cssi/SciSciGPT-SciSciNet huggingface dataset:
Mitigating negative impacts of near-side bus stops on cars

Abstract Bus stops are often placed short distances upstream of signalized intersections. Buses that dwell at one of these so-called near-side stops can impede queued cars upstream from discharging through the intersection during green times. Residual car queues can form at the intersection as a result. The smaller the distance between a stop and its intersection, the greater the problem can be. Models are formulated to address this problem using kinematic wave theory. The models can be used to determine where to place a near-side stop to achieve a target level of residual car queueing. In addition, the models are used herein to develop a scheme for mitigating residual car queues by briefly detaining some buses from reaching the stop. The scheme can be applied selectively, so that the times that detained buses depart from the stop are not postponed. The buses are therefore not delayed over the longer run. Analysis indicates that this bus-holding scheme can significantly reduce car delays and queueing. Our models for placing stops and holding buses are shown to be robust to systematic and random changes in car flow.
Measuring Time Dependence of Dark Energy Density from Type Ia Supernova Data

Observations of high-redshift supernovae imply an accelerating universe that can only be explained by an unusual energy component such as vacuum energy or quintessence. To assess the ability of current and future supernova data to constrain the properties of the dark energy, we allow its density to have arbitrary time dependence, ρX(z). This leads to an equation of state for the dark energy, wX(z) = pX(z)/ρX(z), which is a free function of redshift z. We find that current data of type Ia supernovae (SNe Ia) are consistent with a cosmological constant, with large uncertainties at z 0.5. We show that ρX(z)/ρX(z = 0) can be measured reasonably well to about z = 1.5 using SN Ia data from realistic future SN Ia pencil beam surveys, provided that the weak energy condition (energy density of matter is nonnegative for any observer) is imposed. While it is only possible to differentiate between different models (say, quintessence and k-essence) at z 1.5 using realistic data, the correct trend in the time dependence of the dark energy density can be clearly detected out to z = 2, even in the presence of plausible systematic effects. This would allow us to determine whether the dark energy is a cosmological constant or some exotic form of energy with a time-dependent density.
Reduction of transport theory to multigroup diffusion theory

Abstract The purpose of this paper is two-fold. First, it is shown that all aspects of multigroup diffusion theory can be derived from the general transport equation (written so as to properly account for the thermal motion of the medium) by utilizing only two assumptions, both of which are implicit in any multigroup derivation. These are: (i) the directional neutron density within each group is separable according to n(r, ν, Ω) = n(r, Ω)n(ν) ; (ii) the angular dependence of n(r, Ω) is expandable in a truncated spherical harmonic series. These assumptions lead to a diffusion coefficient defined by an energy average of the transport cross section. It is also shown that the spectrum equation, needed to compute the multigroup constants, can be derived using only the first assumption. Secondly, some of the more interesting (and sometimes neglected) aspects of multigroup diffusion theory are reviewed. In particular: (a) the diffusion coefficient matrix contains off diagonal terms and thus the simple Fick's Law of diffusion does not hold within each group; (b) the molecular motion of the medium enters into the calculation of the thermal group constants twice, first in computing the spectrum and second, in computing the energy-dependent ‘cross sections’ to be averaged over this spectrum.
The Emergence of Economic Organization

Abstract A model of decentralized markets is studied, in which transactors follow simple adaptive rules. Transactions are coordinated by specialist trading firms that bear the costs of market disequilibrium. Starting from an initially autarkic situation in which none of the institutions that support exchange exist, computer simulation shows that for a wide range of parameter values a fully developed market economy will emerge spontaneously. Moreover, in virtually every case where a market economy develops, one of the commodities traded will emerge as a universal medium of exchange, being traded by every firm and changing hands in every act of exchange.
SPECTROSCOPIC ABUNDANCES AND MEMBERSHIP IN THE WOLF 630 MOVING GROUP

The concept of kinematic assemblages evolving from dispersed stellar clusters has remained contentious since Eggen’s initial formulation of moving groups in the 1960s. With high-quality parallaxes from the Hipparcos space astrometry mission, distance measurements for thousands of nearby, seemingly isolated stars are currently available. With these distances, a high-resolution spectroscopic abundance analysis can be brought to bear on the alleged members of these moving groups. If a structure is a relic of an open cluster, the members can be expected to be monolithic in age and abundance in as much as homogeneity is observed in young open clusters. In this work, we have examined 34 putative members of the proposed Wolf 630 moving group using high-resolution stellar spectroscopy. The stars of the sample have been chemically tagged to determine abundance homogeneity and confirm the existence of a homogeneous subsample of 19 stars. Fitting the homogeneous subsample with Yale–Yonsei isochrones yields a single evolutionary sequence of ∼2.7 ± 0.5 Gyr. It is concluded that this 19 star subsample of the Wolf 630 moving group sample of 34 stars could represent a dispersed cluster with an � [Fe/H] �=− 0.01 ± 0.02 and an age of 2.7 ± 0.5 Gyr. In addition, chemical abundances of Na and Al in giants are examined for indications of enhancements as observed in field giants of old open clusters; overexcitation/ionization effects are explored in the cooler dwarfs of the sample; and oxygen is derived from the infrared triplet and the forbidden line at λ6300.
Finite ma corrections for sea quark matrix elements

