cssi/SciSciGPT-SciSciNet huggingface dataset:
The reaction of d-glucose with aminoguanidine

The reaction of D-glucose with aminoguanidine was examined at pH 7.0 and 37 degrees C (phosphate buffer). Under these conditions, the reaction requires ca. 42 days for 50% of the sugar to react, as measured by the disappearance of D-glucose, and at 60 degrees C all the aminoguanidine had reacted within 72 h. The initial product, a beta-D-glucopyranosyl aminoguanidine (1) was obtained in the crystalline state as the trifluoroacetate salt. Data collected on this compound suggests that, in solution, it is largely a glycosylamine in the beta pyranose form. Acetylation gave a crystalline heptaacetate (2), which, in solution (as evidenced by NMR spectroscopy) exists in two different conformational forms. The crystal structure of the heptaacetate also includes two conformers. Both crystallographically independent molecules are in the normal beta pyranose form, with the acetylated guanyl residue occupying different spatial positions relative to the ring.
Bridgehead radicals in organic, chemistry. An efficient construction of the ABDE ring system of the lycoctonine alkaloids

Abstract The reaction of bridgehead radicals with allylic stannanes generates an intermediate for the synthesis of the ABDE ring of the lycoctonine alkaloids.
Moduli spaces of maximally supersymmetric solutions on noncommutative tori and noncommutative orbifolds

A maximally supersymmetric configuration of super Yang-Mills living on a non-commutative torus corresponds to a constant curvature connection. On a non-commutative toroidal orbifold there is an additional constraint that the connection be equivariant. We study moduli spaces of (equivariant) constant curvature connections on non-commutative even-dimensional tori and on toroidal orbifolds. As an illustration we work out the cases of 2 and 4 orbifolds in detail. The results we obtain agree with a commutative picture describing systems of branes wrapped on cycles of the torus and branes stuck at exceptional orbifold points.
GENERAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF THE HARD STATE AS A MAGNETICALLY DOMINATED ACCRETION FLOW

We present one of the first physically motivated two-dimensional general relativistic magnetohydrodynamic numerical simulations of a radiatively cooled black hole accretion disk. The fiducial simulation combines a totalenergy-conserving formulation with a radiative cooling function, which includes bremsstrahlung, synchrotron, and Compton effects. By comparison with other simulations we show that in optically thin advection-dominated accretion flows (ADAFs), radiative cooling can significantly affect the structure, without necessarily leading to an optically thick, geometrically thin accretion disk. We further compare the results of our radiatively cooled simulation to the predictions of a previously developed analytic model for such flows. For the very low stress parameter and accretion rate found in our simulated disk (α ≈ 0.003, ˙ M/ ˙ MEdd ≈ 5 × 10 −6 ), we closely match a state called the “transition” solution between an outer ADAF and what would be a magnetically dominated accretion flow (MDAF) in the interior. The qualitative and quantitative agreement between the numerical and analytic models is quite good, with only a few well understood exceptions. According to the analytic model then, at significantly higher α or ˙ M we would expect a full MDAF to form. The collection of simulations in this work also provides important data for interpreting other numerical results in the literature, as they span the most common treatments of thermodynamics, including simulations evolving (1) the internal energy only; (2) the internal energy plus an explicit cooling function; (3) the total energy without cooling; and (4) the total energy including cooling. We find that the total energy formulation is a necessary prerequisite for proper treatment of radiative cooling in magneto-rotational instability accretion flows, as the internal energy formulation produces a large unphysical numerical cooling of its own. We also find that the relativistic cooling functions must be handled carefully numerically in order to avoid equally unphysical heating or cooling runaways.
Lattice analysis of two-point hadronic correlators in the QCD vacuum

Results from the first lattice QCD analysis of vacuum correlators of local hadronic currents using dispersion relations are presented. We have explored the vector, pseudoscalar, axial, and scalar meson channels, and the proton-like and delta-like baryon channels. The lattice results are shown to agree qualitatively with experimental results in channels where experimental data exist, and shed insight into interacting instanton approximations and sum rule calculations in the other channels.
Orbital Angular Momentum in Scalar Diquark Model and QED

We compare the orbital angular momentum of the ‘quark’ in the scalar diquark model as well as that of the electron in QED (to order α) obtained from the Jaffe–Manohar decomposition to that obtained from the Ji relation. We estimate the importance of the vector potential in the definition of orbital angular momentum.
Stochastic Estimation of the Multi-Variable Mechanical Impedance of the Human Ankle With Active Muscles

This article compares stochastic estimates of multi-variable human ankle mechanical impedance when ankle muscles were fully relaxed, actively generating ankle torque or co-contracting antagonistically. We employed Anklebot, a rehabilitation robot for the ankle, to provide torque perturbations. Muscle activation levels were monitored electromyographically and these EMG signals were displayed to subjects who attempted to maintain them constant. Time histories of ankle torques and angles in the Dorsi-Plantar flexion (DP) and Inversion-Eversion (IE) directions were recorded. Linear time-invariant transfer functions between the measured torques and angles were estimated for the Anklebot alone and when it was worn by a human subject, the difference between these functions providing an estimate of ankle mechanical impedance. High coherence was observed over a frequency range up to 30 Hz. The main effect of muscle activation was to increase the magnitude of ankle mechanical impedance in both DP and IE directions.Copyright © 2010 by ASME
Disproportionation of Ag(II) to Ag(I) and Ag(III) in Fluoride Systems and Syntheses and Structures of (AgF+)2AgF4-MF6-Salts (M = As, Sb, Pt, Au, Ru)

