cssi/SciSciGPT-SciSciNet huggingface dataset:
Effluent mixing zone in a shallow river

A case study was made for a low momentum cooling water plume discharged from the shore into a very shallow river. The maximum width, maximum length, and enclosed surface area of a mixing zone were determined as a function of dilution ratio, discharge to river flow ratio and weather parameters. Theoretical results and extensive field data were reduced to dimensionless relationships given in either graphical or analytical form. From these relationships, appropriate discharge rates and discharge temperatures can be extracted easily for a given riverflow and for specified temperature constraints imposed, e.g., in midstream. It is advocated that similar site-specific information and operational aides can be prepared for any outfall and are necessary to assess the all-time impact of an effluent on a water body.
How important is weight symmetry in backpropagation

Gradient backpropagation (BP) requires symmetric feedforward and feedback connections—the same weights must be used for forward and backward passes. This "weight transport problem" (Grossberg 1987) is thought to be one of the main reasons to doubt BP's biologically plausibility. Using 15 different classification datasets, we systematically investigate to what extent BP really depends on weight symmetry. In a study that turned out to be surprisingly similar in spirit to Lillicrap et al.'s demonstration (Lillicrap et al. 2014) but orthogonal in its results, our experiments indicate that: (1) the magnitudes of feedback weights do not matter to performance (2) the signs of feedback weights do matter—the more concordant signs between feedforward and their corresponding feedback connections, the better (3) with feedback weights having random magnitudes and 100% concordant signs, we were able to achieve the same or even better performance than SGD. (4) some normalizations/stabilizations are indispensable for such asymmetric BP to work, namely Batch Normalization (BN) (Ioffe and Szegedy 2015) and/or a "Batch Manhattan" (BM) update rule.
Using market finance to extend water supply services in peri-urban and rural Kenya

This smart lesson explains how donor funds have been used to leverage domestic market finance and equity for investment in small piped water infrastructure in the peri-urban and rural areas of Kenya. Given the immense pressure on government and donor resources to achieve the Millennium Development Goals (MDGs), this approach shows that leveraging donor funds not only increases the volume of investments financed but improves the sustainability of these investments by linking debt service to system functionality.
The Miner's Dilemma

An open distributed system can be secured by requiring participants to present proof of work and rewarding them for participation. The Bit coin digital currency introduced this mechanism, which is adopted by almost all contemporary digital currencies and related services. A natural process leads participants of such systems to form pools, where members aggregate their power and share the rewards. Experience with Bit coin shows that the largest pools are often open, allowing anyone to join. It has long been known that a member can sabotage an open pool by seemingly joining it but never sharing its proofs of work. The pool shares its revenue with the attacker, and so each of its participants earns less. We define and analyze a game where pools use some of their participants to infiltrate other pools and perform such an attack. With any number of pools, no-pool-attacks is not a Nash equilibrium. We study the special cases where either two pools or any number of identical pools play the game and the rest of the participants are uninvolved. In both of these cases there exists an equilibrium that constitutes a tragedy of the commons where the participating pools attack one another and earn less than they would have if none had attacked. For two pools, the decision whether or not to attack is the miner's dilemma, an instance of the iterative prisoner's dilemma. The game is played daily by the active Bit coin pools, which apparently choose not to attack. If this balance breaks, the revenue of open pools might diminish, making them unattractive to participants.
The demand for, and impact of, youth internships : evidence from a randomized experiment in Yemen

This paper evaluates a youth internship program in the Republic of Yemen that provided firms with a 50 percent subsidy to hire recent graduates of universities and vocational schools. The first round of the program took place in 2014 and required both firms and youth to apply for the program. The paper examines the demand for such a program, and finds that in the context of an economy facing substantial political and economic uncertainty, it appears there is an oversupply of graduates in science, technology, engineering, and mathematics, and a relative undersupply of graduates in marketing and business. Conditional on the types of graduates firms were looking to hire as interns, applicants were then randomly chosen for the program. Receiving an internship resulted in an almost doubling of work experience in 2014, and a 73 percent increase in income during this period compared with the control group. A short-term follow-up survey conducted just as civil conflict was breaking out shows that internship recipients had better employment outcomes than the control group in the first five months after the program ended.
Can minimum wages close the gender wage gap ? evidence from Indonesia

Using manufacturing plant-level census data, this paper demonstrates that minimum wage increases in Indonesia reduced gender wage gaps among production workers, with heterogeneous impacts by level of education and position of the firm in the wage distribution. Paradoxically, educated women appear to have benefitted the most, particularly in the lower half of the firm average earnings distribution. By contrast, women who did not complete primary education did not benefit on average, and even lost ground in the upper end of the earnings distribution. Minimum wage increases were thus associated with exacerbated gender pay gaps among the least educated, and reduced gender gaps among the best educated production workers. Unconditional quantile regression analysis attests to wage compression and lighthouse effects. Changes in relative employment prospects were limited.
Demand-driven propagation : evidence from the great recession

