cssi/SciSciGPT-SciSciNet huggingface dataset:
Non-abelian Toda theory: A completely integrable model for strings on a black hole background

Abstract The present paper studies a completely integrable conformally invariant model in 1 + 1 dimensions that corresponds to string propagation on the two-dimensional black hole background (semi-infinite cigar). Besides the two space-time string fields there is a third (internal) field with a very specific Liouville-type interaction leading to the complete integrability. This system is known as the non-abelian Toda theory. I give the general explicit classical solution. It realizes a rather involved transformation expressing the interacting string fields in terms of (three plus three) functions ϕ j (u) and ϕ j (v) of one light-cone variable only. The latter are shown to lead to standard harmonic oscillator (free-field) Poisson brackets thus paving the way towards quantization. There are three left-moving and three right-moving conserved quantities. The right(left)-moving conserved quantities form a new closed non-linear, non-local Poisson bracket algebra. This algebra is a Virasoro algebra extended by two conformal dimension-two primaries.
Ordinary varieties and the comparison between multiplier ideals and test ideals II

We consider the following conjecture: if X is a smooth projective variety over a field of characteristic zero, then there is a dense set of reductions X_s to positive characteristic such that the action of the Frobenius morphism on the top Zariski cohomology of the structure sheaf on X_s is bijective. We also consider the conjecture relating the multiplier ideals of an ideal J on a nonsingular variety in characteristic zero, and the test ideals of the reductions of J to positive characteristic. We prove that the latter conjecture implies the former one. The converse was proved in a joint paper of the author with V. Srinivas.
Bijections on Rooted Trees with Fixed Size of Maximal Decreasing Subtrees

Recently, Seo and Shin showed that the number of rooted trees on [n + 1] = 1, 2, . . . , n+1 such that the maximal decreasing subtree with the same root has k + 1 vertices is equal to the number of functions f : [n] → [n] such that the image of f contains [k]. We give a bijective proof of this theorem.
Global Existence and Increased Spatial Decay for the Radial Vlasov‐Poisson System with Steady Spatial Asymptotics

A collisionless plasma is modeled by the Vlasov‐Poisson system in three space dimensions. A fixed background of positive charge, which is independent of time and space, is assumed. The situation in which mobile negative ions balance the positive charge as |x|→∞ is considered. Hence the total positive charge, total negative charge, and total energy are infinite. Smooth solutions with appropriate asymptotic behavior for large |x|, which were previously shown to exist locally in time, are continued globally for spherically symmetric data. This is done by showing that the charge density decays at least as fast as |x|−4. Finally, an increased decay rate of |x|−6 is shown in the general case without the assumption of spherical symmetry.
On the control of a clinker cooler through state variable techniques and simulation

This paper relates to an exploratory computer control project for the digital control of a cement plant. The control of the clinker cooler was part of the project. State variable techniques were applied for the synthesis of the control system. Here, the emphasis will be on off-line simulation. A control law will be generated for the control of the over grate differential pressure. It is claimed that simulation techniques are essential tools for the successful design and implementation of digital control in industry.
The Mechanism of Charge Transfer at Electrodes

A detailed theoretical investigation of the roles played by classical electron transfer, quantum mechanical electron transfer and classical proton transfer led to the formulation of a new mechanism of charge transfer in the discharge step of the hydrogen evolution reaction. The mechanism of charge transfer was shown to have general applicability to charge transfer processes at electrodes. The theory led to the recognition of the resonance nature of the activated state, to the determination of the charge distribution in the activated state, and to a better physical understanding of the symmetry factor, $\beta$, in electrode kinetics.
gem-Dialkoxylation of 2-acetylthiophenes and 2-acetylfurans

Reaction of 2-acetyl-substituted thiophenes and furans with alkyl nitrites in the presence of the corresponding aliphatic alcohols and hydrochloric acid leads to the formation of linear acetals of thienyl- and furylglyoxals, whose structure was established by IR, UV, NMR spectroscopy, and mass spectrometry methods. The main paths of the dissociation of the molecules under electron impact were established.
An Effective action for monopoles and knot solitons in Yang-Mills theory

Abstract By comparison with numerical results in the maximal Abelian projection of lattice Yang–Mills theory, it is argued that the nonperturbative dynamics of Yang Mills theory can be described by a set of fields that take their values in the coset space SU(2)/U(1). The Yang–Mills connection is parameterized in a special way to separate the dependence on the coset field. The coset field is then regarded as a collective variable, and a method to obtain its effective action is developed. It is argued that the physical excitations of the effective action may be knot solitons. A procedure to calculate the mass scale of knot solitons is discussed for lattice gauge theories in the maximal Abelian projection. The approach is extended to the SU( N ) Yang–Mills theory. A relation between the large N limit and the monopole dominance is pointed out.
Recent work on Cepheid variables

