cssi/SciSciGPT-SciSciNet huggingface dataset:
GATA: a graphic alignment tool for comparative sequence analysis

Several problems exist with current methods used to align DNA sequences for comparative sequence analysis. Most dynamic programming algorithms assume that conserved sequence elements are collinear. This assumption appears valid when comparing orthologous protein coding sequences. Functional constraints on proteins provide strong selective pressure against sequence inversions, and minimize sequence duplications and feature shuffling. For non-coding sequences this collinearity assumption is often invalid. For example, enhancers contain clusters of transcription factor binding sites that change in number, orientation, and spacing during evolution yet the enhancer retains its activity. Dot plot analysis is often used to estimate non-coding sequence relatedness. Yet dot plots do not actually align sequences and thus cannot account well for base insertions or deletions. Moreover, they lack an adequate statistical framework for comparing sequence relatedness and are limited to pairwise comparisons. Lastly, dot plots and dynamic programming text outputs fail to provide an intuitive means for visualizing DNA alignments. To address some of these issues, we created a stand alone, platform independent, graphic alignment tool for comparative sequence analysis (GATA http://gata.sourceforge.net/ ). GATA uses the NCBI-BLASTN program and extensive post-processing to identify all small sub-alignments above a low cut-off score. These are graphed as two shaded boxes, one for each sequence, connected by a line using the coordinate system of their parent sequence. Shading and colour are used to indicate score and orientation. A variety of options exist for querying, modifying and retrieving conserved sequence elements. Extensive gene annotation can be added to both sequences using a standardized General Feature Format (GFF) file. GATA uses the NCBI-BLASTN program in conjunction with post-processing to exhaustively align two DNA sequences. It provides researchers with a fine-grained alignment and visualization tool aptly suited for non-coding, 0–200 kb, pairwise, sequence analysis. It functions independent of sequence feature ordering or orientation, and readily visualizes both large and small sequence inversions, duplications, and segment shuffling. Since the alignment is visual and does not contain gaps, gene annotation can be added to both sequences to create a thoroughly descriptive picture of DNA conservation that is well suited for comparative sequence analysis.
Young Massive Clusters

Over the past ten years, there has been a revolution in our understanding of massive young stellar clusters in the Galaxy. Initially, there were no known examples having masses >104, yet we now know that there are at least a half dozen such clusters in the Galaxy. In all but one case, the masses have been determined through infrared observations. Several had been identified as clusters long ago, but their massive natures were only recently determined. Presumably, we are just scratching the surface, and we might look forward to having statistically significant samples of coeval massive stars at all important stages of stellar evolution in the near future. I review the efforts that have led to this dramatic turn of events and the growing sample of young massive clusters in the Galaxy.
Chromatic Roots are Dense in the Whole Complex Plane

I show that the zeros of the chromatic polynomials $P_G(q)$ for the generalized theta graphs $\Theta^{(s,p)}$ are, taken together, dense in the whole complex plane with the possible exception of the disc $|q-1| < 1$. The same holds for their dichromatic polynomials (alias Tutte polynomials, alias Potts-model partition functions) $Z_G(q,v)$ outside the disc $|q+v| < |v|$. An immediate corollary is that the chromatic roots of not-necessarily-planar graphs are dense in the whole complex plane. The main technical tool in the proof of these results is the Beraha–Kahane–Weiss theorem on the limit sets of zeros for certain sequences of analytic functions, for which I give a new and simpler proof.
Radiation pressure-driven galactic winds from self-gravitating discs

We study large-scale winds driven from uniformly bright self-gravitating discs radiating near the Eddington limit. We show that the ratio of the radiation pressure force to the gravitational force increases with height above the disc surface to a maximum of twice the value of the ratio at the disc surface. Thus, uniformly bright self-gravitating discs radiating at the Eddington limit are fundamentally unstable to driving large-scale winds. These results contrast with the spherically symmetric case, where super-Eddington luminosities are required for wind formation. We apply this theory to galactic winds from rapidly star-forming galaxies that approach the Eddington limit for dust. For hydrodynamically coupled gas and dust, we find that the asymptotic velocity of the wind is v∞≃ 1.5 vrot and that v∞∝ SFR0.36, where vrot is the disc rotation velocity and SFR is the star formation rate, both of which are in agreement with observations. However, these results of the model neglect the gravitational potential of the surrounding dark matter halo and a (potentially massive) old passive stellar bulge or an extended disc, which act to decrease v∞. A more realistic treatment shows that the flow can either be unbound or bound, forming a ‘fountain flow’ with a typical turning time-scale of tturn∼ 0.1–1 Gyr, depending on the ratio of the mass and radius of the rapidly star-forming galactic disc relative to the total mass and break (or scale) radius of the dark matter halo or bulge. We provide quantitative criteria and scaling relations for assessing whether or not a rapidly star-forming galaxy of given properties can drive unbound flows via the mechanism described in this paper. Importantly, we note that because tturn is longer than the star formation time-scale (gas mass/star formation rate) in the rapidly star-forming galaxies and ultraluminous infrared galaxies for which our theory is most applicable, if rapidly star-forming galaxies are selected as such, they may be observed to have strong outflows along the line of sight with a maximum velocity vmax comparable to ∼1.5 vrot, even though their winds are eventually bound on large scales.
The Satellite-Shaped Co-15 Polyoxotungstate, [Co6(H2O)30{Co9Cl2(OH)3(H2O)9(β-SiW8O31)3}]5-

