cssi/SciSciGPT-SciSciNet huggingface dataset:
Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1

This paper presents the first optical variability study of the Westerlund 1 super star cluster in search of massive eclipsing binary systems. A total of 129 new variable stars have been identified, including the discovery of 4 eclipsing binaries that are cluster members, 1 additional candidate, 8 field binaries, 19 field δ Scuti stars, 3 field W UMa eclipsing binaries, 13 other periodic variables, and 81 long-period or nonperiodic variables. These include the known luminous blue variable, the B[e] star, 11 Wolf-Rayet stars, several supergiants, and other reddened stars that are likely members of Westerlund 1. The bright X-ray source corresponding to the Wolf-Rayet star WR 77o (B) is found to be a 3.51 day eclipsing binary. The discovery of a reddened detached eclipsing binary system implies the first identification of main-sequence stars in Westerlund 1.
The Role of Evolutionary Age and Metallicity in the Formation of Classical Be Circumstellar Disks. I. New Candidate Be Stars in the LMC, SMC, and Milky Way

We present B, V, R, and Hphotometry of eight clusters in the Small Magellanic Cloud, five in the Large Mag- ellanic Cloud, and three Galactic clusters and use two-color diagrams (2-CDs) to identify candidate Be star popu- lations in these clusters. We find evidence that the Be phenomenon is enhanced in low-metallicity environments, based on the observed fractional early-type candidate Be star content of clusters of age 10Y25 Myr. Numerous can- didate Be stars of spectral types B0YB5 were identified in clusters of age 5Y8 Myr, challenging the suggestion of Fabregat&TorrejonthatclassicalBestarsshouldonlybefoundinclustersatleast10Myrold.Theseresultssuggestthat a significant number of B-type stars must emerge onto the zero-age main sequence as rapid rotators. We also detect an enhancement in the fractional content of early-type candidate Be stars in clusters of age 10Y25 Myr, suggestingthat the Be phenomenon does become more prevalent with evolutionary age. We briefly discuss the mechanisms that might contribute to such an evolutionary effect. A discussion of the limitations of using the 2-CD technique to investigate the role evolutionary age and/or metallicity play in the development of the Be phenomenon is offered, and we provide evidence that other B-type objects of very different nature, such as candidate Herbig Ae/Be stars, may contaminate the claimed detections of Be stars via 2-CDs. Subject headingg circumstellar matter — galaxies: clusters: individual (Bruck 60, Bruck 107, HW 43, LH 72, NGC 371, NGC 456, NGC 458, NGC 460, NGC 465, NGC 1850, NGC 1858, NGC 1955, NGC 2027, NGC 2186, NGC 2383, NGC 2439) — Magellanic Clouds — stars: emission-line, Be — techniques: photometric
Negative Probability and Uncertainty Relations

A concise derivation of all uncertainty relations is given entirely within the context of phase-space quantization, without recourse to operator methods, to the direct use of Weyl's correspondence, or to marginal distributions of x and p.
Strategic Trade Policy in a Vertically Related Industry

This paper investigates strategic export intervention in a final-good industry which uses an intermediate good supplied by a foreign monopolist. An export tax-cum-subsidy leads to horizontal and vertical rent extraction. The optimal government intervention in the final-good market is shown to depend on the pricing scheme employed by the intermediate-good producer.
Who survived? Ethiopia's regulatory crackdown on foreign-funded NGOs

ABSTRACTHow do public regulations shape the composition and behavior of non-governmental organizations (NGOs)? Because many NGOs advocate liberal causes, such as human rights, democracy, and gender equality, they upset the political status quo. At the same time, a large number of NGOs operating in the Global South rely on international funding. This sometimes disconnects from local publics and leads to the proliferation of sham or ‘briefcase’ NGOs. Seeking to rein in the politically inconvenient NGO sector, governments exploit the role of international funding and make the case for restricting the influence of NGOs that serve as foreign agents. To pursue this objective, states worldwide are enacting laws to restrict NGOs’ access to foreign funding. We examine this regulatory offensive through an Ethiopian case study, where recent legislation prohibits foreign-funded NGOs from working on politically sensitive issues. We find that most briefcase NGOs and local human rights groups in Ethiopia have disappeare...
Electroweak symmetry breaking by strong dynamics and the collider phenomenology

We discuss the possible signatures in the electroweak symmetry breaking sector by new strong dynamics at future hadron colliders such as the Tevatron upgrade, the LHC and VLHC, and e{sup +}e{sup -} linear colliders. Examples include a heavy Higgs-like scalar resonance, a heavy Technicolor-like vector resonance and pseudo-Goldstone states, non-resonance signatures via enhanced gauge-boson scattering and fermion compositeness.
The economics of poverty traps and persistent poverty: An asset-based approach

