cssi/SciSciGPT-SciSciNet huggingface dataset:
Tomonaga's Model and the Threshold Singularity of X-Ray Spectra of Metals

Singularities near the threshold of the soft x-ray spectra of metals have been predicted by Mahan and have recently been calculated by Nozi\`eres et al. using the model of a localized core hole. We show that the singular behavior can be understood in terms of density waves of the conduction electrons which are excited when, in the absorption process, the core hole is created, providing an attractive potential for the conduction electrons. For the description of the conduction electrons in terms of density waves, Tomonaga's model is adopted.
Visual explorations of dynamics : The standard map

The Macintosh application StdMap allows easy exploration of many of the phenomena of area-preserving mappings. This tutorial explains some of these phenomena and presents a number of simple experiments centered on the use of this program.
Synthesis of diprotected monosubstituted hydrazine derivatives from tert-butyl carbazates and boronic acids.

Diprotected monosubstituted hydrazine derivatives have been prepared via the reaction of tert-butyl carbazates with boronic acids catalyzed by cuprous chloride at room temperature.
Making web annotations persistent over time

As Digital Libraries (DL) become more aligned with the web architecture, their functional components need to be fundamentally rethought in terms of URIs and HTTP. Annotation, a core scholarly activity enabled by many DL solutions, exhibits a clearly unacceptable characteristic when existing models are applied to the web: due to the representations of web resources changing over time, an annotation made about a web resource today may no longer be relevant to the representation that is served from that same resource tomorrow.We assume the existence of archived versions of resources, and combine the temporal features of the emerging Open Annotation data model with the capability offered by the Memento framework that allows seamless navigation from the URI of a resource to archived versions of that resource, and arrive at a solution that provides guarantees regarding the persistence of web annotations over time. More specifically, we provide theoretical solutions and proof-of-concept experimental evaluations for two problems: reconstructing an existing annotation so that the correct archived version is displayed for all resources involved in the annotation, and retrieving all annotations that involve a given archived version of a web resource.
Coulomb drag between two-dimensional and one-dimensional electron gases

We investigate the low-temperature Coulomb drag resistance between a quasi-two-dimensional (2D) electron layer and an electron gas in a quasi-one-dimensional quantum wire theoretically using a Fermi liquid model. The 2D layer is assumed to be degenerate. The dependence of the resistance on the temperature, the layer-wire distance, and the electron density is studied. In high-density wires, the dominant contribution to the drag arises from small-momentum-transfer (i.e., forward) scattering near each Fermi point. In low-density wires, however, backscattering becomes important at low temperatures. The resistance is found to be significantly larger in low-density wires.
VACUUM SYSTEM FOR A THIRTY BILLION ELECTRON VOLT PARTICLE ACCELERATOR

A vaeuum system is being developed for a thirty billion electron volt particle accelerator. The vacuum chamber is a torus one-half mile in circumference with a cross section of 3 in. by 7 in. Approximately fifty getter- ion type pumps will be used on the ring to give the required pressure of 2 x 10/ sup -6/ mm Hg. A linear accelerator yielding fifty million electron volts protons will be used as the injector. The vacuum chamber of this accelerator is 110 ft long and 3 ft in diameter. It will be evacuated to 1 x 10/sup -6/ mm Hg by eleven getterion pumps. The choice of getter-ion pumps has permitted a departure from conventional vacuum system design and operation. Details of some new concepts of initial evacuation, steady state operation, and simplicity of control of a system of this nature will be given. (auth)
Case-control analyses: Geneopardy!

The case-control analyses group focused on a diverse set of questions, including study design, power, and analysis of case-control studies. Papers on study design examined various case-selection strategies, as well as ways to combine information from family- and population-based case-control data. The power of various approaches to case-control analyses was compared in several papers, while two papers chose to apply specific methods to analyzing the data. Two groups examined haplotype-related issues, including resolving unphased haplotypes and comparing haplotype- and single-nucleotide polymorphism-based methods for analyzing data. Finally, one group examined the optimal number of markers for the genomic control approach to population stratification. Genet. Epidemiol. 29(Suppl. 1):S86–S90, 2005. © 2005 Wiley-Liss, Inc.
Modern climate forcing of terrigenous deposition in the tropics (Cariaco Basin, Venezuela)

One approach to deciphering tropical Quaternary paleoclimate records has been to study the composition of terrigenous material in order to infer past changes in hydrologic and atmospheric conditions. Here we present the inorganic geochemistry (major and trace elements) of modern sediment traps and shelf sediments in the tropical Cariaco Basin, Venezuela, in order to characterize seasonal variation in deposition of the terrigenous component and to document linkages within the ocean-atmosphere-climate system. We show that variation in the chemistry of terrigenous input to the Basin is a sensitive monitor of the annual meridional migration of the Intertropical Convergence Zone (ITCZ). Additionally, seasonal terrigenous relative abundances are decoupled from terrigenous absolute fluxes, showing that abundances are not directly related to terrigenous delivery. Changes in mixing between local fluvial sediments, fluvial and/or eolian mafic material, and Saharan dust explains the observed seasonality. The modern seasonal variations are significantly smaller than those observed in the glacial–interglacial paleorecord, indicating that climate sensitivity at the two time scales is very different. A striking contrast in the behavior of Ti/Al between the longer glacial– interglacial time scale and the modern seasonality also suggests that long-term terrigenous deposition is not linked simply to 100kyr shifting of the ITCZ. The modern data can be reconciled with the glacial–interglacial record by invoking generally drier conditions during glacial periods over tropical latitudes, combined with intermittent wet conditions caused by precessional forcing. © 2007 Elsevier B.V. All rights reserved.
HOW TO MEASURE A BEABLE

