cssi/SciSciGPT-SciSciNet huggingface dataset:
Public and Private Forms of Opportunism within the Organization: A Joint Examination of Budget and Effort Behavior

ABSTRACT: We assert that some forms of opportunistic behavior within the organization are relatively transparent and, therefore, public in nature. Further, while organizations can tightly control such public opportunism, it may not be optimal for them to do so in the presence of private opportunism. To study how public and private forms of opportunism differ and interact, we jointly examine budget and effort behavior in a participative budgeting experiment. We group participants into producer/manager pairs and set the parameters such that the producer extracts the largest share of surplus from the manager by publicly setting the budget at zero and privately providing low effort. When the producer unilaterally sets the budget, the public opportunism of budgetary slack is higher and more affected by learning than the private opportunism of low effort. Giving the manager the power to reject the budget not only reduces budgetary slack by about 50 percent, but also generates reciprocity expectations and behavi...
First result of net-charge jet-correlations from STAR

We presented results on azimuthal correlation of net-charge with high p T trigger particles. It is found that the net-charge correlation shape is similar to that of total-charge. On the near-side, the net-charge and total-charge p T spectra have similar shape and both are harder than the inclusives. On the away-side, the correlated spectra are not much harder than the inclusives, and the net-charge/total-charge ratio increases with p T and is similar to the inclusive ratio.
Torus and Z/p actions on manifolds

Abstract Let G be either a finite cyclic group of prime order or S1. We show that if G acts on a manifold or, more generally, on a Poincare duality space M, then each term of the Leray spectral sequence of the map M×GEG→BG satisfies a properly defined “Poincare duality”. As a consequence of this fact we obtain new results relating the cohomology groups of M and MG. We apply our results to study group actions on 3-manifolds.
Fractal pattern formation at elastic-plastic transition in heterogeneous materials

Abstract Fractal patterns are observed in computational mechanics of elastic-plastic transitions in two models of linear elastic/perfectly-plastic random heterogeneous materials: (1) a composite made of locally isotropic grains with weak random fluctuations in elastic moduli and/or yield limits; and (2) a polycrystal made of randomly oriented anisotropic grains. In each case, the spatial assignment of material randomness is a non-fractal, strict-white-noise field on a 256 256× square lattice of homogeneous, square-shaped grains; the flow rule in each grain follows associated plasticity. These lattices are subjected to simple shear loading increasing through either one of three macroscopically uniform boundary conditions (kinematic, mixed-orthogonal or traction), admitted by the Hill-Mandel condition. Upon following the evolution of a set of grains that become plastic, we find that it has a fractal dimension increasing from 0 towards 2 as the material transitions from elastic to perfectly-plastic. While the grains possess sharp elastic-plastic stress-strain curves, the overall stress-strain responses are smooth and asymptote toward perfectly-plastic flows; these responses and the fractal dimension-strain curves are almost identical for three different loadings. The randomness in elastic moduli alone is sufficient to generate fractal patterns at the transition, but has a weaker effect than the randomness in yield limits. In the model with isotropic grains, as the random fluctuations vanish (i.e. the composite becomes a homogeneous body), a sharp elastic-plastic transition is recovered.
Improved Gas Turbine Efficiency Through Alternative Regenerator Configuration

An alternative configuration for a regenerative gas turbine engine cycle is presented that yields higher cycle efficiencies than either simple or conventional regenerative cycles operating under the same conditions. The essence of the scheme is to preheat compressor discharge air with high-temperature combustion gases before the latter are fully expanded across the turbine. The efficiency is improved because air enters the combustor at a higher temperature, and hence heat addition in the combustor occurs at a higher average temperature. The heat exchanger operating conditions are more demanding than for a conventional regeneration configuration, but well within the capability of modern heat exchangers. Models of cycle performance exhibit several percentage points of improvement relative to either simple cycles or conventional regeneration schemes. The peak efficiencies of the alternative regeneration configuration occur at optimum pressure ratios that are significantly lower than those required for the simple cycle. For example, at a turbine inlet temperature of 1300°C (2370°F), the alternative regeneration scheme results in cycle efficiencies of 50 percent for overall pressure ratios of 22, whereas simple cycles operating at the same temperature would yield efficiencies of only 43.8 percent at optimum pressure ratios of 50, which are not feasible with current compressor designs Model calculations for a wide range of parameters are presented, as are comparisons with simple and conventional regeneration cycles.
Understanding Collaboration Success in Context of Cognitive and Social Presence

Collaboration and the success of collaborative efforts has been the focus of much information systems research. Recent measures of collaboration success include effectiveness, efficiency, productivity, commitment, satisfaction with the process, and satisfaction with the outcome. While the possible antecedents of collaboration success are many and varied, we suggest that constructs from the e-learning literature, that evolved independently from the information systems collaboration literature, can be used to explain differences in perceived collaboration success. Results from a recent exploratory study demonstrate that cognitive presence and social presence explain a large amount of the variance of different collaboration success metrics.
AntiLiar: Defending against cheating attacks in mesh based streaming

