cssi/SciSciGPT-SciSciNet huggingface dataset:
Toward a mininum criteria of multi dimensional instanton formation for condensed matter systems

We present near the end of this document a promising research direction as to how to generalize a technique initially applied to density wave current calculations to questions of instanton formation in multi dimensional condensed matter systems. Initially we review prior calculations done through a numerical simulation that the massive Schwinger model used to formulate solutions to CDW transport in itself is insufficient for transport of soliton-antisoliton (S-S’) pairs through a pinning gap model of CDW transport. Using the Peierls condensation energy permits formation of CDW S-S’ pairs in wave functionals. This leads us to conclude that if there is a small spacing between soliton-antisoliton (S-S’) charge centers, and an approximate fit between a tilted washboard potential and the system we are modeling, that instantons are pertinent to current/transport problems. This requires a very large ‘self energy’ final value of interaction energy as calculated between positive and negative charged components of soliton-antisoliton (S-S’) pairs with Gaussian wave functionals as modeled for multi dimensional systems along the lines of Lu’s generalization given below. The links to a saddle point treatment of this instanton formation are make explicit by a comment as to a cosmology variant of instanton formation in multi dimensions we think is , with slight modifications appropriate for condensed matter systems. PACS numbers: 03.75.Lm, 71.45.Lr, 71.55.-i, 78.20.Ci, 85.25.Cp
Variable Selection is Hard

Variable selection for sparse linear regression is the problem of finding, given an m p matrix B and a target vector y, a sparse vector x such that Bx approximately equals y. Assuming a standard complexity hypothesis, we show that no polynomial-time algorithm can find ak 0 -sparse x withkBx yk 2 h(m;p), wherek 0 = k 2 log 1 p andh(m;p) = p C1 m 1 C2 , where > 0;C1 > 0;C2 > 0 are arbitrary. This is true even under the promise that there is an unknownk-sparse vector x satisfyingBx = y. We prove a similar result for a statistical version of the problem in which the data are corrupted by noise. To the authors’ knowledge, these are the first hardness results for sparse regression that apply when the algorithm simultaneously hask 0 > k andh(m;p) > 0.
The Non-Existence of Stable Mechanisms in Incomplete Information Environments

We consider two-sided matching markets, and study the incentives of agents to circumvent a centralized clearing house by signing binding contracts with one another. It is well-known that if the clearing house implements a stable match and preferences are known, then no group of agents can profitably deviate in this manner. We ask whether this property holds even when agents have incomplete information about their own preferences or the preferences of others. We find that it does not. In particular, when agents are uncertain about the preferences of others, every mechanism is susceptible to deviations by groups of agents. When, in addition, agents are uncertain about their own preferences, every mechanism is susceptible to deviations in which a single pair of agents agrees in advance to match to each other.
Statistics, Econometrics and Forecasting

List of figures List of tables Preface Lecture 1. Bank of England Lecture 2. National Institute of Economic and Social Research Appendix: on the questionable virtue of aggregation Notes References Indexes.
Human Papillomavirus Vaccine Initiation among 9-13-Year-Olds in the United States.

The quadrivalent and 9-valent human papillomavirus (HPV) vaccines are licensed for administration among 9–26-year-old males and females, with routine vaccination recommended for 11–12-year-olds. Despite the availability of the vaccine at younger ages, few studies have explored vaccine uptake prior to age 13, and national HPV vaccination surveillance data is limited to 13–17-year-olds. Our objective was to examine rates and predictors of HPV vaccine initiation among 9–13-year-olds in the United States. A national sample of mothers of 9–13-year-olds in the United States (N = 2446) completed a 2014 Web-based survey assessing socio-demographic characteristics, child's HPV vaccination history, provider communication regarding the vaccine, and other attitudes and behaviors pertaining to vaccination and healthcare utilization. The main outcome measure was child's initiation of the HPV vaccine (i.e., receipt of one or more doses). Approximately 35% of the full sample and 27.5% of the 9–10-year-olds had initiated HPV vaccination. Females were more likely than males to have initiated HPV vaccination by the age of 13 but not by younger ages. Strength of health provider recommendation regarding HPV vaccination was a particularly salient predictor of vaccine initiation. Approximately a third of children may be initiating the HPV vaccine series before or during the targeted age range for routine administration of the vaccine. Because coverage remains below national targets, further research aimed at increasing vaccination during early adolescence is needed. Improving providers' communication with parents about the HPV vaccine may be one potential mechanism for increasing vaccine coverage.
Dispersive decay for the 1D Klein-Gordon equation with variable coefficient nonlinearities

We study the 1D Klein-Gordon equation with variable coefficient nonlinearity. This problem exhibits an interesting resonant interaction between the spatial frequencies of the nonlinear coefficients and the temporal oscillations of the solutions. In the case when only the cubic coefficients are variable we prove dispersive decay and smoothness of the solution in weighted spaces with the help of quadratic and cubic normal-forms transformations. In the case of cubic interactions these normal forms appear to be novel.
Colourful Language: Measuring Word-Colour Associations

