cssi/SciSciGPT-SciSciNet huggingface dataset:
A Filtering Model with Steady-State Housing

Abstract The seminal paper in the modern literature on filtering is Sweeney, 1974b. Sweeney assumed that housing deteriorates in quality as it ages, no matter how much is spent on maintenance, and is eventually abandoned. This assumption appears to be inconsistent with the observation that, in European and eastern North American cities, expenditures on housing upgrading and rehabilitation are comparable to expenditures on new housing construction. This paper provides an analytical generalization of Braid's (Braid, 1984) continuum reformulation of a Sweeney-type model by incorporating a maintenance technology that permits upgrading as well as downgrading. It focuses on a case in which: (i) all housing is constructed at a single high quality level; (ii) for a period of time after construction, housing is downgraded until it falls to a critical quality; (iii) thereafter enough is spent on maintenance that housing remains in an interval of qualities forever; and (iv) no abandonment occurs.
Insomnia: Prevalence, Impact, Pathogenesis, Differential Diagnosis, and Evaluation

Insomnia is the most common sleep disorder affecting millions of people as either a primary or comorbid condition. Insomnia has been defined as both a symptom and a disorder, and this distinction may affect its conceptualization from both research and clinical perspectives. Whether insomnia is viewed as a symptom or a disorder, however, it nevertheless has a profound effect on the individual and society. The burden of medical, psychiatric, interpersonal, and societal consequences that can be attributed to insomnia underscores the importance of understanding, diagnosing, and treating the disorder.
Strategic Labeling and Trade of GMOs

The emergence of agricultural biotechnology and the subsequent introduction of genetically modified organisms (GMOs) into the food system have been among the most controversial issues surrounding the increasingly scrutinized agri-food system. They have received considerable attention in the economics literature with the main focus being on the optimal regulatory response to products of biotechnology. This paper builds on the literature on the regulation of products of biotechnology by placing the analysis of labeling decisions in a multi-country context. Specifically, the objective of this study is to examine the effect of the strategic interdependence between countries on their regulatory responses to products of biotechnology. The paper analyzes the strategic effects of national regulatory decisions on labeling of GM products and identifies the determinants of the non-cooperative Nash equilibrium labeling regimes in a small number of producing countries that supply the world market of an agricultural product. Analytical results show that the Nash equilibrium configuration of labeling regimes in countries that have adopted the GM technology depends on (i) the distribution of consumer preferences and the level of consumer aversion to GM products; (ii) the size of the segregation and labeling costs in these countries; (iii) the relative productive efficiency and the cost effectiveness of the GM technology; (iv) the market power of the life science companies; and (v) the strength of intellectual property rights in these countries.
Telomere-Telomere Recombination Is an Efficient Bypass Pathway for Telomere Maintenance in Saccharomyces cerevisiae

Many Saccharomyces telomeres bear one or more copies of the repetitive Y' element followed by approximately 350 bp of telomerase-generated C(1-3)A/TG(1-3) repeats. Although most cells lacking a gene required for the telomerase pathway die after 50 to 100 cell divisions, survivors arise spontaneously in such cultures. These survivors have one of two distinct patterns of telomeric DNA (V. Lundblad and E. H. Blackburn, Cell 73:347-360, 1993). The more common of the two patterns, seen in type I survivors, is tandem amplification of Y' followed by very short tracts of C(1-3)A/TG(1-3) DNA. By determining the structure of singly tagged telomeres, chromosomes in type II survivors were shown to end in very long and heterogeneous-length tracts of C(1-3)A/TG(1-3) DNA, with some telomeres having 12 kb or more of C(1-3)A/TG(1-3) repeats. Maintenance of these long telomeres required the continuous presence of Rad52p. Whereas type I survivors often converted to the type II structure of telomeric DNA, the type II pattern was maintained for at least 250 cell divisions. However, during outgrowth, the structure of type II telomeres was dynamic, displaying gradual shortening as well as other structural changes that could be explained by continuous gene conversion events with other telomeres. Although most type II survivors had a growth rate similar to that of telomerase-proficient cells, their telomeres slowly returned to wild-type lengths when telomerase was reintroduced. The very long and heterogeneous-length telomeres characteristic of type II survivors in Saccharomyces are reminiscent of the telomeres in immortal human cell lines and tumors that maintain telomeric DNA in the absence of telomerase.
Particle motion inside and near a linear half-integer stopband

This paper studies the motion of a particle whose tune is inside and near a linear half-integer stopband. Results are found for the tune and beta functions in the stable region close to an edge of the stopband. It is shown that the eigenvalues and the eigenfunctions of the transfer matrix are real inside the stopband. All the results found are also valid for small accelerators where the large accelerator approximation is not used.
Cournot Competition Under Yield Uncertainty: The Case of the U.S. Influenza Vaccine Market

