cssi/SciSciGPT-SciSciNet huggingface dataset:
Emergence of a Broad Absorption Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007

We report results from a 2003 Far Ultraviolet Spectroscopic Explorer (FUSE) observation and reanalysis of a 1996 Hubble Space Telescope (HST) observation of the unusual X-ray transient Narrow-line Seyfert 1 galaxy WPVS 007. The HST Faint Object Spectrograph (FOS) spectrum revealed mini-BALs (broad absorption lines) with V max ~ 900 km s?1 and FWHM ~550 km s?1. The FUSE spectrum showed that an additional BAL outflow with V max ~ 6000 km s?1 and FWHM ~3400 km s?1 had appeared. WPVS 007 is a low-luminosity object in which such a high-velocity outflow is not expected; therefore, it is an outlier on the MV /v max relationship. Template spectral fitting yielded apparent ionic columns, and a Cloudy analysis showed that the presence of P V requires a high-ionization parameter log(U) ? 0 and high-column density log(N H) ? 23 assuming solar abundances and a nominal spectral energy distribution (SED) for low-luminosity NLS1s with ? ox = ?1.28. A recent long Swift observation revealed the first hard X-ray detection and an intrinsic (unabsorbed) ? ox ?1.9. Using this SED in our analysis yielded lower column density constraints (log(N H) ? 22.2 for Z = 1, or log(N H) ? 21.6 if Z = 5). The X-ray weak continuum, combined with X-ray absorption consistent with the UV lines, provides the best explanation for the observed Swift X-ray spectrum. The large column densities and velocities implied by the UV data in any of these scenarios could be problematic for radiative acceleration. We also point out that since the observed P V absorption can be explained by lower total column densities using an intrinsically X-ray weak spectrum, we might expect to find P V absorption preferentially more often (or stronger) in quasars that are intrinsically X-ray weak.
Optimal clock synchronization

We present a simple, efficient, and unified solution to the problems of synchronizing, initializing, and integrating clocks for systems with different types of failures: crash, omission, and arbitrary failures with and without message authentication. This is the first known solution that achieves optimal accuracy—the accuracy of synchronized clocks (with respect to real time) is as good as that specified for the underlying hardware clocks. The solution is also optimal with respect to the number of faulty processes that can be tolerated to achieve this accuracy.
Personal Characteristics of Salespeople and the Attractiveness of Alternative Rewards

Abstract How do personal characteristics of salespeople affect their desire for the various rewards available to them? Do younger salespeople desire different types and levels of rewards than older salespeople? Are there differences due to job tenure, marital status, family size, and so forth? In this article, the authors attempt to answer these questions. Based on an extensive investigation of the industrial sales forces from two large companies, the authors examine the relationship between personal characteristics and the sales force's valence for various rewards. Although some of the findings are consistent with current sales management practices, some are not, suggesting that present day thinking with respect to the design and administration of rewards may need more careful scrutiny.
The Astrophysics of Ultrahigh-Energy Cosmic Rays

The origin of the highest energy cosmic rays is still unknown. The discovery of their sources is expected to reveal the workings of the most energetic astrophysical accelerators in the Universe. Current observations show a spectrum consistent with an origin in extragalactic astrophysical sources. Candidate sources range from the birth of compact objects to explosions related to gamma-ray bursts or to events in active galaxies. We discuss the main effects of propagation from cosmologically distant sources, including interactions with cosmic background radiation and magnetic fields. We examine possible acceleration mechanisms leading to a survey of candidate sources and their signatures. New questions arise from an observed hint of sky anisotropies and an unexpected evolution of composition indicators. Future observations may reach the necessary sensitivity to achieve charged particle astronomy and to observe ultrahigh-energy photons and neutrinos, which may further illuminate the workings of the Universe a...
An automatic surface inspection system for flat rolled steel

The paper describes a feasibility study of on-line classification of visible defects in flat rolled steel, as the steel emerges from the rolling mill. A visual signal developed by a television camera is processed by a software simulation of the proposed hardware system which stores information from the scans and alerts a small computer when a possible flaw has been detected. A pattern recognition algorithm, executable by the computer, makes the final detection and classification decision before the next coil is rolled. A detailed simulation of the hardware using photographs of steel defects is presented.
A Kaldor Matching Model of Real Wage Declines

A model linking macroeconomic equilibrium and income distribution in balanced growth equilibria is developed as a variant to the Kaldor model of factor shares. It departs from the original Kaldor model in assuming equal saving rates and production determined by a matching process between workers and jobs. Macroeconomic equilibrium (national savings equal to investment) combines with competitive microeconomic behavior to determine the real wage and real interest rate. An increase in the ratio of national debt to employment reduces the real wage, explaining recent declines.
The role of user fees in the cost-benefit analysis of privatization with an application to inpatient psychiatric services in the US