The 15-cobalt-substituted polyoxotungstate [Co6(H2O)30{Co9Cl2(OH)3(H2O)9(β-SiW8O31)3}]5- (1) has been characterized by single-crystal XRD, elemental analysis, IR, electrochemistry, magnetic measurements, and EPR. Single-crystal X-ray analysis was carried out on Na5[Co6(H2O)30{Co9Cl2(OH)3(H2O)9(β-SiW8O31)3}]·37H2O, which crystallizes in the hexagonal system, space group P63/m, with a = 19.8754(17) A, b = 19.8754(17) A, c = 22.344(4) A, α = 90°, β = 90°, γ = 120°, and Z = 2. The trimeric polyanion 1 has a core of nine CoII ions encapsulated by three unprecedented (β-SiW8O31) fragments and two Cl- ligands. This central assembly {Co9Cl2(OH)3(H2O)9(β-SiW8O31)3}17- is surrounded by six antenna-like CoII(H2O)5 groups resulting in the satellite-like structure 1. Synthesis of 1 is accomplished in a simple one-pot procedure by interaction of CoII ions with [γ-SiW10O36]8- in aqueous, acidic NaCl medium (pH 5.4). Polyanion 1 was studied by cyclic voltammetry as a function of pH. The current intensity of its CoII cent...
Homogeneous subsets of a Lipschitz graph and the Corona Theorem

This paper proves the Corona Theorem to be affirmative for domains in the complex plane bounded by thick subsets of a Lipschitz graph. Specifically, the boundary of these domains E0 has a Carleson lower density: ∧ ( B(z, r) ∩ E0) > є 0r for all z ∈ E0 and all r > 0.
Modern Japan's Fourth Challenge: The Political Economy of a Stagnant Population

The paper summarizes the problems that Japan faces during a period of falling and stagnant population and discusses their remedies. The problem of a stagnant population is well recognized and has been studied from a broad perspective by the Japanese government. This paper, however, defines the problem of action under three headings: (1) buying time; (2) building a new relationship between men and women; and (3) the political economy of a stagnant population. JEL Classification Numbers: B1, H4, J1, O15, O50.
Gamma Ray Bursts in the Swift-Fermi Era

Gamma-ray bursts (GRBs) are among the most violent occurrences in the universe. They are powerful explosions, visible to high redshift, and thought to be the signature of black hole birth. They are highly luminous events and provide excellent probes of the distant universe. GRB research has greatly advanced over the past 10 years with the results from Swift, Fermi and an active followup community. In this review we survey the interplay between these recent observations and the theoretical models of the prompt GRB emission and the subsequent afterglows.
The control of a prosthetic arm by EMG pattern recognition

An electromyographic (EMG) signal pattern recognition system is constructed for real-time control of a prosthetic arm through precise identification of motion and speed command. A probabilistic model of the EMG patterns is first formulated in the feature space of integral absolute value (IAV) to describe the relation between a command, represented by motion and speed variables, and location and shape of the corresponding pattern. The model provides the sample probability density function of pattern classes in the decision space of variance and zero crossings based on the relations between IAV, variance, and zero crossings established in this paper. Pattern classification is carried out through a multiclass sequential decision procedure designed with an emphasis on computational simplicity. The upper bound of probability of error and the average number of sample observations are investigated. Speed and motion predictions are used in conjunction with the decision procedure to enhance decision speed and reliability. A decomposition rule is formulated for the direct assignment of speed to each primitive motion involved in a combined motion. A learning procedure is also designed for the decision processor to adapt long-term pattern variation. Experimental results are discussed in the Appendix.
Predicting transcription factor specificity with all-atom models

The binding of a transcription factor (TF) to a DNA operator site can initiate or repress the expression of a gene. Computational prediction of sites recognized by a TF has traditionally relied upon knowledge of several cognate sites, rather than an ab initio approach. Here, we examine the possibility of using structure-based energy calculations that require no knowledge of bound sites but rather start with the structure of a protein–DNA complex. We study the PurR Escherichia coli TF, and explore to which extent atomistic models of protein–DNA complexes can be used to distinguish between cognate and noncognate DNA sites. Particular emphasis is placed on systematic evaluation of this approach by comparing its performance with bioinformatic methods, by testing it against random decoys and sites of homologous TFs. We also examine a set of experimental mutations in both DNA and the protein. Using our explicit estimates of energy, we show that the specificity for PurR is dominated by direct protein–DNA interactions, and weakly influenced by bending of DNA.
Monolith structures, materials, properties and uses

