cssi/SciSciGPT-SciSciNet huggingface dataset:
Why do incumbents sometimes succeed? Investigating the role of interorganizational trust on the adoption of disruptive technology

Abstract Previous research has noted that new firms traditionally have more success with the diffusion of disruptive technologies than do incumbent firms. For the development of disruptive technologies, newer firms appear to be advantageous as they are generally more flexible in resource allocation. However, exceptions can be found in various industries in which incumbents have been able to succeed with their own disruptive technologies. One possible explanation for these exceptions is the influence of pre-existing levels of trust already developed between incumbents and potential buyers of disruptive technologies. In order to explore this further, this article provides a link between interorganizational trust and the adoption of new, disruptive technologies in industrial markets. By surveying 134 current and potential Software-as-a-Service (SaaS) users, we show how pre-existing, interorganizational trust impacts the perceptions a potential buyer has towards a disruptive technology and how these perceptions influence a buyers' intention to adopt a new, disruptive technology. Beyond trust, we use perceived ease of use, perceived value, perceived usefulness and financial stability to create a predictive model for intention to adopt. Holistically, this article provides insight on how buyer–supplier relationships generally favor incumbent firms and can impact a buyers' perception of a new, disruptive technology.
On the complexity of smooth projective toric varieties

In this paper we answer a question posed by V.V. Batyrev. The question asked if there exists a complete regular fan with more than quadratically many primitive collections. We construct a smooth projective toric variety associated to a complete regular fan $\Delta$ in R^d with $n$ generators where the number of primitive collections of $\Delta$ is at least exponential in $n-d$. We also exhibit the connection between the number of primitive collections of $\Delta$ and the facet complexity of the Gr\"obner fan of the associated integer program.
Marginal deformations from branes

We study brane configurations for four dimensional = 1 supersymmetric gauge theories with quartic superpotentials which flow in the infrared to manifolds of interacting superconformal fixed points. We enumerate finite = 2 theories, from which a large class of marginal = 1 theories descend. We give the brane descriptions of these theories in Type IIA and Type IIB string theory. The Type IIB descriptions are in terms of D3 branes in orientifold and generalized conifold backgrounds. We calculate the Weyl and Euler anomalies in these theories, and find that they are equal in elliptic models and unequal in a large class of finite = 2 and marginal = 1 non-elliptic theories.
Numerical simulation of compressible plane jets

Abstract Two- and three-dimensional spatial direct numerical simulations of a compressible plane jet exhausting into a parallel stream are described. These simulations reveal the inadequacy of a two-dimensional model in capturing the totality of the flow physics. In two dimensions, instabilities evolve into highly organized large-scale mixing events; two-dimensional time-averaged turbulence quantities also suffer from artificial vortex organization. Mean normal velocity profiles show a significant reduction in entrainment with increased compressibility, while the effect is much less pronounced in three dimensions. While streamwise and spanwise turbulence intensities exhibit no change with increased compressibility, normal intensity and shear stress are significantly reduced.
Finite Difference Schemes for Diffusion Problems Based on a Hybrid Perturbation–Galerkin Method

A new technique for the development of finite difference schemes for diffusion equations is presented. The model equations are the one space variable advection diffusion equation and the two space variable diffusion equation, each with Dirichlet boundary conditions. A two-step hybrid technique, which combines perturbation methods based on the parameter ρ = Δt/ (Δx) 2 with the Galerkin method, provides a systematic way to develop new finite difference methods, referred to as hybrid equations. The main contributions of this paper include the (J) recovery of classical explicit or implicit finite difference schemes using only the perturbation terms; (2) development of new finite difference schemes, referred to as hybrid equations, which have better stability properties than the classical finite difference equations, permitting the use of larger values of the parameter p; and (3) higher order accurate methods, with either O((Δx) 4 ) or O((Δx) 6 ) truncation error, formed by convex linear combinations of the classical and hybrid equations. The solution of the hybrid finite difference equations requires only a tridiagonal equation solver and, hence, does not lead to excessive computational effort.
When is it valid to assume that heat flux is parallel to B

Abstract It is frequently assumed that heat flow in the plasma scrape-off-layer is everywhere parallel to B , due to the strong anisotropy in electron thermal conductivity. This assumption is convenient but paradoxical. Here are examined three situations where this assumption has sometimes been applied: (1) extrapolating from midplane T e ( R ) measurements to divertor heat flux profile, (2) determining the location of the separatrix from measured midplane T e ( R ), combined with total heat flux leaving the plasma, and (3) predicting the heat flux to plasma-facing components in the scrape-off-layer of diverted plasmas. Numerical solution of the anisotropic, nonlinear heat equation suggests that the first application is poor, the second well justified, and the third far from accurate. Additional plasma physics effects may mitigate these results, but the simple assumption of dominant parallel heat flow due to anisotropy in electron thermal conductivity is not supported in many important cases.
Euler flag enumeration of Whitney stratified spaces