We discuss the finite ma corrections associated with the computation of sea quark matrix elements. We find them to differ from the standard normalization used for valence quarks and to depend strongly on the Lorentz structure of the current under consideration. Phenomenological implications of these results are briefly discussed in two examples. We also mention how the magnitude of the correction factors can be reduced by using a 2-link improved action.
A LOT OF FLAVOR PHYSICS FROM A LITTLE SYMMETRY

Recent neutrino parameter measurements place increasingly stringent on acceptable supersymmetric theories of flavor. A very fruitful approach is the application of non-Abelian discrete gauged flavor symmetries Gf. We discuss a highly successful model using Gf = T′ × Z3 where T′ is a non-Abelian group based on the symmetries of a tetrahedron. This model reproduces the basic features of the U(2) model, and also predicts neutrino masses and mixing angles consistent with either the SMA or LMA scenarios.
Spectral Density of Jacobi Matrices with Small Deviations

We present several new asymptotic trace formulas for Jacobi matrices whose coefficients satisfy a small deviation condition. Our results extend most of the existing trace formulas for Jacobi matrices.
Simply Measuring the Electric Field of Very Long, Complex Pulses

We introduce a simple spectral-interferometric technique for measuring (in time) the intensity and phase of arbitrary complex pulses >1-ns long with <100-fs substructure. It uses a low-resolution spectrometer and multiple replicas of a reference pulse.
Is there an electron wind

Abstract The question of whether there is any momentum transfer to a specimen during electron diffraction, as dictated by Newton's third law, is discussed. It is pointed out that there must be momentum and energy transfer during “elastic” scattering. Even though what is normally considered as “elastic” scattering is in fact inelastic, electron density systems are insensitive to the changes in energy. Therefore the energy changes during diffraction do not prevent coherent interference phenomena such as electron holography and high-resolution electron microscopy. The momentum transfer, in effect, introduces an electron wind which can, mechanically, alter the specimen; the wind is equivalent to a storm with gusts of up to 300 km/h. Experimental evidence in support of this is presented.
Asymptotics for Pseudo-Anosov Elements in Teichmüller Lattices

A Teichmuller lattice is the orbit of a point in Teichmuller space under the action of the mapping class group. We show that the proportion of lattice points in a ball of radius r which are not pseudo-Anosov tends to zero as r tends to infinity. In fact, we show that if R is a subset of the mapping class group, whose elements have an upper bound on their translation length on the complex of curves, then the proportion of lattice points in the ball of radius r which lie in R tends to zero as r tends to infinity.
Predictive Information in a Nonequilibrium Critical Model

We propose predictive information, that is, information between a long past of duration T and the entire infinitely long future of a time series, as a general order parameter to study phase transitions in physical systems independently of the underlying dynamics. It can be used, in particular, to study nonequilibrium transitions and other exotic transitions, where a simpler order parameter cannot be identified using traditional symmetry arguments. As an example, we calculate predictive information for a stochastic nonequilibrium dynamics problem that forms an absorbing state under a continuous change of a parameter. The information at the transition point diverges as ∝logT, and we calculate the expression for a smooth crossover to ∝T 0 away from the transition.
Stereoselective syntheses of chiral (3S,9bS)-1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-ones

Abstract Chiral (3S,9bS)-1,2,3,9b-tetrahydro-5H-imidazo[2,1-a]isoindol-5-ones 11a–11f, 14b,14c and 17a,b were prepared in 78–93% yields with high stereoselectivities (d.e. >99%) by the intermolecular condensations of 2-formylbenzoic acids 10 or 13 or 2-acetylbenzoic acid 15 with chiral diamines 9a–9f and 9h. Compounds 9a–9f and 9h were readily prepared in three steps from optically active N-Boc-α-amino acids 5a–5d.
The larger N-heteroacenes

The history and development of pyrazine- and pyridine-type heteroacenes and their use in solid-state organic electronics are discussed and reviewed. The larger N-heteroacenes are potential electron- or hole-transporting materials and should therefore complement acenes in organic electronics. As they feature electronegative nitrogen ring atoms in their mo- lecular skeleton, issues with oxidation should be less problematic when comparing them to the larger acenes such as pentacene. This paper covers the synthesis and the solid-state pack- ing of larger (tetracene/pentacene-based) N,N-heterocylic acenes as well as the question of the interplay of aromaticity and antiaromaticity in the known larger N-heteroacenes and their N,N-dihydro-derivatives; also illuminated are their optical properties. A literature overview is provided.
NONLINEAR INTERACTION OF COLLIDING BEAMS IN PARTICLE STORAGE RINGS