Abstract We discuss measurement within the context of a theory of “beables”, e.g. theories of de Broglie, Bohm, Bell, Vink, and also “modal” theories. We show that even in an ideal von Neumann measurement, the measured value of a beable may not agree with the value which the beable had before the measurement.
Some New Variance Bounds for Asset Prices

When equity prices are determined as the discounted sum of current and expected future dividends, Shiller (1981) and LeRoy and Porter (1981) derived a relationship between the variance of the price of equities, pt, and the variance of the ex post realized discounted sum of current and future dividends: p*t : Var(p*t ) = Var(pt). The literature has long since recognized that this variance bound is valid only when dividends follow a stationary process. Others, notably West (1988), derive variance bounds that apply when dividends are nonstationary. West shows that the variance in innovations in pt must be less than the variance of innovations in a forecast of the discounted sum of current and future dividends constructed by the econometrician, p't. Here we derive a new variance bound when dividends are stationary or have a unit root, that sheds light on the discussion in the 1980s of the Shiller variance bound: Var(pt - pt 1) = Var(p*t - p*t- 1)! We also derive a variance bound related to the West bound: Var(p't - p't-1) = Var(pt - pt-1).
k-ribbon Fibonacci tableaux

We extend the notion of k-ribbon tableaux to the Fibonacci lattice, a differential poset defined by R. Stanley in 1975. Using this notion, we describe an insertion algorithm that takes k-colored permutations to pairs of k-ribbon Fibonacci tableaux of the same shape, and we demonstrate a color-to-spin property, similar to that described by Shimozono and White for ribbon tableaux. We describe a geometric interpretation of k-ribbon Fibonacci tableaux and use this interpretation to describe a notion of P equivalence for k-ribbon Fibonacci tableaux. In addition, we give an evacuation algorithm which relates the pair of k-ribbon Fibonacci tableaux obtained through the insertion algorithm to the pair of k-ribbon Fibonacci tableaux obtained using Fomin's growth diagrams.
Electric field-induced magnetization switching in interface-coupled multiferroic heterostructures: a highly-dense, non-volatile, and ultra-low-energy computing paradigm

Electric field-induced magnetization switching in multiferroic magnetoelectric devices is promising for computing purposes in beyond Moore's law era. We show here that interface-coupled multiferroic heterostructures, i.e., a ferroelectric layer coupled with a ferromagnetic layer, are particularly suitable for highly-dense, non-volatile, and ultra-low-energy computing. By solving the stochastic Landau–Lifshitz–Gilbert equation of magnetization dynamics in the presence of room-temperature thermal fluctuations, we demonstrate that error-resilient switching of magnetization is possible with a sub-nanosecond delay while expending only a minuscule amount of energy, of ~1 attojoule. Such devices can be operated by drawing energy from the environment without the need for an external battery.
SPH Simulations of Direct Impact Accretion in the Ultracompact AM CVn Binaries

The ultracompact binary systems V407 Vul (RX J1914.4+2456) and HM Cnc (RX J0806.3+1527), a two-member subclass of the AM CVn stars, continue to generate interest because they defy unambiguous classification. Three proposed models remain viable at this time, but none of the three are significantly more compelling than the remaining two, and all three can satisfy the observational constraints if parameters in the models are tuned. One of the three proposed models is the direct impact model of Marsh & Steeghs, in which the accretion stream impacts the surface of a rapidly rotating primary white dwarf directly, but at a near-glancing angle. One requirement of this model is that the accretion stream have a high enough density to advect its specific kinetic energy below the photosphere for progressively more thermalized emission downstream, a constraint that requires an accretion spot size of ~ -->1.2 × 105 km2 or smaller. Because we had at hand a smoothed particle hydrodynamics code optimized for cataclysmic variable accretion disk simulations, it was relatively straightforward for us to adapt it to calculate the footprint of the accretion stream at the nominal radius of the primary white dwarf and thus to test this constraint of the direct impact model. We find that the mass flux at the impact spot can be approximated by a bivariate Gaussian with a standard deviation of -->σ = 164 km in the orbital plane and -->σθ = 23 km in the perpendicular direction. The area of the 2 σ ellipse into which ~86% of the mass flux occurs is roughly 47,400 km2, or roughly half the size estimated by Marsh & Steeghs. We discuss the necessary parameters of a simple model of the luminosity distribution in the postimpact emission region.
POLYCYCLIC-BY-FINITE GROUP ALGEBRAS ARE CATENARY