Abstract The flag vector contains all the face incidence data of a polytope, and in the poset setting, the chain enumerative data. It is a classical result due to Bayer and Klapper that for face lattices of polytopes, and more generally, Eulerian graded posets, the flag vector can be written as a c d -index, a non-commutative polynomial which removes all the linear redundancies among the flag vector entries. This result holds for regular CW complexes. We relax the regularity condition to show the c d -index exists for Whitney stratified manifolds by extending the notion of a graded poset to that of a quasi-graded poset. This is a poset endowed with an order-preserving rank function and a weighted zeta function. This allows us to generalize the classical notion of Eulerianness, and obtain a c d -index in the quasi-graded poset arena. We also extend the semi-suspension operation to that of embedding a complex in the boundary of a higher dimensional ball and study the simplicial shelling components.
Multigrid calculations of a jet in crossflow

A series of numerical calculations are made of a jet in crossflow using progressive mesh refinement up to 2.4 million grid points. A solution algorithm that combined the features of a point-coupled solution of the momentum and continuity equations with multigrid acceleration demonstrated efficient convergence of the governing equations. In comparisons with experimental data, some features of the jet flow field were found to be predicted reasonably well, but the results still remain affected by numerical diffusion.
Low-Pressure, Metastable Growth of Diamond and "Diamondlike" Phases

Diamond may be grown at low pressures where it is the metastable form of carbon. Recent advances in a wide variety of plasma and electrical discharge methods have led to dramatic increases in growth rates. All of these methods have certain aspects in common, namely, the presence of atomic hydrogen and the production of energetic carbon-containing fragments under conditions that support high mobilities on the diamond surface. Some understanding of the processes taking place during nucleation and growth of diamond has been achieved, but detailed molecular mechanisms are not yet known. Related research has led to the discovery of a new class of materials, the "diamondlike" phases. Vapor-grown diamond and diamondlike materials may have eventual applications in abrasives, tool coatings, bearing surfaces, electronics, optics, tribological surfaces, and corrosion protection.
Mesonic correlation functions in the random instanton vacuum

Abstract First, a general model-independent discussion of mesonic correlation functions is given. We derive new inequalities, including one that is stronger than Weingarten's inequality. Then a large set of mesonic correlation functions is calculated in the random instanton liquid model, including diagonal and non-diagonal correlators of u d and u s type flavored currents, as well as a few of the most important unflavored ones. The results are compared with phenomenological expectations and lattice results. Not only the qualitative behaviour is reproduced in all channels, but in most cases this simple model was found to work with amazing accuracy.
A Numerical Model of Cumulus Dynamics and Microphysics.

Abstract A one-dimensional, time-dependent numerical model of cumulus convection is presented. The model considers the processes of horizontal mixing, evaporation, precipitation generation and freezing, as well as the standard thermodynamic and dynamic processes in isolated cumuli. The initial calculations show that: 1) the vertical velocity and liquid water content undergo coupled damped oscillations in time; 2) the rate at which precipitation-sized drops are formed and grow by collection are not sensitive parameters in the amount of rain which falls from the clouds; 3) the amount of liquid water in the form of cloud droplets that must be present in the cloud before a few large drops can be developed is a crucial parameter in determining the amount of rain which falls from the clouds (the higher the threshold cloud liquid water content, the lower the ultimate rainfall amount); and 4) the freezing time and precise ice-nucleation temperature affect the amount of rain that falls from the cloud in a way ofte...
A Scattered Light Echo around SN 1993J in M81

A light echo around SN 1993J was observed 8.2 yr after explosion by a Hubble Space Telescope Wide Field Planetary Camera 2 observation, adding to the small family of supernovae with light echoes. The light echo was formed by supernova light scattered from a dust sheet that lies 220 pc away from the supernova, 50 pc thick along the line of sight, as inferred from the radius and width of the light echo. The dust inferred from the light echo surface brightness is 1000 times denser than the intercloud dust. The graphite-to-silicate fraction cannot be determined by our BVI photometric measurements. However, a pure graphite model can be excluded on the basis of comparison with the data. With future observations, it will be possible to measure the expansion rate of the light echo, from which an independent distance to M81 can be obtained.
Long journey into tunneling