Recent work on Cepheids is reviewed in the areas of (1) the large-amplitude mode behavior, (2) convection, and (3) Cepheid masses. Initial-value type nonlinear calculations have not yet yielded true double-mode behavior. Yet we have the beginnings of a promising theory of modal selection. Theoretical calculations also yield reasonably located red edges to Cepheid (and Cepheid-like) instability regions. Recent observational results have led to increased values of the “pulsation mass,” so that this mass is now in fair agreement with evolution theory. The “Wesselink mass” is also satisfactory. Thus now only “bump” and “beat” masses are possibly discrepant. Some possible ways which have been suggested to alleviate these discrepancies are reviewed. The proposal of helium enrichment in the outer stellar layers can apparently satisfactorily resolve the beat (and perhaps also the bump) mass anomaly. A recent suggestion that part of the pressure in the envelope is due to a tangled magnetic field (not unusually strong) resolves the above mass anomaly about as well as the helium-enrichment idea does. Recent results regarding duplicity and period changes in Cepheids are reviewed.
Thermal indicating paints for ammunition health monitoring

Thermochromic semiconductive polymers that change color in response to external stimuli, such as heat and radiation, can be utilized to monitor the temperature range and elapsed time profiles of stored and prepositioned munitions. These polymers are being tailored to create paints and coatings that will alert Army logistic staff of dangerous temperature exposures. Irreversible indication via color change in multiple thermal bands, 145 F - 164 F (63o-73°C), 165 F - 184 F (74° - 84° C) and over 185 F (>85°C) are possible with these thermochromic polymers. The resulting active coating can be visually inspected to determine if safe temperatures were exceeded. More detailed information, including cumulative time of exposure in certain temperature bands through changes in optical chromaticity describing the vividness or dullness of a color, can be assessed using a hand-held optical densitometer.
Cylindrical IEC Fusion Neutron Source for Broad Area NAA

The development of a unique long cylindrical neutron source for broad area neutron activation analysis (NAA) is presented. This source uses inertial electrostatic confinement (IEC) to produce 2.54 MeV D-D or 14.1 MeV D-T fusion neutrons for applications ranging from security inspection stations to driven-subcritical research assemblies. This design uses a biased grid to initial in a unique “star” mode plasma discharge forming beam-background gas (target) fusion. In spherical geometry it routinely produces ∼108 2.54-MeV D-D fusion neutrons/s at steady-state. Pulsed operation has achieved up to 109 neutrons/sec. (equivalent to 1011 n/s using D-T fill). Indeed, a version of the spherical IEC has been produced commercially as a portable neutron source for industrial NAA applications. Recently a cylindrical (2-dimensional version) design based on the spherical unit has been developed. This provides a unique long “line-like” neutron source for use in broad area NAA. This IEC forms ion beams in the volume between the grounded wall and the concentric cylindrical grid. Those beams converge in the center, much like in the star mode spherical IEC. To date, neutron yields of up to 108 D-D neutrons/sec have been achieved with the cylindrical device. A sealed-off unit using getters for gas storage-control has been developed to simplify use in practical applications such as a luggage inspection station. Such units would be filled with deuterium at a central fueling facility, and sent out to the field. After extended operation, they would be returned to this facility for refilling.Copyright © 2010 by ASME
Titan impacts and escape

Abstract We report on hydrodynamic calculations of impacts of large (multi-kilometer) objects on Saturn’s moon Titan. We assess escape from Titan, and evaluate the hypothesis that escaping ejecta blackened the leading hemisphere of Iapetus and peppered the surface of Hyperion. We carried out two- and three-dimensional simulations of impactors ranging in size from 4 to 100 km diameter, impact velocities between 7 and 15 km s −1 , and impact angles from 0° to 75° from the vertical. We used the ZEUSMP2 hydrocode for the calculations. Simulations were made using three different geometries: three-dimensional Cartesian, two-dimensional axisymmetric spherical polar, and two-dimensional plane polar. Three-dimensional Cartesian geometry calculations were carried out over a limited domain (e.g. 240 km on a side for an impactor of size d i = 10 km), and the results compared to ones with the same parameters done by Artemieva and Lunine (2005) ; in general the comparison was good. Being computationally less demanding, two-dimensional calculations were possible for much larger domains, covering global regions of the satellite (from 800 km below Titan’s surface to the exobase altitude 1700 km above the surface). Axisymmetric spherical polar calculations were carried out for vertical impacts. Two-dimensional plane-polar geometry calculations were made for both vertical and oblique impacts. In general, calculations among all three geometries gave consistent results. Our basic result is that the amount of escaping material is less than or approximately equal to the impactor mass even for the most favorable cases. Amounts of escaping material scaled most strongly as a function of velocity, with high-velocity impacts generating the largest amount, as expected. Dependence of the relative amount of escaping mass f esc = m esc / M i on impactor diameter d i was weak. Oblique impacts (impact angle θ i > 45°) were more effective than vertical or near-vertical impacts; ratios of m esc / M i ∼ 1–2 were found in the simulations.
Unusual Catalytic Properties of Usual Enzymes

