cssi/SciSciGPT-SciSciNet huggingface dataset:
Multifractals, Mumford Curves and Eternal Inflation

We relate the Eternal Symmetree model of Harlow, Shenker, Stanford, and Susskind to constructions of stochastic processes related to quantum statistical mechanical systems on Cuntz-Krieger algebras. We extend the eternal inflation model from the Bruhat-Tits tree to quotients by p-adic Schottky groups, again using quantum statistical mechanics on graph algebras.
Orbifold resolution by D-branes

Abstract We study topological properties of the D-brane resolution of three-dimensional orbifold singularities, C 3 /Λ , for finite abelian groups Λ. The D-brane vacuum moduli space is shown to fill out the backgroun space-time with Fayet-Iliopoulos parameters controlling the size of the blow-ups. This D-brane vacuum moduli space can be classically described by a gauged linear sigma model, which is shown to be non-generic in a manner that projects out non-geometric regions in its phase diagram, as anticipated from a number of perspectives.
Divergent reaction pathways of homologous and isosteric propargyl amides in sequential Ru/Pd-catalyzed annulations for the synthesis of heterocycles.

Cu-catalyzed three-component coupling of imines with benzoyl chloride and terminal arylalkynes followed by enyne ring-closing metathesis (RCM) and Heck cyclization afforded medicinally relevant benzoindolines, cyclopropane-fused indenopyridines, pyrroloquinolines, or 1,7-tetrahydrophenanthrolines via divergent cyclization pathways. Unexpectedly, the Pd-catalyzed cyclization of heterocyclic dienes proceeded via regiodivergent 5-exo or 6-endo pathways depending on the ring size (n = 1, 2) or the presence of isosteric groups (CH vs N). A one-pot protocol for the enyne–RCM/Heck annulation featuring a sequential addition of the Ru and Pd catalysts was developed maximizing the synthetic efficiency.
A new field theoretic approach to criticality

Abstract A reorganized perturbation expansion with a propagator of soft infrared behavior is used to study the critical behavior of the mass gap. The condition of relativistic covariance fixes the form of the soft propagator. Finite approximants to the correlation critical exponent can be obtained in every order of the modified, soft perturbation expansion. Alternatively, a convergent series of exponents in large orders of the soft perturbation expansion is provided by the renormalization group in all spatial dimensions, 1 ⩽ D ⩽ 3. The result of the ϵ-expansion is recovered in the D → 3 limit.
Halide Effects on Cyclopropenium Cation Promoted Glycosylation with Deoxy Sugars: Highly α-Selective Glycosylations Using a 3,3-Dibromo-1,2-diphenylcyclopropene Promoter

A mixture of 3,3-dibromocyclopropene and TBAI promotes highly α-selective glycosylation reactions (up to >20:1) by using deoxy sugar hemiacetal donors. The reaction provides a convenient method for generating highly reactive glycosyl donors in situ from shelf-stable starting materials. Both armed and disarmed sugars undergo the reaction, and selectivity is independent of the configuration of the donor sugar.
Big bad nucleosynthesis: A review

Big Bang Nucleosynthesis represents perhaps the first, and still perhaps the most powerful particle-astrophysics connection. As such, it should provide an example for other work in this area. I discuss the current status of standard model BBN predictions and constraints, and then argue that the issue of observational systematic uncertainties is the key feature limiting our ability to constrain theory with observation. Nevertheless, several very important constraints are currently obtainable. For example, assuming maximal systematic uncertainties in 4 He, D, and 7 Li we find a conservative upper limit of Ω B ≤ 0.16 in order for BBN predictions to agree with observations. Equally significant, we find that BBN predictions are inconsistent unless 4 He abundance by mass is greater than 23.9%, or D + 3 He estimates are incorrect. By contrast, unless systematic uncertainties are taken into account, the quoted 2 σ observational upper limit on the primordial 4 He fraction is 23.8%.
Development of methodology for low exposure, high resolution electron microscopy of biological specimens

Specimen damage resulting from inelastic scattering is one of the factors that limits high-resolution electron microscopy of biological specimens. We have, therefore, sought to develop a method to record images of periodic objects at a reduced electron exposure in order to preserve high-resolution structural detail. The resulting image will tend increasingly to be a statistically noisy one, as the electron exposure is reduced to lower and lower values. Construction of a statistically defined image from such data is possible by spatial averaging of the electron signals from a large number of identical unit cells. In this paper, we have first investigated the theory pertaining to the attainable resolution as a function of the electron exposure, the magnification, and several other relevant parameters. In addition, we report experimental results obtained with a commercial image intensifier and with nuclear track photographic emulsion, both of which are highly sensitive recording devices. Usable images can be recorded and processed at exposures in the image plane as low as 10−3 electrons/μm2 (1.6 × 10−14 coulomb/cm2).
Facile Routes to NiF62-, AgF4-, AuF6-, and PtF6- Salts Using O2+ as a Source of O2F in Anhydrous HF

