cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurements And Analysis Of Helium-Like Triplet Ratios In The X-Ray Spectra Of O-Type Stars

We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of heliumliketripletsintheX-rayspectraof O-typestars,includingaccountingforthespatialdistributionoftheX-ray-emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X-ray-emitting plasma spatially distributed in the wind above some minimum radius R0. We find minimum radii of formation typically in the range of 1:25 < R0/R� < 1:67, which is consistent with results obtained independentlyfrom line profilefits. Wefindno evidence for anomalously low f /iratios, and we do not require the existence of X-ray-emitting plasmas at radii that are too small to generate sufficiently strong shocks.
Cycloaddition of phosphenium ions to norbornadiene and quadricyclane

Abstract Bis(dimethylamino)-, bis(diethylamino)-, and chloro(diisopropylamino)phosphenium ions ( 1a–c , respectively) react cleanly with norbornadiene ( N ) to yield the homo-1,4-cycloadducts ( 2a–c ). In addition, 1c reacts cleanly with quadricyclane ( Q ) to yield the same product.
Contribution of first-principles energetics to the Ca-Mg thermodynamic modeling

Abstract The first-principles energetics of the constituent elements Ca and Mg and the Mg2Ca C14 laves phase (C14) in the Ca–Mg binary system were used in the computational thermodynamic modeling, with models for the Gibbs energy of individual phases. C14 was modeled as (Ca,Mg)2(Ca,Mg)1 with four end-members. The first-principles calculations were performed using two computer codes: (i) WIEN2K based on the full-potential linearized augmented plane-wave (FLAPW) method and (ii) VASP based on the pseudo-potentials and a plane wave basis set. The total energies of the pure Ca and Mg in the fcc, bcc, and hcp structures, three laves phase structures of Mg2Ca, and the four end-members of C14 were calculated at 0 K. The enthalpies of formation of the four end-members were obtained accordingly and used as input data in evaluating the Gibbs energy functions of C14. The entropy contribution in the Gibbs energy function for C14 was obtained through its liquidus data. Special quasirandom structures are used to mimic random mixing in the C14 laves phase for two compositions, i.e. (Mg)2(Ca0.5,Mg0.5) and (Ca0.5,Mg0.5)2(Ca). The complete thermodynamic description of the Ca–Mg binary system with C14 modeled as a solution phase was obtained by this combined computational thermodynamics/first-principles approach showing a good agreement with experimental data and previous modeling in the literature.
Escaping from Swarms

Swarming behavior extends across multiple length scales in biology ranging from bacteria to whales. Swarms are affected differently by erratic, dissenting behavior, sometimes a swarm will follow an agent which changes directions, such as a school of fish when they are done feeding, while other times the swarm lets the individual leave the group while the swarm continues on its way, like a few birds leaving the flock to land in a tree. This research investigates the different universal swarm characteristics that can lead to these different kinds of behaviors. We model flocks with a finite number of agents utilizing a velocity alignment interaction and a Lennard-Jones potential, which provides both cohesive and repulsive interactions between neighboring agents. In the swarming regime of our model, an agent is selected at random to “escape” the flock, by choosing a particular direction to travel in, and no longer align with it's neighbors. We found that close to the swarming transition the escapee was unable to escape, while deeper in the swarming regime the swarm was more stable and the particle was able to escape with little effect on the rest of the swarm. Our research sheds light on the varied responses of swarms to internal dissent and suggests optimal strategies to escape or reorient swarms that exploit these responses.
MATCHING CHARACTERISTIC CODES: EXPLOITING TWO DIRECTIONS

Combining incoming and outgoing characteristic formulations can provide numerical relativists with a natural implementation of Einstein's equations that better exploits the causal properties of the spacetime and gives access to both null infinity and the interior region simultaneously (assuming the foliation is free of caustics and crossovers). We discuss how this combination can be performed and illustrate its behavior in the Einstein–Klein–Gordon field in 1D.
Effect of the renin-angiotensin system in the vascular disease of type II diabetes mellitus

Abstract A universal underlying abnormality in the pathogenesis of hypertension, atherosclerosis, myocardial dysfunction, and diabetic glomerulosclerosis involves alteration in smooth muscle cell structure, function, and growth. Angiotensin II, through its effects on contractility, growth, and the sympathetic nervous system, may potentially play a key role in this pathologic process and, thus, contribute to the development of these cardiovascular and renal complications of diabetes mellitus. Angiotensin-converting enzyme inhibitors and some direct renin inhibitors prevent or slow the progression of some of these complications, which further suggests a pathologic role for the renin-angiotensin system in diabetes mellitus.
Photometric effects of accretion disks in long-period eclipsing binaries

Accretion disks are invoked in a variety of astrophysical settings, ranging from stellar-mass black holes to active galactic nuclei. There is now little doubt that true accretion disks can also occur in binaries containing non-degenerate stars (Peters 1980; Plavec et al. 1984; Polidan 1987). In this paper, I will discuss some of the properties of disks observed photometrically in the long-period systems KU Cyg and RZ 0ph.
Skyrmions and semilocal strings in cosmology