N 1923, during the infancy of the quantum theory, de Broglie [ 11 introducted a new fundamental hypothesis that matter may be endowed with a dualistic natureparticles may also have the characteristics of waves. This hypothesis, in the hands of Schrodinger [2] found expression in the definite form now known as the Schrodinger wave equation, whereby an electron or a particle is assumed to be represented by a solution to this equation. The continuous nonzero nature of such solutions, even in classically forbidden regions of negative kinetic energy, implies an ability to penetrate such forbidden regions and a probability of tunneling from one classically allowed region to another. The concept of tunneling, indeed, arises from this quantum-mechanical result. The subsequent experimental manifestations of this concept can be regarded as one of the early triumphs of the quantum theory. In 1928, theoretical physicists believed that tunneling could occur by the distortion, lowering or thinning, of a potential barrier under an externally applied high electric field. Oppenheimer [3] attributed the autoionization of excited states of atomic hydrogen to the tunnel effect: The coulombic potential well which binds an atomic electron could be distorted by a strong electric field so that the electron would see a finite potential barrier through which it could tunnel. Fowler and Nordheim [4] explained, on the basis of electron tunneling, the main features of the phenomenon of electron emission from cold metals by high external electric fields, which had been unexplained since its observation by Lilienfeld [SI in 1922. They proposed a one-dimensional model. Metal electrons are confined by a potential wall whose height is determined by the work function 9 plus the Fermi energy E/, and the wall thickness is substantially decreased with an externally applied high electric field, allowing electrons to tunnel through the potential wall, as shown in Fig. 1. They successfully derived the well-known Fowler-Nordheim formula for the current as a function of electric field F: J = AF* exp [-4(2nr)1'*t$a'*/3kF]. An application of these ideas which followed almost immediately came in the model for a decay as a tunneling process put forth by Gamow [6] and Gurney and Condon [7]. Subsequently, Rice [8] extended this theory to the description of molecular dissociation. The next important development was an attempt to invoke tunneling in order to understand transport properties of electrical contacts between two solid conductors. The problems of metal-to-metal and semiconductor-to-metal contacts are important technically, because they are directly related to electrical switches and rectifiers or detectors.
A versatile synthesis of unsymmetrical 3,3'-bioxindoles: stereoselective Mukaiyama aldol reactions of 2-siloxyindoles with isatins.

A new synthesis of 3,3′-bioxindoles is reported that is well suited for the preparation of unsymmetrical structures. In the key step, 3-hydroxy-3,3′-bioxindoles are constructed by Mukaiyama aldol reaction of 2-siloxyindoles with isatins These tertiary carb inols are formed in high diastereoselectivities, with substitution at various positions of the isatin and the 2-siloxyindole being tolerated.
Measurement of Ion Current Density at Ground Level in the Vicinity of High Voltage DC Transmission Lines

Sensors for measuring vertical current density at ground level near high voltage dc (HVDC) transmission lines are subject to error when the sensor is not in the ground plane. The magnitude of this error, for guarded and unguarded sensors, has been investigated using hoth dc electric fields with space charge and ac electric fields in a parallel plate facility. For conditions like those expected under HVDC transmission lines, the results obtained using ac and dc methods agreed to within experimental uncertainty. The measuired errors are as large as 25 percent for guarded sensors and significantly larger for unguarded sensors. Data for various sensor elevations and guarding are presented in graphs to aid the designer. Comparisons with results from an IEEE Working Group field day are also presented.
Silyl-Directed, Iridium-Catalyzed ortho-Borylation of Arenes. A One-Pot ortho-Borylation of Phenols, Arylamines, and Alkylarenes

The regioselectivity of the borylation of arenes catalyzed by the combination of 4,4′-di-tert-butylbipyridine (dtbpy) and [Ir(cod)Cl]2 has typically been governed by steric effects. We describe a strategy that makes use of a new substituent for ortho-functionalization to overcome this bias. We show that arenes containing hydrosilyl substituents on an atom attached to the arene ring undergo borylation at the position ortho to the hydrosilyl group. Using iridium-catalyzed formation of silyl ethers and silylamines from silanes and either phenols or arylamines, we have developed the ortho-borylation into a one-pot conversion of free phenols and monoprotected anilines into hydroxy- and amino-substituted organoboron derivatives.
An Overdensity of i-Dropouts among a Population of Excess Field Objects in the Virgo Cluster*

Using a set of deep imaging data obtained by the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) shortly after its deployment, Yan, Windhorst, & Cohen found a large number of F775W-band dropouts (i-dropouts), which are consistent with being galaxies at z ≈ 6. The surface density of i-dropouts thus derived, however, is an order of magnitude higher than those subsequent studies found in other deep ACS fields, including the Hubble Ultra Deep Field (HUDF). Here we revisit this problem, using both existing and new data. We confirm that the large overdensity of i-dropouts does exist in this field, and that their optical-to-IR colors are similar to those in the HUDF. However, we have discovered that the i-dropout overdensity is accompanied by an even larger excess of faint field objects in this region and its vicinity. This large excess of field objects is most likely caused by the fact that we have resolved the faint diffuse light extending from an interacting galaxy pair in the Virgo Cluster, M60/NGC 4647, which lies several arcminutes away from the region where the excess is found. The i-dropouts in this field are within the magnitude range where this excess of field objects occurs, and their spatial distribution seems to follow the same gradient as the entire excess field population. This excess population is also red in color, and the red wing of its color distribution continuously extends to the regime where the i-dropouts reside. While we still cannot completely rule out the possibility that the overdensity of i-dropouts might be a genuine large-scale structure of galaxies at z ≈ 6, we prefer the interpretation that most of them are part of the excess stellar population related to M60/NGC 4647.
The "parahippocampal place area" responds preferentially to high spatial frequencies in humans and monkeys.

