cssi/SciSciGPT-SciSciNet huggingface dataset:
Related lending and banking development

Does related lending have positive or negative effects on the development of banking systems? We analyze a unique cross-country data set covering 74 countries from 1990 to 2007, and find that related lending, on average, does not have any effect on the growth of credit. We do find, however, that there are conditional relationships: related lending tends to retard the growth of banking systems when rule of law is weak, whereas it tends to promote the growth of banking systems when rule of law is strong. We also find that related lending appears to be associated with looting when banks are owned by non-financial firms, but that it does not do so when non-financial firms are owned by banks. Our results indicate that whether related lending is positive or pernicious depends critically on the institutional context in which it takes place; there is no single “best policy” regarding related lending. These findings are robust to alternative specifications, including IV regressions.
Interpretation of light-scattering spectra in terms of particle displacements.

Quasielastic light-scattering spectroscopy is regularly used to examine the dynamics of dilute solutions of diffusing mesoscopic probe particles in fluids. For probes in a simple liquid, the light-scattering spectrum is a simple exponential; the field correlation function g(1)(q,τ) of the scattering particles is related to their mean-square displacements X2¯≡⟨(Δx(τ))2⟩ during τ via g(1)(q,τ)=exp(−12q2X2¯). However, demonstrations of this expression refer only to identical Brownian particles in simple liquids and show that if the form is correct then it is also true for all τ that g(1)(q,τ)=exp(−Γτ), a pure exponential in τ. In general, g(1)(q,τ) is not a single exponential in time. A correct general form for g(1)(q,τ) in terms of the X2n¯, replacing the incorrect exp(−12q2X2¯), is obtained. A simple experimental diagnostic determining when the field correlation function gives the mean-square displacement is identified, namely, g(1)(q,τ) only reveals X2¯ if g(1)(q,τ) is a single exponential in τ. Contrariw...
Learning tastes through social interaction

Abstract This paper offers an information-based model of social interaction, and analyzes optimal investment and pricing of services that facilitate interaction in a duopoly. Agents have uncertainty over their preferences but are aware that they are correlated with others’, so there exists an incentive to communicate with others in the population. When a firm's good can be bundled with a coordination mechanism for its consumers, its value is endogenously determined due to a consumption externality. Although this mechanism increases total surplus, it is underprovided and consumer surplus decreases.
The readily available tert-pentyl group as a most effective simple directing group for asymmetric synthesis: a case study on Salen-Mn(III)-catalyzed epoxidation

Abstract The tert -pentyl group has been found to produce a pronounced stereodirecting effect, which is manifested in a study on Salen–Mn(III) complexes bearing such groups.
Experimental antenna impedance measurements in a magnetized plasma

Summary form only given. The characteristic impedance of two antennas immersed in a magnetized plasma have been measured by monitoring the reflection coefficient using a network analyzer. The first antenna is spherical, the second a short (1 Lt) monopole. There have been numerous theoretical studies done on antenna impedance in magnetized plasmas, but experimental measurements are more rare, primarily because of difficulties involving eliminating effects of the antenna circuitry and/or mounting hardware. Previously impedance measurements were made using a spherical antenna in a unmagnetized plasma, in which it was found that the impedance could be modeled as a capacitive sheath in series with a RLC tank circuit resonant at the plasma frequency. The introduction of a magnetic field would complicate the interpretation of these results by providing a preferred direction and subsequent sheath distortion. A cylindrical antenna in a magnetized plasma environment presents geometrical complications even beyond this. Where applicable, experimental impedance curves are compared with analytic and simulation results. The experimental work was performed in the large volume space physics simulation chamber (SPSC) at NRL where the plasma is characterized by electron densities and temperatures of ne = 106-1011 cm-3 and Te = 1 eV
Critical exponent for 3-D percolation conductivity, revisited

When we apply finite-size-scaling analysis to Monte-Carlo calculations of the electrical conductivity of simple-cubic, bond- and site-percolation lattices, we obtain a correlation-length critical exponent in good agreement with current values but, for the conductivity exponent, we find t=2.06±0.16, significantly higher than the value currently cited. This new value appears, however, in essential agreement with a recently proposed theoretical conjecture Analyse, selon une methode de loi d'echelle, des calculs de Monte Carlo de la conductivite electrique de reseaux cubiques simples de percolation de sites et de liens pour determiner l'exposant critique de la longueur de correlation, en accord avec les valeurs couramment citees, et l'exposant de la conductivite t=2,06±0,16, nettement superieur aux valeurs acceptees jusqu'ici (nouveau resultat qui confirme une conjecture theorique proposee recemment)
CHANDRA DISCOVERY OF 10 NEW X-RAY JETS ASSOCIATED WITH FR II RADIO CORE-SELECTED AGNs IN THE MOJAVE SAMPLE

