cssi/SciSciGPT-SciSciNet huggingface dataset:
Formation of charmonium states in heavy-ion collisions and thermalization of charm

We examine the possibility to utilize in-medium charmonium formation in heavy-ion interactions at collider energy as a probe of the properties of the medium. This is possible because the formation process involves recombination of charm quarks which imprints a signal on the resulting normalized transverse momentum distribution containing information about the momentum distribution of the quarks. We have contrasted the transverse momentum spectra of J/ψ, characterized by 〈p T 2〉, which result from the formation process in which the charm quark distributions are taken at opposite limits with regard to thermalization in the medium. The first uses charm quark distributions unchanged from their initial production in a pQCD process, appropriate if their interaction with the medium is negligible. The second uses charm quark distributions which are in complete thermal equilibrium with the transversely expanding medium, appropriate if a very strong interaction between charm quarks and medium exists. We find that the resulting 〈p T 2〉 of the formed J/ψ should allow one to differentiate between these extremes, and that this differentiation is not sensitive to variations in the detailed dynamics of in-medium formation. We include a comparison of predictions of this model with preliminary PHENIX measurements, which indicates compatibility with a substantial fraction of in-medium formation.
BrainSuite: An automated cortical surface identification tool

We describe a new magnetic resonance (MR) image analysis tool that produces cortical surface representations with spherical topology from MR images of the human brain. The tool provides a sequence of low-level operations in a single package that can produce accurate brain segmentations in clinical time. The tools include skull and scalp removal, image nonuniformity compensation, voxel-based tissue classification, topological correction, rendering, and editing functions. The collection of tools is designed to require minimal user interaction to produce cortical representations. In this paper we describe the theory of each stage of the cortical surface identification process. We then present classification validation results using real and phantom data. We also present a study of interoperator variability.
Ion Exchange in Sodium Borosilicate Glasses

The kinetics of K+-Na+ exchange in sodium borosilicate glasses containing 20 mol% Na2O were studied as a function of glass composition and exchange time and temperature. The distribution of K in the glass after exchange in molten KNO3 was determined using an electron microprobe. In those specimens which were not chemically attacked by the molten salt, the K profiles were consistent with Fickean behavior. The calculated interdiffusion coefficients varied with local composition in each specimen. This composition dependence and its variation with temperature could be fitted approximately to a mixed-alkali model using the Nernst-Planck relation for diffusive fluxes. However, some deviation from this behavior, presumably as a result of the generation of microscopic stresses around an exchange site, was observed. The dependence of the apparent activation energy, Ẽ, on the B/Si ratio was analogous to that of the activation energy for ionic conduction in these glasses: Ẽ decreased with increasing fraction of nonbridging oxygen. This result disagrees with the presumed behavior in sodium aluminosilicate glasses.
Evaluation and development techniques for computer assisted instruction programs

Computer-Assisted Instruction presents the individual conducting educational research with the potential for more controlled and reliable experimental design and data collection. Certain features of programmed instruction also present new challenges to the researcher. Chief among these is a problem related to the individualization of programmed instruction. The authors have developed automated experimental design routines which are used to partially overcome these problems. This procedure will be referred to as "Computer-Assisted Pairing" or CAP.
A Weakly Compressible Flow Model and Rapid Convergence Methods

Application au calcul des ecoulements stationnaire et instationnaire non visqueux d'un modele d'ecoulement faiblement compressible aux petits nombres de Mach
Experimental hepatoportoenterostomy: duct mucosal healing with hybrid biliary-intestinal epithelium forming an autoanastomosis

Permanent bile flow following hepatoportoenterostomy for biliary atresia is presumed to follow mucosal healing of the biliary tract to the intestinal epithelium, but the morphology of the anastomosis and the histology of the neo-biliary duct is not known. Experimental portoenterostomies were constructed in five normal 10-kg mini-pigs at approximately 3 months of age to study the healing of the anastomosis. The extrahepatic bile duct was resected in continuity with an en-bloc 1.5 × 0.3-cm segment of liver at the porta hepatis and biliary drainage was achieved with a Roux-en-Y jejunal limb. The bile duct remnant at the porta hepatis measured 3 mm in diameter. HIDA scan performed at 2 months showed prompt excretion of the radioisotope and normal function of the jejunal limb. Animals were killed at 2 weeks, 1 month, and 3 months following operation and the intact hepatobiliary anastomosis examined by routine histology and histochemical staining for acid and neutral mucins. At 2 weeks the biliary epithelial ducts were hyperplastic and showed evidence of cellular regeneration and cholangitis. By 1 month the biliary and intestinal epithelia were in close approximation. At 3 months the biliary-intestinal epithelium was healed, forming a funnel-like autoanastomosis with normal proximal biliary epithelium and distal intestinal epithelium. An intervening zone of hybrid biliary-intestinal epithelium showed basal crypts with characteristics of biliary epithelium, while the superficial glandular epithelium resembled intestinal villi. Mucin histochemistry of the hybrid epithelial lining revealed predominantly neutral mucins in the basal region of the mucosa characteristic of biliary mucosa. The luminal epithelium revealed a high acid mucin content, including goblet cells. A microvillus brush border, rich in neutral mucin, was also present apically on the luminal most cells. We conclude that: (1) hepatoportoenterostomy in normal mini-pigs is a reproducible model to study healing of the anastomosis; (2) a continuous, intact hepatobiliary-intestinal mucosa is present within 3 months following portoenterostomy; and (3) the neo-epithelium has a hybrid biliary-intestinal appearance. This study may have application to understanding the cause of cholangitis following portoenterostomy for biliary atresia.
The Detection of Low-Mass Companions in Hyades Cluster Spectroscopic Binary Stars

