cssi/SciSciGPT-SciSciNet huggingface dataset:
Low-field current-hysteretic oscillations in spin-transfer nanocontacts

We measured spin-transfer-driven, large-amplitude, current-hysteretic, low-frequency $(l500\phantom{\rule{0.3em}{0ex}}\mathrm{MHz})$, narrowband oscillations in nanocontacts made to spin valve structures. The oscillations occur in zero field, persist up to $5\phantom{\rule{0.3em}{0ex}}\mathrm{mT}$ for in-plane applied fields, and to beyond $400\phantom{\rule{0.3em}{0ex}}\mathrm{mT}$ for out-of-plane fields. Unlike for previous measurements, here the oscillation frequency is well below that for uniform-mode ferromagnetic resonance, is a weak function of the applied field and current, and is highly anharmonic. The oscillations are hysteretic with dc current, appearing at high currents but persisting to lower currents upon decrease of the current. We suggest that these observations are consistent with the dynamics of a nonuniform magnetic state, one nucleated by both the spin-transfer torque and dc current-generated Oersted fields, with dynamics driven by spin transfer. The electrical oscillations are large amplitude and narrowband, with the largest amplitudes on the order of $1\phantom{\rule{0.3em}{0ex}}\mathrm{mV}$ and the narrowest linewidths below $1\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$.
Oxidative Cyclizations: The Asymmetric Synthesis of (−)-Alliacol A

A tandem anodic coupling-Friedel-Crafts alkylation strategy has been used to rapidly complete the asymmetric synthesis of alliacol A. The anodic oxidation reaction allowed for the generation of a new bond between two nucleophiles. In the synthesis, the absolute stereochemistry of the final natural product is set relative to a methyl group that is incorporated early in the sequence using an asymmetric Michael reaction.
Hf(IV)-Catalyzed Enantioselective Epoxidation of N-Alkenyl Sulfonamides and N-Tosyl Imines

Asymmetric epoxidation of allylic and homoallylic amine derivatives catalyzed by Hf(IV)–bishydroxamic acid complexes is described. Under similar conditions, aldimine and ketimine produced oxaziridines. The sulfonyl group is demonstrated to be an effective directing group for these transformations.
Pope John Paul II and Catholic Opinion Toward the Death Penalty and Abortion

Objective. Research on opinion leadership examines the convergence of opinion between elites and masses on issues of public policy. I examine the confluence of opinion between Pope John Paul II and American Catholics on the death penalty and legalized abortion. Method. I use data from three nationally representative opinion surveys and one statewide survey conducted prior to John Paul’s death. Results. The results support the supposition that Catholics who esteemed the pope are more negative in their evaluations of the death penalty and abortion. Conclusions. John Paul II, as leader of the Catholic Church, may have influenced Catholic opinion on political issues. Research on public opinion has demonstrated the influence of elites in shaping mass attitudes (e.g., Lazarsfeld, Berelson, and Gaudet, 1944; Zaller, 1992). Elites may be especially influential in the domain of religion and politics, where clergy have the opportunity to shape the attitudes of congregants. Such influence may be particularly likely among Roman Catholics, who traditionally look to the church hierarchy to set Catholic ‘‘policy’’ on issues of faith and morals. To the extent this is true, the pope in particular stands in a position of strong potential influence. In contrast to the leadership of most other faith traditions, for Catholics, the pope has the power to speak for the whole church. To be sure, American Catholics are known for defying church teachings on issues such as contraception, and few Catholics are likely to accede blindly to papal pronouncements. Yet some Catholics at least may heed teachings of the church and the pope. A few studies (e.g., Welch et al., 1993) have addressed the influence of Catholic clergy, including American bishops (e.g., Wald, 1992), on lay Catholics. However, no study to date has looked at the potential influence of the pope on Catholic opinion. Catholics are almost one-quarter of the U.S. electorate. The influence of the pope on Catholic opinion may have consequences not only for Catholics but for American politics. In this article, I use the unfortunate death of Pope John Paul II as an opportunity to begin to address the question of papal influence on Catholic political attitudes. Using data collected before the death of Pope John Paul,
The Price of a Smile: Hedging and Spanning in Option Markets

The volatility smile changed drastically around the crash of 1987, and new option pricing models have been proposed to accommodate that change. Deterministic volatility models allow for more flexible volatility surfaces but refrain from introducing additional risk factors. Thus, options are still redundant securities. Alternatively, stochastic models introduce additional risk factors, and options are then needed for spanning of the pricing kernel. We develop a statistical test based on this difference in spanning. Using daily S&P 500 index options data from 1986-95, our tests suggest that both in- and out-of-the-money options are needed for spanning. The findings are inconsistent with deterministic volatility models but are consistent with stochastic models that incorporate additional priced risk factors, such as stochastic volatility, interest rates, or jumps. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Constraints on gas giant satellite formation from the interior states of partially differentiated satellites

