cssi/SciSciGPT-SciSciNet huggingface dataset:
Environmental Protection, Rare Disasters and Discount Rates

The Stern Review's evaluation of environmental protection stresses low discount rates and uncertainty about environmental effects. An appropriate model for analysing this uncertainty and the associated discount rates requires sufficient risk aversion and fat-tailed uncertainty to account for the observed equity premium. Calibrations based on Epstein–Zin preferences and existing analyses of rare macroeconomic disasters suggest that optimal environmental investment can be a significant share of GDP even with reasonable rates of time preference. Optimal environmental investment increases with risk aversion and the probability and typical size of environmental disasters, but decreases with uncertainty about policy effectiveness.
Model-Based Reinforcement Learning for Infinite-Horizon Approximate Optimal Tracking

This brief paper provides an approximate online adaptive solution to the infinite-horizon optimal tracking problem for control-affine continuous-time nonlinear systems with unknown drift dynamics. To relax the persistence of excitation condition, model-based reinforcement learning is implemented using a concurrent-learning-based system identifier to simulate experience by evaluating the Bellman error over unexplored areas of the state space. Tracking of the desired trajectory and convergence of the developed policy to a neighborhood of the optimal policy are established via Lyapunov-based stability analysis. Simulation results demonstrate the effectiveness of the developed technique.
A uniform estimate for Fourier restriction to simple curves

We prove a uniform Fourier extension-restriction estimate for a certain class of curves in ℝ d .
Convolutional codes with maximum distance profile

Abstract Maximum distance profile codes are characterized by the property that two trajectories which start at the same state and proceed to a different state will have the maximum possible minimum distance from each other relative to any other convolutional code of the same rate and degree. In this paper we use methods from systems theory to characterize maximum distance profile codes algebraically. The main result shows that maximum distance profile codes form a generic set inside the variety which parametrizes the set of convolutional codes of a fixed rate and a fixed degree.
Free surface electrospinning from a wire electrode

Abstract Electrostatic jetting from a free liquid surface offers an alternative to conventional electrospinning in which jets are emitted from spinnerets. In this work we analyze a system in which a wire electrode is swept (in a rotary motion) through a bath containing a polymeric solution in contact with a high voltage, resulting in entrainment of the fluid, the formation of liquid droplets on the wire and electrostatic jetting from each liquid droplet. Solutions of polyvinylpyrrolidone in ethanol were used as test systems to evaluate each stage of the process. The volumes of individual droplets on the wire were measured by photographic methods and correlated with the viscosity, density and surface tension of the liquid, and with system parameters such as electrode rotation rate and wire diameter. The local electric field in the absence of liquid entrainment was modeled using conventional electrostatics, and jet initiation was found to occur consistently at the angular position where the electric field exceeds a critical value of 34 kV/cm, regardless of rotation rate. Two operating regimes were identified. The first is an entrainment-limited regime, in which all of the entrained liquid is jetted from the wire electrode. The second regime is field-limited, in which the residence time of the wire electrode in an electric field in excess of the critical value is too short to deplete the fluid on the wire. The productivity of the system was measured and compared to the theoretical values of liquid entrainment. As expected, highest productivity occurred at high applied potentials and high rotation rates.
The Child is Father of the Man: Foresee the Success at the Early Stage

Understanding the dynamic mechanisms that drive the high-impact scientific work (e.g., research papers, patents) is a long-debated research topic and has many important implications, ranging from personal career development and recruitment search, to the jurisdiction of research resources. Recent advances in characterizing and modeling scientific success have made it possible to forecast the long-term impact of scientific work, where data mining techniques, supervised learning in particular, play an essential role. Despite much progress, several key algorithmic challenges in relation to predicting long-term scientific impact have largely remained open. In this paper, we propose a joint predictive model to forecast the long-term scientific impact at the early stage, which simultaneously addresses a number of these open challenges, including the scholarly feature design, the non-linearity, the domain-heterogeneity and dynamics. In particular, we formulate it as a regularized optimization problem and propose effective and scalable algorithms to solve it. We perform extensive empirical evaluations on large, real scholarly data sets to validate the effectiveness and the efficiency of our method.
Spitzer Space Telescope Observations of the Aftermath of Microlensing Event MACHO-LMC-5

We have carried out photometry of the microlensing event MACHO-LMC-5 with Spitzer Infrared Array Camera (IRAC) 10 years after the magnification of the LMC source star was recorded. This event is unique in the annals of gravitational microlensing: the lensing star itself has been observed using the Hubble Space Telescope (once with WFPC2 and twice with ACS/HRC). Since the separation between the source and lens at the epoch of the Spitzer observations was ~024, the two stars cannot be resolved in the Spitzer images. However, the IRAC photometry clearly establishes that the lens is an M5 dwarf star from its infrared excess, which in turn yields a mass of ~0.2 M⊙. This demonstrates the potential of Spitzer to detect the lenses in other gravitational microlensing events.
Rapid sampling of all-atom peptides using a library-based polymer-growth approach.

