cssi/SciSciGPT-SciSciNet huggingface dataset:
A novel algorithm for material discrimination using a dual energy imaging system

Dual energy imaging is a technique whereby an object is scanned with X-rays of two interleaved energies to extract information about the object's atomic composition (Z). This technique is based on the fact that the X-ray absorption coefficient decreases with X-ray energy for low-Z materials, but begins to increase for high-Z materials due to the onset of pair production. Methods using the ratio of the attenuations of high-energy to low-energy images as an indicator of Z value have been proposed by several people. However, the statistical errors associated with the systems make those indicators unreliable. Methods that calculate the probability of high Z encounter a problem of what is the threshold probability to call high Z to minimize both miss and false alarm. We have developed an "adaptive regional masking" method that avoids the predicament of a single threshold. Our method is adaptive because the threshold for determining high Z varies adaptively in different regions on the image. The "mask" refers to the location of objects in the thickness map that mask to possible high-Z regions. Adaptive thresholding improves detection, while masking reduces false alarms. Test results show an increased accuracy of high-Z detection using this approach. In this paper, we discuss the approach and show some sample test results illustrating the effectiveness of the method.
Spacecraft thermal blanket cleaning - Vacuum baking or gaseous flow purging

The mass losses and the outgassing rates per unit area of three thermal blankets consisting of various combinations of Mylar and Kapton, with interposed Dacron nets, were measured with a microbalance using two methods. The blankets at 25 deg C were either outgassed in vacuum for 20 hours, or were purged with a dry nitrogen flow of 3 cu. ft. per hour at 25 deg C for 20 hours. The two methods were compared for their effectiveness in cleaning the blankets for their use in space applications. The measurements were carried out using blanket strips and rolled-up blanket samples fitting the microbalance cylindrical plenum. Also, temperature scanning tests were carried out to indicate the optimum temperature for purging and vacuum cleaning. The data indicate that the purging for 20 hours with the above N2 flow can accomplish the same level of cleaning provided by the vacuum with the blankets at 25 deg C for 20 hours, In both cases, the rate of outgassing after 20 hours is reduced by 3 orders of magnitude, and the weight losses are in the range of 10E-4 gr/sq cm. Equivalent mass loss time constants, regained mass in air as a function of time, and other parameters were obtained for those blankets.
Children’s cognitive skill development in Britain and the United States

This paper compares the cognitive test scores of children in Great Britain and the United States in vocabulary, reading, mathematics, and memory of words and numbers. Children aged 5–9 years in Britain systematically outperform their US counterparts on reading and mathematics tests, while children aged 10–14 years show far fewer differences. In most comparisons for white children aged 10–14 years, there are no statistical differences in the distributions of test scores between the British and United States children. The explanation for the observed differences between the younger children in the two nations in reading and mathematics may be the earlier age of entry into formal schooling in Britain. The similarity of the observed skills of the older children in the two nations, given the differences in social and economic conditions experienced by those children, challenges the notion that these differences are critically important in the children’s cognitive development. The six tests used in this study a...
Contact handle decompositions

Abstract We review Giroux's contact handles and contact handle attachments in dimension three and show that a bypass attachment consists of a pair of contact 1 and 2-handles. As an application we describe explicit contact handle decompositions of infinitely many pairwise non-isotopic overtwisted 3-spheres. We also give an alternative proof of the fact that every compact contact 3-manifold (closed or with convex boundary) admits a contact handle decomposition, which is a result originally due to Giroux.
Generalized uniform covering maps relative to subgroups

Abstract In “Rips complexes and covers in the uniform category” (Brodskiy et al., preprint [4] ) the authors define, following James (1990) [5] , covering maps of uniform spaces and introduce the concept of generalized uniform covering maps. Conditions for the existence of universal uniform covering maps and generalized uniform covering maps are given. This paper extends these results by investigating the existence of these covering maps relative to subgroups of the uniform fundamental group and the fundamental group of the base space.
Preparation and Characterization of Oil-Dosed Phases Created by Supercritical Fluid on Polymer Materials

Ultra-high molecular weight polyethylene (UHMWPE) and polyamide 66 (PA66) were used as model polymers in order to conduct research on the preparation and characterization of oil-dosed phases created by supercritical fluid on polymer materials. Dioctyl adipate (DOA, Mw = 370) and alkyldiphenylether (ADE, Mw = 440) were the lubrication oils used to impregnate the polymer. Oil impregnation conditions were controlled to between 40 and 150°C and 10 and 20 MPa in a supercritical carbon dioxide (scCO2) environment. Experimental results showed that the total amount of oil impregnation correlated with processing temperature and duration. After impregnation, phases with a crystal structure different from the inside were observed on the polymer surface areas. The depth profile and chemical distribution of oil-dosed phases by scCO2 impregnation were analyzed using Fourier-transform infrared (FTIR) spectroscopy. FTIR spectroscopy results have shown that it is possible to create phases having high concentrations of lub...
On J-orders of elements of $KO(CP^{m})$

