cssi/SciSciGPT-SciSciNet huggingface dataset:
Examination of the role of the duocarmycin SA methoxy substituents: Identification of the minimum, fully potent DNA binding subunit

Abstract The preparation and examination of 4–7 revealed that (+)- 5 and (+)-duocarmycin SA were indistinguishable. In contrast, 6 and 7 exhibited properties more analogous to 4 illustrating that the C6 and C7 methoxy substituents of duocarmycin SA contribute little or nothing to its properties. Thus, the C5 methoxy substituent of the 5,6,7-trimethoxyindole subunit of duocarmycin SA is necessary and sufficient for observation of the full potency of the natural product.
Engineering Feasibility of Induced Strain Actuators for Rotor Blade Active Vibration Control

Rotor blade vibration reduction based on Higher Harmonic Control—Individual Blade Control (HHC-IBC) principles is presented as a possible area of application of Induced Strain Actuation (ISA). Recent theoretical and experimental work on achieving HHC-IBC through conventional and ISA means is reviewed. Though the force-displacement and power-energy estimates vary significantly, some common-base values are identified. Hence, a bench-mark specification for a tentative HHC-IBC device based on the aerodynamic servo-flap principle operated through ISA means is developed. Values for the invariant quantities of energy, power and force-displacement product are identified, along with actual displacement and force values of practical interest. The implementation feasibility of this specification into an actual ISA device is then discussed. It is shown that direct actuation is not feasible due to the large required length of the ISA device, resulting in excessive compressibility effects (displacement loss and parasit...
Self-synchronous parametric amplification using Josephson junctions

A new way to use Josephson junctions for parametric amplification with phase control is proposed. The dc current bias of the junction is adjusted such that the Josephson oscillation automatically synchronizes with the input signal and oscillates at twice the signal frequency with the proper relative phase. The impedance of the junction then has a negative resistive component which can be used for amplification. Extension to other phase sensitive circuits is also discussed.
Radiocarbon dating of prehistoric rock paintings by selective oxidation of organic carbon

DATING of prehistoric rock paintings (pictographs) has traditionally relied on indirect evidence. This includes inferences based on the archaeological context, such as superpositions of pictorial styles1 and the depiction of images that constrain their ages1,2, as well as dating of deposits that either cover the art in situ3,4 or contain separated fragments of the painted surface5. Migration of ions between the bulk rock and the natural coatings that form on a newly exposed surface has also been exploited to date petroglyphs (rock carvings) in desert regions6–13. Until recently14–17, however, direct dating (by radiocarbon techniques) of pictographs has not been possible18,19, mainly because of the problem of separating inorganic carbon from the organic material in the pigments. Here we report on a new technique which allows this separation to be effected by using a low-temperature, low-pressure oxygen plasma to oxidize selectively the organic component; this may then be analysed using standard14C methods. We have applied this technique to a portion of a pictograph from the Lower Pecos region of southwest Texas (Fig. 1). The date obtained, 3,865±100 yr BP (before present) is consistent with that expected on the basis of archaeological inference20. As organic carbon is a ubiquitous component of pictograph paints, this technique should be applicable to rock paintings throughout the world.
ON HIGHER ARTHUR-MERLIN CLASSES

We study higher Arthur-Merlin classes defined via several natural probabilistic operators BP, R and coR. We investigate the complexity classes they define, and a number of interactions between these operators and the standard polynomial time hierarchy. We prove a hierarchy theorem for these higher Arthur-Merlin classes involving interleaving operators, and a theorem giving non-trivial upper bounds to the intersection of the complementary classes in the hierarchy.
Young people's digital lives: The impact of interpersonal relationships and digital media use on adolescents' sense of identity

The current study investigates the joint effects of interpersonal relationships and digital media use on adolescents' sense of identity. Questionnaires were administered to a sample of 2079 students (57% female) between the ages of 11 and 19years (M=15.4years) attending one of seven secondary schools in Bermuda. Using structural equation modeling, the author found that mothers and friends play an important role in adolescents' lives, with both relationships contributing in positive ways to respondents' self-concept clarity. Further, the results showed that mother relationship quality affected adolescents' self-concept clarity both directly and indirectly, through the positive impact it had on friendship quality. Friends also played a mediating role in relation to aspects of adolescents' digital media use. Specifically, the negative association detected between online identity expression/exploration and self-concept clarity was mediated partially by low friendship quality. Going online to communicate with one's friends appeared to play a more positive role in adolescents' sense of identity. The results showed that online peer communication affected self-concept clarity indirectly through its positive impact on friendship quality.
Steady-state radiative cooling rates for low-density, high-temperature plasmas

