cssi/SciSciGPT-SciSciNet huggingface dataset:
The Coase Theorem: Some Experimental Tests

IN The Problem of Social Cost,1 Ronald Coase investigated the economic effects of liability rules for externalities when the affected parties can bargain with each other. More specifically, Coase posited that a change in a liability rule will leave the agents' production and consumption decisions both unchanged and economically efficient within the following (implicit) framework: (a) two agents to each externality (and bargain), (b) perfect knowledge of one another's (convex) production and profit or utility functions, (c) competitive markets, (d) zero transactions costs; (e) costless court system,2 (f) profit-maximizing producers and expected utility-maximizing consumers, (g) no wealth effects, (h) agents will strike mutually advantageous bargains in the absence of transactions costs. This result-commonly called the "Coase Theorem"-has generated a great deal of economic and legal discussion, much of it aimed at exploring the effects of weakening one or another of the model's assumptions.3 Some of the most common theoretical discussions focus on the
Income Distribution, Market Size, and Industrialization

When world trade is costly, a country can profitably industrialize only if its domestic markets are large enough. In such a country, for increasing returns technologies to break even, sales must be high enough to cover fixed setup costs. We suggest two conditions conducive to industrialization. First, a leading sector, such as agriculture or exports, must grow and provide the source of autonomous demand for manufactures. Second, income generated by this leading sector must be broadly enough distributed that it materializes as demand for a broad range of domestic manufactures. These conditions have been important in several historical growth episodes.
Towards optimal performance-area trade-off in adders by synthesis of parallel prefix structures

This paper proposes an efficient algorithm to synthesize prefix graph structures that yield adders with the best performance-area trade-off. For designing a parallel prefix adder of a given bit-width, our approach generates prefix graph structures to optimize an objective function such as size of prefix graph subject to constraints like bit-wise output logic level. Besides having the best performance-area trade-off our approach, unlike existing techniques, can (i) handle more complex constraints such as maximum node fanout or wire-length that impact the performance/area of a design and (ii) generate several feasible solutions that minimize the objective function. Generating several optimal solutions provides the option to choose adder designs that mitigate constraints such as wire congestion or power consumption that are difficult to model as constraints during logic synthesis. Experimental results demonstrate that our approach improves performance by 3% and area by 9% over even a 64-bit full custom designed adder implemented in an industrial high-performance design.
Boundary depth in Floer theory and its applications to Hamiltonian dynamics and coisotropic submanifolds

We assign to each nondegenerate Hamiltonian on a closed symplectic manifold a Floer-theoretic quantity called its “boundary depth,” and establish basic results about how the boundary depths of different Hamiltonians are related. As applications, we prove that certain Hamiltonian symplectomorphisms supported in displaceable subsets have infinitely many nontrivial geometrically distinct periodic points, and we also significantly expand the class of coisotropic submanifolds which are known to have positive displacement energy. For instance, any coisotropic submanifold of contact type (in the sense of Bolle) in any closed symplectic manifold has positive displacement energy, as does any stable coisotropic submanifold of a Stein manifold. We also show that any stable coisotropic submanifold admits a Riemannian metric that makes its characteristic foliation totally geodesic, and that this latter, weaker, condition is enough to imply positive displacement energy under certain topological hypotheses.
A decision-guidance framework for sustainability performance analysis of manufacturing processes

Life cycle assessment (LCA) frameworks are widely used to assess the sustainability of manufacturing processes. Although they have several advantages such as systematic estimation and efficiency, they have significant limitations due to a lack of functionality to perform sustainability analysis. Specifically, they do not fully support dynamic and diverse characteristics of manufacturing processes nor cover technical details for the further analysis, such as simulation, prediction, and optimization. In addition, they do not provide a unified modeling environment in which to perform various sustainability analysis tasks. In this paper, a decision-guidance framework has been presented to improve sustainability in manufacturing processes while addressing the deficiencies in existing LCA frameworks. The proposed framework consists of six phases: goal and scope definition, data collection, model generation, sustainability performance analysis, interpretation, and decision support and guidance, which is designed in terms of functionality, usability, flexibility/reusability, and interoperability. To demonstrate the use of the framework, a case study of a turning process has been performed.
Algorithms for Equality and Unification in the Presence of Notational Definitions

Abstract Notational definitions are pervasive in mathematical practic and are therefore supported in must automated theorem proving systems. In this paper we investigate their interaction with algorithms for testing equality and unification. We propose a syntactic criterion on definitions which avoids their expansion in many cases without losing soundess or completeness with respect to βηδ-conversion.
Hop chains: Secure routing and the establishment of distinct identities

