cssi/SciSciGPT-SciSciNet huggingface dataset:
Will additional federal enforcement improve the performance of pipelines in the U.S.

Abstract This paper provides the first empirical analysis of the effectiveness of regulatory enforcement in increasing the environmental and safety performance of U.S. natural gas and hazardous liquid pipeline operators. The analysis combines data on federal regulatory inspections, enforcement actions, and penalties with data on injuries, fatalities, property damage, and barrels of product lost through pipeline “incidents” for 2006–2011 for the 344 largest pipeline operators in the U.S. The results of the analysis do not provide compelling evidence that either federal inspections or civil penalties are particularly effective in increasing performance; however, the number of federal cases initiated against an operator does have a significant effect on many forms of performance, although not for incidents in general. The results also suggest that some targeting of federal enforcement resources is based on past performance, but there may be room for even more effective targeting. Finally, the analysis reveals interesting patterns between state and federal enforcement efforts.
The White Dwarfs Within 20 Parsecs of the Sun: Kinematics and Statistics

We present the kinematical properties, distribution of spectroscopic subtypes, and stellar population subcomponents of the white dwarfs within 20 pc of the Sun. We find no convincing evidence of halo white dwarfs in the total 20 pc sample of 129 white dwarfs nor is there convincing evidence of genuine thick disk subcomponent members within 20 parsecs. Virtually, the entire 20 pc sample likely belongs to the thin disk. The total DA to non-DA ratio of the 20 pc sample is 1.6, a manifestation of deepening envelope convection which transforms DA stars with sufficiently thin H surface layers into non-DAs. The addition of five new stars to the 20 pc sample yields a revised local space density of white dwarfs of (4.9 ± 0.5) × 10–3 pc–3 and a corresponding mass density of (3.3 ± 0.3) × 10–3 M ☉ pc–3. We find that at least 15% of the white dwarfs within 20 parsecs of the Sun (the DAZ and DZ stars) have photospheric metals that possibly originate from accretion of circumstellar material (debris disks) around them. If this interpretation is correct, this suggests the possibility that the same percentage have planets or asteroid-like bodies orbiting them.
Temperature dependence of turnover in a Sc(OTf)3-catalyzed intramolecular Schmidt reaction

The intramolecular Schmidt reaction of ketones and tethered azides is an efficient method for the generation of amides and lactams. This reaction is catalyzed by Lewis acids, which tightly bind the strongly basic amide product and result in product inhibition. We report herein conditions to achieve a catalytic Schmidt reaction using substoichiometric amounts of the heat-stable Lewis acid Sc(OTf)3. This species was shown to effectively release products of the Schmidt reaction in a temperature-dependent fashion. Thus, heat was able to promote catalyst turnover. A brief substrate scope was conducted using these conditions.
“Hearing from All Sides” How Legislative Testimony Influences State Level Policy-Makers in the United States

Background: This paper investigates whether state legislators find testimony influential, to what extent testimony influences policy-makers’ decisions, and defines the features of testimony important in affecting policy-makers’ decisions. Methods: We used a mixed method approach to analyze responses from 862 state-level legislators in the United States (U.S.). Data were collected via a phone survey from January-October, 2012. Qualitative data were analyzed using a general inductive approach and codes were designed to capture the most prevalent themes. Descriptive statistics and cross tabulations were also completed on thematic and demographic data to identify additional themes. Results: Most legislators, regardless of political party and other common demographics, find testimony influential, albeit with various definitions of influence. While legislators reported that testimony influenced their awareness or encouraged them to take action like conducting additional research, only 6% reported that testimony changes their vote. Among those legislators who found testimony influential, characteristics of the presenter (e.g., credibility, knowledge of the subject) were the most important aspects of testimony. Legislators also noted several characteristics of testimony content as important, including use of credible, unbiased information and data. Conclusion: Findings from this study can be used by health advocates, researchers, and individuals to fine tune the delivery of materials and messages to influence policy-makers during legislative testimony. Increasing the likelihood that information from scholars will be used by policy-makers may lead to the adoption of more health policies that are informed by scientific and practice-based evidence.
Magnetic resonance coronary angiography

MR imaging was performed using a superconducting 1.5 Tesla Siemen's Magnetom SP whole body imaging system with a standard planar elliptical spine coil used as an rf receiver. The imaging sequence consisted of a gradient-echo sequence with incremented flip angle series and k-space segmentation such that 6 or 8 phase-encoding steps were acquired in rapid sequence, constituting one segment. Sixteen or 20 interleaved segments were acquired so as to complete the 120, 128, or 160 X 256 matrix. A fat saturation pulse was applied prior to each segment so as to null signal from epicardial fat and thus enhance signal from coronary flow. A repetition time (TR) of 13 msec and an echo time (TE) of 8 msec were used with a slice thickness of 4 or 5 mm and 230 mm field-of-view (in-plane resolution of 1.4 - 1.9 mm X 0.9 mm). All imaging was performed within a single breath-hold.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Laminar flow over a small unsteady three dimensional hump