This paper is inspired by the recurring mismatch between demand and supply in the U.S. influenza vaccine market. Economic theory predicts that an oligopolistic market with unregulated but costly entry will experience excess entry and oversupply, not the undersupply observed in the market for influenza vaccine in recent years. In this paper, we examine the interaction between yield uncertainty, a key characteristic of many production processes, including that for influenza vaccine, and firms' strategic behavior. We find that yield uncertainty can contribute to a high degree of concentration in an industry and a reduction in the industry output and the expected consumer surplus in equilibrium. We use parameter values loosely based on the U.S. influenza vaccine market to numerically illustrate the impact of yield uncertainty.
Automating the design of asynchronous sequential logic circuits

The computer-aided design process described simplifies the task of designing asynchronous sequential logic circuits (ASLCs). It provides a highly structured, interactive approach for modeling sequential logic functions and for mapping these models into ASLC architectures and gate-level circuits. A design automation system that implements this process has been developed and tested. It contains five modules: (1) the behavioral descriptor, which maps the functional design specification into a primitive flow table; (2) the merger, which minimizes the number of states needed to implement the functional model; (3) the connector, which adds cycles and states, as needed, to avoid critical rates; (4) the assigner, which encodes the states and generates the state excitation table and output table; and (5) the equation generator, which eliminates static hazards and converts the state excitation table and output table into two-level, sum-of-product expressions for the state equations and output equations. This task-oriented system provides a convenient way to describe the functional behavior of sequential logic functions. It can reduce the design cycle time and improve the reliability of the overall ASLC design process and can also be used to facilitate the investigation of alternative ASLC architectures for the purpose of optimizing the performance of a specific sequential logic function. >
Fourier Analysis of Time-Stamped Signals Using a Small Number of Samples

This paper concerns the Fourier analysis of measurements taken at times that are not at all uniformly spaced yet are accurately known. Such can be the case when measurements are obtained by networked sensors with accurate or synchronized clocks using common Internet Protocol networks or other networks that do not guarantee timely data delivery. Such can also be the case when the object being measured is only sporadically available for measurement. A method for computing a complex spectrum from a minimal number of samples taken at nonuniform time intervals is described. The novelty of this paper lies in the method's ability to minimize the number of samples required to ensure a desired accuracy. A practical application of the method lies in doing spectral analysis of signals obtained from networked sensors where acquiring each sample is expensive in time, power, or money, and so, the number of samples taken is to be minimized. The method has been tested on two rather different sets of actual measurements: one taken via smart sensors connected to the Internet and the other taken by a number of observational astronomers using a variety of apparatus over decades.
Feedback control as a framework for understanding tradeoffs in biology

Synopsis Control theory arose from a need to control synthetic systems. From regulating steam engines to tuning radios to devices capable of autonomous movement, it provided a formal mathematical basis for understanding the role of feedback in the stability (or change) of dynamical systems. It provides a framework for understanding any system with regulation via feedback, including biological ones such as regulatory gene networks, cellular metabolic systems, sensorimotor dynamics of moving animals, and even ecological or evolutionary dynamics of organisms and populations. Here, we focus on four case studies of the sensorimotor dynamics of animals, each of which involves the application of principles from control theory to probe stability and feedback in an organism’s response to perturbations. We use examples from aquatic (two behaviors performed by electric fish), terrestrial (following of walls by cockroaches), and aerial environments (flight control by moths) to highlight how one can use control theory to understand the way feedback mechanisms interact with the physical dynamics of animals to determine their stability and response to sensory inputs and perturbations. Each case study is cast as a control problem with sensory input, neural processing, and motor dynamics, the output of which feeds back to the sensory inputs. Collectively, the interaction of these systems in a closed loop determines the behavior of the entire system.
Popularity, novelty and attention

We analyze the role that popularity and novelty play in attracting the attention of users to dynamic websites. We do so by determining the performance of three different strategies that can be utilized to maximize attention. The first one prioritizes novelty while the second emphasizes popularity. A third strategy looks myopically into the future and prioritizes stories that are expected to generate the most clicks within the next few minutes. We show that the first two strategies should be selected on the basis of the rate of novelty decay, while the third strategy performs sub-optimally in most cases. We also demonstrate that the relative performance of the first two strategies as a function of the rate of novelty decay changes abruptly around a critical value, resembling a phase transition in the physical world.
China's accession to the World Trade Organization - The services dimension

China's General Agreement on Trade in Services (GATS) commitments represent the most radical services reform program negotiated in the World Trade Organization. China has promised to eliminate over the next few years most restrictions on foreign entry and ownership, as well as most forms of discrimination against foreign firms. These changes are in themselves desirable. However, realizing the gains from, and perhaps even the sustainability of, liberalization will require the implementation of complementary regulatory reform and the appropriate sequencing of reforms. Three issues, in particular, merit attention: 1) Initial restrictions on the geographical scope of services liberalization could encourage the further agglomeration of economic activity in certain regions-to an extent that is unlikely to be reversed completely by subsequent countrywide liberalization. 2) Restrictions on foreign ownership (temporary in most sectors but more durable in telecommunications and life insurance) may dampen the incentives of foreign investors to improve firm performance. 2) Improved prudential regulation and measures to deal with the large burden of non-performing loans on state banks are necessary to deliver the benefits of liberalization in financial services. And in basic telecommunications and other network-based services, meaningful liberalization will be difficult to achieve without strengthened pro-competitive regulation.
Changes in major element hydrochemistry of the Pecos River in the American Southwest since 1935