We present a secure routing protocol that is immune to Sybil attacks and that can tolerate collusion of Byzantine routers. It can tolerate either initial collusion of Byzantine routers or runtime collusion of non-adjacent Byzantine routers, both in the absence of runtime collusion between adjacent routers. For these settings, the calculated distance from a destination to a node is not smaller than the actual shortest distance from the destination to the node. The protocol can also simultaneously tolerate initial collusion of Byzantine routers and runtime collusion of adjacent Byzantine routers but in the absence of runtime collusion between non-adjacent routers. For this setting, it guarantees a bound on the difference between the calculated distance and the actual shortest distance. The bound depends on the number of Byzantine routers on a path. The protocol makes very weak timing assumptions and requires synchronization only between neighbors or second neighbors. We propose to use this protocol for secure localization of routers using hop-count distances, which can be then used as a proof of identity of nodes.
The mictomagnetic transition in Cu-Mn

Abstract The isothermal magnetization processes in the alloy Cu81Mn19 are found to undergo a qualitative change, involving the sudden appearance of magnetic hysteresis, at the temperature (∼ 85°K) at which the initial susceptibility has a sharp maximum.
Reductive arene ortho-silanolization of aromatic esters with hydridosilyl acetals.

This work describes the design and application of a single-pot, reductive arene C–H silanolization of aromatic esters for synthesis of ortho-formyl arylsilanols. This strategy involves a sequence of two transition metal (Ir and Rh)-catalyzed reactions for reductive arene ortho-silylation directed by hydridosilyl acetals and hydrolysis.
The Energy dependence of the saturation momentum from RG improved BFKL evolution

Abstract We study the energy dependence of the saturation momentum in the context of the collinearly improved Leading and Next to Leading BFKL evolution, and in the presence of saturation boundaries. We find that the logarithmic derivative of the saturation momentum is varying very slowly with Bjorken- x , and its value is in agreement with the Golec-Biernat and Wusthoff model in the relevant x region. The scaling form of the amplitude for dipole–dipole or dipole–hadron scattering in the perturbative side of the boundary is given.
Dividend variability and stock market swings

This paper examines the extent to which swings in stock prices can be related to variations in the discounted value of expected future dividends when investors face uncertainty about their future behaviour. I develop an econometric model that accounts for the instability of U.S. dividend growth and discount rates during the past 120 years. Estimates of the model reveal that changing forecasts of future dividend growth account for more than 90% of the predictable variations in dividend-prices. The estimates also imply that instability in the dividend and discount rate processes contribute significantly to the predictability of long-horizon stock returns.
Black holes in five-dimensional gauged supergravity with higher derivatives

We examine five-dimensional = 2 gauged supergravity including terms up to four derivatives. These additional terms correspond to the supersymmetric completion of R2, and were originally obtained in hep-th/0611329 using conformal supergravity techniques. Here we integrate out the auxiliary fields and obtain the on-shell action for minimal supergravity with such corrections. We then construct R-charged AdS black holes to linear order in the four derivative terms and investigate the effect of these corrections on their thermodynamical properties. Finally, we relate the geometrical coefficients governing the four-derivative corrections to gauge theory data using holographic anomaly matching. This enables us to obtain a microscopic expression for the entropy of the solutions.
Minimal Betti Numbers

We give conditions for determining the extremal behavior for the (graded) Betti numbers of squarefree monomial ideals. For the case of non-unique minima, we give several conditions which we use to produce infinite families, exponentially growing with dimension, of Hilbert functions which have no smallest (graded) Betti numbers among squarefree monomial ideals and all ideals. For the case of unique minima, we give two families of Hilbert functions, one with exponential and one with linear growth as dimension grows, that have unique minimal Betti numbers among squarefree monomial ideals.
Nonparametric estimation and inference on conditional quantile processes

This paper presents estimation methods and asymptotic theory for the analysis of a nonparametrically specified conditional quantile process. Two estimators based on local linear regressions are proposed. The first estimator applies simple inequality constraints while the second uses rearrangement to maintain quantile monotonicity. The bandwidth parameter is allowed to vary across quantiles to adapt to data sparsity. For inference, the paper first establishes a uniform Bahadur representation and then shows that the two estimators converge weakly to the same limiting Gaussian process. As an empirical illustration, the paper considers a dataset from Project STAR and delivers two new findings.
The Political Economy of Trans-Pacific Business Linkages

The current level and future evolution of trans-Pacific business linkages are tightly linked to domestic politics in Latin American countries. Where the structure of a nation's political institutions offer credible checks and balances against discretionary policymaking, external linkages including those with Pacific partners are stronger. Future liberalization including the formation of an FTAA is more likely when new policymakers arrive in office or when existing policymakers feel strong internal or external pressure to shift the course of their trade policy. A given liberalization is more likely to be sustained when coupled with short-term observable improvement in social and economic indicators. Countries with political institutions that fail to limit policymakers' discretion are particularly sensitive to a failure to demonstrate clear and immediate results. An analysis of the potential of an FTAA to influence trans-Pacific business linkages based on these arguments suggests that adoption is far from certain and that northern and southern countries alike will have to design an agreement with particular attention to social and economic consequences in Latin American countries.
Calibration system for the 3072 channel scintillating fiber/VLPC test facility for the D0 upgrade at Fermilab