Abstract For 47 elements in the range 2 ≤ Z ≤ 92, steady-state radiative cooling rates, average charge states 〈 Z 〉, and mean-square charge states 〈 Z 2 〉 have been calculated for low-density, high-temperature plasmas ( n e ≲ 10 16 electrons/cm 3 and T = 0.002–100 keV). The average-ion model described in the Appendix was used. The 47 materials treated include many materials of interest in controlled fusion research. The results are presented in graphs and tables. The graphs show curves calculated from the model and least-squares polynomial fits to these curves. The tables present coefficients for the least-squares fits.
A removable auxiliary for amidomercuration reactions: The stereoselective preparation of substituted n-acyl pyrrolidines and piperidines☆

Abstract Salicylamide condenses with γ,δ- or δ,e-unsaturated aldehydes to give cyclic amidals which readily undergo diastereoselective mercury(II)-mediated amidocyclization. The resulting products serve as versatile intermediates for further elaboration as nitrogen heterocycles.
New multi-scale supersymmetric models with flavor changing neutral current suppression

Abstract We discuss the phenomenology of a class of supersymmetric models in which some of the quark and lepton superfields are an integral part of a dynamical supersymmetry breaking sector. The corresponding squarks and sleptons are much heavier than any other superpartners, and could naturally have masses as high as ∼ 40 TeV. We discuss a general set of conditions for acceptable flavor-changing neutral currents and natural electroweak symmetry breaking, and identify two particularly interesting new classes of theories. We discuss how phenomenological signatures of such multi-scale models at the CERN LEP II and Fermilab Tevatron colliders could significantly differ from previously considered scenarios. In particular, we give experimental signals which could be present if the left-handed selectron is much lighter than the right-handed one.
Managed competition in health care reform: just another American dream, or the perfect solution?

Throughout the post-World War II decades, the United States has wrestled in its own unique style with a problem that is shared by all modern societies: how to achieve a reasonably equitable distribution of health care, without losing control of total spending on health care, and without suffocating the delivery system with controls and regulations that inhibit technical progress. Because an equitable distribution of health care inevitably requires at least some government regulation, and because government regulations tend to impose rigidity on any system, it is widely believed in the United States (and elsewhere) that a trade-off actually exists between fairness in the distribution of care and the health system’s ability to innovate. This troublesome trade-off bedevils American policy makers to this day.
Dusty plasmas : A topical review

Ionized gases laden with fine charged dust grains, referred to as dusty plasmas, occur in a wide variety of cosmic and terrestrial environments. Dust is an almost ubiquitous component of the space environment, and occurs in laboratory plasmas including plasmas used for processing, and the novel crystallized dusty plasmas. In this review, selected topics in the physics of dusty plasmas are considered, with an emphasis on strongly coupled dusty plasmas. This includes a parameter survey of dusty plasmas, and discussion of dust charging mechanisms, some characteristics of dust Coulomb crystals, and effects of strong coupling on dust acoustic waves.
The Proton Distribution Function in Weakly Magnetized Turbulent Plasmas

We calculate the proton distribution function due to heating by subsonic, Alfvenic turbulence in a weakly magnetized collisionless plasma. The distribution function is nonthermal. For nonrelativistic energies it is an exponential of the magnitude of the proton velocity. For ultrarelativistic energies, it can be characterized as a power law with a momentum-dependent slope. We briefly discuss the implications of this work for gamma-ray emission (via pion decay) from hot accretion flows.
Comparison of pressure-transient response in intensely and sparsely fractured reservoirs

In this paper a comprehensive analytical model is presented to quantify the pressure-transient behavior of a naturally fractured reservoir with a continuous matrix-block-size distribution and interporosity skin. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Drawdown and interference type curves are developed with rectangular probability density functions. The results obtained extend previous dual-porosity models by incorporating fracture spacing variability. In the absence of interporosity skin, intensely and sparsely fractured reservoirs show distinctions in the pressure response. Uniformity of a fractured reservoir also significantly affects pressure responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block-size variability, for example, can exhibit a nonfractured (homogeneous) reservoir response. The results may be used to estimate matrix-block-size variability and the degree of fracture intensity from drawdown and interference well tests.
A note on supersymmetry breaking

Abstract Using a simple observation based on holomorphy, we argue that any model which spontaneously breaks supersymmetry for some range of a parameter will do so generically for all values of that parameter, modulo some isolated exceptional points. Conversely, a model which preserves supersymmetry for some range of a parameter will also do so everywhere except at isolated exceptional points. We discuss how these observations can be useful in the construction of new models which break supersymmetry and discuss some simple examples. We also comment on the relation of these results to the Witten index.
The effect of ICRF on the Alcator C scrape-off layer plasma

