cssi/SciSciGPT-SciSciNet huggingface dataset:
Time-domain finite element modeling of dispersive media

A general formulation is developed to model the dispersion effect in the time-domain finite element method (TDFEM). This TDFEM is based on the second-order vector wave equation, in contrast to most FDTD schemes that solve the first-order Maxwell equations. The required convolution integral is evaluated recursively without the need to store the electric fields of all past time steps. This evaluation is made to be of second order in accuracy by adopting a linear interpolation for the fields within each time step. The proposed formulation is shown to be valid for plasma, Debye, and Lorentz media with a single or multiple poles. Three-dimensional numerical examples are given to demonstrate its efficacy.
An analysis of earthquake frequency data

abstract Analyses of tidal forces present during occurrence of the major earthquakes recorded in periods of several years duration are presented for two regions along the San Andreas fault in central California. Components of tidal force and their time rates of change are computed for each earthquake in the sample. The distributions of these force and jerk quantities for actual earthquakes are compared with corresponding distributions obtained for pseudo-earthquakes generated under the hypothesis of random occurrence. It is concluded that the evidence provided by these analyses does not support the hypothesis that tidal-force levels or rates of change have significant effects on earthquake occurrences in the regions considered.
Gauge fields-strings duality and the loop equation

Abstract We explore gauge fields–strings duality by means of the loop equations and the zigzag symmetry. The results are striking and incomplete. Striking — because we find that the string ansatz proposed in [? ] satisfies gauge theory Schwinger–Dyson equations precisely at the critical dimension D cr =4 . Incomplete — since we get these results only in the WKB approximation and only for a special class of contours. The ways to go beyond these limitations and in particular the OPE for operators defined on the loop are also discussed.
PRESENTATIONS AND MODULE BASES OF INTEGER-VALUED POLYNOMIAL RINGS

Let D be an integral domain with quotient field K. For any set X, the ring Int(DX) of integer-valued polynomials onDX is the set of all polynomials f ∈ K[X] such that f(DX) ⊆ D. Using the t-closure operation on fractional ideals, we find for any set X a D-algebra presentation of Int(DX) by generators and relations for a large class of domains D, including any unique factorization domain D, and more generally any Krull domain D such that Int(D) has a regular basis, that is, a D-module basis consisting of exactly one polynomial of each degree. As a corollary we find for all such domains D an intrinsic characterization of the D-algebras that are isomorphic to a quotient of Int(DX) for some set X. We also generalize the well-known result that a Krull domain D has a regular basis if and only if the Polya–Ostrowski group of D (that is, the subgroup of the class group of D generated by the images of the factorial ideals of D) is trivial, if and only if the product of the height one prime ideals of finite norm q is principal for every q.
The mtr locus is a two-gene operon required for transcription attenuation in the trp operon of Bacillus subtilis.

Abstract We have cloned and characterized the mtr operon of Bacillus subtilis. This operon encodes a presumed RNA-binding regulatory protein that is required for attenuation control of the trp operon. We have shown that the mtr operon consists of two structural genes, mtrA and mtrB, predicted to encode 22-kDa and 8-kDa polypeptides, respectively. MtrB shows homology with RegA, an RNA-binding regulatory protein of bacteriophage T4. The lesions in several mtr mutants were localized to mtrB or the putative mtr promoter. Several mtrB alleles were dominant to mtr+, suggesting that the regulatory factor is a multimeric protein. The in vivo action of the mtrA and mtrB gene products was analyzed in an E. coli strain containing a trpE-lacZ gene fusion under control of the B. subtilis trp promoter/attenuator region. Both MtrA and MtrB were necessary for regulation of beta-galactosidase production.
Electrochemistry of vanadium electrodes Part 1. Cyclic voltammetry in aqueous solutions

Abstract Cyclic voltammograms for stationary and rotating vanadium disc electrodes were obtained in aqueous solutions over a wide pH range. A number of multiple-cycle potential programs were employed. The repetitive cycling was accompanied by a gradual accumulation of an adsorbed layer at the vanadium electrode surface. The chemical nature of the layer was independent of pH, and was assigned as V(III) oxyhydroxide intermediates in the process of anodic dissolution of vanadium. The two major voltammetric features were the oxidation of V(III) oxyhydroxide to V(IV), and the reduction of V(IV) oxide species to V(III). Different rate-determining steps were shown to govern the anodic dissolution of vanadium in acidic and alkaline solutions.
TRANSITORINESS OF MARKET POWER AND ANTITRUST ACTIVITY

The economic rationale for how much market power is tolerable has so far been based mainly on static considerations; ideally, however, it should discriminate between persistent and transitory market power. I propose a dynamic dominant-firm type of model where the firm's use of market power, when it is discovered by an antitrust agency, will be penalized. Equilibrium entails a threshold market share above which the market tends toward monopoly and below which the market tends to competition. One may propose the region below this threshold to be the safety zone. The size of this region depends on how fast market power depreciates. In industries in which this depreciation is fast and where, as a result, monopoly power is more transitory, the safety zone should be wider, and there should be less policy intervention.
Preconversion treatments of low-rank coal