United States. National Aeronautics and Space Administration (Chandra X-ray Observatory (U.S.) Award G08-9113A)
Preparation of La2Zr2O7 by Sol—Gel Route

The La2Zr2O7 phase was prepared from metal acetylacetonates by a sol—gel route without any intermediate phase formation. X-ray peaks appeared at a temperature as low as 500°C at the positions expected for La2Zr2O7, although they were broad. The crystal structure of La2Zr2O7 was found to be of the fluorite type below 900°C and of thepyrochlore type above 1000°C. The substitution of a small amount of Eu for La was carried out to investigate the crystal structure from the viewpoint of fluorescence, and these results confirmed the formation of fluorite type La2Zr2O7 below 900°C.
Two-sided uncertainty in the monopoly agenda setter model

We extend the Romer-Rosenthal model of representative democracy to a signaling environment, in which (i) only the representatives knows the ‘status quo’ outcome resulting if her take-it-or-leave-it policy proposal is rejected by the voters, while (ii) only the voters know their true preferences over policies. A separating sequential equilibrium is shown to exist, and to uniquely satisfy a common equilibrium refinement. Furthermore, this equilibrium has the property that, relative to the environment where the status quo is known to the voter, there is a downward bias in the setter's proposal, and an associated upward bias in the probability of the proposal's acceptance by the voter.
Does partial melting explain geophysical anomalies

Abstract The existence of partial melt is frequently invoked to explain geophysical anomalies such as low seismic wave velocity and high electrical conductivity. I review various experimental and theoretical studies to evaluate the plausibility of this explanation. In order for a partial melt model to work, not only the presence of melt, but also the presence of appropriate amount of melt needs to be explained. Using the mineral physics observations on the influence of melt on physical properties and the physics and chemistry of melt generation and transport, I conclude that partial melt model for the asthenosphere with homogeneous melt distribution does not work. One needs to invoke inhomogeneous distribution of melt if one wishes to explain observed geophysical anomalies by partial melting. However, most of models with inhomogeneous melt distribution are either inconsistent with some geophysical observations or the assumed structures are geodynamically unstable and/or implausible. Therefore partial melt models for the geophysical anomalies of the asthenosphere are unlikely to be valid, and some solid-state mechanisms must be invoked. The situation is different in the deep upper mantle where melt could completely wet grain-boundaries and continuous production of melt is likely by “dehydration melting” at around 410-km. In the ultralow velocity zone in the D″ layer, where continuous production of melt is unlikely, easy separation of melt from solid precludes the partial melt model for low velocities and high electrical conductivity unless the melt density is extremely close to the density of co-existing solid minerals or if there is a strong convective current to support the topography of the ULVZ region. Compositional variation such as Fe-enrichment is an alternative cause for the anomalies in the D″ layer.
A convenient one-pot synthesis of 4-amino-3-arylpyrazoles from α-phthaloylaminoacetophenones

Abstract Condensation of α-phthaloylaminoacetophenones 1a-c with N,N-dimethylformamide dimethyl acetal afforded the novel enamines 3a-c . Cyclization of 3 with hydrazine, alkylhydrazine or phenylhydrazine salts ( 4a-d ) gave 4-phthaloylamino-3-arylpyrazoles 7–9 in high yields. Deprotection of 7–9 was accomplished with hydrazine to provide 4-amino-3-arylpyrazoles 5 in good yields.
The thiazolium-catalyzed Sila-Stetter reaction: conjugate addition of acylsilanes to unsaturated esters and ketones.

A new acyl anion addition reaction between acylsilanes and α,β-unsaturated conjugate acceptors promoted by a nucleophilic organic catalyst has been disclosed. The 1,4-dicarbonyl products produced in this reaction are highly useful synthons. Neutral carbenes (or zwitterions) generated in situ from commercial thiazolium salts are used as effective catalysts for the reaction which is in contrast to established anionic catalysts typically employed to promote the required Brook rearrangement (1,2-silyl shift from carbon to oxygen) involved in the reported reaction. This process successfully utilizes acylsilanes as tunable acyl anion progenitors and is tolerant of a wide range of structural diversity on the acylsilane or the conjugate acceptor.
Compatibility and Proprietary Standards: The Impact of Conversion Technologies in IT Markets with Network Effects

In markets that exhibit network effects, the presence of digital conversion technologies provides an alternative mechanism to achieve compatibility. This study examines the impact of conversion technologies on market equilibrium in the context of sequential duopoly competition and proprietary technology standards. We analyze this question by departing from the extant literature to endogenize the decision to provide a converter and incorporate explicit negotiations between firms concerning the extent of conversion. We argue that these choices better reflect the environment facing firms in digital goods industries and find that these decisions change some of the established results in the literature. Specifically, we find that unless network effects are very large, the subgame-perfect equilibrium (SPNE) involves firms' agreeing to provide digital converters at a sufficiently low price to all consumers. At this equilibrium, both the entrant and the incumbent are better off because the provision of converters alleviates price competition in the market and leads to both higher product revenues and higher proceeds from the sale of converters. Moreover, under some circumstances, the provision of converters is welfare enhancing. These findings have important implications for research and practice in the adoption of new digital goods as the introduction of conversion technologies can reduce the social costs of standardization without compromising the benefits of network effects.
Heat-spreading analysis of a heat sink base embedded with a heat pipe

