cssi/SciSciGPT-SciSciNet huggingface dataset:
Buffer management in real-time active database systems

Real-time active database systems (RTADB) have attracted the attention of researchers in recent times. Such systems are envisioned as control systems for environments as diverse as process control, network management and automated financial trading. Sensors distributed throughout the system report the state of the system to the database. Unacceptable state reports typically results in corrective actions being triggered with deadlines. Thus RTADB's incorporate both real-time as well as active characteristics. We study buffer management in RTADB. Buffer management is recognized as not being a well studied area in real-time systems. As a result of our work, we postulate PAPER, a new buffer management scheme that relies on two strategies: prefetching and priority based buffer replacement. We report the result of studies of the performance of PAPER, as compared to that of existing buffer management algorithms. The insights derived from this paper impact both real-time database systems as well as real-time, active database systems.
Fitness and entropy production in a cell population dynamics with epigenetic phenotype switching

Motivated by recent understandings in the stochastic natures of gene expression, biochemical signaling, and spontaneous reversible epigenetic switchings, we study a simple deterministic cell population dynamics in which subpopulations grow with different rates and individual cells can bi-directionally switch between a small number of different epigenetic phenotypes. Two theories in the past, the population dynamics and thermodynamics of master equations, separately defined two important concepts in mathematical terms: the fitness in the former and the (non-adiabatic) entropy production in the latter. Both of them play important roles in the evolution of the cell population dynamics. The switching sustains the variations among the subpopulation growth, thus sustains continuous natural selection. As a form of Price’s equation, the fitness increases with (i) natural selection through variations and (ii) a positive covariance between the per capita growth and switching, which represents a Lamarchian-like behavior. A negative covariance balances the natural selection in a fitness steady state — “the red queen” scenario. At the same time the growth keeps the proportions of subpopulations away from the “intrinsic” switching equilibrium of individual cells, thus leads to a continuous entropy production. A covariance, between the per capita growth rate and the “chemical potential” of subpopulation, counteracts the entropy production. Analytical results are obtained for the limiting cases of growth dominating switching and vice versa.
Capital Flows to Developing Countries: The Allocation Puzzle

The textbook neoclassical growth model predicts that countries with faster productivity growth should invest more and attract more foreign capital. We show that the allocation of capital flows across developing countries is the opposite of this prediction: capital does not flow more to countries that invest and grow more. We call this puzzle the “allocation puzzle”. Using a wedge analysis, we find that the pattern of capital flows is driven by national saving: the allocation puzzle is a saving puzzle. Further disaggregation of capital flows reveals that the allocation puzzle is also related to the pattern of accumulation of international reserves. The solution to the “allocation puzzle”, thus, lies at the nexus between growth, saving, and international reserve accumulation. We conclude with a discussion of some possible avenues for research.
Security when people matter: structuring incentives for user behavior

Humans are "smart components" in a system, but cannot be directly programmed to perform; rather, their autonomy must be respected as a design constraint and incentives provided to induce desired behavior. Sometimes these incentives are properly aligned, and the humans don't represent a vulnerability. But often, a misalignment of incentives causes a weakness in the system that can be exploited by clever attackers. Incentive-centered design tools help us understand these problems, and provide design principles to alleviate them. We describe incentive-centered design and some tools it provides. We provide a number of examples of security problems for which Incentive Centered Design might be helpful. We elaborate with a general screening model that offers strong design principles for a class of security problems.
Rewriting in Practice

We discuss applications of rewriting in three different areas: design and analysis of algorithms, theorem proving and term rewriting, and modeling and analysis of biological processes.
The porphyrias: advances in diagnosis and treatment.

The inborn errors of heme biosynthesis, the porphyrias, are 8 genetically distinct metabolic disorders that can be classified as “acute hepatic,” “hepatic cutaneous,” and “erythropoietic cutaneous” diseases. Recent advances in understanding their pathogenesis and molecular genetic heterogeneity have led to improved diagnosis and treatment. These advances include DNA-based diagnoses for all the porphyrias, new understanding of the pathogenesis of the acute hepatic porphyrias, identification of the iron overload-induced inhibitor of hepatic uroporphyrin decarboxylase activity that causes the most common porphyria, porphyria cutanea tarda, the identification of an X-linked form of erythropoietic protoporphyria due to gain-of-function mutations in erythroid-specific 5-aminolevulinate synthase (ALAS2), and new and experimental treatments for the erythropoietic prophyrias. Knowledge of these advances is relevant for hematologists because they administer the hematin infusions to treat the acute attacks in patients with the acute hepatic porphyrias, perform the chronic phlebotomies to reduce the iron overload and clear the dermatologic lesions in porphyria cutanea tarda, and diagnose and treat the erythropoietic porphyrias, including chronic erythrocyte transfusions, bone marrow or hematopoietic stem cell transplants, and experimental pharmacologic chaperone and stem cell gene therapies for congenital erythropoietic protoporphyria. These developments are reviewed to update hematologists on the latest advances in these diverse disorders.
Openness, Uncertainty, and Social Spending: Implications for the Globalization? Welfare State Debate

