake solar neutrino experiment and compares them with results for earlier data, revealing the harmonic content in the Ar-37 production in the Homestake experiment.
Is a Plumber or a New Financial Architect Needed to End global International Liquidity Problems

How one interprets volatility in the international financial markets and therefore chooses a policy stance regarding these markets depend on the underlying economic theory that one explicitly, or implicitly, utilizes to explain the role of financial markets in a market-oriented entrepreneurial economy. There are two major alternative theories of financial markets: (1) the classical efficient market theory (hereafter EMT) and (2) Keynes’s liquidity preference theory (hereafter LPT). Each produces a different set of policy prescriptions. EMT advocates call for a liquidity plumber to patch up some short-run stresses in today’s efficient international financial flow system. LPT proponents believe that the current system is structurally flawed. Consequently, it will require an architect to build a new international financial structure on more solid foundations.
Gamma-ray lines from interstellar grains

The letter points out the existence of a hitherto unknown component of gamma-ray line emission: very narrow (FWHM less than 5 keV) lines from interstellar grains. The prime candidate for detection is the line at 6.129 MeV from O-16, but other very narrow lines could also be detected at 0.847, 1.369, 1.634, 1.779, and 2.313 MeV from Fe-56, Mg-24, Ne-20, Si-28, and N-14. Measurements of this line emission can provide information on the composition, size, and spatial distribution of interstellar grains.
1-(BENZENESULFONYL)PYRROLE-3-CARBOXALDEHYDE

(1995). 1-(BENZENESULFONYL)PYRROLE-3-CARBOXALDEHYDE. Organic Preparations and Procedures International: Vol. 27, No. 4, pp. 503-506.
Alternative supersymmetric spectra

Abstract We describe the features of supersymmetric spectra, alternative to and qualitatively different from that of most versions of the MSSM. The spectra are motivated by extensions of the MSSM with an extra U (1)′ gauge symmetry, expected in many grand unified and superstring models, which provide a plausible solution to the μ problem, both for models with supergravity and for gauge-mediated supersymmetry breaking. Typically, many or all of the squarks are rather heavy (larger than one TeV), especially for the first two families, as are the sleptons in the supergravity models. However, there is a richer spectrum of Higgs particles, neutralinos, and (possibly) charginos. Concrete examples of such spectra are presented, and the phenomenological implications are briefly discussed.
Rogue waves in oceanic turbulence

A stochastic model of wave groups is presented to explain the occurrence of exceptionally large waves, usually referred to as rogue waves. The model leads to the description of the non-Gaussian statistics of large waves in oceanic turbulence and to a new asymptotic distribution of their crest heights in a form that generalizes the Tayfun model. The new model explains the unusually large crests observed in flume experiments of narrow-band waves. However, comparisons with realistic oceanic measurements gathered in the North Sea during an intense storm indicate that the generalized model agrees with the original Tayfun distribution.
On simplicial commutative algebras with Noetherian homotopy

Abstract In this paper, we introduce a strategy for studying simplicial commutative algebras over general commutative rings R. Given such a simplicial algebra A, this strategy involves replacing A with a connected simplicial commutative k(℘) -algebra A(℘) , for each ℘∈ Spec(π0A), which we call the connected component of A at ℘ . These components retain most of the Andre–Quillen homology of A when the coefficients are k(℘) -modules ( k(℘)= residue field of ℘ in π0A). Thus, these components should carry quite a bit of the homotopy theoretic information for A. Our aim will be to apply this strategy to those simplicial algebras which possess Noetherian homotopy. This allows us to have sophisticated techniques from commutative algebra at our disposal. One consequence of our efforts will be to resolve a more general form of a conjecture of Quillen that was posed in Invent. Math. 142 (3) (2000) 547.
Measurement and Analysis of Modulated Doublet Mode Response in Mock Bladed Disks