Interaction of Ag+ salts in anhydrous liquid hydrogen fluoride, aHF, with AgF4- salts gives amorphous red-brown diamagnetic AgIAgIIIF4, which transforms exothermally to brown, paramagnetic, microcrystalline AgIIF2 below 0 °C. AgIAuIIIF4 prepared from Ag+ and AuF4- in aHF has a tetragonal unit cell and a KBrF4 type lattice, with a = 5.788(1) A, c = 10.806(2) A, and Z = 4. Blue-green AgIIFAsF6 disproportionates in aHF (in the absence of F- acceptors) to colorless AgIAsF6 and a black pseudotrifluoride, (AgIIF+)2AgIIIF4-AsF6-. The latter and other (AgF)2AgF4MF6 salts are also generated by oxidation of AgF2 or AgF+ salts in aHF with F2 or in solutions of O2+MF6- salts (M = As, Sb, Pt, Au, Ru). Single crystals of (AgF)2AgF4AsF6 were grown from an AgFAsF6/AsF5 solution in aHF standing over AgF2 or AgFBF4, with F2 as the oxidant. They are monoclinic, P2/c, at 20 °C, with a = 5.6045(6) A, b = 5.2567(6) A, c = 7.8061(8) A, β = 96.594(9)°, and Z = 1. The structure consists of (AgF)nn+ chains (F−Ag−F = 180°, Ag−F−Ag ...
TeV symmetry and the little hierarchy problem

Constraints from precision electroweak measurements reveal no evidence for new physics up to 5–7 TeV, whereas naturalness requires new particles at around 1 TeV to address the stability of the electroweak scale. We show that this ``little hierarchy problem'' can be cured by introducing a symmetry for new particles at the TeV scale. As an example, we construct a little Higgs model with this new symmetry, dubbed T-parity, which naturally solves the little hierarchy problem and, at the same time, stabilize the electroweak scale up to 10 TeV. The model has many important phenomenological consequences, including consistency with the precision data without any fine-tuning, a stable weakly-interacting particle as the dark matter candidate, as well as collider signals completely different from existing little Higgs models, but rather similar to the supersymmetric theories with conserved R-parity.
Preconditioned domain decomposition scheme for three-dimensional aerodynamic sensitivity analysis

A discrete sensitivity analysis algorithm had previously been developed and applied to two-dimensional aerodynamic optimization problems, where the computational domains were discretized by using single grids. The sparse, unsymmetric systems of linear equations resulting from this algorithm were solved by a direct matrix inversion matrix. However, for large two-dimensional problems and, practically, all three-dimensional problems, direct inversion methods become inapplicable, primarily due to the prohibitive computer storage needed. In an attempt to alleviate such hindrances, the sensitivity analysis with domain decomposition (SADD) scheme was developed. This scheme divides the computational domain into smaller and nonoverlapping subdomains (multiblock grids) that are solved separately. Then, the final solution is constructed from the subdomain solutions. As the number of grid points in the interface boundaries of the subdomains becomes large, the computer memory required to store the effective coefficient matrix of these interface points starts to increase. Presented in this Technical Note is a preconditioned iterative procedure to overcome this particular problem.
In Situ Compressive Sensing

Compressive sensing (CS) is a framework that exploits the compressible character of most natural signals, allowing the accurate measurement of an w-dimensional real signal u in terms of n<<m real measurements v. The CS measurements may be represented in terms of an ntimesm matrix that defines the linear relationship between v and u. In this paper we demonstrate that similar linear mappings of the form u rarr v are manifested naturally by wave propagation in complex media, and therefore in situ CS measurements may be performed simply by exploiting the complex propagation and scattering properties of natural environments. A similar phenomenon is observed in time-reversal imaging, to which connections are made. In addition to presenting the basic in situ CS framework, a simple but practical example problem is considered.
Extension Theorems for Reductive Group Actions on Compact Kaehler Manifolds

It is obvious that the topological closure of an orbit of an algebraic group acting algebraically on a projective manifold over tE is an algebraic set containing the orbit as a Zariski open set. This article treats the above situation when the group is a connected reductive complex Lie group acting holomorphically on a compact Kaehler manifold. Recall (cf. § II below) that a connected complex reductive Lie group, G, has the structure of a linear algebraic group, and this algebraic structure is compatible with the underlying analytic structure. Let G be any projective manifold in which G is Zariski open and which induces the above algebraic structure on G. A complex connected Lie group G is said to act projeetively on a compact Kaehler manifold X if G acts holomorphically on X and the Lie algebra of holomorphic vector-fields that G generates on X is annihilated by every holomorphic one form on X. This definition is justified in § II. Note (cf. §III) that G acts projectively on X if either H~(X, Q)=0, or G is semi-simple, or if every generator of the solvable radical of G has a fixed point on X, or if G is linear algebraic acting algebraically on a projective X. The main result of the paper (cf. § II) where G is as above for reduct i~ G is: Proposition. Let G be a complex connected reduetive Lie group acting projeetively on a compact Kaehler X. Let q~: Y ~ X be a hotomorphic map where Y is a normal reduced complex space. Consider the equivariant map q~:G× Y ~ X , ~ extends meromorphically (in the sense of Remmert) to CJ × Y. Taking Y to be a point one gets the analog of the result mentioned in the opening sentence. Another simple corollary is the classical result that the linear algebraic structure chosen on G which makes it algebraic is unique; and in fact that any reductive connected subgroup of a linear algebraic group over ~ is an algebraic subgroup. As a further application of the techniques used a new proof of an improved form of a fixed point theorem (cf. [20]) of the author is given: Proposition. Let S be a complex solvable Lie group acting holomorphically on a compact Kaehler manifold X. The following are equivalent:
Surface reconstructions in molecular beam epitaxy of SrTiO3

