cssi/SciSciGPT-SciSciNet huggingface dataset:
The subword complexity of a class of infinite binary words

The gap function of an infinite word over the binary alphabet {0,1} gives the distances between consecutive 1's in this word. In this paper we study infinite binary words whose gap function is injective or ''almost injective.'' A method for computing the subword complexity of such words is given. A necessary and sufficient condition for a function to be the subword complexity function of a binary word whose gap function is increasing is obtained.
A Catalog of Candidate Intermediate-Luminosity X-Ray Objects

ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, intermediate-luminosity (LX[2-10 keV] ≥1039.0 ergs s-1) X-ray objects (IXOs, a.k.a. ULXs [ultraluminous X-ray sources]) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz ≤ 5000 km s-1 from the Third Reference Catalog of Bright Galaxies. We have defined the cutoff LX for IXOs so that it is well above the Eddington luminosity of a 1.4 M☉ black hole (1038.3 ergs s-1), so as not to confuse IXOs with "normal" black hole X-ray binaries. This catalog is intended to provide a baseline for follow-up work with Chandra and XMM-Newton, and with space- and ground-based survey work at wavelengths other than X-ray. We demonstrate that elliptical galaxies with IXOs have a larger number of IXOs per galaxy than nonelliptical galaxies with IXOs and note that they are not likely to be merely high-mass X-ray binaries with beamed X-ray emission, as may be the case for IXOs in starburst galaxies. Approximately half of the IXOs with multiple observations show X-ray variability, and many (19) of the IXOs have faint optical counterparts in DSS optical B-band images. Follow-up observations of these objects should be helpful in identifying their nature.
Time Simulations of the Response of Maneuvering Flexible Aircraft

This work is concerned with time simulations of the response of flying flexible aircraft to initial conditions and external excitations, such as gusts. The simulations are based on a unified formulation of the problem of dynamics and control of maneuvering flexible aircraft developed recently by the authors. The formulation represents a seamless integration of pertinent material from the areas of analytical dynamics, structural dynamics, aerodynamics, and controls. It incorporates both the aircraft rigid-body motions and elastic deformations and it includes the aerodynamic, propulsion, gravity, and control forces, all in a rigorous manner. The formulation lends itself to efficient computer processing of the aircraft response. The formulation contains improvements over the earlier formulation by the authors in the form of a reduced-order structural model and newly designed, easier-to-implement controller and state observer. The corresponding time simulations are entirely new, and no similar results have been obtained by other investigators. The developments should help with the design of the new generation of unmanned aerial vehicles (UAVs) and in particular with the design of autonomous UAVs controlled by autopilots.
Switching speed distribution of spin-torque-induced magnetic reversal

The switching probability of a single-domain ferromagnet under spin-current excitation is evaluated using the Fokker-Planck equation (FPE). In the case of uniaxial anisotropy, the FPE reduces to an ordinary differential equation in which the lowest eigenvalue λ1 determines the slowest switching events. We have calculated λ1 using both analytical and numerical methods. It is found that the previous model based on thermally distributed initial magnetization states [J. Z. Sun et al., Proc. SPIE 5359, 445 (2004)] can be accurately justified in some useful limiting conditions.
Synthesis of Chiral 3-Substituted Indanones via an Enantioselective Reductive-Heck Reaction

An efficient intramolecular palladium-catalyzed, asymmetric reductive-Heck reaction has been developed, which allowed for the synthesis of either enantiomerically enriched 3-substituted indanones or alpha-exo-methylene indanones depending on the base used.
Moral virtue and reasons for action

Moral virtue is a central notion in ethics, and understanding it is a challenge for action theory and moral psychology. It is no easy task to provide an account of it, but even a plausible account of what moral virtue is leaves largely open the difficult question of what it is to act virtuously and the related question of how we can ensure that we do so act. To see the problem, I want to address, consider two points. First, although we can fulfill our obligations by doing the right things—call this behavioral fulfillment of obligation—we deserve little or no credit for doing them if we do not do them for one or more reasons of the right kind. Such creditworthiness is a necessary condition for virtuous fulfillment of obligation. Second, given that acting virtuously is in part a matter of acting for the right kind of reason, and that (as I shall argue) we cannot at will determine for what reasons we act, we cannot act virtuously at will. This holds even when the act that virtue calls for, such as apologizing, is one we can perform at will. Apologizing can be done for a reason of mere self-protection, which is inappropriate to virtue—at least to the kind of virtue, such as respectfulness, which an apology should express. This limitation on acting virtuously is disturbing, perhaps even paradoxical. We think of ourselves as having the voluntary power to conduct ourselves in morally admirable ways. Do we not have that power after all? I shall argue that, in certain ways and under certain conditions, we do. The theory to be presented here will indicate those ways and conditions. It will also bear on the extent to which Aristotle was right in thinking that virtue itself is up to us.1
The Sound of Tropical Cyclones