The steady state response of spatially modulated doublet modes that occur in low count flexible bladed disks is investigated for the case in which the structure is driven by a harmonic travelling wave excitation source. Finite-element simulation and modal testing of prototypical bladed-disk structures demonstrate the presence of particular wavenumbers, beyond the base number of nodal diameters, which contaminate and distort the appearance of certain doublet modes. The manner in which the natural frequency and wavenumber content of such modes shift and split as functions of the number of blades and their span angle is discussed in the light of a companion perturbation analysis for rotationally periodic structures. Resonance conditions are established and verified through simultaneous measurements made with a spin test stand using sensors that are placed in the rotating (structure) and stationary (excitation) frames of reference. The travelling wave response components of a repeated frequency doublet mode are shown to propagate either in the same or opposite direction as the excitation source, depending on whether certain algebraic relationships between the excitation order, the base number of nodal diameters, and the contamination wavenumbers are satisfied. To the extent that such components can travel at different phase speeds and directions relative to one another, the placement of sensors on the structure can be optimized to best measure the response amplitude. Conversely, other placements can result in submaximal measurement of peak vibration amplitude over the structure.
One-pot, one- and multi-carbon homologation of alkyl halides; reaction of grignard reagents with chloroiodomethane

Abstract Reaction of a Grignard reagent (RMgX) with chloroiodomethane affords the corresponding iodide (RI) and, depending on R, solvent, and temperature, iodides which are one-carbon and multicarbon homologs of RX. Allyl iodide but not allyl bromide can be monohomologated by the combined action of chloroiodomethane and isopropyl Grignard.
Extending the Scope of NMR Spectroscopy with Microcoil Probes

Capillary NMR (CapNMR) spectroscopy has emerged as a major breakthrough for increasing the mass-sensitivity of NMR spectroscopic analysis and enabling the combination of NMR spectroscopy with other analytical techniques. Not only is the acquisition of high-sensitivity spectra getting easier but the quality of CapNMR spectra obtained in many small-molecule applications exceeds what can be accomplished with conventional designs. This Minireview discusses current CapNMR technology and its applications for the characterization of mass-limited, small-molecule and protein samples, the rapid screening of small-molecule or protein libraries, as well as hyphenated techniques that combine CapNMR with other analytical methods.
Is S = 1 for c = 1?

Abstract The c = 1 string in the Liouville field theory approach is shown to possess a nontrivial tree-level S-matrix which satisfies the factorization property implied by unitary, if all the extra massive physical states are included.
Formation of compact stellar clusters by high-redshift galaxy outflows. II. effect of turbulence and metal-line cooling

In the primordial universe, low-mass structures with virial temperatures less than 10{sup 4} K were unable to cool by atomic line transitions, leading to a strong suppression of star formation. On the other hand, these 'minihalos' were highly prone to triggered star formation by interactions from nearby galaxy outflows. In Gray and Scannapieco, we explored the impact of nonequilibrium chemistry on these interactions. Here we turn our attention to the role of metals, carrying out a series of high-resolution three-dimensional adaptive mesh refinement simulations that include both metal cooling and a subgrid turbulent mixing model. Despite the presence of an additional coolant, we again find that outflow-minihalo interactions produce a distribution of dense, massive stellar clusters. We also find that these clusters are evenly enriched with metals to a final abundance of Z {approx} 10{sup -2} Z{sub sun}. As in our previous simulations, all of these properties suggest that these interactions may have given rise to present-day halo globular clusters.
Double non-global logarithms in-n-out of jets

