cssi/SciSciGPT-SciSciNet huggingface dataset:
An Evaluation of the Toxicity of Accumulated Sediments in Forebays of Stormwater Wetlands and Wetponds

Forebays, small settling basins placed at the inlet of Stormwater Best Management Practices, encourage sedimentation with the intention of pollutant consolidation and capture. Regularly, accumulated sediments are excavated to restore forebay storage volume and to further prevent contamination of downstream waterbodies during large storm events. Disposal measures vary according to the toxicity of sediments. To test for the potential toxicity of forebay spoils, 30 stormwater wetland and wetpond forebays of varying age, size, and upstream landuse were sampled across North Carolina and analyzed for seven metals: cadmium, chromium, copper, iron, lead, nickel, and zinc. Ten of 30 sites were also sampled near the outlet structures for spatial comparison of settled sediment and pollutant presence. The relative toxicity of all sampled sediment metal concentrations was evaluated using existing aquatic health sediment guidelines and US Environmental Protection Agency standards for the land application of biosolids (40 CFR503). Of 30 sites, 17 exceeded sediment guidelines for aquatic health, emphasizing the need for routine forebay sediment removal. However, all samples were less than 40 CFR 503 limits with factors of safety ranging from 2.3 to 28, indicating that land application of forebay sediment is unlikely to pose an environmental threat. Additionally, forebay sediment tended to have lower metal toxicity than sediment collected at the pond or wetland outlet.
Eigenvalues of Toeplitz Operators on the Annulus and Neil Algebra

By working with all collection of all the Sarason Hilbert Hardy spaces for the annulus algebra an improvement to the results of Aryana and Clancey on eigenvalues of self-adjoint Toeplitz operators on an annulus is obtained. The ideas are applied to Toeplitz operators on the Neil algebra. These examples may provide a template for a general theory of Toeplitz operators with respect to an algebra.
Time-Dependent Warping, Fluxes, and NCYM

We describe the supergravity solutions dual to D6-branes with both time-dependent and time-independent B-fields. These backgrounds generalize the Taub-NUT metric in two key ways: they have asymmetric warp factors and background fluxes. In the time-dependent case, the warping takes a novel form. Kaluza-Klein reduction in these backgrounds is unusual, and we explore some of the new features. In particular, we describe how a localized gauge-field emerges with an analogue of the open string metric and coupling. We also describe a gravitational analogue of the Seiberg-Witten map. This provides a framework in supergravity both for studying non-commutative gauge theories, and for constructing novel warped backgrounds.
On non-intersecting arithmetic progressions

We prove that if one has k non-intersecting arithmetic progressions of integers, with common differences 2 <= q_1,...,q_k <= x, then k < x exp((-1/6 + o(1)) sqrt(log x loglog x)). This improves a result of Szemeredi and Erdos.
Temperatures and non-ideal expansion in ultrarelativistic nucleus-nucleus collisions

Abstract The hadronic phase space distributions calculated with the transport model RQMD for central S (200 A GeV) on S and Pb (160 A GeV) on Pb collisions are analyzed to study the deviations from ideal hydrodynamical evolution. After thermalization, the source stays in approximate kinetic equilibrium for about 2 fm/ c at a temperature close to 140 MeV. The freeze-out state resembles a thermal system at a temperature of 130 MeV. This freeze-out temperature is lower than values derived from fits to measured particle ratios and transverse momentum spectra. The processes in RQMD to which the differences can be attributed to are the absence of chenical equilibrium at freeze-out and the non-ideal expansion of the hadromic matter. The collective flow velocities of heavier particles are smaller by about 20 to 30% in comparison to the dominantly pionic fluid.
Space-Efficient Manifest Contracts

The standard algorithm for higher-order contract checking can lead to unbounded space consumption and can destroy tail recursion, altering a program's asymptotic space complexity. While space efficiency for gradual types---contracts mediating untyped and typed code---is well studied, sound space efficiency for manifest contracts---contracts that check stronger properties than simple types, e.g., "is a natural'' instead of "is an integer''---remains an open problem. We show how to achieve sound space efficiency for manifest contracts with strong predicate contracts. The essential trick is breaking the contract checking down into coercions: structured, blame-annotated lists of checks. By carefully preventing duplicate coercions from appearing, we can restore space efficiency while keeping the same observable behavior.
Proactive Resource Allocation: Harnessing the Diversity and Multicast Gains

This paper introduces the novel concept of proactive resource allocation for wireless networks, through which the predictability of user behavior is exploited to balance the wireless traffic over time, and significantly reduces the bandwidth required to achieve a given blocking/outage probability. We start with a simple model in which smart wireless devices are assumed to predict the arrival of new requests and submit them to the network time slots in advance. Using tools from large deviation theory, we quantify the resulting prediction diversity gain to establish that the decay rate of the outage event probabilities increases with the prediction duration . Remarkably, we also show that, in the cognitive networking scenario, the appropriate use of proactive resource allocation by primary users improves the diversity gain of the secondary network at no cost in the primary network diversity. We also shed light on multicasting with predictable demands and show that proactive multicast networks can achieve a significantly higher diversity gain that scales superlinearly with . Finally, we conclude by a discussion of the new research questions posed under the umbrella of the proposed proactive wireless resource framework.
Comparison of Mid-Lobe versus Lateral Systematic Sextant Biopsies in the Detection of Prostate Cancer