The effect of a small three dimensional hump (whose shape varies some way in time) on an incompressible boundary layer is studied, using extensions to triple deck theory, for a number of regimes of unsteadiness. The effects on both two dimensional and three dimensional boundary layers are considered. These results are used to consider the interaction between a boundary layer and a small vibrating panel, situated on an otherwise flat surface.
Host galaxy bulge predictors of supermassive black hole mass

A variety of host galaxy (bulge) parameters are examined in order to determine their predictive power in ascertaining the masses of the supermassive black holes (SMBHs) at the centers of the galaxies. Based on a sample of 23 nearby galaxies, comprised of both elliptical galaxies and spiral/lenticular bulges, we identify a strong correlation between the bulge gravitational binding energy (Eg), as traced by the stellar light profile, and the SMBH mass (M•), such that M• ∝ E. The scatter about the relationship indicates that this is as strong a predictor of M• as the velocity dispersion (σ), for the elliptical galaxy subsample. Improved mass-to-light ratios, obtained with IFU spectroscopy and I-band photometry by the SAURON group, were used for those sample galaxies where available, resulting in an energy predictor with the same slope, but with reduced scatter. Alternative M• predictors such as the gravitational potential and the bulge mass are also explored, but these are found to be inferior when compared with both the bulge gravitational binding energy and bulge velocity dispersion predictors, for the full galaxy sample.
Simple Fit of Data Relating Supermassive Black Hole Mass to Galaxy Pitch Angle

Seigar et al. have recently demonstrated a new, tight correlation between galactic central supermassive black hole (BH) mass and the pitch angle of the spiral arm in disk galaxies which they attribute to other indirect correlations. They fit a double power law, governed by five parameters, to the BH mass as a function of pitch. Noting the features of their fitted curve, we show that a simple linear proportion of the BH mass to the cotangent of the pitch angle can obtain the same fit, within error. Such a direct, elegant fit may help shed light on the nature of the correlation.
Empirical Constraints on Proton and Electron Heating in the Fast Solar Wind

This paper presents analyses of measured proton and electron temperatures in the high-speed solar wind that are used to calculate the separate rates of heat deposition for protons and electrons. It was found that the protons receive about 60% of the total plasma heating in the inner heliosphere, and that this fraction increases to approximately 80% by the orbit of Jupiter. The empirically derived partitioning of heat between protons and electrons is in rough agreement with theoretical predictions from a model of linear Vlasov wave damping. For a modeled power spectrum consisting only of Alfvenic fluctuations, the best agreement was found for a distribution of wavenumber vectors that evolves toward isotropy as distance increases.
Designing a collection development plan for SailorSM

From a simple idea came a library network that only ever wanted to connect Marylanders to their libraries and the resources they offered. What SailorSM has become is a national model for public libraries and state planning telecommunications networks and library systems integration. Policies for network development of hardware and software, as well as content, are essential. Summarizes the design and implementation of a small, but critical, part of SailorSM, that of collection development of Internet resources.
The Existence of Steady States in Multisector Capital Accumulation Models with Recursive Preferences

Abstract This paper proves the existence of a non-trivial stationary optimal path in a multi-sectoral capital accumulation model with recursive preferences. The reduced-form recursive preferences are represented by an aggregator funtion. I introduce a new form ofδ-normality that is appropriate for use with recursive preferences. Under some mild conditions on the aggregator, non-trivial steady states exist when the technology is bounded andδ-normal.Journal of Economic LiteratureClassification Numbers: D90, C61, C62.
Global-Scale Winds at the Venus Cloud-Top Inferred from Cloud Streak Orientations

Abstract The orientations of the small cloud streaks that are always found at mid-latitudes in ultraviolet images of the Venus cloud-top provide a means for characterizing the global-scale circulation, including the wind field on the night side of Venus. Assuming that small clouds act as passive tracers of the cloud-top wind field, the orientation of cloud streaks is determined by the wind shear that the cloud has recently experienced. The typical deformation time for small clouds is about 50 hr, or one-half of a cloud-top rotation, so clouds viewed on the sunlit half of Venus show the influence of daytime and nighttime winds. By recording the orientations of cloud streaks and their variation with local solar time, we for the first time use cloud orientation information to place a constraint on the amplitudes of the Hadley circulation and solar thermal tides at the cloud-top level. A large solar thermal tide with a cloud-top meridional wind amplitude at 45° latitude of between 5.5–10.5 m sec −1 is found to be necessary to account for the observed variation with local solar time of cloud streak orientations. Maximum poleward tidal winds occur in the early afternoon. The cloud-top Hadley circulation is estimated to have an amplitude at 45° latitude of between 3.5 and 8.5 m s −1 . This means the Hadley circulation may not be the dominant contributor to cloud-top meridional velocities, and that equatorward meridional velocities may exist over a portion of the night side at the Venus cloud-top.
Synthesis of Stair-Stepped Polymers Containing Dibenz[a,h]anthracene Subunits