We show that reflection high-energy electron diffraction (RHEED) can be used as a highly sensitive tool to track surface and resulting film stoichiometry in adsorption-limited molecular beam epitaxy of (001) SrTiO3 thin films. Even under growth conditions that yield films with a lattice parameter that is identical to that of stoichiometric bulk crystals within the detection limit of high-resolution x-ray diffraction (XRD), changes in surface reconstruction occur from (1 × 1) to (2 × 1) to c(4 × 4) as the equivalent beam pressure of the Ti metalorganic source is increased. These surface reconstructions are correlated with a shift from mixed SrO/TiO2 termination to pure TiO2 termination. The crossover to TiO2 surface termination is also apparent in a phase shift in RHEED oscillations observed at the beginning of growth. Comparison with prior results for carrier mobilities of doped films shows that the best films are grown under conditions of a TiO2-saturated surface [c(4 × 4) reconstruction] within the XRD growth window.
The Frequency of Consumer Expenditure: An Empirical Analysis

How does the observed pattern of household purchases vary, as we extend or shorten the period of observation? An empirical analysis of data from the U.S. Consumer Expenditure Survey, Interview Survey, from 1987–1989, reveals that there is considerable heterogeneity across disaggregate goods and across households in the frequency of expenditure. Issues of data quality and of the implications of the period of observation for Tobit analysis are also discussed.
An economic comparison of conventional and reduced-chemical farming systems in Iowa

Labor requirements, production costs, yields, and economic returns were evaluated for conventional and reduced-chemical cropping systems in northeast Iowa from 1978 to 1989. Continuous corn (C-C) and corn-soybean (C-Sb) rotations represented the conventional system; a corn-oat-meadow (C-O-M) rotation represented the reducedchemical system. The C-C and C-Sb rotations used both commercial pesticides and fertilizers. The C-O-M rotation used manure for fertilization and applied pesticides only in emergencies. Operations for all systems were implemented by one farm manager. The C-Sb rotation had the highest corn yield over the 12-year period, and the C-O-M rotation the lowest. The corn within the C-O-M rotation, however, produced the second highest average return to land, labor, and management. With costs of production substantially lower than the conventional systems, the C-O-M corn crop had competitive returns despite lower yield. The C-Sb average return to land, labor, and management was significantly higher than for the other systems. Hourly labor charges of 50 had little effect on the rankings of economic returns. Because of unusually high alfalfa reseeding costs and low average oat yields, returns to the C-O-M rotation were significantly lower than C-Sb but comparable to C-C. With better alfalfa establishment and higher average oat yields, the reduced-chemical system might have been competitive with the C-Sb conventional system.
Ciclo gonadal de hembras reproductoras de trucha arcoiris (Oncorhynchus mykiss) en la piscicultura de Río Blanco, Los Andes, Chile

Se realizo un estudio del ciclo reproductivo gonadal anual en hembras de truchas arcoiris de la piscicultura de Rio Blanco, durante el periodo comprendido entre su primer y segundo desove, mediante el uso de los indicadores macroscopicos: indice gonadosomatico (IGS) y diametro de los ovocitos. De acuerdo a la evolucion del indice gonadosomatico y diametro de los ovocitos se sugiere que el ciclo gonadal de trucha arcoiris, dura aproximadamente un ano, durante el cual los ovocitos pasan por tres etapas de desarrollo, etapa temprana, etapa de crecimiento y etapa de maduracion. Se observo que un 2% de la poblacion de hembras no alcanzo su madurez gonadal.
Large-Scale Structure and the Redshift-Distance Relation

In efforts to demonstrate the linear Hubble law v=Hr from galaxy observations, the underlying simplicity is often obscured by complexities arising from magnitude-limited data. In this Letter, we point out a simple but previously unremarked fact: the shapes and orientations of structures in redshift space contain in themselves independent information about the cosmological redshift-distance relation. The orientations of the voids in the CfA slice support the Hubble law, giving a redshift-distance power index p=0.83±0.36 (void data from Slezak, de Lapparent, & Bijoui) or p=0.99±0.38 (void data from Malik & Subramanian).
Reduction of C60 using anhydrous hydrazine

Abstract Buckminsterfullerene (C 60 ) can be reduced by anhydrous hydrazine to yield a mixture of C 60 H 2 , C 60 H 4 and other more highly reduced fullerenes.
Adaptive refinement and nonlinear fluid problems