This paper provides empirical evidence for the Keynesian demand-driven propagation: initial rounds of job losses lead to additional rounds of job losses. The paper shows that U.S. counties with higher pre-existing exposure to tradable industries experienced larger job losses in non-tradable sectors during the Great Recession. This was arguably because laid-off tradable workers cut their consumption, which hurts local non-tradable firms. The finding is not driven by exposure to the construction sector, by the collapse in house prices, or by credit supply problems. In addition, the spillover is stronger when the focus is on the job losses of more income-elastic non-tradable sectors.
Inversion of high‐rate (1 sps) GPS data for rupture process of the 11 March 2011 Tohoku earthquake (Mw 9.1)

[1] The space-time fault displacement history of the 11 March 2011 Tohoku (Mw 9.1) megathrust earthquake is obtained by least-squares inversion of high-rate (1 sample per second) GPS ground motions recorded in Japan. Complete near-source time-varying and static ground motions for periods ≥25 s are fit in the inversion using a normal mode formalism to compute the Green functions. The basic rupture pattern is stable for various choices of model parameters and solution smoothing, and excellent fits to the complete seismo-geodetic ground motions are obtained. The preferred solution has concentrations of slip near the trench and hypocenter, with sub-fault source time function durations of ∼30–70 s and maximum slip of ∼60 m. Down-dip slip spreads over a wider area with smaller maximum slip (<∼10–15 m). Inversion of the high-rate GPS data exploits both the timing and total displacement information in the ground motions, yielding stable estimates of the seismic moment (∼4.8 × 1022 Nm; Mw = 9.1) and slip distribution.
Virtual coordinates with backtracking for void traversal in geographic routing

Geographical routing protocols have several desirable features for use in ad hoc and sensor networks but are susceptible to voids and localization errors. Virtual coordinate systems which overlay a coordinate system on the nodes offer an alternative that is more resilient to localization errors. However, we show that it is vulnerable to different forms of the void problem where packets reach nodes with no viable next hop in the forwarding set. In addition, it is possible for nodes with the same coordinates to arise at different points in the network in the presence of voids. This paper identifies and analyzes these problems. It also compares several existing routing protocols based on Virtual Coordinate systems. Finally, we propose a routing algorithm that uses geographic routing in the greedy phase and virtual coordinates with backtracking to overcome voids and achieve high connectivity in the greedy phase with higher overall path quality and more resilience to localization errors. We demonstrate these properties using extensive simulation studies.
Essential circles and Gromov–Hausdorff convergence of covers

The δ-covers of Sormani–Wei ([20]) are known not to be “closed” with respect to Gromov–Hausdorff convergence. In this paper we use the essential circles introduced in [19] to define a larger class of covering maps of compact geodesic spaces called “circle covers” that are “closed” with respect to Gromov–Hausdorff convergence and include δ-covers. In fact, we use circle covers to completely understand the limiting behavior of δ-covers. The proofs use the descrete homotopy methods developed by Berestovskii, Plaut, and Wilkins, and in fact we show that when δ = 3e 2, the Sormani–Wei δ-cover is isometric to the Berestovskii–Plaut–Wilkins e-cover. Of possible independent interest, our arguments involve showing that “almost isometries” between compact geodesic spaces result in explicitly controlled quasi-isometries between their e-covers. Finally, we use essential circles to strengthen a theorem of E. Cartan by finding a new (even for compact Riemannian manifolds) finite set of generators of the fundamental gro...
Violence, Aggression, and Ethics: The Link Between Exposure to Human Violence and Unethical Behavior

Can exposure to media portrayals of human violence impact an individual’s ethical decision making at work? Ethical business failures can result in enormous financial losses to individuals, businesses, and society. We study how exposure to human violence—especially through media—can cause individuals to make less ethical decisions. We present three experiments, each showing a causal link between exposure to human violence and unethical business behavior, and show this relationship is mediated by an increase in individual hostility levels as a result of exposure to violence. Using observational data, we then provide evidence suggesting that this relationship extends beyond the context of our experiments, showing that companies headquartered in locations marked by greater human violence are more likely to fraudulently misstate their financial statements and exhibit more aggressive financial reporting. Combined, our results suggest that exposure to human violence has significant and real effects on an individual’s ethical decision making.
Robust passenger itinerary planning using transit AVL data

Automatic vehicle location (AVL) data can be used for a variety of operational and planning purposes at a transit agency. One possible application is for passenger itinerary planning, where the passenger seeks to go from an origin to a destination in some "optimal" way. The AVL data give actual vehicle arrival and departure times, which in turn can give more robust itineraries to passengers. A method to determine such robust itineraries is described, and an example of the bus network in Tucson, Arizona (USA) is used to illustrate the method. Advantages of this method over traditional itinerary planning methods are also outlined.
Policy improvement for POMDPs using normalized importance sampling

