cssi/SciSciGPT-SciSciNet huggingface dataset:
Global Diffusion on a Tight Three-Sphere

We consider an integrable Hamiltonian system weakly coupled with a pendulum-type system. For each energy level within some range, the uncoupled system is assumed to possess a normally hyperbolic invariant manifold diffeomorphic to a three-sphere, which bounds a strictly convex domain, and whose stable and unstable invariant manifolds coincide. The Hamiltonian flow on the three-sphere is equivalent to the Reeb flow for the induced contact form. The strict convexity condition implies that the contact structure on the three-sphere is tight. When a small, generic coupling is added to the system, the normally hyperbolic invariant manifold is preserved as a three-sphere, and the stable and unstable manifolds split, yielding transverse intersections. We show that there exist trajectories that follow any prescribed collection of invariant tori and Aubry–Mather sets within some global section of the flow restricted to the three-sphere. In this sense, we say that the perturbed system exhibits global diffusion on the tight three-sphere.
Physical Conditions of the Coronal Line Region in Seyfert Galaxies

The launch of the Infrared Space Observatory and new atomic data have opened a window for the study of high-ionization gas in active galactic nuclei (AGNs). We present the results of a large number of photoionization simulations of the "coronal line" region in AGNs, employing new atomic data from the Opacity and Iron Projects. Our grid of line emission spans 8 orders of magnitude in gas density and 14 orders of magnitude in ionizing flux in an effort to identify the optimal conditions in which these lines form. We show that coronal lines form at distances from just outside the broad-line region to ~400L1/243.5 pc, in gas with ionization parameter -2.0 log U(H) 0.75, corresponding to gas densities of 102-108.5 cm-3, with electron temperatures ~12,000-150,000 K. A large range of distances from the central source implies significant line width variation among the coronal lines. We identify several line ratios that could be used to measure relative abundances, and we use these to show that the coronal line gas is likely to be dust free.
Satisfiers and dissatisfiers: a two-factor model for website design and evaluation

Proliferating Web-user interface studies prompt a need for theoretical approaches. This study presents a two-factor model that can guide Website design and evaluation. According to the model, there are two types of Website design factors: hygiene and motivator. Hygiene factors are those whose presence make a Website functional and serviceable, and whose absence causes user dissatisfaction (thus dissatisfiers). Motivator factors, on the other hand, are those that add value to the Website by contributing to user satisfaction (thus satisfiers). An empirical study is conducted in two phases. In Phase I, 44 core features and 12 categories of features were identified by a total of 76 subjects as Web design factors. In Phase II, 79 different subjects distinguished hygiene and motivator factors in the context of a particular Website (CNN.com). The results showed that the two-factor model provides a means for Web-user interface studies. In addition, Subjects in Phase II commented that, as time passes or familiarity increases with certain design factors, their identification of what are hygiene and motivator factors might change, promoting further investigation and possible expansion of the model. Suggestions for Website designs and evaluation, and further research directions are provided.
Almost-Rainbow Edge-Colorings of Some Small Subgraphs

Let f(n,p,q) be the minimum number of colors necessary to color the edges of Kn so that every Kp is at least q-colored. We improve current bounds on these nearly "anti-Ramsey" numbers, first studied by Erdýos and Gyarfas. We show that f(n,5,9) ≥ 7 n−3, slightly improving the bound of Axenovich. We make small improvements on bounds of Erdýos and Gyarfas by showing 5 n+1 ≤ f(n,4,5) and for all even n 6≡1(mod 3), f(n,4,5) ≤ n− 1. For a complete bipartite graph G = Kn,n, we show an n-color construction to color the edges of G so that every C4 ⊆ G is colored by at least three colors. This improves the best known upper bound of Axenovich, Furedi, and Mubayi.
Kraft Inequality and Zero-Error Source Coding With Decoder Side Information

For certain source coding problems, it is well known that the Kraft inequality provides a simple sufficient condition for the existence of codes with given codeword lengths. Motivated by this fact, a sufficient condition based on the Kraft inequality can also be sought for the problem of zero-error instantaneous coding with decoder side information. More specifically, it can be envisioned that a sufficient condition for the existence of such codes with codeword lengths {l x} is that for some 0<alphales<1 SigmaxepsivFscr (2-l x)lesalpha for each clique Fscr in the characteristic graph G of the source-side information pair. In this correspondence, it is shown that (1) if the above is indeed a sufficient condition for a class G of graphs, then it is possible to come as close as 1-log2 alpha bits to the asymptotic limits for each graph in G, (2) there exist graph classes of interest for which such a can indeed be found, and finally (3) no such n can be found for the class of all graphs.
A relation between approaches to integrability in superconformal Yang-Mills theory

We make contact between the infinite-dimensional non-local symmetry of the type-IIB superstring on AdS5 × S5 and a non-abelian infinite-dimensional symmetry algebra for the weakly coupled superconformal gauge theory. We explain why the planar limit of the one-loop dilatation operator is the hamiltonian of a spin chain, and show that it commutes with the g2N = 0 limit of the non-abelian charges.
Rule‐based noise cancellation: a fuzzy line enhancer