We have observed a large sample of spectroscopic binary stars in the Hyades cluster, using high-resolution infrared spectroscopy to detect low-mass companions. We combine our double-lined infrared measurements with well-constrained orbital parameters from visible light single-lined observations to derive dynamical mass ratios. Using these results, along with photometry and theoretical mass-luminosity relationships, we estimate the masses of the individual components in our binaries. In this paper we present double-lined solutions for 25 binaries in our sample, with mass ratios from ~0.1 to 0.8. This corresponds to secondary masses as small as ~0.15 M?. We include here our preliminary detection of the companion to vB 142, with a very small mass ratio of -->q = 0.06 ? 0.04; this indicates that the companion may be a brown dwarf. This paper is an initial step in a program to produce distributions of mass ratio and secondary mass for Hyades cluster binaries with a wide range of periods, in order to better understand binary star formation. As such, our emphasis is on measuring these distributions, not on measuring precise orbital parameters for individual binaries.
Photonic Hyper-Crystals

We introduce a new luniversality classr of artificial optical media - photonic hyper- crystals. These hyperbolic metamaterials with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals.
Option Contracts and Vertical Foreclosure

A model of vertical integration is studied. Upstream firms sell differentiated inputs; downstream firms bundle them to make final products. Downstream products are sold as option contracts, which allow consumers to choose from a set of commodities at predetermined prices. The model is illustrated by examples in telecommunication and health markets. Equilibria of the integration game must result in upstream input foreclosure and downstream monopolization. Consumers may or may not benefit from integration.
High Performance Work Systems and Organizational Outcomes: The Mediating Role of Information Quality.

Using data on registered nurses and nursing assistants in 50 acute-care hospital units, the author explores the relationships among high performance work systems, information quality, and performance quality within a context shaped by equivocal information—information that can be interpreted in multiple and sometimes conflicting ways. He finds that the quality of information available for decision-making, which largely depends on the interpretative skills of the workers who are exposed to important equivocal information, partially mediates how employee knowledge, work design, and total quality management systems affect organizational performance (which is measured as the inverse of medication error incidence). Providing employees with extensive relevant knowledge and enabling them to use their skills during even seemingly routine tasks improves the effective quality of information they bring to decision-making, and thereby promotes high performance quality.
What role should investigative facts play in the evaluation of scientific evidence

Concern about contextual bias has led some authorities to recommend that forensic scientists know as little as possible about the facts of the underlying case when interpreting physical evidence; but concern about contextual ignorance has led other authorities to recommend, to the contrary, that forensic scientists know as much as possible in order to frame questions properly. This article recommends a case manager model that addresses both concerns. This article also responds to standard objections to the use of blind procedures in forensic science, explaining why contextual bias cannot be conquered through willpower; why use of domain-irrelevant contextual facts undermines the value of forensic evidence; how a well-known cognitive illusion (the ‘introspection illusion’) can mislead forensic scientists into thinking they can control their biases, when they cannot; and how a paradoxical feature of forensic inference (the ‘criminalist's paradox’) can mislead analysts into thinking they should rely on conte...
Radial profiles of solids loading and flux in a gas–solid circulating fluidized bed

Abstract An electrical-impedance tomography (EIT) system has been developed to non-invasively measure radial voidage profiles in the riser of a pilot-scale circulating fluidized bed (CFB), yielding quantitative information that is validated by comparison to a gamma-densitometry tomography (GDT) system. EIT and GDT were applied to the CFB riser (14-cm inner diameter, 5.77-m height) containing fluid catalytic cracking particles in air. For all cases, the average and near-wall voidages from EIT and GDT agreed to within 0.03 and 0.07, respectively. This good agreement suggests that, where feasible, EIT can be used in place of GDT, which is advantageous since EIT systems are often safer, less expensive, and faster than GDT systems. The results also compared well to two correlations for radial voidage profile from the literature. Finally, a procedure for determining radial solids flux profiles from radial voidage profiles using an additional correlation [M.J. Rhodes, X.S. Wang, H. Cheng, T. Hirama, B.M. Gibbs, Similar profiles of solids flux in circulating fluidized-bed risers, Chemical Engineering Science 47 (1992) 1635–1643] was investigated. It was found that the accuracy of this correlation strongly depends on the voidage and/or solids flux measurement at the riser center.
Regiospecific Carbonylative Annulation of Iodophenol Acetates and Acetylenes To Construct the Flavones by a New Catalyst of Palladium−Thiourea−dppp Complex

