cssi/SciSciGPT-SciSciNet huggingface dataset:
The Number of Independent Sets in a Graph with Small Maximum Degree

Let ind(G) be the number of independent sets in a graph G. We show that if G has maximum degree at most 5 then $${\rm ind}(G) \leq 2^{{\rm iso}(G)} \prod_{uv \in E(G)} {\rm ind}(K_{d(u),d(v)})^{\frac{1}{d(u)d(v)}}$$ (where d(·) is vertex degree, iso(G) is the number of isolated vertices in G and K a,b is the complete bipartite graph with a vertices in one partition class and b in the other), with equality if and only if each connected component of G is either a complete bipartite graph or a single vertex. This bound (for all G) was conjectured by Kahn. A corollary of our result is that if G is d-regular with 1 ≤ d ≤ 5 then $${\rm ind}(G) \leq \left(2^{d+1}-1\right)^\frac{|V(G)|}{2d},$$ with equality if and only if G is a disjoint union of |V(G)|/2d copies of K d,d . This bound (for all d) was conjectured by Alon and Kahn and recently proved for all d by the second author, without the characterization of the extreme cases. Our proof involves a reduction to a finite search. For graphs with maximum degree at most 3 the search could be done by hand, but for the case of maximum degree 4 or 5, a computer is needed.
Managers' Motives to Withhold Segment Disclosures and the Effect of SFAS No. 131 on Analysts' Information Environment

Using retroactive disclosures required by Statement of Financial Accounting Standards (SFAS) No. 131, we examine managers' incentives for withholding segment information under SFAS No. 14 and the impact of SFAS No. 131 on analysts' information environment for a sample of firms that previously reported as single‐segment firms and initiated segment disclosure with SFAS No. 131. We examine this set of firms because they likely had the strongest incentives to withhold segment information and analysts potentially had the most to gain when these firms were forced to begin providing segment disclosures under SFAS No. 131. We find that these firms used the latitude in SFAS No. 14 to hide profitable segments operating in less competitive industries than their primary operations. However, we find no evidence to suggest that these firms used the latitude in SFAS No. 14 to mask poor performance. In contrast, our results suggest that by withholding segment information, these firms allowed themselves to appear as if th...
Choosing What to Protect: Strategic Defensive Allocation against an Unknown Attacker

We study a strategic model in which a defender must allocate defensive resources to a collection of locations and an attacker must choose a location to attack. In equilibrium, the defender sometimes optimally leaves a location undefended and sometimes prefers a higher vulnerability at a particular location even if a lower risk could be achieved at zero cost. The defender prefers to allocate resources in a centralized (rather than decentralized) manner, the optimal allocation of resources can be non-monotonic in the value of the attacker's outside option, and the defender prefers her defensive allocation to be public rather than secret. Copyright 2007 Blackwell Publishing, Inc..
The Hamiltonian Approach to Yang-Mills (2+1): An Update and Corrections to String Tension

Yang-Mills theories in 2+1 (or 3) dimensions are interesting as nontrivial gauge theories in their own right and as effective theories of QCD at high temperatures. I shall review the basics of our Hamiltonian approach to this theory, emphasizing symmetries with a short update on its status. We will show that the calculation of the vacuum wave function for Yang-Mills theory in 2+1 dimensions is in the lowest order of a systematic expansion. Expectation values of observables can be calculated using an effective interacting chiral boson theory, which also leads to a natural expansion as a double series in the coupling constant (to be interpreted within a resummed perturbation series) and a particular kinematical factor. The calculation of the first set of corrections in this expansion shows that the string tension is modified by about ?0.3% to ?2.8% compared to the lowest order value. This is in good agreement with lattice estimates.
Numerical Studies of the Effects of Active and Passive Circulation Enhancement Concepts on Wind Turbine Performance

The aerodynamic performance of a wind turbine rotor equipped with circulation enhancement technology (trailing edge blowing or Gurney flaps) is investigated using a three-dimensional unsteady viscous flow analysis. The National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine (HAWT) is chosen as the baseline configuration. Experimental data for the baseline case is used to validate the flow solver, prior to its use in exploring these concepts. Calculations have been performed for axial and yawed flow at several wind conditions. Results presented include radial distribution of the normal and tangential forces, shaft torque, root flap moment, and surface pressure distributions at selected radial locations. At low wind speed (7 m/s) where the flow is fully attached, it is shown that a Coanda jet at trailing edge is effective at increasing circulation resulting in an increase of lift and the chordwise thrust force. This leads to an increased amount of net power generation compared to the baseline configuration for moderate blowing coefficients (Cμ ≤ 0.075). A passive Gurney flap was found to increase the bound circulation and produce increased power in a manner similar to Coanda jet. At high wind speed (15 m/s) where the flow is separated, both the Coanda jet and Gurney flap become ineffective. The effects of these two concepts on the root bending moments have also been studied.
Loop Calculus and Belief Propagation for q-ary Alphabet: Loop Tower

