cssi/SciSciGPT-SciSciNet huggingface dataset:
Bayesian inference for finite mixtures of generalized linear models with random effects

We present an hierarchical Bayes approach to modeling parameter heterogeneity in generalized linear models. The model assumes that there are relevant subpopulations and that within each subpopulation the individual-level regression coefficients have a multivariate normal distribution. However, class membership is not known a priori, so the heterogeneity in the regression coefficients becomes a finite mixture of normal distributions. This approach combines the flexibility of semiparametric, latent class models that assume common parameters for each sub-population and the parsimony of random effects models that assume normal distributions for the regression parameters. The number of subpopulations is selected to maximize the posterior probability of the model being true. Simulations are presented which document the performance of the methodology for synthetic data with known heterogeneity and number of sub-populations. An application is presented concerning preferences for various aspects of personal computers.
Designing zeolite catalysts for size- and shape-selective reactions: Selective hydrogenation of acetylene in the presence of butadiene and ethylene

In the production of ethylene from the steam cracking of natural gas, small amounts of acetylene and butadiene are produced. Downstream, acetylene can present a hazard in a cryogenic separation process while nonselective hydrogenation removes acetylene as well as valuable ethylene and butadiene. With the aid of adsorption measurements, a selective hydrogenation catalyst has been designed. Small-pore zeolites, which serve as catalytic supports and provide reactant selective control, were ion-exchanged with Ni2+ and subsequently reduced. Compared to a commercial catalyst in which 60% of butadiene and all of the acetylene are hydrogenated, these new catalysts totally hydrogenate acetylene with only 10–20% hydrogenation of the butadiene and almost no hydrogenation of ethylene. To achieve selective hydrogenation, poisoning of the metal sites on the external zeolite surface is essential in order to obtain a product spectrum dominated by catalytic sites within the zeolite framework.
Mapping of Transition Metal Redox Energies in Phosphates with NASICON Structure by Lithium Intercalation

The position of several transition metal redox energies with respect to the Fermi energy of lithium in phosphates with sodium super ionic conductor (NASICON) framework were determined electrochemically upon lithium intercalation. The materials studied were , and all having NASICON framework. The positions of the redox couples were found centered at the following energies: at 3.8 eV, at 2.8 eV, at 2.5 eV, at 2.2 eV, at 1.8 eV, and at 1.7 eV below the Fermi energy of lithium. Several of these redox couples were found to overlap each other. Some of these materials look promising as positive electrode materials for ‐ion batteries.
The Effect of Housing Wealth on College Choice: Evidence from the Housing Boom

We use NLSY97 data to examine how home price variation affects the quality of postsecondary schools students attend. We find a $10,000 increase in housing wealth increases the likelihood of public flagship university enrollment relative to nonflagship enrollment by 2.0 percent and decreases the relative probability of attending a community college by 1.6 percent. These effects are driven by lower-income families, predominantly by altering student application decisions. We also find home price changes affect direct quality measures of institutions students attend. Furthermore, for lower-income students, each $10,000 increase in home prices leads to a 1.8 percent increase in the likelihood of completing college.
Ring expansions of alkynyl cyclopentanols with iodine and Koser's reagent

Abstract Equimolar amounts of iodine, Koser's reagent, and 1-bromoethynylcyclopentanols with none, one or two methyl groups in the α-position lead to ring expansions in acetonitrile at room temperature in yields of 75 to 85%. In the so-formed 2-[bromoiodomethylidene]cyclohexanones, the (Z) isomer was preferred exclusively in the unsubstituted compound. The Z E ratio was 7.7 for the dimethyl compound and 3.3 for the monomethyl case. The corresponding bromine and Koser's reagent with 1-iodoethynylcyclopentanol afforded a ring expanded product with Z E ratio of 12:1.
Palladium-catalyzed cross-coupling reactions of heterocyclic silanolates with substituted aryl iodides and bromides.

Sodium silanolates derived from a number of heterocyclic silanols undergo cross-coupling with a variety of aromatic iodides and bromides under mild conditions. In situ deprotonation of the silanols with an equivalent amount of sodium hydride in toluene generates the sodium salt that couples with iodides under the action of Pd2(dba)3·CHCl3 in good yield at room temperature to 50 °C. The aromatic bromides also couple with these salts under the action of the Pd(I) catalyst 12.
Static Friction between Elastic Solids due to Random Asperities

Several workers have established that the Larkin domains for two three-dimensional nonmetallic elastic solids in contact with each other at a disordered but atomically flat interface are enormously large, implying that there should be negligible static friction per unit area in the macroscopic solid limit. In contrast, the present Letter argues that when the Larkin domains are calculated for disorder on the multiasperity scale, they are much smaller than the interface size. This can account for the virtual universal occurrence of static friction.
The Formation of stellar clusters: Mass spectra from turbulent molecular cloud fragmentation

