cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies in artificial aphasia: experiments in processing change.

Abstract Computational neurolinguistics, an integrated approach to cognitive modelling of neural processes which may subserve natural language performance, attempts to build computational models that model behavior on two levels: at the neural process level and at the human performance level in its normal state and under pathological conditions. HOPE [8–14, 17] is one example of such a model. It demonstrates how the design and implementation of such models can provide insights into how a brain-like architecture can produce a behavior as complex as natural language. This paper will briefly describe the neurally motivated or ‘natural computation’ processes which produce the model's observable and verifiable behavioral results. Experiments with artificially induced aphasia on HOPE will then be described, showing that the results of simulation produce hypothesized patient profiles that are unique. These profiles illustrate the suggested contribution of the computational neurolinguistics research approach as a tool for investigating the breakdown of language performance and its potential contribution to understanding brain function.
The Hopkins Ultraviolet Telescope: The Final Archive

The Hopkins Ultraviolet Telescope (HUT) was a 0.9 m telescope and moderate-resolution (Delta)lambda equals 3 A) far-ultraviolet (820-1850 A) spectrograph that flew twice on the space shuttle, in 1990 December (Astro-1, STS-35) and 1995 March (Astro-2, STS-67). The resulting spectra were originally archived in a nonstandard format that lacked important descriptive metadata. To increase their utility, we have modified the original datareduction software to produce a new and more user-friendly data product, a time-tagged photon list similar in format to the Intermediate Data Files (IDFs) produced by the Far Ultraviolet Spectroscopic Explorer calibration pipeline. We have transferred all relevant pointing and instrument-status information from locally-archived science and engineering databases into new FITS header keywords for each data set. Using this new pipeline, we have reprocessed the entire HUT archive from both missions, producing a new set of calibrated spectral products in a modern FITS format that is fully compliant with Virtual Observatory requirements. For each exposure, we have generated quicklook plots of the fully-calibrated spectrum and associated pointing history information. Finally, we have retrieved from our archives HUT TV guider images, which provide information on aperture positioning relative to guide stars, and converted them into FITS-format image files. All of these new data products are available in the new HUT section of the Mikulski Archive for Space Telescopes (MAST), along with historical and reference documents from both missions. In this article, we document the improved data-processing steps applied to the data and show examples of the new data products.
Numerical Prediction of Pitch Damping Stability Derivatives for Finned Projectiles

Reynolds-averaged Navier–Stokes computational fluid dynamics and linear flight mechanics theory were used to compute the pitch damping dynamic stability derivatives for two basic finned projectiles using two numerical methods, namely, the transient planar pitching method and the steady lunar coning method. Numerical results were compared with free-flight and wind-tunnel experimental data for Mach numbers in the range of 0.5–4.5. The accuracy, efficiency, and dependence of these methods on various aerodynamic and numerical modeling parameters were investigated. The numerical methods generally showed good agreement with each other, except at some transonic Mach numbers. Both methods showed good to excellent agreement with experimental data in the high transonic and supersonic Mach regimes. In the subsonic and low transonic regimes, agreement between numerical and experimental data was less favorable. The accuracy of the free-flight test data in these regimes was uncertain due to instances of large scatter, ...
Metabolic aging and predicted longevity: results of a cross-sectional study in post-menopausal women.

Background and aims: The extent to which general characteristics of metabolic aging contribute to differences in life span among individuals remains uncertain. The objective of this study was to examine the association of age-related physiological and metabolic variables with predicted longevity in post-menopausal women. Methods: Subjects were 33 healthy women aged 55–65 years. Total and resting energy expenditure, body temperature, immune function as assessed by a delayed-type hypersensitivity skin test (DTH), lipid profile, and reported dietary intake were measured. Results: There were no significant associations between longevity, energy expenditure, body temperature, lipid profile, or dietary intake. However, there was a significant association of predicted longevity with DTH (partial r=0.44, p=0.023). Conclusions: These results suggest that immune function may predict familial differences in longevity, while energy expenditure, body temperature, lipid profile, and dietary intake are unrelated. Although the small sample size may have limited the ability to detect metabolic effects on longevity in this study, the general approach may be broadly applicable to examinations of metabolic aging in humans.
Mechanisms, kinetics, and dynamics of oxidation and reactions on oxide surfaces investigated by scanning probe microscopy

Advances in scanning probe microscopies (SPM) have allowed the mechanisms and rates of adsorption, diffusion and reactions on surfaces to be characterized by directly observing the motions of the individual atoms and molecules involved. The importance of oxides as thermal and photocatalysts, chemical sensors, and substrates for epitaxial growth has motivated dynamical SPM studies of oxide surfaces and their formation. Work on the TiO(2) (110) surface is reviewed as an example of how dynamic SPM studies have revealed unexpected interactions between adsorbates and defects that influence macroscopic reaction rates. Studies following diffusion, adsorption and phase transitions on bulk and surface oxides are also discussed. A perspective is provided on advanced SPM techniques that hold great promise for yielding new insights into the mechanisms and rates of elemental processes that take place either during oxidation or on oxide surfaces, with particular emphasis on methods that extend the time and chemical resolution of dynamical SPM measurements.
A simple approach for pricing equity options with Markov switching state variables