Tests were performed to study the effects of various preconversion treatments on the first-stage conversion of Indian Head lignite to THF-soluble products. Solvents investigated included coal-derived anthracene oil, a cresylic acid solvent, and tetralin; gases tested included hydrogen, carbon monoxide, and argon. The preconversion treatment was performed as a 60-min soak at a low temperature. The results of this preliminary study indicate that the use of this type of preconversion treatment can effectively enhance conversion to soluble materials and improve the quality of the first-stage product yield structure. The most effective preconversion treatment consisted of the combination of tetralin, argon, and H2S (added as a reaction promoter) reacted at 448 K.
CORE: Frustrated Magnets, Charge Fractionalization, and QCD

I explain how to use a simple method to extract the physics of lattice Hamiltonian systems which are not easily analyzed by exact or other numerical methods. I will then use this method to establish the relationship between QCD and a special class of generalized, highly frustrated anti-ferromagnets.
Thermal canister experiment on OSS-1

The purpose of the Thermal Canister Experiment carried by the Space Shuttle STS-3 flight was to determine the ability of a device using controllable heat pipes to maintain simulated instruments at selected temperature levels, in zero gravity and under varying internal and external thermal loads. A total of 11 data points were achieved during the flight, including the control of canister walls, of instrument simulators and of temperatures in two different zones, as well as passive thermal control. The set point variation ranged from 5 to 23 C, with power changes of 165-325 watts. Better fluid distribution in the heat pipes during zero-g operation showed improved performance over ground tests, and a temperature stability of + or - 2 C was demonstrated between Orbiter maneuvers in which the cargo bay was shadowed from the sun and those in which full solar exposure of the cargo bay existed.
International Trade, Regional Free Trade Agreements, and Economic Development

In 1991, Krugman illustrated that natural (regional) free trade agreements (FTAs) are likely to be welfare-enhancing if intercontinental costs are prohibitively high, but are likely to be welfare-reducing if such costs are zero. In 1995, Frankel, Stein and Wei extended the analysis to consider positive but nonprohibitive transport costs. This paper extends these models to allow for countries of different economic size. Large countries will tend to have higher relative wages, influencing the relative gains and losses from natural FTAs. For even modest differences in size, intracontinental FTAs are welfare-enhancing for larger countries, regardless of strong preferences for diversity or low intercontinental transport costs.
Atomic nitrogen densities near the polar cusp

The neutral atmospheric composition spectrometer on board the Dynamics Explorer 2 spacecraft sampled several major and minor thermospheric gases including atomic nitrogen. We present here a selection of passes over the polar cusp that provide a quantitative measure of N densities in this region and provide evidence of localized density increases due to soft particle precipitation. Increases in N densities are frequently observed but are smaller than accompanying increases in N2 densities. Our observations support earlier studies suggesting that (1) N densities increase more rapidly than O densities during periods of high solar EUV flux and (2) N densities are larger in the summer hemisphere than in the winter hemisphere. A series of passes in February 1983, late in the lifetime of DE 2, indicated N densities at 200 km altitude were a factor of 2 larger near the southern cusp than near the northern cusp.
Twisted vertex representations and spin characters

We establish a new group-theoretic realization of the basic representations of the twisted affine and twisted toroidal algebras in the same spirit of our new approach to the McKay correspondence. Our vertex operator construction provides a unified description to the character tables for the spin cover of the wreath product of the twisted hyperoctahedral groups and an arbitrary finite group.
A GKM description of the equivariant cohomology ring of a homogeneous space

Let T be a torus of dimension n > 1 and M a compact T-manifold. M is a GKM manifold if the set of zero dimensional orbits in the orbit space M/T is zero dimensional and the set of one dimensional orbits in M/T is one dimensional. For such a manifold these sets of orbits have the structure of a labelled graph and it is known that a lot of topological information about M is encoded in this graph. In this paper we prove that every compact homogeneous space M of non-zero Euler characteristic is of GKM type and show that the graph associated with M encodes geometric information about M as well as topological information. For example, from this graph one can detect whether M admits an invariant complex structure or an invariant almost complex structure.
Flower orientation influences ovary temperature during frost in peach