Polycyclic aromatic monomers based on substituted dibenz[a,h]anthracene frameworks have been prepared in high yields. From these, several fluorescent stair-stepped conjugated polymers containing fused aromatic subunits have been synthesized via Sonogashira polycondensations and Glaser-type oxidative couplings. The new polymers were characterized by NMR spectroscopy, gel-permeation chromatography (GPC), UV−vis, and fluorescence spectroscopy.
Structure and arithmetic complexity of products and inverses of Toeplitz matrices

We derive a formula for the product of two Toeplitz matrices that is similar to the Trench formula for the inverse of a Toeplitz matrix. We then derive upper and lower bounds for number of multiplications required to compute the inverse or the product of Toeplitz matrices and consider several special cases, e.g., symmetry, as well. The lower bounds for the general cases are in agreement with earlier results, but the specialized lower bounds and all the upper bounds are new. Both upper and lower bounds are O(n2) and differ only in lower order terms.
Complete RNA inverse folding: computational design of functional hammerhead ribozymes

Nanotechnology and synthetic biology currently constitute one of the most innovative, interdisciplinary fields of research, poised to radically transform society in the 21st century. This paper concerns the synthetic design of ribonucleic acid molecules, using our recent algorithm, RNAiFold, which can determine all RNA sequences whose minimum free energy secondary structure is a user-specified target structure. Using RNAiFold, we design ten cis-cleaving hammerhead ribozymes, all of which are shown to be functional by a cleavage assay. We additionally use RNAiFold to design a functional cis-cleaving hammerhead as a modular unit of a synthetic larger RNA. Analysis of kinetics on this small set of hammerheads suggests that cleavage rate of computationally designed ribozymes may be correlated with positional entropy, ensemble defect, structural flexibility/rigidity and related measures. Artificial ribozymes have been designed in the past either manually or by SELEX (Systematic Evolution of Ligands by Exponential Enrichment); however, this appears to be the first purely computational design and experimental validation of novel functional ribozymes. RNAiFold is available at http://bioinformatics.bc.edu/clotelab/RNAiFold/.
High-dose carbon ion implantation studies in silicon

Abstract The electrical properties of crystalline silicon (c-Si) subjected to high-dose (10 17 cm -2 ) implantation of carbon with varying post-anneal conditions have been investigated. The electrical barrier formation and carrier transport across the implanted layer have been studied using metal-implanted layer-silicon structures. In the as-implanted samples, a Schottky diode-like behavior is seen but with a very high diode ideality factor. The well-known influence of ion damage on the silicon surface barrier is clearly evident, but in addition we see the domination of transport by an Si-C buried layer formed after annealing. Spectroscopic ellipsometry measurements and FTIR spectroscopy confirm the formation of buried Si-C.
Representations of robustly stabilizing controllers for systems with parameter uncertainty

In this paper we consider the problem of robust stabilization for systems with parameter uncertainty. We first formulate a design methodology and then demonstrate how it leads to analytical and graphical solutions. We show that in the case of SISO plant families with linear uncertainty and, two-parameter compensators, one can obtain a representation of all robustly stabilizing controllers of a fixed order. By introducing a ‘rectangular overbound’ of value sets in the complex plane we also show how one can obtain representations of m-parameter robustly stabilizing compensators of a fixed order.
High electric fields in a superconducting RFQ structure

High surface electric fields have been obtained in the first tests of a superconducting RF quadrupole device. The RF quadrupole fields were generated between niobium vanes 6.5 cm in length, with an edge radius of 2 mm and a beam aperture of 6-mm diameter. In tests at 4.2 K, the 64-MHz device operated CW at peak surface electric fields of 128 MV/m. Virtually no electron loading was observed at fields below 100 MV/m. It was possible to operate at surface fields of 210 MV/m in pulses of 1-ms duration using a 2.5-kW RF source. For the vane geometry tested, more than 10 cm/sup 2/ of surface support a field greater than 90% of the peak field. The result indicates that electric fields greater than 100 MV/cm can be obtained over an appreciable area, sufficient for some accelerator applications. It also shows that superconducting RF technology may provide an extended range of options for RF quadrupole design.
Leiter on the Legal Realists

In this essay reviewing Brian Leiter’s recent book Naturalizing Jurisprudence, I focus on two positions that distinguish Leiter’s reading of the American legal realists from those offered in the past. The first is his claim that the realists thought the law is only locally indeterminate – primarily in cases that are appealed. The second is his claim that they did not offer a prediction theory of law, but were instead committed to a standard positivist theory. Leiter’s reading is vulnerable, because he fails to discuss in detail those passages from the realists that inspired past interpretations. My goal is to see how Leiter’s reading fares when these passages are considered. I argue that Leiter is right that the realists’ indeterminacy thesis has only a local scope. Those passages that appear to claim that the law is globally indeterminate actually address three other topics: judicial supremacy, judges’ roles as finders of fact, and the moral obligation to adjudicate as the law commands. With respect to the prediction theory, however, I conclude that Leiter’s position cannot be defended. Indeed the realists offered two ‘prediction’ theories of law. According to the first, which is best described as a decision theory, the law concerning an event is whatever concrete judgment a court will issue when the event is litigated. According to the second, the law is reduced, not to concrete judgments, but to regularities of judicial (and other official) behavior in a jurisdiction. I end this essay with the suggestion that the realists’ advocacy of the second prediction theory indirectly vindicates Leiter’s reading of the realists as prescient jurisprudential naturalists.
Child labor legislation: effective, benign, both, or neither?