We show that group algebras kG of polycyclic-by-finite groups G, where k is a field, are catenary: If P = I0 ( I1 ( � � � ( Im = Pand P = J0 ( J2 ( � � � ( Jn = Pare both saturated chains of prime ideals of kG, then m = n.
Oxidation Induced Stress-Rupture of Fiber Bundles

The effect of oxidation on the stress-rupture behavior of fiber bundles was modeled. It is shown that oxidation-induced fiber strength degradation results in the delayed failure of the associated fiber bundle and that the fiber bundle strength decreases with time as t{sup {minus}{1/4}}. It is also shown that the temperature dependence of the bundle loss of strength reflects the thermal dependence of the mechanism controlling the oxidation of the fibers. The effect of gauge length on the fiber bundle strength was also analyzed. Numerical examples are presented for the special case of Nicalon fibers.
Beating randomized response on incoherent matrices

Computing accurate low rank approximations of large matrices is a fundamental data mining task. In many applications however the matrix contains sensitive information about individuals. In such case we would like to release a low rank approximation that satisfies a strong privacy guarantee such as differential privacy. Unfortunately, to date the best known algorithm for this task that satisfies differential privacy is based on naive input perturbation or randomized response: Each entry of the matrix is perturbed independently by a sufficiently large random noise variable, a low rank approximation is then computed on the resulting matrix. We give (the first) significant improvements in accuracy over randomized response under the natural and necessary assumption that the matrix has low coherence. Our algorithm is also very efficient and finds a constant rank approximation of an m x n matrix in time O(mn). Note that even generating the noise matrix required for randomized response already requires time O(mn).
Shape-Controlled Conversion of β-Sn Nanocrystals into Intermetallic M-Sn (M = Fe, Co, Ni, Pd) Nanocrystals

The ability to control the shape of metal nanocrystals is critical to applications such as catalysis, magnetism, and plasmonics. Despite significant advances in controlling the shapes of single-metal nanocrystals, rigorous shape control of multimetal nanocrystals remains challenging, and has been limited largely to alloy systems of similar metals. Here we describe a robust strategy that produces shape-controlled intermetallic nanocrystals involving elements of notably different reduction potentials, reduction kinetics, and reactivity. The approach utilizes shape- and size-controlled β-Sn nanocrystals as reactive templates that can be converted into binary M-Sn (M = Fe, Co, Ni, Pd) intermetallic compounds by reaction with appropriate metal salt solutions under reducing conditions. The result, demonstrated in detail for the FeSn2 system, is a variety of nanostructures with morphologies that include spheres, cubes, hollow squares, U-shaped structures, nanorods, and nanorod dimers. Our experiments demonstrate...
Enantioselective intermolecular free radical conjugate additions. Application of a pyrazole template

Abstract An achiral pyrazole template has been evaluated in enantioselective conjugate radical additions. The enantioselectivity using the pyrazole template is inferior to those obtained from an oxazolidinone template. The two templates give products of opposite configuration using the same chiral Lewis acid.
Dephasing in open quantum dots

Shape-averaged magnetoconductance (weak localization) is used for the first time to obtain the electron phase coherence time tf in open ballistic GaAs quantum dots. Values for tf in the range of temperature T from 0.34 to 4 K are found to be independent of dot area, and are not consistent with the tf ~ T 22 behavior expected for isolated dots. Surprisingly, tfsT d agrees quantitatively with the predicted dephasing time for disordered two-dimensional electron systems. [S0031-9007(98)06449-7] PACS numbers: 73.20.Fz, 72.70. + m, 73.23. ‐ b Decoherence is the process by which the quantum mechanical properties of a microscopic system are transformed into the familiar classical behavior seen in macroscopic objects. Mesoscopic electronic systems, which exhibit strong coherent quantum mechanical effects such as weak localization and universal conductance fluctuations (UCF), are ideal for investigations of decoherence. The key quantity in these phenomena is the phase coherence time tf, which determines the energy and length scales at which quantum behavior is seen. Considerable theoretical [1‐4] and experimental [5 ‐ 9] study has been directed toward understanding the mechanisms responsible for the loss of phase coherence (dephasing) and their dependence on temperature, dimensionality, and disorder. Most studies of dephasing in mesoscopic systems have focused on disordered 1D and 2D conductors, where the dimensional crossover for quantum corrections to transport and interactions responsible for dephasing occurs when the sample width exceeds the phase coherence length ,f › p Dtf and thermal length ,T › p D ¯
Recent Advances in the Chemistry of Metallacarboranes