Abstract Ovary temperatures of upward- and downward-facing flowers of ‘Junegold’ peach ( Prunus persica (L.) Batsch) were measured on five nights in March 1991 to determine whether differential survival of ovaries following frost was related to flower orientation. Flowering twigs were removed from mature trees and positioned horizontally approximately 1.5 m above ground level prior to occurrence of low temperatures (0–5°C). Thermocouples were inserted through the hypanthium to contact ovaries of upward- and downward-facing flowers, and temperature and meteorological data were logged every 5 min. Under clear, calm conditions, temperature of upward-facing flowers averaged 0.33°C lower than that of downward-facing flowers during the coldest period of the night, with maximal differences of 0.77°C. Under cloudy, calm conditions, temperature differences between upward- and downward-facing flowers were less frequently observed and lower in magnitude (0.08–0.15°C). Under windy conditions (> 2.5 m s −1 ), no temperature difference between upward- and downward-facing flowers occurred despite strongly negative net radiation. Differences in radiant heat exchange when forced convection was minimized are proposed to have caused the differential temperatures between flowers of different orientation. Based on known values of ovary cold tolerance, it is concluded that differences in survival of up to 38% could occur due to flower orientation when air temperature reaches critical values.
Coarse quotient mappings between metric spaces

We give a definition of coarse quotient mapping and show that several results for uniform quotient mapping also hold in the coarse setting. In particular, we prove that any Banach space that is a coarse quotient of Lp ≡ Lp[0, 1], 1 < p < ∞, is isomorphic to a linear quotient of Lp. It is also proved that lq is not a coarse quotient of lq for 1 < p < q < ∞ using Rolewicz’s property (β).
The Milky Way's kiloparsec-scale wind: A hybrid cosmic-ray and thermally driven outflow

We apply a wind model, driven by combined cosmic-ray and thermal-gas pressure, to the Milky Way, and show that the observed Galactic diffuse soft X-ray emission can be better explained by a wind than by previous static gas models. We find that cosmic-ray pressure is essential to driving the observed wind. Having thus defined a "best-fit" model for a Galactic wind, we explore variations in the base parameters and show how the wind's properties vary with changes in gas pressure, cosmic-ray pressure, and density. We demonstrate the importance of cosmic rays in launching winds, and the effect cosmic rays have on wind dynamics. In addition, this model adds support to the hypothesis of Breitschwerdt and collaborators that such a wind may help to explain the relatively small gradient observed in γ-ray emission as a function of galactocentric radius.
The black hole final state

We propose that in quantum gravity one needs to impose a final state boundary condition at black hole singularities. This resolves the apparent contradiction between string theory and semiclassical arguments over whether black hole evaporation is unitary.
THE PECULIAR GLOBULAR CLUSTER SYSTEM OF THE S0 GALAXY NGC 7457

We present Hubble Space Telescope photometry and Keck spectroscopy of globular clusters (GCs) in the nearby S0 galaxy NGC 7457. The V – I color-magnitude diagram of GCs lacks the clear bimodality present in most early-type galaxies; there may be a significant population of intermediate-color objects. Of 13 spectroscopically observed GCs, two are unusually metal-rich and feature bright [O III] emission lines. We conclude that one probably hosts a planetary nebula and the other a supernova remnant. Such emission-line objects should be more common in an intermediate-age stellar population than in an old one. We therefore suggest that, in addition to the typical old metal-rich and old metal-poor GC subpopulations, there may be a third subpopulation of an intermediate age. Such a subpopulation may have been formed ~2-3 Gyr ago, in the same star-forming event that dominates the stellar population of the center of the galaxy.
Contrasteric carboximide hydrolysis with lithium hydroperoxide

Abstract The use of lithium hydroperoxide for the highly regioselective hydrolysis of a range of carboximides is described. Numerous cases are provided where the regioselectivities exhibited by this reagent are dramatically different than the complementary reactions with hydroxide.
Nested Support Vector Machines

One-class and cost-sensitive support vector machines (SVMs) are state-of-the-art machine learning methods for estimating density level sets and solving weighted classification problems, respectively. However, the solutions of these SVMs do not necessarily produce set estimates that are nested as the parameters controlling the density level or cost-asymmetry are continuously varied. Such nesting not only reflects the true sets being estimated, but is also desirable for applications requiring the simultaneous estimation of multiple sets, including clustering, anomaly detection, and ranking. We propose new quadratic programs whose solutions give rise to nested versions of one-class and cost-sensitive SVMs. Furthermore, like conventional SVMs, the solution paths in our construction are piecewise linear in the control parameters, although here the number of breakpoints is directly controlled by the user. We also describe decomposition algorithms to solve the quadratic programs. These methods are compared to conventional (non-nested) SVMs on synthetic and benchmark data sets, and are shown to exhibit more stable rankings and decreased sensitivity to parameter settings.
Sparse Covers for Sums of Indicators

For all $$n, \epsilon >0$$ , we show that the set of Poisson Binomial distributions on $$n$$ variables admits a proper $$\epsilon $$ -cover in total variation distance of size $$n^2+n \cdot (1/\epsilon )^{O(\log ^2 (1/\epsilon ))}$$ , which can also be computed in polynomial time. We discuss the implications of our construction for approximation algorithms and the computation of approximate Nash equilibria in anonymous games.
Clinical Decision Making Using Teleradiology in Urology