We adapted existing polymer growth strategies for equilibrium sampling of peptides described by modern atomistic forcefields with a simple uniform dielectric solvent. The main novel feature of our approach is the use of pre-calculated statistical libraries of molecular fragments. A molecule is sampled by combining fragment configurations – of single residues in this study – which are stored in the libraries. Ensembles generated from the independent libraries are reweighted to conform with the Boltzmann-factor distribution of the forcefield describing the full molecule. In this way, high-quality equilibrium sampling of small peptides (4–8 residues) typically requires less than one hour of single-processor wallclock time and can be significantly faster than Langevin simulations. Furthermore, approximate, clash-free ensembles can be generated for larger peptides (up to 32 residues in this study) in less than a minute of single-processor computing. We discuss possible applications of our growth procedure to free energy calculation, fragment assembly protein-structure prediction protocols, and to “multi-resolution” sampling.
Solution of Euler's Equations of Motion and Eulerian Angles for near symmetric rigid bodies subject to constant moments

Analytic expressions are found for Euler's Equations of Motion and for the Eulerian Angles for both symmetric and near symmetric rigid bodies under the influence of arbitrary constant body-fixed torques. These solutions provide the body-fixed angular velocities and the attitude of the body, respectively, as functions of time. They are of special interest in applications to spinning spacecraft (such as the Galileo Spacecraft to be launched in 1984) because they include the effect of time-varying spin rate. Thus they can be applied to spin-up and spin-down maneuvers as well as to error analysis for thruster misalignments. The solutions are given for arbitrary initial conditions in terms of Fresnel, Sine and Cosine Integrals. Numerical integration of the governing differential equations has verified that the approximate analytic solutions are very accurate in many physical situations of interest.
Detection of Specularity Using Stereo in Color and Polarization Space

We propose a specularity detection method based on a synergistic integration of color and polarization information from multiple views. The presence of specularity in images may cause many traditional computer vision processes to produce misleading results. Recent physics-based detection methods have provided much success in locating specularity; however, no single cue reveals the full structure of specular reflections. Our method merges multiple-view color and polarization, two physically independent but highly effective cues, in a way that they mutually benefit from each other. In a fused color and polarization space, the proposed algorithm compares the distributions of sensor data from multiple views for detection of specularity. We show that the efficacy of this new cue extends beyond that of the sum of its parts, and confirming experimental results are presented.
Generalized synthesis of cis- and trans-dioxorhenium(V) (Bi)pyridyl complexes

Abstract : Efficient new synthetic routes to trans-(O)-2Re(py-X)2(py-Y)2+ and cis-(O)2Re(bpy-Y2)(py-X)2+ complexes have been devised (py is pyridine; bpy is 2,2'-bipyridine). The new routes make use of labile cis-(O)2Re(py-X)2(I) species as preparative intermediates. The most useful new features of the synthetic chemistry are: (1) the ability to prepare trans species containing electron- withdrawing substituents, (2) the ability to prepare mixed-ligand trans- dioxorhenium species. and (3) generalization of the cis-dioxorhenium preparation.
An Assessment of Dynamical Mass Constraints on Pre-Main-Sequence Evolutionary Tracks

We have assembled a database of stars having both masses determined from measured orbital dynamics and sufficient spectral and photometric information for their placement on a theoretical H-R diagram. Our sample consists of 115 low-mass (M < 2.0 M_☉) stars, 27 pre-main-sequence and 88 main-sequence. We use a variety of available pre-main-sequence evolutionary calculations to test the consistency of predicted stellar masses with dynamically determined masses. Despite substantial improvements in model physics over the past decade, large systematic discrepancies still exist between empirical and theoretically derived masses. For main-sequence stars, all models considered predict masses consistent with dynamical values above 1.2 M_☉ and some models predict consistent masses at solar or slightly lower masses, but no models predict consistent masses below 0.5 M_☉, with all models systematically underpredicting such low masses by 5%-20%. The failure at low masses stems from the poor match of most models to the empirical main sequence below temperatures of 3800 K, at which molecules become the dominant source of opacity and convection is the dominant mode of energy transport. For the pre-main-sequence sample we find similar trends. There is generally good agreement between predicted and dynamical masses above 1.2 M_☉ for all models. Below 1.2 M_☉ and down to 0.3 M_☉ (the lowest mass testable), most evolutionary models systematically underpredict the dynamically determined masses by 10%-30%, on average, with the Lyon group models predicting marginally consistent masses in the mean, although with large scatter. Over all mass ranges, the usefulness of dynamical mass constraints for pre-main-sequence stars is in many cases limited by the random errors caused by poorly determined luminosities and especially temperatures of young stars. Adopting a warmer-than-dwarf temperature scale would help reconcile the systematic pre-main-sequence offset at the lowest masses, but the case for this is not compelling, given the similar warm offset at older ages between most sets of tracks and the empirical main sequence. Over all age ranges, the systematic discrepancies between track-predicted and dynamically determined masses appear to be dominated by inaccuracies in the treatment of convection and in the adopted opacities.
Fluorine‐substituted ligands for the peroxisome proliferator‐activated receptor gamma (Pparγ): Potential imaging agents for metastatic tumors