Most carborane derivatives of the icosahedral (C2B10) or small cage (C2B4) systems are formed by varying the groups on the cage carbon atoms. This is usually accomplished in the original carborane synthesis by treating substituted acetylenes with either the decaborane(14) or pentaborane(9) precursors to give directly carboranes that have adjacent carbon atoms in the cage (“carbon atoms adjacent”). The larger cages are obtained as closo-icosahedra, while the small-cage C2B4 carboranes have nido structures as well as a cage geometry in which the carbon atoms are separated by a boron atom. Although these “carbon atoms apart” or nido-2,4-(CR)2B4H6 carboranes are thermodynamically more stable and are more symmetric than the “carbon atoms adjacent” isomers, they have not been as well studied, mainly because they must be synthesized from their “carbon atoms adjacent” analogues through a sequential series of oxidative cage-closure/reductive cage-opening reactions. We have concentrated much of our recent research on the reactivity patterns of C(cage)-appended alkyl- and silylamido, alkyloxo, alkylphosphido, and alkylthio derivatives of the “carbon atoms apart” carboranes. We have also sought to develop a safe, bench-scale preparation of small-cage carboranes that does not require isolating and handling dangerous and toxic carborane precursors such as pentaborane(9). This microreview discusses the latest developments towards such a process and the subsequent reaction chemistry of the “carbon atoms apart” carboranes. ((© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Thin-film media—current and future technology

In the last ten years, the fundamental technology of recording media has evolved from particulate to thin film. The introduction of magnetoresistive heads in 1990 has had further impact on the design of thin-film media. Changes in substrates, magnetic films, overcoats, and lubrication form the basis of the evolution. Design concepts and manufacturing considerations for high-areal-density thin-film disks are described in this paper, with reflections on future enhancements required for media of the next generation.
RIM Propeller for Micro Autonomous Underwater Vehicles

Micro autonomous underwater vehicles (AUVs) need small-scale, powerful and safe propulsion systems especially when they are performing missions in pipes and other confined environments. However, the most conventional propulsion systems do not satisfy all three requirements: small, powerful and safe. A micro propulsion system meeting those requirements are developed based on the RIM propeller concept. It is compact and powerful; the complete motor-propeller assembly is 33mm in diameter, 12mm in depth and 16g in weight, and it is capable of producing 0.4N thrust in static water given a 7.1W power input. The paper presents the design, manufacturing and integration of the micro RIM propeller in an AUV.© 2014 ASME
Higgs production with a central jet veto at NNLL+NNLO

United States. Dept. of Energy. Office of High Energy and Nuclear Physics (contract DE-FG02-94ER40818)
Association between audit opinion and provision of non‐audit services

Purpose – While a few US studies on the impact of the provision of non‐audit services on auditor judgment have found potential harm to independence, it is the purpose of this study to investigate whether the British and Australian auditors' involvement with both audit and non‐audit services for the same clients may also produce similar results.Design/methodology/approach – The parametric t‐tests and the nonparametric Mann‐Whitney tests are used in this study on the empirical data from the British and Australian companies to examine the potential for loss of independence when high levels of non‐audit services are provided to audit clients.Findings – The results corroborated the US Securities and Exchange Commission's contention that the provision of non‐audit services may indeed impair independence.Research limitations/implications – No attempts were made to isolate the effects of other factors that could result in the issuance of qualified opinions. In addition, the sample used in this investigation is co...
EFFECTIVE SUBGRID MODELING FROM THE ILES SIMULATION OF COMPRESSIBLE TURBULENCE

Implicit large eddy simulation (ILES) has provided many computer simula- tions with an efficient and effective model for turbulence. Thecapacity for ILES has been shown to arise from a broad class of numerical methods with specific properties producing non-oscillatory solutions using limiters that provide these methods with nonlinear stabil- ity. The use of modified equation has allowed us to understand the mechanisms behind the efficacy of ILES as a model. Much of the understanding of theILES modeling has proceeded in the realm of incompressible flows. Here, we extend this analysis to compress- ible flows. While the general conclusions are consistent with our previous findings the compressible case has several important distinctions. Like the incompressible analysis, the ILES of compressible flow is dominated by an effective self-similarity model (1, 3, 24). Here, we focus on one of these issues, the form of the effective subgrid model for the conservation of mass equations. In the mass equation, the leading order model is a self- similarity model acting on the joint gradients of density and velocity. The dissipative ILES model results from the limiter and upwind differencing resulting in effects propor- tional to the acoustic modes in the flow as well as the convective effects. We examine the model is several limits including the incompressible limit. This equation differs from the standard form found in the classical Navier-Stokes equations, but generally follows the form suggested by Brenner (5) in a modification of Navier-Stokes necessary to suc- cessfully reproduce some experimentally measure phenomena. The implications of these developments are discussed in relation to the usual turbulence modeling approaches.
Synthesis of N-Substituted Azetidin-3-ones

Abstract Addition of RC(0)Cl (R = OEt, Me, or Ph) across the highly strained N-C(3) o-bond in 3-bromomethyl-l-azabicyclo[1.1.0]butane (1) afforded the corresponding N-acyl-3-bromomethyl-3-chloroazetidines (2a-2c, respectively). Subsequent zinc promoted eliminative dehalogenation of 2a-2c produced the corresponding N-acyl-3-methyleneazetidines (3a-3c, respectively). Finally, ozonolysis of 3a-3c afforded the corresopnding N-acylazetidin-3-ones (4a-4c, respectively).
The nature of ferroelectricity under pressure