Using a personal computer-based teleradiology system, we compared accuracy, confidence, and diagnostic ability in the interpretation of digitized radiographs to determine if teleradiology-imported studies convey sufficient information to make relevant clinical decisions involving urology. Variables of diagnostic accuracy, confidence, image quality, interpretation, and the impact of clinical decisions made after viewing digitized radiographs were compared with those of original radiographs.We evaluated 956 radiographs that included 94 IV pyelograms, four voiding cystourethrograms, and two nephrostograms. The radiographs were digitized and transferred over an Ethernet network to a remote personal computer-based viewing station. The digitized images were viewed by urologists and graded according to confidence in making a diagnosis, image quality, diagnostic difficulty, clinical management based on the image itself, and brief patient history. The hard-copy radiographs were then interpreted immediately afterwa...
Possible radio emission from Uranus at 0.5 MHz

Radio emission from the direction of Uranus has been detected in data from the Goddard radio astronomy experiment on the IMP-6 spacecraft. Previously, emission from the direction of Jupiter and Saturn had been observed by IMP-6 at a number of frequencies near 1 MHz and were identified through an analysis of the phase of the observed modulated signal detected from the spinning dipole antenna. This technique was applied to the direction of Uranus with possible positive results. Over the approximately 500 days of data, three to six bursts with unique spectral characteristics have been found. The events persisted less than 3 minutes and are strongest in intensity near 0.5 MHz. Identification with Uranus is confused by the likely presence of low-level terrestrial and solar emission. Because of the unfavorable angular separation of earth and Uranus, there is a possibility that the bursts are atypical terrestrial magnetospheric phenomena, although the uniqueness of the set of events indicates the probable detection of radiation from Uranus.
Solar and Interplanetary Particles Re-Accelerated at the Solar Wind Termination Shock

We consider the acceleration of solar/interplanetary particles at the solar wind termination shock, predict the expected composition and energy spectra, and discuss possible observable consequences
Global plate tectonics and the secular motion of the Pole

Astronomical data compiled during the last 70 years by the international organizations (ILS/IPMS, BIH) providing the coordinates of the instantaneous pole, clearly shows a continuous drift of the “mean pole” (≡barycenter of the wobble cycle with respect to the Conventional International Origin (CIO). This study was undertaken to investigate the possibility of an actual secular motion of the barycenter (approximated by the earth’s maximum principal moment of inertia axis or axis of figure) due to differential mass displacements from lithospheric plate rotations. The method assumes the earth’s crust modeled as a mosaic of 1° × 1° blocks, each one moving independently with their corresponding absolute plate velocities. The differential contributions to the earth’s second-order tensor of inertia were computed, resulting in no significant displacement of the earth’s axis of figure. In view of the above, the possibleapparent displacement of the “mean pole” as a consequence of station drifting due to absolute plate motions was also analyzed, again without great success. As a further step the old speculation of the whole crust possibly sliding over the upper mantle is revived and the usefulness of the CIO is questioned.
Stable, Compact, Bright Biofunctional Quantum Dots with Improved Peptide Coating

We developed a new peptide, natural phytochelatin (PC), which tightly binds to CdSe/ZnS quantum dots’ (QDs) surfaces and renders them water-soluble. Coating QDs with this flexible and all-hydrophilic peptide offers high colloidal stability, adds only 0.8–0.9 nm to the radius of the particles (as compared to their original inorganic radius), preserves very high quantum yield (QY) in water, and affords facile bioconjugation with various functional groups. We demonstrate specific targeting (with minimal nonspecific binding) of such fluorescein-conjugated QDs to ScFv-fused mouse prion protein expressed in live N2A cells. We also demonstrated homogeneous in vivo biodistribution with no significant toxicity in live zebrafish.
Spacecraft position and attitude formation control using line-of-sight observations

This paper studies formation control of an arbitrary number of spacecraft based on a serial network structure. The leader controls its absolute position and absolute attitude with respect to an inertial frame, and the followers control its relative position and attitude with respect to another spacecraft assigned by the serial network. The unique feature is that both the absolute attitude and the relative attitude control systems are developed directly in terms of the line-of-sight observations between spacecraft, without need for estimating the full absolute and relative attitudes, to improve accuracy and efficiency. Control systems are developed on the nonlinear configuration manifold, guaranteeing exponential stability. Numerical examples are presented to illustrate the desirable properties of the proposed control system.
Hard X-Ray Spectra of Broad-Line Radio Galaxies from the Rossi X-Ray Timing Explorer