When there is no asset sale and thus no lump sum revenues to accrue to the government, one of the major benefits of privatization is then absent. Because of this, the revenues that were previously obtained from private clients assume more importance. This article incorporates these client revenues fully into a cost-benefit framework and applies the framework to an evaluation of the privatization of psychiatric wards in nonfederal general hospitals in the United States. We find that the privatization of psychiatric services in general hospitals would provide a social gain only if the change took place using for-profit rather than nonprofit hospitals, a finding that depends crucially on including the excess burden effects of public revenues.
Approximately Optimal Mechanisms for Strategyproof Facility Location: Minimizing $L_p$ Norm of Costs

This paper is concerned with the problem of locating a facility on a line in the presence of strategic agents, also located on that line. Each agent incurs a cost equal to her distance to the facility whereas the planner wishes to minimize the Lp norm of the vector of agent costs. The location of each agent is only privately known, and the goal is to design a strategyproof mechanism that approximates the optimal cost well. It is shown that the median mechanism provides a 21−1/p approximation ratio, and that this is the optimal approximation ratio among all deterministic strategyproof mechanisms. For randomized mechanisms, two results are shown: First, for any integer p larger than 2, no mechanism—from a rather large class of randomized mechanisms—has an approximation ratio better than that of the median mechanism. This is in contrast to the case of p = 2 and p = ∞ where a randomized mechanism provably helps improve the worst case approximation ratio. Second, for the case of 2 agents, the Left-Right-Middle...
Stochastic Discount Factor Models and the Equity Premium Puzzle

One view of the equity premium puzzle is that in the standard asset-pricing model with time-separable preferences, the volatility of the stochastic discount factor, for plausible values of risk aversion, is too low to be consistent with consumption and asset return data. We adopt this characterization of the puzzle, due to Hansen and Jagannathan (1991), and establish two results: (i) resolutions of the puzzle based on complete frictionless markets and non-separabilities in preferences are very sensitive to small changes in the consumption data, and (ii) models with frictions avoid this sensitivity problem. Using quarterly data from 1947-97, we calibrate a state non-separable model and a time non-separable model to satisfy the Hansen-Jagannathan volatility bound and show that the two resolutions are not robust. We support our argument via a bootstrap experiment where the models almost always violate the bound. These violations are primarily due to the fact that small changes in consumption growth moments imply changes in the mean of the stochastic discount factor, which render the volatility of the stochastic discount factor to be too low relative to the bound. Asset-pricing models with frictions, however, are much more successful in the bootstrap experiment relative to the case without frictions.
Social Networks and the Risk of Gunshot Injury

Direct and indirect exposure to gun violence have considerable consequences on individual health and well-being. However, no study has considered the effects of one’s social network on gunshot injury. This study investigates the relationship between an individual’s position in a high-risk social network and the probability of being a victim of a fatal or non-fatal gunshot wound by combining observational data from the police with records of fatal and non-fatal gunshot injuries among 763 individuals in Boston’s Cape Verdean community. A logistic regression approach is used to analyze the probability of being the victim of a fatal or non-fatal gunshot wound and whether such injury is related to age, gender, race, prior criminal activity, exposure to street gangs and other gunshot victims, density of one’s peer network, and the social distance to other gunshot victims. The findings demonstrate that 85 % all of the gunshot injuries in the sample occur within a single social network. Probability of gunshot victimization is related to one’s network distance to other gunshot victims: each network association removed from another gunshot victim reduces the odds of gunshot victimization by 25 % (odds ratio = 0.75; 95 % confidence interval, 0.65 to 0.87). This indirect exposure to gunshot victimization exerts an effect above and beyond the saturation of gunshot victimization in one’s peer network, age, prior criminal activity, and other individual and network variables.
The preparation and reactions of chiral phosphorous acid diamides

Abstract Chiral phosphorous acid diamides were prepared by condensation of N,N′-disubstituted C 2 diamines with PCl 3 followed by an equivalent of water. Deprotonation of these acids with n-butyl lithium or LDA gave the lithium salt which reacted smoothly with alkyl halides to give the substituted phosphonamides in good yield.
Turbulent pressure field in a co-annular jet

Single-point and two-point fluctuating static pressure measurements have been made in the initial mixing and transition regions in a co-annular circular jet. Space scales, correlation and time scales in the convected frame, and convection velocities have been determined for both broad-band and narrow-band frequency components. Analytical functionals describing the structural behavior of the turbulent pressure field have been developed from the data which are suitable for direct application in predicting the sound power level radiated from this turbulent field. Effects of both area and velocity ratios are incorporated in the model. A b BB dc,dEp x> y Nomenclature = anisotropy factor = mixing layer width = broad band = diameter of core or of bypass nozzle = decay coefficients in axial, radial, and lateral directions, respectively = broad-band axial length scale for pressure = narrow-band radial and lateral
Tree-Independent Dual-Tree Algorithms