Abstract This paper presents a characterization of the Alcator C scrape-off layer (SOL) plasma during ICRF second harmonic hydrogen fast wave heating experiments. The SOL plasma parameters were measured using a multifunctional probe, Janus, which is capable of simultaneously measuring the ion and electron parameters both parallel and antiparallel with respect to the toroidal magnetic field. The probe data indicate, at low value of injected RF power, that there is direct edge heating and density increases at radii greater than that of the antenna Faraday shield. Increasing the injected RF power spreads both the temperature and density increases throughout the edge region, flattening the radial profiles. Varying the position of the resonance layer in the main plasma does not significantly change the effect of ICRF on the SOL parameters. Given this single spatial point characterization of the SOL, a crude estimate of power flow into and through the edge plasma indicate that ≈ 20% of the ICRF power launched from the antenna is absorbed directly in the SOL plasma. Additional observation of the impurity source rates confirms the conclusions of an earlier paper, which attributed increasing central densities of high-Z impurities to the increase in physical sputtering rate at both the ICRF antenna's Faraday shield.
Perpetuities in fair leader election algorithms

We consider a broad class of fair leader election algorithms, and study the duration of contestants (the number of rounds a randomly selected contestant stays in the competition) and the overall cost of the algorithm. We give sufficient conditions for the duration to have a geometric limit distribution (a perpetuity built from Bernoulli random variables), and for the limiting distribution of the total cost (after suitable normalization) to be a perpetuity. For the duration, the proof is established via convergence (to 0) of the first-order Wasserstein distance from the geometric limit. For the normalized overall cost, the method of proof is also convergence of the first-order Wasserstein distance, augmented with an argument based on a contraction mapping in the first-order Wasserstein metric space to show that the limit approaches a unique fixed-point solution of a perpetuity distributional equation. The use of these two steps is commonly referred to as the contraction method.
Allenyl azide cycloaddition chemistry. photochemical initiation and CuI mediation leads to improved regioselectivity.

Irradiation of 2-(3-alkenyl)allenylphenyl azides in the presence of excess CuI furnished functionalized 2,3-cyclopentenylindoles in good yield with only trace amounts of competitive C−N-bonded regioisomeric products. These results represent a significant departure from the modest-to-nonexistent regioselectivity that attended thermal cyclization of these allenyl azide substrates.
Compositions of Polynomials with Coefficients in a Given Field

Abstract Let F ⊂ K be fields of characteristic 0, and let K [ x ] denote the ring of polynomials with coefficients in K . Let p ( x ) = ∑ k = 0 n a k x k ∈ K [ x ], a n ≠ 0. For p ∈ K [ x ]\ F [ x ], define D F ( p ), the F deficit of p , to equal n − max{0 ≤ k ≤ n : a k ∉ F }. For p ∈ F [ x ], define D F ( p ) = n . Let p ( x ) = ∑ k = 0 n a k x k and let q ( x ) = ∑ j = 0 m b j x j , with a n ≠ 0, b m ≠ 0, a n , b m ∈ F , b j ∉ F for some j ≥ 1. Suppose that p ∈ K [ x ], q ∈ K [ x ]\ F [ x ], p , not constant. Our main result is that p ∘ q ∉ F [ x ] and D F ( p ∘ q ) = D F ( q ). With only the assumption that a n b m ∈ F , we prove the inequality D F ( p ∘ q ) ≥ D F ( q ). This inequality also holds if F and K are only rings. Similar results are proven for fields of finite characteristic with the additional assumption that the characteristic of the field does not divide the degree of p . Finally we extend our results to polynomials in two variables and compositions of the form p ( q ( x , y )), where p is a polynomial in one variable.
Spectrally resolved neurophotonics: the optical BOLD effect and vascular components in the mammalian brain

We developed a broad band spectral technique that is independent of the light transport modality to separate optical changes in scattering and absorption in the cat’s brain due to the hemodynamic signal following visual stimulation.
Bridged Links and Tangle Presentations of Cobordism Categories

Abstract We develop a calculus of surgery data, called bridged links , which involves besides links also pairs of balls that describe one-handle attachments. As opposed to the usual link calculi of Kirby and others this description uses only elementary, local moves (namely modifications and isolated cancellations), and it is valid also on non-simply connected and disconnected manifolds. In particular, it allows us to give a presentation of a 3-manifold by doing surgery on any other 3-manifold with the same boundary. Bridged link presentations on unions of handlebodies are used to give a Cerf-theoretical derivation of presentations of 2+1-dimensional cobordisms categories in terms of planar ribbon tangles and their composition rules. As an application we give a different, more natural proof of the Matveev–Polyak presentations of the mapping class groups, and, furthermore, find systematically surgery presentations of general mapping tori. We discuss a natural extension of the Reshetikhin Turaev invariant to the calculus of bridged links. Invariance follows now—similar as for knot invariants—from simple identifications of the elementary moves with elementary categorical relations for invariances or cointegrals, respectively. Hence, we avoid the lengthy computations and the unnatural Fenn–Rourke reduction of the original proofs. Moreover, we are able to start from a much weaker “modularity”-condition, which implies the one of Turaev. Generalizations of the presentation to cobordisms of surfaces with boundaries are outlined.
Entropy-driven phase separation and configurational correlations on a lattice: some rigorous results.