Abstract The Pecos River, situated in eastern New Mexico and western Texas, receives water from a drainage area of 91 000 km 2 . There are primarily two major water inputs, namely snowmelt from winter storms in the headwater region of the southern Rocky Mountains and runoff from warm-season monsoonal rainfall in the lower valley. The Pecos River suffers from high levels of total dissolved solids (TDS >5000 mg L −1 ) under normal flow conditions. This not only poses serious problems for agricultural irrigation and safe drinking water supply, but also results in a permanent loss of biodiversity. This study examines changes in stream flow and water chemistry of the Pecos River over the last 70 a to better understand the long-term variability in stream salinity and the role of agricultural practices in salt transfer. A TDS record from the lower Pecos River near Langtry (Texas) back to 1935 was extracted to show a distinct pattern of decadal variability similar to the Pacific Decadal Oscillation (PDO), in which stream salinity is overall above average when the PDO is in positive (warm) phase and below average when the PDO is in negative (cold) phase. This is due to: (1) the dissolved salts contributed to the river are largely from dissolution of NaCl and CaSO 4 -bearing minerals (e.g., halite and gypsum) in the upper basin, (2) the amount of the dissolved salts that reach the lower basin is mainly determined by the stream flow yield in the upper basin and (3) the stream flow yield from the upper basin is positively correlated with the PDO index. This further attests that large-scale climatic oscillation is the major source of long-term changes in stream flow and salinity of the Pecos River. On the other hand, there is also a strong indication that the rate of salt export has been affected by reservoir operations and water diversions for agricultural practices.
Sundial: Using Sunlight to Reconstruct Global Timestamps

This paper investigates postmortem timestamp reconstruction in environmental monitoring networks. In the absence of a time-synchronization protocol, these networks use multiple pairs of (local, global) timestamps to retroactively estimate the motes' clock drift and offset and thus reconstruct the measurement time series. We present Sundial , a novel offline algorithm for reconstructing global timestamps that is robust to unreliable global clock sources. Sundial reconstructs timestamps by correlating annual solar patterns with measurements provided by the motes' inexpensive light sensors. The surprising ability to accurately estimate the length of day using light intensity measurements enables Sundial to be robust to arbitrary mote clock restarts. Experimental results, based on multiple environmental network deployments spanning a period of over 2.5 years, show that Sundial achieves accuracy as high as 10 parts per million (ppm), using solar radiation readings recorded at 20 minute intervals.
Optimal dynamic actuator location in distributed feedback control of a diffusion process

In this paper, the problem of distributed neutralisation of toxic 2D diffusion process is discussed. The diffusion process is modelled by a parabolic partial differential equation system. A group of mobile robots which can release neutralising chemicals are sent to detoxify the pollution. We attempt to solve the optimal actuator location problem by using Centroidal Voronoi Tessellations (CVT). A new simulation platform (Diff-MAS2D) for measurement scheduling and controls in distributed parameter systems is also introduced in this paper. Simulation results show the effectiveness of our proposed method.
A convenient masking group for aryl iodides

Abstract 1-Aryl-3,3-dialkyltriazenes give excellent yields of easily isolated aryl iodides upon treatment with methyl iodide.
Late-Stage Fluorination: From Fundamentals to Application

In this brief account, we review work from our lab with a focus on late-stage introduction of fluorine and fluorinated functional groups into small molecules. We attempt to highlight practical developments, which we believe may have potential for industrial applications, and critically reflect on developments that may not yet meet the bar for practical use.
Advanced technology and knowledge transfer

This paper reports on a specific food and agribusiness industry project, employing new technological capabilities to better transfer expert knowledge. Knowledge transfer and technical support are key components of this project. VisIT, which stands for visualization of information tool, is a powerful organizational tool, which provides an Internet-based graphical learning environment. As a means to more effectively disseminate knowledge, the project support group desired to employ the VisIT technology to create "expert search maps". Before devoting extensive resources to the use of the VisIT technology, an evaluation of this approach was conducted relative to more traditional methods used on the Internet. The hypothesis of the study is that the students with access to the graphical expert search map will have a better understanding of the complex issues as compared to students given the now traditional linear list of search results. The study results in counterintuitive findings. These findings have significant implications for managers as well as for researchers developing knowledge management tools.
Chromium, molybdenum and tungsten

This chapter reviews the literature reported during 2011 on some important advances in the areas of catalysis, bioinorganic, and organometallic chemistry for the chromium triad. Research highlights for each metal during the year are also given.
The Gompers v. Buck's Stove Saga: A Constitutional Case Study in Dialogue, Resistance, and the Freedom of Speech