Fluorine-substituted analogs of ligands for the peroxisome proliferator-activated receptor gamma (PPARγ), a new target for tumors imaging, retained receptor binding affinity in vitro, but did not show receptor-mediated uptake in vivo.
Prognostic value of right ventricular ejection fraction determined by cardiac magnetic resonance

Introduction Although studies have shown that right ventricular ejection fraction (RVEF) is an independent predictor of survival in patients with myocardial infarction and moderate left heart failure, there is scant data available on the prognostic significance of RVEF in patients with preserved left ventricular ejection fraction (LVEF), partly due to challenges in imaging the right ventricle (RV) due to its amorphous geometry. Recent technological advances in cardiac magnetic resonance (CMR) have allowed the RVEF to be assessed with greater accuracy.
Impact modeling with smooth particle hydrodynamics

Abstract Smooth Particle Hydrodynamics (SPH) is a new computational technique well suited to computation of hypervelocity impact phenomena. This paper reviews the characteristics, philosophy, and a bit of the derivation of the method. As illustrations of the technique, several test case computations and several application computations are shown.
Fabrication of detectors and transistors on high-resistivity silicon

A new process for the fabrication of silicon p-i-n diode radiation detectors is described. The utilization of backside gettering in the fabrication process results in the actual physical removal of detrimental impurities from critical device regions. This reduces the sensitivity of detector properties to processing variables while yielding low diode reverse-leakage currents. In addition, gettering permits the use of processing temperatures compatible with integrated-circuit fabrication. P-channel MOSFETs and silicon p-i-n diodes have been fabricated simultaneously on 10 k..cap omega../center dot/cm silicon using conventional integrated-circuit processing techniques. 25 refs., 5 figs.
Lewis Acid-Promoted Carbon−Carbon Bond Cleavage of Aziridines: Divergent Cycloaddition Pathways of the Derived Ylides

Lewis acids are shown to cleave the carbon−carbon bond of activated aziridines at ambient temperature. The derived metal-coordinated azomethine ylides undergo cycloaddition reactions with electron-rich alkenes. Cyclic alkenes afford products that are formally [4+2] adducts most likely derived from a Mannich-type addition to the ylide, followed by intramolecular Friedel−Crafts alkylation. Alternatively, acyclic alkenes undergo [3+2] cycloaddition to give new pyrrolidine products.
Maximum likelihood estimation of discrete control processes

Consider the following “inverse stochastic control” problem. A statistician observes a realization of a controlled stochastic process $\{ d_t ,x_t \} $ consisting of the sequence of states $x_t$, a...
Synthesis and calpain inhibitory activity of α-ketoamides with 2,3-methanoleucine stereoisomers at the P2 position

A series of novel ketoamides incorporating all four 2,3-methanoleucine stereoisomers at the P2 position was synthesized. The compounds displayed a wide variation in Ki values for inhibition of calpain I depending on the configuration of the P2 methanoleucine residue. However, similar variation in cathepsin B inhibition was not observed suggesting that the S2 pocket of calpain I is more stereosensitive than that of cathepsin B.
Syntheses of amino acids from aliphatic carboxylic acid by glow discharge electrolysis.

GLOW discharge electrolysis (GDE)1,2 has been studied mainly on inorganic compounds such as water, ammonia, and metal ions in aqueous solutions. Little study has been done, however, on the chemistry of GDE using organic compounds3–7 although experimental results indicate that the application of GDE to organic compounds is a promising area in chemistry and is especially interesting in connection with the concept of chemical evolution.
Brane world models with bulk scalar fields

Abstract We examine several different types of five-dimensional stationary space–times with bulk scalar fields and parallel 3-branes. We study different methods for avoiding the appearance of space–time singularities in the bulk for models with and without cosmological expansion. For nonexpanding models, we demonstrate that in general the Randall–Sundrum warp factor is recovered in the asymptotic bulk region, although elsewhere the warping may be steeper than exponential. We show that nonsingular expanding models can be constructed as long as the gradient of the bulk scalar field vanishes at zeros of the warp factor, which are then analogous to the particle horizons found in expanding models with a pure AdS bulk. Since the branes in these models are stabilized by bulk scalar fields, we expect there to be no linearly unstable radion modes. As an application, we find a specific class of expanding, stationary solutions with no singularities in the bulk in which the four-dimensional cosmological constant and mass hierarchy are naturally very small.
The Type 2 Intramolecular Diels–Alder Reaction: Synthesis and Chemistry of Bridgehead Alkenes