[reaction: see text] Regiospecific carbonylative annulation of o-iodophenol acetates and acetylenes mediated by palladium-thiourea-dppp complex in the presence of base at 40 degrees C under a balloon pressure of CO generates diversified flavones in high yields. This newly developed synthetic technology provides a highly efficient method for potential application to the combinatorial synthesis of those heterocycles on the solid support.
Nitro and nitroso transformations in superacids

Abstract Novel transformations involving the nitro and nitroso groups in superacid media are discussed and summarized. NO 2 -diprotonation is a key reaction for nitro PAHs, forming N , N -dihydroxyiminium–arenium dications whereas nitrosoarenes are N , O -diprotonated to form hydroxyiminium–arenium dications. In nitropyrenes a facile cyclization involving the nitro group leads to five- and/or six-membered ring heterocyclic cations. Nitro cyclization also occurs in nitroalkylbenzenes but at higher temperatures. Multinuclear NMR data for the resulting persistent NO 2 -diprotonated dications and their cyclized analogs are gathered and the structural requirements to bring about nitro cyclization are assessed. Conjugated nitroalkenes such as nitrostyrene and nitroethene are NO 2 -diprotonated to form hydroxyiminium–carbenium dications. β-Heteroatom-substituted nitroethylenes are C , O -diprotonated and subsequently form hydroxynitrilium ions. Nitronate salts and unsubstituted nitroalkanes are activated in superacids via their protonated nitronic acid. β-ethoxycarbonyl-substituted nitroalkanes are activated via the O , O -diprotonated aci -nitro species with further O -protonation to give dioxonium–carbenium trications or via hydroxynitrilium ions. The NMR characteristics for the dihydroxyiminium–carbenium dications and hydroxynitrilium ions from various 2-nitroalkenes and their nucleophile quenching-derived cations are also gathered. The mechanistic aspects emphasizing dicationic (and tricationic) intermediates, their interplay and the potential synthetic benefits of these transformations which greatly extend the chemistry of the nitro group are highlighted.
A system for automatic personalized tracking of scientific literature on the Web

We introduce a system as part of the CiteSeer digital library project for automatic tracking of scientific literature that is relevant to a user’s research interests. Unlike previous systems that use simple keyword matching, CiteSeer is able to track and recommend topically relevant papers even when keyword based query profiles fail. This is made possible through the use of a heterogenous profile to represent user interests. These profiles include several representations, including content based relatedness measures. The CiteSeer tracking system is well integrated into the search and browsing facilities of CiteSeer, and provides the user with great flexibility in tuning a profile to better match his or her interests. The software for this system is available, and a sample database is online as a public service.
NUROA: A numerical roadmap algorithm

Motion planning has been studied for nearly four decades now. Complete, combinatorial motion planning approaches are theoretically well-rooted with completeness guarantees but they are hard to implement. Sampling-based and heuristic methods are easy to implement and quite simple to customize but they lack completeness guarantees. Can the best of both worlds be ever achieved, particularly for mission critical applications such as robotic surgery, space explorations, and handling hazardous material? In this paper, we answer affirmatively to that question. We present a new methodology, NUROA, to numerically approximate the Canny's roadmap, which is a network of one-dimensional algebraic curves. Our algorithm encloses the roadmap with a chain of tiny boxes each of which contains a piece of the roadmap and whose connectivity captures the roadmap connectivity. It starts by enclosing the entire space with a box. In each iteration, remaining boxes are shrunk on all sides and then split into smaller sized boxes. Those boxes that are empty are detected in the shrink phase and removed. The algorithm terminates when all remaining boxes are smaller than a resolution that can be either given as input or automatically computed using root separation lower bounds. Shrink operation is cast as a polynomial optimization with semialgebraic constraints, which is in turn transformed into a (series of) semidefinite programs (SDP) using the Lasserre's approach. NUROA's success is due to fast SDP solvers. NUROA correctly captured the connectivity of multiple curves/skeletons whereas competitors such as IBEX and Realpaver failed in some cases. Since boxes are independent from one another, NUROA can be parallelized particularly on GPUs. NUROA is available as an open source package at http://nuroa.sourceforge.net/.
Damascene Copper electroplating for chip interconnections

Damascene Cu electroplating for on-chip metallization, which we conceived and developed in the early 1990s, has been central to IBM's Cu chip interconnection technology. We review here the challenges of filling trenches and vias with Cu without creating a void or seam, and the discovery that electrodeposition can be engineered to give filling performance significantly better than that achievable with conformal step coverage. This attribute of superconformal deposition, which we call superfilling, and its relation to plating additives are discussed, and we present a numerical model that represents the shape-change behavior of this system.
Investigation of Lightpipe Volumetric Radiation Effects in RTP Thermometry

