cssi/SciSciGPT-SciSciNet huggingface dataset:
Zeus-2D Simulations of Laser-Driven Radiative Shock Experiments

A series of experiments is underway using the Omega laser to examine radiative shocks of astrophysical relevance. In these experiments, the laser accelerates a thin layer of low-Z material, which drives a strong shock into xenon gas. One-dimensional numerical simulations using the HYADES radiation hydrodynamics code predict that radiation cooling will cause the shocked xenon to collapse spatially, producing a thin layer of high density (i.e., a collapsed shock). Preliminary experimental results show a less opaque layer of shocked xenon than would be expected assuming that all the xenon accumulates in the layer and that the X-ray source is a pure Kα source. However, neither of these assumptions is strictly correct. Here we explore whether radial mass and/or energy transport may be significant to the dynamics of the system. We report the results of two-dimensional numerical simulations using the ZEUS-2D astrophysical fluid dynamics code. Particular attention is given to the simulation method.
Effect of channel estimation error on M-QAM BER performance in Rayleigh fading

We determine the bit error rate (BER) of multi-level quadrature amplitude modulation (M-QAM) in flat Rayleigh fading with imperfect channel estimates. Despite its high spectral efficiency, M-QAM is not commonly used over fading channels because of the channel amplitude and phase variation. Since the decision regions of the demodulator depend on the channel fading, the estimation error of the channel variation can severely degrade the demodulator performance. Among the various fading estimation techniques, pilot symbol assisted modulation (PSAM) proves to be an effective choice. We first characterize the distribution of the amplitude and phase estimates using PSAM. We then use this distribution to obtain the BER of M-QAM as a function of the PSAM and channel parameters. By using a change of variables our exact BER expression has a particularly simple form that involves just a few finite range integrals. This approach can be used to compute BER for any value of M. We compute the BER for 16-QAM and 64-QAM numerically and verify our analytical results by computer simulation. We show that for these modulations, amplitude estimation error leads to a 1 dB degradation in E/sub b//N/sub o/ and combined amplitude-phase estimation error leads to 2.5 dB degradation for the parameters we consider.
Does “Political Bias” in the DIT or DIT‐2 Threaten Validity in Studies of CPAs?

The Defining Issues Test (DIT) has been popular among accounting researchers, and will surely find continued applications. The DIT‐2 is still new to accounting research. Fisher and Sweeney (1998, 2002) and Sweeney and Fisher (1998, 1999) build upon other critical research to claim that the DIT P score is a preference measure strongly related to political beliefs. Experimental subjects, when asked to respond from an “extremely liberal” perspective or to “identify the statements designed to represent the highest levels of moral judgment,” tend to respond differently than under official DIT instructions. However, Rest et al. (1999) reject this approach to validity testing, claiming that appropriate tests should address the variance explained over and above other constructs. Based on random samples of CPAs in public accounting practice (741 taking the DIT in 1995 and 261 taking the DIT‐2 in 2001, each of whom also responded to political preference scales) we measure the amount of variance shared by the “ethic...
Experimental Examination of Prechamber Heat Release in a Large Bore Natural Gas Engine

A common solution in reducing NOx emissions to meet new emission regulations has been lean burn combustion. However, with very lean air∕fuel (A∕F) ratios, both carbon monoxide and hydrocarbon emissions become unacceptably high due to the spark misfiring and combustion instabilities. In order to mitigate this, a prechamber ignition system is often used to stabilize combustion at very lean A∕F ratios. In this paper, the heat release in a retrofit prechamber system installed on a large bore natural gas engine is examined. The heat release analysis is based on dynamic pressure measurements both in the main chamber and prechamber. The Woschni correlation is utilized to model heat transfer. Based on heat release modeling and test data analysis, the following observations are made. Main chamber heat release rates are much more rapid for prechamber ignition compared to spark ignition. During combustion in the prechamber, much of the fuel flows into the main chamber unreacted. About 52% of the mass in the prechamber, at ignition, flows into the main chamber during prechamber combustion. Prechamber total heat release, pressure rise, and maximum jet velocity all increase with increasing prechamber equivalence ratio. Prechamber combustion duration and coefficient of variation of peak pressure are minimized at a prechamber equivalence ratio of about 1.09.
Bank Portfolio Exposure to Emerging Markets and Its Effects on Bank Market Value