The extraction of a desired signal from extraneous noise is a typical research topic in the field of signal processing. The filter used to realize this task to enhance a narrow-band signal in the presence of broadband noise is called a line enhancer. In this paper, line enhancement (noise cancellation) by using fuzzy theory is introduced. By using a fuzzy logic approach, the locations of the lower bound and the upper bound of the main power band, in the spectrum of an arbitrary narrow-band signal that is corrupted by a broad-band noise, can be detected. The membership functions are described mathematically by sets of line equations based on analytic geometry rather than by conventional graphics and fuzzy inference is therefore mathematically implemented in software. A proper band-pass linear FIR filter is then automatically generated, based on the detected information to filter and finally enhance the signal of interest. The computer simulation, which is analyzed in this paper, demonstrates satisfactory results. The implementation considerations of the proposed fuzzy line enhancer are compared with those of the existing adaptive line enhancers; it is satisfactory, and the algorithm is simpler.
Inhibition of interdiffusion from MCrAlY overlay coatings by application of a Ni-Re interlayer

The durability of protective coatings on combustion turbine blades and vanes is a critical issue in the power generation industry. Coating life usually dictates the refurbishment intervals for these components, and these intervals have generally been of shorter duration than desired by the operators of the equipment. Both MCrAlY and aluminide type coatings protect against oxidation and hot corrosion by forming a protective Al{sub 2}O{sub 3} surface layer. Degradation of the coatings occurs by depletion of the aluminum content of the coating through interdiffusion with the substrate and through the formation and spallation of an external Al{sub 2}O{sub 3} scale. The results obtained in this study clearly show that the application of a thin interlayer of Ni-Re beneath the MCrAlY coating can significantly decrease the growth rate of the inner {beta}-NiAl depletion zone. Order of magnitude reductions in the inner depletion zone thickness formed at 1000 h were obtained with both the Ni-32 wt.% Re and the Ni-47 wt.% Re interlayer coatings. Since formation of the inner depletion zone is believed to result from interdiffusion with the substrate, these results suggest that the Ni-Re interlayer provided a significant impediment to the inward diffusion of Al into the substrate.
More chiral operators on the lattice

Abstract Instead of the Ginsparg–Wilson (GW) relation we only require generalized chiral symmetry and show that this results in a larger class of Dirac operators describing massless fermions, which in addition to GW fermions and to the ones proposed by Fujikawa includes many more general ones. The index turns out to depend solely on a basic unitary operator. We use spectral representations to analyze the new class and to obtain detailed properties. We also show that our weaker conditions still lead properly to Weyl fermions and to chiral gauge theories.
Income taxation and marital decisions

Differential tax treatment of married and single people is a key feature of the tax code in the US and other countries. We analyze its equilibrium and welfare effects in a matching model with search frictions and nontransferable utility. We find that an increase in taxes on married people unambiguously reduces the equilibrium number of marriages, but it need not make both men and women more reluctant to marry. We also show that it is optimal to give married couples a preferential tax treatment. A quantitative analysis using US data reveals that relatively large changes in taxes are associated with small changes in the number of marriages and divorces. Finally, we extend the model to allow for cohabitation as an alternative to marriage, and find that the number of marriages becomes more sensitive to increases in the marriage tax penalty. The magnitude of the resulting changes, however, is still moderate.
Low Peclet Number Heat Transfer in a Laminar Tube Flow Subjected to Axially Varying Wall Heat Flux

Since the analysis of Schneider demonstrating the importance of axial conduction in the thermal entry region for low Peclet number flows, there have been several attempts to account for both axially conduction and axially varying wall boundary conditions in hydrodynamically developed laminar flows. Nagasue obtained a closed-form solution to representing the axial flux distribution with a power section. Solutions were found for monomial heating, with the total solution obtained by superposition. This representation is computationally impractical for sinusoidal, exponential, and other practically important axial flux distributions having slowly convergent power series. Several investigators have also used purely numerical methods to solve this problem. Unfortunately, these methods are inefficient due to the need to recompute the whole solution each time the axial heat flux distribution at the wall is changed, as in iterative design. Thus, there do not appear to be any general methods available for the solution of the important problem if hydrodynamically developed low Peclet number flow in a tube with axially varying wall heat flux. The authors have recently developed such a method. The purpose of the present work is to demonstrate its usefulness by presenting results for several wall heat flux distributions of interest.
Carotid Artery Stenting Versus Carotid Endarterectomy: Current Status

Carotid occlusive disease remains an important cause of ischemic stroke. The results of large, randomized, clinical trials have established the benefit of surgical revascularization in patients with symptomatic or asymptomatic carotid stenosis. The introduction of balloon angioplasty and stenting of the extracranial carotid artery as a potential alternative to surgery has been received with enthusiasm by patients and physicians. Whether or not this enthusiasm is justified fully has yet to be determined. This article reviews established and emerging data from clinical trials evaluating the safety and efficacy of carotid endarterectomy, carotid angioplasty, and stenting.
Geometrical aspects of fivebranes in heterotic/F-theory duality in four dimensions