In case of a dispute with employers a Judge can now permanently rivet your jaws and lips. You must not utter the very thoughts that GOD has put into your mind. Samuel Gompers1
A New and Efficient Synthesis of Enamido Dienes and Dienamido Olefins for Intramolecular Diels-Alder Additions Leading to Hydroquinolones and Alkaloids

Abstract The enamido or dienamido functionality is directly and efficiently introduced into a bifunctional or more general context by alkylation of the previously unreported enolates of enamides or dienamides. These alkylations provide an extremely convenient method for the synthesis of bifunctional enamido dienes and dienamido olefins, both of which are readily converted to hydroquinolones by intramolecular Diels-Alder cycloaddition.
A Non Standard Model Higgs at the LHC as a Sign of Naturalness

Light states associated with the hierarchy problem affect the Higgs LHC production and decays. We illustrate this within the MSSM and two simple extensions applying the latest bounds from LHC Higgs searches. Large deviations in the Higgs properties are expected in a natural SUSY spectrum. The discovery of a non-Standard-Model Higgs may signal the presence of light stops accessible at the LHC. Conversely, the more the Higgs is Standard-Model-like, the more tuned the theory becomes. Taking the ratio of different Higgs decay channels at the LHC cancels the leading QCD uncertainties and potentially improves the accuracy in Higgs coupling measurements to the percent level. This may lead to the possibility of doing precision Higgs physics at the LHC. Finally, we entertain the possibility that the ATLAS excess around 125 GeV persists with a Higgs production cross-section that is enhanced compared to the SM. This increase can only be accommodated in extensions of the MSSM and it may suggest that stops lie below 400 GeV, likely within reach of next year’s LHC run.
Dynamic camera calibration to estimate mean vehicle speed

In this paper, we present an algorithm to estimate mean vehicle speed from un-calibrated roadside cameras. The algorithm presented creates a new virtual speed sensor that leverages the large numbers of low quality cameras already installed by transportation agencies. The calibration problem considered here is complicated by the ability of the operation staff to pan, tilt, and zoom the un-calibrated roadside cameras. It is in this framework that we present an algorithm that: (1) performs a simplified dynamic calibration and (2) estimates mean vehicle speed. In the work presented, we wish to estimate the mean vehicle speeds and we will demonstrate that a simplified, and perhaps less accurate form of calibration is adequate to make an accurate mean speed estimate. We use 10-second video sequences as training sets to dynamically calibrate the camera. Our proposed method detects moving vehicles in a set of consecutive frames. This information, together with a mean vehicle dimension, allows us to estimate a scaling factor for a one-dimensional transformation between motion in the image and motion in the earth coordinates. As a result, our algorithm requires the estimation of fewer camera calibration parameters. We validate our algorithm with both simulated data and real world traffic scenes.
Photochemical ring-contraction of fused bicyclic 4-pyrones: A novel 2-step cyclopentannulation approach

Abstract Fused bicyclic 4-pyrones were prepared by condensation of enamines derived from cyclic ketones with diketene or substituted 1,3-dioxin-4-ones. Photolysis in a hydroxylic medium led to bicyclo[n3.0]alkenones bearing oxygenation at both angular positions. This process is occurs via regioselective nucleophilic solvent attack on the intermediate tricyclic oxyallyl zwitterion. The efficiency of the transformation was found to be dependent upon the size of the ring fused to the 4-pyrone.
Relay Selection from a Battery Energy Efficiency Perspective

The battery nonlinearity has never been considered for energy analysis in relay networks. In this letter, we adopt the realistic nonlinear battery model, apply the battery energy consumption results in to general relay networks, investigate the optimum and suboptimum energy allocation solutions for relaying transmission, and establish the relay selection criterion from the battery energy efficiency perspective. Our analyses and comparisons show that relaying does not always increase the system energy efficiency. We further establish closed-form conditions that can be easily checked to determine whether the relay transmission is preferable to the direct transmission. Numerical examples are also presented to verify these results.
Do Macro Variables, Asset Markets or Surveys Forecast Inflation Better?

Abstract Surveys do! We examine the forecasting power of four alternative methods of forecasting U.S. inflation out-of-sample: time-series ARIMA models; regressions using real activity measures motivated from the Phillips curve; term structure models that include linear, non-linear, and arbitrage-free specifications; and survey-based measures. We also investigate several methods of combining forecasts. Our results show that surveys outperform the other forecasting methods and that the term structure specifications perform relatively poorly. We find little evidence that combining forecasts produces superior forecasts to survey information alone. When combining forecasts, the data consistently places the highest weights on survey information.
On the performance of affine policies for two-stage adaptive optimization: a geometric perspective