1. IntroductionThe pricing of American options on stocks wasrendered computable by the work of Cox et al. (1979)(CRR) and the ensuing work of Jarrow and Rudd(1983). They developed a convergent option pricingscheme in a Black–Merton–Scholes world (Black andScholes 1973, Merton 1973) on a discrete-time lattice.In this setting stock prices ½SðtÞ are assumed to followa geometric Brownian motion, i.e.dSðtÞ¼ ðtÞSðtÞdtþ ðtÞSðtÞdZðtÞ , Sð0Þ S
A two-atom picture of coherent atom–molecule quantum beats

A simple two-atom model is shown to describe a Bose–Einstein condensate of alkali atoms subjected to external magnetic field ramps near a Feshbach resonance. The implications uncovered for two atoms in a trap can be applied at least approximately to a many-atom condensate. A connection to observations is accomplished by scaling the trap frequency to achieve a density comparable to that of the experiments, which yields the fraction of atom pairs in the gas that become molecules. A sudden approximation is used to model the external magnetic field ramps in the vicinity of a two-body Feshbach resonance. The results of this model are compared with recent experimental observations of Donley et al (2002 Nature 417 529).
SYNTHESIS OF CYCLOBUTANE ANALOGUES OF THE ANTIVIRAL CYCLOPROPANE NUCLEOSIDE A-5021

Cyclobutane analogues of the antiviral cyclopropane nucleoside A-5021 were synthesized from 1-cyano-1,2-bis(methoxycarbonyl)cyclobutane via 1) isolation of both diastereomers by crystallization, 2) reduction to aminodiol, 3) coupling with 2-amino-4,6-dichloropyrimidine, and 4) guanine ring formation. Despite their structural resemblance to A-5021, the compounds were devoid of antiherpetic activity.
Beyond Creole Nationalism? Language Policies, Education and the Challenge of State Building in Post-conflict Southern Sudan

Abstract This paper seeks to go beyond a focus on the role of elites in low-capacity states to consider the interaction of language policies and mass responses to these policies in southern Sudan. It reviews processes of elite formation in southern Sudan, the impact of the civil war and the current challenges facing state building there. In common with many post-colonial states, nationalism in Sudan, both north and south, has been elite led and has been characterized by persistent attempts by Khartoum-based governments to impose their conception of the Sudanese state on southern Sudan and resistance to such efforts. Official language policies in southern Sudan have alternated between English and Arabic reflecting this ongoing contestation of identity. This paper considers the impact of the most recent language policy change in favour of English from a local southern Sudanese perspective. It concludes that, while the new language policy has had an impact on people's expectations and, hence, on their profes...
Giant Molecular Outflows Powered by Protostars in L1448

These maps were acquired using the On-The-Fly (OTF) capability of the NRAO 12-meter telescope atop Kitt Peak in Arizona.
The Cosmology Large Angular Scale Surveyor (CLASS): 40 GHz Optical Design

The Cosmology Large Angular Scale Surveyor (CLASS) instrument will measure the polarization of the cosmic microwave background at 40, 90, and 150 GHz from Cerro Toco in the Atacama desert of northern Chile. In this paper, we describe the optical design of the 40 GHz telescope system. The telescope is a diffraction limited catadioptric design consisting of a front-end Variable-delay Polarization Modulator (VPM), two ambient temperature mirrors, two cryogenic dielectric lenses, thermal blocking filters, and an array of 36 smooth-wall scalar feedhorn antennas. The feed horns guide the signal to antenna-coupled transition-edge sensor (TES) bolometers. Polarization diplexing and bandpass definition are handled on the same microchip as the TES. The feed horn beams are truncated with 10 dB edge taper by a 4 K Lyot-stop to limit detector loading from stray light and control the edge illumination of the front-end VPM. The field-of-view is 19 deg x 14 deg with a resolution for each beam on the sky of 1.5 deg. FWHM.
Carbon-hydrogen bond activation over tungsten carbide catalysts

Tungsten carbides with surface areas ranging from 4 to 39 m2/g were prepared by the temperatureprogrammed carburization of tungsten oxide and nitride powders with pure CH 4 or a 48.9% CH4 in H 2 mixture. Oxygen uptakes on the carbides were low most likely because of the presence of graphitic carbon at the surface. Nevertheless, the carbides were active and selective for the dehydrogenation of butane at temperatures between 623 and 723 K and atmospheric pressure with and without n 2 in the reactant feed. With H2 in the feed, the higher surface area carbides ( _> 36 m2/g) were as active as a Pt-Sn/"y-A1203 catalyst, but their selectivities were different. Without H 2 in the feed, the selectivities of the carbides were similar to those of the Pt-Sn/'y-Al203 catalyst, but their reaction rates were 1-3 orders of magnitude lower. The high surface area materials were also active for the hydrogenolysis of butane. Because the catalytic properties of the carbides varied with the average particle size, we concluded that butane dehydrogenation was structure-sensitive over these materials, and suspected that this behavior was due to variations in the surface stoichiometry as well as the particle faceting.
Photoelectric Emission from Dust Grains Exposed to Extreme Ultraviolet and X-Ray Radiation