When two beams of high energy particles moving in opposite directions are brought into collision, a large amount of energy is available for the production of new particles. However to obtain a sufficiently high event rate for rare processes, such as the production of the intermediate vector boson (Z/sub 0/ and W/sup + -/), large beam currents are also required. Under this circumstance, the high charge density of one beam results in a classical electromagnetic interaction on the particles in the other beam. This very nonlinear space charge force, caled the beam-beam force, limits the total circulating charge and, thereby, the ultimate performance of the colliding ring system. The basic nature of the beam-beam force is discussed, indicating how it is quite different in the case of continuous beams, which cross each other at an angle as compared to the case of bunched beams which collide head-on. Some experimental observations on the beam-beam interaction in proton-proton and electron-positron beams are then reviewed and interpreted. An important aspect of the beam-beam problem in storage rings is to determine at what point in the analysis of the particle dynamics is it relevant to bring in the concepts of stochasticity, slow diffusion, andmore » resonance overlap. These ideas are briefly discussed.« less
Free-electron lasers with very slow wiggler taper

A highly accurate, explicit asymptotic solution of the electron energy and phase is found for a class of free-electron lasers (FELs) with very long wavelength beams, very low electron energies, and very slow taper of the wiggler field relative to the wiggler period. Dimensionless variables are defined and normalized, and three small parameters which characterize the operation of the FEL are identified. Due to the explicit asymptotic nature of the solution, the results may be directly used to calculate features such as the escape distance of the electron from the potential well and the effects of the various physical parameters. One important advantage of the very slow wiggler taper is the increased efficiency of the energy transfer from the electron beam to the signal field due to increased bucket width. Numerical calculations are performed to verify all results. >
Regenerative vapor cycle with isobutane as working fluid

Abstract One of the methods of generating geothermal power is to use a suitable working fluid which extracts heat from geothermal fluids and generates power in a closed cycle. This paper presents a discussion of an improvement of the basic closed cycle with isobutane as a working fluid. A regenerative heat exchanger is added for heating the cold condensate of isobutane with the highly superheated exhaust. The addition of this heat exchanger can result in a significant reduction in the size of heat rejection equipment. Furthermore, the waste brine of the improved system is at such a high temperature that the waste heat can be economically utilized for desalting water for industrial uses.
Migration of Star Clusters and Nuclear Rings

Star clusters that form in nuclear rings appear to be at slightly larger radii than the gas. We argue that the star clusters move out from the gas in which they are formed because of satellite-disk tidal interactions. In calculating the dynamics of this star cluster and gas ring system, we include the effects of dynamical friction of the background stars in the host galaxy on the star cluster, and inflowing gas along the bar onto the nuclear ring at the two contact points. We show that the final separation is of the order of the Hill radius of the nuclear ring, which is typically 20%-30% of its radius. Massive star clusters can reach half of this separation very quickly and produce a factor of a few enhancement in the gas surface density. If this leads to star formation in addition to the (ongoing) formation of star clusters near the contact points, a possible (initial) azimuthal age gradient may become diluted or even disappear. Finally, if the star clusters are massive and/or numerous enough, we expect the nuclear ring to migrate inward, away from the (possibly) associated (inner) Lindblad resonance. We discuss how these predictions may be tested observationally.
Adaptation and convergence of behavior in repeated experimental Cournot games

Abstract This research examines results from laboratory experiments in which five human subjects participate as sellers in a Cournot oligopoly environment. The central issue is whether repeated play among a group of privately informed subjects will lead to convergence to a unique, static, noncooperative Nash equilibrium. The experiments were designed so that the implications of different hypotheses about adaptation and convergence, such as the best response dynamic and fictitious play, could be distinguished. The results provide, at best, only partial support for the hypothesis that behavior of privately informed subjects will converge to the static Nash equilibrium when play is repeated. Total output averaged over time periods and across experiments is greater than, but still close to, predicted equilibrium total output. However, observed intertemporal variation in total output and heterogeneity in individual choices are inconsistent with convergence to the static Nash equilibrium.
Dystonia in corticobasal degeneration.

OBJECTIVE: To characterize the clinical features, particularly dystonia, in patients with clinically diagnosed or pathologically proven corticobasal degeneration (CBD). BACKGROUND: Although dystonia has been reported in many neurodegenerative disorders, it has not been studied in CBD. Dystonia, often accompanied by painful rigidity and fixed contractures, is one of the most disabling features of CBD. METHODS: The medical records, imaging studies, and videotapes of 66 patients who satisfied the clinical criteria of CBD, evaluated between 1988 and 1998, were reviewed. The occurrence, nature, and distribution of dystonic features were analyzed and correlated with other features of CBD. RESULTS: Of the 66 patients with CBD, 39 (59.0%) had dystonia. The mean age at onset of initial symptoms was 63.9 years (range 44–75). In 20 (51.0%) patients, dystonic symptoms began in one arm, while 13 (33.0%) patients had initial leg involvement. At least one arm was affected in 36 (92.0%) dystonic patients. Although 11 (28.0%) patients had leg dystonia, the leg was the predominant site of involvement in only 1 patient. Only 12 (31.0%) patients had dystonia involving the head, neck, or trunk in the course of the disease. The diagnosis of CBD was confirmed in all 4 patients who had autopsies. CONCLUSION: In this large series of CBD patients we found that asymmetric limb dystonia, particularly affecting one arm, is a common manifestation of CBD; dystonia may be the initial manifestation of this neurodegenerative disorder. Axial or leg dystonia, without significant involvement of an arm, is rare. There is no effective treatment for this relentless disorder, except for temporary relief of dystonia and pain, with local botulinum toxin injections. © 2001 Movement Disorder Society.
Security Analyst and Stock Market Efficiency in Anticipating Tax‐Motivated Income Shifting