Advances in first-principles computational approaches have, over the past fifteen years, made possible the investigation of physical properties of ferroelectric systems. In particular, such approaches have led to a microscopic understanding of the occurrence of ferroelectricity in perovskite oxides at ambient pressure. In this article, we report ab initio studies on the effect of hydrostatic pressure on the ferroelectricity in perovskites and related materials. We found that, unlike common belief, these materials exhibit ferroelectricity at high enough pressure. We also explain, in detail the (unusual) nature of this ferroelectricity.
Theory of the Raman Effect in Metals

A theory of the Raman scattering of light by the optical vibration modes of polyatomic metals is presented. A microscopic theory has been developed which describes the modulation of the electronic susceptibility tensor χ μν (ω) by long wavelength optical phonons. We will discuss the various mechanisms which contribute to the change in χ μν with excitation of an optical mode. We point out that in a metal, χ μν may be modulated by odd parity LO phonons, since carrier density fluctuations are associated with them.
The Markov consumption problem

Abstract The paper provides a new model of consumption behavior under uncertainty as the solution to a continuous-time dynamic control problem in which an individual moves between employment and unemployment according to a Markov process. Behavior at low asset levels and at break-even points is analyzed. An iterative procedure is developed to derive numerical solutions. The solution takes the form of two curves relating consumption to assets, one for each state of employment.
A Dynamical System Model of the Traffic Assignment Problem

Abstract User equilibrium is a central concept for studying transportation networks, and one can view it as the result of a dynamical process of drivers’ route choice behavior. In this paper, based on a definition of O–D first-in-first-out violation, we propose a new dynamical system model of the route choice behavior at the aggregate, route level for both static and dynamic transportation networks. An equilibrium of such a dynamical system can be a user equilibrium or a partial user equilibrium. We prove that, for static, symmetric traffic assignment problem with fixed or variable demand, only user equilibria are stable for the dynamical system, and the objective function in the mathematical programming formulation [Beckmann, M., McGuire, C.B., Winsten, C.B., 1956. Studies in the Economics of Transportation. Yale University Press, New Haven, Connecticut, also published as Rand-RM-1488-PR, Rand Corporation, Santa Monica, CA, May 12, 1955.] can be considered as the potential energy of the dynamical system. We then present an Euler-based perturbation method for finding user equilibrium and solve two examples for both static and dynamic traffic assignment problems. This new model is simple in form and could be applied to analyze other properties of transportation networks.
Slow Passage through Resonance in Mathieu's Equation

We investigate slow passage through the 2:1 resonance tongue in Mathieu's equation. Using numerical integration, we find that amplification or de-amplification can occur. The amount of amplification (or de-amplification) depends on the speed of travel through the tongue and the initial conditions. We use the method of multiple scales to obtain a slow flow approximation. The Wentzel-Kramers-Brillouin (WKB) method is then applied to the slow flow equations to obtain an analytic approximation.
Microdegree polarimetry using a diode laser for glucose detection

Current techniques for quantification of blood glucose, particularly in the home environment, have lacked precision. In our investigations into the rotatory effects of glucose upon the polarization vector of light, we have developed a polarimeter capable of microdegree precision. At the present sensitivity, normal physiological levels of blood glucose could be measured within 1%. A linear regression of output voltage corresponding to optical rotation, yielded a standard of deviation of 4.4 microdegrees and a coefficient of linear correlation of 99991. Current and future research is focusing on the elimination of confounding factors such as other optically active substances.
Prolonged implantation of an antibiotic cement spacer for management of shoulder sepsis in compromised patients.

The purpose of this report is to present the preliminary results after treatment of shoulder sepsis with prolonged implantation of an antibiotic-loaded cement spacer in a selected group of compromised patients. The current study included 11 patients (9 men and 2 women) with a mean age of 64 years (range, 36-79 years). All patients were treated with radical debridement, implantation of an antibiotic-impregnated polymethylmethacrylate spacer, and 6 weeks of antibiotic therapy. The subjective complaints, range of motion of the shoulder, functional outcome (mini-Quick Disability of the Arm, Shoulder, and Hand score), and radiographic findings were evaluated. At a mean follow-up of 22 months (range, 15-26 months), 9 patients were free of infection, with pain relief and adequate shoulder function for activities of daily living. Radiographic evaluation revealed no loosening or fracture of the spacer and no progressive degenerative changes involving the glenoid. Prolonged implantation of the spacer may be a useful alternative in selected patients with poor general condition.
Continuum observations at 350 microns of high-redshift molecular emission line galaxies