Dual-tree algorithms are a widely used class of branch-and-bound algorithms. Unfortunately, developing dual-tree algorithms for use with different trees and problems is often complex and burdensome. We introduce a four-part logical split: the tree, the traversal, the point-to-point base case, and the pruning rule. We provide a meta-algorithm which allows development of dual-tree algorithms in a tree-independent manner and easy extension to entirely new types of trees. Representations are provided for five common algorithms; for k-nearest neighbor search, this leads to a novel, tighter pruning bound. The meta-algorithm also allows straightforward extensions to massively parallel settings.
Frameworks for Teaching and Learning Business Ethics within the Global Context: Background of Ethical Theories

In this article, we provide a summary of several major traditional and contemporary philosophical and psychological perspectives on ethical conduct for businesses, along with five different sets of internationally accepted ethical guidelines for corporations operating anywhere in the world. We include examples of corporate codes of conduct from particular multinational corporations. Our orienting framework of ethics theory is expanded to include a discussion of both Western and non-Western frameworks, including those of Confucianism, Buddhism, and Native American traditions, allowing faculty and students to explore ethical problems that honor a wide array of national, cultural, and ethnic contexts and differences.
Why doctors choose small towns: A developmental model of rural physician recruitment and retention

Shortages of health care professionals have plagued rural areas of the USA for more than a century. Programs to alleviate them have met with limited success. These programs generally focus on factors that affect recruitment and retention, with the supposition that poor recruitment drives most shortages. The strongest known influence on rural physician recruitment is a "rural upbringing," but little is known about how this childhood experience promotes a return to rural areas, or how non-rural physicians choose rural practice without such an upbringing. Less is known about how rural upbringing affects retention. Through twenty-two in-depth, semi-structured interviews with both rural- and urban-raised physicians in northeastern California and northwestern Nevada, this study investigates practice location choice over the life course, describing a progression of events and experiences important to rural practice choice and retention in both groups. Study results suggest that rural exposure via education, recreation, or upbringing facilitates future rural practice through four major pathways. Desires for familiarity, sense of place, community involvement, and self-actualization were the major motivations for initial and continuing small-town residence choice. A history of strong community or geographic ties, either urban or rural, also encouraged initial rural practice. Finally, prior resilience under adverse circumstances was predictive of continued retention in the face of adversity. Physicians' decisions to stay or leave exhibited a cost-benefit pattern once their basic needs were met. These results support a focus on recruitment of both rural-raised and community-oriented applicants to medical school, residency, and rural practice. Local mentorship and "place-specific education" can support the integration of new rural physicians by promoting self-actualization, community integration, sense of place, and resilience. Health policy efforts to improve the physician workforce must address these complexities in order to support the variety of physicians who choose and remain in rural practice.
Synthesis of Diamond from Carbon Disulfide in Hydrogen

The synthesis of diamond has been accomplished from carbon disulfide (CS2) in hydrogen (H2) using tungsten hot filament chemical vapor deposition. A continuous layer was deposited on silicon and characterized using Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy. The polycrystalline film exhibited a sharp Raman peak at 1331.4 cm−1 and a broad low–intensity peak at approximately 1500 cm−1. X–ray diffraction analysis showed peaks corresponding to the {111}, {220}, and {311} reflections of diamond with evidence of (110) texture. Diamond growth from CS2 in H2 was observed to be highly faceted by scanning electron microscopy.
Optimal search performance in unstructured peer-to-peer networks with clustered demands

This paper derives the optimal search time and the optimal search cost that can be achieved in unstructured peer-to-peer networks when the demand pattern exhibits clustering (i.e. file popularities vary across the set of nodes in the network). Clustering in file popularity patterns is evident from measurements on deployed peer-to-peer file sharing networks. In this paper, we provide mechanisms for modeling clustering in file popularity distributions and the consequent non-uniform distribution of file replicas. We derive relations that show the effect of the number of replicas of a file on the search time and on the search cost for a search for that file for the clustered demands case in such networks for both random walk and flooding search mechanisms. The derived relations are used to obtain the optimal search performance for the case of flooding search mechanisms. The potential performance benefit that clustering in demand patterns affords is captured by our results. Interestingly, the performance gains are shown to be independent of whether the search network topology reflects the clustering in file popularity (the optimal file replica distribution to obtain these performance gains, however, does depend on the search network topology).
Measurement of thermo-elastic deformation of an optic using a polarization-based shearing interferometer