Loop calculus introduced in (M. Chertkov and V. Chernyak, 2006) constitutes a new theoretical tool that explicitly expresses the symbol maximum-a-posteriori (MAP) solution of a general statistical inference problem via a solution of the belief propagation (BP) equations. This finding brought a new significance to the BP concept, which in the past was thought of as just a loop-free approximation. In this paper we continue a discussion of the loop calculus. We introduce an invariant formulation which allows to generalize the loop calculus approach to a q-are alphabet.
The stellar velocity distribution in the solar neighbourhood

We explore the heating of the velocity distribution in the solar neighbourhood by stochastic spiral waves. Our investigation is based on direct numerical integration of initially circular test-particle orbits in the sheared sheet. We confirm the conclusion of other investigators that heating by spiral structure can explain the principal features of the age–velocity dispersion relation and other parameters of the velocity distribution in the solar neighbourhood. In addition, we find that heating by strong transient spirals can naturally explain the presence of small-scale structure in the velocity distribution (‘moving groups’). Heating by spiral structure also explains why the stars in a single velocity-space moving group have a wide range of ages, a result that is difficult to understand in the traditional model in which these structures result from inhomogeneous star formation. Thus we suggest that old moving groups arise from irregularities in the Galactic potential rather than from irregularities in the star formation rate.
The Thurston Metric on Hyperbolic Domains and Boundaries of Convex Hulls

We show that the nearest point retraction is a uniform quasi-isometry from the Thurston metric on a hyperbolic domain $${\Omega \subset{\hat{\mathbb C}}}$$ to the boundary Dome(Ω) of the convex hull of its complement. As a corollary, one obtains explicit bounds on the quasi-isometry constant of the nearest point retraction with respect to the Poincare metric when Ω is uniformly perfect. We also establish Marden and Markovic’s conjecture that Ω is uniformly perfect if and only if the nearest point retraction is Lipschitz with respect to the Poincare metric on Ω.
High-performance deuterium-lithium neutron source for fusion materials and technology testing

A new approach to a deuterium-lithium neutron source aimed at meeting the near-term requirements of a high-flux high-energy International Fusion Materials Irradiation Facility (IFMIF) is discussed. The concept employs multiple accelerator modules providing deuteron beams to two liquid-lithium jet targets oriented at right angles. This beam-target geometry provides much larger test volumes than can be attained with a single beam and target and produces significant regions of low neutron-flux gradient. A preliminary beam-dynamics design has been obtained for a 250-mA reference accelerator module. Neutron-flux levels and irradiation volumes were calculated for a neutron source incorporating two such modules, and interaction of the beam with the lithium jet was studied using a thermal-hydraulic computer simulation. Cost estimates are provided for a range of beam currents, and a possible facility staging sequence is suggested. >
Automated volcanic eruption detection using MODIS

Abstract The moderate resolution imaging spectroradiometer (MODIS) flown on-board NASA's first earth observing system (EOS) platform, Terra, offers complete global data coverage every 1–2 days at spatial resolutions of 250, 500, and 1000 m. Its ability to detect emitted radiation in the short (4 μm)- and long (12 μm)-wave infrared regions of the electromagnetic spectrum, combined with the excellent geolocation of the image pixels (∼200 m), makes it an ideal source of data for automatically detecting and monitoring high-temperature volcanic thermal anomalies. This paper describes the underlying principles of, and results obtained from, just such a system. Our algorithm interrogates the MODIS Level 1B data stream for evidence of high-temperature volcanic features. Once a hotspot has been identified, its details (location, emitted spectral radiance, satellite observational parameters) are written to an ASCII text file and transferred via file transfer protocol (FTP) to the Hawaii Institute of Geophysics and Planetology (HIGP), where the results are posted on the Internet ( http://modis.higp.hawaii.edu ). The global distribution of volcanic hotspots can be examined visually at a variety of scales using this website, which also allows easy access to the quantitative data contained in the ASCII files themselves. We outline how the algorithm has proven robust as a hotspot detection tool for a wide range of eruptive styles at both permanently and sporadically active volcanoes including Soufriere Hills (Montserrat), Popocatepetl (Mexico), Bezymianny (Russia), and Merapi (Java), amongst others. We also present case studies of how the system has allowed the onset, development, and cessation of discrete eruptive events to be monitored at Nyamuragira (Congo), Piton de la Fournaise (Reunion Island), and Shiveluch (Russia).
Molecular Line Profile Fitting with Analytic Radiative Transfer Models