We present a new method for estimating the expected return of a POMDP from experience. The estimator does not assume any knowledge of the POMDP, can estimate the returns for finite state controllers, allows experience to be gathered from arbitrary sequences of policies, and estimates the return for any new policy. We motivate the estimator from function-approximation and importance sampling points-of-view and derive its bias and variance. Although the estimator is biased, it has low variance and the bias is often irrelevant when the estimator is used for pair-wise comparisons. We conclude by extending the estimator to policies with memory and compare its performance in a greedy search algorithm to the REINFORCE algorithm showing an order of magnitude reduction in the number of trials required.
The potential of translational bioinformatics approaches for pharmacology research

The field of bioinformatics has allowed the interpretation of massive amounts of biological data, ushering in the era of ‘omics’ to biomedical research. Its potential impact on pharmacology research is enormous and it has shown some emerging successes. A full realization of this potential, however, requires standardized data annotation for large health record databases and molecular data resources. Improved standardization will further stimulate the development of system pharmacology models, using translational bioinformatics methods. This new translational bioinformatics paradigm is highly complementary to current pharmacological research fields, such as personalized medicine, pharmacoepidemiology and drug discovery. In this review, I illustrate the application of transformational bioinformatics to research in numerous pharmacology subdisciplines.
The energy budget for X‐ray to infrared reprocessing in Compton‐thin and Compton‐thick active galaxies

Heavily obscured active galactic nuclei (AGNs) play an important role in contributing to the cosmic X-ray background (CXRB). However, the AGNs found in deep X-ray surveys are often too weak to allow direct measurement of the column density of obscuring matter. One method adopted in recent years to identify heavily obscured, Compton-thick AGNs under such circumstances is to use the observed mid-infrared-to-X-ray luminosity ratio as a proxy for the column density. This is based on the supposition that the amount of energy lost by the illuminating X-ray continuum to the obscuring matter and reprocessed into infrared emission is directly related to the column density and that the proxy is not sensitive to other physical parameters of the system (aside from contamination by dust emission from, for example, star-forming regions). Using Monte Carlo simulations, we find that the energy losses experienced by the illuminating X-ray continuum in the obscuring matter are far more sensitive to the shape of the X-ray continuum and to the covering factor of the X-ray reprocessor than they are to the column density of the material. Specifically we find that it is possible for the infrared to X-ray luminosity ratio for a Compton-thin source to be just as large as that for a Compton-thick source even without any contamination from dust. Since the intrinsic X-ray continuum and covering factor of the reprocessor are poorly constrained from deep X-ray survey data, we conclude that the mid-infrared-to-X-ray luminosity ratio is not a reliable proxy for the column density of obscuring matter in AGNs even when there is no other contribution to the mid-infrared luminosity aside from X-ray reprocessing. This conclusion is independent of the geometry of the obscuring matter.
What Regulatory Frameworks are More Conducive to Mobile Banking? Empirical Evidence from Findex Data

Mobile banking services offer great potential to expand financial services, particularly payment services, to the poor. They also provide a convenient and cost effective way to access bank accounts. This paper constitutes a first attempt to explain statistically what factors contribute to mobile banking usage, with a particular focus on the regulatory framework. The authors construct an index that measures the existence of laws and regulation that support mobile banking activity for 35 countries. Using variations in regulatory environments across these countries and armed with newly released data on mobile banking usage by approximately 37,000 individuals in these 35 countries, the paper sheds light on the importance of laws and regulation in supporting mobile banking. The analysis finds that a supporting regulatory framework is associated with higher usage of mobile banking for the general population as well as for the unbanked.
The learning curve and factors affecting warm ischemia time during robot-assisted partial nephrectomy.

Introduction: The learning curve for robotic partial nephrectomy was investigated for an experienced laparoscopic surgeon and factors associated with warm ischemia time (WIT) were assessed. Materials and Methods: Between 2007 and 2014, one surgeon completed 171 procedures. Operative time, blood loss, complications and ischemia time were examined to determine the learning curve. The learning curve was defined as the number of procedures needed to reach the targeted goal for WIT, which most recently was 20 min. Statistical analyses including multivariable regression analysis and matching were performed. Results: Comparing the first 30 to the last 30 patients, mean ischemia time (23.0-15.2 min, P Conclusions: Adoption of robotic assistance for a surgeon experienced with laparoscopic surgery was associated with low complication rates even during the initial cases of robot-assisted partial nephrectomy. Ischemia time decreased while no significant changes in blood loss, operating time or complications were seen. The largest decrease in ischemia time was associated with adopting evidence-based goals and new techniques, and was not felt to be related to a learning curve.
Consumption Dynamics, Asset Pricing, and Welfare Effects under Information Processing Constraints