O{sub 2}{sup +} salts dissolved in liquid anhydrous hydrogen fluoride (aHF) at 20 C or below oxidize aHF solutions of PtF{sub 6}{sup 2{minus}} to PtF{sub 6}{sup {minus}}. The parent base of O{sub 2}{sup +} salts in aHF (O{sub 2}F{sub (solv)}) generated with alkali fluoride is long-lived below {minus}50 C. An aHF solution of O{sub 2}F{sub (solv)} oxidizes Au(III) to Au(V) below {minus}50 C (20{sub 2}F{sub (solv)} + AuF{sub 4}{sup {minus}}{sub (solv)} {yields} AuF{sub 6}{sup {minus}}{sub (solv)} + 2O{sub 2(g)}). In situ generation of O{sub 2}F{sub (solv)} (O{sub 2}{sup +}{sub (solv)} + F{sup {minus}}{sub (solv)} {yields} O{sub 2}F{sub (solv)}) with AgF{sub 2} or NiF{sub 2} in suspension in the aHF made basic with alkali fluoride gives AgF{sub 4}{sup {minus}} and NiF{sub 6}{sup 2{minus}} salts. Low solubility of AAsF{sub 6}(A = Cs, K) in aHF provides for the metathetical preparation of (O{sub 2}){sub 2}PdF{sub 6} solutions in aHF. Removal of aHF, even at {minus}60 C, results in some O{sub 2} and F{sub 2} loss, to a composition approaching (O{sub 2})PdF{sub 5}.
Child support enforcement policy and unmarried fathers' employment in the underground and regular economies

Some scholars have suggested that a negative consequence of strengthening child support enforcement is to encourage fathers to shift from regular sector to underground employment. We employ data from the Fragile Families and Child Wellbeing Study to investigate the relationship between the strength of child support enforcement (CSE) and levels of underground and regular sector employment among unmarried fathers. We find that, in general, living in a city with stricter CSE is associated with fewer hours of underground employment. We find little evidence that stronger enforcement is associated with employment or hours in the regular sector. © 2007 by the Association for Public Policy Analysis and Management.
Not just a matter of time: field differences and the shaping of electronic media in supporting scientific communication

The shift towards the use of electronic media in scholarly communication appears to be an inescapable imperative. However, these shifts are uneven, both with respect to field and with respect to the form of communication. Different scientific fields have developed and use distinctly different communicative forums, both in the paper and electronic arenas, and these forums play different communicative roles within the field. One common claim is that we are in the early stages of an electronic revolution, that it is only a matter of time before other fields catch up with the early adopters, and that all fields converge on a stable set of electronic forums. A social shaping of technology (SST) perspective helps us to identify important social forces -centered around disciplinary constructions of trust and of legitimate communication- that pull against convergence. This analysis concludes that communicative plurality and communicative heterogeneity are durable features of the scholarly landscape, and that we are likely to see field differences in the use of and meaning ascribed to communications forums persist, even as overall use of electronic communications technologies both in science and in society as a whole increases.
Folic Acid-Mediated Targeting of Cowpea Mosaic Virus Particles to Tumor Cells

Cowpea mosaic virus (CPMV) is a well-characterized nanoparticle that has been used for a variety of nanobiotechnology applications. CPMV interacts with several mammalian cell lines and tissues in vivo. To overcome natural CPMV targeting and redirect CPMV particles to cells of interest, we attached a folic acid-PEG conjugate by using the copper-catalyzed azide-alkyne cycloaddition reaction. PEGylation of CPMV completely eliminated background binding of the virus to tumor cells. The PEG-folate moiety allowed CPMV-specific recognition of tumor cells bearing the folate receptor. In addition, by testing CPMV formulations with different amounts of the PEG-FA moiety displayed on the surface, we show that higher-density loading of targeting ligands on CPMV may not be necessary for efficient targeting to tumor cells. These studies help to define the requirements for efficiently targeting nanoparticles and protein cages to tumors.
CF2 and CFCl fluorescence from VUV excitation of C2F3Cl

The photoexcitation process of the C2F3Cl molecule was investigated in the 106-230-nm region using synchrotron radiation as a light source. Photoabsorption and fluorescence cross sections were measured and used to determine the fluorescence quantum yield. Fluorescence yield starts to appear at 170 nm and increases to about 2 percent at 155 nm. The fluorescence spectra were dispersed to identify the emitting species. The (A-X) systems of CFCl (at excitation wavelengths 155 and 123.9 nm) and CF2 (at 123.9 nm) are observed. The dissociation processes that produced these excited species are discussed.
The performance of a superconducting micro-undulator prototype

Abstract We report on the performance of a prototype of a superferric micro-undulator. The micro-undulator consists of a continuous winding of niobium-titanium wire wound on a low-carbon-steel yoke. It is about three periods long with a period of 8.8 mm and a gap of 4.4 mm. The undulator achieves a peak magnetic field on axis of over0.5 T. Asymmetry of the field pattern due to a dipole component was identified, analyzed and a correction has been applied to the undulator ends to produce a symmetric field distribution. Within the precision of the measurement the field pattern produced by the superferric undulator needed no correction.
The effect of vibrational energy on the reaction of molecular hydrogen with atomic oxygen

