cssi/SciSciGPT-SciSciNet huggingface dataset:
MOSFET solid state switching circuit improves the 0 to 99% rise time for framing camera deflection electronics

We have improved the 0 to 99% rise time voltage on our 2 frame deflection plates from 160 nS to 65 nS with the addition of a peaking circuit that works in conjunction with our primary 2 frame deflection circuitry. Our peaking technique has applications to other HV pulsers including those which must drive 51 ohm loads. Generally, rise time voltages are measured between 10 and 90%. To minimize the camera image blur resulting from the dynamic influence of deflection plate potentials acting on photocathode electrons, it was necessary to design a circuit that would rise from 0 to the 99% voltage level in under 100 nS. Once this voltage was reached, it was necessary to stay within 1% of the attained voltage level for a duration of 1 uS. This was accomplished with the use of MOSFET solid state switching.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Anaerobic methane oxidation and the formation of dolomite

Abstract We examine the link between organic matter degradation, anaerobic methane oxidation (AMO), and sulfate depletion and explore how these processes potentially influence dolomitization. We determined rates and depths of AMO and dolomite formation for a variety of organic-rich sites along the west African Margin using data from Ocean Drilling Program (ODP) Leg 175. Rates of AMO are calculated from the diffusive fluxes of CH4 and SO4, and rates of dolomite formation are calculated from the diffusive flux of Mg. We find that the rates of dolomite formation are relatively constant regardless of the depth at which it is forming, indicating that the diffusive fluxes of Mg and Ca are not limiting. Based upon the calculated log IAP values, log Ksp values for dolomite were found to narrowly range between −16.1 and −16.4. Dolomite formation is controlled in part by competition between AMO and methanogenesis, which controls the speciation of dissolved CO2. AMO increases the concentration of CO32− through sulfate reduction, favoring dolomite formation, while methanogenesis increases the pCO2 of the pore waters, inhibiting dolomite formation. By regulating the pCO2 and alkalinity, methanogenesis and AMO can regulate the formation of dolomite in organic-rich marine sediments. In addition to providing a mechanistic link between AMO and dolomite formation, our findings provide a method by which the stability constant of dolomite can be calculated in modern sediments and allow prediction of regions and depth domains in which dolomite may be forming.
Antenna arrays technologies for advanced wireless systems

Phased array antennas have and will continue to be a critically important component in the development of future wireless systems with applications in communications, radar, and satellite technologies. In spite of the significant advances in the design of modern phased array antennas, there continue to be significant and growing need for developing high performance systems that are also low cost and with beam steering capabilities. In this paper we describe some of the antenna array designs that focus on achieving this goal. We will start with one approach that is based on an analog phase-shifting approach and involves an integrated use of ferroelectric materials and the Continuous Transverse Stub (CTS) antenna array technologies. A complementary design which is based on digital beamforming and the utilization of the Hybrid Smart Antenna technique recently developed by our group will then be described. This will be followed with comments regarding the trade-off between the analog and digital phase shifting techniques. We will conclude the chapter with a description of a novel ultra-wideband and low profile ground plane which is based on a hybrid ferrite and Electromagnetic Band Gap (EBG) materials design. In all cases simulation results and experimental validation, whenever available, will be presented and aspects of the required future work to fully enable these technologies will be discussed.
Type II Quasars from the Sloan Digital Sky Survey. V. Imaging Host Galaxies with the Hubble Space Telescope

Type II quasars are luminous active galactic nuclei (AGNs) whose centers are obscured by large amounts of gas and dust. In this paper we present three-band Hubble Space Telescope images of nine type II quasars with redshifts 0.2 MB > -26, but optical obscuration allows their host galaxies to be studied unencumbered by bright nuclei. Each object has been imaged in three continuum filters (UV, blue, and yellow) placed between the strong emission lines. The spectacular, high-quality images reveal a wealth of details about the structure of the host galaxies and their environments. Six of the nine galaxies in the sample are elliptical galaxies with de Vaucouleurs light profiles, one object has a well-defined disk component, and the remaining two have marginal disks. Stellar populations of type II quasar hosts are more luminous (by a median of 0.3-0.7 mag, depending on the wavelength) and bluer (by about 0.4 mag) than are M* galaxies at the same redshift. When smooth fits to stellar light are subtracted from the images, we find both positive and negative residuals that become more prominent toward shorter wavelengths. We argue that the negative residuals are due to kiloparsec-scale dust obscuration, while most positive residuals are due to the light from the nucleus scattered off interstellar material in the host galaxy. Scattered light makes a significant contribution to the broadband continuum emission and can be the dominant component of the extended emission in the UV in extreme cases.
Double Neutron Star Systems and Natal Neutron Star Kicks