In the context of the statutory tax rate reductions enacted in the Tax Reform Act of 1986, this paper investigates the degree to which capital market participants anticipate and correctly interpret temporary income effects of tax‐motivated income shifting. We find evidence consistent with financial analysts' earnings forecasts failing to anticipate earnings management that shifts income from fourth quarters in higher tax rate years to immediately following first quarters of lower tax rate years. The evidence suggests that this failure is not the result of a decision to ignore the income shifting, but rather an inability to recognize temporary components of reported earnings. We also find evidence that market prices do not fully reflect the temporary income effects of tax‐motivated income shifting, and that analyst inefficiency explains about half of the market inefficiency. We interpret these inefficiencies as potentially important costs of tax planning that could limit the ability of public firm managers...
A summary of software measurement experiences in the software engineering laboratory

Abstract The practice of measuring software is increasingly seen as a valuable tool in the overall development of high-quality software projects. Software measurement attempts to use known, quantifiable, objective, and subjective measures to compare and profile software projects and products. To compute these measures effectively, data that characterize the software project and product are needed. This paper covers aspects of data collection and software measurement as they have been applied by one particular organization, the Software Engineering Laboratory (SEL). The measurement results include the experiences and lessons learned through numerous experiments conducted by the SEL on nearly 60 flight dynamics software projects. These experiments have attempted to determine the effect of various software development technologies on overall software project quality and on specific measures such as productivity, reliability, and maintainability.
The mighty man-computer team

If the Martians, Venusians, or Plutonians ever bother to observe the antics of their neighbors on the Planet Earth, they must be vastly amused by our attitude toward the digital automatic computer, the DAC for short. While professing to be completely baffled by the frenzied rush on the part of the lemmings to be drowned in the sea, we---earthlings---have perversely chosen to denigrate the unsurpassable human brain by affixing to a pile of wires and tubes that ludicrous title "The Thinking Machine." What a churlish way to thank Mother Nature for our bountiful mental endowment which dwarfs into insignificance those fabulous gifts of magic, lavished upon their favorites by the doting fairy godmothers.
Differential Posets have Strict Rank Growth: A Conjecture of Stanley

We establish strict growth for the rank function of an r-differential poset. We do so by exploiting the representation theoretic techniques developed by Reiner and the author (Order 26(3):197–228, 2009) for studying related Smith forms.
Coherent states and N dimensional coordinate noncommutativity

Considering coordinates as operators whose measured values are expectations between generalized coherent states based on the group SO(N,1) leads to coordinate noncommutativity together with full N dimensional rotation invariance. Through the introduction of a gauge potential this theory can additionally be made invariant under N dimensional translations. Fluctuations in coordinate measurements are determined by two scales. For small distances these fluctuations are fixed at the noncommutativity parameter while for larger distances they are proportional to the distance itself divided by a very large number. Limits on this number will be available from LIGO measurements.
An experimental investigation of the interaction of primary and secondary stresses in fuel plates

If the load is not relieved as a structure starts to yield, the induced stress is defined as primary stress. If the load relaxes, as a structure begins to yield the induced stress is defined as secondary stress. In design, it is not uncommon to give more weight to primary stresses than to secondary stresses. However, knowing when this is good design practice and when it is not good design practice represents a problem. In particular, the fuel plates in operating reactors contain both primary stresses and secondary stresses, and to properly assess a design there is a need to assign design weights to the stresses. Tests were conducted on reactor fuel plates intended for the advanced neutron source (ANS) to determine the potential of giving different design weights to the primary and secondary stresses. The results of these tests and the conclusion that the stresses should be weighted the same are given in this paper.
Dopaminergic and serotonergic neurotransmitters in bone marrow transplant patients

