cssi/SciSciGPT-SciSciNet huggingface dataset:
Dislocation-mediated melting near isostructural critical points.

We study the interplay between an isostructural critical point and dislocation-mediated two-dimensional melting, using a combination of Landau and continuum elasticity theory. If dislocations are excluded, coupling to the elastic degrees of freedom leads to mean-field critical exponents. When dislocations are allowed, modified elastic constants lead to a phase buried in the solid state near the critical point. Consistent with a proposal of Bladon and Frenkel, we find an intervening hexatic phase near the critical point of the first-order isostructural transition line. Very close to the critical point, a transition from the hexatic phase to a modulated-bond-angle state is possible. Ising transitions in symmetrically confined two-dimensional colloidal crystals with attractive wall potentials require a different model free energy, which we also discuss. \textcopyright{} 1996 The American Physical Society.
Application of serine- and threonine-derived cyclic sulfamidates for the preparation of S-linked glycosyl amino acids in solution- and solid-phase peptide synthesis.

Cyclic sulfamidates were synthesized in 60% yield from l-serine and allo-l-threonine, respectively. These sulfamidates reacted with a variety of unprotected 1-thio sugars in aqueous bicarbonate buffer (pH 8) to afford the corresponding S-linked serine- and threonine-glycosyl amino acids with good diastereoselectivity (≥97%) after hydrolysis of the N-sulfates. The serine-derived sulfamidate was incorporated into a simple dipeptide to generate a reactive dipeptide substrate that underwent chemoselective ligation with a 1-thio sugar to afford an S-linked glycopeptide. This sulfamidate was also incorporated into a peptide on a solid support in conjunction with solid-phase peptide synthesis. Chemoselective ligation of a 1-thio sugar with the cyclic sulfamidate was achieved on the solid support, followed by removal of the N-sulfate. Finally, the peptide chain of the resulting support-bound S-linked glycopeptide was extended using standard peptide synthesis procedures.
Rapidly Solidified Alloys for Permanent Magnets

The magnetic and structural properties of melt-spun Fe-R-B alloys are reviewed. The hard magnetic properties of these alloys are attributed to the presence of a highly anisotropic tetragonal phase Fe 14 R 2 B which in the case of ribbons occurs in very fine grains. The interachoot of domain walls with this fine microstructure leads to the observed high coercivities. The effects of partial substitution of iron, rare-earth and boron on the formation of Fe 14 R 2 B and on its magnetic properties are also discussed.
A medium access control protocol for voice and data integration in receiver-oriented DS-CDMA PCNs

Abstract Primarily used in military communications in the past, code division multiple access (CDMA) is recently found to be attractive for personal communications as well. As a large number of mobile hosts are supported within a cell and a wide range of services are provided, one of the most important issues in a CDMA personal communication network is how to control the uplink access to the shared wireless spectrum. In this paper, we address this issue in a realistic situation where the receiver-oriented transmission protocol is employed and the packet loss due to multiple access interference (MAI) cannot be ignored. A medium access control protocol for voice and data integration is proposed. It solves the problems of code assignment and MAI control at the same time. A Markov chain model is used to analyze the protocol and the analytical results are shown to be very close to simulations. Based on the modeling, the effectiveness of the protocol's MAI control is demonstrated and some system design issues are investigated.
Ground-state properties of Heisenberg spin chains.

The ground-state properties of some finite antiferromagnetic Heisenberg rings with N spins at the isotropic point have been investigated using a modified Lanczos method. Rings with spin 1 and (3/2 have been studied and new results are presented for the correlation functions and the structure factor up to N=16 (12) for S=1 ((3/2). Evidence in support of Haldane's conjecture is found. The correlation functions for S=(3/2 behave as predicted by Affleck.
On the linear response and scattering of an interacting molecule-metal system.

A many-body Green’s function approach to the microscopic theory of plasmon-enhanced spectroscopy is presented within the context of localized surface-plasmon resonancespectroscopy and applied to investigate the coupling between quantum-molecular and classical-plasmonic resonances in monolayer-coated silver nanoparticles. Electronic propagators or Green’s functions, accounting for the repeated polarizationinteraction between a single molecule and its image in a nearby nanoscale metal, are explicitly computed and used to construct the linear-response properties of the combined molecule-metal system to an external electromagnetic perturbation. Shifting and finite lifetime of states appear rigorously and automatically within our approach and reveal an intricate coupling between molecule and metal not fully described by previous theories. Self-consistent incorporation of this quantum-molecular response into the continuum-electromagnetic scattering of the molecule-metal target is exploited to compute the localized surface-plasmon resonance wavelength shift with respect to the bare metal from first principles.
A fast distributed approximation algorithm for minimum spanning trees