Peer-to-peer (P2P) mesh based streaming systems have gained widespread use for multicasting of audio and video. In approaches based on BitTorrent, members of the swarm share their content availability through gossiping, and redistribute file pieces cached locally. However, such systems are vulnerable to cheating attacks such as fake reporting, selective omission, fake block attack, and neighbor selection attack. These attacks will severely impact quality of service, waste resources, and discourage cooperation among participants. A defense mechanism, called AntiLiar, is proposed for defending against cheating attacks in mesh based streaming. AntiLiar uses a secure progress log that consists of commitments and one-time signatures, and maintains consistency for an expanded neighbor view. Experimental results demonstrate that AntiLiar minimizes required costs, and improves service quality over alternatives in the face of cheating attacks.
Disinflation with imperfect credibility

Abstract This paper presents a theory of the real effects of disinflation. As in New Keynesian models, price adjustment iis staggered across firms. As in New Classical models, credibility is imperfect: the monetary authority may not complete a promised disinflation. The combination of imperfect credibility and staggering yields more plausible results than either of these assumptions alone. In particular, an announced disinflation reduces expected output if credibility is sufficiently low.
Spark Chambers - State of the Art

A review of the present state of spark chamber technology is presented. The properties of spark chambers are reviewed and a summary of recent developments is given. An effort is made to make the survey of recent developments as complete as possible. Emphasis is given to technical problems which remain to be solved.
The effect of surface roughness on the phase of neutrons specularly reflected at grazing incidence

Abstract The effect of surface roughness on the specular intensity of a reflected neutron beam can be calculated using the distorted wave Born approximation (DWBA). For Gaussian roughness the result obtained is the familiar expression of Nevot and Croce. When the distribution of surface heights, z, is proportional to cosh−2(z/2d), the reflectance calculated from the DWBA is sinh[πd(k1 − k2)]/sinh[πd(k1+k2)]. Here k1 and k2 are the components of neutron wave vectors perpendicular to the interface, evaluated outside and inside the reflecting medium, and d is a measure of the amplitude of the interfacial roughness. This result for the reflectance differs by a phase factor from that obtained in an exact calculation for an interface with the corresponding graded refractive index. The phase difference between the two expressions is small, scaling as ∼d3, and usually has little effect on measured reflectivities of multilayered structures. Ways in which the phase could be determined are discussed.
Big Bang Nucleosynthesis Predictions for Precision Cosmology

The determination of the primeval deuterium abundance has opened a precision era in big bang nucleosynthesis, making accurate predictions more important than ever before. We present in analytic form new, more precise predictions for the light-element abundances and their error matrix. Using our predictions and the primeval deuterium abundance, we infer a baryon density of ΩBh2 = 0.020 ± 0.002 (95% confidence level) and find no evidence for stellar production (or destruction) of 3He beyond burning D into 3He. Conclusions about 4He and 7Li currently hinge on possible systematic errors in their measurements.
Atomic structure and phase transformations in Pu alloys

Abstract Plutonium and plutonium-based alloys containing Al or Ga exhibit numerous phases with crystal structures ranging from simple monoclinic to face-centered cubic. Only recently, however, has there been increased convergence in the actinides community on the details of the equilibrium form of the phase diagrams. Practically speaking, while the phase diagrams that represent the stability of the fcc δ-phase field at room temperature are generally applicable, it is also recognized that Pu and its alloys are never truly in thermodynamic equilibrium because of self-irradiation effects, primarily from the alpha decay of Pu isotopes. This article covers past and current research on several properties of Pu and Pu-(Al or Ga) alloys and their connections to the crystal structure and the microstructure. We review the consequences of radioactive decay, the recent advances in understanding the electronic structure, the current research on phase transformations and their relations to phase diagrams and phase stability, the nature of the isothermal martensitic δ → α′ transformation, and the pressure-induced transformations in the δ-phase alloys. New data are also presented on the structures and phase transformations observed in these materials following the application of pressure, including the formation of transition phases.
A randomized, double-blind trial of the interaction between cranberry juice and warfarin

