cssi/SciSciGPT-SciSciNet huggingface dataset:
Excess capacity as a policing device

Abstract A great deal of recent work has been devoted to the question of whether an incumbent firm can successfully deter entry by investing in excess capacity. This paper demonstrates that a dominant firm may invest in excess capacity even when it is certain that this will not deter entry. Rather, the excess capacity is held by the dominant firm in order to ensure that its competitors will exercise appropriate restraint in their own output decisions. An example is provided that illustrates that the rate of return on the capital invested in excess capacity may be very high.
On the Tree Packing Conjecture

The Gyarfas tree packing conjecture states that any set of $n-1$ trees $T_{1},T_{2},\dots, T_{n-1}$ such that $T_i$ has $n-i+1$ vertices packs into $K_n$ (for $n$ large enough). We show that $t=\frac{1}{10}n^{1/4}$ trees $T_1,T_2,\dots, T_t$ such that $T_i$ has $n-i+1$ vertices packs into $K_{n+1}$ (for $n$ large enough). We also prove that any set of $t=\frac{1}{10}n^{1/4}$ trees $T_1,T_2,\dots, T_t$ such that no tree is a star and $T_i$ has $n-i+1$ vertices packs into $K_{n}$ (for $n$ large enough). Finally, we prove that $t=\frac{1}{4}n^{1/3}$ trees $T_1,T_2,\dots, T_t$ such that $T_i$ has $n-i+1$ vertices packs into $K_n$ as long as each tree has maximum degree at least $2n^{2/3}$ (for $n$ large enough). One of the main tools used in the paper is the famous spanning tree embedding theorem of Komlos, Sarkozy, and Szemeredi [Combin. Probab. Comput., 10 (2001), pp. 397--416].
Scanning simulation procedures for calculation of the entropy, the pressure and the chemical potential of many-chain systems

Using the scanning and the hypothetical scanning methods we study a system of many chains with excluded volume contained in a “box” on a square lattice. With these methods the sampling probability P of a configuration can be calculated and therefore the entropy S is known (S ∼ ln P) without the need to resort to thermodynamic integration. Thus, the pressure and the chemical potential can be calculated with high accuracy directly from the entropy using standard thermodynamic relations. The computer simulation results are compared to the approximate theories of Flory, Huggins, Miller and Guggenheim and to the recent improved theories of Freed and co-workers.
Approaches for modeling magnetic nanoparticle dynamics

Magnetic nanoparticles are useful biological probes as well as therapeutic agents. There have been several approaches used to model nanoparticle magnetization dynamics for both Brownian as well as Neel rotation. The magnetizations are often of interest and can be compared with experimental results. Here we summarize these approaches including the Stoner-Wohlfarth approach, and stochastic approaches including thermal fluctuations. Non-equilibrium related temperature effects can be described by a distribution function approach (Fokker-Planck equation) or a stochastic differential equation (Langevin equation). Approximate models in several regimes can be derived from these general approaches to simplify implementation.
Electron Densities in Planetary Nebulae

A large sample of forbidden lines -[O II], [S II], [Ar IV], and [N I]— have been analyzed to obtain electron densities for 134 planetary nebulae.
Implications of the chiral anomaly for quantum Hall-effect devices.

The anomaly equation ${\ensuremath{\partial}}_{\ensuremath{\mu}}$${J}_{5}$${}^{\ensuremath{\mu}}$=-(${e}^{2}$/8${\ensuremath{\pi}}^{2}$ ${\ensuremath{\Elzxh}}^{2}$c) (${F}_{\ensuremath{\lambda}\ensuremath{\sigma}}^{\mathrm{*}}$${F}^{\ensuremath{\lambda}\ensuremath{\sigma}}$) is used to derive a relationship between the filling factor (\ensuremath{\nu}) and the Hall conductance on the gate capacitor of a field-effect-transistor device. In addition, the chiral phase (\ensuremath{\theta}) states are shown to be related to those of the filling factor by \ensuremath{\Vert}\ensuremath{\theta}〉=\ensuremath{\Vert}2\ensuremath{\pi}\ensuremath{\nu}〉. .AE
Using the Computer to Improve Unit Teaching

Dr. Robert S. Harnack and associates have developed a revolutionary method designed to eliminate the disadvantages, but to retain and improve the advantages of unit teaching. The electronic computer is applied to provide teachers with pre-planning suggestions from a large Computer-Based Resource Unit coded to the students' individual characteristics and objectives.
Simulation modeling and methodology

Simulation is one of the most powerful analysis tools available to those responsible for the design and/or operation of complex processes or systems. It is heavily based upon computer science, mathematics, probability theory and statistics: yet the process of simulation modeling and experimentation remains very much an intuitive art. Simulation is a very general and somewhat ill-defined subject. For the purpose of this paper, we will define simulation as, "the or process of designing a computerized model of a system (or process) and conducting experiments with this model for the purpose either of understanding the behavior of the system and/or of evaluating various strategies for the operation of the system." Thus we will understand the process of simulation to include both the construction of the model and the analytical use of the model for studying a Problem.
Chiral Ru-Based Complexes for Asymmetric Olefin Metathesis: Enhancement of Catalyst Activity through Steric and Electronic Modifications