AbstractUnderwater ambient sound levels beneath tropical cyclones were measured using hydrophones onboard Lagrangian floats, which were air deployed in the paths of Hurricane Gustav (2008) and Typhoons Megi (2010) and Fanapi (2010). The sound levels at 40 Hz–50 kHz from 1- to 50-m depth were measured at wind speeds up to 45 m s−1. The measurements reveal a complex dependence of the sound level on wind speed due to the competing effects of sound generation by breaking wind waves and sound attenuation by quiescent bubbles. Sound level increases monotonically with increasing wind speed only for low frequencies ( 200 Hz), sound level first increases and then decreases with increasing wind speed. There is a wind speed that produces a maximum sound level for each frequency; the wind speed of the maximum sound level decreases with frequency. Sound level at >20 kHz mostly decreases with wind speed over the wind range 15–45 m s−1. The sound field is nearly uniform with depth in the...
A fully implicit Navier-Stokes algorithm using an unstructured grid and flux difference splitting

Abstract An implicit algorithm is developed for the two-dimensional, compressible, laminar Navier-Stokes equations using an unstructured grid of triangles. A sell-centered data structure is employed with the flow variables stored at the centroids of the triangles. The algorithm is based on Roe's flux difference split method for the inviscid fluxes, and a discrete representation of the viscous fluxes and heat transfer using Gauss' Theorem. Linear reconstruction of the flow variables to the cell faces, employed for the inviscid terms, provides second-order spatial accuracy. Interpolation of the flow variables to the nodes is achieved using a second-order accurate method. Temporal discretization employs Euler, trapezoidal or 3-point backward differencing. The complete, exact Jacobian of the inviscid and viscous terms is derived. The algorithm is applied to the Riemann Shock tube problem, a supersonic laminar boundary layer on a flat plate, and subsonic viscous flow past an NACA0012 airfoil. Results are in excellent agreement with theory and previous computations.
Global color and albedo variations on Triton

Global multispectral mosaics of Triton have been produced from Voyager approach images; six spectral units are defined and mapped. The margin of the south polar cap (SPC) is scalloped and ranges in latitude from + 10 deg to -30 deg. A bright fringe is closely associated with the cap's margin; form it, diffuse bright rays extend north-northeast for hundreds of kilometers. Thus, the rays may consist of fringe materials that were redistributed by northward-going Coriolis-deflected winds. From 1977 to 1989, Triton's full-disk spectrum changed from markedly red and UV-dark to nearly neutral white and UV-bright. This spectral change can be explained by new deposition of nitrogen frost over both the northern hemisphere and parts of a formerly redder SPC. Frost deposition in the southern hemisphere during southern summer is possible over relatively high albedo areas of the cap (Stansberry et al., 1990), which helps to explain the apparent stability of the unexpectedly large SPC and the presence of the bright fringe.
Chiral C2 -Symmetric CuII Complexes as Catalysts for Enantioselective Hetero-Diels-Alder Reactions.

Air-stable and recyclable, the CuII -(bis)oxazoline complex 1 efficiently catalyzes diastereo- and enantioselective hetero-Diels-Alder reactions between β,γ-unsaturated α-keto acid derivatives 2 and vinyl ethers for the synthesis of substituted dihydropyrans 3 [Eq. (1)]. Results of the crystal structure analysis of 1 in combination with calculations on model compounds indicate the formation of a reactive intermediate through replacement of the two H2 O ligands with a chelating substrate. X=OEt, N(OMe)Me; R=alkyl, aryl, alkoxy, thiobenzyl.
Large Overlaid Cognitive Radio Networks: From Throughput Scaling to Asymptotic Multiplexing Gain

We study the asymptotic performance of two multi-hop overlaid ad-hoc networks that utilize the same temporal, spectral, and spatial resources based on random access schemes. The primary network consists of Poisson distributed legacy users with density λ^{(p)} and the secondary network consists of Poisson distributed cognitive radio users with density λ^{(s)} = (λ^{(p)})^beta (β > 0, β ≠ 1) that utilize the spectrum opportunistically. Both networks are decentralized and employ ALOHA medium access protocols where the secondary nodes are additionally equipped with range-limited perfect spectrum sensors to monitor and protect primary transmissions. We study the problem in two distinct regimes, namely β > 1 and 0 1. On the contrary, spectrum sensing turns out to be unnecessary when β < 1 and employing spectrum sensors cannot improve the network performances.
An Improved Procedure for the Synthesis of 1,3-Dideazaadenosine

Abstract The preparation of the titled compound has been conveniently achieved in five steps, and in 43% overall yield. The large scale monoreduction of 2,6-dinitroaniline, and the stannic chloride catalyzed glycosylation of 4 to obtain 6 as the only product (86%) are two important reactions in this five step synthesis.
SYMBOL hardware debugging facilities

The SYMBOL system is a full-scale working demonstration of an ALGOL-like, high-level, general-purpose, procedural language and a multi-processing, multi-programming operating system implemented directly in hardware. The results have proven the versatility of the design, construction, and testing techniques that were developed to enable a small number of people to implement such a major system in a reasonable time and at a relatively low cost.
Inter-Modal Network Externalities and Transport Development: Evidence from Roads, Canals, and Ports During the English Industrial Revolution

How does the development of one transport mode influence the development of another? This paper uses time-series data to test whether inter-model network externalities influenced the development of road, canal, and port infrastructure in England from 1760 to 1830. The main finding is that road development had a positive effect on canal development. The results suggest that the option value of waiting to invest in a canal diminished when nearby road improvements were initiated because there was less uncertainty about future profits from canal tolls. They also suggest a reinterpretation of road transport in the Industrial Revolution and point to the general importance of inter-modal network externalities.
Enantioselective synthesis of cyclobutanes via sequential Rh-catalyzed bicyclobutanation/Cu-catalyzed homoconjugate addition.