We derive the leading non-global logarithms (NGLs) of ratios of jet masses m 1,2 and a jet energy veto Λ due to soft gluons splitting into regions in and out of jets. Such NGLs appear in any exclusive jet cross section with multiple jet measurements or with a veto imposed on additional jets. Here, we consider back-to-back jets of radius R produced in e + e − collisions, found with a cone or recombination algorithm. The leading NGLs are of the form $\alpha_{\text{s}}^2{\text{l}}{{\text{n}}^2}(\Lambda /{m_{{1},{2}}})$ or $\alpha_{\text{s}}^2{\text{l}}{{\text{n}}^2}({m_1}/{m_2})$ . Their coefficients depend both on the algorithm and on R. We consider cone, kT, anti-kT, and Cambridge-Aachen algorithms. In addition to determining the full algorithmic and R dependence of the leading NGLs, we derive new relations among their coefficients. We also derive to all orders in α s a factorized form for the soft function S(k L , k R , Λ) in the cross section σ(m 1, m 2, Λ) in which dependence on each of the global logs of μ/k L , μ/k R and μ/Λ determined by the renormalization group are separated from one another and from the non-global logs. The same kind of soft function, its associated non-global structure, and the algorithmic dependence we derive here will also arise in exclusive jet cross sections at hadron colliders, and must be understood and brought under control to achieve precise theoretical predictions.
Child health: equity in the non-industrialized countries.

Abstract Significant improvements have been made in infant and child survival globally in recent decades. In spite of a substantial literature describing achievements to date and strategies for continuation of this progress, there has been relatively little attention directed toward the issue of equity in global child health outcomes. This paper briefly reviews global improvements in child health outcomes over the past four decades, but then provides evidence that there has been substantial variation in these improvements, both between nations and within non-industrialized nations. The identifying characteristics of high risk populations are summarized. The specific diseases and disease complexes associated with mortality in populations with different mortality rates are presented as background to a discussion of the anticipated increase in ‘effort’ (both personnel and material resources) that will be necessary for sustained improvement in child survival. In this context, the Acquired Immunodeficiency Syndrome is likely to further increase disparities in health outcomes. Finally, prospects for increased equity in the future are discussed.
A 10 MHz beam counter and a multiplicity detector for the E864 spectrometer

Abstract The E864 experiment at BNL requires a beam counter and multiplicity detector system that can perform at an incident beam rate of 10 7 Au ions per second. We have developed and tested a 150 μm thick quartz Cherenkov beam counter and a scintillator based multiplicity-trigger counter during the first run of this experiment in 1994. We obtained a time resolution of 78 ps for the beam counter at an incident beam rate 5 × 10 5 Hz and 100 ps at a rate of 1 × 10 7 Hz. Pulse height discrimination is used to obtain a minimum bias and a 10% centrality trigger from the multiplicity detectors. The multiplicity counter has a time resolution of 250 ps.
A Simplified Synthesis of the Diastereomers of Levuglandin E2

Abstract We report a synthesis of Levuglandin E2, as a mixture of easily separable diastereomers (15‐E2‐isoketals). The key feature is the protection of its reactive aldehyde as dimethyl acetal, which is introduced with 2,2‐dimethoxyethanal and removed in minutes with Montmorillonite K‐10. The synthesis could be modified to the preparation of 15‐E2‐isoketals with stable isotopes or with radiolabels.
Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate

Previous research has shown that phonetic categories have a graded internal structure that is highly dependent on acoustic-phonetic contextual factors, such as speaking rate; these factors alter not only the location of phonetic category boundaries, but also the location of a category’s best exemplars. The purpose of the present investigation, which focused on the voiceless category as specified by voice onset time (VOT), was to determine whether a higher order linguistic contextual factor, lexical status, which is known to alter the location of the voiced—voiceless phonetic category boundary, also alters the location of the best exemplars of the voiceless category. The results indicated that lexical status has a more limited and qualitatively different effect on the category’s best exemplars than does the acousticphonetic factor of speaking rate. This dissociation is discussed in terms of a production-based account in which perceived best exemplars of a category track contextual variation in speech production.
Large Fracture Toughness Boron-Epoxy Composites

The high tensile strengths of strong interfacial bonding may be combined with the large fracture toughness of weak interfacial bonding in brittle fiber/brittle matrix composites by intermittently coating the filaments before layup so as to have random alternate weak and strong regions. Appropriate coating materials enable Cook-Gordon Mode I interfacial debonding to take place, which produces very long pull-out lengths with an associated large contribution to toughness. Unidirectional boron-epoxy composites have been so made which have toughnesses greater than 200 kJ/sq m while retaining rule of mixtures tensile strengths. Similar trends have been observed for crossply layups.