Abstract Two principal and related topics are considered: (1) adaptive mesh refinement for finite element computations, and (2) mesh refinement specifically for nonlinear flow problems. In the first instance the residual and associated trace theorems for variational problems are introduced to relate the solution error to a computable residual. This provides a theoretical basis for a mesh refinement strategy. A corresponding adaptive refinement procedure that automatically and selectively refines the mesh is formulated and implemented for a class of nonlinear transport problems in chemical engineering. In particular, a nonlinear problem with a boundary-layer solution is investigated. The strategy of interweaving Newton solution and mesh refinement proves particularly efficient. Two-dimensional compressible and transonic flows are next examined. Mesh refinement of subrogions of the flow field is applied to yield high solution accuracy near a singularity for both the linear and nonlinear flows. Refinement and Newton iteration are combined, together with Mach number parameterization, to determine an efficient and accurate solution algorithm. Similar points for nonlinear viscous problems are also reviewed.
Theta functions and symmetric weight enumerators for codes over imaginary quadratic fields

In this paper we continue the study of codes over imaginary quadratic fields and their weight enumerators and theta functions. We present new examples of non-equivalent codes over rings of characteristic $$p=2$$p=2 and $$p=5$$p=5 which have the same theta functions. We also look at a generalization of codes over imaginary quadratic fields, providing examples of non-equivalent pairs with the same theta function for $$p=3$$p=3 and $$p=5$$p=5.
microRNA-10b enhances pancreatic cancer cell invasion by suppressing TIP30 expression and promoting EGF and TGF-β actions.

Increased microRNA-10b (miR-10b) expression in the cancer cells in pancreatic ductal adenocarcinoma (PDAC) is a marker of disease aggressiveness. In the present study, we determined that plasma miR-10b levels are significantly increased in PDAC patients by comparison with normal controls. By gene profiling, we identified potential targets downregulated by miR-10b, including Tat-interacting protein 30 (TIP30). Immunoblotting and luciferase reporter assays confirmed that TIP30 was a direct miR-10b target. Downregulation of TIP30 by miR-10b or siRNA-mediated silencing of TIP30 enhanced epidermal growth factor (EGF)-dependent invasion. The actions of miR-10b were abrogated by expressing a modified TIP30 cDNA resistant to miR-10b. EGF-induced EGF receptor (EGFR) tyrosine phosphorylation and extracellular signal–regulated kinase phosphorylation were enhanced by miR-10b, and these effects were mimicked by TIP30 silencing. The actions of EGF in the presence of miR-10b were blocked by EGFR kinase inhibition with erlotinib and by dual inhibition of PI3K (phosphatidylinositol 3′-kinase) and MEK. Moreover, miR-10b, EGF and transforming growth factor-beta (TGF-β) combined to markedly increase cell invasion, and this effect was blocked by the combination of erlotinib and SB505124, a type I TGF-β receptor inhibitor. miR-10b also enhanced the stimulatory effects of EGF and TGF-β on cell migration and epithelial–mesenchymal transition (EMT) and decreased the expression of RAP2A, EPHB2, KLF4 and NF1. Moreover, miR-10b overexpression accelerated pancreatic cancer cell (PCC) proliferation and tumor growth in an orthotopic model. Thus, plasma miR-10b levels may serve as a diagnostic marker in PDAC, whereas intra-tumoral miR-10b promotes PCC proliferation and invasion by suppressing TIP30, which enhances EGFR signaling, facilitates EGF–TGF-β cross-talk and enhances the expression of EMT-promoting genes, whereas decreasing the expression of several metastasis-suppressing genes. Therefore, therapeutic targeting of miR-10b in PDAC may interrupt growth-promoting deleterious EGF–TGF-β interactions and antagonize the metastatic process at various levels.
Field Induced Supersolid Phase in Spin-One Heisenberg Models

We use numerical methods to demonstrate that the phase diagram of $S=1$ Heisenberg models with uniaxial anisotropy contains an extended supersolid phase. We show that this Hamiltonian is a particular case of a more general and ubiquitous model that describes the low-energy spectrum of some isotropic and frustrated spin-dimer systems. This result is crucial for finding a spin supersolid state in real magnets.
Isovortical orbits in uniformly rotating coordinates

For the conservative, two degree-of-freedom system with autonomous potential functionV(x,y) in rotating coordinates; $$\dot u - 2n\upsilon = V_x , \dot \upsilon + 2nu = V_y $$ , vorticity (v x -u y ) is constant along the orbit when the relative velocity field is divergence-free such that: $$u(x,y,t) = \psi _y , \upsilon (x,y,t) = - \psi _x $$ . Unlike isoenergetic reduction using the Jacobi, integral and eliminating the time,non-singular reduction from fourth to second-order occurs when (u,v) are determined explicitly as functions of their arguments by solving for ψ (x, y, t). The orbit function ψ satisfies a second-order, non-linear partial differential equation of the Monge Ampere type: $$2(\psi _{xx} \psi _{yy} - \psi _{xy}^2 ) - 2(\psi _{xx} + \psi _{yy} ) + V_{xx} + V_{yy} = 0$$ . Isovortical orbits in the rotating frame arenot level curves of ψ because it contains time explicitly due to coriolis effects. Rather, (x, y) coordinates along the orbit are obtained, from (u, v) either by numerical integration of the kinematic equations, or by partial differentiation of the Legendre transform ⋏ of ψ. In the latter case, ⋏ is shown to satisfy a non-linear, second-order partial differential equation in three independent variables, derived from the Monge-Ampere Equation. Complete reduction to quadrature is possible when space-time symmetries exist, as in the case of central force motion.
Research universities, technology transfer, and job creation: What infrastructure, for what training?