Photoelectric emission from dust plays an important role in grain charging and gas heating. To date, detailed models of these processes have focused primarily on grains exposed to soft radiation fields. We provide new estimates of the photoelectric yield for neutral and charged carbonaceous and silicate grains, for photon energies exceeding 20 eV. We include the ejection of electrons from both the band structure of the material and the inner shells of the constituent atoms, as well as Auger and secondary electron emission. We apply the model to estimate gas-heating rates in planetary nebulae and grain charges in quasar environments. For these applications, secondary emission can be neglected; the combined effect of inner shell and Auger emission is small, although not always negligible. Finally, we investigate the survivability of dust in quasar host galaxies. For unobscured lines of sight, dust can be destroyed out to distances ~1 kpc.
Extensions to total variation denoising

The total variation denoising method, proposed by Rudin, Osher and Fatermi, 92, is a PDE-based algorithm for edge-preserving noise removal. The images resulting from its application are usually piecewise constant, possibly with a staircase effect at smooth transitions and may contain significantly less fine details than the original non-degraded image. In this paper we present some extensions to this technique that aim to improve the above drawbacks, through redefining the total variation functional or the noise constraints.
Two-dimensional rotational spin-echo nuclear magnetic resonance in solids: correlation of chemical shift and dipolar interactions

Two-dimensional NMR techniques which sep. the chem. shift and heteronuclear dipolar interactions were applied to samples spinning at the magic angle. Because of the inhomogeneous nature of the 2 interactions, rotational echoes were obsd. in the time domain of each dimension. The corresponding Fourier transforms yield rotational sideband spectra which provide information on the principal values and relative orientations of the shift and dipolar tensors, and from the latter, internuclear distances may be calcd. The techniques therefore provide a means for obtaining structural data, for example, 13C-1H and 15N-1H distances, in powder samples. [on SciFinder (R)]
Climate variability in the Amundsen and Bellingshausen Seas

Satellite data reveal a 20% decline in sea ice extent in the Amundsen and Bellingshausen Seas in the two decades following 1973. This change is negatively correlated with surface air temperatures on the west side of the Antarctic Peninsula, which have increased ;0.58C decade21 since the mid-1940s. The recession was strongest during summer, when monthly average minima in 1991‐92 removed much of the incipient multiyear ice over the continental shelf. This would have lowered the regional-mean ice thickness, impacting snow ice formation, brine production, and vertical heat flux. The northern ice edge contracted by ;18 of latitude in all seasons from 1973‐79 to 1987‐93, returning toward mean conditions in 1993‐95. The decline included multiyear cycles of several years in length, superimposed on high interannual variability. A review of atmospheric forcing shows winds consistent with mean and extreme ice extents, and suggests links to larger-scale circulation changes in the South Pacific. Historical ocean measurements are sparse in this sector, but mixed-layer depths and upper pycnoclines beneath the sea ice resemble those in the Weddell Sea. Weaker surface currents or changes in the upwelling of Circumpolar Deep Water on the continental shelf could have contributed to the anomaly persistence.
Probing the universe at redshift 10 and beyond

Abstract The signature of objects in the very early universe lies deep in the near infrared bands. The Primordial Explorer ( PRIME ) is a proposed NASA Explorer-class mission aimed at the z > 10 universe. PRIME will find the youngest and the most luminous galaxies and quasars, thereby enabling the determination of the epoch of galaxy formation and that of reionization of the intergalactic medium.
Controlling transport and chemical functionality of magnetic nanoparticles.

A wide range of metal, magnetic, semiconductor, and polymer nanoparticles with tunable sizes and properties can be synthesized by wet-chemical techniques. Magnetic nanoparticles are particularly attractive because their inherent superparamagnetic properties make them desirable for medical imaging, magnetic field assisted transport, and separations and analyses. With such applications on the horizon, synthetic routes for quickly and reliably rendering magnetic nanoparticle surfaces chemically functional have become an increasingly important focus. This Account describes common synthetic routes for making and functionalizing magnetic nanoparticles and discusses initial applications in magnetic field induced separations. The most widely studied magnetic nanoparticles are iron oxide (Fe2O3 and Fe3O4), cobalt ferrite (CoFe2O4), iron platinum (FePt), and manganese ferrite (MnFe2O4), although others have been investigated. Magnetic nanoparticles are typically prepared under either high-temperature organic phase ...
A spanning set for VOA modules

We develop a spanning set for weak modules of C2 co-finite vertex operator algebras. This spanning set has certain finiteness properties that we use to show weak modules are Cn co-finite and An(M) is finite dimensional.
Changes in the Funded Status of Retirement Plans after the Adoption of SFAS No. 158: Economic Improvement or Balance Sheet Management?†