Abstract Extruded monolith substrates are widely used in automotive and stationary emission control reactors such as selective catalytic reduction (SCR) units. Monoliths are increasingly being used, developed, and evaluated as catalyst supports in many new reactor applications such as chemical and refining processes, catalytic combustion, ozone abatement, and others. This paper gives a general overview of monolith fabrication, characteristics and typical use. Several commercial product applications and new developments for use of monolith reactors in automotive, stationary and chemical industry are discussed.
Migration velocity analysis for TI media in the presence of quadratic lateral velocity variation

ABSTRACTOne of the most serious problems in anisotropic velocity analysis is the trade-off between anisotropy and lateral heterogeneity, especially if velocity varies on a scale smaller than the maximum offset. We have developed a P-wave MVA (migration velocity analysis) algorithm for transversely isotropic (TI) models that include layers with small-scale lateral heterogeneity. Each layer is described by constant Thomsen parameters e and δ and the symmetry-direction velocity V0 that varies as a quadratic function of the distance along the layer boundaries. For tilted TI media (TTI), the symmetry axis is taken orthogonal to the reflectors. We analyzed the influence of lateral heterogeneity on image gathers obtained after prestack depth migration and found that quadratic lateral velocity variation in the overburden can significantly distort the moveout of the target reflection. Consequently, medium parameters beneath the heterogeneous layer(s) are estimated with substantial error, even when borehole informa...
Neruda, poeta del siglo XX

En una de sus ultimas publicaciones, el distinguido escritor chileno, Jose Miguel Varas, plantea y pone de relieve la cuestion de Neruda, Poeta Nacional. Lo escribe asi, con mayusculas, en la “Introduccion” a su Neruda clandestino, libro que sale a luz justamente a los 99 anos de edad del poeta y que va a constituir con seguridad un buen punto de partida para las festividades y conmemoraciones que ya empiezan a multiplicarse en Europa, en las Americas y, desde luego, en el pais del poeta1. Quizas sea conveniente hablar un poco de este libro, para actualizar lo que voy a exponer en este trabajo, que no es otra cosa que la posicion de Neruda en las letras y en la poesia del siglo XX.
Back Pain in Children

Back pain in a young child or adolescent is an unusual complaint and must be regarded as a possible indication of the presence of significant pathology. Functional and mechanical causes of back pain in this age group are uncommon; therefore, it is most important that a vigorous attempt be made to establish the primary diagnosis. The purpose of this paper is to review the distinctive features of the history and physical examination that may lead to accurate diagnosis, and to outline a logical approach to the laboratory and radiographic evaluation for each of the major causes of back pain. HISTORY A carefully obtained medical history is frequently the most helpful factor in establishing a diagnosis. In addition to providing important information, it also establishes an attitude of mutual trust and understanding between the physician and patient. A skillfully taken history can help the physician gain vital insight into the patient9s attitude toward his or her disease and suggest areas to be emphasized for further evaluation. Specific aspects of the history that are most revealing include: the mode of onset, nature and severity of the pain; a change in symptoms; and associated systemic complaints (Table 1). The mode of onset should be determined as specifically as possible.
A history of paleoflood hydrology in the United States, 1800”1970

The origins of paleoflood hydrology in the United States can be traced back to the beginning of the 19th century, when windgaps and watergaps in the Applachians were believed to have been eroded by extraordinary floods as large lakes that were ponded behind the ridges rapidly drained. Sediment evidence for extraordinary floods was evoked several decades later when glacial sediments in New England were interpreted as deposits from the great Biblical deluge, and estimates of the depth and velocity of the great flood were attempted. The popularization of the glacial origins of drift by Agassiz by 1840 resulted in strong beliefs in uniformitarianism and waning interests in paleoflood investigations. The documentation of the origins of the channeled scablands in eastern Washington by catastrophic glacial outbreak floods, begun by Bretz in the early 1920s, led to renewed interest in paleoflood hydrology. Subsequent efforts to reconstruct hydraulic variables of past floods used conventional open channel flow equations applied to other enormous Pleistocene floods. The elevation of sediments was used as a paleostage estimator in the 1880s, and botanical techniques for estimating paleoflood frequency and magnitude were well documented by the mid-1960s. Since 1970, an exponential expansion has occurred in the recognition and use of paleoflood hydrology in the United States.
Professional Preparation Guidelines: An AMEG Imperative.