We present a study of analytic models of starless cores whose line profiles have "infall asymmetry," or blue-skewed shapes indicative of contracting motions. We compare the ability of two types of analytical radiative transfer models to reproduce the line profiles and infall speeds of centrally condensed starless cores whose infall speeds are spatially constant and range between 0 and 0.2 km s-1. The model line profiles of HCO+ (J = 1 → 0) and HCO+ (J = 3 → 2) are produced by a self-consistent Monte Carlo radiative transfer code. The analytic models assume that the excitation temperature in the front of the cloud is either constant ("two-layer" model) or increases inward as a linear function of optical depth ("hill" model). Each analytic model is matched to the line profile by rapid least-squares fitting. The blue-asymmetric line profiles with two peaks, or with a blueshifted peak and a red shifted shoulder, can be well fitted by one or both of the analytic models. Two-peak profiles are best matched by the "HILL5" model (a five parameter version of the hill model), with an rms error of 0.01 km s-1, while the "TWOLAYER6" model underestimates the infall speed by a factor of ~2. For red-shoulder profiles, the HILL5 and TWOLAYER6 fits reproduce infall speeds equally well, with an rms error of 0.04 km s-1. The fits are most accurate when the line has a brightness temperature greater than 3 K. Our most accurate models tend to not only reproduce the line profile shape but also match the excitation conditions along the line of sight. A better match to the line profile shape does not necessarily imply a better match to the infall speed. We provide guidance on how to minimize the risk of obtaining a poor infall speed fit. A peak signal-to-noise ratio of at least 30 in the molecular line observations is required for performing these analytic radiative transfer fits to the line profiles. Moderate amounts of depletion and beam smoothing do not adversely affect the accuracy of the infall speeds obtained from these models.
A new proposed simplified classification of coronary artery bifurcation lesions and bifurcation interventional techniques

Current classification systems of coronary bifurcation lesions are confusing and difficult to memorize. As coronary revascularization techniques become increasingly complex, it is important to establish a universal classification system. This manuscript proposes a simplified classification system that uses a combination of letters and numbers to provide a clinically relevant anatomic description of a given coronary artery bifurcation lesion. This classification consists of the prefix B (for Bifurcation lesion), followed by the addition of 4 separate suffixes. The first suffix consists of one of the letters C, N, S, or L. C = Close to the bifurcation: the lesion is close to a bifurcation, but the distance from the carina is more than the width of the plaque protruding into the lumen; N = Bifurcation lesion with one branch being Nonsignificant: nonsignificant being defined as less than 2.0 mm vessel diameter; S = Small proximal segment; or L = Large proximal segment: large defined as more than two-thirds of the sum of the diameters of both branch vessels. The second suffix describes the number of diseased ostia. 1M = only the Main vessel ostium is involved; 1S = only the Side branch ostium is involved; or 2 = both ostia are involved. The third suffix classifies the angle between the bifurcation vessels and uses the letters V or T; V = the angle between the two branches is less than 70 degrees, T = angle more than 70 degrees. The fourth suffixes are optional: CA for calcified, LM for left main involvement.
Talented Young Writers' Relationships with Writing

Through a qualitative research design, the author explored how eight talented young creative writers related to their craft. The construct, “relationship with writing,” emerged as the study’s overarching theme; this theme includes students’ influences, goals, values, identity, and emotions as these relate to writing. The findings indicated identity development and the expression of an authentic self were central to students’ relationships with writing. Multiple positive influences led students to view writing as a means to understand and express their identities. Students valued academic writing, but felt creative writing was more congruent with their emotions, goals, and values. Overall, students’ relationships with writing can be described as positive, personal, and context dependent.
An Alternative Method for Measuring Financial Frictions

Costly state verification models predict that the sensitivity of borrowing costs to financial leverage is positively related to the level of state verification costs (financial frictions). This paper constructs a measure of financial frictions that is consistent with this prediction of theory. Using bond deals from 47 countries, financial frictions are captured as the sensitivity of bond spreads to the issuing firms’ financial leverage. This dynamic measure of financial frictions provides new insights into three characteristics of financial frictions. 1) In contrast to the inferences drawn from widely-used measures, financial frictions display a large degree of variability, and have decreased over time. 2) The effect of financial frictions on private credit supply has decreased both in significance and magnitude over time. 3) Bankruptcy reforms, in general, have not been effective in improving creditor/borrower rights.
Female sexual dysfunction.

Female sexual dysfunction can drastically diminish quality of life for many women. It is estimated that in the United States 40% of women have sexual complaints. These conditions are frequently underdiagnosed and undertreated. Terminology and classification systems of female sexual dysfunction can be confusing and complicated, which hampers the process of clinical diagnosis, making accurate diagnosis difficult. There are few treatment options available for female sexual dysfunctions, however, some interventions may be of benefit and are described. Additional treatments are in development. The development of clear clinical categories and diagnostic guidelines for female sexual dysfunction are of utmost importance and can be of great benefit for clinical and public health uses and disease-related research.
Schrödinger’s Cataplex

We discuss elementary entwiners that cross-weave the variables of certain integrable models: Liouville, sine-Gordon, and sinh-Gordon field theories in two-dimensional spacetime, and their quantum mechanical reductions. First we define a complex time parameter that varies from one energy-shell to another. Then we explain how field propagators can be simply expressed in terms of elementary functions through the combination of an evolution in this complex time and a duality transformation.
A Dynamic Model of Differential Human Capital and Criminal Activity