Abstract Longitudinal data on household living standards open the way to a deeper analysis of the nature and extent of poverty. While a number of studies have exploited this type of data to distinguish transitory from more chronic forms of income or expenditure poverty, this paper develops an asset-based approach to poverty analysis that makes it possible to distinguish deep-rooted, persistent structural poverty from poverty that passes naturally with time due to systemic growth processes. Drawing on the economic theory of poverty traps and bifurcated accumulation strategies, this paper briefly discusses some feasible estimation strategies for empirically identifying poverty traps and long-term, persistent structural poverty, as well as relevant extensions of the popular Foster-Greer-Thorbecke class of poverty measures. The paper closes with reflections on how asset-based poverty can be used to underwrite the design of persistent poverty reduction strategies.
Fracture statistics of brittle materials with intergranular cracks

Abstract A statistical theory for intergranular crack frequency as a function of crack size has been developed for polycrystalline materials. On the assumption that the cracks are penny-shaped and that brittle fracture is caused by overstressing the weakest link, the crack frequency was converted into a statistical theory of fracture. The implications of this theory were examined and compared with those of Weibull and of Fisher, Holloman and McClintock. In general, the predicted behavior is in reasonable agreement with experimental observations, although whether agreement is significantly better than Weibull's theory will require detailed examination. Among the attractive features of the new theory are: (1) a closer relationship to fracture mechanics and to material structure and properties compared with the Weibull theory and (2) a capacity for refinement so as to model the actual material structure more closely, which should result in improved agreement with experiment.
Laser-cooled atoms inside a hollow-core photonic-crystal fiber

We describe the loading of laser-cooled rubidium atoms into a single-mode hollow-core photonic-crystal fiber. Inside the fiber, the atoms are confined by a far-detuned optical trap and probed by a weak resonant beam. We describe different loading methods and compare their trade-offs in terms of implementation complexity and atom-loading efficiency. The most efficient procedure results in loading of $~30$,000 rubidium atoms, which creates a medium with an optical depth of $~180$ inside the fiber. Compared to our earlier study [1] this represents a sixfold increase in the maximum achieved optical depth in this system.
Tumors of the Small Intestine

This collective review includes all available case reports and series of smooth muscle (stromal) tumors of the small intestine in the world literature from 1881 to 1996. We identified 1074 patients with leiomyoma (LM) and 1689 with leiomyosarcoma (LMS). Our purpose was to update our previous review, which encompassed case reports and series from 1881 to 1959, which included 350 LMs and 257 LMSs. The peak incidence of smooth muscle tumors in the small intestine in both male and female patients was between the ages of 50 and 59. Most commonly, the presenting complaint was gastrointestinal bleeding. Computed tomography was found to detect LM and LMS most successfully and had the additional advantage of locating metastatic disease. The jejunum contained the highest numbers of smooth muscle tumors, followed by the ileum and then the duodenum, with malignant lesions in all locations typically attaining larger diameters than benign tumors. The overall rate of metastatic spread of LMS ranged from 24% to 50%, with the liver being most commonly involved. Unlike other sarcomas, both hematogenous and lymphatic spread were common. The 5-year survival of 705 patients with LMS from 22 series was 27. 8%. For both benign and malignant smooth muscle tumors of the small intestine, surgery remains the treatment of choice, with little efficacy reported for irradiation, chemotherapy, or both.
Upper limit on dimming of cosmological sources by intergalactic grey dust from the soft X-ray background

Active galactic nuclei (AGN) produce a dominant fraction (F AGN ~ 80per cent) of the soft X-ray background (SXB) at photon energies 0.5 < E < 2 keV. If dust pervaded throughout the intergalactic medium, its scattering opacity would have produced diffuse X-ray haloes around AGN. Taking account of known galaxies and galaxy clusters, only a fraction F halo ≤ 10 per cent of the SXB can be in the form of diffuse X-ray haloes around AGN. We therefore limit the intergalactic opacity to optical/infrared photons from large dust grains, with radii in the range a = 0.2-2.0 μm, to a level τ GD ≤ 0.15(F halo /10 per cent)(F AGN /80per cent) -1 to a redshift z ~ 1. Our results are only weakly dependent on the grain size distribution in this size range or the redshift evolution of the intergalactic dust. Stacking X-ray images of AGN can be used to improve our constraints and diminish the importance of dust as a source of systematic uncertainty for future supernova surveys which aim to improve the precision on measuring the redshift evolution of the dark energy equation-of-state.
Voyager Photometry of Saturn's A Ring