All major professional credentialing activities, such as those endorsed by the AACD, require effective preparation in measurement and evaluation of persons. Substantive standardized guidelines for ...
Atomic Fluorescence Study of High Temperature Aerodynamic Levitation

Ultraviolet laser induced atomic fluorescence has been used to characterize supersonic jet aerodynamic levitation experiments. The levitated specimen was a 0.4 cm sapphire sphere that was separately heated at temperatures up to 2327K by an infrared laser. The supersonic jet expansion and thermal gradients in the specimen wake were studied by measuring spatial variations in the concentration of atomic Hg added to the levitating argon gas stream. Further applications of atomic fluorescence in containerless experiments, such as ideal gas fluorescence thermometry and containerless process control are discussed.
Technological Discontinuities and Complementary Assets: A Longitudinal Study of Industry and Firm Performance

We suggest that the type of complementary assets (generic versus specialized) needed to commercialize a new technology is critical in determining the industry- and firm-level performance implications of a competence-destroying technological discontinuity. At the industry level, we hypothesize that incumbent industry performance declines if the new technology can be commercialized through generic complementary assets, whereas incumbent industry performance improves if the new technology can be commercialized through specialized complementary assets. At the firm level, we posit that an incumbent firm's financial strength has a stronger positive impact on firm performance in the postdiscontinuity time period if the new technology can be commercialized through generic complementary assets. We hypothesize, however, that an incumbent firm's R&D capability has a stronger positive impact on firm performance in the postdiscontinuity time period if the new technology can be commercialized through specialized complementary assets. Drawing on multi-industry, time series, and panel data over a 26-year period to analyze pre- and postdiscontinuity industry and firm performance, we find broad support for our theoretical model.
The origin of granite: The role and source of water in the evolution of granitic magmas

Temperature and water content are the two most important parameters in the formation of granitic magmas. Evidence from volcanic and plutonic lithologies suggests that water contents of 2 to 4 wt. % are present in most silicic magmas. Calculations based on the stability of biotite yield water fugacities within the melt phase from about 500 to 2,000 bars, although these calculations determine the log f H 2 O and the effective uncertainty of ±0.5 log units yields a large absolute uncertainty. Comparison with crystallization experiments demonstrates that less than 2% water would require significant percentages of crystallization at temperatures above 900 °C with liquidus temperatures about 1000 °C. Water contents greatly in excess of 4 wt. % would mean that the magma would become vapor saturated at high pressures and would tend to crystallize during ascent to a fine-grained granite before reaching shallow depths. The main sources of water for magma generation are the dehydration of hydrous silicates within the crust and volatiles transported into the crust from subducted oceanic crust and upper mantle in the form of hydrous basalts and andesites. Dehydration reactions of muscovite, biotite, and horn-blende are of particular significance. Anatectic granites may be partially classified in terms of the probable dehydration reaction responsible for their generation. Melts generated from muscovite dehydration are relatively cool, peraluminous in composition, high in K/Na ratio, and generally high in initial 87 Sr/ 86 Sr and delta 18 O. Biotite-generated melts tend to be higher in temperatures, peraluminous to meta-aluminous in composition, moderately high in K/Na ratio, and relatively high in strontium and oxygen ratios. Both types may contain metasedimentary enclaves. Granitoids generated by hornblende dehydration would be much higher in initial temperature, peralka-line to meta-aluminous in composition, and lower in K/Na ratio and in general would have lower strontium and oxygen ratios. Volatiles deposited in hydrothermally altered oceanic crust and upper mantle will be released during subduction in the form of hydrous basalts and andesites. These melts are important energy-transfer mechanisms to drive anatexis within the crust. If these melts encounter a silicic magma chamber when intruding the crust, they will be trapped below the lower-density granitic melt. While partially quenching against the cooler melt, they may release volatiles and heat, which will aid in the melting process. Granites generated in this way will vary in their geochemical properties, depending on the relative importance of crustal versus mantle magma systems. In general, they will have moderate to high initial temperatures, be meta-aluminous in composition, be variable but somewhat low in K/Na ratio, and have lower initial strontium and delta 18 O ratios than will melts derived completely from the crust. The fact that most terrestrial spreading centers are subaqueous thus may aid in the formation of a thick granitic continental crust.
Shock (Blast) Mitigation by “Soft” Condensed Matter

It is a common point that “soft” condensed matter (like granular materials or foams) can reduce damage caused by impact or explosion. It is attributed to their ability to absorb significant energy. This is certainly the case for quasistatic type of deformation at low velocity of impact widely used for packing of fragile devices. At the same time a mitigation of blast phenomena must take into account shock wave properties of “soft” matter which very often exhibit highly nonlinear, highly heterogeneous and dissipative behavior. This paper considers applications of “soft” condensed matter for blast mitigation using simplified approach, presents analysis of some anomalous effects and suggestions for future research in this exciting area.
Rapid benchmarking for semantic web knowledge base systems