We extend the literature on openness and spending in developing countries arguing that the effect of increasing openness depends on both regime type and the level of openness. Democracies respond to increases in openness by increasing spending while dictatorships respond by decreasing spending. However, the degree to which countries pursue the strategy of choice depends on the level of openness. In autarkic countries, an increase in import competition has more severe consequences for perceptions of job insecurity and dislocation. In response, government management of openness will be more vigorous under these conditions regardless of whether the leader increases or decreases spending. Economic selection mechanisms at work will produce an outcome wherein, at higher levels of openness, further import liberalization has smaller effects on perceptions of job insecurity and dislocation. Hence, both the demand and the supply of government management of openness will be lower.
Satisfying the Haar condition in halfband FIR filter design

A reformulation of the FIR symmetric halfband filter design problem is described that allows elimination of the constraints on coefficients from the design, thereby facilitating the direct use of the Parks-McClellan design procedure. In this procedure, it is only necessary to use a single-frequency care-band for approximation with about one-half the filter order of the halfband filter. >
Job assignment and promotion under statistical discrimination: evidence from the early careers of lawyers

Minorities continue to be severely underrepresented at the top levels of most occupations despite making dramatic gains in initial access to them. This fact is particularly striking in the legal profession where blacks are well represented in each associate class yet face significantly lower probabilities of making partner. To explain this divergence in the career paths of blacks and whites, I develop a dynamic model of statistical discrimination in which firms diversify their workforce by lowering the hiring standard for blacks. Despite such a diversity goal at hiring, task assignment and promotion decisions are not constrained by this policy. In this institutional setting, the model predicts that although blacks are more likely to be hired compared to observably similar whites, they are more likely to be placed in worse tasks and less likely to be promoted conditional on the same set of observables. However, conditional on task assignment, blacks and whites face similar promotion rates. I test the model's predictions using new data from the After the JD study -- a unique longitudinal survey tracking the professional lives of more than 4,000 lawyers. Compared to whites of similar credentials, blacks are much more likely to be hired into the best law firms. However, they are assigned to worse tasks and are less likely to be a partner. This black-white difference in promotion rates can be explained by quality differences in task assignments early in the associates' careers even controlling for measures of effort and career preferences. Results from this paper provide a unique explanation for the underrepresentation of minorities at the top of professional ladders by revealing how incompatible strategies in job assignment can reduce the number of minority promotions compared to the case without affirmative action.
Analysis of Aerodynamically Induced Whirling Forces in Axial Flow Compressors

A new analytical model to predict the aerodynamic forces in axial flow compressors due to asymmetric tip-clearance is introduced. The model captures the effects of tip-clearance induced distortion (i.e. forced shaft whirl), unsteady momentum-induced tangential blade forces and pressure induced forces on the spool. Pressure forces are shown to lag the tip-clearance asymmetry, resulting in a tangential (i.e. whirl-inducing) force due to spool pressure. This force can be of comparable magnitude to the classical Alford force. Prediction and elucidation of the Alford force is also presented.In particular, a new parameter denoted as the blade loading indicator is deduced. This parameter depends only on stage geometry and mean flow and determines the direction of whirl tendency due to tangential blade loading forces in both compressors and turbines.All findings are suitable for incorporation into an overall dynamic system analysis and integration into existing engine design tools.Copyright © 2000 by ASME
Polylogarithms, regulators, and Arakelov motivic complexes

We construct an explicit regulator map from Bloch’s Higher Chow group complex to the Deligne complex of a complex algebraic variety X. We define the Arakelov motivic complex as the cone of this map shifted by one. Its last cohomology group is (a version of) the Arakelov Chow group defined by H. Gillet and C. Soule. We relate the Grassmannian n–logarithms (defined as in [G5]) to the geometry of symmetric space SLn(C)/SU(n). For n = 2 we recover Lobachevsky’s formula expressing the volume of an ideal geodesic simplex in the hyperbolic space via the dilogarithm. Using the relationship with symmetric spaces we construct the Borel regulator on K2n−1(C) via the Grassmannian n–logarithms. We study the Chow dilogarithm and prove a reciprocity law which strengthens Suslin’s reciprocity law for Milnor’s group K 3 on curves. Our note [G5] can serve as an introduction to this paper.
Fractal steganography using artificially generated images

There exist a variety of fractal-based data hiding methods in an image. The main contribution of the previous work was to embed data by modifying the original, pre-existing image or embedding an encrypted datastream in an image. In this paper, we propose a fractal based approach for hiding sensitive information in a cover image (including artificially generated fractal images). The fractal parameters of the image are altered by the steganographic data while the image is generated. This results in an image that is generated with the data already hidden in it and not added after the fact. We show that the input parameters of the algorithm, such as the type of fractal and number of iterations, will serve as a simple encryption key for the hidden information. We also explain how the capacity of the image is affected by the variation of the parameters. Finally, we demonstrate that the proposed algorithms are immune to the commonly used steganographic detection algorithms.
The “Competence” of Children: No Longer All or None