Abstract An upper bound of 6 × 10 10 cm 3 /moles on the rate constant for the reaction of atomic oxygen with vibrationally excited H 2 has been deduced from laboratory observations and from detailed computer calculations. From this result it can be shown that no more than 30% of the vibrational energy of H 2 is effective in overcoming the activation energy for the O + H 2 reaction.
A simple class of N = 3 gauge/gravity duals

We find the gravity duals to an infinite series of = 3 Chern-Simons quiver theories. They are AdS4 × M7 vacua of M-theory, with M7 in a certain class of 3-Sasaki-Einstein manifolds obtained by a quotient construction. The field theories can be engineered from a brane configuration; their geometry is summarized by a ``hyperKahler toric fan'' that can be read off easily from the relative angles of the branes. The singularity at the tip of the cone over M7 is generically not an orbifold. The simplest new manifolds we consider can be written as the biquotient U(1)\U(3)/U(1). We also comment on the relation between our theories and four-dimensional = 1 theories with the same quiver.
New lower bound techniques for VLSI

In this paper, we use crossing number and wire area arguments to find lower bounds on the layout area and maximum edge length of a variety of new and computationally useful networks. In particular, we describe
Radially localized helicon modes in nonuniform plasma

A radial density gradient in an axisymmetric cylindrical plasma column forms a potential well for nonaxisymmetric helicon modes (m{ne}0 ). This paper presents an analytic description of such modes in the limit of small longitudinal wave numbers. The corresponding mode equation indicates the possibility of efficient resonant absorption of rf power in helicon discharges at unusually low frequencies. (c) 2000 The American Physical Society.
Optimal Trust Design in Mass Tort Bankruptcy

Many firms have filed for bankruptcy to manage mass tort liabilities, most notably asbestos producers. We model a bankruptcy procedure that optimally balances the liquidity needs of present claimants and an uncertain number of future claimants. We find that future claimants should receive greater awards in expectation than present claimants as compensation for bearing greater future claims risk. We also find that allocating more value to contractual creditors in bankruptcy makes an earlier filing more likely, which may increase overall welfare. Optimal risk-sharing implies that creditors should receive equity in a trust fund, with tort claimants receiving senior debtlike securities.
Dynamic Fracture Analysis of Adhesively Bonded Joints Using Explicit Methods

An experimental and computational study of adhesively bonded test configuration of the double cantilevered beams (DCB) using Cohesive Zone Models under dynamic loading is presented. Explicit methods which have a marked advantage over implicit methods for dynamic analysis have been used. The response of the DCB test specimens were modeled in LS-DYNA R . Cohesive zone model (CZM) which define the interfacial tractions to the opening displacements are used to model crack initiation and crack growth in the adhesive. Parameters for the CZM law are determined using experimental data from simple test configurations like the DCB for Mode I. The CZM law implemented through a user defined material model (UMAT) was used to model the adhesive in the adhesively bonded DCBs. Simulations for DCB with aluminum adherends correlated very well to the experiments. Good correlation between the simulation and the experiment for the composite DCB is achieved if the displacement history of the adherend tip, obtained from digital images, is used as the prescribed boundary conditions, instead of the conventional assumption of a constant velocity being imparted to the adherends tips by the falling wedge in the drop tower.
The Effect of Seller Income Taxes on Acquisition Price: Evidence from Purchases of Taxable and Tax‐Exempt Hospitals

This paper investigates the impact of the seller's tax liability on the price paid in hospital acquisitions. Lock‐in theory predicts that for a given asset, asset holders with larger tax liabilities demand a higher price to compensate for income tax liabilities generated on the sale. We apply this theory to a sample of hospital acquisitions by for‐profit firms where the primary difference among target hospitals is the seller's tax status—either taxable or tax‐exempt. Consistent with the predicted lock‐in effect, the evidence indicates that purchase prices are higher when the seller is taxable than when the seller is tax‐exempt. Thus, our findings suggest that seller tax liabilities are positively related to purchase prices.
New Trade Models, New Welfare Implications

We show that endogenous firm selection provides a new welfare margin for heterogeneous firm models of trade (relative to homogeneous firm models). Under some parameter restrictions, the trade elasticity is constant and is a sufficient statistic for welfare, along with the domestic trade share. However, even small deviations from these restrictions imply that trade elasticities are variable and differ across markets and levels of trade costs. In this more general setting, the domestic trade share and endogenous trade elasticity are no longer sufficient statistics for welfare. Additional empirically observable moments of the micro structure also matter for welfare. (JEL F12, F13, F41) Over the last decade, new theories of trade with heterogeneous firms in differentiated product markets have been developed. These theories were designed to account for features of disaggregated trade data: only some firms export, exporters are more productive than non-exporters, and trade liberalization induces intra-industry reallocations of resources between those different types of firms. These reallocations represent a new potential channel for the gains from trade. However, the implications of these models for aggregate welfare (combining together all welfare channels) were left unanswered. In a recent paper, Arkolakis, Costinot, and Rodriguez-Clare ( 2012)—henceforth, ACR—show that there exists a class of heterogeneous and homogeneous firm models in which a country’s domestic trade share and the elasticity of trade with respect to variable trade costs are sufficient statistics for the aggregate welfare gains from trade. Therefore, if the different models within this class are calibrated to the same domestic trade share and the same trade elasticity, they imply the same welfare gains from trade. Based on this result, ACR ( 2012, p. 94) summarizes the contribution of new theories of heterogeneous firms to the aggregate welfare implications of trade as “So far, not much.”
Information Fusion in Continuous Assurance