A calibration system for the testing of scintillating fibers and visible light photon counters (VLPC) has been constructed at Notre Dame and installed in a cosmic ray test facility at Fermilab. The purpose of the cosmic ray test is to assess the viability of the fiber tracking technique for the upgraded D0 central detector. The purpose of this calibration system is to monitor the performance of the 3072 fiber VLPC detector elements for continuity, gain and uniformity of response. Here we report on the design, construction and operation of the calibration system. >
A general method for the reductive dechlorination of 4,4-dichlorocyclobutenones

Abstract Exposure of 4,4-dichlorocyclobutenones to the action of zinc dust in ethanol containing 5 equiv each of AcOH and TMEDA results in smooth reductive dechlorination producing simple cyclobutenones.
The robustness of the independent private value model in Bayesian mechanism design

In a Bayesian model of group decision-making, dependence among the agents' types has been shown to have a beneficial effect on the design of incentive compatible mechanisms that achieve the efficient choice associated with complete information. This effect is shown here to depend as much upon the use of large monetary transfers among the agents as it does upon dependence: if the transfers are bounded in magnitude, then nonexistence in the case of independence of an efficient, incentive compatible, ex ante budget-balanced and interim individually rational mechanism is robust to the introduction of a small amount of dependence among types. This robustness result supports the use of the simplifying assumption of independence in mechanism design.
Effective actions for bosonic topological defects.

A gauge field theory is considered which admits p-dimensional topological defects, expanding the equations of motion in powers of the defect thickness. In this way an effective action and effective equation of motion is derived for the defect in terms of the coordinates of the p-dimensional worldsurface defined by the history of the core of the defect.
Gender Differences in Substrate Utilisation During Exercise

The selection and utilisation of metabolic substrates during endurance exercise are regulated by a complex array of effectors. These factors include, but are not limited to, endurance training and cardiorespiratory fitness, exercise intensity and duration, muscle morphology and histology, hormonal factors and diet. Although the effects of these factors on substrate utilisation patterns are well understood, the variation in substrate utilisation during endurance exercise between males and females is not. Because of the extreme heterogeneity in exercise protocols and individuals studied, the differences in substrate utilisation between males and females remain somewhat inconclusive. Regardless of heterogeneity, if the results from studies are interpreted collectively, an apparent gender difference in the selection and metabolism of substrates can be seen in sedentary individuals. However, this difference between genders diminishes as the level of cardiorespiratory fitness is increased to that of highly trained individuals.
A Theory for the Radius of the Transiting Giant Planet HD 209458B

Using a full frequency-dependent atmosphere code that can incorporate irradiation by a central primary star, we calculate self-consistent boundary conditions for the evolution of the radius of the transiting planet HD 209458b. Using a well-tested extrasolar giant planet evolutionary code, we then calculate the behavior of this planet's radius with age. The measured radius is in fact a transit radius that resides high in HD 209458b's inflated atmosphere. Using our derived atmospheric and interior structures, we find that irradiation plus the proper interpretation of the transit radius can yield a theoretical radius that is within the measured error bars. We conclude that if HD 209458b's true transit radius is at the lower end of the measured range, an extra source of core heating power is not necessary to explain the transit observations.
Isolation and synthesis of caprolactins A and B, new caprolactams from a marine bacterium

Abstract Two new caprolactams have been isolated from an unidentified Gram-positive bacterium obtained from a deep-ocean sediment sample. Caprolactins A (1) and B (2), which were obtained as an inseparable mixture, are composed of cyclic-L-lysine linked to 7-methyloctanoic acid and 6-methyloctanoic acid, respectively. The structures were proposed using spectroscopic methods and confirmed by synthesis. Both caprolactins A and B are cytotoxic towards human epidermoid carcinoma (KB) cells and human colorectal adenocarcinoma (LoVo) cells and exhibit antiviral activity towards Herpes simplex type II virus.
Noncontact measurement of the elastic constants of plutonium at elevated temperatures

Abstract The elastic constants at elevated temperature were measured for pure a -phase Pu and Pu-1wt%Ga delta-stabilized alloy. Test temperatures ranged from ambient to 119°C for the a -phase Pu and to about 500° C for the delta-stabilized Pu alloy. A recently developed noncontact testing technique was used that incorporated high energy laser deposition with Michelson displacement interferometry. Young's modulus and the shear modulus decreased linearly as the temperature increased. The testing was limited by mirror degradation at phase change temperatures.
Increased Efficiency in Cross-Metathesis Reactions of Sterically Hindered Olefins

Efficiency in olefin cross-metathesis reactions is affected upon reducing the steric bulk of N-heterocyclic carbene ligands of ruthenium-based catalysts. For the formation of disubstituted olefins containing one or more allylic substituents, the catalyst bearing N-tolyl groups is more efficient than the corresponding N-mesityl catalyst. In contrast, the formation of trisubstituted olefins is more efficient using the N-mesityl-containing catalyst. A hypothesis to explain this dichotomy is described.
Signatures of technicolor models with the GIM mechanism