Since many real-world concepts are associated with colour, for example danger with red, linguistic information is often complimented with the use of appropriate colours in information visualization and product marketing. Yet, there is no comprehensive resource that captures concept--colour associations. We present a method to create a large word--colour association lexicon by crowdsourcing. We focus especially on abstract concepts and emotions to show that even though they cannot be physically visualized, they too tend to have strong colour associations. Finally, we show how word--colour associations manifest themselves in language, and quantify usefulness of co-occurrence and polarity cues in automatically detecting colour associations.
The method of polarized traces for the 2D Helmholtz equation

We present a solver for the 2D high-frequency Helmholtz equation in heterogeneous acoustic media, with online parallel complexity that scales optimally as O ( N L ) , where N is the number of volume unknowns, and L is the number of processors, as long as L grows at most like a small fractional power of N. The solver decomposes the domain into layers, and uses transmission conditions in boundary integral form to explicitly define "polarized traces", i.e., up- and down-going waves sampled at interfaces. Local direct solvers are used in each layer to precompute traces of local Green's functions in an embarrassingly parallel way (the offline part), and incomplete Green's formulas are used to propagate interface data in a sweeping fashion, as a preconditioner inside a GMRES loop (the online part). Adaptive low-rank partitioning of the integral kernels is used to speed up their application to interface data. The method uses second-order finite differences. The complexity scalings are empirical but motivated by an analysis of ranks of off-diagonal blocks of oscillatory integrals. They continue to hold in the context of standard geophysical community models such as BP and Marmousi 2, where convergence occurs in 5 to 10 GMRES iterations. While the parallelism in this paper stems from decomposing the domain, we do not explore the alternative of parallelizing the systems solves with distributed linear algebra routines.
False discovery rate smoothing

ABSTRACTWe present false discovery rate (FDR) smoothing, an empirical-Bayes method for exploiting spatial structure in large multiple-testing problems. FDR smoothing automatically finds spatially localized regions of significant test statistics. It then relaxes the threshold of statistical significance within these regions, and tightens it elsewhere, in a manner that controls the overall false discovery rate at a given level. This results in increased power and cleaner spatial separation of signals from noise. The approach requires solving a nonstandard high-dimensional optimization problem, for which an efficient augmented-Lagrangian algorithm is presented. In simulation studies, FDR smoothing exhibits state-of-the-art performance at modest computational cost. In particular, it is shown to be far more robust than existing methods for spatially dependent multiple testing. We also apply the method to a dataset from an fMRI experiment on spatial working memory, where it detects patterns that are much more b...
Amplitudes for massive vector and scalar bosons in spontaneously-broken gauge theory from the CHY representation

In the formulation of Cachazo, He, and Yuan, tree-level amplitudes for massless particles in gauge theory and gravity can be expressed as rational functions of the Lorentz invariants k a · k b , ϵ a · k b , and ϵ a · ϵ b , valid in any number of spacetime dimensions. We use dimensional reduction of higher-dimensional amplitudes of particles with internal momentum κ to obtain amplitudes for massive particles in lower dimensions. In the case of gauge theory, we argue that these massive amplitudes belong to a theory in which the gauge symmetry is spontaneously broken by an adjoint Higgs field. Consequently, we show that tree-level n-point amplitudes containing massive vector and scalar bosons in this theory can be obtained by simply replacing k a · k b with k a · k b − κ a κ b in the corresponding massless amplitudes, where the masses of the particles are given by |κ a |.
Quinientos años de olvido: historiografía e historia de la mujer en México

Revision historiografica sobre la historia de la mujer en Mexico durante los ultimos quinientos anos. Se hace hincapie en la diferencia que existe entre la labor de rescate de informacion e interpretacion sobre aspectos del pasado de la mujer mexicana ­que constituye la historia de la mujer en Mexico­ y el trabajo historiografico, entendido como la reflexion sistematica sobre metodologia utilizada para realizar dicha historia.
Iridium‐Catalyzed Dynamic Kinetic Isomerization: Expedient Synthesis of Carbohydrates from Achmatowicz Rearrangement Products

A highly stereoselective dynamic kinetic isomerization of Achmatowicz rearrangement products was discovered. This new internal redox isomerization provided ready access to key intermediates for the enantio- and diastereoselective synthesis of a series of naturally occurring sugars. The nature of the de novo synthesis also enables the preparation of both enantiomers.
$\mathcal{N}=2$ Supersymmetric Janus Solutions and Flows: From Gauged Supergravity to M Theory

We investigate a family of SU(3)×U(1)×U(1)-invariant holographic flows and Janus solutions obtained from gauged $$ \mathcal{N} $$ = 8 supergravity in four dimensions. We give complete details of how to use the uplift formulae to obtain the corresponding solutions in M theory. While the flow solutions appear to be singular from the four-dimensional perspective, we find that the eleven-dimensional solutions are much better behaved and give rise to interesting new classes of compactification geometries that are smooth, up to orbifolds, in the infra-red limit. Our solutions involve new phases in which M2 branes polarize partially or even completely into M5 branes. We derive the eleven-dimensional supersymmetries and show that the eleven-dimensional equations of motion and BPS equations are indeed satisfied as a consequence of their four-dimensional counterparts. Apart from elucidating a whole new class of eleven-dimensional Janus and flow solutions, our work provides extensive and highly non-trivial tests of the recently-derived uplift formulae.
Setting Reasonable Performance Targets for Public Service Delivery