Abstract It has been pointed out that cosmic string solutions can exist in gauge field theories with broken symmetry even when gp1(G/H) is trivial. The stability of such semilocal defects is not guaranteed by topology and depends on dynamical considerations. In the literature it has been tacitly assumed that if stable, such strings would from in the Early Universe in a manner analogous to the formation of a network of more robust topologically-stable strings. In this paper we find that except for unnaturally small values of the correlation length, a network of semilocal strings does not firm. Instead, delocalized skyrmionic string configurations, which expand with the Hubble flow, dominate.
The Katzman Automatic Imaging Telescope Gamma-Ray Burst Alert System, and Observations of GRB 020813

We present the technical details of the gamma-ray burst (GRB) alert system of the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory and the successful observations of the GRB 020813 optical afterglow with this system. KAIT responds to GRB alerts robotically, interrupts its prearranged program, and takes a sequence of images for each GRB alert. A grid-imaging procedure is used to increase the efficiency of the early-time observations. Different sequences of images have been developed for different types of GRB alerts. With relatively fast telescope slew and CCD readout speed, KAIT can typically complete the first observation within 60 s after receiving a GRB alert, reaching a limiting magnitude of ~19. Our reduction of the GRB 020813 data taken with KAIT shows that unfiltered magnitudes can be reliably transformed to a standard passband with a precision of ~5%, given that the color of the object is known. The GRB 020813 optical afterglow has an exceptionally slow early-time power-law decay index, although other light-curve parameters and the optical spectral index are fairly typical of GRBs.
Magnetic helicity in the solar wind

Abstract Magnetic helicity measurements in the solar wind are a useful diagnostic for a wide range of physical processes. The helicity has been related to magnetic flux rope ejection at the sun, wave instabilities driven by energetic particles, interplanetary turbulence dynamics, and dissipation to name just four classes of observations. We will review magnetic helicity observations in the solar wind spanning a wide range of heliocentric distances, latitudes, spatial scales, and dynamical processes in an effort to determine what is typical of the helicity spectrum and what can be viewed as a signature of identifiable dynamical processes.
Genus 2 mapping class groups are not Kähler

The goal of this note is to prove that the mapping class groups of closed orientable surfaces of genus 2 (with punctures) are not Kahler. An application to compactifications of the moduli space of genus g curves (with punctures) is given.
Regioselective ruthenium catalyzed hydrohydroxyalkylation of dienes with 3-hydroxy-2-oxindoles: prenylation, geranylation, and beyond.

The direct conversion of secondary to tertiary alcohols via ruthenium(0) catalyzed C–C coupling of substituted 3-hydroxy-2-oxindoles with various dienes is described. Coupling occurs in a completely regioselective manner in the absence of stoichiometric byproducts.
BRADLEY–TERRY CHOICE PROBABILITY IN MAXIMUM LIKELIHOOD AND EIGENPROBLEM SOLUTIONS

The Bradley–Terry model (BT) is commonly used for evaluation of choice preferences by paired comparison data in various areas of applied psychology, advertising, and marketing research. The estimation of BT parameters of preference is usually achieved in an iterative procedure based on the maximum likelihood approach. In this paper an easier way of finding these parameters via an eigenproblem is considered. This approach corresponds to solving a Chapman–Kolmogorov system of equations to estimate the steady-state probabilities of the compared items. Both techniques produce very similar results, but the eigenvector solution is simpler for applications and suggests an interpretation of BT preferences as the choice probabilities. The suggested approach can facilitate the paired comparison estimations and be utilized in various practical aims of managerial decision making.
Simulating nonlinear neutrino flavor evolution

We discuss a new kind of astrophysical transport problem: the coherent evolution of neutrino flavor in core collapse supernovae. Solution of this problem requires a numerical approach which can simulate accurately the quantum mechanical coupling of intersecting neutrino trajectories and the associated nonlinearity which characterizes neutrino flavor conversion. We describe here the two codes developed to attack this problem. We also describe the surprising phenomena revealed by these numerical calculations. Chief among these is that the nonlinearities in the problem can engineer neutrino flavor transformation which is dramatically different to that in standard Mikheyev–Smirnov–Wolfenstein treatments. This happens even though the neutrino mass-squared differences are measured to be small, and even when neutrino self-coupling is sub-dominant. Our numerical work has revealed potential signatures which, if detected in the neutrino burst from a Galactic core collapse event, could reveal heretofore unmeasurable properties of the neutrinos, such as the mass hierarchy and vacuum mixing angle θ13.
Fuel cells for transportation

The 150th anniversary of the Grove Fuel Cell provided an excellent opportunity to review the status of fuel cell technology and its potential applications. One of the most exciting and most challenging of these applications is in transportation. A fuel cell powered vehicle is conceptually simple. The fuel cell provides an efficient means of converting chemical energy to electricity. If a fuel cell with adequate power capacity could be housed within the engine compartment of a vehicle, its electrical output could be used to drive an electric motor for propulsion as well as all of the electrical ancillary equipment of a modern vehicle. (author).
A Survey of Approaches to Solving Inverse Problems for Lossless Layered Media Systems