We prove that if there is a phase separation in a fully packed (FP) athermal system, it must be between pure components only. We then rigorously demonstrate that no phase separation in an athermal FP state of hard particle mixtures on a lattice is possible merely due to size disparity or nonadditivity, if the configurations are weakly correlated, i.e., are quasirandom. We consider a mixture of linear polymers at all packing fractions and argue that no phase separation is possible in an athermal state. The last result also applies to a mixture of flexible particles and hard dimers. Our results contradict many recent numerical results.
N-linked glycan profiling of GGTA1/CMAH knockout pigs identifies new potential carbohydrate xenoantigens.

Background The temporary or long-term xenotransplantation of pig organs into people would save thousands of lives each year if not for the robust human antibody response to pig carbohydrates. Genetically engineered pigs deficient in galactose α1,3 galactose (gene modified: GGTA1) and N-glycolylneuraminic acid (gene modified: CMAH) have significantly improved cell survival when challenged by human antibody and complement in vitro. There remains, however, a significant portion of human antibody binding. Methods To uncover additional xenoantigens, we compared the asparagine-linked (N-linked) glycome from serum proteins of humans, domestic pigs, GGTA1 knockout pigs, and GGTA1/CMAH knockout pigs using mass spectrometry. Carbohydrate structures were determined with assistance from GlycoWorkbench, Cartoonist, and SimGlycan software by comparison to existing database entries and collision-induced dissociation fragmentation data. Results Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis of reduced and solid-phase permethylated glycans resulted in the detection of high-mannose, hybrid, and complex type N-linked glycans in the 1000–4500 m/z ion range. GGTA1/CMAH knockout pig samples had increased relative amounts of high-mannose, incomplete, and xylosylated N-linked glycans. All pig samples had significantly higher amounts of core and possibly antennae fucosylation. Conclusions We provide for the first time a comparison of the serum protein glycomes of the human, domestic pig, and genetically modified pigs important to xenotransplantation.
Improving the recognition of fingerprint biometric system using enhanced image fusion

Fingerprints recognition systems have been widely used by financial institutions, law enforcement, border control, visa issuing, just to mention few. Biometric identifiers can be counterfeited, but considered more reliable and secure compared to traditional ID cards or personal passwords methods. Fingerprint pattern fusion improves the performance of a fingerprint recognition system in terms of accuracy and security. This paper presents digital enhancement and fusion approaches that improve the biometric of the fingerprint recognition system. It is a two-step approach. In the first step raw fingerprint images are enhanced using high-frequency-emphasis filtering (HFEF). The second step is a simple linear fusion process between the raw images and the HFEF ones. It is shown that the proposed approach increases the verification and identification of the fingerprint biometric recognition system, where any improvement is justified using the correlation performance metrics of the matching algorithm.
No early warning signals for stochastic transitions: insights from large deviation theory

In the study of Boettiger & Hastings [[1][1]], we demonstrated that conditioning on observing a purely stochastic transition from one stable basin to another could generate time-series trajectories that could be mistaken for an early warning signal of a critical transition (such as might be due to a
Modeling the Impact of Technical Change on Emissions Abatement Investments in Developing Countries

The cost of greenhouse gas (GHG) mitigation over time depends on both the rate of technical change in leading-edge technologies and the diffusion of knowledge and capabilities throughout international markets. This paper presents a framework developed by the U.S. Environmental Protection Agency (EPA) and RTI International (RTI) for incorporating technical change in non-CO2 GHG mitigation projections over time. An engineering (bottom-up) approach is used to model technical change as a set of price and productivity factors that change over time as a function of technology advances and the location of developing countries relative to the technology efficiency frontier. S-shaped diffusion curves are generated, which demonstrate the maturity of the market for a given technology in a given region. The framework is demonstrated for coal mine methane mitigation technologies in the United States and China, but it is applicable for the full range of technology adoption issues.
Highly selective copper-catalyzed ring expansion of vinyl thiiranes: application to synthesis of biotin and the heterocyclic core of plavix.

We report herein a new, highly selective, mild copper-catalyzed vinyl thiirane ring-expansion protocol for the formation of 2,5-dihydrothiophenes. Preliminary substrate scope and applications of this new synthetic disconnection to the formal racemic total synthesis of biotin and the synthesis of the antiplatelet blockbuster pharmaceutical agent Plavix are described.
Local structure of ideal shapes of knots

Abstract Relatively extremal knots are the relative minima of the ropelength functional in the C 1 topology. They are the relative maxima of the thickness (normal injectivity radius) functional on the set of curves of fixed length, and they include the ideal knots. We prove that a C 1 , 1 relatively extremal knot in R n either has constant maximal (generalized) curvature, or its thickness is equal to half of the double critical self distance. This local result also applies to the links. Our main approach is to show that the shortest curves with bounded curvature and C 1 boundary conditions in R n contain CLC (circle–line–circle) curves, if they do not have constant maximal curvature.
Remittances and inequality reconsidered: Direct, indirect, and intertemporal effects