Abstract This study estimates a model of banking company equity returns taking into consideration book value and market value measures of their exposure to emerging markets debt. In this estimation, general systematic market factors, such as the rate of return on the S&P500 stock index and yields on a constant maturity 5-year Treasury note, are held constant such that the exposure variables are accounting for effects due to banks’ exposure to emerging market debt. The results, although not uniform among banking companies, support the hypothesis that the extent of exposure to emerging market debt are factored into the valuation of banking company equity contemporaneously. The inclusion of a market value indicator adds to the explanation of equity returns of some banks. It is also clear that knowing the extent of the exposure on a book value basis is important information alone that may allow investors to take account of or evaluate the effects of changes in banking company equity valuation from LDC debt exposures. We also perform an event study for three major debt crises to determine whether the market recognizes the effects of these events on bank valuation. The event study results show that there is little information from identifying the time period of the crises on banking company equity returns. Explanations for this are that the information of these possible crises has been embedded in bank changes in exposure and that the market valuation of the emerging market debt is already accounted for by our model.
Multicasting in Large Wireless Networks: Bounds on the Minimum Energy Per Bit

In this paper, we consider scaling laws for maximal energy efficiency of communicating a message to all the nodes in a wireless network, as the number of nodes in the network becomes large. Two cases of large wireless networks are studied-dense random networks and constant density (extended) random networks. In addition, we also study finite size regular networks in order to understand how regularity in node placement affects energy consumption. We first establish an information-theoretic lower bound on the minimum energy per bit for multicasting in arbitrary wireless networks when the channel state information is not available at the transmitters. Upper bounds are obtained by constructing a simple flooding scheme that requires no information at the receivers about the channel states or the locations and identities of the nodes. The gap between the upper and lower bounds is only a constant factor for dense random networks and regular networks, and differs by a poly-logarithmic factor for extended random networks. Furthermore, we show that the proposed upper and lower bounds for random networks hold almost surely in the node locations as the number of nodes approaches infinity.
A cayley tree immune network model with antibody dynamics

A Cayley tree model of idiotypic networks that includes both B cell and antibody dynamics is formulated and analysed. As in models with B cells only, localized states exist in the network with limited numbers of activated clones surrounded by virgin or near-virgin clones. The existence and stability of these localized network states are explored as a function of model parameters. As in previous models that have included antibody, the stability of immune and tolerant localized states are shown to depend on the ratio of antibody to B cell lifetimes as well as the rate of antibody complex removal. As model parameters are varied, localized steady-states can break down via two routes: dynamically, into chaotic attractors, or structurally into percolation attractors. For a given set of parameters percolation and chaotic attractors can coexist with localized attractors, and thus there do not exist clear cut boundaries in parameter space that separate regions of localized attractors from regions of percolation and chaotic attractors. Stable limit cycles, which are frequent in the two-clone antibody B cell (AB) model, are only observed in highly connected networks. Also found in highly connected networks are localized chaotic attractors. As in experiments by Lundkvist et al. (1989. Proc. natn. Acad. Sci. U.S.A. 86 , 5074–5078), injection of Ab 1 antibodies into a system operating in the chaotic regime can cause a cessation of fluctuations of Ab 1 and Ab 2 antibodies, a phenomenon already observed in the two-clone AB model. Interestingly, chaotic fluctuations continue at higher levels of the tree, a phenomenon observed by Lundkvist et al. but not accounted for previously.
"Designer acids": combined acid catalysis for asymmetric synthesis.

Lewis and Bronsted acids can be utilized as more-effective tools for chemical reactions by sophisticated engineering ("designer acids"). The ultimate goal of such "designer acids" is to form a combination of acids with higher reactivity, selectivity, and versatility than the individual acid catalysts. One possible way to take advantage of such abilities may be to apply a "combined acids system" to the catalyst design. The concept of combined acids, which can be classified into Bronsted acid assisted Lewis acid (BLA), Lewis acid assisted Lewis acid (LLA), Lewis acid assisted Bronsted acid (LBA), and Bronsted acid assisted Bronsted acid (BBA), can be a particularly useful tool for the design of asymmetric catalysis, because combining such acids will bring out their inherent reactivity by associative interaction, and also provide more-organized structures that allow an effective asymmetric environment.
NEMO-3D based atomistic simulation of a double quantum dot structure for spin-blockaded transport

This work combines an atomistic electronic structure calculation with many-body rate equations to simulate the current-voltage (I–V) characteristics of a weakly-coupled Double Quantum Dot (DQD) system in the spin-blockade regime. Here we performed a NEMO-3D based, atomistic simulation of the geometry of the DQD to obtain its single electron eigen-states, hopping parameters, and Coulomb integrals followed by the evaluation of I–V characteristics with the many-electron spectrum of the DQD system, derived from this single-electron parameter set. The many-electron spectra and wave-functions are evaluated by exact-diagonalization of the many-electron system. The Hamiltonian is constructed from single electron eigen-states, hopping parameters and Coulomb integrals derived from atomistic NEMO 3-D simulations. Calculated I–V characteristics exhibit multiple regions of prominent Negative Differential Resistances (NDRs) that resemble the experimental trends. Unlike resonant tunnelling devices, however, level crossings in DQDs are negligible, and the NDRs result from a delicate interplay of delocalization, orbital offset and Coulomb interaction.
Reversibility of the time-dependent shortest path problem