Reaching agreement on a reasonable performance target is a challenge, with costs associated with getting it wrong. Attention in the literature has focused on the potential negative effects of gaming or of creaming. However, even if there is no gaming or creaming taking place, there can still be costs associated with setting a level of the performance target that is either too low or too high. On the one hand, if the negotiated performance target is too low, there is a strong risk that the target would be met without any change in behavior or performance from what would have been realized without a performance management system. In that case, there would be no benefit -- only the cost of covering the administrative costs associated with developing the monitoring and management systems. On the other hand, if the negotiated performance target is too high, there could also be significant costs. The exact nature of the costs depends on which one of two unattractive options the principal chooses to follow once it becomes apparent that the performance targets were set unrealistically high. If the principal chooses simply to waive any possible repercussions for the agents for not meeting the performance targets, this can undermine the credibility of the system. If the principal insists on holding agents to meeting the performance targets -- no matter how unrealistic they were -- this can breed resentment and adversely affect future productivity. This paper considers some approaches to target setting that have been used in the literature and proposes an approach based on the use of quantile regressions to construct a Characteristic Adjusted Performance distribution of performance to guide the selection of targets. The paper then presents two concrete examples of applications of this approach related to the setting of targets on School Test Scores and Improvement in Homicide rates in Police Districts in the State of Minas Gerais, Brazil.
Large neutrino mixing angles in unified theories

Typically in unified theories the neutrino mixing angles, like the Cabibbo-Kobayashi-Maskawa (CKM) angles of the quarks, are related to the small mass ratios between fermions of different generations and are therefore quite small. A new approach for explaining the intergenerational mass hierarchies is proposed here which, while giving small CKM angles, naturally leads to neutrino angles of order unity. Such large mixing angles may be required for a resolution of the atmospheric neutrino anomaly and may also be relevant for the solar neutrino puzzle. The mechanism presented here provides a framework in which novel approaches to the fermion mass question can arise. In particular, within this framework a variant of the texture idea allows highly predictive models to be constructed, an illustrative example of which is given. It is shown how the neutrino mixing angles may be completely determined in such schemes.
On power and performance tradeoff of L2 cache compression

This paper presents the power-performance trade off of three different cache compression algorithms. Cache compression improves performance, since the compressed data increases the effective cache capacity by reducing the cache misses. The unused memory cells can be put into sleep mode to save static power. The increased performance and saved power due to cache compression must be more than the delay and power consumption added due to CODEC(COmpressor and DECompressor) block respectively. Among the studied algorithms, powerdelay characteristic of Frequent Pattern compression(FPC) is found to be the most suitable for cache compression.
Effect of bisphenol A on human endometrial stromal fibroblasts in vitro

This study evaluated the effects of bisphenol A (BPA) on human endometrial stromal fibroblast (ESF) differentiation and expression of genes involved in oestrogen metabolism. Human ESF from eight hysterectomy specimens were cultured and treated with 5-100 μmol/l of BPA ± oestradiol or 8-br-cAMP for 48 h. mRNA expression was analysed by real-time reverse-transcription PCR. 8-br-cAMP-induced human ESF decidualization was confirmed by expression of insulin-like growth factor binding protein-1 (IGFBP1) and prolactin secretion. Short-term exposure (48 h) decreased human ESF proliferation (P<0.04) not due to apoptosis. High doses of BPA significantly induced IGFBP1 mRNA and protein, decreased P450scc mRNA, reversed the 8-br-cAMP-induced increase in HSD17B2 (oestradiol to oestrone conversion) in a dose-dependent manner and down-regulated HSD17B1 expression (oestrone to oestradiol conversion; P ≤ 0.03). 8-br-cAMP significantly potentiated this effect (P=0.028). BPA had no significant effect on aromatase and PPAR γ expression. The oestrogen-receptor antagonist ICI had no effect on gene expression in BPA-treated cells, and oestrogen receptor α, but not oestrogen receptor β, was significantly down-regulated by high doses of BPA (P=0.028). BPA has an endocrine-disrupting effect on human ESF function and gene expression but the underlying mechanisms appear not to involve oestrogen-mediated pathways.
A Survey on the Turaev Genus of Knots

The Turaev genus of a knot is a topological measure of how far a given knot is from being alternating. Recent work by several authors has focused attention on this interesting invariant. We discuss how the Turaev genus is related to other knot invariants, including the Jones polynomial, knot homology theories, and ribbon-graph polynomial invariants.
Opportunities for use of exact statistical equations