In this paper, we survey approaches to solving inverse problems for lossless layered systems. Such systems can be modeled in two different ways, by nonparametric or parametric models. We review both models, but concentrate our attention on inverse and estimation procedures for parametric models. Algebraic inverse procedures are described for determining the reflection coefficient parameters when measurements are noise free. An extension of these procedures to the case of noisy data is also discussed; but, resulting reflection coefficient values are suboptimal. Finally, we describe two procedures for estimating reflection coefficients from noisy data. One of these, which is very promising, is a maximum-likelihood procedure, which is not only able to provide estimates of reflection coefficients, but is also able to provide estimates of another set of parameters, layer travel times. These maximum-likelihood estimates are optimal.
N-acyloxyphthalimides as nitrogen radical precursors in the visible light photocatalyzed room temperature C-H amination of arenes and heteroarenes

This paper reports a room temperature visible light photocatalyzed method for the C–H amination of arenes and heteroarenes. A key enabling advance in this work is the design of N-acyloxyphthalimides as precursors to nitrogen-based radical intermediates for these transformations. A broad substrate scope is presented, including the selective meta-amination of pyridine derivatives. A radical aromatic substitution mechanism is proposed.
Vibrationally Excited HCN around AFGL 2591: A Probe of Protostellar Structure

Vibrationally excited molecules with submillimeter rotational transitions are potentially excellent probes of physical conditions near protostars. This study uses observations of the v = 1 and v = 2 ro-vibrational modes of HCN (4-3) to probe this environment. The presence or absence and relative strengths of these ro-vibrational lines probe the gas excitation mechanism and physical conditions in warm, dense material associated with protostellar disks. We present pilot observations from the Heinrich Hertz Submillimeter Telescope and follow-up observations from the Submillimeter Array. All vibrationally excited HCN (4-3) v = 0, v = 1, and v = 2 lines were observed. The existence of the three v = 2 lines at approximately equal intensity imply collisional excitation with a density of greater than (1010 cm–3) and a temperature of >1000 K for the emitting gas. This warm, high-density material should directly trace structures formed in the protostellar envelope and disk environment. Further, the line shapes of the v = 2 emission may suggest a Keplerian disk. This Letter demonstrates the utility of this technique which is of particular interest due to the recent inauguration of the Atacama Large Millimeter Array.
A comprehensive analysis of electric dipole moment constraints on CP-violating phases in the MSSM

We analyze the constraints placed on individual CP-violating phases in the minimal supersymmetric extension of the Standard Model (MSSM) by current experimental bounds on the electric dipole moments (EDMs) of the neutron, Thallium, and Mercury atoms. We identify the four CP-violating phases that are individually highly constrained by current EDM bounds, and we explore how these phases and correlations among them are constrained by current EDM limits. We also analyze the prospective implications of the next generation of EDM experiments. We point out that all other CP-violating phases in the MSSM are not nearly as tightly constrained by limits on the size of EDMs. We emphasize that a rich set of phenomenological consequences is potentially associated with these generically large EDM-allowed phases, ranging from B physics, electroweak baryogenesis, and signals of CP-violation at the CERN Large Hadron Collider and at future linear colliders. Our numerical study takes into account the complete set of contributions from one-and two-loop EDMs of the electron and quarks, one-and two-loop Chromo-EDMs of quarks, the Weinberg 3-gluon operator, and dominant 4-fermion CP-odd operator contributions, including contributions which are both included and not included yet in the CPsuperH2.0 package. We also introduce an open-source numerical package, 2LEDM, which provides the complete set of two-loop electroweak diagrams contributing to the electric dipole moments of leptons and quarks.
Spiral structure and star formation. II - Stellar lifetimes and cloud kinematics

The reliability studies using continuum gas dynamical calculations becomes questionable in connection with the apparent clumpiness of the Galaxy's interstellar medium (ISM). Roberts and Hausman (1984) have, therefore, presented a detailed model of a disk galaxy in which the ISM consists entirely of 'cloud particles', which orbit ballistically in the galaxy's gravitational field, collide inelastically with one another, and give birth to and subsequently interact with young star associations. The effects of changing the clouds's collisional mean free path have been examined, and the variations in the young star system's spiral morphology have been explored. The present investigation is concerned with a further study of this clumpy, cloudy ISM model, taking into account longer mean free path models likely to be appropriate for systems of molecular clouds. Attention is also given to the kinematics of clouds as they orbit under the influence of galactic gravity, collisions, and supernova remnants.
Light-Scattering Study of the Glass Transition in Lubricants

The sound velocity of four lubricants has been measured as a function of temperature and pressure using Brillouin scattering. A change in slope of the velocity as a function of temperature or pressure allowed the determination of the glass transition temperature and pressure. The glass transition data were used to construct a phase diagram for each lubricant. The data indicate that the glass transition temperature increased with pressure at a rate which ranged from 120 to 200 C/GPa. The maximum pressure attained was 0.69 GPa and the temperature range was from 25 to 100 C.
On Distinct Distances from a Vertex of a Convex Polygon