Anti-Bredt alkenes, bicyclic molecules that contain a bridgehead double bond, were for many years regarded as chemical curiosities. The type 2 intramolecular Diels-Alder (IMDA) reaction provides a one-step entry into this fascinating class of molecules. The reaction has made available numerous anti-Bredt alkenes for structural and chemical studies. X-ray crystallography has revealed the magnitude of the deformations associated with the bridgehead double bond, and rate studies of reactions of bridgehead alkenes have allowed quantification of the kinetic consequences of the torsional distortions. More recently, the type 2 intramolecular Diels-Alder reaction and the resulting anti-Bredt alkenes have found application in organic synthesis. The constraints resulting from the connectivity in the Diels-Alder precursor creates a strong regio- and stereochemical bias in the cycloaddition step. The end result of this bias is the stereoselective synthesis of highly substituted six-membered rings. The reaction also achieves a facile synthesis of seven- and eight-membered rings in a single step from acyclic precursors. The utility of this reaction has been verified in recent applications of the type 2 IMDA reaction as a key step in the total synthesis of complex natural products.
Chaos in the cobweb model with a new learning dynamic

Abstract The new learning dynamic of Brown et al. [(1950). Solutions of games by differential equation. In: Kuhn, H.W., Tucker, A.W. (Eds.), Contributions to the Theory of Games I. Annals of Mathematics Studies, vol. 24. Princeton University Press, Princeton] is introduced to macroeconomic dynamics via the cobweb model with rational and naive forecasting strategies. This dynamic has appealing properties such as positive correlation and inventiveness. There is persistent heterogeneity in the forecasts and chaotic behavior with bifurcations between periodic orbits and strange attractors for the same range of parameter values as in previous studies. Unlike Brock and Hommes [(1997). A rational route to randomness. Econometrica (65), 1059–1095], however, there exist intuitively appealing steady states where one strategy dominates, and there are qualitative differences in the resulting dynamics of the two approaches. There are similar bifurcations in a parameter that represents how aggressively agents switch to better performing strategies.
A matrix equation for association schemes

Let be a self-dual P-polynomial association scheme. Then there are at most 12 diagonal matricesT such that (PT)3 =I. Moreover, all of the solutions for the classical infinite families of such schemes (including the Hamming scheme) are classified.
Ordering Actions for Visibility

Several research projects are studying architectures for distributed computing that are founded on the notion of atomic actions operating on objects (instances of abstract data types). Such projects as Clouds at Georgia Tech and Archons at Carnegie-Mellon University are evaluating this approach as the foundation for constructing distributed operating systems. Objects are not new to operating systems. They provide substantial benefits in such dimensions as protection and synchronization, as well as their inherent organizational characteristics. This paper is concerned with synchronization to control ordering, a function often associated with objects. Conventional approaches require substantial extension for the action environment. Typically, they are based on (or equivalent to) general semaphores. Semaphores take no account of the visibility requirements of actions however, and consequently they can allow an action to progress beyond the point at which its effects can be undone. Also, they do not account for failures.
Electromagnetic signal propagation in crystals

The propagation of the electromagnetic signals generated by localized electromagnetic current distributions in perfect crystals is analyzed under the hypotheses that dispersion and magnetic anisotropy are negligible and all wavelengths are large compared with interatomic distances. The signal fields are shown to converge asymptotically in energy, for t→∞;, to the sum of two waves which propagate outward from the source region with the group velocities of the crystal. The polarizations and waveforms of these waves are calculated explicitly in terms of the crystal parameters and the source field.
Is the Food and Drug Administration Safe and Effective

In the United States, the Food and Drug Administration (FDA) provides public oversight of the safety and efficacy of drugs; medical devices; biologics like vaccines and blood products; cosmetics; radiation-emitting electronic products; veterinary products; and all foods, except meat and poultry (which are regulated by the Department of Agriculture). According to the FDA, the products it regulates account for more than one-fifth of U.S. consumer spending. In the area of medical products, the FDA is responsible for determining whether marketed products are both safe and effective before and after they have been marketed. In this paper, we will explore whether the policies of the agency itself are safe and effective. We stress two issues, one static and one dynamic. The static issue concerns the potential duplication inefficiency when product safety is protected not only by the FDA but also by the private sector through product liability law. Put another way, what is the rationale for using product liability and the FDA to regulate drug safety? While intuitively it may seem that two systems must be better than one in ensuring drug safety, each system comes with costs. We then turn to the dynamic issue, the speed-safety trade off, and consider the extent to which higher safety is achieved at a cost of later market entry of effective and even life-saving products. We assess the Prescription Drug User Fee Acts (PDUFAs), which increased the speed of the agency's regulatory process starting in 1992, although according to some, at the cost of reducing drug safety. We conclude by suggesting a research agenda for future work on the Food and Drug Administration.
N+ + C60 reactive scattering: Substitution, charge transfer, and fragmentation

N + +C 60 reactive scattering has been studied over the collision energy range from 1 to 80 eV. Charge transfer, producing C 60 + is the dominant low-energy channel. At high collision energies a significant fraction of the charge-transfer products also fragment producing C 60-2n + (n=1-8). Chemical reactivity of C 60 with N + is low compared to that observed for B + , C + , and O + and shows evidence of a barrier for N addition
Multi-Channel SQUID System for MEG and Ultra-Low-Field MRI

A seven-channel system capable of performing both magnetoencephalography (MEG) and ultra-low-field magnetic resonance imaging (ULF MRI) is described. The system consists of seven second-order SQUID gradiometers with 37 mm diameter and 60 mm baseline, having magnetic field resolution of 1.2-2.8 fT/radicHz . It also includes four sets of coils for 2D Fourier imaging with pre-polarization. The system's MEG performance was demonstrated by measurements of auditory evoked response. The system was also used to obtain a multi-channel 2D image of a whole human hand at the measurement field of 46 microtesla with 3 by 3 mm resolution.
Links between traumatic brain injury and ballistic pressure waves originating in the thoracic cavity and extremities.

