cssi/SciSciGPT-SciSciNet huggingface dataset:
Pain description by nurses and physicians

Abstract The purpose of this study was to determine if nurses and physicians selected similar words to describe painlike experiences and to determine how they rated terms commonly used to describe pain. Thirty-seven registered nurses and 21 physicians comprised the sample. The Visual Analogue Scale (VAS) was used to measure the terms ache , hurt , and pain . The McGill Pain Questionnaire (MPQ) provided a list of word descriptors from which the subjects selected words that best represented the terms ache, hurt, and pain. There was no significant difference between the nurses and physicians in the mean rating of any of the pain terms on the VAS. The nurses and physicians chose very similar word descriptors from the MPQ to discriminate one pain term from another. These findings suggest that nurses and physicians may have a common understanding of the language used to describe painlike experiences.
Fluorescence Anisotropy Controlled by Light Quenching

We demonstrated that fluorescence anisotropy can be effectively decreased or increased in the presence of light quenching, depending on relative polarizations of excitation and quenching pulses. For parallel light quenching, anisotropy decreases to 0.103 and z-axis symmetry is preserved. In the presence of perpendicular light quenching, the steady-state anisotropy of a pyridine-2-glycerol solution increases from 0.368 for an unquenched sample to 0.484 for a quenched one. We show that the angular distribution of transition moments loses z-axis symmetry in the presence of perpendicular light quenching. In these cases we used more general definitions of anisotropy. Induced by light quenching, anisotropy can be applied in both steady-state and time-resolved measurements. In particular, the systems with low or no anisotropy can be investigated with the proposed technique.
First order conditions for semidefinite representations of convex sets defined by rational or singular polynomials

A set is called semidefinite representable or semidefinite programming (SDP) representable if it equals the projection of a higher dimensional set which is defined by some Linear Matrix Inequality (LMI). This paper discusses the semidefinite representability conditions for convex sets of the form $${S_{\mathcal {D}}(f) =\{x\in \mathcal {D} : f(x) \geq 0 \}}$$. Here, $${\mathcal {D}=\{x\in \mathbb {R}^n : g_1(x) \geq 0, \ldots, g_m(x) \geq 0 \}}$$ is a convex domain defined by some “nice” concave polynomials g i (x) (they satisfy certain concavity certificates), and f(x) is a polynomial or rational function. When f(x) is concave over $${\mathcal {D}}$$, we prove that $${S_{\mathcal {D}}(f) }$$ has some explicit semidefinite representations under certain conditions called preordering concavity or q-module concavity, which are based on the Positivstellensatz certificates for the first order concavity criteria:$$f(u) + \nabla f(u)^T(x-u) -f(x) \geq 0, \quad \forall \, x, u \in \mathcal {D}.$$ When f(x) is a polynomial or rational function having singularities on the boundary of $${S_{\mathcal {D}}(f)}$$, a perspective transformation is introduced to find some explicit semidefinite representations for $${S_{\mathcal {D}}(f)}$$ under certain conditions. In the special case n = 2, if the Laurent expansion of f(x) around one singular point has only two consecutive homogeneous parts, we show that $${S_{\mathcal {D}}(f)}$$ always admits an explicitly constructible semidefinite representation.
Evaluation of magnetic helicity in homogeneous turbulence

A technique for the measurement of magnetic helicity from values of the two point magnetic field correlation matrix under the assumption of spatial homogeneity is presented. Knowledge of a single scalar function of space, derivable from the correlation matrix, suffices to determine the magnetic helicity. The technique is illustrated by reporting the first measurement of the magnetic helicity of the solar wind.
THE WHIQII SURVEY: METALLICITIES AND SPECTROSCOPIC PROPERTIES OF LUMINOUS COMPACT BLUE GALAXIES

As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift (0.4 ≲ z ≲ 0.8) galaxies with blue colors that appear physically compact on the sky. The sample includes 15 true Luminous Compact Blue Galaxies (LCBGs) and an additional 27 slightly less extreme emission-line systems. These galaxies represent a highly evolving class that may play an important role in the decline of star formation since z ~ 1, but their exact nature and evolutionary pathways remain a mystery. Here, we use emission lines to determine metallicities and ionization parameters, constraining their intrinsic properties and state of star formation. Some LCBG metallicities are consistent with a "bursting dwarf" scenario, while a substantial fraction of others are not, further confirming that LCBGs are a highly heterogeneous population but are broadly consistent with the intermediate redshift field. In agreement with previous studies, we observe overall evolution in the luminosity-metallicity relation at intermediate redshift. Our sample, and particularly the LCBGs, occupies a region in the empirical R_(23)-O_(32) plane that differs from luminous local galaxies and is more consistent with dwarf irregulars at the present epoch, suggesting that cosmic "downsizing" is observable in even the most fundamental parameters that describe star formation. These properties for our sample are also generally consistent with lying between local galaxies and those at high redshift, as expected by this scenario. Surprisingly, our sample exhibits no detectable correlation between compactness and metallicity, strongly suggesting that at these epochs of rapid star formation, the morphology of compact star-forming galaxies is largely transient.
Core-Collapse Simulations of Rotating Stars