Objective: Systematic sextant biopsies are a powerful tool in the diagnosis of prostate cancer. Interpretation of the histopathologic results of these biopsies plays a central role in treatment decisions. This biopsy approach was originally described as sampling the prostate in the mid-lobe, parasagittal plane at the apex, mid-gland, and base, bilaterally. Morphometric analysis of prostate specimens has revealed that most clinically significant cancers are mainly located in the posterolateral aspect of the gland, not the mid-lobe. We sought to determine if cancer detection could be improved by obtaining more laterally placed biopsies. Materials and Methods: Forty-one patients underwent transrectal ultrasound with mid-lobe sextant as well as lateral sextant biopsies. Biopsy specimens were evaluated for Gleason grade and length of cancer present in each core. The mid-lobe and lateral biopsy results were then compared. Results: Thirteen of 41 patients (31.7%) were found to have no cancer on either biopsy set. Cancer was detected by both the mid-lobe and the lateral biopsies in 19 patients (46.3%). In 6 patients (14.6%), only the lateral biopsies revealed cancer, and in 3 patients (7.3%), only the mid-lobe biopsies revealed cancer. Conclusions: Laterally-placed systematic sextant biopsies may yield an improved diagnosis rate in patients with palpable nodularity in the lateral aspect of the prostate, patients without any palpable abnormalities but with elevated PSA levels, and in those patients undergoing repeat biopsies.
Do you believe in magic? Exploring the conceptualization of augmented reality and its implications for the user in the field of library and information science

Augmented reality technology has implications for the ways that the field of library and information science (LIS) serves users and organizes information. Through content analysis, the author examined how augmented reality (AR) is conceptualized within a sample of LIS literature from the Library and Information Science and Technology Abstracts (LISTA) database and Google Blogs postings, and whether Radical Change Theory (RCT) and the digital age principles of interactivity, connectivity and access are present in the discussion of this technology. The analysis of data led to the identification of 14 categories comprised of 132 total codes across sources within the data set. The analysis indicates that the conceptualization of AR, while inconsistent, suggests expectations that overall, the technology will enhance the user experience. This can lead to future examinations of user behavior, response and observation of technologies like AR.
Low-energy inverse problems in three-body scattering

We consider low-energy inverse problems in three-body scattering. We show that if all unknown interactions are small in an appropriate sense then the two-cluster to two-cluster S-matrices given at low energies determine the Fourier transform of the effective interaction in a ball.
Reheating after supercooling in the chiral phase transition

Abstract We study the conversion of the latent heat of a supercooled quark-gluon plasma into excitations of the pion field. Supercooling is predicted to occur in the late stages of the evolution of a quark-gluon plasma produced in energetic heavy-ion collisions, if the QCD phase transition is of first order. The supercooled, chirally symmetric state, which contains potential energy associated with an energetically unfavorable field configuration, eventually rolls down to the true minimum of the effective chiral potential. When this motion is described in terms of the linear sigma-model, we find that the energy of the coherent σ-field is very efficiently converted into pionic excitations due to anharmonic oscillations around the minimum. The system is expected to partially thermalize before its disintegration.
Control of decoherence and correlation in single quantum dissipative oscillator systems

Abstract A single quantum dissipative oscillator described by the Lindblad equation serves as a model for a nanosystem. This model is solved exactly by using the ambiguity function. The solution shows the features of decoherence (spatial extent of quantum behavior), correlation (spatial scale over which the system localizes to its physical dimensions), and mixing (mixed- state spatial correlation). A new relation between these length scales is obtained here. By varying the parameters contained in the Lindblad equation, it is shown that decoherence and correlation can be controlled. We indicate possible interpretation of the Lindblad parameters in the context of experiments using engineered reservoirs.
Local existence and uniqueness for exterior static vacuum Einstein metrics

We study solutions to the static vacuum Einstein equations on exterior domains with prescribed metric and mean curvature on the inner boundary. It is proved that for any such boundary data near the standard round boundary data in Euclidean space, there exists a unique AF solution to the static vacuum equations realizing the boundary data, which is close to the standard flat solution.
Making Choices While Smelling, Tasting, and Listening: The Role of Sensory (Dis)similarity When Sequentially Sampling Products:

