cssi/SciSciGPT-SciSciNet huggingface dataset:
Conformal Techniques in String Theory and String Field Theory

Abstract The application of some conformal and Riemann surface techniques to string theory and string field theory is described. First a brief review of Riemann surface techniques and of the Polyakov approach to string theory is presented. This is followed by a discussion of some features of string field theory and of its Feynman rules. Specifically, it is shown that the Feynman diagrams for Witten's string field theory respect modular invariance, and in particular give a triangulation of moduli space. The Polyakov formalism is then used to derive the Feynman rules that should follow from this theory upon gauge fixing. It should also be possible to apply this derivation to deduce the Feynman rules for other gauge-fixed string field theories. Following this, Riemann surface techniques are turned to the problem of proving the equivalence of the Polyakov and light-cone formalisms. It is first shown that the light-cone diagrams triangulate moduli space. Then the Polyakov measure is worked out for these diagrams, and shown to equal that deduced from the light-cone gauge-fixed formalism. Also presented is a short description of the comparison of physical states in the two formalisms. The equivalence of the two formalisms in particular constitutes a proof of the unitarity of the Polyakov framework for the closed bosonic string.
Chemiluminescent chemical sensors for inorganic and organic vapors

Abstract A novel class of chemiluminescent, chemical sensors are described which are based upon the immobilization of a chemiluminescent reagent, luminol or tris(2,2′-bipyridyl)ruthenium(III) (Ru(bpy) 3 3+ ), between a miniature photomultiplier tube and a teflon diffusion membrane. The membrane serves to separate the chemiluminescent matrix from a sampled stream of air. Luminol was immobilized within a hydrogel support matrix and utilized for the detection of ppm levels of chlorinated hydrocarbons, including CCl 4 (g), CHCl 3 (g) and CH 2 Cl 2 (g). This was achieved via the incorporation of a heated Pt filament into the inlet as a pre-oxidative step prior to passage of the gas stream across the teflon membrane. In an alternate approach, the organometallic complex, Ru(bpy) 3 3+ ), an electrochemically regenerable chemiluminescent reagent, was investigated as a reagent for monitoring trace levels of strongly reducing vapors such as hydrazine or ammonia vapor. This approach has been developed into a prototype, real-time instrument. We report the initial testing of a hand-held instrument which is similar to the cell utilized for the luminol chemiluminescence, with the exception that a three electrode electrochemical cell has been incorporated into the system for continuously regenerating the chemiluminescent reagent, Ru(bpy) 3 3+ .
Spectra of circularly polarized radiation from astrophysical OH masers

A striking feature of astrophysical masers is the tendency for either one or the other of the circular polarizations to dominate in the radiation from the strong, widely observed masing transitions of OH at 18 cm. Spectral line profiles are calculated for polarized maser radiation due to the combined effects of a velocity gradient and, as is indicated for these transitions, a Zeeman splitting that is at least comparable with the thermal contributions to the breadths of the spectral lines. The resulting spectral features are similar in appearance, including the presence of large net circular polarization and narrow line breadths, to the commonly observed spectra of OH masers in molecular clouds. The calculations presented here are performed as a function of frequency without making the approximations of a large velocity gradient. Rapid cross relaxation, which has been advocated by others for the OH masers, is assumed.
Three-dimensional course of the vestibular aqueduct

Three-dimensional (3-D) reconstruction methods were employed to study the anatomy of the vestibular aqueducts (VAs) in ten postmortem temporal bone specimens obtained from ten individuals aged 4 months to 70 years at death. After reconstruction, the ten 3-D images of VAs were superimposed on one another and differences evaluated. The VA showed postnatal growth and variations in size and shape. However, the variations in angle at which the VA bends near the isthmus were not correlated with age. Furthermore, study of the superimposed images revealed that the 3-D course of the VA was essentially the same in individuals of all ages, despite its wide variability in size and shape. These results indicate that the basic course of the VA is determined before early infancy although the VA grows thereafter, suggesting that VA anomalies such as “large vestibular aqueduct syndrome” (in which the VA takes an abnormally straight and wide course) may be established prenatally.
Wage-Poor Mothers and Moral Economy

This article explores the subaltern work and family care practices of 300 low-wage women. Although US welfare reform enforced the labor market as the sole route for family support, many, often single–mother, families remain wage impoverished. Their work habits orbit around keeping children safe and defy market norms. Furthermore, in wage-poor America and beyond, this defiance is understood as morally legitimate, representing a hidden challenge to an economic ideology that subordinates humanity to the market.
The Digit Principle

Abstract A number of constructions in function field arithmetic involve extensions from linear objects using digit expansions. This technique is described here as a method of constructing orthonormal bases in spaces of continuous functions. We illustrate several examples of orthonormal bases from this viewpoint, and we also obtain a concrete model for the continuous functions on the integers of a local field as a quotient of a Tate algebra in countably many variables.
Impulse generated during unsteady maneuvering of swimming fish