This paper studies consumption dynamics, asset returns and optimal portfolio choice, and welfare losses under information processing constraints (it is also called rational inattention (RI) in Sims (2003).) in two canonical macroeconomic models: the permanent income hypothesis model (PIH) and the consumption-based capital asset pricing model (CCAPM). It is shown that incorporating RI into these otherwise standard macroeconomic models can provide an additional propagation mechanism and largely affect the intertemporal allocation of consumption, which makes the models better explain the data in some important aspects. The main contributions of this paper are: Þrst, we propose a tractable analytical approach to solve the multivariate LQ or approximate LQ models with information constraints; second, given the closed-form solutions, we address a variety of consumption and asset pricing puzzles, and show how incorporating RI may resolve these puzzles in the correct direction; third, we Þnd that the utility costs due to deviating from the Þrst best instantly adjusted path are very trivial, which can rationalize a key assumption in Sims (2003) that consumers only devote small fractions of their capacity in observing and processing information; Þnally, we compare the RI model with the habit formation model. In addition, we consider the extension to the risk-sensitive PIH model, in which the risk-sensitive preference combined with labor income uncertainty generates precautionary savings motive and then allows us to examine the effects of RI on both precautionary savings and the marginal propensity to consume out of income.
Analysis of quasi-optimal polynomial approximations for parameterized PDEs with deterministic and stochastic coefficients

In this work, we present a generalized methodology for analyzing the convergence of quasi-optimal Taylor and Legendre approximations, applicable to a wide class of parameterized elliptic PDEs with finite-dimensional deterministic and stochastic inputs. Such methods construct an optimal index set that corresponds to the sharp estimates of the polynomial coefficients. Our analysis, furthermore, represents a novel approach for estimating best M-term approximation errors by means of coefficient bounds, without the use of the standard Stechkin inequality. In particular, the framework we propose for analyzing asymptotic truncation errors is based on an extension of the underlying multi-index set into a continuous domain, and then an approximation of the cardinality (number of integer multi-indices) by its Lebesgue measure. Several types of isotropic and anisotropic (weighted) multi-index sets are explored, and rigorous proofs reveal sharp asymptotic error estimates in which we achieve sub-exponential convergence rates [of the form $$M \text {exp}({-(\kappa M)^{1/N}})$$ , with $$\kappa $$ a constant depending on the shape and size of multi-index sets] with respect to the total number of degrees of freedom. Through several theoretical examples, we explicitly derive the constant $$\kappa $$ and use the resulting sharp bounds to illustrate the effectiveness of Legendre over Taylor approximations, as well as compare our rates of convergence with current published results. Computational evidence complements the theory and shows the advantage of our generalized framework compared to previously developed estimates
Pd2@Sn184-: Fusion of Two Endohedral Stannaspherenes

Stannaspherene refers to an icosahedral 12-atom Sn cage cluster (Sn122-) and has also been found to be able to trap all transition metals to form gaseous endohedral clusters (M@Sn12-). During exploratory solution syntheses of endohedral stannaspherenes, a new closo-deltahedral cluster, Pd2@Sn184-, has been isolated as a (2,2,2-crypt)K+ salt through the reaction of K4Sn9 and Pd[P(C6H5)3]4 in ethylenediamine solutions and characterized via X-ray crystallography. The new Pd2@Sn184- cluster has pseudo-D3d symmetry and is composed of 18 Sn atoms encapsulating two Pd atoms. It can be viewed as the fusion of two endohedral stannaspherenes (Pd@Sn122-) along their C3 axis by removing a Sn3 triangle on each Sn12 unit at the cluster−cluster interface. Electronic structure calculations show that Pd2@Sn184- consists of a Sn184- cage with two zero-valent Pd atoms and possesses a highly stable electronic configuration.
Central quotients of biautomatic groups

The quotient of a biautomatic group by a subgroup of the center is shown to be biautomatic. The main tool used is the Neumann-Shapiro triangulation of Sn-1, associated to a biautomatic structure on \({\bf Z}^n\). Among other applications, a question of Gersten and Short is settled by showing that direct factors of biautomatic groups are biautomatic.
Matching with Stochastic Arrival

We study matching in a dynamic setting, with applications to the allocation of public housing. In our model, objects of different types that arrive stochastically over time must be allocated to agents in a queue. For the case that the objects share a common priority ordering over agents, we introduce a strategy-proof mechanism that satisfies certain fairness and efficiency properties. More generally, we show that the mechanism continues to satisfy these properties if and only if the priority relations satisfy an acyclicity condition. We then turn to an application of the framework by evaluating the procedures that are currently being used to allocate public housing. The estimated welfare gains from adopting the new mechanism are substantial, exceeding $5,000 per applicant.
Design of Digital Loaded-Line Phase-Shift Networks for Microwave Thin-Film Applications