A shearing interferometer is presented that uses polarization control to shear the wavefront and to modulate the interference pattern. The shear is generated by spatial walk-off in a birefringent crystal. By adjusting the orientation of the birefringent crystal, the components of the wavefront gradient can be independently measured to allow determination of the full wavefront vector gradient as well as reconstruction of the wavefront. Further, the monolithic nature of the crystal used for shearing allows the interferometer to be set up without need for precise alignment of any components. An algorithm incorporating homodyne detection is presented, which analyzes the modulated interferograms to determine the components of the wavefront gradient, from which the wavefront is reconstructed. The thermal deformation of a mirror subject to heating from absorption of a Gaussian pump beam was accurately observed with a sensitivity better than λ/160. We show that this sensitivity is scale invariant, and present a method to account for the nonuniform spatial frequency response of the interferometer.
Dehydrogenations with lead tetraacetate. Ketone to enone transformations in the 2-(aminocarbonyl)- and 2-(carbalkoxy)cycloalkanone series

Abstract Cyclic β-ketoesters and β-ketoamides are converted to 2-(carbalkoxy)- and 2-(aminocarbonyl)-2-cycloalken-1-ones by treatment with Pb(OAc)4 and Cu(OAc)2 in benzene.
A MODEL SELECTION TEST FOR BIVARIATE FAILURE-TIME DATA

In this paper, we address two important issues in semiparametric survival model selection for censored data generated by the Archimedean copula family: method of estimating the parametric copulas and data reuse. We demonstrate that for selection among candidate copula models that might all be misspecified, estimators of the parametric copulas based on minimizing the selection criterion function may be preferred to other estimators. To handle the issue of data reuse, we put model selection in the context of hypothesis testing and propose a simple test for model selection from a finite number of parametric copulas. Results from a simulation study and two empirical illustrations confirm our theoretical findings.We thank the editor Peter Phillips, three anonymous referees, and Hal White for their comments, which greatly improved the paper. An earlier version of this paper was presented at the 2005 World Congress Meetings of the Econometric Society, the 2005 Joint Statistical Meetings, the University of Waterloo, and the University of Western Ontario. Chen acknowledges support from the National Science Foundation and the C.V. Starr Center at NYU. Fan acknowledges support from the National Science Foundation. We thank Demian Pouzo for excellent research assistance on the numerical work in this paper and Weijing Wang for providing us with the Fortran code for computing the bivariate Kaplan–Meier estimator of Dabrowska (1988).
The Polar (WO2F4) 2- Anion in the Solid State

The cis-[WO2F4]2- anion is inherently acentric and contains polarizable WO bonds, making it a good candidate for second-harmonic generation (SHG). However, the orientational disorder commonly found in crystal structures containing [WO2F4]2- must be understood as a first step toward engineering a polar SHG material with this anion. The strategy of crystallizing the [WO2F4]2- anion with two different cations, which was successful in ordering the related [NbOF5]2- and cis-[MoO2F4]2- anions, is able to order one of the two WO bonds. Close inspection of bond lengths and anisotropic thermal ellipsoids in disordered [WO2F4]2- compounds gives insight into disorder mechanisms and suggests strategies for eliminating orientational disorder. Crystal data: for [pyH]2[Cu(py)4(WO2F4)2], tetragonal, space group I4122 (No. 98), with a = 11.339(2) A, c = 30.489(6) A, and Z = 4; for Cu(pyz)2WO2F4·(pyz)(H2O) polymorph I, tetragonal, space group I4/mcm (No. 140), with a = 9.745(1) A, c = 16.565(3) A, and Z = 4; for Cu(pyz)2W...
THE COBE DIRBE POINT SOURCE CATALOG

We present the COBE DIRBE Point Source Catalog, an all-sky catalog containing infrared photometry in 10 infrared bands from 1.25 to 240 μm for 11,788 of the brightest near and mid-infrared point sources in the sky. Since DIRBE had excellent temporal coverage (100-1900 independent measurements per object during the 10 month cryogenic mission), the Catalog also contains information about variability at each wavelength, including amplitudes of variation observed during the mission. Since the DIRBE spatial resolution is relatively poor (07), we have carefully investigated the question of confusion and have flagged sources with infrared-bright companions within the DIRBE beam. In addition, we filtered the DIRBE light curves for data points affected by companions outside of the main DIRBE beam but within the sky portion of the scan. At high Galactic latitudes (|b| > 5°), the Catalog contains essentially all of the unconfused sources with flux densities greater than 90, 60, 60, 50, 90, and 165 Jy at 1.25, 2.2, 3.5, 4.9, 12, and 25 μm, respectively, corresponding to magnitude limits of approximately 3.1, 2.6, 1.7, 1.3, -1.3, and -3.5. At longer wavelengths and in the Galactic plane, the completeness is less certain because of the large DIRBE beam and possible contributions from extended emission. The Catalog also contains the names of the sources in other catalogs, their spectral types, variability types, and whether or not the sources are known OH/IR stars. We discuss a few remarkable objects in the Catalog, including the extremely red object OH 231.8+4.2 (QX Pup), an asymptotic giant branch star in transition to a proto-planetary nebula, which has a DIRBE 25 μm amplitude of 0.29 ± 0.07 mag.
Privacy preserving web-based email