Let $KO(CP^m)$ be the KO-ring of the complex projective space $CP^m.$ By means of methods of rational D-series, a formula for the J-orders of elements of $KO(CP^m)$ is given. Explicit formulas are given for computing the J-orders of the canonical generators of $KO(CP^m)$ and the J-order of any complex line bundle over $CP^m.$
General relativistic geodetic spin precession in binary pulsar b1913+16: mapping the emission beam in two dimensions

We have carefully measured the pulse profile of the binary pulsar PSR B1913+16 at 21 cm wavelength for 20 years, in order to search for variations that result from general relativistic geodetic precession of the spin axis. The profile width is found to decrease with time in its inner regions, while staying essentially constant on its outer skirts. We fitted these data to a model of the beam shape and precession geometry. Four equivalent solutions are found, but evolutionary considerations and polarization data select a single preferred model. While the current data sample only a limited range of latitudes owing to the long precessional cycle, the preferred model shows a beam elongated in the latitudinal direction and hourglass-shaped.
Synthesis, structure, and properties of Ca2ZnN2

Abstract We report the synthesis and physical properties of the new ternary nitride Ca2ZnN2, prepared by the reaction of Ca3N2 and Zn in N2 gas at 680°C. The structure, determined by X-ray powder diffraction and refined by Rietveld profile analysis, is tetragonal ( I4 mmm ) with a = 3.5835(4) A, c = 12.6583(7) A, and Z = 2. The structure features condensed nitrogen-centered metal octahedra and a linear coordination of Zn by two nitrogen atoms. Conductivity and magnetic measurements show that Ca2ZnN2 is insulating and diamagnetic.
Diffusion-limited binding explains binary dose response for local arterial and tumour drug delivery.

Background: Local drug delivery has transformed medicine, yet it remains unclear how drug efficacy depends on physicochemical properties and delivery kinetics. Most therapies seek to prolong release, yet recent studies demonstrate sustained clinical benefit following local bolus endovascular delivery. Objectives: The purpose of the current study was to examine interplay between drug dose, diffusion and binding in determining tissue penetration and effect. Methods: We introduce a quantitative framework that balances dose, saturable binding and diffusion, and measured the specific binding parameters of drugs to target tissues. Results: Model reduction techniques augmented by numerical simulations revealed that impact of saturable binding on drug transport and retention is determined by the magnitude of a binding potential, Bp, ratio of binding capacity to product of equilibrium dissociation constant and accessible tissue volume fraction. At low Bp ( 40), drug transport exhibits threshold dependence on applied surface concentration. Conclusions: In this paradigm, drugs and antibodies with large Bp penetrate faster and deeper into tissues when presented at high concentrations. Threshold dependence of tissue transport on applied surface concentration of paclitaxel and rapamycin may explain threshold dose dependence of in vivo biological efficacy of these drugs.
Evidence for Stellar Streaming in the Cores of Elliptical Galaxies: A Kinematic Signature of Mergers?

We present evidence for non-Gaussian velocity fields within the cores of luminous elliptical galaxies. This evidence is based on high signal-to-noise ratio, medium-resolution spectroscopy of the cores of early-type members of the Virgo and Coma Clusters obtained with the Wisconsin-Indiana-Yale-NOAO 3.5 m telescope. The Virgo data were acquired using an integral-field unit (DensePak), which allows the velocity field to be sampled over a variety of spatial scales. The Coma data were obtained through single 2'' diameter fibers. The cross-correlation profiles of luminous elliptical galaxies show considerable structure, often having several features with amplitudes as high as 10% that of the cross-correlation peak itself. This structure is most obvious within a radius of 15 (at Virgo), or ≤100 pc, and is nearly undetectable when the data are binned over R < 15'', or ≤1 kpc. Similar features are found in the single-fiber spectra of the luminous elliptical galaxies in the Coma Cluster, suggesting that they are ubiquitous in giant elliptical galaxies. Interestingly, only the most luminous elliptical galaxies show these phenomena; the central regions of lower luminosity elliptical galaxies have regular Gaussian-like profiles. We interpret this kinematic structure as "stellar streaming" and suggest that these phenomena could be a relic signature of the merger history of luminous elliptical galaxies.
A PHOTON-COUNTING MULTICHANNEL SPECTROMETER.

A multichannel detector system is described in which the positions of individual photon events in a high-gain image intensifier are decoded in the output of a video detector. The high-gain intensifier consists of a pair of three-stage electrostatic image-tube assemblies each containing three fiber-optically-coupled tubes potted in a rugged package with an internal high-voltage supply. Operation of the electrooptical system is discussed along with the pulse-detection process and the operation of the spectrograph in which the image-tube assembly is mounted. It is noted that the spectrometer detects 1.0 count/sec per A for an object of magnitude 13.0 at the peak of its response in the visual band when no light is lost on the slit, that a 10% coincidence correction is reached at an overall count rate of 860 per sec, and that the response follows an exponential law up to count rates of about 4000 per sec. The measured spectrum of the Seyfert galaxy NGC 5548 is provided as an example of the raw data produced by the instrument on a 1.5 meter telescope.
One-Pot Synthesis of 3-Azido- and 3-Aminopiperidines by Intramolecular Cyclization of Unsaturated Amines

A highly efficient one-pot synthesis of 3-azidopiperidines has been achieved by an intramolecular cyclization of unsaturated amines that allows for the nucleophilic installation of an azide moiety. This method unlocks the versatile employment of the azide functionality in the preparation and biological studies of piperidine-containing structures. This strategy has been expanded for the direct incorporation of a variety of nitrogen nucleophiles, and thus it provides a rapid and modular synthesis of 3-amino and 3-amidopiperidines of important pharmaceutical and biological relevance. Particularly noteworthy is that the regioselectivity of this transformation enables the formation of the anti-Markovnikov-type adduct, complementing Markovnikov-based olefin amino functionalization methods.
Disparity between symptomatic and physiologic outcomes following esophageal lengthening procedures for antireflux surgery.