The major objective of this paper is to stress that enzymes, in addition to their “normal” reactions (reflected in their names), often can catalyze other, sometimes quite different processes. The latter, although unimportant for the enzyme-producing organism, can be very valuable for biotechnological applications. The considered examples of “unnatural” catalytic activities of common enzymes, taken from the author’s recent studies include: (I) reduction of aromatic compounds catalyzed by glucose oxidase; (II) prochiral and enantiomeric stereo-specificity of galactose oxidase in the oxidation of non-sugar, three carbon alcohols; (III) selective hydroxylation of aromatic compounds catalyzed by peroxidase; (IV) geometrically and positionally specific oxidation of aromatic aldehydes catalyzed by xanthine oxidase.
Nilpotent orbits in classical Lie algebras over finite fields of characteristic 2 and the Springer correspondence

Let G be an adjoint algebraic group of type B, C, or D over an algebraically closed field of characteristic 2. We construct a Springer correspondence for the Lie algebra of G. In particular, for orthogonal Lie algebras in characteristic 2, the structure of component groups of nilpotent centralizers is determined and the number of nilpotent orbits over finite fields is obtained.
A High Yield Neutron Target for Cancer Therapy

A rotating target has been developed that has the potential for providing an initial yield of 1013 neutrons per second by the T(d,n) He4 reaction, and a useable lifetime in excess of 600 hours. This yield and lifetime are indicated for a 300 KV and 30 mA deuteron accelerator and a 30 ?m thick titanium tritide film formed of the stoichiometric compound TiT2. The potential for extended lifetime is made possible by incorporating a sputtering electrode that permits use of titanium tritide thicknesses much greater than the deuteron range. The electrode is used to remove in situ depleted titanium layers to expose fresh tritide beneath. The utilization of the rotating target as a source of fast neutrons for cancer therapy is discussed.
Giant planet formation with pebble accretion

Abstract In the core accretion model for giant planet formation, a solid core forms by coagulation of dust grains in a protoplanetary disk and then accretes gas from the disk when the core reaches a critical mass. Both stages must be completed in a few million years before the disk gas disperses. The slowest stage of this process may be oligarchic growth in which a giant-planet core grows by sweeping up smaller, asteroid-size planetesimals. Here, we describe new numerical simulations of oligarchic growth using a particle-in-a-box model. The simulations include several processes that can effect oligarchic growth: (i) planetesimal fragmentation due to mutual collisions, (ii) the modified capture rate of planetesimals due to a core’s atmosphere, (iii) drag with the disk gas during encounters with the core (so-called “pebble accretion”), (iv) modification of particle velocities by turbulence and drift caused by gas drag, (v) the presence of a population of mm-to-m size “pebbles” that represent the transition point between disruptive collisions between larger particles, and mergers between dust grains, and (vi) radial drift of small objects due to gas drag. Collisions between planetesimals rapidly generate a population of pebbles. The rate at which a core sweeps up pebbles is controlled by pebble accretion dynamics. Metre-size pebbles lose energy during an encounter with a core due to drag, and settle towards the core, greatly increasing the capture probability during a single encounter. Millimetre-size pebbles are tightly coupled to the gas and most are swept past the core during an encounter rather than being captured. Accretion efficiency per encounter increases with pebble size in this size range. However, radial drift rates also increase with size, so metre-size objects encounter a core on many fewer occasions than mm-size pebbles before they drift out of a region. The net result is that core growth rates vary weakly with pebble size, with the optimal diameter being about 10 cm. The main effect of planetesimal size is to determine the rate of mutual collisions, fragment production and the formation of pebbles. 1-km-diameter planetesimals collide frequently and have low impact strengths, leading to a large surface density of pebbles and rapid core growth via pebble accretion. 100-km-diameter planetesimals produce fewer pebbles, and pebble accretion plays a minor role in this case. The strength of turbulence in the gas determines the scale height of pebbles in the disk, which affects the rate at which they are accreted. For an initial solid surface density of 12 g/cm2 at 5 AU, with 10-cm diameter pebbles and a disk viscosity parameter α = 10 - 4 , a 10-Earth mass core can form in 3 My for 1–10 km diameter planetesimals. The growth of such a core requires longer than 3 My if planetesimals are 100 km in diameter.
N=1 Conformal Superspace in Four Dimensions

Abstract We construct in detail an N = 1 , D = 4 superspace with the superconformal algebra as the structure group and discuss its relation to prior component approaches and the existing Poincare superspaces.
Tunable terahertz quantum cascade lasers with external gratings

We demonstrate a frequency tunable external cavity terahertz quantum cascade laser using an abutted antireflection-coated silicon lens to reduce facet reflection and as a beam-forming element, with an external grating providing frequency selective optical feedback. Angle tuning of the grating allows a single longitudinal mode of the laser ridge to be selected, resulting in discontinuous tuning over a 165 GHz range around a center frequency of 4.4 THz. Another device exhibited 145 GHz of total tuning with 9 GHz of continuous tuning near the longitudinal modes of the laser.
Water-mediated catalyst preactivation: an efficient protocol for C-N cross-coupling reactions.

