cssi/SciSciGPT-SciSciNet huggingface dataset:
Metastable Behavior for Bootstrap Percolation on Regular Trees

We examine bootstrap percolation on a regular (b+1)-ary tree with initial law given by Bernoulli(p). The sites are updated according to the usual rule: a vacant site becomes occupied if it has at least θ occupied neighbors, occupied sites remain occupied forever. It is known that, when b>θ≥2, the limiting density q=q(p) of occupied sites exhibits a jump at some pT=pT(b,θ)∈(0,1) from qT:=q(pT) pT. We investigate the metastable behavior associated with this transition. Explicitly, we pick p=pT+h with h>0 and show that, as h↓0, the system lingers around the “critical” state for time order h−1/2 and then passes to fully occupied state in time O(1). The law of the entire configuration observed when the occupation density is q∈(qT,1) converges, as h↓0, to a well-defined measure.
Coverage statistics for sequence census methods

Background: We study the statistical properties of fragment coverage in genome sequencing experiments. In an extension of the classic Lander-Waterman model, we consider the effect of the length distribution of fragments. We also introduce a coding of the shape of the coverage depth function as a tree and explain how this can be used to detect regions with anomalous coverage. This modeling perspective is especially germane to current highthroughput sequencing experiments, where both sample preparation protocols and sequencing technology particulars can affect fragment length distributions. Results: Under the mild assumptions that fragment start sites are Poisson distributed and successive fragment lengths are independent and identically distributed, we observe that, regardless of fragment length distribution, the fragments produced in a sequencing experiment can be viewed as resulting from a two-dimensional spatial Poisson process. We then study the successive jumps of the coverage function, and show that they can be encoded as a random tree that is approximately a Galton-Watson tree with generation-dependent geometric offspring distributions whose parameters can be computed. Conclusions: We extend standard analyses of shotgun sequencing that focus on coverage statistics at individual sites, and provide a null model for detecting deviations from random coverage in high-throughput sequence census based experiments. Our approach leads to explicit determinations of the null distributions of certain test statistics, while for others it greatly simplifies the approximation of their null distributions by simulation. Our focus on fragments also leads to a new approach to visualizing sequencing data that is of independent interest.
Myosin VI lever arm rotation: Fixed or variable?

Reifenberger et al. (1) reported in PNAS that the myosin VI lever arms tilt by 180° on each step. This contrasts with Sun et al. (2), wherein we found variable degrees of axial and azimuthal tilting, consistent with the known variable step size of myosin VI. There are several differences between the two papers, which are listed here and clarified in a web publication (3).
The Exergy Cost of Information Processing: A Comparison of Computer-Based Technologies and Biological Systems

Processing information (analysis, storing, retrieving, sharing) is the primary function of modern computer-based information systems. Systems of this type generally require an input flow of exergy (available energy) to function. Information processing systems now are evolving in two directions. One direction is toward bigger and more sophisticated systems. The other is toward systems that are more compact and portable. In both cases, the energy efficiency is becoming an increasingly important design issue. This paper summarizes an exploration of the exergy cost of processing information at the component and system levels in state-of-the-art information processing systems. The energy efficiency characteristics of computer-based information technologies are also compared to estimates of the energy efficiency of biological information processing in brains of mammals. Energy efficiencies of processors and systems are quantified in terms of the ratio of processing capacity to the exergy input rate. Available data suggest that for recent generations of processors, the ratio of processing capacity to exergy input rate has been increasing proportional to the square root of processor speed. Despite this increase, the energy efficiency of computer-based systems is currently substantially below the estimated efficiency of biological systems. Unless processor energy efficiencies are greatly increased, the development of information processing systems that match human brain performance will be hindered by the need for large power supplies and high-capacity heat rejection systems.
The Nature of Radio Emission from Distant Galaxies: The 1.4 GHz Observations

We have conducted a deep radio survey with the Very Large Array at 1.4 GHz of a region containing the Hubble Deep Field (HDF). This survey overlaps previous observations at 8.5 GHz allowing us to investigate the radio spectral properties of microjansky sources to flux densities greater than 40 μJy at 1.4 GHz and greater than 8 μJy at 8.5 GHz. A total of 371 sources have been cataloged at 1.4 GHz as part of a complete sample within 20' of the HDF. The differential source count for this region is only marginally sub-Euclidean and is given by n(S) = (8.3 ± 0.4)S-2.4±0.1 sr-1 Jy-1. Above about 100 μJy the radio source count is systematically lower in the HDF as compared to other fields. We conclude that there is clustering in our radio sample on size scales of 1'-40'. The 1.4 GHz-selected sample shows that the radio spectral indices are preferentially steep (1.4 = 0.85) and that the sources are moderately extended with average angular size θ = 18. Optical identification with disk-type systems at z ~ 0.1-1 suggests that synchrotron emission, produced by supernovae remnants, is powering the radio emission in the majority of sources. The 8.5 GHz sample contains primarily moderately flat spectrum sources (8.5 = 0.35), with less than 15% inverted. We argue that we may be observing an increased fraction of optically thin bremsstrahlung over synchrotron radiation in these distant star-forming galaxies.
Intermediate coupling model of the cuprates

