cssi/SciSciGPT-SciSciNet huggingface dataset:
Trade and civil conflict: Revisiting the cross-country evidence *

This paper revisits and expands the evidence on the impact of trade shocks on intra-state conflict with a large sample of developing countries in the 1960-2010 period. The results suggest that increases in the prices of a country's exported commodities raise the country's risk of civil conflict and its duration. The effect on conflict risk is mainly driven by the price of point-source commodities, in line with the rapacity effect theory of conflict. However, the paper does not find support for the opportunity cost theory via exported commodities. The analysis also finds that intense trading with contiguous countries is associated with lower duration of intra-state conflict, consistent with the idea that such trade reduces the incentive of contiguous countries to fuel conflict in their neighbor. Trading with neighbors is also associated with a lower risk of conflict, when such trade occurs under trade agreements. By contrast, neither imported commodity prices nor the economic cycle in export markets appears to exert any influence on the probability or duration of conflict. The paper identifies several conditions under which changes in the value of exported commodities cease to matter for conflict probability.
Planetary Imaging Concept Testbed Using a Recoverable Experiment–Coronagraph (PICTURE C)

An exoplanet mission based on a high-altitude balloon is a next logical step in humanity’s quest to explore Earthlike planets in Earthlike orbits orbiting Sunlike stars. The mission described here is capable of spectrally imaging debris disks and exozodiacal light around a number of stars spanning a range of infrared excesses, stellar types, and ages. The mission is designed to characterize the background near those stars, to study the disks themselves, and to look for planets in those systems. The background light scattered and emitted from the disk is a key uncertainty in the mission design of any exoplanet direct imaging mission, thus, its characterization is critically important for future imaging of exoplanets.
Crack deflection as a toughening mechanism in SiC-whisker-reinforced MoSi2

Crack propagation in SiC-whisker-reinforced MoSi2 was studied. In particular, the deflection angles of the cracks were examined to determine the degree to which they are affected by the whisker reinforcement. The composite studied was hot-pressed MoSi2 with 20 vol% vapor-liquid-solid β-SiC whiskers. A substantial difference was found between the deflection angles of cracks formed in the reinforced MoSi2 and those in a control sample with no whiskers, showing the process of crack deflection as an important, but not the only, toughening mechanism.
Shape-based peak identification for ChIP-Seq

The identification of binding targets for proteins using ChIP-Seq has gained popularity as an alternative to ChIP-chip. Sequencing can, in principle, eliminate artifacts associated with microarrays, and cheap sequencing offers the ability to sequence deeply and obtain a comprehensive survey of binding. A number of algorithms have been developed to call "peaks" representing bound regions from mapped reads. Most current algorithms incorporate multiple heuristics, and despite much work it remains difficult to accurately determine individual peaks corresponding to distinct binding events. Our method for identifying statistically significant peaks from read coverage is inspired by the notion of persistence in topological data analysis and provides a non-parametric approach that is statistically sound and robust to noise in experiments. Specifically, our method reduces the peak calling problem to the study of tree-based statistics derived from the data. We validate our approach using previously published data and show that it can discover previously missed regions. The difficulty in accurately calling peaks for ChIP-Seq data is partly due to the difficulty in defining peaks, and we demonstrate a novel method that improves on the accuracy of previous methods in resolving peaks. Our introduction of a robust statistical test based on ideas from topological data analysis is also novel. Our methods are implemented in a program called T-PIC (T ree shape P eak I dentification for C hIP-Seq) is available at http://bio.math.berkeley.edu/tpic/ .
Open regionalism in the Andean Community: a trade flow analysis

This article evaluates the extent to which the establishment of the Andean Free Trade Zone (AFTZ) has led to an improvement of intra-regional trade, as promised by open regionalism, without reducing extra-regional trade. Open regionalism is a dynamic process in which economic agreements serve as intermediate steps towards integration with the world economy. The calculations of ex post income elasticities of import demand show that the establishment of the AFTZ in 1993 led to an increase in Andean Community trade, and not to a contraction of extra-regional trade. The intensity of trade index and the propensity to export intra- and extra-regionally confirm this finding. The article discusses these results in the context of the multilateral trading system and the trade relations between the Andean Community and the rest of the world.
An experimental study of Quartets MaxCut and other supertree methods