Design, synthesis, characterization, and catalytic activity of six enantiomerically pure Ru-based metathesis catalysts are disclosed (3a-3f). The new chiral catalysts were prepared through steric and electronic alterations of the parent catalyst system (3). The present studies indicate that the effect of structural modifications of chiral complex 3 does not always correspond to those of the related achiral complexes. The present findings illustrate that modified Ru complexes (3e and 3f) deliver reactivity levels that are more than 2 orders of magnitude higher than 3. Reactivity and physical data are provided that shed light on the origin of activity differences. Some members of the new generation of chiral Ru catalysts promote asymmetric ring-opening (AROM) and ring-closing (ARCM) metatheses that cannot be effected by the first generation chiral catalyst (3).
Computational evaluation and comparison of some nitramine properties

A computational study of six nitramines, R/sub 1/R/sub 2/NNO/sub 2/, has been carried out with the objective of gaining a better understanding of how the properties of the NNO/sub 2/ group are affected by the natures of R/sub 1/ and R/sub 2/. An ab initio SCF procedure was used, with the initial step being the determination of each molecule's optimized geometry. This was subsequently used to compute its bond orders, dipole moment, and electrostatic potential. In most instances, the NNO/sub 2/ portions of the molecules are planar, due to the strong electron-withdrawing effect of the nitro group; the amino-type nitrogen can better respond to this when in a planar configuration. One consequence is that the N-NO/sub 2/ bonds possess some degrees of double bond character; their bond orders range from 1.36 to 1.63, with the weaker bonds corresponding to the more electron-withdrawing R/sub 1/ and R/sub 2/ groups. The strong negative electrostatic potentials normally associated with the lone pairs of amino-type nitrogens are greatly weakened or eliminated in most of these molecules; several of them show evidence of significant hyperconjugation, resulting in enhanced acidic character.
The Effects of Motion on Distributed Detection in Mobile Ad Hoc Sensor Networks

We consider a set of mobile wireless sensors that collect observations about a brief, localized event. As they continue to move about, one of them processes its observations, decides that an event of interest occurred, and wants to determine if other sensors confirm its results. This sensor assumes the role of a Cluster Head (CH) and requests that all other sensors that collected observations at that time/location reply to it with their decisions. The motion of the sensors since the observation time determines how many wireless hops their decision must cross to reach the CH. We analyze the effect of this motion in the 1D case by modeling each sensor's motion as a Correlated Random Walk (CRW). We also account for measurement errors and communication or processing errors in each wireless hop. Quantities, such as the error probability of the final decision at the CH and the minimum energy required to collect the local decisions from all relevant sensors, can then be directly calculated as functions of time a...
Symmetry of massive Rarita-Schwinger fields

We derive the general Lagrangian and propagator for a vector-spinor field in d-dimensions and show that the physical observables are invariant under the so-called point transformation symmetry. Until now the symmetry has not been exploited in any nontrivial way, presumably because it is not an invariance of the classical action nor is it a gauge symmetry. Nevertheless, we develop a technique for exploring the consequences of the symmetry leading to a conserved vector current and charge. The current and charge are identically zero in the free field case and only contribute in a background such as a electromagnetic or gravitational field. The current can couple spin- fields to vector and scalar fields and may have important consequences in intermediate energy hadron physics as well as linearized supergravity. The consistency problem which plagues higher spin field theories is then discussed and some ideas regarding the possibility of solutions are presented.
Biochemical evidence for an alternate pathway in N-linked glycoprotein biosynthesis

N-linked glycosylation in archaea has generally been assumed to follow the logic determined for bacterial and eukaryotic pathways. Biochemical investigations of the process in Methanococcus voltae now allow the functional assignment of three enzymes that generate and use an unusual monophosphate intermediate, drawing distinctions between domains of life.
A Distributive Lattice Connected with Arithmetic Progressions of Length Three

Let $$\mathcal {T}$$ be a collection of 3-element subsets $$S$$ of $$\{1,\dots ,n\}$$ with the property that if $$i<j<k$$ and $$a<b<c$$ are two 3-element subsets in $$S$$ , then there exists an integer sequence $$x_1<x_2<\cdots <x_n$$ such that $$x_i,x_j,x_k$$ and $$x_a,x_b,x_c$$ are arithmetic progressions. We determine the number of such collections $$\mathcal {T}$$ and the number of them of maximum size. These results confirm two conjectures of Noam Elkies.
Synthesis of main-group graphite fluoroanion salts with chlorine-assisted oxidation by Lewis-acid fluorides