The relationship between the maneuvering kinematics of a Giant Danio (Danio aequipinnatus) and the resulting vortical wake is investigated for a rapid, ‘C’-start maneuver using fully time-resolved (500 Hz) particle image velocimetry (PIV). PIV illuminates the two distinct vortices formed during the turn. The fish body rotation is facilitated by the initial, or “maneuvering” vortex formation, and the final fish velocity is augmented by the strength of the second, “propulsive” vortex. Results confirm that the axisymmetric vortex ring model is reasonable to use in calculating the hydrodynamic impulse acting on the fish. The total linear momentum change of the fish from its initial swimming trajectory to its final swimming trajectory is balanced by the vector sum of the impulses of both vortex rings. The timing of vortex formation is uniquely synchronized with the fish motion, and the choreography of the maneuver is addressed in the context of the resulting hydrodynamic forces.
Gromov–Witten invariants of blow-ups along submanifolds with convex normal bundles

When the normal bundle NZ=X is convex with a minor assumption, we prove that genus 0 GW–invariants of the blow-up BlZ X of X along a submanifold Z , with cohomology insertions from X , are identical to GW–invariants of X . Under the same hypothesis, a vanishing theorem is also proved. An example to which these two theorems apply is when NZ=X is generated by its global sections. These two main theorems do not hold for arbitrary blow-ups, and counterexamples are included.
Causal Factors and Costs of Home Plumbing Corrosion: An Investigation of Sample Selection Bias

Abstract High incidences of pinhole leaks, which occur in home plumbing due to pitting corrosion of water pipes, have been observed in parts of the U.S. such as the Maryland suburbs of Washington D.C. This research evaluates factors associated with pinhole leak occurrences and assesses the costs incurred by consumers from corrosion. Statistical analysis of Maryland survey responses suggests that the probability of pinhole leak occurrences is associated with the type of pipes installed and the distance of the dwelling from a water treatment plant. The number of leaks and location of pinhole leaks in the dwelling drive the financial costs of pinhole leak damage. Correcting for sample selection bias influences the estimated coefficients and statistical significance of the model. Research findings will inform policymakers, program managers, and water utilities on the importance of reducing corrosion in home drinking water infrastructure. Introduction Pinhole leaks are small holes in drinking water plumbing caused by pitting corrosion, a type of corrosion concentrated on a very small area of the pipe. Theories as to the origins of pinhole leaks vary and there are a few proven causes (Edwards et. al, 2004). Edwards suggests that removal of natural organic matter mandated by tighter Environmental Protection Agency (EPA) drinking water standards can contribute to the problem in combination with other factors, since natural organic matter can be an inhibitor to the corrosion-inducing chemical reactions. Pipe failures can also result from other factors including faulty installation or wearing of copper due to friction by rubbing against a surface (Fleishman, 2001).
Whole-body Vibratory Response Study Using a Nonlinear Multi-body Model of Seat-occupant System with Viscoelastic Flexible Polyurethane Foam

Vehicle occupants are exposed to low frequency vibrations with possible harmful effects such as mild discomfort, lower back pain, and even injury to the spine. Occupational drivers and operators of heavy machinery are exposed to significantly longer duration and higher levels of vibration. Thus, the modeling and prediction of biodynamic response of seated occupants to such vibrations is very important. Since the properties of seating foam affect the response of the occupant, there is need for good models of seat-occupant systems through which the effects of foam properties on the dynamic response can be directly evaluated. A nonlinear planar seat-occupant model which incorporates the nonlinear viscoelastic behavior of seating foam has been developed. This model is used to study response of the occupant to harmonic excitation applied at the seat base, in terms of the frequency response in vertical and fore-and-aft directions, the deflection shapes at resonance, as well as the seat-to-head-transmissibility. In addition, to better understand the role of flexible polyurethane foam in characterizing the system behavior, the response of a single-degree-of-freedom foam-block system is also studied. The effects of different masses riding on the foam block and undergoing vertical vibrations at different acceleration levels are also investigated.
The Effect of Electoral Institutions on Tort Awards