A simplified model predicting the heat transfer performance of a heat sink base with a high thermal conductivity was developed. Numerical analysis was performed using the commercial software FLUENT. The investigation indicates that for heat sink bases with a high effective thermal conductivity, such as the base embedded with a typical heat pipe, the entire heat sink can be modeled as a flat plate with a uniform temperature and an effective convection heat transfer coefficient. This simplified model can be used to determine the heat transfer performance of a heat sink embedded with a typical heat pipe or vapor chamber.
Automatic Creation of Domain-Specific Reconfigurable CPLDs for SoC

This paper presents tools that automate the creation of domain-specific complex programmable logic devices (CPLDs), targeted for systems-on-a-chip. By tailoring full-crossbar-based CPLDs to the domains that they support, we provide results that beat fixed reconfigurable architectures by 5.5times-11.8times on average in terms of area-delay product. We also create sparse-crossbar-based CPLD architectures, using a novel switch-smoothing algorithm that makes the crossbars amenable to layout. This algorithm reduced the wire jog pitch of our largest layout from 48 to just 3, allowing for a compact very-large-scale-integration layout. These sparse-crossbar-based CPLDs require just 0.37times the area and 0.30times the delay of our full-crossbar-based CPLDs. We also address the question of how best to add resources to a CPLD in order to support future, unknown circuits, concluding that the best strategy is to add 5% to the crossbar switch density and to provide additional programmable logic arrays of the same size found in the base architecture
Superconductivity in compressed iron: Role of spin fluctuations

The recent discovery of superconductivity in hexagonal iron under pressure poses a question about whether it is of conventional (phonon) or unconventional (magnetic) origin. We present first-principles calculations of the electron-phonon coupling in iron at $P\ensuremath{\gtrsim}15 \mathrm{GPa},$ and argue that a conventional mechanism can explain the appearance of superconductivity, but not its rapid disappearance at $P\ensuremath{\gtrsim}30 \mathrm{GPa}.$ We suggest that spin fluctuations, ferro- and/or antiferromagnetic, play a crucial role in superconductivity in this case.
Mean Stator Loading Effect on the Acoustic Response of a Rotating Cascade

Discrete-frequency tones generated by unsteady blade row interactions are of particular concern in the design of advanced turbine engines. With a rotor ‐ stator mounted in a duct, only certain specie c spatial modes are generated by the rotor ‐ stator interaction, where the generated modes are a function of the number of rotor blades and stator vanes. In addition, only some of these modes propagate to the far e eld, with the rest decaying before reaching the far e eld. Thus, it is only those spatial modes that propagate to the far e eld that represent the discrete-frequency noise received by an observer. This paper’ s aim is to determine the ine uence of steady stator loading on the acoustic response of an annular cascade. To accomplish this, the existence of the propagating modes generated by a rotor ‐ stator interaction must e rst be verie ed. Microphones placed in an axial plane in the outer annulus of the inlet of the Purdue Annular Cascade Research Facility are sampled simultaneously over one rotor revolution, and an ensemble-averaged data set is acquired. With the microphone signals treated as a function of time and space, dual Fourier transforms are utilized to determine the magnitude of the spatial modes at multiples of blade pass frequency. The wave equation is used to predict the propagation characteristics of these modes in the inlet duct. The two predicted propagating modes were found to have signie cantly higher amplitudes than modes that were predicted to decay, or were not to be generated by the rotor ‐ stator interaction, and steady stator loading had a profound ine uence on acoustic response of the cascade. The acoustic response at blade pass and twice blade pass frequency increased by more than 20 dB for angles of attack ranging from 220 to 25 deg.
Returns to Schooling and Bayesian Model Averaging: A Union of Two Literatures

Abstract. In this paper, we review and unite the literatures on returns to schooling and Bayesian model averaging. We observe that most studies seeking to estimate the returns to education have done so using particular (and often different across researchers) model specifications. Given this, we review Bayesian methods which formally account for uncertainty in the specification of the model itself, and apply these techniques to estimate the economic return to a college education. The approach described in this paper enables us to determine those model specifications which are most favored by the given data, and also enables us to use the predictions obtained from all of the competing regression models to estimate the returns to schooling. The reported precision of such estimates also account for the uncertainty inherent in the model specification. Using U.S. data from the National Longitudinal Survey of Youth (NLSY), we also revisit several ‘stylized facts’ in the returns to education literature and examine if they continue to hold after formally accounting for model uncertainty.
Phosphonate Aldehyde Annulation. A One-Pot Synthesis of δ-Hydroxy Cyclopentenoic Esters