An icy satellite whose interior is composed of a homogeneous ice/rock mixture must avoid melting during its entire history, including during its formation when it was heated by deposition of accretional energy and short-lived radioisotopes. Estimates of the temperature rise associated with radiogenic and accretional heating, coupled with limits on satellite melting can be used to constrain the timing of formation of a partially differentiated satellite relative to the origin of the calcium–aluminum-rich inclusions (CAI’s) as a function of its accretion timescale and the protosatellite disk temperature (Td). Geological characterization and spacecraft radio tracking data suggest that Callisto, the outermost regular satellite of Jupiter, and Saturn’s mid-sized satellite Rhea, are partially differentiated if their interiors are in hydrostatic equilibrium. Because the specific conditions during the satellites’ formation are uncertain, we determine accretional temperature profiles for a range of values for Td and accretion time scales with the limiting assumption that impactors deposit all their energy close to the surface, leading to maximally effective radiative cooling. We find that Callisto can remain unmelted during formation if it accreted on a time scale longer than 0.6 Myr. Considering both radiogenic and accretional heating, Callisto must have finished accreting no earlier than ∼4 Myr after formation of CAI’s for Td = 100 K. Warmer disks or larger impactors that deposit their energy at depth in the satellite would require longer and/or later formation times. If Rhea accreted slowly (in 10 5
Dephasing of interacting tunneling systems

We investigate the phase coherence time of weakly interacting tunneling systems (TSs). We show that those neighbors of a TS, for which the interaction energy with the TS of interest exceeds its line width, form together with the TS a cluster. Thus, not only the resonance frequency of a TS depends on the actual state of all its neighbors but a relaxation of any neighbor might also lead to a loss of the phase coherence for the TS or more precisely for the cluster. Additionally the coupling to the phonons force the TS, excited with its resonance frequency which is determined by the states of the neighbors, to additional oscillations with frequencies corresponding to situations with the neighbors in different states. This leads to beats with periods given by 2π/J with the interaction J between the TS and a neighbor. Within an two pulse echo experiment both effects cancel out at times shorter than the beat period and, thus, the neighbor does not contribute to the dephasing of the TS at short times. Averaging over the parameter distribution of the standard tunneling model of glasses we obtain the same results as given by spectral diffusion (Phys. Rev. B 16 (1977) 2879).
Temporal variations in extension rate on the Lone Mountain fault and strain distribution in the eastern California shear zone–Walker Lane

The eastern California shear zone (ECSZ) and Walker Lane represent an evolving segment of the Pacific–North America plate boundary in the western United States. Understanding temporal variations in strain accumulation and release along plate boundary structures is critical to assessing how deformation is accommodated throughout the lithosphere. Late Pleistocene displacement along the Lone Mountain fault suggests that the Silver Peak–Lone Mountain (SPLM) extensional complex is an important structure in accommodating and transferring strain within the ECSZ and Walker Lane. Using geologic and geomorphic mapping, differential global positioning system surveys, and terrestrial cosmogenic nuclide (TCN) geochronology, we determined rates of extension across the Lone Mountain fault in western Nevada. The Lone Mountain fault displaces the northwestern Lone Mountain and Weepah Hills piedmonts and is the northeastern component of the SPLM extensional complex, a series of down-to-the-northwest normal faults. We mapped seven distinct alluvial fan deposits and dated three of the surfaces using 10 Be TCN geochronology, yielding ages of 16.5 ± 1.2 ka, 92 ± 9 ka, and 137 ± 25 ka for the Q3b, Q2c, and Q2b deposits, respectively. The ages were combined with scarp profile measurements across the displaced fans to obtain minimum rates of extension; the Q2b and Q2c surfaces yield an extension rate between 0.1 ± 0.1 and 0.2 ± 01 mm/yr and the Q3b surface yields a rate of 0.2 ± 0.1–0.4 ± 0.1 mm/yr, depending on the dip of the fault. Active extension on the Lone Mountain fault suggests that it helps partition strain off of the major strike-slip faults in the northern ECSZ and transfers deformation to the east around the Mina deflection and northward into the Walker Lane. Combining our results with estimates from other faults accommodating dextral shear in the northern ECSZ reveals an apparent discrepancy between short- and long-term rates of strain accumulation and release. If strain rates have remained constant since the late Pleistocene, this could reflect transient strain accumulation, similar to the Mojave segment of the ECSZ. However, our data also suggest a potential increase in strain rates between ca. 92 ka and ca. 17 ka, and possibly to present day, which may also help explain the mismatch between long- and short-term rates of deformation in the region.
Vibration Frequency and Ionization Potential : Halide Molecules

IT has been observed that a systematic correlation is possible between the sum of normal vibration frequencies of a molecule and the first ionization potentials of its constituent atoms.
Semantic clustering for region-based image retrieval