Politicians are not neutral maximizers of the public good, they respond to incentives just like other individuals. We apply the same reasoning to those politicians in robes called judges. We argue that elected judges, particularly partisan elected judges, have an incentive to redistribute wealth from out of state defendants (non voters) to instate plaintiffs (voters). The partisan electoral hypothesis is tested first using data on 75,000 tort awards from across the states. We control for differences in injuries, state incomes, poverty levels, selection effects and other factors that may cause awards to differ across the states. One difference which appears difficult to control for is that each state has its own body of tort law. We take advantage of a peculiar aspect of American Federalism to make this distinction. In cases involving citizens of different states, aptly called diversity of citizenship cases, Federal judges apply state law to decide disputes. Diversity of citizenship cases allow us to test whether differences in awards are caused by differences in electoral systems or differences In state law. The evidence from the cross state regressions and from the diversity of citizenship cases, strongly supports the partisan election hypothesis. In cases involving out of state defendants and in state plaintiffs the average award (conditional on winning) is 42% higher in partisan than in non partisan states; approximately 2/3 rds of the larger award is due to a bias against out of state defendants and the remainder due to generally higher awards against businesses in partisan states.
The Rescorla-Wagner Algorithm and Maximum Likelihood Estimation of Causal Parameters

This paper analyzes generalization of the classic Rescorla-Wagner (R-W) learning algorithm and studies their relationship to Maximum Likelihood estimation of causal parameters. We prove that the parameters of two popular causal models, ΔP and PC, can be learnt by the same generalized linear Rescorla-Wagner (GLRW) algorithm provided genericity conditions apply. We characterize the fixed points of these GLRW algorithms and calculate the fluctuations about them, assuming that the input is a set of i.i.d. samples from a fixed (unknown) distribution. We describe how to determine convergence conditions and calculate convergence rates for the GLRW algorithms under these conditions.
The Effect of Credit on the Export Performance of Colombian Exporters

In this paper we use Colombian manufacturing data on exports and external financing for the period 1998 2006 to estimate the credit elasticity of exports. We use bank-firm linked data to construct a supply side instrument for a manufacturer’s demand of credit, which we use to address the reverse causality between a manufacturer’s export revenue and its demand for credit. We find that access to credit produces a significant increase on a manufacturer’s export revenue explained by the positive effect of credit on an exporter’s market reach - number of destinations -. Across manufacturers the effect of credit on a manufacturer’s export revenue varies by size. While medium sized manufacturers use credit to increase their market reach, market penetration and product mix, large manufacturers only use credit to increase their market reach. Small manufacturers do not seem to benefit from bank credit.
Boondoogles and expropriation : rent-sseking and policy distortion when property rights are insecure

Most analyses of property rights and economic development point to the negative influence of insecure property rights on private investment. The authors focus instead on the largely unexamined effects of insecure property rights on government policy choices. They identify one significant anomaly-dramatically higher public investment in countries with insecure property rights-and use it to make the following broad claims about insecure property rights; 1) They increase rent-seeking. 2) They may reduce the incentives of governments to use tax revenues for productive purposes, such as public investment. 3) They do so whether one regards the principal problem of insecure property rights as the maintenance of law and order, which government spending can potentially remedy, or as the threat of expropriation by government itself, and therefore not remediable by government spending. The authors present substantial empirical evidence to support these claims.
Dissipative Preparation of Spin Squeezed Atomic Ensembles in a Steady State

We present and analyze a new approach for the generation of atomic spin-squeezed states. Our method involves the collective coupling of an atomic ensemble to a decaying mode of an open optical cavity. We demonstrate the existence of a collective atomic dark state, decoupled from the radiation field. By explicitly constructing this state we find that it can feature spin squeezing bounded only by the Heisenberg limit. We show that such dark states can be deterministically prepared via dissipative means, thus turning dissipation into a resource for entanglement. The scaling of the phase sensitivity taking realistic imperfections into account is discussed.
Local Control Design Methodologies for a Hierarchic Control Architecture

Many active structures, such as smart skins or optical mirrors, require a high density of sensors and actuators to achieve the desired levels of performance. The problems associated with the design and implementation of controllers for this group of active structures have previously led to the development of a hierarchic control architecture. By combining a centralized global controller and a set of residual controllers in a two level arrangement, the architecture removes many of these design and implementation difficulties. The central controller is based on aggregate structural information, and the residual, or local, controllers are distributed to complement the dynamic behavior of the structure. Three decentralized methodologies that are suitable for implementation as local controllers in the hierarchic architecture are developed and analyzed in this paper. Consistent with many applications for smart skins and typical mirror designs, these controllers are developed for structures that exhibit a high degree of spatial symmetry. The three approaches are distinguished by the communication constraints imposed during the control design process. The first design only allows collocated feedback. The second technique constrains the exchange of information to be within an isolated region of the structure. The third approach permits communication between adjacent local controllers, so that measurements from neighboring regions of the structure are available. Simulation results from the control of a long beam in bending are used to compare these local control design methodologies in terms of both the overall performance and implementation requirements.
Concept for a low cost, high efficiency precipitation radar system based on ferroelectric reflectarray antenna

This work proposes a concept on a novel scanning phased array, based on thin film ferroelectric phase shifters, for an X-band precipitation monostatic radar.
Improved self-absorption correction for extended x-ray absorption fine-structure measurements