ABSTRACT : We extend continuous assurance research by proposing a novel continuous assurance architecture grounded in information fusion research. Existing continuous assurance architectures focus primarily on methods of monitoring assurance clients' systems to detect anomalous activities and have not addressed the question of how to process the detected anomalies. Consequently, actual implementations of these systems typically detect a large number of anomalies, with the resulting information overload leading to suboptimal decision making due to human information processing limitations. The proposed architecture addresses these issues by performing anomaly detection, aggregation, and evaluation. Within the proposed architecture, artifacts developed in prior continuous assurance, ontology, and artificial intelligence research are used to perform the detection, aggregation, and evaluation information fusion tasks. The architecture contributes to the academic continuous assurance literature and has implicat...
Titan's transport-driven methane cycle

The mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed. A global- and annual-mean estimate of surface fluxes indicated only 1% of the insolation, or {approx}0.04 W m{sup -2}, is exchanged as sensible and/or latent fluxes. Since these fluxes are responsible for driving atmospheric convection, it has been argued that moist convection should be quite rare and precipitation even rarer, even if evaporation globally dominates the surface-atmosphere energy exchange. In contrast, climate simulations indicate substantial cloud formation and/or precipitation. We argue that the top-of-atmosphere (TOA) radiative imbalance is diagnostic of horizontal heat transport by Titan's atmosphere, and thus constrains the strength of the methane cycle. Simple calculations show the TOA radiative imbalance is {approx}0.5-1 W m{sup -2} in Titan's equatorial region, which implies 2-3 MW of latitudinal heat transport by the atmosphere. Our simulation of Titan's climate suggests this transport may occur primarily as latent heat, with net evaporation at the equator and net accumulation at higher latitudes. Thus, the methane cycle could be 10-20 times previous estimates. Opposing seasonal transport at solstices, compensation by sensible heat transport, and focusing of precipitation by large-scale dynamics could further enhance the local, instantaneous strength of Titan'smore » methane cycle by a factor of several. A limited supply of surface liquids in regions of large surface radiative imbalance may throttle the methane cycle, and if so, we predict more frequent large storms over the lakes district during Titan's northern summer.« less
Geometrical spin frustration and ferromagnetic ordering in (MnxPb2-x)Pb2Sb4Se10.

Engineering the atomic structure of an inorganic semiconductor to create isolated one-dimensional (1D) magnetic subunits that are embedded within the semiconducting crystal lattice can enable chemical and electronic manipulation of magnetic ordering within the magnetic domains, paving the way for (1) the investigation of new physical phenomena such as the interactions between electron transport and localized magnetic moments at the atomic scale and (2) the design and fabrication of geometrically frustrated magnetic materials featuring cooperative long-range ordering with large magnetic moments. We report the design, synthesis, crystal structure and magnetic behavior of (MnxPb2–x)Pb2Sb4Se10, a family of three-dimensional manganese-bearing main-group metal selenides featuring quasi-isolated [(MnxPb2–x)3Se30]∞ hexanuclear magnetic ladders coherently embedded and uniformly distributed within a purely inorganic semiconducting framework, [Pb2Sb4Se10]. Careful structural analysis of the magnetic subunit, [(MnxPb...
Vortex core excitations in superconductors with frustrated antiferromagnetism

Abstract Motivated by recent discovery of cobalt oxide and organic superconductors, we apply an effective model with strong antiferromagnetic and superconducting pairing interaction to a related lattice structure. It is found that the antiferromagnetism is highly frustrated and a broken-time-reversal-symmetry chiral d + id′-wave pairing state prevails. In the mixed state, we have solved the local electronic structure near the vortex core and found no local induction of antiferromagnetism. This result is in striking contrast to the case of copper oxide superconductors. The calculated local density of states indicates the existence of low-lying quasiparticle bound states inside the vortex core, due to a fully gapped chiral pairing state. The prediction can be directly tested by scanning tunneling microscopy.
Absorbed Dose from 7-GeV Bremsstrahlung in a PMMA Phantom

Electron storage rings generate energetic bremsstrahlung photons through radiative interaction of the particle beam with the residual gas molecules and other components inside the storage ring. At the Advanced Photon Source (APS), where the stored beam energy is 7 GeV, bremsstrahlung generated in the straight sections of the insertion devices comes down through the beamlines. The resulting absorbed dose distributions by this radiation in a 300 mm × 300 mm × 300 mm tissue substitute phantom were measured with LiF:Mg, Ti (TLD-700) thermoluminescent dosimeters. The average normalized absorbed dose, in a cross sectional area of 100 mm2 at a depth of 150 mm of the PMMA phantom, was measured as 3.3 × 106 mGy h−1W−1 for a 7-GeV bremsstrahlung spectrum.
Error Probability Analysis of Peaky Signaling over Fading Channels