Abstract Saturn's A Ring samples a wide range of dynamical environments, from the relatively unperturbed, optically thick inner region to the outer part of the ring, which contains numerous density waves. We analyze Voyager images of the A Ring to determine how the reflectivity of different radial regions varies with lighting and viewing geometry. We model our data with a classical radiative transfer code that includes the illumination of the rings by the Sun and Saturn. The particles in the inner and mid-A Ring have Bond albedos near 0.5 and are more backscattering than satellites of comparable albedo. The region outside the Encke Gap becomes progressively less backscattering with increasing radius. Particle properties change abruptly outside the Keeler Gap; particles here have an albedo near 0.6 and a Lambert-like phase function. In contrast with previous suggestions, the abundance of free, submicrometer "dust" is small throughout the entire A Ring; this conclusion holds even in the outermost A Ring, which is strongly perturbed by density waves. Models derived from low-phase data, assuming only macroscopic particles, correctly predict the high- phase reflectivity of the outer A Ring and individual strong density waves in the mid-A Ring. However, the inner and mid-A Ring are typically darker at high phase by a factor of two than our models predict. This discrepancy may be due to the reduced multiple scattering from a layer in which the particles are more closely packed. We have also studied the quadrupole azimuthal brightness asymmetry of the A Ring. The asymmetry has a full amplitude of 35% in the mid-A Ring in low-phase Voyager 2 images. We present results on its behavior and possible implications for the structure of the rings. Finally, we compare our results with studies using other data sets to synthesize our current understanding of the nature of the A Ring.
Nucleon-nucleon scattering from effective field theory

Abstract We perform a non-perturbative calculation of the 1S0 NN scattering amplitude, using an effective field theory (EFT) expansion. The expansion we advocate is a modification of what has been used previously; it is not a chiral expansion in powers of mπ. We use dimensional regularization throughout, and the MS renormalization scheme; our final result depends only on physical observables. We show that the EFT expansion of the quantity |p| cotθ(p) converges at momenta much greater than the scale A that characterizes the derivative expansion of the EFT Lagrangian. Our conclusions are optimistic about the applicability of an EFT approach to the quantitative study of nuclear matter.
Low temperature n-butyllithium-induced [3,3]-sigmatropic rearrangement/electrophile trapping reactions of allyl-1,1-dichlorovinyl ethers. Synthesis of β-, γ- and δ-lactones.

Treatment of allyl-1,1-dichlorovinyl ethers with n-BuLi at −78 °C, followed by quenching with ketones, epoxides, and oxetanes, leads to highly substituted β-, γ-, and δ-lactones in good to excellent yields.
Minimum-weight design of laminated composite plates for postbuckling performance

Minimum-weight design of simply-supported, symmetrically laminated, thin, rectangular, specially orthotropic laminated plates for buckling and postbuckling strength is investigated. The postbuckling analysis is based on an Marguerre-type energy method extended to generally orthotropic plates with a special consideration of the mode change in the postbuckling load regime. The failure load of laminates is calculated by the maximum strain failure criterion based on the in-plane strains. Design variables are individual layer thicknesses with specified fiber orientations and assumed to take only discrete values corresponding to multiples of the lamina thickness. The optimization with discrete valued design is achieved by introducing additional penalty terms, in the form of a sine function, to the regular pseudo-objective function of sequential unconstrained minimization technique (SUMT). The proposed optimization technique is applied to the design of rectangular laminates made up of 0, ± 45, 90 degree laminae with various aspect ratios loaded by axial compressive loads.
Explaining the appearance and success of voter referenda for open-space conservation

This paper provides an empirical investigation of the factors that influence the appearance and success of voter referenda to raise public funds for open-space conservation. We take advantage of a data set that includes detailed information on all such referenda that occurred in the United States between 1998 and 2003. Combining these data with information from the U.S. Census and state-specific variables, we conduct a nationwide analysis along with focused studies of referenda that occurred in New Jersey and Massachusetts. The paper provides the first investigation of how funding mechanisms and funding rates affect voter support for public acquisition of open space. We also provide evidence on the relationship between existing patterns of open space and voter support for open-space referenda. As open-space initiatives continue to gain popularity at the ballot box, the descriptive insights of this paper should prove useful for both policy-makers and advocates working in the area of land use management.
Coin flipping from a cosmic source: On error correction of truly random bits

We study a problem related to coin flipping, coding theory, and noise sensitivity. Consider a source of truly random bits x ∈ l0, 1rn, and k parties, who have noisy version of the source bits yi ∈ l0, 1rn, when for all i and j, it holds that P[y ji = xj] = 1 - e, independently for all i and j. That is, each party sees each bit correctly with probability 1 - e, and incorrectly (flipped) with probability e, independently for all bits and all parties. The parties, who cannot communicate, wish to agree beforehand on balanced functions fi: l0, 1rn → l0, 1r such that P[f1(y1) = … = fk(yk)] is maximized. In other words, each party wants to toss a fair coin so that the probability that all parties have the same coin is maximized. The function fi may be thought of as an error correcting procedure for the source x. When k = 2,3, no error correction is possible, as the optimal protocol is given by fi(yi) = y 1i . On the other hand, for large values of k, better protocols exist. We study general properties of the optimal protocols and the asymptotic behavior of the problem with respect to k, n, and e. Our analysis uses tools from probability, discrete Fourier analysis, convexity, and discrete symmetrization. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
Synthesis of N-(2,5-Dicarboxyphenyl)maleimide

Abstract The synthesis and characterization of N-(2,5-dicarboxyphenyl)male-imide prepared from 2-aminoterephthalic acid and maleicanhydride is described.
Closed-loop digital control of an impact printer hammer