This paper describes the design approach, fabrication techniques, and electrical performance for two types of microwave hybrid thin-film phase shifters. Emphasisis placed on the practical aspects of the overall design and fabrication. A simplified set of design equations for loaded-line phase-shift networks is presented and divided into three categories based on the type of loading employed. The two circuits presented are a 4-bit 90 /spl deg/ network employing single-section multibits to minimize physical size, and a 4-bit 360 /spl deg/ network employing the 45 /spl deg/ section as a basic building block.
Far-Infrared and Submillimeter Polarization of OMC-1 Evidence for Magnetically Regulated Star Formation

This paper presents large-scale polarization maps (8' × 8') of the Orion molecular cloud (OMC-1) at far-infrared (100 μm; 35'' resolution) and submillimeter (350 μm; 18'' resolution) wavelengths. The magnetic field shows a pinch at scales less than 0.5 pc with a centroid that is on the OMC-1 ridge, a site of high-mass star formation. We infer that gravitational collapse pulled the magnetic field into an hourglass shape. We estimate that the magnetic, kinetic, and gravitational energies are in equipartition on the ridge and that the magnetic energy dominates in the surrounding ambient envelope. We consider a model in which the ridge and thus high-mass stars gravitationally collapsed out of a cloud that was initially supported by the magnetic field. At flux peaks, there is a reduction in the percent polarization. This effect is discussed in relation to temperature, optical depth, and wavelength.
Energetics and Crystal Chemical Systematics among Ilmenite, Lithium Niobate, and Perovskite Structures

Transitions from chain silicates to garnet, ilmenite, and perovskite structures are important in deep earth geophysics and solid-state chemistry. Titanates and other oxides also show polymorphism among ilmenite, lithium niobate (metastable), and perovskite structures. This review brings together the evidence from the recent mineralogical and materials science literature linking the crystal chemistry, thermodynamics, and occurrence of these polymorphs at high pressure and temperature. A-site ordered multicomponent titanate perovskites are also discussed. A common feature of the perovskite structure is its high vibrational entropy.
Rapid x-ray variability of neutron stars in low-mass binary systems

The dramatic discovery with the Rossi X-Ray Timing Explorer satellite of remarkably coherent ∼300–1200 Hz oscillations in the X-ray brightness of some sixteen neutron stars in low-mass binary systems has spurred theoretical modeling of these oscillations and investigation of their implications for the neutron stars and accretion flows in these systems. High-frequency oscillations are observed both during thermonuclear X-ray bursts and during intervals of accretion-powered emission and appear to be a characteristic feature of disk-accreting neutron stars with weak magnetic fields. In this review we focus on the high-frequency quasi-periodic oscillations (QPOs) seen in the accretion-powered emission. We first summarize the key properties of these kilohertz QPOs and then describe briefly the models that have been proposed to explain them. The existing evidence strongly favors beat-frequency models. We mention several of the difficulties encountered in applying the magnetospheric beat-frequency model to the kilohertz QPOs. The most fully developed and successful model is the sonic-point beat-frequency model. We describe the work on this model in some detail. We then discuss observations that could help to distinguish between models. We conclude by noting some of the ways in which study of the kilohertz QPOs may advance our understanding of dense matter and strong gravitational fields.
Reconstruction at ordered Au(110)-aqueous interfaces as probed by atomic-resolution scanning tunneling microscopy.

Atomic-resolution scanning-tunneling-microscopy images of ordered Au(110) in aqueous 0.1M ${\mathrm{HClO}}_{4}$, reported as a function of electrode potential, provide an unusually detailed picture of surface reconstruction. Lowering the potential of a freshly annealed surface to -0.3 versus saturated calomel electrode (SCE) yield images consisting primarily of domains having (1\ifmmode\times\else\texttimes\fi{}2) symmetry. While the (1\ifmmode\times\else\texttimes\fi{}2) structure exhibits an atomic density commensurate with the usual ``missing-row'' model, the images suggest that significant relaxation of both top- and second-layer atoms occurss. Three-atom-wide ribbons, lying along the [11\ifmmode\bar\else\textasciimacron\fi{}0] direction, are seen to provide the basic building blocks of the reconstruction; these units also yield ``added-row'' domains of (1\ifmmode\times\else\texttimes\fi{}n) symmetry, with n=3 or higher. The reconstruction is lifted, yielding the (1\ifmmode\times\else\texttimes\fi{}1) Au(110) surface, rapidly (within \ensuremath{\sim}2 s) upon altering the potential to 0 V vs SCE, yet reappears immediately upon returning to -0.3 V.
A Survey for ``Normal'' Irregular Satellites around Neptune: Limits to Completeness