We study the four double neutron star systems found in the Galactic disk in terms of the orbital characteristics of their immediate progenitors and the natal kicks imparted to neutron stars. Analysis of the effect of the second supernova explosion on the orbital dynamics, combined with recent results from simulations of rapid accretion onto neutron stars, lead us to conclude that the observed systems could not have been formed had the explosion been symmetric. Their formation becomes possible if kicks are imparted to the radio-pulsar companions at birth. We identify the constraints imposed on the immediate progenitors of the observed double neutron stars and calculate the ranges within which their binary characteristics (orbital separations and masses of the exploding stars) are restricted. We also study the dependence of these limits on the magnitude of the kick velocity and the time elapsed since the second explosion. For each of the double neutron stars, we derive a minimum kick magnitude required for their formation, and for the two systems in close orbits (10 R☉), we find it to exceed 200 km s-1. Lower limits are also set to the center-of-mass velocities of double neutron stars, and we find them to be consistent with the current proper motion observations.
NbFe1.28Te3, a quasi-layered ternary niobium telluride compound

Abstract NbFe 1.28 Te 3 , a new ternary niobium telluride compound, was synthesized via solid state reactions. The crystal structure of this compound was determined by single crystal X-ray diffraction methods. The structure belongs to the monoclinic space group P 2 1 / m (number 11) and is isostructural with TaFe 1.25 Te 3 . The following cell constants were obtained from the analysis: a = 7.373 A , b = 3.648 A , c = 9.965 A , β = 108.81 o , Z = 2 . The final refinement yielded R = 3.5% and R w = 4.6%. The structure can be described as a quasi-two-dimensional layered type. It consists of an Nb-Fe1-Nb metal network “sandwiched” by the Te and Fe2 atoms from above and below. This would result in an “NbFe 2 Te 3 ” layer if the Fe2 sites were fully occupied. Connections between the layers are made through Fe2-Te2 bonds. The Fe2 atoms reside in square pyramidal sites and are bonded to four basal Te atoms from one layer and an apical Te2 atom from the adjacent layer. The partial occupancy of the Fe2 sites leads to a non-stoichiometric formula NbFe 1.28 Te 3 . The metal-metal bonding in this structure is quite unusual.
Actinide-specific complexing agents: their structural and solution chemistry

The synthesis of a series of tetracatecholate ligands designed to be specific for Pu(IV) and other actinide(IV) ions has been achieved. Although these compounds are very effective as in vivo plutonium removal agents, potentiometric and voltammetric data indicate that at neutral pH full complexation of the Pu(IV) ion by all four catecholate groups does not occur. Spectroscopic results indicate that the tetracatecholates, 3,4,3-LICAMS and 3,4,3-LICAMC, complex Am(III). The Am(IV)/(III)-catecholate couple (where catecholate = 3,4,3-LICAMS or 3,4,3-LICAMC) is not observed, but may not be observable due to the large currents associated with ligand oxidation. However, within the potential range where ligand oxidation does not occur, these experiments indicate that the reduction potential of free Am(IV)/(III) is probably greater than or equal to + 2.6 V vs NHE or higher. Proof of the complexation of americium in the trivalent oxidation state by 3,4,3-LICAMS and 3,4,3-LICAMC elimates the possibility of tetracatholates stabilizing Am(IV) in vivo.
Exploring Illuminative Systems in Informal Networks of Adults

Abstract Whenever we feel those ‘higher’ and hard to define sensations like synchronicity, love, wholeness, and appreciation is this a pattern or a metaphorical illuminative system that is part of a larger ecological network or evolutionary design meant to establish homeostasis within the planet? Meeting as groups in person, or posting online to an interactive website, adults track, record, and describe in layman's terms their everyday encounters with illumination. Illumination in this sense could encompass both spiritual and/or secular significance. Participants build data files of illuminative sensation recorded in video, text, sound bite, drawing, and/or journaling. This spatial and sensory awareness activity, initiating from an appreciative foundation, eventually leads to participants conducting informal skillshares where adults teach to one another the strengths they possess when illuminated. Next adults collectively design new courses, programs, and products for their immediate community. A pilot study reveals that adults yearn for opportunities to talk about illuminative moments with one another.
A photochemical strategy for lignin degradation at room temperature.

The development of a room-temperature lignin degradation strategy consisting of a chemoselective benzylic oxidation with a recyclable oxidant ([4-AcNH-TEMPO]BF4) and a catalytic reductive C–O bond cleavage utilizing the photocatalyst [Ir(ppy)2(dtbbpy)]PF6 is described. This system was tested on relevant lignin model substrates containing β-O-4 linkages to generate fragmentation products in good to excellent yields.
Will Employers Drop Health Insurance Coverage Because Of The Affordable Care Act

Since the passage of the Affordable Care Act, there has been much speculation about how many employers will stop offering health insurance once the act’s major coverage provisions take effect. Some observers predict little aggregate effect, but others believe that 2014 will mark the beginning of the end for our current system of employer-sponsored insurance. We use theoretical and empirical evidence to address the question, “How will employers’ offerings of health insurance change under health reform?” First, we describe the economic reasons why employers offer insurance. Second, we recap the relevant provisions of health reform and use our economic framework to consider how they may affect employers’ offerings. Third, we review the various predictions that have been made about those offerings under health reform. Finally, we offer some observations on interpreting early data from 2014.
Discovery of a Candidate Protoplanetary Disk around the Embedded Source IRc9 in Orion