Abstract This article proposes and tests a method for estimating direct, indirect, and intertemporal effects of migrant remittances on the size distribution of income as measured by a Gini coefficient. Empirical findings based on new matched longitudinal data from Mexico support the hypothesis that migrant remittances have indirect short-term effects and long-term asset accumulation effects on the level and distribution of household-farm income. They point to the importance of considering new influences on income inequality if policymakers are not indifferent to the distributional impact of development programs and policies.
An X-Ray Photometry System. I. Chandra ACIS

We present a system of X-ray photometry for the Chandra satellite. X-ray photometry can be a powerful tool to obtain flux estimates, hardness ratios, and colors unbiased by assumptions about spectral shape and independent of temporal and spatial changes in instrument characteristics. The system we have developed relies on our knowledge of effective area and the energy-to-channel conversion to construct filters similar to photometric filters in the optical bandpass. We show that the filters are well-behaved functions of energy and that this X-ray photometric system is able to reconstruct fluxes to within about 20%, without color corrections, for non-pathological spectra. Even in the worst cases it is better than 50%. Our method also treats errors in a consistent manner, both statistical and systematic.
Palladium-phosphinous acid-catalyzed cross-coupling of aryl and acyl halides with aryl-, alkyl-, and vinylzinc reagents.

Several palladium−phosphinous acids have been prepared and employed in cross-coupling reactions of aryl or acyl halides with aliphatic and aromatic organozinc reagents. The POPd7-catalyzed reaction of aryl halides, including electron-rich aryl chlorides, and arylzinc reagents was found to afford biaryls exhibiting alkoxy, alkylthio, amino, ketone, cyano, nitro, ester, and heteroaryl groups in 75−93% yield. Excellent results were obtained with sterically hindered substrates which gave di- and tri-ortho-substituted biaryls in up to 92% yield. Aryl halides also undergo POPd7-catalyzed aryl−vinyl and aryl−alkyl bond formation under mild conditions. Styrenes and alkylarenes were prepared in 79−93% yield from aryl halides and vinyl or alkylzinc reagents. The replacement of aryl halides by acyl halides provides access to ketones which were produced in up to 98% yield when POPd was used as catalyst. This approach overcomes the limited substrate scope, reduced regiocontrol, and low functional group tolerance of tr...
Genetic studies in nzb mice

Hybrid NZB X NZW or NZB X DBA/2 females have markedly accelerated development of autoimmunity when compared with their respective male littermates. This difference is attributable to the ability of male sex hormones to retard the expression of autoimmunity. In contrast to the sex differences in expression of autoimmunity in F1 mice, parental NZB males and females have only minor differences in disease expression. We have been investigating the basis for the difference in anti-T cell antibody production between NZB and F1 mice. In this study, the appearance of antibodies cytotoxic for T cells (NTA) was studied in NZB and DBA/2 mice and in their F1 hybrids and backcross progeny. A major sex difference in NTA production was observed in the F1 hybrids; females produced more NTA than did males. Castration of males led to a marked increase in NTA production. Furthermore, the NTA production of castrated male and female F1 mice was significantly suppressed by administration of testosterone in Silastic capsules. In contrast to the studies in F1 mice, we found little difference between intact male and female parental NZB mice at any age studied. Furthermore, NZB mice of both sexes who were given androgen-containing capsules at 2 weeks of age failed to demonstrate a decrease in NTA production. This result suggested an androgen insensitivity in NZB mice with regard to NTA production. This insensitivity, which appears to be a recessive trait, may help to explain why NZB mice do not manifest the sex differences in disease expression observed in the F1 hybrids.
Directional Selectivity and its Use in Early Visual Processing

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of $\nabla ^{2}$G(x, y) * I(x,y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative $\delta $[$\nabla ^{2}$G(x, y) * I(x, y)]/$\partial $t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180 degrees. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.
Coisotropic branes, noncommutativity, and the mirror correspondence

We study coisotropic A-branes in the sigma model on a four-torus by explicitly constructing examples. We find that morphisms between coisotropic branes can be equated with a fundamental representation of the noncommutatively deformed algebra of functions on the intersection. The noncommutativity parameter is expressed in terms of the bundles on the branes. We conjecture these findings hold in general. To check mirror symmetry, we verify that the dimensions of morphism spaces are equal to the corresponding dimensions of morphisms between mirror objects.
A spectrally accurate direct solution technique for frequency-domain scattering problems with variable media

This paper presents a direct solution technique for the scattering of time-harmonic waves from a bounded region of the plane in which the wavenumber varies smoothly in space. The method constructs the interior Dirichlet-to-Neumann (DtN) map for the bounded region via bottom-up recursive merges of (discretization of) certain boundary operators on a quadtree of boxes. These operators take the form of impedance-to-impedance (ItI) maps. Since ItI maps are unitary, this formulation is inherently numerically stable, and is immune to problems of artificial internal resonances. The ItI maps on the smallest (leaf) boxes are built by spectral collocation on tensor-product grids of Chebyshev nodes. At the top level the DtN map is recovered from the ItI map and coupled to a boundary integral formulation of the free space exterior problem, to give a provably second kind equation. Numerical results indicate that the scheme can solve challenging problems 70 wavelengths on a side to 9-digit accuracy with 4 million unknowns, in under 5 min on a desktop workstation. Each additional solve corresponding to a different incident wave (right-hand side) then requires only 0.04 s.
Chemistry of High-Temperature Superconductors