We consider two-stage adjustable robust linear optimization problems with uncertain right hand side $$\mathbf {b}$$b belonging to a convex and compact uncertainty set $$\mathcal{U}$$U. We provide an a priori approximation bound on the ratio of the optimal affine (in $$\mathbf {b}$$b) solution to the optimal adjustable solution that depends on two fundamental geometric properties of $$\mathcal{U}$$U: (a) the "symmetry" and (b) the "simplex dilation factor" of the uncertainty set $$\mathcal{U}$$U and provides deeper insight on the power of affine policies for this class of problems. The bound improves upon a priori bounds obtained for robust and affine policies proposed in the literature. We also find that the proposed a priori bound is quite close to a posteriori bounds computed in specific instances of an inventory control problem, illustrating that the proposed bound is informative.
Consistent unscented incremental smoothing for multi-robot cooperative target tracking

In this paper, we study the problem of multi-robot cooperative target tracking, where a team of mobile robots cooperatively localize themselves and track (multiple) targets using their onboard sensor measurements as well as target stochastic kinematic information, and which is hence termed cooperative localization and target tracking (CLATT). A novel efficient, consistent, unscented incremental smoothing (UIS) algorithm is introduced. The key idea of the proposed approach is that we employ unscented transform to numerically compute Jacobians so as to attain reduced linearization errors, while further imposing appropriate constraints on the unscented transform to ensure correct observability properties for the incrementally-linearized system. In particular, for the first time we analyze the observability properties of the optimal batch maximum a posteriori (MAP)-based CLATT system, and show that the Fisher information (Hessian) matrix without prior has a nullspace of dimension three, corresponding to the global state information. However, this may not be the case when the Jacobians (and thus the Hessian) are computed canonically by the standard unscented transform, thus negatively impacting the estimation performance. To address this issue, we formulate an observability-constrained unscented transform, and find its closed-from solution as the projection of the canonical unscented Jacobian (i.e., computed by the standard unscented transform) onto an appropriate observable subspace such that the resulting Hessian has a nullspace of correct dimensions. The proposed approach is tested extensively through Monte Carlo simulations as well as a real-world experiment, and is shown to outperform the state-of-the-art incremental smoothing algorithm. Observability analysis for the batch-MAP based CLATT system.Efficient, consistent, unscented incremental smoothing (UIS) algorithm.Achieving reduced linearization errors and correct observability.Outperforming the state-of-the-art incremental estimation algorithms.
DID THE 2007 LEGAL ARIZONA WORKERS ACT REDUCE THE STATE'S UNAUTHORIZED IMMIGRANT POPULATION?

We test for an effect of Arizona's 2007 Legal Arizona Workers Act (LAWA) on the proportion of the state's population characterized as noncitizen Hispanic. We use the synthetic control method to select a group of states against which Arizona's population trends can be compared. We document a notable and statistically significant reduction in the proportion of the Hispanic noncitizen population in Arizona. The decline observed matches the timing of LAWA's implementation, deviates from the time series for the synthetic control group, and stands out relative to the distribution of placebo estimates for other states in the nation.
Stable radiation-controlling boundary conditions for the generalized harmonic Einstein equations

This paper is concerned with the initial-boundary value problem for the Einstein equations in a first-order generalized harmonic formulation. We impose boundary conditions that preserve the constraints and control the incoming gravitational radiation by prescribing data for the incoming fields of the Weyl tensor. High-frequency perturbations about any given spacetime (including a shift vector with a subluminal normal component) are analysed using the Fourier–Laplace technique. We show that the system is boundary stable. In addition, we develop a criterion that can be used to detect weak instabilities with polynomial time dependence, and we show that our system does not suffer from such instabilities. A numerical robust stability test supports our claim that the initial-boundary value problem is most likely to be well posed even if non-zero initial and source data are included.
Seeing Stars: Exploiting Class Relationships for Sentiment Categorization with Respect to Rating Scales

We address the rating-inference problem, wherein rather than simply decide whether a review is "thumbs up" or "thumbs down", as in previous sentiment analysis work, one must determine an author's evaluation with respect to a multi-point scale (e.g., one to five "stars"). This task represents an interesting twist on standard multi-class text categorization because there are several different degrees of similarity between class labels; for example, "three stars" is intuitively closer to "four stars" than to "one star".We first evaluate human performance at the task. Then, we apply a meta-algorithm, based on a metric labeling formulation of the problem, that alters a given n-ary classifier's output in an explicit attempt to ensure that similar items receive similar labels. We show that the meta-algorithm can provide significant improvements over both multi-class and regression versions of SVMs when we employ a novel similarity measure appropriate to the problem.
Monotonic Convergence in an Information-Theoretic Law of Small Numbers

An "entropy increasing to the maximum" result analogous to the entropic central limit theorem (Barron 1986; Artstein 2004) is obtained in the discrete setting. This involves the thinning operation and a Poisson limit. Monotonic convergence in relative entropy is established for general discrete distributions, while monotonic increase of Shannon entropy is proved for the special class of ultra-log-concave distributions. Overall we extend the parallel between the information-theoretic central limit theorem and law of small numbers explored by Kontoyiannis (2005) and HarremoEumls (2007, 2008, 2009). Ingredients in the proofs include convexity, majorization, and stochastic orders.
Force and motion control of a constrained flexible robot arm