In this paper, the performance of signaling strategies with high peak-to-average power ratio is analyzed in both coherent and noncoherent fading channels Two recently proposed modulation schemes, namely on-off binary phase-shift keying and on-off quaternary phase-shift keying, are considered. For these modulation formats, the optimal decision regions used at the detector are identified and analytical expressions for the error probabilities are obtained. Numerical techniques are employed to compute the error probabilities. It is concluded that increasing the peakedness of the signals results in reduced error rates for a given power level and hence improve the energy efficiency.
PROTON DECAY IN TERAVOLT UNIFICATION

Model building based on Abelian quiver gauge theories gives models which resemble trinification, originally proposed with yottavolt unification. However, unification occurs in the teravolt range so proton decay must be completely excluded in the scalar sector. It is straightforward to accomplish this by a discrete symmetry which is a generalized baryon number B. Unlike in trinification, this is possible because quarks and leptons acquire masses from relevant operators which appear in four-dimensional conformal symmetry breaking.
K-band Properties of Galaxy Clusters and Groups: Brightest Cluster Galaxies and Intracluster Light

We investigate the near-infrared K-band properties of the brightest cluster galaxies (BCGs) in a sample of 93 X-ray galaxy clusters and groups, using data from the Two Micron All Sky Survey. Our cluster sample spans a factor of 70 in mass, making it sensitive to any cluster mass-related trends. We derive the cumulative radial distribution for the BCGs in the ensemble and find that 70% of the BCGs are centered in the cluster to within 5% of the virial radius r200; this quantifies earlier findings that BCG position coincides with the cluster center as defined by the X-ray emission peak. We study the correlations between the luminosity of the BCGs (Lb) and the mass and the luminosity of the host clusters, finding that BCGs in more massive clusters are more luminous than their counterparts in less massive systems and that the BCGs become less important in the overall cluster light (L200) as cluster mass increases. By examining a large sample of optically selected groups, we find that these correlations hold for galactic systems less massive than our clusters (<3 × 1013 M☉). From the differences between luminosity functions in high- and low-mass clusters, we argue that BCGs grow in luminosity mainly by merging with other luminous galaxies as the host clusters grow hierarchically; the decreasing BCG luminosity fraction (Lb/L200) with cluster mass indicates that the rate of luminosity growth in BCGs is slow compared to the rate at which clusters acquire galaxy light from the field or other merging clusters. Utilizing the observed correlation between the cluster luminosity and mass and a merger tree model for cluster formation, we estimate that the amount of intracluster light (ICL) increases with cluster mass; our calculations suggest that in 1015 M☉ clusters more than 50% of total stellar mass is in ICL, making the role of ICL very important in the evolution and thermodynamic history of clusters. The cluster baryon fraction accounting for the ICL is in good agreement with the value derived from cosmic microwave background observations. The inclusion of ICL reduces the discrepancy between the observed cluster cold baryon fraction and that found in hydrodynamical simulations. Based on the observed iron abundance in the intracluster medium, we find that the ICL predicted by our model, together with the observed galaxy light, match the iron mass-to-light ratio expected from simple stellar population models, provided that the Salpeter initial mass function is adopted. The ICL also makes it easier to produce the "iron excess" found in the central regions of cool-core clusters.
Putting Hate in Its Place: The Codification of Bias Crime Laws in a Model Penal Code

Begun in 1952 and completed in 1962, the drafting of the Model Penal Code (M.P.C.) constituted an unparalleled stride forward in the development of the criminal law. Since 1962 however, our society, crime, and our society’s perception of crime have changed. With the benefit of hindsight, certain provisions of the Model Penal Code appear ill conceived, or if not ill conceived, at least profoundly outdated. If the Model Penal Code is to be true to its name, some degree of remodeling is needed. But remodeling implies more than repair and renovation: It implies wholesale elimination of some provisions and whole-cloth invention of others. In this latter category of provisions to be added fall, first, those needed to address antisocial phenomena that were either unknown or
The Infrared Surface Brightness Fluctuation Distances to the Hydra and Coma Clusters

We present IR surface brightness fluctuation (SBF) distance measurements to NGC 4889 in the Coma Cluster and to NGC 3309 and NGC 3311 in the Hydra Cluster. We explicitly corrected for the contributions to the fluctuations from globular clusters, background galaxies, and residual background variance. We measured a distance of 85 ± 10 Mpc to NGC 4889 and a distance of 46 ± 5 Mpc to the Hydra Cluster. Adopting recession velocities of 7186 ± 428 km s-1 for Coma and 4054 ± 296 km s-1 for Hydra gives a mean Hubble constant of H0=87 ± 11 km s-1 Mpc-1. Corrections for residual variances were a significant fraction of the SBF signal measured, and, if underestimated, would bias our measurement toward smaller distances and larger values of H0. Both the near-IR camera and multiobject spectrometer on the Hubble Space Telescope and large-aperture ground-based telescopes with new IR detectors will make accurate SBF distance measurements possible to 100 Mpc and beyond.
A subelliptic Taylor isomorphism on infinite-dimensional Heisenberg groups