We present the results from a series of two-dimensional core-collapse simulations using a rotating progenitor star. We find that the convection in these simulations is less vigorous because (1) rotation weakens the core bounce that seeds the neutrino-driven convection and (2) the angular momentum profile in the rotating core stabilizes against convection. The limited convection leads to explosions that occur later and are weaker than the explosions produced from the collapse of nonrotating cores. However, because the convection is constrained to the polar regions, when the explosion occurs it is stronger along the polar axis. This asymmetric explosion may explain the polarization measurements of core-collapse supernovae. These asymmetries also provide a natural mechanism to mix the products of nucleosynthesis out into the helium and hydrogen layers of the star. We also discuss the role the collapse of these rotating stars plays in the generation of magnetic fields and neutron star kicks. Given a range of progenitor rotation periods, we predict a range of supernova energies for the same progenitor mass. The critical mass for black hole formation also depends upon the rotation speed of the progenitor.
The relation between the waveguide and overlap implementations of Kaplan's domain wall fermions

Abstract Recently, Narayanan and Neuberger proposed that the fermion determinant for a lattice chiral gauge theory be defined by an overlap formula. The motivation for that formula comes from Kaplan's five-dimensional lattice domain wall fermions. In the case that the target continuum theory contains 4 n chiral families, we show that the effective action defined by overlap formula is identical to the effective action of a modified waveguide model that has extra bosonic ghost fields. This raises serious questions about the viability of the overlap formula for defining chiral gauge theories on the lattice.
Solitons in the Camassa-Holm shallow water equation

Abstract We study the class of shallow water equations of Camassa and Hold derived from the Lagrangian, L = ∫ [ 1 2 ( ϕ x x x x − ϕ x ) ϕ t − 1 2 ( ϕ x ) 3 − 1 2 ϕ x ( ϕ x x ) 2 − 1 2 κ ϕ x 2 ] d x , using a variational approach. This class contains “peakons” for k=0, which are solitons whose peaks have a discontinuous first derivative. We derive approximate solitary wave solutions to this class of equations using trial variational functions of the form u(x,t)=ψx=A(t) expt[-β(t)|x-q(t)|2n] in a time-dependent variational calculation. For the case k=0 we obtain the exact answer. For k≠0 we obtain the optimal variational solution. For the variational solution having fixed conserved momentum P=∝1/2 (u2+ux2), dx, the soliton's scaled amplitude, A/P1/2, and velocity, q ˙ / P 1 / 2 , depend only on the variable z = κ / P . We prove that these scaling relations are true for the exact soliton solutions to the Camassa-Holm equation.
Simulated plasma facing component measurements for an in situ surface diagnostic on Alcator C-Mod.

The ideal in situ plasma facing component (PFC) diagnostic for magnetic fusion devices would perform surface element and isotope composition measurements on a shot-to-shot (∼10 min) time scale with ∼1 μm depth and ∼1 cm spatial resolution over large areas of PFCs. To this end, the experimental adaptation of the customary laboratory surface diagnostic—nuclear scattering of MeV ions—to the Alcator C-Mod tokamak is being guided by ACRONYM, a Geant4 synthetic diagnostic. The diagnostic technique and ACRONYM are described, and synthetic measurements of film thickness for boron-coated PFCs are presented.
Effect of sulfur on the interaction of nickel with ethylene

Abstract Although it is well known that sulfur acts as a poison for many nickel catalyzed reactions, it is now being recognized that certain benefits can be derived from following a partial and well controlled sulfidation treatment of the metal. The current investigation was undertaken to ascertain the influence of sulfur on the formation of carbon filaments arising from the nickel catalyzed decomposition of ethylene/hydrogen mixtures. We have determined not only variations in the concentrations of the gaseous products, but also the amount and characteristics of the solid carbon deposit, as a function of several parameters. It is suggested that the observed enhancement in carbon filament growth following pre-treatment of nickel in low levels of H 2 S (4–50 ppm) is related to a reconstruction of the metal surface. The inhibition of catalytic activity resulting from a more severe pre-treatment in H 2 S is ascribed to the formation of a 2-D or 3-D bulk sulfide. Pre-adsorption of sulfur on nickel induced some major perturbations in the morphological characteristics of the filamentous carbon deposit, which are generated in the form of regularly coiled structures. In contrast, those produced from unadulterated metal particles were found to be relatively straight. This change in growth mode indicates that sulfur is modifying the diffusion characteristics of carbon species through the catalyst particle.
Complex Rational Numbers in Quantum mechanics

