cssi/SciSciGPT-SciSciNet huggingface dataset:
Governance and Performance Implications of Diversification Strategies: Evidence from Large U.S. Firms

Recent research focuses on explaining the diversification discount. However, there is little direct evidence regarding the relation among ownership structure, corporate governance, and corporate diversification. The results in this paper suggest that agency issues do not account for firms adopting a particular diversification strategy. Also, the performance consequences of the shift in the diversification strategy and the subsequent changes in institutional and block ownership structures are not related to agency issues. In fact, investors seem not to avoid diversified firms "per se". We suggest that observed board and ownership differences between diversified and focused firms are due to their being at different stages of corporate evolution. Copyright 2004 by the Eastern Finance Association.
Modernization vs. Dependency Revisited: Effects of Foreign Direct Investment on Food Security in Less Developed Countries

Food security is of great urgency in the developing world. Many countries have sought to attract foreign capital to promote development and reduce hunger. But how do foreign direct investment (FDI) inflows affect food security? Extant research based on dependency and modernization arguments or the globalization debate offers contradictory theoretical predictions and produces conflicting evidence. We resolve the puzzle by disaggregating FDI. Foreign investments in distinct economic sectors have disparate attributes, producing different welfare consequences for food security. We test our arguments using the food security indicators recommended by the Food and Agriculture Organization (FAO) and new data on sector-specific FDI inflows to 56 developing and transition economies between 1981 and 2001. We find highly robust evidence that manufacturing FDI improves food security. We also find that primary-sector FDI reduces food security and that service-sector FDI has an ambiguous but sometimes negative effect. These results are largely robust under different statistical methods, additional control variables, and alternative measures of food security. Our research offers policy lessons for how to improve food security and demonstrates how to resolve theoretically the long-standing dependency-modernization controversy that has informed the contemporary debate between the pro- and anti-globalization camps.
Intramolecular SN2′ cyclization of an alkyllithium species onto a methoxy allyl ether is syn selective

The preference for syn- or anti-addition of an intramolecular SN2′ cyclization of an alkyllithium species onto a methoxy allyl ether has been proven unequivocally to take place by a syn SN2′ mechanism.
Small deviations for time-changed Brownian motions and applications to second-order chaos

We prove strong small deviations results for Brownian motion under independent time-changes satisfying their own asymptotic criteria. We then apply these results to certain stochastic integrals which are elements of second-order homogeneous chaos.
Calculations of Mie back‐scattering of microwaves from ice spheres

Thunderstorms containing hail have been found to have extremely large radar reflectivities. Experimental work by Atlas, Harper, Ludlam and Macklin (1960) has shown that hailstones may have unexpectedly large back-scattering cross-sections. In order to shed additional light on this problem, the normalized back-scattering cross-sections (σb) of spherical ice particles with complex index of refraction N = 1·78 – 0–0024i (N = m – mki where m is the ordinary index of refraction, and mk is the Mie absorption coefficient) were calculated from the complete Mie equations. Small intervals of α (= 2πa/λ where a is the radius of the scattering particle and λ is the wavelength of incident radiation) were taken up to a value of 30. The back-scattering from large ice spheres is shown to be considerably higher than that from water spheres of the same size. In general, the differences between the reflectivities of ice and water spheres increase with increasing α up to an α of about 60. Calculations of (σb) were made for various values of the complex index of refraction in order to better understand the properties of the back-scattering equations.
Crystal growth, structure determination and magnetic properties of Ba4Ir3O10 and Ba4(Co0.4Ir0.6)Ir2O10 ☆

Abstract Single crystals of the isostructural compounds Ba 4 Ir 3 O 10 and Ba 4 (Co 0.4 Ir 0.6 )Ir 2 O 10 were grown from a molten potassium carbonate flux. The two compounds crystallize in the orthorhombic space group Cmca with lattice parameters of a =5.780(2), b =13.339(5) and c =13.216(5) A for Ba 4 Ir 3 O 10 , and a =5.776(2), b =13.255(4) and c =13.110(4) A for Ba 4 (Co 0.4 Ir 0.6 )Ir 2 O 10 . The structure consists of groups of three face-sharing octahedra, which in turn share vertices, forming an undulating two-dimensional sheet. The magnetic susceptibility plot for Ba 4 Ir 3 O 10 is featureless with an experimentally determined magnetic moment of 2.79 BM corresponding well to the theoretical value for all Ir 4+ . Ba 4 (Co 0.4 Ir 0.6 )Ir 2 O 10 , on the other hand, exhibits very complex magnetic behavior with two magnetic transitions at 100 and 75 K, indicative of ferromagnetic and anti-ferromagnetic interactions, respectively.
Two-Layer Feature Reduction for Sparse-Group Lasso via Decomposition of Convex Sets