This paper explores the relationship between the state-specific child labor legislation and the decline in child labor that occurred in the US between 1880 and 1900. The existing literature that addresses this question uses a difference-in-difference estimation technique. We contribute to this literature in two ways. First, we argue that this estimation technique can produce misleading results due to (a) the possibility of multiplicity of equilibria and (b) the non-linearity of the underlying econometric model. Second, we develop an empirical strategy to identify the mechanism by which the legislation affected child labor decisions. In particular, besides establishing whether the legislation was effective or not, our analysis may determine whether the legislation constituted a benign policy or not, i.e., whether the legislation constrained the behavior of families (not benign) or whether it changed the labor market to a new equilibrium in which families voluntarily respected the law (benign).
Biologically motivated machine intelligence

Biological systems routinely solve problems involving pattern recognition and feature extraction. Such problems do not appear to admit similarly routine algorithmic solutions; the power of biological systems in this regard apparently arises from nonalgorithmic dynamics. It is our intention to explore, and to develop principles of, functional characteristics of natural (biological) intelligence with a view to their realization through an appropriate automation model.
Gradients of Laplacian eigenfunctions on the Sierpinski gasket

We use spectral decimation to provide formulae for computing the harmonic tangents and gradients of Laplacian eigenfunctions on the Sierpinski Gasket. These formulae are given in terms of special functions that are defined as infinite products.
Space-Time Aspects of Quasiparticle Propagation

We discuss how spin–charge separation is realized in a simple double-layer geometry, how mass renormalization affects time-of-flight in compressible Hall states, and how quantum drifts can reveal the effective charge, mass and quantum statistics in incompressible Hall states. We also discuss the possibility of observing the effect of fractional statistics directly in scattering. Finally we propose that, as a result of incompressibility and reflecting the fundamental charge–flux relation, charged probes induce macroscopic rotation of Hall fluids.
Nineteen-electron adducts in the photochemistry of Cp2Fe2(CO)4 (Cp = η5-C5H5)

La reaction inverse de la dismutation peut etre evitee par reaction d'un des produits. Mecanisme de la dismutation mettant en jeu des composes d'addition a 19 electrons qui sont des reducteurs puissants
Quantum-enhanced positioning and clock synchronization

A wide variety of positioning and ranging procedures are based on repeatedly sending electromagnetic pulses through space and measuring their time of arrival. The accuracy of such procedures is classically limited by the available power and bandwidth. Quantum entanglement and squeezing have been exploited in the context of interferometry1,2,3,4,5, frequency measurements6, lithography7 and algorithms8. Here we report that quantum entanglement and squeezing can also be employed to overcome the classical limits in procedures such as positioning systems, clock synchronization and ranging. Our use of frequency-entangled pulses to construct quantum versions of these protocols results in enhanced accuracy compared with their classical analogues. We describe in detail the problem of establishing a position with respect to a fixed array of reference points.
Secure communication via quantum illumination

In the quantum illumination protocol for secure communication, Alice prepares entangled signal and idler beams via spontaneous parametric downconversion. She sends the signal beam to Bob, while retaining the idler. Bob imposes message modulation on the beam he receives from Alice, amplifies it, and sends it back to her. Alice then decodes Bob's information by making a joint quantum measurement on the light she has retained and the light she has received from him. The basic performance analysis for this protocol--which demonstrates its immunity to passive eavesdropping, in which Eve can only listen to Alice and Bob's transmissions--is reviewed, along with the results of its first proof-of-principle experiment. Further analysis is then presented, showing that secure data rates in excess of 1 Gbps may be possible over 20-km-long fiber links with technology that is available or under development. Finally, an initial scheme for thwarting active eavesdropping, in which Eve injects her own light into Bob's terminal, is proposed and analyzed.
Performance evaluation of optical mesh restoration schemes

This paper investigates the performance of various schemes for restoration of lightpaths in an optical mesh network. We consider schemes in which backup paths for links or paths are pro-computed, but wavelength assignment is either pro-computed (static) or done dynamically upon failure (dynamic). In static restoration we compare the performance of link and path restoration in terms of capacity requirement and restoration time. For the dynamic restoration, we consider several dynamic wavelength reservation schemes such as backward and forward reservation with different portion of wavelength to be reserved in both directions. Their performance is evaluated in terms of restoration speed and restorability. Simulation results indicate that path protection requires less capacity than link protection for 100% restorability, and dynamic restoration with backward wavelength reservation shows better restorability than static restoration schemes, when the extra capacity is relatively small. Forward wavelength reservation shows faster restoration speed with lower restorability than the backward wavelength reservation. In general, the optimal restoration scheme depends on extra capacity available and restoration time limit.
Singularities of Cox rings of Fano varieties

Abstract We show that the Cox ring of a smooth complete Fano variety over the complex numbers has Gorenstein canonical singularities.
Metal-catalyzed silacyclopropanation of mono- and disubstituted alkenes.