A protocol for forming a highly active Pd(0) catalyst from Pd(OAc)2, water, and biaryldialkylphosphine ligands has been developed. This protocol generates a catalyst system, which exhibits excellent reactivity and efficiency in the coupling of a variety of amides and anilines with aryl chlorides.
Progressive Damage Analysis of Random Chopped Fiber Composite Using Finite Elements

The mechanical properties of random chopped fiber composites are analyzed using micromechanical principles. A progressive damage model is adopted to investigate the damage and failure of the material. A representative volume element is generated numerically based on microscopic observations that capture the complex mesostructure of the random chopped fiber composite specimens. Sequentially the mechanical properties are obtained using a micromechanics approach, particularly, the homogenization method. The underlying hypothesis insinuates that damage mechanisms such as matrix cracking, fiber damage, and interfacial debonding are responsible for the damaged behavior of the composite. Matrix cracking and fiber damage are modeled by progressive degradation of their respective stiffnesses. The interfacial debonding is modeled with a cohesive zone model. The prediction of uniaxial tensile response is compared with experimental data.
Traces on the skein algebra of the torus

Abstract For a surface F, the Kauffman bracket skein module of F × [ 0 , 1 ] , denoted K ( F ) , admits a natural multiplication which makes it an algebra. When specialized at a complex number t, nonzero and not a root of unity, we have K t ( F ) , a vector space over C . In this paper, we will use the product-to-sum formula of Frohman and Gelca to show that the vector space K t ( T 2 ) has five distinct traces. One trace, the Yang–Mills measure, is obtained by picking off the coefficient of the empty skein. The other four traces on K t ( T 2 ) correspond to the four singular points of the moduli space of flat SU ( 2 ) -connections on the torus.
Venous Thromboembolism in Children

With improved pediatric survival from serious underlying illnesses, greater use of invasive vascular procedures and devices, and a growing awareness that vascular events occur among the young, venous thromboembolism (VTE) increasingly is recognized as a critical pediatric concern. This review provides background on etiology and epidemiology in this disorder, followed by an indepth discussion of approaches to the clinical characterization, diagnostic evaluation, and management of pediatric VTE. Prognostic indicators and long-term outcomes are considered, with emphasis on available evidence underlying current knowledge and key questions for further investigation.
The CsLnMSe3 semiconductors (Ln = rare-earth element, Y; M = Zn, Cd, Hg).

CsLnCdSe3 (Ln = Ce, Pr, Sm, Gd, Tb, Dy, Y) and CsLnHgSe3 (Ln = La, Ce, Pr, Nd, Sm, Gd, Y) have been synthesized at 1123 K. These isostructural materials crystallize in the layered KZrCuS3 structure type in the orthorhombic space group Cmcm and are group X extensions of the previously characterized Zn compounds. The structure is composed of two-dimensional [LnMSe3] layers that stack perpendicular to [010] and are separated by layers of face- and edge-sharing CsSe8 bicapped trigonal prisms. Because there are no Se−Se bonds in the structure of CsLnMSe3 (M = Zn, Cd, Hg), the formal oxidation states of Cs/Ln/M/Se are 1+/3+/2+/2−. CsSmHgSe3 does not adhere to the Curie−Weiss law, whereas CsCeHgSe3 and CsGdHgSe3 are Curie−Weiss paramagnets with μeff values of 2.77 and 7.90 μB, corresponding well with the theoretical values of 2.54 and 7.94 μB for Ce3+ and Gd3+, respectively. Single-crystal optical absorption measurements were performed with polarized light perpendicular to the (010) and (001) crystal faces of th...
Analysis of gene networks in white adipose tissue development reveals a role for ETS2 in adipogenesis

Obesity is characterized by an expansion of white adipose tissue mass that results from an increase in the size and the number of adipocytes. However, the mechanisms responsible for the formation of adipocytes during development and the molecular mechanisms regulating their increase and maintenance in adulthood are poorly understood. Here, we report the use of leptin-luciferase BAC transgenic mice to track white adipose tissue (WAT) development and guide the isolation and molecular characterization of adipocytes during development using DNA microarrays. These data reveal distinct transcriptional programs that are regulated during murine WAT development in vivo. By using a de novo cis-regulatory motif discovery tool (FIRE), we identify two early gene clusters whose promoters show significant enrichment for NRF2/ETS transcription factor binding sites. We further demonstrate that Ets transcription factors, but not Nrf2, are regulated during early adipogenesis and that Ets2 is essential for the normal progression of the adipocyte differentiation program in vitro. These data identify ETS2 as a functionally important transcription factor in adipogenesis and its possible role in regulating adipose tissue mass in adults can now be tested. Our approach also provides the basis for elucidating the function of other gene networks during WAT development in vivo. Finally these data confirm that although gene expression during adipogenesis in vitro recapitulates many of the patterns of gene expression in vivo, there are additional developmental transitions in pre and post-natal adipose tissue that are not evident in cell culture systems.
Cohomogeneity one manifolds with positive Euler characteristic

We classify those manifolds of positive Euler characteristic on which a Lie group G acts with cohomogeneity one, where G is classical simple.
SN 2006gy: An Extremely Luminous Supernova in the Galaxy NGC 1260