Abstract Graphite intercalation compounds of main-group acid fluorides have been prepared for the first time utilizing Cl 2 as an oxidizing agent. The reactions of several acid fluorides (GeF 4 , PF 5 and BF 3 ) with graphite and either Cl 2 or Cl 2 +HF can produce intercalation salts similar to those obtained by the action of elemental fluorine and the acid fluoride on graphite. These reactions have been followed by X-ray powder diffraction, IR spectroscopy and elemental analysis. The vacuum-stable products of all these reactions are graphite intercalation salts of fluoroanions containing only traces of chlorine. The reaction enthalpies for the appropriate reduction half-reactions have been calculated and found to correlate closely with the extent of intercalation observed. These results are compared with those obtained previously on reactions which generate graphite fluorometallate salts, and are discussed in terms of a simple thermodynamic model for graphite intercalation.
Optimal pricing in a free market wireless network

We consider an ad-hoc wireless network operating within a free market economic model. Users send data over a choice of paths, and scheduling and routing decisions are updated dynamically based on time varying channel conditions, user mobility, and current network prices charged by intermediate nodes. Each node sets its own price for relaying services, with the goal of earning revenue that exceeds its time average reception and transmission expenses. We first develop a greedy pricing strategy that maximizes social welfare while ensuring all participants make non-negative profit. We then construct a (non-greedy) policy that balances profits more evenly by optimizing a profit fairness metric. Both algorithms operate in a distributed manner and do not require knowledge of traffic rates or channel statistics. This work demonstrates that individuals can benefit from carrying wireless devices even if they are not interested in their own personal communication.
Digital subtraction angiography of the aortic arch

We evaluated the utility of intravenous digital subtraction angiography (IV DSA) for diagnosing lesions of the aortic arch and great vessels in 25 patients. Digital subtraction angiography (DSA) was found useful in evaluating congenital and acquired lesions of the arch and great vessel origins, and it proved adequate for follow-up of patients who had graft replacement. Cases examined included: right aortic arch, double arch, aortic coarctation, aberrant vascular origins, aortic aneurysm and pseudoaneurysm, changes in atherosclerotic great vessels, and revascularization procedures for patients with pulmonary atresia and aortic interruption. In our experience, DSA is a useful tool for screening and following patients with aortic arch or great vessel lesions; it is often the only diagnostic imaging examination necessary.
PROBING THE STAR FORMATION HISTORY AND INITIAL MASS FUNCTION OF THE z ∼ 2.5 LENSED GALAXY SMM J163554.2+661225 WITH HERSCHEL

We present the analysis of Herschel Spectral and Photometric Imaging Receiver far-infrared (FIR) observations of the z = 2.515 lensed galaxy SMM J163554.2+661225. Combining new 250, 350, and 500 μm observations with existing data, we make an improved fit to the FIR spectral energy distribution of this galaxy. We find a total infrared (IR) luminosity of L(8-1000 μm) = 6.9 ± 0.6 × 1011 L ☉, a factor of three more precise over previous L IR estimates for this galaxy, and one of the most accurate measurements for any galaxy at these redshifts. This FIR luminosity implies an unlensed star formation rate (SFR) for this galaxy of 119 ± 10 M ☉ yr–1, which is a factor of 1.9 ± 0.35 lower than the SFR derived from the nebular Paα emission line (a 2.5σ discrepancy). Both SFR indicators assume an identical Salpeter initial mass function (IMF) with slope Γ = 2.35 over a mass range of 0.1-100 M ☉; thus this discrepancy suggests that more ionizing photons may be necessary to account for the higher Paα-derived SFR. We examine a number of scenarios and find that the observations can be explained with a varying star formation history (SFH) due to an increasing SFR, paired with a slight flattening of the IMF. If the SFR is constant in time, then larger changes need to be made to the IMF by either increasing the upper mass cutoff to ~200 M ☉, or a flattening of the IMF slope to 1.9 ± 0.15, or a combination of the two. These scenarios result in up to double the number of stars with masses above 20 M ☉, which produce the requisite increase in ionizing photons over a Salpeter IMF with a constant SFH.
Pt-Catalyzed Enantioselective Diboration of Terminal Alkenes with B2(pin)2

The Pt-catalyzed enantioselective addition of bis(pinacolato)diboron to simple monosubstituted alkenes is described. This reaction occurs in the presence of a readily available chiral phosphonite ligand and is effective with a variety of terminal alkene substrates. Importantly, the reaction can operate with catalyst loadings of only 1 mol % Pt. While oxidation of the intermediate 1,2-bis(boronate) ester provides the chiral 1,2-diol as the reaction product, the intermediate may also be subjected to homologation/oxidation to furnish a chiral 1,4-diol as the reaction product.
The Search for Intergalactic Hydrogen Clouds in Voids