Statement of Financial Accounting Standards No. 158 (SFAS 158) requires all companies to report the funded status of defined benefit pension plans and other postretirement plans, such as retiree healthcare plans, on the balance sheet for fiscal years ending after December 15, 2006. Prior to this, underfunded retirement plans were often not recorded as a liability on company‟s balance sheets. At the end of 2005, the average defined benefit pension plan of the companies in this study was underfunded by $324 million and the average other postretirement plan was underfunded by $760 million. After the adoption of SFAS 158 in 2006, this average underfunding decreased. After controlling for changes in market conditions, I find that companies with debt contracting incentives to manage their balance sheets had a larger increase in their defined benefit pension plan funded status subsequent to the adoption of SFAS 158. This increase was at least partially due to the choice of assumptions used to measure the pension obligation.
On combinatorial formulas for Macdonald polynomials

A recent breakthrough in the theory of (type A) Macdonald polynomials is due to Haglund, Haiman and Loehr, who exhibited a combinatorial formula for these polynomials in terms of a pair of statistics on fillings of Young diagrams. Ram and Yip gave a formula for the Macdonald polynomials of arbitrary type in terms of so-called alcove walks; these originate in the work of Gaussent�Littelmann and of the author with Postnikov on discrete counterparts to the Littelmann path model. In this paper, we relate the above developments, by explaining how the Ram�Yip formula compresses to a new formula, which is similar to the Haglund�Haiman�Loehr one but contains considerably fewer terms
The impact of Superfund sites on local property values: Are all sites the same?☆

It is generally assumed that all Superfund sites negatively impact property values, that the impact is similar for all sites, and that the impact disappears once the site has been cleaned. This paper examines several Superfund sites across the US and finds that some have the expected impact, while others have either no impact or a positive impact on local property values. The effect does not necessarily disappear for sites that have been cleaned. Using a meta-analysis approach to examine what factors contribute to a decrease in property values, we find that larger sites in areas with fewer blue-collar workers are more likely to have a negative impact.
Agroclavine hydroxylase of Claviceps purpurea

Abstract The 60–80% ammonium sulfate fraction of Claviceps purpurea PRL 1980 catalyzed the conversion of agroclavine to elymoclavine. The reaction required NADPH. EDTA and cyanide inhibited the reaction. Agroclavine increased the rate of oxidation of NADPH. The increase in rate was 4.8 μmoles NADPH per h mg protein at 25° and pH 7.0. The pH optimum was pH 7.0–7.2. The results indicate that a mixed function oxygenase in C. purpurea PRL 1980 catalyzes the hydroxylation of agroclavine to elymoclavine with concomitant oxidation of NADPH.
MANAGE - An interactive simulation model for evaluating the effects of management structure on organization performance

This paper reports on progress to date in developing a computerized simulation - optimization model of the general management structure of a firm. This model called MANAGE, offers a framework wherein the profit performance of a company can be simulated and assessed under a variety of structural configurations. MANAGE also incorporates certain behavioral parameters that impact upon successful communication within corporate organizations. The paper describes the general framework of the model; the manner in which various structural, behavioral, and economic variables are incorporated into the model or can be set as desired by the user; and the nature of the outputs that are produced. The paper also describes the manner in which MANAGE generates profit solutions under various combinations of behavioral, heirarchical and economic conditions and compares them with traditional optimal economicsresults. The paper concludes with a brief discussion of the potential applications of MANAGE.
Conjugate Hard X-Ray Footpoints in the 2003 October 29 X10 Flare: Unshearing Motions, Correlations, and Asymmetries

We present a detailed imaging and spectroscopic study of the conjugate hard X-ray (HXR) footpoints (FPs) observed with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) in the 2003 October 29 X10 flare. The double FPs first move toward and then away from each other, mainly parallel and perpendicular to the magnetic neutral line, respectively. The transition of these two phases of FP unshearing motions coincides with the direction reversal of the motion of the loop-top (LT) source, and with the minima of the estimated loop length and LT height. We find temporal correlations between the HXR flux, spectral index, and magnetic field strength of each FP. The HXR flux exponentially correlates with the magnetic field strength, which also anticorrelates with the spectral index before the second HXR peak's maximum, suggesting that particle acceleration sensitively depends on the magnetic field strength and/or reconnection rate. Asymmetries are observed between the FPs: on average, the eastern FP is 2.2 times brighter in HXR flux and 1.8 times weaker in magnetic field strength, and moves 2.8 times faster away from the neutral line than the western FP; the estimated coronal column density to the eastern FP from the LT source is 1.7 times smaller. The two FPs have marginally different spectral indices. The eastern-to-western FP HXR flux ratio and magnetic field strength ratio are anticorrelated only before the second HXR peak's maximum. Neither magnetic mirroring nor column density alone can explain the totality of these observations, but their combination, together with other transport effects, might provide a full explanation. We have also developed novel techniques to remove particle contamination from HXR counts and to estimate effects of pulse pileup in imaging spectroscopy, which can be applied to other RHESSI flares in similar circumstances.
Measurement capabilities of planar Doppler velocimetry using pulsed lasers