Marketers are increasingly allowing consumers to sample sensory-rich experiential products before making purchase decisions. The results of seven experimental studies (two conducted in field settings, three conducted in a laboratory, and two conducted online) demonstrate that the order in which consumers sample products and the level of (dis)similarity between the sensory cues of the products influence choices. In the absence of any moderators, when sampling a sequence of sensory-rich experiential products (e.g., fragrances, chocolates, flavored beverages, music) with similar sensory cues (e.g., smell, taste, color, sound), consumers prefer the first product in the sequence. However, when sampling a sequence of products with dissimilar sensory cues, consumers prefer the last product. These findings (1) contribute to a better understanding of the role of sequential sensory cues on consumer choice formation, (2) have implications for effects related to sensory habituation and sensory trace fading, and (3) h...
Payoff equivalence between Bayesian and ex post individually rational dominant strategy mechanisms

An efficient, interim individually rational, ex post budget balanced Bayesian mechanism is shown to be payoff equivalent to an ex post individually rational and ex ante budget balanced dominant strategy mechanism. This result simplifies the search for mechanisms that implement efficient allocation rules by pointing to a class of Groves mechanisms. It eliminates the strict requirement of common knowledge of priors and can be applied to many problems of incomplete information.
A continuum model for carbon nanotube-infused polyimides

Polyimides are presently being investigated for a wide range of aeronautic, aerospace and industrial applications due to the fact that they have good thermal and chemical resistance yet are flexible. Within the realm of aerospace applications, polyimides can be employed for deployment, positioning, and vibration attenuation of large structures including thin-film membrane mirrors and gossamer antennas. The inclusion of single wall carbon nanotubes raises the conductivity levels to permit electric discharge. Additionally, they augment the electromechanical coupling properties of piezoelectric polyimides to provide them with actuator capabilities. We present a temperature-dependent material model based on elasticity theory which characterizes stiffness through the material as a function of varying concentrations of single wall nanotubes (SWNT). We begin by investigating the temperature affects on the polyimide. We then discuss the effects of SWNT volume concentration on the composite storage modulus. The composite model takes into account the alignment, interphase, and geometry of the SWNTs.
A relativistic quark model for mesons based on numerical solutions of the Bethe-Salpeter equation

Abstract A study is made to determine if the results of the nonrelativistic quark model can be reproduced by a fully relativistic model of deeply bound spin - 1 2 quarks. It is found that the relativistic model does not reproduce the nonrelativistic results, even when the quarks have nonrelativistic momenta. However, the model is rather successful in accounting for the known properties of mesons. Numerical solutions to the Bethe-Salpeter equation are obtained for pseudoscalar and vector bound states of equal mass quark-antiquark pairs, with either a scalar, pseudoscalar, or neutral vector exchange interaction. The interaction function corresponds to single particle exchange, with the addition of either one or two regulating terms. It is found that the second regulator allows the internal quark momentum to be nonrelativistic, but that the spinor structure of the wave function remains highly relativistic. Only the scalar interaction can account for the observed spectrum of states. The pseudoscalar interaction yields a vector state of lower mass than the pseudoscalar state, and the vector interaction leads to a vector state which lies approximately one quark mass above the pseudoscalar state. The λ quark is taken as slightly heavier than the p and n, and the perturbation treatment of the mass difference leads to a quadratic mass formula. The decay amplitudes for π, K → μν are calculated, and it is found, independent of parameters, that ƒ π ≈ ƒ K for either a scalar or vector interaction, in agreement with experiment and in contrast with the nonrelativistic model. The amplitudes for ϱo, ω, φ → e+e−, μ+μ− are also calculated, but in this case the ratios (again parameter independent) are in minor discrepancy with experiment. The question of the additivity of quark amplitudes is examined by calculating (with significant restrictions) the magnetic moments of the vector mesons and the amplitudes for magnetic transitions such as ω → πoγ. The magnetic moments of the vector mesons have the same (trivial) ratios to each other as in the nonrelativistic model, but they are strongly enhanced over the sum of the quark magnetic moments. The amplitude for magnetic transitions, however, is related to the quark magnetic moments in approximately the same ratio as in the nonrelativistic model. The model is also used to obtain parameter dependent predictions for the masses and decay amplitudes. These predictions are not experimentally correct, but are generally well within an order of magnitude for a wide range of the parameters. The most significant defect discovered of the model is the presence of ghost states (the daughters of the vector mesons, with JPC = 0+−) with masses of about 2 BeV.
Plasma simulation as eigenvalue problem

A numerical integration of the Vlasov equation replaces the continuous eigenvalue spectrum of the problem by a discrete spectrum, which can be represented by the eigenvalue spectrum of a finite matrix. This matrix must be dissipative, i.e., the eigenvalues must have a negative real part in order to avoid recurrence effects. Several dissipative terms in the diagonal of the matrix are studied numerically and analytically and the influence of various parameters is investigated. It is shown that a decrease of the last few off-diagonal terms in the matrix may also enhance the damping.
Asymptotic crossover in polymer blends.