This paper explores closed-loop digital control of a high-speed impact printer hammer in the presence of sensor measurement noise and disturbances. Conventional control of high-speed impact printers is accomplished without feedback; hence disturbances, such as mechanical and magnetic interaction between hammers and hammer settle-out period, force long delays between hammer firings to assure proper time and velocity of impact. By computer simulation, we show the feasibility of using the solenoid actuator to control both time and velocity of impact
Ester derived titanium enolate aldol reaction: chelation controlled diastereoselective synthesis of syn-aldols

A chelation controlled and highly diastereoselective synthesis of syn-aldols is described. Aldol reaction of commercially available l-phenylalaninol derived esters with a variety of bidentate oxyaldehydes proceeded with excellent syn-diastereoselectivities and isolated yields.
Probik: Protein Backbone Motion by Inverse Kinematics

To investigate the parameters of the protein design problem that we are exploring in collaboration with biochemists, we have developed a tool that uses inverse kinematics to support moving small fragments of protein backbone, while respecting biochemists' desires to “remain in favorable regions of the Ramachandran plot” and “preserve ideal geometry”. By presenting estimates of derivatives in response to motion, we are able to refine these qualitative desires as we work with our collaborators. We then explore low-dimensional bases to parametrize the space of backbone motions.
Testing bipartiteness of geometric intersection graphs

We show how to test the bipartiteness of an intersection graph of n line segments or simple polygons in the plane, or of an intersection graph of balls in d-dimensional Euclidean space, in time O(n log n). More generally, we find subquadratic algorithms for connectivity and bipartiteness testing of intersection graphs of a broad class of geometric objects. Our algorithms for these problems return either a bipartition of the input or an odd cycle in its intersection graph. We also consider lower bounds for connectivity and k-colorability problems of geometric intersection graphs. For unit balls in d dimensions, connectivity testing has equivalent randomized complexity to construction of Euclidean minimum spanning trees, and for line segments in the plane connectivity testing has the same lower bounds as Hopcroft's point-line incidence testing problem; therefore, for these problems, connectivity is unlikely to be solved as efficiently as bipartiteness. For line segments or planar disks, testing k-colorability of intersection graphs for k > 2 is NP-complete.
Ionicity and the theory of Schottky barriers

We have investigated the role of ionicity in metal-semiconductor Schottky barriers by examining interfaces of increasing semiconductor ionicity. The electronic structure of four separate interfaces consisting of jellium (of Al density) in contact with the (111) surface of Si and the (110) surfaces of GaAs, ZnSe, and ZnS is investigated through the use of a self-consistent pseudopotential method. The barrier height and the surface density of states in the semiconductor band gap are determined. The phenomenological index of interface behavior S (studied by Kurtin, McGill, and Mead for semiconductors of different ionicity) is discussed in terms of a simple model involving metal-induced states in the semiconductor gap.
The (4+3)-cycloaddition reaction: simple allylic cations as dienophiles

The (4+3)-cycloaddition of allylic cations to dienes is a powerful method for the direct synthesis of seven-membered rings. Recent developments in this area have included new methods for the generation of allylic cations, diastereoselective and catalytic, enantioselective reactions, an increased understanding of the diverse mechanistic possibilities of the reaction and applications to the total synthesis of natural products and their analogues.
Structural optimization with approximate sensitivities

Computational efficiency in structural optimization can be enhanced if the intensive computations associated with the calculation of the sensitivities, that is, gradients of the behavior constraints, are reduced. Approximation to gradients of the behavior constraints that can be generated with a small amount of numerical calculations is proposed. Structural optimization with these approximate sensitivities produced correct optimum solution. Approximate gradients performed well for different nonlinear programming methods, such as the sequence of unconstrained minimization technique, method of feasible directions, sequence of quadratic programming and sequence of linear programming. Structural optimization with approximate gradients can reduce by one third the CPU time that would otherwise be required to solve the problem with explicit closed-form gradients. The proposed gradient approximation shows potential to reduce intensive computation that has been associated with traditional structural optimization.
Statistical analysis of communications range and reliability in the presence of interference

A statistical method is developed for analysis of interference in land mobile communications systems. Reduction of communication range and degradation of system reliability are calculated. This method can be used for cases in which a desired signal is transmitted by a base station (or mobile unit) and received by a mobile unit (or base station) and is interfered with by a signal transmitted either by a fixed station or a mobile unit. The spatial probability distribution of mobile units is considered. The method is applicable to any frequency band for which path loss statistics are known, and an example of this method is given which calculates reduction in communication range, area, and degradation of communication reliability for different values of splatter protection, and distributions of mobile units.
Hierarchical optimal force-position control of complex manufacturing processes