Analytical models of a spectral filter that contains iodine vapor and of the noise sources associated with charge-coupled-device (CCD) detector technology are combined with a planar Doppler velocimetry (PDV) signal analysis to evaluate the measurement capabilities of PDV for quantitative aerodynamic research and production wind-tunnel testing applications. The criteria for optimizing the filter cell and calibrating the frequency scale of its transmission function are described. The measurement uncertainty limits owing to scientific-grade CCD detector performance are then evaluated, and an analysis is developed of the scattering properties of aerosols suitable for aerodynamic flow seeding. The combined results predict that single-pulse PDV measurements with velocity measurement uncertainties as small as 2 m/s should be possible in aerodynamic test facilities for measurement distances of tens of meters.
The new look pMSSM with neutralino and gravitino LSPs

The pMSSM provides a broad perspective on SUSY phenomenology. In this paper we generate two new, very large, sets of pMSSM models with sparticle masses extending up to 4 TeV, where the lightest supersymmetric particle (LSP) is either a neutralino or gravitino. The existence of a gravitino LSP necessitates a detailed study of its cosmological effects and we find that Big Bang Nucleosynthesis places strong constraints on this scenario. Both sets are subjected to a global set of theoretical, observational and experimental constraints resulting in a sample of ∼225k viable models for each LSP type. The characteristics of these two model sets are briefly compared. We confront the neutralino LSP model set with searches for SUSY at the 7 TeV LHC using both the missing (MET) and non-missing ET ATLAS analyses. In the MET case, we employ Monte Carlo estimates of the ratios of the SM backgrounds at 7 and 8 TeV to rescale the 7 TeV data-driven ATLAS backgrounds to 8 TeV. This allows us to determine the pMSSM parameter space coverage for this collision energy. We find that an integrated luminosity of ∼5–20 fb−1 at 8 TeV would yield a substantial increase in this coverage compared to that at 7 TeV and can probe roughly half of the model set. If the pMSSM is not discovered during the 8 TeV run, then our model set will be essentially void of gluinos and lightest first and second generation squarks that are ≲700–800 GeV, which is much less than the analogous mSUGRA bound. Finally, we demonstrate that non-MET SUSY searches continue to play an important role in exploring the pMSSM parameter space. These two pMSSM model sets can be used as the basis for investigations for years to come.
Oxidative Reactivity and Cytotoxic Properties of a Platinum(II) Complex Prepared by Outer-Sphere Amide Bond Coupling.

Abstract Benzyl amine was coupled to the dangling carboxylic acid groups of the platinum(II) complex [Pt(edda)Cl2], where edda = ethylenediamine-N,N′-diacetic acid, to give the diamide-tethered complex [Pt(L)Cl2] (1), where L = ethylenediamine-N,N′-bis(N-benzylacetamide). Complex 1 was oxidized with both PhICl2 and Br2. Oxidation with PhICl2 cleanly afforded the tetrachloride complex, [Pt(L)Cl4] (2), whereas oxidation with Br2 gave rise to several mixed halide complexes of the general formula, [Pt(L)ClxBr4-x], where x = 1, 2, or 3. Complexes 1 and 2 were fully characterized by 1H, 13C, and 195Pt NMR spectroscopy, as well as by ESI-MS. These compounds exist as a mixture of diastereomers that arise from the chirality of the two coordinated nitrogen atoms. Crystal structures of 1, 2, and [Pt(L)ClxBry] (3) are reported. Although refined as the tetrabromide complex [Pt(L)Br4], the crystal structure of 3 is a mixture of species with site-occupancy disorder of chloride and bromide ligands. DFT calculations indicate that the two sets of diastereomers of 1 and 2 are effectively thermoneutral, a conclusion that is also supported by the observation of both members of each pair by NMR spectroscopy. The cytotoxicity of 1 and 2 was measured by the MTT assay in HeLa cells and compared to that of cisplatin. Both exhibit IC50 values close to 50 μM and are therefore substantially less toxic than cisplatin, for which the IC50 is 1 μM.
African Americans’ pursuit of self-employment

We examine causes of black/white gaps in self-employment entry rates in the United States by recognizing that industry context heavily shapes impacts of owner resource endowments on the likelihood of successful entry. Barriers to entry, briefly stated, are high in some lines of business and low in others. We therefore proceed by explaining self-employment entry into separate subgroups of high- and low-barrier industries. Higher entry rates typifying whites, relative to African Americans, are traditionally interpreted as reflections of the former group’s greater personal wealth and human-capital resources. This consensus view, however, is simplistic: personal wealth holdings have no positive explanatory power for predicting entry into low-barrier lines of business. Our findings demonstrate, furthermore, that high educational attainment is a strong, positive predictor of entry into high-barrier fields, but not into low-barrier industries. Because industry context indeed shapes entry patterns, “one-size-fits-all” econometric models commonly used to predict entry into self-employment fall short.
Theory of convective droplet vaporization with unsteady heat transfer in the circulating liquid phase