Recent web-based applications offer users free service in exchange for access to personal communication, such as on-line email services and instant messaging. The inspection and retention of user communication is generally intended to enable targeted marketing. However, unless specifically stated otherwise by the collecting service's privacy policy, such records have an indefinite lifetime and may be later used or sold without restriction. In this paper, we show that it is possible to protect a user's privacy from these risks by exploiting mutually oblivious, competing communication channels. We create virtual channels over online services (e.g., Google's Gmail, Microsoft's Hotmail) through which messages and cryptographic keys are delivered. The message recipient uses a shared secret to identify the shares and ultimately recover the original plaintext. In so doing, we create a wired “spread-spectrum” mechanism for protecting the privacy of web-based communication. We discuss the design and implementation of our open-source Java applet, Aquinas, and consider ways that the myriad of communication channels present on the Internet can be exploited to preserve privacy.
Commensurability of 1-cusped hyperbolic 3-manifolds

We give examples of non-fibered hyperbolic knot complements in homology spheres that are not commensurable to fibered knot complements in homology spheres. In fact, we give many examples of knot complements in homology spheres where every commensurable knot complement in a homology sphere has non-monic Alexander polynomial.
Contagious Rebellion and Preemptive Repression

Civil conflict appears to be contagious—scholars have shown that civil wars in a state’s neighborhood make citizens more likely to rebel at home. However, war occurs when both rebels and the state engage in conflict. How do state authorities respond to the potential for civil conflict to spread? We argue that elites will anticipate the incentive-altering effects of civil wars abroad and increase repression at home to preempt potential rebellion. Using a Bayesian hierarchical model and spatially weighted conflict measures, we find robust evidence that a state will engage in higher levels of human rights violations as civil war becomes more prevalent in its geographic proximity. We thus find evidence that states violate rights as a function of the internal politics of other states. Further, we argue authorities will act not to mimic their neighbors but rather to avoid their fate.
DTMOS: its derivatives and variations, and their potential applications

Since the first introduction of dynamic threshold voltage MOSFET (DTMOS) in 1994 (Assaderaghi et al, 1994), many novel and interesting proposals have been made regarding this device. Some of the proposals have focused on improving the original design and overcoming its limitations, while others have found circuit and system applications for it. This paper briefly reviews the DTMOS concept, and its advantages over conventional CMOS. Next, the main limitations and disadvantages of the device are touched upon, while covering some of the suggestions for optimizing the device. A rich category of circuit applications for DTMOS and its derivatives have been created in the short period following DTMOS inception. Some of the proposed circuit applications are mentioned next. Finally, the author's views on future directions of the device are presented.
Structural Analysis of Hydroxylamines, Oximes and Hydroxamic Acids: Trends and Patterns

1 Introduction 2 Gas Phase Structures 3 Crystal Phase Structures 4 Summary 5 Acknowledgment Keywords: structural analysis of hydroxylamines, oximes and hydroxamic acids-trends and patterns; gas phase structures and accurate gas phase molecular structures; inter- and intramolecular interactions-available to hydroxylamines, oximes and hydroxamic acids; NOH group, structural element linking hydroxylamines, oximes and hydroxamic acids; hydroxylamine configuration and conformations; gas phase oximes, typically having C–N–O–H conformation of 5A; crystal phase structures; structures of molecules-effects of intramolecular electrostatic interactions
What makes cities more competitive ? spatial determinants of entrepreneurship in India

Policy makers in both developed and developing countries want to make cities more competitive, attract entreprepreneurs, boost economic growth, and promote job creation. The authors examine the spatial location of entrepreneurs in India in manufacturing and services sectors, as well as in the formal and informal sectors, in 630 districts spread across 35 states/union territories. They quantify entrepreneurship as young firms that are less than three years old, and define entry measures through employment in these new establishments. They develop metrics that unite the incumbent industrial structures of districts with the extent to which industries interact through the traditional agglomeration channels. The two most consistent factors that predict overall entrepreneurship for a district are its education and the quality of local physical infrastructure. These patterns are true for manufacturing and services. These relationships are much stronger in India than those found for the United States. The authors also find strong evidence of agglomeration economies in India's manufacturing sector. This influence is through both traditional Marshallian economies like a suitable labor force and proximity to customers and through the Chinitz effect that emphasizes small suppliers. India's footprints in structural transformation, urbanization, and manufacturing sector are still at an early stage. At such an early point and with industrial structures not yet entrenched, local policies and traits can have profound and lasting impacts by shaping where industries plant their roots.
Kinematics and aerodynamics of the velocity vector roll