We use the method of stable degenerations to study the local geometry of Calabi-Yau fourfolds for F-theory compactifications dual to heterotic compactifications on a Calabi-Yau threefold with fivebranes wrapping holomorphic curves in the threefold. When fivebranes wrap intersecting curves, or when many fivebranes wrap the same curve, the dual fourfolds degenerate in interesting ways. We find that some of these can be usefully described in terms of degenerations of the base of the elliptic fibrations of these fourfolds. We use Witten's criterion to determine which of the fivebranes can lead to the generation of a non-perturbative superpotential.
The euro and the stability pact

Abstract This paper begins by discussing the inherent conflict between the simultaneous existence of a single currency for the countries of the European Economic and Monetary Union (EMU) and the independent fiscal policies of those countries. The Stability and Growth Pact was an attempt to reconcile that conflict. I describe how EMU governments have chosen to ignore the Stability Pact's constraint on budget deficits and how they sought to undermine it by changing the rules themselves. The final part of the paper describes the actual resolution of the issue by the agreement reached at the end of March 2005 by the European Council. The new policy effectively abandons the Stability Pact and leaves the way open to much larger sustained deficits.
The June 23, 2001 Peru earthquake and the southern Peru subduction zone

[1] The plate boundary between the South American and Nazca plate along the south-central Peru coast has been the site of large destructive earthquakes for many centuries, including the June 23, 2001 (MW=8.4) event. This underthrusting event has a fault area of 320 km by 100 km based on relocated aftershocks during the first three weeks following the mainshock. Modeling of the teleseismic broadband P waves of the 2001 Peru earthquake indicates two pulses of moment release with the larger second pulse located 130 km southeast of the mainshock initiation, indicating a unilateral rupture to the southeast. Based on intensity and tsunami reports, previous earthquakes in 1868 and 1604 were larger than the 2001 earthquake, while an event in 1784 was smaller. This provides further evidence that the size of earthquakes along the Peru coast has changed between successive earthquake cycles.
Deviation of International Practical Temperatures from Thermodynamic Temperatures in the Temperature Range from 273.16 K to 730 K.

The range over which thermodynamic temperatures have been realized by gas thermometry at the NBS has been extended to 730 K. The results are preserved by measuring the corresponding international practical temperatures. The difference between them is expressed as the following polynomial: T / K - T 68 / K 68 = - 120 , 887.784 / T 68 2 + 1213.53295 / T 68 - 4.3159552 + 6.44075647 × 10 - 3 T 68 - 3.56638846 × 10 - 6 T 68 2 which is valid in the range 273 to 730 K. The difference found and the estimated uncertainties at the three defining fixed points in the range covered are [Table: see text].
The financing of business start-ups

Abstract This article investigates the determinants of capital structure and types of financing used around business start-ups utilizing a survey that reduces the confounding effects of survivorship bias. In particular, the influence of start-up size, asset structure, organization type, growth orientation, and owners' characteristics are examined both in the choice and in the magnitude of finance use. The results are consistent with the theoretical models incorporating issues, such as information asymmetries, agency theory, and transaction costs. The results also demonstrate linkages among providers of finance, maturity of assets, and the capital structure of start-ups. While the results provide insights into business finances near the time of creation, some recommendations for future research are discussed.
Improvement of Observer/Kalman Filter Identification (OKID) by Residual Whitening

This paper presents a time-domain method to identify a state space model of a linear system and its corresponding observer/Kalman filter from a given set of general input-output data. The identified filter has the properties that its residual is minimized in the least squares sense, orthogonal to the time-shifted versions of itself, and to the given input-output data sequence. The connection between the state space model and a particular auto-regressive moving average description of a linear system is made in terms of the Kalman filter and a deadbeat gain matrix. The procedure first identifies the Markov parameters of an observer system, from which a state space model of the system and the filter gain are computed. The developed procedure is shown to improve results obtained by an existing observer/Kalman filter identification method, which is based on an auto-regressive model without the moving average terms. Numerical and experimental results are presented to illustrate the proposed method.
Remarks on logarithmic K-stability

We introduce the logarithmic version of K-stability by generalizing Donaldson's algebraic formulation of K-stability.
Image random file access routines

Abstract In any large image processing system a set of routines that access the image data is vital. This paper discusses the required image access routines. This set of routines maintains a file format called SIF (standard image format) that is a structured random access file storing both pixel data and image processing history information. The image access routines are built on top of the kernel, an “operating system” set of routines which is fully described in “An operating system interface for transportable image processing software,” Computer Vision, Graphics, and Image Processing , 23 , July 1983.
Palladium-Catalyzed Synthesis of N-Aryl-2-benzylindolines via Tandem Arylation of 2-Allylaniline: Control of Selectivity through in Situ Catalyst Modification