We present a method for rapid development of benchmarks for Semantic Web knowledge base systems. At the core, we have a synthetic data generation approach for OWL that is scalable and models the real world data. The data-generation algorithm learns from real domain documents and generates benchmark data based on the extracted properties relevant for benchmarking. We believe that this is important because relative performance of systems will vary depending on the structure of the ontology and data used. However, due to the novelty of the Semantic Web, we rarely have sufficient data for benchmarking. Our approach helps overcome the problem of having insufficient real world data for benchmarking and allows us to develop benchmarks for a variety of domains and applications in a very time efficient manner. Based on our method, we have created a new Lehigh BibTeX Benchmark and conducted an experiment on four Semantic Web knowledge base systems. We have verified our hypothesis about the need for representative data by comparing the experimental result to that of our previous Lehigh University Benchmark. The difference in both experiments has demonstrated the influence of ontology and data on the capability and performance of the systems and thus the need of using a representative benchmark for the intended application of the systems.
Using ISS Telescopes for Electromagnetic Follow-up of Gravitational Wave Detections of NS-NS and NS-BH Mergers

The International Space Station offers a unique platform for rapid and inexpensive deployment of space telescopes. A scientific opportunity of great potential later this decade is the use of telescopes for the electromagnetic follow-up of ground-based gravitational wave detections of neutron star and black hole mergers. We describe this possibility for OpTIIX, an ISS technology demonstration of a 1.5 m diffraction limited optical telescope assembled in space, and ISS-Lobster, a wide-field imaging X-ray telescope now under study as a potential NASA mission. Both telescopes will be mounted on pointing platforms, allowing rapid positioning to the source of a gravitational wave event. Electromagnetic follow-up rates of several per year appear likely, offering a wealth of complementary science on the mergers of black holes and neutron stars.
Photochemical analogue of the bergman cycloaromatization reaction

Abstract Irradiation of an enediyne analog yields a cyclized product expected from a thermal Bergman rearrangement.
Calculation of Unsteady and Three-Dimensional Boundary-Layer Flows

NUMERICAL solution technique has been developed and analyzed for the laminar, time-dependent and threedimensional boundary-layer equations. The method has been applied to a rotating flat plate in forward flight, which is of direct interest to helicopter rotors. The numerical method itself is a modification of the implicit schemes used in two- and threedimensional boundary-layer problems and the most significant difficulties were the initial value problem and reversed flow. The combined problem of both time-dependent influences and three-dimensionality on the flat plate exhibited a much different behavior than either of the effects along. The most interesting behavior occurred near the retreating blade portion of the cycle where retreating blade stall has been a recurring problem. Content In the present paper, a three-dimensional and time-dependent boundary layer has been calculated by a numerical method. The flow problem studied consisted of a rotating flat plate in forward flight, and the flow conditions were laminar and incompressible. This particular problem presents many interesting features, both in the areas of numerical analysis and for understanding the complex interactions in three-dimensional and time-dependent flows. The geometry of the present problem is shown in Fig. 1. During one part of the cycle, the forward flight velocity adds to the rotational velocity, while on the other part the two velocities subtract from each other. Also, it should be pointed out that the cross-flow velocity has components from both the forward and rotational motions. A prerequisite for any boundary-layer problem is an inviscid solution to be used as an outer boundary condition for the viscous flow. The inviscid solution for the present problem has been worked out by McCroskey and Yaggy,1 with various examples given by Dwyer and McCroskey.2 The appropriate laminar, incompressible boundary-layer equations for the present problem are: continuity
Sequential amplitude estimation in multiuser communications

Considers the problem of multiuser amplitude estimation, i.e., the problem of estimating the amplitudes of several digital communications signals superimposed in the same channel. This problem is of importance in communications environments such as spread-spectrum radio networks, in which nonorthogonal multiplexing is used. Multiuser amplitude estimation is a critical prerequisite to the optimum demodulation of such signals using, for example, Verdu's algorithm. In the present paper, a sequential detection-estimation approach is applied to this problem, and several estimation paradigms, including the method of moments and likelihood-based estimators, are considered. The consistency, asymptotic variance, and complexity of these estimators are examined. A new method of constructing a recursive consistent and asymptotically efficient estimation algorithm out of a consistent estimator sequence is also suggested and is applied to the current setup. It is seen that detector-estimators that use these estimators in Verdu's algorithm result, asymptotically, in (known-amplitude) optimum error probabilities with little relative increase in complexity per demodulated bit. >
Rational design of metal-organic frameworks with anticipated porosities and functionalities

Metal–organic frameworks have emerged as a new category of porous materials that have intriguing structures and diverse applications. Even though the early discovery of new MOFs appears to be serendipitous, much effort has been made to reveal their structure–property relationships for the purpose of rationally designing novel frameworks with expected properties. Until now, much progress has been made to rationalize the design and synthesis of MOFs. This highlight review will outline the recent advances on this topic from both our and other groups and provide a systematic overview of different methods for the rational design of MOFs with desired porosities and functionalities. In this review, we will categorize the recent efforts for rational MOF design into two different approaches: a structural approach and a functional approach.
Focusing on Short-term Achievement Gains Fails to Produce Long-term Gains