Supertree methods represent one of the major ways by which the Tree of Life can be estimated, but despite many recent algorithmic innovations, matrix representation with parsimony (MRP) remains the main algorithmic supertree method. We evaluated the performance of several supertree methods based upon the Quartets MaxCut (QMC) method of Snir and Rao and showed that two of these methods usually outperform MRP and five other supertree methods that we studied, under many realistic model conditions. However, the QMC-based methods have scalability issues that may limit their utility on large datasets. We also observed that taxon sampling impacted supertree accuracy, with poor results obtained when all of the source trees were only sparsely sampled. Finally, we showed that the popular optimality criterion of minimizing the total topological distance of the supertree to the source trees is only weakly correlated with supertree topological accuracy. Therefore evaluating supertree methods on biological datasets is problematic. Our results show that supertree methods that improve upon MRP are possible, and that an effort should be made to produce scalable and robust implementations of the most accurate supertree methods. Also, because topological accuracy depends upon taxon sampling strategies, attempts to construct very large phylogenetic trees using supertree methods should consider the selection of source tree datasets, as well as supertree methods. Finally, since supertree topological error is only weakly correlated with the supertree's topological distance to its source trees, development and testing of supertree methods presents methodological challenges.
Biologically inspired design principles for Scalable, Robust, Adaptive, Decentralized search and automated response (RADAR)

Distributed search problems are ubiquitous in Artificial Life (ALife). Many distributed search problems require identifying a rare and previously unseen event and producing a rapid response. This challenge amounts to finding and removing an unknown needle in a very large haystack. Traditional computational search models are unlikely to find, nonetheless, appropriately respond to, novel events, particularly given data distributed across multiple platforms in a variety of formats and sources with variable and unknown reliability. Biological systems have evolved solutions to distributed search and response under uncertainty. Immune systems and ant colonies efficiently scale up massively parallel search with automated response in highly dynamic environments, and both do so using distributed coordination without centralized control. These properties are relevant to ALife, where distributed, autonomous, robust and adaptive control is needed to design robot swarms, mobile computing networks, computer security systems and other distributed intelligent systems. They are also relevant for searching, tracking the spread of ideas, and understanding the impact of innovations in online social networks. We review design principles for Scalable Robust, Adaptive, Decentralized search with Automated Response (Scalable RADAR) in biology. We discuss how biological RADAR scales up efficiently, and then discuss in detail how modular search in the immune system can be mimicked or built upon in ALife. Such search mechanisms are particularly useful when components have limited capacity to communicate and when physical distance makes communication more costly.
Infinite Dimensional Free Algebra and the Forms of the Master Field

We find an infinite-dimensional free algebra which lives at large N in any SU(N)-invariant action or Hamiltonian theory of bosonic matrices. The natural basis of this algebra is a free-algebraic generalization of Chebyshev polynomials and the dual basis is closely related to the planar connected parts. This leads to a number of free-algebraic forms of the master field including an algebraic derivation of the Gopakumar–Gross form. For action theories, these forms of the master field immediately give a number of new free-algebraic packagings of the planar Schwinger–Dyson equations.
Teaching heart function: one application of medical computer animation

Medicine has developed current methods of teaching heart function over several centuries. There have been few fundamental changes in these teaching techniques over the last several decades. The method of text study followed by laboratory activity is essentially the same for both undergraduate and medical school students. For the latter, a more comprehensive study of experimental animals is involved, and surgical procedures are observed on patients. Once in medical school, almost all teaching is by demonstration, with a very small number of students per instructor.
Modeling the Effects of H1N1 Influenza Vaccine Distribution in the United States

Abstract Objective We analyzed the effects of the timing of vaccine distribution in 11 US states during the 2009 H1N1 influenza pandemic. Methods By using reported data on the fraction of patients presenting with flu-related symptoms, we developed a transformation that allowed estimation of the state-specific temporal flu wave curve, representing the number of new infections during each week. We also utilized data describing the weekly numbers of vaccine doses delivered and administered. By using a simple difference equations model of flu progression, we developed two influenza wave curves: first, an "observable" curve that included the beneficial effects of vaccinations, and second, an unobservable curve that depicted how the flu would have progressed with no vaccine administered. We fit the observable curve to match the estimated epidemic curve and early exponential growth associated with R 0 , the reproductive number. By comparing the number of infections in each scenario, we estimated the infections averted by the administration of vaccine. Results Southern states experienced peak infection several weeks before northern states, and most of the vaccine was delivered well after the peak of the southern flu wave. Our models suggest that the vaccine had minimal ameliorative impact in the southern states and measurable positive impact in the northern states. Vaccine delivery after peak also results in a smaller fraction of the population's seeking the vaccine. Conclusions Our analysis suggests that current Centers for Disease Control and Prevention policy of allocating flu vaccine over time in direct proportion to states' populations may not be best in terms of averting nationally the maximum possible number of infections.
Surfactant Mediated Electrochemical Deposition of Ag on Au(111)

Electrochemical surfactant mediated growth of Ag on Au(111) was investigated experimentally using in situ scanning tunneling microscopy. Almost ideal layer-by-layer growth of Ag was obtained using 0.8 of a monolayer of Pb as a surfactant. Atomically flat epitaxial Ag thin films, 200 monolayer in thickness were grown on Au(111) using this technique. Energy dispersive X-ray analysis and Rutherford backscattering spectrometry showed no traces of Pb in the Ag layers grown. © 1999 The Electrochemical Society. S1099-0062(98)12-030-8. All rights reserved.
Reconstructing the world in 3D: bringing games with a purpose outdoors