Therapeutic warfarin therapy is highly influenced by concomitant drug therapy or dietary factors by effecting warfarin metabolism or vitamin K status. Cranberry juice (CJ) was recently implicated to influence the INR in patients on warfarin based on a number of brief anecdotal or case reports. This study was designed to determine what influence, if any, daily cranberry juice consumption has on INR levels and plasma warfarin concentrations in patients stably anticoagulated with warfarin. Patients on warfarin for a variety of indications from a population of anticoagulation clinic patients were selected because of their past history of stable anticoagulation and willingness to participate in the study. Major inclusion criteria required a therapeutic INR range of 2.0 – 3.0, no hepatic or renal dysfunction, a stable INR (1.7 – 3.3) on at least 2 measurements within 8 weeks prior to study entry, and informed consent. The study consisted of a 2 week lead-in phase (with weekly INRs in range); a 2 week intervention phase (double-blind daily consumption of an 8 oz glass of cranberry juice or placebo); and a one week follow-up phase (35 day total). Any patient with an out of range INR during the intervention phase ceased the intervention but continued through follow-up. 30 patients were randomized, 14 to CJ and 16 to placebo. 28.6% (4/14) in the CJ group developed a minimally elevated INR and 7.1%(1/14) developed a low INR during the intervention phase. 25% (4/16) in the control group developed a minimally elevated INR during the intervention. There was no significant difference in the mean INRs from each group on each day of measurement except for day 11 of the intervention phase when the CJ group was significantly higher than the placebo group (p
Solar enhanced oil recovery; An assessment of economic feasibility

Abstract There are several qualitative reasons why steam enhanced oil recovery (EOR) appears to be well suited to solar energy use. These include favorable characteristics with regard to energy utilization, land availability, energy form, and geographical location. A number of technical questions require further research before the characteristics of solar enhanced oil recovery (SEOR) can be precisely specified or optimum systems designed. However, a cost model based on a number of working assumptions indicates competitiveness with conventional fuel-burning EOR systems at crude prices and solar collector system costs which can be reasonably expected to occur in the near future; e.g., for a nominal parameter set, including a solar energy system cost of $200/m 2 , the breakeven crude oil price is $11.90/bbl.
Compression of uniform embeddings into Hilbert space

Abstract If one tries to embed a metric space uniformly in Hilbert space, how close to quasi-isometric could the embedding be? We answer this question for finite dimensional CAT(0) cube complexes and for hyperbolic groups. In particular, we show that the Hilbert space compression of any hyperbolic group is 1.
Completely reducible Lie subalgebras

Let G be a connected and reductive group over the algebraically closed field K. J-P. Serre has introduced the notion of a G-completely reducible subgroup H ⊂ G. In this paper, we give a notion of G-complete reducibility—G-cr for short—for Lie subalgebras of Lie(G), and we show that if the closed subgroup H ⊂ G is G-cr, then Lie(H) is G-cr as well.
A Procedure Using Manufacturing Variance to Design Gears With Minimum Transmission Error

This paper deals with the design of spur gears that have minimum transmission error and are insensitive to manufacturing variance. We address two stages of design: (1) generation of candidate designs (selection of number of teeth, pressure angle, etc.), and (2) tooth profile modification. The first stage involves a search of discrete combinations of design variables, while the second stage utilizes numerical optimization techniques. The key research issue is finding a candidate design and its profile modification that not only has low transmission error, but is insensitive to variations in the design values caused by the manufacturing process. To achieve this goal, the procedure applies Taguchi’s concept of parameter design. In this paper, we consider a design problem with a set specification: fixed center distance, speed ratio, and transmission torque. We seek to find a limited number of candidate designs by applying conventional design generation techniques and some design heuristics. For each candidate design, the procedure determines the optimum profile modification (linear tip relief) by linking the Load Distribution Program (LDP) for gears with an optimization program package (OPTPAK). From the resulting peak optimum, we further seek the statistical optimum using an algorithm developed in this paper. The statistical optimum shows a nominal increase in the transmission error, but is quite insensitive to typical process error associated with gear manufacturing. The developed algorithm readily applies to other gear designs as well as other types of machine elements. In particular, we foresee our procedure to be particularly effective for helical gears. We hope to further our method by developing a means to add statistical heuristics to the discrete design generation stage.
Regulation of alpha‐synuclein expression in alcohol‐preferring and ‐non preferring rats

The a-synuclein (Snca) gene is expressed at higher levels in alcohol-naive, inbred alcohol-preferring (iP) rats than in alcohol-non preferring (iNP) rats. Snca modulates dopamine transmission and the dopamineregic system, which play a role in mediating the rewarding properties of alcohol consumption. Thus, understanding regulation of Snca gene expression could provide insight into the relationship of Snca and alcohol consumption. To study regulation of rat Snca expression, 1912 bp of the iP and iNP 5¢-regions were cloned and se- quenced. 5¢-rapid amplification of cDNA ends (RACE), primer extension and RT-PCR mapped three transcription start site clusters (clusters TSS1, TSS2 and TSS3), suggesting that the Snca proximal promoter region has a complex architecture. This proximal promoter region has three TATA-less core promoters containing SP1 binding sites, initiator elements and downstream core promoter elements, which are often located in such promoters. Snca-luc constructs transiently transfected into SK-N-SH neuroblastoma cells showed that the region from )1912 to )1746 contained a strong core promoter, and that the entire approximately 2 kb region had significant pro- moter activity. Five polymorphisms identified between the iP and iNP in the proximal promoter region did not influence differential expression between the strains. In contrast, a single nucleotide polymorphism (SNP) at +679 in the 3¢-un- translated region (UTR) resulted in a 1.3-fold longer half-life of iP mRNA compared with iNP mRNA, which is consistent with the differential expression observed between the iP and iNP strains. These results suggest that regulation of rat Snca gene expression is complex and may contribute to alcohol prefer- ence in the iP rats.
Analytical Modeling of the Weak Lensing of Standard Candles. I. Empirical Fitting of Numerical Simulation Results