We report the detection of spatially extended mid-infrared emission around the luminous embedded star IRc9 in OMC-1, as seen in 8.8, 11.7, and 18.3 μm images obtained with the Thermal-Region Camera and Spectrograph on Gemini South. The extended emission is asymmetric, and the morphology is reminiscent of warm dust disks around other young stars. The putative disk has a radius of roughly 15 (700 AU) and a likely dust mass of almost 10 M⊕. The infrared spectral energy distribution of IRc9 indicates a total luminosity of ~100 L☉, implying that it will become an early A-type star when it reaches the main sequence. Thus, the candidate disk around IRc9 may be a young analog of the planetary debris disks around Vega-like stars and the disks of Herbig Ae stars, and may provide a laboratory in which to study the earliest phases of planet formation. A disk around IRc9 may also add weight to the hypothesis that an enhanced T Tauri-like wind from this star has influenced the molecular outflow from the OMC-1 core.
A New Method for the Cleavage of Nitrobenzyl Amides and Ethers.

A mild and efficient o- and p-nitrobenzyl cleavage protocol was developed. o- and p-nitrobenzyl groups were easily removed from a variety of substrates using 20% aqueous NaOH in methanol at 75 °C, presumably via oxidation at the benzylic position by oxygen dissolved in the solution. These easily introducible and removable nitrobenzyl groups can serve as valuable protecting groups for the synthesis of multifunctional, complex molecules.
Some interesting violations of the Breitenlohner-Freedman bound

We demonstrate that AdS5 × Tpq is unstable, in the sense of Breitenlohner and Freedman, for unequal p and q. This settles, negatively, the long-standing question of whether the Tpq manifolds for unequal p and q might correspond to non-supersymmetric fixed points of the renormalization group. We also show that the AdS3 × S7 vacuum of Sugimoto's USp(32) open string theory is unstable. This explains, at a heuristic level, the apparent absence of a heterotic string dual.
Silent error detection in numerical time-stepping schemes

Errors due to hardware or low-level software problems, if detected, can be fixed by various schemes, such as recomputation from a checkpoint. Silent errors are errors in application state that have escaped low-level error detection. At extreme scale, where machines can perform astronomically many operations per second, silent errors threaten the validity of computed results. We propose a new paradigm for detecting silent errors at the application level. Our central idea is to frequently compare computed values to those provided by a cheap checking computation, and to build error detectors based on the difference between the two output sequences. Numerical analysis provides us with usable checking computations for the solution of initial-value problems in ODEs and PDEs, arguably the most common problems in computational science. Here, we provide, optimize, and test methods based on Runge-Kutta and linear multistep methods for ODEs, and on implicit and explicit finite difference schemes for PDEs. We take the heat equation and Navier-Stokes equations as examples. In tests with artificially injected errors, this approach effectively detects almost all meaningful errors, without significant slowdown.
Dynamics and spectral weights of shake-up valence excitations in transition metal K-edge resonant inelastic x-ray scattering

K. H. Ahn,1 A. J. Fedro,2,3 and Michel van Veenendaal2,3 1Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102, USA 2Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA 3Department of Physics, Northern Illinois University, De Kalb, Illinois 60115, USA Received 7 August 2008; revised manuscript received 4 December 2008; published 7 January 2009
Chains in the Bruhat order

We study a family of polynomials whose values express degrees of Schubert varieties in the generalized complex flag manifold G/B. The polynomials are given by weighted sums over saturated chains in the Bruhat order. We derive several explicit formulas for these polynomials, and investigate their relations with Schubert polynomials, harmonic polynomials, Demazure characters, and generalized Littlewood-Richardson coefficients. In the second half of the paper, we study the classical flag manifold and discuss related combinatorial objects: flagged Schur polynomials, 312-avoiding permutations, generalized Gelfand-Tsetlin polytopes, the inverse Schubert-Kostka matrix, parking functions, and binary trees.
Total Synthesis of the CP Molecules CP-263,114 and CP-225,917- Part 1: Synthesis of Key Intermediates and Intelligence Gathering.