Abstract Exact structure function equations are an efficient means of obtaining asymptotic laws such as inertial range laws, as well as all measurable effects of inhomogeneity and anisotropy that cause deviations from such laws. “Exact” means that the equations are obtained from the Navier–Stokes equation or other hydrodynamic equations without any approximation. A pragmatic definition of local homogeneity lies within the exact equations because terms that explicitly depend on the rate of change of measurement location appear within the exact equations; an analogous statement is true for local stationarity. An exact definition of averaging operations is required for the exact equations. Careful derivations of several inertial range laws have appeared in the literature recently in the form of theorems. These theorems give the relationships of the energy dissipation rate to the structure function of acceleration increment multiplied by velocity increment and to both the trace of and the components of the th...
Optimal trajectories for aeroassisted orbital transfer

Consideration is given to classical and minimax problems involved in aeroassisted transfer from high earth orbit (HEO) to low earth orbit (LEO). The transfer is restricted to coplanar operation, with trajectory control effected by means of lift modulation. The performance of the maneuver is indexed to the energy expenditure or, alternatively, the time integral of the heating rate. Firist-order optimality conditions are defined for the classical approach, as are a sequential gradient-restoration algorithm and a combined gradient-restoration algorithm. Minimization techniques are presented for the aeroassisted transfer energy consumption and time-delay integral of the heating rate, as well as minimization of the pressure. It is shown that the eigenvalues of the Jacobian matrix of the differential system is both stiff and unstable, implying that the sequential gradient restoration algorithm in its present version is unsuitable. A new method, involving a multipoint approach to the two-poing boundary value problem, is recommended.
Industry structure and horizontal takeovers: Analysis of wealth effects on rivals, suppliers, and corporate customers

Abstract We examine the wealth effects of horizontal takeovers on rivals of the merging firms, and on firms in the takeover industry's supplier and customer industries. Inconsistent with the collusion and buyer power motives, we find significant positive abnormal returns to rivals, suppliers, and corporate customers for the subsample of takeovers with positive combined wealth effect to target and bidder shareholders. Overall, our findings suggest that the average takeover in our sample is driven by efficiency considerations. However, we find evidence suggesting that horizontal takeovers increase the buyer power of the merging firms if suppliers are concentrated.
Duality in Sp and SO gauge groups from M theory

Abstract We describe fivebrane configurations in M theory whose 4-d spacetime contains N = 1 supersymmetric Sp or SO gauge fields and fundamentals of these groups. We show how field-theory dualities for Sp and SO groups can be derived using these fivebrane configurations in M theory.
On the nature of the order parameter in HTSC and influence of impurities

Abstract The previously proposed model, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons, is supplemented by a small short-range repulsion of Hund's or spin-fluctuation origin. This permits one to explain the change of sign of the order parameter in a natural way and to resolve the seeming conflicts between existing experimental data. The influence of impurity scattering on T c , the order parameter at T = 0 and the density of states, including the energy gap, are studied for the same model. A simple argument shows that the small-angle scattering due to ionized impurities does not change the superconducting parameters, and all changes come from the large-angle scattering. For the vicinity of the singularity the “out scattering” has a small probability, since the density of states beyond the singularity is low. Therefore, the suppression of the gap in this vicinity is weak, and the same is true for T c . On the other hand, the scattering of electrons distant from the singularity into the singular region is much larger, due to the enhanced density of states. Since the order parameter beyond the singularity is still defined by its value in the singular region, it scales with this value and varies only slightly. However, the energy gap in this region, which does not coincide with the order parameter, increases rapidly with impurity concentration so that the gap becomes isotropic in the strong scattering limit. These conclusions agree with preliminary experimental observations.
On the demand for smoking quitlines

Using recent cross-state U.S. data, this paper estimates the demand for calls to smoking quitlines. Besides formal insights into the determinants of quitline demand, another key contribution is to provide unique insights on the role of related internet resources, using two novel measures. Results show that higher cigarette prices, lower income, and greater government resources increase the demand for quitline calls, with the internet measures having positive but statistically insignificant effects. In terms of magnitude, the elasticity of quitline calls with respect to cigarette prices was about four times greater than that with respect to public funds for quitlines. Policy implications are discussed.
Growth and characterization of organic semiconductor heterojunctions and multiple quantum wells

We have grc,n isotype organic semiconductor heterojunctions consistirx of CuPc (copper phthalocyanine) , PTCDA (3 , 4 , 9 , 10 pexylenetetraca.thoxylic dianhydride) arxl P]XBI (3 ,4,9, 10 perylenetetracarboxylic-bis--benzirnidazole). tharge transport: properties at the organic heterointerfaces have been studied usir current-voltage and capacitance-voltage ineasurenents. Organic raultiple quantum well structures have been grn by organic molecular beam deposition. The unusual crystallfrie and optical properties of such stnictures will be discussed.
Improving Efficiency and Using E10 for Higher Loads in Boosted HCCI Engines