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via competitive accretion from the surrounding cloud material. This process is investigated using numerical models of self-gravitating molecular cloud dynamics, where no turbulent support is included, where turbulence is allowed to decay freely, and where it is continuously replenished on large, intermediate, and small scales, respectively. Molecular cloud regions without turbulent driving sources, or where turbulence is driven on large scales, exhibit rapid and efficient star formation in a clustered mode, whereas interstellar turbulence that carries most energy on small scales results in isolated star formation with low efficiency. The clump-mass spectrum of shock-generated density fluctuations in non-self-gravitating hydrodynamic supersonic turbulence is not well fit by a power law, and it is too steep at the high-mass end to be in agreement with the observational data. When gravity is included in the turbulence models, local collapse occurs, and the spectrum extends toward larger masses as clumps merge together; then a power-law description dN/dM M? becomes possible with slope ? -2. In the case of pure gravitational contraction, i.e., in regions without turbulent support, the clump-mass spectrum is shallower with ? ? -3/2. The mass spectrum of protostellar cores in regions with no turbulent support and where turbulence is replenished on large scales, however, is well described by a lognormal or by multiple power laws, similar to the stellar initial mass function (IMF) at low and intermediate masses. The model clusters are not massive enough to allow for comparison with the high-mass part of the IMF. In the case of small-scale turbulence, the core mass spectrum is too flat compared to the IMF for all masses.
Compressible Boundary-Layer Stability Calculations for Sweptback Wings with Suction

The stability of the laminar boundary layers on two transonic wings of infinite span with distributed suction is investigated with the compressible, parallel-flow stability theory. Both wings have supercritical airfoil sections; one has a sweep angle of 23 deg, the other of 35 deg. Zero-frequency disturbances are used to represent cross-flow instability, and disturbances with the wavenumber vector aligned with the local flow direction represent traveling-wave instability. In both cases, the maximum spatial amplification rate is used as a measure of the instability. For the suction, distributions with constant mass flux downstream of the starting point are used. The main objective is to determine how the maximum amplification rate varies with the magnitude and starting point of the suction. It is found for both types of disturbances that the maximum amplification rate varies almost linearly with the suction magnitude up to at least the point where the amplification rate is halved. Different starting locations for the suction in the first 4% of the chord were found to affect cross-flow instability, but to have little influence on traveling-wave instability.
BAR-HALO FRICTION IN GALAXIES. III. HALO DENSITY CHANGES

The predicted central densities of dark matter halos in CDM models exceed those observed in some galaxies. Weinberg & Katz argue that angular momentum transfer from a rotating bar in the baryonic disk can lower the halo density,buttheyalsocontendthat N-bodysimulations of this processwill not reveal thetruecontinuumresult unless many more than the usual numbers of particles are employed. Adopting their simplified model of a rotating rigid bar in a live halo, I have been unable tofind any evidence to support their contention. Ifind that both the angular momentum transferred and the halo density change are independent of the number of particles over the range usually employed, up to that advocated by these authors. I show that my results do not depend on any numerical parameters and that field methods perform equally with grid methods. I also identify the reasons that the required particle number suggestedbyWeinberg&Katzisexcessive.Ifurthershowthatwhencountervailingcompressionbybaryonicsettlingis ignored, moderate bars can reduce the mean density of the inner halo by 20%Y30%. Long, massive, skinny bars can reduce the mean inner density by a factor � 10. The largest density reductions are achieved at the expense of removing mostoftheangularmomentumlikelytoresideinthebaryoniccomponent.Compressionof thehalobybaryonicsettling must reduce, and may even overwhelm, the density reduction achievable by bar friction. Subject headingg galaxies: evolution — galaxies: formation — galaxies: halos — galaxies: kinematics and dynamics — galaxies: spiral
A Simulation Study of Work-in-Process Inventory Drive Systems and their Effect on Operational Measurements

This simulation study compares three operational measures of performance through the exploration of three work-in-process (WIP) inventory drive systems and their associated inventory buffer characteristics. The three drive systems under study are a push, a pull and a hybrid push-pull system. While these systems have many aspects in common, their buffer management systems do not. The data analysis was based on information gathered from three computer-simulated flow shop assembly lines all operating in the same environment. Hypotheses concerning the operational performance measurements were established, independent variables were controlled and manipulated and a conclusion was drawn as to which system would afford the operation optimum results. While inventory has traditionally been considered and is currently being shown as an asset from an accounting point of view, it is obvious from the findings of this study, that excess WIP inventory, above the minimal requirements for production, may have a negative effect on the operational measurements evaluated.
Metastability in the Furstenberg-Zimmer Tower

According to the Furstenberg-Zimmer structure theorem, every measure-preserving system has a maximal distal factor, and is weak mixing relative to that factor. Furstenberg and Katznelson used this structural analysis of measure-preserving systems to provide a perspicuous proof of Szemeredi’s theorem. Beleznay and Foreman showed that, in general, the transfinite construction of the maximal distal factor of a separable measure-preserving system can extend arbitrarily far into the countable ordinals. Here we show that the Furstenberg-Katznelson proof does not require the full strength of the maximal distal factor, in the sense that the proof only depends on a combinatorial weakening of its properties. We show that this combinatorially weaker property obtains fairly low in the transfinite construction, namely, by the ωω ω th level.
Thermoelectric power of graphite intercalation compounds