Spectacular advances in superconductors have taken place in the past two years. The upper temperature for superconductivity has risen from 23 K to 122 K, and there is reason to believe that the ascent is still ongoing. The materials causing this excitement are oxides. Those oxides that superconduct at the highest temperatures contain copper-oxygen sheets; however, other elements such as bismuth and thallium play a key role in this new class of superconductors. These superconductors are attracting attention because of the possibility of a wide range of applications and because the science is fascinating. A material that passes an electrical current with virtually no loss is more remarkable when this occurs at 120 K instead of 20 K.
Experimental results of large-scale structures in jet flows and their relation to jet noise production

Experiments have been performed to determine the role of large-scale turbulent structures in the production of jet noise. Axisymmetric turbulent jet flows at ambient stagnation temperature have been observed with the aid of flow visualization techniques. Jet Mach numbers at the nozzle exit ranged between 0.1 and 0.9, and the Reynolds number, based on nozzle exit diameter, was approximately 10 to the 6th. Large organized turbulent structures existed as far downstream of the nozzle exit as 7 diameters. High-speed schlieren motion pictures synchronized with near-field pressure measurements of an excited jet indicated that strong instantaneous peaks in the pressure signal occurred whenever a merging process between two large-scale organized structures occurred. This pressure pulse propagated at a speed which was somewhat larger than the velocity of the jet at the nozzle exit.
Ionic Liquids with Fluorine-Containing Cations

Interest in ionic liquids with fluorine-containing cations has grown markedly in recent years. The syntheses, characterization and properties of quaternary fluoroalkyl-substituted ammonium, imidazolium, triazolium, pyridinium, pyrazinium, pyridazinium, pyrimidinium, piperazinium, pyrrolidinium, oxazolidinium, and morpholinium salts have been studied in detail. By modifying the anion or the fluorine-containing substituent on the cation, a wide range of properties of fluorine-containing ionic liquids can be tuned, including viscosity, melting point, density, conductivity, solubility, liquid range, thermal and hydrolytic stability. They are promising solvents for electrochemical, photovoltaic, surfactant and synthetic applications. In this Microreview, only the literature dealing with ionic liquids that involve fluorine-containing cations is presented. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Stacked PMOS clamps for high voltage power supply protection

Abstract Large p-channel MOS (PMOS) field-effect transistors (FETs) with multiple gates can be arranged to provide ESD protection to high voltage on-chip power supplies in submicron integrated circuits. These clamps divide the supply voltage among several gate oxides; the circuitry accompanying the large series FETs provides near-maximum gate drive during the ESD for high pulsed current. Layouts are densely packed because minimum dimensions can be used and because no contact is needed between the stacked gates. The designs for high voltage are extensions of the large PMOS FET ESD clamps and timed drive circuitry that are used to clamp ordinary on-chip power supply lines.
Mapping surface currents from HF radar radial velocity measurements using optimal interpolation

[1] An optimal interpolation (OI) method to compute surface vector current fields from radial velocity measurements derived from high-frequency (HF) radars is presented. The method assumes a smooth spatial covariance relationship between neighboring vector currents, in contrast to the more commonly used un-weighted least-squares fitting (UWLS) method, which assumes a constant vector velocity within a defined search radius. This OI method can directly compute any quantities linearly related to the radial velocities, such as vector currents and dynamic quantities (divergence and vorticity) as well as the uncertainties of those respective fields. The OI method is found to be more stable than the UWLS method and reduces spurious vector solutions near the baselines between HF radar installations. The OI method produces a covariance of the uncertainty of the estimated vector current fields. Three nondimensional uncertainty indices are introduced to characterize the uncertainty of the vector current at a point, representing an ellipse with directional characteristics. The vector current estimation using the OI method eliminates the need for multiple mapping steps and optimally fills intermittent coverage gaps. The effects of angular interpolation of radial velocities, a commonly used step in the preprocessing of radial velocity data prior to vector current computation in the UWLS method, are presented.
Measuring consumer uncertainty about future inflation