This paper presents a dynamic model of criminal activity. Individuals are endowed with legal and criminal human capital. Potential incomes in legal and criminal sectors depend on the level of the relevant human capital, the rate of return and random shocks. Human capital can be enhanced by participating in both sectors. Legal human capital can also be enhanced through investment. Human capital is subject to depreciation. Individuals maximize expected discounted lifetime utility, which depends on consumption. The model allows analyses of the effects of recessions, imprisonment/rehabilitation scenarios, sanctions and returns to human capital. New insights, such as hysteresis in criminal behaviour, are obtained.
A Semiparametric Bayesian Model for Detecting Synchrony Among Multiple Neurons

We propose a scalable semiparametric Bayesian model to capture dependencies among multiple neurons by detecting their cofiring (possibly with some lag time) patterns over time. After discretizing time so there is at most one spike at each interval, the resulting sequence of 1s (spike) and 0s (silence) for each neuron is modeled using the logistic function of a continuous latent variable with a gaussian process prior. For multiple neurons, the corresponding marginal distributions are coupled to their joint probability distribution using a parametric copula model. The advantages of our approach are as follows. The nonparametric component (i.e., the gaussian process model) provides a flexible framework for modeling the underlying firing rates, and the parametric component (i.e., the copula model) allows us to make inferences regarding both contemporaneous and lagged relationships among neurons. Using the copula model, we construct multivariate probabilistic models by separating the modeling of univariate marginal distributions from the modeling of a dependence structure among variables. Our method is easy to implement using a computationally efficient sampling algorithm that can be easily extended to high-dimensional problems. Using simulated data, we show that our approach could correctly capture temporal dependencies in firing rates and identify synchronous neurons. We also apply our model to spike train data obtained from prefrontal cortical areas.
Military Service in the Life Course

AbstractWe review research published in the past 15 years that explores the relationship between military service and the life course, focusing on criminal careers, marital status, lifelong health, and socioeconomic attainment. Throughout the review, we note the extent to which studies find that veterans experienced different outcomes in different historical periods, ranging from World War II to the more recent voluntary armed forces. The effects of military service depend on whether health, criminal, socioeconomic, or marital outcomes are considered. They also depend on the timing and era of service, and veterans’ family background and individual characteristics such as race and delinquency. Nevertheless, the evidence to date suggests one general conclusion: Veterans exposed to combat have suffered worse outcomes than noncombat veterans and than nonveterans. We conclude with suggestions for future research including a tighter integration of the research questions and strategies that have been employed to...
Astronomy with Small Telescopes

The All Sky Automated Survey is monitoring the entire sky to about 14 mag with a cadence of about 1 day; it has discovered about 105 variable stars, most of them new. The instrument used for the survey had an aperture of 7 cm. A search for planetary transits has led to the discovery of about a dozen confirmed planets, so-called hot Jupiters, providing information on planetary masses and radii. Most discoveries were done with telescopes with apertures of 10 cm. We propose a search for optical transients covering the entire sky with a cadence of 10-30 minutes and a limit of 12-14 mag, with an instant verification of all candidate events. The search will be made with a large number of 10 cm instruments, and the verification will be done with 30 cm instruments. We also propose a system to be located at the L1 point of the Earth-Sun system to detect "killer asteroids." With a limiting magnitude of about 18 mag, it could detect 10 m boulders several hours prior to their impact and provide warning against Tunguska-like events, as well as provide news about spectacular but more modest, harmless impacts.
Cyclobutane—Physical Properties and Theoretical Studies

1 Introduction 2 Cycloalkane Structures and Bonding 3 Bond Strengths 4 Energies of Cycloalkanes 5 NMR Spectra of Cycloalkanes 6 Cyclopropyl and Cyclobutyl Cations 7 Interaction of Cyclopropane and Cyclobutane Rings with Electron-Deficient Centers 8 Protonated Cyclopropanes and Cyclobutanes 9 Thermal Formation of Cyclobutanes by Cycloaddition and Thermal Cleavage 10 Antiaromaticity in Cyclobutadiene 11 Summary Keywords: cycloalkane structures and bonding; cyclobutane - very reactive and ‘normal’ cycloalkanes; cycloalkane energies; NMR spectra of cycloalkanes; cyclopropyl and cyclobutyl cations; cyclopropane and cyclobutane rings with electron-deficient centers; protonated cyclopropanes and cyclobutanes; antiaromaticity in cyclobutadiene
Asymptotic Expansion of the Bergman Kernel via Perturbation of the Bargmann–Fock Model

We give an alternate proof of the existence of the asymptotic expansion of the Bergman kernel associated with the kth tensor powers of a positive line bundle L in a \(\frac{1}{\sqrt{k}}\)-neighborhood of the diagonal using elementary methods. We use the observation that after rescaling the Kahler potential \(k\varphi \) in a \(\frac{1}{\sqrt{k}}\)-neighborhood of a given point, the potential becomes an asymptotic perturbation of the Bargmann–Fock metric. We then prove that the Bergman kernel is also an asymptotic perturbation of the Bargmann–Fock Bergman kernel.
Selling Australia as ‘clean and green’*