The short-term emphasis engendered by No Child Left Behind (NCLB) has focused research predominantly on unraveling the complexities and uncertainties in assessing short-term results, rather than developing methods and assessing results over the longer term. In this paper we focus on estimating long-term gains and address questions important to evaluating schools and identifying educational policies and practices that produce long-term sustained gains. Estimates are made of annual pass rates on state exams using fixed effect models for six years of pass rates at grades 3, 6, 8 and 10; the percentages of schools making statistically significant gains, gains, losses, and statistically significant losses in pass rates are determined. Estimates are contrasted using models that include and exclude demographic characteristics. The percentages of schools with statistically significant gains varied markedly from 38 to 6 at grades 6 and 10, respectively; the percentage of schools with statistically significant declines ranged from less than 8
Optimal financial contracting: Debt versus outside equity

This article presents a theory of outside equity based on the control rights and the maturity design of equity. I show that outside equity is a tacit agreement between investors and management supported by the equity-holders' right to dismiss management regardless of performance and by the lack of a prespecified expiration date on equity. As a tacit agreement outside equity is sustainable despite management's potential for manipulating the cash flows and regardless of how costly it is for equity-holders to establish a case against managerial wrongdoing. I establish that the only outside equity that investors are willing to hold in equilibrium is that with unlimited life, the very outside equity that corporations issue. Consistent with empirical evidence, this model predicts that debt-equity ratios are higher (lower) in industries with low (high) cash flow variability. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Anomalous quantum Hall conductivity and resonances in coupled layers

A two-layer system coupled via tunneling and with different carrier masses in each layer is investigated in the integer quantum Hall regime. Striking deviations of the one-layer Hall conductivity from the usual quantization are found, if resonance between Landau levels of different layers is achieved. The appearance of negative jumps in the Hall conductivity is also predicted under suitable conditions. The results obtained are robust against moderate disorder in the system.
The role of boundary layer capacitance at blocking electrodes in the interpretation of dielectric cure data in adhesives

Abstract The use of dielectric measurement techniques for monitoring the cure of adhesives and matrix resins used in composite materials is well known. Either parallel-plate electrodes or recently introduced dielectric microsensors can be used. During a typical cure, the quantitative results obtained from dielectric measurements early in cure, where the resin is a viscous liquid, have been shown to depend on the presence or absence of blocking layers at one or both electrodes. This paper reports a quantitative evaluation of the effects of blocking layers on the interpretation of such dielectric data. The approach follows that used for dilute electrolytes, which is a reasonable model for the liquid resins, in which ion conduction will always be present to some degree. It is shown, first, that blocking layers can be modeled as capacitances in series with the bulk adhesive; second, that when the dielectric loss factor of the material is high (which is typically true early in cure), the apparent dielectric re...
Bayesian Sequential Change Diagnosis

Sequential change diagnosis is the joint problem of detection and identification of a sudden and unobservable change in the distribution of a random sequence. In this problem, the common probability law of a sequence of i.i.d. random variables suddenly changes at some disorder time to one of finitely many alternatives. This disorder time marks the start of a new regime, whose fingerprint is the new law of observations. Both the disorder time and the identity of the new regime are unknown and unobservable. The objective is to detect the regime-change as soon as possible, and, at the same time, to determine its identity as accurately as possible. Prompt and correct diagnosis is crucial for quick execution of the most appropriate measures in response to the new regime, as in fault detection and isolation in industrial processes, and target detection and identification in national defense. The problem is formulated in a Bayesian framework. An optimal sequential decision strategy is found, and an accurate numerical scheme is described for its implementation. Geometrical properties of the optimal strategy are illustrated via numerical examples. The traditional problems of Bayesian change-detection and Bayesian sequential multi-hypothesis testing are solved as special cases. In addition, a solution is obtained for the problem of detection and identification of component failure(s) in a system with suspended animation.
How many angels can dance on the head of a pin? Development of next generation turbodiesel controls

This paper covers several aspects of the emerging problems faced in diesel engine control development. In particular the interaction of three issues will be considered: (i) increasingly stringent regulation on diesel engine emissions is leading to the introduction of additional hardware subsystems and tighter control performance requirements; (ii) diesel engine powertrains are highly nonlinear plants, with significant multivariable interactions among subsystems, and many different engine layouts are encountered in practice; and (iii) the computing environment in modern automotive electronic control units (ECUs) is very restricted with a processor speed is typically slower than 60 MHz and only a few MB of flash memory. The convergence of these three issues is creating control engineering requirements and development opportunities. While the emissions requirements must be met according to law, the market demands require fuel efficiency, drivability, and low cost. The paper provides automotive control engineers with intuitive tools for the design of advanced controllers.
Optimal Fiscal Policy with Endogenous Product Variety