Depigmentation of neurons in the substantia nigra (SN) is found in patients dying after bone marrow transplantation (BMT). This study examined neurochemical striatal changes related to BMT. Caudate nucleus and putamen of 6 BMT subjects and 10 age-matched controls were analyzed for levels of dopamine (DA), homovanillic acid (HVA), 5-hydroxyindoleamine (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA), by high pressure liquid chromatography-electron capture detection (HPLC-ECD). In addition, assays of the enzymatic activities of monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B), choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) were performed. Cholinergic markers, ChAT and AChE, were reduced in BMT caudate (p < 0.05) but not in the putamen. A recovery toward normal cholinergic enzymatic activity was identified with increased post-transplant survival time. The level of DA was reduced 50% in BMT caudate and putamen while HVA was increased 30%, however, neither reduction achieved statistical significance. Increasing post-transplant survival time correlated with decreased levels of DA in caudate nucleus and putamen in the early post-transplant period, while HVA was increased over the same interval but tended to return to normal levels with increasing survival time. Two-fold increases of BMT caudate 5-HT (p < 0.003) and 5-HIAA were found; similar changes were noted in putamen 5-HT and 5-HIAA (p < 0.0008). Significant increases in MAO-A and B were found in BMT caudate (p < 0.0001 and p < 0.06, respectively) and putamen (p < 0.0005 and p < 0.006, respectively). No statistically significant changes were noted in the 5-HT, 5-HIAA, or MAO A or MAO B with increasing post-transplant survival. Whether these changes are the result of physiologic or toxic effects is unknown.
Design of Controls to Attenuate Loads in the Controls Advanced Research Turbine

Designing wind turbines to maximize energy production and increase fatigue life is a major goal of the wind industry. To achieve this goal, we must design wind turbines to extract maximum energy and reduce component and system loads. This paper applies modern state-space control design methods to a two-bladed teetering-hub upwind machine located at the National Wind Technology Center. The design objective is to regulate turbine speed in region 3 (above rated wind speed) and enhance damping in several lowdamped flexible modes of the turbine. The controls approach is based on the Disturbance Accommodating Control (DAC) method and provides accountability for wind-speed disturbances. First, controls are designed using the single control input rotor collective pitch to stabilize the first drive-train torsion as well as the tower first fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances first drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections caused by wind shear.
One-pot asymmetric synthesis of tert-butanesulfinyl-protected amines from ketones by the in situ reduction of tert-butanesulfinyl ketimines

Abstract A one-pot method for the asymmetric synthesis of tert -butanesulfinyl-protected amines is described. The ketones bd2 are condensed with (R)-tert -butanesulfinamide bd1 and the tert -butanesulfinyl imine intermediates reduced in situ with NaBH 4 to afford the sulfinamides bd4 in 66–86% yield and with drs from 90:10 to 97:3 for both aryl alkyl and dialkyl ketones. Ti(OEt) 4 serves as both a water scavenger and catalyst for imine condensation, and as a Lewis acid that provides enhanced reduction rates and dr.
Pollution Measurements of a Swirl-Can Combustor

Pollutant levels of oxides of nitrogen, unburned hydrocarbons, and carbon monoxide were measured for an experimental, annular, swirl can combustor. The combustor was 42 inches in diameter, incorporated 120 modules, and was specifically designed for elevated exit temperature performance. Test conditions included combustor inlet temperatures of 600, 900 and 1050 F, inlet pressures of 5 to 6 atmospheres, reference velocities of 69 to 120 feet per second and fuel-air ratios of 0.014 to 0.0695. Tests were also conducted at a simulated engine idle condition. Results demonstrated that swirl can combustors produce oxides of nitrogen levels substantially lower than conventional combustor designs. These reductions are attributed to reduced dwell times resulting from short combustor length, quick mixing of combustion gases with diluent air, and to uniform fuel distributions resulting from the swirl can approach. Radial staging of fuel at idle conditions resulted in increases in combustion efficiencies and corresponding reductions in pollutant levels.
Nitroxide sensing of a DNA microenvironment: mechanistic insights from EPR spectroscopy and molecular dynamics simulations.

The behavior of the nitroxide spin labels 1-oxyl-4-bromo-2,2,5,5-tetramethylpyrroline (R5a) and 1-oxyl-2,2,5,5-tetramethylpyrroline (R5) attached at a phosphorothioate-substituted site in a DNA duplex is modulated by the DNA in a site- and stereospecific manner. A better understanding of the mechanisms of R5a/R5 sensing of the DNA microenvironment will enhance our capability to relate information from nitroxide spectra to sequence-dependent properties of DNA. Toward this goal, electron paramagnetic resonance (EPR) spectroscopy and molecular dynamics (MD) simulations were used to investigate R5 and R5a attached as Rp and Sp diastereomers at phosphorothioate pSC7 of d(CTACTGpSC7Y8TTAG). d(CTAAAGCAGTAG) (Y = T or U). X-band continuous-wave EPR spectra revealed that the dT8 to dU8 change alters nanosecond rotational motions of Rp-R5a but produces no detectable differences for Sp-R5a, Rp-R5, and Sp-R5. MD simulations were able to qualitatively account for these spectral variations and provide a plausible physi...
MODEL FOR SMALL NEUTRINO MASSES AT THE TeV SCALE

We propose a model for neutrino mass generation in which no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses mνD ≤ MeV are generated at the one-loop level. Small left-handed Majorana neutrino masses can be generated via the seesaw mechanism with right-handed neutrino masses MR of order TeV scale.
Efficacy of an Oral Angiotensin-Converting Enzyme Inhibitor (Captopril) in Severe Hypertension