We review the intermediate coupling model for treating electronic correlations in the cuprates. Spectral signatures of the intermediate coupling scenario are identified and used to adduce that the cuprates fall in the intermediate rather than the weak or the strong coupling limits. A robust, ‘beyond local-density approximation’ framework for obtaining wide-ranging properties of the cuprates via a GW-approximation based self-consistent self-energy correction for incorporating correlation effects is delineated. In this way, doping- and temperature-dependent spectra, from the undoped insulator to the overdoped metal, in the normal as well as the superconducting state, with features of both weak and strong coupling can be modeled in a material-specific manner with very few parameters. Efficacy of the model is shown by considering available spectroscopic data on electron- and hole-doped cuprates from angle-resolved photoemission, scanning tunneling microscopy/spectroscopy, neutron scattering, inelastic light s...
The constitutionality of mandates to purchase health insurance.

Health insurance mandates have been a component of many recent health care reform proposals. Because a federal requirement that individuals transfer money to a private party is unprecedented, a number of legal issues must be examined. This paper analyzes whether Congress can legislate a health insurance mandate and the potential legal challenges that might arise, given such a mandate. The analysis of legal challenges to health insurance mandates applies to federal individual mandates, but can also apply to a federal mandate requiring employers to purchase health insurance for their employees. There are no constitutional barriers for Congress to legislate a health insurance mandate as long as the mandate is properly designed and executed, as discussed below. This paper also considers the likelihood of any change in the current judicial approach to these legal questions.
Quasar feedback: more bang for your buck

We propose a ‘two-stage’ model for the effects of feedback from a bright quasar on the cold gas in a galaxy. It is difficult for winds or other forms of feedback from near the accretion disc to directly impact (let alone blow out of the galaxy) dense molecular clouds at ∼kpc. However, if such feedback can drive a weak wind or outflow in the hot, diffuse interstellar medium (a relatively ‘easy’ task), then in the wake of such an outflow passing over a cold cloud, a combination of instabilities and simple pressure gradients will drive the cloud material to effectively expand in the direction perpendicular to the incident outflow. This shredding/expansion (and the corresponding decrease in density) may alone be enough to substantially suppress star formation in the host. Moreover, such expansion, by even a relatively small factor, dramatically increases the effective cross-section of the cloud material and makes it much more susceptible to both ionization and momentum coupling from absorption of the incident quasar radiation field. We show that even a moderate effect of this nature can dramatically alter the ability of clouds at large radii to be fully ionized and driven into a secondary outflow by radiation pressure. Since the amount of momentum and volume which can be ionized by observed quasar radiation field is more than sufficient to affect the entire cold gas supply once it has been altered in this manner (and the ‘initial’ feedback need only initiate a moderate wind in the low-density hot gas), this reduces by an order of magnitude the required energy budget for feedback to affect a host galaxy. Instead of ∼5 per cent of the radiated energy (∼100 per cent momentum) needed if the initial feedback must directly heat or ‘blow out’ the galactic gas, if only ∼0.5 per cent of the luminosity (∼10 per cent momentum) can couple to drive the initial hot outflow, this mechanism could be efficient. This amounts to hot gas outflow rates from near the accretion disc of only ∼5–10 per cent of the black hole accretion rate.
Warped Vacuum Statistics

We consider the effect of warping on the distribution of type IIB flux vacua constructed with Calabi-Yau orientifolds. We derive an analytical form of the distribution that incorporates warping and find close agreement with the results of a Monte Carlo enumeration of vacua. Compared with calculations that neglect warping, we find that for any finite volume compactification, the density of vacua is highly diluted in close proximity to the conifold point, with a steep drop-off within a critical distance.
Psychiatric Features in Children with Genetic Syndromes: Toward Functional Phenotypes

Neurodevelopmental disorders with identified genetic etiologies present a unique opportunity to study gene-brain-behavior connections in child psychiatry. Parsing complex human behavior into dissociable components is facilitated by examining a relatively homogenous genetic population. As children with developmental delay carry a greater burden of mental illness than the general population, familiarity with the most common genetic disorders will serve practitioners seeing a general child population. In this article, basic genetic testing and 11 of the most common genetic disorders are reviewed, including the evidence base for treatment. Based on their training in child development, family systems, and multimodal treatment, child psychiatrists are well positioned to integrate cognitive, behavioral, social, psychiatric, and physical phenotypes, with a focus on functional impairment.
Coulomb effects in low energy proton–proton scattering

Abstract Using a recently developed effective field theory for the interactions of nucleons at non-relativistic energies, we calculate non-perturbatively Coulomb corrections to proton–proton scattering. Including the dimension-eight derivative interaction in the PDS regularization scheme, we recover a modified form of the Blatt–Jackson relation between the scattering lengths. The effective range receives no corrections from the Coulomb interactions to this order. Also the case of scattering in channels where the Coulomb force is attractive, is considered. This is of importance for hadronic atoms.
A laboratory for the study of graphical man-machine communication