With the proliferation of applications that demand content-based image retrieval, two merits are becoming more desirable. The first is the reduced search space, and the second is the reduced ''semantic gap.'' This paper proposes a semantic clustering scheme to achieve these two goals. By performing clustering before image retrieval, the search space can be significantly reduced. The proposed method is different from existing image clustering methods as follows: (1) it is region based, meaning that image sub-regions, instead of the whole image, are grouped into. The semantic similarities among image regions are collected over the user query and feedback history; (2) the clustering scheme is dynamic in the sense that it can evolve to include more new semantic categories. Ideally, one cluster approximates one semantic concept or a small set of closely related semantic concepts, based on which the ''semantic gap'' in the retrieval is reduced.
A SHORT SYNTHESIS OF AN ACETYLENIC ALCOHOL FROM THE SPONGE CRIBROCHALINA VASCULUM

A short synthesis of the acetylenic alcohol from cribrochalina vasculum is described. No protecting groups are used in this synthesis. The key step is an enzymatic resolution of a racemic mixture of the title compound.
Syntactic image modeling using stochastic tree grammars

Publisher Summary This chapter presents some results on stochastic tree languages and their application to image modeling, in particular to texture modeling. An image is described as a composition of its components, called sub-images and primitives. In recent years, stochastic languages have been used in the modeling of image structures. For one-dimensional signal and line patterns, the one-dimensional string representation appears to be quite natural and efficient. However, for two-dimensional images and three-dimensional scenes, an extension from the one-dimensional string language approach to higher dimensions will often result in a more efficient representation. One natural extension of one-dimensional string languages to high-dimensional languages is tree languages. A string could be regarded as a single-branch tree. The capability of having more than one branch often gives trees a more efficient image representation. The probability distribution of the trees representing images can be used to model the noisy situations.
An empirical analysis of the impact of federal budget deficits on long-term nominal interest rate yields, 1973.2–1995.4, using alternative expected inflation measures

Abstract Using two alternative measures of expected inflation, this study investigates the impact of federal budget deficits on nominal long-term interest rate yields for the 1973.2–1995.4 period. Based on an open-economy loanable funds framework, four instrumental variable estimates in first differences are provided. In all cases, the budget deficit is found to elevate the nominal long-term interest rate.
Choosing strategic responses to address emerging environmental regulations: size, perceived influence and uncertainty

How companies respond to impending regulations is a significant aspect of corporate strategy. Regulations, especially environmental regulations, are expanding quickly and increasingly important to firm success. The threat of impending environmental regulation forces companies to choose levels of strategic responses on a continuum from passive to active. Using practitioner oriented research and existing theoretical models of corporate response, this study finds that the type of strategic response is negatively related to size, positively related to state uncertainty and negatively related to effect/response uncertainty. Based on existing literature and the results of this study, the paper suggests that simplifying the uncertainty construct could lead to more definitive findings in future research. The study results also suggest that a curvilinear relationship may exist between managerial perception of influence and level of strategic response. Most importantly, the findings could have a significant impact on firm decision making regarding environmental investments. For example, it is hoped that firms will be able to use the findings of this study to further understand and anticipate their competitors' decisions. Practitioners may also benefit from the conclusions on uncertainty in that they may be able to more cleanly parse the types of uncertainty immersed in impending environmental regulations. Finally, firms may be better able to understand decisions by their own managers and their competitors' managers in terms of their perceived influence over the regulatory process. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Photoinduced Electron Transfer Counter to the Bias Field in Coupled Quantum Wells

Optical excitation of electrons in an asymmetric double quantum well is theoretically examined. The well is biased to align the excited levels and permit resonant electron tunneling. Emphasis is made on the photoinduced transfer of electrons counter to the bias electric field force. A density-matrix approach is developed to describe optical excitations in the presence of an arbitrary dephasing. The excitation profiles obtained for cases of different dephasing reveal the full range of tunneling coupling between the wells from completely coherent to incoherent (stepwise).
THE DISTRIBUTION OF NONSTATIONARY AUTOREGRESSIVE PROCESSES UNDER GENERAL NOISE CONDITIONS

. In this paper we consider the long-run distribution of a multivariate autoregressive process of the form xn=An-1xn-1+ noise, where the noise has an unknown (possibly nonstationary and nonindependent) distribution and An is a (generally) time-varying transition matrix. It can easily be shown that the process xn need not have a known long-run distribution (in particular, central limit theorem effects do not generally hold). However, if the distribution of the noise approaches a known distribution as n gets large, we show that the distribution of xn may also approach a known distribution for large n. Such a setting might occur, for example, when transient effects associated with the early stages of a system's operation die out. We first present a general result that applies for arbitrary noise distributions and general An. Several special cases are then presented that apply for noise distributions in the infinitely divisible class and/or for asymptotically constant coefficient An. We illustrate the results on a problem in characterizing the asymptotic distribution of the estimation error in a Kalman filter.
Radiative Transfer Simulations of Cosmic Reionization. I. Methodology and Initial Results