We present a distributed algorithm that constructs an O(log n)-approximate minimum spanning tree (MST) in any arbitrary network. This algorithm runs in time O(D(G) + L(G, w)) where L(G, w) is a parameter called the local shortest path diameter and D(G) is the (unweighted) diameter of the graph. Our algorithm is existentially optimal (up to polylogarithmic factors), i.e., there exist graphs which need Ω(D(G) + L(G, w)) time to compute an H-approximation to the MST for any $$H\,\in\,[1, \Theta({\rm log} n)]$$ . Our result also shows that there can be a significant time gap between exact and approximate MST computation: there exists graphs in which the running time of our approximation algorithm is exponentially faster than the time-optimal distributed algorithm that computes the MST. Finally, we show that our algorithm can be used to find an approximate MST in wireless networks and in random weighted networks in almost optimal O(D(G)) time.
Flat directions in the scalar potential of the supersymmetric standard model

Abstract The scalar potential of the Minimal Supersymmetric Standard Model (MSSM) is nearly flat along many directions in field space. We provide a catalog of the flat directions of the renormalizable and supersymmetry-preserving part of the scalar potential of the MSSM, using the correspondence between flat directions and gauge-invariant polynomials of chiral superfields. We then study how these flat directions are lifted by non-renormalizable terms in the superpotential, with special attention given to the subtleties associated with the family index structure. Several flat directions are lifted only by supersymmetry-breaking effects and by supersymmetfc terms in the scalar potential of surprisingly high dimensionality.
Dense Plasma Focus $Z$ -Pinches for High-Gradient Particle Acceleration

The final Z-pinch stage of a dense plasma focus (DPF) could be used as a simple, compact, and potentially rugged plasma-based high-gradient accelerator with fields at the 100-MV/m level. In this paper, we review previously published experimental beam data that indicate the feasibility of such a DPF-based accelerator, qualitatively discuss the physical acceleration processes in terms of the induced voltages, and as a starting point, examine the DPF acceleration potential by numerically applying a self-consistent DPF system model that includes the induced voltage from both macroscopic and instability-driven plasma dynamics. Applications to the remote detection of high explosives and a multistaged acceleration concept are briefly discussed.
Optimization of hybrid-rocket-booster fuel-grain design

A ballistics model has been developed for investigating the influence of fuel-grain design on the overall performance of hybrid rocket boosters. The model, based on steady, one-dimensional compressible flow, includes the capability to handle arbitrary wagon-wheel fuel-section designs. To properly evaluate tradeoffs associated with a booster, stagnation-pressure losses are evaluated and a throttling capability is included. Results of the ballistics calculations are presented for both liquid oxygen and 90% hydrogen peroxide oxidizers assuming hydroxy-terminated polybutadiene as fuel. Vehicle interactions are considered by investigating a design capable of accomplishing the Titan 34D booster mission. Results indicate that the liquid-oxygen systems tend to optimize to a higher number of ports and mass-flux levels than the hydrogen peroxide systems.
NEATER: filtering of over-sampled data using non-cooperative game theory

In this paper, we present a method for the filteriNg of ovEr-sampled dAta using non-cooperaTive gamE theoRy (NEATER) to address the imbalanced data problem. Specifically, the problem is formulated as a non-cooperative game where all the data are players and the goal is to uniformly and consistently label all of the synthetic data created by any over-sampling technique. The proposed algorithm does not require any prior assumptions and selects representative synthetic instances while generating a very small number of noisy data. We present extensive experimental results over a large collection of datasets using three different classifiers to demonstrate the advantages of our method.
Have Equity REITs Experienced Periodically Collapsing Bubbles

This paper uses the momentum threshold autoregressive (MTAR) model and the residuals-augmented Dickey–Fuller (RADF) test to examine the possibility of Evans’ (1991) periodically collapsing bubbles in the equity REIT market. The results are mixed. The MTAR model indicates that overall real equity REIT prices and dividends are cointegrated with asymmetric adjustment towards the long-run equilibrium. However, the estimated coefficients of the MTAR model do not indicate the presence of periodically collapsing bubbles. Adjustment in the standard cointegration tests of bubbles for skewness and excess kurtosis via the RADF test fails to reject the null hypothesis of no cointegration, leaving the possibility of periodically collapsing bubbles. The MTAR and RADF results with respect to equity REIT sub-sectors are mixed. Lodging is the only sub-sector in which both the MTAR and RADF results support periodically collapsing bubbles. Moreover, market fundamentals proxied by two alternative measures of capacity utilization do not explain either real equity REIT prices or dividends.
Repeated signaling games

Abstract I analyze a class of repeated signaling games in which the informed player's type is persistent and the history of actions is perfectly observable. In this context, a large class of possibly complex sequences of signals can be supported as the separating equilibrium actions of the “strong type” of the informed player. I characterize the set of such sequences. I also characterize the sequences of signals in least cost separating equilibria (LCSE) of these games. In doing this, I introduce a state variable that can be interpreted as a measure of reputation. This gives the optimization problem characterizing the LCSE a recursive structure. I show that, in general, the equilibrium path sequences of signals have a simple structure. The shapes of the optimal sequences depend critically on the relative concavities of the payoff functions of different types, which measure the relative preferences towards payoff smoothing.
A new approach to social assistance : Latin America's experience with conditional cash transfer programs