Engineering has evolved rapidly during the last fifteen years as analysis techniques geared to the computational power of a slide rule and desk calculator have been replaced by techniques which make extensive use of computers. During these years, however, graphical techniques for conversion of design ideas to final products have not changed significantly, nor has the role of drawings in engineering design changed. The drawing plays a vital role in each phase of the evolution of a product. The original design proposals, the engineering analysis, the design compromises, and the prototype product fabrication all depend on graphical communication among engineers and designers. Whether the product is to be machined, assembled, stamped, wired, welded or hand modeled, a drawing is made so that a two-dimensional representation of the product may be reviewed by the engineers concerned with the product. Prior to the final product drawing, many ideas are exchanged by the use of sketches, drawings, plots, and engineering reports.
31P NMR studies of cis-[RhCl(CO)(bis-phosphine)] complexes

Abstract Further examples of complexes with the previously unique ci s-chelated [RhCl(CO)(bis-phosphine)] structure are reported where bis-phosphine=R 2 P- (C 2 B 10 H 10 )PR′ 2 with R and R′=C 6 H 5 or NMe 2 . In the unsymmetrical R ≠ R′ example only the isomer with PPh 2 trans to Cl is formed. These complexes as well as the analogous dppe complex show interesting fluxional behavior under CO implying the existence of a five-coordinate [RhCl(CO) 2 (bis-phosphine)] species. The compound trans -[RhCl(CO){Ph 2 P(C 2 B 10 H 10 )H} 2 ] is also described.
CORDIC arithmetic for an SVD processor

Abstract Arithmetic issues in the calculation of the Singular Value Decomposition (SVD) are discussed. Traditional algorithms using hardware division and square root are replaced with the special-purpose CORDIC algorithms for computing vector rotations and inverse tangents. The CORDIC 2 × 2 SVD processor can be twice as fast as one assembled from traditional hardware units. A CORDIC SVD processor array is suitable for VLSI implementation and is important for use in real-time signal processing applications.
UV and EUV observations of stellar coronal structure and activity

Abstract Ultraviolet (HST, FUSE) and extreme-ultraviolet (EUVE) observations of stellar coronae and flare-related activity are reviewed, with particular attention being devoted to the coronas information that is obtainable in the ultraviolet but not from the X-ray region. The coronas temperature, density, and emission measure distributions of active stars are significantly different from quiescent solar coronas conditions, thus allowing broader study of the underlying physical processes. Stellar coronae are magnetically-confined plasmas typically with substantially higher heating rates and temperatures than encountered in the Quiet Sun. Conditions are similar to solar flares but the question of the flare contribution during “quiescence” is still unresolved. The properties of stellar flares observed in long EUVE monitoring observations and the relationship between. events seen in different atmospheric regions are discussed. UV coronas forbidden lines, e.g. Fe XXI 13541 , Fe XII 1242, 1349 A , Fe XVIII 975 A, and Fe XIX 1118 A are commonly detected in active dwarfs and giants; these lines currently provide the only resolved spectroscopic diagnostics of conditions within stellar coronae. The UV coronas lines generally have widths consistent with thermal broadening and are unshifted. Currently only tantalising glimpses of flare-related motions have been detected.
APPLICATION OF NUCLEAR ELECTRIC PROPULSION TO MANNED MARS MISSIONS

This paper presents some interim results of a continuing feasibility study of a manned Mars landing mission using a combination of nuclear rocket and nuclear electric propulsion. These include 1) an analytical tool for simultaneously optimizing the vehicle design and its associated trajectory, 2) a typical resultant vehicle/trajectory concept, and 3) preliminary parametric performance data. The results indicate that a straightforward vehicle design using standard Saturn V launch vehicles is reasonably feasible. The required initial mass in Earth orbit lies between 400,000 and 900,000 kg; depending on trip time, Earth return conditions, and powerplant specific weight. An electrical power of 3-8 Mw is required at a powerplant specific weight of 10-20 kg/kw.
A prism coupler technique for characterizing thin film II-VI semiconductor systems

This article has two objectives. First, we determine the indices of refraction n of a series of molecular beam epitaxy-grown Zn1−xCdxSe epilayers using a technique based on coupling of evanescent waves via a prism into a semiconductor film. Highly precise values of n, and their dependence on the alloy composition x, are obtained for photon energies below the band gap of the alloy material. And second, we use these results to demonstrate the usefulness of the prism coupler method as a very reliable, convenient, and accurate tool for simultaneous determination of composition of semiconductor alloys in thin film form (since n depends on composition), and the film thickness. This method determines the film thickness with typical uncertainty of less than 0.5%.
ATW neutronics design studies