We present a new hybrid code for large-volume, high-resolution simulations of cosmic reionization, which utilizes an N-body algorithm for dark matter, physically motivated prescriptions for baryons and star formation, and an adaptive ray-tracing algorithm for radiative transfer of ionizing photons. Two test simulations, each with 3 billion particles and 400 million rays in a 50 Mpc h-1 box, have been run to give initial results. Halos are resolved down to virial temperatures of 104 K for the redshift range of interest in order to robustly model star formation and clumping factors. This is essential to correctly account for ionization and recombination processes. We find that the halos and sources are strongly biased with respect to the underlying dark matter, re-enforcing the requirement of large simulation boxes to minimize cosmic variance and to obtain a qualitatively correct picture of reionization. We model the stellar initial mass function (IMF) by following the spatially dependent gas metallicity evolution, and distinguish between the first generation, Population III (PopIII) stars and the second generation, Population II (PopII) stars. The PopIII stars with a top-heavy IMF produce an order of magnitude more ionizing photons at high redshifts z 10, resulting in a more extended reionization. In our simulations, complete overlap of H II regions occurs at z ≈ 6.5, and the computed mass- and volume-weighted residual H I fractions at 5 z 6.5 are both in good agreement with high-redshift quasar absorption measurements from the Sloan Digital Sky Survey (SDSS). The values for the Thomson optical depth are consistent within 1 - σ of the current best-fit value from third-year Wilkinson Microwave Anisotropy Probe (WMAP) results.
Lessons Learned from the Hubble Space Telescope (HST) Contamination Control Program

Over the past two decades, the Hubble Space Telescope (HST) contamination control program has evolved from a ground-based integration program to a space-based science-sustaining program. The contamination controls from new-generation scientific instruments and orbital replacement units were incorporated into the HST contamination control program to maintain scientific capability over the life of the telescope. Long-term, on-orbit scientific data have shown that the contamination controls implemented for the instruments, servicing mission activities (Orbiter, astronauts, and mission), and on-orbit operations successfully protected the HST from contamination and the instruments from self-contamination.
Field analysis of mercury in water, sediment and soil using static headspace analysis

We developed a field screening method for the rapid analysis of mercury (Hg) in water, soil and sediment which can be applied cost-effectively at Hg-contaminated sites. The samples are chemically pretreated in ordinary containers, followed by analysis of the sample headspace Hg vapor using a portable commercially-available analyzer. Mercury in water samples is reduced directly by the addition of stannous chloride, while solids are first digested with aqua regia or piranha solution to liberate the Hg from the solids. Aided by vigorous agitation after addition of the reductant, the elemental Hg partitions between the solution and headspace according to Henry’s Law. The method requires about 2 and 15 minutes to complete for water and solids, respectively. The method provides very useful detection limits for water (0.1 μg/L) and solids (≤ 2 μg/g). Intercomparisons with laboratory-analyzed environmental samples have shown reasonable agreement.
Resonant electrical control systems

The electrical phase shift between the current and the applied voltage in a series-resonant circuit as the resonant-circuit tuning is varied is used as the basis of operation for resonant electrical control systems. The author discusses application of such systems to aircraft and industrial problems, and to single and multiphase radio control.
Gauged Q balls

Classical non-topological soliton configurations are considered within the theory of a complex scalar field with a gauged U symmetry. Their existence and stability against dispersion are demonstrated and some of their properties are investigated analytically and numerically. The soliton configuration is such that inside the soliton the local U symmetry is broken, the gauge field becomes massive and for a range of values of the coupling constants the soliton becomes a superconductor pushing the charge to the surface. Furthermore, because of the repulsive Coulomb force, there is a maximum size for these objects, making impossible the existence of Q-matter in bulk form. Also briefly discussed are solitons with fermions in a U gauge theory.
Alternative method of suprapubic assistance in operative cystoscopy

Complications of tension-free vaginal tape (TVT) procedures have become more prevalent as the procedure has become more popular for the treatment of stress urinary incontinence. A common complication of TVT slings is bladder perforation, which is estimated to occur in 0.7–24% of treated patients. While easily treated if identified intraoperatively, unrecognized bladder perforation generally requires further surgery to correct. We propose a novel minimally invasive technique using the suture passer of the Carter–Thomason CloseSure system for suprapubic assistance during cystoscopic removal of TVT mesh from the bladder. This novel approach allows for the avoidance of an open incision or a larger accessory port placed through the bladder to assist with mesh excision.
Design of Cooling Systems for Electronic Equipment Using Both Experimental and Numerical Inputs

This paper presents a methodology for the design and optimization of the cooling system for electronic equipment. In this approach, inputs from both experimentation and numerical modeling are to be used concurrently to obtain an acceptable or optimal design. The experimental conditions considered are driven by the numerical simulation, and vice versa. Thus, the two approaches are employed in conjunction, rather than separately, as is the case in traditional design methods. Numerical simulation is used to consider different geometries, materials and dimensions, whereas experiments are used for obtaining results for different flow rates and heat inputs, since these can often be varied more easily in experiments than in simulations. Also, transitional and turbulent flows are more accurately and more conveniently investigated experimentally. Thus, by using both the approaches concurrently, the entire design domain is covered, leading to a rapid, convergent, and realistic design process. Two simple configurations of electronic cooling systems are used to demonstrate this approach.Copyright © 2003 by ASME
Doppler shift methods for plasma diagnostics