Weak lensing leads to the non-Gaussian magnification distribution of standard candles at a given redshift z, p(μ|z). In this paper we give accurate and simple empirical fitting formulae of the weak lensing numerical simulation results with the generalized Dyer-Roeder prescription. The smoothness parameter essentially represents the amount of matter that can cause magnification of a given source. Since matter distribution in our universe is inhomogeneous, we can think of our universe as a mosaic of cones centered on the observer, each with a different value of . We define the direction-dependent smoothness parameter via the Dyer-Roeder equation; there is a unique mapping between and the magnification of a source. We find that the distribution of at a given z, p(|z), is well described by a modified Gaussian distribution. For the same matter distribution, i.e., the same p(|z), different values of Ωm and ΩΛ can lead to very different magnification distributions. Our formulae can be conveniently used to calculate the weak lensing effects for observed Type Ia supernovae at arbitrary redshifts.
Regio- and stereochemically controlled formation of hydroxamic acids from indium triflate-mediated nucleophilic ring-opening reactions with acylnitroso-Diels-Alder adducts.

Abstract Treatment of acylnitroso-Diels–Alder [2.2.1] bicyclic adducts 2a – b with indium triflate in an alcohol solvent induces ring-opening reactions to afford monocyclic anti-1,2-, anti-1,4-, and syn-1,4-hydroxamic acids with good to excellent regio- and stereoselectivity (up to 7:86:7). Treatment of [2.2.2] bicyclic nitroso adducts 2c – d under similar reaction conditions generates only anti-1,2- and anti-1,4-hydroxamic acids with anti-1,4-product being predominant (up to 17:83).
Aeroelastic Optimization of Flapping Wing Venation: A Cellular Division Approach

The aeroelastic response of a biologically inspired flappingmembrane wing to unsteady inertial and aerodynamic forces is strongly predicated upon the topological distribution of the underlying skeletal reinforcement (venation patterns). Proper exploitation of this relationship may enable the development of effective flapping wing micro air vehicles. The skeletal topology is parameterized into a developmental programwhich, when compiled and executed, evolves the wing topology in stages. A genetic algorithm can optimize the details of this program, rather than explicitly considering the topology itself, thus removing the link between design variables and topological geometry resolution. This cellular division tool is coupled to an unsteady aeroelastic representation of a flapping wing in forward flight in order to obtain the Pareto tradeoff curves between thrust generation, lift generation, and input power requirements. The topologies obtained along the front provide an understanding of the key relationships between skeletal topology, aeroelastic behavior, and performance metrics during flapping flight.
Edgeless graphs are the only universal fixers

Given two disjoint copies of a graph G, denoted G1 and G2, and a permutation π of V (G), the graph πG is constructed by joining u ∈ V (G1) to π(u) ∈ V (G2) for all u ∈ V (G1). G is said to be a universal fixer if the domination number of πG is equal to the domination number of G for all π of V (G). In 1999 it was conjectured that the only universal fixers are the edgeless graphs. Since then, a few partial results have been shown. In this paper, we prove the conjecture completely.
Gelation for Marcus–Lushnikov process

The Marcus–Lushnikov process is a simple mean field model of coagulating particles that converges to the homogeneous Smoluchowski equation in the large mass limit. If the coagulation rates grow sufficiently fast as the size of particles get large, giant particles emerge in finite time. This is known as gelation, and such particles are known as gels. Gelation comes in different flavors: simple, instantaneous and complete. In the case of an instantaneous gelation, giant particles are formed in a very short time. If all particles coagulate to form a single particle in a time interval that stays bounded as total mass gets large, then we have a complete gelation. In this article, we describe conditions which guarantee any of the three possible gelations with explicit bounds on the size of gels and the time of their creations.
Eternal Black Holes and Superselection in AdS/CFT

It has been argued i) that Lorentz-signature solutions with wormholes connecting n asymptotically AdS regions describe bulk quantum states dual to n entangled but non-interacting CFTs and ii) that such bulk wormhole states should be identied with similar entangled but non-interacting bulk systems, each describing quantum geometries with only a single asymptotic region. But if the wormhole is to behave semiclassically, we show that conjecture (ii) cannot hold. Instead, the theory of asymptotically AdS bulk quantum gravity must admit superselection sectors with respect to the CFT observables that are labeled by the type of wormhole connections allowed between black holes. Moreover, these superselection sectors are indistinguishable in the dual CFT. Finally, we describe restrictions on the possible superselection sectors associated with the spin-statistics relation and the expectation that black holes lying in distinct asymptotically AdS regions may be approximated by well-separated black holes in a single asymptotically AdS region.
The productivity convergence debate: a theoretical and methodological reconsideration