Susceptibility and specific-heat data for a low-molecular-weight polymer blend near its critical point of unmixing are compared with a match-point renormalization-group theory which describes the crossover from classical mean-field to fluctuation-dominated behavior near the critical temperature. Using the Flory-Huggins form of the bare free-energy density, the crossover function requires only two free parameters.
Small curvature surfaces in hyperbolic 3-manifolds

In a paper of Menasco and Reid, it is conjectured that there exist no hyperbolic knots in S3 for which the complement contains a closed embedded totally geodesic surface. In this note, we show that one can get "as close as possible" to a counter-example. Specifically, we construct a sequence of hyperbolic knots {Kn} with complements containing closed embedded essential surfaces having principal curvatures converging to zero as n tends to infinity. We also construct a family of two-component links for which the complements contain closed embedded totally geodesic surfaces of arbitrarily large genera. In addition, we prove that a closed embedded surface with sufficiently small principal curvatures is not only quasi-Fuchsian (a result of Thurston's), but it is also either acylindrical or the boundary of a twisted I-bundle.
Simple bounds from the perturbative regime of inflation

We examine the conditions under which a perturbative expansion around an inflating background is valid. When inflation is driven by a single field with a general sound speed, we find a lower limit on the sound speed related to the amplitude of the inflationary power spectrum. Generalizing the sound speed constraints to include scale dependence can limit the number of e-folds obtained in the perturbative regime and restrict otherwise apparently viable models. We also show that, for models with a low sound speed, eternal inflation cannot occur in the perturbative regime.
Learning texture discrimination masks

A neural network texture classification method is proposed in this paper. The approach is introduced as a generalization of the multichannel filtering method. Instead of using a general filter bank, a neural network is trained to find a minimal set of specific filters, so that both the feature extraction and classification tasks are performed by the same unified network. The authors compute the error rates for different network parameters, and show the convergence speed of training and node pruning algorithms. The proposed method is demonstrated in several texture classification experiments. It is successfully applied in the tasks of locating barcodes in the images and segmenting a printed page into text, graphics, and background. Compared with the traditional multichannel filtering method, the neural network approach allows one to perform the same texture classification or segmentation task more efficiently. Extensions of the method, as well as its limitations, are discussed in the paper.
Primordial Black Holes as Dark Matter: The Power Spectrum and Evaporation of Early Structures

We consider the possibility that massive primordial black holes are the dominant form of dark matter. Black hole formation adds a Poisson noise to the matter density fluctuations. We use Lyα forest observations to constrain this Poisson term, which constrains the black hole masses to be less than approximately a few times 104 M☉. We also find that structures with less than ~103 black holes evaporate by now.
Turnover intentions of Indian IS professionals

One of the major challenges facing the Indian IT services industry is the high rate of turnover among Indian IS professionals. Turnover rates have been reported as high as 100% annually. Despite the serious problem, we are unaware of any academic research that has studied the determinants of turnover among Indian IS professionals. We aim to contribute to the literature by understanding Turnover Intentions of Indian IS professionals. We developed an initial model of Turnover Intentions based on the IS and Organizational Behavior literatures. The most commonly identified determinants of Turnover Intentions in these literatures were Organizational Commitment (emotional attachment to an organization) and Job Satisfaction. However, the research that identified these determinants was primarily tested on Western workers. We assessed the applicability of this model by interviewing 25 Indian IS professionals. We found strong support that Job Satisfaction affects Turnover Intentions among Indian IS professionals. However, Organizational Commitment was found to be a troublesome construct. Many Indian participants did not relate to the concept of an emotional attachment to an organization. Instead, they talked in terms that better mapped to the construct Organizational Satisfaction. The interviews also uncovered another important determinant of Turnover Intention: Social Norms. Social Norms, as evidenced by significant family pressure to reside in the same city as the employee's family, emerged as a major reason for Turnover Intentions. Our revised model identifies Job Satisfaction, Organizational Satisfaction, and Social Norms as the main determinants of Turnover Intentions among Indian IS Professionals. We also identify four implications for practice. The most worrisome implication for Western clients is that Indian IS professionals do not like performing routine IT maintenance work or merely programming from predefined specifications--the bulk of work sent offshore. Indian IS professionals preferred client-facing activities, design and development work.
Mapping the Spatiotemporal Dynamics of Calcium Signaling in Cellular Neural Networks Using Optical Flow

An optical flow gradient algorithm was applied to spontaneously forming networks of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling with single pixel resolution. Optical flow estimates the direction and speed of motion of objects in an image between subsequent frames in a recorded digital sequence of images (i.e., a movie). Computed vector field outputs by the algorithm were able to track the spatiotemporal dynamics of calcium signaling patterns. We begin by briefly reviewing the mathematics of the optical flow algorithm, and then describe how to solve for the displacement vectors and how to measure their reliability. We then compare computed flow vectors with manually estimated vectors for the progression of a calcium signal recorded from representative astrocyte cultures. Finally, we applied the algorithm to preparations of primary astrocytes and hippocampal neurons and to the rMC-1 Muller glial cell line in order to illustrate the capability of the algorithm for capturing different types of spatiotemporal calcium activity. We discuss the imaging requirements, parameter selection and threshold selection for reliable measurements, and offer perspectives on uses of the vector data.
Rule Learning in Symmetric Normal-Form Games: Theory and Evidence