Given a set P of n points in convex position in the plane, we prove that there exists a point $p \in P$ such that the number of distinct distances from p is at least $\lceil (13n-6)/36 \rceil.$ The best previous bound, $\lceil n/3 \rceil,$ from 1952, is due to Moser.
Reactions of salicylaldehydes with alkyl cyanoacetates on the surface of solid catalysts: syntheses of 4H-chromene derivatives

Substituted 4H-chromene derivatives are a new class of compounds that bind Bcl-2 protein and induce apoptosis in tumor cells. Here we report an efficient synthetic method for the preparation of these compounds from salicylaldehyde derivatives and alkyl cyanoacetates under solid-phase catalysis.
Online learning for combinatorial network optimization with restless Markovian rewards

Combinatorial network optimization algorithms that compute optimal structures taking into account edge weights form the foundation for many network protocols. Examples include shortest path routing, minimal spanning tree computation, maximum weighted matching on bipartite graphs, etc. We present CLRMR, the first online learning algorithm that efficiently solves the stochastic version of these problems where the underlying edge weights vary as independent Markov chains with unknown dynamics. The performance of an online learning algorithm is characterized in terms of regret, defined as the cumulative difference in rewards between a suitably-defined genie, and that obtained by the given algorithm. We prove that, compared to a genie that knows the Markov transition matrices and uses the single-best structure at all times, CLRMR yields regret that is polynomial in the number of edges and nearly-logarithmic in time.
A mammalian functional-genetic approach to characterizing cancer therapeutics

Identifying mechanisms of drug action remains a fundamental impediment to the development and effective use of chemotherapeutics. Here we describe an RNA interference (RNAi)-based strategy to characterize small-molecule function in mammalian cells. By examining the response of cells expressing short hairpin RNAs (shRNAs) to a diverse selection of chemotherapeutics, we could generate a functional shRNA signature that was able to accurately group drugs into established biochemical modes of action. This, in turn, provided a diversely sampled reference set for high-resolution prediction of mechanisms of action for poorly characterized small molecules. We could further reduce the predictive shRNA target set to as few as eight genes and, by using a newly derived probability-based nearest-neighbors approach, could extend the predictive power of this shRNA set to characterize additional drug categories. Thus, a focused shRNA phenotypic signature can provide a highly sensitive and tractable approach for characterizing new anticancer drugs.
The FIRST-2MASS Red Quasar Survey. II. An Anomalously High Fraction of LoBALs in Searches for Dust-Reddened Quasars

We present results on a survey to find extremely dust-reddened Type 1 quasars. Combining the FIRST radio survey, the 2MASS Infrared Survey and the Sloan Digital Sky Survey, we have selected a candidate list of 122 potential red quasars. With more than 80% spectroscopically identified objects, well over 50% are classified as dust-reddened Type 1 quasars, whose reddenings (E(B – V)) range from approximately 0.1 to 1.5 mag. They lie well off the color selection windows usually used to detect quasars and many fall within the stellar locus, which would have made it impossible to find these objects with traditional color selection techniques. The reddenings found are much more consistent with obscuration happening in the host galaxy rather than stemming from the dust torus. We find an unusually high fraction of broad absorption line (BAL) quasars at high redshift, all but one of them belonging to the low-ionization BAL (LoBAL) class and many also showing absorption in the metastable Fe II line (FeLoBAL). The discovery of further examples of dust-reddened LoBAL quasars provides more support for the hypothesis that BAL quasars (at least LoBAL quasars) represent an early stage in the lifetime of the quasar. The fact that we see such a high fraction of BALs could indicate that the quasar is in a young phase in which quasar feedback from the BAL winds is suppressing star formation in the host galaxy.
Evidence for Inverted Spectrum 20-GHz Emission in the Galactic Plane

A comparison of a 19 GHz full-sky map with the WMAP satellite K-band (23 GHz) map indicates that the bulk of the 20 GHz emission within 7° of the Galactic plane has an inverted (rising) spectrum with an average spectral index α = 0.21 ± 0.05. While such a spectrum is inconsistent with steep-spectrum synchrotron (α ~ -0.7) and flat-spectrum free-free (α ~ -0.1) emission, it is consistent with various models of electric dipole emission from thermally excited spinning dust grains, as well as models of magnetic dipole emission from ferromagnetic dust grains. Several regions in the plane, e.g., near the Cygnus arm, have spectra with even larger α. While the low signal-to-noise ratio of the 19 GHz data precludes a detailed map of the spectral index, especially off the Galactic plane, it appears that the bulk of the emission in the plane is correlated with the morphology of dust. Regions with higher 23 GHz flux tend to have harder spectra. Off the plane, at Galactic latitudes 7° < |b| < 20°, the spectrum steepens to α = -0.16 ± 0.15.
GRAVITATIONAL LENSING STATISTICS AND CONSTRAINTS ON THE COSMOLOGICAL CONSTANT REVISITED