Sparse-Group Lasso (SGL) has been shown to be a powerful regression technique for simultaneously discovering group and within-group sparse patterns by using a combination of the l1 and l2 norms. However, in large-scale applications, the complexity of the regularizers entails great computational challenges. In this paper, we propose a novel two-layer feature reduction method (TLFre) for SGL via a decomposition of its dual feasible set. The two-layer reduction is able to quickly identify the inactive groups and the inactive features, respectively, which are guaranteed to be absent from the sparse representation and can be removed from the optimization. Existing feature reduction methods are only applicable for sparse models with one sparsity-inducing regularizer. To our best knowledge, TLFre is the first one that is capable of dealing with multiple sparsity-inducing regularizers. Moreover, TLFre has a very low computational cost and can be integrated with any existing solvers. Experiments on both synthetic and real data sets show that TLFre improves the efficiency of SGL by orders of magnitude.
Forecast 4D‐Var: Exploiting Model Output Statistics

Forecasts of certain weather elements are improved by linearly relating observed elements to past observations, climatological information, and numerical weather-prediction-model output. Model Output Statistics (MOS) is a statistical post-processing of model output that is capable of forecasting some subgrid scale, synoptically-forced events and of correcting some systematic, but state dependent, model bias. This tendency of accounting for model error is exploited by feeding MOS forecasts back into the state estimation problem. MOS forecasts and their associated uncertainty are treated as ‘observations’ of the future system state, and a four-dimensional variational assimilation procedure is employed to improve the original analysis and resulting model forecast. In a simple-model scenario, it is found that this approach has a small negative impact on the magnitude of forecast errors relative to MOS with a decrease in the number of very good forecasts, but a large positive impact on the variance about the forecast errors: forecast busts are reduced. As a further step, a second round of MOS is performed on the new model forecasts in a manner identical to the original MOS approach. This second application of MOS results in a significant reduction in both the forecast errors and the variance about those errors relative to the first application of MOS, and includes an increase in very good forecasts. Copyright © 2003 Royal Meteorological Society
Financial Versus Monetary Mercantilism-Long-run View of Large International Reserves Hoarding

The sizable hoarding of international reserves by several East Asian countries has been frequently attributed to a modern version of monetary mercantilism – hoarding international reserves in order to improve competitiveness. Taking a long-run perspective, we point out that manufacturing exporters in East Asia frequently used financial mercantilism – subsidizing the cost of capital – during decades of high growth. The switches to sizable hoarding of international reserves happened when growth floundered or deep crises erupted, exacerbating financial fragility as the legacy of past financial mercantilism. As financial fragility may lead to currency crises, the rise of non-performing loans provides impetus for the precautionary hoarding of international reserves, making it harder to disentangle the monetary mercantilism from precautionary response to the heritage of past financial mercantilism. Monetary mercantilism also raises the prospects of competitive hoarding -- exporters of competing manufacturing goods to third markets would adopt a similar hoarding policy, in order to mitigate their deteriorating competitiveness following the adoption of monetary mercantilism by a competitor. Competitive hoarding, owing to the negative externalities associated with it, can dissipate competitiveness gains and result in excess reserves. It may also encourage the formation of institutions like regional funds, in an attempt to curb these adverse externalities.
Contemporaneous Dual Catalysis: Aldol Products from Non‐Carbonyl Substrates

The aldol reaction represents an important class of atom-economic carbon-carbon bond-forming reactions vital to modern organic synthesis. Despite the attention this reaction has received, issues related to chemo- and regioselectivity as well as reactivity of readily enolizable electrophiles remain. To help overcome these limitations, a new direct approach toward aldol products that does not rely upon carbonyl substrates is described. This approach employs room-temperature contemporaneous lanthanum/vanadium dual catalysis, whereby a vanadium-catalyzed 1,3-transposition of allenols is coupled with a lanthanum-catalyzed Meinwald rearrangement of epoxides in situ to directly form aldol products.
The Circulation of Ideas across Academic Communities: When locals re-import exported ideas

The circulation of ideas across academic communities is central to academic pursuits and has attracted much past scholarly attention. As North American-based scholars with European ties, we decided to examine the impact of Organization Studies in North American academia with the objective of understanding what, if anything, makes some Organization Studies articles more likely to have impact in North America than others. To set the stage for better understanding the role of Organization Studies in this academic community, we first present the key characteristics of North American academia. Secondly, relying on archival data spanning the first 29 years of Organization Studies (1980 to 2008, inclusive), we identify an apparent dynamic of select re-importation of exported ideas. Put otherwise, top North American journals tend to re-import ideas authored (and exported) by select North American scholars in Organizations Studies. Thirdly, we discuss the implications of this process on the field of organization studies and on the circulation of ideas across academic communities.
Minimizing weighted flow time

We consider the problem of minimizing the total weighted flow time on a single machine with preemptions. We give an online algorithm that is O(k)-competitive for k weight classes. This implies an O(log W)-competitive algorithm, where W is the maximum to minimum ratio of weights. This algorithm also implies an O(log n p log P)-approximation ratio for the problem, where P is the ratio of the maximum to minimum job size and n is the number of jobs. We also consider the nonclairvoyant setting where the size of a job is unknown upon its arrival and becomes known to the scheduler only when the job meets its service requirement. We consider the resource augmentation model, and give a (1 p e)-speed, (1 p1/e)-competitive online algorithm.
The design and pricing of fixed‐ and moving‐window contracts: An application of Asian‐Basket option pricing methods to the hog‐finishing sector