A binary representation of complex rational numbers and their arithmetic is described that is not based on qubits. It takes account of the fact that 0s in a qubit string do not contribute to the value of a number. They serve only as place holders. The representation is based on the distribution of four types of systems, corresponding to +1, -1, +i, -i, along an integer lattice. Complex rational numbers correspond to arbitrary products of four types of creation operators acting on the vacuum state. An occupation number representation is given for both bosons and fermions.
On the Origins of Eccentric Close-In Planets

Strong tidal interaction with the central star can circularize the orbits of close-in planets. With the standard tidal quality factor Q of our solar system, estimated circularization times for close-in extrasolar planets are typically shorter than the ages of the host stars. While most extrasolar planets with orbital radii -->a 0.1 AU indeed have circular orbits, some close-in planets with substantial orbital eccentricities have recently been discovered. This new class of eccentric close-in planets implies that either their tidal Q factor is considerably higher, or circularization is prevented by an external perturbation. Here we constrain the tidal Q factor for transiting extrasolar planets by comparing their circularization times with accurately determined stellar ages. Using estimated secular perturbation timescales, we also provide constraints on the properties of hypothetical second planets exterior to the known ones.
Looking in the mirror: Comparing INGO networks across issue areas

International Relations scholarship has begun to focus a great deal of attention on social networks and their influence on political outcomes. In this paper, we contribute to this effort by examining the network relationships of international non-governmental organizations (INGOs) across four issues areas: the environment, health, human rights, and development. Using originally coded data on over 4000 INGOs, we find that the characteristics of network relations across the four areas are in fact quite different. Further, we find that these differences are driven in part by the characteristics of the INGOs, including whether they are located in the global North or South and their ties to intergovernmental organizations. Finally, we highlight the crucial “bridge” role of organizations that focus on a “hybrid” of multiple issue-areas within the overall network.
A review of the stroke volume response to upright exercise in healthy subjects

Traditionally, it has been accepted that, during incremental exercise, stroke volume plateaus at 40% of Vo(2)max. However, recent research has documented that stroke volume progressively increases to Vo(2)max in both trained and untrained subjects. The stroke volume response to incremental exercise to Vo(2)max may be influenced by training status, age, and sex. For endurance trained subjects, the proposed mechanisms for the progressive increase in stroke volume to Vo(2)max are enhanced diastolic filling, enhanced contractility, larger blood volume, and decreased cardiac afterload. For untrained subjects, it has been proposed that continued increases in stroke volume may result from a naturally occurring high blood volume. However, additional research is needed to evaluate the importance of blood volume, or other mechanisms, that influence the stroke volume response to exercise in untrained subjects.
Asymmetric petasis reactions catalyzed by chiral biphenols.

Chiral biphenols catalyze the enantioselective Petasis reaction of alkenyl boronates, secondary amines, and ethyl glyoxylate. The reaction requires the use of 15 mol % of (S)-VAPOL as the catalyst, alkenyl boronates as nucleophiles, ethyl glyoxylate as the aldehyde component, and 3 A molecular sieves as an additive. The chiral α-amino ester products are obtained in good yields (71−92%) and high enantiomeric ratios (89:11−98:2). Mechanistic investigations indicate single ligand exchange of acyclic boronate with VAPOL and tetracoordinate boronate intermediates.
Inefficient Redistribution and Inefficient Redistributive Politics

This paper examines the effect of inefficient redistribution in Myerson’s (American Political Science Review 87:856–869, 1993) model of redistributive politics. Regardless of the absolute levels of the efficiency of political parties’ transfers to different voter segments, parties have incentive to (stochastically) shift resources away from voter segments with large relative efficiency gaps between the two parties’ transfers towards voter segments with smaller relative efficiency gaps. Because of this dependence on relative, and not absolute, levels of efficiency, the parties’ optimal strategies may lead to large discrepancies between the sum of the budgetary transfers and the sum of the effective transfers.
More on advice on structuring compilers and proving them correct

Abstract Following Lockwood Morris, a method for algebraically structuring a compiler and proving it correct is described. An example language with block structure and side-effects is presented. This determines an initial many-sorted algebra L which is the ‘abstract syntax’ of the example language. Then the semantics of L is completely determined by describing a semantic algebra M ‘similar’ to L . In particular, initiality of L ensures that there is a unique homomorphism Lsem: L →> M . This is algebraically structuring the semantic definition of the language. A category of flow-charts over a stack machine is used as a target language for the purposes of compilation. The semantics of the flow charts (Tsem: T → S ) is also algebraically determined given interpretations of the primitive operations on the stack and store. The homomorphism comp: L → T is the compiler which is also uniquely determined by presenting an algebra T of flowcharts similar to L . This is algebraically structuring the compiler. Finally a function encode: M → S describes source meanings in terms of target meanings. The proof that the compiler is correct reduces to a proof that encode: M → S is a homomorphism; then both comp ∘ Tsem and Lsem ∘ encode are homomorphisms from L to S and they must be equal because there is only one homomorphism from L to S .
The best keying protocol for sensor networks