We re-analyze constraints on the cosmological constant that can be obtained by examining the statistics of strong gravitational lensing of distant quasars by intervening galaxies, focusing on uncertainties in galaxy models (including velocity dispersion, luminosity functions, core radii and magnification bias effects) and on the parameters of the galaxy distribution and luminosity functions. In the process we derive new results on magnification biasing for galaxy lenses with nonzero core radii, and on how to infer the proper velocity dispersions appropriate for use in lensing statistics. We argue that the existing data do not disfavor a large cosmological constant. In fact, for a set of reasonable parameter choices, using the results of five optical quasar lensing surveys we find that a maximum likelihood analysis favors a value of Ω0 in the range ≈ 0.25–0.55 in a flat universe. An open cosmology is not favored by the same statistical analysis. Systematic uncertainties are likely to be dominant, however, as these results are sensitive to uncertainties in our understanding of galaxy luminosity functions, and dark matter velocity dispersions, as well as the choice of lensing survey, and to a lesser extent the existence of core radii. Further observational work will be required before it is possible to definitively distinguish between cosmological models on the basis of gravitational lensing statistics.
The Size and Shape of the Oblong Dwarf Planet Haumea

We use thermal radiometry and visible photometry to constrain the size, shape, and albedo of the large Kuiper belt object Haumea. The correlation between the visible and thermal photometry demonstrates that Haumea’s high amplitude and quickly varying optical light curve is indeed due to Haumea’s extreme shape, rather than large scale albedo variations. However, the well-sampled high precision visible data we present does require longitudinal surface heterogeneity to account for the shape of lightcurve. The thermal emission from Haumea is consistent with the expected Jacobi ellipsoid shape of a rapidly rotating body in hydrostatic equilibrium. The best Jacobi ellipsoid fit to the visible photometry implies a triaxial ellipsoid with axes of length 1,920 × 1,540 × 990 km and density 2.6 g cm ^(−3) , as found by Lellouch et al. (A&A, 518:L147, 2010. doi:10.1051/0004-6361/201014648). While the thermal and visible data cannot uniquely constrain the full non-spherical shape of Haumea, the match between the predicted and measured thermal flux for a dense Jacobi ellipsoid suggests that Haumea is indeed one of the densest objects in the Kuiper belt.
Counts and Sizes of Galaxies in the Hubble Deep Field South: Implications for the Next Generation Space Telescope

Science objectives for the Next Generation Space Telescope (NGST) include a large component of galaxy surveys, both imaging and spectroscopy. The Hubble Deep Field data sets include the deepest observations ever made in the ultraviolet, optical, and near-infrared, reaching depths comparable to that expected for NGST spectroscopy. We present the source counts, galaxy sizes, and isophotal filling factors of the Hubble Deep Field South (HDF-S) images. The observed integrated galaxy counts reach over 500 galaxies per square arcminute at magnitudes AB 29. We compare observed sizes in the optical and near-infrared using the HDF-S Near Infrared Camera and Multi-Object Spectrometer image, showing that after taking into account the different point-spread functions and pixel sizes of the images, galaxies are smaller in the near-infrared than they are in the optical. We analyze the isophotal filling factor of the HDF-S STIS image and show that this image is mostly empty sky even at the limits of galaxy detection, a conclusion we expect to hold true for NGST spectroscopy. At the surface brightness limits expected for NGST imaging, however, about a quarter of the sky is occupied by the outer isophotes of AB < 30 galaxies, requiring deblending to detect the faintest objects. We discuss the implications of these data on several design concepts for the NGST near-infrared spectrography. We compare the effects of resolution and the confusion limit of various designs, as well as the multiplexing advantages of either multiobject or full-field spectroscopy. We argue that the optimal choice for NGST spectroscopy of high-redshift galaxies is a multiobject spectrograph (MOS) with target selection by a microelectromechanical systems (MEMS) device. If this technology does not become available in the next few years, then the second choice would be either a mechanical MOS using movable slits or fibers, or an integral field spectrograph.
Fast and scalable conflict detection for packet classifiers

Packet filters provide rules for classifying packets based on header fields. High speed packet classification has received much study. However, the twin problems of fast updates and fast conflict detection have not received much attention. A conflict occurs when two classifiers overlap, potentially creating ambiguity for packets that match both filters. For example, if Rule 1 specifies that all packets going to CNN be rate controlled and Rule 2 specifies that all packets coming from Walmart be given high priority, the rules conflict for traffic from Walmart tc CNN. There has been prior work on efficient conflict detection for two-dimensional classifiers. However, the best known algorithm for conflict detection for general classifiers is the naive O(N2) algorithm of comparing each pair of rules for a conflict. In this paper, we describe an efficient and scalable conflict detection algorithm for the general case that is significantly faster. For example, for a database of 20000 rules, our algorithm is 40 times faster than the naive implementation. Even without considering conflicts, our algorithm also provides a packet classifier with fast updates and fast lookups that can be used for stateful packet filtering.
Silylene oxonium ylides: di-tert-butylsilylene insertion into C-O bonds

Abstract Allylic ethers undergo insertions of silylenes into C–O bonds to form allylic silanes. Silylene insertion into C–O acetal bonds was also observed. Formation of silylene ylide intermediates led to [1,2]-Stevens rearrangement products as well as [2,3]-sigmatropic products depending upon the steric environment of the starting allylic ether.
Sequence and expression of the murine diazepam binding inhibitor.