Abstract Work to develop novel advanced laser spectroscopy plasma diagnostic methods is described. The methods are based on observing the Doppler shift in the absorption lines of ionic species. Two methods under study are velocity modulated laser spectroscopy and two-beam Doppler shift laser spectroscopy. The theoretical basis of the methods is described and preliminary experimental results presented.
Forced convection boiling from a nonflush simulated electronic chip

An experimental investigation has been undertaken to determine the effect of heated surface height on forced convective boiling. An inert fluorocarbon, FC-72 (3M Industrial Chemical Products Division) is circulated through a vertical rectangular channel at velocities of 1-4 m/s and subcoolings of 20 and 35°C. Results for five surface heights, as measured relative to the flow channel wall, were obtained. These were 0.127-mm recessed, 0.229-, 0.457-, and 0.635-mm protruded and flush with the flow channel wall. A reduction in critical heat flux (CHF) occurred at low velocities, while an increase occurred at higher velocities for the protruded cases. A reduction of CHF occurred at all velocities for the recessed condition. Additional results in the velocity range of 5-7 m/s are presented for the flush condition. This data shows that for velocities greater than 4 m/s, CHF becomes weakly dependent on the Weber number. Weak dependence on Weber number also implies a direct proportionality to velocity and a weak dependence on heated length.
Threshold phenomena in nonlinear currents upon metallization of Si(001)

Using a novel combination of fundamental and harmonic polarizations, we have used optical second-harmonic (SH) generation to probe the nonlinear currents induced parallel to the surface plane of a Si(001) crystal upon adsorption of Na, K, and Cs. For all three alkalis, we observe abrupt thresholds in SH intensity and relative SH phase shift at the same coverage of very nearly one-sixth of a monolayer. We speculate that these thresholds correspond to insulator-metal transitions, and that a recently observed low-coverage (2 × 3) structure is a Mott-Hubbard-like insulator.
Quantitative Theory of the Influence Electrostatic Generator

A rigorous mathematical theory of the static machine is given and applied in detail to a simple four element machine of a type exemplified by the Kelvin replenisher. It is shown that the potentials of each of the inductors after $n$ cycles satisfies an equation of the form ${V}_{n}={C}_{1}{{r}_{1}}^{n}+{C}_{2}{{r}_{2}}^{n}$, where ${r}_{1}$ and ${r}_{2}$ are constants which depend only on the coefficients of capacity and the coefficients of induction of the elements in two configurations, and ${C}_{1}$ and ${C}_{2}$ are constants which depend both on the initial values of the potentials of the inductors and the coefficients of capacity and of induction of the elements in the two determining configurations. The values of the various constants for a non-symmetrical machine, and also for a symmetrical machine are given in tables. It is shown that theoretically the potential produced by an ordinary static machine will increase without limit, approach a constant value, or decrease to zero, depending on the phase at which the brushes are grounded.
Asymptotic optimality of the static frequency caching in the presence of correlated requests

Renewed interest in caching algorithms stems from their application to content distribution on the Web. When documents are of equal size and their requests are independent and equally distributed, it is well known that static algorithm that keeps the most frequently requested documents in the cache is optimal. However, there are no explicit caching algorithms that are provably optimal when the requests are statistically correlated. In this paper, we show, maybe somewhat surprisingly, that keeping the most frequently requested documents in the cache is still optimal for large cache sizes even if the requests are strongly correlated. We model the statistical dependency of requests using semi-Markov modulated processes that can capture strong statistical correlation, including the empirically observed long-range dependence in the Web access sequences. Although frequency algorithm and its practical version least-frequently-used policy is not commonly used in practice due to their complexity and static nature, our result provides a benchmark for evaluating the popular heuristic schemes. In particular, an important corollary of our main theorem and recent result from [9] is that the widely used least-recently-used heuristic is asymptotically near-optimal under the semi-Markov modulated requests and generalized Zipf's law document frequencies.
Non-Vacuum AdS Cosmologies and the Approach to Equilibrium of Entanglement Entropy

We extend the standard results for vacuum asymptotically locally anti-de Sitter (AlAdS) spacetimes, showing that such spacetimes can be constructed as foliations where the induced metric on each hypersurface satisfies Einsteinʼs equation with stress–energy. By an appropriate choice of stress–energy on the hypersurfaces, the resulting AlAdS spacetime satisfies Einsteinʼs equation with a negative cosmological constant and physical stress tensor. We use this construction to obtain AlAdS solutions whose boundaries are FRW cosmologies sourced by a massless scalar field or by a perfect fluid obeying the strong energy condition. We focus on FRW universes that approach Minkowski spacetime at late times, yielding AlAdS spacetimes that approach either the Poincare patch of pure AdS or the AdS soliton, which we view as late time equilibrium states. As an application of these solutions, we use the AdS/CFT correspondence to study the approach to equilibrium of the entanglement entropy and of the boundary stress tensor of the boundary CFT. We find that the energy of the asymptotically AdS solitonic solution is consistent with the conjecture that the AdS soliton is the lowest-energy solution to Einsteinʼs equation with negative cosmological constant. The time dependent correction to the entanglement entropy is found to decay like a power law, with the rate set by the Hubble parameter and the power determined by the equation of state of the cosmic fluid.
One money, one market : the effect of common currencies on trade