“Green and clean” has been used as a key marketing tool to promote Australian products overseas. The rationale is that consumers are generally concerned about personal health and the environment and will choose, and pay price premiums, for products that are perceived to be clean (good for them) and green (good for the environment) over alternative products. But is Australia seen as clean and green? Is it really why people buy Australia? This paper attempts to investigate such questions.
Molecular dynamics study of neutral and multiply charged sodium clusters

Abstract The fission mechanism of multiply charged sodium clusters was investigated with molecular dynamics and a new potential featuring a local density approximation second-moment approach. We show that the critical si which 2+, 3+ and 4+ charged clusters undergo fission due to Coulomb forces depends strongly on the cluster temperature. The smallest critical size occur for cold clusters. Master curves predicting upper bounds to the cluster temperature at the fissioning critical size are provided. A scaling of the cluster ion critical size with a power law of the total charge is used to predict the energy barrier that sodium clusters need to surmount to undergo fission.
Radial Distribution of Dust Grains around HR 4796A

We present high dynamic range images of circumstellar dust around HR 4796A that were obtained with MIRLIN at the Keck II telescope at lambda = 7.9, 10.3, 12.5, and 24.5 mum. We also present a new continuum measurement at 350 mum obtained at the Caltech Submillimeter Observatory. Emission is resolved in Keck images at 12.5 and 24.5 mum with point-spread function FWHM values of 0".37 and 0".55, respectively, and confirms the presence of an outer ring centered at 70 AU. Unresolved excess infrared emission is also detected at the stellar position and must originate well within 13 AU of the star. A model of dust emission fitted to flux densities at 12.5, 20.8, and 24.5 mum indicates that dust grains are located 4(-2)(+3) AU from the star with effective size 28 +/- 6 mum and an associated temperature of 260 +/- 40 K. We simulate all extant data with a simple model of exozodiacal dust and an outer exo-Kuiper ring. A two-component outer ring is necessary to fit both Keck thermal infrared and Hubble Space Telescope scattered-light images. Bayesian parameter estimates yield a total cross-sectional area of 0.055 AU(2) for grains roughly 4 AU from the star, and an outer-dust disk composed of a narrow large-grain ring embedded within a wider ring of smaller grains. The narrow ring is 14 +/- 1 AU wide with inner radius 66 +/- 1 AU and total cross-sectional area 245 AU2. The outer ring is 80 +/- 15 AU wide with inner radius 45 +/- 5 AU and total cross-sectional area 90 AU2. Dust grains in the narrow ring are about 10 times larger and have lower albedos than those in the wider ring. These properties are consistent with a picture in which radiation pressure dominates the dispersal of an exo-Kuiper belt.
The common patterns of nature

We typically observe large-scale outcomes that arise from the interactions of many hidden, small-scale processes. Examples include age of disease onset, rates of amino acid substitutions and composition of ecological communities. The macroscopic patterns in each problem often vary around a characteristic shape that can be generated by neutral processes. A neutral generative model assumes that each microscopic process follows unbiased or random stochastic fluctuations: random connections of network nodes; amino acid substitutions with no effect on fitness; species that arise or disappear from communities randomly. These neutral generative models often match common patterns of nature. In this paper, I present the theoretical background by which we can understand why these neutral generative models are so successful. I show where the classic patterns come from, such as the Poisson pattern, the normal or Gaussian pattern and many others. Each classic pattern was often discovered by a simple neutral generative model. The neutral patterns share a special characteristic: they describe the patterns of nature that follow from simple constraints on information. For example, any aggregation of processes that preserves information only about the mean and variance attracts to the Gaussian pattern; any aggregation that preserves information only about the mean attracts to the exponential pattern; any aggregation that preserves information only about the geometric mean attracts to the power law pattern. I present a simple and consistent informational framework of the common patterns of nature based on the method of maximum entropy. This framework shows that each neutral generative model is a special case that helps to discover a particular set of informational constraints; those informational constraints define a much wider domain of non-neutral generative processes that attract to the same neutral pattern.
Chemical Combinatorics for Alkane-Isomer Enumeration and More

Standard combinatorial enumeration techniques for alkanes are considered with a view to the extension to a widened range of chemically interesting features. As one brief point it is noted that these standard techniques naturally associate to generational schemes and thence have nomenclatural interpretations, which may be made to achieve some similarity to the standard IUPAC nomenclature. Our primary focus is the illustration that such combinatorial techniques are sufficient to enable computation of several graph-theoretic structural invariants averaged over (different types of) isomer classes. Such averages (and associated isomer counts) are tabulated for structural isomers for up to N = 40 carbons, where there are ∼1014 isomers (though the computational methodology should rather readily extend to at least N = 80 where there should be ∼1028 isomers). The averages for invariants are utilized to estimate several physicochemical properties averaged over these same isomer classes. The properties currently so ...
Using Data Mining to Detect Anomalous Producer Behavior: An Analysis of Soybean Production and the Federal Crop Insurance Program