Abstract An experiment, consisting of two 15-period runs with 5 × 5 games, was designed to test Stahl's [International Journal of Game Theory28, 111–130 (1999)] model of boundedly rational behavioral rules and rule learning for symmetric normal-form games with unique symmetric Nash equilibria. A player begins with initial propensities on a class of evidence-based behavioral rules and, given experience over time, adjusts her propensities in proportion to the past performance of the rules. The experimental data provide significant support for rule learning and heterogeneity characterized by three modes. We also strongly reject “Nash learning” and “Cournot dynamics” in favor of rule learning. Journal of Economic Literature Classification Numbers: C72, C90, C51, C52.
On Exponential Ergodicity of Multiclass Queueing Networks

One of the key performance measures in queueing systems is the decay rate of the steady-state tail probabilities of the queue lengths. It is known that if a corresponding fluid model is stable and the stochastic primitives have finite moments, then the queue lengths also have finite moments, so that the tail probability ℙ(⋅>s) decays faster than s −n for any n. It is natural to conjecture that the decay rate is in fact exponential. In this paper an example is constructed to demonstrate that this conjecture is false. For a specific stationary policy applied to a network with exponentially distributed interarrival and service times, it is shown that the corresponding fluid limit model is stable, but the tail probability for the buffer length decays slower than s −log s .
Friedel-Crafts Acylation of Aromatic Hydrocarbons Using Zeolites

Abstract A convenient heterogeneous catalytic methodology for Friedel-Crafts acylation of benzene and toluene using various aliphatic carboxylic anhydrides over zeolites at 250 °C is described. An interesting para selectivity is observed in the case of acylation of toluene over HZSM-5.
On the 17-keV conundrum

Abstract Recent developments in pursuance of the 17-keV neutrino are discussed with emphasis upon experiments employing solid state detectors. Studies have shown that electron scattering effects are the likely origin of the anomalies observed in β decay spectra measured at Oxford and Guelph. While missing links remain, it is improbable that a 17-keV neutrino exists in nature and a resolution of this conundrum is within reach.
Alkylation of adenine with t-propargyl chlorides: acetylene/allene ratio and N9/N7 regioselectivity☆

Abstract Alkylation of adenine ( 6 ) with dialkylpropargyl chlorides 3a and 3b gave N 9 - and N 7 -acetylenes 7a , 7b and 9a , 9b accompanied by N 9 -allenes 8a , 8b . Bromoallene 10a gave only 7a and 7b but no allene 8a . Reaction of propargyl chloride with 6 led only to N 9 -propargyladenine ( 7c ) whereas chloroallene 10b afforded 7c and allene 8c . The possible reaction course will be discussed with emphasis on the influences of structure, reagent and solvent on acetylene/allene ratio and N 9 /N 7 regioselectivity of alkylation. The nonequivalent methylene groups of 7b and 9b have Δδ 0.67 and 1.07, respectively, appearing as sextets in the 1 H NMR spectra.
SiC platelet-reinforced Al2O3 composites by free sintering of coated inclusions

Abstract SiC platelets were coated with a fine-grained Al 2 O 3 precursor powder by controlled heterogeneous precipitation from solution. After calcination, the coated platelets were compacted and sintered at a constant heating rate of 5 °C min −1 in a helium atmosphere. The parameters that control the coating process and the sintering behaviour of the coated powders were investigated. For given reactant and platelet concentrations, pH and temperature, the presence of a small amount of poly(vinylpyrrolidone) (PVP) produced a more homogeneous coating which, in turn, produced an improvement in the sinterability of the coated platelets. Composites formed from the coated platelets, with an initial matrix density of 40–45% of the theoretical and containing ≈ 20 vol% platelets, reached nearly full density after sintering at 1800 °C for min. By comparison, similar composites formed by mechanical mixing of the SiC platelets and freely precipitated Al 2 O 3 powder reached a density of only ≈ 70% of the theoretical under identical sintering conditions. The strength and fracture toughness of the sintered composites formed from the coated platelets were measured in three-point loading at room temperature. For the composite containing 20 vol% platelets, the strength and fracture toughness values were MPa and 5.4 MPa m 1 2 , respectively. They are comparable to the highest values reported for similar composites produced by hot-pressing of mechanically mixed systems.
On vertex algebras and their modules associated with even lattices

Abstract We study vertex algebras and their modules associated with possibly degenerate even lattices, using an approach somewhat different from others. Several known results are recovered and a number of new results are obtained. We also study modules for Heisenberg algebras and we classify irreducible modules satisfying certain conditions and obtain a complete reducibility theorem.
Four-dimensional supersymmetric dyonic black holes in eleven-dimensional supergravity