Currency unions Their dramatic effect on international trade A gravity model is used to assess the separate effects of exchange rate volatility and currency unions on international trade. The panel data, bilateral observations for five years during 1970–90 covering 186 countries, includes 300+ observations in which both countries use the same currency. I find a large positive effect of a currency union on international trade, and a small negative effect of exchange rate volatility, even after controlling for a host of features, including the endogenous nature of the exchange rate regime. These effects, statistically significant, imply that two countries sharing the same currency trade three times as much as they would with different currencies. Currency unions like the European EMU may thus lead to a large increase in international trade, with all that that entails. — Andrew Rose
Cap-and-Trade Bycatch Management with Costly Avoidance and Stock Uncertainty

ABSTRACT Regulations to reduce bycatch of non-marketed marine species often impose gear restrictions, reductions in harvest of the target species, and/or spatial and temporal closures of the fishing ground. These regulations can exact significant social costs in commercial fisheries. We evaluate performance of a cap-and-trade bycatch management policy. Harvest of a target fish species, costly avoidance of the bycatch species, and harvesting efficiency are examined in a stochastic production environment with and without at-sea observability of bycatch, and with and without trade in harvest quotas and bycatch caps. Our results suggest that precise implementation of a socially optimal management plan is possible only if bycatch is observable and trade in fish quotas and bycatch cap is frictionless. Conditions exist in which quota/permit trading raises bycatch relative to a no-trade environment. The results offer useful guidance for designing cap-and-trade bycatch management programs. JEL Code: Q2.
Nonlinear Realization of N=2 Superconformal Symmetry and Brane Effective Actions

Since there is an incompatibility of simultaneously nonlinear breaking the superconformal symmetry and the dilatation symmetry with the dilaton taken as the compensator field, in the present paper is shown an alternative mechanism of spontaneous breaking the N=2 superconformal symmetry to the N=0 case. By using the approach of nonlinear transformations one finds that it leads to a space-filling brane theory with Weyl scale W(1,3) symmetry. The dynamics of the resulting Weyl scale invariant brane, along with that of other Nambu–Goldstone fields, is derived in terms of the building blocks of the vierbein and the covariant derivative from the Maurer–Cartan one-forms. A general coupling of the matter fields localized on the brane world volume to these NG fields is also constructed.
Hyperpolarizabilities for the one-dimensional infinite single-electron periodic systems. I. Analytical solutions under dipole-dipole correlations

The analytical solutions for the general-four-wave-mixing hyperpolarizabilities χ(3)[−(ω1+ω2+ω3);ω1,ω2,ω3] on infinite chains under both Su–Shrieffer–Heeger and Takayama–Lin–Liu–Maki models of trans-polyacetylene are obtained through the scheme of dipole-dipole correlation. Analytical expressions of dc Kerr effect χ(3)(−ω;0,0,ω), dc-induced second-harmonic generation χ(3)(−2ω;0,ω,ω), optical Kerr effect χ(3)(−ω;ω,−ω,ω), and dc electric-field-induced optical rectification χ(3)(0;ω,−ω,0) are derived. By including or excluding ∇k terms in the calculations, comparisons show that the intraband contributions dominate the hyperpolarizabilities if they are included. ∇k term or intraband transition leads to the break of the overall permutation symmetry in χ(3) even for the low-frequency and nonresonant regions. Hence it breaks the Kleinman [Phys. Rev. 126, 1977 (1962)] symmetry that is directly based on the overall permutation symmetry. Our calculations provide a clear understanding of the Kleinman symmetry breaks...
Cationic palladium(II)-catalyzed stereoselective glycosylation with glycosyl trichloroacetimidates.

The development of a new method for stereoselective glycosylation with glycosyl trichloroacetimidate donors employing cationic palladium(II), Pd(CH3CN)4(BF4)2, is described. This process employs Pd(CH3CN)4(BF4)2 as an efficient activator, providing access to a variety of disaccharides and glycopeptides. This reaction is highly stereoselective and proceeds under mild conditions with low catalyst loading. Interestingly, this palladium catalysis directs β-glucosylations in the absence of classical neighboring group participation.
A prediction model for separated-flow transition

The present study formulates an improved approach for analyzing separated-flow transition that differentiates between the transition process in boundary layers that are laminar at separation and those that are already transitional at separation. The paper introduces new parameters that are necessary in classifying separated-flow transition modes and in accounting for the concomitant evolution of transition in separated shear layer and the average effect of periodic separation bubble build-up and vortex shedding. At least three separated-flow transition modes are positively distinguished: (a) transitional separation, with the transition starting upstream of the separation point and developing mostly as natural transition, (b) laminar separation/short bubble mode, with the onset of transition induced downstream of the separation point by inflexional instability and with a quick transition completion, and (c) laminar separation/long bubble mode, with the onset of transition also induced downstream of the separation point by inflexional instability, and with the transition completion delayed. Passing from one mode to another takes place continuously through a succession of intermediate stages. The location of maximum bubble elevation has been proved to be the controlling parameter for the separated flow behavior. It was found that, downstream of the separation point, the experimental data expressed in terms ofmore » distance Reynolds number Re{sub x} can be correlated better than momentum or displacement thickness Reynolds number. For each mode of separated-flow transition, the onset of transition, the transition length, and separated flow general characteristic are determined. This prediction model is developed mainly on low free-stream turbulence flat plate data and limited airfoil data. Extension to airfoils and high turbulence environment requires additional study.« less
Quality of Life in Advanced Prostate Cancer: Results of a Randomized Therapeutic Trial