Conditional cash transfers (CCTs) are an innovative and increasingly popular approach to social assistance. They provide money to poor families contingent upon certain behavior, usually investments in human capital such as keeping children in school or taking them to health centers on a regular basis. These programs are perhaps the clearest policy manifestation of a new line of thinking on the long-term role of social assistance programs. Not only are they instruments for short-term poverty alleviation, but they also encompass longer-term economic growth and human capital development objectives. They have been adopted internationally and in several countries they have been scaled up to become integral components of poverty alleviation strategies.
Coupled Consolidation and Contaminant Transport in Compressible Porous Media

This paper presents an experimental and numerical investigation of coupled consolidation and contaminant transport in compressible porous media. Numerical simulations were performed using the CST2 computational model, in which a dual-Lagrangian framework is used to separately follow the motions of fluid and solid phases during consolidation. Diffusion and large strain consolidation-induced transport tests were conducted on composite specimens of kaolinite slurry consisting of an upper uncontaminated layer and a lower layer contaminated with potassium bromide. Assessment of the importance of the consolidation process on solute transport is based on measured and simulated solute breakthrough curves and final contaminant concentration profiles. CST2 simulations closely match the experimental data for three different loading conditions. Diffusion and consolidation-induced advection made important contributions to solute transport and mass outflow in this study. Additional simulations indicate that consolidati...
UNVEILING NEUTRINO MIXING AND LEPTONIC CP VIOLATION

We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three-family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle θ13 and the CP-phase δ. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.
Small groups, big gains: efficacy of a tier 2 phonological awareness intervention with preschoolers with early literacy deficits.

Purpose The purpose of the present study was to evaluate the efficacy of a phonological awareness (PA) intervention, designed for Tier 2 instruction in a Response to Intervention (RTI) model, deliv...
On the influence of a flexural biasing state on the velocity of piezoelectric surface waves

Abstract A system of linear electroelastic equations for small fields superposed on a bias is applied in the determination of the velocity of acoustic surface waves in piezoelectric substrates subject to flexural biasing stresses. The influence of the biasing stresses appears in the boundary conditions as well as the differential equations. Direct calculations performed for both quartz and lithium niobate when the spatial variation of the flexural biasing state is omitted indicate that the biasing stresses in the boundary conditions have an important influence of the surface wave velocity. In addition, perturbation calculations are performed which include the influence of the spatial variation of all flexural biasing terms and it is shown that, for substrate thickness-to-wavelength ratios well within the practical range, the spatial variation in the biasing state has an appreciable effect on the velocity of acoustic surface waves.
Collaborative 20 Questions for Target Localization

We consider the problem of 20 questions with noise for multiple players under the minimum entropy criterion in the setting of stochastic search, with application to target localization. Each player yields a noisy response to a binary query governed by a certain error probability. First, we propose a sequential policy for constructing questions that queries each player in sequence and refines the posterior of the target location. Second, we consider a joint policy that asks all players questions in parallel at each time instant and characterize the structure of the optimal policy for constructing the sequence of questions. This generalizes the single player probabilistic bisection method for stochastic search problems. Third, we prove an equivalence between the two schemes showing that, despite the fact that the sequential scheme has access to a more refined filtration, the joint scheme performs just as well on average. Fourth, we establish convergence rates of the mean-square error and derive error exponents. Finally, we obtain an extension to the case of unknown error probabilities. This framework provides a mathematical model for incorporating a human in the loop for active machine learning systems.
Toward Expressive and Scalable Sponsored Search Auctions

Internet search results are a growing and highly profitable advertising platform. Search providers auction advertising slots to advertisers on their search result pages. Due to the high volume of searches and the users' low tolerance for search result latency, it is imperative to resolve these auctions fast. Current approaches restrict the expressiveness of bids in order to achieve fast winner determination, which is the problem of allocating slots to advertisers so as to maximize the expected revenue given the advertisers' bids. The goal of our work is to permit more expressive bidding, thus allowing advertisers to achieve complex advertising goals, while still providing fast and scalable techniques for winner determination.
Organophosphorus and Carbamate Insecticides as Substitutes for DDT in Controlling the Tobacco Flea Beetle on Flue-Cured Tobacco