Abstract We investigate the production and the decays of pseudo-Goldstone bosons (PGBs) predicted by technicolor theories with the GIM mechanism (TC-GIM). The TC-GIM models contain exotic fermion families that do not interact under weak SU(2), but they do have color and hypercharge interactions. These fetmions form PGBs, which are the lightest exotic particles in the TC-GIM models. The spectrum of PGBs consists of color octets, leptoquarks and neutral particles. The masses of leptoquarks and color octets depend on a free parameter—the scale of confining interactions. Characteristic for TC-GIM models is a very light (≈ GeV) neutral particle with anomalous couplings to gauge boson pairs. We show how current experiments constrain the free parameters of the models. The best tests are provided by the pp pp → TT and e + e − → P 0 γ reactions. Experiments at LHC and NLC can find PGBs of TC-GIM models in a wide range of parameter space. However, TC-GIM models can be distinguished from other TC models only if several PGBs are discovered.
Does Sutton apply to supermarkets

This paper presents empirical evidence that endogenous fixed costs play a central role in determining the equilibrium structure of the supermarket industry. Using the framework developed in Sutton (1991), I construct a model of supermarket competition where escalating investment in firm level distribution systems is driven by the incentive to produce a greater variety of products in every store. Using the observed networks of store and warehouse locations, I identify 51 distinct geographic markets covering nearly the entire United States and empirically verify their relative independence. Employing a store level census, I demonstrate that the industrial organization of these markets is a natural oligopoly in which a small number of firms (between 4 and 6) capture the majority of sales, regardless of market size. While the total number of firms does scale up with the size of the market, the expansion is limited to a competitive fringe of low quality stores.
The period lattice for Enriques surfaces

We simplify the usual statement of the Torelli theorem for complex Enriques surfaces, by means of a lattice-theoretic trick. This allows easy proofs of several known results, which previously required intricate arithmetic arguments. The main new result is that the moduli space has contractible universal cover.
Copper(II) Triflate, a New Reagent for Mild Dehydration of Alcohols: Synthetic Usefulness and Mechanistic Insight

The effectiveness of copper(II) triflate (copper(II) trifluoromethanesulfonate) as a new dehydrating reagent for a variety of alcohols has been demonstrated. Based on several control experiments, a possible mechanism is suggested.
Novel quenched disorder fixed point in a two-temperature lattice gas

We investigate the effects of quenched randomness on the universal properties of a two-temperature lattice gas. The disorder modifies the dynamical transition rates of the system in an anisotropic fashion, giving rise to a new fixed point. We determine the associated scaling form of the structure factor, quoting critical exponents to two-loop order in an expansion around the upper critical dimension dc = 7. The close relationship with another quenched disorder fixed point, discovered recently in this model, is discussed.
A renormalized equation for the three-body system with short-range interactions

We study the three-body system with short-range interactions characterized by an unnaturally large two-body scattering length. We show that the off-shell scattering amplitude is cutoff independent up to power corrections. This allows us to derive an exact renormalization group equation for the three-body force. We also obtain a renormalized equation for the off-shell scattering amplitude. This equation is invariant under discrete scale transformations. The periodicity of the spectrum of bound states originally observed by Efimov is a consequence of this symmetry. The functional dependence of the three-body scattering length on the two-body scattering length can be obtained analytically using the asymptotic solution to the integral equation. An analogous formula for the three-body recombination coefficient is also obtained.
Finite populations induce metastability in evolutionary search

Abstract We introduce an analytical model that predicts the dynamics of a simple evolutionary algorithm in terms of the flow in the space of fitness distributions. In the limit of infinite populations the dynamics is derived in closed form. We show how finite populations induce periods of stasis - “fitness epochs” - and rapid jumps - “innovations”. The analysis identifies the epochs with the flow's metastable fixed points and gives exact predictions of epoch fitness level and population distribution.
Scaling laws for drag of a compliant body in an incompressible viscous flow

Motivated by an important discovery on the drag scaling law (the 4/3 power law) of a flexible fibre in a flowing soap film by Alben et al. (Nature vol. 420, 2002, p.479) at high Reynolds numbers (2000<Re<40000), we investigate drag scaling laws at moderate Re for a compliant fibre tethered at the midpoint and submerged in an incompressible viscous flow using the immersed boundary (IB) method. Our work shows that the scaling of drag with respect to oncoming flow speed varies with Re, and the exponents of the power laws decrease monotonically from approximately 2 towards 4/3 as Re increases from 10 to 800.
Lifestyle changes and risks of criminal victimization