Extended x-ray absorption fine-structure (EXAFS) data collected in the fluorescence mode are susceptible to an apparent amplitude reduction due to the self-absorption of the fluorescing photon by the sample before it reaches a detector. Previous treatments have made the simplifying assumption that the effect of the EXAFS on the correction term is negligible, and that the samples are in the thick limit. We present a nearly exact treatment that can be applied for any sample thickness or concentration, and retains the EXAFS oscillations in the correction term.
Pulmonary thromboembolism during adult liver transplantation: incidence, clinical presentation, outcome, risk factors, and diagnostic predictors

Background Intraoperative pulmonary thromboembolism (PTE) is an often overlooked cause of mortality during adult liver transplantation (LT) with diagnostic challenge. The goals of this study were to investigate the incidence, clinical presentation, and outcome of PTE and to identify risk factors or diagnostic predictors for PTE. Methods Four hundred and ninety-five consecutive, isolated, deceased donor LTs performed in an institution for a 3 yr period (2004–6) were analysed. The standard technique was a piggyback method with veno-venous bypass without prophylactic anti-fibrinolytics. The clinical diagnosis of PTE was made with (i) acute cor pulmonale, and (ii) identification of blood clots in the pulmonary artery or observation of acute right heart pressure overload with or without intracardiac clots with transoesophageal echocardiography. Results The incidence of PTE was 4.0% (20 cases); cardiac arrest preceded the diagnosis of PTE [75% (15)] and PTE occurred during the neo-hepatic phase [85% (17)], especially within 30 min after graft reperfusion [70% (14)]. Operative and 60 day mortalities of patients with PTE were higher (P Conclusions These findings confirmed clinical significance of PTE during adult LT and suggested the possibility of predicting this devastating complication.
Employment, deterrence, and crime in a dynamic model

Using maximum likelihood techniques and monthly panel data we solve and estimate an explicitly dynamic model of criminal behavior where current criminal activity impacts future labor market outcomes. We show that the threat of future adverse effects in the labor market when arrested acts as a strong deterrent to crime. Moreover, such forward-looking behavior is estimated to be important. Hence, policies that weaken this deterrence will be much less effective in fighting crime. This suggests that prevention is more powerful than redemption since anticipated redemption allows criminals to look forward to negating the consequences of their crimes.
A tale of two option markets: Pricing kernels and volatility risk ☆

Abstract Using both S&P 500 option and recently introduced VIX option prices, we study pricing kernels and their dependence on multiple volatility factors. We first propose nonparametric estimates of marginal pricing kernels, conditional on the VIX and the slope of the variance swap term structure. Our estimates highlight the state-dependence nature of the pricing kernels. In particular, conditioning on volatility factors, the pricing kernel of market returns exhibit a downward sloping shape up to the extreme end of the right tail. Moreover, the volatility pricing kernel features a striking U-shape, implying that investors have high marginal utility in both high and low volatility states. This finding on the volatility pricing kernel presents a new empirical challenge to both existing equilibrium and reduced-form asset pricing models of volatility risk. Finally, using a full-fledged parametric model, we recover the joint pricing kernel, which is not otherwise identifiable.
The Political Consequences of Assassination

The assassination of a political leader is among the highest-profile acts of political violence, and conventional wisdom holds that such events often have substantial political, social, and economic effects on states. We investigate the extent to which the assassination of a head of state affects political stability through an analysis of all assassinations of heads of state between 1952 and 1997. We examine the political consequences of assassination by assessing the levels of political unrest, instability, and civil war in states that experience the assassination of their head of state. Our findings support the existence of an interactive relationship among assassination, leadership succession, and political turmoil: in particular, we find that assassinations' effects on political instability are greatest in systems in which the process of leadership succession is informal and unregulated.
Molten flux synthesis of an analogous series of layered alkali samarium selenogermanate compounds.

In this work, we used the molten chalcogenide flux synthetic method to form an analogous series of alkali samarium selenogermanates, with the general formula ASmGeSe4 (A = K, Rb, Cs). Using a constant reactant stoichiometry, we relate the monoclinic KLaGeSe4 structure type to the orthorhombic CsSmGeS4 structure type. KSmGeSe4 [in space group P21 with cell parameters a = 6.774(1) A, b = 6.994(1) A, c = 8.960(2) A, β = 108.225(3)°, and V = 403.2(1) A3 (Z = 2)], RbSmGeSe4 [in space group P212121 with cell parameters a = 6.7347(8) A, b = 7.0185(9) A, c = 17.723(2) A, and V = 837.7(2) A3 (Z = 4)], and CsSmGeSe4 [in space group P212121 with cell parameters a = 6.707(2) A, b = 7.067(2) A, c = 18.334(6) A, and V = 869.1(5) A3 (Z = 4)] were formed under identical synthetic conditions by changing the identity of the alkali ion from K to Rb or Cs, respectively. Additionally, with the substitution of sodium into the reaction, a triclinic structure with the approximate formula NaSmGeSe4 was found with the cell paramet...
Self-Confirming Equilibrium and the Lucas Critique