We are interested in reconstructing real world locations as detailed 3D models, but to achieve this goal, we require a large quantity of photographic data. We designed a game to employ the efforts and digital cameras of everyday people to not only collect this data, but to do so in a fun and effective way. The result is PhotoCity, a game played outdoors with a camera, in which players take photos to capture flags and take over virtual models of real buildings. The game falls into the genres of both games with a purpose (GWAPs) and alternate reality games (ARGs). Each type of game comes with its own inherent challenges, but as a hybrid of both, PhotoCity presented us with a unique combination of obstacles. This paper describes the design decisions made to address these obstacles, and seeks to answer the question: Can games be used to achieve massive data-acquisition tasks when played in the real world, away from standard game consoles? We conclude with a report on player experiences and showcase some 3D reconstructions built by players during gameplay.
Phase 1 study of human plasma-derived plasmin (TAL-05-00018) in hemodialysis graft occlusion.

Abstract Introduction Hemodialysis grafts often fail because of stenosis at the venous anastomosis resulting in thrombosis. Percutaneous intervention involves thrombolysis with plasminogen activators, mechanical removal of thrombus, and angioplasty of the stenotic lesions. Objectives This article describes a phase I trial using plasmin (human) TAL 05-00018, a direct-acting fibrinolytic agent, to evaluate safety and, secondarily, to establish effective thrombolytic dosing. Patients/methods Six cohorts of five patients with acute HD graft occlusion documented by fistulagrams were treated with increasing dosages of plasmin (1, 2, 4, 8, 12, and 24 mg) infused within the graft over 30 min via two criss-crossed pulse-spray catheters. The primary efficacy endpoint was at least 50% thrombolysis, as determined by fistulography. Results There was no significant change in plasma alpha-2 antiplasmin or fibrinogen concentration, major bleeding did not occur, and there were no deaths. Serious adverse events in four patients were not related to the study drug. There was a dose­response relationship for the primary efficacy endpoint, all five subjects receiving 24 mg achieving more than 75% lysis. Conclusion This first phase I study of plasmin (human) TAL 05-00018, infused into thrombosed HD grafts, documents safety at all doses and an effective thrombolytic dosage of 24 mg indicating that further investigation into locally delivered plasmin is warranted.
Assessing Asset Pricing Anomalies

The optimal portfolio strategy is developed for an investor who has detected an asset pricing anomaly but is not certain that the anomaly is genuine rather than merely apparent. The analysis takes account of the fact that the parameters of both the underlying asset pricing model and the anomalous returns are estimated rather than known. The value that an investor would place on the ability to invest to exploit the apparent anomaly is also derived and illustrative calculations are presented for the Fama and French SMB and HML portfolios, whose returns are anomalous relative to the CAPM. An asset pricing anomaly is a statistically significant difference between the realized average returns associated with certain characteristics of securities, or on portfolios of securities formed on the basis of those characteristics, and the returns that are predicted by a particular asset pricing model. What is anomalous with respect to one model may be consistent with the predictions of other asset pricing models. For example, an excess return associated with a security’s dividend yield is anomalous with respect to the basic capital asset pricing model (CAPM) but is consistent with extensions that incorporate investor taxes. Some anomalies are inconsistent with any known rational asset pricing model; they appear to represent “money left on the table.” Such examples include the NASDAQ anomaly [Brennan, Chordia, and Subrahmanyam (1998)], the apparent slow adjustment of stock prices to earnings announcements [Ball and Brown (1968), Bernard and Thomas (1990)], and the existence of momentum (as well as longer-term reversals) in individual security returns, which was documented by Jegadeesh and Titman (1993). Sometimes these anomalies may be explicable within a model that posits certain “nonrational” behavior on the part of investors. 1
Synthesis, Structure, and Fluorescence of Isomeric Indolizinediones. Carbonyl-Bridged Isodipyrrinones

In “one-pot” reactions, pyrrole-α- and β-aldehydes condense readily with 4-ethyl-3-methyl-3-pyrrolin-2-one to give isodipyrrinone analogs, which undergo intramolecular cyclization when the pyrrolealdehyde possesses an α or β-CO2R group. The resulting regioisomeric pyrroloindolizinediones, with structures confirmed by NMR analysis, exhibit strong fluorescence, with quantum yields (φF) as high as 0.91 at λem∼450–550 nm.
Inhibitors of DNA polymerase β from Schoepfia californica

Fractionation of a hexane extract prepared from the plant Schoepfiacalifornica was carried out by bioassay guided fractionation, affording five inhibitors of DNA polymerase β; four of these were shown to be anacardic acid and structurally related derivatives, while the fifth was oleic acid.
Asymmetric transfer hydrogenation over Ru–TsDPEN catalysts supported on siliceous mesocellular foam