The reaction of ketone enolates with phosphonate aldehyde 2 afforded cyclopentenols 3 or keto esters 4 in a one-pot procedure.
A necessary but insufficient condition for the stochastic binary choice problem

Abstract The “stochastic binary choice problem” is the following: Let there be given n alternatives, to be denoted by N = {1, …, n}. For each of the n! possible linear orderings {≻m}m = 1n of the alternatives, define a matrix Yn × n(m)(1 ≤ m ≤ n!) as follows: Y ab (m) = 1 0 a≻ m b otherwise. Given a real matrix Qn × n, when is Q in the convex hull of {Y(m)}m? In this paper some necessary conditions on Q—the “diagonal inequality”—are formulated and they are proved to generalize the Cohen-Falmagne conditions. A counterexample shows that the diagonal inequality is insufficient (as are hence, perforce, the Cohen-Falmagne conditions). The same example is used to show that Fishburn's conditions are also insufficient.
Reliability and validity of the apathy evaluation scale

This article presents evidence for the reliability and construct validity of the Apathy Evaluation Scale (AES). Conceptually, apathy is defined as lack of motivation not attributable to diminished level of consciousness, cognitive impairment, or emotional distress. Operationally, the AES treats apathy as a psychological dimension defined by simultaneous deficits in the overt behavioral, cognitive, and emotional concomitants of goal-directed behavior. Three versions of the AES (clinician, informant, and self-rated) were evaluted for 123 subjects, ages 53-85, meeting research criteria for right or left hemisphere stroke, probable Alzheimer's disease, major depression, or well elderly control. Multiple forms of reliability (internal consistency, test-retest, and interrater) were satisfactory. Several types of validity evidence are presented for each version of the scale, including the following: ability of the AES to discriminate between groups according to mean levels of apathy, discriminability of apathy ratings from standard measures of depression and anxiety, convergent validity between the three versions of the scale, and predictive validity measures derived from observing subjects' play with novelty toys and videogames. Guidelines for the administration of the AES are presented, along with suggestions for potential applications of the scale to clinical and research questions.
A method for estimating both the solubility parameters and molar volumes of liquids

Development of an indirect method of estimating the solubility parameter of high molecular weight polymers. The proposed method of estimating the solubility parameter, like Small's method, is based on group additive constants, but is believed to be superior to Small's method for two reasons: (1) the contribution of a much larger number of functional groups have been evaluated, and (2) the method requires only a knowledge of structural formula of the compound.
Fuzzy logic control of an active power line conditioner

Fuzzy logic and active power line conditioners (APLC) are two tools that are being increasingly applied to power quality problems. In this paper, a switch-mode APLC that uses fuzzy logic to control the semiconductor switches is described. Frequency-domain analysis is used to determine the desired compensation current, and a rule-based piecewise-linear fuzzy proportional-integral controller (FPIC) provides the appropriate switching pattern of the APLC to generate the actual compensation current. MATLAB simulations and experimental measurements on a low-power (700 VA), digital signal processor-based, hardware prototype show that the APLC produces excellent results despite the use of a relatively low switching frequency, which is necessary to minimize semiconductor switching losses. The simulations and measurements are in good agreement and show that the APLC/FPIC system can significantly improve line current total harmonic distortion and power factor during both steady-state and transient operating conditions.
More on the decoder error probability for Reed-Solomon codes

A combinatorial technique similar to the principle of inclusion and exclusion is used to obtain an exact formula for P/sub E/(u), the decoder error probability for Reed-Solomon codes. The P/sub E/(u) for the (255, 223) Reed-Solomon code used by NASA and for the (31, 15) Reed-Solomon code (JTIDS code) are calculated using the exact formula and are observed to approach the Qs of the codes rapidly as u gets large. An upper bound for the expression mod P/sub E/(u)/Q-1 mod is derived and shown to decrease nearly exponentially as u increases. >
Rendering translucent materials using photon diffusion

We present a new algorithm for rendering translucent materials that combines photon tracing with diffusion. This combination makes it possible to efficiently render highly scattering translucent materials while accounting for internal blockers, complex geometry, translucent inter-scattering, and transmission and refraction of light at the boundary causing internal caustics. These effects cannot be accounted for with previous rendering approaches using the dipole or multipole diffusion approximations that only sample the incident illumination at the surface of the material. Instead of sampling lighting at the surface we trace photons into the material and store them volumetrically at their first scattering interaction with the material. We hierarchically integrate the diffusion of light from the photons to compute the radiant emittance at points on the surface of the material. For increased accuracy we use the incidence plane of the photon and the viewpoint on the surface to blend between three analytic diffusion approximations that best describe the geometric configuration between the photon and the shading point. For this purpose we introduce a new quadpole diffusion approximation that models diffusion at right angled edges, and an attenuation kernel to more accurately model multiple scattering near a light source. The photon diffusion approach is as efficient as previous Monte Carlo sampling approaches based on the dipole or multipole diffusion approximations, and our results demonstrate that it is more accurate and capable of capturing several illumination effects previously ignored when simulating the diffusion of light in translucent materials.
Three-dimensional localization of spins in diamond using 12C implantation