Two fundamental issues which have been ignored in the convergence debate are addressed in this paper. First, there has been little attention paid to the development of a general model which is able to explain convergence or divergence. Second, in the rush to put data to a convergence hypothesis, researchers have failed to consider certain methodological procedures with respect to the treatment of capital. To remedy this problem we use an input-output approach to measure catch-up. To address the theoretical lacunae we present case studies of Portugal and Japan, two countries which by 1959 had attained the threshold level of development required to join the 'convergence club', but which, for various historical (path-dependent) reasons, have diverged rapidly from each other in the period since the late 1950s. (c) 1996 Academic Press Limited Copyright 1996 by Oxford University Press.
How do hydrodynamic instabilities affect 3D transport in geophysical vortices

Abstract Three-dimensional (3D) transport within geophysical vortices (e.g. ocean eddies) is important in understanding processes at a variety of scales, ranging from plankton production to climate variability. 3D transport can be affected by hydrodynamic instabilities of geophysical vortices; however, how the instabilities affecting 3D transport is not clear. Focusing on barotropic, inertial and 3D instabilities, we investigate the joint impacts of instabilities on 3D transport by using analytical methods and direct numerical simulations. We discover for the first time that material can be exchanged through 3D pathways which link a family of vortices generated by the instabilities in a single, initially unstable vortex. We also show that instabilities can increase the magnitude of vertical velocity, mixing rate and vertical material exchange. Besides, we find that instabilities can cause the kinetic energy wavenumber spectrum to have a power-law regime different than the classic regimes of k - 5 / 3 and k - 3 , and propose a new energy spectrum to interpret the non-classic regime.
X-ray Source Populations in Galaxies

This paper gives a short review of recent studies of the X-ray source populations of nearby galaxies. A more complete review of this subject can be found in Fabbiano & White (2003), from where this talk was partially extracted.
When Is Ours Better Than Mine? A Framework for Understanding and Altering Participation in Commercial Sharing Systems

Abstract Sharing systems are increasingly challenging sole ownership as the dominant means of obtaining product benefits, making up a market estimated at more than US$100 billion annually in 2010. Consumer options include cell phone minute-sharing plans, frequent-flyer-mile pools, bicycle-sharing programs, and automobile-sharing systems, among many others. However, marketing research has yet to provide a framework for understanding and managing these emergent systems. The authors conceptualize commercial sharing systems within a typology of shared goods. Using three studies, they demonstrate that beyond cost-related benefits of sharing, the perceived risk of scarcity related to sharing is a central determinant of its attractiveness. The results suggest that managers can use perceptions of personal and sharing partners' usage patterns to affect risk perceptions and subsequent propensity to participate in a commercial sharing system.
Electron trap states and low frequency noise in tunnel junctions

We present the results of measurements of the low frequency excess, or 1/f, noise in small area Nb/Nb 2 O 5 /PbBi and Nb/Nb 2 O 5 /PbAuIn tunnel junctions. Our study shows that the low frequency noise in all of these devices arises from fluctuations in the tunnel barrier transmission coefficient due to changes in the barrier shape. These time dependent barrier deformations appear to be due to charge capture and emission by electron traps in the tunnel barrier material. We find that Nb 2 O 5 barriers prepared either by Reactive Ion Beam Oxidation (RIBO) or by the Raider-Drake Plasma Oxidation process have one particular type of charge trap which dominates the noise spectrum. The density of these noise sources can be controlled in a variety of ways: Improved processing techniques result in higher quality Current-Voltage characteristics and a simultaneous decrease in the density of noise sources. Further, we find that ion implantation of the barrier with Boron results in a decrease in the density of noise sources. The detailed energy density of states for the noise sources also can be modified by thermal cycling and by application of large bias voltages. We will discuss the implications that our single tunnel junction measurements have for the production of extremely low noise SQUID magnetometers.
A FIREWALLING SCHEME FOR SECURING MPOA-BASED ENTERPRISE NETWORKS

A well-known security problem with MPOA is that cut-through connections generally bypasses firewall routers if there are any. None of the previously proposed approaches solved the problem properly. In this paper, we propose a novel firewalling scheme for MPOA that nicely fixes the security hole. Our firewalling scheme has three outstanding advantages that make it ideal for securing MPOA-based enterprise networks. First, based on our novel concept of "logical chokepoints", our firewalling scheme does not require the existence of physical chokepoints inside the network. Second, the scheme is nicely embedded into the MPOA protocol so that its cost, performance overhead, and protocol complexity are reduced to a minimum. Third, the scheme is centrally administered so that it scales well to very large networks.
Factors which Limit the Value of Additional Redundancy in Human Rated Launch Vehicle Systems