A class of 4-dimensional supersymmetric dyonic black hole solutions that arise in an effective 11-dimensional supergravity compactified on a 7-torus is presented. We give the explicit form of dyonic solutions with diagonal internal metric, associated with the Kaluza-Klein sector as well as the three-form field, and relate them to a class of solutions with a general internal metric by imposing a subset of SO(7) ⊂ E7 transformations. We also give the field transformations which relate the above configurations to 4-dimensional ground state configurations of Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz sector of type-IIA strings on a 6-torus.
Catalytic, Enantioselective, Intramolecular Carbosulfenylation of Olefins

The first catalytic, enantioselective carbosulfenylation of alkenes with an aromatic nucleophile is described, using a BINAM-based selenophosphoramide catalyst. E-Alkyl- and aryl-substituted alkenes afforded tetrahydronaphthalenes with complete diastereospecificity, and generally high enantiomeric ratios.
Nonlinear self-duality in even dimensions

We show that the Born-Infeld theory with n complex abelian gauge fields written in an auxiliary field formulation has a U(n,n) duality group. We conjecture the form of the Lagrangian obtained by eliminating the auxiliary fields and then introduce a new reality structure leading to a Born-Infeld theory with n real gauge fields and an Sp(2n,IR) duality symmetry. The real and complex constructions are extended to arbitrary even dimensions. The maximal noncompact duality group is U(n,n) for complex fields. For real fields the duality group is Sp(2n,IR) if half of the dimension of space-time is even and O(n,n) if it is odd. We also discuss duality under the maximal compact subgroup, which is the self-duality group of the theory obtained by fixing the expectation value of a scalar field. Supersymmetric versions of self-dual theories in four dimensions are also discussed.
Molecular bridge effects on distant charge tunneling

The question arises as to whether different hydrocarbon bridges should give different electron-trransfer rates. This question is answered on the basis of energetic and topological (interference) effects that can be gleaned from one-electron models. A discussion of model compound electron-transfer rates based on this interpretation is given. The approximations implicit in the periodic models used here (and in previous work) are carefully justified.
A practical synthesis of L-FMAU from L-arabinose.

Abstract A practical synthesis of 2′-deoxy-2′-fluoro-5-methyl-β-L-arabinofuranosyl uracil (14 July 19, L-FMAU) was developed from L-arabinose. L-Arabinose was converted to L-ribose 5, which was used for the synthesis of bromosugar 12 via 2,3,5-O-tribenzoyl-1-O-acetyl-β-L-ribofuranose 8, which was subjected to condensation with silylated thymine and the resulting protected L-FMAU 13 was deprotected to afford L-FMAU in 14 steps in 8 % overall yield.
Chemoenzymatic synthesis of iminocyclitol derivatives: A useful library strategy for the development of selective fucosyltransfer enzymes inhibitors

A chemoenzymatic strategy has been developed for the synthesis of libraries of iminocyclitol derivatives for the discovery of new and selective fucosidase inhibitors.
Charge stripes and spin correlations in copper-oxide superconductors

To obtain superconductivity in a layered copper-oxide compound, it is necessary to introduce charge carriers into the antiferromagnetic CuO{sub 2} planes. Recent neutron diffraction studies of the system La{sub 1.6-x}Nd{sub 0.4}Sr{sub x}CuO{sub 4} provide evidence that the dopant-induced holes choose to segregate into periodically-spaced stripes which separate antiferromagnetic domains, in a manner similar to that found in hole-doped La{sub 2}NiO{sub 4}. The charge and spin stripe modulations are identified by the appearance of scattering at incommensurate positions. In the Nd-doped system, elastic scattering is observed, corresponding to static stripes. In pure La{sub 2-x}Sr{sub x}CuO{sub 4}, the magnetic scattering that is observed is purely inelastic. Where samples with and without Nd, but with the same Sr concentration, have been measured, the incommensurate (IC) splittings of the magnetic signal are found to be essentially identical. It has been proposed that the spin correlations in the two systems are fundamentally the same, thus implying similar charge correlations. The static nature of the stripes in the Nd-doped system is attributed to pinning of the otherwise dynamic correlations by a special distortion of the lattice. That distortion is driven by purely ionic interactions and is stabilized by the smaller ionic radius of the substituted Nd.
Gravitational infall onto molecular filaments. II. externally pressurized cylinders

Two aspects of the evolution of externally pressurized, hydrostatic filaments are discussed. (1) The free-fall accretion of gas onto such a filament will lead to filament parameters (specifically, FWHM-column-density relations) inconsistent with the observations of Arzoumanian et al., except for two cases: for low-mass, isothermal filaments, agreement is found as in the analysis by Fischera & Martin. Magnetized cases, for which the field scales weakly with the density as Bn 1/2, also reproduce observed parameters. (2) Realistically, the filaments will be embedded not only in gas of non-zero pressure, but also of non-zero density. Thus, the appearance of sheet-embedded filaments is explored. Generating a grid of filament models and comparing the resulting column density ratios and profile shapes with observations suggests that the three-dimensional filament profiles are intrinsically flatter than isothermal, beyond projection and evolution effects.
Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