Abstract A hierarchical optimal controller is developed in this paper to regulate the machining force and axis positions, simultaneously, in a micro end milling process. The process is divided into two levels of decision making. The bottom level includes the measurable states, which in this work comprises the axis positions. The top level includes the higher order objectives, which can be derived from the bottom level objectives by an aggregation relationship. In this work, the top level's objective is to regulate the machining force. A series of simulations were conducted in which the weighting between the top and the bottom level objectives is adjusted within the feasible range. The results demonstrated that excellent tracking of both axis positions and machining force are achieved during the steady state regardless of the weighting. However, the transient performance of the system could be systematically shaped to achieve better performance of either objective. For the purpose of comparison a decentralized optimal controller was constructed and simulated for the feasible range of controller weights. When the axis position errors were weighted heavily, both controllers were able to regulate the axis errors well, while the hierarchical controller had smaller machining force errors. When the machining force errors were weighted heavily, although the machining force error decreased for the decentralized controller the axis position errors increased significantly. However, with heavy machining force weighting, the hierarchical controller was able to manipulate the axial errors in a way that while the machining force error was reduced, the contour error (i.e., smallest deviation from the tool tip to the desired contour) remained small.
Strain effects on oxygen migration in perovskites

Fast oxygen transport materials are necessary for a range of technologies, including efficient and cost-effective solid oxide fuel cells, gas separation membranes, oxygen sensors, chemical looping devices, and memristors. Strain is often proposed as a method to enhance the performance of oxygen transport materials, but the magnitude of its effect and its underlying mechanisms are not well-understood, particularly in the widely-used perovskite-structured oxygen conductors. This work reports on an ab initio prediction of strain effects on migration energetics for nine perovskite systems of the form LaBO3, where B = [Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Ga]. Biaxial strain, as might be easily produced in epitaxial systems, is predicted to lead to approximately linear changes in migration energy. We find that tensile biaxial strain reduces the oxygen vacancy migration barrier across the systems studied by an average of 66 meV per percent strain for a single selected hop, with a low of 36 and a high of 89 meV decrease in migration barrier per percent strain across all systems. The estimated range for the change in migration barrier within each system is ±25 meV per percent strain when considering all hops. These results suggest that strain can significantly impact transport in these materials, e.g., a 2% tensile strain can increase the diffusion coefficient by about three orders of magnitude at 300 K (one order of magnitude at 500 °C or 773 K) for one of the most strain-responsive materials calculated here (LaCrO3). We show that a simple elasticity model, which assumes only dilative or compressive strain in a cubic environment and a fixed migration volume, can qualitatively but not quantitatively model the strain dependence of the migration energy, suggesting that factors not captured by continuum elasticity play a significant role in the strain response.
RATIONAL BELIEFS IN EXTENSIVE GAMES

Given an extensive game, with every node x and every player i a subsct K,(x) of the set of terminal nodes is associated, and is given the interpretation of player I's knowledge (or information) at node x. A belief of player i is a function that assoeiates with every node x an element of the set K,(x). A belief system is an n-tuple of beliefs, onc for cach player. A belief system is rational if it satisfies some natural consistency properties. The main result of the paper is that the notion of rational belief system gives rise to a refinement of the notion of subgame-perfect equilibrium.
A general sequential time-space tradeoff for finding unique elements

An optimal $\Omega (n^2 )$ lower bound is shown for the time-space product of any R branching program that determines those values which occur exactly once in a list of n integers in the range $[1,R]$ where $R \geqq n$. This $\Omega (n^2 )$ tradeoff also applies to the sorting problem and thus improves the previous time-space tradeoffs for sorting. Because the R-way branching program is such a powerful model, these time-space product tradeoffs also apply to all models of sequential computation that have a fair measure of space such as off-line multitape Turing machines and off-line log-cost random access machines (RAMs).
Single-flask preparation of polyazatriaryl ligands by sequential borylation/Suzuki–Miyaura coupling

Abstract We report a convenient single-flask methodology for the preparation of polyazatriaryl products with relevance to luminescence, catalysis, and pharmacology. The diborylation of 1,3-dibromobenzenes and double Suzuki–Miyaura coupling produces 1,3-diheteroarylbenzenes. Similarly, borylation of heteroaryl halides and double coupling to 2,6-dichloropyridine produces 2,6-diheteroarylpyridines. This methodology appears general in producing challenging polyheteroaryl targets as long as the boronic esters have no ortho heteroatoms and coupling avoids adjacent oxygens.
SET: An algorithm for consistent matrix completion

A new algorithm, termed subspace evolution and transfer (SET), is proposed for solving the consistent matrix completion problem. In this setting, one is given a subset of the entries of a low-rank matrix, and asked to find one low-rank matrix consistent with the given observations. We show that this problem can be solved by searching for a column space that matches the observations. The corresponding algorithm consists of two parts — subspace evolution and subspace transfer. In the evolution part, we use a line search procedure to refine the column space. However, line search is not guaranteed to converge, as there may exist barriers along the search path that prevent the algorithm from reaching a global optimum. To address this problem, in the transfer part, we design mechanisms to detect barriers and transfer the estimated column space from one side of the barrier to the another. The SET algorithm exhibits excellent empirical performance for very low-rank matrices.
Cohomology in one-dimensional substitution tiling spaces