We report observations of 15 high-redshift (z = 1 – 5) galaxies at 350 μm using the Caltech Submillimeter Observatory and Submillimeter High Angular Resolution Camera II array detector. Emission was detected from eight galaxies, for which far-infrared luminosities, star formation rates (SFRs), total dust masses, and minimum source size estimates are derived. These galaxies have SFRs and star formation efficiencies comparable to other high-redshift molecular emission line galaxies. The results are used to test the idea that star formation in these galaxies occurs in a large number of basic units, the units being similar to star-forming clumps in the Milky Way. The luminosity of these extreme galaxies can be reproduced in a simple model with (0.9-30)×106 dense clumps, each with a luminosity of 5 × 105 L ☉, the mean value for such clumps in the Milky Way. Radiative transfer models of such clumps can provide reasonable matches to the overall spectral energy distributions (SEDs) of the galaxies. They indicate that the individual clumps are quite opaque in the far-infrared. Luminosity-to-mass ratios vary over two orders of magnitude, correlating strongly with the dust temperature derived from simple fits to the SED. The gas masses derived from the dust modeling are in remarkable agreement with those from CO luminosities, suggesting that the assumptions going into both calculations are reasonable.
Mid-infrared imaging of the young binary star hen 3-600: Evidence for a dust disk around the primary

We present high-resolution mid-infrared observations of the nearby late-type young binary system Hen 3-600. The binary, at a distance of ~50 pc, could be a member of the TW Hydrae association, the nearest known group of young stars, with an age of a few million years. Our images make it possible for the first time to determine which star in the pair, separated by 14, harbors the mid-infrared excess detected by IRAS. In the near-infrared, where the radiation is primarily photospheric, Hen 3-600A (M3) and Hen 3-600B (M3.5) have a flux ratio of 1.6. At 4.8, 10.8, and 18.2 μm, the primary becomes increasingly dominant over the secondary, suggesting that most of the circumstellar dust in the system resides around Hen 3-600A. Comparison of the spectral energy distribution (SED) of Hen 3-600A to the median SED of classical T Tauri stars suggests that its disk may be truncated by the secondary and provides tentative evidence for a central disk hole. The distribution of dust in the Hen 3-600 system may provide important clues to the formation and evolution of protoplanetary disks in close binaries.
Entanglement from longitudinal and scalar photons

The covariant quantization of the electromagnetic field in the Lorentz gauge gives rise to longitudinal and scalar photons in addition to the usual transverse photons. It is shown here that the exchange of longitudinal and scalar photons can produce entanglement between two distant atoms or harmonic oscillators. The form of the entangled states produced in this way is very different from that obtained in the Coulomb gauge, where the longitudinal and scalar photons do not exist. A generalized gauge transformation is used to show that all physically observable effects are the same in the two gauges, despite the differences in the form of the entangled states. An approach of this kind may be useful for a covariant description of the dynamics of quantum information processing.
SEC Market Risk Disclosures: Implications for Judgment and Decision Making

In this paper, we draw on judgment and decision‐making research to examine the behavioral implications of the SEC's Financial Reporting Release No. 48 on market risk disclosures. While these disclosures have been examined using archival data, no research has investigated how these disclosures might affect individual users of financial statements. The purpose of our paper is to draw on research in the judgment and decision‐making arena to identify and analyze the behavioral implications of the new risk disclosures. We offer three conclusions. First, FRR No. 48 users may have more complex evaluations of risk than perhaps anticipated by the SEC. Second, the flexibility accorded firms in FRR No. 48 will adversely affect users' risk judgments. Third, because the Release does not require disclosure of certain quantitative information that is important to risk assessments, inappropriate risk assessments may result. We believe our insights can help others conduct research in this important area and can help the S...
Number of people with glaucoma worldwide.

AIM: To estimate the prevalence of glaucoma among people worldwide. METHODS: Available published data on glaucoma prevalence were reviewed to determine the relation of open angle and angle closure glaucoma with age in people of European, African, and Asian origin. A comparison was made with estimated world population data for the year 2000. RESULTS: The number of people with primary glaucoma in the world by the year 2000 is estimated at nearly 66.8 million, with 6.7 million suffering from bilateral blindness. In developed countries, fewer than 50% of those with glaucoma are aware of their disease. In the developing world, the rate of known disease is even lower. CONCLUSIONS: Glaucoma is the second leading cause of vision loss in the world. Improved methods of screening and therapy for glaucoma are urgently needed.
The Term Structure with Semi-credible Targeting

The Federal Reserve sets targets for interest rates which it enforces through direct market intervention. These targets are changed periodically. In this paper, we develop a term structure model in which the short rate is subject to a control which keeps it close to a target which changes from time to time. The probability of target changes is not constant in the model, but changes as a function of observables. The model performs well at explaining the shifts in the yield curve that accompany target changes. IN U.S. FINANCIAL MARKETS, the Federal Reserve Bank (the Fed) is a unique player. Usually we assume that market participants are price takers in financial markets. However, there is evidence that this is not true of the Fed. In fact, the Fed sets targets for short-term rates which it attempts to maintain by market intervention, injecting or withdrawing funds from the market to keep the rates near their targets. Targets are changed from time to time and market participants know when such a target change occurs. They may, in fact, have some limited ability to forecast such target changes. Several recent papers have provided evidence that models which allow the short rate to revert toward a mean, which is itself a random process, perform
On the Presence of Water and Global Circulation in the Transiting Planet HD 189733b