We demonstrate three-dimensional localization of a single nitrogen-vacancy (NV) center in diamond by combining nitrogen doping during growth with a post-growth 12C implantation technique that facilitates vacancy formation in the crystal. We show that the NV density can be controlled by the implantation dose without necessitating increase of the nitrogen incorporation. By implanting a large 12C dose through nanoscale apertures, we can localize an individual NV center within a volume of (∼180 nm)3 at a deterministic position while repeatedly preserving a coherence time (T2) > 300 μs. This deterministic position control of coherent NV centers enables integration into NV-based nanostructures to realize scalable spin-sensing devices as well as coherent spin coupling mediated by photons and phonons.
Do Fluctuations in U.S. Inflation Rates Reflect Infrequent Large Shocks or Frequent Small Shocks

We investigate whether fluctuations in U.S. inflation rates are better described by infrequently occurring large shocks or by frequently occurring small shocks. We estimate a model that encompasses the two hypotheses within the framework of non-Gaussian state-space models. Our results indicate support for infrequently occurring large shocks, but this weakens somewhat once we allow for outliers and conditional heteroskedasticity. It appears that, for the purpose of forecasting monthly U.S. inflation rates, recognizing the distinction between frequent small shocks and infrequent large shocks does not matter much once outliers and conditional heteroskedasticity are allowed for.
Maximum life spiral bevel reduction design

Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque, and power. Significant parameters in the design are: the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear, and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.
POX 52: A DWARF SEYFERT 1 GALAXY WITH AN INTERMEDIATE-MASS BLACK HOLE

We describe new optical images and spectra of POX 52, a dwarf galaxy with an active nucleus that was originally detected in the POX objective-prism survey. While POX 52 was originally thought to be a Seyfert 2 galaxy, the new data reveal an emission-line spectrum very similar to that of the dwarf Seyfert 1 galaxy NGC 4395, with broad components to the permitted line profiles, and we classify POX 52 as a Seyfert 1 galaxy. The host galaxy appears to be a dwarf elliptical, and its brightness profile is best fit by a S?rsic model with an index of 3.6 ? 0.2 and a total magnitude of MV = -17.6. Applying mass-luminosity-line width scaling relations to estimate the black hole mass from the broad H? line width and nonstellar continuum luminosity, we find MBH ? 1.6 ? 105 M?. The stellar velocity dispersion in the host galaxy, measured from the Ca II ?8498, 8542 lines, is 36 ? 5 km s-1, also suggestive of a black hole mass of order 105 M?. Further searches for active nuclei in dwarf galaxies can provide unique constraints on the demographics of black holes in the mass range below 106 M?.
Asymmetric Mannich Reaction of Dicarbonyl Compounds with α-Amido Sulfones Catalyzed by Cinchona Alkaloids and Synthesis of Chiral Dihydropyrimidones

The highly enantioselective cinchona alkaloid-catalyzed Mannich reaction of dicarbonyl compounds with alpha-amido sulfones as acyl imine precursors is described. The reaction requires 10 mol % of the cinchona alkaloid catalyst, which serves as a general base to generate acyl imines in situ, and aqueous Na2CO3 to maintain the concentration of free alkaloid catalyst. The reaction products are obtained in good yields and high enantioselectivities, and in diastereoselectivities that range from 1:1 to >95:5. The cinchonine-catalyzed reactions provide practical access to highly functionalized building blocks which have been employed in the synthesis of chiral dihydropyrimidones, a class of compounds rich in diverse biological activity. Dihydropyrimidone modifications include a highly diastereoselective hydrogenation of the enamide moiety, using an H-Cube flow hydrogenator and a Rh(II)-mediated 1,3-dipolar cycloaddition to afford highly functionalized complex heterocycles.
Whistleblower laws and exposed corruption in the United States

This research creates a unique internet-based measure of awareness about state-level whistleblower laws and provisions to examine their effects on observed corruption in the United States. Are whistleblower laws complementary or substitutes for other, more direct, corruption control measures? Placing the analysis within the corruption literature, the findings show that greater whistleblower awareness results in more observed corruption and this finding holds across specifications. Internet awareness about whistleblower laws seems relatively more effective at exposing corruption than the quantity and quality of state whistleblower laws themselves.
Estimates of Consumer Loss Due to Monopoly in the U.S. Food Manufacturing Industries