Although esophageal lengthening procedures (Collis gastroplasty) have been recommended as an adjunct to antireflux surgery in patients with shortened esophagus, there are few data on physiologic outcomes in these patients. This study details the long-term outcomes in patients who underwent antireflux surgery with Collis gastroplasty. All patients undergoing esophagogastric fundoplication (EGF) with a Collis gastroplasty for the management of gastroesophageal reflux disease or paraesophageal hernia were identified from a prospectively maintained database. Symptom questionnaires were used during followup to assess symptomatic outcomes. Barium esophogram, upper endoscopy with biopsy, and catheterless esophageal acid monitoring (BRAVO system) were recommended for all patients. Patients with abnormal results of physiologic studies underwent further treatment based on a standardized algorithm. Between 1996 and 2002, a total of 68 patients underwent EGF with Collis gastroplasty. Twenty-seven (40%) had a large paraesophageal hernia, and 20 (30%) had undergone a prior EGF. Fifty-six (82%) of the procedures were performed laparoscopically. Mean follow-up time was 30 months, with 10 (15%) patients lost to latest follow-up. Symptomatic outcome data were available for 85% of patients, with significant improvements reported for heartburn (86%), chest pain (90%), dysphagia (89%), and regurgitation (91%). Most patients (84%) were off medications. Physiologic data were completed in 37% of the patients. Of those undergoing physiologic follow-up studies, 17% had recurrent hiatal hernia, and 80% had endoscopically identified esophagitis and pathologic esophageal acid exposure on pH testing. Despite this, 65% of the patients with objectively identified abnormalities reported significant symptomatic improvement compared to their preoperative symptoms. Two patients developed changes associated with Barrett’s esophagus that were not present preoperatively. Distal esophageal injury can persist after EGF with Collis gastroplasty, despite significant symptomatic improvements. Appropriate follow-up in these patients requires objective surveillance, which should eventuate in further treatment if esophageal acid is not completely controlled. Although the Collis gastroplasty is conceptually appealing, these results call into question the liberal application of this technique during EGF.
Drug-induced psoriasis: results from pharmacovigilance tools under investigation.

A recent publication 1 by Dika et al. reviewed the literature (mainly consisting of case reports and cases series) on drug-induced psoriasis. They provided probability scores (Psoriatic Drug Erupti...
Observations of Thermal Plasma in a Solar Limb Flare

All but a small portion of the top of the 1991 October 21 flare was occulted by the solar limb. Thus, both the Bragg crystal spectrometer (BCS) and the soft X-ray telescope (SXT) on Yohkoh observed only a small region of flaring plasma. Using observations from those instruments, we have determined the temporal behavior of the emission measure, temperature, and nonthermal broadening in the loop-top source. We find that for a portion of the decay phase of this flare, the temperatures determined using the Fe XXV, Ca XIX, and S XV BCS channels and SXT filter ratios all agree. Assuming that the plasma is isothermal, we determine the abundances of Fe XXII, Fe XXIII, and Fe XXIV relative to Fe XXV. Comparing the results with recent ionization equilibrium calculations, we find that there are discrepancies between the Fe XXII-to-Fe XXV ratio, the Fe XXIII-to-Fe XXV ratio, and the Fe XXIV-to-Fe XXV ratio and ionization equilibrium calculations, which we attribute to uncertainties in the ionization balance calculations.
Uranium–lead isotope systematics of Mars inferred from the basaltic shergottite QUE 94201