Asian-Basket type moving window contracts are an increasingly used risk management tool in US hog sector. The moving window contract is decomposed into a portfolio of a long Asian-Basket put and a short Asian-Basket call option. A projected breakeven price is used to determine the floor price, and then Monte Carlo simulation methods are used to price both a moving and a fixed window contract. These methods provide unbiased pricing of fixed and moving window hog finishing contracts of one-year duration.
Palladium-catalyzed enantioselective oxidation of alcohols: a dramatic rate acceleration by Cs2CO3/t-BuOH.

The addition of Cs_2CO_3 and t-BuOH provides a dramatic rate acceleration in the palladium-catalyzed aerobic oxidative kinetic resolution of secondary alcohols while maintaining the selectivity of the process.
Quasienantiomers and Quasiracemates: New Tools for Identification, Analysis, Separation, and Synthesis of Enantiomers

The old adage "never mix pure organic compounds" holds in spades for enantiomers. After going to all the trouble to make enantiopure molecules, who in their right mind would ever mix them to make a racemate? Quasienantiomers are almost enantiomers, but not quite. Yet unlike enantiomers, the interest is not so much in separating them but in mixing them to make quasiracemates. This backwards thinking opens new possibilities for identification, analysis, separation and synthesis of enantiomers. A short history is provided, the terms are defined and illustrated, and recent applications of quasienantiomers, quasiracemates and related species are reviewed.
Ultrafast anisotropic ballistic electron transport in Au films

Femtosecond reflectivity measurements on Au films and modeling showed damped oscillations. This results from ballistic transport of quasiparticles bouncing between the film surfaces and propagating with velocities determined by the actual Fermi surface of Au.
Domain Walls, Triples and Acceleration

We present a construction of domain walls in string theory. The domain walls can bridge both Minkowski and AdS string vacua. A key ingredient in the construction are novel classical Yang-Mills congurations, including instantons, which interpolate between toroidal Yang-Mills vacua. Our construction provides a concrete framework for the study of inating metrics in string theory. In some cases, the accelerating space-time comes with a holographic description. The general form of the holographic dual is aeld theory with parameters that vary over space-time.
The role of structure in the protein dynamical transition

The protein dynamical transition is investigated as a function of protein structure using terahertz time domain spectroscopy (THz-TDS). Measurements performed for native state and denatured hen egg white lysozyme (HEWL) show that protein structure is not necessary for the dynamical transition. We find the temperature dependence follows activated behavior and there is no evidence of a fragile to strong transition. Measurements of short chain poly alanine show a dynamical transition down to penta-alanine, however no transition is observed for di-alanine or tri-alanine. These measurements demonstrate that the temperature dependence arises strictly from the interaction of the side chains with the solvent. The lack of a transition for shorter chain polypeptides may indicate the temperature dependence arises from a net ordering of the adjacent water which scales with the length of the polypeptide chain.
Rotation Sets of Billiards with One Obstacle

We investigate the rotation sets of billiards on the m-dimensional torus with one small convex obstacle and in the square with one small convex obstacle. In the first case the displacement function, whose averages we consider, measures the change of the position of a point in the universal covering of the torus (that is, in the Euclidean space), in the second case it measures the rotation around the obstacle. A substantial part of the rotation set has usual strong properties of rotation sets.
Non-radial pulsation models of the H-alpha profile in BW Vulpeculae.

The profile of the Hydrogen alpha spectral line in the largeamplitude Beta Cephei star BW Vulpeculae was modeled in terms of a linear, non-radially moving, and rotating stellar atmosphere. The pulsation and rotation parameters were derived from fitting the radial velocity amplitude, and the best fit was obtained for l=2, m=-2, ?=90°, rotation velocity=120 km/sec, and pulsation amplitude=27 km/sec. When the line profiles are compared to this model, the fit is quite encouraging for most phases, but several discrepancies remain. At the time of writing, it is not clear whether these can be made to disappear by increasing the sophistication of the model, or whether a completely different physical model (e.g. radial) is necessary.
Reactive oxygen species and mitochondrial adenosine triphosphate-regulated potassium channels mediate helium-induced preconditioning against myocardial infarction in vivo.