Time-dependent shortest path problems arise in a variety of applications; e.g., dynamic traffic assignment (DTA), network control, automobile driver guidance, ship routing and airplane dispatching. In the majority of cases one seeks the cheapest (least generalized cost) or quickest (least time) route between an origin and a destination for a given time of departure. This is the “forward” shortest path problem. In some applications, however, e.g., when dispatching airplanes from airports and in DTA versions of the “morning commute problem”, one seeks the cheapest or quickest routes for a given arrival time. This is the “backward” shortest path problem. It is shown that an algorithm that solves the forward quickest path problem on a network with first-in-first-out (FIFO) links also solves the backward quickest path problem on the same network. More generally, any algorithm that solves forward (or backward) problems of a particular type is shown also to solve backward (forward) problems of a conjugate type.
On the Convergence of Local Expansions of Layer Potentials

In a recently developed quadrature method (quadrature by expansion or QBX), it was demonstrated that weakly singular or singular layer potentials can be evaluated rapidly and accurately on-surface by making use of local expansions about carefully chosen off-surface points. In this paper, we derive estimates for the rate of convergence of these local expansions, providing the analytic foundation for the QBX method. The estimates may also be of mathematical interest, particularly for microlocal or asymptotic analysis in potential theory.
A double-sided multiunit combinatorial auction for substitutes: Theory and algorithms

Combinatorial exchanges have existed for a long time in securities markets. In these auctions buyers and sellers can place orders on combinations, or bundles of different securities. These orders are conjunctive: they are matched only if the full bundle is available. On business-to-business (B2B) exchanges, buyers have the choice to receive the same product with different attributes; for instance the same product can be produced by different sellers. A buyer indicates his preference by submitting a disjunctive order, where he specifies the quantity he wants of each particular good and what limit price he is willing to pay for each good, thus providing a subjective valuation of each attribute. Only the goods with the best prices will be traded. This article considers a doubled-sided multiunit combinatorial auction for substitutes, that is, a uniform price auction where buyers and sellers place both types of orders, conjunctive (AND orders) and disjunctive (XOR orders). We show that linear competitive prices exist. We also propose an algorithm to clear the market, which is particularly efficient when the number of traders is large, and the goods are divisible.
Ultrasound of Thyroid Nodules

Thyroid nodules can be detected in 4% to 8% of the adult population by palpation, but in 40% to 50% of the population by ultrasound. The overwhelming majority of these represent benign hyperplastic nodules or adenomas. Approximately 5% of nodules are malignant, with papillary carcinoma representing approximately 75% to 80% of primary thyroid malignancies. Although many sonographic features have been studied as a means of distinguishing benign from malignant nodules, ultrasound- guided fine-needle aspiration with cytologic evaluation remains a mainstay in the management of palpable and incidentally detected nodules. This article reviews the current techniques for sonographic evaluation of the thyroid and the imaging features of the various types of thyroid nodules.
Measuring message propagation and social influence on Twitter.com

Although extensive studies have been conducted on top of online social networks OSNs, it is not clear how to characterise information propagation and social influence, two types of important but not well defined social behaviour. This paper presents a measurement study of 58 M messages collected from 700 K users on Twitter.com, a popular social medium. We analyse the propagation patterns of general messages and show how breaking news Michael Jackson's death spread through Twitter. Furthermore, we evaluate different social influences by examining their stabilities, assessments, and correlations. This paper addresses the complications and challenges we encounter when measuring message propagation and social influence on OSNs. We believe that our results here provide valuable insights for future OSN research.
Think about the joints

Background Musculoskeletal problems are common in children. The majority are self-limiting and related to trauma; however the symptoms can be feature of serious medical conditions. It has been previously shown that musculoskeletal examination is poorly documented. Musculoskeletal examination is a station on the RCPCH clinical exam. Teaching resources on how to perform musculoskeletal examinations are freely available together with guidelines on when musculoskeletal examination should be performed.
Link prediction by de-anonymization: How We Won the Kaggle Social Network Challenge

This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.com. The goal of the contest was to promote research on real-world link prediction, and the dataset was a graph obtained by crawling the popular Flickr social photo sharing website, with user identities scrubbed. By de-anonymizing much of the competition test set using our own Flickr crawl, we were able to effectively game the competition. Our attack represents a new application of de-anonymization to gaming machine learning contests, suggesting changes in how future competitions should be run. We introduce a new simulated annealing-based weighted graph matching algorithm for the seeding step of de-anonymization. We also show how to combine de-anonymization with link prediction—the latter is required to achieve good performance on the portion of the test set not de-anonymized—for example by training the predictor on the de-anonymized portion of the test set, and combining probabilistic predictions from de-anonymization and link prediction.
Asian Century or Multi-polar Century?