We examine the role of off-path "superstitions" in macro-economics, and show how a false belief about off-path play is the key element underlying both the Lucas Critique and the game-theoretic concept of self-confirming equilibrium. However, the impact of false beliefs in these two cases is different: In the Lucas case, a policy maker's incorrect beliefs about off-path play can lead to the adoption of mistaken policy innovation. However, the consequences of such an innovation provide evidence that the belief that motivated them was wrong. In contrast, play may never escape an undesirable self-confirming equilibrium, as the action implied by the mistaken belief does not generate data that contradicts it; escape from the self-confirming equilibrium requires that players do a sufficient amount of experimentation with off-path actions.
Measuring the galaxy power spectrum with future redshift surveys

Precision measurements of the galaxy power spectrum P(k) require a data analysis pipeline that is both fast enough to be computationally feasible and accurate enough to take full advantage of high-quality data. We present a rigorous discussion of different methods of power spectrum estimation, with emphasis on the traditional Fourier method and linear (Karhunen-Loeve; KL) and quadratic data compression schemes, showing in what approximations they give the same result. To improve speed, we show how many of the advantages of KL data compression and power spectrum estimation may be achieved with a computationally faster quadratic method. To improve accuracy, we derive analytic expressions for handling the integral constraint, since it is crucial that finite volume effects are accurately corrected for on scales comparable to the depth of the survey. We also show that for the KL and quadratic techniques, multiple constraints can be included via simple matrix operations, thereby rendering the results less sensitive to Galactic extinction and misestimates of the radial selection function. We present a data analysis pipeline that we argue does justice to the increases in both quality and quantity of data that upcoming redshift surveys will provide. It uses three analysis techniques in conjunction: a traditional Fourier approach on small scales, a pixelized quadratic matrix method on large scales, and a pixelized KL eigenmode analysis to probe anisotropic effects such as redshift-space distortions.
The relative importance of myocardial energy metabolism compared with ischemic contracture in the determination of ischemic injury in isolated perfused rabbit hearts.

The mechanical effects of ischemic contracture may be important in the development of irreversible cellular damage as it increases mechanical stress on sarcolemmal membranes and restricts endocardial perfusion. To assess the relative importance of these mechanical effects compared with decreased energy supply in the development of irreversible injury, the effects of inhibiting ischemic contracture with 2,3-butanedione monoxime (BDM), an agent that disrupts excitation-contraction coupling, were delineated in isovolumically contracting isolated rabbit hearts. Administration of 20 mmol/L BDM in 12 hearts subjected to 60 minutes of low-flow ischemia prevented ischemic contracture (left ventricular end-diastolic pressure [LVEDP], 12 +/- 3 compared with 48 +/- 14 mm Hg in 20 control hearts; P < .001), reduced membrane damage (creatine kinase [CK] release, -54% compared with control hearts; P < .05), and enhanced functional recovery during reperfusion (left ventricular developed pressure [LVDP], 86 +/- 10% of baseline compared with 56 +/- 23% in control hearts; P < .01). These observations were not related to increased intracavitary pressure and its effects on flow distribution, since venting the left ventricle in additional hearts did not result in improved function during reperfusion. Although it would be tempting to conclude that BDM protected ischemic myocardium by preventing ischemic contracture, administration of BDM was also associated with reduced depletion of ATP during ischemia, perhaps related to diminished energy demand. To distinguish between the relative importance of inhibiting contracture from provision of adequate energy, the period of ischemia was extended to 120 minutes. BDM still prevented ischemic contracture (LVEDP, 10 +/- 6 mm Hg) and preserved ATP stores, but it did not prevent membrane damage (CK release, 483 +/- 254 U/g dry weight) or contractile failure during reperfusion (LVDP, 68 +/- 7% of baseline). In contrast, increasing the rate of anaerobic glycolysis during ischemia by doubling glucose and insulin in the presence of BDM markedly decreased membrane damage (CK release, 114 +/- 72 U/g dry weight; P < .05) and contractile failure during reperfusion (LVDP, 88 +/- 7% recovery of baseline; P < .01). These results suggest that insufficient energy production is primarily responsible for myocardial ischemic damage, whereas mechanical effects of ischemic contracture appear to play only a minor role.
Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models 1 .
Bismuth Compounds in Organic Synthesis. Bismuth Nitrate Catalyzed Chemoselective Synthesis of Acylals from Aromatic Aldehydes