Objectives: Helium produces preconditioning by activating prosurvival kinases, but the roles of reactive oxygen species (ROS) or mitochondrial adenosine triphosphate– regulated potassium (KATP) channels in this process are unknown. The authors tested the hypothesis that ROS and mitochondrial KATP channels mediate helium-induced preconditioning in vivo. Design: A randomized, prospective study. Setting: A university research laboratory. Participants: Male New Zealand white rabbits. Interventions: Rabbits (n 64) were instrumented for the measurement of systemic hemodynamics and subjected to a 30-minute left anterior descending coronary artery (LAD) occlusion and 3 hours of reperfusion. In separate experimental groups, rabbits (n 7 or 8 per group) were randomly assigned to receive 0.9% saline (control) or 3 cycles of 70% helium–30% oxygen administered for 5 minutes interspersed with 5 minutes of an air-oxygen mixture before LAD occlusion with or without the ROS scavengers N-acetylcysteine (NAC; 150 mg/kg) or N-2 mercaptoproprionyl glycine (2-MPG; 75 mg/kg), or the mitochondrial KATP antagonist 5-hydroxydecanoate (5-HD; 5 mg/kg). Statistical analysis of data was performed with analysis of variance for repeated measures followed by Bonferroni’s modification of a Student t test. Measurements and Main Results: The myocardial infarct size was determined by using triphenyltetrazolium chloride staining and presented as a percentage of the left ventricular area at risk. Helium significantly (p < 0.05) reduced infarct size (23 4% of the area at risk; mean standard deviation) compared with control (46 3%). NAC, 2-MPG, and 5-HD did not affect irreversible ischemic injury when administered alone (49 5%, 45 6%, and 45 3%), but these drugs blocked reductions in infarct size produced by helium (45 4%, 45 2%, and 44 3%). Conclusions: The results suggest that ROS and mitochondrial KATP channels mediate helium-induced preconditioning in vivo.
Communicative language teaching

(1987). Communicative language teaching. Theory Into Practice: Vol. 26, Teaching Foreign Languages, pp. 235-242.
The Effect of a Market Orientation on Business Performance: A Study of Small‐Sized Service Retailers Using MARKOR Scale

Conventional marketing wisdom holds that a market orientation provides a company with a better understanding of its customers, competitors, and environment, which subsequently leads to superior firm performance. While researchers have explored the relationship between market orientation and business performance in different organizations, such studies in small-sized service retailers are scarce. This study investigates potential influences of market orientation on small-sized service retailer performance. Data for this study were collected through personal interviews, and Kohli, Jaworski, and Kumar's market orientation scale was used to specify the dimensions of a market-oriented organization. Results indicated that Kohli, Jaworski, and Kumar's market orientation scale provided a good measure of market orientation in this setting. Also, the results of analyses indicated a significant link between market orientation and small-sized service retailer performance. The managerial implications are discussed.
After Midnight: A Regression Discontinuity Design in Length of Postpartum Hospital Stays

Patients who receive more hospital treatment tend to have worse underlying health, confounding estimates of the returns to such care. This paper compares the costs and beneflts of extending the length of hospital stay following delivery using a discontinuity in stay length for infants born close to midnight. Third-party reimbursement rules in California entitle newborns to a minimum number of hospital \days," counted as the number of midnights in care. A newborn delivered at 12:05 a.m. will have an extra night of reimbursable care compared to an infant born minutes earlier. We use a dataset of all California births from 1991-2002, including nearly 100,000 births within 20 minutes of midnight, and flnd that children born just prior to midnight have signiflcantly shorter lengths of stay than those born just after midnight, despite similar observable characteristics. Furthermore, a law change in 1997 entitled newborns to a minimum of 2 days in care. The midnight discontinuity can therefore be used to consider two distinct treatments: increasing stay length from one to two nights (prior to the law change) and from two to three nights (following the law change). On both margins, we flnd no efiect of stay length on readmissions or mortality for either the infant or the mother, and the estimates are precise. The results suggest that for uncomplicated births, longer hospitals stays incur substantial costs without apparent health beneflts.
Statistical analysis of a semilinear hyperbolic system advected by a white in time random velocity field

We study a system of semilinear hyperbolic equations passively advected by smooth white noise in time random velocity fields. Such a system arises in modelling non-premixed isothermal turbulent flames under single-step kinetics of fuel and oxidizer. We derive closed equations for one-point and multi-point probability distribution functions (PDFs) and closed-form analytical formulae for the one-point PDF function, as well as the two-point PDF function under homogeneity and isotropy. Exact solution formulae allow us to analyse the ensemble-averaged fuel/oxidizer concentrations and the motion of their level curves. We recover the empirical formulae of combustion in the thin reaction zone limit and show that these approximate formulae can either underestimate or overestimate average concentrations when the reaction zone is not tending to zero. We show that the averaged reaction rate slows down locally in space due to random advection-induced diffusion, and that the level curves of ensemble-averaged concentration undergo diffusion about mean locations.
The European Central Bank and the Euro: The First Year

The creation of the euro and the European Central Bank is a remarkable and unprecedented event in economic and political history: creating a supranational central bank and leaving eleven countries without national currencies of their own. The experience of the first year confirms that one size fits all' monetary policy is not suitable for Europe because cyclical and inflation conditions vary substantially among countries. Labor market policies during this first year will increase this problem in the future and may lead to more trade protectionism. The paper explores reasons why cyclical unemployment, structural unemployment, and inflation may all be higher in the future as a result of the single currency. Although some advocate the euro despite its economic problems because of its assumed favorable effects on European political cohesiveness, the paper argues that it is more likely to lead to political conflict within Europe and with the Unites States.
Impact of California's air pollution laws on black carbon and their implications for direct radiative forcing