The velocity-vector roll is defined as an angular rotation of an airplane about its instantaneous velocity vector, constrained to be performed at constant angle of attack (AOA), no sideslip, and constant velocity. Consideration of the aerodynamic force equations leads to requirements for body-axis yawing and pitching rotations that must be present to satisfy these constraints. Here, the body-axis rotations and the constraints are used in the moment equations to determine the aerodynamic moments required to perform the velocity-vector roll. The total aerodynamic moments, represented in the reference body-axis coordinate system, are then analyzed to determine the conditions under which their maxima occur. It is shown, for representative tactical airplanes, that the conditions for maximum pitching moment are strongly a function of the orientation of the airplane, occurring at about 90 deg of bank in a level trajectory. Maximum required pitching moment occurs at peak roll rate and is achieved at an AOA in excess of 45 deg. The conditions for maximum rolling moment depend on the value of the roll mode time constant. For a small time constant (fast response) the maximum rolling moment occurs at maximum roll acceleration and zero AOA, largely independent of airplane orientation; for a large time constant, maximum required rolling moment occurs at maximum roll rate, at maximum AOA, and at 180 deg of bank in level flight. The maximum yawing moment occurs at maximum roll acceleration and maximum AOA and is largely independent of airplane orientation. Results are compared with those obtained using conventional assumptions of zero pitch and yaw rates and show significant improvement, especially in the prediction of maximum-pitching-moment requirements.
Prizes and Productivity: How Winning the Fields Medal Affects Scientific Output

Knowledge generation is key to economic growth, and scientific prizes are designed to encourage it. But how does winning a prestigious prize affect future output? We compare the productivity of Fields Medal recipients (winners of the top mathematics prize) to that of similarly brilliant contenders. The two groups have similar publication rates until the award year, after which the winners’ productivity declines. The medalists begin to “play the field,” studying unfamiliar topics at the expense of writing papers. It appears that tournaments can have large postprize effects on the effort allocation of knowledge producers.
Acceptance of New Medicaid Patients by Primary Care Physicians and Experiences with Physician Availability among Children on Medicaid or the Children's Health Insurance Program.

Objective To estimate the relationship between physicians' acceptance of new Medicaid patients and access to health care.
Solar Thermochemical Energy Storage Through Carbonation Cycles of SrCO3/SrO Supported on SrZrO3

Solar thermochemical energy storage has enormous potential for enabling cost-effective concentrated solar power (CSP). A thermochemical storage system based on a SrO/SrCO3 carbonation cycle offers the ability to store and release high temperature (≈1200 °C) heat. The energy density of SrCO3/SrO systems supported by zirconia-based sintering inhibitors was investigated for 15 cycles of exothermic carbonation at 1150 °C followed by decomposition at 1235 °C. A sample with 40 wt % of SrO supported by yttria-stabilized zirconia (YSZ) shows good energy storage stability at 1450 MJ m−3 over fifteen cycles at the same cycling temperatures. After further testing over 45 cycles, a decrease in energy storage capacity to 1260 MJ m−3 is observed during the final cycle. The decrease is due to slowing carbonation kinetics, and the original value of energy density may be obtained by lengthening the carbonation steps.
New Horizons: Long-range Kuiper Belt targets observed by the Hubble Space Telescope

We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 epochY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of approx. 0.02 arcsec (approx. 700 km at 44 AU) and delta m less than or equal to 0.5.
Properties of Black Holes in Toroidally Compactified String Theory

We review the macroscopic and microscopic properties of black holes of toroidally compactified heterotic and Type II string theory in dimensions 4 ≤ D ≤ 9. General charged rotating black hole solutions are obtained by acting on a generating solution with classical duality symmetries. In D = 4, D = 5 and 6 ≤ D ≤ 9, the generating solution for both toroidally compactified Type II and heterotic strings is specified by the ADM mass, [D−12]-angular momentum components and five, three and two charges, respectively. We give the Bekenstein-Hawking entropy for these solutions, address the BPS-saturated limit and compare the results to calculations of the microscopic entropy both in the NS-NS sector and the R-R sector of the theory. We also interpret such black hole solutions as dimensionally reduced intersecting p-branes of M-theory.
Doppler features from wind turbine scattering in the presence of ground

The time-varying Doppler signatures of a wind turbine in the presence of ground are simulated and interpreted. Both a point-scatterer model and high-frequency ray tracing are used to simulate the ground effect. The Doppler spectrogram shows two additional blade flashes due to the single and double ground bounce returns. The effects of stationary as well as moving ground are studied.
Pan-Arctic land?atmospheric fluxes of methane and carbon dioxide in response to climate change over the 21st century