We present the results of hard X-ray observations of four broad-line radio galaxies (BLRGs) with the Rossi X-Ray Timing Explorer. The original motivation behind the observations was to search for systematic differences between the BLRGs and their radio-quiet counterparts, the Seyfert galaxies. We do, indeed, find that the Fe Kα lines and Compton "reflection" components, which are hallmarks of the X-ray spectra of Seyfert galaxies, are weaker in BLRGs by about a factor of 2. This observational result is in agreement with the conclusions of other recent studies of these objects. We examine several possible explanations for this systematic difference, including beaming of the primary X-rays away from the accretion disk, a low iron abundance, a small solid angle subtended by the disk to the primary X-ray source, and dilution of the observed spectrum by beamed X-rays from the jet. We find that a small solid angle subtended by the disk to the primary X-ray source is a viable and appealing explanation, while all others suffer from drawbacks. We interpret this as an indication of a difference in the inner accretion disk structure between Seyfert galaxies and BLRGs, namely that the inner accretion disks of BLRGs have the form of an ion-supported torus or an advection-dominated accretion flow, which irradiates the geometrically thin outer disk.
Cumyl phenyl sulfide forms bicumyl instead of cumyllithium upon reductive lithiation. Thiophenoxide as a leaving group in nucleophilic substitution by SET

Abstract Upon reduction with aromatic radical-anions, cumyl phenyl sulfide (1S) yields mainly bicumyl (2) rather than the expected cumyllithium (3), despite a literature report, herein revealed to be in error, that anion 3 is produced. Related examples from the literature are compiled. A suggested mechanism involves a single electron transfer from the generated cumyllithium (3) to the cumyl phenyl sulfide (1S) leading to thiophenoxide anion and two cumyl radicals, which mainly couple in a solvent cage. Such a thiophenoxide displacement by anion 3 has been demonstrated experimentally. Para tert-butyl groups, either on the phenyl or cumyl ring, increase the ratio of the cumyllithium to the bicumyl, presumably by sterically inhibiting the pi complexation thought to be necessary for electron transfer.
An agenda for the design and study of international environmental agreements

Abstract The combination of a general greening of international political debate, and the events of 1992 at the Rio Earth Summit have led to great interest in the question of global environmental protection. While it is recognized that international environmental agreements (IEAs) are the means by which the earth's fragile environment is most likely to be protected, this recognition has been recent. Hence there is very little formal research on the design and study of IEAs. As such, in this paper, I propose and describe a research agenda for the design and study of IEAs. Very generally, I propose that we frame the IEA design question as a problem in mechanism design. We will then be able to use, inter alia, the theory of common agency and the theory of hierarchies to generate interesting new theoretical and practical insights into the workings of IEAs.
Signal correlator with programmable variable time delay based on optical coherent transients

Abstract An optical coherent transient signal correlator with variable true time delay is experimentally demonstrated. Storage of a pattern waveform in a spectral-spatial population grating is achieved by interfering it with two chirped pulses instead of a single brief reference pulse. Correlative signal processing results when a data waveform probes that grating, stimulating an emitted coherent output signal after the appropriate time delay. The signal is the result of a six-wave mixing process that can be as efficient as the traditional four-wave mixing process using a single brief reference pulse. Frequency shifting of the two chirped pulses enables programming of a variable time delay in the grating without changing the timing of the programming pulses. This concept is experimentally demonstrated with variable time delays over 448 ns (offset by greater than 1 μs) for the auto-correlation of a code with an experimentally limited bandwidth of 40 MHz. Processing bandwidths exceeding 10 GHz are achievable in materials such as Tm 3+ :YAG (0.1 at%).
Silver Nanoparticle-Catalyzed Diels−Alder Cycloadditions of 2′-Hydroxychalcones

Metal nanoparticles are currently being employed as catalysts for a number of classical chemical transformations. In contrast, identification of novel reactions of nanoparticles, especially toward the synthesis of complex natural products and derivatives, is highly underdeveloped and represents a bourgeoning area in chemical synthesis. Herein, we report silica-supported silver nanoparticles as solid, recyclable catalysts for Diels-Alder cycloadditions of 2'-hydroxychalcones and dienes in high yield and turnover number. The use of silver nanoparticle catalysts is further demonstrated by the total synthesis of the cytotoxic natural product panduratin A employing a highly electron-rich dienophile and Lewis acid sensitive diene.
Is the Cosmic Microwave Background Really Non-Gaussian?

Two recent papers have claimed detection of non-Gaussian features in the COBE Differential Microwave Radiometer sky maps of the cosmic microwave background. We confirm these results, but argue that Gaussianity is still not convincingly ruled out. Since a score of non-Gaussianity tests have now been published, one might expect some mildly significant results even by chance. Moreover, in the case of one measure that yields a detection, a bispectrum statistic, we find that if the non-Gaussian feature is real, it may well be due to detector noise rather than a non-Gaussian sky signal, since a signal-to-noise analysis localizes it to angular scales smaller than the beam. We study its spatial origin in case it is nonetheless due to a sky signal (e.g., a cosmic string wake or flat-spectrum foreground contaminant). It appears highly localized in the direction b = 395, l = 257°, since removing a mere five pixels inside a single COBE beam area centered there makes the effect statistically insignificant. We also test Gaussianity with an eigenmode analysis which allows a sky map to be treated as a random number generator. A battery of tests of this generator yields results consistent with Gaussianity.
A solid phase CBZ chloride equivalent — a new matrix specific linker