Abstract Many sensor networks (especially networks of mobile sensors or networks that are deployed to monitor crisis situations) are deployed in an arbitrary and unplanned fashion. Thus, any sensor in such a network can end up being adjacent to any other sensor in the network. To secure the communications between every pair of adjacent sensors in such a network, each sensor x in the network needs to store n − 1 symmetric keys that sensor x shares with all the other sensors, where n is an upper bound on the number of sensors in the network. This storage requirement of the keying protocol is rather severe, especially when n is large and the available storage in each sensor is modest. Earlier efforts to redesign this keying protocol and reduce the number of keys to be stored in each sensor have produced protocols that are vulnerable to impersonation, eavesdropping, and collusion attacks. In this paper, we present a fully secure keying protocol where each sensor needs to store ( n + 1 ) / 2 keys, which is much less than the n − 1 keys that need to be stored in each sensor in the original keying protocol. We also show that in any fully secure keying protocol, each sensor needs to store at least ( n − 1 ) / 2 keys.
Can Miracles Lead to Crises? The Role of Optimism in Emerging Markets Crises

Emerging market financial crises are abrupt and dramatic usually occurring after a precrisis bonanza. This paper develops an equilibrium asset pricing model with informational frictions in which crisis itself is a consequence of the investor optimism in the period preceding the crisis. If preceded by a sequence of positive signals, a small, negative noise shock can trigger a downward adjustment in investors' beliefs, asset prices, and consumption. The magnitude of this downward adjustment increases with the level of optimism attained prior to the negative signal. Moreover, with informational frictions, asset prices display persistent effects in response to transitory shocks.
Total Syntheses of Kapakahines E and F

This article describes the synthesis of kapakahines E and F, along with what we believe to be a general method for the total synthesis of the kapakahine family of marine natural products. The method utilizes a unique heterodimerization reaction between bromopyrroloindolines and indole nucleophiles, a novel pyrroloindoline-to-α-carboline rearrangement, and a Negishi coupling reaction of C(3)-iodoindoles.
Viscosity Effects on the Propagation of Acoustic Transients

The propagation of an impulsive excitation applied at the origin of a lossy viscous medium is studied by operational techniques as the excitation advances through the medium. The solution of the governing partial differential equation (PDE) for such transient propagation problems has been elusive. Such solution is found as an infinite sum of properly weighted successive integrals of the complementary error function, and it is quantitatively examined here using a one-dimensional model in space and time. As expected, as the transient advances through space, its amplitude decreases, and its width broadens. Such is the damping effect of viscosity that one would anticipate from elementary considerations in related disciplines such as electrodynamics. Such is also the smoothing-out effect of dispersion. We also obtain an approximate solution of the present boundary-initial value problem based on the method of steepest descents. This approximation agrees with the first term of the complete analytic solution given here. The pertinent dispersion relation associated with the governing parabolic PDE is shown to impose a restrictive condition on the allowable values of the propagation speed and the kinematic viscosity coefficient, thus assuring that propagation with attenuation does take place. Various numerical results illustrate and quantitatively describe the propagation of the transient pulse in several nondimensional graphs.
A Wavelet Monte Carlo Method for Turbulent Diffusion with Many Spatial Scales

A new algorithm is developed here for Monte Carlo simulation of turbulent diffusion with random velocity fields having a power law spatial spectrum, arbitrarily many statistical scales, long range correlations, and infrared divergence. This algorithm uses an expansion of the moving average representation of a Gaussian random field via a specific orthonormal basis which exploits the scaling behavior of the random field and yields a compact representation of the field despite infrared divergence. The orthonormal basis involves a family of wavelets due to Alpert and Rokhlin and the vanishing of a large number of moments for this basis (order 3 or 4) is crucial for compact representation of the statistical velocity field. The authors also develop a rigorous practical a priori energy criterion for truncation of the wavelet expansion; furthermore, for moment cancellations with orders 3 or 4 and a fixed energy tolerance, the number of Gaussian random basis elements needed by the method is sublinear in the exponent m, where 1 < |x| < 2m denotes the range of active velocity scales. The algorithm developed here has remarkably low variance as regards sampling errors. For example, for the infrared divergent velocity spectrum corresponding to the Kolmogoroff spectrum in an exactly solvable model, the velocity structure function is simulated accurately for separation distances over more than five decades with only 792 random basis elements and 100 ensemble realizations; with this same singular spectrum in the model problem, the pair dispersion statistic for the passive scalar can be determined within errors of 3% throughout over five decades of pair separation distance with only 792 random elements, 1000 realizations, and a few hours calculation on a workstation. All of the computational algorithms and results are presented for a nontrivial exactly solvable model and are described within a mathematical framework of error analysis where analytic, sampling, and discretization errors are treated separately.
Forecasting Lightning Threat Using Cloud-Resolving Model Simulations