A major obstacle to the widespread implementation of rapid thermal processing (RTP) is the challenge of wafer temperature measurement. Frequently, lightpipe radiation thermometers are used to measure wafer temperatures in RTP reactors. While the lightpipe distorts the wafer temperature profile less than temperature measurement techniques which require physical contact, the presence of the lightpipe influences the wafer temperature profile. This paper presents the results of a theoretical study exploring that influence for an idealized RTP reactor in which the wafer is treated as a nonconducting, opaque, constant-heat-flux surface imaged by the lightpipe. The coupled radiation/ conduction transport in the lightpipe measurement enclosure is solved numerically. Radiation transfer in the system is modeled with varying levels of rigor, ranging from a simple volumetrically nonparticipating treatment to a full spectral solution of the radiative transfer equation. The results reveal a rather significant effect of the lightpipe on the wafer temperature, which depends on the separation between the lightpipe tip and the wafer. The study illustrates clearly the need to model the lightpipe as a volumetrically participating, semitransparent medium, and further, the importance of accounting for spectral variation of the lightpipe properties in the prediction of the radiative transfer. Finally, two primary mechanisms are identified by which the lightpipe affects the wafer temperature distribution.
GIS-based estimation of housing amenities: the case of high grounds and stagnant streams

We use GIS and econometric methods to estimate the marginal implicit values of environmental amenities associated with residential land parcels in the mountain town of Logan, Utah. Amenities include proximity to open spaces (such as parks, golf courses and lakes), commercial zones, major roads, streams, and general visibility of surrounding topography in the valley as determined by the elevation of the land parcel. The amenity value estimates are corrected for spatial autocorrelation. We find spatially dependent relationships between (1) a parcel’s value and its elevation, and (2) a parcel’s value and its adjacency to a stagnant stream. To our knowledge, this is the first hedonic study to assess the effect of stream stagnancy on land value.
NEUTROPENIA AND DEFECTIVE CHEMOTAXIS ASSOCIATED WITH BINUCLEAR, TETRAPLOID MYELOID-MONOCYTIC LEUKOCYTES

NEUTROPENIA AND DEFECTIVE CHEMOTAXIS ASSOCIATED WITH BINUCLEAR, TETRAPLOID MYELOID-MONOCYTIC LEUKOCYTES
Solution of N = 2 gauge theories via compactification to three dimensions

A number of N = 2 gauge theories can be realized by brane configurations in Type IIA string theory. One way of solving them involves lifting the brane configuration to M-theory. In this paper we present an alternative way of analyzing a subclass of these theories (elliptic models). We observe that upon compactification on a circle one can use a version of mirror symmetry to map the original brane configuration into one containing only D-branes. Simultaneously the Coulomb branch of the four-dimensional theory is mapped to the Higgs branch of a five-dimensional theory with three-dimensional impurities. The latter does not receive quantum corrections and can be analyzed exactly. The solution is naturally formulated in terms of an integrable system, which is a version of a Hitchin system on a punctured torus.
Weapons-Grade MOX fuel burnup characteristics in Advanced Test Reactor irradiation

Abstract Mixed Oxide (MOX) test capsules prepared with weapons-derived plutonium have been irradiated to a burnup of 50 GWd/t. The MOX fuel was fabricated at Los Alamos National Laboratory (LANL) by a master-mix process and has been irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Previous withdrawals of the same fuel have occurred at 9, 21, 30, 40, and 50 GWd/t. Oak Ridge National Laboratory (ORNL) manages this test series for the Department of Energy's Fissile Materials Disposition Program (FMDP). A UNIX BASH (Bourne Again SHell) script CMO has been written and validated at the INL to couple the Monte Carlo transport code MCNP with the depletion and buildup code ORIGEN-2 (CMO). The new Monte Carlo burnup analysis methodology in this paper consists of MCNP coupling through CMO with ORIGEN-2 (MCWO). MCWO is a fully automated tool that links the Monte Carlo transport code MCNP with the radioactive decay and burnup code ORIGEN-2. The fuel burnup analyses presented in this study were performed using MCWO. MCWO analysis yields time-dependent and neutron-spectrum-dependent minor actinide and Pu concentrations for the ATR small I-irradiation test position. The purpose of this paper is to validate both the Weapons-Grade Mixed Oxide (WG-MOX) test assembly model and the new fuel burnup analysis methodology by comparing the computed results against the neutron monitor measurements and the irradiated WG-MOX post-irradiation examination (PIE) data.
Sol-Gel Processed Inorganic and Organically Modified Composites for Nonlinear Optics and Photonics

The newly emerging field of Nonlinear Optics and Photonics offers tremendous opportunities for material scientists. In this paper, chemical processing using the sol-gel method is described for the preparation of new composite materials of both a silica glass and a V2O5 gel with a wπ conjugated polymer poly-p-phenylene vinylene up to 5d% by weight. The composite films show highly improved optical quality with large third-order nonlinear optical coefficients, the latter from the conjugated polymer. Optical waveguiding through the film has been achieved. Nonlinear optical studies using femtosecond degenerate four wave mixing and power dependent waveguide coupling have been successfully performed. Also, to investigate the use of such films for optical recording, a two-dimensional grating structure has successfully been produced.
Belief Propagation for Min-Cost Network Flow: Convergence and Correctness