A model for the temperature variations of the thermoelectric power (TEP) of acceptor graphite intercalation compounds (GIC's) is presented. At low temperatures, the TEP in GIC's increases monotonically with $T$, then levels off above \ensuremath{\sim}200 K in striking contrast to that of pristine graphite. The diffusion contribution to the TEP is proportional to $T$ and its magnitude is small as compared with that of the observed data. This observed behavior is attributed to the phonon drag effect. In the temperature region where the TEP is weakly temperature dependent, phonon relaxation is mainly controlled by the Rayleigh scattering due to point defects. The resultant TEP, which is composed of the phonon drag and diffusion terms, leads to a nearly $T$-independent value. Since the cross-sectional diameter of the Fermi surface in GIC's is larger than that of pristine graphite, the relaxation rate of the Rayleigh scattering, which is given by $\frac{1}{{t}_{I}(q)}=f{q}^{3}$, becomes very large at high temperatures ($Tg100$ K). At low temperatures, where the boundary scattering plays a dominant role, the TEP is proportional to ${T}^{3}$. Detailed calculations are carried out by solving the phonon-carrier-coupled Boltzmann equation.
The Oregon Health Plan: A Process for Reform

Abstract [Kitzhaber JA: The Oregon health plan : A process for reform. Ann Emerg Med February 1994;23:330-333]
A Policy Analysis of the Federal Growth Model Pilot Program's Measures of School Performance: The Florida Case

Abstract As test-based educational accountability has moved to the forefront of national and state education policy, so has the desire for better measures of school performance. No Child Left Behind's (NCLB) status and safe harbor measures have been criticized for being unfair and unreliable, respectively. In response to such criticism, in 2005 the federal government announced the Growth Model Pilot Program, which permits states to use projection models (a type of growth model) in their accountability systems. This article uses historical longitudinal data from a large school district to empirically show the inaccuracy of one state's projection model, to demonstrate how projection models are very similar to NCLB's original status measure, and to contrast projection models with value-added models. As policy makers debate the reauthorization of NCLB, this research can provide guidance on ways to improve the current measurement of school performance.
Completion of Katz-Qin-Ruan’s enumeration of genus-two plane curves

We give a formula for the number of genus-two fixed-complex-structure degree-d plane curves passing through 3d−2 points in general position. This is achieved by completing Katz-Qin-Ruan’s approach. This paper’s formula agrees with the one obtained by the author in a completely different way.
Dual Molecular Signals Mediate the Bacterial Response to Outer-Membrane Stress

In Gram-negative bacteria, outer-membrane integrity is essential for survival and is monitored by the σ(E) stress-response system, which initiates damage-repair pathways. One activating signal is unassembled outer-membrane proteins. Using biochemical and genetic experiments in Escherichia coli, we found that off-pathway intermediates in lipopolysaccharide transport and assembly provided an additional required signal. These distinct signals, arising from disruptions in the transport and assembly of the major outer-membrane components, jointly determined the rate of proteolytic destruction of a negative regulator of the σ(E) transcription factor, thereby modulating the expression of stress-response genes. This dual-signal system permits a rapid response to dysfunction in outer-membrane biogenesis, while buffering responses to transient fluctuations in individual components, and may represent a broad strategy for bacteria to monitor their interface with the environment.
Chemoselective three-component coupling via a tandem Pd-catalyzed boron-Heck and Suzuki reactions

A new approach is herein reported to prepare biaryl derivatives via a tandem Pd-catalyzed boron-Heck and Suzuki reactions. This one-pot tandem process avoided purification or addition of extra catalyst between steps. The resulting biaryl compounds can be prepared with substrate variability in good to moderate yields.
An FIO Calculus for Marine Seismic Imaging: Folds and Cross Caps

We consider a linearized inverse problem arising in offshore seismic imaging. Following Nolan and Symes (1997b), one wishes to determine a singular perturbation of a smooth background soundspeed in...
Ruthenium-catalyzed silyl ether formation and enyne metathesis sequence: synthesis of siloxacycles from terminal alkenyl alcohols and alkynylsilanes.

Two consecutive ruthenium-catalyzed reactions have been achieved for the synthesis of siloxacycles from terminal alkenyl carbenols and alkynylsilanes. The metal-catalyzed dehydrogenative condensation between alcohols and silanes, generating molecular hydrogen as the only byproduct, allows for the subsequent enyne metathesis without isolating the intermediate silyl ethers. This system provides a streamlined synthesis of synthetically useful building blocks.
Stereoselective intramolecular cyclopropanations: Enantioselective syntheses of 1α,25-dihydroxyvitamin D3 A-ring precursors