Traditionally, under a fixed age set by the state, the child existed as an essentially disenfranchised member of the community. Current developments are demanding a variability in our assignment of autonomous rights, forcing a concept of "variable" competency. The courts increasingly require guidance as to "maturity" and "judgment" of children in their capacity to speak for themselves. This paper attempts to define some of the general conditions that limit competence and begins the process of establishing some general guidelines to help in deciding when we ought to allow children to enter into the decision-making process in important areas concerning their lives and futures. Journal of the American Academy of Child Psychiatry , 21, 2:153–162, 1982.
An Avoidance Model for Short-Range Order Induced by Soft Repulsions in Systems of Rigid Rods

The effects of soft repulsions on hard particle systems are calculated using an avoidance model which improves upon the simple mean field approximation. The method not only yields a better free energy, but also gives an estimate for the short-range positional order induced by soft repulsions. The results indicate little short-range order for isotropically oriented rods. However, for parallel rods short-range order increases to significant levels as the particle axial ratio increases.
WHAM : a WENO-based general relativistic numerical scheme -I. Hydrodynamics

Active galactic nuclei, X-ray binaries, pulsars and gamma-ray bursts are all believed to be powered by compact objects surrounded by relativistic plasma flows driving phenomena such as accretion, winds and jets. These flows are often accurately modelled by the relativistic magnetohydrodynamic (MHD) approximation. Time-dependent numerical MHD simulations have proven to be especially insightful, but one regime that remains difficult to simulate is when the energy scales (kinetic, thermal, magnetic) within the plasma become disparate. We develop a numerical scheme that significantly improves the accuracy and robustness of the solution in this regime. We use a modified form of the weighted essentially non-oscillatory (WENO) method to construct a finite-volume general relativistic hydrodynamics code called wham that converges at fifth order. We avoid (1) field-by-field decomposition by adaptively reducing down to two-point stencils near discontinuities for a more accurate treatment of shocks and (2) excessive reduction to low-order stencils, as in the standard WENO formalism, by maintaining high-order accuracy in smooth monotonic flows. Our scheme performs the proper surface integral of the fluxes, converts cell-averaged conserved quantities to point-conserved quantities before performing the reconstruction step, and correctly averages all source terms. We demonstrate that the scheme is robust in strong shocks, very accurate in smooth flows and maintains accuracy even when the energy scales in the flow are highly disparate.
Vinyl isocyanates in alkaloid synthesis. Camptothecin model studies

Abstract Model studies directed toward camptothecin employing a vinyl isocyanate-enamine cyclocondensation as the key synthetic step are reported.
BioVLAB-MMIA-NGS: microRNA–mRNA integrated analysis using high-throughput sequencing data

Motivation It is now well established that microRNAs (miRNAs) play a critical role in regulating gene expression in a sequence-specific manner, and genome-wide efforts are underway to predict known and novel miRNA targets. However, the integrated miRNA-mRNA analysis remains a major computational challenge, requiring powerful informatics systems and bioinformatics expertise. Results The objective of this study was to modify our widely recognized Web server for the integrated mRNA-miRNA analysis (MMIA) and its subsequent deployment on the Amazon cloud (BioVLAB-MMIA) to be compatible with high-throughput platforms, including next-generation sequencing (NGS) data (e.g. RNA-seq). We developed a new version called the BioVLAB-MMIA-NGS, deployed on both Amazon cloud and on a high-performance publicly available server called MAHA. By using NGS data and integrating various bioinformatics tools and databases, BioVLAB-MMIA-NGS offers several advantages. First, sequencing data is more accurate than array-based methods for determining miRNA expression levels. Second, potential novel miRNAs can be detected by using various computational methods for characterizing miRNAs. Third, because miRNA-mediated gene regulation is due to hybridization of an miRNA to its target mRNA, sequencing data can be used to identify many-to-many relationship between miRNAs and target genes with high accuracy. Availability and implementation http://epigenomics.snu.ac.kr/biovlab_mmia_ngs/.
Variations in thermospheric composition - A model based on mass spectrometer and satellite drag data

The seasonal-latitudinal and the diurnal variations of composition observed by mass spectrometers on the OGO 6 satellite are represented by two simple empirical formulae, each of which uses only one numerical parameter. The formulae are of a very general nature and predict the behavior of these variations at all heights and for all levels of solar activity; they yield a satisfactory representation of the corresponding variations in total density as derived from satellite drag. It is suggested that a seasonal variation of hydrogen might explain the abnormally low hydrogen densities at high northern latitudes in July 1964.
A natural SUSY Higgs near 125 GeV