Purpose: Identifying patients at risk of traumatic brain injury (TBI) is important because research suggests prophylactic treatments to reduce risk of long-term sequelae.Method: This review conside...
HIGHLY IONIZED PLASMA IN THE HALO OF A LUMINOUS SPIRAL GALAXY NEAR z = 0.225*

We present analyses of the physical conditions in the and multiphase absorption systems detected in the ultraviolet Hubble Space Telescope/STIS and FUSE spectra of the quasar H 1821+643 (mV = 14.2, zem = 0.297). Both absorbers are likely associated with the extended halo of a ~2L* B Sbc-Sc galaxy situated at a projected distance of ~116 h –1 71 kpc from the sight line. The z = 0.22496 absorber is detected in C II, C III, C IV, O III, O VI, Si II, Si III, and H I (Ly α-Lyθ) at >3σ significance. The components of Si III and Si II are narrow with implied temperatures of T 3 × 104 K. The low and intermediate ions in this absorber are consistent with an origin in a T ~ 104 K photoionized gas with [Si/H] and [C/H] of ~–0.6 dex. In contrast, the broader O VI absorption is likely produced in collisionally ionized plasma under nonequilibrium conditions. The system has broad Ly α (BLA) and C III absorption offset by v = –53 km s–1 from O VI. The H I and C III line widths for the BLA imply T = 1.1 × 105 K. For non-equilibrium cooling we obtain [C/H] ~–1.5 dex and N(H) = 3.2 × 1018 cm–2 in the BLA. The O VI, offset from the BLA with no detected H I or C III, is likely collisionally ionized at T ~ 3 × 105 K. From the observed multiphase properties and the proximity to a luminous galaxy, we propose that the z = 0.22496 absorber is an extragalactic analog of a highly ionized Galactic HVC, in which the O VI is produced in transition temperature plasma (T ~ 105 K) at the interface layers between the warm (T < 5 × 104 K) HVC gas phase and the hot (T 106 K) coronal halo of the galaxy. The z = 0.22638 O VI-BLA absorber could be tracing a cooling condensing fragment in the nearby galaxy's hot gaseous halo.
Perverse sheaves on real loop Grassmannians

The aim of this paper is to identify a certain tensor category of perverse sheaves on the loop Grassmannian Grℝ of a real form Gℝ of a connected reductive complex algebraic group G with the category of finite-dimensional representations of a connected reductive complex algebraic subgroup \(\check{H}\) of the dual group \(\check{G}\). The root system of \(\check{H}\) is closely related to the restricted root system of Gℝ. The fact that \(\check{H}\) is reductive implies that an interesting family of real algebraic maps satisfies the conclusion of the Decomposition Theorem of Beilinson-Bernstein-Deligne.
The canonical pencils on Horikawa surfaces

The complex surfaces X1 and X2 are simply-connected, non-spin, and have the same Euler characteristic e.X1/ D e.X2/ D 116 and signature .X1/ D .X2/ D 72; hence by a classical result of Freedman they are homeomorphic. Moreover, the homeomorphism between them can be chosen so that the canonical classes KX1 and KX2 are the image of each other under the induced map on cohomology. However, X1 and X2 are not deformation equivalent as complex surfaces [16]. The question of whether X1 and X2 are diffeomorphic is open to this date; although the expected answer is negative, a result of Friedman and Morgan [10] shows that X1 and X2 cannot be distinguished using Seiberg–Witten theory.
Tortured Relations: Human Rights Abuses and Counterterrorism Cooperation

Two big assumptions fuel current mobilization against and policy discussions about the U.S. war on terror and its implications for human rights and international cooperation. First, terrorism creates strong pressures on governments—especially democracies—to restrict human rights. Second, these restrictions are not only immoral and illegal, but also counterproductive to curbing terrorism. If these two assumptions are correct, then democracies face a vicious circle: terrorist attacks provoke a reaction that makes it harder to defeat terrorist organizations.
A note on “anomalous” chiral gauge theories

Abstract We show that the lattice regularization of chiral gauge theories proposed by Kaplan, when applied to a (2 + 1)-dimensional domain wall, produces a (1 + 1)-dimensional theory at low energy even if the gauge anomaly produced by chiral fermions does not cancel. But the corresponding statement is not true in higher dimensions.
Variability of Spectral Tristimulus Values