Technology transfer and innovation are considered major drivers of sustainable development; they place knowledge and its dissemination in society at the heart of the development process. This article considers the role of research universities, and how they can interact with key actors and institutions involved in ‘innovation ecosystems’. Considering various approaches of innovation and institutional analysis design (IAD), it proposes an institutional model of innovation where different authorities produce rules and knowledge that can be mobilized and/or changed in their respective action arenas. On this conceptual basis, one initiative is described: integrated poles of excellence (IPEs) for renewable energy in West Africa, which were conceptualized as a resource and knowledge centre connected to project implementation.
Effects of Cell Shape and Strut Cross-Sectional Area Variations on the Elastic Properties of Three-Dimensional Open-cell Foams

Abstract The Voronoi tessellation technique and the finite element (FE) method are utilized to investigate the microstructure–property relations of three-dimensional (3-D) cellular solids (foams) that have irregular cell shapes and non-uniform strut cross-sectional areas (SCSAs). Perturbations are introduced to a regular packing of seeds to generate a spatially periodic Voronoi diagram with different degrees of cell shape irregularity (amplitude a ), and to the constant SCSA to generate a uniform distribution of SCSAs with different degrees of SCSA non-uniformity (amplitude b ). Twenty FE models are constructed, based on the Voronoi diagrams for twenty foam samples (specimens) having the same pair of a and b , to obtain the mean values and standard deviations of the elastic properties. Spatially periodic boundary conditions are applied to each specimen. The simulation results indicate that for low-density imperfect foams, the elastic moduli increase as cell shapes become more irregular, but decrease as SCSAs get less uniform. When the relative density ( R ) increases, the elastic moduli of imperfect foams increase substantially, while the Poisson's ratios decrease moderately. The effect of the interaction between the two types of imperfections on foam elastic properties appears to be weak. In addition, it is found that the strut cross-sectional shape has a significant effect on the foam properties. Also, the elastic response of foams with the cell shape and SCSA imperfections appears to be isotropic regardless of changes in a , b and R and the strut cross-sectional shape.
Equivalence of Simplicial Ricci Flow and Hamilton's Ricci Flow for 3D Neckpinch Geometries

Hamilton’s Ricci flow (RF) equations were recently expressed in terms of the edge lengths of a d-dimensional piecewise linear (PL) simplicial geometry, for d ≥ 2. The structure of the simplicial Ricci flow (SRF) equations are dimensionally agnostic. These SRF equations were tested numerically and analytically in 3D for simple models and reproduced qualitatively the solution of continuum RF equations including a Type-1 neckpinch singularity. Here we examine a continuum limit of the SRF equations for 3D neck pinch geometries with an arbitrary radial profile. We show that the SRF equations converge to the corresponding continuum RF equations as reported by Angenent and Knopf.
Cash flow instability and the demand for liquid assets by firms in Brazilian Manufacturing

Abstract This study examines the impact of cash flow instability on the firm demand for liquid assets. The instability arises from foreign sources in the form of exchange rate variability and the extent of foreign trade and domestically from inflation and interest rate volatility. We also investigate whether multinational subsidiaries react differently than domestic firms to these factors. Data from a large sample of manufacturing firms in Brazil show that multinational subsidiaries hold fewer liquid assets and respond differently than domestic firms to exchange rate variability and foreign involvement. The two groups exhibit similar behavior in response to the domestic sources of instability.
Combinatorial constructions of modules for infinite-dimensional Lie algebras, I. Principal subspace

This is the first of a series of papers studying combinatorial (with no “subtractions”) bases and characters of standard modules for affine Lie algebras, as well as various subspaces and “coset spaces” of these modules. In part I we consider certain standard modules for the affine Lie algebra g, g: = sl(n + 1, C), n ≥ 1, at any positive integral level k and construct bases for their principal subspaces (introduced and studied recently by Feigin and Stoyanovsky (1994)). The bases are given in terms of partitions: a color i, 1 ≤ i ≤ n, and a charge s, 1 ≤ s ≤ k, are assigned to each part of a partition, so that the parts of the same color and charge comply with certain difference conditions. The parts represent “Fourier coefficients” of vertex operators and can be interpreted as “quasi-particles” enjoying (two-particle) statistical interaction related to the Cartan matrix of g. In the particular case of vacuum modules, the character formula associated with our basis is the one announced in Feigin and Stoyanovsky (1994). New combinatorial characters are proposed for the whole standard vacuum ĝ-modules at level one.
The synthesis of 2-substituted-1,4-dihydropyridines

Abstract Reaction of the 2-hydroxymethyl-1,4-dihydropyridines 7 and 13 with SO2Cl2limidazole followed by treatment with nucleophiles affords 2-substituted-l,4-dihydropyridines via the intermediacy of the 2-chloromethyl compounds 14 and 18, respectively.
The status of Run II at Fermilab