Distributed, iterative algorithms operating with minimal data structure while performing little computation per iteration are popularly known as message passing in the recent literature. Belief propagation (BP), a prototypical message-passing algorithm, has gained a lot of attention across disciplines, including communications, statistics, signal processing, and machine learning as an attractive, scalable, general-purpose heuristic for a wide class of optimization and statistical inference problems. Despite its empirical success, the theoretical understanding of BP is far from complete. With the goal of advancing the state of art of our understanding of BP, we study the performance of BP in the context of the capacitated minimum-cost network flow problem---a cornerstone in the development of the theory of polynomial-time algorithms for optimization problems and widely used in the practice of operations research. As the main result of this paper, we prove that BP converges to the optimal solution in pseudopolynomial time, provided that the optimal solution of the underlying network flow problem instance is unique and the problem parameters are integral. We further provide a simple modification of the BP to obtain a fully polynomial-time randomized approximation scheme (FPRAS) without requiring uniqueness of the optimal solution. This is the first instance where BP is proved to have fully polynomial running time. Our results thus provide a theoretical justification for the viability of BP as an attractive method to solve an important class of optimization problems.
Holography in the flat space limit

Matrix theory and the AdS/CFT correspondence provide nonperturbative holographic formulations of string theory. In both cases the finite N theories can be thought of as infrared regulated versions of flat space string theory in which removing the cutoff is equivalent to letting N go to infinity. In this paper we consider the nature of this limit. In both cases the holographic mapping becomes completely nonlocal. In matrix theory this corresponds to the growth of D0-brane bound states with N. For the AdS/CFT correspondence there is a similar delocalization of the holographic image of a system as N increases. In this case the limiting theory seems to require a number of degrees of freedom comparable to large N matrix quantum mechanics.
Green Payments and Dual Policy Goals

Abstract We use a mechanism design framework to analyze the optimal design of green payment policies with the dual goals of conservation and income support for small farms. Each farm is characterized by two dimensions of attributes: farms size and conservation efficiency. The policymaker may not be able to use the attributes as an explicit criterion for payments. We characterize optimal policy when conservation efficiency is unobservable to policymakers, and when farm size is also unobservable. An income support goal is shown to reduce the conservation distortion caused by asymmetric information. The cost of optimal green payment mechanisms is shown to depend crucially on whether large or small farms have greater conservation efficiency.
Confirmation of single-mode FEL operation

Abstract Experimental results from the UC Santa Barbara FEL are reviewed. At saturation, macroscopic and microscopic time-structure records give clear evidence of discrete time structure and single dominant longitudinal-mode operation.
Differential-equation-based seismic data filtering

Suppressing noise and enhancing useful seismic signal by filtering is one of the important tasks of seismic data processing. Conventional filtering methods are implemented through either the convolution operation or various mathematical transforms. We describe a methodology for studying and implementing filters, which, unlike conventional filtering methods, is based on solving differential equations in the time and space domain. We call this differential‐equation‐based filtering (DEBF). DEBF does not require that seismic data be stationary, so filtering parameters can vary with every time and space point. Examples with two‐dimensional (2-D) synthetic and field seismic data demonstrate that the DEBF method accomplishes the desired time‐ and space‐varying temporal and move‐out filtering at lower cost than conventional frequency‐wavenumber‐domain filtering. The computational advantage in 3-D would be much greater.
Conjugate Addition Reactions Mediated by Samarium(II) Iodide.

Samarium(II) iodide in conjunction with a catalytic low-valent transition metal species has been employed to promote the conjugate addition reaction of primary and secondary alkyl halides onto α,β-unsaturated esters and amides. The method has been determined to be quite general and hence has been extended to the cyclization reactions of alkyl halides onto α,β-unsaturated lactones, lactams, and nitriles. The cyclization reactions described herein provide a very general approach to the synthesis of functionalized carbocycles from simple acyclic precursors with excellent diastereoselectivity and under very mild reaction conditions.
Time-Accurate Computations of Isolated Circular Synthetic Jets in Crossflow

Results from unsteady Reynolds-averaged Navier-Stokes computations are described for two different synthetic jet flows issuing into a turbulent boundary layer crossflow through a circular orifice. In one case the jet effect is mostly contained within the boundary layer, while in the other case the jet effect extends beyond the boundary layer edge. Both cases have momentum flux ratios less than 2. Several numerical parameters are investigated, and some lessons learned regarding the CFD methods for computing these types of flow fields are outlined. Results in both cases are compared to experiment.
The Origins of Ethnolinguistic Diversity