Abstract Uranium–lead ratios (commonly represented as 238U/204Pb = μ) calculated for the sources of martian basalts preserve a record of petrogenetic processes that were active during early planetary differentiation and formation of martian geochemical reservoirs. To better define the range of μ values represented by the source regions of martian basalts, we completed U–Pb elemental and isotopic analyses on whole rock, mineral and leachate fractions from the martian meteorite Queen Alexandra Range 94201 (QUE 94201). The whole rock and silicate mineral fractions have unradiogenic Pb isotopic compositions that define a narrow range (206Pb/204Pb = 11.16–11.61). In contrast, the Pb isotopic compositions of weak HCl leachates are more variable and radiogenic. The intersection of the QUE 94201 data array with terrestrial Pb in 206Pb/204Pb–207Pb/204Pb–208Pb/204Pb compositional space is consistent with varying amounts of terrestrial contamination in these fractions. We calculate that only 1–7% contamination is present in the purified silicate mineral and whole rock fractions, whereas the HCl leachates contain up to 86% terrestrial Pb. This terrestrial Pb contamination generated a 206Pb–207Pb array in the QUE fractions that appears to represent an ancient age, which contrasts with a much younger crystallization age of 327 ± 10 Ma derived from Rb–Sr and Sm–Nd isochrons (Borg L. E., Nyquist L. E., Taylor L. A., Wiesmann H. and Shih C. -Y. (1997) Constraints on Martian differentiation processes from Rb–Sr and Sm–Nd isotopic analyses of the basaltic shergottite QUE 94201. Geochim. Cosmochim. Acta 61, 4915–4931). Despite the contamination, and accepting 327 ± 10 Ma as the crystallization age, we use the U–Pb data to determine the initial 206Pb/204Pb of QUE 94201 to be 11.086 ± 0.008 and to calculate the μ value of its mantle source to be 1.82 ± 0.01. The μ value calculated for the QUE 94201 source is the lowest determined for any martian basalt source, and, when compared to the highest values determined for martian basalt sources, indicates that μ values in martian source reservoirs vary by at least a factor of two. Additionally, the range of source μ values indicates that the μ value of bulk silicate Mars is approximately three. The amount of variation in the μ values of the mantle sources (μ ∼ 2–4) is greater than can be explained by igneous processes involving silicate phases alone. We suggest the possibility that a small amount of sulfide crystallization may generate greater extents of U–Pb fractionation during formation of the mantle sources of martian basalts.
Optimal Weighting Factor for Single-Step Trapezoidal Method

A new optimal weighting factor for a single-step trapezoidal method, θ = 0.618, has been developed to solve transient linear and nonlinear heat conduction problems. The numerical results based on the optimal weighting factor developed, through both linear and nonlinear benchmark tests, are compared with other commonly used single-step trapezoidal methods with emphasis on the combination of both accuracy and efficiency in the solution. The optimal weighting factor of single-step method has been proved to be very accurate, stable, and efficient. The relevant features for the single-step trapezoidal methods are also addressed.Copyright © 2003 by ASME
A Method for Correlating Severity of Different Seismic Qualification Tests

A general methodology has been developed for correlating the severity of various seismic qualification motions that can have very different dynamic characteristics. The approach is based on a vibrational equivalence concept which allows a severity comparison between two different waveforms. The comparison is in terms of a fragility ratio, which is a ratio of vibrational input level to that which the specific equipment is capable of sustaining at its fragility level. Measurement of the severity at both levels can be characterized in terms of response spectrum, power spectrum, or other parameters which may be used, or have been used, in typical equipment qualification procedures. Relationships among the various parameters are defined so that transformations from one to another are possible.
The Coulomb branch of N = 1 supersymmetric gauge theory with adjoint and fundamental matter☆

We consider N = 1 SU(Nc) gauge theory with an adjoint matter field Φ, Nf flavors of fundamentals Q and antifundamentals Q, and tree-level superpotential of the form QΦ^lQ. This superpotential is relevant or marginal for lN_f ≤ 2N_c. The theory has a Coulomb branch which is not lifted by quantum corrections. We find the exact effective gauge coupling on the Coulomb branch in terms of a family of hyperelliptic curves, thus providing a generalization of known results about N = 2 SUSY QCD to N = 1 context. The Coulomb branch has singular points at which mutually nonlocal dyons become massless. These singularities presumably correspond to new N = 1 superconformal fixed points. We discuss them in some detail for N_c = 2,N_f = 1.
Dynamical fermions in Hamiltonian lattice gauge theory

Abstract We describe a first attempt to understand dynamical fermions within a Hamiltonian framework. As a testing ground we study compact QED3, which shares some important features of QCD4 such as confinement, glueballs, mesons, and chiral symmetry breaking. We discuss the methods used and show data for the chiral condensate.
Cooperative Tandem Catalysis by an Organometallic Complex and a Metalloenzyme

Although chemical and enzymatic catalysts have been combined, reactions in which an organometallic catalyst and a metalloenzyme work cooperatively to create products, which cannot be generated with either catalyst alone or in comparable yields by sequential reactions of the two catalysts, have not been reported. Such reactions are challenging to achieve, in part because the milieu in which these catalysts operate are typically different. Herein, two classes of catalysts are demonstrated to react cooperatively in the same system. Combination of a metathesis catalyst and a P450 enzyme lead to a dynamic equilibration of alkenes and a selective epoxidation of the cross-metathesis products. These results show the potential of combining the two classes of catalysts for synthetic transformations.
Computational and experimental progress on laser-activated gas avalanche switches for broadband, high-power electromagnetic pulse generation