Abstract The problem of liquid droplet vaporization in a hot convective gaseous environment is analyzed. A new gas-phase viscous, thermal and species concentration boundary layer analysis is developed using an integral approach. The gas-phase analysis is coupled with a modified form of a previous liquid-phase analysis for the internal motion and heat transfer [S. Prakash and W. A. Sirignano, Int. J. Heat Mass Transfer21, 885–895 (1978)]. The coupled problem is solved for three hydrocarbon fuels (n-hexane, n-decane, and n-hexadecane). The results show that the droplet vaporization is unsteady, and that the temperature distribution within the droplet is nonuniform for a significant part of the droplet lifetime. Some of the results are compared with the already existing correlations after correcting them for the heat flux into the liquid phase.
Current account dynamics and degree of capital mobility

By modelling the current account balances (as a percentage of GDP) in a dynamic AR(1) model, Taylor (2002) proposed to use speed of mean reversion of the dynamics of the current account as a tool for measurement of capital mobility and confirmed the stylized fact of U-Shape degree of capital mobility through the last two centuries with this new approach. With the assumption that countries obey their Long-Run Budget Constraint (LRBC), the OLS estimate of the degree of current account persistency in Taylor (2002) is downward bias due to small sample and high serial correlation of current account ratios with its lags. By correcting these biases with the Andrews (1993) exact median-unbiased estimation, we find that the confidence intervals for half-life estimates include 1 year (which was used as a benchmark) in 37 out of 75 country–period cases, which cast some doubt on the use of half-life estimate as a practical measure of capital mobility.
XML and information retrieval: a SIGIR 2000 workshop

XML - the eXtensible Markup Language has recently emerged as a new standard for data representation and exchange on the Interact. It is believed that it will become a universal format for data exchange on the Web and that in the near future we will find vast amounts of documents in XML format on the Web. As a result, it has become crucial to address the question of how large collections of XML documents can be sorted and retrieved efficiently and effectively.To date, most work on storing, indexing, querying, and searching documents in XML has stemmed from the database community's work on semi-structured data. An alternative approach, that has received less attention to date, is to view XML documents as a collection of text documents with additional tags and relations between these tags. IR techniques have traditionally been applied to search large sets of textual data and should thus be extended to encode the structure and semantics inherent in XML documents. Integrating IR and XML search techniques will enable more sophisticated search on the structure as well as the content of these documents, while leveraging the success of IR techniques in document similarity ranking and keyword search.The SIGIR workshop on XML and information retrieval was held July 28th, in Athens Greece. The goal of the workshop was to bring together researchers and practitioners interested in XML and IR to discuss and define the most relevant topics in the relation between these two technologies, present recent results, and propose future directions for research. The topics for discussion included:• How to extend IR technologies to search XML documents• How to integrate XML structure in IR indexing structures• How to query XML documents both on content and structure• How to introduce the semantics inherent in XML into the search process• How to adopt database indexing techniques in an IR frameworkThe opening session of the workshop consisted of a survey of search engines for XML documents. This was followed by three technical sessions: query languages, retrieval algorithms, and IR systems for XML documents. The final talk of the day, "Searching Annotated Language Resources in XML", by Nancy Ide was given from the perspective of potential users of XML search systems and opened many topics for discussion. The workshop was concluded with a panel discussion where the panelists outlined their vision of the future of XML search.
Dynamic critical behavior of the classical anisotropic BCC Heisenberg antiferromagnet

Abstract Using a recently implemented integration method [Krech et al.] based on an iterative second-order Suzuki–Trotter decomposition scheme, we have performed spin dynamics simulations to study the critical dynamics of the BCC Heisenberg antiferromagnet with uniaxial anisotropy. This technique allowed us to probe the narrow asymptotic critical region of the model and estimate the dynamic critical exponent z=2.25±0.08. Comparisons with competing theories and experimental results are presented.
Ab initio study of the low-temperature phases of lithium imide

We present a low-temperature structural model for lithium imide $({\text{Li}}_{2}\text{NH})$ that is consistent with experimental studies. Using the cluster expansion formalism and density-functional theory, we have identified a low-energy crystal structure for lithium imide with 96 atoms per unit cell. This low-energy structure is consistent with experimental diffraction patterns, and we propose that the symmetry of the structure may be increased at finite temperature due to thermal fluctuations. In addition, our results suggest that lithium motion is relatively facile between octahedral and tetrahedral sites, which may help explain how lithium diffuses through this material.
Biosynthesis of cyanogenic glycosides

Cyanogenic glycosides are secondary plant compounds that occur widely in the plant kingdom. They are the source of HCN which can render the plant toxic if it is taken as food. The enzymes responsible for production of the HCN have long been known. More recent biosynthetic studies have established certain protein amino acids as precursors of the aglycones, and indicate N-hydroxyamino acids, aldoximes, nitriles and α-hydroxynitriles as intermediates. In sorghum the several biosynthetic enzymes catalyzing the flow of carbon atoms from l-tyrosine through such nitrogenous intermediates are located in a membrane fraction and may be capable of metabolic channeling.
Effective theories for real-time correlations in hot plasmas