Future changes of pan-Arctic land‐atmospheric methane (CH4) and carbon dioxide (CO2) depend on how terrestrial ecosystems respond to warming climate. Here, we used a coupled hydrology‐biogeochemistry model to make our estimates of these carbon exchanges with two contrasting climate change scenarios (no-policy versus policy) over the 21st century, by considering (1) a detailed water table dynamics and (2) a permafrost-thawing effect. Our simulations indicate that, under present climate conditions, pan-Arctic terrestrial ecosystems act as a net greenhouse gas (GHG) sink of 0:2 Pg CO2-eq. yr 1 , as a result of a CH4 source (53 Tg CH4 yr 1 ) and a CO2 sink ( 0:4 Pg C yr 1 ). In response to warming climate, both CH4 emissions and CO2 uptakes are projected to increase over the century, but the increasing rates largely depend on the climate change scenario. Under the non-policy scenario, the CH4 source and CO2 sink are projected to increase by 60% and 75% by 2100, respectively, while the GHG sink does not show a significant trend. Thawing permafrost has a small effect on GHG sink under the policy scenario; however, under the no-policy scenario, about two thirds of the accumulated GHG sink over the 21st century has been offset by the carbon losses as CH4 and CO2 from thawing permafrost. Over the century, nearly all CO2-induced GHG sink through photosynthesis has been undone by CH4-induced GHG source. This study indicates that increasing active layer depth significantly affects soil carbon decomposition in response to future climate change. The methane emissions considering more detailed water table dynamics continuously play an important role in affecting regional radiative forcing in the pan-Arctic.
Estimation and Testing of the Union Wage Effect Using Panel Data

We present estimates of the union wage effect controlling for unmeasured individual effects, and subject the conventional fixed-effects model to specification tests. For PSID men the union wage effect is 5-8% after controlling for person effects, as opposed to 20% in cross-section. Omnibus tests based on an unrestricted reduced form and instrumental variables tests based on differencing are consistent with conventional models. Tests based on comparing those who enter and leave union coverage provide evidence against the usual model. We find evidence for interactions between union status and other variables even after controlling for person effects.
Competitive Weighted Matching in Transversal Matroids

Consider a bipartite graph with a set of left-vertices and a set of right-vertices. All the edges adjacent to the same left-vertex have the same weight. We present an algorithm that, given the set of right-vertices and the number of left-vertices, processes a uniformly random permutation of the left-vertices, one left-vertex at a time. In processing a particular left-vertex, the algorithm either permanently matches the left-vertex to a thus-far unmatched right-vertex, or decides never to match the left-vertex. The weight of the matching returned by our algorithm is within a constant factor of that of a maximum weight matching, generalizing the recent results of Babaioff et al.
A superconducting linac for the energy amplifier

Because of the safer and more reliable mode of operation, a Superconducting Linac has been proposed as the proton beam accelerator which drives a nuclear plant based on the concept of the Energy Amplifier. An example based on the net generation of 400 MW (electric) is described. This requires a proton beam energy of 1 GeV with a continuous beam current of 10 mA, corresponding to a beam power of 10 MW. Two frequencies cases, 360 and 805 MHz, have been considered for the Linac design. Performance and cost comparison for the two cases are given.
A Novel Electrophilic Diamination Reaction of Alkenes.

A three-component electrophilic reaction transforms olefins into imidazoline and diamine derivatives. Rhodium(II) heptafluorobutyrate dimer (2 mol %) was utilized as the catalyst and N,N-dichloro-p-toluenesulfonamide (TsNCl2 ) and acetonitrile as the nitrogen sources. Modest to good yields (45-82 %) and high regio- and stereoselectivity were achieved.
Electromagnetic meson production in the nucleon resonance region

Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed. We give a description of current experimental facilities with electron and photon beams and present a unified derivation of most of the phenomenological approaches being used to extract the resonance parameters from the data. The analyses of π and η production data and the resulting transition form factors for the Δ(1232)P33, N(1535)S11, N(1440)P11, and N(1520)D13 resonances are discussed in detail. The status of our understanding of the reactions with production of two pions, kaons, and vector mesons is also reviewed.
Clinical Observations on Asthma in Pregnancy

We retrospectively reviewed 200 cases of asthma during pregnancy among 22,651 deliveries during a recent 3-year period. Specific attention was given to arterial blood gases during an asthmatic attack and to the course of the disease during the peripartum period. We found that the alveolar-arterial oxygen gradient was the most sensitive arterial blood gas indicator of impaired pulmonary function. The rate of preterm delivery was 16%, comparable to that of our total population. Twelve percent of patients presented in labor with an asthmatic attack. Of particular note, cesarean section was associated with an 18-fold greater relative risk of postpartum exacerbation than was vaginal delivery.
Dynamic pricing with limited supply