We surveyed 1.75 deg2 of sky near Neptune to an R-band 50% detection efficiency of 25.8 mag (corresponding to radii of about 17 km for an assumed albedo of 0.04). We discovered one new outer satellite, Psamathe (S/2003 N1), about 20 km in radius with a distant retrograde orbit and moderate eccentricity. Until 2003 Neptune was only known to have two satellites that exhibited orbital signatures indicative of capture. Both of these, Triton and Nereid, are unusual when compared to the irregular satellites of other giant planets. With recent discoveries of four additional satellites by Holman et al. it is now apparent that Neptune has a distant "normal" irregular satellite system in which the satellites have radii and orbital properties similar to those of the satellites of other giant planets. We find that the satellite size distribution at Neptune is not well determined given the few objects known to date, being especially sensitive to the inclusion of Triton and Nereid in the sample. Finally, we note that Psamathe and S/2002 N4 have similar semimajor axes, inclinations, and eccentricities. They may be fragments of a once-larger satellite.
Method for distributed transaction commit and recovery using Byzantine Agreement within clusters of processors

This paper describes an application of Byzantine Agreement [DoSt82a, DoSt82e, LyFF82] to distributed transaction commit. We replace the second phase of one of the commit algorithms of [MoLi83] with Byzantine Agreement, providing certain trade-offs and advantages at the time of commit and providing speed advantages at the time of recovery from failure. The present work differs from that presented in [DoSt82b] by increasing the scope (handling a general tree of processes, and multi-cluster transactions) and by providing an explicit set of recovery algorithms. We also provide a model for classifying failures that allows comparisons to be made among various proposed distributed commit algorithms. The context for our work is the Highly Available Systems project at the IBM San Jose Research Laboratory [AAF-KM83].
Improving food environments in schools: tracking progress.

Making positive changes in the types of foods available to children in schools has the potential to have a substantial impact on their dietary intakes and the prevalence of childhood obesity. Although federal regulation requires that school districts have policies about all foods offered on school campuses and many states have enacted their own policies, research on the implementation and impact of policies that target competitive foods is just beginning to emerge. Researchers working in this area should carefully examine the rigor of policies under study as well as implementation of the policies at the school level. The use of a common set of tools to measure policy rigor and the types of foods available would enhance this important area of research and should be encouraged.
An introduction to stochastic unit-root processes

Abstract A class of nonlinear processes which have a root that is not constant, but is stochastic, and varying around unity is introduced. The process can be stationary for some periods, and mildly explosive for others. Stochastic unit roots are seen to arise naturally in economic theory, as well as in everyday macroeconomic applications. It is shown that standard tests, such as the augmented Dickey-Fuller test, cannot easily distinguish between exact unit roots and stochastic unit roots. An alternative test which has difference stationarity as the null suggests that exact unit-root models are often rejected in favor of more general nonlinear stochastic unit-root (STUR) models. Estimation is discussed, and, a forecast comparison of linear random walk and AR(p) models, time-varying parameter models, and STUR models suggests that this new class of processes is potentially useful, particularly when the objective is multi-step ahead forecasting.
Dihadron fragmentation: In vacuum and in matter

Two particle correlations within a single jet produced in deeply inelastic scattering (DIS) off a large nucleus as well as in heavy-ion collisions are explored. These are performed within the framework of the medium modified dihadron fragmentation functions. The modification occurs due to gluon bremsstrahlung induced by multiple scattering. The modified fragmentation functions for dihadrons are found to follow closely that of single hadrons leading to a weak nuclear suppression of their ratios as measured by HERMES in DIS experiments. Meanwhile, a moderate medium enhancement of the near-side correlation of two high pT hadrons is found in central heavy-ion collisions, partially due to trigger bias caused by the competition between parton energy loss and the initial Cronin effect.
Validity of the bead-spring model for describing the linear viscoelastic properties of single-strand DNA under strongly denaturing conditions

Using a normal mode analysis, we predict the infinite dilution linear viscoelastic properties of single-strand (ss) DNA molecules and compare the results to the linear viscoelastic data of Shusterman et al. (Phys Rev Let 92(4):048303, 2004) obtained by monitoring the diffusion of a fluorescently labeled terminus of the molecule. To compute the overall best global fit, we constrain the hydrodynamic interaction parameter, h*, equilibrium root mean square spring extension, b, and the number of Kuhn steps per spring, N K,S, to be equal for the strands compared. The fits using the bead-spring model for all but 23,100 base ss-DNA strands match the experimental data at long times with significant deviations at intermediate and short times. However, parameters fitted separately to all individual strand lengths predict results well. The best fits to data for 2,400 and 6,700 base pairs yield N K,S ∼12 and h* = 0.12. These values are similar to those found for conventional polymers such as polystyrene which have been successfully modeled with N K,S ∼7 and h* = 0.15, indicating ss-DNA and polystyrene exhibit analogous hydrodynamic behavior.
Estimation of Lightning Stroke Peak Current as a Function of Peak Electric Field and the Normalized Amplitude of Signal Strength: Corrections and Improvements