The Accelerator Transmutation of Waste (ATW) concept has been proposed as a transuranics (TRU) (and long-lived fission product) incinerator for processing the 87,000 metric tonnes of Light Water Reactor (LWR) used fuel which will have been generated by the time the currently deployed fleet of commercial reactors in the US reach the end of their licensed lifetime. The ATW is proposed to separate the uranium from the transuranics and fission products in the LWR used fuel, to fission the transuranics, to send the LWR and ATW generated fission products to the geologic repository and to send the uranium to either a low level waste disposal site or to save it for future use. The heat liberated in fissioning the transuranics would be converted to electricity and sold to partially offset the cost of ATW construction and operations. Options for incineration of long-lived fission products are under evaluation. A six-year science-based program of ATW trade and system studies was initiated in the US FY 2000 to achieve two main purposes: (1) “to evaluate ATW within the framework of nonproliferation, waste management, and economic considerations,” and (2) “to evaluate the efficacy of the numerous technical options for ATW system configuration.” This paper summarizes the results from neutronics and thermal/hydraulics trade studies which were completed at Argonne National Laboratory during the first year of the program. Core designs were developed for Pb-Bi eutectic (LBE) cooled and Na cooled 840 MWth fast spectrum transmuter designs employing recycle. Additionally, neutronics analyses were performed at Argonne for a He cooled 600 MWth hybrid thermal and fast core design proposed by General Atomics Co. which runs critical for 34 and subcritical for 14 of its four year once-thru burn cycle. The mass flows and the ultimate loss of transuranic isotopes to the waste stream per unit of heat generated during transmutation have been calculated on a consistent basis and are compared. (Long-lived fission product incineration has not been considered in the studies reported here.)
The response of the coupled magnetosphere-ionosphere-thermosphere system to a 25% reduction in the dipole moment of the Earth's magnetic field

[1] The Earth's magnetic field changes in orientation and strength over time. We study the response of the magnetosphere-ionosphere-thermosphere system to a 25% reduction in magnetic field intensity, using the coupled magnetosphere-ionosphere-thermosphere (CMIT) model. Simulations were performed with a dipole moment of 8 × 1022 A m2, close to the present-day value, and a dipole moment of 6 × 1022 A m2, both under the same solar wind conditions, intermediate solar activity (F10.7 = 150), and for March equinox and June solstice. The 25% reduction in field strength causes the magnetosphere to shrink and the polar cap to expand, in agreement with theory. The Pedersen and the Hall ionospheric conductances increase by 50%–60% and 60%–65%, respectively. This causes a ∼9%–12% decrease in electric potential and a ∼20% increase in field-aligned currents during equinox. Ion E × B drift velocities are enhanced by ∼10%–15%. The Joule heating also increases, by 13%–30%, depending on the season. Changes in the neutral temperature structure are caused partly by changes in Joule heating and partly by changes in the neutral wind. The neutral wind itself is also affected by changes in neutral temperature and by changes in ion velocities. The changes in the neutral wind, together with changes in the vertical component of the E × B drift, affect the height of the ionospheric F2 layer. Changes in electron density are related to changes in the O/N2 ratio. The global mean increase in neutral temperature causes the thermosphere to expand, resulting in a global mean uplift of the ionosphere. These effects are generally smaller during solstice.
New insights for corporate strategists from a renowned value investor

Purpose – This “masterclass” article explains how modern value investing analysis can guide corporate strategists and corporate development departments. It shows how executives can use some key insights from the recently published book by Martin J. Whitman and Fernando Diz, Modern Security Analysis (Hoboken, NJ: Wiley, 2013). Design/methodology/approach – This masterclass includes an interview with the lead author of the book, value investor Martin J. Whitman. Findings – The insights contained within Modern Security Analysis can and should be leveraged by corporate executives and strategists to create value for their firms. Practical implications – This article supports earlier work published in Strategy & Leadership that shows Graham and Dodd-based valuation and analysis is a viable avenue of academic research and a viable method with which to assess corporate strategic initiatives (such as mergers and acquisitions, share buy-backs, risk management, etc.). Originality/value – This analysis provides senior executives with a guide to the assessment tools used by the most successful value investors and an explanation of their relevance to corporate strategy.
A Comparative Study of the Economic Reforms in China and India: What Can We Learn?

Abstract The last quarter of the twentieth century was characterized by economic reforms in many formerly state-dominated economies. Among them, the reform attempts by China and India have attracted increasing attention in the popular media and academic research. This paper contribute to this research by using institutional theory to analyse the reforms in China and India and develop a framework to explain how reforms evolve. This study contributes to the theoretical understanding of the dynamics of reform, helps policy-makers to formulate reform strategy, and international business executives to project the developmental trends in two of the world's largest emerging markets.
Computation of reacting flowfield with radiation interaction in chemical lasers

A numerical procedure has been developed to provide a rapid and stable solution of the reacting and radiating flowfield in chemical laser cavities. A marching technique, implicit in both fluid mechanics and chemistry, is employed in solving the two-dimensional mixing layer equations. The aerokinetics and radiation interaction is calculated iteratively by solving the aerokinetic equations for the gain distribution and the propagation equations for the radiation field. In the iterative solution, a linearization method which leads to enhanced numerical efficiency is employed.
Existence theorems of coupled fixed points