Abstract We examine the temporal and the spatial trends in the concentrations of black carbon (BC) – recorded by the IMPROVE monitoring network for the past 20 years – in California. Annual average BC concentrations in California have decreased by about 50% from 0.46 μg m−3 in 1989 to 0.24 μ gm−3 in 2008 compared to the corresponding reductions in diesel BC emissions (also about 50%) from a peak of 0.013 Tg Yr−1 in 1990 to 0.006 Tg Yr−1 by 2008. We attribute the observed negative trends to the reduction in vehicular emissions due to stringent statewide regulations. Our conclusion that the reduction in diesel emissions is a primary cause of the observed BC reduction is also substantiated by a significant decrease in the ratio of BC to non-BC aerosols. The absorption efficiency of aerosols at visible wavelengths – determined from the observed scattering coefficient and the observed BC – also decreased by about 50% leading to a model-inferred negative direct radiative forcing (a cooling effect) of −1.4 W m−2 (±60%) over California.
Sulfur's impact on core evolution and magnetic field generation on Ganymede

[1] Analysis of the melting relationships of potential core forming materials in Ganymede indicate that fluid motions, a requirement for a dynamo origin for the satellite’s magnetic field, may be driven, in part, either by iron (Fe) ‘‘snow’’ forming below the coremantle boundary or solid iron sulfide (FeS) floating upward from the deep core. Eutectic melting temperatures and eutectic sulfur contents in the binary Fe-FeS system decrease with increasing pressure within the interval of core pressures on Ganymede (<14 GPa). Comparison of melting temperatures to adiabatic temperature gradients in the core suggests that solid iron is thermodynamically stable at shallow levels for bulk core compositions more iron-rich than eutectic (i.e., <21 wt % S). Calculations based on highpressure solid-liquid phase relationships in the Fe-FeS system indicate that iron snow or floatation of solid iron sulfide, depending on whether the core composition is more or less iron-rich than eutectic, is an inevitable consequence of cooling Ganymede’s core. These results are robust over a wide range of plausible three-layer internal structures and thermal evolution scenarios. For precipitation regimes that include Fe-snow, we present scaling arguments that give typical Rossby and magnetic Reynolds numbers consistent with dynamo action occurring in Ganymede’s core. Furthermore, by applying recently derived scaling relationships relating magnetic field strength to buoyancy flux, we obtain estimates of surface magnetic field strength comparable with observed values.
A New Type of Carbon Resistance Thermometer with Excellent Thermal Contact at Millikelvin Temperatures

Using a new brand of commercially available carbon resistor we built a cryogenic thermometer with an extremely good thermal contact to its thermal environment. Because of its superior thermal contact the thermometer is insensitive to low levels of spurious radio frequency heating. We calibrated our thermometer down to 5 mK using a quartz tuning fork He-3 viscometer and measured its thermal resistance and thermal response time.
Phase noise modeling of opto-mechanical oscillators

We build upon and derive a precise far from carrier phase noise model for radiation pressure driven opto-mechanical oscillators and show that calculations based on our model accurately match published phase noise data for such oscillators. Furthermore, we derive insights based on the equations presented and calculate phase noise for an array of coupled disk resonators, showing that it is possible to achieve phase noise as low as −80 dBc/Hz at 1 kHz offset for a 54 MHz opto-mechanical oscillator.
The Cosmological Mass Function in the Zel'dovich Approximation

: The Press-Schechter theory of the cosmological mass function and its modifications allow constraint of cosmological scenarios of structure formation. Recently, a few new models that explored the influence of anisotropic collapse on the shape of the mass function have been suggested. I discuss in more detail a particular model that assumes a fluid particle becomes part of a gravitationally bound halo when the smallest eigenvalue of the deformation tensor of the filtered initial density field reaches a certain threshold (like the filtered density contrast reaches the threshold in the Press-Schechter formalism). Choosing the smallest eigenvalue guarantees that the fluid particle in question experiences collapse along all three axes. The model shows a better agreement with the N-body simulations than with the standard Press-Schechter model.
Outcomes for critically ill patients with HIV and severe sepsis in the era of highly active antiretroviral therapy