Abstract Aromatic aldehydes are smoothly converted into the corresponding acylals in good yields in the presence of 3–10 mol% Bi(NO3)3·5H2O. Ketones are not affected under the reaction conditions. The relatively non-toxic nature of the catalyst, its ease of handling, easy availability and low cost make this procedure especially attractive for large-scale synthesis.
Temperature and Solvent Dependent Catalytic Transfer Hydrogenolysis in Aromatic Aldehydes and Ketones Via Ammonium Formate

Abstract Temperature control and solvent specification are used to reduce aromatic aldehydes and ketones to intermediate alcohols rather than methylene derivatives using HCO2NH4 as a catalytic hydrogen transfer agent. A mechanism for the catalytic reduction is proposed.
Maternal Serologic Screening to Prevent Congenital Toxoplasmosis: A Decision-Analytic Economic Model

Objective: To determine a cost-minimizing option for congenital toxoplasmosis in the United States. Methodology/Principal Findings: A decision-analytic and cost-minimization model was constructed to compare monthly maternal serological screening, prenatal treatment, and post-natal follow-up and treatment according to the current French (Paris) protocol, versus no systematic screening or perinatal treatment. Costs are based on published estimates of lifetime societal costs of developmental disabilities and current diagnostic and treatment costs. Probabilities are based on published results and clinical practice in the United States and France. One- and two-way sensitivity analyses are used to evaluate robustness of results. Universal monthly maternal screening for congenital toxoplasmosis with follow-up and treatment, following the French protocol, is found to be cost-saving, with savings of $620 per child screened. Results are robust to changes in test costs, value of statistical life, seroprevalence in women of childbearing age, fetal loss due to amniocentesis, and to bivariate analysis of test costs and incidence of primary T. gondii infection in pregnancy. Given the parameters in this model and a maternal screening test cost of $12, screening is cost-saving for rates of congenital infection above 1 per 10,000 live births. If universal testing generates economies of scale in diagnostic tools—lowering test costs to about $2 per test—universal screening is cost-saving at rates of congenital infection well below the lowest reported rates in the United States of 1 per 10,000 live births. Conclusion/Significance: Universal screening according to the French protocol is cost saving for the US population within broad parameters for costs and probabilities.
Quantized anomalous Hall insulator in a nanopatterned two-dimensional electron gas

We propose that a quantum anomalous Hall insulator (QAHI) can be realized in a nanopatterned two-dimensional electron gas (2DEG) with a small in-plane magnetic field and a high carrier density. The Berry curvatures originating from the in-plane magnetic field and Rashba and Dresselhaus spin-orbit coupling, in combination with a nanoscale honeycomb lattice potential modulation, lead to topologically nontrivial insulating states in the 2DEG without Landau levels. In the bulk insulating gaps, the anomalous Hall conductivity is quantized $\ensuremath{-}{e}^{2}/h$, corresponding to a finite Chern number $\ensuremath{-}1$. There exists one gapless chiral edge state on each edge of a finite-size 2DEG.
The Quiet Period Goes out with a Bang

We examine the expiration of the IPO quiet period, which occurs after the 25th calendar day following the offering. For IPOs during 1996 to 2000, we find that analyst coverage is initiated immediately for 76 percent of these firms, almost always with a favorable rating. Initiated firms experience a five-day abnormal return of 4.1 percent versus 0.1 percent for firms with no coverage. The abnormal returns are concentrated in the days just before the quiet period expires. Abnormal returns are much larger when coverage is initiated by multiple analysts. It does not matter whether a recommendation comes from the lead underwriter or not. COMPANIES PARTICIPATING in an initial public offering (IPO) face numerous regulatory restrictions that prohibit certain activities while the company is "in registration"After completion of an IPO, a firm is still considered to be in registration for an additional period of time. During this time, 25 days during our sample period which is termed the post-IPO "quiet" period, firms may make statements of fact regarding business developments and may respond to inquiries from analysts and shareholders regarding factual matters. However, U.S. Securities and Exchange Commission (SEC) regulations generally prohibit firms and their underwriters from publishing opinions concerning valuation and from making forward-looking statements regarding earnings, revenues, and similar items. The logic behind the SEC's quiet period regulations is that all material information should be contained in the prospectus. Although there is an extensive literature concerning equity IPOs, this paper appears to be the first to specifically examine events surrounding the end of the quiet period.1 For 1,611 IPOs over the period 1996 to 2000, we find that analyst coverage is initiated immediately 76 percent of the time following quiet period
Adaptive quantification of model uncertainties by rational approximation

An adaptive rational approximation approach for quantifying the effect of uncertainty is presented. It is shown that a tight frequency upper bound on the uncertainty is obtainable by adaptive rational approximation. The identifier, which consists of the plant identifier and the uncertainty identifier, is discussed. The plant identifier gives a nominal model which has lower complexity than that of the true plant. Errors between the estimated nominal model and the true plant are characterized by a sequence of rational functions which converges to the accurate upper bound of the uncertainty in the frequency domain. Since approximation and identification are grouped together, the whole procedure is completely automatic. This allows robust control and adaptive control to be combined. >
How to understand divergent views on bipolar disorder in youth.