Routine activity/lifestyle theories have been used to explain temporal changes in crime rates, the social ecology of crime, and individuals' risks of criminal victimization. Using a panel of 33,773 individuals and 19,005 households at two points in time, the current study extends previous research by examining whether changes in lifestyles are associated with changes in individuals' risks of personal and property victimization. Changes in lifestyles which signal greater target visibility or exposure to motivated offenders (greater daytime and nighttime activity outside the home) and reduced guardianship (decreases in the number of household members) are generally associated with increased risks of both types of victimization. Persons who maintained high levels of nighttime activity outside the household were also more likely to remain victims at both time periods. However, “active” lifestyle changes (increased precautionary actions) did not have their expected impact on reducing victimization risks, and several other changes over time also were inconsistent with expectations. The paper concludes with a discussion of the role of “passive” and “active” lifestyle changes on victimization risks and the implications of our findings for developing sociological theories of criminal victimization.
Integer solution to synthesis of communication networks

This paper describes a polynomial-time algorithm for the following problem: Let ri,j be the given requirements for all i, j ∈ {1, ', n}, with ri,j = rj,i for i, j. Find integer capacities ci,j for all i, j ∈ {1, ', n} such that considering 1, ', n as the vertices of an undirected network N, with capacities ci,j: i for for all i â j there exists a flow in N from i to j of value, at least ri,j; ii âi<jci,j is minimized. This is the integer version of Gomory and Hu's problem to synthesize an undirected network. It is shown that rounding holds when there is no node with unit potential.
Effect of Intermolecular Forces on the Static and Dynamic Performance of Air Bearing Sliders: Part II—Dependence of the Stability on Hamaker Constant, Suspension Preload and Pitch Angle

Intermolecular and surface forces contribute significantly to the total forces acting on air bearing sliders for flying heights below 5 nm. Their contributions to the total force increase sharply with the reduction in flying height, and hence their existence can no longer be ignored in air bearing simulation for hard disk drives. Various experimentally observed dynamic instabilities can be explained by the inclusion of these forces in the model for low flying sliders. In this paper parametric studies are presented using a 3-DOF model to better understand the effect of the Hamaker constants, suspension pre load and pitch angle on the dynamic stability/instability of the sliders. A stiffness matrix is used to characterize the stability in the vertical, pitch, and roll directions. The fly height diagrams are used to examine the multiple equilibriums that exist for low flying heights. It has been found that the system instability increases as the magnitude of the van der Waals force increases. It has also been found that higher suspension pre load and higher pitch angles tend to stabilize the system.
Forced spreading of films and droplets of colloidal suspensions

When a thin film of a colloidal suspension flows over a substrate, uneven distribution of the suspended particles can lead to an uneven coating. Motivated by this phenomenon, we analyse the flow of perfectly wetting films and droplets of colloidal suspensions down an inclined plane. Lubrication theory and the rapid-vertical-diffusion approximation are used to derive a coupled pair of one-dimensional partial differential equations describing the evolution of the interface height and particle concentration. Precursor films are assumed to be present, the colloidal particles are taken to be hard spheres, and particle and liquid dynamics are coupled through a concentration- dependent viscosity and diffusivity. We find that for sufficiently high Peclet numbers, even small initial concentration inhomogeneities produce viscosity gradients that cause the film or droplet front to evolve continuously in time instead of travelling without changing shape as happens in the absence of colloidal particles. At high enough particle concentrations, particle diffusion can lead to the formation of long-lived secondary flow fronts in films. Our results suggest that particle concentration gradients can have a dramatic influence on interface evolution in flowing films and droplets, a finding which may be relevant for understanding the onset of patterns that are observed experimentally.
Fire models for assessment of nuclear power plant fires

Abstract This paper reviews the state-of-the-art in available fire models for the assessment of nuclear power plant fires. The advantages and disadvantages of three basic types of fire models (zone, field, and control volume) and Sandia's experience with these models will be discussed. It is shown that the type of fire model selected to solve a particular problem should be based on the information that is required. Areas of concern which relate to all nuclear power plant fire models are identified.
Occultation and Microlensing

Occultation and microlensing are different limits of the same phenomenon of one body passing in front of another body. We derive a general exact analytic expression that describes both microlensing and occultation in the case of spherical bodies with a source of uniform brightness and a nonrelativistic foreground body. We also numerically compute the case of a source with quadratic limb darkening. In the limit that the gravitational deflection angle is comparable to the angular size of the foreground body, both microlensing and occultation occur as the objects align. Such events can be used to constrain the size ratio of the lens and source stars, the limb-darkening coefficients of the source star, and the surface gravity of the lens star (if the lens and source distances are known). Application of these results to microlensing during transits in binaries and giant-star microlensing is discussed. These results unify the microlensing and occultation limits and should be useful for rapid model fitting of microlensing, eclipse, and "micro-occultation" events.
Polarization of atomic radiation in stochastic plasma fields