Two new approaches are proposed and developed for making time and space dependent, quantitative short-term forecasts of lightning threat, and a blend of these approaches is devised that capitalizes on the strengths of each. The new methods are distinctive in that they are based entirely on the ice-phase hydrometeor fields generated by regional cloud-resolving numerical simulations, such as those produced by the WRF model. These methods are justified by established observational evidence linking aspects of the precipitating ice hydrometeor fields to total flash rates. The methods are straightforward and easy to implement, and offer an effective near-term alternative to the incorporation of complex and costly cloud electrification schemes into numerical models. One method is based on upward fluxes of precipitating ice hydrometeors in the mixed phase region at the-15 C level, while the second method is based on the vertically integrated amounts of ice hydrometeors in each model grid column. Each method can be calibrated by comparing domain-wide statistics of the peak values of simulated flash rate proxy fields against domain-wide peak total lightning flash rate density data from observations. Tests show that the first method is able to capture much of the temporal variability of the lightning threat, while the second method does a better job of depicting the areal coverage of the threat. Our blended solution is designed to retain most of the temporal sensitivity of the first method, while adding the improved spatial coverage of the second. Exploratory tests for selected North Alabama cases show that, because WRF can distinguish the general character of most convective events, our methods show promise as a means of generating quantitatively realistic fields of lightning threat. However, because the models tend to have more difficulty in predicting the instantaneous placement of storms, forecasts of the detailed location of the lightning threat based on single simulations can be in error. Although these model shortcomings presently limit the precision of lightning threat forecasts from individual runs of current generation models,the techniques proposed herein should continue to be applicable as newer and more accurate physically-based model versions, physical parameterizations, initialization techniques and ensembles of forecasts become available.
On the avalanche-finiteness of Abelian Sandpiles

Abstract We prove a necessary and sufficient condition for an Abelian Sandpile Model (ASM) to be avalanche-finite, namely: all unstable states of the system can be brought back to stability in finite number of topplings. The method is also computationally feasible since it involves no greater than O(N3) arithmetic computations where N is the total number of sites of the system.
Synthesis of (-)-Hamigeran B

The synthesis of (−)-hamigeran B has been achieved, based on a new approach to cyclopentane construction, the rhodium-mediated intramolecular C−H insertion of α-aryl−α-diazoketones. The endo-isopropyl group was installed by selective hydrogenation of a cyclopropylidene substituent.
Studying and Modeling the Connection between People's Preferences and Content Sharing

People regularly share items using online social media. However, people's decisions around sharing---who shares what to whom and why---are not well understood. We present a user study involving 87 pairs of Facebook users to understand how people make their sharing decisions. We find that even when sharing to a specific individual, people's own preference for an item (individuation) dominates over the recipient's preferences (altruism). People's open-ended responses about how they share, however, indicate that they do try to personalize shares based on the recipient. To explain these contrasting results, we propose a novel process model of sharing that takes into account people's preferences and the salience of an item. We also present encouraging results for a sharing prediction model that incorporates both the senders' and the recipients' preferences. These results suggest improvements to both algorithms that support sharing in social media and to information diffusion models.
Palladium catalyzed activation of borane–amine adducts: rate enhancement of amine–borane methanolysis in the reduction of nitrobenzenes to anilines

Abstract Hydrolytically stable borane–amines can be activated in situ through palladium catalysis and perform reductions not possible otherwise. Hence, borane–trimethylamine is an efficient hydrogen-transfer reagent for the open vessel reduction of nitroaryls to anilines. Likewise, the palladium catalyzed methanolysis/decomplexation of stable borane–amine adducts is accelerated by the action of nitrobenzene.
Technological Change as Reflected in Hotel Property Prices

This paper investigates the effects of age on the sale prices of hotel real estate. Value erosion of commercial property due to the passage of time may be offset by renovation, although substantial follow-on investment usually occurs several years following construction. Obsolescence produces value losses during the post-construction period prior to new investment that result from technological change (Colwell & Ramsland, Journal of Real Estate Finance and Economics, 8(1), 47–63, 2003). A hedonic model is specified to allow age to measure the effects of obsolescence in hotel prices. Although the long-run obsolescence rate for hotel properties of 1.93%/year aligns closely with the rate estimated elsewhere for retail properties, the path of obsolescence through time shows some marked departures. Contrary to the theory and the empirical results from the retail real estate market, hotel prices do not reveal much more obsolescence in the years immediately following construction than later. Also, the age and sale price relation turns positive nearing the third decade of the lives of hotels indicating a vintage effect. Thus, a V-shaped obsolescence function emerges that either may be explained by a fixed-cost renovation expenditure function or a vintage effect produced by the demand for surviving assets. A series of tests of hotel brand-specific obsolescence rates reveals considerable variation in these rates among seasoned properties, perhaps an indication of a convex renovation expenditure function and sequential follow-on investment.
An efficient oxidative dearomatization–radical cyclization approach to symmetrically substituted bicyclic guttiferone natural products