Field experiments conducted in North Carolina during 1961-65 to compare the residual effectiveness of insecticidal sprays against Epitrix hirtipennis (Melsheimer) on flue-cured tobacco showed that, for the number of days indicated after application, the following treatments provided control similar to that obtained with 1 lb per acre of DDT: (1) for 10 days. 0.5 lb of carbofuran, Dasanit®( O, O -dicthyl O -[ P -(methylsulfinyl) phenyl] phosphorotluoate), dinwthoate. Gardona® (2-chloro-1-(2-4,5-trichlorophenyl) vinyl dimethyl phosphate), Imidan® ( O, O- dimethyl S-phthalimidornethyl phosphorodithioate), and Supracide® (S-((2-methoxy-5-oxo-∆2-1,3,4-thiadiazolin-4-yl) methyl) O, O -dimethyl phosphorodithioate), and 1 lb of aminocarb and MCA-600 (benzo[b]thien-4-yl methylcarbamate), (2) for 6 days, 0.25 lb of azinphosmethyl. 0.5 lb of dicrotophos and phosphamidon, and 1 lb of carbaryl, and (3) for 3 days, 0.25 lb of parathion and 1 lb of carbanolate. One-fourth lb of methyl parathion, 0.5 lb of diazinon, endosulfan, malathion, and naled, and 1 lb of TDE provided control inferior to that of 1 lb of DDT for 3 days and no significant control thereafter. Variable control was obtained with monocrotophos.
Searching for the light dark gauge boson in GeV-scale experiments

We study current constraints and search prospects for a GeV scale vector boson at a range of low energy experiments. It couples to the Standard Model charged particles with a strength ≤ 10−3 − 10−4 of that of the photon. The possibility of such a particle mediating dark matter self-interactions has received much attention recently. We consider searches at low energy high luminosity colliders, meson decays, and fixed target experiments. Based on available data, searches both at colliders and in meson decays can discover or exclude such a scenario if the coupling strength is on the larger side. We emphasize that a dedicated fixed target experiment has a much better potential in searching for such a gauge boson, and outline the desired properties of such an experiment. Two different optimal designs should be implemented to cover the range of coupling strength 10−3 − 10−5, and <10−5 of the photon, respectively. We also briefly comment on other possible ways of searching for such a gauge boson.
Decoding dendritic cell function through module and network analysis.

Abstract Systems biology approaches that utilize large genomic data sets hold great potential for deciphering complex immunological process. In this paper, we propose such an approach to derive informative modules and networks from large gene expression data sets. Our approach starts with the clustering of such data sets to derive groups of tightly co-expressed genes, also known as co-expression modules. These modules are then converted into co-expression networks, and combined with transcriptional regulatory and protein interaction data to generate integrated networks that can help decipher the regulatory structure of these modules. We use this approach to derive the first set of modules and networks focused on dendritic cells (DCs). These cells are responsible for sampling the local environment to inform the adaptive immune system about peripheral stimuli, thus leading to the induction of an immune response. Using the ImmGen gene expression data set, we derive co-expression modules and integrated networks for the pDC, cDC and CD8 + DC subsets. In addition to recapitulating genes known to regulate the functions of these subsets, these networks reveal several novel genes and interactions that might have important roles in DC biology.
Computing yields on enhanced CDs

Abstract In this paper, we seek to provide a framework for comparing certificates of deposit (CD) products that vary in their features. There are now fixed-rate CDs with no early withdrawal penalties as well as floating-rate CDs with guaranteed floors. With the model developed here, we examine the required change in the effective annual rate required in basis points to make CD products with embedded derivatives (called enhanced CDs) comparable with the standard CD products (ones with large early withdrawal penalties). This framework is beneficial for both retail customers seeking to make rational comparisons and bank executives seeking to provide optimal liability products and seeking to manage the resulting interest rate risk.
Pseudogap, charge and spin responses in the Hubbard model

Abstract We have studied in terms of the effective T-matrix the self-energy part for both the attractive (U 0) Hubbard models. It is shown that the “fluctuation” pairing for strong coupling at T>T c for the attractive Hubbard model does not cause any pseudogap behavior in the density of states. It is shown in the RPA that the attractive Hubbard model stands for the incompressible and nearly ferromagnetic liquid (F s 0 =9.0, F a 0 =−0.47 for |U|N F =0.9). Thus, the attractive Hubbard model is an adequate model for liquid 3 He. However, the repulsive Hubbard model in the RPA represents a highly compressible and nearly antiferromagneic liquid (F s 0 =−0.47, F a 0 =9.0 for UN F =0.9). We have also shown that a pseudogap exists in the charge response for the attractive Hubbard model. In contrast, the pseudogap in the spin response appears to exist for the repulsive Hubbard model only.
Adiabatic quantum computation with Cooper pairs

We propose a new variant of the controlled-NOT quantum logic gate based on adiabatic level-crossing dynamics of the q-bits. The gate has a natural implementation in terms of the Cooper pair transport in arrays of small Josephson tunnel junctions. An important advantage of the adiabatic approach is that the gate dynamics is insensitive to the unavoidable spread of junction parameters.
Studying Space Plasmas from a Lunar Base