Abstract Two efficient enantioselective syntheses of an A-ring precursor to 1 α,25-dihydroxyvitamin D3 have been developed. The key step in these sequences involves the stereoselective cyclopropanation of a chiral γ-alkoxy-α-diazo-β-keto ester. In one sequence, the 1 α-hydroxy group was introduced in the first step by a diastereoselective ene reaction and in the other sequence by use of (S)-malic acid as starting material. Both routes eliminate the need for a SeO2 oxidation.
ICESat validation of SRTM C‐band digital elevation models

[1] The Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud, and land Elevation Satellite (ICESat) provides a globally-distributed data set well suited for evaluating the vertical accuracy of Shuttle Radar Topography Mission (SRTM) digital elevation models (DEMs). The horizontal error (2.4 ± 7.3 m) and vertical error (0.04 ± 0.13 m per degree of incidence angle) for the ICESat data used are small compared to those for SRTM. Using GLAS echo waveforms we document differences between the SRTM C-band phase center and the highest, centroid, and lowest elevations within ICESat laser footprints in the western United States. In areas of low relief and sparse tree cover, the mean and standard deviation of elevation differences between the ICESat centroid and SRTM are −0.60 ± 3.46 m. The differences are −5.61 ± 15.68 m in high relief, sparse tree cover areas, and −3.53 ± 8.04 m in flat areas with dense tree cover. The largest differences occur in rugged, densely-vegetated regions.
Criteria for comparison of methods of solution of the inverse heat conduction problem

Abstract Some criteria are presented for comparing methods of solution of the inverse heat conduction problem. These include accuracy when using exact data, insensitivity to measurement errors, and stability for small time steps. The criteria are applied to a method previously given by the author; it is shown herein that as measurement errors become larger, the time steps must increase for a given accuracy of the calculated surface heat flux or temperature. New results are also presented for a multiple number of temperature sensors. In addition, it is demonstrated how the procedure can be applied to correlated measurement errors. Some methods used by other investigators are also briefly considered.
The Investment Effect of Taxation: Evidence from a Corporate Tax Kink

This paper exploits bunching of firms at a tax kink as quasi-experimental variation to identify the effect of a tax rate change on investment (reported capital allowances). The idea is that firms with a taxable income slightly above the kink have an incentive to reduce their income to bunch at the kink, and increasing investment is one possible strategy for that. This means that bunching of firms should be accompanied by a spike in investment at the kink. Building on the standard bunching framework, I estimate the frequency distribution of firms around the kink and the share of bunchers with excess investments at the extensive and intensive margins. I apply this approach to administrative tax return data for the universe of UK firms from 2001 to 2007 and show that investment by small firms responds significantly to a tax rate change. I find large and significant spikes in the share of capital investors and median capital costs at the £10,000 kink. The spikes are larger in 2002–05, when the kink is larger, and for quickly depreciating capital items, which yield larger tax reductions. Different pieces of evidence suggest that the investment spikes are at least partly driven by avoidance and evasion behaviour such as misreporting and claiming capital allowances for personal-use items.
Rigid-body structural mode coupling on a forward swept wing aircraft

Aeroelastic studies of a free-flying forward swept wing (FSW) aircraft have shown that the static aeroelastic divergence exhibited on cantilevered FSW's is replaced with a low-frequency flutter mode due to coupling between the wing divergent mode and the aircraft short-period mode. Studies of possible means of increasing this flutter speed have indicated that adding structural stiffness would result in prohibitive weight or drag penalties. An active flutter control system that employed the existing stability augmentation system of the aircraft was shown to increase the flutter speed by 40% without a performance penalty. The active flutter control system actually decreased the workload of the aircraft stability augmentation system. The coupling between the wing divergent mode and the aircraft short-period mode is also shown to have detrimental effects on flying qualities, ride qualities, and gust loads, but these effects are minimized by the active flutter control system.
Analysis of Signals Under Compositional Noise With Applications to SONAR Data

In this paper, we consider the problem of denoising and classification of SONAR signals observed under compositional noise, i.e., they have been warped randomly along the x-axis. The traditional techniques do not account for such noise and, consequently, cannot provide a robust classification of signals. We apply a recent framework that: 1) uses a distance-based objective function for data alignment and noise reduction; and 2) leads to warping-invariant distances between signals for robust clustering and classification. We use this framework to introduce two distances that can be used for signal classification: a) a y-distance, which is the distance between the aligned signals; and b) an x-distance that measures the amount of warping needed to align the signals. We focus on the task of clustering and classifying objects, using acoustic spectrum (acoustic color), which is complicated by the uncertainties in aspect angles at data collections. Small changes in the aspect angles corrupt signals in a way that amounts to compositional noise. We demonstrate the use of the developed metrics in classification of acoustic color data and highlight improvements in signal classification over current methods.
Gravitational Radiation Damping in Systems With Compact Components

The radiation reaction force and balance equations are derived for slow-motion, gravitationally bound systems with compact components such as neutron stars and black holes. To obtain these results, use is made of the Einstein-Infeld-Hoffmann (EIH) procedure. As a consequence, all quantities involved in the derivation are finite and hence no renormalization is required. Furthermore, no laws of motion for the components need be assumed. Approximate expressions for the fields required to evaluate the EIH surface integrals are obtained using the methods of matched asymptotic expansions and multiple time scales. The results obtained are the same as those derived previously for systems with noncompact components.
Floodplains and wood