The widespread attention given our research by the profession and its inclusion in a number of textbooks of agricultural economics gives us a special obligation not only to defend our work forthrightly but also to give potential critics maximum access to our underlying data.' In the latter regard, the authors of the current comment, Marion and Grinnell (hereafter MG) were supplied with the raw data for our analysis over five years ago.2 The MG comment focuses on only the first and third approaches used by PC to estimate consumer loss. The first approach was a sum of estimates for the various components of consumer loss. Where components could not be independently estimated, the authors adapted to food manufacturing estimates published by Scherer for the whole economy.3 The second approach was a regression model of census price-cost margins (PCM) adapted from original work by Collins and Preston.4 The third approach involved an original model in which the average price differences between national brands and private labels were used as observations on the dependent variable. Consumer loss was calculated using the variation of the dependent variable that was associated with market structure characteris-
Teaching basic science: Dr Fox in the physiology chicken coop

Summary. In a variation of the Dr Fox study, an educational specialist delivered a lecture in the first-year course on physiology. A highly expressive teaching style was used for content which was determined by physiology teachers. The aim was to determine whether students would note a difference. According to student evaluations, this was the highest rated lecture in the 1984 course. The lecture was repeated in the 1985 and 1986 courses with positive, but less high ratings. No students detected that the lecturer was not a physiologist.
Jet Transport Response to a Horizontal Wind Vortex

The dynamic response of a twin-jet transport aircraft encountering a horizontal wind vortex (or rotor) on final approach to landing is investigated. Computer simulations determine the effects of vortex strength, vortex length, lateral entry position, vertical entry position, and encounter incidence angle on the aircraft's roll response. Maximum roll rate and roll angle increase proportionally with vortex strength and length until a saturation length is reached. Roll response is highly dependent on entry location: changes in lateral entry position largely affect maximum roll angle while changes in vertical entry position affect maximum roll rate. Peak roll rate and roll angle obtain their largest values at near-zero incidence angles. The response is highly dependent on the precise initial conditions of the encounter—even small variations in initial condition cause significant changes in aircraft roll response. IRCRAFT that encounter strong vortical winds during flight can experience violent angular and translational motions. Rotating wind fields are produced by the tip vortices of other aircraft or by naturally occurring sheared wind flows. As a consequence of structural similarities in the flows, studies of aircraft encounters with wake and wind vortices are com- plementary. Greater knowledge of aircraft-vortex interactions is needed for the investigation of unsolved accidents and for preventing future accidents through the development of new vortex detection and warning systems, pilot training pro- grams, and departure-preventing control system designs. The importance of understanding aircraft/wind-vortex in- teractions was highlighted by a recent jet transport accident that may have been caused by a mountain-wave wind vortex (also called a "wind rotor").1 On March 3, 1991, a twin-jet transport aircraft on final approach to landing rolled upside down and pitched nose down before contacting the ground at high speed. The entire event, from steady, level flight 1000 ft above the ground to impact, took less than 10 s. All pas- sengers and crew members perished. The National Transportation Safety Board (NTSB) consid- ered a mountain-wave wind vortex as a possible cause of the accident. Strong winds flowing over mountains prevailed on the day of the accident; such winds can produce "downslope windstorms" characterized by wave features extending for many miles beyond the mountains.2"4 If encountered at the proper orientation, a wind vortex may well have the strength to roll the aircraft to an unrecoverable roll angle. Neverthe- less, limited knowledge of how a wind vortex affects a trans- port aircraft along with lack of flight evidence prevented pos- itive determination of this accident's cause.1 While the research reported here is motivated by the ref- erenced accident, it is not a study of that specific accident. Instead, it is an exploration of the wind rotor and aircraft flight conditions that could lead to severe flight path upset for small jet transports, with emphasis on "open-loop" aircraft
On sound transmission into a thin cylindrical shell under “flight conditions”

In the context of airborne-noise transmission through an aircraft fuselage, a mathematical model is presented for sound transmission into a stiffened cylindrical shell. The stiffening effect of the ring frames and stringers is approximated by a 'smeared'-stiffener theory which includes the eccentricity of the stiffeners. Numerical results are presented for a typical narrow-bodied jet in cruising flight. A comparison is made between noise transmission into a monococque shell and into a stiffened shell. The stiffeners are shown to greatly increase TL for small incidence angles, so that the effective 'window' for noise transmission is restricted to the neighborhood of normal incidence. Flow is shown to increase TL for sound waves propagating 'upstream' against the flow. Stiffeners are also shown to raise the ring frequency at which a dip in cylinder TL occurs. Limitations of the 'smeared'-stiffener theory are also discussed.
Ruthenium-catalyzed two-component addition to form 1,3-dienes: optimization, scope, applications, and mechanism.