Abstract The Run II at Fermilab is progressing steadily. In the Run IIa scheme, 36 antiproton bunches collide with 36 proton bunches at CDF and D0 interaction regions in the Tevatron at 980 GeV beam energy. The current status and performance of the Fermilab Accelerator Complex is reviewed. The plans for Run IIb along with the Antiproton Source upgrade and incorporation of the Recycler Ring in the accelerator chain are outlined. The prospects of achieving Run II integrated luminosity goal of 15 fb −1 are discussed.
Rapid Removal of Benzyloxycarbonyl Groups from 1,4,7,10-Tetraazacyclododecane Derivatives by Catalytic Transfer Hydrogenation

Abstract We report that N-benzyloxycarbonyl groups can be conveniently removed from 1,4,7,10-tetraazacyclododecanes by catalytic transfer hydrogenation with cyclohexene and 5% palladium–carbon catalyst. The process is rapid, selective, inexpensive, and is high yielding.
I-Xe dating of Allende inclusions - Antiquity and fine structure

Two inclusions from the Allende meteorite exhibit multiple I-Xe isochrons corresponding to an age difference of 3.7 + or - 1.5 m.y. for their constituent minerals. Consequently, I-Xe dating can establish, independently of thermodynamic models, a partial sequence of formation for minerals that incorporated radioactive I-1290. Additionally, the results give an estimate of the cooling rate for the solar nebula when validity of thermodynamic models is assumed.
An intelligent control system for rocket engines: need, vision, and issues

Several components of intelligence are defined. Within the context of these definitions an intelligent control system for rocket engines is described. The description includes a framework for development of an intelligent control system, including diagnostics, coordination, and direct control. Some current results and issues are presented. >
Sulfur, Nitrogen, and Amino Acid Balance, and Digestibility of Low-Sulfur and Sulfur-Supplemented Diets Fed to Lactating Cows

Abstract Eight mature lactating Holstein cows were divided into two groups. The low-sulfur group received a concentrate mix containing 0.10% sulfur and the sulfur-supplemented group received the same concentrate mix containing 0.18% sulfur. Both groups were fed the same corn silage (0.09% sulfur, dry basis) and the respective concentrate mix ad libitum at a ratio of 6.3 to 1.0. Eighty per cent of the ad libitum intake was fed during the balance and digestibility trials. The low-sulfur group excreted significantly less sulfur in urine but not in feces or milk. All cows were in negative sulfur and nitrogen balance. The supplemental sulfur was inefficiently utilized, as indicated by the increased urinary excretion of sulfur and by no effect on sulfur balance. Apparently, inorganic sulfur only partially met the cow's total dietary sulfur requirement. Balance of amino acids was very similar for both groups. All animals were essentially in balance for methionine, cystine, and tyrosine, negative balance for glutamic acid and lysine, and in positive balance for histidine, arginine, aspartic acid, threonine, serine, glycine, alanine, valine, isoleucine, leucine, phenylalanine, and proline. There was a positive balance of both essential and nonessential amino acids as two separate groups.
Fraud dynamics and controls in organizations

This paper develops an agent-based model to examine the emergent dynamic characteristics of fraud in organizations. In the model, individual heterogeneous agents, each of whom can have motive and opportunity to commit fraud and a pro-fraud attitude, interact with each other. This interaction provides a mechanism for cultural transmission through which attitudes regarding fraud can spread. Our benchmark analysis identifies two classes of organizations. In one class, we observe fraud tending toward a stable level. In the other class, fraud dynamics are characterized by extreme behaviors; organizations with mostly honest behavior suddenly change their state to mostly fraudulent behavior and vice versa. These changes seem to occur randomly over time. We then modify our model to examine the effects of various mechanisms thought to impact fraud in organizations. Each of these mechanisms has different impacts on the two classes of organizations in our benchmark model, with some mechanisms being more effective in organizations exhibiting stable levels of fraud and other mechanisms being more effective in organizations exhibiting unstable extreme behavior. Our analysis and results have general implications for designing programs aimed at preventing fraud and for fraud risk assessment within the audit context.
International overborrowing: A decomposition of credit and currency risks

Summary The severity of the financial crises enveloping the “tiger” economies of Southeast Asia in 1997 came as a surprise to many observers. This paper uses a simple Fisherian model of the “overborrowing syndrome” to compare the Asian crises of 1997 with earlier overborrowing episodes in Mexico and Chile. While important similarities exist, the crises in Southeast Asia have been exacerbated by the unhedged foreign exchange positions of Asian banks. These open currency positions not only imposed significant additional losses on the banks following devaluation, they also magnified the scale of overborrowing during the cycle's initial boom phase. Failure to limit the exposure of banks to foreign exchange risk therefore increased the magnitude of the boom—bust overborrowing cycle both ex ante and ex post. The paper highlights the importance of effective regulation and supervision of capital markets, with a focus on limiting the speculative currency positions of banks, especially those that form the core of the domestic payments system and therefore enjoy a (possibly implicit) public guarantee. Improving the institutional infrastructure of financial supervision is the only effective way of mitigating the macroeconomic costs of overborrowing.
Complementary branching ratios by satellite excitation.