Detailed models are compared to recent infrared observations of the nearby extrasolar planet HD 189733b. It is demonstrated that atmospheric water is present and that the planet's day side has a nonisothermal structure down to gas pressures of ~0.1 bars. Furthermore, model spectra with different amounts of CO are compared to the observations and an atmosphere absent of CO is excluded at roughly 2 σ. Constraining the CO concentration beyond that is unfortunately not possible with the current Spitzer photometry. However, radically enhanced (or depleted) metal abundances are unlikely and the basic composition of this planet is probably similar to that of its host star. When combined with Spitzer observations, a recent ground-based upper limit for the K-band dayside flux allows one to estimate the day-to-night energy redistribution efficiency to be ~43%.
Acoustical properties of highly porous fibrous materials

Highly porous, fibrous bulk sound absorbing materials are studied with a view toward understanding their acoustical properties and performance in a wide variety of applications including liners of flow ducts. The basis and criteria for decoupling of acoustic waves in the pores of the frame and compressional waves in the frame structure are established. The equations of motion are recast in a form that elucidates the coupling mechanisms. The normal incidence surface impedance and absorption coefficient of two types of Kevlar 29 and an open celled foam material are studied. Experimental values and theoretical results are brought into agreement when the structure factor is selected to provide a fit to the experimental data. A parametric procedure for achieving that fit is established. Both a bulk material quality factor and a high frequency impedance level are required to characterize the real and imaginary part of the surface impedance and absorption coefficient. A derivation of the concepts of equivalent density and dynamic resistance is presented.
An electron diffraction study on the structure and conformational composition of 1-bromo-3-methyl-2-butene

Abstract The molecular structure of 1-bromo-3-methyl-2-butene has been studied at a nozzle-tip temperature of 306 K. The major component of the vapor, if not all, consists of the gauche conformer. Three theoretical models have been used to fit the data. A two-conformer model is found to fit the data slightly, but not significantly, better than the static and dynamic one-conformer models. The geometrical parameter values ( r g and ∠ α ) obtained from least-squares analyses are: r (C-H) = 1.078(9)A, r (C=C) = 1.360(9) A, r (C-C) = 1.505(4) A, r (C-Br) = 1.969(9) A, ∠C 1 C 2 =C 3 = ∠C 4 C 3 =C 2 =126° (5), ∠C 5 C 3 =C 2 = 122° (6), ∠BrCC = 110.7° (11), ∠HCC = 111.4° (34), and τ 0 =98° (15).
Noncooperative Entry Deterrence, Uncertainty, and the Free Rider Problem

Previous authors who have considered the issue of noncooperative entry deterrence have not found the free rider problem to be a significant factor. These authors, however, have only considered models in which the exact investment needed to deter entry is known with certainty. In this paper I add uncertainty to the models investigated by these previous authors, and demonstrate that the free rider problem can be significant, but is not so in all cases. That is, for certain types of entry deterring investments the introduction of uncertainty causes the oligopoly to underinvest in entry deterrence; however, for other types no underinvestment result arises.
Model simulations of particle aggregation effect on colloid exchange between streams and streambeds.

Colloids found in natural streams have large reactive surface areas, which makes them significant absorbents and carriers for pollutants. Stream–subsurface exchange plays a critical role in regulating the transport of colloids and contaminants in natural streams. Previous process-based multiphase exchange models were developed without consideration of colloid–colloid interaction. However, many studies have indicated that aggregation is a significant process and needs to be considered in stream process analysis. Herein, a new colloid exchange model was developed by including particle aggregation in addition to colloid settling and filtration. Self-preserving size distribution concepts and classical aggregation theory were employed to model the aggregation process. Model simulations indicate that under conditions of low filtration and high degree of particle–particle interaction, aggregation could either decrease or increase the amount of colloids retained in streambeds, depending on the initial particle si...
Mesoscopic Metal Particles and Wires by Electrodeposition

The electrodeposition of metal onto a low energy electrode surface like graphite or H-terminated silicon produces mesoscopic metal particles that are broadly distributed in diameter. Broad size distributions are observed even in cases where the nucleation of metal is temporally controlled. For this reason, electrodeposition has been infrequently used as a means for obtaining metal nanostuctures. The central problem is the diffusional “cross-talk” that exists between neighboring metal nanostructures on the electrode surface. Evidence for this diffusional interparticle coupling is encoded into particle size and position distributions obtained from experimental data and from Brownian Dynamics computer simulations of nanostructure growth. Diffusional cross-talk between nanostructures can be turned off using either of two growth strategies described in this paper. These methods permit the size-selective electrodeposition of metal nanoparticles and nanowires that are narrowly distributed in diameter.
Trade, employment, and inequality in postreform China