A synthetic labyrinth endowed with countless obstacles, yet filled with numerous hidden treasures, had to be overcome to reach the CP molecules CP-263,114 (1) and CP-225,917 (2). Their complex molecular frameworks coupled with the array of sensitive functionalities present amount to a formidable synthetic challenge. Moreover, these compounds possess interesting biological properties. Although the first synthetic strategies ended before the goals were achieved, in spite of careful preparation and numerous model studies, enough information was gathered en route to enable a revised approach to be formulated, which finally culminated in success.
The Self-Regulated Growth of Supermassive Black Holes

We present a series of simulations of the self-regulated growth of supermassive black holes (SMBHs) in galaxies via three different fueling mechanisms: major mergers, minor mergers, and disk instabilities. The SMBHs in all three scenarios follow the same black hole fundamental plane (BHFP) and correlation with bulge binding energy seen in simulations of major mergers, and observed locally. Furthermore, provided that the total gas supply is significantly larger than the mass of the SMBH, its limiting mass is not influenced by the amount of gas available or the efficiency of black hole growth. This supports the assertion that SMBHs accrete until they reach a critical mass at which feedback is sufficient to unbind the gas locally, terminating the inflow and stalling further growth. At the same time, while minor and major mergers follow the same projected correlations (e.g., the MBH-σ and Magorrian relations), SMBHs grown via disk instabilities do not, owing to structural differences between the host bulges. This finding is supported by recent observations of SMBHs in pseudobulges and bulges in barred systems, as compared to those hosted by classical bulges. Taken together, this provides support for the BHFP and binding energy correlations as being more "fundamental" than other proposed correlations in that they reflect the physical mechanism driving the coevolution of SMBHs and spheroids.
The Acoustic Analysis of the Vowels from the Phonographic Record

Many attempts have been made to determine vowel timbre from the phonographic record, with more or less of success. The difficulties of transcription on a sufficiently large scale has proved considerable. With the aid of Dr. F. C. Van Dyck, Professor of Physics, in Rutgers College, I have succeeded in constructing an apparatus at once simple and satisfactory, and have reached results that seem worthy of consideration.
Ga(III)-Catalyzed Cycloisomerization Approach to (±)-Icetexone and (±)-Epi-Icetexone

A Ga(III)-catalyzed cycloisomerization reaction provides expedient access to a benzannulated cycloheptadiene bearing a cyano group, which has been applied to the syntheses of several icetexane diterpenoids including icetexone and epi-icetexone. Key to the synthesis is a novel in situ generated diazene rearrangement.
A rapid entry to highly functionalized p-methoxybenzoates: Synthesis of aromatic portion of milbemycin β3

Abstract A wide variety of easily accessible Hagemann's esters are converted to p-methoxybenzoates with iodine and methanol.
Monoidal algebraic model structures

Abstract Extending previous work, we define monoidal algebraic model structures and give examples. The main structural component is what we call an algebraic Quillen two-variable adjunction; the principal technical work is to develop the category theory necessary to characterize them. Our investigations reveal an important role played by “cellularity”–loosely, the property of a cofibration being a relative cell complex, not simply a retract of such–which we particularly emphasize. A main result is a simple criterion which shows that algebraic Quillen two-variable adjunctions correspond precisely to cell structures on the pushout-products of generating (trivial) cofibrations. As a corollary, we discover that the familiar monoidal model structures on categories and simplicial sets admit this extra algebraic structure.
Churning: Excessive trading in retail securities accounts

Abstract Churning involves excessive trading by stockbrokers in order to generate commissions. Current practice uses the turnover ratio to detect excessive trading. The turnover ratio is a flawed indicator of the actual harm of excessive trading which is commissions. This paper examines the intersection of law and financial analysis in the retail securities arena. A unique set of data from 23 actual churning cases is used to argue that the turnover ratio should be replaced by a more direct measure of the trading costs: the commission to equity ratio. An appropriate benchmark related to the return on common stocks is suggested to gauge excessive trading in a commission context.
Carbon abatement in the fuel market with biofuels: Implications for second best policies ☆

A carbon tax on fuel would penalize carbon intensive fuels like gasoline and shift fuel consumption to less carbon intensive alternatives like biofuels. Since biofuel production competes for land with agricultural production, a carbon tax could increase land rents and raise food prices. This paper analyzes the welfare effect of a carbon tax on fuel consisting of gasoline and biofuel in the presence of a labor tax, with and without a biofuel subsidy. The market impacts of a carbon tax are also compared with that of a subsidy. Findings show that if a carbon tax increases biofuel demand, the tax interaction effect due to higher fuel prices is exacerbated by higher land rent and food prices and greater erosion of the carbon tax base. Thus, the second best optimal carbon tax for fuel is lower with biofuel in the fuel mix, especially if biofuel is subsidized.
A Meta-Analysis of the Relationship between Trait Mindfulness and Substance Use Behaviors

Abstract Background The relationship between trait mindfulness and substance use behaviors has been inconsistent across studies. The current meta-analysis aimed at quantifying the magnitude of this relationship, and at determining how this relationship varies in context of (1) mindfulness facets, (2) substance type, (3) sample characteristics, and (4) substance use severity. Methods Using electronic databases, the literature search yielded 303 articles, but only 39 articles met inclusion criteria to be included in this meta-analysis. The relationship was quantified as a Pearson's r correlation coefficient for all studies. Results Findings indicated a small, negative, and significant trait mindfulness-substance use behaviors relationship (r = −0.13). This relationship varied across substance type, clinical status of the sample, and substance use severity. Mindfulness facet was not a significant moderator; however, only particular facets (e.g., acting with awareness, non-judgment, and non-reactivity) were consistently associated with substance use behaviors. Conclusions This meta-analysis quantified the trait mindfulness-substance use behaviors relationship, which can be used as future effect size estimates. Findings also indicated that the trait mindfulness-substance use behaviors relationship was more robust: (1) for alcohol and tobacco use compared to marijuana use behaviors; (2) for problematic compared to non-problematic substance use behaviors; and (3) with inpatient compared to outpatient and non-clinical samples. Further work should continue to examine if acting with awareness, non-judgment, and non-reactivity mindfulness facets are more robustly associated with substance use behaviors. Failure to consider these factors, or collapsing across these factors, could explain the smaller or inconsistently reported associations across previous studies.
Ultra-violet solar radiation