Abstract Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.
Aerodynamic Detuning Analysis of an Unstalled Supersonic Turbofan Cascade

An approach to passive flutter control is aerodynamic detuning, defined as designed pasage-to-passage differences in the unsteady aerodynamic flow field of a rotor blade row. Thus, aerodynamic detuning directly affects the fundamental driving mechanism for flutter. A model to demonstrate the enhanced supersonic aeroelastic stability associated with aerodynamic detuning is developed. The stability of an aerodynamicaly detuned cascade operating in a supersonic inlet flow field with a subsonic leading edge locus analyzed, with the aerodynamic detuning accomplished by means of nonuniform circumferential spacing of adjacent rotor blades. The unsteady aerodynamic forces and moments on the blading are defined in terms of influence coefficients in a manner that permits the stability of both a conventional uniformally spaced rotor configuration as well as the detuned nonuniform circumferentialy spaced rotor to be determined. With Verdon's uniformly spaced Cascade B as a baseline, this analysis is then utilized to demonstrate the potential enhanced aeroelastic stability associated with this particular type of aerodynamic detuning.
Unipotent elements in small characteristic, III☆

Abstract We give a uniform description of the decomposition of the unipotent variety of a classical group in arbitrary characteristic into pieces (considered in a non-uniform way in the earlier parts of this series).
Large Poisson Games

Abstract Existence of equilibria is proven for Poisson games with compact type sets and finite action sets. Then three theorems are introduced for characterizing limits of probabilities in Poisson games when the expected number of players becomes large. The magnitude theorem characterizes the rate at which probabilities of events go to zero. The offset theorem characterizes the ratios of probabilities of events that differ by a finite additive translation. The hyperplane theorem estimates probabilities of hyperplane events. These theorems are applied to derive formulas for pivot probabilities in binary elections, and to analyze a voting game that was studied by Ledyard. Journal of Economic Literature Classification Numbers: C63, C70.
Local white matter geometry from diffusion tensor gradients

We introduce a mathematical framework for computing geometrical properties of white matter fibers directly from diffusion tensor fields. The key idea is to isolate the portion of the gradient of the tensor field corresponding to local variation in tensor orientation, and to project it onto a coordinate frame of tensor eigenvectors. The resulting eigenframe-centered representation then makes it possible to define scalar indices (or measures) that describe the local white matter geometry directly from the diffusion tensor field and its gradient, without requiring prior tractography. We derive new scalar indices of (1) fiber dispersion and (2) fiber curving, and we demonstrate them on synthetic and in vivo data. Finally, we illustrate their applicability to a group study on schizophrenia.
Automating planning and scheduling of shuttle payload operations

Abstract This paper describes the DATA-CHASER Automated Planner/Scheduler (DCAPS) system for automated generation and repair of command sequences for the DATA-CHASER shuttle payload. DCAPS uses general Artificial Intelligence (AI) heuristic search techniques, including an iterative repair framework in which the system iteratively resolves conflicts with the state, resource, and temporal constraints of the payload activities. DCAPS was used in the operations of the shuttle payload for the STS-85 shuttle flight in August 1997 and enabled a 80% reduction in mission operations effort and a 40% increase in science return.
Tuning the Sign of Photoinduced Changes in Magnetization: Spin Transitions in the Ternary Metal Prussian Blue Analogue NaαNi1−xCox[Fe(CN)6]β·nH2O

Tuning the composition of the ternary transition-metal Prussian blue analogue NaαNi1−xCox[Fe(CN)6]β·nH2O allows the sign of the photoinduced change in magnetization to be controlled. The parent cobalt hexacyanoferrate material is well-known to display photoinduced and thermal charge-transfer-induced spin transitions (CTISTs). Upon partial replacement of Co ion sites with NiII, irradiation with halogen light can cause either an increase or a decrease in magnetization, depending upon the extent of NiII substitution, the applied field, and the temperature. For all compositions with x > 0, photoexcitation generates new moments according to the same mechanism observed for the parent x = 1 compound. However, the presence of NiII introduces a superexchange of opposite sign, providing a mechanism for controlling the sign of the change in magnetization with applied light. Additionally, dilution of the spin-crossover material reduces the magnitude and hysteresis of the thermal CTIST effect. These effects can be qua...
Split reductions of simple abelian varieties

Consider an absolutely simple abelian variety $X$ over a number field $K$. We show that if the absolute endomorphism ring of $X$ is commutative and satisfies certain parity conditions, then $X_\idp$ is absolutely simple for almost all primes $\idp$. Conversely, if the absolute endomorphism ring of $X$ is noncommutative, then $X_\idp$ is reducible for $\idp$ in a set of positive density.
Reconstructing the Subsurface Three-dimensional Magnetic Structure of a Solar Active Region Using SDO/HMI Observations