This study systematically investigates the effects of various engine operating parameters on the thermal efficiency of a boosted HCCI engine, and the potential of E10 to extend the high-load limit beyond that obtained with conventional gasoline. Understanding how these parameters can be adjusted and the trade-offs involved is critical for optimizing engine operation and for determining the highest efficiencies for a given engine geometry. Data were acquired in a 0.98 liter, single-cylinder HCCI research engine with a compression-ratio of 14:1, and the engine facility was configured to allow precise control over the relevant operating parameters. The study focuses on boosted operation with intake pressures (Pin) ≥ 2 bar, but some data for Pin < 2 bar are also presented. Two fuels are considered: 1) an 87-octane gasoline, and 2) E10 (10% ethanol in this same gasoline) which has a lower autoignition reactivity for boosted operation. This study considers several engine operating parameters, including: intake temperature, fueling rate, engine speed, fuel type, and the effect of various amounts of mixture stratification using three fueling methods: fully premixed, early-DI, and premixed + late-DI (termed partial fuel stratification, PFS). The effects of these operating parameters on the factors affecting thermal efficiency, such as combustion phasing (CA50), amount of EGR required, ringing intensity, combustion efficiency, γ = cp/cv, and heat transfer are also explored and discussed. The study showed that in general, thermal efficiency improves when parameters are adjusted for lower intake temperatures, less CA50 retard, and less EGR, as long as the ringing intensity is ≤ 5 MW/m 2 to prevent knock, and combustion efficiency is good (i.e. ≥ about 96%). Additionally, applying a small amount of mixture stratification (using PFS or early-DI fueling) improves efficiency by allowing more CA50 advance when boost levels are sufficient for these fuels to be φ-sensitive. E10 gives a small increase in thermal efficiency because EGR requirements are reduced. E10 is also effective for increasing the maximum load for P in ≥ 2.4 bar, and increasing the high-load limit to IMEPg = 18.1 bar, with no engine knock and ultra-low NOx and soot emissions, compared to IMEPg = 16.3 bar for gasoline. Overall, this study showed that the efficiencies for boosted HCCI can be increased above their already good baseline values. For our engine configuration, improvements of 3-5 thermal-efficiency percentage units were achieved corresponding to a reduction in fuel consumption of 7-11%. Copyright © 2012 SAE International.
Alkoxy radicals in organic synthesis. A novel approach to spiroketals

Abstract Photolysis of an unsaturated alcohol in the presence of HgO and iodine generates an alkoxy radical which can cyclize to form a five-membered ring ether. If a hemiketal is employed, a spiroketal can be formed in good yield.
Growth Polynomials for Additive Quadruples and ( h , k )-Tuples

Consider the interval of integers Im,n = {m, m + 1, m + 2, . . . , m + n − 1}. For fixed integers h, k, m, and c, let \({\Phi^{(c)}_{h,k,m}(n)}\) denote the number of solutions of the equation (a1 + . . . + ah) − (ah+1 + . . . + ah+k) = c with \({a_i \in I_{m,n}}\) for all i = 1, . . . , h + k. This is a polynomial in n for all sufficiently large n, and the growth polynomial is constructed explicitly.
Sanding down the Edges Paradoxical Impediments to Organizational Change

In contrast to population ecology and new institutionalist approaches that cite the external environment as the culprit for inertia, this article steps inside the organization to show how internal processes render change ineffective. It is argued that the very same processes described in the literature as prerequisites for success are paradoxically those that make change less likely to occur. Detailed examples of failed organizational change from a Fortune 50 corporation and a metropolitan teaching hospital illustrate the ways in which the organizational system not only sands down the sharp edges of ambitious change agendas, but also uses the change process itself as fuel for perpetuating the status quo. The final section relates these basic paradoxes to deeper roots of change in social systems and suggests ways of changing the way we change in light of the resiliency and resistance of the organizational system.
The Long-Term Performance of Corporate Bonds (and Stocks) Following Seasoned Equity Offerings

Previous studies document negative long-term abnormal stock returns following seasoned equity offering (SEO) issuances and conclude that markets are inefficient. Other studies, however, argue that these results are a manifestation of risk mismeasurement (i.e., the bad-model problem), not market inefficiency. We test the efficient market hypothesis (EMH) and avoid the bad-model problem by examining the long-term performance of our sample firms' bonds and stocks following their SEOs. Our results are inconsistent with the EMH. We also provide evidence that SEOs transfer wealth from shareholders to bondholders because SEOs reduce default risk. Copyright 2002, Oxford University Press.
Modular redundancy without voters decreases complexity of restoring organ

Fault-tolerant modules have usually been implemented through the use of static fault-masking or dynamic spare-switching. But a new class of MR (Modular Redundancy), the Responsive schemes, promises higher reliability levels and more efficient implementations for medium to high degrees of redundancy. In particular, Siftout Modular Redundancy (SMR) does not use voters and provides a 2-out-of-N redundancy with a very simple restoring organ. The complexity of implementation is analyzed for several MR's and reliability figures are compared for three 2-out-of-N schemes. SMR is shown to have the best performance.
Equilibrium in abstract economies without ordered preferences

Abstract We extend a theorem of G. Debreu on the existence of equilibrium in a generalized N -person game (‘A Social Equilibrium Existence Theorem’). Applying standard techniques the result can be used to prove the existence of equilibrium in economies with interdependent preferences, price-dependent preferences and preferences which may be both non-transitive and non-complete. This generalizes a recent theorem of A. Mas-Colell.
The optical effects of small iron particles that darken but do not redden: Evidence of intense space weathering on Mercury