Defining the exact mechanisms by which the brain processes visual objects and scenes remains an unresolved challenge. Valuable clues to this process have emerged from the demonstration that clusters of neurons (“modules”) in inferior temporal cortex apparently respond selectively to specific categories of visual stimuli, such as places/scenes. However, the higher-order “category-selective” response could also reflect specific lower-level spatial factors. Here we tested this idea in multiple functional MRI experiments, in humans and macaque monkeys, by systematically manipulating the spatial content of geometrical shapes and natural images. These tests revealed that visual spatial discontinuities (as reflected by an increased response to high spatial frequencies) selectively activate a well-known place-selective region of visual cortex (the “parahippocampal place area”) in humans. In macaques, we demonstrate a homologous cortical area, and show that it also responds selectively to higher spatial frequencies. The parahippocampal place area may use such information for detecting object borders and scene details during spatial perception and navigation.
Generative models versus underlying symmetries to explain biological pattern

Mathematical models play an increasingly important role in the interpretation of biological experiments. Studies often present a model that generates the observations, connecting hypothesized process to an observed pattern. Such generative models confirm the plausibility of an explanation and make testable hypotheses for further experiments. However, studies rarely consider the broad family of alternative models that match the same observed pattern. The symmetries that define the broad class of matching models are in fact the only aspects of information truly revealed by observed pattern. Commonly observed patterns derive from simple underlying symmetries. This article illustrates the problem by showing the symmetry associated with the observed rate of increase in fitness in a constant environment. That underlying symmetry reveals how each particular generative model defines a single example within the broad class of matching models. Further progress on the relation between pattern and process requires deeper consideration of the underlying symmetries.
Localization of brain angiotensinogen mRNA by hybridization histochemistry

Abstract The topographical distribution of rat brain angiotensinogen (Ao) mRNA was determined using hybridization histochemistry (in situ hybridization) with two different hybridization probes, a 32P-labelled 42 residue oligonucleotide and a full-length complementary (antisense) RNA labelled with either sulfur 35 or phosphorus 32. Low levels of Ao mRNA sequences were detected throughout the brain while high levels were restricted to specific areas often corresponding to classical nuclear boundaries. All areas in which angiotensin II-like immunoreactivity had been previously detected contained moderate to high levels of Ao mRNA and many previously undetected areas were also found to contain high levels of this mRNA. The results underline the ubiquitous presence of angiotensinogen-synthesizing cells in the brain and support previous evidence that the angiotensinogen gene could be expressed by several types of brain cells.
The Low Level of Debris Disk Activity at the Time of the Late Heavy Bombardment: A Spitzer Study of Praesepe

We present 24 μm photometry of the intermediate-age open cluster Praesepe. We assemble a catalog of 193 probable cluster members that are detected in optical databases, the Two Micron All Sky Survey (2MASS), and at 24 μm, within an area of ~2.47 deg2. Mid-IR excesses indicating debris disks are found for one early-type and for three solar-type stars. Corrections for sampling statistics yield a 24 μm excess fraction (debris disk fraction) of 6.5% ± 4.1% for luminous and 1.9% ± 1.2% for solar-type stars. The incidence of excesses is in agreement with the decay trend of debris disks as a function of age observed for other cluster and field stars. The values also agree with those for older stars, indicating that debris generation in the zones that emit at 24 μm falls to the older 1-10 Gyr field star sample value by roughly 750 Myr. We discuss our results in the context of previous observations of excess fractions for early- and solar-type stars. We show that solar-type stars lose their debris disk 24 μm excesses on a shorter timescale than early-type stars. Simplistic Monte Carlo models suggest that, during the first Gyr of their evolution, up to 15%-30% of solar-type stars might undergo an orbital realignment of giant planets such as the one thought to have led to the Late Heavy Bombardment, if the length of the bombardment episode is similar to the one thought to have happened in our solar system. In the Appendix, we determine the cluster's parameters via bootstrap Monte Carlo isochrone fitting, yielding an age of 757 Myr (±36 Myr at 1σ confidence) and a distance of 179 pc (±2 pc at 1σ confidence), not allowing for systematic errors.
On multiplicativity of Fourier coefficients at cusps other than infinity

This paper treats the problem of determining conditions for the Fourier coefficients of a Maass–Hecke newform at cusps other than infinity to be multiplicative. To be precise, the Fourier coefficients are defined using a choice of matrix in \(\mathit{SL}(2, \mathbb{Z})\) which maps infinity to the cusp in question. Let c and d be the entries in the bottom row of this matrix, and let N be the minimal level. In earlier work with Dorian Goldfeld and Min Lee, we proved that the coefficients will be multiplicative whenever N divides 2cd. This paper proves that they will not be multiplicative unless N divides 576cd. Further, if one assumes that the Hecke eigenvalue vanishes less than half the time, then this number drops to 4cd, and a precise condition governing the case where N divides 4cd and not 2cd is obtained.
Categorified symplectic geometry and the string Lie 2-algebra