With an extinction-corrected V-band peak absolute magnitude of about -22, supernova SN 2006gy is probably the brightest SN ever observed. We report on multiwavelength observations of this SN and its environment. Our spectroscopy shows an Hα emission line as well as absorption features that may be identified as Si II lines at low expansion velocity. The slow brightening, the peak luminosity, and the Hα emission line resemble those observed in hybrid Type IIn/Ia SNe (also known as Type IIa) and may suggest that SN 2006gy is related to the Type IIa SNe class. The host galaxy, NGC 1260, is dominated by an old stellar population with solar metallicity. However, our high-resolution adaptive optics images reveal a dust lane in this galaxy, and there appears to be an H II region in the vicinity of the SN. The extraordinarily large peak luminosity, ~3 × 10^(44) ergs s^(-1), demands a dense circumstellar medium, regardless of the mass of the progenitor star. The inferred mass-loss rate of the progenitor is ~0.1 M_☉ yr^(-1) over a period of ~10 yr prior to explosion. Such an high mass-loss rate may be the result of a binary star common envelope ejection. The total radiated energy in the first 2 months is about 1.1 × 10^(51) ergs, which is only a factor of 2 less than that available from a super-Chandrasekhar Type Ia explosion. Therefore, given the presence of a star-forming region in the vicinity of the SN and the high-energy requirements, a plausible scenario is that SN 2006gy is related to the death of a massive star
Assessing Asset Indices

This paper compares how results using various methods to construct asset indices match results using per capita expenditures. The analysis shows that inferences about inequalities in education, health care use, fertility, child mortality, as well as labor market outcomes are quite robust to the specific economic status measure used. The measures-most significantly per capita expenditures versus the class of asset indices-do not, however, yield identical household rankings. Two factors stand out in predicting the degree of congruence in rankings between per capita expenditures and an asset index. First is the extent to which per capita expenditures can be explained by observed household and community characteristics. In settings with small transitory shocks to expenditure, or with little measurement error in expenditure, the rankings yielded by the alternative approaches are most similar. Second is the extent to which expenditures are dominated by individually consumed goods such as food. Asset indices are typically derived from indicators of goods which are effectively public at the household level, while expenditures are often dominated by food, an almost exclusively private good. In settings where private goods such as food are the main component of expenditures, asset indices and per capita consumption yield the least similar results, although adjusting for economies of scale in household expenditures reconciles the results somewhat.
Network Analyzer Calibration for Cryogenic On-Wafer Measurements

A cryogenic probe station for on-wafer microwave measurements has been developed at Sandia National Laboratories to explore basic device physics and characterize advanced components for low-temperature applications. The station was designed to operate over a temperature range of 20 to 300 K with a frequency range of DC to 50 GHz. Due to the vacuum and the low temperature environment, the use of microwave probes and the calibration of network analyzer measurements are somewhat elaborate. This paper presents guidelines for probe use and calibration in this environment.
Examples of hypersurfaces flowing by curvature in a Riemannian manifold

This paper gives some examples of hypersurfaces ϕt(M n ) evolving in time with speed determined by functions of the normal curvatures in an (n + 1)-dimensional hyperbolic manifold; we emphasize the case of flow by harmonic mean curvature. The examples converge to a totally geodesic submanifold of any dimension from 1 to n, and include cases which exist for infinite time. Convergence to a point was studied by Andrews, and only occurs in finite time. For dimension n = 2, the destiny of any harmonic mean curvature flow is strongly influenced by the genus of the surface M 2 .
Superconformally covariant OPE and general gauge mediation

We consider using broken superconformal symmetry and the super operator product expansion (sOPE) to constrain and analyze hidden sector theories that couple to our gauge forces and are not necessarily weakly coupled. Conformal and supersymmetry breaking are IR effects, associated with field or spurion expectation values, whereas the sOPE is determined in the UV and hence does not notice the breaking. The broken superconformal symmetry relates OPE coefficients of superconformal descendant operators to those of the superconformal primaries. We apply these ideas to the current correlators of general gauge mediation (GGM). We also consider analyticity properties of these correlators, e.g. their discontinuities, and use the optical theorem to relate them to total scattering cross sections from visible to hidden sector states, e.g. σ(vis + vis → hidden), analogous to σ(e + e − → hadrons) in QCD. We discuss how the current-current OPE can be truncated to the first few terms to get a good approximation to the visible sector soft masses of GGM.
Photon dependence of inorganic nitrogen transport by phytoplankton in perennially ice-covered antarctic lakes

15N was used to examine the influence of Photosynthetic Photon Flux Density (PPFD) on NO3 − and NH4 + transport by phytoplankton in the shallow and deep-chlorophyll layers of Lakes Fryxell and Vanda, Antarctica. The response observed in Lake Vanda could be modelled with a four parameter equation previously used to model photosynthesis. Only the 9 m NH4 + transport experiments in Lake Fryxell could be modelled with this equation. Other experiments in Lake Fryxell showed either no response to PPFD or a linear increase with no saturation at the PPFD levels used. Distinct trends were observed in transport parameters both between depths and between nitrogen species. Overall, the parameters indicate that phytoplankton in these lakes possess nitrogen transport affinities similar to those reported for other aquatic systems.
A nested logit model of strategic promotion