The work of Abbot and his colleagues has shown that the radiation from the Sun varies and that the variation is most pronounced in the violet end of the spectrum. Whether we regard the variation as due to a change in temperature, a variable transmission of the outer solar envelope or a variable emissivity, this effect on the ultra-violet is to be expected. Dobson in England using a photographic method, measured the ultra-violet solar radiation transmitted by silver-films on thirty-four days in 1922, and found variations as great as five hundred per cent, and a standard daily range of thirty per cent outside the atmosphere. It occurred to the writer that the uncertainties of photography could be eliminated by measuring the radiation directly with a thermo-couple; that disturbances of the atmosphere could be made differential by standardizing the ultra-violet with the green region of the spectrum which varies only slightly; that the accuracy could be increased by making the apparatus automatic, which would permit an increase in the number of observations, and that the combination of this procedure with the favorable atmospheric conditions on Mount Wilson might lead to results of some interest.
Quasiparticle effective mass for the two- and three-dimensional electron gas

We calculate the quasiparticle effective mass for the electron gas in two and three dimensions in the metallic region. We employ the single-particle scattering potential coming from the Sj\"olander-Stott theory and enforce the Friedel sum rule by adjusting the effective electron mass in a scattering calculation. In three dimensions (3D) our effective mass is a monotonically decreasing function of ${\mathit{r}}_{\mathit{s}}$ throughout the whole metallic domain, as implied by the most recent numerical results. In two dimensions (2D) we obtain reasonable agreement with the experimental data, as well as with other calculations based on the Fermi-liquid theory. We also present results of a variety of different treatments for the effective mass in 2D and 3D. \textcopyright{} 1996 The American Physical Society.
AP/(N2 + C2H2 + C2H4) gaseous fuel diffusion flame studies

Abstract Counterflow diffusion flame experiments and modeling results are presented for a fuel mixture consisting of N 2 , C 2 H 2 , and C 2 H 4 flowing against decomposition products from a solid AP pellet. The flame zone simulates the diffusion flame structure that is expected to exist between reaction products from AP crystals and a hydrocarbon binder. Quantitative species and temperature profiles have been measured for one strain rate, given by a separation of 5 mm, between the fuel exit and the AP surface. Species measured include C 2 H 2 , C 2 H 4 , N 2 , CN, NH, OH, CH, C 2 , NO, NO 2 , O 2 , CO 2 , H 2 , CO, HCl, H 2 O, and soot volume fraction. Temperature was measured using a combination of a thermocouple at the fuel exit and other selected locations, spontaneous Raman scattering measurements throughout the flame, NO vibrational populations, and OH rotational population distributions. The burning rate of the AP was also measured for this flame’s strain rate. The measured eighteen scalars are compared with predictions from a detailed gas-phase kinetics model consisting of 105 species and 660 reactions. Model predictions are found to be in good agreement with experiment and illustrate the type of kinetic features that may be expected to occur in propellants when AP particles burn with the decomposition products of a polymeric binder.
The Problem of Hipparcos Distances to Open Clusters. I. Constraints from Multicolor Main-Sequence Fitting*

Parallax data from the Hipparcos mission allow the direct distance to open clusters to be compared with the distance inferred from main-sequence (MS) fitting. There are surprising differences between the two distance measurements, indicating either the need for changes in the cluster compositions or reddening, underlying problems with the technique of MS fitting, or systematic errors in the Hipparcos parallaxes at the 1 mas level. We examine the different possibilities, focusing on MS fitting in both metallicity-sensitive B-V and metallicity-insensitive V-I for five well-studied systems (the Hyades, Pleiades, α Per, Praesepe, and Coma Ber). The Hipparcos distances to the Hyades and α Per are within 1 σ of the MS-fitting distance in B-V and V-I, while the Hipparcos distances to Coma Ber and the Pleiades are in disagreement with the MS-fitting distance at more than the 3 σ level. There are two Hipparcos measurements of the distance to Praesepe; one is in good agreement with the MS-fitting distance and the other disagrees at the 2 σ level. The distance estimates from the different colors are in conflict with one another for Coma but in agreement for the Pleiades. Changes in the relative cluster metal abundances, age related effects, helium, and reddening are shown to be unlikely to explain the puzzling behavior of the Pleiades. We present evidence for spatially dependent systematic errors at the 1 mas level in the parallaxes of Pleiades stars. The implications of this result are discussed.
On the geometry of the quantum poincaré group