Corrections and improvements have been made to published equations relating return stroke peak current and peak electric field for cloud-to-ground lightning. The original equations were derived from measurements made at the Rocket-Triggered-Lightning Program facility at the Kennedy Space Center in Florida. Some previous articles include errors in the conversion of equations from units of volts per meter, for peak electric field, into Lightning Location and Protection units, representing normalized signal strength amplitude. This article presents the proper conversion procedure and the resultant corrected equations. Furthermore, equations are presented that were produced by converting other published relationships. Finally, we combined 1985--1988 RTLP data to produce equations based on more data than has been used previously; the resulting equation for peak current as a function of normalized signal strength amplitude supports previous evidence that the slope should be near 0.2 for a zero intercept. All relationships are tabulated, and three are graphically compared against the data.
Diminished or Just Different? A Factorial Vignette Study of Privacy as a Social Contract

A growing body of theory has focused on privacy as being contextually defined, where individuals have highly particularized judgments about the appropriateness of what, why, how, and to whom information flows within a specific context. Such a social contract understanding of privacy could produce more practical guidance for organizations and managers who have employees, users, and future customers all with possibly different conceptions of privacy across contexts. However, this theoretical suggestion, while intuitively appealing, has not been empirically examined. This study validates a social contract approach to privacy by examining whether and how privacy norms vary across communities and contractors. The findings from this theoretical examination support the use of contractual business ethics to understand privacy in research and in practice. As predicted, insiders to a community had significantly different understandings of privacy norms as compared to outsiders. In addition, all respondents held different privacy norms across hypothetical contexts, thereby suggesting privacy norms are contextually understood within a particular community of individuals. The findings support two conclusions. First, individuals hold different privacy norms without necessarily having diminished expectations of privacy. Individuals differed on the factors they considered important in calculating privacy expectations, yet all groups had robust privacy expectations across contexts. Second, outsiders have difficulty in understanding the privacy norms of a particular community. For managers and scholars, this renders privacy expectations more difficult to identify at a distance or in deductive research. The findings speak directly to the needs of organizations to manage a diverse set of privacy issues across stakeholder groups.
Galaxy Populations and Evolution in Clusters. III. The Origin of Low-Mass Galaxies in Clusters: Constraints from Stellar Populations

Low-mass galaxies in nearby clusters are the most numerous galaxy type in the universe, yet their origin and properties remain largely unknown. To study basic questions concerning these galaxies we present the results of a survey designed to constrain the characteristics and properties of the stellar populations in a magnitude-complete sample of low-mass cluster galaxies (LMCGs) in the center of the Perseus Cluster. Using deep, high-quality WIYN UBR images to obtain photometric and structural properties, we demonstrate that the 53 LMCGs in our sample have a significant scatter about the color-magnitude relationship at MB > -15. By comparing single-burst stellar population models with our photometry, we argue that stellar populations in LMCGs all have ages greater than 1 Gyr, with redder LMCGs containing stellar metallicities [Fe/H] > -0.5. By assuming that the colors of LMCGs reflect metallicity and have coevolved with the giant elliptical galaxies, we find a wide range of values, from solar to [Fe/H] about -3. We argue from this that LMCGs have multiple origins and fundamentally differ from Local Group dwarf spheroidal or elliptical galaxies. The inferred lower metallicities of the bluer LMCGs imply that these are possibly primordial galaxies formed through self-enrichment and stellar feedback provided by winds from supernovae. We also investigate several other formation scenarios for these LMCGs, including self-enrichment induced by the confinement of metals in halos by the intracluster medium, in situ formation out of intracluster gas, systems with extreme dark halos, and remnants of previously higher mass systems. We conclude that roughly half of all low-mass cluster galaxies in the center of Perseus have stellar populations and kinematic properties, as discussed in previous papers in this series, consistent with being the remnants of stripped galaxies accreted into clusters several gigayears ago.
Water-soluble polymer-bound, recoverable palladium(0)-phosphine catalysts

Abstract The synthesis of a water-soluble polymer-bound Pd(0)-phosphine catalyst is described. This soluble polymeric catalyst is soluble in aqueous or mixed aqueous/organic media and has high activity in nucleophilic allylic substitution and in sp-sp2 coupling reactions of aryl iodides with terminal alkynes. The catalyst can be recycled efficiently by solvent or thermal precipitation methods.
Dynamics of radical pair reactions in micelles

On etudie par photolyse laser pulsee le comportement des radicaux phenyl-1 ethyle, cumyle et diphenyl-methyle solubilises dans des micelles de lauryl sulfate de Na et de chlorure de palmityl trimethylammonium
A non-nested test of the AIDS vs. the translog demand system

Abstract A non-nested test is used to examine the relative explanatory power of the AIDS and translog demand system. Empirical results based on Chinese urban household data suggest that these two demand systems are not significantly different in explanatory power and elasticity estimates.
Detection and assessment of wood decay in glulam beams using a decay rate approach