Abstract By associating with a mixed monotone operator a monotone operator on product space, several existence theorems of coupled fixed points are proved.
Efficient linear and nonlinear heat conduction with a quadrilateral element

A method is presented for performing efficient and stable finite element calculations of heat conduction with quadrilaterals using one-point quadrature. The stability in space is obtained by using a stabilization matrix which is orthogonal to all linear fields and its magnitude is determined by a stabilization parameter. It is shown that the accuracy is almost independent of the value of the stabilization parameter over a wide range of values; in fact, the values 3, 2 and 1 for the normalized stabilization parameter lead to the 5-point finite difference, 9-point finite difference and fully integrated finite element operators, respectively, for rectangular meshes; numerical experiments reported here show that the three have identical rates of convergence in the L2 norm. Eigenvalues of the element matrices, which are needed for stability limits, are also given. Numerical applications are used to show that the method yields accurate solutions with large increases in efficiency, particularly in nonlinear problems.
A Genuine Intermediate-Age Globular Cluster in M33*

We present deep integrated-light spectroscopy of nine M33 globular clusters taken with the Hectospec instrument at the MMT Observatory. Based on our spectroscopy and previous deep color-magnitude diagrams obtained with HST WFPC2, we present evidence for the presence of a genuine intermediate-age globular cluster in M33. The analysis of Lick line indices indicates that all globular clusters are metal-poor ([Z/H] -1.0) and that cluster M33-C38 is ~5-8 Gyr younger than the rest of the sample M33 star clusters. We find no evidence for a population of blue horizontal-branch stars in the CMD of M33-C38, which rules out the possibility of an artificially young spectroscopic age due to the presence of hot stars. We infer an initial mass of (0.8-1.2) × 105 M☉ for M33-C38, which implies that intermediate-age clusters with masses similar to those of Galactic globular clusters were able to form and survive in M33, although it is not yet clear with which dynamical component of M33—thin disk, thick disk, halo—the cluster is associated.
Kinetic mixing and the supersymmetric gauge hierarchy

The most general Lagrangian for a model with two U(1) gauge symmetries contains a renormalizable operator which mixes their gauge kinetic terms. Such kinetic mixing can be generated at arbitrarily high scales but will not be suppressed by large masses. In models whose supersymmetry (SUSY)-breaking hidden sectors contain U(1) gauge factors, we show that such terms will generically arise and communicate SUSY breaking to the visible sector through mixing with hypercharge. In the context of the usual supergravity- or gauge-mediated communication scenarios with D-terms of order the fundamental scale of SUSY breaking, this effect can destabilize the gauge hierarchy. Even in models for which kinetic mixing is suppressed or the D-terms are arranged to be small, this effect is a potentially large correction to the soft scalar masses and therefore introduces a new measurable low-energy parameter. We calculate the size of kinetic mixing both in field theory and in string theory, and argue that appreciable kinetic mixing is a generic feature of string models. We conclude that the possibility of kinetic mixing effects cannot be ignored in model building and in phenomenological studies of the low-energy SUSY spectra.
A Non-Heme Iron-Mediated Chemical Demethylation in DNA and RNA

DNA methylation is arguably one of the most important chemical signals in biology. However, aberrant DNA methylation can lead to cytotoxic or mutagenic consequences. A DNA repair protein in Escherichia coli, AlkB, corrects some of the unwanted methylations of DNA bases by a unique oxidative demethylation in which the methyl carbon is liberated as formaldehyde. The enzyme also repairs exocyclic DNA lesions—that is, derivatives in which the base is augmented with an additional heterocyclic subunit—by a similar mechanism. Two proteins in humans that are homologous to AlkB, ABH2 and ABH3, repair the same spectrum of lesions; another human homologue of AlkB, FTO, is linked to obesity. In this Account, we describe our studies of AlkB, ABH2, and ABH3, including our development of a general strategy to trap homogeneous protein−DNA complexes through active-site disulfide cross-linking. AlkB uses a non-heme mononuclear iron(II) and the cofactors 2-ketoglutarate (2KG) and dioxygen to effect oxidative demethylation o...
Water recovery by membrane permeation

Research into the problems concerned with the recovery of potable water f rom metabolic waste has progressed to that point wherein several techniques have been studied and evaluated. Reference 1 probably contains the most complete bibliography, description, and evaluation of possible methods for water recovery. Paraphrasing f rom this report , it i s pointed out in the conclusions that the vacuum pyrolysis method in which potable water i s produced f rom mixed human waste, and wash water, is operationally most advanced. This technique, which has been fully tested both chemically and biologically, was originally devised in this Laboratory2 and further improved under support of the National Aeronaut ics and Space Administration3. It has cer ta in advantages that other methods do not have, For example, the raw mater ia l may be processed immediately after collection with no pr ior t reatment. Also, the recovered produce is acceptable in potability after passage over a heated catalyst following vaporization and does not require further treatment by ion exchange, charcoal, chemical oxidation, o r any other methods.
Global Optimal Attitude Estimation using Uncertainty Ellipsoids