As an alternative to the strongly reducing conditions necessary for the formation of silacyclopropanes, silylene transfer was developed as a mild, functional group tolerant method of silacyclopropanation. Complex silacyclopropanes were formed from functionalized alkenes using cyclohexane di-tert-butyl silacyclopropane, 1, as the source of t-Bu2Si. Di-tert-butyl silylene can be generated from 1 through the use of a catalytic amount of a metal salt. At −27 °C, silver triflate catalyzes the transfer of t-Bu2Si from 1 to mono- and disubstituted alkenes stereospecifically and diastereoselectively. In situ functionalization of silacyclopropanes with catalytic zinc bromide and methyl formate provides for an expedient one-flask synthesis of complex oxasilacyclopentanes from alkenes.
Active intermediation in a monetary overlapping generations economy

Abstract This paper establishes that the profit-seeking activities of private intermediaries can ensure Pareto efficiency in the standard pure-exchange monetary overlapping generations economy without the need for government monetary or fiscal policy intervention. Moreover, these profit-seeking activities are shown to rule out all aperiodic and k -periodic cycles for k greater than 2. Contrary to much recent work on intermediation, the profit opportunities that arise for intermediaries in this context are not due to assumed frictions or asymmetric information. Rather, they are due to the dynamic open-ended structure of the economy, which permits debt roll-over.
Maximum likelihood degree of variance component models

Most statistical software packages implement numerical strategies for computation of maximum likelihood estimates in random effects models. Little is known, however, about the algebraic complexity of this problem. For the one-way layout with random effects and unbalanced group sizes, we give formulas for the algebraic degree of the likelihood equations as well as the equations for restricted maximum likelihood estimation. In particular, the latter approach is shown to be algebraically less complex. The formulas are obtained by studying a univariate rational equation whose solutions correspond to the solutions of the likelihood equations. Applying techniques from computational algebra, we also show that balanced two-way layouts with or without interaction have likelihood equations of degree four. Our work suggests that algebraic methods allow one to reliably find global optima of likelihood functions of linear mixed models with a small number of variance components.
In polytopes, small balls about some vertex minimize perimeter

In (the surface of) a convex polytope Pn in ℝn+1, for small prescribed volume, geodesic balls about some vertex minimize perimeter.
Universal point sets for planar three-trees

For every n ź N , we present a set S n of O ( n 3 / 2 log ź n ) points in the plane such that every planar 3-tree with n vertices has a straight-line embedding in the plane in which the vertices are mapped to a subset of S n . This is the first subquadratic upper bound on the cardinality of universal point sets for planar 3-trees, as well as for the class of 2-trees and serial parallel graphs.
Non-triviality of the A-polynomial for knots in S^3

The A-polynomial of a knot in S^3 defines a complex plane curve associated to the set of representations of the fundamental group of the knot exterior into SL(2,C). Here, we show that a non-trivial knot in S^3 has a non-trivial A-polynomial. We deduce this from the gauge-theoretic work of Kronheimer and Mrowka on SU_2-representations of Dehn surgeries on knots in S^3. As a corollary, we show that if a conjecture connecting the colored Jones polynomials to the A-polynomial holds, then the colored Jones polynomials distinguish the unknot.
The public sector and health care

This paper specifies a model of the determinans of total expenditure on health care. The model shows how this expenditure is divided between the public and private sectors when public expenditures are chosen by majority rule. From the theoretical model I derive two equations determining the private and public expenditures on health care as shares of GDP. The equations are estimated using OECD panel data with two-way fixed effects and with simultaneous correction for heteroeskedasticity and serial correlation. The results include estimates of the price and income elasticities of public and private demands for health care as well as estimates of the crowdingout effects of public on private expenditures.
Name disambiguation from link data in a collaboration graph

The entity disambiguation task partitions the records belonging to multiple persons with the objective that each decomposed partition is composed of records of a unique person. Existing solutions to this task use either biographical attributes, or auxiliary features that are collected from external sources, such as Wikipedia. However, for many scenarios, such auxiliary features are not available, or they are costly to obtain. Besides, the attempt of collecting biographical or external data sustains the risk of privacy violation. In this work, we propose a method for solving entity disambiguation task from link information obtained from a collaboration network. Our method is non-intrusive of privacy as it uses only the time-stamped graph topology of an anonymized network. Experimental results on two real-life academic collaboration networks show that the proposed method has satisfactory performance.
The Emergence of Corporate Governance from Wall St. to Main St.: Outside Directors, Board Diversity, Earnings Management, and Managerial Incentives to Bear Risk