Detailed in this communication is an efficient synthetic approach towards the guttiferone family of natural products. Oxidatively unraveling a para-quinone monoketal followed by consecutive 5-exo radical cyclizations provides the bicyclic core. An additional strength of this approach is a late stage asymmetric desymmetrization of an advanced symmetric intermediate.
Faddeev-Jackiw approach to hidden symmetries

Abstract The study of hidden symmetries within Dirac′s formalism does not possess a systematic procedure due to the lack of first-class constraints to act as symmetry generators. On the other hand, in the Faddeev-Jackiw approach, gauge and reparametrization symmetries are generated by the null eigenvectors of the sympletic matrix and not by constraints, suggesting the possibility of dealing systematically with hidden symmetries throughout this formalism. It is shown in this paper that indeed hidden symmetries of noninvariant or gauge fixed systems are equally well described by null eigenvectors of the sympletic matrix, just as the explicit invariances. The Faddeev-Jackiw approach therefore provide a systematic algorithm for treating all sorts of symmetries in an unified way. This technique is illustrated here by the SL(2,R) affine Lie algebra of the 2D induced gravity proposed by Polyakov, which is a hidden symmetry in the canonical approach of constrained systems via Dirac′s method, after conformal and reparametrization invariances have been fixed.
Binary rule encoding schemes: a study using the compact classifier system

Several binary rule encoding schemes have been proposed for Pittsburgh-style classifier systems. This paper focus on the analysis of how rule encoding may bias the scalability of learning maximally general and accurate rules by classifier systems. The theoretical analysis of maximally general and accurate rules using two different binary rule encoding schemes showed some theoretical results with clear implications to the scalability of any genetic-based machine learning system that uses the studied encoding schemes. Such results are clearly relevant since one of the binary representations studied is widely used on Pittsburgh-style classifier systems, and shows an exponential shrink of the useful rules available as the problem size increases.
Gamma-ray tracking: Utilizing new concepts in the detection of gamma-radiation

Gamma-ray tracking in a closed array of highly segmented HPGe detectors is a new concept for the detection of γ-radiation. Each of the interacting γ-rays is identified and separated by measuring the energies and positions of individual interactions and by applying tracking algorithms to reconstruct the scattering sequences, even if many γ-rays hit the array at the same time. The three-dimensional position and the energy of interactions are determined by using two-dimensionally segmented Ge detectors along with pulse-shape analysis of the signals. Such a detector will have new and much improved capabilities compared to current γ-ray spectrometer. One implementation of this concept, called GRETA (Gamma-Ray Energy Tracking Array), is currently being under development at LBNL.
A process calculus for Mobile Ad Hoc Networks

We present the @w-calculus, a process calculus for formally modeling and reasoning about Mobile Ad Hoc Wireless Networks (MANETs) and their protocols. The @w-calculus naturally captures essential characteristics of MANETs, including the ability of a MANET node to broadcast a message to any other node within its physical transmission range (and no others), and to move in and out of the transmission range of other nodes in the network. A key feature of the @w-calculus is the separation of a node's communication and computational behavior, described by an @w-process, from the description of its physical transmission range, referred to as an @w-process interface. Our main technical results are as follows. We give a formal operational semantics of the @w-calculus in terms of labeled transition systems and show that the state reachability problem is decidable for finite-control @w-processes. We also prove that the @w-calculus is a conservative extension of the @p-calculus, and that late bisimulation equivalence (appropriately lifted from the @p-calculus to the @w-calculus) is a congruence. Congruence results are also established for a weak version of late bisimulation equivalence, which abstracts away from two types of internal actions: @t-actions, as in the @p-calculus, and @m-actions, signaling node movement. We additionally define a symbolic semantics for the @w-calculus extended with the mismatch operator, along with a corresponding notion of symbolic bisimulation equivalence, and establish congruence results for this extension as well. Finally, we illustrate the practical utility of the calculus by developing and analyzing formal models of a leader election protocol for MANETs and the AODV routing protocol.
Rethinking the term “pi-stacking”

It has become common to reference “pi-stacking” forces or “pi–pi interactions” when describing the interactions between neighbouring aromatic rings. Here, we review experimental and theoretical literature across several fields and conclude that the terms “pi-stacking” and “pi–pi interactions” do not accurately describe the forces that drive association between aromatic molecules of the types most commonly studied in chemistry or biology laboratories. We therefore propose that these terms are misleading and should no longer be used. Even without these terms, electrostatic considerations relating to polarized pi systems, as described by Hunter and Sanders, have provided a good qualitative starting place for predicting and understanding the interactions between aromatics for almost two decades. More recent work, however, is revealing that direct electrostatic interactions between polarized atoms of substituents as well as solvation/desolvation effects in strongly interacting solvents must also be considered and even dominate in many circumstances.
Phase and coherence singularities generated by the interference of partially coherent fields