Abstract Interactions between floodplains and wood date to the Carboniferous, when stable, multithread channel deposits appear with the evolution of tree-like plants. Foundational geologic texts, such as Lyell's, 1830 Principles of Geology, describe floodplain–wood interactions, yet modern technical literature describes floodplain–wood interactions in detail for only a very limited range of environments. This likely reflects more than a century of deforestation, flow regulation, and channel engineering, including instream wood removal, which has resulted in severe wood depletion in most of the world's river networks. Instream wood affects floodplain form and process by altering flow resistance, conveyance and channel–floodplain connectivity, and influencing lateral and vertical accretion of floodplains. Instream wood reflects floodplain form and process as the floodplain influences wood recruitment via bank erosion and overbank flow, and wood transport and storage via floodplain effects on stage-discharge relations and flow resistance. Examining turnover times for instream wood at the reach scale in the context of a wood budget, floodplain characteristics influence fluvial transport and dynamics (wood recruitment), valley geometry (wood transport and storage), and hydraulics and river biota (wood decay and breakage). Accumulations of wood that vary from in situ jams and beaver dams in small channels to transport jams and log rafts in very large rivers can create stable, multithread channels and floodplain wetlands. Floodplain–wood interactions are best understood for a subset of small to medium-sized rivers in the temperate zone. We know little about these interactions on very large rivers, or on rivers in the tropical or boreal regions. This review suggests that most, if not all, channels and floodplains within forested catchments in the temperate zone historically had much greater wood loads and consequently much more obvious and important influences from wood than do heavily modified contemporary catchments. For many rivers in the temperate zone, direct and indirect removal of instream wood very likely caused a fundamental shift in channel and floodplain process and form, as has been demonstrated in detail for specific rivers of diverse size in several regions. Failure to explicitly include floodplain–wood interactions creates a misleading conceptual model of floodplain dynamics in forested catchments.
An interactive system for aiding management decision making

An interactive application program running on the PDP11 UNIX time-sharing system is described. This program allows files describing sets of objects to be searched, and each object evaluated against a selection expression. Objects satisfying the expression are kept in primary storage as sets (linked lists), and the user can delete or move objects from one set to another under control of other interactively composed selection criteria. The system thereby "assists" the user's decision making process. Examples of objects might include people, machines, rooms, organizations, cities and tasks. The program itself is not revolutionary in concept, although it does take some ideas from artificial intelligence. However, its rapid and evolutionary development on a minicomputer shows how highly accessible and affordable computers with good software production tools can bring the computer, as a decision making aid, to organizations not previously able to make effective use of computation. Furthermore, the utilization of advanced software tools has permitted a flexible English-like man-machine interface to be developed, allowing use by computer-naive managers.
Assessing and improving commonality and diversity within a product family

At a time when product differentiation is a major indicator of success in the global market, each company is looking to offer competitive and highly differentiated products. This differentiation issue is restricted by the design of platform-based products that share modules and/or components. It is not easy to differentiate products in a market that is often overwhelmed by numerous options. A platform-based approach can be risky because competition in the global market can become an internal competition among similar products within the family if there is not enough differentiation in the family. Thus, the goal for the product platform is to share elements for common functions and to differentiate each product in the family by satisfying different targeted needs. To assess commonality in the family, numerous indices have been proposed in the literature. Nevertheless, existing indices focus on commonality and reflect an increase in value when commonality increases but do not positively reflect an increase in the value as a result of diversity; hence, the commonality versus diversity index (CDI) is introduced in this paper to assess the commonality and diversity within a family of products or across families. The CDI has variable levels of depth analysis to help designers design or improve the product family. Two case studies using single-use cameras and power tool families highlight the usefulness of this new index.
Discovery of a 105-ms X-ray Pulsar in Kesteven-79: On the Nature of Compact Central Objects in Supernova Remnants

We report the discovery of 105-ms X-ray pulsations from the compact central object (CCO) in the supernova remnant \snr\ using data acquired with the {\it Newton X-Ray Multi-Mirror Mission). Using two observations of the pulsar taken 6-days apart we derive an upper limit on its spin-down rate of $\dot P 18.5$-kyr. The latter exceeds the remnant's estimated age, suggesting that the pulsar was born spinning near its current period. The X-ray spectrum of \psr\ is best characterized as a blackbody of temperature $kT {BB) =, 0.43\pm0.02$ keV, radius $R-{BB) \approx 1.3$-km, and $~I{\rm bol) = 5.2 \times 10A{33)$ ergs-sSA{-1)$ at $d = 7.1$-kpc. The sinusoidal light curve is modulated with a pulsed fraction of $>45\%$, suggestive of a small hot spot on the surface of the rotating neutron star. The lack of a discernible pulsar wind nebula is consistent with an interpretation of \psr\ as a rotation-powered pulsar whose spin-down luminosity falls below the empirical threshold for generating bright wind nebulae, $\dot E-{\rm c) = 4 \times 10A{36)$-ergs-sSA{-I)$. The age discrepancy suggests that its $\dot E$ has always been below $\dot E c$, perhaps a distinguishing property of the CCOs. Alternatively, the X-ray spectrum of \psr\ suggests a low-luminosity AXP, but the weak inferred $B-{\rm p)$ field is incompatible with a magnetar theory of its X-ray luminosity. The ordinary spin parameters discovered from \psr\ highlight the inability of existing theories to explain the high luminosities and temperatures of CCO thermal X-ray spectra.
The vibrational assignment of tetronic acid