Author(s): Moinpour, CM; Savage, MJ; Troxel, A; Lovato, LC; Eisenberger, M; Veith, RW; Higgins, B; Skeel, R; Yee, M; Blumenstein, BA; Crawford, ED; Meyskens, FL | Abstract: BackgroundFor patients with metastatic prostate cancer, treatment is primarily palliative, relying mainly on the suppression of systemic androgen hormone levels. To help document the achievement of palliation and to characterize positive and negative effects of treatment, we evaluated quality-of-life (QOL) parameters in patients with metastatic prostate cancer who were randomly assigned to two methods of androgen deprivation.MethodsPatients (n = 739) with stage M1 (bone or soft tissue metastasis) prostate cancer were enrolled in a QOL protocol that was a companion to Southwest Oncology Group INT-0105, a randomized double-blind trial comparing treatment with bilateral orchiectomy (surgical castration) plus either flutamide or placebo. Patients completed a comprehensive battery of QOL questionnaires at random assignment to treatment and at 1, 3, and 6 months later. Data were collected on three treatment-specific symptoms (diarrhea, gas pain, and body image), on physical functioning, and on emotional functioning. All P values are two-sided.ResultsQuestionnaire return rates for this study never dropped below 80%; only 2% of the patients did not submit baseline QOL assessments. Cross-sectional analyses (corrected for multiple testing) identified statistically significant differences that favored orchiectomy plus placebo for two of the five primary QOL parameters as follows: patients receiving flutamide reported more diarrhea at 3 months (P = .001) and worse emotional functioning at 3 and 6 months (both Pl.003). Longitudinal analyses replicated these findings. Other analyzed QOL parameters favored the group receiving placebo but were not statistically significant after adjustment for multiple testing.ConclusionsWe found a consistent pattern of better QOL outcomes at each follow-up assessment during the first 6 months of treatment for orchiectomized patients with metastatic prostate cancer who received placebo versus flutamide. Improvement over time was evident in both treatment groups but more so for patients receiving placebo.
Effects of Noise on Ecological Invasion Processes: Bacteriophage-Mediated Competition in Bacteria

Pathogen-mediated competition, through which an invasive species carrying and transmitting a pathogen can be a superior competitor to a more vulnerable resident species, is one of the principle driving forces influencing biodiversity in nature. Using an experimental system of bacteriophage-mediated competition in bacterial populations and a deterministic model, we have shown in Joo et al. [Proc. R. Soc. B273,1843–1848 (2006)] that the competitive advantage conferred by the phage depends only on the relative phage pathology and is independent of the initial phage concentration and other phage and host parameters such as the infection-causing contact rate, the spontaneous and infection-induced lysis rates, and the phage burst size. Here we investigate the effects of stochastic fluctuations on bacterial invasion facilitated by bacteriophage, and examine the validity of the deterministic approach. We use both numerical and analytical methods of stochastic processes to identify the source of noise and assess its magnitude. We show that the conclusions obtained from the deterministic model are robust against stochastic fluctuations, yet deviations become prominently large when the phage are more pathological to the invading bacterial strain.
SYNTHETIC SUPRAMOLECULAR CHEMISTRY

For many decades, the construction of organic compounds in the laboratory has relied on the remarkable abilities of the 20th century ‘alchemists’ — namely, synthetic organic chemists — to make and break covalent bonds. Careful selection of functional groups and reaction conditions, in conjunction with protection/deprotection protocols, constitute the ‘secrets’ and ‘tricks’ of their ‘art’ which is commensurate with ‘traditional’ organic synthesis [1,2]. Indeed, relying on multistep reaction sequences, the total syntheses of structurally intricate molecular compounds which are constructed entirely using covalent bonds — e.g., brevetoxin B [3], palytoxin [4], and the calichearubicins [5] — have been realized in recent times. These very elegant and successful syntheses have required enormous intellectual and hands-on effort by large teams of chemists over rather long periods of time — very often, several years. Moreover, these extremely complex, and often particularly beautiful, examples represent close to state-of-the-art as far as ‘traditional’ organic synthesis is concerned. Alas, they also highlight the difficulties and limitations associated with classical organic syntheses — specifically, that the multistep aspect of such syntheses can be extremely laborious and time-consuming. With the possible exception of some dendritic structures [6], it is becoming apparent that the construction of nanoscopic structures, of the same complexities as those found in biological systems, using these classical methods is out of the reach of even the most talented and optimistic of the 20th century chemists!
Tandem Au-catalyzed 3,3-rearrangement-[2 + 2] cycloadditions of propargylic esters : Expeditious access to highly functionalized 2,3-indoline-fused cyclobutanes