Abstract Treatment of TentaGel S resin (1) with phosgene provides matrix linked chloroformate (2), which is converted to the corresponding carbamoylated derivatives 3a and 3b. Alternatively, Wang resin provides the imidazolide (7a), which is readily transformed to amides and esters by treatment with nitrogen and carbon nucleophiles, respectively.
Radio Emission from Young Supernovae and Supernova Remnants in Arp 299

We have made sensitive milliarcsecond-resolution radio images of the nearby merger galaxy Arp 299 at four epochs spread over 18 months between 2003 and 2005. The combined data revealed a total of 30 point sources in the two primary merger nuclei. Twenty-five of these are found in the northeastern nucleus (component "A" = IC 694) over a region ~100 pc in diameter, while five are in the southwestern nucleus (component "B1" = NGC 3690) within a region ~30 pc in size. These objects are interpreted as young supernovae and supernova remnants; the ratio of the source counts in nuclei A and B1 is approximately equal to the ratio of their predicted supernova rates. An approximate luminosity function has been derived for nucleus A, and indicates that it might contain as many as 500-1000 compact radio sources more powerful than Cassiopeia A; the integrated flux density of these sources would be about 20% of the total flux density seen at lower resolution. A new supernova occurred in nucleus B1 in the first half of 2005, having a peak radio power at least 2000 times the present power of Cas A. This supernova is located within 0.4 pc (projected distance) of an apparently older supernova remnant, making it very likely that this indicates the presence of a massive super star cluster within nucleus B1. Comparison of the typical radio flux densities of our compact radio sources to the observed X-ray luminosities of nuclei A and B1 indicates that it is possible that one radio source in each nucleus actually could be associated with an active galactic nucleus rather than being a supernova remnant.
Fundamental tradeoffs in distributed algorithms for rate adaptive multimedia streams

Rate adaptive multimedia streams adjust the encoding rate dynamically (with corresponding changes in media content resolution) in response to changing levels of congestion along the route. The field of optimization based congestion control has yielded sophisticated distributed algorithms for resource allocation among competing elastic streams. In this work we study the fundamental tradeoffs for a class of optimization based distributed algorithms for rate adaptive streams. We focus on three tradeoffs: (i) the tradeoff between maximizing client average quality of service (QoS) and client fairness, (ii) the tradeoff between granularity of control (both temporal and spatial) and QoS, and (iii) the tradeoff between maximizing the received volume and minimizing the fluctuations in received rate. We illustrate these tradeoffs through extensive ns-2 simulations on two distinct topologies - (i) a single bottleneck like and (ii) a linear network.
Learning and time-varying macroeconomic volatility

Abstract This paper presents a DSGE model in which agents׳ learning about the economy can endogenously generate time-varying macroeconomic volatility. Economic agents use simple models to form expectations and need to learn the relevant parameters. Their gain coefficient is endogenous and is adjusted according to past forecast errors. The model is estimated using likelihood-based Bayesian methods. The endogenous gain is jointly estimated with the structural parameters of the system. The estimation results show that private agents appear to have often switched to constant-gain learning, with a high constant gain, during most of the 1970s and until the early 1980s, while reverting to a decreasing gain later on. As a result, the model can generate a pattern of volatility, which is increasing in the 1970s and falling in the second half of the sample, with a decline that can roughly match the magnitude of the so-called “Great Moderation” in the 1984–2007 period. The paper also documents how a failure to incorporate learning into the estimation may lead econometricians to spuriously find time-varying volatility in the exogenous shocks, even when these have constant variance by construction.
Broad-Spectrum Enantioselective Diels−Alder Catalysis by Chiral, Cationic Oxazaborolidines

The cationic chiral Lewis acids 1 and 2, generated by triflic acid protonation of the corresponding neutral oxazaborolidines, serve as excellent catalysts for Diels−Alder addition of cyclopentadiene to a wide variety of dienophiles. Adducts have been obtained in excellent yield and enantioselectivity from α,β-unsaturated esters, lactones, and cyclic ketones. The absolute facial selectivity for each of these substrates follows a common pattern which differs from that observed with α,β-enals. The different reaction channels can be understood in terms of pathways via complexes 3 (for α,β-enals) and 4 (for α,β-enones and esters).
The phenomenology of SUSY models with a gluino LSP

Abstract In this paper we study the experimental consequences of a theory which naturally has a heavy, stable (or almost stable) gluino. We define the boundary conditions at a messenger scale M ∼ 10 14 GeV which lead to this alternative phenomenologically acceptable version of the minimal supersymmetric standard model. In this theory, either the gluino or the gravitino is the lightest supersymmetric particle (LSP). If the gravitino is the LSP, then the gluino is the next-to-LSP with a lifetime on the order of 100 years. In either case, the gluino is (for all practical purposes) a stable particle with respect to experiments at high energy accelerators. Thus the standard missing energy signature for SUSY fails. A stable gluino forms a color singlet hadron, the lightest of which is assumed to be an isoscalar gluino-gluon bound state ( R 0 ). The R 0 has strong interactions and will interact in a hadronic calorimeter; depositing some fraction of its kinetic energy. Finally, in the case the gravitino is the LSP, bounds from searches for stable heavy isotopes of hydrogen or oxygen do not apply to the metastable R 0 .
Torsion in graph homology