Let G denote an infinite-dimensional Heisenberg-like group, which is a class of infinite-dimensional step 2 stratified Lie groups. We consider holomorphic functions on G that are square integrable with respect to a heat kernel measure which is formally subelliptic, in the sense that all appropriate finite-dimensional projections are smooth measures. We prove a unitary equivalence between a subclass of these square integrable holomorphic functions and a certain completion of the universal enveloping algebra of the “Cameron–Martin” Lie subalgebra. The isomorphism defining the equivalence is given as a composition of restriction and Taylor maps.
Fast timing recovery for linearly and nonlinearly modulated systems

Digital phase lock loops (PLLs) are often used in timing acquisition systems. It is known that some non-data-aided timing error detectors occasionally cause hangup problems in digital PLLs. In this paper, we introduce a novel two step antihangup timing recovery scheme. Through intensive simulations, we show that this enhanced scheme greatly reduces the probability of hangup, and speeds up the timing recovery process for both linearly and nonlinearly modulated systems.
Does the Addition of a Duration Improve the Liso-Epeak Relation for Gamma-Ray Bursts?

Firmani et al. proposed a new gamma ray burst (GRB) luminosity relation that showed a significant improvement over the Liso- Epeak relation (where Liso is the isotropic peak luminosity and Epeak is the photon energy of the spectral peak for the burst). The new proposed relation simply modifies the Epeak value by multiplying it by a power of T0.45, where T0.45 is a particular measure of the GRB duration. We begin by reproducing the results of Firmani for his 19 bursts. We then test the Firmani relation for the same 19 bursts, except that we use independently measured values for Liso, T0.45, and Epeak, and we find that the relation deteriorates substantially. We further test the relation by using 60 GRBs with measured spectroscopic redshifts, and find a relation that has a comparable scatter as the original L iso-Epeak relation. That is, a much larger sample of bursts does not reproduce the small scatter as reported by Firmani et al. Finally, we investigate whether the Firmani relation is improved by the use of any of 32 measures of duration (e.g., T90, T50, T90/Npeak, the fluence divided by the peak flux, T0.30, and T0.60) in place of T0.45. The quality of each alternative duration measure is evaluated with the root mean square of the scatter between the observed and fitted logarithmic Liso values. Although we find that some durations yield slightly better results than T0.45, the differences between the duration measures are minimal. We find that the addition of a duration does not add any significant improvement to the Liso- Epeak relation. We also present a simple and direct derivation of the Firmani relation from both the Liso-Epeak and Amati relations. In all, we conclude that the Firmani relation neither has an independent existence nor does it provide any significant improvement on previously known relations that are simpler.
Uniform high-order spectral methods for one- and two-dimensional Euler equations

Uniform high order spectral methods to solve multi-dimensional Euler equations for gas dynamics are discussed. Uniform high order spectral approximations with spectral accuracy in smooth regions of solutions are constructed by introducing the idea of the Essentially Non-Oscillatory (ENO) polynomial interpolations into the spectral methods. The authors present numerical results for the inviscid Burgers' equation, and for the one dimensional Euler equations including the interactions between a shock wave and density disturbance, Sod's and Lax's shock tube problems, and the blast wave problem. The interaction between a Mach 3 two dimensional shock wave and a rotating vortex is simulated.
Incentives, CEO Compensation, and Shareholder Wealth in a Dynamic Agency Model☆☆☆

Abstract M. Jensen and K. Murphy (1990,J. Polit. Econ.98, 225–264) argue that the observed pay–performance sensitivity of CEO compensation is too low to be consistent with formal agency theory. This paper uses a dynamic agency model to offer a resolution of the Jensen and Murphy puzzle. We show that the dynamic agency model can predict either a positive or a negative pay–performance sensitivity, depending on the parameter values of the model and the distribution of the CEOs' initial expected discounted utilities. For a large variety of parameter values and for properly chosen distributions of initial CEO expected discounted utilities, our model is capable of generating data where the pay–performance sensitivity is significantly positive but very small, as in Jensen and Murphy's data. The key to our result is a compensation rigidity that is created endogenously by the optimal dynamic contract.Journal of Economic LiteratureClassification Numbers: C63, D82, G30.
Observation-assisted optimal control of quantum dynamics

This paper explores the utility of instantaneous and continuous observations in the optimal control of quantum dynamics. Simulations of the processes are performed on several multilevel quantum systems with the goal of population transfer. Optimal control fields are shown to be capable of cooperating or fighting with observations to achieve a good yield, and the nature of the observations may be optimized to more effectively control the quantum dynamics. Quantum observations also can break dynamical symmetries to increase the controllability of a quantum system. The quantum Zeno and anti-Zeno effects induced by observations are the key operating principles in these processes. The results indicate that quantum observations can be effective tools in the control of quantum dynamics.
Importance of biologically active aurora-like ultraviolet emission: stochastic irradiation of Earth and Mars by flares and explosions.