The naturalness of a Higgs boson with a mass near 125 GeV is explored in a variety of weak-scale supersymmetric models. A Higgs mass of this size strongly points towards a non-minimal implementation of supersymmetry. The Minimal Supersymmetric Standard Model now requires large A-terms to avoid multi-TeV stops. The ne-tuning is at least 1% for low messenger scales, and an order of magnitude worse for high messenger scales. Naturalness is signicantly improved in theories with a singlet supereld
The Increased Use of Gas Turbines as Commercial Marine Engines

Aeroderivative gas turbines are being increasingly utilized as commercial marine engines. The primary reason is discussed and several recent GE aeroderivative gas turbine commercial marine applications are described. Finally, the potential for future commercial marine aeroderivative gas turbine application is presented.
On the chemical bonding effects in the Raman response: Benzenethiol adsorbed on silver clusters

We study the effects of chemical bonding on Raman scattering from benzenethiol chemisorbed on silver clusters using time-dependent density functional theory (TDDFT). Raman scattering cross sections are computed using a formalism that employs analytical derivatives of frequency-dependent electronic polarizabilities, which treats both off-resonant and resonant enhancement within the same scheme. In the off-resonant regime, Raman scattering into molecular vibrational modes is enhanced by one order of magnitude and shows pronounced dependence on the orientation and the local symmetry of the molecule. Additional strong enhancement of the order of 10(2) arises from resonant transitions to mixed metal-molecular electronic states. The Raman enhancement is analyzed using Raman excitation profiles (REPs) for the range of excitation energies 1.6-3.0 eV, in which isolated benzenethiol does not have electronic transitions. The computed vibrational frequency shifts and relative Raman scattering cross sections of the metal-molecular complexes are in good agreement with experimental data on surface enhanced Raman scattering (SERS) from benzenethiol adsorbed on silver surfaces. Characterization and understanding of these effects, associated with chemical enhancement mechanism, may be used to improve the detection sensitivity in molecular Raman scattering.
Chern class formulas for quiver varieties

Our goal in this paper is to prove a formula for the general degeneracy locus Xr associated to an oriented quiver of type An. If we are given a sequence of vector bundles and vector bundle maps E0 ! /1 E1 ! /2 E2 y! y! Eny1 ! /n En on an algebraic variety X , and a collection r  rij0 i<j n of non-negative integers, there is a degeneracy locus Xr  Xr E   Xr E ;/  de®ned by Xr  fx 2 X j rank Ei x ! Ej x rij 8 i < jg : 1:1
Correlation of Hybrid Rocket Propellant Regression Measurements with Enthalpy-Balance Model Predictions

An enthalpy-balance fuel-grain regression model is presented. The regression model, based on the longitudinally averaged fuel recession rates, is shown to accurately predict the chamber pressure, thrust and specific impulse performance of small and medium scale hybrid rocket motors. The key to the model predictions is the longitudinal enthalpy balance between the fuel grain heat of ablation and the convective heat transfer from the flame zone to the model surface. Convective heat transfer is related to the surface skin friction using the Reynolds analogy for turbulent flow. Simple flat plate models are used to predict the longitudinally averaged skin friction coefficient. Chemical properties of the combustion products were evaluated using the NASA Computer Equilibrium with Applications (CEA) Combustion code. Model predictions for a nitrous oxide (N 2 O) and hydroxylterminated poly butadiene (HTPB) motor are compared to data from a small-scale test firing with a 10.2-cm diameter motor. Suggestions for model improvements are offered.
Security and privacy in computer systems

With the advent of computer systems which share the resources of the configuration among several users or several problems, there is the risk that information from one user (or computer program) will be coupled to another user (or program). In many cases, the information in question will bear a military classification or be sensitive for some reason, and safeguards must be provided to guard against the leakage of information. This session is concerned with accidents or deliberate attempts which divulge computer-resident information to unauthorized parties.
Compact Zwitterion-Coated Iron Oxide Nanoparticles for Biological Applications

The potential of superparamagnetic iron oxide nanoparticles (SPIONs) in various biomedical applications, including magnetic resonance imaging (MRI), sensing, and drug delivery, requires that their surface be derivatized to be hydrophilic and biocompatible. We report here the design and synthesis of a compact and water-soluble zwitterionic dopamine sulfonate (ZDS) ligand with strong binding affinity to SPIONs. After ligand exchange, the ZDS-coated SPIONs exhibit small hydrodynamic diameters, and stability with respect to time, pH, and salinity. Furthermore, small ZDS coated SPIONs were found to have a reduced nonspecific affinity (compared to negatively charged SPIONs) toward serum proteins; streptavidin/dye functionalized SPIONs were bioactive and thus specifically targeted biotin receptors.
Entropic Priors for Discrete Probabilistic Networks and for Mixtures of Gaussians Models