Previous studies suggest that a diazepam binding inhibitor (DBI, also referred to as endozepine) present in the brain may function anxiogenically as a modulator of the γ-aminobutyric acid receptor complex (GABAA). An expression library representing mouse brain mRNA was screened using antisera that recognizes the 11 kDa DBI protein. A cDNA clone was isolated and sequenced. Comparison of the amino acid sequence of mouse DBI to that for human, rat and bovine DBI shows that the size of DBI is conserved at 87 amino acids in all of these mammals. DBI cDNA hybridizes to an mRNA of about 600 nucleotides. This mRNA is not restricted to the brain, being prevalent in other organs such as the liver and kidney. Its moderate to high abundance, as judged from mRNA levels, in several organs suggests that DBI might have functions other than, or in addition to, the possible regulation of benzodiazepine binding sites.
On the magnitudes of some small cyclotomic integers

We prove the last of five outstanding conjectures made by R.M. Robinson from 1965 concerning small cyclotomic integers. In particular, given any cyclotomic integer $\beta$ all of whose conjugates have absolute value at most 5, we prove that the largest such conjugate has absolute value one of four explicit types given by two infinite classes and two exceptional cases. We also extend this result by showing that with the addition of one form, the conjecture is true for $\beta$ with magnitudes up to 5+1/25.
A carrier-based PWM scheme for neutral-point voltage balancing in three-level inverters

A significant problem with neutral-point-clamped three-level inverters is the fluctuation in the neutral-point voltage. In this paper, a capacitor voltage balancing technique for carrier-based three-level pulsewidth modulation (PWM) is developed, with improved voltage control capability at high modulation index. The method incorporates a novel scheme that requires measurements of only the motor currents and capacitor voltages to implement voltage balancing control, and does not need to determine the direction of power flow between the inverter and the motor.
Preliminary Work Concerning the Near-Wake Structure of the Darrieus Turbine

The work presented here in i s in tended t o p rov ide a p r e l i m i n a r y i n d i c a t i o n o f t h e na tu re o f t h e near wake s t r u c t u r e behind a Darr ieus t u r b i n e . A more impor tant aspect o f t h e work, however, i s t o examine t h e p o t e n t i a l o f a vor tex a n a l y t i c a l model i n making near wake p r e d i c t i o n s . Near wake p r e d i c t i o n s us ing t h i s model a re compared w i t h a f u l l s c a l e Darr ieus t u r b i n e o p e r a t i n g i n a n a t u r a l wind environment. The purpose o f t h i s paper i s t o present some p r e l i m i n a r y r e s u l t s w i t h regard t o u t i l i z a t i o n o f a vo r tex rode1 f o r p r e d i c t i n g wake s t r u c t u r e s . I n o rder t o p lace t h i s work i n proper perspec t i ve t h e f o l l o w i n g b r i e f rev iew i s g iven t o c h a r a c t e r i z e t h e s t a t e o f t h e a r t w i t h regard t o both a n a l y t i c a l and experimental i n v e s t i g a t i o n s which have been undertaken i n t h e pas t .
Perceived 'usefulness' of online consumer reviews: An exploratory investigation across three services categories

Online reviews, a form of online word-of-mouth (eWOM), have recently become one of the most important sources of information for modern consumers. Recent scholarship involving eWOM often focuses on the transmission and impact of online reviews but sheds less light on the underlying processes that drive consumers' receptions of them. Similarly, few studies have explored the recipients' perspectives in the context of various services. This study addresses the aforementioned gaps in extant literature. The research model in this study is built upon the rich stream of literature related to how people are influenced by information and is tested on reviews collected from Yelp.com, a popular online advisory website dedicated to services businesses throughout the United States. The results of the study show that a combination of both reviewer and review characteristics are significantly correlated with the perceived usefulness of reviews. The study also finds several results that are anomalous to established knowledge related to consumers' information consumption, both offline and online. The authors present the results of the study and discuss their significance for research and practice.
Unstable products of smooth curves

We give examples of smooth manifolds with negative first Chern class which are slope unstable with respect to certain polarisations, and so have Kahler classes that do not admit any constant scalar curvature Kahler metrics. These manifolds also have unstable Hilbert and Chow points. We compare this to the work of Song-Weinkove on the J-flow.
The Pricing of Sequential Bank Loans

The theory of financial intermediation assigns banks a unique role in the resolution of information asymmetry. Banks, in general, obtain private information about the borrower and the project during the screening of loan applicants and during the monitoring of loan recipients. Incumbent banks, in particular, utilize information obtained while monitoring previous loan extensions to resolve information asymmetry when granting subsequent loans. We examine the rate on a sequence of loans to a borrower and find that the incumbent bank information advantage has finite magnitude and is quickly reflected in the pricing of the second loan. We also find that the lending relationship does not deteriorate to the detriment of the borrower. This study also provides further evidence supporting the hypothesis that an incumbent bank resolves information asymmetry during the monitoring of loan extensions.
Recent Advances in Metallabenzene Chemistry