Anderson and Putnam showed that the cohomology of a substitution tiling space may be computed by collaring tiles to obtain a substitution which "forces its border." One can then represent the tiling space as an inverse limit of an inflation and substitution map on a cellular complex formed from the collared tiles; the cohomology of the tiling space is computed as the direct limit of the homomorphism induced by inflation and substitution on the cohomology of the complex. For one-dimensional substitution tiling spaces, we describe a modification of the Anderson-Putnam complex on collared tiles that allows for easier computation and provides a means of identifying certain special features of the tiling space with particular elements of the cohomology.
Exotic decays of a heavy neutral Higgs through HZ/AZ channel

Models of electroweak symmetry breaking with extended Higgs sectors are theoretically well motivated. In this study, we focus on the Two Higgs Doublet Model with a low energy spectrum containing scalars H and a pseudoscalar A. We study the decays A → HZ or H → AZ, which could reach sizable branching fractions in certain parameter regions. With detailed collider analysis, we obtain model independent exclusion bounds as well as discovery reach at the 14 TeV LHC for the process: gg → A/H → HZ/AZ, looking at final states bbll, ττll and ZZZ(4l + 2j) for l = e, μ. We further interpret these bounds in the context of the Type II Two Higgs Doublet Model, considering three different classes of processes: A → h 0 Z, A → H 0 Z, and H 0 → AZ, in which h 0 and H 0 are the light and heavy CP-even Higgses respectively. For 100 fb−1 integrated luminosity at the 14 TeV LHC, we find that for parent particle mass around 300–400 GeV, A → h 0 Z has the greatest reach when H 0 is interpreted as the 126 GeV Higgs: most regions in the tan β versus sin(β − α) plane can be excluded and a significant fraction at small and large tan β can be covered by discovery. For 126 GeV h 0, only relatively small tan β ≲ 10 (5) can be reached by exclusion (discovery) while a wide range of sin(β − α) is accessible. For A → H 0 Z, the reach is typically restricted to sin(β − α) ~ ±1 with tan β ≲ 10 in bbll and ττll channels. The ZZZ(4l2j) channel, on the other hand, covers a wide range of 0.3 < | sin(β − α)| < 1 for tan β ≲ 4. H 0 → AZ typically favors negative values of sin(β − α), with exclusion/discovery reach possibly extending to all values of tan β. A study of exotic decays of extra Higgses appearing in extensions of the Standard Model would extend the reach at the LHC and provides nice complementarity to conventional Higgs search channels.
Social capital, barriers to production and capital shares: implications for the importance of parameter heterogeneity from a nonstationary panel approach

Recent advances in the growth literature have proposed that difficult-to-quantify concepts such as social capital may play an important role in explaining the degree of persistent income disparity that is observed among countries. Other recently explored possibilities include institutional mechanisms which generate barriers to aggregate production. An important limitation for empirical work in this area stems from the fact that it is difficult to distinguish sources of heterogeneity when direct observations are not available. In this study, we show how developments in the analysis of nonstationary panels can aid in this endeavor. In contrast to traditional dynamic panel data analysis, this approach focuses explicitly on low-frequency behavior. Under relatively mild assumptions, the approach can be used to infer properties of aggregate production which are robust to the presence of large classes of unobserved features. In this framework we are able to estimate and test the distribution of production function parameters that would be required in order to generate conditional forecast convergence of per capita incomes even when some of the key factors required to explain growth are unobserved. The results indicate that in order to fully explain the observed persistence in the disparity of per capita incomes, the manner in which unobserved mechanisms influence production must go beyond merely accounting for differences in the trending behavior of aggregate productivity. Specifically, if such mechanisms are to be successful empirically, they must also be able to account for cross-country heterogeneity in steady-state capital shares. This adds to a growing literature that provides support for models with multiple production regimes. Copyright © 2007 John Wiley & Sons, Ltd.
Risk Taking as Self Discipline in Contractual Relationships

Abstract This paper considers an agency model in which the principal is privately informed of her production technology. In our model, the principal can require the agent to adopt the principal’s technology for production, or alternatively, to adopt a technology in the market. Information about the market technology’s efficiency is publicly available, and thus can be acquired. We show that, if the variation in technological efficiency is large, the principal prefers to delay acquisition of information about the market technology. The reason is that, the principal uses uncertainty as a device to provide a truth‐telling incentive to herself, which, in turn, lowers the cost of inducing the agent to accept the contract.
Negotiation versus manipulation: The impact of alternate forms of LDC government behavior on the design of international environmental agreements*