I present the results of a search for intergalactic hydrogen clouds in voids. Clouds are detected by their H I Lyα absorption lines in the Hubble Space Telescope spectra of low-redshift active galactic nuclei. The parameter with which the environments of clouds are characterized is the tidal field, for this places a lower limit on the cloud mass density that is dynamically stable against disruption. The summing of the tidal fields along these lines of sight is managed by the use of galaxy redshift catalogs. The analytical methodology employed here has been designed to detect gas clouds whose expansion following reionization is restrained by dark matter perturbations. The end products of the analysis of data are the cloud equivalent width distribution functions (EWDFs) of catalogs formed by sorting clouds according to various tidal field upper or lower limits. Cloud EWDFs are steep in voids [d log(d/dz)/d log() = ~ -1.5 ± 0.2] but flatter in high tidal field zones ( ~ -1.5 ± 0.6). The most probable cloud Doppler parameters are ~30 km s-1 in voids and ~60 km s-1 in proximity to galaxies. In voids the cumulative line density at low EW ( 15 mA) is essentially equal to that of the mean EWDF, ~500 per unit redshift. The void filling factor is found to be 0.87 ≤ fv ≤ 0.94. The void EWDF is remarkably uniform over this volume, with a possible tendency for more massive clouds to be in void centers. The size and nature of the void cloud population suggested by this study is completely unanticipated by the results of published three-dimensional simulations, which predict that most clouds are in filamentary structures around galaxy concentrations and that very few observable absorbers would lie in voids. Strategies for modeling this population are briefly discussed.
Nonlinear evolution of the magnetothermal instability in two dimensions

In weakly magnetized, dilute plasmas in which thermal conduction along magnetic field lines is important, the usual convective stability criterion is modified. Instead of depending on entropy gradients, instability occurs for small wavenumbers when (∂P/∂z)(∂ ln T/∂z) > 0, which we refer to as the Balbus criterion. We refer to the convective instability that results in this regime as the magnetothermal instability (MTI). We use numerical MHD simulations that include anisotropic electron heat conduction to follow the growth and saturation of the MTI in two-dimensional, plane-parallel atmospheres that are unstable according to the Balbus criterion. The linear growth rates measured in the simulations agree with the weak-field dispersion relation. We investigate the effect of strong fields and isotropic conduction on the linear properties and nonlinear regime of the MTI. In the nonlinear regime, the instability saturates and convection decays away when the atmosphere becomes isothermal. Sustained convective turbulence can be driven if there is a fixed temperature difference between the top and bottom edges of the simulation domain, and if isotropic conduction is used to create convectively stable layers that prevent the formation of unresolved, thermal boundary layers. The largest component of the time-averaged heat flux is due to advective motions. These results have implications for a variety of astrophysical systems, such as the temperature profile of hot gas in galaxy clusters and the structure of radiatively inefficient accretion flows.
Phenolic acid amides: a new type of DNA strand scission agent from Piper caninum

Abstract In a survey of the active components of crude plant extracts for their ability to cleave DNA, a crude extract prepared from Piper caninum was found to induce the relaxation of supercoiled pBR322 plasmid DNA in the presence of Cu 2+ . Bioassay-guided fractionation was carried out on this extract, guided by an in vitro DNA strand scission assay. Three active principles were isolated and identified as N - cis -feruloyl tyramine ( 1 ), N - trans -feruloyl tyramine ( 2 ), and 1-cinnamoylpyrrolidine ( 3 ). Compounds 1 – 3 represent a structurally new type of DNA strand scission agent.
Exploring Logic Artificial Chemistries: An Illogical Attempt?

Robustness to a wide variety of negative factors and the ability to self-repair is an inherent and natural characteristic of all life forms on earth. As opposed to nature, man-made systems are in most cases not inherently robust and a significant effort has to be made in order to make them resistant against failures. This can be done in a wide variety of ways and on various system levels. In the field of digital systems, for example, techniques such as triple modular redundancy (TMR) are frequently used, which results in a considerable hardware overhead. Biologically-inspired computing by means of biochemical metaphors offers alternative paradigms, which need to be explored and evaluated. Here, we are interested to evaluate the potential of nature-inspired artificial chemistries and membrane systems as an alternative information representing and processing paradigm in order to obtain robust and spatially extended Boolean computing systems in a distributed environment. We investigate conceptual approaches inspired by artificial chemistries and membrane systems and compare proof-of-concepts. First, we show, that elementary logical functions can be implemented. Second, we illustrate how they can be made more robust and how they can be assembled to larger-scale systems. Finally, we discuss the implications for and paths to possible genuine implementations. Compared to the main body of work in artificial chemistries, we take a very pragmatic and implementation-oriented approach and are interested in realizing Boolean computations only. The results emphasize that artificial chemistries can be used to implement Boolean logic in a spatially extended and distributed environment and can also be made highly robust, but at a significant price
The Pairwise Velocity Distribution of Galaxies in the Las Campanas Redshift Survey

We present a novel measurement of the pairwise peculiar velocity distribution function of galaxies on scales r<3200 km s-1 in the Las Campanas Redshift Survey. The distribution is well described by a scale-independent exponential with a width τ, where σ12 = √2τ=363 km s-1. The signal is very stable. Results from the northern and southern sets of slices agree within ±13 km s-1, and the fluctuations among the six individual survey slices vary as ±44 km s-1. The distribution was determined using a Fourier-space deconvolution of the redshift-space distortions in the correlation function. This technique is insensitive to the effect of rich clusters in the survey and recovers the entire distribution function rather than just its second moment. Taken together with the large effective volume of the survey, 6.0 × 106 h-1 Mpc3, we believe this to be a definitive result for r-band-selected galaxies with absolute magnitudes -18.5 < Mr < -22.5 and z < 0.2.
Two-Photon Oxygen Sensing with Quantum Dot-Porphyrin Conjugates