This study explores the determinants of ethnolinguistic diversity within as well as across countries, shedding light on its geographic origins. The empirical analysis conducted across countries, virtual countries, and pairs of contiguous regions establishes that geographic variability, captured by variation in regional land quality and elevation, is a fundamental determinant of contemporary linguistic diversity. The findings are consistent with the proposed hypothesis that differences in land endowments gave rise to location-specific human capital, leading to the formation of localized ethnicities. (JEL J15, J24, Z13)
Gauged Gravity via Spectral Asymptotics of non-Laplace type Operators

We construct invariant differential operators acting on sections of vector bundles of densities over a smooth manifold without using a riemannian metric. The spectral invariants of such operators are invariant under both the diffeomorphisms and the gauge transformations and can be used to induce a new theory of gravitation. It can be viewed as a matrix generalization of Einstein general relativity that reproduces the standard Einstein theory in the weak deformation limit. Relations with various mathematical constructions such as Finsler geometry and Hodge-de Rham theory are discussed.
Manipulation can be hard in tractable voting systems even for constant-sized coalitions

Abstract Voting theory has become increasingly integrated with computational social choice and multiagent systems. Computational complexity has been extensively used as a shield against manipulation of voting systems, however for several voting schemes this complexity may cause calculating the winner to be computationally difficult. Of the many voting systems that have been studied with regard to election manipulation, a few have been found to have an unweighted coalitional manipulation problem that is NP-hard for a constant number of manipulators despite having a winner problem that is in P. We survey this interesting class of voting systems and the work that has analyzed their complexity.
IRS and ESR Characterizations of Nanocomposite Thin Films Derived From Alkanethiolates and Gold Nanoparticles

A key to the ultimate technological applications of core-shell nanoparticle materials is the understanding of the structure-property correlation. This work focuses on the characterizations of the structural properties for composite thin films derived from gold nanoparticles and thiolates using infrared reflectance spectroscopic (IRS) and electron spin resonance (ESR) techniques. IRS provides information on molecular packing and ordering of the shell components in the films, which relates to the molecular interactions and interfacial reactivities. ESR probes the conduction electron spin resonance properties of the nanosized cores, which can be correlated with the network or environmental electronic effects on the crystal cores. Results are discussed in terms of their correlation with the nanoparticle core sizes and the organic shell functionality.
Obstacle avoidance using predictive vision based on a dynamic 3D world model

We have designed and implemented a fast predictive vision system for a mobile robot based on the principles of active vision. This vision system is part of a larger project to design a comprehensive cognitive architecture for mobile robotics. The vision system represents the robot's environment with a dynamic 3D world model based on a 3D gaming platform (Ogre3D). This world model contains a virtual copy of the robot and its environment, and outputs graphics showing what the virtual robot "sees" in the virtual world; this is what the real robot expects to see in the real world. The vision system compares this output in real time with the visual data. Any large discrepancies are flagged and sent to the robot's cognitive system, which constructs a plan for focusing on the discrepancies and resolving them, e.g. by updating the position of an object or by recognizing a new object. An object is recognized only once; thereafter its observed data are monitored for consistency with the predictions, greatly reducing the cost of scene understanding. We describe the implementation of this vision system and how the robot uses it to locate and avoid obstacles.
Supergauge interactions and electroweak baryogenesis

We present a complete treatment of the diffusion processes for supersymmetric electroweak baryogenesis that characterizes transport dynamics ahead of the phase transition bubble wall within the symmetric phase. In particular, we generalize existing approaches to distinguish between chemical potentials of particles and their superpartners. This allows us to test the assumption of superequilibrium (equal chemical potentials for particles and sparticles) that has usually been made in earlier studies. We show that in the Minimal Supersymmetric Standard Model, superequilibrium is generically maintained — even in the absence of fast supergauge interactions — due to the presence of Yukawa interactions. We provide both analytic arguments as well as illustrative numerical examples. We also extend the latter to regions where analytical approximations are not available since down-type Yukawa couplings or supergauge interactions only incompletely equilibrate. We further comment on cases of broken superequilibrium wherein a heavy superpartner decouples from the electroweak plasma, causing a kinematic bottleneck in the chain of equilibrating reactions. Such situations may be relevant for baryogenesis within extensions of the MSSM. We also provide a compendium of inputs required to characterize the symmetric phase transport dynamics.
Central extensions of preprojective algebras, the quantum Heisenberg algebra, and 2-dimensional complex reflection groups

Preprojective algebras of quivers were introduced in 1979 by Gelfand and Ponomarev [GP], because for quivers of finite ADE type, they are models for indecomposable representations (they contain each indecomposable exactly once). Twenty years later, these algebras and their deformed versions introduced in [CBH] (for arbitrary quivers) became a subject of intense interest, since their representation varieties, called quiver varieties, played an important role in geometric representation theory. Ironically, it is exactly for quivers of finite ADE type that preprojective algebras fail to have good properties—they are not Koszul and their deformed versions are not flat.
Stereochemical and spectroscopic studies on the reaction of allylstannanes with aldehydes