We show that if a state decays to produce a fraction R of products in one of two decay channels, then one can obtain the complementary fraction, 1-R, by exciting the character of a different state, but at the location of the first state's resonance. This structure will appear as a satellite to the second state with a branching ratio that depends only on the first state's decay interactions. Since this requires the real excitation of a state far off resonance, this process will be important only for short-lived states, which have long wings in their excitation spectra. We illustrate this effect with the 6pns and 6pnd autoionizing states of barium.
Synthetic strategies toward hetidine and hetisine-type diterpenoid alkaloids

Within the diterpenoid alkaloid family of natural products, the hetidine and hetisine structural types have been the targets of a number of synthetic studies. Various strategies have been pursued to access the azacyclic moiety of these natural products as well as the characteristic [2.2.2] bicyclic structural motif. This perspective article examines the different disconnections and approaches that have been applied to the synthesis of these natural products to date.
Massive type II in double field theory

We provide an extension of the recently constructed double field theory formulation of the low-energy limits of type II strings, in which the RR fields can depend simultaneously on the 10-dimensional space-time coordinates and linearly on the dual winding coordinates. For the special case that only the RR one-form of type IIA carries such a dependence, we obtain the massive deformation of type IIA supergravity due to Romans. For T-dual configurations we obtain a ‘massive’ but non-covariant formulation of type IIB, in which the 10-dimensional diffeomorphism symmetry is deformed by the mass parameter.
Serotonin1A receptors are increased in postmortem prefrontal cortex in schizophrenia

Serotonin-5-HT1A receptors were measured with [3H]8-hydroxy-2-(di-n-propyl)aminotetralin ([3H]8-OH-DPAT) in postmortem prefrontal cortex of 12 pairs of subjects with schizophrenia and age-matched control subjects. The saturation binding isotherms of [3H]8-OH-DPAT revealed high- and low-affinity binding sites. The density (Bmax) of the high-affinity sites was significantly elevated by an average of 79% in subjects with schizophrenia. The dissociation constant (Kd) of the high-affinity sites in subjects with schizophrenia was not significantly different from the control subjects. These results provide further evidence for a role of the serotonergic system in the pathophysiology of schizophrenia.
Open conditions for infinite multiplicity eigenvalues on elliptic curves

Abstract Let E be an elliptic curve defined over a number field K. We show that for each root of unity ζ, the set Σ ζ of σ ∈ Gal ( K ¯ / K ) such that ζ is an eigenvalue of infinite multiplicity for σ acting on E ( K ¯ ) ⊗ C has non-empty interior. For the eigenvalue −1, we can show more: for any σ in Gal ( K ¯ / K ) , the multiplicity of the eigenvalue −1 is either 0 or ∞. It follows that Σ −1 is open.
Resonant Doppler velocimeter

Narrow linewidth tunable lasers augur a new kind of laser Doppler velocimetry employing resonant absorption and fluorescence from trace atomic species rather than scattering from particles. This technique may provide better turbulence and small volume information than present velocimetry.
Asymmetric aldol reactions of an α′-benzoyl titanium enolate

Abstract Diastereofacial selectivities of 97–99.7% can be conveniently obtained in aldol reactions of the chiral titanium enolate derived from the ketone C 2 H 5 COCH(OCOPh) cyclo -C 6 H 11 , with representative aldehydes.
Chemical engineering and the postmodern world

Postmodernism is a critical reaction to the real and perceived excesses of science and technology and to their social and philosophical implications. Postmodernism rejects the assumption that science has a special and privileged claim to truth, a claim that is fundamental to chemical engineering. The postmodern spirit demands that chemical engineers give attention not only to society's material needs but also to its humanistic concerns. Because chemical engineering is unavoidably a part of, not apart from, the society that it serves, our profession must reinvent itself to meet society's expectations.
IMPROVING FOREGROUND SUBTRACTION IN STATISTICAL OBSERVATIONS OF 21 cm EMISSION FROM THE EPOCH OF REIONIZATION

Statistical observations of the epoch of reionization using the 21 cm line of neutral hydrogen have the potential to revolutionize our understanding of structure formation and the first luminous objects. However, these observations are complicated by a host of strong foreground sources. Several foreground-removal techniques have been proposed in the literature, and it has been assumed that these would be used in combination to reveal the epoch of reionization (EOR) signal. By studying the characteristic subtraction errors of the proposed foreground-removal techniques, we identify an additional subtraction stage that can further reduce the EOR foreground contamination, and study the interactions between the foreground-removal algorithms. This enables us to outline a comprehensive foreground-removal strategy that incorporates all previously proposed subtraction techniques. Using this foreground-removal framework and the characteristic subtraction errors, we discuss the complementarity of different foreground-removal techniques and the implications for array design and the analysis of EOR data.
The quark beam function at NNLL

In hard collisions at a hadron collider the most appropriate description of the initial state depends on what is measured in the final state. Parton distribution functions (PDFs) evolved to the hard collision scale Q are appropriate for inclusive observables, but not for measurements with a specific number of hard jets, leptons, and photons. Here the incoming protons are probed and lose their identity to an incoming jet at a scale μ B ≪ Q, and the initial state is described by universal beam functions. We discuss the field-theoretic treatment of beam functions, and show that the beam function has the same RG evolution as the jet function to all orders in perturbation theory. In contrast to PDF evolution, the beam function evolution does not mix quarks and gluons and changes the virtuality of the colliding parton at fixed momentum fraction. At μ B , the incoming jet can be described perturbatively, and we give a detailed derivation of the one-loop matching of the quark beam function onto quark and gluon PDFs. We compute the associated NLO Wilson coefficients and explicitly verify the cancellation of IR singularities. As an application, we give an expression for the next-to-next-to-leading logarithmic order (NNLL) resummed Drell-Yan beam thrust cross section.
Stability of the protogalactic clouds - I: Field length in the adiabatic models