The antihypertensive effect of captopril was assessed during short- and long-term periods in ten patients with elevated blood pressure readings that were uncontrollable by standard therapy (supine diastolic blood pressure of greater than 100 mm Hg with a regimen of propranolol hydrochloride, hydralazine hydrochloride, and hydrochlorothiazide). When given alone, captopril therapy was unable to normalize the blood pressure in any patient. The addition of hydrochlorothiazide to the captopril therapy normalized the blood pressure in one patient and sharply improved the blood pressure in four others. The blood pressure in the remaining patients responded inadequately to this combination. The addition of propranolol to captopril and hydrochlorothiazide reduced the blood pressure further in most cases (seven on the ten patients had normal blood pressure readings while they received these three drugs). In four patients, the blood pressure response to the added propranolol was unrelated to changes in plasma angiotensin II concentration. Captopril was helpful in the management of refractory hypertension in most cases.
Work costs and nonconvex preferences in the estimation of labor supply models

Abstract Works costs have not been adequately handled in labor supply estimation, likely due to their complexity. We show that, if work costs are not accounted for in the budget and time constraints in a structural labor supply model, they will be subsumed into the data generating preferences. Even if underlying preferences over consumption and leisure are convex, the presence of unobservable work costs can make these preferences appear nonconvex. However, we show that, under plausible conditions, policy relevant calculations, such as estimates of the effect of tax changes on labor supply and deadweight loss measures, are not affected by the fact that estimated preferences incorporate work costs.
Morphology of the ventral frontal cortex in schizophrenia: relationship with social dysfunction

Abstract Background: Studies have reported premorbid as well as postonset social dysfunction in schizophrenia. This impairment has also been observed to emerge after lesions in the ventral aspect of the frontal cortex (i.e., straight gyrus and orbitofrontal cortex). Methods: Magnetic resonance imaging scans were obtained from 45 male patients with schizophrenia and 45 matched control subjects. Cortical gray matter volume and surface area were determined for the ventral frontal cortex (VFC), subdivided into the orbitofrontal cortex (OFC) and the straight gyrus (SG). Results: The global measures of gray matter volume and surface area in the VFC was not significantly different between patients and control subjects; however, there was a regional difference, with the right SG volume and surface area being smaller in patients compared with control subjects. Volume of the VFC had an inverse correlation with measurements of both premorbid and postdiagnosis social function. The smaller the gray matter in these regions, the greater the social dysfunction. There was no relationship between morphology of this brain region and any other clinical variable. Conclusions: Morphology of the VFC is directly related to abnormal social function in schizophrenia, including measures of social dysfunction that predate the onset of illness.
Practical synthesis of perylene-monoimide building blocks that possess features appropriate for use in porphyrin-based light-harvesting arrays

Abstract Perylene-monoimide dyes with solubilizing aryloxy substituents at the perylene perimeter and a synthetic handle on the N-aryl group are valuable building blocks for incorporation as accessory pigments in porphyrin-based light-harvesting arrays. A family of such dyes has been prepared by reaction of 1,6,9-tris(4-tert-butylphenoxy)perylene-3,4-dicarboxylic anhydride with a set of 4-iodo/ethynyl anilines (with or without 2,6-diisopropyl substituents) in the presence of Zn(OAc)2·2H2O in imidazole/mesitylene at 130°C. The workup procedures throughout the synthesis have been streamlined for scale-up purposes, minimizing chromatography. Two bis(perylene)porphyrin building blocks were prepared in a rational manner and examined in Sonogashira and Glaser polymerizations. The two isopropyl groups on the N-aryl group and the three 4-tert-butylphenoxy groups at the perylene perimeter are essential for high solubility of the bis(perylene)porphyrins and corresponding oligomers in organic solvents.
On the Evaluation of Government Programs to Reduce Environmental Risk

This paper attempts to identify the correct benefit measure for a government project which might reduce the subjective probability of an environmental risk to health. The evaluation of government projects whose costs or benefits are uncertain occupies a considerable literature including Arrow and Lind, Fisher, and Graham. The value of reducing the probability of an adverse state (outcome) has been examined by Cook and Graham and more recently by Gallagher and Smith. In the latter two papers it was assumed that the individual at risk had access to perfect insurance or contingent claims markets. In such a perfect world the value of reducing the probability of an adverse state could be bounded by measures which Cook and Graham referred to as ransom and compensation and which Gallagher and Smith show to correspond to the more traditional Hicksian notions of compensating and equivalent variation. If the assumption of perfect contingent claims markets does not hold, it is not possible to set upper and lower bounds on the value of reducing the probability of an adverse state. While general forms of health insurance are available to individuals at risk from an environmental hazard, specific policies do not allow for the continuous adjustment (reallocation of wealth) assumed to occur when the individual has access to perfect markets. In the next section a more plausible model is constructed. It assumes that the individual has a finite set of self-protective actions which he or she may take in response to a risk to future health. In addition, the government may undertake a project to reduce the risk to health. It is assumed that both the selfprotective action and the government project have the ability to influence the subjective (personal) probability of the future states, "continued good health" or "ill-health." There are three major conclusions which emerge from this model. (a) The value of the government project is an option price (Graham) which may be zero or positive. If positive, the benefits from the project may take the form of cost-savings, risk (probability) reduction, or both. (b) The value of the government project is dependent on the set of self-protective actions and may change as new actions become available or the effectiveness of existing actions is reassessed by the individual. (c) The method of contingent valuation, in theory, would appear capable of eliciting the proper option price estimates for the project's value to the individual. It is even possible to distinguish between the value attributable to cost-savings and risk reduction. In the next section I present the model and demonstrate the above conclusions. In the final section an assessment is made of the in-
Improving the response time of a switching regulator using sensit and design/ASTAP