Abstract Submicroscopic iron particles larger than about 50 nm, infused throughout mineral grains or glasses, are abundant in planetary materials altered by their environment such as shocked meteorites and lunar agglutinate glasses. Such particles darken their host material but do not redden their spectra but to date there has been no theoretical treatment of their optical effects. Using Mie theory, we modify the Hapke (2001) radiative transfer model of the effects of space weathering to include these effects. Comparison with laboratory measurements shows that the new treatment reproduces the relationship between submicroscopic iron size, abundance and reflectance. We apply this new model to near-IR spectra of Mercury recently obtained by the MESSENGER spacecraft and find that submicroscopic iron is much more abundant on Mercury than in lunar soils, with typical total submicroscopic iron abundances near 3.5 wt.% compared to about 0.5 wt.% for lunar soils We also find that the ratio of iron particles that darken but do not redden to the abundance of very small iron particles that impart the red slope to space weathered material is much larger than lunar (6 vs. 2). Both the total submicroscopic iron abundance and ratio of particle size fractions are consistent with the higher production of melt and vapor in micrometeorite impact on Mercury relative to the Moon ( Cintala, 1992 ) that enables more accumulation of space weathering products before sequestration by regolith overturn. The radiative transfer model cannot directly constrain the abundance of opaque minerals on Mercury because of ambiguities between the darkening effects of opaques and submicroscopic iron particles larger than 50 nm, but assuming the opaques are the ultimate source of the submicroscopic iron, our results place a lower limit of 4–20 wt.% on opaque abundance on Mercury depending on the composition of the opaque phase and whether titanium metal also contributes to the space weathering effect.
Laboratory Formation of OBrO and Its Reactivity toward Ozone at 298 K

Bromine dioxide, OBrO, has been formed in our laboratory using three methods in a discharge flow reactor: (1) O + Br2; (2) Br + O3; and (3) microwave discharge of a Br2/O2/He mixture. The OBrO radical was detected using a mass spectrometer at m/e = 111/113. A new mechanism is proposed to account for the formation of the OBrO in these methods. The key to this mechanism is the self-reaction of vibrationally excited BrO. At 298 K, ground-state OBrO does not notably react with ozone, and an upper limit rate constant for the reaction of the ground-state OBrO with ozone was estimated to be k13 ≤ 5 × 10-16 cm3 molecule-1 s-1. The vibrationally excited OBrO, on the other hand, is at least 3 orders of magnitude more reactive toward ozone than the ground-state OBrO, with a rate constant of k13a = (5.4 ± 2.7) × 10-13 cm3 molecule-1 s-1.
Energy confinement scaling in tokamaks: Some implications of recent experiments with ohmic and strong auxiliary heating

Recent results from confinement scaling experiments on tokamaks with ohmic and strong auxiliary heating are reviewed. An attempt is made to draw these results together into a low-density ohmic confinement scaling law, and a scaling law for confinement with auxiliary heating. The auxiliary heating confinement law may also serve to explain the saturation in tau/sub E/ vs anti n/sub e/ observed in some ohmic heating density scaling experiments.
Interfacial Ordering in a Liquid Crystal Near the Nematic - Isotropic Transition

Abstract The molecular ordering of the liquid crystal 8CB near a surfactant-coated glass surface has been studied using evanescent-wave ellipsometry. Surface molecular ordering was measured in the isotropic phase, and both bulk and surface ordering were measured simultaneously in the nematic phase in the vicinity of the nematic-isotropic transition temperature T NI.Two kinds of behavior were observed, depending on the strength of the surface-liquid crystal interaction in a given sample. (1) For samples with a strong surface-liquid crystal interaction, at temperatures above T NI the interface is wet by a homeotropically oriented, ordered layer whose thickness diverges as the temperature T approaches T NI. For T < T NI, the interface is wet by an surface region of enhanced nematic order whose thickness increases as T → T NI but remains finite at T NI. (2) For samples with a weak surface-liquid crystal interaction, at temperatures above T NI the interface is wet by an ordered layer whose thickness increases ...
Why culture in economics

This article responds to the points raised by Deirdre McCloskey, Emily Chamlee-Wright, Rob Garnett and Solomon Stein in the symposium on my book Understanding the Culture of Markets (Routledge 2013).
Characterization of a semidiurnal eastward‐propagating tide at high northern latitudes with Mars Global Surveyor electron density profiles

[1] Apparent phase velocities of zonal structure, estimated from Mars Global Surveyor (MGS) electron density profiles, are used to identify and characterize SE1, the semidiurnal eastward-propagating tide with zonal wave number one, at high northern latitudes during the summer of Mars Year 26. SE1 shows impressive phase stability with altitude, season, and local time. SE1 maintains a presence at amplitudes between 5 and 15% of the zonal mean at 125 ± 10 km altitude for most of the summer season. Further analyses using MGS electron density profiles will contribute to the identification and characterization of nonmigrating tides in the upper atmosphere of Mars.
Recovery of elasticity of aged human epithelial cells in vitro