The gas avalanche switch, a high-voltage, picosecond-speed switch, has been proposed. The basic switch consists ofpulse-charged electrodes, immersed in a high-pressure (7—800 atm) gas. An avalanche discharge is induced in the gasbetween the electrodes by ionization from a picosecond-scale laser pulse. The avalanching electrons move toward the anode,causing the applied voltage to collapse in picoseconds. This voltage collapse, if rapid enough, generates electromagneticwaves. A two-dimensional (2D), finite difference computer code solves Maxwell's equations for transverse magnetic modesfor rectilinear electrodes between parallel plate conductors, along with electron conservation equations for continuity,momentum, and energy. Collision frequencies for ionization and momentum and energy transfer to neutral molecules areassumed to scale linearly with neutral pressure. Electrode charging and laser-driven electron deposition are assumed to beinstantaneous.Code calculations are done for a pulse generator geometry, consisting of an 0.7 mm wide by 0.8 mm high, beveled,rectangular center electrode between grounded parallel plates at 2 mm spacing in air. In one operational mode, a uniformdistribution of initial electrons is induced in the gap between the center electrode and the lower plate. With the centerelectrode at 227 kV positive and 15 atm pressure, voltage pulses of 24 1 kV, 2 Ps rise times, 8 ps full widths at halfmaximum (FWHM), 30 ps durations, and 24 GHz 3 dB bandwidths are induced at the ends of the plates by passingelectromagnetic waves. Similar pulses occur at 292 kV, 27 atm and 3.9 MV, 700 atm. Slower pulses are generated at
Transport and current reversal in stochastically driven ratchets

Abstract We present analytic results for the current in a system moving in an arbitrary periodic potential and driven by weak Gaussian noise with an arbitrary power spectrum which are valid to order ( t c t r ) 2 , where t c is the largest characteristic time of the noise, and t r is the characteristic intrawell relaxation time. The dependence of the current on the shape of the potential, and on the shape of the power spectrum of the noise is illustrated. It is demonstrated that the direction of the current is opposite when the power spectrum of the noise has a minimum or maximum at zero frequency. A simple physical mechanism for this behavior is suggested. The behavior of the system in the limit of slow noise ( t c ⪢ t r ) is also discussed.
Testing Satisfiability of CNF Formulas by Computing a Stable Set of Points

We show that a conjunctive normal form (CNF) formula F is unsatisfiable if and only if there is a set of points of the Boolean space that is stable with respect to F. So testing the satisfiability of a CNF formula reduces to looking for a stable set of points (SSP). We give some properties of SSPs and describe a simple algorithm for constructing an SSP for a CNF formula. Building an SSP can be viewed as a "natural" way of search space traversal. This naturalness of search space examination allows one to make use of the regularity of CNF formulas to be checked for satisfiability. We illustrate this point by showing that if a CNF F formula is symmetric with respect to a group of permutations, it is very easy to make use of this symmetry when constructing an SSP. As an example, we show that the unsatisfiability of pigeon-hole CNF formulas can be proven by examining only a set of points whose size is quadratic in the number of holes. Finally, we introduce the notion of an SSP with excluded directions and sketch a procedure of satisfiability testing based on the construction of such SSPs.
Monitoring an Automated System for a Single Failure: Vigilance and Task Complexity Effects:

The present study examined the effects of task complexity and time on task on the monitoring of a single automation failure during performance of a complex flight simulation task involving tracking...
Hardware design reflecting software requirements

All of the features that have been designed into digital computers may be considered to be, at least to some extent, reflections of software needs.
Atomistics of tensile failure in fused silica: weakest-link models revisited

In weakest link models the failure of a single microscopic element of a brittle material causes the failure of an entire macroscopic specimen, just as a chain fails if one link fails. Pristine samples of glass, such as optical communications fiber, approach their ideal strength, and their brittle tensile failure has been descried by this model. The statistics of weakest link models are calculable in terms of the statistics of the individual links, which, unfortunately, are poorly known. Use of the skewness of the failure distribution may permit simultaneous determination of the statistics of the individual weak links and of their number density, which indicates their physical origin. However, the applicability of weakest link models to real materials remains unproven.
Rights, Resistance, and Revolution in the Western Tradition: Early Protestant Foundations

This chapter focuses on the development of rights talk in the pre-Enlightenment Protestant tradition. More particularly, it shows how early modern Protestants, especially followers of Genevan reformer John Calvin, developed a theory of fundamental rights as part and product of a broader constitutional theory of resistance and military revolt against tyranny. With unlimited space, the chapter documents how various Calvinist groups from 1550 to 1650 helped to define and defend each and every one of the rights that would later appear in the American Bill of Rights and other eighteenth-century instruments, and how these Calvinists condoned armed revolution to vindicate these fundamental rights when they were chronically and pervasively breached by a tyrant. The chapter also focuses on the early development of these Calvinist ideas during the sixteenth-century French wars of religion, and then sketches out the channels of later influence of these ideas within and beyond the Protestant tradition. Keywords: Calvinists; French wars; John Calvin; military revolt; Protestant tradition; theory of fundamental rights; theory of resistance
A Programmable Majority Logic Array Using Molecular Scale Electronics

In recent years, many advances have been made in the development of molecular scale electronics which have inspired interest in using the devices thereof for memory and logic. This paper describes the design of a logic architecture using a particular class of molecular devices. Specifically, it is shown that the feature of hysteretic switching common to many molecular devices can be utilized to build programmable arrays. Also utilized in the designs presented here are molecular devices which exhibit negative differential resistance (NDR), a property useful for providing signal restoration at the nanoscale. This work begins by describing the potential for both programmability and NDR in molecular scale electronics. These ideas are then brought together in the design of a programmable logic array based on majority logic.
On the chain-level intersection pairing for PL manifolds