A solar active region (AR) is a three-dimensional (3D) magnetic structure formed in the convection zone, whose property is fundamentally important for determining the coronal structure and solar activity when emerged. However, our knowledge of the detailed 3D structure prior to its emergence is rather poor, largely limited by the low cadence and sensitivity of previous instruments. Here, using the 45?s high-cadence observations from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we are able for the first time to reconstruct a 3D data cube and infer the detailed subsurface magnetic structure of NOAA AR 11158, and to characterize its magnetic connectivity and topology. This task is accomplished with the aid of the image-stacking method and advanced 3D visualization. We find that the AR consists of two major bipoles or four major polarities. Each polarity in 3D shows interesting tree-like structure, i.e., while the root of the polarity appears as a single tree-trunk-like tube, the top of the polarity has multiple branches consisting of smaller and thinner flux tubes which connect to the branches of the opposite polarity that is similarly fragmented. The roots of the four polarities align well along a straight line, while the top branches are slightly non-coplanar. Our observations suggest that an active region, even appearing highly complicated on the surface, may originate from a simple straight flux tube that undergoes both horizontal and vertical bifurcation processes during its rise through the convection zone.
Winding number analysis of invertible workspaces for redundant manipulators

Conventional controllers for nonredundant manipulators include an algorithm for computing a kinematic inverse func tion, which gives joint coordinates corresponding to a desired position and orientation of the end-effector. In a generaliza tion of this approach to redundant manipulators, the non- uniqueness of the inverse function can be used to move or eliminate kinematical singularities. However, it appears that for almost all manipulators, there is no inverse function that is free of singularities on the whole reachable workspace. This paper illustrates how a simple idea from topology, called a winding number, can be used to discover restrictions on invertible workspaces. A short tutorial introducing the engi neer to the relevant aspects of winding numbers is included, and results for four planar manipulators are worked out in detail.
Strategic properties of heterogeneous serial cost sharing

Abstract We show that the Serial Cost Sharing method for heterogeneous goods [J. Econ. Theory 87 (1999) 275], and a large number of other cost sharing mechanisms, have the same strong strategic properties as the Serial Cost Sharing method for homogeneous goods [J. Econ. Theory 64 (1992) 178; Econometrica 60 (1992) 1009], including uniqueness of the Nash equilibrium for all utility profiles and cost functions, dominance solvability, solvability in overwhelmed actions, and robustness to coalitional deviations. We describe several applications to cost/surplus sharing and the Internet.
DISTORTED BLACK HOLES WITH CHARGE

We present new solutions to the Einstein–Maxwell equations representing a class of charged distorted black holes. These solutions are static-axisymmetric and are generalizations of the distorted black hole solutions studied by Geroch and Hartle. Physically, they represent a charged black hole distorted by external matter fields. We discuss the zeroth and first law for these black holes. The first law is proved in two different forms, one motivated by the isolated horizon framework and the other using normalizations at infinity.
Prognosis of ischaemic stroke is improving similarly in patients with type 2 diabetes as in nondiabetic patients in Finland.

Background Case fatality of first ischaemic stroke has improved markedly during the past two decades. Aims To investigate whether stroke patients with type 2 diabetes have shared this favourable development. Methods Nation-wide registers were used to identify all patients with type 2 diabetes in Finland during 1988–2002. All first ischaemic strokes among them and also among all nondiabetic persons were identified from the National Hospital Discharge Register and the Causes of Death Register. Trends over time were calculated, for age-standardised case fatality of first stroke events, separately for two time periods: 0–27 and 28–364 days after the onset of stroke. These trends were compared between patients with type 2 diabetes and nondiabetic patients. Results Altogether, 23 097 first-ever ischaemic strokes were recorded among 222 940 persons with type 2 diabetes. The 28 day case fatality was 1·1–1·3 times higher, and the one-year case fatality of 28 day survivors was 1·4–2·2 times higher in patients with type 2 diabetes compared with nondiabetic patients. A significant decline in case fatality trends was observed, but the trends did not differ between type 2 diabetes and nondiabetic patients. Conclusions The study revealed a positive development in survival after the first stroke event in persons with type 2 diabetes, similar to the development in nondiabetic persons. However, the level of case fatality has remained higher in patients with type 2 diabetes.
Regulatory competition or regulatory harmonization? A silly question?

The debate over 'competition versus harmonization' in regulatory policy often confuses the pertinent alternatives. This comment argues that neither pure regulatory competition nor complete regulatory harmonization is desirable or feasible where important international cross-border effects of regulation arise. Instead, a considerable degree of cooperation is almost always needed, yet non-homogeneity of regulatory policies is almost always desirable as well. This proposition holds virtually regardless of the subject matter of regulation.