United States agricultural policy has involved crop insurance programs since the era of the Great Depression and the Dust Bowl. Initially federal crop insurance was designed and implemented to help farmers overcome prevented planting losses and to minimize risk due to low prices. However in contemporary times, it is unclear whether the producer's primary benefit of the federal crop insurance program is risk reduction or income enhancement. Rather than using crop insurance to manage risk as intended, a limited number of producers have exploited the program. In April 2002, the Deputy Administrator for Compliance estimated that 25 percent of all claims in the federal crop insurance program contain some element of fraud, waste, and abuse. Overall, the crop insurance program provides positive gains for participating producers. In reinsurance year 2000, insured producers paid $2.54 billion in premium for $34.4 billion of coverage or liability and received $2.58 billion of indemnities for crop losses (RMAOnline). Fraud, waste, and abuse are a continuing concern within the federal crop insurance program. Congress in 2000 passed legislation to expand and strengthen the program to address concerns regarding fraud, waste, and abuse. The Agricultural Risk Protection Act (ARPA) of 2000 was a major vote of confidence for the federal crop insurance program, and included $8.2 billion in funding over five years to enhance and improve the federal crop insurance program. ARPA requires the USDA Risk Management Agency (RMA) to conduct program wide efforts (compliance, education, and insurance services) to prevent fraud, waste, and abuse. Growth in the size and complexity of the crop insurance program makes prevention and 1
Effective Carrier Mobility in Surface-Space Charge Layers

Carriers held to a region near the surface by the potential well of a space charge layer may have their mobility reduced by surface scattering, if the width of the well is of the order of a mean free path. An effective mobility, which may differ from the bulk mobility by as much as a factor of ten, has been obtained from a solution of the Boltzmann equation. Solutions have been carried out for two types of potential functions: (a) a linear potential corresponding to a constant space-charge field, and (b) a solution of Poisson's equation including an external bias applied normal to the surface. The results have been used to calculate changes in surface conductance of germanium with changes in surface potential and predict the "field effect" and "channel effect" mobilities.
The Very Low Mass Component of the Gliese 105 System

Multiple-epoch, multicolor images of the astrometric binary Gliese 105A and its very low mass companion Gliese 105C have been obtained using the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2) and near-infrared camera and multiobject spectrometer (NICMOS). The optical and near-infrared colors of Gl 105C strongly suggest a spectral type of M7 V for that star. Relative astrometric measurements spanning 3 yr reveal the first evidence of Gl 105C's orbital motion. Previous long-term astrometric studies at Sproul and McCormick Observatories have shown that the period of Gl 105A's perturbation is ~60 yr. To satisfy both the observed orbital motion and Gl 105A's astrometric period, Gl 105C's orbit must have an eccentricity of ~0.75 and a semimajor axis of ~15 AU. Measurements of Gl 105A's radial velocity over 12 yr show a linear trend with a slope of 11.3 m s-1 yr-1, which is consistent with these orbital constraints and a nearly face-on orbit. As no other faint companions to Gl 105A have been detected, we conclude that Gl 105C is probably the source of the 60 yr astrometric perturbation.
svaseq: removing batch effects and other unwanted noise from sequencing data

It is now known that unwanted noise and unmodeled artifacts such as batch effects can dramatically reduce the accuracy of statistical inference in genomic experiments. These sources of noise must be modeled and removed to accurately measure biological variability and to obtain correct statistical inference when performing high-throughput genomic analysis. We introduced surrogate variable analysis (sva) for estimating these artifacts by (i) identifying the part of the genomic data only affected by artifacts and (ii) estimating the artifacts with principal components or singular vectors of the subset of the data matrix. The resulting estimates of artifacts can be used in subsequent analyses as adjustment factors to correct analyses. Here I describe a version of the sva approach specifically created for count data or FPKMs from sequencing experiments based on appropriate data transformation. I also describe the addition of supervised sva (ssva) for using control probes to identify the part of the genomic data only affected by artifacts. I present a comparison between these versions of sva and other methods for batch effect estimation on simulated data, real count-based data and FPKM-based data. These updates are available through the sva Bioconductor package and I have made fully reproducible analysis using these methods available from: https://github.com/jtleek/svaseq.
The Human Brain Evolving: A Personal Retrospective

Minor controversies notwithstanding, the evolution of the human brain has been an intermingled composite of allometric and nonallometric increases of brain volume and reorganizational events such as the reduction of primary visual cortex and a relative increase in both posterior association and (most probably) prefrontal cortex, as well as increased cerebral asymmetries, including Broca’s and Wernicke’s regions, with some of these changes already occurring in australopithecine times. As outlined in Holloway (1967), positive feedback (amplificationdeviation) has been a major mechanism in size increases. Exactly how this m´ elange of organs evolved will require many more paleontological discoveries with relatively intact crania, an unraveling of the genetic bases for both brain structures and their relationship to behaviors, and a far more complete picture of how the brain varies between male and female and among different populations throughout the world. After all, the human brain is still evolving, but for how long is quite uncertain.
Strain in layered nanocrystals