This paper describes a fundamental procedure for deriving “within” and “between” variances and covariances in the spectral tristimulus values. The within variances are based on the replications of color-mixture data by an observer. The between variances are based on differences among the color-mixture data of individual observers. A statistical model for the system in which the experimental data are obtained is given, expected values (means), variances, and covariances are developed, and the method by which these variances and covariances may be distributed among the sources of uncertainties in the experimental data is presented. There is developed a procedure for determining the uncertainties in the constants of a linear transformation to a system analogous to the present CIE system. The formulas for variances and covariances after linear transformation are given for an arbitrary choice of transformation constants. The complete set of variances and covariances derived from an arbitrary transformation is listed for 20 mμ intervals. This set, together with the mean spectral tristimulus values, forms a complete standard observer system. The between-observer variabilities are found to be about 10% of the averages of the color-mixture data and the average ratio of the between-observer variabilities to the within-observer variabilities is found to be about 5.7.
Periodic sub-wavelength electron beam lithography defined photonic crystals for mode control in semiconductor lasers

Surface structure lasers possess lithographically defined patterns, such as gratings and waveguides, on the wafer surface and are usually fabricated without semiconductor regrowth. Optical surface structures typically require sub-micron to nano-scale accuracy in fabrication. For surface structures with more complex geometries, electron beam lithography offers the necessary flexibility, control, and accuracy in fabrication. However, a challenge with electron beam lithography is the patterning of large (~1mm by 1mm) areas while maintaining the fabrication accuracy. In this work, we demonstrate two electron beam lithography techniques in a process for the fabrication of surface structure lasers with large areas that require sub-micron to nanometer accuracy. The first technique uses proximity effect correction to fabricate two-dimensional surface gratings each consisting of approximately one million 100nm diameter circles over an 800µm by 160µm area. The second part of the process uses overlay lithography with an alignment accuracy better than 45nm over a 1mm by 3.2mm area to planarize waveguide array lasers.
Hypomethylation of ras oncogenes in chemically induced and spontaneous b6c3f1 mouse liver tumors

The male hybrid B6C3F1 mouse exhibits a 30% spontaneous hepatoma incidence, and both males and females of this strain are sensitive to chemical induction of liver tumors. The Ha-ras, Ki-ras, and myc oncogenes have been implicated in a variety of solid tumors. Specifically, Ha- and, less frequently Ki-ras have been reported to be activated in B6C3F1 mouse liver tumors, and such activated oncogenes frequently contain a particular point mutation. In light of indications that the transforming capacity of some oncogenes is directly related to the level of the gene product, we hypothesized that transcriptional control of Ha-ras, Ki-ras, and myc is compromised in B6C3F1 mouse liver tumors. A positive correlation has been established between gene expression and hypomethylation. Therefore, the methylation states of these genes were examined in spontaneous liver tumors and in tumors induced by two diverse hepatocarcinogens: phenobarbital and chloroform. Ha-ras was found to be hypomethylated in all tumors examined, whereas Ki-ras was sometimes hypomethylated; such hypomethylation might play a role in the promotion stage of carcinogenesis. The methylation state of myc was unaltered, although this gene appeared to be amplified in tumors. These results suggest that a component of the mechanism by which these oncogenes are activated in B6C3F1 mouse liver tumors involves loss of stringent control of expression, via hypomethylation of the ras oncogenes and, possibly, amplification of myc. These results support the assertion that tumors induced by different classes of carcinogens or arising spontaneously share common biochemical pathways of oncogene activation during tumorigenesis.
Curved Flats and Isothermic Surfaces

We show how pairs of isothermic surfaces are given by curved flats in a pseudo Riemannian symmetric space and vice versa. Calapso’s fourth order partial differential equation is derived and, using a solution of this equation, a Mobius invariant frame for an isothermic surface is built.
A Practical, Accurate and Very General Core Loss Model for Nonsinusoidal Waveforms

Nonsinusoidal voltage waveforms are quite common in high frequency power conversion magnetics. Low frequency nonsinusoidal waveforms are also common in ac motor applications with waveforms such as pulsewidth modulation and six-step. Previous attempts to model these losses, based on the Steinmetz equation, can work only in a limited range of frequencies, flux density excitations, and waveforms. In this paper, we present a very practical, yet very general and accurate model, for core loss calculations in case of nonsinusoidal voltage waveforms. We show the model is equally applicable to low and high frequencies, metallic as well as nonmetallic (e.g., ferrites) core materials, by comparing the model prediction with measured data for various waveforms, frequencies, and flux densities. The model can be used for the design of high frequency transformers and inductors for use in switched mode power supplies. The model can also be used for ac motors where it is hard to estimate "derating factor" and to avoid uncontrolled temperature rise
Electron micropulse diagnostics and results for the Los Alamos free-electron laser

Abstract The electron beam diagnostics used in the Los Alamos free electron laser are described. These include the standard beam current, position and profile monitors as well as more elaborate energy and temporal spectrometers. Emphasis is given to the latter devices, which provide three-dimensional representations of the electron beam current as a function of energy and time in the picosecond region. These results were used to determine the performance of the accelerator and the laser. Crucial accelerator parameters were the energy spread and temporal shape of the micropulse. Essential laser parameters were the extraction efficiency and the duration of lasing during an individual micropulse.
Convergence of the Aumann–Davis–Maschler and Geanakoplos bargaining sets