Let M be a compact oriented PL manifold and let C∗M be its PL chain complex. The domain of the chain-level intersection pairing is a subcomplex of C∗M⊗C∗M. We prove that the inclusion map from this subcomplex to C∗M⊗C∗M is a quasi-isomorphism. An analogous result is true for the domain of the iterated intersection pairing. Using this, we show that the intersection pairing gives C∗M a structure of partially defined commutative DGA, which in particular implies that C∗M is canonically quasi-isomorphic to an E∞ chain algebra.
Issues in Water Resource Economics: Discussion

The authors have made courageous efforts to accomplish rather ambitious objectives with varying degrees of success. Both the water quantity and quality issues are addressed, and the differing approaches provide useful insights into alternative policy options for solving a variety of water problems. Although quite a diverse set of water issues is covered in the papers, a number of common themes do emerge. First, the potentially important role of water markets and synthetic market information in addressing both water quality and quantity issues is addressed by Howe and Saliba. Given the usefulness of markets and market information in economic decisions, greater consideration of and experimentation with such alternatives is needed in the water policy arena. Second, two of the papers illustrate the growing recognition of the importance of the groundwater contamination problem. Anderson, Opaluch, and Sullivan (AOS) treat groundwater quality as a potential constraint under which producers may have to operate. In a less traditional approach, Saliba suggests that quality should be treated as a policy variable with different quality goals for different sources. Such quality goals would be dictated by the expected marginal benefits and costs involved. Third, there is explicit emphasis on the more static issues in water allocation. Yet, the intertemporal issues may be more critical, and market information may be less accurate in resolving them. As Schultz has indicated, short-run crises may receive primary attention but the long-run shifts in supply and demand are usually the critical factors to society. AOS do develop a dynamic model which is solved subject to a regulatory constraint. The more important policy problem may be establishing regulatory constraints in a dynamic economic context. Issues
Mapping Statistical Process Variations Toward Circuit Performance Variability: An Analytical Modeling Approach

An analytical gate delay model is developed by integrating short-channel effects and the Alpha-power law-based timing model. As verified with an industrial 90-nm technology, this analytical approach accurately predicts both nominal delay and delay variability over a wide range of power supply conditions including subthreshold and strong- inversion regions. Excellent model scalability enables efficient mapping between process variations and delay variability at the gate level. Based on this model, the impact of various physical effects on delay variability has been identified. While the variation of effective channel length is the leading source for delay variability at the current 90-nm node, delay variability is actually more sensitive to the variation of threshold voltage, especially in the subthreshold region. Furthermore, the limitation of low-power design techniques is investigated in the presence of process variations, particularly dual Vth and L biasing. These techniques become less effective at low VDD due to excessive delay variability.
Microwave residual surface resistance of superconductors

Two distinct models account for the microwave residual surface resistance of superconducting cavities with equally good agreement with the measured temperature and frequency dependence. In presenting his phonon-generation model. Passow claimed that Rabinowitz's fluxoid power-loss model of residual resistance does not fit the experimental data, whereas his does. In fact, the two models have essentially the same temperature and frequency dependence. Furthermore, Passow's phonon-generation model cannot explain the observed sensitivity to details of sample preparation and history while the fluxoid model can.
The Value of "Value Pricing" of Roads: Second-Best Pricing and Product Differentiation

Abstract Some road-pricing demonstrations use “value pricing,” in which travelers can choose between a free but congested roadway and a priced roadway. Recent research has uncovered a potentially serious problem for such demonstrations: second-best tolls may be far lower than those typically charged, and from a welfare perspective, the latter may be worse than not pricing at all. That research, however, assumes that all travelers are identical and it therefore neglects the benefits of product differentiation. Using a model with two user groups, we find that accounting for heterogeneity in value of time is important in evaluating constrained policies, and improves the relative performance of policies that offer differential prices.
Mining billion-node graphs: patterns, generators and tools

What do graphs look like? How do they evolve over time? How to handle a graph with a billion nodes? We present a comprehensive list of static and temporal laws, and some recent observations on real graphs (like, e.g., "eigenSpokes"). For generators, we describe some recent ones, which naturally match all of the known properties of real graphs. Finally, for tools, we present "oddBall" for discovering anomalies and patterns, as well as an overview of the PEGASUS system which is designed for handling Billion-node graphs, running on top of the "hadoop" system.
Auditor‐Provided Tax Services: The Effects of a Changing Regulatory Environment

This study investigates auditor‐provided tax services from 2000 to 2002, during which fees paid to auditors for nonaudit services (NAS) were disclosed, but separate disclosure of tax service fees w...
The Ponzano–Regge Model and Parametric Representation