Abstract The orientational preference for the reacting double bonds in the Lewis acid-induced reaction of allylic stannanes and aldehydes has been examined. Model system 1 shows a strong and Lewis-acid independent preference for the synclinal orientation of double bonds. A possible stereoelectronic basis for this preference is discussed. A13C-NMR spcctroscopic study of the reaction between crotyltrialkylstannanes (9) and acetaldehyde (10), pivaldehyde (11) and 4-t-butylbenzaldehyde (12) in the presence of BF3·OEt2 and SnCl4 is described. The spectroscopic study reveals that with BF3·OEt2 only direct addition occurs while with SnCl4 the pathway (addition vs. metathesis) is stoichiometry and aldehyde dependent. The mechanism of metathesis and chlorostannane isomerization is discussed.
Theory of Superconductivity

Although superconductivity falls into the domain where one would expect ordinary non-relativistic quantum mechanics to be valid, it has proved to be extremely difficult to obtain an adequate theoretical explanation of this remarkable phenomenon. In spite of the large amount of excellent experimental and theoretical work devoted to the problem, there remain major unsettled questions. However, the area in which the answers are to be found has been narrowed considerably. There are very strong indications, if not quite a proof, that superconductivity is essentially an extreme case of diamagnetism rather than a limit of infinite conductivity. The isotope effect indicates that the superconducting phase arises from interactions between electrons and lattice vibrations.
Bacterial interference among strains of Staphylococcus aureus in man.

Factors related to artificial colonization by and persistence of Staphylococcus aureus (strain 502A) were characterized. Carriers of S. aureus were treated with antibiotics and antibacterial soaps and challenged with strain 502A. All subjects who lost their original S. aureus after treatment with antibiotics were colonized successfully with either 1.5 x 108 or 2 x 109 colony-forming units of strain 502A; these bacteria persisted in 67%-80% of subjects for 23 weeks. Eighty percent of subjects became colonized by strain 502A with persistence in 17% when the original strain(s) of S. aureus were reduced but not eliminated. Subjects not treated with antibiotics and challenged with strain 502A were temporarily colonized, and the extent of colonization was related to dose. A challenge inoculum of 109 S. aureus 502A caused colonization in 100%, while 50% were colonized with 107 and 105 colony-forming units. Of the 12 subjects in this group, persistence at 10 weeks was noted in only a single individual who received an inoculum of 2.1 x 109. Colonization and persistence in subjects who initially resisted colonization by strain 502A and were treated later with antibiotics were similar to those in treated subjects. The data suggest that (1) eradication of the original strain of S. aureus is an important factor for optimal colonization and persistence of strain 502A; (2) it is possible to overwhelm the normal mucosa of persons who carry S. aureus with large numbers of strain 502A; and (3) carriers who initially rejected artificial colonization can become susceptible to colonization by and persistence of S. aureus strain 502A after treatment with antibiotics.
Gap Forcing: Generalizing the Lévy-Solovay Theorem

The Levy-Solovay Theorem[8] limits the kind of large cardinal embeddings that can exist in a small forcing extension. Here I announce a generalization of this theorem to a broad new class of forcing notions. One consequence is that many of the forcing iterations most commonly found in the large cardinal literature create no new weakly compact cardinals, measurable cardinals, strong cardinals, Woodin cardinals, strongly compact cardinals, supercompact cardinals, almost huge cardinals, huge cardinals, and so on.
Immunological localization of dopamine-beta-hydroxylase on the chromaffin granule membrane.

Publisher Summary This chapter presents a study examining immunological localization of dopamine-β-hydroxylase (DBH) on the chromaffin granule membrane. The effect of antibodies to bovine DBH on the activity of the enzyme in lysed and intact bovine medullary granules was examined. Granules were lysed by homogenization in 0.005 M Tris HCl containing 0.1% Triton X-100, and aliquots of the homogenate were incubated with either normal goat serum (NGS) or anti-DBH serum (a-DBH) at 37°C. The solutions were then assayed for DBH activity. Intact granules in isotonic sucrose medium were incubated with either NGS or a-DBH and then assayed for DBH activity. Comparable preparations of intact vesicles were incubated with either NGS or a-DBH, spun at 100,000g and the supernatant assayed for DBH activity. Incubation of lysed granules with a-DBH resulted in about 80% inhibition of the enzyme. Intact granules had about 50% of the DBH activity of lysed granules. Incubation of the intact granules with a-DBH reduced the activity to 22% of the total DBH activity. This represents a 56% inhibition of the enzyme activity of the intact granules.
Suppression of sympathetic nervous system during fasting

Two days of fasting in rats significantly reduces the turnover of norepinephrine in the heart. In contrast to the effects of ganglionic blockade in fed controls, similar blockade in fasted animals is without significant effect on [3H]-norepinephrine retention or endogenous norepinephrine in the heart. These data are consistent with suppression of centrally mediated sympathetic activity in the fasted state. The decrease in norepinephrine turnover during fasting is completely reversed by 1 day of refeeding.
Free Riders, Holdouts, and Public Use: A Tale of Two Externalities