Geanakoplos [17] defined a notion of bargaining set, and proved that his bargaining set is approximately competitive in large finite transferable utility (TU) exchange economies with smooth preferences. Shapley and Shubik [26] showed that the Aumann–Davis–Maschler bargaining set is approximately competitive in replica sequences of TU exchange economies with smooth preferences. We extend Geanakoplos’ result to nontransferable utility (NTU) exchange economies without smooth preferences, and we extend the Shapley and Shubik result to non-replica sequences of NTU exchange economies with smooth preferences.
Asymptotically Matched Spacetime Metric for Non-Precessing, Spinning Black Hole Binaries

We construct a closed-form, fully analytical 4-metric that approximately represents the spacetime evolution of non-precessing, spinning black hole binaries from innite separations up to a few orbits prior to merger. We employ the technique of asymptotic matching to join a perturbed Kerr metric in the neighborhood of each spinning black hole to a near-zone, post-Newtonian metric farther out. The latter is already naturally matched to a far-zone, post-Minkowskian metric that accounts for full temporal retardation. The result is a 4-metric that is approximately valid everywhere in space and in a small bundle of spatial hypersurfaces. We here restrict our attention to quasicircular orbits, but the method is valid for any orbital motion or physical scenario, provided an overlapping region of validity or buer zone exists. A simple extension of such a metric will allow for future studies of the accretion disk and jet dynamics around spinning back hole binaries.
Some recent developments in nuclear charged particle detectors

Abstract The latest developments of large-area, position sensitive gas-filled ionization chambers are described. Multi-wire-proportional chambers as position-sensing and parallel-plate-avalanche counters as time-sensing detectors at low pressure (5 Torr) have proven to be useful and reliable instruments in heavy ion physics. Gas (proportional) scintillation counters, used mainly for x-ray spectroscopy, have recently been applied as particle detectors. Finally, a brief description of a large plastic scintillator spectrometer, the Plastic Ball, is given and some of the first test and calibration data are shown.
Synthesis of isochromans via the titanium tetrachloride assisted cyclization of acetals of phenethyl alcohols

Abstract This paper reports the preparation of five 3,4-dihydro-1 H -2-benzopyrans in good yields via the TiCl 4 promoted cyclization of acetals derived from phenethyl alcohols.
The histologic spectrum of apocrine breast proliferations: A comparative study of morphology and DNA content by image analysis

Abstract Apocrine features occurring in sclerosing adenosis (apocrine adenosis), atypical ductal hyperplasia (ADH), and non-comedo ductal carcinoma in situ (DCIS) often add to diagnostic difficulty. We have evaluated the usefulness of DNA content determined by image analysis in apocrine metaplasia and hyperplasia, apocrine adenosis, ADH, DCIS, lobular carcinoma in situ, invasive ductal carcinoma, and infiltrating lobular carcinoma as a potential diagnostic aid in some of these problematic breast lesions with apocrine features. Infiltrating ductal carcinoma and DCIS were further subdivided into high- or low-grade category based on nuclear features. Microscopic fields containing 63 lesions were identified in slides from breast excisions. From each selected area 100 cells in corresponding fields in paired Feulgen-stained sections were digitized for computerized ploidy analysis with lymphocyte nuclei in the same slides serving as internal diploid controls. Aneuploidy was assessed using combined DNA index and modified Auer histogram criteria for DNA content abnormalities. There was strong association between the assessment of nuclear grade and ploidy (Fisher's exact test, P
SAVING DOLPHINS: BOYCOTTS, TRADE SANCTIONS, AND UNOBSERVABLE TECHNOLOGY*

Consumers boycott some goods because they do not approve the ways they are manufactured. I examine the efficacy of boycotts and the role of trade policy in influencing the foreign exporter’s technology choice. Even when its technology choice is unobservable, boycott threats can prompt the foreign firm to adopt the technology consumers prefer. Import policy can augment this effect, but when boycotts can have a substantial impact on demand, a use of ad valorem tariffs yields the unintended result. Specific tariffs and quotas are free of this defect, but specific tariffs are more effective than quotas in addressing consumers’ concern.
Phase error compensation for a 3-D shape measurement system based on the phase-shifting method

This paper describes a novel phase error compensation method for reducing the measurement error caused by nonsinusoidal waveforms in phase-shifting methods. For 3-D shape measurement sys- tems using commercial video projectors, the nonsinusoidal waveform of the projected fringe patterns as a result of the nonlinear gamma of pro- jectors causes significant phase measurement error and therefore shape measurement error. The proposed phase error compensation method is based on our finding that the phase error due to the nonsinusoidal wave- form depends only on the nonlinearity of the projector's gamma. There- fore, if the projector's gamma is calibrated and the phase error due to the nonlinearity of the gamma is calculated, a lookup table that stores the phase error can be constructed for error compensation. Our experimen- tal results demonstrate that by using the proposed method, the measure- ment error can be reduced by 10 times. In addition to phase error com- pensation, a similar method is also proposed to correct the nonsinusoidality of the fringe patterns for the purpose of generating a more accurate flat image of the object for texture mapping. While not relevant to applications in metrology, texture mapping is important for applications in computer vision and computer graphics. © 2007 Society of
Asymptotic rate of quantum ergodicity in chaotic euclidean billiards