The results of a study on the combined joint motion control, vibration control, and force control of a constrained rigid-flexible robot arm for both regulation and tracking are presented. A nonlinear modified Corless-Leitmann controller is proposed for control of the flexible motion using only joint actuators. Experimental studies, which demonstrate the effectiveness of the proposed method, are described
INFORMATION AND EMPLOYEE EVALUATION: EVIDENCE FROM A RANDOMIZED INTERVENTION IN PUBLIC SCHOOLS

A large body of research suggests that improving teacher quality is an important channel for raising student achievement. However, in order to selectively retain highly effective teachers, or provide training to teachers who need it, school administrators must be able to accurately evaluate teacher performance. One potential tool to improve teacher evaluation is the use of information based on student achievement outcomes. To assess the merits of providing such information to school administrators, the New York City Department of Education disseminated reports on the performance of individual teachers to a randomly selected subset of volunteer principals in the school year 2007-2008. Several important facts emerge from our analysis of this pilot program. First, the estimates of teacher performance reported to principals were correlated with principals’ preexisting beliefs about teacher effectiveness, as reflected in both their opinions and their actions (e.g., classroom observations). Second, principals changed their subjective ratings of teachers in response to the information in the reports, establishing that value-added reports provided new information that principals felt was useful. Finally, our results suggest that the information in the reports raised the probability that teachers with low performance estimates left their school at the end of the pilot year. Collectively, these results suggest that information on how individual teachers impact student achievement may help principals raise teacher quality in their schools.
Heterojunction Vertical Band-to-Band Tunneling Transistors for Steep Subthreshold Swing and High on Current

We propose a heterojunction vertical tunneling field-effect transistor and show using self-consistent ballistic quantum transport simulations that it can provide very steep subthreshold swings and high on current, thereby improving the scalability of TFETs for high performance. The turn-on in the pocket region of the device is dictated by the modulation of heterojunction barrier height. The steepness of turn-on is increased because of simultaneous onset of tunneling in the pocket and the region underneath and also due to the contribution of vertical tunneling in the pocket to the current. These factors can be engineered by tuning heterojunction band offsets.
MR imaging of Tolosa-Hunt syndrome.

The Tolosa-Hunt syndrome consists of painful ophthalmoplegia caused by cavernous sinus inflammation, which is responsive to steroid therapy. The MR features of 11 patients with the clinical diagnosis of Tolosa-Hunt syndrome were studied. Two patients had normal MR studies of the orbit and cavernous sinuses. In nine patients, abnormal signal and/or mass lesions were seen in the cavernous sinuses; in eight cases, the abnormality was hypointense relative to fat and isointense with muscle on short TR/TE images and isointense with fat on long TR/TE scans. Extension into the orbital apex was seen in eight cases. In six of nine cases the affected cavernous sinus was enlarged; in five of nine it had a convex outer margin. One patient had a thrombosed cavernous sinus and superior ophthalmic vein in addition to a cavernous sinus soft-tissue mass. The signal intensity of Tolosa-Hunt syndrome in this limited series was similar to that of orbital pseudotumor and is confined to a limited differential diagnosis, which i...
Erasure generation and interleaving for meteor-burst communications with fixed-rate and variable-rate coding

Erasure generation techniques are investigated in conjunction with symbol interleaving as methods to improve the performance of meteor-burst communication systems. Erasure generation via Viterbi's (1982) ratio-threshold test (RTT) and a Bayesian scheme are both considered. It is found that a system using fixed-rate coding, interleaving, and erasure generation can significantly outperform more complex variable-rate coding schemes which do not use erasures.
Dermal Uptake of 18 Dilute Aqueous Chemicals: In Vivo Disappearance-Method Measures Greatly Exceed In Vitro-Based Predictions

Average rates of total dermal uptake (Kup ) from short-term (e.g., bathing) contact with dilute aqueous organic chemicals (DAOCs) are typically estimated from steady-state in vitro diffusion-cell measures of chemical permeability (Kp ) through skin into receptor solution. Widely used ("PCR-vitro") methods estimate Kup by applying diffusion theory to increase Kp predictions made by a physico-chemical regression (PCR) model that was fit to a large set of Kp measures. Here, Kup predictions for 18 DAOCs made by three PCR-vitro models (EPA, NIOSH, and MH) were compared to previous in vivo measures obtained by methods unlikely to underestimate Kup . A new PCR model fit to all 18 measures is accurate to within approximately threefold (r = 0.91, p 0.63) all tend to underestimate the Kup measures by mean factors (UF, and p value for testing UF = 1) of 10 (EPA, p 0.05), so vapor pressure appears not to explain the significant in vivo/PCR-vitro discrepancy. Until this discrepancy is explained, careful in vivo measures of Kup should be obtained for more chemicals, the expanded in vivo database should be compared to in vitro-based predictions, and in vivo data should be considered in assessing aqueous dermal exposure and its uncertainty.
A Rectangular Logic Array