A glulam beam retired from the field and without visible indications of wood decay was used. Towards detection and assessing wood decay, X-ray computer tomography and ultrasonic measurements were carried out. It was observed that decrease in mass density with increasing levels of wood decay affects x-rays attenuation and allows radioscopy to detect and assess wood decay. To detect and assess decay when only one lateral side of the beam is available, a modified impulse-echo is presented. The modified impulse-echo approach is based on observing the dynamic response of each lamina in the glulam beam to the drop of a steel sphere onto a steel plate coupled to the glulam beam lamina and upon a decay rate analysis of the corresponding time domain signal in a frequency band of interest. The selection of the frequency band of interest only requires knowledge of the nominal transverse dimensions of each lamina in the beam and of the corresponding wood species. It was observed that decay rate analysis allows detection and assessment of wood decay. The decay rate approach leads to an overall rate of false calls of 7.2%. Considering the variability that exists in wood including the presence of splits, orientation and thickness of growth rings, etc., this relative low rate of false calls makes this approach very attractive. Results show that results from both X-ray computer tomography and impulse-echo decay-rated based measurements are consistent with each other and can be used to detect and assess wood decay in structural lumber.
Commentary on Vibeke Asmussen Frank, Bagga Bjerge, and Esben Houborg: Medicalization Can Be Beneficial, But Is No Guarantee for User Influence

Denmark was for decades considered the liberal exception in Nordic drug and drug user treatment policy—the Netherlands of the north, closer to the international drug market, tolerant, and liberal. ...
Discovery of Fast X-Ray Oscillations during the 1998 Giant Flare from SGR 1900+14

We report the discovery of complex high-frequency variability during the 1998 August 27 giant flare from SGR 1900+14 using the Rossi X-Ray Timing Explorer (RXTE). We detect an ≈84 Hz quasi-periodic oscillation (QPO) during a 1 s interval beginning approximately 1 minute after the initial hard spike. The amplitude is energy-dependent, reaching a maximum of 26% (rms) for photons above 30 keV and is not detected below 11 keV, with a 90% confidence upper limit of 14% (rms). Remarkably, additional QPOs are detected in the average power spectrum of data segments centered on the rotational phase at which the 84 Hz signal was detected. Two signals, at 53.5 and 155.1 Hz, are strongly detected, while a third feature at 28 Hz is found with lower significance. These QPOs are not detected at other rotational phases. The phenomenology seen in the SGR 1900+14 flare is similar to that of QPOs recently reported by Israel et al. from the 2004 December 27 flare from SGR 1806-20, suggesting that they may have a common origin, perhaps torsional vibrations of the neutron star crust. Indeed, an association of the four frequencies (in increasing order) found in SGR 1900+14 with l = 2, 4, 7, and 13 toroidal modes appears plausible. We discuss our findings in the context of this model and show that if the stars have similar masses, then the magnetic field in SGR 1806-20 must be about twice as large as in SGR 1900+14, broadly consistent with estimates from pulse timing. We briefly discuss how mode identifications could lead to constraints on the nuclear equation of state.
The Vacuum in Nonisentropic Gas Dynamics

Abstract We investigate the vacuum in nonisentropic gas dynamics in one space variable, with the most general equation of states allowed by thermodynamics. We recall physical constraints on the equations of state and give explicit and easily checkable conditions under which vacuums occur in the solution of the Riemann problem. We then present a class of models for which the Riemann problem admits unique global solutions without vacuums.
Near-Optimal Unit Root Tests with Stationary Covariates with Better Finite Sample Size

Numerous tests for integration and cointegration have been proposed in the literature. Since Elliott, Rothemberg, and Stock (1996), the search for tests with better power has moved in the direction of finding tests with some optimality properties both in univariate and multivariate models. Although the optimal tests constructed so far have asymptotic power that is indistinguishable from the power envelope, it is well known that they can have severe size distortions in finite samples. This paper proposes a simple and powerful test that can be used to test for unit root or for no cointegration when the cointegration vector is known. Although this test is not optimal in the sense of Elliott and Jansson (2003), it has better finite sample size properties while having asymptotic power curves that are indistinguishable from the power curves of optimal tests. Similarly to Hansen (1995), Elliott and Jansson (2003), Zivot (2000), and Elliott, Jansson and Pesavento (2005) the proposed test achieves higher power by using additional information contained in covariates correlated with the variable being tested. The test is constructed by applying Hansen's test to variables that are detrended under the alternative in a regression augmented with leads and lags of the stationary covariates. Using local to unity parametrization, the asymptotic distribution of the test under the null and the local alternative is analytically computed.
GENERICITY OF FILLING ELEMENTS

An element of a finitely generated non-Abelian free group F(X) is said to be filling if that element has positive translation length in every very small minimal isometric action of F(X) on an ℝ-tree. We give a proof that the set of filling elements of F(X) is exponentially F(X)-generic in the sense of Arzhantseva and Ol'shanskii. We also provide an algebraic sufficient condition for an element to be filling and show that there exists an exponentially F(X)-generic subset consisting only of filling elements and whose membership problem has linear time complexity.