Khovanov homology for knots has generated a flurry of activity in the topology community. This paper studies the Khovanov type cohomology for graphs with a special attention to torsion. When the underlying algebra is Z[x]/(x 2 ), we determine precisely those graphs whose cohomology contains torsion. For a large class of algebras, we show that torsion often occurs. Our investigation of torsion led to other related general results. Our computation could potentially be used to predict the Khovanov-Rozansky sl(m) homology of knots (in particular (2, n) torus knot). We also predict that our work is connected with Hochschild and Connes cyclic homology of algebras.
Influence of Bottom Refraction on the Propagation of Underwater Sound

Experimental measurements [J. S. Hanna, J. Acoust. Soc. Am. 53: 1686 (1973); R. E. Christensen et al., J. Acoust. Soc, Am. 57: 1421 (1975)] of the transmission loss of underwater sound propagating over an ocean bottom containing unconsolidated sediments have presented evidence on the presence of bottom-refracted energy being returned into the water column. The bottom refractions manifest themselves either via their pulse arrival times (indicating bottom-refracted paths), or via their interference with steady-state transmission loss data attributable to bottom reflections alone. The theoretical interpretation of these experiments has so far been carried out in the form of transmission-loss estimates based on ray theory and ray spreading. In a previous study [A. Nagl et al., J. Acoust. Soc. Am. 63: 739 (1978)], we have devised a normal-mode program of underwater sound propagation containing water layers of linear velocity gradients. This program has been extended to a bottom containing unconsolidated sediment layers of different densities and velocity gradients, and shown to reproduce bottom-refracted fields interfering with reflected sound. The interference minima can be used to determine the sound speeds and their gradients in the bottom layers.
The Bond Market's q

I propose an implementation of the q-theory of investment using bond prices instead of equity prices. Credit risk makes corporate bond prices sensitive to future asset values, and q can be inferred from bond prices. With aggregate U.S. data, the bond market's q fits the investment equation six times better than the usual measure of q, it drives out cash flows, and it reduces the implied adjustment costs by more than an order of magnitude. Theoretical interpretations for these results are discussed.
Toward A Positive Theory of State Supreme Court Decision Making

State Supreme Courts have grown in importance during the last thirty years in the formation of public policy. Their judgements determine many aspects of constitutional law, tort reform, judicial selection, and campaign finance reform, among others. A vast body of literature has been developed that analyzes State Supreme Court decision making, which emphasizes the conditioning effects of the legal and institutional environment. This article expands on this previous work by incorporating the interaction of the judiciary with other government institutions, and applies the Positive Political Theory approach to law and legal institutions to the State Supreme Court. In addition, the neo-institutionalist literature of the selection process is incorporated to defend a systematic approach towards decision making. Towards that end, this article explores how judicial decisions are conditioned by institutional rules, resulting in a formal modeling of how the State Supreme Courts interact with political actors to form...
Behavioral Treatment Options for Urinary Incontinence

Abstract Behavioral treatments improve bladder control by changing the incontinent patient's behavior, especially his or her voiding habits, and by teaching skills for preventing urine loss. These treatments are effective for most outpatient men and women with stress, urge, or mixed incontinence. The average reduction in the frequency of incontinence ranges from 57% to 86%. In long-term care settings, treatment is generally more challenging and yields more modest results. The advantages of behavioral interventions include the absence of side-effects, patient comfort, and high levels of patient satisfaction. Although most patients who receive behavioral treatment achieve significant improvement, most are not completely dry. Thus, there is a need for research to explore ways to enhance the effectiveness of these conservative therapies. Combining behavioral treatment with other treatments may have additive effects. Research is also needed to understand better the mechanisms of therapeutic change, the best methods for teaching pelvic floor muscle control, the optimal exercise regimens, the predictors of outcome, and the efficacy of behavioral treatments in men. Although behavioral interventions are more accepted today than 20 years ago, they are still not widely available or integrated into most clinical practices, and we know little of how effective they will be in these settings. Thus, it will be important to develop and evaluate creative modes of delivery, such as group intervention (especially by nonphysician providers), in a variety of clinical settings.
Supporting OpenMP on cell

The Cell processor is a heterogeneous multi-core processor with one power processing engine (PPE) core and eight synergistic processing engine (SPE) cores. There is a significant amount of ongoing research in programming models and tools that attempts to make it easy to exploit the computation power of the Cell architecture. In our work, we explore supporting OpenMP on the Cell processor. It is attractive to support OpenMP because programmers can continue using their familiar programming model, and existing code can be re-used. We base our work on IBM's XL compiler, and developed new components in the XL compiler and a new runtime library. Three major issues are addressed: (1) synchronization support on heterogeneous cores; (2) code generation targeting the different instruction sets; (3) data transfers and implement the OpenMP memory model. We present experimental results for some SPEC OMP 2001 and NAS benchmarks to demonstrate the effectiveness of this approach. A visualization tool based on Paraver is also used to provide some insights into actual thread and synchronization behaviors.
Enterprise restructuring and social benefits