Abstract Infrared and FT-Raman spectra of both deuterated and undeuterated tetronic acid have been examined. The enol form predominates in the solid form, but some keto form is apparent in the spectra. Reported here are the tentative assignments for all bands observed from 4000 to 200 cm −1 . Group frequencies obtained by comparing the spectral data acquired with vibrational assignments of similar compounds by other investigators were used to aid the assignment. The spectra are consistent with a C S point group, indicating the structure of tetronic acid to be planar in the solid state.
Quantifying Ventilatory Reserve to Predict Respiratory Failure in Exacerbations of COPD

We developed a concept of VR in patients with acute exacerbation of advanced COPD and tested the hypothesis that it is predictable and clinically useful in the ER. Our concept of VR was based on the idea that a threshold VF and a MSV capacity are measurable; ie, VR = MSV – VF. We measured resting minute ventilation, the 15-s MVV, FEV 1 and ABG values in 13 patients with exacerbation of COPD in the ER and 11 stable subjects with similar degrees of COPD. We tested if measures of VR could distinguish between ER patients progressing to respiratory failure, ER patients who avoided progression to respiratory failure and stable patients. There were significant differences in measures of the mean VR between various groups of patients. We conclude that in this COPD population, VR can be accurately predicted in the ER and that it may be a clinically valid predictor of patient outcomes.
Cooperative dual catalysis: application to the highly enantioselective conjugate cyanation of unsaturated imides.

Cooperative heterobimetallic catalysis was used as a design principle to achieve a highly reactive system for the enantioselective conjugate addition of cyanide to α,β-unsaturated imides. A dual-catalyst pathway involving chiral (salen)Al complex 1b and chiral (pybox)Er complex 4b provides measurable improvements in rates and enantioselectivities relative to single-catalyst systems. Mechanistic studies point to a cooperative bimetallic mechanism involving activation of the imide by the Al complex and activation of cyanide by the Er complex.
An analysis of three-dimensional elasto-plastic sinusoidal contact

Researchers have developed many models to simulate the elasto-plastic contact of spheres. However, there does not appear to exist a closed-form analytical model for elasto-plastic three-dimensional sinusoidal contact. This work uses a finite element model (FEM) to characterize elasto-plastic sinusoidal contact. Although at initial contact the sphere and sinusoidal case are very similar and can both be described by the classic elastic Hertz contact case, once the contact is pressed past a certain range of deformation the two cases are very different. The model produces equations which can be used to approximately relate the area of contact to the contact pressure for elasto-plastic sinusoidal contact. The equations are fit to the FEM results and existing elastic solutions of sinusoidal contact. An empirical expression for the average pressure which causes complete contact between elasto-plastic sinusoidal contacts is also provided.
A Schwarz lemma on the polydisk

We prove a generalization of the infinitesimal portion of the classical Schwarz lemma for functions from the polydisk to the disk. In particular, we describe the functions which play the role of automorphisms of the disk in this context-they turn out to be rational inner functions in the Schur-Agler class of the polydisk with an added symmetry constraint. In addition, some sufficient conditions are given for a function to be of this type.
A flexible synthesis of 2,3-disubstituted indoles from aminobenzyl phosphonium salts. A direct synthesis of rutaecarpine.

The reaction of substituted (2-aminobenzyl)triphenylphosphonium bromides with aromatic aldehydes or α,β-unsaturated aldehydes constitutes a new synthesis of 2,3-disubstitued indoles in high yields. The adduct from 4-oxo-3,4-dihydroquinazoline-2-carbaldehyde was an advanced intermediate in the synthesis of several rutaecarpines.
Hierarchical Structure Formation and Chemical Evolution of Galaxies