A two component coupling of an allene and an activated olefin to form 1,3-dienes has been developed. The requisite allenes are synthesized either from terminal alkynes by a one carbon homologation using copper(I) iodide, paraformaldehyde, and diisopropylamine, via an ortho ester-Claisen rearrangement from a propargylic alcohol, or via a Wittig type reaction on a ketene generated in situ from an acid chloride. Mono- through tetrasubstituted allenes could be synthesized by these methods. Either cyclopentadienylruthenium(II) cyclooctadiene chloride or cyclopentadienylruthenium(II) trisacetonitrile hexafluorophosphate catalyze the addition reaction. When the former catalyst is employed, an alkyne activator is added to help generate the active catalyst. Through systematic optimization studies, a range of conditions was examined. The optimal conditions consisted of the use of cerium(III) trichloride heptahydrate as a cocatalyst in dimethylformamide as a solvent at 60 °C. The reaction was found to be chemoselect...
Self-sustained activity in networks of gain-modulated neurons

Abstract Simulation studies have shown that recurrently connected neurons are capable of sustaining non-uniform profiles of activity in the absence of tuned input. These attractor networks are the basis for models of working memory and other processes where information about transient stimuli is stored temporarily. In addition, there is strong evidence that neurons often interact by affecting each other's gain. Here I study a minimal recurrent network that takes gain interactions into account. I show analytically that, in agreement with results of computer simulations, a center-surround organization gives rise to two types of stable solutions: a uniform state in which all neurons fire at the same rate, and a self-sustained profile of activity that may be centered at any point in the network. This theoretical framework based on nonlinear neuronal interactions is, in general, a powerful tool for investigating recurrent network dynamics.
Does Compulsory School Attendance Affect Schooling and Earnings

We establish that season of birth is related to educational attainment because of school start age policy and compulsory school attendance laws. Individuals born in the beginning of the year start school at an older age, and can therefore drop out after completing less schooling than individuals born near the end of the year. Roughly 25 percent of potential dropouts remain in school because of compulsory schooling laws. We estimate the impact of compulsory schooling on earnings by using quarter of birth as an instrument for education. The instrumental variables estimate of the return to education is close to the ordinary least squares estimate, suggesting that there is little bias in conventional estimates. Every developed country in the world has a compulsory schooling requirement, yet little is known about the effect these laws have on educational attainment and earnings.1 This paper exploits an unusual natural experiment to estimate the impact of compulsory schooling laws in the United States. The experiment stems from the fact that children born in different months of the year start school at different ages, while compulsory schooling laws generally require students to remain in school until their sixteenth or seventeenth birthday. In effect, the interaction of school-entry requirements and compulsory schooling laws compel students born
Stability of nitrogen-oxygen cages N12O2, N14O2, N14O3, and N16O4.

Molecules consisting entirely of nitrogen have been studied extensively for their potential as high energy density materials (HEDM). However, many such molecules are too unstable to serve as practical energy sources. This has prompted many studies of molecules that are mostly nitrogen but which incorporate heteroatoms into the structure to provide additional stability. In the current study, cages of three-coordinate nitrogen are viewed as candidates for stabilization by insertion of oxygen atoms into the nitrogen framework. Cages of N12, N14, and N16 with four-membered rings are studied because four-membered rings have been previously shown to be a destabilizing influence. Insertion of oxygen atoms, which converts N−N bonds to N−O−N bonding groups, relieves ring strain and can potentially result in stable molecules. These molecules are studied by theoretical calculations, using Hartree−Fock and Moller−Plesset (MP3 and MP4) theories, to determine the dissociation energies of the molecules. The primary resu...
The use of molten salts as physical models for the study of solidification in metals and semiconductors

Product morphology in metal casting and semiconductor crystal growth is strongly influenced by the nature of the solid-liquid interface during solidification. Since in situ observation of solification in these technologically important systems is not possible, investigators have resorted to the use of physical models, such as water and organic liquids, which while they are transparent to visible light, suffer from the fact that their Prandtl numbers are too high. Molten alkali halides are better physical models in this respect, and are transparent to visible light. The purpose of the present study is to examine solidification in the LiCl-KCl system to determine if phenomena such as solute rejection can be observed by laser schlieren imaging.
Oscillating asymmetric dark matter

We study the dynamics of dark matter (DM) particle-antiparticle oscillations within the context of asymmetric DM. Oscillations arise due to small DM number-violating Majorana-type mass terms, and can lead to recoupling of annihilation after freeze-out and washout of the DM density. Asymmetric DM oscillations "interpolate" between symmetric and asymmetric DM freeze-out scenarios, and allow for a larger DM model-building parameter space. We derive the density matrix equations for DM oscillations and freeze-out from first principles using nonequilibrium field theory, and our results are qualitatively different than in previous studies. DM dynamics exhibits particle-vs-antiparticle "flavor" effects, depending on the interaction type, analogous to neutrino oscillations in a medium. "Flavor-sensitive" DM interactions include scattering or annihilation through a new vector boson, while "flavor- blind" interactions include scattering or s-channel annihilation through a new scalar boson. In particular, we find that flavor-sensitive annihilation does not recouple when coherent oscillations begin, and that flavor-blind scattering does not lead to decoherence.
Pattern Selection in Solidification