We recently found a considerable increase in rigidity of human epithelial cells during aging in vitro. This is important because the loss in elasticity of epithelial tissues with aging contributes to many human diseases. We also found that cultured cells had three distinct regions of rigidity and that the increase in rigidity correlated with an increase in density of cytoskeletal fibers. However, it was not clear which type of fiber was important. Atomic force microscopy and immunofluorescence microscopy were used in this study to characterize aging human epithelial cells in vitro, both before and after treatment with cytochalasin B. We found that the fibers associated with increased rigidity were mostly F-actin microfilaments. Furthermore, using cytochalasin B, a chemical that inhibits polymerization of F-actin, we restored the rigidity of old cells to the young level in all three areas of rigidity simultaneously. These results clarify how the cell mechanics changes during aging in vitro, and they may be relevant for treatment of age-related loss of elasticity in epithelial tissues.
The geometry of stable quotients in genus one

Stable quotients provide an alternative to stable maps for compactifying spaces of maps. When \(n \ge 2\), the space \(\overline{Q}_{g}({\mathbb {P}}^{n-1},d) = \overline{Q}_{g}(G(1,n),d)\) compactifies the space of degree \(d\) maps of smooth genus \(g\) curves to \({\mathbb {P}}^{n-1}\), while \(\overline{Q}_{g}(G(1,1),d) \simeq \overline{M}_{1, d \cdot \epsilon }/S_d\) is a quotient of a Hassett weighted pointed space. In this paper we study the coarse moduli schemes associated to the smooth proper Deligne–Mumford stacks \(\overline{Q}_{1}({\mathbb {P}}^{n-1},d)\), for all \(n \ge 1\). We show these schemes are projective, unirational, and have Picard number 2. Then we give generators for the Picard group, compute the canonical divisor, the cones of ample divisors, and in the case \(n=1\) the cones of effective divisors. We conclude that \(\overline{Q}_{1}({\mathbb {P}}^{n-1},d)\) is Fano if and only if \(n(d-1)(d+2) < 20\). Moreover, we show that \({\overline{Q}}_{1}({\mathbb {P}}^{n-1},d)\) is a Mori Fiber space for all \(n,d\), hence always minimal in the sense of the minimal model program. In the case \(n=1\), we write in addition a closed formula for the Poincare polynomial.
An analysis of short pulse and dual frequency radar techniques for measuring ocean wave spectra from satellites

Scanning beam microwave radars were used to measure ocean wave directional spectra from satellites. In principle, surface wave spectral resolution in wave number can be obtained using either short pulse (SP) or dual frequency (DF) techniques; in either case, directional resolution obtains naturally as a consequence of a Bragg-like wave front matching. A four frequency moment characterization of backscatter from the near vertical using physical optics in the high frequency limit was applied to an analysis of the SP and DF measurement techniques. The intrinsic electromagnetic modulation spectrum was to the first order in wave steepness proportional to the large wave directional slope spectrum. Harmonic distortion was small and was a minimum near 10 deg incidence. NonGaussian wave statistics can have an effect comparable to that in the second order of scattering from a normally distributed sea surface. The SP technique is superior to the DF technique in terms of measurement signal to noise ratio and contrast ratio.
Capital utilization and capital accumulation: Theory and evidence

A firm may acquire additional capital input by purchasing new capital or by increasing the utilization of its current capital. The margin between capital accumulation and capital utilization is studied in a model of dynamic factor demand where the firm chooses capital, labour and their rates of utilization. A direct measure of capital utilization-the work week of capital-is incorporated into the theory and estimates. The estimates imply that capital stock is costly to adjust while the work week of capital is essentially costless to adjust. The estimated response of the capital stock to changes in its price and in the required rate of return is more rapid than found in other estimates.
Quantum Field Theory Is Not Merely Quantum Mechanics Applied to Low Energy Effective Degrees of Freedom

It is commonly assumed that quantum field theory arises by applying ordinary quantum mechanics to the low energy effective degrees of freedom of a more fundamental theory defined at ultra-high-energy/short-wavelength scales. We shall argue here that, even for free quantum fields, there are holistic aspects of quantum field theory that cannot be properly understood in this manner. Specifically, the “subtractions” needed to define nonlinear polynomial functions of a free quantum field in curved spacetime are quite simple and natural from the quantum field theoretic point of view, but are at best extremely ad hoc and unnatural if viewed as independent renormalizations of individual modes of the field. We illustrate this point by contrasting the analysis of the Casimir effect, the renormalization of the stress-energy tensor in time-dependent spacetimes, and anomalies from the point of quantum field theory and from the point of view of quantum mechanics applied to the independent low energy modes of the field. Some implications for the cosmological constant problem are discussed.
Electric field control of magnetism using BiFeO3-based heterostructures