A new synthesis of N-aryl-2-benzylindolines from 2-allylanilines and two different aryl bromides is described. This transformation involves two different sequential metal-catalyzed reactions that lead to the formation of two C−N bonds and one C−C bond in a one-pot process. The selective installation of two different aryl groups in these reactions is accomplished by in situ modification of the palladium catalyst prior to addition of the second aryl bromide.
A representative consumer theory of distribution

This paper introduces various sources of consumer heterogeneity in one-sector representative consumer (RC) growth models and develops tools to study the evolution of the distribution of consumptions, assets, and incomes. These tools are applied to the Ramsey-Cass-Koopmans model of optimal savings and the ArrowRomer model of productive spillovers. The RC property per se places very few restrictions on the nature of observed distributions, and a wide range of distributive dynamics and income mobility patterns can arise as the equilibrium outcome. An example illustrates how to use these tools to generate quantitative predictions and
Stability of oscillating hexagons in rotating convection

Abstract Breaking the chiral symmetry, rotation induces a secondary Hopf bifurcation in weakly nonlinear hexagon patterns which gives rise to oscillating hexagons. We study the stability of the oscillating hexagons using three coupled Ginzburg–Landau equations. Close to the bifurcation point, we derive reduced equations for the amplitude of the oscillation, coupled to the phase of the underlying hexagons. Within these equations, we identify two types of long-wave instabilities and study the ensuing dynamics using numerical simulations of the three coupled Ginzburg–Landau equations.
Three-dimensional solution NMR spectroscopy of complex structures and mixtures.

This paper reviews the non-biological applications of three dimensional NMR (3D-NMR) spectroscopy methodologies for studying chemical structures in polymer science, dendrimer research, organometallic chemistry, organosilicon chemistry, and mixtures of small organic molecules. Four methodologies for solving chemical structure problems are described, where the appropriate method is determined by the presence or absence of a third X nucleus (in addition to 1H and 13C) with suitable NMR properties.
Nonlinear instability for the critically dissipative quasi-geostrophic equation

We prove that linear instability implies non-linear instability in the energy norm for the critically dissipative quasi-geostrophic equation.
Trade Routes and Contradictory Spheres of Influence: Movement of Rhyolite Through the Heart of the Western Mojave Desert

AbstractA geochemical study of seven discrete areas within two rhyolitic formations in the Antelope Valley, California, has demonstrated that rhyolite artifacts could be sourced in the western Mojave Desert ( ). Provenance analysis of obsidian and rhyolite artifacts from four Late Prehistoric sites located on the northern and southern edges of the western Mojave Desert suggest direct procurement practices and the presence of a trade network through the Antelope Valley. Less clear is whether evidence for the movement of materials can effectively be used to infer particular cultural territories or specific cultural interactions. Ethnographic work in the Antelope Valley suggests that the areas surrounding each rhyolitic formation, as well as the archaeological sites, may have each been controlled by a different group. The boundaries described by ethnographers may not have accurately reflected the prehistoric territories of groups in the area, as mission contact likely altered regional populations prior to re...
Feasibility of a synchrotron storage ring for neutral polar molecules

Using calculations and mathematical modeling, we demonstrate the feasibility of constructing a synchrotron storage ring for neutral polar molecules. The lattice is a racetrack type 3.6 m in circumference consisting of two 180° arcs, six bunchers, and two long straight sections. Each straight section contains two triplet focusing lenses and space for beam injection and experiments. The design also includes a matched injector and a linear decelerator. Up to 60 bunches can be loaded and simultaneously stored in the ring. The molecules are injected at 90 m/s but the velocity of the circulating beam can be decelerated to 60 m/s after injection. The modeling uses deuterated ammonia (14N2H3) molecules in a weak-field seeking state. A beam that survives 400 turns (15 s), has horizontal and vertical acceptances of 35 and 70 mm mrad, respectively, and an energy acceptance of ±2%.
Effect of massive neutron exposure on the distortion of reactor graphite

Abstract Distortion of reactor-grade graphites was studied at varying neutron exposures ranging up to 16×1021 neutrons/cm2 (nvt) † at temperatures of irradiation ranging from 425 to 800°C. This exposure level corresponds to approximately 100,000 megawatt days per adjacent ton of fuel MWd/At in a graphite-moderated reactor. A conventional-coke graphite, CSF, and two needle-coke graphites, NC-7 and NC-8, were studied. At all temperatures of irradiation the contraction rate of these graphites increased with increasing neutron exposure in the direction parallel to the extrusion axis, and the needle-coke and CSF graphites contracted approximately the same amount. In the transverse direction the graphites contracted at all irradiation temperatures with the exception of NC-7 at 800°C which contracted and then expanded. Volume contractions were derived from the linear contractions.
Apparent measurement errors in "Development of biomechanical response corridors of the thorax to blunt ballistic impacts".