During the late 1960s and early 1970s, space plasma physics research on and near the moon thrived, with several satellites operating in lunar orbit and several sets of instruments arrayed on the lunar surface. The moon was found to be a uniquely "clean" plasma physics observatory when compared with all other celestial bodies visited by spacecraft. Having no atmosphere and no intrinsic magnetic field, and no induced magnetic field because of its very poor electrical conductivity, it provides little advance warning of its presence to approaching space plasmas which, therefore, impinge directly on its surface. Magnetic lines of force from external sources thread through the moon in a rectilinear manner almost as though it did not exist. It is anticipated that space plasma physics will remain an active discipline when a lunar base becomes possible, and that the moon will be the site of much important research whose exact nature is impossible to foresee.
Zwittermicin A, an antifungal and plant protection agent from Bacillus cereus

Abstract Zwittermicin A (1), a new linear aminopolyol, was isolated from Bacillus cereus UW85 and its structure was determined by spectroscopic methods.
Effect of waveform on the effectiveness of tangential dither forces to cancel friction-induced oscillations

High-frequency dither forces are often used to reduce unwanted vibration in frictional systems. This paper examines how the effectiveness of these dither-cancellation techniques is influenced by the nature of periodic signal employed. The paper investigates a single-degree-of-freedom (sdof) system consisting of a mass in frictional contact with a translating belt using two different models of friction. Prior work by the authors focused on sinusoidal dither waveforms. This paper extends this analysis to general, periodic dither forces. Using an averaging technique, the optimal waveforms are determined among periodic signals having either unit-amplitude or unit-rms value. For unit-amplitude dither signals, it is found that square waveforms are able to quench self-excited oscillations with the smallest amplitude of all waveforms of equal strength at every belt speed. Among unit-rms dither waveforms, square waves are best for low belt speeds, but sinusoidal dither is revealed to be best in higher ranges of belt speed. After studying generic waveforms, the results are specialized for three specific examples: sinusoidal, triangular, and square. In particular, the relative performance of the three waveforms is studied using an averaging technique as well as direct time integration.
Thompson's group F is not almost convex

Abstract We show that Thompson's group F does not satisfy Cannon's almost convexity condition AC ( n ) for any positive integer n with respect to the standard generating set with two elements. To accomplish this, we construct a family of pairs of elements at distance n from the identity and distance 2 from each other, which are not connected by a path lying inside the n -ball of length less than k for increasingly large k . Our techniques rely upon Fordham's method for calculating the length of a word in F and upon an analysis of the generators' geometric actions on the tree pair diagrams representing elements of F .
The logical design of a 1-microsecond parallel adder using 1-megacycle circuitry

Synopsis: The logical design of a parallel adder is developed which is capable of adding two 53-bit numbers in 1 micro-second. The design makes use of basically the same 1-megacycle circuitry which has been used successfully in the National Bureau of Standards' SEAC and DYSEAC computers. An analysis of the functional relationships of the carry digits to the augend and addend digits shows that it is feasible to form many carries simultaneously at the expense of relatively few components. The Boolean expressions for many successive carry digits can be expanded as explicit functions of some one lower-order carry, and of the relevant augend and addend digits. These somewhat complicated expressions are simplified by making substitutions for the common terms and factors they contain. These common terms and factors, called auxiliary carry functions, are implemented separately. All functional forms fit within the wide limits of gating complexity allowed by the type of circuitry to be used.
Expert Review Of Drug Patent Applications: Improving Health In The Developing World

Many developing countries have enacted intellectual property laws allowing patents on pharmaceutical products. These countries now must figure out how to provide legitimate protection of innovative discoveries while avoiding drug patents that do not conform to their laws. Using case-study examples, including the antiretroviral tenofovir disoproxil fumarate (TDF, or Viread), we demonstrate the importance of having outside experts participate in the review of drug patents. Vibrant patent review systems require sharing information among developing countries and active consultation with local public health authorities.
Transient Loads Control of a Variable Speed Rotor During Lagwise Resonance Crossing

Varying rotor speed during operation is a potential way to improve rotorcraft performance. The transient aeroelastic response of a stiff in-plane rotor system undergoing variable speed operation in forward flight is considered. During crossing of the fundamental lag mode near 2/rev, high transient lag bending moments are observed. The flapping amplitude and duration of the resonance crossing event have a strong influence on the peak lagwise root bending moment. Embedded chordwise fluidlastic dampers are explored as a way to reduce the peak bending moments. Determination of the fluidlastic damper properties is based on the analysis of a two degree-of-freedom blade-damper system. Parametric studies show that tuning port area ratios, loss factors, and device mass can be modified to enhance damper performance, and control the stroke. Results indicate that more than 6% critical lag damping can be provided around the resonance rotor speed, and that approximately 65% peak-to-peak moment reduction can be achieved...
Ag nanowire formation within mesoporous silica

Uniform Ag nanowires have been synthesized within nanoscale channels of mesoporous silica SBA-15 by a simple chemical approach, which involves AgNO3 impregnation, followed by thermal decomposition.
Heat transport experiments in superfluid helium