The criteria of stability and response, as measured by the phase margin, and the frequency of the zero dB crossing are crucial to the successful design of the control circuitry of any power supply, including switching regulators. Using several unpublished techniques, these performance functions were written in a form suitable for ASTAP, so that their sensitivities with respect to the statistically specified elements and parameters could be calculated automatically and their corresponding best and worst combinations determined automatically. The same performance criteria were also used in DESIGN/ASTAP to systematically improve the response of the control circuitry of the switching regulator while maintaining its stability, i. e., its phase margin, at 45 degrees.
Extended lanthanide–transition metal arrays with cyanide bridges: syntheses, structures, and catalytic applications

Abstract Systematic synthetic procedures produced several different structural types of extended lanthanide–transition metal (group 10) complexes with cyanide bridges. Of these, one-dimensional ladder arrays containing a Yb–Pd combination have been converted to bimetallic heterogeneous catalysts on an oxide (SiO 2 ) surface that is more effective than supported Pd alone. Two lanthanide–Cu(I) complexes have been prepared. One type, an inclusion complex consists of lanthanide(III) cations encapsulated in the pockets of a three-dimensional anionic array that contains Cu(I)–CN–Cu(I) bridges. The second type, an extended layer complex, consists of joined five-membered rings in a “tile-like” pattern with Ln–CN–Cu and Cu–CN–Cu bridges.
Finite-Size Effects at First-Order Transitions

Finite-size rounding of a first-order phase transition is studied in “block”- and “cylinder”-shaped ferromagnetic scalar spin systems. Crossover in shape is investigated and the universal form of the rounded susceptibility peak is obtained. Scaling forms on the low-temperature side of the critical point are considered both above and below the borderline dimensionality, d > = 4. A method of phenomenological renormalization, applicable to both odd and even field derivatives, is suggested and used to estimate universal amplitudes for two-dimensional Ising models at T = T c .
Pulsars as the Source of the WMAP Haze

The WMAP haze is an excess in the 22 to 93 GHz frequency bands of WMAP extending about 10 degrees from the galactic center. We show that synchrotron emission from electron-positron pairs injected into the interstellar medium by the galactic population of pulsars with energies in the 1 to 100 GeV range can explain the frequency spectrum of the WMAP haze and the drop in the average haze power with latitude. The same spectrum of high energy electron-positron pairs from pulsars, which gives rise to the haze, may also generate the observed excesses in AMS, HEAT and PAMELA. We discuss the spatial morphology of the pulsar synchrotron signal and its deviation from spherical symmetry, which may provide an avenue to determine the pulsar contribution to the haze.
Low-high junction theory applied to solar cells

Abstract Recent use of alloying techniques for rear contact formation has yielded a new kind of Si solar cell, the back surface field (BSF) cell, with abnormally high open-circuit voltage ( V oc ) and improved radiation resistance. Several analytical models for V oc based on the reverse saturation current are formulated to explain these observations. The zero SRV case of the conventional cell model, the drift field model, and the low-high junction (LHJ) model can predict the experimental trends. The LHJ model applies the theory of the LHJ and is considered to reflect a more realistic view of cell fabrication. This model can predict the experimental trends observed for BSF cells. Detailed descriptions and derivations for the models are included. The correspondence between them are discussed. This modeling suggests that the meaning of minority carrier diffusion length measured in BSF cells should be re-examined.
Cursed Resources? Political Conditions and Oil Market Outcomes

We analyze how a country's political institutions affect oil production within its borders. We find a pronounced negative relationship between political openness and volatility in oil production, with democratic regimes exhibiting less volatility than more autocratic regimes. This relationship holds across a number of robustness checks including using different measures of political conditions, instrumenting for political conditions and using several measures of production volatility. Political openness also affects other oil market outcomes, including total production as a share of reserves. Our findings have implications both for interpreting the role of institutions in explaining differences in macroeconomic development and for understanding world oil markets.
Computing the refined stability condition