"Development of biomechanical response corridors of the thorax to blunt ballistic impacts" (Bir, C., Viano, D., King, A., 2004, Journal of Biomechanics 37, 73-79.) contains apparent measurement errors. Areas under several force vs. time (Fig. 2) and force vs. deflection curves (Fig.4) differ significantly from the momentum and kinetic energy changes, respectively. These differences violate Newton's second law and the work-energy theorem.
Doubled-cubic Ca2NF

Crystals of dicalcium nitride fluoride, Ca 2 NF, grown from the melt have been characterized by X-ray diffraction and were found to have a cubic (Fd3m) structure. Owing to ordering of N and F atoms along all three cell axes, the cell edge is doubled relative to the rocksalt-type structure reported previously. Residual electron density at an interstitial tetrahedral site was refined as a Frenkel defect of F atoms, giving a final composition of Ca 2 N(F 0.913 ) oct (F 0.087 ) tet .
Impact of virtual channels and adaptive routing on application performance

Research on multiprocessor interconnection networks has primarily focused on wormhole switching, virtual channel flow control, and routing algorithms to enhance their performance. The rationale behind this research is that by alleviating the network latency for high network loads, the overall system performance would improve. Many studies have used synthetic workloads to support this claim. However, such workloads may not necessarily capture the behavior of real applications. In this paper, we have used parallel applications for a closer examination of the network behavior. In particular, the performance benefit from enhancing a 2D mesh with virtual channels (VCs) and a fully adaptive routing algorithm is examined with a set of shared-memory and message passing applications. Execution time and average message latency of shared memory applications are measured using execution-driven simulation and by varying many architectural attributes that affect the network workload. The communication traces of message passing applications, collected on an IBM-SP2, are used to run a trace-driven simulation of the mesh architecture to obtain message latency. Simulation results show that VCs and adaptive routing can reduce the network latency to varying degrees depending on the application. However, these modest benefits do not translate to significant improvements in the overall execution time because the load on the network is not high enough to exploit the advantages of the network enhancements. Moreover, this benefit may be negated if the architectural enhancements increase the network cycle time. Rather, emphasis should be placed on improving the raw network bandwidth and faster network interfaces. Index Terms—Adaptive routing, architectural simulation, interconnection network, mesh network, performance evaluation, virtual channels. E
An Efficient Synthesis of 2-Trimethylsilyl-2-propenal, A Useful Three-Carbon Synthon

Abstract A formal efficient synthesis of 2-trimethylsilyl-2-propenal (2), a potentially useful synthetic reagent, is hereby described. The readily available α-bromovinyltrimethylsilane can be converted into 2-trimethylsilyl-2-propen-1-ol (1) via Grignard formation followed by addition of paraformaldehyde. The alcohol 1 can be oxidized using Jones reagent or PCC to yield the desired aldehyde 2.
Fair Enough? Inviting Inequities in State Health Benefits

Giving states the right to determine their own essential health benefits is politically savvy. But will it mean shoddy health care for some and top-of-the-line health care for others? And what if variations in quality lead to disability, dysfunction, or premature death?
Law of large numbers for superdiffusions: The non-ergodic case

In previous work of D. Turaev, A. Winter and the author, the Law of Large Numbers for the local mass of certain superdiffusions was proved under an ergodicity assumption. In this paper we go beyond ergodicity, that is we consider cases when the scaling for the expectation of the local mass is not purely exponential. Inter alia, we prove the analog of theWatanabe–Biggins LLN for super-Brownian motion.
Structure of partially premixed n-heptane–air counterflow flames

Abstract To avoid the complexities associated with the droplet/vapor transport and nonuniform evaporation processes, a fundamental investigation of liquid fuel combustion in idealized configurations is very useful. An experimental–computational investigation of prevaporized n -heptane nonpremixed and partially premixed flames established in a counterflow burner is described. There is a general agreement between various facets of our nonpremixed flame measurements and the literature data. The partially premixed flames are characterized by a double flame structure. This becomes more distinct as the strain rate decreases and partial premixing increases, which also increases the separation distance between the two reaction zones. The peak partially premixed flame temperature increases with increasing premixing of the fuel stream. The peak CO 2 and H 2 O concentrations are relatively insensitive to partial premixing. The CO and H 2 peak concentrations on the premixed side increase as the fuel-side equivalence ratio decreases. These species are transported to the nonpremixed reaction zone where they oxidize. The C 2 species have peaks in the premixed reaction zone. The concentrations of olefins are ten times larger than those of the corresponding paraffins. The oxidizer is present in partially premixed flames throughout the combustion system and there are no regions characterized by simultaneous high temperature and high fuel concentration. As a result, pyrolysis reactions leading to soot formation are greatly diminished.
Analysis of queue length prediction from probe vehicles problem with bunch arrival headways

This paper discusses the real-time prediction of queue lengths from probe vehicles for the Bunch arrival headways at an isolated intersection for undersaturated conditions. The paper incorporates the bunching effect of the traffic into the evaluation of the accuracy of the predictions as a function of proportion of probe vehicles to entire vehicle population. Formulations are presented for predicting the expected queue length and its variance based on Negative Exponential and Bunched Exponential vehicle headways. Numerical results for both vehicle headway types are documented to show how prediction errors behave by the volume to capacity ratio and probe proportions. It is found that the Poisson arrivals generate conservative confidence intervals and demand higher probe proportions compared to Bunched Exponential headways at the same arrival rate and probe proportion.
A symmetry for the cosmological constant