New measurements of the boundary resistance in superfluid4He (2 ppb3He) nearT λ are reported in a cell of improved design with parallel polished copper surfaces. In contrast to several previous experiments, the largeQ-dependent boundary resistance anomaly observed previously was no longer detected. However the small, weakly divergent boundary resistance was observed and the results are compared with previous experiments and predictions. Measurements with this new cell of the thermal conductivity and relaxation times in dilute superfluid mixtures of3He in4he are reported above 1.5 K. They confirm predictions for the bulk fluid; the diffusion coefficientsD iso for isolated3He impurities so obtained are then internally consistent.
Use of 2,3-bis(phenylsulfonyl)-1,3-butadiene as a reagent for the synthesis of azapolycyclic ring systems

2,3-Bis(phenylsulfonyl)-1,3-butadiene undergoes ready Michael addition with various primary amines to ultimately produce dihydropyrrolidines by a mechanism involving a proton shift after the initial conjugate addition followed by a subsequent intramolecular cyclization. A related transformation occurs with soft carbanion nucleophiles such as malonate esters. N-Alkyl imines also react to produce tetrahydropyridines by a sequence of reactions involving the transient intermediacy of a 1,3-diphenylsulfonyl diene. When the malonate ester contains a tethered π -bond, an initially formed allene undergoes a subsequent intramolecular [2+2]-cycloaddition to give bicyclo[4.2.0]-adducts.
Can the Topex/Poseidon altimetry data be used to estimate air‐sea heat flux in the North Atlantic?

We propose a novel approach to directly invert large-scale anomalous annual net air-sea heat flux from the Topex/Poseidon altimetry data in the North Atlantic. The major advantage of this new approach over the conventional bulk formula approach is that it does not need those climate parameters used in the conventional bulk formula calculation in estimating the large-scale anomalous annual net air-sea heat flux. Comparison with expendable bathythermograph data demonstrates that it is a feasible approach.
A New Foil Air Bearing Test Rig for Use to 700°C and 70,000 rpm

A new test rig has been developed for evaluating foil air bearings at high temperatures and speeds. These bearings are self-acting hydrodynamic air bearings which have been successfully applied to a variety of turbomachinery operating up to 650°C. This unique test rig is capable of measuring bearing torque during start-up, shutdown and high speed operation. Load capacity and general performance characteristics, such as durability, can be measured at temperatures to 700°C and speeds to 70,000 rpm. This paper describes the new test rig and demonstrates its capabilities through the preliminary characterization of several bearings. The bearing performance data from this facility can be used to develop advanced turbomachinery incorporating high temperature oil-free air bearing technology. Presented as a Society of Tribologists and Lubrication Engineers paper at the World Tribology Congress in London, United Kingdom, September 9–12, 1997
The political economy of constitutional choice: a study of the 2005 Kenyan constitutional referendum

Recent studies of the linkages between the wealth of nations and the institutions of governance suggest that concentrating political power in a monarchy or a ruling coalition impedes economic growth and, moreover, that while power-diffusing reforms can enhance the wellbeing of society in general, opposition by groups benefiting from the status quo is predictable. In November 2005, Kenyans rejected a proposed constitution that, despite promises made by their new chief executive, would not have lessened the powers of the presidency. Using a unique, constituency-level dataset on the referendum vote, we estimate a model of the demand for power diffusion and find that ethnic groups’ voting decisions are influenced by their expected gains and losses from constitutional change. The results also highlight the importance of ethnic divisions in hindering the power-diffusion process, and thus establish a channel through which ethnic fragmentation adversely impacts economic development.
An approximate Herbrand's theorem and definable functions in metric structures

We develop a version of Herbrand's theorem for continuous logic and use it to prove that definable functions in infinite-dimensional Hilbert spaces are piecewise approximable by affine functions. We obtain similar results for definable functions in Hilbert spaces expanded by a group of generic unitary operators and Hilbert spaces expanded by a generic subspace. We also show how Herbrand's theorem can be used to characterize definable functions in absolutely ubiquitous structures from classical logic.
Conformal anomaly of submanifold observables in AdS/CFT correspondence☆

Abstract We analyze the conformal invariance of submanifold observables associated with k-branes in the AdS/CFT correspondence. For odd k, the resulting obsrvables are conformally invariant, and for even k, they transform with a conformal anomaly that is given by a local expression which we analyze in detail for k = 2.
A carbenoid ring expansion route to the first member of a newly discovered diterpene class. Total synthesis of 18-oxo-3-virgene

Abstract Virginia 115 tobacco cultivars produce the structurally unusual diterpene 2 , which has presently been synthesized from bicyclic ketone 3 .
Controversy in the management of optic nerve glioma.