When a laser pulse of certain polarization or an electron beam excites atoms in a plasma, the atomic spectrum of the radiation emitted by the atoms exhibits differently polarized line core and line wings. This unusual effect, which is predicted to occur under a variety of conditions, can be accompanied by the appearance of the forbidden component in the spectrum, with polarization opposite to that of the exciting laser pulse.
Modeling the conditional distribution of interest rates as a regime-switching process

Abstract This paper develops a generalized regime-switching (GRS) model of the short-term interest rate. The model allows the short rate to exhibit both mean reversion and conditional heteroskedasticity and nests the popular generalized autoregressive conditional heteroskedasticity (GARCH) and square root process specifications. The conditional variance process accommodates volatility clustering and dependence on the level of the interest rate. A first-order Markov process with state-dependent transition probabilities governs the switching between regimes. The GRS model is compared with various existing models of the short rate in terms of (1) the statistical fit of short-term interest rate data and (2) out-of-sample forecasting performance.
Cardiovascular effects of antidepressant drugs: updated

It has long been evident that the tricyclic antidepressants have serious cardiovascular effects. This becomes an increasingly important issue as patient populations age. In addition, there is now strong evidence that depression increases the incidence of ischemic heart disease. Taken together these issues make the safety of antidepressant drugs even more important. The tricyclic antidepressants have long been able to produce orthostatic hypotension and this propensity is increased in patients with cardiac disease. In addition, the tricyclics prolong conduction and in overdose this leads to serious cardiac complications. Although only a limited amount of data are available, the serotonin reuptake inhibitors show no evidence of harm. In fact, there is some evidence that the selective serotonin reuptake inhibitor drugs may be beneficial for patients with cardiovascular disease.
A domain-decomposed fast poisson solver on a rectangle

We present a new domain decomposed fast Poisson solver on a rectangle divided into parallel strips or boxes. The method first performs uncoupled fast solves on each subdomain, and then the interface variables are computed exactly by Fast Fourier Transform, without computing or inverting the capacitance matrix explicitly. Finally, the solution on the interior of the subdomains can be computed by one more fast solve on each subdomain. This method is especially suited for parallel implementation, since the independent problems in the subdomains can be solved in parallel, and the communication involves the interface variables only.
Hydrogen bond controlled aggregation of guanidinium-carboxylate derivatives in the solid state

In this paper, we report the synthesis and aggregation properties of new self-complementary organic molecules containing guanidinium and carboxylate groups. The crystal structures of the guanidinium carboxylates showed linear bidentate hydrogen bonding between the guanidinium and the carboxylate groups. In the case of phenyl derivative 7, steric factors force a non-planar geometry for the hydrogen bonding subunit. Substitution of the phenyl by a pyridine leads to the formation of an intramolecular hydrogen bond and a planar conformation for the subunit. As a result, the simple intramolecularly hydrogen bonded molecule maintains a rigid control of binding group disposition in a manner similar to more complex multiple fused ring systems.
Effect of temperature on the uniform field breakdown strength of electronegative gases

In general, the electron attachment rate constant ka (〈e〉, T), as a function of the mean electron energy 〈e〉 and temperature T for electronegative gases which attach electrons nondissociative ily, decreases greatly with T from room temperature to T≲600 K, while the ka (〈e〉, T) of electronegative gases which attach electrons dissociatively increases with increasing T. Based on recent studies at our laboratory on ka (〈e〉, T), we investigated the variation with T (∼295–575 K) of the uniform field breakdown strength, (E/N)lim, for three classes of electronegative gases: (a) gases such as c‐C4F8 (and c‐C4F6, 1−C3F6) which attach strongly low‐energy (≲1 eV) electrons nondissociatively and for which ka (〈e〉, T) decreases precipitously with T above ambient: (b) gases such as C2F6 and CF3Cl which attach electrons exclusively dissociatively and whose ka (〈e〉, T) increases with T; and (c) gases such as C3F8 and n‐C4F10 which attach electrons both nondissociatively and dissociatively over a common low‐energy range an...
Fast Ultrasonic Imaging in a Liquid Filled Pipe

A new method is described for the imaging of the interior of a liquid filled metallic pipe using acoustical techniques. The experimental system incorporates an array of 20 acoustical transducers and is capable of capturing the images of moving bubbles at a frame rate in excess of 300/s. The transducers are mounted circumferentially around the pipe. Each transducer is pulsed in sequence, and the echoes reflected from vapor bubbles in the interior are detected, digitized and processed by a computer to generate an image. The high rate of speed was achieved by the use of newly developed software and electronic circuitry. This approach has eliminated most of the spurious echo signals which degraded the performance of previous imaging systems. The capability of the method is illustrated by imaging actual vapor bubbles in rapid sequence in the pipe.
Atomic-beam measurement of parity nonconservation in cesium