We discuss the sequence of effective theories needed to understand the qualitative, and quantitative, behavior of real-time correlators hA (t)A(0)i in ultrarelativistic plasmas. We analyze in detail the case where A is a gauge-invariant conserved current. This case is of interest because it includes a correlation recently measured in lattice simulations of classical, hot, SU(2)-Higgs gauge theory. We find that simple perturbation theory, free kinetic theory, linearized kinetic theory, and hydrodynamics are all needed to understand the correlation for different ranges of time. We emphasize how correlations generically have power-law decays at very large times due to non-linear couplings to long-lived hydrodynamic modes.
The hysteretic Hopfield neural network

A new neuron activation function based on a property found in physical systems-hysteresis-is proposed. We incorporate this neuron activation in a fully connected dynamical system to form the hysteretic Hopfield neural network (HHNN). We then present an analog implementation of this architecture and its associated dynamical equation and energy function. We proceed to prove Lyapunov stability for this new model, and then solve a combinatorial optimization problem (i.e., the N-queen problem) using this network. We demonstrate the advantages of hysteresis by showing increased frequency of convergence to a solution, when the parameters associated with the activation function are varied.
THE DETERMINATION OF REDDENING FROM INTRINSIC VR COLORS OF RR LYRAE STARS

New R-band observations of 21 local field RR Lyrae variable stars are used to explore the reliability of minimum light (V - R) colors as a tool for measuring interstellar reddening. For each star, R-band intensity mean magnitudes and light amplitudes are presented. Corresponding V-band light curves from the literature are supplemented with the new photometry, and (V - R) colors at minimum light are determined for a subset of these stars as well as for other stars in the literature. Two different definitions of minimum light color are examined, one which uses a Fourier decomposition to the V and R light curves to find (V - R) at minimum V-band light, (V - R) {sup F} {sub min}, and the other which uses the average color between the phase interval 0.5-0.8, (V - R){sup {phi}}{sup (0.5-0.8)} {sub min}. From 31 stars with a wide range of metallicities and pulsation periods, the mean dereddened RR Lyrae color at minimum light is (V - R) {sup F} {sub min,0} = 0.28 {+-} 0.02 mag and (V - R){sup {phi}}{sup (0.5-0.8)} {sub min,0} = 0.27 {+-} 0.02 mag. As was found by Guldenschuh et al. using (V - I) colors, any dependencemore » of the star's minimum light color on metallicity or pulsation amplitude is too weak to be formally detected. We find that the intrinsic (V - R) of Galactic bulge RR Lyrae stars are similar to those found by their local counterparts and hence that bulge RR0 Lyrae stars do not have anomalous colors as compared to the local RR Lyrae stars.« less
Biosynthetic origin of [7.7]paracyclophanes from cyanobacteria

Abstract The biosyntheses of nostocyclophane D ( 1 ) and cylindrocyclophane D ( 2 ) have been investigated by the administration of sodium [1,2- 13 C 2 ]acetate, sodium [1- 13 C, 2 H 3 ]acetate, sodium [2- 13 C, 2 H 3 ]acetate, sodium [ 2 H 3 ]acetate, sodium [1- 13 C, 18 O 2 ]acetate, sodium [2- 13 C, 18 O 2 ]acetate, l -[methyl- 13 C]methionine, and l -[methyl- 13 C, 2 H 3 ]methionine to cultures of the cyanobacteria Nostoc linckia and Cylindrospermum licheniforme , respectively. The isotopically labeled compounds produced by these feeding experiments indicate that the structural skeletons of these [7.7]paracyclophanes are polyketides that have been constructed by dimerization of acetate-derived nonaketides. Acetate has also been identified as the source of the branched methyl groups in cylindrocyclophane D.
An essential role for Frizzled5 in neuronal survival in the parafascicular nucleus of the thalamus

Frizzled5 (Fz5), a putative Wnt receptor, is expressed in the retina, hypothalamus, and the parafascicular nucleus (PFN) of the thalamus. By constructing Fz5 alleles in which beta-galactosidase replaces Fz5 or in which Cre-mediated recombination replaces Fz5 with alkaline phosphatase, we observe that Fz5 is required continuously and in a cell autonomous manner for the survival of adult PFN neurons, but is not required for proliferation, migration, or axonal growth and targeting of developing PFN neurons. A motor phenotype associated with loss of Fz5 establishes a role for the PFN in sensorimotor coordination. Transcripts coding for Wnt9b, the likely Fz5 ligand in vivo, and beta-catenin, a mediator of canonical Wnt signaling, are both downregulated in the Fz5(-/-) PFN, implying a positive feedback mechanism in which Wnt signaling is required to maintain the expression of Wnt signaling components. These data suggest that defects in Wnt-Frizzled signaling could be the cause of neuronal loss in degenerative CNS diseases.
Production and utilization of computer manpower in U.S. higher education

During the past five years the Computer Science Project of the Southern Regional Education Board (SREB) has conducted three surveys on Computers in U.S. Higher Education including their utilization and related educational programs. These studies have resulted in three publications the first by the SREB and the latter two by the National Science Foundation.
Closed Continuous-Flow Centrifuge