Enantiomerically enriched cyclobutanes are constructed by a three-component process in which t-butyl (E)-2-diazo-5-arylpent-4-enoates are treated with Rh2(S-NTTL)4 to provide enantiomerically enriched bicyclobutanes, which can subsequently engage in homoconjugate addition/enolate trapping sequence to give densely functionalized cyclobutanes with high diastereoselectivity. This three-component, two-catalyst procedure can be carried out in a single flask. Rh2(S-NTTL)4-catalyzed reaction of t-butyl (Z)-2-diazo-5-phenylpent-4-enoate gives the Buchner cyclization product in excellent enantioselectivity.
Fluorous dienophiles are powerful diene scavengers in Diels-Alder reactions.

Three fluorous dienophiles have been synthesized, and their value in scavenging an excess diene after Diels−Alder reactions is shown. The resulting fluorous derivatives are separated by solid-phase extraction on fluorous silica gel (FSPE). The fluorous [1,2,4]triazoline-3,5-dione 10 reacted with most dienes within seconds or minutes.
The algorithmization of counterfactuals

Recent advances in causal reasoning have given rise to a computation model that emulates the process by which humans generate, evaluate and distinguish counterfactual sentences. Though compatible with the "possible worlds" account, this model enjoys the advantages of representational economy, algorithmic simplicity and conceptual clarity. Using this model, the paper demonstrates the processing of counterfactual sentences on a classical example due to Ernest Adam. It then gives a panoramic view of several applications where counterfactual reasoning has benefited problem areas in the empirical sciences.
Minuteman inertial guidance assessment - The next best thing to flight tests

Techniques have been developed and implemented to enable the continuous assessment of Minuteman inertial guidance performance and in-flight reliability in a situation of relatively few flight tests planned for the remaining service lifetime of the weapon system. The Minuteman force consists of 1000 deployed missiles with guidance systems in full-time operation. Inertial Measurement Unit Performance Data are collected continuously for processing by the Minuteman Data Analysis System. Output data products provide observability of critical parameters measured during the calibration mode and during the normal strategic alert operating mode. Algorithms facilitate the prompt identification of performance anomalies as well as the ensemble statistical characterization of performance parameters. A simulated flight test is used to augment the in-flight reliability data base and to detect possible incipient degradation under the stresses representative of flight. The simulated flight environment is modeled from actual flight shock and vibration data. Systems are selected from the force for this non-destructive test on an unbiased sampling basis.
Towards optimal broadcast in wireless networks

Broadcast is a fundamental operation in networks, especially in wireless Mobile Ad Hoc NETworks (MANET). For example, some form of broadcasting is used by all on-demand MANET routing protocols, when there is uncertainty as to the location of the destination node, or for service discovery. Being such a basic operation of the networking protocols, the importance of efficient broadcasting has long been recognized by the networking community. Numerous papers proposed increasingly more efficient implementation of broadcasting, while other studies presented bounds on broadcast performance. In this work, we present a new approach to efficient broadcast in networks with dynamic topologies, such as MANET, and we introduce a new broadcasting algorithm for such networking environments. We evaluate our algorithm, showing that its performance comes remarkably close to the corresponding theoretical performance bounds. Furthermore, we compare the performance of the proposed algorithm with other recently proposed schemes, especially in the context of various mobility settings.
Fluorescent Switches Based on Photochromic Compounds

The photochemical transformations associated with photochromic compounds can be exploited to switch the emission of complementary fluorophores under the influence of optical stimulations. Specifically, fluorescent and photochromic components can be integrated within the same molecular or supramolecular assembly and the significant changes in thestereoelectronic properties associated with the photoinduced interconversion of one component can be designed to modulate the emission intensity and/or wavelength of the other. In particular, the modifications in absorption properties, conjugation, dipole moment, redox potentials and shape of a photochrome can all be transduced effectively into reversible alterations of the emissive behavior of a fluorophore. Furthermore, some of these ingenious mechanisms for fluorescence modulation can be extended from relatively small molecular and supramolecular assemblies to large macromolecular, nanostructured and biomolecular constructs. In fact, a diversity of chemical systems with photoswitchable luminescence have already emerged on the basis of these operating principles and choice of functional components. Ultimately, these fundamental studies on the photochemical and photophysical signature of multicomponent assemblies might well lead to a new generation of photonic materials with unique properties for possible applications in biomedical imaging and sensing as well as in information processing and storage.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of lactosamine derivatives using β-d-galactosidase from Bacillus circulans