Habitable planets will be subject to intense sources of ionizing radiation and fast particles from a variety of sources - from the host star to distant explosions - on a variety of timescales. Monte Carlo calculations of high-energy irradiation suggest that the surfaces of terrestrial-like planets with thick atmospheres (column densities greater than about 100 g cm-2) are well protected from directly incident X-rays and γ-rays, but we find that sizeable fractions of incident ionizingradiation from astrophysical sources can be redistributed to biologicallyand chemically important ultraviolet wavelengths, a significant fraction of which can reach the surface. This redistribution is mediated by secondary electrons, resulting from Compton scattering and X-ray photoabsorption, the energies of which are low enough to excite and ionize atmospheric molecules and atoms, resulting in a rich aurora-like spectrum. We calculate the fraction of energy redistributed into biologically and chemically important wavelength regions for spectra characteristic of stellar flares and supernovae using a Monte-Carlo transport code and then estimate the fraction of this energy that is transmitted from the atmospheric altitudes of redistribution to the surface for a few illustrative cases. For atmospheric models corresponding to the Archean Earth, we assume no significant ultraviolet absorbers, only Rayleigh scattering, and find that the fraction of incident ionizing radiation that is received at the surface in the form of redistributed ultraviolet in the biologically relevant 200-320 nm region (UV-C and UV-B bands) can be up to 4%. On the present-day Earth with its ultraviolet ozone shield, this fraction is found to be 0.2%. Both values are many orders of magnitude higher than the fraction of direct ionizing radiation reaching the surface. This result implies that planetary organisms will be subject to mutationally significant, if intermittent, fluences of UV-B and harder radiation even in the presence of a narrow-band ultraviolet shield like ozone. We also calculate the surficial transmitted fraction of ionizing radiation and redistributed ultraviolet radiation for two illustrative evolving Mars atmospheres whose initial surface pressures were 1 bar. We discuss the frequency with which redistributed ultraviolet flux from parent star flares exceeds the parent star ultraviolet flux at the planetary surface. We find that the redistributed ultraviolet from parent star flares is probably a fairly rare intermittent event for habitable zone planets orbiting solar-type stars except when they are young, but should completely dominate the direct steady ultraviolet radiation from the parent star for planets orbiting all stars less massive than about 0.5 solar masses. Our results suggest that coding organisms on such planets (and on the early Earth) may evolve very differently than on contemporary Earth, with diversity and evolutionary rate controlled by a stochastically varying mutation rate and frequent hypermutation episodes.
Convergence of step-by-step methods for non-linear integro-differential equations.

The theory of consistent step-by-step methods for solving Volterra integral equations is extended to nonsingular Volterra integro-differential equations. It is shown that standard step-by-step algorithms for these more general equations are convergent. Several numerical examples are included.
Hydrogen bonding Part 41. Stoichiometry, thermodynamics of dissociation, and IR spectra of the hydrates of N,N-dimethylpiperazine dioxide

Abstract Vapor pressure vs. H 2 O content studies show that N,N -dimethylpiperazine dioxide forms stable crystalline hydrates which contain 3 and 1.5 mol H 2 O. There is also a higher hydrate with ≈5 mol H 2 O; however, this compound is too efflorescent for study. The trihydrate is much less stable than the sesquihydrate; at 25°C P H 2 O is 8.92 Torr over the trihydrate and 0.47 Torr over the sesquihydrate. The greater stability of the lower hydrate relative to the higher is due to enthalpic rather than entropic effects, which is the opposite of what is observed for diarylpiperazine dioxide hydrates.
The City of Providence, RI: A Case Examining the Financial Condition of a U.S. Municipality

ABSTRACT: This case is intended for use in a wide variety of learning contexts, including undergraduate and graduate government and not-for-profit accounting courses, advanced accounting courses, public policy courses, along with courses that address municipal pensions at the college or university level, or other training programs. The case achieves four primary objectives: developing proficiency in ratio analyses for a municipality, conducting research related to the financial status of a municipality, improving critical thinking and problem-solving skills, and developing an awareness of potential public interest issues facing municipal leaders. We find that students benefit from analyzing the financial condition of the City of Providence, RI and develop critical thinking skills through their analyses.
Symmetry and Composition in Probabilistic Theories

The past decade has seen a remarkable resurgence of the old programme of finding more or less a priori axioms for the mathematical framework of quantum mechanics. The new impetus comes largely from quantum information theory; in contrast to work in the older tradition, which tended to concentrate on structural features of individual quantum systems, the newer work is marked by an emphasis on systems in interaction. Within this newer work, one can discern two distinct approaches: one is ''top-down'', and attempts to capture in category-theoretic terms what is distinctive about quantum information processing. The other is ''bottom up'', attempting to construct non-classical models and theories by hand, as it were, and then characterizing those features that mark out quantum-like behavior. This paper blends these approaches. We present a constructive, bottom-up recipe for building probabilistic theories having strong symmetry properties, using as data any uniform enlargement of the symmetric group S(E) of any set, to a larger group G(E). Subject to some natural conditions, our construction leads to a monoidal category of fully symmetric test spaces, in which the monoidal product is ''non-signaling''.
BRITISH OFFICIAL PUBLICATIONS—III. ACCESSIBILITY AND USE