Guest Editor's Introduction: The introduction of the NCI/IBM 2990 Blood Cell Separator made possible the processing of plasma and white cells by uninterrupted whole blood flow through a centrifugal apparatus. The story of the development of the separator relates the involvement of G.T. Judson whose son suffered from leukemia. Judson, a research engineer with IBM, and Freireich at the National Cancer Institute designed and fabricated a prototype device that would therapeutically remove WBCs. The initial emphasis on WBC removal later shifted to plasma removal. This paper reprinted here with permission was printed in Nature vol. 217, page 816–818 (1968), and describes the basic design and operational details of the device.
Cutting sequences, regular polygons, and the Veech group

We describe the cutting sequences associated to geodesic flow on regular polygons, in terms of a combinatorial process called derivation. This work is an extension of some of the ideas and results in Smillie and Ulcigrai’s recent paper, where the analysis was made for the regular octagon. It turns out that the main structural properties of the octagon generalize in a natural way.
Asymptotics of random lozenge tilings via Gelfand–Tsetlin schemes

A Gelfand–Tsetlin scheme of depth $$N$$ is a triangular array with $$m$$ integers at level $$m$$ , $$m=1,\ldots ,N$$ , subject to certain interlacing constraints. We study the ensemble of uniformly random Gelfand–Tsetlin schemes with arbitrary fixed $$N$$ th row. We obtain an explicit double contour integral expression for the determinantal correlation kernel of this ensemble (and also of its $$q$$ -deformation). This provides new tools for asymptotic analysis of uniformly random lozenge tilings of polygons on the triangular lattice; or, equivalently, of random stepped surfaces. We work with a class of polygons which allows arbitrarily large number of sides. We show that the local limit behavior of random tilings (as all dimensions of the polygon grow) is directed by ergodic translation invariant Gibbs measures. The slopes of these measures coincide with the ones of tangent planes to the corresponding limit shapes described by Kenyon and Okounkov (Acta Math 199(2):263–302, 2007). We also prove that at the edge of the limit shape, the asymptotic behavior of random tilings is given by the Airy process. In particular, our results cover the most investigated case of random boxed plane partitions (when the polygon is a hexagon).
Dynamic State Estimation of a Synchronous Machine Using PMU Data: A Comparative Study

Accurate information about dynamic states is important for efficient control and operation of a power system. This paper compares the performance of four Bayesian-based filtering approaches in estimating dynamic states of a synchronous machine using phasor measurement unit data. The four methods are extended Kalman filter, unscented Kalman filter, ensemble Kalman filter, and particle filter. The statistical performance of each algorithm is compared using Monte Carlo methods and a two-area-four-machine test system. Under the statistical framework, robustness against measurement noise and process noise, sensitivity to sampling interval, and computation time are evaluated and compared for each approach. Based on the comparison, this paper makes some recommendations for the proper use of the methods.
Gold(I)-Catalyzed Enantioselective Carboalkoxylation of Alkynes

A highly enantioselective carboalkoxylation of alkynes catalyzed by cationic (DTBM-MeO-Biphep)gold(I) complexes is reported. Various optically active β-alkoxyindanone derivatives were obtained in good yields with high enantioselectivities. Furthermore, this methodology was extended to the enantioselective synthesis of 3-methoxycyclopentenones. The reaction is proposed to proceed through an enantioselective cyclization of intermediates containing vinylgold(I) and prochiral oxocarbenium moieties.
On second variation of Perelman’s Ricci shrinker entropy

In this paper we provide a detailed proof of the second variation formula, essentially due to Richard Hamilton, Tom Ilmanen and the first author, for Perelman’s ν-entropy. In particular, we correct an error in the stability operator stated in Theorem 6.3 of (Cao in Adv Lect Math 11:1–38, 2010). Moreover, we obtain a necessary condition for linearly stable shrinkers in terms of the least eigenvalue and its multiplicity of certain Lichnerowicz type operator associated to the second variation.
Proline-based P, N ligands in asymmetric allylation and the Heck reaction.

A series of phosphine−oxazoline ligands based on proline are reported. These ligands are synthesized from commercially available trans-4-hydroxy-l-proline in four steps. The ability of this type of ligand to catalyze allylic alkylation in an asymmetric fashion as well as the asymmetric Heck reaction is reported. The best of these ligands gave a palladium complex, which catalyzed the addition of dimethylmalonate to cyclopentenyl acetate in excellent yield and up to 96% ee. This same system catalyzed the Heck reaction between dihydrofuran and cyclohexene in up to 86% ee. These ligands appear to differ from the traditional phosphine−oxazoline ligands in that the stereochemistry of the stereogenic carbon next to the oxazoline is not necessarily the dominant chiral center in the induction of selectivity.
(Perfluoroalkyl)polyfluoroarenes by copper-promoted cross-coupling of perfluoroalkyl halides and polyfluoroarenes

Abstract Group 11 and 12 metals act as halogen acceptors to promote a selective cross-coupling between perfluoroalkyl halides and polyfluoroarenes to give (perfluoroalkyl)polyfluoroarenes. This reaction is a non-catalytic, fluorine analog of Friedel-Crafts alkylation in hydrocarbon chemistry.