A rectangular logic array is described that can realize any combinational switching function. Straightforward analysis and synthesis procedures are described and the realizations of a number of special functions are given. These include threshold functions, parity functions, symmetric functions, and universal logic functions. Other properties of the array which are examined include diagnostic procedures, isolating defective cells, bounds on the array size, and possible implementations of the basic cell.
Epoxidation of olefins by β-bromoalkoxydimethylsulfonium ylides

Olefins can be converted to their respective epoxides in a one-pot procedure by dissolving the olefin in anhydrous DMSO, adding NBS to the reaction mixture to generate a β-bromoalkoxydimethylsulfonium ylide, and then adding DBU to the reaction mixture. A large variety of alkenes were successfully epoxidized with yields largely dependent on the structure of the alkene. Most importantly, the facial selectivity of this one-pot process is the opposite of that observed when using traditional epoxidizing reagents. Electron-poor alkenes are not epoxidized under these conditions.
The Importance of Obtaining a High-Paying Job

Given the high level of job mobility in the United States, one might think that obtaining a low-paying job would have only temporary consequences. However, using longitudinal data, I find that state dependence in wages is large and persistent. If two comparable individuals start jobs that pay a different wage, about 60% of the wage differential is still present four years later. Moreover, about 50% of the wage differential is still present for workers who have switched employers during that period. The results indicate that the jobs acquired by individuals have long- term effects on their future careers. I also examine the mechanisms that lead to state dependence. In a stigma model, prospective employers use wages as a signal of ability. Thus, getting a poor job can lead the market to believe that an individual has low ability. In the learning-by-doing model, workers who get high-paying jobs also attain greater opportunities to acquire human capital. The evidence suggests that both stigma and learning by doing models contribute to state dependence in wages.
Averting Regulatory Enforcement: Evidence from New Source Review

This paper explores firms' response to regulatory enforcement. New Source Review (NSR), a provision of the Clean Air Act, imposes stringent emissions limitations on significantly modified older power plants. In 1999, the Environmental Protection Agency (EPA) sued owners of 46 plants for NSR violations. We study how electricity companies respond to both the perceived threat of future action, and the action itself. A discrete choice model estimates plants likelihood of being named in lawsuits increases with large historic emissions and investments. On the eve of the lawsuits, emissions at plants with a one standard deviation greater probability of being sued fell approximately 10%.
Are There Cultural Universals

A la question «Y a-t-il des universaux culturels?», l'A. repond d'emblee par une reduction a l'absurde: oui, sans quoi la communication entre les cultures serait impossible. Le probleme, et c'est a lui que les analyses linguistiques de l'A. s'attaquent, devient alors de savoir s'il existe des schemes de concepts qui puissent etre partages par toute l'humanite
Informality and Development

In developing countries, informal firms account for up to half of economic activity. They provide livelihood for billions of people. Yet their role in economic development remains controversial. Some, like Hernando De Soto (1989, 2000), see informal firms as an untapped reservoir of entrepreneurial energy, held back by government regulations. In this view, unleashing this energy by reducing entry regulations or improving property rights would fuel growth and development. Others, like Levy (2008), take a more cynical view, stressing the advantages enjoyed by informal firms and workers from avoiding taxes and regulations. A report from the McKinsey Global Institute describes informal firms as parasites competing unfairly with law-abiding formal firms (Farrell 2004). In this view, informality should be suppressed, not unleashed. Still others follow the development tradition of Lewis (1954), Harris and Todaro (1970), and more recently Rauch (1991) and see informality as a byproduct of poverty. From this dual perspective, formal and informal firms are fundamentally different. Productive formal entrepreneurs pay taxes and bear the cost of government regulation to reach new customers, raise capital, and access public goods. These entrepreneurs are often educated and find it more profitable to run bigger formal firms rather than the smaller informal ones. In contrast, informal entrepreneurs are typically uneducated and unproductive, and they run small businesses producing low-quality products for low-income customers using little capital and
Studies on the formation and incorporation of streptolidine in the biosynthesis of the peptidyl nucleoside antibiotic streptothricin F.