The records of 16 patients with optic nerve glioma treated between 1961 and 1984 were reviewed. All patients except two had extension of tumor beyond the chiasm to the hypothalamus, adjacent brain and/or along the posterior optic tract. Eleven of 16 cases were biopsy-proven, two patients had craniotomy and visual inspection but no biopsy was performed, and in two cases the biopsy was not diagnostic. Fourteen patients received radiation therapy, usually consisting of 50 Gy in 5 weeks (range 40-56 Gy), one patient was treated surgically and one with chemotherapy. With a follow-up of 1 to 20 years, 7 of the 14 patients irradiated are alive, three patients are dead of disease at 3, 6 and 9 years post-treatment, three were lost to follow-up at 1, 8, and 8 years, and one is dead of intercurrent disease at 5.5 years. Overall vision was improved in five patients and stable in seven following treatment. In two patients, vision could not be evaluated because of young age at presentation. Four patients had recurrences. One was retreated with 30 Gy in 3 weeks and shows no evidence of disease at 20 years. The three other patients died of their disease. There is controversymore » over the best treatment for these patients. Based on these results and a review of the literature, the authors recommendation is to irradiate tumors with extension beyond the chiasm at the time of presentation rather than waiting for increasing symptoms because function that is lost may not always be recovered. Chemotherapy needs to be further investigated but holds promise, especially for the younger children.« less
Determination of the axial vector form factor in the radiative decay of the pion

Abstract The branching ratio for the decay π → e νγ has been measured in a counter experiment in which the e + was detected in a magnetic spectrometer and the γ-ray in a lead-glass hodoscope. The number of observed events is 226.2 ± 22.4. The branching ratio into that part of phase space with electron momentum above 56 MeV/ c and the electron-photon opening angle greater than 132° is found to be (5.6 ± 0.7) × 10 −8 . From the measured branching ratio we determine γ, the ratio of the axial vector tovector form factors. The vector from factor is computed using CVC and the π 0 lifetime. For T π 0 = 0.828 × 10 −16 s, γ = 0.44 ± 0.12 or γ = − 2.36 ± 0.12 is obtained. The measurement is compared with several theoretical predictions.
Engineered Piezoelectricity in Graphene

We discover that piezoelectric effects can be engineered into nonpiezoelectric graphene through the selective surface adsorption of atoms. Our calculations show that doping a single sheet of graphene with atoms on one side results in the generation of piezoelectricity by breaking inversion symmetry. Despite their 2D nature, piezoelectric magnitudes are found to be comparable to those in 3D piezoelectric materials. Our results elucidate a designer piezoelectric phenomenon, unique to the nanoscale, that has potential to bring dynamical control to nanoscale electromechanical devices.
Test Functions, Schur-Agler Classes and Transfer-Function Realizations: The Matrix-Valued Setting

Given a collection of test functions, one defines the associated Schur–Agler class as the intersection of the contractive multipliers over the collection of all positive kernels for which each test function is a contractive multiplier. We indicate extensions of this framework to the case where the test functions, kernel functions, and Schur–Agler-class functions are allowed to be matrix- or operator-valued. We illustrate the general theory with two examples: (1) the matrix-valued Schur class over a finitely-connected planar domain and (2) the matrix-valued version of the constrained Hardy algebra (bounded analytic functions on the unit disk with derivative at the origin constrained to have zero value). Emphasis is on examples where the matrix-valued version is not obtained as a simple tensoring with $${{\mathbb C}^{N}}$$ of the scalar-valued version.
The Nuclear Starburst in NGC 253

We have obtained long-slit spectra of NGC 253 in the J, H, K, and N bands, broadband images in the J, H, and Ks bands, narrowband images centered at the wavelengths of Brγ and H2(1, 0) S(1), and imaging spectroscopy centered on [Ne II] (12.8 μm). We have subtracted a composite stellar spectrum from the galaxy spectrum to measure faint emission lines that otherwise would be buried in the complicated continuum structure. We use these data and data from the literature in a comprehensive reassessment of the starburst in this galaxy. We confirm that the [Fe II] emission is predominantly excited by supernova explosions and show that the rate of these events can be derived from the strength of the infrared [Fe II] lines. Although the H2 emission superficially resembles a thermally excited spectrum, most of the H2 infrared luminosity is excited by fluorescence in low-density gas. We confirm the presence of a bar and also show that this galaxy has a circumnuclear ring. The relation of these features to the gaseous bar seen in CO is in agreement with the general theoretical picture of how gas can be concentrated into galaxy centers by bars. We derive a strong upper limit of ~37,000 K for the stars exciting the emission lines. We use velocity-resolved infrared spectra to determine the mass in the starburst region. Most of this mass appears to be locked up in the old, preexisting stellar population. Using these constraints and others to build an evolutionary synthesis model, we find that the initial mass function (IMF) originally derived to fit the starburst in M82 also accounts for the properties of NGC 253; this IMF is similar to a modified Salpeter IMF. The models indicate that rapid massive star formation has been ongoing for 20-30 million yr in NGC 253; that is, it is in a late phase of its starburst. Its optical spectrum has characteristics of a transitional H II/weak-[O I] LINER. We model the emission-line spectrum expected from a late phase starburst and demonstrate that it reproduces these characteristics.
Survey of time-optimal attitude maneuvers