We present a new measurement of parity nonconservation in cesium. In this experiment, a laser excited the 6S\ensuremath{\rightarrow}7S transition in an atomic beam in a region of static electric and magnetic fields. The quantity measured was the component of the transition rate arising from the interference between the parity nonconserving amplitude, ${\mathrm{scrE}}_{\mathrm{PNC}}$, and the Stark amplitude, \ensuremath{\beta}E. Our results are Im${\mathrm{scrE}}_{\mathrm{PNC}/\mathrm{\ensuremath{\beta}}=\mathrm{\ensuremath{-}}1.65\ifmmode\pm\else\textpm\fi{}0.13}$ mV/cm and ${C}_{2p}$=-2\ifmmode\pm\else\textpm\fi{}2, where ${C}_{2p}$ is the proton-axial-vector--electron-vector neutral-current coupling constant. These results are in agreement with previous less precise measurements in cesium and with the predictions of the electroweak standard model. We give a detailed discussion of the experiment with particular emphasis on the treatment and elimination of systematic errors. This experimental technique will allow future measurements of significantly higher precision.
The Resonant Response of a Rectangular Plate With an Elastic Edge Restraint

Peak resonant response of thin rectangular plate with elastic edge restraint under concentrated load
Gravitational radiation from strongly magnetized white dwarfs

The magnetic fields of white dwarfs distort their shape generating an anisotropic moment of inertia. A magnetized white dwarf that rotates obliquely relative to the symmetry axis has a mass quadrupole moment that varies in time, so it will emit gravitational radiation. The Laser Interferometer Space Antenna (LISA) mission may be able to detect the gravitational waves from two nearby, rapidly rotating white dwarfs.
Hybrid position/force control of manipulators

A new conceptually simple approach to controlling compliant motions of a robot manipulator is presented. The 'hybrid' technique described combines force and torque information with positional data to satisfy simultaneous position and force trajectory constraints specified in a convenient task related coordinate system. Analysis, simulation, and experiments are used to evaluate the controller's ability to execute trajectories using feedback from a force sensing wrist and from position sensors found in the manipulator joints. The results show that the method achieves stable, accurate control of force and position trajectories for a variety of test conditions.
Introduction to the Special Issue on Marketing and Operations Management Interfaces and Coordination

In this special issue, the contributing authors address several emerging marketing and operations interface problems and develop innovative approaches for solving them. Specifically, by explicitly modeling active consumer behavior under different pricing schemes, the papers in this special issue examine how firms can coordinate their marketing and operations to improve their competitiveness and profit. The papers also provide insights on how to develop and operate new and innovative market mechanisms.
The oscillatory behavior of the high-temperature expansion of Dyson's hierarchical model: A renormalization group analysis

We calculate 800 coefficients of the high-temperature expansion of the magnetic susceptibility of Dyson's hierarchical model with a Landau-Ginzburg measure. Log-periodic corrections to the scaling laws appear as in the case of an Ising measure. The period of oscillation appears to be a universal quantity given in good approximation by the logarithm of the largest eigenvalue of the linearized RG transformation, in agreement with a possibility suggested by Wilson and developed by Niemeijer and van Leeuwen. We estimate γ to be 1.300 (with a systematic error of the order of 0.002), in good agreement with the results obtained with other methods, such as the e-expansion. We briefly discuss the relationship between the oscillations and the zeros of the partition function near the critical point in the complex temperature plane.
Laser flash photolysis generation of high-valent transition metal-oxo species: insights from kinetic studies in real time.

High-valenttransition metal−oxo species are active oxidizing species in many metal-catalyzed oxidation reactions in both Nature and the laboratory. In homogeneous catalytic oxidations, a transition metal catalyst is oxidized to a metal−oxo species by a sacrificial oxidant, and the activated transition metal−oxo intermediate oxidizes substrates. Mechanistic studies of these oxidizing species can provide insights for understanding commercially important catalytic oxidations and the oxidants in cytochrome P450 enzymes. In many cases, however, the transition metal oxidants are so reactive that they do not accumulate to detectable levels in mixing experiments, which have millisecond mixing times, and successful generation and direct spectroscopic characterization of these highly reactive transients remain a considerable challenge. Our strategy for understanding homogeneous catalysis intermediates employs photochemical generation of the transients with spectroscopic detection on time scales as short as nanoseco...
A PARAMETER SPACE EXPLORATION OF GALAXY CLUSTER MERGERS. I. GAS MIXING AND THE GENERATION OF CLUSTER ENTROPY

We present a high-resolution set of adiabatic binary galaxy cluster merger simulations using FLASH. These are the highest resolution simulations to date of such mergers using an adaptive mesh refinement grid-based code with Eulerian hydrodynamics. In this first paper in a series, we investigate the effects of merging on the entropy of the hot intracluster gas, specifically with regard to the ability of merging to heat and disrupt cluster "cool cores." We find, in line with recent works, that the effect of fluid instabilities that are well resolved in grid-based codes is to significantly mix the gases of the two clusters and to significantly increase the entropy of the gas of the final merger remnant. This result is characteristic of mergers over a range of initial mass ratio and impact parameter. In line with this, we find that the kinetic energy associated with random motions is higher in our merger remnants which have high-entropy floors, indicating that the motions have efficiently mixed the gas and heated the cluster core with gas of initially high entropy. We examine the implications of this result for the maintenance of high-entropy floors in the centers of galaxy clusters and the derivation of the properties of dark matter from the thermal properties of the X-ray-emitting gas.
CP violation and electroweak baryogenesis in extensions of the standard model