Streptothricin F (STF, 1) is a peptidyl nucleoside antibiotic produced by Streptomyces lavendulae. Studies were conducted to address the formation and timing of incorporation of the arginine-derived base streptolidine (4) during the biosynthesis of 1. [guanidino-13C]Streptolidine (10) was prepared by modification of an established method and used in whole-cell incorporation experiments. Analysis of the purified STF by 13C NMR revealed a 1.9% enrichment of the guanidino carbon, confirming 4 as an advanced precursor to 1 and supporting proposals that 1 is assembled via a convergent biosynthetic pathway. To identify advanced intermediates in the conversion of l-arginine to 4, (2S,3R)-[guanidino-13C]capreomycidine (32) was prepared from oxazolidine aldehyde (18) via 1,1-dimethylethyl (4R,1‘S)-4-(1‘,3‘-diaminopropyl)-2,2-dimethyl-3-oxazolidinecarboxylate (30). Treatment of 30 with Br13CN yielded the corresponding diprotected amino alcohol, which was readily converted to 32. The STF isolated from whole-cell inc...
Synthesis of oxygen heterocycles

A generalised scheme for the synthesis of flavones, flavonones and chromones involving 3-acyl-γ-pyrone intermediates has been developed. Convenient synthesis of other oxygen heterocycles using similar procedure have been outlined.
Dueling network architectures for deep reinforcement learning

In recent years there have been many successes of using deep representations in reinforcement learning. Still, many of these applications use conventional architectures, such as convolutional networks, LSTMs, or auto-encoders. In this paper, we present a new neural network architecture for model-free reinforcement learning. Our dueling network represents two separate estimators: one for the state value function and one for the state-dependent action advantage function. The main benefit of this factoring is to generalize learning across actions without imposing any change to the underlying reinforcement learning algorithm. Our results show that this architecture leads to better policy evaluation in the presence of many similar-valued actions. Moreover, the dueling architecture enables our RL agent to outperform the state-of-the-art on the Atari 2600 domain.
A novel approach for sensorless control of PM machines down to zero speed without signal injection or special PWM technique

A novel approach is developed in this paper for sensorless control of permanent magnet (PM) machines down to zero speed without signal injection or special pulsewidth modulation (PWM) techniques. Taking advantage of the low inductance in a PM machine, the phase current ripples under a conventional PWM excitation are measured to derive the rotor position and speed. The new approach can also be used to estimate the rotor position at standstill if a minor rotor saliency exists. Neither prior knowledge of machine parameters, nor any special signal injection, is needed for the rotor position detection. Sensorless control of a PM machine based on the proposed scheme has been investigated by comprehensive computer simulations. Experimental results are presented to verify the effectiveness of the approach.
Trifluoroethylsulfonate protected monosaccharides in glycosylation reactions

A variety of sulfo-protected monosaccharide donors and acceptors were investigated in glycosylation reactions. Trifluoroethylsulfonate (SO3TFE) group was compatible with a wide range of activation conditions commonly used with fluoride, imidate, and sulfide donors. In addition, the influence of a SO3TFE group, at the critical 2-position in glycosyl donor, on the stereoselectivity of the glycosylation reaction was studied.
Pyridinium chlorochromate catalyzed oxidation of alcohols to aldehydes and ketones with periodic acid

Abstract A facile pyridinium chlorochromate (PCC) catalyzed (2 mol %) oxidation of alcohols to ketones and aldehydes using 1.05 equiv of H 5 IO 6 in acetonitrile is described here.
Structural stability of linear dynamically varying (LDV) controllers

Abstract LDV systems are linear systems with parameters varying according to a nonlinear dynamical system. This paper examines the robust stability of such systems in the face of perturbations of the nonlinear system. Three classes of perturbations are examined: differentiable functions, Lipschitz continuous functions and continuous functions. It is found that in the first two cases the system remains stable. Whereas, if the perturbations are among continuous functions, the closed-loop may not be asymptotically stable, but, instead, is asymptotically bounded with the diameter of the residual set bounded by a function that is continuous in the size of the perturbation. It is also shown that in the case of differential perturbations, the resulting optimal LDV controller is continuous in the size of the perturbation. An example is presented that illustrates the continuity of the variation of the controller in the case of a nonstructurally stable dynamical system.
Controlling Buildings: A New Frontier in Feedback

The protection of civil structures, including their material contents and human occupants, is without doubt a worldwide priority of the most serious current importance. Such protection may range from reliable operation and comfort, on the one hand, to survivability on the other. Examples of such structures leap to one's mind, and include buildings, offshore rigs, towers, roads, bridges, and pipelines. In like manner, events that cause the need for such protective measures are earthquakes, winds, waves, traffic, lightning, and-today, regrettably-deliberate acts. Indications are that control methods will be able to make a genuine contribution to this problem area, which is of great economic and social importance. In this article, we review the rapid recent developments which have been occurring in the area of controlled civil structures, including full-scale implementations, actuator types and characteristics, and trends toward the incorporation of more modern algorithms and technologies.
Fear itself: The effects of distressing economic news on birth outcomes.

I use new administrative data on mass layoffs and plant closings to study the effects of distressing economic news. Exposure to stressful events during pregnancy can impair fetal development. I find that announcement of impending job losses leads to a transient decrease in the mean birth weight within the firm's county one to four months before the job losses. A loss of 500 jobs corresponds roughly to a decrease of 15–20 g and 16 percent greater risk of low birth weight. Layoffs announced late in pregnancy are most strongly linked to decreased birth outcomes.