We present an analytical and phenomenological model for metal enrichment in halos based on hierarchical structure formation. This model assumes that astration of normal stellar populations along with Type II supernovae (SNe II) already occurs at very high redshift. It focuses on the regime of [Fe/H] -1, in which SNe Ia are major contributors, is also discussed in general. For halos that are not disrupted by SN II explosions, the chemical evolution of the gas and stars is explicitly determined by the rate of gas infall as compared with the astration rate and the corresponding rate of metal production by SNe II per H atom in the gas. This model provides a good description of the data on [Fe/H] for damped Lyα systems over a wide range of redshift, 0.5 < z < 5. For all halos not disrupted by SN II explosions, if there is a cessation of gas infall, the metallicities of the stars follow a bimodal distribution. This distribution is characterized by a sharp peak at the value of [Fe/H] corresponding to the time of infall cessation and by a broad peak at a higher value of [Fe/H] corresponding to the subsequent period of astration during which the bulk of the remaining gas forms stars. Such a distribution can be compared with that observed for the Galactic halo stars. If the gas in a halo is rapidly lost on cessation of infall, then an assemblage of stars with a very sharply defined [Fe/H] value will be left behind. This assemblage of stars may be accreted by a larger system and become a globular cluster of the larger system. We discuss the masses and metallicities of the globular clusters in this model considering the criterion for the onset of astration and possible disruption of low-mass halos by SN II explosions. The implications of possible globular clusters with very low metallicities of [Fe/H] ≾-3 are also discussed.
One-pot Claisen rearrangement/O-methylation/alkene isomerization in the synthesis of ortho-methoxylated phenylisopropylamines

Abstract An improved synthesis of a potent serotonin agonist 1a and its novel derivative 1b is described, making use of a Claisen rearrangement whose unstable phenolic product is methylated and isomerized in situ . This method may be of general use in the synthesis of o -methoxylated phenethylamine derivatives. The synthesis also includes an unusual, one pot demethylation/primary alcohol bromination with boron tribromide.
XenLoop: a transparent high performance inter-VM network loopback

Advances in virtualization technology have focused mainly on strengthening the isolation barrier between virtual machines (VMs) that are co-resident within a single physical machine. At the same time, a large category of communication intensive distributed applications and software components exist, such as web services, high performance grid applications, transaction processing, and graphics rendering, that often wish to communicate across this isolation barrier with other endpoints on co-resident VMs. State of the art inter-VM communication mechanisms do not adequately address the requirements of such applications. TCP/UDP based network communication tends to perform poorly when used between co-resident VMs, but has the advantage of being transparent to user applications. Other solutions exploit inter-domain shared memory mechanisms to improve communication latency and bandwidth, but require applications or user libraries to be rewritten against customized APIs--something not practical for a large majority of distributed applications. In this paper, we present the design and implementation of a fully transparent and high performance inter-VM network loopback channel, called XenLoop, in the Xen virtual machine environment. XenLoop does not sacrifice user-level transparency and yet achieves high communication performance between co-resident guest VMs. XenLoop intercepts outgoing network packets beneath the network layer and shepherds the packets destined to co-resident VMs through a high-speed inter-VM shared memory channel that bypasses the virtualized network interface. Guest VMs using XenLoop can migrate transparently across machines without disrupting ongoing network communications, and seamlessly switch between the standard network path and the XenLoop channel. In our evaluation using a number of unmodified benchmarks, we observe that XenLoop can reduce the inter-VM round trip latency by up to a factor of 5 and increase bandwidth by a up to a factor of 6.
Can tax policy help explain state-level macroeconomic growth?

Abstract This paper empirically tests the role of tax distortions in explaining state-level economic growth through the estimation of disaggregated personal income, general sales and property tax rates. The results show that these disaggregated tax rates generate predictions more consistent with growth theory.
Asymmetric Synthesis of Tertiary Benzylic Alcohols

Vinyl, aryl, and alkynyl organometallics add to ketones containing a stereogenic sulfoxide. Tertiary alcohols are generated in diastereomerically and enantiomerically pure form. Reductive lithiation converts the sulfoxide into a variety of useful functional groups.
Gain Function And Hydrocarbon Indicators

Gassmann’s equation is usually used to describe the fluid saturation effects on seismic velocity. A general assumption is that pore fluid pressure generated in seismic wave front has enough time to equilibrium. In this study, we use the Gassmann’s equation to define “Gain Function”. Then, we discuss properties of the gain function for consolidated sandstone and weakly cemented sands from deep-water.
Dark energy, a cosmological constant, and type Ia supernovae

We focus on uncertainties in supernova measurements, in particular of individual magnitudes and redshifts, to review to what extent supernovae measurements of the expansion history of the universe are likely to allow us to constrain a possibly redshift-dependent equation of state of dark energy, w(z). We focus in particular on the central question of how well one might rule out the possibility of a cosmological constant w = −1. We argue that it is unlikely that we will be able to significantly reduce the uncertainty in the determination of w beyond its present bounds, without significant improvements in our ability to measure the cosmic distance scale as a function of redshift. Thus, unless the dark energy significantly deviates from w(z) = −1 at some redshift, very stringent control of the statistical and systematic errors will be necessary to have a realistic hope of empirically distinguishing exotic dark energy from a cosmological constant.
Infall of the Elliptical Galaxy NGC 1404 into the Fornax Cluster