A deterministic attitude estimation problem for a rigid body in a potential field, with bounded attitude and angular velocity measurement errors is considered. An attitude estimation algorithm that globally minimizes the attitude estimation error is obtained. Assuming that the initial attitude, the initial angular velocity and measurement noise lie within given ellipsoidal bounds, an uncertainty ellipsoid that bounds the attitude and the angular velocity of the rigid body is obtained. The center of the uncertainty ellipsoid provides point estimates, and the size of the uncertainty ellipsoid measures the accuracy of the estimates. The point estimates and the uncertainty ellipsoids are propagated using a Lie group variational integrator and its linearization, respectively. The attitude and angular velocity estimates are optimal in the sense that the sizes of the uncertainty ellipsoids are minimized.
Framework for classifying logical operators in stabilizer codes

Entanglement, as studied in quantum information science, and nonlocal quantum correlations, as studied in condensed matter physics, are fundamentally akin to each other. However, their relationship is often hard to quantify due to the lack of a general approach to study both on the same footing. In particular, while entanglement and nonlocal correlations are properties of states, both arise from symmetries of global operators that commute with the system Hamiltonian. Here, we introduce a framework for completely classifying the local and nonlocal properties of all such global operators, given the Hamiltonian and a bipartitioning of the system. This framework is limited to descriptions based on stabilizer quantum codes, but may be generalized. We illustrate the use of this framework to study entanglement and nonlocal correlations by analyzing global symmetries in topological order, distribution of entanglement, and entanglement entropy.
The formaldehyde decomposition chain mechanism

A kinetic mechanism for the chain decomposition of formaldehyde consistent with recent theoretical and experimental results is presented. This includes new calculations and measurements of the rate constant for the abstraction reaction The calculation uses a multi-reference configuration interaction wavefunction to construct the potential energy surface which is used in a tunneling-corrected TST calculation of the rate constant. The rate constant for the bond fission at high temperatures was determined by an RRKM extrapolation of direct low temperature measurements. This mechanism has been successfully tested against laser-schlieren measurements covering the temperature range 2200–3200 K. These measurements are insensitive to all but the above two reactions and they confirm the large, non-Arrhenius rate for the abstraction reaction derived here from theory. Modeling of previous experiments using IR emission, ARAS, and CO laser absorption with this mechanism is quite satisfactory. The branching ratio of the rate of the faster molecular dissociation (CH2O + (M) CO + H2 + (M)), to that of the bond fission reaction, was estimated to be no more than 2 or 3 over 2000 to 3000 K. Such a ratio is consistent with one recent theoretical estimate and most of the experimental observations. © 1993 John Wiley & Sons, Inc.
Irreversibility, mechanical entanglement and thermal melting in superconducting vortex crystals with point impurities

Abstract We discuss the onset of irreversibility and entanglement of vortex lines in high T c superconductors due to point disorder and thermal fluctuations using a simplified cage model. A combination of Flory arguments, known results from directed polymers in random media, and a Lindemann criterion are used to estimate the field and temperature dependence of irreversibility, mechanical entanglement and thermal melting. The qualitative features of this dependence, including its nonmonotonicity when disorder is sufficiently strong, are in good agreement with recent experiments.
Vector - tensor multiplet in N=2 superspace with central charge

Abstract We use the four-dimensional N = 2 central charge superspace to give a geometrical construction of the Abelian vector-tensor multiplet consisting, under N = 1 supersymmetry, of one vector and one linear multiplet. We derive the component field supersymmetry and central charge transformations, and show that there is a super-Lagrangian, the higher components of which are all total derivatives, allowing us to construct superfield and component actions.
Angular momentum of isolated systems

Penrose’s twistorial approach to the definition of angular momentum at null infinity is developed so that angular momenta at different cuts can be meaningfully compared. This is done by showing that the twistor spaces associated with different cuts of \(\mathcal{J}^+\) can be identified as manifolds (but not as vector spaces). The result is a well-defined, Bondi–Metzner–Sachs-invariant notion of angular momentum in a radiating space–time; the difficulties and ambiguities previously encountered are attached to attempts to express this in special-relativistic terms, and in particular to attempts to identify a single Minkowski space of origins. Unlike the special-relativistic case, the angular momentum cannot be represented by a purely j = 1 quantity Mab, but has higher-j contributions as well. Applying standard kinematic prescriptions, these higher-j contributions are shown to correspond precisely to the shear. Thus it appears that shear and angular momentum should be regarded as different aspects of a single unified concept.
The TOUGH Codes—A Family of Simulation Tools for Multiphase Flow and Transport Processes in Permeable Media