Abstract The problems of availability and access to British official publications in the country of origin are examined by means of case studies of the acquisitions policies and systems of bibliographic control in various types of libraries in Britain: parliamentary, governmental, university and public.
The Green Revolution and the productivity paradox: evidence from the Indian Punjab

The author provides district-level estimates of the contribution of technical change to agricultural output growth in the Indian Punjab from 1960 to 1993. Contrary to widespread belief, productivity growth in the Punjab was surprisingly low during the green revolution (in the mid-1960s), when modern hybrid seed varieties were being adopted. It improved later, after adoption of the new varieties was essentially complete. The author proposes three reasons for this pattern: (1) The standard measure of total factor productivity overstates the contribution of capital to output growth at the expense of the productivity residual. High-yielding varieties introduced in the 1960s helped spur output growth by making crops responsive to water and fertilizer, which not only allowed but indeed encouraged far greater use of capital inputs. This increase in the elasticity of the output response to capital inputs is incorporated into the index of factor accumulation and therefore excluded from the measure of total factor productivity growth. As a result, the contribution of technical change to growth in Punjab's agriculture during the green revolution is probably underestimated. (2) The overstatement of the capital contribution during the green revolution is exacerbated by indivisibilities in capital inputs. (3) Productivity growth did not come from the adoption of modern varieties alone. Improved resource management and public investment in infrastructure also helped improve productivity.
Synthetic and kinetic studies of substituent effects in the furan intramolecular Diels-Alder reaction

Abstract The Intramolecular Diels-Alder reactions (IMDA) of a series of 2-sulfone substituted 1-furyl-4-penten-1-ols, 5a-c , have been studied. As the steric demands of the alkyl group on the sulfone was increased the rate and product yields in the IMDA reaction have also been observed to increase. The kinetics of these systems have been studied in detail as well as solvent effects to quantify substituent group effects in the cyclization reactions. Activated dienophiles (CO 2 Me) in these systems have been shown to be very reactive, cyclizing at ambient temperature.
Graphoepitaxy Control of the Deposition of Cationic Polymer Micelles on SiO2 Surfaces

The concept of graphoepitaxy is applied to the deposition of cationic polymer micelles (formed from poly(styrene)-block-poly(2-vinylpyridine) in pH 1 aqueous solution) from the solution phase onto ...
The two types of flare-associated filament eruptions

Using 15 years of high-resolution solar film obtained at Big Bear Solar Observatory we studied flare-associated filament eruptions. In addition to the ‘classical’ type eruption consisting of expansion and breakup, we find evidence of another type where a layer is ‘shed’ from the filament and erupts while the inversion line filament below (or, what is left of it) remains in place. Both types of eruptions are presented in the paper. It is hoped that the new evidence will shed new light on the understanding of the role of filaments in flares.
Lower bounds and uniqueness for solutions of evolution inequalities in a Hilbert space

Publisher Summary This chapter discusses lower bounds and uniqueness for solutions of evolution inequalities in a Hilbert space. The form of the inequality will offer a wider range of applicability of results to partial differential equations. Let H be a Hubert space with inner product (,) and norm ∥·∥. By C[J,H], one denotes the space of continuous functions from the real interval J into the Hubert space H. If u ∈ C [J, H], then denotes the derivative of u with respect to t in the strong topology of H. This obtains general lower bounds and two uniqueness theorems for the solutions on an interval J of the real line R. One shall use the inequality m(t)≥∥u(t)∥2 , which is valid as P(u(t)) ≥0.
Enantioselective synthesis of tetrahydroquinolines, tetrahydroquinoxalines, and tetrahydroisoquinolines via Pd-Catalyzed alkene carboamination reactions

A catalyst composed of Pd2(dba)3 and (S)-Siphos-PE provides excellent results in Pd-catalyzed alkene carboamination reactions between aniline derivatives bearing pendant alkenes and aryl or alkenyl halides. These transformations generate tetrahydroquinolines and tetrahydroquinoxalines that contain quaternary carbon stereocenters with high levels of asymmetric induction. In addition this catalyst also effects the asymmetric synthesis of tetrahydroisoquinolines via related transformations of 2-allylbenzylamines. In contrast to most other approaches to the asymmetric synthesis of these compounds, which frequently involve functional group interconversion or a single C–C or C–N bond-forming event, the carboamination reactions generate both a C–N bond, a C–C bond, and a stereocenter.
Amino Acid-Derived Enaminones: A Study in Ring Formation Providing Valuable Asymmetric Synthons

A new reaction for the preparation of enaminones has been discovered. This method employs β-amino acids as starting materials to allow diversification as well as incorporation of chirality. The β-amino acids, once converted to ynones, are readily cyclized to the desired six-membered enaminone via a two-step, one-pot protocol. Although disguised as a 6-endo-dig cyclization, the reagents employed in the transformation play a direct role in bond making and bond breaking, thus changing the mode of addition.
Characterization of New Infrared Nonlinear Optical Material with High Laser Damage Threshold, Li2Ga2GeS6

A new thio-germanium sulfide Li2Ga2GeS6 has been synthesized for the first time and its structure was found to be isomorphous with AgGaGeS4, which is well-known as a promising infrared NLO material...