We study Ramsey-optimal scal policy in an economy in which product creation is the result of forward-looking investment decisions by rms. There are two main results. First, depending on the particular form of variety aggregation, rms’ dividend payments may be either subsidized or taxed in the long run. This policy balances monopoly incentives for product creation with the welfare benet of product variety. In the most empirically relevant form of variety
A computational model of the interaction between external and internal cues for the control of hippocampal place cells

Abstract Place cell activity in the hippocampus depends in a complex way on the information from two major sensory sources: External (e.g., visual) cues and internal cues (self-motion, vestibular cues). Dissociation of the two inputs in the presence of the animal modifies the place fields in ways that depend on the magnitude of the difference: If the mismatch is small, place fields typically follow the external cues, but if the mismatch is large, their activity is determined mainly by the internal cues. The dynamics underlying the interaction between the external and internal cues in the hippocampus is not completely known, but is an important issue in understanding the hippocampus’ role in spatial learning and navigation. In this paper, we propose an attractor model of the hippocampus which captures the interaction between external and internal sensory inputs to the hippocampus. The proposed mechanism accounts for the difference seen in the experimental results in the case of a small versus a large discrepancy between the visual and idiothetic information.
Economic Geography, Trade, and War

An agent-based model in which economic exchange and military conflict are emergent processes is used to explore the relationship between trade and war. The model of exchange is an applied analysis of the eco- nomics of trading networks. The model of conflict treats war as a breakdown in interstate bargaining due to incomplete information. The simulations explore how initial economic geography, state revisionism, defen- sive advantage, and technological advancement akin to globalization affect both trade and war. The results show that the relationship between trade and war depends on third factors, and an inverse relationship between trade and war emerges from compact geographies with revisionist states.
Polar optical phonons in wurtzite spheroidal quantum dots: theory and application to ZnO and ZnO/MgZnO nanostructures

Polar optical-phonon modes are derived analytically for spheroidal quantum dots with wurtzite crystal structure. The developed theory is applied to freestanding spheroidal ZnO quantum dots and to spheroidal ZnO quantum dots embedded into a MgZnO crystal. The wurtzite (anisotropic) quantum dots are shown to have strongly different polar optical-phonon modes in comparison with zincblende (isotropic) quantum dots. The obtained results allow one to explain and accurately predict phonon peaks in the Raman spectra of wurtzite nanocrystals, nanorods (prolate spheroids), and epitaxial quantum dots (oblate spheroids).
Optical processing in Radon space

The Radon transform can be used to reduce two-dimensional or three-dimensional signal-processing problems to a series of one-dimensional problems. We discuss the use of incoherent optical systems and one-dimensional filters for convolutions, correlations, and spectrum analysis in two or three dimensions.
The kinematic origin of the cosmological redshift

A common belief about big-bang cosmology is that the cosmological redshift cannot be properly viewed as a Doppler shift (that is, as evidence for a recession velocity) but must be viewed in terms of the stretching of space. We argue that, contrary to this view, the most natural interpretation of the redshift is as a Doppler shift, or rather as the accumulation of many infinitesimal Doppler shifts. The stretching-of-space interpretation obscures a central idea of relativity, namely that it is always valid to choose a coordinate system that is locally Minkowskian. We show that an observed frequency shift in any spacetime can be interpreted either as a kinematic (Doppler) shift or a gravitational shift by imagining a suitable family of observers along the photon’s path. In the context of the expanding universe, the kinematic interpretation corresponds to a family of comoving observers and hence is more natural.
Mechanical robustness of Pseudomonas aeruginosa biofilms

Biofilms grow on various surfaces and in many different environments, a phenomenon that constitutes major problems in industry and medicine. Despite their importance little is known about the viscoelastic properties of biofilms and how these depend on the chemical microenvironment. Here, we find that the mechanical properties of Pseudomonas aeruginosa (P.a.) biofilms are highly robust towards chemical perturbations. Specifically, we observe that P.a. biofilms are able to fully regain their initial stiffness after yielding is enforced, even in the presence of chemicals. Moreover, only trivalent ions and citric acid significantly affect the biofilm elasticity, the first of which also alters the texture of the material. Finally, our results indicate that biofilm mechanics and bacteria viability inside the biofilm are not necessarily linked which suggests that targeting bacteria alone might not be sufficient for biofilm removal strategies.
Epidemiology of Sexually Transmitted Infections Among Offenders Following Arrest or Incarceration.