Supramolecular assemblies of a quantum dot (QD) associated to palladium(II) porphyrins have been developed to detect oxygen (pO2) in organic solvents. Palladium porphyrins are sensitive in the 0–160 Torr range, making them ideal phosphors for in vivo biological oxygen quantification. Porphyrins with meso pyridyl substituents bind to the surface of the QD to produce self-assembled nanosensors. Appreciable overlap between QD emission and porphyrin absorption features results in efficient Forster resonance energy transfer (FRET) for signal transduction in these sensors. The QD serves as a photon antenna, enhancing porphyrin emission under both one- and two-photon excitation, demonstrating that QD-palladium porphyrin conjugates may be used for oxygen sensing over physiological oxygen ranges.
Fundamental Economic Shocks and the Macroeconomy

En el ultimo tiempo, se ha observado un renovado interes en evaluar modelos economicos en un contexto de choques economicos especificos identificados empiricamente. Por lo general estos choques se identifican uno por uno, pasando por alto las posibles correlaciones entre ellos, o se identifican en el contexto de un vector autorregresivo estructural (SVAR) usando restricciones solo debilmente relacionadas con la teoria economica. En este articulo desarrollamos un enfoque alternativo que utiliza medidas de choques economicos derivados explicitamente de modelos economicos para identificar multiples impulsos estructurales ortogonales. Con este enfoque identificamos choques tecnologicos, de tasa marginal de sustitucion (oferta laboral) y de politica monetaria en el contexto de un FAVAR. Luego examinamos la distribucion bayesiana posterior para las respuestas de un numero alto de variables macroeconomicas y financieras endogenas a estos tres choques. Los choques dan cuenta de la preponderancia de las fluctuaciones de actividad, productividad y precios. Los choques tecnologicos tienen un impacto permanente sobre las medidas de actividad economica, en tanto los otros choques son mas transitorios. Los insumos laborales tienen una respuesta inicial pequena a los choques tecnologicos, y la respuesta va aumentando en forma consistente sobre un periodo de cinco anos. La lenta respuesta del consumo al choque tecnologico es incoherente con una formulacion simple de la hipotesis del ingreso permanente, pero seria coherente con un modelo de formacion de habitos. La politica monetaria tiene una respuesta mas bien pequena al choque tecnologico, pero tiene una reaccion contraciclica frente al mas ciclico choque de oferta laboral. Este choque mas ciclico tiene el impacto mas fuerte sobre las tasas de interes. Los precios de las acciones responden a los tres tipos de perturbacion. Tambien se revisan varias otras implicancias empiricas de nuestro enfoque.
Linear complexity hexahedral mesh generation

Abstract We show that any polyhedron forming a topological ball with an even number of quadrilateral sides can be partitioned into O n topological cubes, meeting face to face. The result generalizes to non-simply-connected polyhedra satisfying an additional bipartiteness condition. The same techniques can also be used to reduce the geometric version of the hexahedral mesh generation problem to a finite case analysis amenable to machine solution.
Researching Initiatives and Referendums in Arkansas

SUMMARY This bibliographic essay and guide to researching Arkansas initiatives and referendums is intended to assist anyone interested in this vital subject.
Interacting in chaos

In considering which research problems to work on next, one must consider the key uses for future computing technology. To such roles are the support of interpersonal communication and the management, analysis and synthesis of massive amounts of information. When one considers the Macintosh and the impact it has had on computing it is important to understand that it was fundamentally not a computing engine but a communications device. The medium for communication was paper rather than electronic but the Mac was and is all about creating paper artifacts for communication among people. Even today when one examines a software catalog for Windows or the Mac, more than 90% of the software offered is focused on internet or paper-based communications. There is very little that computes or calculates in the classical sense.
Isotopic anomalies in the early solar system

Abstract The primitive meteorites known as “carbonaceous chondrites” provide the best available information concerning the nuclear composition of the matter in the solar system at the time of formation of the sun and planets. Several light elements show “isotopic anomalies” which appear to result from major nucleosynthetic events occurring just before collapse of the solar nebula. For example, the earliest-condensed mineral grains contain excesses of 16O up to 5%, while maintaining “normal” 17 O 18 O ratios. Magnesium contains 26Mg excesses up to 10%, which are attributable to the decay of 7 × 105 year 26Al. Neon has “anomalous” excesses of 22Ne. Although the evidence is less clear-cut, there may also be nucleosynthetic excesses of 13C and 15N. Nuclear processes occurring within the solar system are inadequate to account for most of these observations. The isotopic anomalies have been interpreted as evidence for a supernova “trigger” for formation of the solar system. The 16O “anomaly” is not restricted to the primitive meteorites, but is found to varying degrees in all meteorites, reflecting the inhomogeneous distribution of the 16O-rich component in the early solar system. This provides the basis for a genetic classification of meteorites and planets.
Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