Abstract We review the construction of the multiparametric inhomogeneousorthogonal quantum group ISO q,r (N) as a projection from SO q , r ( N +2), and recall the conjugation that for N =4 leads to the quantum Poincare group. We study the properties of the universal enveloping algebra U q,r ( iso(N) ), and give an R -matrix formlation. A quantum Lie algebra and a bicovariant differential calculus on twisted ISO(N) are found.
The Complexity of Finding Top-Toda-Equivalence-Class Members

We identify two properties that for P-selective sets are effectively computable. Namely, we show that, for any P-selective set, finding a string that is in a given length's top Toda equivalence class (very informally put, a string from $\Sigma^n$ that the set's P-selector function declares to be most likely to belong to the set) is ${\rm FP}^{\Sigma^p_2}$ computable, and we show that each P-selective set contains a weakly- $P^{\Sigma^p_2}$-rankable subset.
Quantum Hall effect in higher dimensions, matrix models and fuzzy geometry

We give a brief review of the quantum Hall effect in higher dimensions and its relation to fuzzy spaces. For a quantum Hall system, the lowest Landau level dynamics is given by a one-dimensional matrix action whose large N limit produces an effective action describing the gauge interactions of a higher dimensional quantum Hall droplet. The bulk action is a Chern–Simons type term whose anomaly is exactly cancelled by the boundary action given in terms of a chiral, gauged Wess–Zumino–Witten theory suitably generalized to higher dimensions. We argue that the gauge fields in the Chern–Simons action can be understood as parametrizing the different ways in which the large N limit of the matrix theory is taken. The possible relevance of these ideas to fuzzy gravity is explained. Other applications are also briefly discussed.
Dynamic Forces From Single Gland Labyrinth Seals: Part II—Upstream Coupling

The standard lumped parameter model for flow in an eccentrically offset labyrinth seal, which assumes constant upstream and downstream boundary conditions, has been extended to include the effects ofa nonuniform upstream cavity flow due to coupling. This new model predicts that the upstream perturbations in pressure and azimuthal velocity caused by this coupling can have a very strong impact on the pressure distribution in the seal gland itself. Augmentation by a factor of four, over the uniform inlet model, is predicted under some circumstances. Although no precise comparison to the experimental data with this new model was possible, due to the lack of control over the face seal venting the upstream cavity to the center hub plenum, the calculated effect of this coupling was shown to be approximately what was required to restore quantitative agreement between the data and theory
Generalizations of Eulerian partially ordered sets, flag numbers, and the Möbius function

A partially ordered set is r-thick if every nonempty open interval contains at least r elements. This paper studies the flag vectors of graded, r-thick posets and shows the smallest convex cone containing them is isomorphic to the cone of flag vectors of all graded posets. It also defines a k-analogue of the Mobius function and k-Eulerian posets, which are 2k-thick. Several characterizations of k-Eulerian posets are given. The generalized Dehn-Sommerville equations are proved for flag vectors of k-Eulerian posets. A new inequality is proved to be valid and sharp for rank 8 Eulerian posets.
Field theoretic branes and tachyons of the QCD string

Abstract Dvali and Shifman have proposed a field-theoretic mechanism for localizing gauge fields to “branes” in higher dimensional spaces using confinement in a bulk gauge theory. The resulting objects have a number of qualitative features in common with string theory D-branes; they support a gauge field and flux strings can end on them. In this letter, we explore this analogy further, by considering what happens when N of these “branes” approach each other. Unlike in the case of D-branes, we find a reduction of the gauge symmetry as the “branes” overlap. This can be attributed to a tachyonic instability of the flux string stretching between the branes.
Verticillium Wilt of Apricots

Following a brief introduction on the economic importance and reported causes of apricot dieback, the author describes the symptoms, both external and internal, induced by Verticillium dahliae Kleb., the wide host-range of this fungus, and its diagnostic features on various culture media. Verticillium wilt characteristically affects vigorously growing trees, the latter being most susceptible from 3 to 10 years old. There is either a sudden wilting or a progressive dieback; necrosis is clearly visible and vessels become occluded. Optimum mycelial growth occurs at 22–24°C (range 9–33 °C) and at pH 6.1–6.85 (range 3–3.5–12). Factors affecting growth of the pathogen, particularly the role of ascorbic acid content of fruit trees, are discussed. Epidemiology and control are also reviewed. There are no means for curing diseased trees; breeding offers the best chance for control.
Open Compared With Laparoscopic Approach to Burch Colposuspension: A Cost Analysis