A siliceous mesocellular foam-immobilized Ru–TsDPEN complex exhibited excellent catalytic reactivity, enantioselectivity and reusability in the asymmetric transfer hydrogenation of an imine and ketones.
Large deviation asymptotics and control variates for simulating large functions

Consider the normalized partial sums of a real-valued function F of a Markov chain, $$\phi_{n}:=n^{-1}\sum_{k=0}^{n-1}F(\Phi(k)),\qquad n\ge1.$$ The chain {Φ(k):k≥0} takes values in a general state space $\mathsf {X}$, with transition kernel P, and it is assumed that the Lyapunov drift condition holds: $PV\le V-W+b\mathbb{I}_{C}$ where $V: \mathsf {X}\to(0,\infty)$, $W: \mathsf {X}\to[1,\infty)$, the set C is small and W dominates F. Under these assumptions, the following conclusions are obtained: 1. It is known that this drift condition is equivalent to the existence of a unique invariant distribution π satisfying π(W)<∞, and the law of large numbers holds for any function F dominated by W: $$ϕ_n→ϕ:=π(F),\qquad\mathrm{a.s.}, n→∞.$$ 2. The lower error probability defined by $\mathsf {P}\{\phi_{n}\le c\}$, for c<ϕ, n≥1, satisfies a large deviation limit theorem when the function F satisfies a monotonicity condition. Under additional minor conditions an exact large deviations expansion is obtained. 3. If W is near-monotone, then control-variates are constructed based on the Lyapunov function V, providing a pair of estimators that together satisfy nontrivial large asymptotics for the lower and upper error probabilities. In an application to simulation of queues it is shown that exact large deviation asymptotics are possible even when the estimator does not satisfy a central limit theorem.
Manufacturing Immunity to Disease in a Test Tube: The Magic Bullet Realized

Although it took over one hundred years, Ehrlich's concept of the magic bullet is now a reality. Today, therapeutic antibodies are, arguably, the most important class of new drugs for the treatment of illnesses ranging from Alzheimer's disease to cancer. The emergence of therapeutic antibodies had to wait for advances in immunochemistry that allowed construction of antibodies in vitro. The centerpiece of the new technology is the combinatorial antibody library, which essentially allows one to synthesize an artificial immune system with a diversity that exceeds that of the natural repertoire. The construction of such libraries was perceived to be difficult because, if the natural immune system was to be used as the starting material, construction of the libraries would entail protocols that are the opposite of usual cloning. In gene cloning one starts with complexity and reduces it to a singularity. In the generation of diversity by construction of combinatorial antibody libraries, one starts with a collection of clones, randomly expands their complexity, and then returns them to recoverable singularities. The methods developed to accomplish this seemingly formidable task now allow construction of antibodies in a test tube to any antigen. These synthetic antibodies may be qualitatively and quantitatively superior to those of nature.
A short, stereospecific synthesis of dihydrooxazoles from serine and threonine derivatives

Abstract Cyclization of serine and threonine derivatives with Burgess reagent provides a one-step, streospecific access to 4,5-dihydrooxazoles. Noteworthy features of this new methodology include mild experimental conditions, and the absence of β-lactam, aziridine, or dehydroamino acid side products.
Diagrammatic analysis of correlations in polymer fluids: Cluster diagrams via Edwards’ field theory

Abstract Edwards’ functional integral approach to the statistical mechanics of polymer liquids is amenable to a diagrammatic analysis in which free energies and correlation functions are expanded as infinite sums of Feynman diagrams. This analysis is shown to lead naturally to a perturbative cluster expansion that is closely related to the Mayer cluster expansion developed for molecular liquids by Chandler and co-workers. Expansion of the functional integral representation of the grand-canonical partition function yields a perturbation theory in which all quantities of interest are expressed as functionals of a monomer–monomer pair potential, as functionals of intramolecular correlation functions of non-interacting molecules, and as functions of molecular activities. In different variants of the theory, the pair potential may be either a bare or a screened potential. A series of topological reductions yields a renormalized diagrammatic expansion in which collective correlation functions are instead expressed diagrammatically as functionals of the true single-molecule correlation functions in the interacting fluid, and as functions of molecular number density. Similar renormalized expansions are also obtained for a collective Ornstein–Zernicke direct correlation function, and for intramolecular correlation functions. A concise discussion is given of the corresponding Mayer cluster expansion, and of the relationship between the Mayer and perturbative cluster expansions for liquids of flexible molecules. The application of the perturbative cluster expansion to coarse-grained models of dense multi-component polymer liquids is discussed, and a justification is given for the use of a loop expansion. As an example, the formalism is used to derive a new expression for the wave-number dependent direct correlation function and recover known expressions for the intramolecular two-point correlation function to first-order in a renormalized loop expansion for coarse-grained models of binary homopolymer blends and diblock copolymer melts.
THE USE OF DYNAMIC FINANCIAL ANALYSIS TO DETERMINE WHETHER AN OPTIMAL GROWTH RATE EXISTS FOR A PROPERTY-LIABILITY INSURER