Conventional CMOS based logic and magnetic based data storage devices require the shuttling of electrons for data processing and storage. As these devices are scaled to increasingly smaller dimensions in the pursuit of speed and storage density, significant energy dissipation in the form of heat has become a center stage issue for the microelectronics industry. By taking advantage of the strong correlations between ferroic orders in multiferroics, specifically the coupling between ferroelectric and magnetic orders (magnetoelectricity), new device functionalities with ultra-low energy consumption can be envisioned. In this article, we review the advances and highlight challenges toward this goal with a particular focus on the room temperature magnetoelectric multiferroic, BiFeO3, exchange coupled to a ferromagnet. We summarize our understanding of the nature of exchange coupling and the mechanisms of the voltage control of ferromagnetism observed in these heterostructures.
A general display terminal system

Large multiprocessing computer systems using large capacity, high-speed direct-access storage have become very common. Likewise, high speed display terminals are becoming increasingly popular, especially in special applications such as airline reservations systems. Display terminals offer an even greater potential in making available the resources of the large computer system and its data base to the majority of computer users in their office area. A generalized display capability of this type is superior to a terminal system tied to the relatively slow typewriter terminals, cards, or to a data base which is incompatible with non-terminal facilities.
The Complex Stone{Weierstrass Property

The compact Hausdor space X has the CSWP i every subalgebra of C(X;C) which separates points and contains the constant functions is dense in C(X;C). Results of W. Rudin (1956) and Homan and Singer (1960) show that all scattered X have the CSWP and many non-scattered X fail the CSWP, but it was left open whether having the CSWP is just equivalent to being scattered. Here, we prove some general facts about the CSWP; in particular we show that if X is a compact ordered space, then X has the CSWP i X does not contain a copy of the Cantor set. This provides a class of non-scattered spaces with the CSWP. Among these is the double arrow space of Aleksandrov and Urysohn. The CSWP for this space implies a Stone{Weierstrass property for the complex regulated functions on the unit interval. 1. Introduction. All spaces discussed in this paper are Hausdor. Definition 1.1. If X is compact, then C(X) = C(X;C) is the algebra of continuous complex-valued functions on X, with the usual supremum norm.Av C(X) means thatA is a subalgebra of C(X) which separates points and contains the constant functions. IfAv C(X) is self-adjoint (f 2A$ f 2A), thenA is dense in C(X) by the standard Stone{Weierstrass Theorem for real-valued functions. Definition 1.2. The compact space X has the Complex Stone{Weier- strass Property (CSWP) i everyAv C(X) is dense in C(X). The CSWP may be considered a notion of \smallness" by the following easy
Peer effects in medical school

Abstract Using data on the universe of students who graduated from US medical schools between 1996 and 1998, we examine whether the abilities and specialty preferences of a medical school class affect a student's academic achievement in medical school and his choice of specialty. We mitigate the selection problem by including school-specific fixed effects, and show that this method yields an upper bound on peer effects for our data. We estimate positive peer effects that disappear when school-specific fixed effects are added to control for the endogeneity of a peer group. We find no evidence that peer effects are stronger for blacks, that peer groups are formed along racial lines, or that students with relatively low ability benefit more from their peers than students with relatively high-ability. However, we do find some evidence that peer groups form along gender lines.
Drug dealers, retaliation, and deterrence.

Abstract Background Illicit drug sellers have limited access to formal mediation and therefore are rational targets to predators. As such, dealers are especially reliant on retaliation to deter victimization. Prior scholarship on dealers, retaliation, and deterrence has focused largely on general deterrence, or the effect of punishing one person on others. Research is yet to shed much light on other types of deterrence that dealers engage in. Methods This paper addresses that gap by drawing on qualitative data obtained in interviews with 25 unincarcerated drug sellers from disadvantaged neighborhoods in St. Louis, Missouri. Results We find that dealers' use of retaliation is linked to four kinds of deterrence—general, specific, situational, and permeating—and that these are combined into three forms: namely, specific-situational; specific-permeating; and comprehensive (i.e., all four kinds simultaneously). Conclusion Implications for research, theory, and "criminal justice" are discussed. Specifically, we call for future scholarship to examine how each type of deterrence affects the others, and suggest that both predation against and retaliation by drug dealers might be reduced by granting them greater access to formal means of dispute resolution.
Hygroscopic growth of self-assembled layered surfactant molecules at the interface between air and organic salts.

Abstract We report here the self-assembly of surfactant molecules at the interface of air and the hygroscopic quaternary ammonium salt tetrabutylammonium acetate (TBAAc). Homogeneously dissolved surfactant molecules at 100 °C self-assemble upon contacting air due to high moisture adsorption by the organic salt when cooling down. Highly ordered lamellar phases with different lattice spacings have been observed when surfactants with various lengths of alkyl chains were used. CnTMAB/TBAAc systems showed all-trans conformation of interior methylene carbons and interdigited bilayers with an average CH2 increment of 0.119 nm, while CnNH2/TBAAc systems showed trans/gauche mixed conformations of interior methylene carbons and bilayers with an average CH2 increment of 0.247 nm. CnNH2s in CnNH2/TBAAc formed bilayers through water-mediated intermolecular hydrogen bonds with a water layer thickness of 0.51–0.61 nm. In CnTAB/TBAAc, as the head group of CnTAB is bigger, the interdigited bilayer thickness (d-spacing) is smaller, because the bigger head groups accommodate enough space for alkyl tails to come in between them.