Phase singularities of both the wavefield and correlation function, generated by partially coherent fields emerging from pinholes in an opaque screen, were numerically investigated. A new type of mixed field/correlation singularity was found to occur.
Some questions for the information society

Abstract A set of broad questions is offered, as well as some brief and tentative answers, in the hope that this initial inventory will stimulate a better list, continuously updated and addressed in greater depth. Will we live in an Information Society? Not necessarily, as realities, perceptions, or fashions change. Will we experience a communications revolution? Probably, but we have yet to fully consider the multiple impacts of a revolution that has yet to run its course. Will we communicate better? Little attention has been given to this question; overall improvements seem likely in work, commerce, health, and entertainment, but potential benefits seem problematic in education, in politics, between groups, and within families. Will our lives be better? Again quite uncertain, although there will surely be winners and losers. Who has to learn what? A new standard of literacy will probably be demanded for our underdeveloped Information Society. Who will address these questions? Everyone and no one, as ind...
Stereospecific synthesis of 2-thiophosphatidylcholines; A new class of biologically active phospholipid analogues

Abstract A new stereospecific synthesis of biologically active sn -2-thiophosphatidylcholines is reported.
A Bivariate Chromatic Polynomial for Signed Graphs

We study Dohmen---Ponitz---Tittmann's bivariate chromatic polynomial $$c_\Gamma (k,l)$$cΓ(k,l) which counts all $$(k+l)$$(k+l)-colorings of a graph $$\Gamma $$Γ such that adjacent vertices get different colors if they are $$\le k$$≤k. Our first contribution is an extension of $$c_\Gamma (k,l)$$cΓ(k,l) to signed graphs, for which we obtain an inclusion---exclusion formula and several special evaluations giving rise, e.g., to polynomials that encode balanced subgraphs. Our second goal is to derive combinatorial reciprocity theorems for $$c_\Gamma (k,l)$$cΓ(k,l) and its signed-graph analogues, reminiscent of Stanley's reciprocity theorem linking chromatic polynomials to acyclic orientations.
QUARK ORBITAL ANGULAR MOMENTUM IN THE BARYON

Analytical and numerical results, for the orbital and spin content carried by different quark flavors in the baryons, are given in the chiral quark model with symmetry breaking. The reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the proton as a function of the partition factor κ and the chiral splitting probability a is shown. The cancellation between the spin and orbital contributions in the spin sum rule and in the baryon magnetic moments is discussed.
Utilities, preferences, and substantive goods

People’s utility levels are meant to be measures of their well-being. Early utilitarians defined them in terms of people’s happiness. Modern economics defines them in terms of people’s actual preferences. But in ethics they have to be defined in terms of people’s informed preferences. I shall discuss the relationship between people’s desires and preferences, and that between their reasoned and unreasoned preferences. I shall argue that people’s basic desires are much the same, whereas their preferences are often very different. Finally, I shall argue, contrary to Scanlon’s theory, that the things that are good for us are beneficial to us ultimately because they satisfy our biological and psychological needs and our personal interests.
Spectral methods for multi-dimensional diffusion problems

Numerical calculations of diffusion processes in complex geometries in multi-dimensions is of current interest in many applications involving the solution of the coupled equations of radiation transport or thermal conduction, as well as in applications involving unstable hydrodynamic flows. The application of pseudospectral techniques to the implicit solution of the diffusion equation in a distorted two-dimensional grid for both linear and nonlinear problems is considered. The implicit pseudospectral equations on an m × n mesh result in a full P × P matrix (P = (nm)2) which can be inverted by the methods we introduce. The examples given illustrate the success of pseudospectral techniques applied to the solution of these problems. The computational and memory requirements for machine implementation of pseudospectral techniques for a given accuracy are shown to be superior to those of standard finite difference technique. Coordinate transformations and interface patching techniques of interest in mixed Eulerian-Lagrangian modeling are illustrated in several examples.
Three dimensional mirror symmetry and partition function on S 3

We provide non-trivial checks of $ \mathcal{N} $ = 4, D = 3 mirror symmetry in a large class of quiver gauge theories whose Type IIB (Hanany-Witten) descriptions involve D3 branes ending on orbifold/orientifold 5-planes at the boundary. From the M-theory perspective, such theories can be understood in terms of coincident M2 branes sitting at the origin of a product of an A-type and a D-type ALE (Asymtotically Locally Euclidean) space with G-fluxes. Families of mirror dual pairs, which arise in this fashion, can be labeled as (A m−1 , D n ), where m and n are integers. For a large subset of such infinite families of dual theories, corresponding to generic values of n ≥ 4, arbitrary ranks of the gauge groups and varying m, we test the conjectured duality by proving the precise equality of the S 3 partition functions for dual gauge theories in the IR as functions of masses and FI parameters. The mirror map for a given pair of mirror dual theories can be read off at the end of this computation and we explicitly present these for the aforementioned examples. The computation uses non-trivial identities of hyperbolic functions including certain generalizations of Cauchy determinant identity and Schur’s Pfaffian identity, which are discussed in the paper.
Tropolactones A-D, four meroterpenoids from a marine-derived fungus of the genus Aspergillus