Objective: To compare postoperative course and hospital charges of an open versus laparoscopic approach to Burch colposuspension for the treatment of genuine stress urinary incontinence. Methods: A retrospective chart review was performed to identify all patients undergoing open or laparoscopic Burch colposuspension by the same surgeon over a 2-year period. Patients undergoing additional surgical procedures at the time of colposuspension were excluded from the study. Twenty-one patients underwent open Burch colposuspension and 17 patients underwent laparoscopic colposuspension. Demographic data including age, parity, height, and weight were collected for each group. Both groups also were compared with regard to operative time, operating room charges, estimated blood loss, intraoperative complications, change in postoperative hematocrit, time required to resume normal voiding, length of hospital stay, and total hospital charges. Results: The laparoscopic colposuspension group had significantly longer operative times (110 versus 66 minutes, P < .01) and increased operating room charges ($3479 versus $2138, P < .001). There was no statistical difference in estimated blood loss or change in postoperative hematocrit between the two groups. No major intraoperative complications occurred in either group. Mean length of hospital stay was 1.3 days for the laparoscopic group and 2.1 days for the open group (P < .005). However, total hospital charges for the laparoscopic group were significantly higher ($4960 versus $4079, P < .01). Conclusion: Laparoscopic colposuspension has been described as a minimally invasive, cost-effective technique for the surgical correction of stress urinary incontinence. Although the laparoscopic approach was found to be associated with a reduction in length of hospital stay, it had significantly higher total hospital charges than the traditional open approach because of expenses associated with increased operative time and use of laparoscopic equipment.
Optimizing throughput on guaranteed-bandwidth WAN networks for the Large Synoptic Survey Telescope (LSST)

The Large Synoptic Survey Telescope (LSST) is a proposed 8.4-meter telescope that will be located in the Andes mountains in Chile. Every 17 seconds, a 6.4 GB image is transferred to Illinois for immediate processing. That transfer needs to complete within approximately five seconds. LSST is provisioning an international WAN with a 10Gbps bandwidth guarantee for this and other project-related data transfers. The stringent latency requirement drives a re-examination of TCP congestion control for this use case. Specifically, prior work on dedicated Long Fat Networks (LFNs) does not go far enough in fully leveraging the opportunity provided by the bandwidth guarantee. This paper presents an approach for how optimal network throughput can be obtained for the LSST use case, and the conditions under which any project can achieve data throughput rates on long-distance networks approaching wire speed.
Efficiency of lattice conditional independence models for multinormal samples with non-monotone missing data

For multivariate normal data with non-monotone (i.e. arbitrary) missing data patterns, lattice conditional independence (LCI) models determined by the observed data patterns can be used to obtain closed-form MLEs (Andersson and Perlman, 1991, 1993). In this paper, three procedures — LCI models, the EM algorithm, and the complete-data method — are compared by means of a Monte Carlo experiment. When the LCI model is accepted by the LR test, the LCI estimate is more efficient than those based on the EM algorithm and the complete-data method. When the LCI model is not accepted, the LCI estimate may lose efficiency but still may be more efficient than the EM estimate if the observed data is sparse. When the LCI model appears too restrictive, it may be possible to obtain a less restrictive LCI model by.discarding only a small portion of the incomplete observations. LCI models appear to be especially useful when the observed data is sparse, even in cases where the suitability of the LCI model is uncertain.
A one-pot synthesis of 3,3′-methylenebis(2-arylamino-4H-chromen-4-one) from C-(4-oxo-4H-1-benzopyran-3-yl)-N-arylnitrone

Abstract 2-(Arylamino)-4-oxo-4H-chromene-3-carbaldehyde 3 (R2 = aryl) produces 12H-chromeno[2,3-b]quinolin-12-one 4 when treated with sarcosine, piperidine or diethylamine, but produces 3,3′-methylenebis(2-arylamino-4H-chromen-4-one) 8 when treated with the same amine in the presence of an excess of formaldehyde. Compound 3 (R2 = alkyl) was found to be less reactive than the N-aryl analogues towards the deformylative Mannich-type reaction.
Impedance-match and element-pattern constraints for finite arrays

It is shown how an N -element antenna array may in principle be impedance matched by means of a specially designed interconnecting feed network to N real generators (for arbitrary excitation of these generators). The resulting element patterns for a single excited element (a single generator) in the terminated-array environment are then calculated. It is shown that for closely spaced regular arrays a condition of partial match, as contrasted with perfect match for all excitations, is the more appropriate design objective. The theory is illustrated through application to a uniform array of line sources. Element patterns obtained with an appropriately matched finite array are compared with those from the corresponding matched infinite-array model, the latter patterns having been obtained previously by an independent technique. The range of finite-array parameters to which the infinite-array model approximately applies is discussed.
City size and geographic segmentation in the municipal bond market

Abstract Anecdotal evidence suggests that the municipal bond market for issues of small cities operates differently from the market for issues of large cities. This research verifies differences in the determinants of net interest costs between a sample of small cities and a sample of large cities issuing general obligation debt during 1982. In particular, for the small city sample being unrated was not a significant factor in determining net interest costs, supporting claims that small unrated cities are able to substitute other sources of information for ratings and place their issues without paying higher net interest costs.
Neutrino and axion emissivities of neutron stars from nucleon–nucleon scattering data