Summary The “rise of Asia” is something of a myth. During 1990–2005 China accounted for 28% of global growth, measured at PPP. India accounted for 9%. The rest of developing Asia, with nearly a billion people, accounted for only 7%, the same as Latin America. Hence there is no general success of Asian developing economies. China has grown better than its developing neighbors because it started its reform with a better base of human capital, has been more open to foreign trade and investment, and created good investment climates in coastal cities. China’s success changes the equation going forward: its wages are now two to three times higher than in the populous Asian countries (India, Pakistan, Bangladesh, Vietnam, Indonesia), and China will become an ever-larger importer of natural resource and labor-intensive products. Developing countries need to become more open and improve their investment climates to benefit from these opportunities. China itself faces new challenges that could hamper its further development: unsustainable trade imbalance with the U.S., energy and water scarcity and unsustainable use of natural resources, and growing inequality and social tension. To address the first two of these challenges, good cooperation between China and the U.S. is essential. I conclude that we are more likely to be facing a “multi-polar century,” than an Asian century.
Synthesis of 7-cyano- and 7-acetamido-indoles via cyanocarbonation/hydrogenation of 7-formyl indole

A procedure for the synthesis of 7-cyano and 7-acetamido indoles via cyanocarbonation/hydrogenation of 7-formyl indole is presented. The process can be efficiently scaled up to provide multigram quantities of the desired compounds in good yield. A small survey of substrate scope indicates that the reaction may prove generally useful for the synthesis of aryl acetonitriles.
Bubble Formation in Glass by Reaction with Silicon and Silicon-Germanium Alloys

The cause of bubbles at a glass/Si, glass/SiGe interface, which form when some glasses are fused on Si or SiGe, was determined. Water, bonded as OH groups in the glass, was reduced by the Si at high temperatures to form H2. The gas released by this reaction formed bubbles only in those glasses with low permeability to H2.
Effects of intoxicating free-choice alcohol consumption during adolescence on drinking and impulsivity during adulthood in selectively bred high-alcohol preferring mice.

Background Abuse of alcohol during adolescence continues to be a problem, and it has been shown that earlier onset of drinking predicts increased alcohol abuse problems later in life. High levels of impulsivity have been demonstrated to be characteristic of alcoholics, and impulsivity has also been shown to predict later alcohol use in teenage subjects, showing that impulsivity may precede the development of alcohol use disorders. These experiments examined adolescent drinking in a high-drinking, relatively impulsive mouse population and assessed its effects on adult drinking and adult impulsivity. Methods Experiment 1: Selectively bred high-alcohol preferring (HAPII) mice were given either alcohol (free-choice access) or water only for 2 weeks during middle adolescence or adulthood. All mice were given free-choice access to alcohol 30 days later, in adulthood. Experiment 2: Adolescent HAPII mice drank alcohol and water, or water alone, for 2 weeks, and were then trained to perform a delay discounting task as adults to measure impulsivity. In each experiment, effects of volitional ethanol (EtOH) consumption on later behavior were assessed. We expected adolescent alcohol exposure to increase subsequent drinking and impulsivity. Results Mice consumed significant quantities of EtOH, reaching average blood ethanol concentrations (BECs) of 142 mg/dl (adolescent) or 154 mg/dl (adult) in Experiment 1. Adolescent mice in Experiment 2 reached an average of 108 mg/dl. Mice exposed to alcohol in either adolescence or adulthood showed a transient increase in EtOH consumption, but we observed no differences in impulsivity in adult mice as a function of whether mice drank alcohol during adolescence. Conclusions These findings indicate that HAPII mice drink intoxicating levels of alcohol during both adolescence and adulthood and that this volitional intake has long-term effects on subsequent drinking behavior. Nonetheless, this profound exposure to alcohol during adolescence does not increase impulsivity in adulthood, indicating that long-term changes in drinking are mediated by mechanisms other than impulsivity.
Practical Design and Flight Test of a Yo-Yo Wire-Boom Deployment System

Ay o-yo-type wire-boom deployment system has been developed and flight tested on a sounding rocket mission. The goal of the work has been to validate a new mechanism that rapidly deploys wire booms from a spinning spacecraft. This work takes a theoretical system design and implements it in practical hardware. The limitations inherent in practical hardware necessitated new theoretical developments. A modified stability analysis has been developed for the case of nonzero axial separation between the wire-boom base attachment points and the spacecraft’s center of mass. This modified stability analysis dictates that a stable design is impractical for many missions because very large wire-boom tip masses are needed and because the three-dimensional deployment transients are very sensitive to small asymmetries. This problem has led to the development of design criteria and analysis techniques, which permit a short-duration mission to use a slightly unstable nutation mode. These techniques have been used to design a system that has been flown on two daughter spacecraft that were part of a formation of three sounding rocket subpayloads. Each daughter spacecraft deployed four 3-m-long wire booms in under 10 s and maintained a low level of spin instability for the remaining 700 s of the mission. The nutation oscillations showed a slow exponential growth, but the coning half-angles of both spacecraft never exceeded 16 deg.
Selection Bias in College Admissions Test Scores