Layered nanocrystals consist of a core of one material surrounded by a shell of a second material. We present computation of the atomistic strain energy density in a layered nanocrystal, using an idealised model with a simple cubic lattice and harmonic interatomic potentials. These computations show that there is a critical size r ∗ for the shell thickness rs at which the energy density has a maximum. This critical size is roughly independent of the geometry and material parameters of the system. Interestingly, this critical size agrees with the shell thickness at which the quantum yield has a maximum, as observed in several systems and thus leads one to support the hypothesis that maximal quantum yield is strongly correlated with maximal elastic energy density.
A Non-linear Lower Bound for Planar Epsilon-nets

We show that the minimum possible size of an e-net for point objects and line (or rectangle)-ranges in the plane is (slightly) bigger than linear in $\frac{1}{\epsilon}$. This settles a problem raised by Matousek, Seidel and Welzl (Proc. 6th Annu. ACM Sympos. Comput. Geom., pp. 16–22, 1990).
Direct Signaling between Platelets and Cancer Cells Induces an Epithelial-Mesenchymal-Like Transition and Promotes Metastasis

SUMMARY Interactions of cancer cells with the primary tumor microenvironment are important determinants of cancer progression toward metastasis but it is unknown whether additional prometastatic signals are provided during the intravascular transit to the site of metastasis. Here, we show that platelet-tumor cell interactions are sufficient to prime tumor cells for subsequent metastasis. Platelet-derived TGFb and direct platelettumor cell contacts synergistically activate the TGFb/Smad and NF-kB pathways in cancer cells, resulting in their transition to an invasive mesenchymal-like phenotype and enhanced metastasis in vivo. Inhibition of NF-kB signaling in cancer cells or ablation of TGFb1 expression solely in platelets protects against lung metastasis in vivo. Thus, cancer cells rely on platelet-derived signals outside of the primary tumor for efficient metastasis.
Dibs! Customer Territorial Behaviors

“Third Place” servicescapes are often created to reflect home-like characteristics, expecting customers to relax, mingle, and consume their purchases. Yet, customers coopt the space, often using it...
Evaluation of ecohydrologic model parsimony at local and regional scales in a semiarid grassland ecosystem

In this study, a zero-dimensional land surface model based on a vertically averaged representation of soil moisture in the root-zone is coupled with grass dynamics represented by live and dead biomass pools. Five variants of the model combined the different time steps (daily vs interstorm), representations of potential evapotranspiration (PET), and constant versus variable water use efficiency (WUE). Model results were compared with field observations of soil moisture, live and dead biomass, and leaf area index (LAI) from a long-term experiment in the Nebraska Sand Hills (NSH), USA. Results show that the simplest model configuration using a constant WUE term, PET represented from a cosine function, and an inter-storm model time step can capture grass dynamics nearly as well as daily model simulations with variable WUE. The model is then applied across the NSH to investigate the performance of the model across a climate gradient, and identify parameters that can be calibrated to improve regional predictions. For this purpose a senescence parameter that controls the decay of live aboveground vegetation is further calibrated at 14 different locations across NSH. Model calibrations revealed the dependence of the senescence parameter to regional variations in annual precipitation. Relating the senescence coefficient to annual precipitation using an empirical equation improved the model predictions at the regional scale, and revealed a strong climatic control on grass LAI. Finally, the model is tested against some existing empirical equations that relate annual grassland productivity to annual precipitation and evapotranspiration. Copyright  2011 John Wiley & Sons, Ltd.
A Pieri rule for skew shapes

The Pieri rule expresses the product of a Schur function and a single row Schur function in terms of Schur functions. We extend the classical Pieri rule by expressing the product of a skew Schur function and a single row Schur function in terms of skew Schur functions. Like the classical rule, our rule involves simple additions of boxes to the original skew shape. Our proof is purely combinatorial and extends the combinatorial proof of the classical case.
INTEGRO-DIFFERENTIAL STOCHASTIC RESONANCE

A new class of stochastic resonator (SRT) and Stochastic Resonance (SR) phenomena are described. The new SRT consist of a classical SRT, one or more time derivative circuits and the same number of time integrators. The incoming signal with additive noise is first time derivated, then passes through the classical SRT and finally it is time integrated. The resulting SR phenomena show a well defined SR. Moreover the signal transfer and SNR are the best at the high frequency end. A particular property of the new system is the much smoother output signal due to the time integration.
Does category labeling lead to forgetting