We give a parametric representation of the effective noncommutative field theory derived from a \({\kappa}\) -deformation of the Ponzano–Regge model and define a generalized Kirchhoff polynomial with \({\kappa}\) -correction terms, obtained in a \({\kappa}\) -linear approximation. We then consider the corresponding graph hypersurfaces and the question of how the presence of the correction term affects their motivic nature. We look in particular at the tetrahedron graph, which is the basic case of relevance to quantum gravity. With the help of computer calculations, we verify that the number of points over finite fields of the corresponding hypersurface does not fit polynomials with integer coefficients, hence the hypersurface of the tetrahedron is not polynomially countable. This shows that the correction term can change significantly the motivic properties of the hypersurfaces, with respect to the classical case.
Gamma-ray polarimetry

Abstract An astrophysics application of a low-noise Double-sided Silicon Strip Detector (DSSD) is described. A Semiconductor Multiple-Compton Telescope (SMCT) is being developed to explore the γ-ray universe in the 0.1– 20 MeV energy range. Excellent energy resolution and polarization sensitivity are key features of the SMCT. We have developed prototype modules for a low-noise DSSD system that achieved an energy resolution of 1.3 keV (FWHM) for 122 keV at 0°C. Results of a gamma-ray imaging test are also presented.
OXIDANT MECHANISMS IN TOXIC ACUTE RENAL FAILURE

Over the last decade, there is accumulating evidence for a role of reactive oxygen metabolites in the pathogenesis of a variety of renal diseases, including gentamicin, glycerol, cisplatin, and cyclosporine A models of toxic acute renal failure. Gentamicin has been shown both in in vitro and in vivo studies to enhance the generation of reactive oxygen metabolites. Iron is important in models of tissue injury, presumably because it is capable of catalyzing free-radical formation. Gentamicin has been shown to cause release of iron from renal cortical mitochondria. Scavengers of reactive oxygen metabolites as well as iron chelators provide protection in gentamicin-induced nephrotoxicity. In glycerol-induced acute renal failure, an animal model of rhabdomyolysis, there is enhanced generation of hydrogen peroxide, and scavengers of reactive oxygen metabolites and iron chelators provide protection. Although the dogma is that the myoglobin is the source of iron, recent studies suggest that cytochrome P450 may be an important source of iron in this model. In addition, there are marked alterations in antioxidant defenses, such as glutathione, as well as changes in heme oxygenase. Several recent in vitro and in vivo studies indicate an important role of reactive oxygen metabolites in cisplatin-induced nephrotoxicity. Thus, catalytic iron is increased both in vitro and in vivo by cisplatin, and iron chelators as well as hydroxyl radical scavengers have been shown to be protective. Recent studies indicate that cytochrome P450 may also be an important source of the catalytic iron in cisplatin nephrotoxicity. Cyclosporine A has been shown to enhance generation of hydrogen peroxide in vitro and enhance lipid peroxidation in vitro and in vivo. Antioxidants have been shown to be protective in cyclosporine A nephrotoxicity. This collective body of evidence suggests an important role for reactive oxygen metabolites in toxic acute renal failure and may provide therapeutic opportunities of preventing or treating acute renal failure in humans.
Chiral N-Acetyl Selone-Promoted Aldol Reactions

Abstract The chiral oxazolidineselone functionality was found to be an excellent partner in the stereospecific acetate aldol reaction with aldehydes via the titanium enolates. Good stereocontrol was obtained as determined by NMR spectroscopy. The oxazolidineselone also provided a straightforward way to establish the stereopurity of the coupling reaction through 77Se NMR spectroscopy.
Modeling the Surface X-ray Emission and Viewing Geometry of PSR J0821–4300 in Puppis A

We present a model for the unusual X-ray pulse profiles of PSR J0821–4300, the compact central object in supernova remnant Puppis A. We show that a pair of thermal, antipodal hot spots on the neutron star (NS) surface is able to fully account for the pulsar's double blackbody spectrum and energy-dependent pulse profile, including the observed 180° phase reversal at 1.2 keV. By comparing the recorded pulse modulation and phase to the model predictions, we strongly constrain the hot-spot pole (ξ) and the line-of-sight (ψ) angles with respect to the spin axis. For a nominal radius of R = 12 km and distance D = 2.2 kpc, we find (ξ, ψ) = (86°, 6°), with 1σ error ellipse of (2°, 1°); this solution is degenerate in the two angles. The best-fit spectral model for this geometry requires that the temperatures of the two emission spots differ by a factor of 2 and their areas by a factor of ~20. Including a cosine-beamed pattern for the emitted intensity modifies the result, decreasing the angles to (84°, 3°); however this model is not statistically distinguishable from the isotropic emission case. We also present a new upper limit on the period derivative of (2σ), which limits the global dipole magnetic field to Bs < 2.0 × 1011 G, confirming PSR J0821–4300 as an anti-magnetar. We discuss the results in the context of observations and theories of nonuniform surface temperature on isolated NSs of both weak and strong magnetic field. To explain the nonuniform temperature of PSR J0821–4300 may require a crustal field that is much stronger than the external, global dipole field.
Quenched Degrees of Freedom in Symmetric Diblock Copolymer Thin Films