Prior research on the aging phenomenon has demonstrated that new business for property-liability (P-L) insurers generates high loss ratios that gradually decline as a book of business goes through successive renewal cycles. Although the experience on new business is initially unprofitable, the renewal book of business eventually becomes profitable over time. Within this context, insurers need to manage their exposure growth in order to maximize long run profitability. Dynamic financial analysis (DFA), a relatively new tool for P-L insurers, utilizes Monte Carlo simulation to generate the overall financial results for an insurer under a large number of scenarios. This article uses a publicly available DFA model—along with the estimated market value of an insurer, based on 1990‐2001 data for stock P-L insurers and underlying financial variables—to determine optimal growth rates of a P-L insurer based on mean‐variance analysis, stochastic dominance, and constraints on leverage.
Virus-Based Chemical and Biological Sensing

Viruses have recently proven useful for the detection of target analytes such as explosives, proteins, bacteria, viruses, spores, and toxins with high selectivity and sensitivity. Bacteriophages (often shortened to phages), viruses that specifically infect bacteria, are currently the most studied viruses, mainly because target-specific nonlytic phages (and the peptides and proteins carried by them) can be identified by using the well-established phage display technique, and lytic phages can specifically break bacteria to release cell-specific marker molecules such as enzymes that can be assayed. In addition, phages have good chemical and thermal stability, and can be conjugated with nanomaterials and immobilized on a transducer surface in an analytical device. This Review focuses on progress made in the use of phages in chemical and biological sensors in combination with traditional analytical techniques. Recent progress in the use of virus-nanomaterial composites and other viruses in sensing applications is also highlighted.
BLACK HOLE SPINS OF RADIO SOURCES

A new approach to constraining or determining the spin of a massive black hole is proposed. A key parameter in the analysis is the dimensionless ratio, r, of the energy released to the mass of the hole. It is shown that the black hole spin j may be written as a function of the dimensionless ratio of the black hole spin energy to the black hole mass. When extraction of the black hole spin energy powers an outflow from the hole, the ratio r provides an indication of the black hole spin. The method is applied to a sample of 19 very powerful classical double radio galaxies with a range of size and redshift. The sources are found to have remarkably similar values of r and j, implying that the sources have very similar physical conditions at the time the outflow is generated. The weighted mean value of the spins is 0.12 ± 0.01. A sample of 29 central dominant galaxies is also studied; most of these sources have amorphous or FRI radio structure. The sources have a broad range of ratios r, and correspondingly broad range of black hole spins j with values from about 0.001 to 0.4, and a median value of about 0.03. The broad range probably results from the fact that each source is observed at a different stage in its lifetime. The intrinsic range of parameters could be as tight as it is for the powerful classical double radio galaxies.
A high-performance lateral geometry transistor for complementary integrated circuits

The lateral geometry transistor has shown itself to be highly useful in the realization of low-frequency integrated circuits. This simple structure has been limited essentially to dc applications, however, by bandwidth and switching time performance. The p-n-p device to be described in this paper substantially overcomes these deficiencies by the addition of an n+ diffusion directly beneath the emitter region. As a result of the steeper gradient at the bulk, or planar, portion of the emitter-base junction, injection occurs primarily near the surface. It is possible to control the dimensions of the buried layer such that injection of carriers greater than a few micrometers from the collector will be minimized. A further consequence of the n+ region is the introduction of a graded base such that minority carrier transport is enhanced. The improved transistor structure has demonstrated the feasibility of obtaining an f_{T} of 10 MHz to 20 MHz at collector currents of 100 µA and rise, fall, and storage times in the tens of nanoseconds.
Closed Loop System Identification with Genetic Algorithms

High-performance control design for a flexible space structure is challenging as highfidelity plant models are difficult to obtain a priori. Uncertainty in the control design models typically require a very robust, low-performance control design, which must be tuned onorbittoachievetherequiredperformance.Closed-loopsystemidentificationisoftenrequired to obtain a multivariable open-loop plant model based on closed-loop response data. To provide an accurate initial plant model to guarantee convergence for standard local optimization methods, this paper presents a global parameter optimization method using genetic algorithms. A minimal representation of the state space dynamics is used to mitigate the nonuniqueness and overparameterization of general state space realizations. This controlrelevant system identification procedure stresses the joint nature of the system identification and control design problem by seeking to obtain a model that minimizes the difference between the predicted and actual closed-loop performance.
On the Use of a Scale-Dependent Filter in Channel Model Integrations

Abstract A channel model using a finite-difference gridpoint method is described. Integrations with this model produce large amplitude, high wavenumber “noise” near the lateral walls, which corrupts the interior solution. A technique is presented that employs scale-dependent filters to eliminate the generation of the boundary noise, while leaving the interior flow relatively unchanged. The effectiveness of the technique is demonstrated.
Predicting Preschooler Obesity at Birth: The Role of Maternal Obesity in Early Pregnancy