The National Aeronautics and Space Administration (NASA) has embarked on an ambitious program to return humans to the moon and beyond. As NASA moves forward in the development and design of new launch vehicles for future space exploration, it must fully consider the implications that rule-based requirements of redundancy or fault tolerance have on system reliability/risk. These considerations include common cause failure, increased system complexity, combined serial and parallel configurations, and the impact of design features implemented to control premature activation. These factors and others must be considered in trade studies to support design decisions that balance safety, reliability, performance and system complexity to achieve a relatively simple, operable system that provides the safest and most reliable system within the specified performance requirements. This paper describes conditions under which additional functional redundancy can impede improved system reliability. Examples from current NASA programs including the Ares I Upper Stage will be shown.
Network-Based Consensus Averaging With General Noisy Channels

This paper focuses on the consensus averaging problem on graphs under general imperfect communications. We study a particular class of distributed consensus algorithms based on damped updates, and using the ordinary differential equation method, we prove that the updates converge almost surely to the consensus average for various models of perturbation of data exchanged between nodes. The convergence is not asymptotic in the size of the network. Our analysis applies to various types of stochastic disturbances to the updates, including errors in update calculations, dithered quantization and imperfect data exchange among nodes. Under a suitable stability condition, we prove that the error between estimated and true averages is asymptotically Gaussian, and we show how the asymptotic covariance is specified by the graph Laplacian. For additive perturbations, we show how the scaling of the asymptotic MSE is controlled by the spectral gap of the Laplacian.
A convenient route to alkyl, alkynyl and aryl substituted 7-azabicyclo[2.2.1]heptadienes

Abstract 3-Bromopropiolates underwent a smooth [4+2] cycloaddition reaction with N -acylpyrroles to afford N -acyl-2-alkoxycarbonyl-3-bromo-7-azabicyclo[2.2.1]heptadienes in good yields. The 3-bromo-2,7-dimethoxycarbonyl-7-azabicyclo[2.2.1]heptadiene was further transformed to 3-alkyl-, 3-alkynyl- and 3-aryl-2,7-dimethoxycarbonyl-7-azabicyclo[2.2.1]heptadiene derivatives via palladium catalyzed and organocopper coupling reactions.
New Prophosphatranes: Novel intermediates to five‐coordinate phosphatranes

The reaction of N(CH 2 CH 2 NHMe) 3 with P(NMe 2 ) 3 or P(NMe 2 ) 2 Cl yields the phosphatrane precursor N(CH 2 CH 2 NMe) 2 P, 4. With oxydizing agents or electrophiles 4 is converted to the untransannulated four-coordinated derivatives N(CH 2 CH 2 NMe) 3 P-X, (X:O,S,Se,N 3 Ph,NPh, I CS 2 , 1/2 PtCl 2 ). The structures of the compounds described are discussed by 1 H, 13 C, and 31 P n.m.r. data
Phase-field modeling of coring during solidification of Au–Ni alloy using quaternions and CALPHAD input

Abstract A numerical method for the simulation of microstructure evolution during the solidification of an alloy is presented. The approach is based on a phase-field model including a phase variable, an orientation variable given by a quaternion, the alloy composition and a uniform temperature field. Energies and diffusion coefficients used in the model rely on thermodynamic and kinetic databases in the framework of the CALPHAD methodology. The numerical approach is based on a finite volume discretization and an implicit time-stepping algorithm. Numerical results for solidification and accompanying coring effect in a Au–Ni alloy are used to illustrate the methodology.
Exciton Absorption in the Presence of Excited F Centers

A rich spectrum of absorption bands is observed at 7\ifmmode^\circ\else\textdegree\fi{}K near the fundamental absorption edge of KI, RbI, CsI, and RbBr crystals containing $F$ centers in the relaxed excited state. The large population of excited $F$ centers necessary for these experiments is achieved with a $Q$-switched ruby laser. The results are discussed in terms of models of excitons formed near excited $F$ centers.
Automorphism group of Batyrev Calabi–Yau threefolds

In this paper, we will prove that all Batyrev Calabi–Yau threefolds, arising from a crepant resolution of a generic hyperplane section of a toric Fano–Gorenstein fourfold, have finite automorphism group. Together with the Morrison conjecture, this suggests that all Batyrev Calabi–Yau threefolds should have a polyhedral Kahler (ample) cone.
The Radio and X-Ray Luminous SN 2003bg and the Circumstellar Density Variations around Radio Supernovae