Abstract We develop a new and general method to calculate the effects of CP violation from extensions of the standard model on the mechanism of electroweak baryogenesis. We illustrate its applicability in the framework of two-higgs doublet models.
Keck Deep Fields. I. Observations, Reductions, and the Selection of Faint Star-forming Galaxies at Redshifts z ~ 4, 3, and 2*

We introduce a very deep, lim ~ 27, multicolor imaging survey of very faint star-forming galaxies at z ~ 4, 3, 2.2, and 1.7. This survey, carried out on the Keck I telescope, uses the very same UnGI filter system that is employed by the Steidel team to select galaxies at these redshifts and thus allows us to construct identically selected but much fainter samples. However, our survey reaches ~1.5 mag deeper than the work of Steidel and his group, letting us probe substantially below the characteristic luminosity L* and thus study the properties and redshift evolution of the faint component of the high-z galaxy population. The survey covers 169 arcmin2 in three spatially independent patches on the sky and—to ≤ 27—contains 427 GI-selected z ~ 4 Lyman break galaxies, 1481 UnG-selected z ~ 3 Lyman break galaxies, 2417 UnG-selected z ~ 2.2 star-forming galaxies, and 2043 UnG-selected z ~ 1.7 star-forming galaxies. In this paper, the first in a series, we introduce the survey, describe our observing and data reduction strategies, and outline the selection of our z ~ 4, 3, 2.2, and 1.7 samples.
Pyramid algorithms as models of human cognition

There is growing body of experimental evidence showing that human perception and cognition involves mechanisms that can be adequately modeled by pyramid algorithms. The main aspect of those mechanisms is hierarchical clustering of information: visual images, spatial relations, and states as well as transformations of a problem. In this paper we review prior psychophysical and simulation results on visual size transformation, size discrimination, speed-accuracy tradeoff, figure-ground segregation, and the traveling salesman problem. We also present our new results on graph search and on the 15-puzzle.
Effective tachyonic potential in closed string field theory

Abstract We calculate the effective tachyonic potential in closed string field theory up to the quartic term in the tree approximation. This involves an elementary four-tachyon vertex and a sum over the infinite number of Feynman graphs with an intermediate massive state. We show that both the elementary term and the sum can be evaluated as integrals of some measure over different regions in the moduli space of four-punctured spheres. We show that both elementary and effective couplings give negative contributions to the quartic term in the tachyon potential. Numerical calculations show that the fourth-order term is big enough to destroy a local minimum which exists in the third-order approximation.
Gene selection with guided regularized random forest

The regularized random forest (RRF) was recently proposed for feature selection by building only one ensemble. In RRF the features are evaluated on a part of the training data at each tree node. We derive an upper bound for the number of distinct Gini information gain values in a node, and show that many features can share the same information gain at a node with a small number of instances and a large number of features. Therefore, in a node with a small number of instances, RRF is likely to select a feature not strongly relevant. Here an enhanced RRF, referred to as the guided RRF (GRRF), is proposed. In GRRF, the importance scores from an ordinary random forest (RF) are used to guide the feature selection process in RRF. Experiments on 10 gene data sets show that the accuracy performance of GRRF is, in general, more robust than RRF when their parameters change. GRRF is computationally efficient, can select compact feature subsets, and has competitive accuracy performance, compared to RRF, varSelRF and LASSO logistic regression (with evaluations from an RF classifier). Also, RF applied to the features selected by RRF with the minimal regularization outperforms RF applied to all the features for most of the data sets considered here. Therefore, if accuracy is considered more important than the size of the feature subset, RRF with the minimal regularization may be considered. We use the accuracy performance of RF, a strong classifier, to evaluate feature selection methods, and illustrate that weak classifiers are less capable of capturing the information contained in a feature subset. Both RRF and GRRF were implemented in the ''RRF'' R package available at CRAN, the official R package archive.
On the equivariant cohomology of rotation groups and Stiefel manifolds

Abstract In this paper, we compute the RO ( Z / 2 ) -graded equivariant cohomology of rotation groups and Stiefel manifolds with particular involutions.
Design and synthesis of a hapten for the radioimmunoassay of bupropion.

The synthesis of a hapten useful in the radioimmunoassay of bupropion is described. Since bupropion has no functional group that can be easily derivatized, a hydroxypropyl group was incorporated into the molecule. Studies in cross-reactivity with possible metabolites required the synthesis of the 4′-hydroxy analogue of bupropion. This synthesis is also described.