Abstract The paper uses provincial-level Chinese foreign trade statistics, and a 1981 World Bank input-output table for China, to explore the impact of economic reform on employment, trade, and income inequality. The author concludes that trade increases regional inequality, and that 1981 trade decreased total employment in China, but that by 1985, due largely to the agricultural response to reform, net trade had become jobcreating.
The Period and Magnetic Field Distributions of Cataclysmic Variables: Implications for their Evolution

Comparison of the period distributions of various classes of CVs confirms an extreme bias of the synchronous AM Her systems toward short orbital periods, while the DQ Her systems do not differ significantly from the distribution of non-magnetic systems. This suggests either strong selection effects or enhanced evolution of the AM Her systems. There is as yet no obvious bimodality in either the magnetic field distributions of isolated white dwarfs or of CV primaries. However, clear differences between the two exist: the strongest being that magnetic primaries are overrepresented among short period CVs by more than an order of magnitude in comparison to the field white dwarfs.
Jamming model for the extremal optimization heuristic

Extremal optimization, a recently introduced meta-heuristic for hard optimization problems, is analysed on a simple model of jamming. The model is motivated first by the problem of finding lowest energy configurations for a disordered spin system on a fixed-valence graph. The numerical results for the spin system exhibit the same phenomenology found in all earlier studies of extremal optimization, and our analytical results for the model reproduce many of these features.
The consequences of the US DOJ’s antitrust activities: A macroeconomic perspective

Do the antitrust law enforcement activities of the US Department of Justice act as exogenous “technology shocks” or as “markup shocks” limiting market power and promoting economic growth? We analyze annual time series data from 1947 to 2003 on three measures of federal antitrust intervention: the ratio of the Antitrust Division’s budgetary expenditures to GDP as well as the numbers of civil and criminal antitrust cases instituted. We find that changes in the levels of these policy variables act like negative technology shocks and that the negative effects are transitory; antitrust policy generates no subsequent offsetting increases in productivity.
Euler flutter analysis of airfoils using unstructured dynamic meshes

Modifications to a two-dimensional unsteady Euler code for the aeroelastic analysis of airfoils are described. The modifications involve including the structural equations of motion and their simultaneous time-integration with the governing flow equations. A novel aspect of the capability is that the solutions are obtained using unstructured grids made up of triangles. Comparisons are made with parallel calculations performed using linear theory and a structured grid Euler code to assess the accuracy of the unstructured grid Euler results. Results are presented for a flat plate airfoil and the NACA 0012 airfoil to demonstrate applications of the Euler code for generalized force computations and aeroelastic analysis. In these comparisons, two different finite-volume discretizations of the Euler equations on unstructured meshes were employed. Sensitivity of the Euler results to changes in numerical parameters were also investigated.
Curvature actions on Spin(n) bundles

We compute the number of linearly independent ways in which a tensor of Weyl type may act upon a given irreducible tensor-spinor bundle ν over a Riemannian manifold. Together with the analogous but easier problem involving actions of tensors of Einstein type, this enumerates the possible curvature actions on ν.
Ultraviolet Hubble Space Telescope Observations of the Jet in M87

We present new ultraviolet photometry of the jet in M87 obtained from Hubble Space Telescope (HST) WFPC2 imaging. We combine these ultraviolet data with previously published photometry for the knots of the jet in radio, optical, and X-ray and fit three theoretical synchrotron models to the full data set. The synchrotron models consistently overpredict the flux in the ultraviolet when fitted over the entire data set. We show that if the fit is restricted to the radio through ultraviolet data, the synchrotron models can provide a good match to the data. The break frequencies of these fits are much lower than previous estimates. The implied synchrotron lifetimes for the bulk of the emitting population are longer than in earlier work but still much shorter than the estimated kinematic lifetimes of the knots. The observed X-ray flux cannot be successfully explained by the simple synchrotron models that fit the ultraviolet and optical fluxes. We discuss the possible implications of these results for the physical properties of the M87 jet. We also observe increased flux for the HST-1 knot that is consistent with previous results for flaring. This observation fills in a significant gap in the time coverage early in the history of the flare and therefore sets constraints on the initial brightening of the flare.
Looking at Individual Subjects in Research on Judgment and Decision Making (or anything)

Many questions in judgment and decision-making research, and, indeed, in experimental psychology generally, concern the existence of effects, and the explanation of effects shown to exist. These questions do not concern the prevalence of effects in any particular population. It is thus appropriate to look for effects in single subjects. If one person shows the effect, then it exists. This argument implies that it is sometimes appropriate to test effects across cases or rounds, without testing across subjects. It also implies that, in some experiments, effects in opposite directions may exist. I recommend looking for such effects by carrying out statistical tests on individual subjects. I describe a few methods, varying in formality, that can be used to deal with the inevitable problem of doing multiple tests of the same hypothesis: probability-probability plots; tests of the distribution of p-values; and correction for multiple testing with step-down resampling. I also present a few examples, some of which show effects in both directions and some of which do not.