Free riders and holdouts are distinct market failures that potentially impede the completion of otherwise beneficial transactions. The key difference is that the free rider problem is a demand side externality that requires taxation to compel payment for a public good, while the holdout problem is a supply side externality that requires eminent domain to force the sale of land for large scale projects. This paper highlights the distinction between these two problems and uses the resulting insights to clarify the meaning of the public use requirement of the Fifth Amendment takings clause.
Difluoromethylene compounds as precursors to ketones, carboxylic acids, esters, amides and carbonates

A review of difluoromethylene compounds as precursors to carbonyl compounds. Many ketones, carboxylic acids, esters, amides and carbonates, especially trifluoroalanine dipeptides, can be easily achieved due to the reactivity of difluoromethylene compounds or generated through the reactive difluoromethylene intermediates.
Transport in Polyiodide Networks of a Self-Assembled Lithium Iodide Battery

As MEMS devices for biomedical and other applications continue to develop and decrease in dimensions, the demand for power supplies with the appropriate size and energy density continues to grow. Although energy density is an important factor, one of the most crucial factors is the ability to fabricate cells in a variety of shapes so to enable the greatest design flexibility when fabricating a device. Recently our group has introduced an electrochemically self formed battery to grant a path towards the greatest flexibility. In short, a nanocomposite of an alkali halide such as lithium iodide is placed between current collectors and polarized thereby creating a lithium anode and polyiodide cathode in-situ. As with primary lithium-iodine cells the transport within the cathode is a complex mechanism involving the Li+, I-, and e- all within the polyiodide network. After our recent work on in-situ EIS evaluation of the technology, we have launched on an effort to greater understand the limiting transport mechanisms in the positive electrode as a function of polyiodide network development. An in-depth characterization study was performed on the LiI-I2-PVP-H20 at various molar ratios to understand the structural and conductivity changes that take place during formation of the cell A combination of AC impedance and DC polarization studies were used for the impedance characterization in conjunction with blocking electrode methodology for separating the conductivity into its electronic and ionic portions. Also, FTIR and Raman were used to structurally characterize the samples for both the polyiodide formation and the interaction between the polyiodides and polyvinylpyrrolidone (PVP). Being non conjugated, PVP was chosen as it does not intrinsically contribute to the conductivity of the composite but does induce the formation of polyiodide species. As different molar ratio composites are prepared, the concentration of different polyiodide species (I3-, I5-, In-) within the composite change and affect the overall conductivity. A 3-dimensional plot of composite conductivity reveals a high electronic conductivity ridge for samples containing either LiI anhydrous or monohydrate at a constant I2 to PVP ratio. These 3-dimensional plots also allow us to correlate represent in an ex-situ format the electronic and ionic conductivity of the cathode/electrolyte at various depths of discharge.
Effects of Density Ratio on the Hydrodynamics of Film Cooling

This paper presents the results of a detailed hydrodynamic study of a row of inclined jets issuing into a crossflow with a density ratio of injectant to freestream of two. Laser Doppler anemometry was used to measure the vertical and streamwise components of velocity for a jet-to-freestream mass flux ratio of 0.5. Mean velocity components and turbulent Reynolds normal and shear stress components were measured at locations in a vertical plane along the centerline of the jet from 1 diameter upstream to 30 diameters downstream of the jet. The results, which have application to film cooling, give a quantitative picture of the entire flow field, from the approaching flow upstream of the jet, through the interaction region of the jet and freestream, to the relaxation region downstream where the flow field approaches that of a standard turbulent boundary layer.Copyright © 1989 by ASME
Regio- and Enantioselective Catalytic Cyclization of Pyrroles onto N-Acyliminium Ions

The regio- and enantioselective cyclization of pyrroles onto N-acyliminium ions generated in situ from hydroxylactams is reported. Modest to excellent ee's and yields are obtained in these novel Pictet−Spengler-type reactions with a chiral thiourea-pyrrole catalyst. Useful synthetic transformations of the versatile pyrroloindolizidinone and pyrroloquinolizidinone products are presented.
The use of recombinant fusion proteases in the affinity purification of recombinant proteins.

In the affinity purification of recombinant fusion proteins, the rate-limiting step is usually the efficient proteolytic cleavage and removal of the affinity tail and the protease from the purified recombinant protein. We have developed a rapid, convenient, and efficient method of affinity purification that can overcome this limitation. In one example of the method, the protease 3C from a picornavirus (3Cpro), which cleaves specific sequences containing a minimum of 6–7 amino acids, has been expressed as a fusion with glutathione S-transferase. The resultant recombinant “fusion protease” cleaves fusion proteins bearing (from the aminoterminus) the same affinity tail as the fusion protease, a 3Cpro cleavage recognition site, and the recombinant protein of interest. The recombinant protein is purified in a single chromatographic step, which removes both the affinity tail and the fusion protease. The advantages over existing methods include much improved specificity of proteolytic cleavage, complete removal of the protease and the affinity tail in one step, and the option of adding any desired amount of fusion protease to ensure efficient cleavage. The potential flexibility of the method is shown by the use of various affinity tails and alternative fusion proteases.