We report extensive radio and X-ray observations of SN 2003bg, whose spectroscopic evolution shows a transition from a broad-lined Type Ic to a hydrogen-rich Type II, and later to a typical hydrogen-poor Type Ibc. We show that the extraordinarily luminous radio emission is well described by a self-absorption-dominated synchrotron spectrum, while the observed X-ray emission at t ≈ 30 days is adequately fit by inverse Compton scattering of the optical photons off of the synchrotron-emitting electrons. Our radio model implies a subrelativistic ejecta velocity, ν(overbar) ≈ 0.24c, at t_0 ≈ 10 days after the explosion, which emphasizes that broad optical absorption lines do not imply relativistic ejecta. We find that the total energy of the radio-emitting region evolves as E ≈ 7.3 × 10^(48)(t/t_0)^(0.4) ergs, assuming equipartition of energy between relativistic electrons and magnetic fields (e_e = e_B = 0.1). The circumstellar density is well described by a stellar wind profile, with modest (factor of ~2) episodic density enhancements that produce abrupt achromatic flux variations. We estimate an average mass-loss rate of M ≈ 3 × 10^(-4) M_☉ yr^(-1) (assuming a wind velocity of ν_w = 10^3 km s^(-1)) for the progenitor, consistent with the observed values for Galactic Wolf-Rayet stars. Comparison with other events reveals that ~50% of radio supernovae show similar short-timescale flux variations, attributable to circumstellar density irregularities. Specifically, the radio light curves of SN 2003bg are strikingly similar to those of the Type IIb SN 2001ig, suggestive of a common progenitor evolution for these two events. Based on the relative intensity of the inferred density enhancements, we conclude that the progenitors of SNe 2003bg and 2001ig experienced quasi-periodic mass-loss episodes just prior to the SN explosion. Finally, this study emphasizes that abrupt radio light-curve variations cannot be used as a reliable proxy for an engine-driven explosion, including off-axis gamma-ray bursts.
Continuous Flow Photochemistry for the Rapid and Selective Synthesis of 2’-Deoxy and 2’,3’-Dideoxynucleosides

A new photochemical flow reactor has been developed for the photo-induced electron-transfer deoxygenation reaction to produce 2′-deoxy and 2′,3′-dideoxynucleosides. The continuous flow format significantly improved both the efficiency and selectivity of the reaction, with the streamlined multi-step sequence directly furnishing the highly desired unprotected deoxynucleosides.
A technical description of atmospheric sounding by GPS occultation

Abstract In recent years, the global positioning system (GPS) has been exploited via radio occultation techniques to obtain profiles of refractivity, temperature, pressure and water vapor in the neutral atmosphere and electron density in the ionosphere. The GPS/MET experiment, which placed a GPS receiver in a low-Earth orbit, provided a wealth of data which was used to test this concept and the accuracy of the retrievals. Several investigations have already demonstrated that the retrieval accuracies obtained with GPS/MET is already comparable, if not better, than the more traditional atmospheric sensing techniques (e.g., radiosondes). Even though the concept of atmospheric profiling via radio occultation is quite a simple one, care must be taken to separate the numerous factors that can affect the occulted signal. These include the motion of the satellites, clock drifts, relativistic effects, the separation of the ionosphere and the neutral atmosphere, and the contribution of the upper atmosphere where sensitivity of the GPS signal is weak. In addition, care must be taken to use proper boundary conditions, use proper smoothing intervals and interpolation schemes to avoid retrieving artificial atmospheric structures, and most importantly detect and correct phase measurement errors introduced by sharp refractivity gradients in the atmosphere. This work describes in some detail the several steps involved in processing such data. In particular, it describes a system that was developed at the Jet Propulsion Laboratory and used to process the GPS/MET data. Several examples of retrieved refractivity, temperature and water vapor profiles are shown and compared to analyses from the European Center for Medium-range Weather Forecast (ECMWF). Statistical comparisons of GPS/MET and ECMWF temperatures for data collected during June 21–July 4, 1995, indicate that differences are of order 1– 2 K at northern latitudes where the ECMWF analyses are most accurate.
Spectral decomposition approach for transient analysis of multi-server discrete-time queues

Abstract Discrete time queueing systems are extensively used in modeling the ATM environment at the cell level. This paper examines the transient behavior of a discrete time FCFS multiple server queue. For the arrival process we assume a general discrete time Markovian batch arrival process, where the batch size distribution of the arrivals in successive slots is governed by a finite state discrete time Markov chain. We show that once the spectral decomposition of the “probability generating matrix” of the arrival process is obtained, the complete solution in the transform domain may be given. Using the complex analysis technique and Cauchy's integral formula, we present an efficient numerical method for the numerical calculation of a few performance measures of interest, namely transient probability of queue being empty, and the mean of the queue length distribution. We also generalize our numerical method in the situations where the superposition of a number of independent arrival sources are fed to the queue. It is shown that the numerical complexity of obtaining the transient solution in this case can be substantially reduced by using the approach based on the Kronecker product. The finite buffer case is also analyzed.
CONSTRAINING THE NATURE OF X-RAY CAVITIES IN CLUSTERS AND GALAXIES