Numerical simulation has become a widely practiced andaccepted technique for studying flow and transport processes in thevadose zone and other subsurface flow systems. This article discusses asuite of codes, developed primarily at Lawrence Berkeley NationalLaboratory (LBNL), with the capability to model multiphase flows withphase change. We summarize history and goals in the development of theTOUGH codes, and present the governing equations for multiphase,multicomponent flow. Special emphasis is given to space discretization bymeans of integral finite differences (IFD). Issues of code implementationand architecture are addressed, as well as code applications,maintenance, and future developments.
Opportunities for leasing in the broiler industry

This study develops theoretical models of leasing from the perspectives of both the lessor and lessee. The models address effects of tax distortions and imperfect debt markets on the value of leasing. Analysis of the broiler industry shows that leasing is an important financing consideration for broiler houses and equipment which can benefit both the lessor and lessee because of the tax and debt market environment.
Dynamics of phase transitions induced by a heat bath

Abstract We study the non-equilibrium dynamics of a symmetry-restoring phase transition in a scalar field theory, the “system”, linearly coupled to another scalar field taken as a “heat bath”. The “system” is initially in an ordered low-temperature phase, and the heat bath is at a temperature close to the critical temperature for the system. We estimate the time at which the phase transition to the disordered (symmetric) phase takes place. We derive, and integrate the one-loop effective equations of motion for the order parameter that include the effects of the heat bath. A semiclassical Langevin equation is derived and it is found that it contains a non-dissipative, non-markoviaan kernel, the noise term is colored and correlated on time scales determined by the temperature of the heat bath. The range of validity of the Langevin equation and a consistent procedure to incorporate corrections are discussed.
An Evaluation of the World Economic Outlook Forecasts

This paper conducts a series of statistical tests to evaluate the quality of the World Economic Outlook (WEO) forecasts for a very large cross section of countries. It assesses whether forecasts were unbiased and informationally efficient, characterizes the process whereby WEO forecasts get revised as the predicted period draws closer, and compares the precision of the WEO forecasts to private sector forecasts known as “consensus forecasts” and published by Consensus Economics on a monthly basis. The results suggest that the performance of the WEO forecasts is similar to that of the consensus forecasts.
Entry trajectory shaping for Shuttle-deployed experiments

The availability of the Space Transportation System has provided a unique opportunity for deployment of atmospheric entry experiments. These experiments require a trajectory design that provides a well-defined and controlled flight environment. Items addressed in this paper include control of thermal and aerodynamic loading consistent with the test objectives, maintenance of acceptable velocity-altitude conditions, and accommodation of tracking and recovery requirements. Various strategies, including constant-drag flight, equilibrium glide, and controlled linear velocity-altitude flight segments are employed to effect desired trajectory conditions. Algorithms to match thermal constraints to entry conditions and vehicle aerodynamic configuration are also discussed.
Combination Therapy: Medicated Urethral System for Erection Enhances Sexual Satisfaction in Sildenafil Citrate Failure Following Nerve-Sparing Radical Prostatectomy

The objective of our study was to assess the effec- tiveness of combining medicated urethral system for erection (MUSE) with sildenafil citrate in men unsatisfied with the sildenafil alone. Baseline and follow-up data from 23 patients (mean age, 62.5 6 5.23 years) unsatisfied with the use of the sildenafil citrate alone for the treatment of erectile dysfunction following nerve-sparing rad- ical prostatectomy (mean use, 4 attempts/100-mg dose) was ob- tained. All patients started oral sildenafil citrate more than 6 months after radical prostatectomy. Combination therapy was initiated using 100 mg sildenafil citrate orally 1 hour prior to intercourse. Patients used combination therapy for a minimum of 4 attempts prior to as- sessment with the Sexual Health Inventory of Men (International In- dex for Erectile Function-5) and visual analog scale to gauge rigidity (0-100). The effect of therapy on the total International Index for Erectile Function (IIEF) score and penile rigidity score was as- sessed. Of the 23 patients, 4 (17%) had no improvement with the addition of medicated urethral system for erection and discontinued the drug, while 19 (83%) reported improvement with the penile rigid- ity and sexual satisfaction. The IIEF scores of these 19 patients showed significant improvements in each sexual domain, and the patients reported that erection was sufficient for vaginal penetration 80% of the time. Rigidity scores on a scale of 0-100 with sildenafil alone averaged 38% (23-53) for men and 46% (26-67) for their partners. With the addition of MUSE, scores increased to 76% for men and 62% for their partners. We conclude that the addition of MUSE to sildenafil improved sexual satisfaction and penile rigidity in patients unsatisfied with sildenafil alone.
Coupled Force and Moment Parameter Estimation for Aircraft