Research into aromatic metallacycles, though discussed in the literature over the last quarter century, has undergone a major expansion since 2000. A wide variety of new metallabenzenes, encompassing new synthetic methods and new metal centers, is now available. New aromatic metallacycle topologies (iridanaphthalene, osmabenzynes) have been isolated and characterized. The first metallabenzene valence isomers (iridabenzvalenes, rhodabenzvalenes) and constitutional isomers (isoosmabenzenes) are now known. This review discusses the synthesis, chemistry, and physical properties of these intriguing aromatic compounds.
Assessment of calving progress and reference times for obstetric intervention during dystocia in Holstein dairy cows

The objectives of this observational study were (1) to assess the time from the appearance of the amniotic sac (AS) or feet outside the vulva to birth in Holstein cows (primiparous and multiparous) with (dystocia) or without assistance (eutocia) at calving, and (2) to estimate reference times to be used as guidelines for obstetric intervention in Holstein cows that need assistance during difficult births. Cows (n = 92) from 1 commercial dairy operation were used in this study. Periparturient dairy cows (primiparous, n = 58; multiparous, n = 34) were placed in a maternity pen and constantly monitored until birth. The calving ease of cows, time from AS or feet appearance to birth, calving progress from a subset of 15 cows (frequency and duration of abdominal contractions during labor), calf birth weight, calf sex, and stillbirths (born dead or died within 24 h after birth) were recorded. The reference times for obstetric intervention during dystocia were estimated based on values from unassisted births (normal). The normal range of times from the appearance of AS or feet outside the vulva to birth was estimated based on the mean + 2 standard deviations (SD) of unassisted births. According to farm protocol, assistance was provided to cows without calving progress 80 min after AS appearance or earlier (e.g., to correct malpositions). Cows with dystocic births had a longer time from AS appearance to birth and increased incidence of stillbirth compared with cows with eutocic calvings. After the appearance of the AS, calving progress was evident every 15 min for eutocic births. The estimated reference times (mean + 2 SD) from AS appearance to birth were 69.7 min and from feet appearance to birth were 64.6 min for eutocic births. Findings from this study suggested that calving personnel should start assisting cows 70 min after AS appearance (or 65 min after feet appearance) outside the vulva. The time spent in labor (straining) combined with the time from the appearance of the AS or feet to birth, and the assessment of calving progress (as described for eutocic births) should be used as guidelines for obstetric intervention during difficult births under field conditions. These reference times should be interpreted in combination with adequate obstetrical knowledge and examination.
Frequent (flier) frustration and the dark side of word‐of‐web: exploring online dysfunctional behavior in online feedback forums

Purpose – Following the perspective of frustration theory customer frustration incidents lead to frustration behavior such as protest (negative word‐of‐mouth). On the internet customers can express their emotions verbally and non‐verbally in numerous web‐based review platforms. The purpose of this study is to investigate online dysfunctional customer behavior, in particular negative “word‐of‐web” (WOW) in online feedback forums, among customers who participate in frequent‐flier programs in the airline industry.Design/methodology/approach – The study employs a variation of the critical incident technique (CIT) referred to as the critical internet feedback technique (CIFT). Qualitative data of customer reviews of 13 different frequent‐flier programs posted on the internet were collected and analyzed with regard to frustration incidents, verbal and non‐verbal emotional effects and types of dysfunctional word‐of‐web customer behavior. The sample includes 141 negative customer reviews based on non‐recommendati...
Asymmetric reduction of aromatic ketones in pyridinium-based ionic liquids

Abstract The asymmetric reduction of aromatic ketones has been studied in pyridinium-based room temperature ionic liquids, namely, 1-ethyl-pyridinium tetrafluoroborate, [EtPy] + [BF 4 ] − and 1-ethyl-pyridinium trifluoroacetate, [EtPy] + [CF 3 COO] − . Ionic liquids were employed as solvents, while ( R )-BINOL and ( R )-BINOL-Br were used as chiral promoters. The effects of solvent, reaction time, temperature, catalyst loading and substituents were investigated. The reduction could be easily carried out in both ionic liquids with lower catalyst loading. 1-Ethyl-pyridinium tetrafluoroborate was recycled and reused efficiently.
Environmental Choices and Hyperbolic Discounting: An Experimental Analysis

Environmental goods such as carbon abatement or green space development often generate benefit streams that may not occur until far into the future. How individual consumers value such amenities, therefore, depends critically on the discount rate. The usual assumption is that agents discount future values using constant, exponential rate, but there is some evidence from the lab suggesting that discount functions are more likely quasi-hyperbolic. We compare estimates of subjects’ rate of intertemporal time preference for financial rewards and environmental goods using multiple price-list and a new matrix multiple price list approaches. Our objective is to determine if discount functions for environmental and monetary goods differ, and to estimate the structure of discounting in both contexts. We find that financial discount functions are not hyperbolic, but those for environmental goods are. Discount rates for environmental goods are generally lower than for financial rewards, but are still above zero. Consumers, therefore, value long-lived environmental goods differently than financial goods.
PROBING THE 5TH DIMENSION WITH THE QCD STRING