Abstract Data from college admissions tests can provide a valuable measure of student achievement, but the non-representativeness of test-takers is an important concern. We examine selectivity bias in both state-level and school-level SAT and ACT averages. The degree of selectivity may differ importantly across and within schools, and across and within states. To identify within-state selectivity, we use a control function approach that conditions on scores from a representative test. Estimates indicate strong selectivity of test-takers in “ACT states,” where most college-bound students take the ACT, and much less selectivity in SAT states. To identify within- and between-school selectivity, we take advantage of a policy reform in Illinois that made taking the ACT a graduation requirement. Estimates based on this policy change indicate substantial positive selection into test participation both across and within schools. Despite this, school-level averages of observed scores are extremely highly correlated with average latent scores, as across-school variation in sample selectivity is small relative to the underlying signal. As a result, in most contexts the use of observed school mean test scores in place of latent means understates the degree of between-school variation in achievement but is otherwise unlikely to lead to misleading conclusions.
Places to Go: Challenges to Multicultural Art Education in a Global Economy.

This article examines the relationship between globalization and postmodern multicultural art education. The questions that drive my investigation are: What is the role of postmodern multiculturalism in this current phase of globalization and what challenges does globalization pose for multiculturalism? I explore the shifts in the field of art that have occurred due to globalization and then discuss their implications for postmodern art education.
Schubert varieties as variations of Hodge structure

We (1) characterize the Schubert varieties that arise as variations of Hodge structure (VHS); (2) show that the isotropy orbits of the infinitesimal Schubert VHS ‘span’ the space of all infinitesimal VHS; and (3) show that the cohomology classes dual to the Schubert VHS form a basis of the invariant characteristic cohomology associated with the infinitesimal period relation (a.k.a. Griffiths’ transversality).
Anion–arene adducts: C–H hydrogen bonding, anion–π interaction, and carbon bonding motifs

This article summarizes experimental and theoretical evidence for the existence of four distinct binding modes for complexes of anions with charge-neutral arenes. These include C–H hydrogen bonding and three motifs involving the arene–π system—the noncovalent anion–π interaction, weakly covalent σ interaction, and strongly covalent σ interaction.
Designing next-generation platforms for evaluating scientific output: what scientists can learn from the social web.

Traditional pre-publication peer review of scientific output is a slow, inefficient, and unreliable process. Efforts to replace or supplement traditional evaluation models with open evaluation platforms that leverage advances in information technology are slowly gaining traction, but remain in the early stages of design and implementation. Here I discuss a number of considerations relevant to the development of such platforms. I focus particular attention on three core elements that next-generation evaluation platforms should strive to emphasize, including (a) open and transparent access to accumulated evaluation data, (b) personalized and highly customizable performance metrics, and (c) appropriate short-term incentivization of the userbase. Because all of these elements have already been successfully implemented on a large scale in hundreds of existing social web applications, I argue that development of new scientific evaluation platforms should proceed largely by adapting existing techniques rather than engineering entirely new evaluation mechanisms. Successful implementation of open evaluation platforms has the potential to substantially advance both the pace and the quality of scientific publication and evaluation, and the scientific community has a vested interest in shifting towards such models as soon as possible.
Applications of bismuth(III) compounds in organic synthesis

This review article summarizes the applications of bismuth(III) compounds in organic synthesis since 2002. Although there are an increasing number of reports on applications of bismuth(III) salts in polymerization reactions, and their importance is acknowledged, they are not included in this review. This review is largely organized by the reaction type although some reactions can clearly be placed in multiple sections. While every effort has been made to include all relevant reports in this field, any omission is inadvertent and we apologize in advance for the same (358 references).
HIGH ENERGY ASTROPHYSICS TESTS OF LORENTZ INVARIANCE VIOLATION

Observations of the multi-TeV spectra of the Mkn 501 and other nearby BL Lac objects exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with IR photons having a flux level as determined by various astronomical observations. After correcting for such intergalactic absorption, these spectra can be explained within the framework of synchrotron self-Compton emission models. Stecker and Glashow have shown that the existence of this annihilation via electron-positron pair production puts strong constraints on Lorentz invariance violation. Such constraints have important implications for some quantum gravity and large extra dimension models. A much smaller amount of Lorentz invariance violation has potential implications for understanding the spectra of ultrahigh energy cosmic rays.
Diffusion and mixing in fluid flow