The ongoing unprecedented exponential explosion of available computing power, has radically transformed the methods of statistical inference. What used to be a small minority of statisticians advocating for the use of priors and a strict adherence to bayes theorem, it is now becoming the norm across disciplines. The evolutionary direction is now clear. The trend is towards more realistic, flexible and complex likelihoods characterized by an ever increasing number of parameters. This makes the old question of: What should the prior be? to acquire a new central importance in the modern bayesian theory of inference. Entropic priors provide one answer to the problem of prior selection. The general definition of an entropic prior has existed since 1988 [1], but it was not until 1998 [2] that it was found that they provide a new notion of complete ignorance. This paper re-introduces the family of entropic priors as minimizers of mutual information between the data and the parameters, as in [2], but with a small...
Growth of TiO2 Single Crystals and Bicrystals by the Laser‐Heated Floating‐Zone Method

TiO 2 bicrystals with controlled misorientation have been grown by a laser-heated floating-zone method using a [001] oriented bicrystal seed designed for producing a (210)[001] tilt boundary. The grain boundary and crystal morphology are sensitive to the growth atmosphere, as confirmed by optical and transmission electron microscopies and by the Laue X-ray back-reflection method. These observations are discussed with respect to the nonstoichiometry of TiO 2 .
Inverse passive learning of an input-output-map through update-spline-smoothing

This paper presents a robust method of learning passively a one-dimensional input-output-map when receiving only indirect information about the correct input-output-map (e.g., only the sign of the deviation between the actual estimated output value and the correct output value is obtained). This information is obtained for only one input-output combination per updating cycle. The approach is to increment or decrement step by step the output values of the actually stored map and then to apply global or local cubic spline smoothing in order to avoid "adaptation holes" at points which are never updated or less frequently updated than other points. This method works with noisy measurements as well as slowly time-varying systems. Even discontinuous changes of the desired input-output-relation do not result in instability. Problems of convergence and stability are treated and design rules are given. >
Five-year outcome of major depressive disorder in primary health care.

Method. In the Vantaa Primary Care Depression Study, a stratified random sample of 1119 patients representing primary care patients in a Finnish city was screened for depression with the Primary Care Evaluation of Mental Disorders. SCID-I/P and SCID-II interviews were used to diagnose Axis I and II disorders. The 137 patients with DSM-IV depressive disorder were prospectively followed up at 3, 6, 18 and 60 months. Altogether, 82 % of patients completed the 5-year follow-up, including 102 patients with a research diagnosis of major depressive disorder (MDD) at baseline. Duration of the index episode, recurrences, time spent in major depressive episodes (MDEs) and partial or full remission were examined with a life-chart. Results. Of the MDD patients, 70 % reached full remission, in a median time of 20 months. One-third had at least one recurrence. The patients spent 34 % of the follow-up time in MDEs, 24 % in partial remission and 42 % in full remission. Baseline severity of depression and substance use co-morbidity predicted time spent in MDEs. Conclusions. This prospective, naturalistic, long-term study of a representative cohort of primary care patients with depression indicated slow or incomplete recovery and a commonly recurrent course, which need to be taken into account when developing primary care services. Severity of depressive symptoms and substance use co-morbidity should be systematically evaluated in planning treatment.
Active Site Design in a Chemzyme: Development of a Highly Asymmetric and Remarkably Temperature-Independent Catalyst for the Imino Aldol Reaction.

Unusually robust: A remarkably temperature-independent catalyst has been developed for the imino aldol reaction of imines derived from ortho-aminophenols. This catalyst is prepared from two equivalents of the VAPOL ligand and a zirconium tetraalkoxide. From a consideration of likely intermediates in the catalytic cycle it was deduced that a methyl substituent ortho to the phenol (R1 ) should enhance induction. This resulted in asymmetric inductions in excess of 98 % ee at room temperature as well as at 100°C. TMS=trimethylsilyl.
Tandem C–C coupling – intramolecular acetylenic Schmidt reaction under Pd/C–Cu catalysis

A new one-pot reaction for the regioselective construction of a six-membered fused N-heterocyclic ring leading to isoquinolones under Pd/C–Cu catalysis is described.
The impact of residential neighborhood type on travel behavior: A structural equations modeling approach

Using a system of structural equations, this paper empirically examines the relationship of residential neighborhood type to travel behavior, incorporating attitudinal, lifestyle, and demographic variables. Data on these variables were collected from residents of five neighborhoods in the San Francisco Bay Area in 1993 (final N=515), including “traditional” and “suburban” as well as mixtures of those two extremes. A conceptual model of the interrelationships among the key variables of interest was operationalized with a nine-equation structural model system. The nine endogenous variables included two measures of residential location type, three measures of travel demand, three attitudinal measures, and one measure of job location. In terms of both direct and total effects, attitudinal and lifestyle variables had the greatest impact on travel demand among all the explanatory variables. By contrast, residential location type had little impact on travel behavior. This is perhaps the strongest evidence to date supporting the speculation that the association commonly observed between land use configuration and travel patterns is not one of direct causality, but due primarily to correlations of each of those variables with others. In particular, the results suggest that when attitudinal, lifestyle, and sociodemographic variables are accounted for, neighborhood type has little influence on travel behavior.
Mapping Semantic Networks to Undirected Networks