Abstract Rationale With the advent of highly active antiretroviral therapy (HAART), sepsis has become a more frequent ICU diagnosis for patients with HIV infections. Yet, little is known about the etiologies of acute infections in critically ill patients with HIV and the factors that affect in-hospital mortality. Methods Cases of patients with HIV requiring intensive care specifically for severe sepsis were identified over 27 months. Demographic information, variables related to acute illness severity, variables related to HIV infection, and all acute infections contributing to ICU stay were recorded. Results Of 990 patients admitted to the ICU with severe sepsis, 136 (13.7%) were HIV-infected. There were 194 acute infections among the 125 patients with full data available; 112 of the infections were nosocomial/health care–associated, 55 were AIDS-related, and 27 were community-acquired. Patients with nosocomial/health care–associated and AIDS-related infections had lower CD4 counts and were less likely to be on HAART ( P P = .18) approached statistical significance. Conclusions In this large cohort study, nosocomial/health care–associated infections were common in ICU patients with HIV and severe sepsis. Hospital mortality was associated with acute illness severity, but not clearly associated with variables related to HIV infection. Interventions that aim to prevent or more effectively treat nosocomial infections in critically ill patients with HIV may favorably impact clinical outcomes.
Prices and unit labor costs: a new test of price stickiness $

Abstract This paper investigates the predictions of a simple optimizing model of nominal price rigidity for the dynamics of inflation. Taking as given the paths of nominal labor compensation and labor productivity to approximate the evolution of marginal costs, I determine the path of prices predicted by the solution of the firms’ optimal pricing problem. Model parameters are chosen to maximize the fit with the data. I find evidence of a significant degree of price stickiness and substantial support for the forward-looking model of price setting. The results are robust to the use of alternative forecasting models for the path of unit labor costs, alternative measures of marginal costs, and alternative specifications the model of price staggering.
Commensurability classes of twist knots

In this paper we prove that if MK is the complement of a non-fibered twist knot K in $\mathbb S^3$, then MK is not commensurable to a fibered knot complement in a ℤ/2ℤ-homology sphere. To prove this result we derive a recursive description of the character variety of twist knots and then prove that a commensurability criterion developed by Calegari and Dunfield is satisfied for these varieties. In addition, we partially extend our results to a second infinite family of 2-bridge knots.
Fermion-scalar conformal blocks

We compute the conformal blocks associated with scalar-scalar-fermion-fermion 4-point functions in 3D CFTs. Together with the known scalar conformal blocks, our result completes the task of determining the so-called ‘seed blocks’ in three dimensions. Conformal blocks associated with 4-point functions of operators with arbitrary spins can now be determined from these seed blocks by using known differential operators.
Cooling in Coronal Gas in the M82 Starburst Superwind

We have used the Far Ultraviolet Spectroscopic Explorer to search for O VI λ1031.926 emission at four locations in the starburst superwind of M82. No O VI emission was detected at any of the four pointings, with upper limits less than or equal to the 0.3-2 keV X-ray flux. These observations limit the energy lost through radiative cooling of coronal phase (T ~ 105.5 K) gas to roughly the same magnitude as that lost in the hot phase through X-ray emission, which has been shown to be small. The wind material retains most of its energy and should be able to escape from the gravitational potential of M82, enriching the intergalactic medium with energy and metals. The lack of coronal gas in the wind and observations of spatially correlated X-ray and Hα emission are consistent with a scenario in which the hot wind material overruns cold clouds in the halo or with one in which the Hα and X-ray emission arise at the interface between the hot wind and a cool shell of swept-up interstellar medium, as long as the shock velocity is 150 km s-1. The observed limits on the O VI/Hα and C III/Hα flux ratios rule out shock heating as the source of the T = 104 K gas unless the shock velocity is 90 km s-1.
LINEAR THEORY OF THIN, RADIALLY STRATIFIED DISKS

We consider the nonaxisymmetric linear theory of radially stratified disks. We work in a shearing-sheet-like approximation, in which the vertical structure of the disk is neglected, and develop equations for the evolution of a plane-wave perturbation comoving with the shear flow (a shearing wave, or "shwave"). We calculate a complete solution set for compressive and incompressive short-wavelength perturbations in both the stratified and unstratified shearing-sheet models. We develop expressions for the late-time asymptotic evolution of an individual shwave, as well as for the expectation value of the energy for an ensemble of shwaves that are initially distributed isotropically in k-space. We find that (1) incompressive, short-wavelength perturbations in the unstratified shearing sheet exhibit transient growth and asymptotic decay, but the energy of an ensemble of such shwaves is constant with time; (2) short-wavelength compressive shwaves grow asymptotically in the unstratified shearing sheet, as does the energy of an ensemble of such shwaves; (3) incompressive shwaves in the stratified shearing sheet have density and azimuthal velocity perturbations δΣ, δvy ~ t-Ri (for |Ri| 1), where Ri ≡ N/(Ω)2 is the Richardson number, N is the square of the radial Brunt-Vaisala frequency, and Ω is the effective shear rate; and (4) the energy of an ensemble of incompressive shwaves in the stratified shearing sheet behaves asymptotically as Rit1-4Ri for |Ri| 1. For Keplerian disks with modest radial gradients, |Ri| is expected to be 1, and there is therefore weak growth in a single shwave for Ri < 0 and near-linear growth in the energy of an ensemble of shwaves, independent of the sign of Ri.
A New Approach to Affine Extractors and Dispersers