This paper presents a test of the nature of the pricing and promotion game played by supermarket retailers in a large, U.S. market. Using a nested-logit modeling approach, the results show that retailers set discount depth and promotional frequency in a manner that is less competitive than Bertrand. We also find that the elasticity of substitution among competing stores is lower than among products within each store, but not equal to zero. Therefore, sales do cannibalize existing products, but can also build a significant amount of store-traffic. Relative to strategic factors, price promotions have their greatest impact on store-conditional product demand.
Polypyrrole-clay-modified electrodes

Abstract Polypyrrole-clay-modified electrodes have been prepared by electropolymerization of pyrrole monomer onto clay-modified electrodes from both aqueous and acetonitrile solutions. Both Ru(NH3)63+ and FeSO4 have been incorporated into the clay prior to electropolymerization of pyrrole monomer. Ru(NH3)63+ : clay-modified electrodes exhibit a larger faradaic current attributed to Ru(NH3)63+ upon the imposition of a potential sweep in a pyrrole + acetonitrile solution. The ion redox potential for Fe(II) or Fe(III): clay-modified electrodes in an aqueous solution shifts 300 mV more negative after electropolymerization of pyrrole onto the electrode. The aqueous polymerization of pyrrole at a clay-modified electrode results in a composite material which is mechanically more stable than either the clay or polypyrrole and with a resistance of about 350 Ω. Scanning electron microscopy shows clearly the formation of hemispherical nodules at a clay-modified electrode upo electropolymerization in pyrrole + acetonitrile, and the formation of microparticles upon codeposition of pyrrole and clay in an aqueous solution. The polypyrrole appears to improve the electrochemical properties of ion-incorporated clay-modified electrodes.
Facile synthesis and stabilization of 2-arachidonylglycerol via its 1,3-phenylboronate ester

Abstract 2-Arachidonylglycerol (2-Ara-Gl) was synthesized via the intermediacy of its 1,3-phenylboronic acid ester. The boronate ester is easily stable enough to enable chromatographic resolution from the corresponding 1-Ara-Gl boronate ester on normal phase elution yet immediately and completely hydrolyzes to 2-Ara-Gl and phenylboronic acid, without isomerization, by simple solution in aqueous-organic solvents. The phenylboronate ester of this 2-acylglycerol has the added advantage of being markedly more stable to both isomerization and oxidation upon storage than the labile 2-Ara-Gl.
Syntheses of perfluoroalkyl N-polyethoxylated amides

Abstract Monodisperse perfluoroalkyl N-polyethoxylated amides, CnF2n+1CONH(CH2CH2O)mH, with n = 6, 7, 8 and 9 and m = 2, 3, and 4, are potential nonionic fluorinated surfactants. The syntheses: of these compounds are described.
First enantioselective total synthesis of the endogenous natriuretic agent LLU-α

Abstract The endogenous natriuretic agent LLU-α, 1 , has been synthesized from geraniol 4 in 13 steps and 18% overall yield. The two key steps are a Gassman-Sato process to give the phenol 8 and cyclization of the triol 10 with acid to give the chroman 12 with retention of configuration at the tertiary alcohol center. Final oxidation gave 1 .
Molecular structure of 2,4-dicarba-closo.heptaborane-7 by gas-phase electron diffraction

Abstract Gas phase electron diffraction patterns of 2,4-dicarba-closo-heptaborane were recorded at room temperature. Least squares analysis of the reduced intensity data show that the molecule is a pentagonal bipyramid and confirms the C 2v symmetry in the gas phase. The carbon atoms are located in the pentagonal belt and are separated by one boron atom. No significant departures from planarity of the pentagonal belt are indicated. The bond lengths in the belt are C(4)-B(3), 1.537 A, C(4)-B(5), 1.558 A, and B(5)-B(6), 1.659 A. The distance from the apical B(l) atom to the B(3) is 1.852 A, from the B(1) to the B(5) atom is 1.772 A, and from the B(1) to the C(2) atom is 1.717 A. The bond angles in the pentagonal belt are C(2)B(3)C(4) = 100.5°, B(3)C(4)B(5) = 116.7° and C(4)B(5)B(6) = 103.0°. The angle between B(1)B(3)B(7) = 84.7°. Comparisons are made with structural data and moments of inertia determined by microwave spectroscopy.
Chandra X-Ray Point Sources, Including Supernova 1979C, in the Spiral Galaxy M100

Six X-ray point sources, with luminosities of 4 × 1038-2 × 1039 ergs s-1 in the 0.4-7 keV band, were detected in Chandra observations of the spiral galaxy M100. One source is identified with supernova SN 1979C and appears to have roughly constant X-ray flux for the period 16-20 yr after the outburst. The X-ray spectrum is soft, as would be expected if the X-ray emission is due to the interaction of supernova ejecta with circumstellar matter. Most of the other sources are variable either within the Chandra observation or when compared to archival data. None are coincident with the peak of the radio emission at the nucleus. These sources have harder spectra than the supernova and are likely X-ray binaries. M100 has more bright X-ray sources than typical for spiral galaxies of its size. This is likely related to active star formation occurring in the galaxy.
Sorting on a mesh-connected parallel computer