In recent heterogeneous catalysis, much effort has been made in understanding how the size, shape, and composition of nanoparticles and oxide-metal interfaces affect catalytic performance at the molecular level. Recent advances in colloidal synthetic techniques enable preparing diverse metallic or bimetallic nanoparticles with well-defined size, shape, and composition and porous oxides as a high surface support. As nanoparticles become smaller, new chemical, physical, and catalytic properties emerge. Geometrically, as the smaller the nanoparticle the greater the relative number of edge and corner sites per unit surface of the nanoparticle. When the nanoparticles are smaller than a critical size (2.7 nm), finite-size effects such as a change of adsorption strength or oxidation state are revealed by changes in their electronic structures. By alloying two metals, the formation of heteroatom bonds and geometric effects such as strain due to the change of metal–metal bond lengths cause new electronic structures to appear in bimetallic nanoparticles. Ceaseless catalytic reaction studies have been discovered that the highest reaction yields, product selectivity, and process stability were achieved by determining the critical size, shape, and composition of nanoparticles and by choosing the appropriate oxide support. Depending on the pore size, various kinds of micro-, meso-, and macro-porous materials are fabricated by the aid of structure-directing agents or hard-templates. Recent achievements for the preparation of versatile core/shell nanostructures composing mesoporous oxides, zeolites, and metal organic frameworks provide new insights toward nanocatalysis with novel ideas. In recent heterogeneous catalysis, much effort has been made in understanding how the size, shape, and composition of nanoparticles and oxide-metal interfaces affect catalytic performance at the molecular level. Recent advances in colloidal synthetic techniques enable preparing diverse metallic or bimetallic nanoparticles with well-defined size, shape, and composition and porous oxides as a high surface support. Ceaseless catalytic reaction studies have been discovered that several molecular factors influenced catalytic activity and selectivity including surface structure and composition of nanoparticles, reaction intermediates, adsorbates, and oxidation states in nanocatalysis.
Thermal studies of the state of water in proton conducting fuel cell membranes

Abstract The thermodynamics of acid group hydration was studied for different membranes (including Nafion ® and sulfonated poly(arylene ether sulfone) (BPSH)) and model systems (including an organic/inorganic composite (I/O) and a multiblock polymer (MB-150)). Experiments were carried out with the membranes exposed to different activities of water corresponding to different levels of membrane hydration. Isopiestic sorption shows a significantly greater uptake in water for the multiblock polymer as compared to the others. Differential scanning calorimetry (DSC) was used to study thermal properties to elucidate the state of water in the membranes. A comparison is made of various modes of collecting data using DSC. Based on these data, we discuss the overall understanding of water interactions with these membranes as well as the limitations of thermodynamic data in describing microenvironments within the membrane.
Identifying significant characteristics of organic milk consumers: a CART analysis of an artefactual field experiment

The organic dairy category is one of the fastest growing categories of organic foods in the US. Organic milk consumers generally cite perceived health benefits and lower risk of food contamination, as well as perceived superior quality and environmental sustainability of organic farming methods, as the major motivations for preference of organic over conventional milk. While the attributes of organic milk that are valued by consumers are fairly well-known, more ambiguity exists regarding the demographic characteristics of the typical organic milk consumer. This research makes use of experimental data from 148 adult participants and use a Classification and Regression Tree (CART) analysis, a nonparametric modelling approach, to identify how Willingness-to-Pay (WTP) for organic milk varies with the demographic profile of experiment participants. The study finds that perceived taste of organic milk, concern for the risk of consuming conventional milk, being a primary shopper, and the quantity of milk consume...
Stark transitions in antiprotonic helium

Collisional Stark rates for p 4 He + with 36≤n≤38 are estimated with coupled-channel calculations. Both an atomic and a molecular model are used. Matrix elements of the pHe + -He interaction for the atomic model are approximated with expressions having two or three parameters. Rough estimates for the molecular model are obtained using the generalized Born-Oppenheimer approximation, together with matrix elements for the atomic model. Guesswork, based on interactions of seemingly similar atoms, is used to set fairly wide limits to parameters for the atomic model, it being assumed that the potentials depend only on n, l, and R. Transitions are found to be unlikely. But the rates are sensitive to the potentials. Transitions can be likely if the potentials are different from what can reasonably be guessed by assuming a dependence on only n, l, and R. A potential with a minimum, preferably relatively deep, at relatively small R can cause transitions to be important. It is conjectured that this can occur because pHe + -He potentials depend on the component of pHe + intrinsic angular momentum along R. Also, it is found that the difference in the reduced mass of pHe + and He can cause the rate to be several times higher for p 3 He + than for comparable p 4 He + .
"More Mighty than the Waves of the Sea": Toilers, Tariffs, and the Income Tax Movement, 1880-1913