Four cytotoxic meroterpenoids, tropolactones A-D, were isolated from the whole broth extract of a marine-derived fungus of the genus Aspergillus. The structures of the meroterpenoids were established through a variety of two-dimensional NMR techniques. The absolute configuration of tropolactone A was determined using the modified Mosher method. Tropolactones A-C contain an interesting substituted 2,4,6-cycloheptatriene (tropone) ring, which presumably arises through an oxidative ring expansion from tropolactone D. Tropolactones A, B and C showed in vitro cytotoxicity against human colon carcinoma (HCT-116) with IC50 values of 13.2, 10.9 and 13.9 microg/mL.
Electrical Design and Operation of the Phelix Pulsed Power System

The Precision High Energy-Density Liner Implosion Experiment (PHELIX) is a pulsed power driver capable of delivering multimegampere currents to cylindrical loads. The PHELIX hardware includes novel design features to provide a high-energy conversion efficiency of approximately 10-MA output current per megajoule of stored energy. This is achieved by a rail-gap switched low-inductance Marx design (resistively damped) driving a multifilar air-core pulse transformer. The Marx output cables form the toroidal transformer that is an integral part of the disc line and removable load cassette assembly. The transformer and disc line uses conformal insulation methods and does not require replacement; after each shot, the transformer is completely reusable. Load cassettes can be easily exchanged to facilitate experimental variation. PHELIX is selfcontained within its own transport container and Faraday cage that can be moved from the maintenance building to the Los Alamos Neutron Science Center 800-MeV proton accelerator facility to perform multipulse proton radiography. This paper details the electrical and mechanical design of the Marx and multifilar transformer assemblies as well as presenting the operational performance achieved to date.
Total Synthesis of Maoecrystal V: Early-Stage C–H Functionalization and Lactone Assembly by Radical Cyclization

A total synthesis of the unusual ent-kaurane maoecrystal V is described. The synthesis strategy features a counterintuitive early disconnection of the lactone subunit to a polycyclic enol ether intermediate in order to preserve the central tetrahydrofuran ring until the beginning stages of the synthesis. This strategy enables an application of C–H functionalization at the early phase of the synthesis during the construction of a dihydrobenzofuran intermediate.
p-Branes and the GZK paradox

Abstract In spacetimes with asymmetric extra dimensions, cosmic neutrino interactions may be extraordinarily enhanced by p -brane production. Brane formation and decay may then initiate showers deep in the Earth's atmosphere at rates far above the standard model rate. We explore the p -brane discovery potential of cosmic ray experiments. The absence of deeply penetrating showers at AGASA already provides multi-TeV bounds on the fundamental Planck scale that significantly exceed those obtained from black hole production in symmetric compactification scenarios. This sensitivity will be further enhanced at the Auger observatory. We also examine the possibility that p -brane formation resolves the GZK paradox. For flat compactifications, astrophysical bounds exclude this explanation. For warped scenarios, a solution could be consistent with the absence of deep showers only for extra dimensions with fine-tuned sizes well below the fundamental Planck length. In addition, it requires moderately penetrating showers, so far not reported, and ∼100% modifications to standard model phenomenology at 100 GeV energies.
Dynamical phase transitions in periodically driven model neurons

Transitions between dynamical states in integrate-and-fire neuron models with periodic stimuli result from tangent or discontinuous bifurcations of a return map. We study their characteristic scaling laws and show that discontinuous bifurcations exhibit a kind of phase transition intermediate between continuous and first order. In the model-independent spirit of our analysis we show that a six-dimensional (6D) gating variable model with an attracting limit cycle has similar phase transitions, governed by a 1D return map. This reduction to 1D map dynamics should extend to real neurons in a periodic current clamp setting.
Modelling and simulation of off-chip communication architectures for high-speed packet processors

In this work, we propose a visual, custom-designed, event-driven interconnect simulation framework to evaluate the performance of off-chip multi-processor/memory communications architectures for line cards. The simulator uses the state-of-the-art software design techniques to provide the user with a flexible, robust and comprehensive tool that can evaluate k-ary n-cube based network topologies under non-uniform traffic patterns. The simulator provides full control over essential network parameters and flow control mechanisms such as virtual channels and sub-channeling. We compare three low-dimensional k-ary n-cube based interconnects that can fit into the physical limitations on line cards, where each one of these interconnects has multiple processor-memory configurations. Performance results show that k-ary n-cube architectures perform better than existing interconnects, and they can sustain current line rates and higher. In addition, we provide performance tradeoffs between multiple flow control mechanisms and performance metrics such as throughput, routing accuracy, failure rate and interconnect utilization.