A salient feature of String/Gauge duality is an extra 5th dimension. Here we study the effect of confining deformations of AdS5 and compute the spectrum of a string stretched between infinitely massive quarks and compare it with the quantum states of the QCD flux as determined by Kuti, Juge and Morningstar in lattice simulations. In the long flux tube limit the AdS string probes the metric near the IR cutoff of the 5th dimension with a spectrum approximated by a Nambu-Goto string in 4-d flat space, whereas at short distance the string moves to the UV region with a discrete spectrum for pure AdS5. We also review earlier results on glueballs states and the cross-over between hard and soft diffractive scattering that support this picture.
Target space duality for (0,2) compactifications

Abstract The moduli spaces of two (0, 2) compactifications of the heterotic string can share the same Landau-Ginzburg model even though at large radius they look completely different. It was argued that such a pair of (0, 2) models might be connected via a perturbative transition at the Landau-Ginzburg point. Situations of this kind are studied for some explicit models. By calculating the exact dimensions of the generic moduli spaces at large radius, strong indications are found in favor of a different scenario. The two moduli spaces are isomorphic and complex, Kahler and bundle moduli get exchanged.
The myth of the Folk Theorem

Abstract The Folk Theorem for repeated games suggests that finding Nash equilibria in repeated games should be easier than in one-shot games. In contrast, we show that the problem of finding any Nash equilibrium for a three-player infinitely-repeated game is as hard as it is in two-player one-shot games. More specifically, for any two-player game, we give a simple construction of a three-player game whose Nash equilibria (even under repetition) correspond to those of the one-shot two-player game. Combined with recent computational hardness results for one-shot two-player normal-form games ( Daskalakis et al., 2006 , Chen et al., 2006 , Chen et al., 2007 ), this gives our main result: the problem of finding an (epsilon) Nash equilibrium in a given n × n × n game (even when all payoffs are in { − 1 , 0 , 1 } ) is PPAD-hard (under randomized reductions).
A CCD Time-Series Photometer

We describe a high-speed time-series CCD photometer for the prime focus of the 82 inch (2.1 m) telescope at McDonald Observatory and summarize the observational results we have obtained since it was placed into regular use in 2002 February. We compare this instrument with the three-channel time-series photometers we have previously used for the asteroseismological study of pulsating white dwarf stars, which used photomultiplier tubes (PMTs) as the detectors. We find the CCD instrument is about 9 times more sensitive than the PMT instruments used on the same telescope for the same exposure time. We can therefore find and measure variable white dwarf stars some 2.4 mag fainter than before, significantly increasing the number of such objects available for study.
Rate-dependent energetic processes in hypersonic flows

Abstract In celebration of the first 60 years of the Air Force Office of Scientific Research, several studies of hypersonic flows dominated by rate-dependent energetic processes are revisited. The work presented shows the evolution and advancement of computational capabilities in this area, and illustrates some key lessons learned over the previous decade or so. Early work with Leyva and Hornung in the California Institute of Technology T5 Free-Piston Shock Tunnel had the goal of validating thermochemical models for high-enthalpy flows. Several of these flows are re-analyzed with more advanced numerical methods, resulting in improved comparisons with the experimental measurements. This work was followed by a series of experiments in the Calspan-University at Buffalo Research Center (now CUBRC Inc.) facilities at lower enthalpy conditions. Initial comparisons were poor, but with a better understanding of the facility behavior and the inclusion of key finite-rate processes, excellent agreement was obtained for nitrogen flows. An interesting study related to plasmadynamics and finite-rate processes in a different type of flow is discussed. Finally, it is shown that recent advances in numerical methods that are beginning to enable the direct numerical simulation of key rate-dependent energetic processes in hypersonic flows.
When Organocatalysis Meets Transition‐Metal Catalysis

In the past several years, applications of transition metal complexes in tuning the reactivity of organocatalyst-promoted transformations have attracted increasing attention in the synthetic community. Efforts in this direction have led to the discovery of unprecedented reactivities, which are not accessible through the use of either of these two catalytic systems separately. The concept continues to develop and offers huge potential. This microreview describes and summarizes recent progress in this field, focusing on discussion of the enhancement and diversification of reactivity patterns in organocatalysis through the deployment of transition metal complexes.
Integrated Communication and Control Systems: Part I—Analysis

The paper presents the results of an ICCS analysis focusing on discrete-time control systems subject to time-varying delays. The present analytical technique is applicable to integrated dynamic systems such as those encountered in advanced aircraft, spacecraft, and the real-time control of robots and machine tools via a high-speed network within an autonomous manufacturing environment. The significance of data latency and missynchronization between individual system components in ICCS networks is discussed in view of the time-varying delays.