We study the problem of constructing affine extractors over $\GF(2)$. Previously the only known construction that can handle sources with arbitrarily linear entropy is due to Bourgain (and a slight modification by Yehudayoff), which makes extensive use of complicated inequality manipulations and relies on a careful choice of a polynomial. In this paper we give a new and conceptually much cleaner construction of affine extractors for linear entropy sources that outputs a constant fractionof the entropy with exponentially small error. This matches theprevious best result of Bourgain. The extractor can be pushed tohandle affine sources with entropy $n/\sqrt{\log n \logn}$. This slightly improves Bourgain's result andmatches the recent result of Yehudayoff. We also give a zero-error disperser for affine sources with entropy $n/\sqrt {\log n}$that outputs $n^{\Omega(1)}$ bits. This improves previousconstructions of affine dispersers that output more than 1 bit. In contrast to Bourgain's construction, our construction mainly uses extractor machinery and basic properties of polynomials. Some of our techniques may be of independent interest.
Instantons in partially broken gauge groups

Abstract We discuss the effects of instantons in partially broken gauge groups on the low-energy effective gauge theory. Such effects arise when some of the instantons of the original gauge group G are no longer contained in (or can not be gauge rotated into) the unbroken group H . In cases of simple G and H , a good indicator for the existence of such instantons is the “index of embedding.” However, in the general case one has to examine π 3 ( G / H ) to decide whether there are any instantons in the broken part of the gauge group. We give several examples of supersymmetric theories where such instantons exist and leave their effects on the low-energy effective theory.
Software Framework for Managing Heterogeneity in Mobile Collaborative Systems

Heterogeneity in mobile computing devices and application scenarios complicates the development of collaborative software systems. Heterogeneity includes disparate computing and communication capabilities, differences in users' needs and interests, and semantic conflicts across different domains and representations. In this paper, we describe a software framework that supports mobile collaboration by managing several aspects of heterogeneity. Adopting graph as a common data structure for the application state representation enables us to develop a generic solution for handling the heterogeneities. The effect external forces, such as resource constraints and diverging user interests, can be quantified and controlled as relational and attribute heterogeneity of state graphs. When mapping the distributed replicas of the application state, the external forces inflict a loss of graph information, resulting in many-to-one correspondences of graph elements. A key requirement for meaningful collaboration is maintaining a consistent shared state across the collaborating sites. Our framework makes the best of maximizing the state consistency, while accommodating the external force constraints, primarily the efficient use of scarce system resources. Furthermore, we describe the mobility aspects of our framework, mainly its extension to peer-to-peer scenarios and situations of intermittent connectivity. We describe an implementation of our framework applied to the interoperation of shared graphics editors across multiple platforms, where users are able to share 2D and 3D virtual environments represented as XML documents. We also present performance results, namely resource efficiency and latency, which demonstrate its feasibility for mobile scenarios.
A class of P,T-invariant topological phases of interacting electrons

Abstract We describe a class of parity- and time-reversal-invariant topological states of matter which can arise in correlated electron systems in 2+1-dimensions. These states are characterized by particle-like excitations exhibiting exotic braiding statistics. P and T invariance are maintained by a ‘doubling’ of the low-energy degrees of freedom which occurs naturally without doubling the underlying microscopic degrees of freedom. The simplest examples have been the subject of considerable interest as proposed mechanisms for high-Tc superconductivity. One is the ‘doubled’ version of the chiral spin liquid. The chiral spin liquid gives rise to anyon superconductivity at finite doping and the corresponding field theory is U(1) Chern–Simons theory at coupling constant m=2. The ‘doubled’ theory is two copies of this theory, one with m=2 the other with m=−2. The second example corresponds to Z2 gauge theory, which describes a scenario for spin-charge separation. Our main concern, with an eye towards applications to quantum computation, are richer models which support non-Abelian statistics. All of these models, richer or poorer, lie in a tightly organized discrete family indexed by the Baraha numbers, 2cos(π/(k+2)), for positive integer k. The physical inference is that a material manifesting the Z2 gauge theory or a doubled chiral spin liquid might be easily altered to one capable of universal quantum computation. These phases of matter have a field-theoretic description in terms of gauge theories which, in their infrared limits, are topological field theories. We motivate these gauge theories using a parton model or slave-fermion construction and show how they can be solved exactly. The structure of the resulting Hilbert spaces can be understood in purely combinatorial terms. The highly constrained nature of this combinatorial construction, phrased in the language of the topology of curves on surfaces, lays the groundwork for a strategy for constructing microscopic lattice models which give rise to these phases.
Borrowing Constraints, Parental Altruism and Welfare

This paper investigates the impact of borrowing constraints on welfare in a standard overlappinggenerations model where parental altruism results in transfers. I …nd that the average level of welfare is higher when children cannot borrow against future income. As Bernheim (1989) showed, the Nash-Cournot equilibrium does not maximize the average level of utility of currently living agents; the presence of a borrowing constraint increases children’s savings and parental transfers bringing their levels closer to the optimum, raising children’s welfare as well as average welfare in the short-run and in the long-run. Additionally, borrowing constraints reduce investment on children’s education, decreasing the aggregate level of human capital, but raises aggregate savings and, hence, physical capital.
An Engineered Bivalent Neuregulin Protects Against Doxorubicin-Induced Cardiotoxicity With Reduced Proneoplastic Potential