Introduction P pointing control and rapid maneuvering capabilities have long been part of many space missions; examples include military observation platforms, communications satellites, and exploratory space missions. Rapid retargeting may be an intrinsic part of the mission profile, as in military and exploratory applications, or it may be required to correct, periodically, the guidance and navigation sensors of a spacecraft. Consequently, research in attitude maneuvers and time-optimal controls has been a consistently strong field of study. Of particular interest is the time-optimal attitude maneuver; this problem combines aspects of many different fields, such as mathematics, optimal control theory, spacecraft dynamics, elasticity, and structural mechanics. In the study of attitude maneuvers and control, researchers have investigated the response of satellite control systems to disturbances caused by the influence of solar pressure, gravity gradients, the effectiveness of active control devices, and the best placement of actuators and sensors on a given structure. Numerous studies have been conducted for specific satellite configurations to determine a time-optimal attitude control for a predetermined maneuver. Further, the mathematical procedures required to investigate this problem have inspired a number of papers on techniques to address the difficulties which arise from time-optimal control. This survey reviews the literature of the last thirty years, including many of the more recent advances in the field, covers the aforementioned topics as well as specific attitude maneuvers, and traces the development of time-optimal and near time-optimal control algorithms. We begin by considering the formulation of the time-optimal control problem and the difficulties faced in obtaining the solution. The equations for the rotational motion of any rigid body (Ruler's equations) are quite elegant and compact; they are also coupled and highly nonlinear. In addition, the high angular velocities of time-optimal maneuvers will cause gyroscopic stiffness through the nonlinear terms. Ruler's equations are expressed as
Quantum moduli spaces from matrix models

Abstract In this Letter we show that the matrix model techniques developed by Dijkgraaf and Vafa can be extended to compute quantum deformed moduli spaces of vacua in four-dimensional supersymmetric gauge theories. The examples studied give the moduli space of a bulk D-brane probe in geometrically engineered theories, in the presence of fractional branes at singularities.
The Number of Outcomes in the Pareto-Optimal Set of Discrete Bargaining Games

A set of n players is to bargain over which one of m possible outcomes will be chosen. The preference of outcome i to player j is assumed to be a random variable with all preference rankings equally likely and without ties. This would arise in case the payoffs are chosen as independent samplings from a continuous distribution Fj. The mean and distribution of the number of outcomes in the Pareto-optimal set are calculated for finite m. As m → ∞ the mean is asymptotic to log m + 0.577n-1/n-1! and for n = 2, m → ∞, the distribution approaches the normal distribution. The results are also applied to a problem in multiattribute utility theory. Suppose we wish to select an individual with high values on two personal attributes that are independent and continuously measurable. Of a world population of four billion, the efficient set would have an expectation of 22.7 individuals.
Culture and achievement motivation

This symposium and the papers that compose it reflect the fact that the study of culture and achievement motivation has truly “come of age.” Gone are the days when a few hearty souls from Europe, G...
Decreased Pulmonary Function in Asymptomatic Long Term Survivors After Busulfan-Based Myeloablative Allogeneic Hematopoietic Stem Cell Transplant

Abstract 4474 Pulmonary function post allogeneic hematopoietic stem cell transplant (HSCT) can be impaired by previous exposure to chemotherapy, infection, or underlying chronic graft versus host disease (cGVHD). In this retrospective study, we selected 21 long term transplant survivors with a median follow up of 48 months who had received a related (60%) or unrelated (40%) HSCT conditioned with a myeloablative busulfan-based regimen. All patients had routine pulmonary function tests (PFTs) repeated within two years from transplant and none had respiratory symptoms or a history of chronic lung infection at the time of analysis. Median age was 45 years (range 18–54). Patients had a diagnosis of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) (52%), acute lymphoblastic leukemia (ALL) (14%), chronic myeloid leukemia (CML) (14%), non-Hodgkin lymphoma (NHL) (9%), or chronic lymphocytic leukemia (CLL) (2%). Survival rate at the time of analysis is 90%. We initially compared single parameters of PFTs including corrected diffusion limiting capacity of oxygen (DLCO), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and total lung capacity (TLC) obtained before and after transplant. Post transplant, all PFT parameters showed some degree of reduction compared to pre-transplant values (Figure 1). FEV1 and FEV1/FVC were significantly decreased (108 vs 92,p=0.04 and 86 vs 80%, p=0.04, respectively). Median values of corrected DLCO prior to and after transplant were 83% (range 55–148) and 77%(range 44–146) (p=0.2), respectively. In order to test whether patients with >10% reduction of PFTs had an increased rate of overall cGVHD, we analyzed intra-patient changes in DLCO and FEV1 values. We then divided patients into groups with extensive, limited, or no cGVHD. No correlation was found between the degree of cGVHD and FEV1 or DLCO values. A decrease in pulmonary function was detected in patients who received a busulfan based myeloablative HSCT despite the absence of lung infection or pulmonary cGVHD. This finding, however, did not affect long term survival. Disclosures: No relevant conflicts of interest to declare.