Multisymplectic geometry is a generalization of symplectic geometry suitable for n-dimensional field theories, in which the nondegenerate 2-form of symplectic geometry is replaced by a nondegenerate (n + 1)-form. The case n = 2 is relevant to string theory: we call this '2-plectic geometry.' Just as the Poisson bracket makes the smooth functions on a symplectic manifold into a Lie algebra, the observables associated to a 2-plectic manifold form a 'Lie 2-algebra,' which is a categorified version of a Lie algebra. Any compact simple Lie group G has a canonical 2-plectic structure, so it is natural to wonder what Lie 2-algebra this example yields. This Lie 2-algebra is infinite-dimensional, but we show here that the sub-Lie-2-algebra of left-invariant observables is finite-dimensional, and isomorphic to the already known 'string Lie 2-algebra' associated to G. So, categorified symplectic geometry gives a geometric construction of the string Lie 2-algebra. © 2010, John C. Baez and Christopher L. Rogers.
The effect of the second order GPS ionospheric correction on receiver positions

[1] The Global Positioning System (GPS) transmits two frequencies, allowing users to correct for the first-order ionospheric signal group delay (or phase advance) of 1–50 m. The second-order ionospheric term, caused by the Faraday rotation effect induced by the Earth magnetic field, is about 1000 times smaller and usually ignored. In this study, we implement the 2nd-order correction suggested by Bassiri and Hajj [1993] and investigate its effect on GPS-inferred station positions. The correction causes a latitude dependent ∼0.1–0.5 cm southward shift to the position which is roughly proportional to the integrated electron density above the receiver, and has strong diurnal, seasonal and decadal signatures. By analyzing a three-year time series of equatorial station positions obtained without the 2nd-order correction, a strong semi-annual north-south oscillation is observed, the origin of which has not been hitherto explained. We verify that this apparent oscillation can be largely removed once the 2nd-order correction is applied.
What we (don't) know about black-hole formation in high-energy collisions

Higher-dimensional scenarios allow for the formation of mini black holes from TeV-scale particle collisions. The purpose of this letter is to review and compare different methods for the estimate of the total gravitational energy emitted in this process. To date, black-hole formation has mainly been studied using an apparent horizon search technique. This approach yields only an upper bound on the gravitational energy emitted during black-hole formation. Alternative calculations based on instantaneous collisions of point particles and black-hole perturbation theory suggest that the emitted gravitational energy may be smaller. New and more refined methods may be necessary to accurately describe black-hole formation in high-energy particle collisions.
Interventional cardiology live case presentations: Regulatory considerations†

Live case presentations are increasingly common at interventional cardiology conferences. Taking advantage of significant advances in communication technology, broadcasts of procedures can be viewed as an extension of traditional medical education targeted to large groups of practitioners. However, there are important ethical, commercial, and patient safety issues associated with live cases that deserve attention. Use of investigational devices in live case demonstrations is subject to review and approval by FDA’s Center for Devices and Radiological Health (CDRH), and the outcomes of patients participating in live cases are considered in the overall clinical study results. This article discusses CDRH’s regulatory view of live case presentations with a focus on patient safety, clinical trial integrity, and concerns regarding improper medical device promotion. V C 2010 Wiley-Liss, Inc.
Chaotic motion of a weakly nonlinear, modulated oscillator

Abstract A weakly nonlinear oscillator of natural frequency ω0 and damping ratio δ is driven by an amplitude-modulated force of dimensionless amplitude e, carrier frequency ω, and modulation frequency ω1. Each of (ω - ω0)/ω0, ω1/ω0, and δ is O(e2/3) as e → 0. The response in this resonant neighborhood is a slowly modulated sine wave, the envelope of which is described by three first-order, autonomous, ordinary differential equations. This envelope, which is periodic for δ >> e2/3, is chaotic in certain ranges of (ω - ω0)/ω0 and ω1/ω0 if δ/e2/3 is sufficiently small.
Encore: 3D printed augmentation of everyday objects with printed-over, affixed and interlocked attachments

One powerful aspect of 3D printing is its ability to extend, repair, or more generally modify everyday objects. However, nearly all existing work implicitly assumes that whole objects are to be printed from scratch. Designing objects as extensions or enhancements of existing ones is a laborious process in most of today's 3D authoring tools. This paper presents a framework for 3D printing to augment existing objects that covers a wide range of attachment options. We illustrate the framework through three exemplar attachment techniques - print-over, print-to-affix, and print-through. We implemented these techniques in Encore, a design tool that supports a range of analysis with visualization for users to explore design options and tradeoffs among these metrics. Encore also generates 3D models for production, addressing issues such as support jigs and contact geometry between the attached part and the original object.
Recent advances in the design and construction of synthetic peptides: for the love of basics or just for the technology of it