Objective. Knowing risk factors at birth for the development of childhood obesity could help to identify children who are in need of early obesity prevention efforts. The objective of this study was to determine whether children whose mothers were obese in early pregnancy were more likely to be obese at 2 to 4 years of age. Methods. A retrospective cohort study was conducted of 8494 low-income children who were enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Ohio and were followed from the first trimester of gestation until 24 to 59 months of age. Measured height and weight data from WIC were linked to birth certificate records for children who were born in the years 1992–1996. Obesity among 2- to 4-year-olds was defined as a body mass index (BMI) ≥95th percentile for age and gender. Mothers were classified as obese (BMI ≥30 kg/m 2 ) or nonobese (BMI 2 ) on the basis of BMI measured in the first trimester of the child’s gestation. Results. The prevalence of childhood obesity was 9.5%, 12.5%, and 14.8% at 2, 3, and 4 years of age, respectively, and 30.3% of the children had obese mothers. By 4 years of age, 24.1% of children were obese if their mothers had been obese in the first trimester of pregnancy compared with 9.0% of children whose mothers had been of normal weight (BMI ≥18.5 and 2 ). After controlling for the birth weight, birth year, and gender of the children plus the mothers’ age, race/ethnicity, education level, marital status, parity, weight gain, and smoking during pregnancy, the relative risk of childhood obesity associated with maternal obesity in the first trimester of pregnancy was 2.0 (95% confidence interval [CI]: 1.7–2.3) at 2 years of age, 2.3 (95% CI: 2.0–2.6) at 3 years of age, and 2.3 (95% CI: 2.0–2.6) at 4 years of age. Conclusion. Among low-income children, maternal obesity in early pregnancy more than doubles the risk of obesity at 2 to 4 years of age. In developing strategies to prevent obesity in preschoolers, special attention should be given to newborns with obese mothers.
On the functional CLT for stationary Markov Chains started at a point

We present a general functional central limit theorem started at a point also known under the name of quenched. As a consequence, we point out several new classes of stationary processes, defined via projection conditions, which satisfy this type of asymptotic result. One of the theorems shows that if a Markov chain is stationary ergodic and reversible, this result holds for bounded additive functionals of the chain which have a martingale coboundary in L1 representation. Our results are also well adapted for strongly mixing sequences providing for this case an alternative, shorter approach to some recent results in the literature.
Learning Program Embeddings to Propagate Feedback on Student Code

Providing feedback, both assessing final work and giving hints to stuck students, is difficult for open-ended assignments in massive online classes which can range from thousands to millions of students. We introduce a neural network method to encode programs as a linear mapping from an embedded precondition space to an embedded postcondition space and propose an algorithm for feedback at scale using these linear maps as features. We apply our algorithm to assessments from the Code.org Hour of Code and Stanford University's CS1 course, where we propagate human comments on student assignments to orders of magnitude more submissions.
Transverse impedance bench measurements in NLC/JLC accelerating structures

The wire method is a more rapid and less costly method to measure impedances of RF components compared to methods using a beam. A setup using a single displaced wire to excite and measure transverse resonant modes in accelerating structures for the Next Linear Collider/ Japanese Linear Collider (NLC/JLC) has been built. The RF signal is coupled into and out of the structure using two matching sections with a broadband frequency from 11 to 18 GHz. Their contribution to the scattering parameter is minimized by a calibration technique. A standing wave structure has been measured. Difficulties in accurately predicting the modal loss factors were encountered related to the approximations made and to experimental issues. The measurements are presented and comparisons with simulations are made.
Self-interaction correction to black hole radiance

We consider the modification of the formulas for black hole radiation, due to the self-gravitation of the radiation. This is done by truncating the coupled particle-hole system to a small set of modes, that are plausibly the most significant ones, and quantizing the reduced system. In this way we find that the particles no longer move along geodesics, nor is the action along the rays zero for a massless particle. The radiation is no longer thermal, but is corrected in a definite way that we calculate. Our methods can be extended in a straightforward manner to discuss correlations in the radiation, or between incoming particles and the radiation.
IQF Catfish Retail Pack: A Study of Consumers' Willingness to Pay

The grocery retail channel represents a potential for increased sales for catfish products because of the competitive nature that imported catfish fillets pose at foodservice market channels. The study examined the potential for selling a household-size pack of IQF 6-fillets of catfish through the grocery market channels, and consumers' willingness to pay for the product. Data used were obtained from a survey conducted in selected southern U.S. cities. Results suggest that households will purchase such grocery retail packages and will be willing to pay an average price of $4.37/lb. Important factors found to affect willingness to pay include; fish buying patterns, household size, race, age and gender.
Provably Near-Optimal LP-Based Policies for Revenue Management in Systems with Reusable Resources