Abstract Various lactosamine derivatives that are versatile building blocks for oligosaccharide synthesis were obtained with excellent regioselectivity and moderate to high yields using β- d -galactosidase from Bacillus circulans as the biocatalyst.
Using computational modeling to assess the impact of clinical decision support on cancer screening improvement strategies within the community health centers

Graphical abstractDisplay Omitted We measure CDS impact on cancer screening using statistical and simulation models.Tests of statistical significance alone do not reveal dynamic changes over time.High performers for CDS use and cancer screening learn faster than low performers.Knowledge absorption rate provides a metric to quantify organizational learning.Computational modeling aids in the assessment of CDS impact on cancer screening. Our conceptual model demonstrates our goal to investigate the impact of clinical decision support (CDS) utilization on cancer screening improvement strategies in the community health care (CHC) setting. We employed a dual modeling technique using both statistical and computational modeling to evaluate impact. Our statistical model used the Spearman's Rho test to evaluate the strength of relationship between our proximal outcome measures (CDS utilization) against our distal outcome measure (provider self-reported cancer screening improvement). Our computational model relied on network evolution theory and made use of a tool called Construct-TM to model the use of CDS measured by the rate of organizational learning. We employed the use of previously collected survey data from community health centers Cancer Health Disparities Collaborative (HDCC). Our intent is to demonstrate the added valued gained by using a computational modeling tool in conjunction with a statistical analysis when evaluating the impact a health information technology, in the form of CDS, on health care quality process outcomes such as facility-level screening improvement. Significant simulated disparities in organizational learning over time were observed between community health centers beginning the simulation with high and low clinical decision support capability.
Laser Doppler Velocimeter Measurement in the Tip Region of a Compressor Rotor

The axial and tangential velocity components near the tip region of a compressor rotor were measured by a laser Doppler velocimeter. The measurements were taken at 25 radial locations in the outer twenty percent of the blade span and at 10 axial locations upstream, inside and at the exit of the rotor. The results are interpreted to derive the behavior of the leakage flow, annulus wall boundary layer growth, inviscid effects and the rotor wake decay characteristics in the tip region. The inviscid and annulus wall boundary layer effects dominate up to quarter chord, beyond which the leakage phenomena has a major influence in altering the flow characteristics in the outer ten percent of the blade span. The annulus wall boundary layer undergoes drastic change through the passage. The velocity field measured near the leading edge reveals the effects of rapid acceleration near the suction surface and the stagnation point on the pressure surface.
Products of characters with few irreducible constituents

Abstract We study the solvable groups G that have an irreducible character χ ∈ Irr ( G ) such that χ χ ¯ has at most two nonprincipal irreducible constituents.
Growth and development of infants with end-stage renal disease receiving long-term peritoneal dialysis

The growth and development of four infants with end-stage renal disease receiving long-term peritoneal dialysis was studied during the first year of life. In each patient, dialysis was begun before 4 weeks of age. A nutritional regimen was designed to attain a daily weight gain appropriate for height age while minimizing the blood urea nitrogen level. A neurodevelopmental evaluation of gross and fine motor, cognitive, language, and psychosoclal skills was performed at least every 3 months. At age 1 year, the mean height standard deviation score (SDS) was −1.33±0.2. Weight for height was >95th percentile in one patient and normal in three. Mean caloric and protein intake were 105±20 kcal/kg/d (11.4±2.7 kcal/cm/d) and 2.7 g/kg/d (0.30±0.11 g/cm/d), respectively. Mean blood urea nitrogen was 53.6±17.8 mg/dL. Developmentally, three of the patients were functioning in the normal range and one was midly retarded. However, gross motor skills were delayed in all patients. Although infants with end-stage renal disease are usually severely growth retarded and developmentally delayed, our observations suggest that early nutritional intervention and dialysis can yield improved results.
Trifluoromethyl ketones: properties, preparation, and application

Trifluoromethyl ketones (TFMKs) are exceedingly valuable synthetic targets in their own right and as synthons in the construction of fluorinated pharmacons. This Feature Article provides an overview of the properties of TFMKs, an in-depth discussion of the methods available for their synthesis, and two illustrative examples of their application as key intermediates in medicinal chemistry.
Crystal Structure of 4H BaRuO3: High Pressure Phase Prepared at Ambient Pressure☆

Abstract Single crystals of BaRuO 3 were grown using a BaCl 2 flux at ambient pressure. Most of the crystals had the nine-layer rhombohedral structure (9R) which is considered to be the stable form of BaRuO 3 at ambient pressure. However, some BaRuO 3 crystals in this preparation had the four-layer hexagonal (4H) structure which had been considered as a phase produced only at high pressure (15–30 kbar). The crystal structure of 4H BaRuO 3 was refined for the first time. Single crystal X-ray diffraction data gave a space group of P 6 3 / mmc (No. 194), a =5.729(1) A, c =9.500(1) A, Z =4, a final conventional R (based on F 0 ) of 2.01%, and a wR 2 (based on F 2 0 ) of 4.07%. The structure of 4H BaRuO 3 may be described as perovskite-related with a four-layer stacking of BaO 3 layers in the sequence hchc . This leads to pairs of face-sharing RuO 6 octahedra which are connected to other octahedra by corner sharing. The Ru–Ru distance in the Ru 2 O 9 dimer of 4H BaRuO 3 is 2.537(1) A which indicates the presence of a metal–metal bond.
Trends in health personnel.