Recent corporate events have brought a heightened public awareness to corporate governance issues. Much work has been accomplished to date, but it is clear that much more remains to be done. This paper provides a review of empirical research in four relevant areas of corporate governance. Specifically, the paper provides an overview of (a) the role that outside directors play in monitoring managers, (b) the emerging literature on the impact of board diversity, (c) the existence of and incentives for corporate executives to manage firm earnings, and (d) managerial incentives to bear risk.
High-Temperature Gaseous Corrosion of Si3N4 in H2–H2O and Ar–O2 Environments

Samples of Si3N4 made by chemical vapor deposition (CVD) and hot isostatic pressing (HIP) were exposed for 10 h at 1400°C to H2–H2O and Ar–O2 environments. Variations in weight and surface morphology of the CVD-Si3N4 samples were monitored to determine the corrosion behavior of ‘pure’ Si3N4 as baseline information. Additionally, the room-temperature flexural strengths of the HIP-Si3N4 were determined and correlated with observed changes in weight and microstructure. The corrosion behavior of both materials depended on the level of oxidant (H2O or O2) in the atmosphere, but the magnitudes of the weight changes observed in the HIP-Si3N4 were significantly greater. When the PH2O in the H2 atmospheres was low (PH2O < × 10−5 MPa), significant weight loss and surface degradation occurred in both ceramics, accompanied by reductions in strength of the HIP-Si3N4. However, in atmospheres with PH2O 1 × 10−4 MPa, the weight loss was smaller and the strength of the HIP-Si3N4 was greater than that of the as-received material. Somewhat different behavior was observed in samples exposed to Ar–O2 environments. Weight loss of both silicon nitrides increased with increasing Po2 until a level of about 2 × 10−5 MPa was reached. However, contrary to the results for H2–H2O exposures, even under these conditions the strength of the HIP-Si3N4 material was found to have increased above that of the as-received material.
Evidence for a long range structure in the pion emission source in Au+Au collisions at RHIC

The PHENIX experiment has recently acquired ∼1 billion minimum bias Au+Au events at s = 200 AGeV during the year-2004 run. This high statistics data set, coupled with a state-of-the-art analysis technique, allows for the extraction of 3D emission sources for various particle types. These 3D sources lend fresh insight into the nature of a long-range source previously reported by PHENIX. The new results indicate an anisotropic pion emission source in the pair center of mass system (PCMS) having an extended space-time extent oriented in the outward direction. The two-proton emission source from the same data set is essentially isotropic in the PCMS. These results provide a “window” for viewing the evolution dynamics of the high energy density nuclear matter created at RHIC.
Suppression during binocular rivalry broadens orientation tuning

During binocular-rivalry suppression, an ordinarily visible stimulus is erased from awareness, but how is the sensory representation of that stimulus affected? Although it is established that rivalry suppression attenuates signal strength, the influence of suppression on signal fidelity remains unknown. Here, we show that noise plays a hitherto undiscovered role in the degradation of the percept under suppression. In Experiment 1, we measured psychometric functions for a stimulus presented under dominance and suppression, and found that the slope of these functions was shallower under suppression—a result suggesting that the signal representation was rendered noisier. Experiment 2 then revealed the source of this noise: An examination of the influence of suppression on the orientation bandwidth of noise masking showed that tuning bandwidth is significantly broadened under suppression. Thus, the discriminability of a suppressed stimulus is weakened not only by a general decrease in signal strength, but als...
Holography in the Penrose limit of AdS space

Abstract We discuss the Penrose limit of pure AdS space, which is flat Minkowski space. Even though there is no holographic principle, we construct a “holographic screen” on which information on the corresponding CFT is encoded. The screen is obtained as a gauge-fixing condition upon restricting the Hilbert space to the states that are annihilated by the generator of scale transformations. This constraint leads to Dirac brackets which turn the Poincare algebra into the algebra of the conformal group on the “holographic screen”.
Service Escape: Profiting from Customer Cancellations

This paper explores the benefits of letting customers escape from prepurchased service contracts by offering refunds for cancellations. We show that such a policy creates opportunities for multiple selling in a capacity-constrained service---i.e., collecting cancellation fees from advance buyers who cancel, and then reselling the freed slots. The better the alternative that motivates a cancellation, the more profitable is a refund-for-cancellations policy compared with a no-refund policy that “locks in” customers. In contrast to previous research on money-back guarantees for durable goods, we show that offering refunds for service cancellations can be profitable (1) without charging a higher price compared with a no-refund policy, and (2) even when advance buyers would be willing to abandon the service for no refund. Also, service providers should decrease rather than increase the customer hassle cost of cancellations. Our research also suggests a new profit advantage of advance selling, i.e., capturing some of the consumer-added surplus created when customers find new alternatives (and are therefore willing to pay a fee to terminate the prepurchased contract). Finally, yield-management research typically assumes exogenous “no shows” by advance buyers. We suggest that offering refunds for cancellation reduces the need to reserve capacity for high-paying customers and improves capacity utilization.
Governance as a global development goal? Setting, measuring and monitoring the Post-2015 Development Agenda