Motivated by emerging applications in workforce management, we consider a class of revenue management problems in systems with reusable resources. The corresponding applications are modeled using the well-studied loss network systems. We use an extremely simple linear program (LP) that provides an upper bound on the best achievable expected long-run revenue rate. The optimal solution of the LP is used to devise a conceptually simple control policy that we call the class selection policy (CSP). Moreover, the LP is used to analyze the performance of the CSP and show that it admits uniform performance guarantees. In particular, for the model with a single resource and uniform resource requirements, we prove that the CSP is guaranteed to have an expected long-run revenue rate that is at least half of the best achievable. Furthermore, as the capacity of the system grows to infinity, the CSP is asymptotically optimal, regardless of any other parameter of the problem. Finally, our techniques can be used to analyze the performance of the well-known class of trunk-reservation policies.
Reinforcement learning for adaptive routing

Reinforcement learning means learning a policy-a mapping of observations into actions-based on feedback from the environment. The learning can be viewed as browsing a set of policies while evaluating them by trial through interaction with the environment. We present an application of a gradient ascent algorithm for reinforcement learning to a complex domain of packet routing in network communication and compare the performance of this algorithm to other routing methods on a benchmark problem.
Force tracking in impedance control

This article presents two simple on-line schemes for force tracking within the impedance-control framework. The force- tracking capability of impedance control is particularly important for providing robustness in the presence of large uncertainties or variations in environmental parameters. The two proposed schemes generate the reference position trajec tory required to produce a desired contact force despite lack of knowledge of the environmental stiffness and location. The first scheme uses direct adaptive control to generate the refer ence position on-line as a function of the force-tracking error. Alternatively, the second scheme utilizes an indirect adaptive strategy in which the environmental parameters are estimated on-line, and the required reference position is computed based on these estimates. In both schemes, adaptation allows au tomatic gain adjustment to provide a uniform performance despite variations in the environmental parameters. Simula tion studies are presented for a 7-DOF Robotics R...
Solution methods for one-dimensional viscoelastic problems

A recently developed differential methodology for solution of one-dimensional nonlinear viscoelastic problems is presented. Using the example of an eccentrically loaded cantilever beam-column, the results from the differential formulation are compared to results generated using a previously published integral solution technique. It is shown that the results obtained from these distinct methodologies exhibit a surprisingly high degree of correlation with one another. A discussion of the various factors affecting the numerical accuracy and rate of convergence of these two procedures is also included. Finally, the influences of some 'higher order' effects, such as straining along the centroidal axis are discussed.
Cyclotomic and simplicial matroids

We show that two naturally occurring matroids representable over ℚ are equal: thecyclotomic matroid µn represented by then th roots of unity 1, ζ, ζ2, …, ζn-1 inside the cyclotomic extension ℚ(ζ), and a direct sum of copies of a certain simplicial matroid, considered originally by Bolker in the context of transportation polytopes. A result of Adin leads to an upper bound for the number of ℚ-bases for ℚ(ζ) among then th roots of unity, which is tight if and only ifn has at most two odd prime factors. In addition, we study the Tutte polynomial of µn in the case thatn has two prime factors.
Competition and Bias

We attempt to measure the effect of competition on bias in the context of analyst earnings forecasts, which are known to be excessively optimistic because of conflicts of interest. Our natural experiment for competition is mergers of brokerage houses, which result in the firing of analysts because of redundancy (e.g., one of the two oil stock analysts is let go) and other reasons such as culture clash. We use this decrease in analyst coverage for stocks covered by both merging houses before the merger (the treatment sample) to measure the causal effect of competition on bias. We find that the treatment sample simultaneously experiences a decrease in analyst coverage and an increase in optimism bias the year after the merger relative to a control group of stocks, consistent with competition reducing bias. The implied economic effect from our natural experiment is significantly larger than estimates from OLS regressions that do not correct for the endogeneity of coverage. This effect is much more significant for stocks with little initial analyst coverage or competition.
On directed information and gambling

We study the problem of gambling in horse races with causal side information and show that Masseypsilas directed information characterizes the increment in the maximum achievable capital growth rate due to the availability of side information. This result gives a natural interpretation of directed information I(Yn rarr Xn) as the amount of information that Yn causally provides about Xn. Extensions to stock market portfolio strategies and data compression with causal side information are also discussed.
The Consequences of the “Missing Girls” of China

In the wake of the one-child policy of 1979, China experienced an unprecedented rise in the sex ratio at birth (ratio of male to female births). In cohorts born between 1980 and 2000, there were 22 million more men than women. Some 10.4 percent of these additional men will fail to marry, based on simulations presented here that assess how different scenarios for the sex ratio at birth affect the probability of failure to marry in 21st century China. Three consequences of the high sex ratio and large numbers of unmarried men are discussed: the prevalence of prostitution and sexually transmitted infections, the economic and physical well-being of men who fail to marry, and China's ability to care for its elderly, with a particular focus on elderly males who fail to marry. Several policy options are suggested that could mitigate the negative consequences of the demographic squeeze.
Investors' Recovery Friction and Auditor Liability Rules