We present results from an extensive survey of 64 cavities in the X-ray halos of clusters, groups, and normal elliptical galaxies. We show that the evolution of the size of the cavities as they rise in the X-ray atmosphere is inconsistent with the standard model of adiabatic expansion of purely hydrodynamic models. We also note that the majority of the observed bubbles should have already been shredded apart by Rayleigh-Taylor and Richtmyer-Meshkov instabilities if they were of purely hydrodynamic nature. Instead, we find that the data agree much better with a model where the cavities are magnetically dominated and inflated by a current-dominated MHD jet model, recently developed by Li and coworkers and Nakamura and coworkers. We conduct complex Monte Carlo simulations of the cavity detection process including incompleteness effects to reproduce the cavity sample's characteristics. We find that the current-dominated model agrees within 1 σ, whereas the other models can be excluded at >5 σ confidence. To bring hydrodynamic models into better agreement, cavities would have to be continuously inflated. However, these assessments are dependent on our correct understanding of the detectability of cavities in X-ray atmospheres and will await confirmation when automated cavity detection tools become available in the future. Our results have considerable impact on the energy budget associated with AGN feedback.
The impact of grouping coarseness in alternative grouped-data regression models

Abstract In regression applications, the only available data for the dependent variable have sometimes been grouped or rounded over a known interval. Monte Carlo experiments demonstrate that (i) grouping coarseness will systematically affect the ‘need” for special estimation methods, and (ii) departures from the conventional linear normal regression model will increase the distortion in parameter estimates when interval midpoints are used as proxies for the true values. Normal, exponential, and Weibull regression models are examined. We propose a simple diagnostic test to determine the maximum parameter distortion due to grouping, and an empirical example illustrates this distortion in a household income model.
Kilogram Scale Synthesis of the Pyrazinone Acetic Acid Core of an Orally Efficacious Thrombin Inhibitor

Abstract A multi-kilogram scale synthesis of the orally efficacious thrombin inhibitor 1 has been achieved via construction of the pyrazinone core from an unsymmetric oxalic diamide. Key features include judicious choice of reagents to minimize side products, a key ruthenium catalyzed oxidation, and development of reaction conditions amenable to large-scale synthesis.
Low-complexity multipath diversity through fractional sampling in OFDM

Orthogonal frequency division multiplexing (OFDM) enables low-complexity equalization and has been adopted in several wireless standards. However, OFDM cannot exploit multipath diversity without computationally complex coding and decoding. We show here that by sampling at a rate higher than the symbol rate, which is also known as fractional sampling (FS), one can improve the diversity that the wireless channel can provide in an OFDM system. We propose maximal ratio combining at each subcarrier for the FS-OFDM system, argue that the diversity gains acquired through this approach are related to the spectral shape of the pulse and its excess bandwidth, and derive analytical bit error and symbol error rate expressions for our scheme. We also explore extensions to differentially encoded systems that do not require channel status information at the receiver, multiple-input multiple-output (MIMO) systems that exploit space diversity, and low peak-to-average (PAR) options such as zero-padded (ZP) and cyclic-prefix only (CP-only) transmissions. We corroborate our approach with simulations.
Financial reporting, tax costs, and book-tax conformity

Abstract We investigate the role of book-tax conformity in firms' financial reporting activities using a unique set of publicly traded firms that were forced to switch for tax purposes from the cash method to the accrual method. Prior to the mandated change, little trade-off existed between tax planning and financial reporting goals for these firms. After the change, recognition criteria for tax and financial reporting purposes became more alike, increasing the trade-off between financial reporting and tax objectives. Our results suggest that required use of the accrual method for tax purposes causes firms to defer income for financial statement purposes.
On Rich Lines in Grids

In this paper we show that if one has a grid A×B, where A and B are sets of n real numbers, then there can be only very few “rich” lines in certain quite small families. Indeed, we show that if the family has lines taking on n e distinct slopes, and where each line is parallel to n e others (so, at least n 2e lines in total), then at least one of these lines must fail to be “rich”. This result immediately implies non-trivial sumproduct inequalities; though, our proof makes use of the Szemeredi-Trotter inequality, which Elekes used in his argument for lower bounds on |C+C|+|C.C|.
Catalytic enantioselective conjugate addition of fluorobis(phenylsulfonyl)methane to enals: synthesis of chiral monofluoromethyl compounds

A new highly catalytic enantioselective Michael addition of fluorobis(phenylsulfonyl)methane to alpha,beta-unsaturated aldehydes has been developed for the preparation of chiral monofluoromethyl compounds under mild reaction conditions.
Criticality and entanglement in random quantum systems

We review studies of entanglement entropy in systems with quenched randomness, concentrating on universal behavior at strongly random quantum critical points. The disorder-averaged entanglement entropy provides insight into the quantum criticality of these systems and an understanding of their relationship to non-random ('pure') quantum criticality. The entanglement near many such critical points in one dimension shows a logarithmic divergence in subsystem size, similar to that in the pure case but with a different universal coefficient. Such universal coefficients are examples of universal critical amplitudes in a random system. Possible measurements are reviewed along with the one-particle entanglement scaling at certain Anderson localization transitions. We also comment briefly on higher dimensions and challenges for the future.