The increasing realisation that governance quality is a fundamental element of long-run development has led to its consideration as a desirable development goal in its own right. To contribute to such a process, this paper provides a framework to set, measure and monitor governance goals in the Post 2015 Development Agenda. First, we assess whether existing cross-national measures on governance quality can be exploited to measure and monitor aspects of legal, bureaucratic and administrative quality. Such a �quick fix� approach to measuring governance quality is fraught with challenges. The current practice of measurement is still subject to the short country coverage of most available measures, issues of comparability and legitimacy, as well as methodological shortcomings. Second, we argue that, in the long run, measuring and monitoring governance quality may require reconceptualising �good governance� and designing internationally shared measures that are routinely provided by national statistical offices, (but, international groups should also continue to make their independent measures). Finally, we consider the different approaches to setting governance goals, arguing in favour of a combination of national target setting and minimum standard with continuous improvement.
Heterocyclic sulfoxide and sulfone inhibitors of fatty acid amide hydrolase

A novel series of heterocyclic sulfoxides and sulfones was prepared and examined as potential inhibitors of fatty acid amide hydrolase (FAAH), the enzyme responsible for inactivation of neuromodulating fatty acid amides including anandamide and oleamide.
Electromechanical study of carbon fiber composites

Electromechanical testing involving simultaneous electrical and mechanical measurements under load was used to study the fiber-matrix interface, the fiber residual compressive stress, and the degree of marcelling (fiber waviness) in carbon fiber composites. The interface study involved single fiber pull-out testing while the fiber-matrix contact electrical resistivity was measured. The residual stress study involved measuring the electrical resistance of a single fiber embedded in the matrix while the fiber was subjected to tension through its exposed ends. The marcelling study involved measuring the electrical resistance of a composite in the through-thickness direction while tension within the elastic regime was applied in the fiber direction.
They Come To Play Supply Effects in an Economic Experiment

Our experiment challenges the standard, social preference, interpretation of choices in the double blind dictator game played in the lab without any context. We present treatments formulated to minimize the social preference reasons to give and, despite this, the allocations are identical to our replication of the standard double blind game, implying that altruism might be the wrong interpretation of giving. Instead, we hypothesize that giving might be driven by participants coming to the lab ready ‘to play’. The fact that there are strong correlations between participant responses to an attention deficit, hyperactivity disorder questionnaire and both the rate and level of giving provides direct support for the hypothesis that lab participants impulsively give money away. However, we also show that having players earn their endowments attenuates the bias.
The impact of illegal insider trading in dealer and specialist markets: evidence from a natural experiment ☆

Abstract We examine insider trading in specialist and dealer markets, using the trades of stock brokers who had advance copies of a stock analysis column in Business Week magazine. We find that increases in price and volume occur after informed trades. During informed trading, market makers decrease depth. Depth falls more on the NYSE and Amex than on the Nasdaq. Spreads increase on the NYSE and Amex, but not on the Nasdaq. We find none of these pre-release changes in a nontraded control sample of stocks mentioned in the column. Our results show that insider trading has a negative impact on market liquidity; depth is an important tool to manage asymmetric information risk; and specialist markets are better at detecting informed trades.
The Monoplane Occlusion for Complete Dentures

For many years, the manufacturers of artificial teeth chose newly erupted premolars and molars as their models for posterior teeth. Because of the differences that exist between natural and artificial teeth, the zero degree posterior tooth forms offer several advantages for complete dentures. The most important of these is their ability to better adapt to different occlusal relationships that result from the gradual, but inevitable, reduction in the height of the supporting ridges.
A field trial on the effect of propylene glycol on displaced abomasum, removal from herd, and reproduction in fresh cows diagnosed with subclinical ketosis