This paper examines investor welfare under two different liability regimes for holding auditors liable for investor losses, the due care and the strict liability regimes. In both regimes, the inves...
Transitive permutation groups and equipotent voting rules

Let F a two-alternative voting rule and GF the subgroup of permutations of the voters under which F is invariant. Group theoretic properties of GF provide information about the voting rule F. In particular, sets of imprimitivity of GF describe the ‘committee decomposition’ structure of F and permutation group transitivity of GF (equipotency) is shown to be closely connected with equal distribution of power among the voters. If equipotency replaces anonymity in the hypotheses of May's theorem, voting rules other than simple majority are possible. By combining equipotency with two additional social choice conditions a new characterization of simple majority rule is obtained. Equipotency is proposed as an important alternative to the more restrictive anonymity as a fairness criterion in social choice.
Infiniteness of double coset collections in algebraic groups

Abstract Let G be a linear algebraic group defined over an algebraically closed field. The double coset question addressed in this paper is the following: Given closed subgroups X and P , is the double coset collection X ⧹ G / P finite or infinite? We limit ourselves to the case where X is maximal rank and reductive and P parabolic. This paper presents a criterion for infiniteness which involves only dimensions of centralizers of semisimple elements. This result is then applied to finish the classification of those X which are spherical subgroups. Finally, excluding a case in F 4 , we show that if X ⧹ G / P is finite then X is spherical or the Levi factor of P is spherical. This places great restrictions on X and P for X ⧹ G / P to be finite. The primary method is to descend to calculations at the finite group level and then to use elementary character theory.
Crystal growth and structures of three new platinates: Ln3NaPtO7 (Ln = La, Nd) and La4PtO7

Abstract Single crystals of three lanthanide containing platinates, La3NaPtO7, Nd3NaPtO7 and La4PtO7, were grown from carbonate fluxes. La3NaPtO7 and Nd3NaPtO7 crystallize in the trigonal space group R 3 ¯ c with lattice parameters of a = 5.7458(2) A and c = 35.650(1) A, and a = 5.6862(5) A and c = 34.896(3) A, respectively. La4PtO7 crystallizes in the monoclinic space group I2/m with lattice parameters of a = 9.799(1) A, b = 4.0014(5) A, c = 9.491(1) A and β = 91.759(5)°. La3NaPtO7 and Nd3NaPtO7 are the first all-platinum members of the [AnBn−1O3n][A2O] family of oxides. The difference in structure types of the three compounds arises from the size of the alkali metal cations present in the fluxes. Synthetic conditions as well as the structure differences between these platinates are discussed.
Adolescent Learning and the Internet: Implications for School Leadership and Student Engagement in Learning.

Students were electronically polled about the influence of the Internet in their education and ways teachers could use this resource to motivate them and increase their learning. Responses from the 956 adolescents showed that the school quest to increase student engagement could more often be met through online assignments that facilitate self-directed learning. The practice of teachers spending much of their time preparing and presenting lessons should become more balanced to reflect the powerful presence of the Internet as the main source of student information. This shift requires a new focus in teacher preparation and in-service development for local schools. Specific changes in the roles of principals and teachers to offer greater school support for Internet learning are identified.
Incremental Learning of Difficult Words in Story Contexts: The Role of Spelling and Pronouncing New Vocabulary.

In this exploratory study we examine the value of exposure to the spelling and pronunciation of word forms when introducing the meanings of new and difficult vocabulary words. Kindergarten English learners were randomly assigned to one of two types of storybook reading delivered by tutors. Students in both treatments listened to short stories containing novel target words. In both groups, students were told the meanings of the difficult words when they first appeared in the stories. However, in one of the groups (Definitions-Plus), students were also shown the printed words when they first appeared in the stories, and were asked to pronounce and spell the words aloud. Vocabulary learning was assessed with three researcher-designed measures including receptive vocabulary, vocabulary definitions, and spelling. Results showed that both groups made significant gains on all three measures, with average gains of 8, 4, and 3 %, respectively. Moreover, the Definitions-Plus group had significantly greater spelling gains (d = .57), and exhibited similar, albeit nonsignificant, trends on vocabulary gains (ds = .30 and .41 for receptive and definitional vocabulary, respectively). Results extend previous studies’ results to younger English learner students on general benefits of novel word exposure in story contexts, and specific benefits for spelling and pronunciation practice in learning new words.
Default Estimation for Low-Default Portfolios

Abstract Risk managers at financial institutions are concerned with estimating default probabilities for asset groups both for internal risk control procedures and for regulatory compliance. Low-default assets pose an estimation problem that has attracted recent concern. The problem in default probability estimation for low-default portfolios is that there is little relevant historical data information. No amount of data data-processing can fix this problem. More information is required. Incorporating expert opinion formally is an attractive option. The probability (Bayesian) approach is proposed, its feasibility demonstrated, and its relation to supervisory requirements discussed.