Background—Doxorubicin (DOXO) is an effective anthracycline chemotherapeutic, but its use is limited by cumulative dose-dependent cardiotoxicity. Neuregulin-1β is an ErbB receptor family ligand that is effective against DOXO-induced cardiomyopathy in experimental models but is also proneoplastic. We previously showed that an engineered bivalent neuregulin-1β (NN) has reduced proneoplastic potential in comparison with the epidermal growth factor–like domain of neuregulin-1β (NRG), an effect mediated by receptor biasing toward ErbB3 homotypic interactions uncommonly formed by native neuregulin-1β. Here, we hypothesized that a newly formulated, covalent NN would be cardioprotective with reduced proneoplastic effects in comparison with NRG. Methods and Results—NN was expressed as a maltose-binding protein fusion in Escherichia coli. As established previously, NN stimulated antineoplastic or cytostatic signaling and phenotype in cancer cells, whereas NRG stimulated proneoplastic signaling and phenotype. In neo...
Free Lie algebroids and the space of paths

We construct algebraic and algebro-geometric models for the spaces of unparametrized paths. This is done by considering a path as a holonomy functional on indeterminate connections. For a manifold X, we construct a Lie algebroid \({\mathcal{P}}_X\) which serves as the tangent space to X (punctual paths) inside the space of all unparametrized paths. It serves as a natural receptacle of all “covariant derivatives of the curvature” for all bundles with connections on X.
Higher-Order Solitons in the N-Wave System

The soliton dressing matrices for the higher-order zeros of the Riemann-Hilbert problem for the N-wave system are considered. For the elementary higher-order zero, that is, whose algebraic multiplicity is arbitrary but the geometric multiplicity is 1, the general soliton dressing matrix is derived. The theory is applied to the study of higher-order soliton solutions in the three-wave interaction model. The simplest higher-order soliton solution is presented. In the generic case, this solution describes the breakup of a higher-order pumping wave into two higher-order elementary waves, and the reverse process. In non-generic cases, this solution could describe (i) the merger of a pumping sech wave and an elementary sech wave into two elementary waves (one sech and the other one higher order); (ii) the breakup of a higher-order pumping wave into two elementary sech waves and one pumping sech wave; and the reverse processes. This solution could also reproduce fundamental soliton solutions as a special case.
A survey of techniques for recognizing parallel processable streams in computer programs

State-of-the-art advances---in particular, anticipated advances generated by LSI---have given fresh impetus to research in the area of parallel processing. The motives for parallel processing include the following:1. Real-time urgency. Parallel processing can increase the speed of computation beyond the limit imposed by technological limitations.2. Reduction of turnaround time of high priority jobs.3. Reduction of memory and time requirements for "housekeeping" chores. The simultaneous but properly interlocked operations of reading inputs into memory and error checking and editing can reduce the need for large intermediate storages or costly transfers between members in a storage hierarchy.4. An increase in simultaneous service to many users. In the field of the computer utility, for example, periods of peak demand are difficult to predict. The availability of spare processors enables an installation to minimize the effects of these peak periods. In addition, in the event of a system failure, faster computational speeds permit service to be provided to more users before the failure occurs.5. Improved performance in a uniprocessor multi-programmed environment. Even in a uniprocessor environment, parallel processable segments of high priority jobs can be overlapped so that when one segment is waiting for I/O, the processor can be computing its companion segment. Thus an overall speed up in execution is achieved.
Laurentide Ice Sheet meltwater and abrupt climate change during the last glaciation

[1] A leading hypothesis to explain abrupt climate change during the last glacial cycle calls on fluctuations in the margin of the North American Laurentide Ice Sheet (LIS), which may have routed fresh water between the Gulf of Mexico (GOM) and the North Atlantic, affecting North Atlantic Deep Water variability and regional climate. Paired measurements of δ18O and Mg/Ca of foraminiferal calcite from GOM sediments reveal five episodes of LIS meltwater input from 28 to 45 thousand years ago (ka) that do not match the millennial-scale Dansgaard-Oeschger warmings recorded in Greenland ice. We suggest that summer melting of the LIS may occur during Antarctic warming and likely contributed to sea level variability during marine isotope stage 3.
Strategies for Targeting Protein–Protein Interactions With Synthetic Agents

The development of small-molecule modulators of protein-protein interactions is a formidable goal, albeit one that possesses significant potential for the discovery of novel therapeutics. Despite the daunting challenges, a variety of examples exists for the inhibition of two large protein partners with low-molecular-weight ligands. This review discusses the strategies for targeting protein-protein interactions and the state of the art in the rational design of molecules that mimic the structures and functions of their natural targets.