Objectives. We sought to estimate rates of sexually transmitted infections (STIs) among criminal offenders in the 1 year after arrest or release from incarceration.Methods. We performed a retrospective cohort study of risk of having a positive STI (chlamydia, gonorrhea, or syphilis) or incident-positive HIV test in the 1 year following arrest or incarceration in Marion County (Indianapolis), Indiana. Participants were 247 211 individuals with arrest or incarceration in jail, prison, or juvenile detention between 2003 and 2008.Results. Test positivity rates (per 100 000 and per year) were highest for chlamydia (2968) and gonorrhea (2305), and lower for syphilis (278) and HIV (61). Rates of positive STI and HIV were between 1.5 and 2.8 times higher in female than male participants and between 2.7 and 6.9 times higher for Blacks than Whites. Compared with nonoffenders, offenders had a relative risk of 3.9 for chlamydia, 6.6 for gonorrhea, 3.6 for syphilis, and 4.6 for HIV.Conclusions. The 1-year period follo...
System characteristics of Intrex

The salient features of Intrex have been reported in prior literature. They are updated here and are included as a preamble to the three companion papers being presented at this conference on several technical features of Intrex.
Quasar H II Regions During Cosmic Reionization

Cosmic reionization progresses as HII regions form around sources of ionizing radiation. Their average size grows continuously until they percolate and complete reionization. We demonstrate how this typical growth can be calculated around the largest, biased sources of UV emission such as quasars by further developing an analytical model based on the excursion set formalism. This approach allows us to calculate the sizes and growth of the HII regions created by the progenitors of any dark matter halo of given mass and redshift with a minimum of free parameters. Statistical variations in the size of these pre-existing HII regions are an additional source of uncertainty in the determination of very high redshift quasar properties from their observed HII region sizes. We use this model to demonstrate that the transmission gaps seen in very high redshift quasars can be understood from the radiation of only their progenitors and associated clustered small galaxies. The fit requires the epoch of overlap to be at z = 5.8 {+-} 0.1. This interpretation makes the transmission gaps independent of the age of the quasars observed. If this interpretation were correct it would raise the prospects of using radio interferometers currently under construction to detect the epoch of reionization.
Surface-related multiple elimination on wide-tow marine data

Surface-related multiples typically correspond to the largest component of multiple energy on marine seismic data because the surface is an almost perfect reflector with a reflectivity close to unity and, thus, their elimination is a major goal of seismic processing. Recent work has shown surface-related multiple elimination (SRME) to be effective in attenuating surface-related multiples, particularly in complex geology which may include diffracting features. Figure 1 shows the basic idea behind SRME. A surface-related multiple is recorded at receiver X r due to a shot at location Xs. The event is a surface-related multiple because it undergoes at least one downward reflection at the surface, in this case at A, during its propagation. One readily sees that this surface-related multiple event is the composition of two events: one recorded at A due to a shot at Xs and a second recorded at Xr due to a shot at A. Thus the basic operation in SRME is a spatio-temporal convolution of the data with itself. This gives the correct kinematics of the surface-related multiples, but not their amplitudes. The exact prediction is given by a cross-convolution of the data with the surface-related multiple-free version of the data and with proper accounting for directivity, ghosts, and the obliquity factor. In an iterative formulation, the (i+1)th estimate of the multiples is the cross-convolution of the data U with the ith estimate of the multiple-free data U(i). Figure 1. Basic concept behind SRME. SRME does not require any subsurface information, nor does it make any assumptions about seismic events such as hyperbolicity or moveout separation between primaries and multiples. As a result, SRME can handle arbitrarily complex multiples (including, in particular, diffracted multiples). In fact, SRME appears to be the only effective approach to attenuating diffracted multiples and this …
High-energy nucleon transport

Monte Carlo calculations for high energy nucleon transport in spacecraft radiation shielding
A dynamic epistemic characterization of backward induction without counterfactuals

Abstract We propose a dynamic framework where the rationality of a playerʼs choice is judged on the basis of the actual beliefs that he has at the time he makes that choice. The set of “possible worlds” is given by state-instant pairs ( ω , t ) , where each state specifies the entire play of the game. At every ( ω , t ) the beliefs of the active player provide an answer to the question “what will happen if I take action a ?”, for every available action a . A player is rational at ( ω , t ) if either he is not active or the action he takes is optimal given his beliefs. We characterize backward induction in terms of the following event: the first mover (i) is rational and has correct beliefs, (ii) believes that the active player at date 1 is rational and has correct beliefs, (iii) believes that the active player at date 1 believes that the active player at date 2 is rational and has correct beliefs, etc.
Balance in Random Trees

We prove that a random labeled (unlabeled) tree is balanced. We also prove that random labeled and unlabeled trees are strongly k-balanced for any k ≥ 3. Definition: Color the vertices of graph G with two colors. Color an edge with the color of its endpoints if they are colored with the same color. Edges with different colored endpoints are left uncolored. G is said to be balanced if neither the number of vertices nor and the number of edges of the two different colors differs by more than one.
Stereoselective Synthesis of 2-Deoxy-β-glycosides Using Anomeric O-Alkylation/Arylation

Anomeric O-alkylation/arylation is applied to the synthesis of 2-deoxy-β-glycosides. Treatment of lactols with NaH in dioxane followed by the addition of electrophiles leads to the formation of 2-deoxy-β-glycosides in high yield and high selectivity. The high β-selectivity observed here demonstrates a powerful stereoelectronic effect for the stereoselective formation of acetals under kinetic control.