The quantum unique ergodicity (QUE) conjecture of Rudnick and Sarnak is that every eigenfunction ϕn of the Laplacian on a manifold with uniformly hyperbolic geodesic flow becomes equidistributed in the semiclassical limit (eigenvalue En ∞); that is, “strong scars” are absent. We study numerically the rate of equidistribution for a uniformly hyperbolic, Sinai-type, planar Euclidean billiard with Dirichlet boundary condition (the “drum problem”) at unprecedented high E and statistical accuracy, via the matrix elements 〈ϕn, Âϕm〉 of a piecewise-constant test function A. By collecting 30,000 diagonal elements (up to level n ≈ 7 × 105) we find that their variance decays with eigenvalue as a power 0.48 ± 0.01, close to the semiclassical estimate ½ of Feingold and Peres. This contrasts with the results of existing studies, which have been limited to En a factor 102 smaller. We find strong evidence for QUE in this system. We also compare off-diagonal variance as a function of distance from the diagonal, against Feingold-Peres (or spectral measure) at the highest accuracy (0.7%) thus far in any chaotic system. We outline the efficient scaling method and boundary integral formulae used to calculate eigenfunctions. © 2006 Wiley Periodicals, Inc.
Excursions in polynuclear platinum DNA binding

Polynuclear platinum agents are a structurally unique class of anti-cancer drugs, distinct from the cisplatin family. To describe the chemistry and biology of this class, it was necessary to challenge the accepted paradigms for the structure–activity relationships; design new chemotypes and delineate the structures and consequences of their DNA binding modes. This article summarizes the structural changes induced in DNA by both covalent (bond-forming) and non-covalent (ligand recognition) adducts. Solution (Nuclear Magnetic Resonance), solid state (crystallography) and gas-phase (Electrospray Ionization Mass Spectrometry) techniques have all been used to describe the new DNA structures along with molecular biological techniques. The combined approaches allow molecular description of hitherto unobserved adducts such as long-range major-groove interstrand crosslinks; directional isomers on DNA and a third class of ligand–DNA binding, the phosphate clamp. The phosphate recognition is distinct from ‘‘classic’’ minor-groove recognition or intercalation.
SYNTHESES AND AGGREGATE STUDY OF BISPHENOL-CONTAINING DIAZA-18-CROWN-6 LIGANDS

Abstract Bisphenol-containing diaza-18-crown-6 ligands (1–16) were synthesized as potential membrane-forming amphiphilesvia the one-pot Mannich reaction. Sonication of the crude products in a small amount of MeOH followed by filtration and drying proved to be an efficient method of purifying nearly all compounds. Compounds8 and9 were selected for assay as amphiphiles. Compared to simple, alkylated diazacrown ethers, the stability of the amphisomes formed from these monomers is lower possibly because intramolecular hydrogen bonding prevents formation of intermolecular hydrogen bonds. Bisphenol-containing diaza-18-crown-6 ligands (1–16) were synthesized as potential membrane-forming amphiphiles. Download : Download full-size image
Enantioselective Synthesis of Medium-Ring Heterocycles, Tertiary Ethers, and Tertiary Alcohols by Mo−Catalyzed Ring-Closing Metathesis

The Mo-catalyzed asymmetric ring-closing metathesis (ARCM) of various achiral trienes leads to the formation of medium-ring unsaturated heterocycles in high yield and with excellent enantioselectivity. Reactions may be carried out on gram scale and in the absence of solvent. The unsaturated siloxanes obtained enantioselectively can be readily functionalized to obtain synthetically useful and difficult-to-access tertiary alcohols.
Khovanov-Rozansky homology via a canopolis formalism

In this paper, we describe a canopolis (ie categorified planar algebra) formalism for Khovanov and Rozansky’s link homology theory. We show how this allows us to organize simplifications in the matrix factorizations appearing in their theory. In particular, it will put the equivalence of the original definition of Khovanov‐Rozansky homology and the definition using Soergel bimodules in a more general context, allow us to give a new proof of the invariance of triply graded homology and give a new analysis of the behavior of triply graded homology under the Reidemeister IIb move. 57M27; 13D02 In [9; 10], Khovanov and Rozansky introduced a series of homology theories for links. These theories categorify the quantum invariants for sln , and the HOMFLYPT polynomial. Unfortunately, they remain very difficult to calculate, not least because of the complicated matrix factorizations used in their original combinatorial definition. Later work of I Frenkel, Khovanov and Stroppel [6; 8; 14; 15] has suggested a more systematic definition of these invariants and a connection between these theories and the structure of the BGG category O for the Lie algebra gln , but progress toward computational simplifications along these lines has been slow. In this paper, we will show that these invariants can be understood, computed and in fact, defined in the context of canopolises. We hope that this approach will both lead to computational benefits and help the reader to understand the definition of Khovanov‐ Rozansky homology better. A canopolis 1 is a categorification of the notion of a planar