We study enhancement of diffusive mixing on a compact Riemannian manifold by a fast incompressible flow. Our main result is a sharp description of the class of flows that make the deviation of the solution from its average arbitrarily small in an arbitrarily short time, provided that the flow amplitude is large enough. The necessary and suficient condition on such flows is expressed naturally in terms of the spectral properties of the dynamical system associated with the flow. In particular, we find that weakly mixing flows always enhance dissipation in this sense. The proofs are based on a general criterion for the decay of the semigroup generated by an operator of the form G + iAL with a negative unbounded self-adjoint operator G, a self-adjoint operator L, and parameter A » 1. In particular, they employ the RAGE theorem describing evolution of a quantum state belonging to the continuous spectral subspace of the hamiltonian (related to a classical theorem of Wiener on Fourier transforms of measures). Applications to quenching in reaction-diffusion equations are also considered.
Inertia in social learning from a summary statistic

Abstract We model normal-quadratic social learning with agents who observe a summary statistic over past actions, rather than complete action histories. Because an agent with a summary statistic cannot correct for the fact that earlier actions influenced later ones, even a small presence of old actions in the statistic can introduce very persistent errors. Depending on how fast these old actions fade from view, social learning can either be as fast as if agents' private information were pooled (rate n) or it can slow to a crawl (rate ln ⁡ n ). Consistent with Vives (1993) , the fastest possible rate of learning falls to rate n ( 1 / 3 ) if actions are also observed with noise, but may be much slower. Increasing the sample size of the summary statistic does not lead to faster asymptotic learning and may reduce short run welfare.
Capital Flight from Russia

This paper documents the scale of capital flight from Russia, compares it with that observed in other countries, and reviews policy options. The evidence from other countries suggests that capital flight can be reversed once reforms take hold. The paper argues that capital flight from Russia can only be curbed through a medium-term reform strategy aimed at improving governance and macroeconomic performance, and strengthening the banking system. Capital controls result in costly distortions and should gradually be phased out as part of that medium-term strategy. Copyright Blackwell Publishers Ltd 2001.
Hypocholesterolemic agents III: Inhibition of β‐hydroxy‐β‐methylglutaryl coenzyme a reductase by half acid esters of 1‐(4‐biphenylyl)pentanol

Abstract A series of half acid esters of 1‐(4‐biphenylyl)pentanol was synthesized and assayed for inhibition of rat liver β‐hydroxy‐β‐methylglutaryl coenzyme A reductase. The number of methylenes separating the carboxyl and ester groups was varied from zero to six. A minimum of one methylene was required for reasonable activity. Further separation of the carboxyl and ester groups produced small changes in activity. Investigation of several isomeric ( cis and trans ) half acid esters indicated that activity was independent of configuration. Modification of the acid portion of the glutarate analog by incorporating a 3‐hydroxyl group increased activity sixfold.
The Acute Painful Eye

A number of ocular and nonocular conditions may produce an acutely painful eye or orbit. A careful history and physical examination with special attention to the cornea, sclera, fundus, and cranial nerves will usually delineate the etiology of the pain. In particular, certain life- or vision-threatening conditions such as leaking internal carotid aneurysm, cavernous sinus thrombosis, orbital cellulitis, acute narrow-angle glaucoma, and temporal arteritis must be kept in mind.
On cover times for 2D lattices

We study the cover time $\tau_{\mathrm{cov}}$ by (continuous-time) random walk on the 2D box of side length $n$ with wired boundary or on the 2D torus,and show that in both cases with probability approaching $1$ as $n$ increases,$\sqrt{\tau_{\mathrm{cov}}}=\sqrt{2n^2 [\sqrt{2/\pi} \log n + O(\log\log n)]$. This improves a result of Dembo, Peres, Rosen, and Zeitouni (2004) and makes progresstowards a conjecture of Bramson and Zeitouni (2009).
HEALTH AND AMENITY EFFECTS OF GLOBAL WARMING

A somewhat warmer climate would probably reduce mortality in the United States and provide Americans with valuable benefits. Regressions of death rates in Washington, DC, and in some 89 urban counties scattered across the nation on climate and demographic variables demonstrate that warmer temperatures reduce deaths. The results imply that a 2.5deg. Celsius warming would lower deaths in the United States by about 40,000 per year. Although the data on illness are poor, the numbers indicate that warming might reduce medical costs by about $20 billion annually. Utilizing willingness to pay as a measure of preference, this paper regresses wage rates for a few narrowly defined occupations in metropolitan areas on measures of temperature and size of city and finds that people prefer warm climates. Workers today would be willing to give up between $30 billion and $100 billion annually in wages for a 2.5deg.C increase in temperatures.
The Nonstationarity of Money and Prices in Interdependent Economies

In most nations, paths of monetary aggregates and prices consistently depart from stationary trends. This paper shows that this is a fundamental implication when monetary authorities of interdependent countries seek to smooth their home output and prices in the presence of incomplete world output-market integration and structural asymmetries. Using a two-country model with interdependent output supply schedules, we show that this conclusion holds whether the exchange rate floats or is fixed. It also holds if monetary policies are coordinated. Therefore, optimal monetary policy choices by central banks yield stationary paths for money and prices only under very specific conditions.
Ethics and the Economist: What Climate Change Demands of Us