We study a symmetry, schematically Energy → — Energy, which suppresses matter contributions to the cosmological constant. The requisite negative energy fluctuations are identified with a ``ghost'' copy of the Standard Model. Gravity explicitly, but weakly, violates the symmetry, and naturalness requires General Relativity to break down at short distances with testable consequences. If this breakdown is accompanied by gravitational Lorentz-violation, the decay of flat spacetime by ghost production is acceptably slow. We show that inflation works in our scenario and can lead to the initial conditions required for standard Big Bang cosmology.
A pipelined adaptive lattice filter architecture

The stochastic gradient adaptive lattice filter is pipelined by the application of relaxed look-ahead. This form of look-ahead maintains the functional behavior of the algorithm instead of the input-output mapping and is suitable for pipelining adaptive filters. The sum and product relaxations are employed to pipeline the filter. The hardware complexity of the pipelined filters is the same as for the sequential filter and is independent of the level of pipelining or speedup. Two pipelined architectures along with their convergence analyses are presented to illustrate the tradeoff offered by relaxed look-ahead. Simulation results supporting the conclusions of the convergence analysis are provided. The proposed architectures are then employed to develop a pipelined adaptive differential pulse-code modulation (DPCM) codec for video compression applications. Speedup factors up to 20 are demonstrated via simulations with image data. >
Non-Concentration of Quasimodes for Integrable Systems

We consider the possible concentration in phase space of a sequence of eigenfunctions (or, more generally, a quasimode) of an operator whose principal symbol has completely integrable Hamilton flow...
Enantioselective Organo-SOMO Catalysis : The α-Vinylation of Aldehydes

The first enantioselective organocatalytic α-vinylation of aldehydes has been accomplished. Selective oxidation of chiral enamines, derived from the condensation of aldehydes and a chiral secondary amine catalyst, leads to the production of highly reactive radical cations that exist in an asymmetric environment. These SOMO-activated species undergo direct coupling with readily available potassium organotrifluoroborate salts to yield enantioenriched α-vinyl aldehydes. The described reaction procedure achieves carbon−carbon bond formation in an efficient manner with consistently high levels of enantioinduction and geometrical control for the trans-olefin product. A wide range of both aldehydes and potassium organotrifluoroborate salts, including those typically susceptible to oxidative conditions, are accommodated under the reaction conditions. Results herein further demonstrate the capacity of the SOMO catalysis platform to achieve asymmetric carbon−carbon bond formations that are difficult to access via t...
Caught in a productivity trap: a distributional perspective on gender differences in Malawian agriculture.

In targeting poverty gains, sub-Saharan African governments have emphasized the alleviation of gender differences in agricultural productivity. The empirical studies on the gender gap, however, have frequently used data that were limited regarding geographic and topical coverage, and/or details on intra-household dynamics. The study provides a nationally-representative analysis of the gender gap in Malawi, and decomposes it, for the first time, at the mean and at selected points of the agricultural productivity distribution into (i) a portion driven by gender differences in levels of observable attributes (the endowment effect), and (ii) a portion driven by gender differences in returns to the same set of observables (the structure effect). Sequentially, the authors unpack the relative contributions of different factors towards the gender gap, and suggest future research priorities to inform policy interventions. The authors find that while female-managed plots are, on average, 25 percent less productive, 82 percent of this differential is explained by differences in endowments, mainly due to high-value crop cultivation and levels of household adult male labor inputs. The factors driving the structure effect include child dependency ratio and effectiveness of household adult male labor and inorganic fertilizer. The gender gap increases across the productivity distribution, ranging from 22 percent at the 10th percentile to 37 percent at the 90th percentile. While it is explained predominantly by the endowment effect in the first half of the distribution, the contribution of the structure effect towards the gender gap increases steadily above the median, standing at 34 percent at the 90th percentile.
Mass Distribution and Planet Formation in the Solar Nebula

The surface density profile Σ(r) of the solar nebula protoplanetary disk is a fundamental input to all models of disk processes and evolution. Traditionally it is estimated by spreading out the augmented masses of the planets over the annuli in which the planets orbit today, the so-called minimum-mass solar nebula. Doing so implicitly assumes that the planets completely accreted all planetesimals in their feeding zones, but this assumption has not been tested. Indeed, models of the growth of Uranus and Neptune predict that these planets could not have grown to ~10 M⊕ within the lifetime of the disk, even though they must have, to accrete H/He atmospheres. In this paper we adopt the starting positions of the planets in the "Nice" model of planetary dynamics (Tsiganis and coworkers), in which the solar system started in a much more compact configuration. We derive a surface density profile that is well approximated by the power law Σ(r) = 343(fp/0.5)-1(r/10 AU)-2.168 g cm-2, where fp is the fraction of the solid mass in the form of planetesimals. We show that this profile is inconsistent with a steady state accretion disk but is consistent with a steady state decretion disk that is being photoevaporated. We calculate the growth of planets in the context of this disk model and demonstrate for the first time that all of the giant planets can achieve their isolation masses and begin to accrete H/He atmospheres within the lifetime of the disk. The fit of our inferred Σ(r) to the augmented masses of the planets is excellent (<10%), but only if Uranus and Neptune swtiched places early in the solar system's evolution, a possibility predicted by the Nice model.
On-shell recursion relations for generic theories