There exists an injective, information-preserving function that maps a semantic network (i.e a directed labeled network) to a directed network (i.e. a directed unlabeled network). The edge label in the semantic network is represented as a topological feature of the directed network. Also, there exists an injective function that maps a directed network to an undirected network (i.e. an undirected unlabeled network). The edge directionality in the directed network is represented as a topological feature of the undirected network. Through function composition, there exists an injective function that maps a semantic network to an undirected network. Thus, aside from space constraints, the semantic network construct does not have any modeling functionality that is not possible with either a directed or undirected network representation. Two proofs of this idea will be presented. The first is a proof of the aforementioned function composition concept. The second is a simpler proof involving an undirected binary encoding of a semantic network. Keywords—general-modeling, multi-relational networks, semantic networks
ON THE COMPLEXITY OF ELEMENTARY MODAL LOGICS

Modal logics are widely used in computer science. The complexity of modal satisfiability problems has been investigated since the 1970s, usually proving results on a case-by-case basis. We prove a very general classification for a wide class of relevant logics: Many important subclasses of modal logics can be obtained by restricting the allowed models with first-order Horn formulas. We show that the satisfiability problem for each of these logics is either NP-complete or PSPACE-hard, and exhibit a simple classification criterion. Further, we prove matching PSPACE upper bounds for many of the PSPACE-hard logics.
Self-Enforcing Trade Agreements: Evidence from Time-Varying Trade Policy

The Bagwell and Staiger (1990) theory of cooperative trade agreements predicts new tariffs (i) increase with imports, (ii) increase with the inverse of the sum of the import demand and export supply elasticities, and (iii) decrease with the variance of imports. The authors find US import policy during 1997-2006 to be consistent with this theory. A one standard deviation increase in import growth, the inverse of the sum of the import demand and export supply elasticity, and the standard deviation of import growth changes the probability that the US imposes an antidumping tariff by 35 percent, by 88 percent, and by -76 percent, respectively.
Clinical characteristics and treatment of esophageal atresia: a single institutional experience.

Purpose: Treatment for esophageal atresia has advanced over several decades due to improvements in surgical techniques and neonatal intensive care. Subsequent to increased survival, postoperative morbidity has become an important issue in this disease. The aim of our study was to analyze our experience regarding the treatment of esophageal atresia. Methods: We reviewed and analyzed the clinical data of patients who underwent surgery for esophageal atresia at Severance Children’s Hospital from 1995 to 2010 regarding demographics, surgical procedures, and postoperative outcomes. Results: Seventy-two patients had surgery for esophageal atresia. The most common gross type was C (81.9%), followed by type A (15.3%). Primary repair was performed in 52 patients. Staged operation was performed in 17 patients. Postoperative esophageal strictures developed in 43.1% of patients. Anastomotic leakages occurred in 23.6% of patients, and recurrence of tracheoesophageal fistula was reported in 8.3% of patients. Esophageal stricture was significantly associated with long-gap (≥3 cm or three vertebral bodies) atresia (P = 0.042). The overall mortality rate was 15.3%. The mortality in patients weighing less than 2.5 kg was higher than in patients weighing at least 2.5 kg (P = 0.001). During the later period of this study, anastomotic leakage and mortality both significantly decreased compared to the earlier study period (P = 0.009 and 0.023, respectively). Conclusion: The survival of patients with esophageal atresia has improved over the years and the rate of anastomotic leakage has been significantly reduced. However, overall morbidities related to surgical treatment of esophageal atresia still exists with high incidence.
What is special about the divisors of 24

SummaryWhat is an interesting number theoretic characterization of the divisors of 24 among all positive integers? This paper will provide one answer in terms of modular multiplication tables and will give 5 different proofs based on the Chinese remainder theorem, Dirichlet's theorem on primes in an arithmetic progression, the structure theory of units, the Bertrand-Chebyshev theorem, and its generalisations by Erdős and Ramanujan.
Digital accumulators in phase and frequency tracking loops

Results on the effects of digital accumulators in phase and frequency tracking loops are presented. Digital accumulators or summers are used extensively in digital signal processing to perform averaging or to reduce processing rates to acceptable levels. For tracking the Doppler of high-dynamic targets at low carrier-to-noise ratios, it is shown through simulation and experiment that digital accumulators can contribute an additional loss in operating threshold. This loss was not considered in any previous study and needs to be accounted for in performance prediction analysis. Simulation and measurement results are used to characterize the loss due to the digital summers for three different tracking loops: a digital phase-locked loop, a cross-product automatic frequency tracking loop, and an extended Kalman filter. The tracking algorithms are compared with respect to their frequency error performance and their ability to maintain lock during severe maneuvers at various carrier-to-noise ratios. It is shown that failure to account for the effect of accumulators can result in an inaccurate performance prediction, the extent of which depends highly on the algorithm used. >
The first galaxies: structure and stellar populations