Each quarter Health Affairs reports the significant trends in four sectors of the health care sphere: health personnel in Winter; health status and health care utilization in Spring; health care in...
What Is the Atmosphere's Effect on Earth's Surface Temperature?

It is frequently stated in textbooks and scholarly articles that the surface temperature of Earth is 33°C warmer than it would be without the atmosphere and that this difference is due to the greenhouse effect. This Forum shows that the atmosphere effect leads to warming of only 20°C. This new conclusion requires a revision to all of the relevant literature in K-12, undergraduate, and graduate education material and to science papers and reports.
Quantum integrable systems in one dimension

Abstract A survey is presented of recent developments in one-dimensional integrable systems, in particular generalisations of the one-dimensional Heisenberg spin one-half chain. The power of analytic techniques for the transfer matrix is emphasized. Some remarkable recent results for inverse-square systems are discussed.
The interaction structure and cosmological relevance of mass scales in string motivated supersymmetric theories

Abstract A string motivated, N =1 global supersymmetric, general Lagrangian is obtained that represents an inflaton interacting with the modes of a string. Focus is placed on the Lagrangian's relevance to warm inflation, which is a cosmology based on dissipative dynamics. Several interaction schemes are identified from the general Lagrangian that may have interesting consequences for dissipative dynamics. Distributed-mass-models, which have been shown to solve the horizon problem within a warm inflation regime, are identified in the general Lagrangian.
Distribution Costs and International Trade: A Ricardian Model

This paper studies the role of the distribution sector in determining a country’s pattern and terms of trade. The effect of an improvement in distribution technology is analyzed using a Ricardian trade model with an endogenous distribution sector. The results are found to depend on the magnitude of distribution costs relative to manufacturing costs and preference for distribution services in the trading countries. This has important implications for the Structural Impediments Initiative, which maintains that a more efficient distribution sector in Japan would benefit both the USA and Japan.
MIGRATION OF TRANS-NEPTUNIAN OBJECTS TO THE TERRESTRIAL PLANETS

The orbital evolution of more than 22000 Jupiter-crossing objects under the gravitational influence of planets was investigated. We found that the mean collision probabilities of Jupiter-crossing objects (from initial orbits close to the orbit of a comet) with the terrestrial planets can differ by more than two orders of magnitude for different comets. For initial orbital elements close to those of some comets (e.g., 2P and 10P), about 0.1% of objects got Earth-crossing orbits with semi-major axes a < 2 AU and moved in such orbits for more than a Myr (up to tens or even hundreds of Myrs). Results of our runs testify in favor of at least one of these conclusions: (1) the portion of 1-km former trans-Neptunian objects (TNOs) among near-Earth objects (NEOs) can exceed several tens of percent, (2) the number of TNOs migrating inside the solar system could be smaller by a factor of several than it was earlier considered, (3) most of 1-km former TNOs that had got NEO orbits disintegrated into mini-comets and dust during a smaller part of their dynamical lifetimes if these lifetimes are not small.
The decomposition of unsaturated hydrocarbons on small Pd particles

Abstract The decomposition of propylene, acetylene, and methylacetylene on the surfaces of small supported Pd particles has been investigated using flash thermal desorption of CO, Auger electron spectroscopy, and transmission electron microscopy. Pd crystallite size distributions averaged 2 to 14 nm in diameter. Samples were prepared by vapor deposition of high-purity Pd onto clean mica surfaces cleaved and annealed under ultrahigh vacuum. Our results reveal that (a) the hydrocarbons decompose at certain sites, contaminating such sites to prevent subsequent reaction or CO adsorption and (b) the surface density of decomposition sites is particle size dependent, being greater on smaller particles. A simple kinetic model and computerized curve fitting are used to compare the behavior of the above gases with that of ethylene presented in previous work. This analysis shows a significant difference in decomposition properties between those hydrocarbons containing a double CC bond and those with a triple CC bond.
Red- versus Blue-Shifting Hydrogen Bonds: Are There Fundamental Distinctions?