This article addresses the problem faced by an asymmetrically informed supra-national governmental authority (SNGA) with limited funds that wishes to design an international environmental agreement (IEA) for less developed countries (LDCs). The SNGA can only deal with polluting firms in the LDCs through their national governments. This tripartite hierarchical interaction is studied for two LDCs. The private information of the firms and the governments across the two countries is perfectly correlated. In this setting, we study the effects of two kinds of behavior by the governments of the LDCs. We show that despite the perfect correlation in the private information of governments and firms across the two countries, the SNGA cannot design a first-best IEA. Our analysis suggests that problems arising from the SNGA's inability to monitor the actions of the polluting firms and the national governments are less salient than is commonly believed. However, there is no denying the fact that the succ ess of IEAs is dependent not only on the funds available for environmental protection, but also on the manner in which LDC governments represent polluting firms in their countries.
Improved adaptive resonance theory

Adaptive resonance theory (ART) has been used to develop neural network architectures in order to self-organize pattern recognition codes stably in real-time in response to random input sequences of patterns. A brief background of the motivations and design considerations underlying the development of adaptive resonance networks an outline of their basic operation a new idea for improving the model and some experimental results are discussed in this article. 1.
Regularized partial least squares with an application to NMR spectroscopy

High-dimensional data common in genomics, proteomics, and chemometrics often contains complicated correlation structures. Recently, partial least squares (PLS) and Sparse PLS methods have gained attention in these areas as dimension reduction techniques in the context of supervised data analysis. We introduce a framework for Regularized PLS by solving a relaxation of the SIMPLS optimization problem with penalties on the PLS loadings vectors. Our approach enjoys many advantages including flexibility, general penalties, easy interpretation of results, and fast computation in high-dimensional settings. We also outline extensions of our methods leading to novel methods for non-negative PLS and generalized PLS, an adoption of PLS for structured data. We demonstrate the utility of our methods through simulations and a case study on proton Nuclear Magnetic Resonance (NMR) spectroscopy data.
A note on recurrent random walks

Abstract For any recurrent random walk ( S n ) n ⩾ 1 on R , there are increasing sequences ( g n ) n ⩾ 1 converging to infinity for which ( g n S n ) n ⩾ 1 has at least one finite accumulation point. For one class of random walks, we give a criterion on ( g n ) n ⩾ 1 and the distribution of S 1 determining the set of accumulation points for ( g n S n ) n ⩾ 1 . This extends, with a simpler proof, a result of Chung and Erdos. Finally, for recurrent, symmetric random walks, we give a criterion characterizing the increasing sequences ( g n ) n ⩾ 1 of positive numbers for which lim g n | S n | = 0 .
Quantum computation with quasiparticles of the fractional quantum Hall effect

We propose an approach that enables implementation of anyonic quantum computation in systems of antidots in the two-dimensional electron liquid in the fractional quantum Hall effect (FQHE) regime. The approach is based on the adiabatic transfer of FQHE quasiparticles in the antidot systems, and uses their fractional statistics to perform quantum logic. Advantages of our scheme over other semiconductor-based proposals of quantum computation include the energy gap in the FQHE liquid that suppresses decoherence, and the topological nature of quasiparticle statistics that makes it possible to entangle two quasiparticles without their direct dynamic interaction.
Reasoning about knowledge and probability

We provide a model for reasoning about knowledge and probability together. We allow explicit mention of probabilities in formulas, so that our language has formulas that essentially say «according to agent i, formula φ holds with probability at least b.» The language is powerful enough to allow reasoning about higher-order probabilities, as well as allowing explicit comparisons of the probabilities an agent places on distinct events. We present a general framework for interpreting such formulas, and consider various properties that might hold of the interrelationship between agents' probability assignments at different states. We provide a complete axiomatization for reasoning about knowledge and probability, prove a small model property, and obtain decision procedures
Flying NASA Unmanned Aircraft: A Pilot's Perspective

The National Aeronautics and Space Administration (NASA) is pioneering various Unmanned Aircraft System (UAS) technologies and procedures which may enable routine access to the National Airspace System (NAS), with an aim for Next Gen NAS. These tools will aid in the development of technologies and integrated capabilities that will enable high value missions for science, security, and defense, and open the door to low-cost, extreme-duration, stratospheric flight. A century of aviation evolution has resulted in accepted standards and best practices in the design of human-machine interfaces, the displays and controls of which serve to optimize safe and efficient flight operations and situational awareness. The current proliferation of non-standard, aircraft-specific flight crew interfaces in UAS, coupled with the inherent limitations of operating UAS without in-situ sensory input and feedback (aural, visual, and vestibular cues), has increased the risk of mishaps associated with the design of the "cockpit." The examples of current non- or sub- standard design features range from "annoying" and "inefficient", to those that are difficult to manipulate or interpret in a timely manner, as well as to those that are "burdensome" and "unsafe." A concerted effort is required to establish best practices and standards for the human-machine interfaces, for the pilot as well as the air traffic controller. In addition, roles, responsibilities, knowledge, and skill sets are subject to redefining the terms, "pilot" and "air traffic controller", with respect to operating UAS, especially in the Next-Gen NAS. The knowledge, skill sets, training, and qualification standards for UAS operations must be established, and reflect the aircraft-specific human-machine interfaces and control methods. NASA s recent experiences flying its MQ-9 Ikhana in the NAS for extended duration, has enabled both NASA and the FAA to realize the full potential for UAS, as well as understand the implications of current limitations. Ikhana is a Predator-B/Reaper UAS, built by General Atomics, Aeronautical Systems, Inc., and modified for research. Since 2007, the aircraft has been flown seasonally with a wing-mounted pod containing an infrared scanner, utilized to provide real-time wildfire geo-location data to various fire-fighting agencies in the western U.S. The multi-agency effort included an extensive process to obtain flight clearance from the FAA to operate under special provisions, given that UAS in general do not fully comply with current airspace regulations (e.g. sense-and-avoid requirements).
Two-Beam Spider for Dual-Pulse Single-Shot Characterization