This paper presents the full application of the multipoint aerodynamic model for parameter estimation in high-angle-of-attack and high-angular-rate e ight regimes. This model is intended for use in simulation and control design, and for the study of aerodynamic force distributions on the surfaces of an aircraft. The estimation technique used to illustrate the approach is simple regression with the equation error approach. The multipoint model comprises a set of new parameters describing the aerodynamic force distribution along individual surface components of the aircraft. The aim of this study is to demonstrate that this model allows coupling among the three force and three moment components, which is accounted for in the model. This means that the parameters associated with the six-component equations are thus treated simultaneously. Another advantage of this approach is that the model allows each individual forcegenerating surface element of the aircraft to contribute independently to the total force and moment, rather than some average of these contributions relative to the c.m. The method is applied to measurements from spin e ight test data conducted with a light general aviation aircraft. The results indicate that the method is capable of reproducing, with reasonable accuracy, the force and moment measurements obtained from a e ight other than the one used in the parameter estimation.
Reaction of 2,5-bis(trifluoromethyl)-1,3,4-oxadiazole with primary amines. Synthesis of 4-substituted-3,5-bis(trifluoromethyl)-4H-1,2,4-triazoles

Reaction of 3,5-bis(trifluoromethyl)-1,3,4-oxadiazole (1a) with primary amines under a variety of conditions conveniently produced 4-substituted-3,5-bis(trifluoromethyl)-4H-1.2,4-triazoles 4a in 26-85% yield. Alkyl amines reacted with 1a in methanol at −42° to provide hydrogen-bonded monoadduct-methanol complexes 5a, as determined by X-ray. The reaction of 1a with sterically hindered or strongly electron deficient anilines required high temperatures in the absence of solvent.
Exact derivation of Luttinger liquid relation in a one-dimensional two-component quantum system with hyperbolic interactions

Abstract We present an exact calculation of the Luttinger liquid relation for the one-dimensional, two-component SC model in the interaction strength range −1 s
Large magnetoresistance at room temperature in semiconducting polymer sandwich devices

We report on the discovery of a large, room temperature magnetoresistance (MR) effect in polyfluorene sandwich devices in weak magnetic fields. We characterize this effect and discuss its dependence on field direction, voltage, temperature, film thickness, electrode materials, and (unintentional) impurity concentration. Negative MR is usually observed, but positive MR can also be achieved under high applied electric fields. The MR effect reaches up to 10% at fields of 10 mT at room temperature. The effect shows only a weak temperature dependence and is independent of the sign and direction of the magnetic field. We find that the effect is related to the hole current in the devices. To the best of our knowledge, the discovered effect is not adequately described by any of the MR mechanisms known to date.
On the Poles of Igusa's Local Zeta Function for Algebraic Sets

Let K be a p−adic field, and ZΦ(s, f), s ∈ C, with Re(s) > 0, the Igusa local zeta function associated to f(x) = (f1(x), .., fl(x)) ∈ [K (x1, .., xn)], and Φ a Schwartz-Bruhat function. The aim of this paper is to describe explicitly the poles of the meromorphic continuation of ZΦ(s, f). Using resolution of singularities it is possible to express ZΦ(s, f) as a finite sum of p−adic monomial integrals. These monomial integrals are computed explicitly by using techniques of toroidal geometry. In this way, an explicit list for the candidates to poles of ZΦ(s, f) is obtained.
Quantized orbits and resonant transport

A tight binding representation of the kicked Harper model is used to obtain an integrable semiclassical Hamiltonian consisting of degenerate ”quantized” orbits. New orbits appear when renormalized Harper parameters cross integer multiples of �/2. Commensurability relations between the orbit frequencies are shown to correlate with the emergence of accelerator modes in the classical phase space of the original kicked problem. The signature of this resonant transport is seen in both classical and quantum behavior. An important feature of our analysis is the emergence of a natural scaling relating classical and quantum couplings which is necessary for establishing correspondence.
Seiberg duality in matrix models II

Abstract In this Letter we continue the investigation, within the context of the Dijkgraaf–Vafa programme, of Seiberg duality in matrix models as initiated in [B. Feng, hep-th/0211202 ], by allowing degenerate mass deformations. In this case, there are some massless fields which remain and the theory has a moduli space. With this illustrative example, we propose a general methodology for performing the relevant matrix model integrations and addressing the corresponding field theories which have non-trivial IR behaviour, and which may or may not have tree-level superpotentials.
A systematic martingale construction with applications to permutation inequalities

Abstract We illustrate a process that constructs martingales with help from matrix products that arise naturally in the theory of sampling without replacement. The usefulness of the new martingales is illustrated by the development of maximal inequalities for permuted sequences of real numbers. Some of these inequalities are new and some are variations of classical inequalities like those introduced by A. Garsia in the study of rearrangement of orthogonal series.
Magnetic reconnection: Sweet-Parker versus Petschek

The two theories for magnetic reconnection, one of Sweet and Parker, and the other of Petschek, are reconciled by exhibiting an extra condition in that of Petschek which reduces his theory to that of Sweet and Parker, provided that the resistivity is constant in space. On the other hand, if the resistivity is enhanced by instabilities, then the reconnection rate of both theories is increased substantially, but Petschek’s rate can be faster. A different formula from the usual one is presented for enhanced Petschek reconnection.