Abstract Neutrino and axion production in neutron stars occurs mainly as bremsstrahlung from nucleon–nucleon (NN) scattering. The energy radiated via neutrinos or axions is typically very small compared to other scales in the two-nucleon system. The rate of emission of such “soft” radiation is directly related to the on-shell NN amplitude, and thereby to the NN experimental data. This facilitates the model-independent calculation of the neutrino and axion radiation rates which is presented here. We find that the resultant rates are roughly a factor of four below earlier estimates based on a one-pion-exchange NN amplitude.
Minimal Adaptive Routing on the Mesh with Bounded Queue Size

An adaptive routing algorithm is one in which the path a packet takes from its source to its destination may depend on other packets it encounters. Such algorithms potentially avoid network bottlenecks by routing packets around “hot spots.” Minimal adaptive routing algorithms have the additional advantage that the path each packet takes is a shortest one. For a large class of minimal adaptive routing algorithms, we present an ?(n2/k2) bound on the worst case time to route a static permutation of packets on ann×nmesh or torus with nodes that can hold up tok? 1 packets each. This is the first nontrivial lower bound on adaptive routing algorithms. The argument extends to more general routing problems, such as theh?hrouting problem. It also extends to a large class of dimension order routing algorithms, yielding an ?(n2/k) time bound. To complement these lower bounds, we present two upper bounds. One is anO(n2/k+n) time dimension order routing algorithm that matches the lower bound. The other is the first instance of a minimal adaptive routing algorithm that achievesO(n) time with constant sized queues per node. We point out why the latter algorithm is outside the model of our lower bounds.
ABJM mirrors and a duality of dualities

We clarify how mirror symmetry acts on 3d theories with = 2,3 or 4 supersymmetries and non-abelian Chern-Simons terms and then construct many new examples. We identify a new duality, geometric duality, that allows us to generate large families of gauge theories, with and without Chern-Simons term, that all flow to the same conformal field theory in the infrared. In particular, we find an interesting duality of dualities: a pair of theories related via mirror symmetry can be mapped, via geometric duality, into a pair of gauge theories related by Seiberg duality. This network of dualities can be understood as the simple result that all of these theories are different realizations of one and the same system in M-theory.
Towards Ultra-High Resolution Models of Climate and Weather

We present a speculative extrapolation of the performance aspects of an atmospheric general circulation model to ultra-high resolution and describe alternative technological paths to realize integration of such a model in the relatively near future. Due to a superlinear scaling of the computational burden dictated by stability criterion, the solution of the equations of motion dominate the calculation at ultra-high resolutions. From this extrapolation, it is estimated that a credible kilometer scale atmospheric model would require at least a sustained ten petaflop computer to provide scientifically useful climate simulations. Our design study portends an alternate strategy for practical power-efficient implementations of petaflop scale systems. Embedded processor technology could be exploited to tailor a custom machine designed to ultra-high climate model specifications at relatively affordable cost and power considerations. The major conceptual changes required by a kilometer scale climate model are certain to be difficult to implement. Although the hardware, software, and algorithms are all equally critical in conducting ultra-high climate resolution studies, it is likely that the necessary petaflop computing technology will be available in advance of a credible kilometer scale climate model
Synthesis, chromatographic resolution, and anti-human immunodeficiency virus activity of (±)-calanolide A and its enantiomers

The anti-HIV agent (±)-calanolide A (1) has been synthesized in a five-step approach starting with phloroglucinol [→ 5 → 6 → 11 → 18 → (±)-1], which includes Pechmann reaction, Friedel−Crafts acylation, chromenylation with 4,4-dimethoxy-2-methylbutan-2-ol, cyclization, and Luche reduction. Cyclization of chromene 11 to chromanone 18 was achieved by employing either acetaldehyde diethyl acetal or paraldehyde in the presence of trifluoroacetic acid and pyridine or PPTS. Luche reduction of chromanone 18 at lower temperature preferably yielded (±)-1. Reduction of chromone 12, synthesized by Kostanecki−Robinson reaction from chromene 11, failed to afford (±)-1. The synthetic (±)-1 has been chromatographically resolved into its optically active forms, (+)- and (−)-1. The anti-HIV activities for synthetic (±)-1, as well as resultant (+)- and (−)-1, have been determined. Only (+)-1 accounted for anti-HIV activity, which was similar to the data reported for the natural product, and (−)-1 was inactive.
Temporal bone verrucous carcinoma: outcomes and treatment controversy

Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial.
A Survey of Sequential Monte Carlo Methods for Economics and Finance

This article serves as an introduction and survey for economists to the field of sequential Monte Carlo methods which are also known as particle filters. Sequential Monte Carlo methods are simulation-based algorithms used to compute the high-dimensional and/or complex integrals that arise regularly in applied work. These methods are becoming increasingly popular in economics and finance; from dynamic stochastic general equilibrium models in macro-economics to option pricing. The objective of this article is to explain the basics of the methodology, provide references to the literature, and cover some of the theoretical results that justify the methods in practice.