Two algorithms are presented for sorting n2 elements on an n × n mesh-connected processor array that require O (n) routing and comparison steps. The best previous algoritmhm takes time O(n log n). The algorithms of this paper are shown to be optimal in time within small constant factors. Extensions to higher-dimensional arrays are also given.
Autonomous scene description with range imagery

Abstract This paper presents a program to produce object-centered 3-dimensional descriptions starting from point-wise 3D range data obtained by a light-stripe rangefinder. A careful geometrical analysis shows that contours which appear in light-stripe range images can be classified into eight types, each with different characteristics in occluding vs occluded and different camera/illuminator relationships. Starting with detecting these contours in the iconic range image, the descriptions are generated moving up the hierarchy of contour, surface, object, to scene. We use conical and cylindrical surfaces as primitives. In this process, we exploit the fact that coherent relatinships, such as symmetry, and being coaxial, which are present among lower-level elements in the hierarchy allow us to hypothesize upper-level elements. The resultant descriptions are used for matching and recognizing objects. The analysis program has been applied to complex scenes containing cups, pans, and toy shovels.
The immersed interface method using a finite element formulation

A finite element method is proposed for one dimensional interface problems involving discontinuities in the coefficients of the differential equations and the derivatives of the solutions. The interfaces do not have to be one of grid points. The idea is to construct basis functions which satisfy the interface jump conditions. By constructing an interpolating function of the solution, we are able to give a rigorous error analysis which shows that the approximate solution obtained from the finite element method is second order accurate in the infinity norm. Numerical examples are also provided to support the method and the theoretical analysis. Several numerical approaches are also proposed for dealing with two dimensional problems involving interfaces.
Vacuum nucleon loops and naturalness

Abstract Phenomenological studies support the applicability of naturalness and naive dimensional analysis to hadronic effective lagrangians for nuclei. However, one-baryon-loop vacuum contributions in renormalizable models give rise to unnatural coefficients, which indicates that the quantum vacuum is not described adequately. The effective lagrangian framework accommodates a more general characterization of vacuum contributions without reference to a Dirac sea of nucleons.
Access Control in a Core Calculus of Dependency

The Dependency Core Calculus (DCC) is an extension of the computational lambda calculus that was designed in order to capture the notion of dependency that arises in information-flow control, partial evaluation, and other programming-language settings. We show that, unexpectedly, DCC can also be used as a calculus for access control in distributed systems. Initiating the study of DCC from this perspective, we explore some of its appealing properties.
Autoimmune liver disease

Regional differences in the manifestations of autoimmune hepatitis underscore the importance of genetic and/or environmental factors in its expression. The -308 polymorphism of TNF-A increases susceptibility to type 1 autoimmune hepatitis; HLA DRB1*13 is an important risk factor in South America; and DRB1*07 characterizes type 2 autoimmune hepatitis. Minocycline and mesalazine can trigger the disease, and interferon therapy can accentuate autoimmune manifestations. Autoimmune cholangitis in Japan is similar to primary biliary cirrhosis, and assays for carbonic anhydrase II lack diagnostic specificity. Perinuclear antineutrophil cytoplasmic antibodies are reactive to diverse nuclear antigens, but high mobility nonhistone chromosomal proteins may be important targets in autoimmune hepatitis. T cells can cross-react with viral and host peptides, and the candidacy of glutathione S-transferases as target autoantigens has been weakened. A murine model of PBC will be useful in studying mechanisms of autoreactivity, and cyclosporine has shown promise in the treatment of children with autoimmune hepatitis. Recurrence after liver transplantation is common, and it may require retransplantation. The human transplantation model will be valuable in understanding the host-and organ-specific contributions to disease expression.
Epstein-Barr virus and human malignancies.

EBV has remained the foremost contender for “the first human cancer virus.” It is the cause of infectious mononucleosis, which has been considered a self-limited leukemia. Self-limitation could fail to materialize on rare occasions and, indeed, evidence has been mounting for an etiologic role of EBV in Burkitt's lymphoma (BL) of African children, for which an infectious cause has been postulated on the basis of epidemiologic observations. EBV might be causally related also to nasopharyngeal carcinoma (NPC). EBV fingerprints are found in nearly every BL or NPC biopsy; EBV transforms lymphocytes in vitro into permanently growing lymphoblasts resembling BL cells; EBV induces lympho-proliferative tumors in certain nonhuman primates; and all African BL and Chinese or other NPC patients have antibodies to various EBV-determined antigens, often at high titers, whereas controls have lower titers of some of the antibodies and lack others. Changes in the spectra and titers of antibodies reflect the clinical status and prognosis in BL and the stage of the disease and success of therapy in NPC. These facts oppose a mere passenger role of EBV, but other rare, as yet unknown factors must undoubtedly contribute to expression of its oncogenic potential.
Bias in emission absorption measurements of temperature and atomic density