We show that on-shell recursion relations hold for tree amplitudes in generic two derivative theories in an arbitrary number of dimensions with multiple particle species and diverse spins. For example, in a gauge theory coupled to scalars and fermions, any amplitude with at least one gluon obeys a recursion relation. In (super)gravity coupled to scalars and fermions, the same holds for any amplitude with at least one graviton. This result pertains to a broad class of theories, including QCD, \( \mathcal{N} = 4 \) SYM, and \( \mathcal{N} = 8 \) supergravity.
The subtleties and intricacies of building a constraint length 15 convolutional decoder

A series of algorithms, circuit designs, and analytical techniques as well as a few tricks are presented. Each is essential to the design, which created a constraint-length-15, 1-Mb/s Viterbi decoder. The focus is the maximum-likelihood decoding of very-long-constraint-length convolutional codes, but many of the concepts will find other applications ranging from extremely fast constraint-length-7 decoders to software simulations of codes with constraint lengths even longer than 15. The constraint-length-15 decoder is now working and will form the basis for the coding system used in the next generation of deep space probes. >
The mysteries of the highest energy cosmic rays

We give a summary of the theoretical attempts to make sense of the observational data concerning the highest energy cosmic rays, E > 3 × 10 19 eV .
The form of U.S. in-kind assistance

Child care and housing programs in the United States are marked by quality homogeneity, restricted eligibility, rationing, and copayments that increase as recipients' income rises. Why? I show that these programs can best be explained as attempts to reduce the child care or housing 'poverty gaps,' subject to constraints that require that recipients be treated quite well. Such constraints are justified when the public is really not sure whether the government is acting generously. Copyright 1999 by Oxford University Press.
Effect of diabetic ketosis on jejunal glutaminase.

The intestine is capable of shifting its major fuel source from glutamine in the fed animal to ketone bodies in the fasted animal. Glutaminase (EC 3.5.1.2), the entry enzyme of glutamine oxidation, was examined for its function as a determinant in the utilization of jejunal fuel during diabetes and fasting. Male Sprague-Dawley rats were made ketotic to varied degrees by either fasting or the induction of diabetes with graded doses of streptozotocin (SZ). Specific activity of glutaminase was decreased in the diabetic animals to 64% (p < 0.05) of controls in the group receiving 110 mg/kg SZ and 82% of controls in the group receiving 65 mg/kg SZ and to 78% (p < 0.05) of controls in the fasted animals. The activity of glutaminase in the small intestine was negatively correlated to the concentration of β-hydroxybutyrate in the plasma (r = −0.97, p < 0.025) and jejunum (r = −0.92, p < 0.05) for the four groups of animals. Specific activity of glutaminase was decreased in all cell types isolated along the villus-crypt axis of the small intestine from diabetic and fasted rats compared with control rats. The quantity of glutaminase-protein was determined by a dot immunobinding assay using an antibody to purified glutaminase. The activity of glutaminase relative to immunoreactive glutaminase-protein was significantly decreased (p < 0.05) to 53% of control values in the 110 mg/kg SZ group, 77% in the 65 mg/kg SZ group, and 70% in the fasted group. These data indicate that an inactivation of glutaminase-protein may play a role in the ability of the intestine to shift its fuel source from glutamine to ketone bodies during diabetes and fasting.
A review of cellulosic biofuel commercial-scale projects in the United States.

In contrast to a few years ago, when cellulosic ethanol via enzymatic hydrolysis was the only widely recognized technology for commercially producing cellulosic biofuels, a diversity of approaches are currently under commercial development. While no commercial-scale (≥20 million gallons per year) cellulosic biofuel facilities are operating at present, at least ten biorefinery projects employing six different pathways are expected to begin operations by 2014. These biorefineries will employ the following pathways: (i) catalytic pyrolysis and hydrotreating to hydrocarbons; (ii) gasification and Fischer-Tropsch synthesis to hydrocarbons; (iii) gasification and methanol-to-gasoline synthesis; (iv) dilute acid hydrolysis, fermentation to acetic acid, and chemical synthesis to ethanol; (v) enzymatic hydrolysis to ethanol; and (vi) consolidated bioprocessing (single-step enzyme production, hydrolysis, and fermentation) to ethanol. This review provides an overview of the six pathway technologies, comprehensive descriptions of each of the ten biorefinery projects, and a discussion of the current direction of cellulosic biofuel commercialization efforts and its implications for the revised Renewable Fuel Standard. © 2013 Society of Chemical Industry and John Wiley & Sons Ltd
The fundamental properties of the neutron