Social movements are at once the symptoms and the instruments of social progress. Ignore them and statesmanship is irrelevant; fail to use them and it is weak. Walter Lippmann In the spring of 18...
Observation of an effective magnetic field for light

We observe an effective magnetic field for photons using an on-chip silicon-based Ramsey-type interferometer. This interferometer generates a direction-dependent phase which corresponds to a magnetic field of 0.2 Gauss in an Aharonov-Bohm configuration for electrons.
The primordial helium abundance from updated emissivities

Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Yp. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, & Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, & Stasinska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Yp. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Yp = 0.2465 ± 0.0097, in good agreement with the Planck result of Yp = 0.2485 ± 0.0002. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.
Influence of Land Use on Mallard Nest-Structure Occupancy

We investigated the relationship between land use and mallard (Anas platyrhynchos) occupancy of single- and double-cylinder nest structures on a 658-km2 (254-mile2) western Minnesota, USA, study area from 1997–1999. We used hierarchical logistic regression to spatio-temporally model structure occupancy as a function of land use, number of nearby structures, number of mallard pairs with access to the structure, size of the open-water area including the structure, and structure type. We fit models to data from 4 different-sized buffers around each structure to investigate scale influences. Goodness-of-fit, predictive ability, and amount of reduced spatio-temporal correlation were similar for each buffer-size model. We made inferences using the 1.6-km-radius buffer model because it produced the lowest deviance. The amount and attractiveness of nesting cover (i.e., as indexed by visual obstruction measurements [VOMs]) within a buffer interacted with nest-initiation period (P = 0.003). The VOMs and nest occupancy were positively associated early in the nesting season, but the pattern reversed later in the nesting season. Structure occupancy and area of open water around a structure were related quadratically (P = 0.004), with odds of a structure in median-sized open-water areas being occupied increasing until the open-water area was ~16 ha. Year and nesting-season period interacted (P = 0.002), reflecting different nest-initiation phenology. Number of pairs with access to a structure had no effect on nest initiations (P = 0.7), perhaps due to our inability to account for within-season changes in pair numbers. Number of nearby structures (P = 0.8) was unrelated to initiation probability, but structure density was low (0.05/km2). We suspect that mallard settling patterns and an unmeasured temporal relationship between VOMs and numbers of pairs with access to structures produced the VOM × period interaction. Structures deployed in larger open-water areas where surrounding residual upland cover is abundant can improve mallard nest success early in the nesting season when duckling survival is the greatest and can reduce hen mortality associated with nest destruction and re-nesting.
Genetic linkage of hyperglycemia and dyslipidemia in an intercross between BALB/cJ and SM/J Apoe-deficient mouse strains

Individuals with dyslipidemia often develop type 2 diabetes, and diabetic patients often have dyslipidemia. It remains to be determined whether there are genetic connections between the 2 disorders. A female F2 cohort, generated from BALB/cJ (BALB) and SM/J (SM) Apoe-deficient (Apoe −/−) strains, was started on a Western diet at 6 weeks of age and maintained on the diet for 12 weeks. Fasting plasma glucose and lipid levels were measured before and after 12 weeks of Western diet. 144 genetic markers across the entire genome were used for quantitative trait locus (QTL) analysis. One significant QTL on chromosome 9, named Bglu17 [26.4 cM, logarithm of odds ratio (LOD): 5.4], and 3 suggestive QTLs were identified for fasting glucose levels. The suggestive QTL near the proximal end of chromosome 9 (2.4 cM, LOD: 3.12) was replicated at both time points and named Bglu16. Bglu17 coincided with a significant QTL for HDL (high-density lipoprotein) and a suggestive QTL for non-HDL cholesterol levels. Plasma glucose levels were inversely correlated with HDL but positively correlated with non-HDL cholesterol levels in F2 mice on either chow or Western diet. A significant correlation between fasting glucose and triglyceride levels was also observed on the Western diet. Haplotype analysis revealed that “lipid genes” Sik3, Apoa1, and Apoc3 were probable candidates for Bglu17. We have identified multiple QTLs for fasting glucose and lipid levels. The colocalization of QTLs for both phenotypes and the sharing of potential candidate genes demonstrate genetic connections between dyslipidemia and type 2 diabetes.
Observation of photochromic γ-cyclodextrin host–guest inclusion complexes

Substituted photochromic spiropyrans were included in γ-CD inclusion complexes and the photochromic behavior was monitored optically.
Technology S-curves in renewable energy alternatives: Analysis and implications for industry and government

Plotting the performance of a technology against the money or effort invested in it most often yields an S-shaped curve: slow initial improvement, then accelerated improvement, then diminishing improvement. These S-curves can be used to gain insight into the relative payoff of investment in competing technologies, as well as providing some insight into when and why some technologies overtake others in the race for dominance. Analyzing renewable energies from such a technology S-curve perspective reveals some surprising and important implications for both government and industry. Using data on government R&D investment and technological improvement (in the form of cost reductions), we show that both wind energy and geothermal energy are poised to become more economical than fossil fuels within a relatively short time frame. The evidence further suggests that R&D for wind and geothermal technologies has been under-funded by national governments relative to funding for solar technologies, and government funding of fossil fuel technologies might be excessive given the diminishing performance of those technologies. & 2009 Elsevier Ltd. All rights reserved.
CVD of SiC and AlN using cyclic organometallic precursors