We studied the effect of monomer immobilization (quenching) on the orientation of the lamellae in symmetric diblock copolymer thin films with neutrally wetting surfaces. A small fraction of the monomers immediately next to the solid substrate is presumed to be quenched. Our calculations demonstrate that quenching favors the lamellae orienting perpendicular to the film. Quenching inhibits the order-disorder transition twice as much for the parallel orientation as for the perpendicular orientation.
Agricultural competitiveness: The case of the United States and major EU countries

Abstract Growth in the agricultural GDP of four major European countries is compared with US agricultural growth for the period 1974–1993. The agricultural sector's relative prices are taken into account along with economy-wide factor market adjustments. For Denmark, France, Germany and the UK, the effects of declining real prices and changes in input levels on growth in agricultural GDP are relatively small. Total Factor Productivity (TFP) growth appears to be the major contributor to European agricultural GDP growth. In comparison, TFP is the major source of growth in US agricultural GDP, but its rate of growth is lower than the European countries. In contrast, the declining real prices for US agriculture had a relatively large effect on its GDP. However, in recent years, the effects of declining real prices and declining rates of growth in TFP on European agriculture are relatively large. In the longer-run, the relative competitiveness of US agriculture is largely dependent on its ability to sustain and increase growth in TFP.
Human neutrophil proteinase 3: mapping of the substrate binding site using peptidyl thiobenzyl esters.

Abstract A series of peptidyl thiobenzyl esters was used to map the active site of human leukocyte proteinase 3. The steady-state kinetics parameters reveal the following features regarding the substrate specificity of proteinase 3 and its putative active site: (a) the preferred P1 residue is a small hydrophobic amino acid such as aminobutyric acid, norvaline, valine or alanine (in decreasing order of preferences (b) the enzyme has an extended active site, and (c) its active site is similar to that of the related serine proteinases leukocyte elastase and leukocyte cathepsin G.
Design and implementation of a SMIL player

Synchronized Multimedia Integration Language (SMIL) is a recommendation developed by the Synchronized Multimedia Working Group in the World Wide Web Consortium. SMIL is a simple and standard way to specify a timeline based synchronized multimedia presentation over the Internet. It is a declarative authoring language based on a Extensible Markup Language to define language-specific data types and tags. A SMIL player schedules presentation in a SMIL file, and retrieves media objects on the Web using URLs described in the field. The SMIL file is a plain text file and can be edited using a simple text editor. We present the approaches of implementing a SMIL player within the desktop system constraints. The reference implementation is a Java applet, which follows a platform-neutral programming paradigm and makes use of Java Media Framework. The applet can run in any main stream web browser.
Facilities for microgravity combustion research

Abstract Combustion science and applications have benefited in unforeseen ways from experimental research performed in the low-gravity environment. The capability to control for the first time the influence of gravitational buoyancy has provided some insight into soot formation in droplet combustion, the nature of flammability limits in premixed gases, and the relationship between normal-gravity and low-gravity material flammability that may influence how materials are best selected for routine use in habitable spacecraft. The opportunity to learn about these complex phenomena is derived from the control of the ambient body-force field and, perhaps as importantly, the simplified boundary conditions that can be established in well designed low-gravity combustion experiments. A description of the test facilities and typical experimental apparatus are provided; and conceptual plans for a Space Station Freedom capability, the modular combustion facility, are described.
Dignity at Work

Human dignity, the ability to establish a sense of self-worth and self-respect and to enjoy the respect of others, is necessary for a fully realized life. Working with dignity is a fundamental part of achieving a life well-lived, yet the workplace often poses challenging obstacles because of mismanagement or managerial abuse. Defending dignity and realizing self-respect through work are key to workers' well-being; insuring the dignity of employees is equally important for organizations as they attempt to make effective use of their human capital. In this book Randy Hodson, a sociologist of work and organizational behavior, applies ethnographic and statistical approaches to this topic, offering both a richly detailed, inside look at real examples of dignity in action, and a broader analysis of the pivotal role of dignity at work.
Copper(II) Complexes with Schiff Base Ligands. Synthesis of Some Copper(II) Complexes with Ligands Derived from the Reaction of Pyridine-2-Carboxaldehydes and Aromatic Amines

Abstract A series of copper(II) complexes with ligands derived from the Schiff base reaction of pyridine- 2-carboxaldehyde or 6-methylpyridine-2-carboxal- dehyde with aniline, benzylamine or 2-phenylethylamine has been prepared. These complexes have been characterized by spectroscopic methods. The electronic spectrum of bis( N -phenyl-(6-methyl-2- pyridyl)methylimine) copper(II) tetrafluoroborate has an absorption band at a much higher energy and molar absorptivity than the other complexes. The appearance of this band indicates a major change in geometry caused by the combined steric demands of the 6-methyl group on the pyridine aromatic ring and the rigid aromatic ring of the phenyl group on the imine nitrogen atom.
On a free boundary problem for an American put option under the CEV process

Abstract We consider an American put option under the CEV process. This corresponds to a free boundary problem for a PDE. We show that this free boundary satisfies a nonlinear integral equation, and analyze it in the limit of small ρ = 2 r / σ 2 , where r is the interest rate and σ is the volatility. We use perturbation methods to find that the free boundary behaves differently for five ranges of time to expiry.