Presented here is an analysis of the bias arising from two fundamental difficulties hi applying emission absorption methods to large-scale combustion systems: 1) maintaining clean optical windows; and 2) maintaining the optical alignment. The impetus for the study was an anomalously large temperature measurement uncertainty for potassium D-line measurements hi a coal-fired magnetohydrodynamic (MHD) flow, while no increased uncertainty was observed for the measured seed atom density. The large uncertainty can be explained by a rapid, oscillatory misalignment. This misalignment biases the measured temperature hi the same manner as that for a fouled lamp-side window. Expressions for the biases for fouled optical windows are presented. Expressions are developed for the bias and uncertainty caused by a harmonic misalignment. These expressions provide a consistent explanation of the temperature results. In contrast, the robustness of a two-wavelength emission absorption method for atomic density measurements is demonstrated.
Market fragility and international market crashes

Abstract We extend the Pukthuanthong and Roll (2009) measure of integration to provide an estimate of systemic risk within international equity markets. Our measure indicates an increasing likelihood of market crashes. The conditional probability of market crashes increases substantially following increases of our risk measure. High levels of our risk measure indicate the probability of a global crash is greater than the probability of a local crash. That is, conditional on high levels of systemic risk, the probability of a severe crash across multiple markets is larger than the probability of a crash within a smaller number of markets.
Private credit in 129 countries

We investigate cross-country determinants of private credit, using new data on legal creditor rights and private and public credit registries in 129 countries. We find that both creditor protection through the legal system and information sharing institutions are associated with higher ratios of private credit to GDP, but that the former is relatively more important in the richer countries. An analysis of legal reforms also shows that credit rises after improvements in creditor rights and in information sharing. We also find that creditor rights are remarkably stable over time, contrary to the hypothesis that legal rules are converging. Finally, we find that legal origins are an important determinant of both creditor rights and information sharing institutions. The analysis suggests that public credit registries, which are primarily a feature of French civil law countries, benefit private credit markets in developing countries.
SRB States and Nonequilibrium Statistical Mechanics Close to Equilibrium

Nonequilibrium statistical mechanics close to equilibrium is studied using SRB states and a formula [10] for their derivatives with respect to parameters. We write general expressions for the thermodynamic fluxes (or currents) and the transport coefficients, generalizing the results of [4, 5]. In this framework we give a general proof of the Onsager reciprocity relations.
Holographic entanglement beyond classical gravity

The Renyi entropies and entanglement entropy of 1+1 CFTs with gravity duals can be computed by explicit construction of the bulk spacetimes dual to branched covers of the boundary geometry. At the classical level in the bulk this has recently been shown to reproduce the conjectured Ryu-Takayanagi formula for the holographic entanglement entropy. We study the one-loop bulk corrections to this formula. The functional determinants in the bulk geometries are given by a sum over certain words of generators of the Schottky group of the branched cover. For the case of two disjoint intervals on a line we obtain analytic answers for the one-loop entanglement entropy in an expansion in small cross-ratio. These reproduce and go beyond anticipated universal terms that are not visible classically in the bulk. We also consider the case of a single interval on a circle at finite temperature. At high temperatures we show that the one-loop contributions introduce expected finite size corrections to the entanglement entropy that are not present classically. At low temperatures, the one-loop corrections capture the mixed nature of the density matrix, also not visible classically below the Hawking-Page temperature.
Acid catalysis over CuY zeolites

Recently there has been considerable interest in the Cu-ZSM-5 catalysts for the selective reduction of NO by light hydrocarbons for the purpose of atmospheric pollution abatement. Isobutane and n-pentane cracking were studied over Cu zeolite catalysts and these results were compared with their HY analogues at low conversions and at temperatures of 673 K and below. Three forms of the catalysts were used: those reduced in CO at 773 K; those reduced with H[sub 2] at 473 K; and those in the oxidic form (following flushing with He at 773 K). In contrast with an earlier publication, very little difference in activity was found between the two reduced forms of the catalysts did not differ significantly from each other nor from the H-form of the zeolite. They are typical of a Bronsted acid catalysis. The oxidic form of the catalyst produced excess H[sub 2] in increasing amounts with time on stream. This could be quantitatively accounted for by the coking of the catalyst. These results negate the previous claim that Lewis acid sites are effective in the cracking of light hydrocarbons over Cu zeolites. 16 refs., 8 figs., 6 tabs.
Mechanical Behavior of Fiber-Reinforced SiC/RBSN Ceramic Matrix Composites: Theory and Experiment

The mechanical behavior of continuous fiber reinforced SiC/RBSN (Reaction Bonded Silicon Nitride) composites with various fiber contents is evaluated. Both catastrophic and noncatastrophic failures are observed in tensile specimens. Damage and failure mechanisms are identified via in-situ monitoring using NDE (nondestructive evaluation) techniques through the loading history. Effects of fiber/matrix interface debonding (splitting) parallel to fibers are discussed. Statistical failure behavior of fibers is also observed, especially when the interface is weak. Micromechanical models incorporating residual stresses to calculate the critical matrix cracking strength, ultimate strength, and work of pull-out are reviewed and used to predict composite response. For selected test problems, experimental measurements are compared to analytical predictions.
Education Myth and Public Policymaking

The myth that education is not and should not be influenced by politics dies hard. In the meantime, the myth can be put to use.