There are two divergent viewpoints on the phenomenology and outcome of bipolar I (BP I) disorder in youth. Disparities evolved as unintended consequences from investigators' inconsistencies both in translating the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III, DSM-III-R, and DSM-IV criteria and in operationalizing them differently in their standardized assessments. Rates of conservatively diagnosed BP I are lower both in community studies of youths than in adults and from liberally defined BP I in youths. Rates of co-occurring attention-deficit hyperactivity disorder (ADHD) are lower in conservatively than liberally defined children and adolescents with BP I. Rates of both BP I and of ADHD are lower in offspring of BP I probands, and outcome more closely approximates that of adults with BP I in conservatively versus liberally defined children and teens with BP I. Both perspectives can claim evidence for reliability and validity that support their positions. However, the samples are so di...
Another look at search-based drama management

A drama manager (DM) is a system that monitors an interactive experience, such as a computer game, and intervenes to keep the global experience in line with the author's goals without decreasing a player's interactive agency. In declarative optimization-based drama management (DODM), an author declaratively specifies desired properties of the experience; the DM intervenes in a way that optimizes the specified metric. The initial DODM approach used online search to optimize an experience-quality function. Later work questioned both online search as a technical approach and the experience-quality optimization framework. Recent work on targeted trajectory distribution Markov decision processes (TTD-MDPs) replaced the experience-quality metric with a metric and associated algorithm based on targeting experience distributions. We show that, though apparently quite different on the surface, the original optimization formulation and TTD-MDPs are actually variants of the same underlying search algorithm, and that offline cached search, as is done by the TTD-MDP algorithm, allows the original search-based systems to achieve similar results to TTD-MDPs. Furthermore, we argue that the original idea of optimizing an experience-quality function does not destroy interactive agency, as had previously been argued, and that in fact it can capture that goal directly.
Localization and follow-the-leader control of a heterogeneous group of mobile robots

This paper investigates the control and localization of a heterogeneous (e.g., different sensing, mechanical, computational capabilities) group of mobile robots. The group considered here has several inexpensive sensor-limited and computationally limited robots, which follow a leader robot in a desired formation over long distances. This situation is similar to a search, demining, or planetary exploration situation where there are several deployable/disposable robots led by a more sophisticated leader. Specifically, the robots in this paper are designed for highway safety applications where they automatically deploy and maneuver safety barrels commonly used to control traffic in highway work zones. Complex sensing and computation are performed by the leader, while the followers perform simple operations under the leader's guidance. This architecture allows followers to be simple, inexpensive, and have minimal sensors. Theoretical and statistical analysis of a tracking-based localization method is provided. A simple follow-the-leader control method is also presented, including a method for changing follower's configuration. Experimental results of localization and follow-the-leader formation-motion are included.
Status of xenon ion propulsion technology

This paper describes a working-model xenon ion propulsion subsystem (XIPS) designed for north-south stationkeeping (NSSK) of 2500-kg-class geosynchronous communication satellites. The XIPS consists of a 25-cm-diameter laboratory-model thruster, a breadboard-model power supply, and a flight-prototype pressure regulator (the critical component of the pressure-regulated xenon feed system). With a thrust of 63.5 mN, specific impulse of 2800 sec, and thruster efficiency of 65 percent, the XIPS performance is believed to be the highest ever reported for an ion thruster operated at 1.3-kW input power. The XIPS power supply accepts an input power of about 1.4 kW from a 28- to 35-V bus and converts it into the seven outputs required for startup and operation of the thruster. The simplified power supply contains only about 500 parts and has demonstrated an unprecedented efficiency of 90 percent and a specific mass of about 8 kg/kW. The results of a highly successful wear-mechanism test in which the working-model XIPS was operated for 4350 hours and 3850 ON/OFF cycles are presented. These hours and cycles are equivalent to over ten years of NSSK on large communication satellites.
Longitudinal bunch monitoring at the Fermilab Tevatron and Main Injector synchrotrons

The measurement of the longitudinal behavior of the accelerated particle beams at Fermilab is crucial to the optimization and control of the beam and the maximizing of the integrated luminosity for the particle physics experiments. Longitudinal measurements in the Tevatron and Main Injector synchrotrons are based on the analysis of signals from resistive wall current monitors. This article describes the signal processing performed by a 2 GHz-bandwidth oscilloscope together with a computer running a LabVIEW program which calculates the longitudinal beam parameters.
Cross-correlation based multichannel blind equalization