The treatment of readily available propargylic indole-3-acetates with a catalytic amount of AuCl(PPh3)/AgSbF6 leads to tandem activations of the propargylic esters and the in situ generated allenylic esters, resulting in expeditious access to highly functionalized cyclobutanes with fused 2,3-indoline and γ-lactone rings and an exocyclic E-double bond through sequential 3,3-rearrangement and [2 + 2] cyclization.
SKILL FORMATION IN U.S. ACCOUNTING FIRMS: PRESSURES, TRENDS AND OPTIONS

This report discusses technological, market and strategic factors encouraging change in the dynamics of skill formation in large U.S. accounting firms. Changes in recruiting, organizing, training, retaining and promoting are of crucial importance for the future of the accounting industry. When cost cutting and efficiency are insufficient and where new services are the key to competitiveness, the future of the firm rests on the ability to develop a broad base of higher skills. These changes are perhaps also important for understanding skill formation dynamics in other activities with a high “knowledge intensity”.
Management of Asymptomatic Ovarian and Other Adnexal Cysts Imaged at US: Society of Radiologists in Ultrasound Consensus Conference Statement

The Society of Radiologists in Ultrasound (SRU) convened a panel of specialists from gynecology, radiology, and pathology to arrive at a consensus regarding the management of ovarian and other adnexal cysts imaged sonographically in asymptomatic women. The panel met in Chicago, IL, on October 27-28, 2009, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies, and are thought to represent a reasonable approach to asymptomatic ovarian and other adnexal cysts imaged at ultrasonography.
Spatial Diversity in Invention: Evidence from the Early R&D Labs

This article uses historical data on inventor and firm research and development (R&D) lab locations to examine the technological and geographic structure of corporate knowledge capital accumulation during a formative period in the organization of United States innovation. Despite the localization of inventive activity around the labs, one-quarter of inventors lived outside a 30mile commuting radius of the nearest facility of the firm they assigned their patents to. A strong positive effect of distance from a lab on technological importance is identified, especially for inventors from large cities that were geographically separated from a firm’s labs. A patent case–control method helps explain spatial sourcing by showing that the average quality of externally available inventions was high. Firms selected complementary, not substitute, inventions from non-lab urban locations, suggesting a link between the organization and the geography of innovation.
Polarization aberrations. 1. Rotationally symmetric optical systems

The polarization in isotropic radially symmetric lens and mirror systems in the paraxial approximation is examined. Polarized aberrations are variations in the phase, amplitude, and polarization state of the electromagnetic field across the exit pupil. Some are dependent on the incident polarization state and some are not. Expressions through fourth order for phase, amplitude, linear diattenuation, and linear retardance aberrations are derived in terms of the chief and marginal ray angles of incidence and the Taylor series expansion coefficients of the Fresnel equations for reflection and transmission at uncoated and thin-film-coated interfaces. Applications to polarization ray tracing are discussed.
Sulfonyl derivatives of benzotriazole: Part 1. A novel approach to the activation of carboxylic acids

Abstract 1-Acylbenzotriazoles (8, R = Me, Et, n-Bu and Ph) are prepared in good yields by fusion of benzotriazole and acid chlorides at 80 – 100°C. In cases when the corresponding acid chlorides are not available, 1-acylbenzotriazoles are conveniently available from 1-(1-methanesulfonyl)benzotriazole and the respective carboxylic acids as illustrated by the preparation of 2-, 3-, and 4-pyridoyl-, 2-pyrrolylcarbonyl- and 2-furoyl-benzotriazole in yields of 80 – 95%. Preparations of two sulfonyl derivatives of benzotriazole are also described.
Order and Chaos in Some Trigonometric Series: Curious Adventures of a Statistical Mechanic

This paper tells the story how a MAPLE-assisted quest for an interesting undergraduate problem in trigonometric series led some “amateurs” to the discovery that the one-parameter family of deterministic trigonometric series , p>1, exhibits both order and apparent chaos, and how this has prompted some professionals to offer their expert insights. As to order, an elementary (undergraduate) proof is given that ∀t∈ℝ, with explicitly computed constant α p . As to chaos, the seemingly erratic fluctuations about this overall trend are discussed. Experts’ commentaries are reproduced as to why the fluctuations of are presumably not Gaussian. Inspired by a central limit type theorem of Marc Kac, a well-motivated conjecture is formulated to the effect that the fluctuations of the ⌈t 1/(p+1)⌉-th partial sum of , when properly scaled, do converge in distribution to a standard Gaussian when t→∞, though—provided that p is chosen so that the frequencies {n −p } n∈ℕ are rationally linear independent; no conjecture has been forthcoming for rationally dependent {n −p } n∈ℕ. Moreover, following other experts’ tip-offs, the interesting relationship of the asymptotics of to properties of the Riemann ζ function is exhibited using the Mellin transform.