The OH covalent bond of conventional hydrogen bonds of the OH···O type undergoes a lengthening as a result of the complex formation, and the OH stretching frequency shifts to the red; the same is t...
Cluster Ensemble Selection

This paper studies the ensemble selection problem for unsupervised learning. Given a large library of different clustering solutions, our goal is to select a subset of solutions to form a smaller yet better-performing cluster ensemble than using all available solutions. We design our ensemble selection methods based on quality and diversity, the two factors that have been shown to influence cluster ensemble performance. Our investigation revealed that using quality or diversity alone may not consistently achieve improved performance. Based on our observations, we designed three different selection approaches that jointly consider these two factors. We empirically evaluated their performance in comparison with both full ensembles and a random selection strategy. Our results indicate that by explicitly considering both quality and diversity in ensemble selection, we can achieve statistically significant performance improvement over full ensembles. Copyright © 2008 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 1: 000-000, 2008
Theoretical and numerical properties of a gyrokinetic plasma: issues related to transport time scale simulation

Particle simulation has played an important role for the recent investigations on turbulence transport in magnetically confined plasmas. In this paper, theoretical and numerical properties of a gyrokinetic plasma as well as its relationship with magnetohydrodynamics (MHD) are discussed with the ultimate aim of simulating microturbulence on transport time scale using massively parallel computers.
DESIGN CONSIDERATIONS FOR HIGH-INTENSITY NEGATIVE ION SOURCES

Abstract An attempt has been made to improve the output of negative hydrogen ions, which are extracted directly from a hot-cathode Philips-ion-gauge type of discharge. The discharge chamber has been modified to accord with assumptions made as to the probable formation mechanism of the negative ions observed. Negative hydrogen ion currents in excess of 5 mA have been obtained. Ion source operating parameters, as well as considerations for the utilization of this discharge geometry by negative ion cyclotrons, are discussed.
Designing Institutions to Deal with Terrorism in the United States

The explosion in the 21st century of terrorist activities by Islamic radicals in the United States, Europe and Asia requires reforming the institutions for domestic counterterrorism (CT) and new international relations among individual national CT organizations. This paper discusses the institutional reforms for CT in the United States, focusing particularly on the changes in the FBI. These changes are compared with the way that the British CT activities of the MI5 and MI6 have evolved in response to terrorism in Britain. The paper also discusses the reasons why there is strong cooperation among the CT activities of all the major governments and with the United States in particular, even when those governments do not agree about military cooperation or about the use of economic sanctions.
INDUCED QUANTUM NUMBERS IN SOME 2 + 1 DIMENSIONAL MODELS

The fermion current induced by slow variations in background scalar and gauge fields are computed for a class of 2 + 1 dimensional σ-like models. Local current densities proportional to topological currents in the background fields are found. The coefficient depends discontinuously on certain field ratios. The induced fermion numbers we find, mesh nicely with recent results on induced angular momentum and induced statistics. In particular, the spin and statistics is intimately related to the global parity anomaly. Lattice realizations are suggested.
Mass and Spin Renormalization in Lorentz Electrodynamics

Abstract Lorentz' objection to the Uhlenbeck–Goudsmit proposal of a spin magnetic moment of the electron, namely that the electron's equatorial rotation speed would exceed the speed of light by a factor ≈10, mutated into an objection against Lorentz electrodynamics (LED) itself when the spin magnetic moment became established. However, Lorentz' renormalization calculation, based on the early 20th century's notion of a purely electromagnetic electron, does not qualify as proper from a modern perspective. This paper shows that renormalization treated properly does lead to a mathematically consistent and physically viable LED. A new, relativistically covariant massive LED is presented in which the bare particle has a finite positive bare rest mass and moment of inertia. The particle's electromagnetic self-interaction renormalizes its mass and spin. Most crucially, the renormalized particle is a soliton : after any scattering process its rest mass and spin magnitude are dynamically restored to their pre-scattering values. This guarantees that “an electron remains an electron,” poetically speaking. A renormalization flow study of the limit of vanishing bare rest mass is conducted for this model. This limit yields a purely electromagnetic classical field theory with ultra-violet cutoff at about the electron's Compton wavelength! The renormalized limit model matches the empirical electron data as orderly as one can hope for at the level of Lorentz theory. In particular, no superluminal equatorial speeds occur.
Nonlinear elasticity, fluctuations and heterogeneity of nematic elastomers

Abstract Liquid crystal elastomers realize a fascinating new form of soft matter that is a composite of a conventional crosslinked polymer gel (rubber) and a liquid crystal. These solid liquid crystal amalgams, quite similarly to their (conventional, fluid) liquid crystal counterparts, can spontaneously partially break translational and/or orientational symmetries, accompanied by novel soft Goldstone modes. As a consequence, these materials can exhibit unconventional elasticity characterized by symmetry-enforced vanishing of some elastic moduli. Thus, a proper description of such solids requires an essential modification of the classical elasticity theory. In this work, we develop a rotationally invariant , nonlinear theory of elasticity for the nematic phase of ideal liquid crystal elastomers. We show that it is characterized by soft modes, corresponding to a combination of long wavelength shear deformations of the solid network and rotations of the nematic director field. We study thermal fluctuations of these soft modes in the presence of network heterogeneities and show that they lead to a large variety of anomalous elastic properties, such as singular length-scale dependent shear elastic moduli, a divergent elastic constant for splay distortion of the nematic director, long-scale incompressibility, universal Poisson ratios and a nonlinear stress–strain relation for arbitrary small strains. These long-scale elastic properties are universal , controlled by a nontrivial zero-temperature fixed point and constitute a qualitative breakdown of the classical elasticity theory in nematic elastomers. Thus, nematic elastomers realize a stable “critical phase”, characterized by universal power-law correlations, akin to a critical point of a continuous phase transition, but extending over an entire phase.
The biological potential of Mars, the early Earth, and Europa