Advances in the methods used for the chemical synthesis of peptides, and in the accumulation and analysis of numerous X-ray crystallographic and nuclear magnetic resonance protein and peptide structures, have enabled the design and construction of peptides for investigating basic folding principles, making novel structural motifs, modifying functional activities, developing pharmaceutical drugs and creating new biomaterials. The focus of this review is on recent trends in the design and construction of synthetic peptides for basic science and for various biotechnological applications.
Fermion analogy for layered superconducting films in parallel magnetic field

The equivalence between the Lawrence-Doniach model for films of extreme type-II layered superconductors and a generalization of the back-scattering model for spin-(1/2) electrons in one dimension is demonstrated. This fermion analogy is then exploited to obtain an anomalous H∥−1 tail for the parallel equilibrium magnetization of the minimal double-layer case in the limit of high parallel magnetic fields H∥ for temperatures in the critical regime.
On the Master-Equation Approach to Kinetic Theory: Linear and Nonlinear Fokker-Planck Equations

Abstract We discuss the relationship between kinetic equations of the Fokker‐Planck type (two linear and one nonlinear) and the Kolmogorov (a.k.a. master) equations of certain N‐body diffusion processes, in the context of Kac's propagation‐of‐chaos limit. The linear Fokker‐Planck equations are well known, but here they are derived as a limit N→∞ of a simple linear diffusion equation on 3N‐C‐dimensional N‐velocity spheres of radius∝√N (where C=1 or 4 depending on whether the system conserves energy only or energy and momentum). In this case, a spectral gap separating the zero eigenvalue from the positive spectrum of the Laplacian remains as N→∞, so that the exponential approach to equilibrium of the master evolution is passed on to the limiting Fokker‐Planck evolution in ℝ3. The nonlinear Fokker‐Plank equation is known as Landau's equation in the plasma‐physics literature. Its N‐particle master equation, originally introduced (in the 1950s) by Balescu and Prigogine (BP), is studied here on the 3N‐4‐dimensi...
Shocked Gas and Star Formation in the Centaurus A Radio Galaxy

Observational evidence for shock-induced star formation is found in the northeast radio lobe of the nearby radio galaxy Centaurus A (NGC 5128). A gas cloud, recently detected in H I, is impacted by the adjacent radio jet to the extent that cloud collapse is triggered and loose chains of blue supergiant stars are formed. Diffuse clouds and filaments of ionized gas have been observed near the interface of the H I cloud and the radio jet. These show velocities that cover a range of more than 550 km s-1. Line intensities in their spectra are characteristic of a shock-related origin with strong [N II] and [S II] relative to Hα. The [O III]/Hα line ratio indicates a large range in excitation that is not correlated with velocity. Distinct from this component is a group of four apparently normal H II regions that are excited by embedded young stars and whose velocities are very close to that of the H I cloud. Star formation will continue for as long as the gas cloud remains close to the radio jet. The loose chains of blue stars in the area are resolved only because NGC 5128 is so close. The reported faint blue extensions and plumes in more distant analogs probably have similar origins.
Functional cerebral activation detected by frequency-domain near-infrared spectroscopy

The aim of our study was to explore the possibility of detecting haemodynamic changes in the brain using frequency- domain near-IR spectroscopy by exploiting the phase of the intensity modulated optical signal. To obtain optical signals with eh highest possible signal-to-noise ratio, we performed simultaneous NIRS-fMRI measurements, with subsequent correlation of the time courses of both measurements. The cognitive paradigm used arithmetic calculations, with optical signals acquired with sensors placed on the forehead. In three subjects we demonstrated correlation between the haemodynamic signals obtained using NIRS and BOLD fMRI.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Bell Locality and the Nonlocal Character of Nature

It is demonstrated that hidden variables of a certain type follow logically from a certain local causality requirement (“Bell Locality”) and the empirically well-supported predictions of quantum theory for the standard EPR-Bell set up. The demonstrated hidden variables are precisely those needed for the derivation of the Bell Inequalities. We thus refute the widespread view that empirical violations of Bell Inequalities leave open a choice of whether to reject (i) locality or (ii) hidden variables. Both principles are indeed assumed in the derivation of the inequalities, but since, as we demonstrate here, (ii) actually follows from (i), there is no choice but to blame the violation of Bell's Inequality on (i). Our main conclusion is thus no Bell Local theory can be consistent with what is known from experiment about the correlations exhibited by separated particles. Aside from our conclusion being based on a different sense of locality this conclusion resembles one that has been advocated recently by H.P. Stapp. We therefore also carefully contrast the argument presented here to that proposed by Stapp.
Anonymity and individual risk