The Hubble deep fields (HDFs) continue to be a valuable resource for studying the distant Universe, particularly at z > 2 where their comoving volume becomes large enough to encompass several hundred L * galaxies or their progenitors. Here, I present recent results from a near-infrared (NIR) imaging survey of the HDFnorth with the Near Infrared Camera and Multi–Object Spectrograph (NICMOS), which provides structural and photometric information in the optical rest frame (λλ24000–5500 A) for hundreds of ‘ordinary’ galaxies at 2 12. The space density of UV–bright galaxies in the HDF appears to thin out toward larger redshifts, although surface–brightness selection effects may play an important role.
On the trade-off between the future benefits and riskiness of R&D: a bondholders’ perspective ☆

Abstract Existing studies on the value-relevance of R&D tend to overstate the R&D benefits and shed little light on the trade-off between the R&D benefits (mean effect) and their riskiness (variance effect). This study shows that the variance effect of R&D is on average more significant than their mean effect in bond valuation. Hence, for creditors, the R&D risk dominates their benefits. Furthermore, this study documents that R&D measures alone explain approximately 80% of cross-sectional variations in bond ratings and risk premium. These findings contribute to the debate over R&D accounting and the bond pricing literature.
Stem Cell Factor Gene Transfer Improves Cardiac Function After Myocardial Infarction in Swine

Background— Stem cell factor (SCF), a ligand of the c-kit receptor, is a critical cytokine, which contributes to cell migration, proliferation, and survival. It has been shown that SCF expression increases after myocardial infarction (MI) and may be involved in cardiac repair. The aim of this study was to determine whether gene transfer of membrane-bound human SCF improves cardiac function in a large animal model of MI. Methods and Results— A transmural MI was created by implanting an embolic coil in the left anterior descending artery in Yorkshire pigs. One week after the MI, the pigs received direct intramyocardial injections of either a recombinant adenovirus encoding for SCF (Ad.SCF, n=9) or β-gal (Ad.β-gal, n=6) into the infarct border area. At 3 months post-MI, ejection fraction increased by 12% relative to baseline after Ad.SCF therapy, whereas it decreased by 4.2% ( P =0.004) in pigs treated with Ad.β-gal. Preload-recruitable stroke work was significantly higher in pigs after SCF treatment (Ad.SCF, 55.5±11.6 mm Hg versus Ad.β-gal, 31.6±12.6 mm Hg, P =0.005), indicating enhanced cardiac function. Histological analyses confirmed the recruitment of c-kit+ cells as well as a reduced degree of apoptosis 1 week after Ad.SCF injection. In addition, increased capillary density compared with pigs treated with Ad.β-gal was found at 3 months and suggests an angiogenic role of SCF. Conclusions— Local overexpression of SCF post-MI induces the recruitment of c-kit+ cells at the infarct border area acutely. In the chronic stages, SCF gene transfer was associated with improved cardiac function in a preclinical model of ischemic cardiomyopathy.
Palladium‐Catalyzed Oxidative Intermolecular Difunctionalization of Terminal Alkenes with Organostannanes and Molecular Oxygen

A cationic palladium complex catalyzes the title transformations, which are thought to proceed via a pi-allyl or pi-benzyl intermediate. The regioselectivity of the reaction (1,2- or 1,1-difunctionalization) depends on the type of terminal double bond (conjugated or nonconjugated) in the substrate (see scheme) and appears to be controlled by the relative rates of beta-hydride elimination and transmetalation. DMA=dimethylacetamide, Tf=triflyl.
Protecting quantum information with entanglement and noisy optical modes

We incorporate active and passive quantum error-correcting techniques to protect a set of optical information modes of a continuous-variable quantum information system. Our method uses ancilla modes, entangled modes, and gauge modes (modes in a mixed state) to help correct errors on a set of information modes. A linear-optical encoding circuit consisting of offline squeezers, passive optical devices, feedforward control, conditional modulation, and homodyne measurements performs the encoding. The result is that we extend the entanglement-assisted operator stabilizer formalism for discrete variables to continuous-variable quantum information processing.
Nasoethmoidal and Orbital Fractures

(1989). Nasoethmoidal and Orbital Fractures. Seminars in Ophthalmology: Vol. 4, No. 3, pp. 148-160.
On the 1-Homotopy Type of Lie Groupoids

We propose a notion of 1-homotopy for generalized maps. This notion generalizes those of natural transformation and ordinary homotopy for functors. The 1-homotopy type of a Lie groupoid is shown to be invariant under Morita equivalence. As an application we consider orbifolds as groupoids and study the notion of orbifold 1-homotopy type induced by a 1-homotopy between presentations of the orbifold maps.
Consumer response to the Reagan tax cuts

Abstract This paper uses micro data from the Consumer Expenditure Survey to estimate the response of household consumption to the second and third phases of the Reagan tax cuts. Since these phases were pre-announced, they allow for an unusually clean test of the canonical Life-Cycle/Permanent-Income model. Consumption is found to be excessively sensitive to the tax cuts, counter to the model. Liquidity constraints and other standard explanations do not appear to explain this excess sensitivity. The consumption response is larger than previously estimated for tax refunds and more concentrated in nondurables. These differences have important implications for the structure of tax changes, in particular for choosing between varying withholding rates versus varying ‘lumpy’ final tax payments and refunds.
Intra–day Behavior of Treasury Sector Index Option Implied Volatilities around Macroeconomic Announcements