The use of cyclic organometallic molecules as single-source MOCVD precursors is illustrated by means of examples taken from our recent work on SiC and AlN deposition, with particular focus on SiC. Molecules containing (SiC)2 and (AlN)3 rings as the “core structure” were employed as the source materials for these studies. The organoaluminum amide, [Me2AlNH2]3, was used as the AlN source and has been studied in a molecular beam sampling apparatus in order to determine the gas phase species present in a hot-wall CVD reactor environment. In the case of SiC CVD, a series of disilacyclobutanes, [Si(XX’)CH2]2 (with X and X’ - H, CH3, and CH2SiH2CH3), were examined in a cold-wall, hot-stage CVD reactor in order to compare their relative reactivities and prospective utility as single-source CVD precursors. The parent compound, disilacyclobutane, [SiH2CH2]2, was found to exhibit the lowest deposition temperature (ca. 670 °C) and to yield the highest purity SiC films. This precursor gave a highly textured, polycrystalline film on the Si(100) substrates (70% with a SiC orientation).
Techniques for Verifying the Accuracy of Risk Measurement Models

Risk exposures are typically quantified in terms of a "value at risk" (VaR) estimate. A VaR estimate corresponds to a specific critical value of a portfolio's potential one-day profit and loss distribution. Given their functions both as internal risk management tools and as potential regulatory measures of risk exposure, it is important to assess and quantify the accuracy of an institution's VaR estimates. This study considers the formal statistical procedures that could be used to assess the accuracy of VaR estimates. The analysis demonstrates that verification of the accuracy of tail probability value estimates becomes substantially more difficult as the cumulative probability estimate being verified becomes smaller. In the extreme, it becomes virtually impossible to verify with any accuracy the potential losses associated with extremely rare events. Moreover, the economic importance of not being able to reliably detect an inaccurate model or an under-reporting institution potentially becomes much more pronounced as the cumulative probability estimate being verified becomes smaller. It does not appear possible for a bank or its supervisor to reliably verify the accuracy of an institution's internal model loss exposure estimates using standard statistical techniques. The results have implications both for banks that wish to assess the accuracy of their internal risk measurement models as well as for supervisors who must verify the accuracy of an institution's risk exposure estimate reported under an internal models approach to model risk.
Palladium‐Catalyzed Oxidative Kinetic Resolution with Ambient Air as the Stoichiometric Oxidation Gas

Air is enough to mediate the highly enantioselective oxidation of secondary alcohols at room temperature with palladium(II) and sparteine in nonflammable solvents. Examination of the role of solvents capable of hydrogen bonding and their ability to solvate halide anions led to a novel set of conditions for the highly enantioselective oxidative kinetic resolution of secondary alcohols.
Fluorescence modulation with photochromic switches in nanostructured constructs

This tutorial review illustrates the structural design, photochemical and photophysical properties of nanostructured constructs incorporating luminescent and photochromic components. In these systems, the pronounced structural and electronic modifications that accompany the transformations of the photochromic components can be exploited to modulate the emission intensity of the luminescent components on the basis of electron and energy transfer processes. These photoresponsive systems can be assembled by: (1) integrating fluorescent and photochromic components within the main chain of the same polymer; (2) attaching multiple photochromes to a fluorescent organic polymer or luminescent inorganic nanoparticle; (3) appending either independent fluorophores and photochromes or fluorophore–photochrome dyads to a common polymer scaffold; (4) trapping distinct fluorophores and photochromes within the hydrophobic interior of the same cross-linked polymer. In all instances, the changes in absorbance and/or redox potentials associated with the reversible interconversion of the two states of each photochromic component regulate the radiative deactivation of the luminescent components. As a result, the emission intensity of these nanoscaled assemblies can reversibly be switched between high and low values under the influence of optical stimulations. Thus, these clever operating principles for fluorescence modulation can lead to the development of innovative functional and nanostructured materials with photoresponsive character. In particular, protocols for the optical writing and reading of data as well as luminescent probes for bioimaging applications might ultimately emerge from these fundamental studies on photoresponsive molecular switches.
An analytic approach to stability

The stability method is very useful for obtaining exact solutions of many extremal graph problems. Its key step is to establish the stability property which, roughly speaking, states that any two almost optimal graphs of the same order n can be made isomorphic by changing o(n^2) edges. Here we show how the recently developed theory of graph limits can be used to give an analytic approach to stability. As an application, we present a new proof of the Erdos-Simonovits stability theorem. Also, we investigate various properties of the edit distance. In particular, we show that the combinatorial and fractional versions are within a constant factor from each other, thus answering a question of Goldreich, Krivelevich, Newman, and Rozenberg.