A novel ultrashort pulse characterization device is presented, optimized for simultaneous measurement of two pulses. The device is particularly useful for experimental characterization at low repetition rates, with high laser fluctuations.
Novel bisbenzamidines and bisbenzimidazolines as noncompetitive NMDA receptor antagonists

A series of novel bisbenzamidines and bisbenzimidazolines with different linker connecting the aromatic groups was tested in vitro for NMDA receptor antagonist activity. IC50 values for these compounds ranged from 1.2 to >200 μM. The bisbenzamidine with a homopiperazine ring as the central linker was found to be the most potent NMDA receptor antagonist among all the pentamidine analogues tested so far.
Line-of-Sight Reddening Predictions: Zero Points, Accuracies, the Interstellar Medium, and the Stellar Populations of Elliptical Galaxies

Revised (B-V)0-Mg2 data, which are used to test reddening predictions, are presented for 402 elliptical galaxies. These reddening predictions can tell us both what the intrinsic errors are in this relationship among gE galaxy stellar populations as well as details of nearby structure in the interstellar medium (ISM) of our Galaxy, and of the intrinsic errors in reddening predictions. Using least-squares fits, the explicit 1 σ errors in reddenings predicted by the Burstein-Heiles (BH) method and the Schlegel and coworkers (IR) method are calculated, as well as the 1 σ observational error in the (B-V)0-Mg2 for gE galaxies. It is found that in directions with E(B-V) < 0.100 mag (where most of these galaxies lie), 1 σ errors in the IR reddening predictions are 0.006–0.009 mag in E(B-V), those for BH reddening predictions are 0.011 mag, and the 1 σ agreement between the two reddening predictions is 0.007 mag. The IR predictions have an accuracy of 0.010–0.011 mag in directions with E(B-V) ≥ 0.100 mag, significantly better than those of the BH predictions (0.024–0.025). Both methods yield good evidence that gas-to-dust variations that vary by a factor of 3, both high and low, exist along many lines of sight in our Galaxy. Both methods also predict many directions with E(B-V) < 0.015 mag, despite the difference in zero point that each has assumed. The ~0.02 higher reddening zero point in E(B-V) previously determined by Schlegel and coworkers is confirmed, primarily at the Galactic poles. Independent evidence of reddening at the north Galactic pole (NGP) is reviewed, with the conclusion that directions still exist at the NGP that have E(B-V) 0.01. Two lines of evidence suggest that IR reddenings are overpredicted in directions with high gas-to-dust ratios. As high gas-to-dust directions in the ISM also include the Galactic poles, this overprediction is the likely cause of the E(B-V) ~ 0.02 mag larger IR reddening zero point relative to that of BH.
The Hilbert transform of a measure

Let e be a homogeneous subset of R in the sense of Carleson. Let μ be a finite positive measure on R and H_μ(x) its Hilbert transform. We prove that if lim_(t→∞)t|e∩{x||H_μ(x)|>t}| = 0, then μ_s(e) = 0, where μ_s is the singular part of μ.
Comparing energy-technology alternatives from an environmental perspective☆

A number of individuals and organizations advocate the use of comparative, formal analysis to determine which are the safest methods for producing and using energy. Some have suggested that the findings of such analyses should be the basis upon which final decisions are made about whether to actually deploy energy technologies. Some of those who support formal comparative analysis are in a position to shape the policy debate on energy and environment. An opposing viewpoint is presented, arguing that for technical reasons, analysis can provide no definitive or rationally credible answers to the question of overall safety. Analysis has not and cannot determine the sum total of damage to human welfare and ecological communities from energy technologies. Analysis has produced estimates of particular types of damage; however, it is impossible to make such estimates comparable and commensurate across different classes of technologies and environmental effects. As a result of the deficiencies, comparative analysis connot form the basis of a credible, viable energy policy. Yet, without formal comparative analysis, how can health, safety, and the natural environment be protected. This paper proposes a method for improving the Nation's approach to this problem. The proposal essentially is that health and the environmentmore » should be considered as constraints on the deployment of energy technologies, constraints that are embodied in Government regulations. Whichever technologies can function within these constraints should then compete among themselves. This competition should be based on market factors like cost and efficiency and on political factors like national security and the questions of equity.« less