In addition to providing a probe of great power in condensed matter and nuclear research, the neutron itself is the object of a considerable research effort. The study of the properties of the neutron can shed light on a variety of questions in particle physics, cosmology, astrophysics, and nuclear physics. A summary of the neutron properties is given along with the methods used for their determination and their theoretical implications.
Reversing how to think about ambiguous figure reversals: Spontaneous alternating by uninformed observers

Ambiguous figures are a special class of images that can give rise to multiple interpretations. Traditionally, switching between the possible interpretations of an ambiguous figure, or reversing one's interpretation, has been attributed either to top-down or to bottom-up processes (eg attributed to having knowledge of the nature of the ambiguity, or to a form of neuronal fatigue). Here we present evidence that is incompatible with both forms of explanations. Observers aged 5–9 years can reverse ambiguous figures when uninformed about the ambiguity, negating purely top-down explanations. Further, those children who make these ‘spontaneous’ reversals are more likely to succeed on a high-order theory-of-mind task, negating purely bottom-up explanations.
Faster magnet sorting with a threshold acceptance algorithm

We introduce here a new technique for sorting magnets to minimize the field errors in permanent magnet insertion devices. Simulated annealing has been used in this role, but we find the technique of threshold acceptance produces results of equal quality in less computer time. Threshold accepting would be of special value in designing very long insertion devices, such as long free electron lasers (FELs). Our application of threshold acceptance to magnet sorting showed that it converged to equivalently low values of the cost function, but that it converged significantly faster. We present typical cases showing time to convergence for various error tolerances, magnet numbers, and temperature schedules.
Chandler in a Larger Frame: Markets, Transaction Costs, and Organizational Form in History

In 1977, when Alfred D. Chandler's pathbreaking book The Visible Hand appeared, the large, vertically integrated, “Chandlerian” corporation had dominated the organizational landscape for nearly a century. In some interpretations, possibly including Chandler's own, The Visible Hand and subsequent works constitute a triumphalist account of the rise of that organizational form: the large, vertically integrated firm arose and prospered because of its inherent superiority, in all times and places, to more decentralized, market-oriented production arrangements. A quarter century later, however, the Chandlerian firm no longer dominates the landscape. It is under siege from a panoply of decentralized and market-like forms that often resemble some of the “inferior” nineteenth-century structures that the managerial enterprise had replaced.
A revised structure for the marine bromoindole derivative citorellamine

Abstract The structure of citorellamine has been revised and confirmed by total synthesis to be 2 instead of 1 .
BULK AND BOUNDARY S-MATRICES FOR THE SU(N) CHAIN

Abstract We consider both closed and open integrable antiferromagnetic chains constructed with the SU ( N )-invariant R -matrix. For the closed chain, we extend the analyses of Sutherland and Kulish — Reshetikhin by considering also complex “string” solutions of the Bethe ansatz equations. Such solutions are essential to describe general multiparticle excited states. We also explicitly determine the SU ( N ) quantum numbers of the states. In particular, the model has particle-like excitations in the fundamental representations [ k ] of SU ( N ), with k = 1, …, N − 1. We directly compute the complete two-particle S-matrices for the cases [1] ⊗ [1] and [1] ⊗ [ N − 1 ]. For the open chain with diagonal boundary fields, we show that the transfer matrix has the symmetry SU ( l ) × SU ( N − l ) × U (1), as well as a new “duality” symmetry which maps l → N − l . With the help of these symmetries, we compute by means of the Bethe ansatz for particles of types [1] and [ N − 1 ] the corresponding boundary S-matrices.
Stability of Si–O–F low-K dielectrics: attack by water molecules as function of near-neighbor Si–F bonding arrangements

Abstract Ab initio configuration interaction calculations have been previously used to account for the relatively large decreases (∼20%) in the static dielectric constant of Si–O–F alloys with for F alloy atom concentrations of ∼10 at.%. This study addresses the stability of these alloy films with respect to attack of Si–F bonds by water molecules. The present calculations show that the reactions of isolated Si–F with water molecules differ from the reactions of nearest-neighbor Si–F groups with water molecules. For example, hydrogen attachment of water to two Si–F groups has a bonding energy of ∼0.5 eV, whereas attachment to an isolated Si–F group has an attachment energy smaller by more than a factor of 6. Combining these calculations for interactions with H 2 O with a statistical model of bonding in the alloy films, an upper limit for chemically stable F-corporation has been determined to be ∼11 at.% F, which corresponds to the static dielectric constant of ∼3.3.
Local gradient estimate for p-harmonic functions on Riemannian manifolds

For positive p-harmonic functions on Riemannian mani- folds, we derive a gradient estimate and Harnack inequality with con- stants depending only on the lower bound of the Ricci curvature, the dimension n, p and the radius of the ball on which the function is de- fined. Our approach is based on a careful application of the Moser iter- ation technique and is different from Cheng-Yau's method (2) employed by Kostchwar and Ni (5), in which a gradient estimate for positive p- harmonic functions is derived under the assumption that the sectional curvature is bounded from below.