The potential biomass that could have existed on Mars is constrained by the total amount of energy available to construct it. From an inventory of the available geochemical sources of energy, we estimate that from the time of the onset of the visible geologic record 4 b.y. ago to the present, as much as 20 g cm−2 of biota could have been created. This is the same amount that could have been constructed on the early Earth in only 100 million years. This indicates that there likely was sufficient energy available to support an origin of life on Mars but not sufficient energy to create a ubiquitous and lush biosphere. Similar calculations for Europa suggest that even less geochemical energy would have been available there.
Towards a science of trust

The diverse views of science of security have opened up several alleys towards applying the methods of science to security. We pursue a different kind of connection between science and security. This paper explores the idea that security is not just a suitable subject for science,. but that the process of security is also similar to the process of science. This similarity arises from the fact that both science and security depend on the methods of inductive inference. Because of this dependency, a scientific theory can never be definitely proved, but can only be disproved by new evidence, and improved into a better theory. Because of the same dependency, every security claim and method has a lifetime, and always eventually needs to be improved.In this general framework of security-as-science, we explore the ways to apply the methods of scientific induction in the process of trust. The process of trust building and updating is viewed as hypothesis testing. We propose to formulate the trust hypotheses by the methods of algorithmic learning, and to build more robust trust testing and vetting methodologies on the solid foundations of statistical inference.
The Chern–Gauss–Bonnet Theorem via Supersymmetric Euclidean Field Theories

We prove the Chern–Gauss–Bonnet Theorem using sigma models whose source supermanifolds have super dimension 0|2. Along the way we develop machinery for understanding manifold invariants encoded by families of 0|δ-dimensional Euclidean field theories and their quantization.
Rheology of arc dacite lavas: experimental determination at low strain rates

Andesitic–dacitic volcanoes exhibit a large variety of eruption styles, including explosive eruptions, endogenous and exogenous dome growth, and kilometer-long lava flows. The rheology of these lavas can be investigated through field observations of flow and dome morphology, but this approach integrates the properties of lava over a wide range of temperatures. Another approach is through laboratory experiments; however, previous studies have used higher shear stresses and strain rates than are appropriate to lava flows. We measured the apparent viscosity of several lavas from Santiaguito and Bezymianny volcanoes by uniaxial compression, between 1,109 and 1,315 K, at low shear stress (0.085 to 0.42 MPa), low strain rate (between 1.1 × 10−8 and 1.9 × 10−5 s−1), and up to 43.7 % total deformation. The results show a strong variability of the apparent viscosity between different samples, which can be ascribed to differences in initial porosity and crystallinity. Deformation occurs primarily by compaction, with some cracking and/or vesicle coalescence. Our experiments yield apparent viscosities more than 1 order of magnitude lower than predicted by models based on experiments at higher strain rates. At lava flow conditions, no evidence of a yield strength is observed, and the apparent viscosity is best approached by a strain rate- and temperature-dependent power law equation. The best fit for Santiaguito lava, for temperatures between 1,164 and 1,226 K and strain rates lower than 1.8 × 10−4 s−1, is $$ \log {\eta_{\text{app}}} = - 0.738 + 9.24 \times {10^3}{/}T(K) - 0.654 \cdot \log \dot{\varepsilon } $$ where η app is apparent viscosity and $$ \dot{\varepsilon } $$ is strain rate. This equation also reproduced 45 data for a sample from Bezymianny with a root mean square deviation of 0.19 log unit Pa s. Applying the rheological model to lava flow conditions at Santiaguito yields calculated apparent viscosities that are in reasonable agreement with field observations and suggests that internal shear heating may be significant ongoing heat source within these flows, enabling highly viscous lava to travel long distances.
Dirhodium Tetra(N-arylsulfonylprolinates) as Chiral Catalysts For Asymmetric Transformations of Vinyl- and Aryldiazoacetates

Rhodium(II( prolinates are superb catalysts for asymmetric transformations of vinyldiazoacetates and phenyldiazoacetates. The most well-developed transformation is the [3 + 4] annulation between vinyldiazoacetates and dienes which is a very general method for the stereoselective synthesis of highly functionalized seven-membered rings. Recent studies have led to a general method for asymmetric intermolecular C–H activation which displays promising regio- and diastereocontrol in addition to the enantiocontrol.
Cluster forming and cage fusion in metallacarborane chemistry