Directional solidification of alloys produces a wide variety of cellular or lamellar structures which, depending upon growth conditions, may be reproducibly regular or may behave chaotically. It is not well understood how these patterns are selected and controlled or even whether there ever exist sharp selection mechanisms. A related phenomenon is the spatial propagation of a pattern into a system which has been caused to become unstable against pattern-forming deformations. This phenomenon has some features in common with the propagation of sidebranching modes in dendritic solidification. In a class of one-dimensional models, the nonlinear system can be shown to select the propagating mode in which the leading edge of the pattern is just marginally stable. This stability principle, when applicable, predicts both the speed of propagation and the geometrical characteristics of the pattern which forms behind the moving front. A boundary-layer model for fully two or three dimensional solidification problems appears to exhibit similar mathematical behavior.
Historical issues concerning animal experimentation in the United States.

The use of animals for research and teaching has now become an issue of great concern in the United States. In contrast to the legislative systems in Britain, Scandinavia and many European countries, American scientists can pursue research projects with relative freedom. Recent activities in the United States may effect this practice and future animal experimentation may be subjected to restriction and control by legislation. Events leading to this possibility are similar in many ways to those in 19th century Britain prior to the passage of the Cruelty to Animals Act in 1876 (which licenses scientists, regulates experimentation and carries out inspections). Historically, it seemed that the immediate effect of the 1876 act was to decrease the number of scientists who could conduct experiments on live vertebrate animals in Great Britain and hence the number of experiments and animals. Yet, antivivisection activity in Britain did not decrease but continued toward its goal of abolishing all research with animals. By 1882, the medical scientific community established the Association for the Advancement of Medicine by Research which began to advise the Home Secretary on licensing scientists.... Although the first Humane Society in the United States was established in 1866, it was not until the end of the 19th century when scientific disciplines were necessary for the education of physicians that protests against the use of animals for experimentation became organized. Activities by American animal protection groups have increased since that time and have now culminated in proposed legislation which if passed would not only restrict the use of animals for research but would also interfere with the kinds of research that could be conducted. Legislation in Britain, Scandinavia and in many European countries appears to be efficient and effective because of the relatively small number of research institutions and scientists in those countries. Is legislation in the United States feasible considering the extremely large number of scientists and research institutions? American scientists are facing three possibilities: mandatory regulation (legislation), self-regulation, or some combination of both. Self-regulation of animal experimentation appears to be the optimal choice. It would reflect the success of animal protection groups in raising the consciousness and concerns of scientists about the humane treatment of experimental animals: (1) reducing the numbers of animals used for experimentation, (2) unnecessary duplication of experiments, and (3) minimizing pain and distress. Although scientists are proceeding toward a program(s) of self-regulation, this approach will be based on the scientific method and will not satisfy completely the differences between scientific and animal protection groups. Scientists have become concerned with "the moral and ethical responsibility for the humane treatment of animals in experimentation" whereas animal protection groups are concerned with "the moral rights of animals...."
CLEC access charges and the problem of monopoly power

Abstract The analysis in this paper looks at the problem of excessive originating and terminating access charges imposed by some competitive local exchange carriers (CLECs) in the US. The problem arises because the current institutional structure provides an incentive for CLECs to charge for access service in excess of what a competitive market would indicate. An examination the data shows that the problem of excessive access charges imposed by CLECs is very real. An analysis of terminating access charges for September 2000 reveals that average terminating access charges billed to three interexchange carriers (IXCs) are excessive, exceeding average price cap-regulated incumbent local exchange carrier (ILEC) access charges by 370–470%. A couple of solutions to the problem are offered, including a first-best solution whereby the calling party would be required to pay the for originating access service and have the receiving party pay for terminating access service. A second-best solution would be to limit CLEC’s access charges to an IXC to be less than or equal to the access charges of the ILEC with which it directly competes for customers.
CR-Invariants and the Scattering Operator for Complex Manifolds with Boundary

The purpose of this paper is to describe certain CR-covariant differential operators on a strictly pseudoconvex CR manifold $M$ as residues of the scattering operator for the Laplacian on an ambient complex K\"{a}hler manifold $X$ having $M$ as a `CR-infinity.' We also characterize the CR $Q$-curvature in terms of the scattering operator. Our results parallel earlier results of Graham and Zworski \cite{GZ:2003}, who showed that if $X$ is an asymptotically hyperbolic manifold carrying a Poincar\'{e}-Einstein metric, the $Q$-curvature and certain conformally covariant differential operators on the `conformal infinity' $M$ of $X$ can be recovered from the scattering operator on $X$. The results in this paper were announced in \cite{HPT:2006}.