Soviet era firms provided generous social benefits, including health and child care. Despite recent cuts, firm survey data show that benefits have remained a major component of total compensation. With benefits largely firm-specific and firms dominated by insiders, continuing attachment of workers as well as widespread informal sector participation has resulted. This has impeded restructuring, in part by generating significant set-up costs for new private firms. We simulate the effects of a cut in subsidies to benefits provision. We show that while this leads to falls in benefits and employment and an increase in wages, the outcome critically depends on the availability of alternative providers. The key to cushioning these adverse consequences is the stimulation of a market in benefits provision. Given initial conditions, rapid removal of benefits supports will require transitional income support scheme of transitional support and show that it can be financed from the savings from removal of current subsidies to benefits.
Palladium-catalyzed reaction of fluorinated vinyl iodides with terminal alkynes: a new and general route to fluorinated enynes

Abstract In the presence of cuprous iodide, the palladium-catalyzed coupling reaction of fluorinated vinyl iodides with terminal alkyl and phenyl substituted alkynes gives the corresponding enynes in good yields under mild conditions. The reaction works well with perfluorovinyl, phenyl and phosphoryl substituted iodides, and the stereochemistry in the vinyl iodide was preserved in the enyne products. With a terminal dialkyne the dienyne is formed when two equivalents of the vinyl iodide are used as substrate. However, upon reaction of Z-iodopentafluoropropene with alkynes containing electron- withdrawing groups such as ethoxycarbonyl or perfluoroalkyl, no desired enynes were observed under similar reaction conditions. The coupling reaction can be carried out in a variety of solvents, including DMF, DMSO, HMPA, acetonitrile, dioxane, chloroform, benzene and hexane as well as in excess triethylamine as solvent.
The effect of public policies on recent Swedish fertility behavior

In the literature the recent upsurge in period birth rates is seen as evidence of a pronatalist effect of Sweden's extensive social insurance programs. Yet, these explanations can not account for the downturn in birth rates in the 1970s, the delay in childbearing, and the constancy of cohort birth rates which characterize recent Swedish fertility behavior. To summarize the effect of Sweden's economic and policy environment on the observed fertility patterns, I use a neoclassical economic framework to develop the shadow price of fertility. Although strong simplifying assumptions are imposed, the estimated price series exhibit a negative relationship with period fertility rates and the change in the estimated relative prices of fertility over the life cycle lend modest support for the delayed childbearing.
Consistency of decision processes

If a statistical or a voting decision procedure is used by several subpopulations and if each reaches an identical conclusion, then one might expect this conclusion to be the outcome for the full group. It is shown that this property fails to hold for large classes of decision procedures. The geometric reasons why the consistency does not hold are described. A general theorem is given to characterize the procedures that satisfy this property of “weak consistency”.
Generic conditions for stable hybrid stars

We study the mass-radius curve of hybrid stars, assuming a single first-order phase transition between nuclear and quark matter, with a sharp interface between the quark matter core and nuclear matter mantle. We use a generic parametrization of the quark matter equation of state, which has a constant, i.e. density-independent, speed of sound. We argue that this parametrization provides a framework for comparison and empirical testing of models of quark matter. We obtain the phase diagram of possible forms of the hybrid star mass-radius relation, where the control parameters are the transition pressure, energy density discontinuity, and the quark matter speed of sound. We find that this diagram is sensitive to the quark matter parameters but fairly insensitive to details of the nuclear matter equation of state (EoS). We calculate the maximum hybrid star mass as a function of the parameters of the quark matter EoS, and find that there are reasonable values of those parameters that give rise to hybrid stars with mass above $2{M}_{\ensuremath{\bigodot}}$.
Highly Selective Diels-Alder Reactions of Directly Connected Enyne Dienophiles

The paper describes the course of cycloadditions of Diels-Alder dienophiles containing linked enyne sites, each substituted with activating groups. Consistently, it was found that in the enyne cases the Diels-Alder reaction occurred specifically at the acetylenic center. Furthermore, it was found that the regiochemical sense of the cycloaddition was apparently determined by the remote activating group bound to the olefinic site. This remote acrylyl group totally dominated the course of the cycloaddition, relative to the activating group bound directly on the acetylene site. Explanations for these findings at the computational level are provided. The computations also rationalize the strong preference for cycloaddition to occur at the acetylene linkage and encompass the otherwise surprising regiochemical dominance by the remote ester on the olefinic site. The high selectivities available through such reactions provide important new opportunities in the synthesis of orsenillate type substructures that are found in a variety of natural products of contemporary interest.