We introduce a survey-based measure of uncertainty about future inflation, asking consumers for density forecasts across inflation outcomes. Consumers are willing and able to express uncertainty, showing high response rates and response patterns that are reliably related to qualitative measures of uncertainty. Heterogeneity in expressed uncertainty is associated with demographic characteristics and financial literacy, and measures of central tendency derived from density forecasts are strongly correlated with point forecasts. Furthermore, expressed uncertainty is positively related to point forecast levels and to larger revisions in point forecasts over time.
Preparation and characterization of β-d-fructofuranosyl O-(α-d-galactopyranosyl uronic acid)-(1→6)-O-α-d-glucopyranoside and O-(α-d-galactopyranosyl uronic acid)-(1→6)-d-glucose

beta-D-Fructofuranosyl O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-O-alpha-D-glucopyranoside (3) was prepared by treating raffinose with D-galactose oxidase, followed by hypoiodite oxidation of the resulting aldehyde. Mild acid hydrolysis of 3 gave O-(alpha-D-galactopyranosyl uronic acid)-(1----6)-D-glucose.
Early-Adult Life Correlates of Personality in Parkinson’s Disease

Background : Parkinson’s disease (PD) patients have been described as having an introverted, rigid and harm-avoidant personality, which present decades before motor symptoms begin. Previous studies have relied on subjective reports about patients’ premorbid personalities. The objectives of this study were to examine current personality profiles of PD patients and to assess how personality indicators of early-adult life correlate with current personality. Methods: Data were collected from 89 PD cases and 99 controls through in-person assessments of current personality characteristics and early-adult life personality indicators based on activities and lifestyle patterns during ages 20 - 35 years. Associations of latent variables representing early-adult activity risks, lifestyle risks and routinization with current personality characteristics were studied using Pearson correlations, partialling out the effects of age, sex and education. Results: Greater current levels of neuroticism (OR = 1.05 (95% CI 1.00 - 1.11)) and harm-avoidance (OR = 1.07 (95% CI 1.00 - 1.15)) were evident in cases compared to controls, adjusting for age, sex and education. Significant correlations between early-life indicators and late-life personality characteristics were consistent among cases and controls for associations of early-adult life routinization with current measures of neuroticism (cases: r = 0.33, P = 0.01; controls: r = 0.26, P = 0.04), extraversion (cases: r = -0.33, P = 0.01; controls: r = -0.33, P = 0.04), novelty-seeking (cases: r = -0.33, P = 0.015; controls: r = -0.34, P = 0.007) and harm-avoidance (cases: r = 0.47, P = 0.0003; controls: r = 0.45, P = 0.0002) and for early-adult life activity risks with harm-avoidance (cases: r = -0.47, P = 0.0004; controls: r = -0.42, P = 0.0006). Conclusion: Current personality profile of PD cases, reflected by higher neuroticism and harm-avoidance, may reflect stable personality traits characterized by greater routinization and lower risk-taking in earlier adult life. J Neurol Res. 2014;4(2-3):51-62 doi: http://dx.doi.org/10.14740/jnr280w
Use of cerny epoxides for the accelerated synthesis of glycosaminoglycans.

1,6:2,3-Dianhydrohexopyranoses (Cerny epoxides) are versatile intermediates for the synthesis of glycosaminoglycans. Complex heparan and chondroitin sulfate disaccharide synthons can be assembled from a single common precursor in a short sequence of steps.
Simulations of Gamma-Ray Bursts from External Shocks: Time Variability and Spectral Correlations

We compute burst spectra and time structures arising from synchrotron and inverse Compton scattering by nonthermal electrons accelerated in shocks that form during the interaction between a thin ultrarelativistic fireball and a stationary external medium. We investigate the effect of varying the most important model parameters on the resulting burst spectra, and we present a set of correlations among the spectral and temporal features of the bursts. The spectral hardness, various spectral-temporal correlations, and the spectral evolution of the simulated bursts are compared to those of observed bursts for a representative set of model parameters. Multipulse structures are simulated using a variable magnetic field and anisotropic emission, and the most important spectral and temporal properties of these pulses are compared with observations.
Five-brane effective action in M theory

Abstract On the world-volume of an M-theory five-brane propagates a two-form with self-dual field strength. As this field is non-Lagrangian, there is no obvious framework for determining its partition function. An analogous problem exists in Type IIB superstring theory for the self-dual five-form. The resolution of these problems and definition of the partition function is explained. A more complete analysis of perturbative anomaly cancellation for M-theory five-branes is also presented, uncovering some surprising details.
Shanghai's Trade, China's Growth: Continuity, Recovery, and Change since the Opium War

This paper provides an analysis of China's trade performance from the 1840s to the present. Its focus is on Shanghai, the world's largest port, which began direct trade relations with Western nations starting in 1843. The paper finds that Shanghai had, and continues to have, an important role in China's trade structure. Applying the well-known gravity equation of trade for Shanghai's treaty port period, the paper shows that this relationship fits today's actual trade quite well when projected into the modern period. Second, the foreign presence, as measured by foreign direct investment (FDI), in Shanghai is shown to be related not only to trade in the past, but also to trade today, which suggests that FDI is one of the sources of persistence in foreign trade.
N‐[α‐(o‐ and p‐Methoxyaryl)alkyl]benzotriazoles: Preparation and Use in Synthesis