What effect does labeling an object as a member of a familiar category have on memory for that object? Recent studies suggest that recognition memory can be negatively impacted by categorizing objects during encoding. This paper examines the “representational shift hypothesis” which argues that categorizing an object impairs recognition memory by altering the trace of the encoded memory to be more similar to the category prototype. Previous evidence for this idea comes from experiments in which a basic-level category labeling task was compared to a non-category labeling incidental encoding task, usually a preference judgment (e.g., “Do you like this item?”). In two experiments, we examine alternative tasks that attempt to control for processing demands and the degree to which category information is explicitly recruited at the time of study. Contrary to the predictions of the representational shift hypothesis, we find no evidence that memory is selectively impaired by category labeling. Overall, the pattern of results across both studies appears consistent with well-established variables known to influence memory such as encoding specificity and distinctiveness effects.
Chromatic Bounds on Orbital Chromatic Roots

Given a group G of automorphisms of a graph Γ, the orbital chromatic polynomial OPΓ,G(x) is the polynomial whose value at a positive integer k is the number of orbits of G on proper k-colorings of Γ. Cameron and Kayibi introduced this polynomial as a means of understanding roots of chromatic polynomials. In this light, they posed a problem asking whether the real roots of the orbital chromatic polynomial of any graph are bounded above by the largest real root of its chromatic polynomial. We resolve this problem in a resounding negative by not only constructing a counterexample, but by providing a process for generating families of counterexamples. We additionally begin the program of finding classes of graphs whose orbital chromatic polynomials have real roots bounded above by the largest real root of their chromatic polynomials; in particular establishing this for many outerplanar graphs.
In Search of Real Rigidities

The closed and open economy literatures both work on evaluating the role of real rigidities, but in parallel. This paper brings the two literatures together. We use international price data and exchange rate shocks to evaluate the importance of real rigidities in price setting. We show that, consistent with the presence of real rigidities, the response of reset-price inflation to exchange rate shocks exhibits significant persistence. Individual import prices, conditional on changing, respond to exchange rate shocks prior to the last price change. At the same time, aggregate reset-price inflation for imports, like that for consumer prices, exhibits little persistence. Competitor prices affect firm pricing, and exchange rate pass-through into import prices is greater in response to trade-weighted, as opposed to bilateral, exchange rate shocks. We quantitatively evaluate sticky-price models (Calvo and menu cost) with variable markups at the wholesale level and constant markups at the retail level, consistent with empirical evidence. Variable markups alone generate price sluggishness at the aggregate level, while they fall short of matching price persistence at the micro level. Finally, variable markups magnify the size of the contract multiplier, but their absolute effects are modest unless they are coupled with exogenous sources of persistence.
formation and properties of calcium aluminosilicate glasses

Determination du domaine de vitrification et etude de quelques proprietes (coefficient de dilatation thermique temperatures de transition vitreuse et de ramollissement dilatometrique, indice de refraction). Les resultats montrent que la structure de ces verres n'est peut etre pas aussi proche de celle des verres d'aluminosilicates alcalins qu'on le suppose generalement. On presente des elements qui peuvent suggerer une separation de phase
Confidence, Crashes and Animal Spirits

This article is an attempt to reformulate what I take to be two key insights from Keyness General Theory (Keynes, 1936). The first is that there is something profoundly different about the labour market from most other markets in the economy. The second is that the beliefs of participants in the asset markets have an independent influence on economic activity. In the language of modern dynamic general equilibrium theory, we would say that there is a continuum of labour market equilibria and that beliefs about the value of the stock market select an equilibrium. The General Theory contains many ideas, some of which are internally inconsistent, and Keynes did not try to reconcile his theory with Walrasian economics. That task was carried out by a group of interpreters, including Hansen (1936) and Hicks (1937). The current dominant paradigm, new-Keynesian economics, originated with the third edition of Samuelson’s (1955) undergraduate textbook in which he introduced the idea of the neoclassical synthesis. According to this doctrine, the economy is Keynesian in the short run but classical in the long run. The short run is defined as the period over which not all prices have had time to adjust to their Walrasian levels. This article introduces a different interpretation of the key ideas from the General Theory. 1 Although my work is inspired by Keynesian economics, this article is not about the history of thought. I offer a way of formulating the idea that market economies are not inherently self-stabilising without assuming that prices or wages are prevented from adjusting to their equilibrium levels by some kind of friction. Instead, I claim that high, persistent unemployment is a potentially permanent feature of a market economy in a steady-state equilibrium.
Face Clustering of a Large-scale CAD Model for Surface Mesh Generation

A detailed CAD model needs manual clean-up, or simplifying operations, before a finite element mesh can be automatically generated because such a model consists of hundreds or thousands of faces many of which may be smaller than a desired mesh element size. We propose an automated face clustering method used as a pre-process of surface mesh generation. By decomposing a model into face clusters so that each region can be projected onto a simple parametric surface such as a plane, we obtain a final mesh as an aggregate of sub-meshes for respective clusters without time-consuming manual preparation work. The projection onto a surface realises re-parameterisation as well as suppression of small details. The main contribution of this work is the integration of (1) a greedy algorithm for combining faces into clusters, and (2) geometric indices that reflect various aspects of a preferable shape for a cluster. The validity of the approach is demonstrated with results of clustering and mesh generation for a realistic-scale CAD model.