The classical (inviscid) stability analysis of shock waves is based on the Lopatinski determinant, \Delta---a function of frequencies whose zeros determine the stability of the underlying shock. A careful analysis of \Delta\ shows that in some cases the stable and unstable regions of parameter space are separated by an open set of parameters. Zumbrun and Serre [Indiana Univ. Math. J., 48 (1999) 937--992] have shown that, by taking account of viscous effects not present in the definition of \Delta, it is possible to determine the precise location in the open, neutral set of parameter space at which stability is lost. In particular, they show that the transition to instability under suitably localized perturbations is determined by an "effective viscosity" coefficient. Here, in the simplest possible setting, we propose and implement two new approaches toward the practical computation of this coefficient. Moreover, in a special case, we derive an exact solution of the relevant differential equations.
The Effect of Thermal Matching on the Thermodynamic Performance of Gas Turbine and IC Engine Cogeneration Systems

Computer models have been used to analyze the thermodynamic performance of a gas turbine (GT) cogeneration system and an internal combustion engine (IC) cogeneration system. The purpose of this study was to determine the effect of thermal matching of the load (i.e., required thermal energy) and the output steam fraction (fraction of the thermal output, steam and hot water, which is steam) on the thermodynamic performance of typical cogeneration systems at both full and partial output. The thermodynamic parameters considered were: the net heat rate (NHR), the power-to-heat ratio (PHR), and the fuel savings rate (FSR). With direct use (the steam fractions being different), the NHR of these two systems is similar at full output, the NHR of the IC systems is lower at partial output, and the PHR and the FSR of the GT systems are lower than those of the IC systems over the full range of operating conditions. With thermal matching (to produce a given steam fraction) the most favorable NHR, PHR, and FSR depend on the method of matching the load to the thermal output.
X-ray phase determination by the principle of minimum charge.

When the electron density in a crystal or a quasicrystal is reconstructed from its Fourier modes, the global minimum value of the density is sensitively dependent on the relative phases of the modes. The set of phases that maximizes the value of the global minimum corresponds, by positivity of the density, to the density having the minimum total charge that is consistent with the measured Fourier amplitudes. Phases that minimize the total electronic charge (i.e. the average electron density) have the additional property that the lowest minima of the electron density become exactly degenerate and proliferate within the unit cell. The large number of degenerate minima have the effect that density maxima are forced to occupy ever smaller regions of the unit cell. Thus, by minimization of the electronic charge, the atomicity of the electron density is enhanced as well. Charge minimization applied to simulated crystalline and quasicrystalline diffraction data successfully reproduces the correct phases starting from random initial phases.
Computational-experimental pressure distributions on a transonic, low-aspect-ratio wing

A generic, transonic, supercritical, low aspect-ratio wing was tested at design incidence of 5 deg at Mach numbers from 0.25 to 0.96. Oil-flow studies at the design Mach number of 0.85 showed local-flow separation, which, in retrospect, might have been avoided. At Mach 0.82 with unseparated flow, the surface-flow angles were less than 10 deg. Predictions with the FLO22 transonic potential code are good. Lift interference is strong without tunnel-wall suction. Evidence from this study shows that wings that are optimized for mild shock waves and pressure-recovery gradients generally have small, three-dimensional flow at conditions for unseparated flow.
Mobilities of periodic structures in terms of asymptotic modal properties

The natural frequencies of periodic structures lie in distinct frequency bands and become densely spaced when the number of periodic segments is large. This paper shows that within such frequency bands the structure has modal properties with asymptotic characteristics. This feature of periodic structures is used to develop an asymptotic integral expression for the mobility function.
Light propagation in biological tissue

Biological tissue scatters light mainly in the forward direction where the scattering phase function has a narrow peak. This peak makes it difficult to solve the radiative transport equation. However, it is just for forward peaked scattering that the Fokker-Planck equation provides a good approximation, and it is easier to solve than the transport equation. Furthermore, the modification of the Fokker-Planck equation by Leakeas and Larsen provides an even better approximation and is also easier to solve. We demonstrate the accuracy of these two approximations by solving the problem of reflection and transmission of a plane wave normally incident on a slab composed of a uniform scattering medium.
Complementary Regioselectivity in Rh(III)-Catalyzed Insertions of Potassium Vinyltrifluoroborate via C–H Activation: Preparation and Use of 4-Trifluoroboratotetrahydroisoquinolones

Potassium vinyltrifluoroborate was found to be an efficient partner with benzamide derivatives for Rh(III)-catalyzed annulations. 4-Trifluoroboratotetrahydroisoquinolones were generated under mild conditions, affording a regioisomerically complementary substitution pattern to other alkenes in related reactions. These new boron-containing building blocks were derivatized by N-arylations, retaining the boron substituent for further elaboration.
Simplified Quantum Logic with Trapped Ions

We describe a simplified scheme for quantum logic with a collection of laser-cooled trapped atomic ions. Building on the scheme of Cirac and Zoller, we show how the fundamental controlled-NOT gate between a collective mode of ion motion and the internal states of a single ion can be reduced to a single laser pulse, and the need for a third auxiliary internal electronic state can be eliminated.