Abstract Climate change is changing not only our physical world, but also our intellectual, social, and moral worlds. We are realizing that our situation is profoundly unsafe, interdependent, and uncertain. What, then, does climate change demand of economists, as human beings and as professionals? A discipline of economics based on Enlightenment notions of mechanism and disembodied rationality is not suited to present problems. This essay suggests three major requirements: first, that we take action; second, that we work together; and third, that we focus on avoiding the worst, rather than obtaining the optimal. The essay concludes with suggestions of specific steps that economists should take as researchers, teachers, and in our other roles.
N8− Polynitrogen Stabilized on Multi-Wall Carbon Nanotubes for Oxygen-Reduction Reactions at Ambient Conditions†

Polynitrogen (PN) species (Nn, n from 3 to 8) as highly energetic materials have attracted many theoretical calculations and predictions. N3, N4, N5 or their ions were experimentally detected under high-pressure and high-temperature conditions. Herein, a N8− PN stabilized on the positively charged sidewalls of multi-walled carbon nanotubes (MWNTs) has been synthesized using cyclic voltammetry (CV) under ambient conditions. ATR-FTIR and Raman spectroscopic data assigned on the basis of density functional theory (DFT) calculations support the successful synthesis of a C2h symmetry chain structure of the N8 anion stabilized as MWNT+N8−. Temperature programmed desorption (TPD) data show that MWNT+N8− is thermally stable up to 400 °C. Oxygen-reduction reaction (ORR) experiments carried out using MWNT+N8− as the cathodic catalyst shows that it is very active for ORR with an even higher current density than that of a commercial Pt/carbon catalyst.
Output feedback controllers for systems with structured uncertainty

This paper deals with the design of compensators that provide a guaranteed level of performance, in the sense of L/sub 2/ gain, for systems with time-varying structured uncertainty. For stability, the notion of quadratic stability, using a single Lyapunov function, is used. The uncertainty is assumed to be polytopic (e.g., the uncertainty vector enters the state-space representation of the systems affinely). Earlier results in the characterization of H/sub /spl infin// controllers are used to show that quadratic stability with performance is equivalent to a bi-affine problem. A set of conditions, under which the problem becomes convex, is discussed.
Regulated Formation of an Amyloid-like Translational Repressor Governs Gametogenesis

Message-specific translational control is required for gametogenesis. In yeast, the RNA-binding protein Rim4 mediates translational repression of numerous mRNAs, including the B-type cyclin CLB3, which is essential for establishing the meiotic chromosome segregation pattern. Here, we show that Rim4 forms amyloid-like aggregates and that it is the amyloid-like form of Rim4 that is the active, translationally repressive form of the protein. Our data further show that Rim4 aggregation is a developmentally regulated process. Starvation induces the conversion of monomeric Rim4 into amyloid-like aggregates, thereby activating the protein to bring about repression of translation. At the onset of meiosis II, Rim4 aggregates are abruptly degraded allowing translation to commence. Although amyloids are best known for their role in the etiology of diseases such as Alzheimer's, Parkinson's, and diabetes by forming toxic protein aggregates, our findings show that cells can utilize amyloid-like protein aggregates to function as central regulators of gametogenesis.
Segmentation of SAR images

Based on an SAR speckle statistical model, the authors investigate the feasibility of segmenting SAR images based on a gray-level histogram for one-look and multilook processed SAR images. The classification errors are evaluated and a procedure for the multilevel thresholding of SAR images is devised. The misclassification probabilities for one-look and four-look processed images are calculated and presented, and an unsupervised segmentation algorithm is given. A simulated one-look intensity image and a four-look SIR-B amplitude image are used for illustration. >
Phased Array Feed Calibration, Beamforming and Imaging

Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including calibration and beamforming algorithms, sensitivity optimization, and demonstration of wide field of view imaging, we report experimental results from a 19 element room temperature L-band PAF mounted on the Green Bank 20 Meter Telescope. Formed beams achieved an aperture efficiency of 69% and a system noise temperature of 66 K. Radio camera images of several sky regions are presented. We investigate the noise performance and sensitivity of the system as a function of elevation angle with statistically optimal beamforming and demonstrate cancelation of radio frequency interference sources with adaptive spatial filtering.
Fast drawing of curves for computer display

Now that computer displays with vector and character drawing capabilities are becoming a common form of on-line graphic output device, interest has turned toward providing a curvilinear display capability. Naturally, curves can be drawn as a series of short vectors stored in display memory, but the goal of current research is to provide hardware which draws a curve by generating such vectors, or perhaps, continuous beam motion, from a concise specification of a curve segment.
Defect List Compression