Methoxybenzenes and -naphthalenes are benzotriazolylmethylated in the para-position or if this is blocked in an ortho- position. The methylene groups in the products are readily substituted by electrophiles via the lithiated derivatives. Displacement of the benzotriazole group can be effected by organometallic reagents or by electron-rich benzoid compounds to afford a versatile method for the synthesis of substituted aryl ethers.
Surface area and other measures of ellipsoids

We begin by studying the surface area of an ellipsoid in E^n as the function of the lengths of the semi-axes. We give an explicit formula as an integral over S^n^-^1, use this formula to derive convexity properties of the surface area, to give sharp estimates for the surface area of a large-dimensional ellipsoid, to produce asymptotic formulas for the surface area and the isoperimetric ratio of an ellipsoid in large dimensions, and to give an expression for the surface in terms of the Lauricella hypergeometric function. We then write down general formulas for the volumes of projections of ellipsoids, and use them to extend the above-mentioned results to give explicit and approximate formulas for the higher integral mean curvatures of ellipsoids. Some of our results can be expressed as isoperimetric results for higher mean curvatures.
Combined Infrared Thermal Imaging and Laser Heating for the Study of Materials Thermophysical and Processing Properties at High Temperatures

Focused laser irradiation can easily drive materials to extreme temperatures with very high precision and control. In combination with infrared imaging and material characterization techniques, the resulting thermal load can be assessed to derive meaningful thermophysical properties avoiding interferences that would normally occur with direct contact measurements of temperature. In this focused article we first address technical challenges with the experimental implementation involved in obtaining laser-induced temperature field data from infrared imaging. We then discuss suitable heat transport models for analysis of thermal data and, finally, describe specific examples of thermophysical material parameters derived from combined infrared imaging and laser heating. The aim is to illustrate general principles of this combined laser-based heating and IR thermal imaging approach that are useful for experimentation under extreme conditions, which often remain out of reach of conventional methods.
Hidden actions and hidden characteristics in warranty markets

Abstract Warranties are investigated in a market setting with adverse selection and buyer and seller moral hazard. Competitive equilibrium contracts involve a positive correlation between price and warranty coverage. The relative benefits and costs of input supply for buyers and sellers determine how the warranty contract terms, consumer type and effort, product quality, and product reliability relate. Productivity and cost parameters, along with consumer characteristics, also influence the relative slopes of consumers' indifference curves over price-warranty pairs. The observed reliability of a product may vary inversely or directly with price and warranty coverage.
Synthesis of SQ-32,829, a new nucleoside antiviral agent

Abstract The guanine-containing cyclobutane nucleoside analog SQ-32,829 (1) was synthesized in 8 steps from 1,1-cyclobutanedicarboxylic acid (3).
Use of E-mail to Teach Residents Pediatric Emergency Medicine

Objectives To develop a computer-based teaching program using a hospital health care system to instruct pediatric and medicine-pediatric residents (MPR) in pediatric emergency medicine, and to determine residents' participation, interest, and benefit from the project over 3 years' time. Design Prospective, descriptive. Setting University-affiliated pediatric hospital. Participants Pediatric housestaff. Methods One multiple-choice question about pediatric emergency medicine was sent daily to pediatric residents and MPR via the hospital health care system's internal electronic mail (e-mail) system. Residents were asked to reply electronically with the correct answer. The next day, the correct answer, discussion, and a new question were sent to the residents via e-mail. Main Outcome Measures Tabulated electronic participation for 3 years; self-report surveys of participation after 1 and 3 years' participation. Pretest and posttest scores before and after 1 year of participation. Results From October 3, 1994, to June 14, 1995, 52 of 64 pediatric residents and MPR (81%) elected to receive the e-mail questions, but only 31 (48%) sent electronic replies. The average number of e-mail replies received per resident that year was 38 (22%) of 171 (range, 1-164 e-mail replies; median, 33). In academic years 1995-1996 and 1996-1997, although averages and ranges were similar, regular e-mail participation declined. Residents preferred to participate by reading e-mail only. Pediatric residents and MPR judged e-mail questions to be as educationally valuable or better than Grand Rounds (92%) or our Resident Lecture Series of basic pediatric topics (87%). Conclusion Pediatric residents and MPR do participate in a daily e-mailed question/answer format of teaching, but prefer to do so passively, by reading daily questions only, rather than actively, by sending answers to an e-mail box. This format provides medical education that is uniform, accommodates residents' varying schedules, and is a useful adjunct to other teaching methods.
Self-organization of tidal deltas

Tidal deltas are characterized by a dendritic network of distributaries that transport water and sediments to the ocean. Here, I show that the distributaries self-organize to uniformly redistribute the tidal prism across the entire delta system. The 2 opposite mechanisms of channel formation by avulsion and channel abandonment drive the entire delta toward a critical state at which every channel is close to the silting threshold. Under these conditions the delta reaches self-organized criticality, with changes of its planimetric channel distribution occurring across several spatial scales.