We consider the problem of designing revenue-maximizing online posted-price mechanisms when the seller has limited supply. A seller has k identical items for sale and is facing n potential buyers (“agents”) that are arriving sequentially. Each agent is interested in buying one item. Each agent’s value for an item is an independent sample from some fixed (but unknown) distribution with support [0,1]. The seller offers a take-it-or-leave-it price to each arriving agent (possibly different for different agents), and aims to maximize his expected revenue. We focus on mechanisms that do not use any information about the distribution; such mechanisms are called detail-free (or prior-independent). They are desirable because knowing the distribution is unrealistic in many practical scenarios. We study how the revenue of such mechanisms compares to the revenue of the optimal offline mechanism that knows the distribution (“offline benchmark”). We present a detail-free online posted-price mechanism whose revenue is at most O((k log n)2/3) less than the offline benchmark, for every distribution that is regular. In fact, this guarantee holds without any assumptions if the benchmark is relaxed to fixed-price mechanisms. Further, we prove a matching lower bound. The performance guarantee for the same mechanism can be improved to O(√k log n), with a distribution-dependent constant, if the ratio k/n is sufficiently small. We show that, in the worst case over all demand distributions, this is essentially the best rate that can be obtained with a distribution-specific constant. On a technical level, we exploit the connection to multiarmed bandits (MAB). While dynamic pricing with unlimited supply can easily be seen as an MAB problem, the intuition behind MAB approaches breaks when applied to the setting with limited supply. Our high-level conceptual contribution is that even the limited supply setting can be fruitfully treated as a bandit problem.
“Sticker Shock” in Individual Insurance under Health Reform?

We provide estimates of changes in the annual expected price for insured medical care—defined as the sum of premiums and expected out-of-pocket payments—after the Affordable Care Act (ACA) among consumers who previously bought individual insurance. Using the best available data from the Current Population Survey (CPS) and the Medical Expenditure Panel Survey (MEPS), we find that average prices did not increase substantially in California and in states with federally run exchanges. Our central estimates based on MEPS data on out-of-pocket payments suggest that average prices would not change significantly if the lowest-priced Bronze plan were selected, whereas prices would increase from 8 to 15 percent if the second-lowest-priced Silver plan were selected. (Alternative estimates using CPS data on out-of-pocket spending suggest somewhat higher price increases.) Potentially offsetting changes in the risk premium associated with moving from pre-reform coverage to either Bronze or Silver coverage are estimated...
Explaining Turnover Intention in State Government Examining the Roles of Gender, Life Cycle, and Loyalty

This article tests a model of turnover intention on a large sample of Texas state employees focusing on four issues. First, the findings support a life cycle stability hypothesis, which suggests that age, experience, and geographic preferences reduce turnover intention, an effect compounded by economic/familial constraints for primary wage earners and members of large households. Second, contrary to previous research, the results show that females are significantly less likely to state an intention to quit. This finding reflects changing patterns of labor force participation, as well as the particular advantages that the public sector offers female employees. Third, the results distinguish between the relative contributions of three overlapping concepts: organizational loyalty, voice, and empowerment. Organizational loyalty and empowerment reduce turnover intention, but voice is not a significant factor. Finally, the article provides a detailed test of different personnel policies, providing particular su...
Ring-Closing Metathesis of Allylsilanes As a Flexible Strategy toward Cyclic Terpenes. Short Syntheses of Teucladiol, Isoteucladiol, Poitediol, and Dactylol and an Attempted Synthesis of Caryophyllene

The development of a strategy consisting of allylsilane ring-closing metathesis and subsequent SE′ electrophilic desilylation (allylsilane RCM/SE′) to construct exo-methylidenecycloalkanes is described. Its utility is documented in short syntheses of teucladiol and poitediol. A key transformation in the synthesis of teucladiol is an aldol addition that establishes three stereochemical relationships in one step with ≥10:1 diastereoselectivity and provides a fascinating example of double stereodifferentiation/kinetic resolution with racemic reaction partners in the context of natural product synthesis. The synthesis of (±)-teucladiol required five steps from cyclopentenone and proceeded in 28% overall yield; adaptation of this route to an enantioselective synthesis of (−)-teucladiol enabled the determination of the absolute configuration of this terpene natural product. The use of fluoride-mediated conditions in the final desilylation step preserves the location of the alkene, delivering the natural product...
A new approach to permutation polynomials over finite fields, II

Let p be a prime and q=pκ. We study the permutation properties of the polynomial gn,q∈Fp[x] defined by the functional equation ∑a∈Fq(x+a)n=gn,q(xq−x). The polynomial gn,q is a q-ary version of the reversed Dickson polynomial in characteristic 2. We are interested in the parameters (n,e;q) for which gn,q is a permutation polynomial (PP) of Fqe. We find several families of such parameters and obtain various necessary conditions on such parameters. Initial results, both theoretical and numerical, indicate that the class gn,q contains an abundance of PPs over finite fields, many of which are yet to be explained and understood.