We consider a setting relevant to the design of storage systems in which a list of defective storage blocks, as determined at manufacture time, is stored in a high-speed system controller memory to enable the efficient bypassing of defective blocks in a transparent manner, external to the system. Conventionally, such lists have been compressed losslessly to save on the cost of the controller memory. Under the assumption of a total system cost that is a linear combination of the number of storage blocks and the controller memory size, we study the potential benefits of compressing the defect list using lossy algorithms. The only restriction is that the reconstructed defect list not label any defective storage blocks as being non-defective.
Enhancement-Mode n-Channel GaN MOSFETs on p and n-GaN/Sapphire Substrates

We report on the demonstration of enhancement-mode n-channel GaN high-voltage metal-oxide field-effect transistor (MOSFET) realized on both p and n-GaN epilayer on sapphire substrates. These MOSFETs, with different gate geometries, shows good DC characteristics with world-best field-effect mobility of 167 cm2/V-s and maximum blocking voltage of 940 V.
Pointwise characteristic factors for Wiener–Wintner double recurrence theorem

In this paper we extend Bourgain’s double recurrence result to the Wiener–Wintner averages. Let .
A Test of the Errors-in-Expectations Explanation of the Value/Glamour Stock Returns Performance: Evidence from Analysts' Forecasts

Several empirical studies show that investment strategies that favor the purchase of stocks with low prices relative to conventional measures of value yield higher returns. Some of these studies imply that investors are too optimistic about (glamour) stocks that have had good performance in the recent past and too pessimistic about (value) stocks that have performed poorly. We examine whether investors systematically overestimate (underestimate) the future earnings performance of glamour (value) stocks over the 1976 to 1997 period. Our results fail to support the extrapolation hypothesis that posits that the superior performance of value stocks is because investors make systematic errors in predicting future growth in earnings of out–of–favor stocks.
A nation of immigrants: Assimilation and economic outcomes in the age of mass migration

During the Age of Mass Migration (1850–1913), the United States maintained an open border, absorbing 30 million European immigrants. Prior cross-sectional work finds that immigrants initially held lower-paid occupations than natives but converged over time. In newly assembled panel data, we show that, in fact, the average immigrant did not face a substantial occupation-based earnings penalty upon first arrival and experienced occupational advancement at the same rate as natives. Cross-sectional patterns are driven by biases from declining arrival cohort skill level and departures of negatively selected return migrants. We show that assimilation patterns vary substantially across sending countries and persist in the second generation.
Conjugation to Polymeric Chains of Influenza Drugs Targeting M2 Ion Channels Partially Restores Inhibition of Drug-Resistant Mutants

ABSTRACT By attaching multiple copies of the influenza M2 ion channel inhibitors amantadine (1) and rimantadine (2) to polymeric chains, we endeavored to recover their potency in inhibiting drug-resistant influenza viruses. Depending on loading densities, as well as the nature of the drug, the polymer, and the spacer arm, polymer-conjugated drugs were up to 30-fold more potent inhibitors of drug-resistant strains than their monomeric parents. In particular, a 20% loading density and a short linker group on the negatively charged poly-L-glutamate resulted in one of the most potent inhibitors for 2’s conjugates against drug-resistant influenza strains. Although full recovery of the inhibitory action against drug-resistant strains was not achieved, this study may be a step toward salvaging anti-influenza drugs that are no longer effective. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2450-2459, 2013
Scheduling semiconductor lines using a fluid network model

We present a novel method for "what's next" scheduling of semiconductor manufacturing lines based on the deterministic fluid network model of Chen and Yao. By "what's next" scheduling we mean specifying the order in which jobs are processed at each tool group. The approach we take here is first to determine how to allocate tool capacity among competing job types by solving a series of linear and quadratic programming problems related to the fluid model and then to specify a "what's next" scheduling algorithm designed to track these capacity allocations. The primary advantage of our approach is that it gives rise to a dynamic schedule which is based on global rather than local state information and which is responsive to stochastic changes in the line including tool incapacitation events and operator unavailability. This is in contrast to many other scheduling rules, such as first come first served and closest to completion which are essentially static rules based on local information. We also present some theoretical results about the fluid model that have important implications in the context of semiconductor manufacturing as well as some preliminary simulation results comparing the fluid model to other scheduling policies. >
Neutral Meson Decays into Two Photons from Lattice QCD

A precision determination of the neutral-pion width would improve determinations of the splitting between the up- and down-quark masses, and matrix elements for the decay of neutral mesons into two photons could play a role in the attempt to probe beyond-the-Standard Model physics in muon g 2 experiments. The theoretical error is dominated by hadronic light-by-light diagrams, and since direct measurements are extremely difficult, model calculations factorize it into two-photon diagrams connected by the lightest hadrons. We employ perturbative techniques to express the photon as a superposition of QCD eigenstates accessible in lattice-QCD calculations and found that vector-meson dominance is a poor description of the two-photon decay process when both photons are off shell.