If option implied volatility is an unbiased, efficient forecast of future return volatility in the underlying asset, then we should be able to predict its path around macroeconomic announcements from responses in cash markets. Regressions show that volatilities rise the afternoon before announcements that move cash markets, and that post-announcement volatilities return to normal as rapidly as cash prices do. Although implied volatilities are predictable, the Treasury options market is efficient since informed traders do not earn arbitrage profits once we account for trading costs.
The Large M Limit of Non-Commutative Open Strings at Strong Coupling

Two-dimensional Non-Commutative Open String (NCOS) theory, well-defined perturbatively, may also be studied at strong coupling and for large D-string charge by making use of the Holographic duality. We analyze the zero mode dynamics of a closed string in the appropriate background geometry and map the results onto a sector of strongly coupled NCOS dynamics. We find an elaborate classical picture that shares qualitative similarities with the SL(2,R) WZW model. In the quantum problem, we compute propagators and part of the energy spectrum of the theory; the latter involves interesting variations in the density of states as a function of the level number, and energies scaling inversely with the coupling. Finally, the geometry exhibits a near horizon throat, associated with NCOS dynamics, yet it is found that the whole space is available for Holography. This provides a setting to extend the Maldacena duality beyond the near horizon limit.
Fingerprinting With Equiangular Tight Frames

Digital fingerprinting is a framework for marking media files, such as images, music, or movies, with user-specific signatures to deter illegal distribution. Multiple users can collude to produce a forgery that can potentially overcome a fingerprinting system. This paper proposes an equiangular tight frame fingerprint design which is robust to such collusion attacks. We motivate this design by considering digital fingerprinting in terms of compressed sensing. The attack is modeled as linear averaging of multiple marked copies before adding a Gaussian noise vector. The content owner can then determine guilt by exploiting correlation between each user's fingerprint and the forged copy. The worst case error probability of this detection scheme is analyzed and bounded. Simulation results demonstrate that the average-case performance is similar to the performance of orthogonal and simplex fingerprint designs, while accommodating several times as many users.
Comparison of Preoperative Three-Dimensional Gadolinium-Enhanced Magnetic Resonance Imaging to the Operative Assessment of Abdominal Aortic Aneurysm Anatomy: A Retrospective Study

The purpose of this paper was to compare gadolinium-enhanced magnetic resonance angiography (MRA) and operative evaluation of the anatomic extent of abdominal aortic aneurysms (AAA) and assessment of other visceral arteries and common iliac arteries. A retrospective study was performed on 47 patients who had preoperative gadolinium- enhanced MRA and subsequent AAA repair. The original MRA interpretations were compared to the operative findings. In cases where there was a discrepancy, the MRAs were reassessed. MRA correctly evaluated the proximal extent (distance from renal vessels) of the AAA in 45 of 47 patients (96%), and in all (100%) patients MRA identified the distal extent (relation to aortic bifurcation or extension into iliac vessels) of the aneurysm. Ten of 15 accessory renal arteries were correctly identified (67%). Four of the five missed accessory renal arteries were identified on reassessment. MRA correctly diagnosed 10/12 cases of inferior mesenteric artery (IMA) occlusion. Two, which were c...
The Kantorovich inequality for error analysis of the Kalman filter with unknown noise distributions

The state-space model with random noises is widely used to model dynamic systems. In many practical problems the noise terms will have unknown probability distributions, which is contrary to the usual assumption of Gaussian noises made in state-vector estimation; this assumption is usually made for reasons of mathematical tractability. A problem arises, however, in that inference based on the incorrect Gaussian assumption can lead to misleading or erroneous conclusions. This note shows how the Kantorovich inequality from probability theory has potential for characterizing the estimation error of a Kalman filter in such a non-Gaussian (distribution-free) setting.
A Recursive Maximum Likelihood Estimator for the Online Estimation of Electromechanical Modes With Error Bounds

Accurate and near real-time estimates of electromechanical modes are of great importance since the modal damping is a key indicator of the stability of the power system. If the estimates of the electromechanical modes are to be useful, knowing the variability in the estimates is critically important. This paper presents a method of directly estimating the variance of each mode estimate in addition to estimating the frequency and damping of each mode in an online setting using a recursive maximum likelihood (RML) estimator. The variance estimates are achieved using two closed-form multidimensional Taylor series approximations, the details of which are fully derived here. The proposed method is validated using a Monte Carlo simulation with a low order model of the Western Electricity Coordinating Council (WECC) power system under both ambient and probing conditions, with multiple modes closely spaced in frequency, and is compared to the regularized robust recursive least squares (R3LS) method. It is also successfully applied to phasor measurement unit (PMU) data collected from the actual WECC system, also under both ambient and probing conditions.