Blind equalization is the problem of reconstructing a signal from a filtered version of it, without, knowledge of the signal nor the filter. A novel cross-correlation based framework is proposed for the problem of blind equalization in communications. We assume that we have access to two observations, corresponding to the outputs of two channels excited by the same input. We propose a new algorithm which estimates the channels using as a basic tool the phase of the cross spectrum of functions of the observations. The proposed method is computationally attractive, requires small input sample sizes, and performs well in low signal-to-noise ratios.
Economic and Emissions Implications of Load-Based, Source-Based, and First-Seller Emissions Trading Programs Under California AB32

In response to Assembly Bill 32, the state of California considered three types of carbon emissions trading programs for the electric power sector: load-based, source-based, and first-seller. They differed in terms of their point of regulation and in whether in-state-to-out-of-state and out-of-state-to-in-state electricity sales are regulated. In this paper, we formulate a market equilibrium model for each of the three approaches, considering power markets, transmission limitations, and emissions trading, and making the simplifying assumption of pure bilateral markets. We analyze the properties of their solutions and show the equivalence of load-based, first-seller, and source-based approaches when in-state-to-out-of-state sales are regulated under the cap. A numeric example illustrates the emissions and economic implications of the models. In the simulated cases, “leakage” eliminates most of the emissions reductions that the regulations attempt to impose. Furthermore, “contract reshuffling” occurs to such an extent that all the apparent emissions reductions resulting from changes in sources of imported power are illusory. In reality, the three systems would not be equivalent because there will also be pool-type markets, and the three systems provide different incentives for participating in those markets. However, the equivalence results under our simplifying assumptions show that load-based trading has no inherent advantage compared to other systems in terms of costs to consumers, contrary to claims elsewhere.
Automatic enforcement of access control policies among dynamic coalitions

The need to securely share information on an ad-hoc basis between collaborating entities is increasingly becoming important We propose a coalition based access control model (CBAC), comprised of three layers: coalition, role and user-object layers Our model enables translation of coalition level policies to implementation level access control in a manner similar to that of the layers of the TCP/IP protocol We present a coalition policy translation protocol that allows the implementation level access control details to be piggybacked as the access control policy percolates to the coalition level, and similarly, as the coalition level policy trickles down to the implementation level Under our approach, a user's request to access an object belonging to another coalition entity is automatically translated by employing an approach that considers attributes associated with user credentials and objects Our approach ensures that the individual access control policies of each coalition entity as well as the agreed-upon coalition policies for sharing are enforced.
The Circumstances and Legal Consequences of Non‐GAAP Reporting: Evidence from Restatements*

Our study examines the circumstances of non-GAAP financial reporting by 492 U.S. companies that announced restatements from 1995 to 1999. We focus on income statements to analyze the occurrence and resolution of litigation over restatements and explore the role of accounting items in bringing and resolving this litigation. We provide evidence on the pervasiveness of accounting misstatements, describe their nature, and show how, if at all, they affect litigation. We assess the nature of restatements by determining whether regular, recurring earnings from primary operations (core) or other components of earnings (noncore) are misstated, and we assess their pervasiveness by estimating the number of primary accounts misstated. In our sample, companies with core restatements have higher frequencies of intentional misstatements (fraud) and subsequent bankruptcy or delisting. Likewise, these companies have, on average, more material misstatements, more negative security price reactions to restatement announcements, and more negative security price changes over the six months preceding and following restatement announcements. However, controlling for these and other factors, we find a significant association between accounting items and litigation, whether occurrences or resolutions. Specifically, core restatements — driven primarily by misstatements of revenue, a component of core earnings — and more pervasive restatements each play a role, while misstatements of noncore earnings alone do not.
Chromonic liquid crystals: properties and applications as functional materials

Chromonic liquid crystals (or chromonics) are formed by the self-organization of aromatic compounds with ionic or hydrophilic groups in aqueous solutions. This review summarizes the research on chromonic liquid crystals in the last two decades. The research embraced the studies of commercially available chromonic dyes and drugs, the syntheses and investigations of molecularly designed mesogens, the invention of novel processes for aligning chromonic liquid crystals, and the development of new applications as functional materials and biosensors.
Issues in joint SZ and optical cluster finding

We apply simple optical and SZ (Sunyaev-Zel'dovich) cluster finders to mock galaxy catalogues and SZ flux maps created from dark matter haloes in a (1 h -1 Gpc) 3 dark matter simulation, at redshifts 0.5 and 0.9. At each redshift, the two catalogues are then combined to assess how well they can improve each other, and compared to several variants of catalogues made using SZ flux and galaxy information simultaneously. We use several different criteria to compare the catalogues, and illustrate some of the tradeoffs which arise in tuning the galaxy cluster finders with respect to these criteria. We detail many of the resulting improvements and issues which arise in comparing and combining these two types of data sets.