All gasdynamical models for the evolution of gaseous content of galaxies assume that cooling from the hot, virialized phase to the cold phase occurred through some sort of thermal instability. Subsequent formation of colder clouds embedded in the hot, rarefied medium is a well-known process appearing in many astrophysical circumstances and environments. The characteristics of the condensed clouds depend on the relevant timescales for cloud formation and disruption due to either collisions or one of the operating instabilities. In this paper, the importance of the Kelvin-Helmholtz instability is investigated for the clouds forming in huge gaseous haloes of L galaxies. Recent treatment of this problem by Kamaya (1997) is extended and a more realistic cooling function employed. Results show that the Kelvin-Helmhotz instability proceeds effectively on the same timescale whether we account for self-gravity or not. This has multiple significance, since these objects may have been seen as high-column density absorption line systems against the background QSOs, and probably represent the progenitors of the present-day globular clusters.
Organizing information in Mosaic: a classroom experiment

The power of Mosaic and the simplicity of the HyperText Markup Language for building hypertext documents have created an opportunity for educators at all levels to not only introduce hypermedia in the classroom but to give students the ability to author complex and meaningful hypertext documents. This paper presents a case study of one such experiment, focusing on the organization of students' resulting projects, the relevance of their results to additional projects, and the increased mastery of course material by the students which resulted from organizing and building the hypertext projects.
No Death Star—For Now

A star passing within ~104 AU of the Sun would trigger a comet shower that would reach the inner solar system about 0.18 Myr later. We calculate an a priori probability of ~0.4% that a star has passed this close to the Sun but that the comet shower has not yet reached the Earth. We search the Hipparcos catalogue for such recent close-encounter candidates and, in agreement with Garcia-Sanchez et al., find none. The new result reported in this Letter is an estimation of the completeness of the search. Because of the relatively bright completeness limit of the catalogue itself, V~8, the search is sensitive to only about half the stars that could have had such a near encounter. On the other hand, we show that the search is sensitive to nearly all of the past encounters that would lead to a major shower in the future and conclude that it is highly unlikely that one will occur during the next 0.5 Myr.
Urinary tract infections in childhood: An update

Although controversies remain regarding the definition, diagnosis, and management of urinary tract infections, such infections can pose a major risk to a child's well-being. Bacteriuria or recurrent urinary tract infections often pose difficult management problems. Symptomatic and asymptomatic bacteriuria during infancy are generally characterized by a benign outcome. In some children repeated episodes and, possibly, renal scarring result. The prognosis in young boys may be guarded if neonatal bacteriuria, with or without symptoms, occurs in the presence of anatomic defects. Although a variety of pathogens have been identified as causing urinary tract infections, Enterobacteriaceae are usually the cause of initial uncomplicated lower tract infections. Accepted therapy for such infections is reviewed, as are the combination therapies used for hospitalized patients with upper tract infections. An investigation of piperacillin, a new, extended-spectrum acylaminopenicillin, raises the hope that it may provide effective monotherapy for upper tract infections. The criteria for selecting patients who require radiologic evaluation in the management of urinary tract infections are reviewed.
Development of Hybrid Product Breakdown Structure for NASA Ground Systems

The Product Breakdown Structure is traditionally a method of identification of the products of a project in a tree structure. It is a tool used to assess, plan, document, and display the equipment requirements for a project. It is part of a product based planning technique, and attempts to break down all components of a project in as much detail as possible, so that nothing is overlooked. The PBS for ground systems at the Kennedy Space Center is being developed to encompass the traditional requirements including the alignment of facility, systems, and components to the organizational hierarchy. The Ground Operations Product Breakdown Structure is a hybrid in nature in that some aspects of a work breakdown structure will be incorporated and merged with the Architecture Concept of Operations, Master Subsystem List, customer interface, and assigned management responsibility. The Ground Operations Product Breakdown Structure needs to be able to identify the flexibility of support differing customers (internal and external) usage of ground support equipment within the Kennedy Space Center launch and processing complex. The development of the Product Breakdown Structure is an iterative activity Initially documenting the organization hierarchy structure and relationships. The Product Breakdown Structure identifies the linkage between the customer program requirements, allocation of system resources, development of design goals, and identification logistics products. As the Product Breakdown Structure progresses the incorporation of the results of requirement planning for the customer occurs identifying facility needs and systems. The mature Product Breakdown Structure is baselined with a hierarchical drawing, the Product Breakdown Structure database, and an associated document identifying the verification of the data through the life cycle of the program/product line. This paper will document, demonstrate, and identify key aspects of the life cycle of a Hybrid Product Breakdown Structure. The purpose is to show how a project management and system engineering approach can be utilized for providing flexible customer service in an evolving manned space flight launch processing environment.