Abstract Multidecker sandwich complexes in which transition metal centers are bridged by C 2 B 3 carborane rings are organometallic species by definition, and are close electronic and structural relatives of metallocenes and metal-arene sandwiches. At the same time, these complexes can be described as 7-vertex MC 2 B 3 M′ or MC 2 B 4 metallacarborane clusters and manifest chemical properties typical of that class, such as cage rearrangement and metal insertions into the polyhedral framework. Their “boron cluster” character is particularly evident in metal-promoted oxidative fusion reactions in which two 6-vertex nido -MC 2 B 3 cages are fused face to face to form a 12-vertex M 2 C 4 B 6 cluster. Such fusions often occur as competitive processes in the synthesis of multidecker sandwich complexes via metal stacking reactions. In this article we discuss the propensity of small metal-boron units to undergo clustering, centering on the factors that promote such reactions and strategies that can be employed to control and exploit them for synthetic purposes. Specific examples of unusual cluster geometries, some of them unique, that have been obtained via fusion will be treated from both synthetic and structural perspectives.
Occam's Higgs: A Phenomenological solution to the electroweak hierarchy problem

We propose a phenomenological solution to the electroweak hierarchy problem. It predicts no new particles beyond those in the Standard Model. The Higgs is arbitrarily massive and slow-roll inflation can be implemented naturally. Loop corrections will be negligible even for large cutoffs.
The synthesis of (±)-gelsemine

Abstract The synthesis of (±)-gelsemine has been completed from tetracyclic intermediate 2 via a stereospecific [3,3]-rearrangement followed by a one carbon excision to convert a δ-lactam ( 13 ) to a γ-lactam ( 19 ).
Synthesis of betulinic acid derivatives with activity against human melanoma

Betulinic acid has been modified at C-3, C-20, and C-28 positions and the toxicity of the derivatives has been evaluated against cultured human melanoma (MEL-2) and human epidermoid carcinoma of the mouth (KB) cell lines. This preliminary investigation demonstrates that simple modifications of the parent structure of betulinic acid can produce potentially important derivatives, which may be developed as antitumor drugs.
Finding a Working Balance Between Competitive and Communal Strategies

This paper presents a dynamic framework that describes how firms allocate limited resources between improving their competitive position relative to rivals and their communal position shared with rivals. This dynamic framework outlines how organizational field-level dynamics influence industry attractiveness and thereby alter a firm's incentive to engage in communal strategy relative to competitive strategy. Communal strategy, in turn, can influence the institutions governing an organizational field and thereby shape industry attractiveness. Overall, the interplay between factors exogenous and endogenous to an industry cause change in an organizational field and so determine the nature of the communal environment shared by a firm and its rivals over time. Analysis of this interplay provides insight into the micro-level drivers of macro-level change and furthers understanding of the conditions under which rivalrous firms voluntarily contribute to collective betterment of their industry despite collective rationality.
Complex scattering dynamics and the quantum Hall effect

We review both classical and quantum potential scattering in two dimensions in a magnetic field, with applications to the quantum Hall effect. Classical scattering is complex, due to the approach of scattering states to an infinite number of dynamically bound states. Quantum scattering follows the classical behavior rather closely, exhibiting sharp resonances in place of the classical bound states. Extended scatterers provide a quantitative explanation for the breakdown of the QHE at a comparatively small Hall voltage as seen by Kawaji et al., and possibly for noise effects.
Spanning sets for automorphic forms and dynamics of the frame flow on complex hyperbolic spaces

Let G be a semisimple Lie group with no compact factors, K a maximal compact subgroup of G , and \Gamma a lattice in G . We study automorphic forms for \Gamma if G is of real rank one with some additional assumptions, using a dynamical approach based on properties of the homogeneous flow on \Gamma\backslash G and a Livshitz type theorem we prove for such a flow. In the Hermitian case G=SU(n,1) we construct relative Poincare series associated to closed geodesics on \Gamma\backslash G/K for one-dimensional representations of K , and prove that they span the corresponding spaces of holomorphic cusp forms.
Realization of center symmetry in two adjoint flavor large-N Yang-Mills

We report on the results of numerical simulations of SU(N) lattice Yang Mills with two flavors of (light) Wilson fermion in the adjoint representation. We analytically and numerically address the question of center symmetry realization on lattices with Γ sites in each direction in the large-N limit. We show, by a weak coupling calculation that, for massless fermions, center symmetry realization is independent of Γ, and is unbroken. Then, we extend our result by conducting simulations at non zero mass and finite gauge coupling. Our results indicate that center symmetry is intact for a range of fermion mass in the vicinity of the critical line on lattices of volume 24 . This observation makes it possible to compute infinite volume physical observables using small volume simulations in the limit N → ∞, with possible applications to the determination of the conformal window in gauge theories with adjoint fermions.
Addition of cyclic ethers and acetals to ethyl 3,3-difluoro-2-methylpropenoate

Abstract Ethyl 3,3-difluoro-2-methylpropenoate forms 1 : 1 adducts with tetrahydrofuran and 1,3-dioxolanes under free radical conditions. In contrast no 1 : 1 adducts are observed when tetrahydropyran and 1,3-dioxanes are used as sources of α-alkoxy radicals. An explanation is presented based on FMO and radical stability arguments.
Risk-informed assessment of degraded containment vessels

This study couples structural analyses of four typical U.S. nuclear power plant containments with existing probabilistic risk assessment (PRA) models to assess the effects of degradation. This method is used to determine the increase in the early release frequencies (risk) due to postulated cases of corrosion in the steel liners and shells, as well as other forms of degradation.