The purpose was to determine the effect of oral propylene glycol (PG) administration in fresh cows diagnosed with subclinical ketosis (SCK). Measured outcomes were development of displaced abomasum (DA) and removal from herd in the first 30 d in milk (DIM), conception to first service, and time to conception within 150 DIM. Cows from 4 freestall dairy herds (2 in New York and 2 in Wisconsin) were each tested 6 times for SCK from 3 to 16 DIM on Mondays, Wednesdays, and Fridays using the Precision Xtra meter (Abbott Laboratories, Abbott Park, IL). Subclinical ketosis was defined as a blood β-hydroxybutyrate concentration of 1.2 to 2.9 mmol/L. Cows with SCK were randomized to treatment group (oral PG) or untreated control group (no PG); treatment cows were orally drenched with 300 mL of PG once daily from the day they tested 1.2 to 2.9 mmol/L until the day they tested <1.2 mmol/L. Mixed effects multivariable Poisson regression was used to assess the effect of PG on DA, removal from herd, and conception to first service; a semiparametric proportional hazards model was used to evaluate the days-to-conception outcome. A total of 741 of 1,717 (43.2%) eligible enrolled cows had at least 1 β-hydroxybutyrate test of 1.2 to 2.9 mmol/L. Of these, 372 were assigned to the PG treatment group and 369 to the control group. Thirty-nine cows (5.3%) developed a DA after testing positive for SCK and 30 cows (4.0%) died or were sold within the first 30 DIM. Based on risk ratios, control cows were 1.6 times more likely [95% confidence interval (CI)=1.3 to 2.0] to develop a DA and 2.1 times more likely (95% CI=1.2 to 3.6) to die or be sold than cows treated with PG. In addition, PG-treated cows were 1.3 times more likely (risk ratio 95% CI=1.1 to 1.5) to conceive at first insemination than control cows in 3 of the herds. No difference was observed in days to conception within 150 DIM between treatment groups (hazard ratio for PG cows=1.1, 95% CI=0.8 to 1.4), with a median time to conception of 100 d (95% CI=93 to 111) and 104 d (95% CI=95 to 114) for PG-treated and control cows, respectively. These results show that intensive detection of SCK, followed by treatment of positive cows with oral PG decreased the risk of developing a DA or leaving the herd within the first 30 DIM and increased the risk of conception to first service.
Equivalent network representation for high efficiency corrugated blaze grating

An equivalent network representation is derived for a rectangular corrugation profile grating that has been shown recently to exhibit surprisingly large blaze effect. Under proper conditions, up to 100% power conversion takes place between the incident wave and a single diffracted spectral order. The results herein show that this blaze effect can be attributed to a half-wavelength resonance in the corrugation region. Based on the equivalent network representation, a design procedure has been derived that yields the grating profile parameters (d,h) necessary to achieve the 100% conversion effect.
Entropic Elasticity of Twist-Storing Polymers

We investigate the statistical mechanics of a torsionally constrained polymer. The polymer is modeled as a fluctuating rod with bend stiffness AkBT and twist stiffness CkBT. In such a model, thermal bend fluctuations couple geometrically to an applied torque through the relation Lk = Tw + Wr. We explore this coupling and find agreement between the predictions of our model and recent experimental results on single λ-DNA molecules. This analysis affords an experimental determination of the microscopic twist stiffness (averaged over a helix repeat). Quantitative agreement between theory and experiment is obtained using C = 109 nm (i.e., twist rigidity CkBT = 4.5 × 10-19 erg cm). The theory further predicts a thermal reduction of the effective twist rigidity induced by bend fluctuations. Finally, we find a small reflection of molecular chirality in the experimental data and interpret it in terms of a twist−stretch coupling of the DNA duplex.
Race analysis of traces of asynchronous message-passing programs

An execution of a message-passing program is nondeterministic if message races exist. In this paper, a formal definition of a message race for asynchronous communication is presented. The trace of an execution of a message-passing program is a sequence of send and receive events. For a receive event r in a trace T, its race set is the set of messages in T that have a race with the message received at r and can be received at r during some possible executions of the same program with the same input. A race analysis algorithm analyzes a trace to determine the race set for each receive event in the trace. Three race analysis algorithms are given for three different types of sequences of send and receive events. It is shown that these race analysis algorithms can be used to solve a number of problems in testing and debugging message-passing programs.
Practical synthesis of bis-homoallylic alcohols from dialdehydes or their acetals

Bis-homoallylic alcohols were prepared in good yields by allylation of dialdehydes or their acetals with allyl bromide, tin(II) chloride and potassium iodide in water or water/THF.
Conformal Dimension And Random Groups

We give a lower and an upper bound for the conformal dimension of the boundaries of certain small cancellation groups.
Identification of a Force-Sensing Resistor for Tactile Applications

A force-sensing resistor is a conductive polymer that exhibits a decrease in resistance as the force applied at its surface increases. The aim of this study is to identify the characteristics of th...
A 1/3'' VGA linear wide dynamic range CMOS image sensor implementing a predictive multiple sampling algorithm with overlapping integration intervals

Many tasks performed by machine vision systems involve processing of natural scenes with large intra-frame illumination ratios. Thus, wide dynamic range visible spectrum image sensors are required to achieve adequate processing performance and reliability. An image sensor implementing an algorithm that linearly increases the illumination dynamic range of solid-state pixels is presented. Optimal exposure is achieved with a predictive pixel saturation decision that allows for multiple integration intervals of different duration to run concurrently for different pixels while keeping the sensor frame rate constant. A proof-of-concept chip was fabricated in a 0.18-/spl mu/m CMOS process. Added functionality to standard imagers is mainly concentrated off-pixel so fill factor is not sacrificed. Measured data corroborates the algorithm functionality.