We use three Chandra observations, totaling 134.3 ks, to constrain the dynamical motion of NGC 1404 falling toward the dominant elliptical NGC 1399 through the Fornax Cluster gas. The surface brightness profile of NGC 1404 shows a sharp edge at ~8 kpc from its center in the direction of NGC 1399, characteristic of jumplike temperature and density discontinuities from ram pressure stripping of the galaxy gas, caused by its motion through the surrounding intracluster medium (ICM). We find that the temperature of the galaxy gas inside the edge is ~2.8 times cooler (kT = 0.55 keV with abundance A = 0.73 Z☉) than the cluster gas (kT = 1.53 keV, A = 0.42 Z☉). We use the shape of the surface brightness profile across the edge to fit the position of the edge, the power-law behavior of NGC 1404's density distribution in the leading direction, and the density discontinuity at the edge. The electron density inside the edge (3.9-4.3) × 10-3 cm-3 depends strongly on the gas abundance, while the density of the ICM (7-8) × 10-4 cm-3 depends strongly on the assumed geometry (relative distance) between NGC 1404 and NGC 1399. The corresponding pressure jump of 1.7-2.1 across the leading edge of the galaxy and the cluster free-stream region implies near sonic motion (Mach number 0.83-1.03) for NGC 1404 with a velocity 531-657 km s-1 relative to the surrounding cluster gas. The inclination angle of the motion, inferred using the relative radial velocity between NGC 1404 and 1399 as representative of that between NGC 1404 and the cluster ICM, is uncomfortably large (40°) given the sharpness of the surface brightness edge, suggesting either a nonzero impact parameter between NGC 1404 and 1399 or that NGC 1399 is also moving radially with respect to the cluster ICM.
Synthesis of the 2β,3β-, 2α,3β-, 2β,3α- and 2α,3α- isomers of 6β-hydroxy-3-(p-tolyl)tropane-2-carboxylic acid methyl ester

Abstract 6-Hydroxytropanone ( 8 ) was synthesized by a Mannich type condensation between acetonedicarboxylic acid, methylamine hydrochloride, and the hydrolysis product of 2,5-dimethoxydihydrofuran and was used as the key intermediate for the synthesis of the four racemic isomers of 6β-hydroxy-2-(methoxycarbonyl)-3-( p -tolyl)tropane.
Task-specific ionic liquids for the extraction of metal ions from aqueous solutions

Imidazolium cations, such as those commonly used in preparing ionic liquids (ILs) can easily be derivatized to include task-specific functionality, such as metal ligating groups that when used as part of the solvent or doped into less expensive ILs, dramatically enhance the partitioning of targeted metal ions into the IL phase from water; the strategy of preparing task-specific ILs is applicable to a wide range of designer solvent needs.
Quantization ambiguities and bounds on geometric scalars in anisotropic loop quantum cosmology

We study quantization ambiguities in loop quantum cosmology that arise for space-times with non-zero spatial curvature and anisotropies. Motivated by lessons from different possible loop quantizations of the closed Friedmann–Lemaitre–Robertson–Walker cosmology, we find that using open holonomies of the extrinsic curvature, which due to gauge-fixing can be treated as a connection, leads to the same quantum geometry effects that are found in spatially flat cosmologies. More specifically, in contrast to the quantization based on open holonomies of the Ashtekar–Barbero connection, the expansion and shear scalars in the effective theories of the Bianchi type II and Bianchi type IX models have upper bounds, and these are in exact agreement with the bounds found in the effective theories of the Friedmann–Lemaitre–Robertson–Walker and Bianchi type I models in loop quantum cosmology. We also comment on some ambiguities present in the definition of inverse triad operators and their role.
Coronal Loop Expansion Properties Explained Using Separators

One puzzling observed property of coronal loops is that they are of roughly constant thickness along their length. Various studies have found no consistent pattern of width variation along the length of loops observed by TRACE and SOHO. This is at odds with expectations of magnetic flux tube expansion properties, which suggests that loops are widest at their tops, and significantly narrower at their footpoints. Coronal loops correspond to areas of the solar corona which have been preferentially heated by some process, so this observed property might be connected to the mechanisms that heat the corona. One means of energy deposition is magnetic reconnection, which occurs along field lines called separators. These field lines begin and end on magnetic null points, and loops forming near them can therefore be relatively wide at their bases. Thus, coronal energization by magnetic reconnection may replicate the puzzling expansion properties observed in coronal loops. We present results of a Monte Carlo survey of separator field line expansion properties, comparing them to the observed properties of coronal loops.
Short-term wind power prediction using a wavelet support vector machine

This paper proposes a wavelet support vector machine (WSVM)-based model for short-term wind power prediction (WPP). A new wavelet kernel is proposed to improve the generalization ability of the support vector machine (SVM). The proposed kernel has such a general characteristic that some commonly used kernels are its special cases. Simulation studies are carried to validate the proposed model with different prediction schemes by using the data obtained from the National Renewable Energy Laboratory (NREL). Results show that the proposed model with a fixed-step prediction scheme is preferable for short-term WPP in terms of prediction accuracy and computational cost. Moreover, the proposed model is compared with the persistence model and the SVM model with radial basis function (RBF) kernels. Results show that the proposed model not only significantly outperforms the persistence model but is also better than the RBF-SVM in terms of prediction accuracy.