Abstract Adverse selection economies with private information are generally studied under the assumption that contracts are exclusive. That is, retrading is prohibited. An alternative market mechanism, the anonymous mechanism, is studied here. Risk averse agents trade contingent claims directly and side markets are in equilibrium. The result is the anonymous equilibrium. The anonymous equilibrium results in a set of endogenous transfers and subsidies.
Aryloxypyrazines as highly selective antagonists of Oxytocin

A series of aryloxypyrazines were designed based on structural overlap with previously reported arylpyrazine Oxytocin antagonists. Similarly high levels of Oxytocin antagonism were achievable in this new series. In addition, significant improvements in selectivity over the related vasopressin V1A receptor were also possible.
Expanded Very Large Array Detection of 44.1?GHz Class I Methanol Masers in Sagittarius A

We report on the detection of 44 GHz Class I methanol (CH3OH) maser emission in the Sagittarius A (Sgr A) complex with the Expanded Very Large Array (EVLA). These EVLA observations show that the Sgr A complex harbors at least four different tracers of shocked regions in the radio regime. The 44 GHz masers correlate with the positions and velocities of previously detected 36 GHz CH3OH masers, but less with 1720 MHz OH masers. Our detections agree with theoretical predictions that the densities and temperatures conducive for 1720 MHz OH masers may also produce 36 and 44 GHz CH3OH maser emission. However, many 44 GHz masers do not overlap with 36 GHz methanol masers, suggesting that 44 GHz masers also arise in regions too hot and too dense for 36 GHz masers to form. This agrees with the non-detection of 1720 MHz OH masers in the same area, which are thought to be excited under even cooler and less dense conditions. We speculate that the geometry of the 36 GHz masers outlines the current location of a shock front.
Electron-transfer photoredox catalysis: development of a tin-free reductive dehalogenation reaction.

We report an operationally simple, tin-free reductive dehalogenation system utilizing the well-known visible-light-activated photoredox catalyst Ru(bpy)3Cl2 in combination with iPr2NEt and HCO2H or Hantzsch ester as the hydrogen atom donor. Activated C−X bonds may be reduced in good yields with excellent functional-group tolerance and chemoselectivity over aryl and vinyl C−X bonds. The proposed mechanism involves visible-light excitation of the catalyst, which is reduced by the 3° amine to produce the single-electron reducing agent Ru(bpy)3+. A subsequent single-electron transfer generates the alkyl radical, which is quenched by abstraction of a hydrogen atom. Reductions can be accomplished on a preparative scale with as little as 0.05 mol % Ru catalyst.
Selection by consequences

Human behavior is the joint product of (i) contingencies of survival responsible for natural selection, and (ii) contingencies of reinforcement responsible for the repertoires of individuals, including (iii) the special contingencies maintained by an evolved social environment. Selection by consequences is a causal mode found only in living things, or in machines made by living things. It was first recognized in natural selection: Reproduction, a first consequence, led to the evolution of cells, organs, and organisms reproducing themselves under increasingly diverse conditions. The behavior functioned well, however, only under conditions similar to those under which it was selected.Reproduction under a wider range of consequences became possible with the evolution of processes through which organisms acquired behavior appropriate to novel environments. One of these, operant conditioning, is a second kind of selection by consequences: New responses could be strengthened by events which followed them. When the selecting consequences are the same, operant conditioning and natural selection work together redundantly. But because a species which quickly acquires behavior appropriate to an environment has less need for an innate repertoire, operant conditioning could replace as well as supplement the natural selection of behavior.Social behavior is within easy range of natural selection, because other members are one of the most stable features of the environment of a species. The human species presumably became more social when its vocal musculature came under operant control. Verbal behavior greatly increased the importance of a third kind of selection by consequences, the evolution of social environments or cultures. The effect on the group, and not the reinforcing consequences for individual members, is responsible for the evolution of culture.
Povarov Reactions Involving 3-Aminocoumarins: Synthesis of 1,2,3,4-Tetrahydropyrido[2,3-c]coumarins and Pyrido[2,3-c]coumarins

Condensation of 3-aminocoumarin (5) with 4-nitrobenzaldehyde (8) afforded a 2-azadiene (9), which reacted with various electron-rich alkenes (10 examples) in the presence of Yb(OTf)3 to afford 1,2,3,4-tetrahydropyrido[2,3-c]coumarins. Yields were generally good, but the diastereomeric ratios were highly variable. The products arose through a formal [4 + 2] cycloaddition (inverse electron demand Diels-Alder reaction) followed by tautomerization. As such, these are examples of the Povarov reaction. A range of 1,2,3,4-tetrahydropyrido[2,3-c]coumarins was then synthesized using a three-component version of this reaction, which involves in situ formation of the 2-azadiene component. Some of these products were converted into the corresponding pyrido[2,3-c]coumarins upon treatment with various oxidants, the most effective of which proved to be nitrous gases.
Regulatory competition and regulatory jurisdiction

This article seeks to assess the limits of competition, and the need for regulation of competition, among regulatory jurisdictions. The market for regulation involves competition among states, and may be regulated by supra-state law including international law generated by international institutions, such as the WTO or the EU. The question of how competition among states should be regulated is analogous to the question asked often in domestic policy debates: how should competition among firms be regulated? This article looks to the theory of property law and, to a lesser extent, competition law, as well as to the Tiebout model, to suggest answers. This article argues that it is impossible to generalize about the benefits of competition in regulation, and that a number of factors must be considered. These factors cannot be simply totted up by a researcher who then provides definitive policy advice. First, the regulatory competition model, like all models, has particular parameters that must be met in order for it to apply. These parameters cannot be assumed, but must be evaluated in particular cases. Second, the parameters are never completely met, placing us in the realm of the theory of the second best. The realm of the theory of the second best calls for legislative deliberation rather than judicial or scholarly determination. Third, these factors are incommensurable and involve interpersonal comparison of utility. Therefore, again, the design of regulatory competition, like other decisions about regulation, is best left for political determination, informed by scholarly analyses of these factors.
A lower bound on computational complexity given by revelation mechanisms

This paper establishes a lower bound on the computational complexity of smooth functions between smooth manifolds. It generalizes one for finite (Boolean) functions obtained (by Arbib and Spira [2]) by counting variables. Instead of a counting procedure, which cannot be used in the infinite case, the dimension of the message space of a certain type of revelation mechanism provides the bound. It also provides an intrinsic measure of the number of variables on which the function depends. This measure also gives a lower bound on computational costs associated with realizing or implementing the function by a decentralized mechanism, or by a game form.
Process Development for 257 nm Photomask Fabrication Using Environmentally Stable Chemically Amplified Photoresists

Consumer demand for faster computers, increased data storage space, and higher density memory arrays has driven development efforts in photomask production the way of the wafer fab. This drive has pushed mask fabrication toward smaller and more uniform features. It has thus inspired the creation of a deep ultraviolet, or DUV, (257 nm) optical pattern generator and an attendant resist process for mask fabrication. A DUV photoresist process based on precoated photomask blanks is presented herein with a demonstrably robust resist, both in terms of plate shelf life and latent image stability. Benchmark lithographic performance in resolution, depth of focus (DOF), linearity, and iso/dense bias are presented. In addition, the ambient atmospheric stability of the resist system is explored. Traditional maskmaking has, until now, excluded a post-exposure bake (PEB) step. Equipment requirements and resist critical dimension (CD) performance as a function of PEB are also presented. Photoresist process parameter space is defined and discussed herein. Precoated mask blank post-apply bake (PAB) stability is also examined as it relates to after-develop inspection (ADI) CDs. Dark erosion tests are employed to study photoresist contrast uniformity as it relates to ADI CDs. First-pass specifications for incoming raw materials are also proposed.
An atmospheric outburst on Neptune from 1986 through 1989

Abstract In two independent long-term programs (visual photometry and methane-band imaging), we find that Neptune underwent a period of unusual atmospheric activity from 1986 through 1989. This outburst was characterized by (1) increased 8900-A methane-band brightness both for the dominant bright feature by 0.3 mag and for the hemisphere opposite that feature by 0.14 mag, and (2) increased standard deviation of the mean yearly magnitudes at visual and near-infrared wavelengths by over a factor of 2. By 1989 when Voyager 2 encountered Neptune, the near-infrared standard deviations and brightness had returned to normal, although the visual standard deviations were still marginally high. We interpret the observations as a localized source of upwelling, qualitatively similar to “great white spots” seen periodically on Saturn.
Stability of jammed packings II: the transverse length scale

As a function of packing fraction at zero temperature and applied stress, an amorphous packing of spheres exhibits a jamming transition where the system is sensitive to boundary conditions even in the thermodynamic limit. Upon further compression, the system should become insensitive to boundary conditions provided it is sufficiently large. Here we explore the linear response to a large class of boundary perturbations in 2 and 3 dimensions. We consider each finite packing with periodic-boundary conditions as the basis of an infinite square or cubic lattice and study properties of vibrational modes at arbitrary wave vector. We find that the stability of such modes can be understood in terms of a competition between plane waves and the anomalous vibrational modes associated with the jamming transition; infinitesimal boundary perturbations become irrelevant for systems that are larger than a length scale that characterizes the transverse excitations. This previously identified length diverges at the jamming transition.
The Interpolation of Time Series by Related Series

Abstract The construction of most comprehensive economic time series involves the estimation of some components for some dates by interpolation between values (“benchmarks”) for earlier and later dates. This is often done by using a related series known for all relevant dates. In practice, the bulk of such interpolation uses only a single related series, its values for only three dates—the interpolation date, one prior date, and one later date—and the values of the given series for only the prior and later dates. For this special case, some current methods are defective on formal grounds and all may frequently yield less accurate estimates than straight-line or other mathematical interpolation. Converting the problem into a simple bivariate regression problem suggests a generalization of current methods that takes account of the correlation between the movements of the given series and the related series.