cssi/SciSciGPT-SciSciNet huggingface dataset:
Convective dispersion without molecular diffusion

Abstract A method-of-moments scheme is invoked to compute the asymptotic, long-time mean (or composite) velocity and dispersivity (effective diffusivity) of a two-state particle undergoing one-dimensional convective–diffusive motion accompanied by a reversible linear transition (“chemical reaction” or “change in phase”) between these states. The instantaneous state-specific particle velocity is assumed to depend only upon the instantaneous state of the particle, and the transition between states is assumed to be governed by spatially independent, first-order kinetics. Remarkably, even in the absence of molecular diffusion, the average transport of the “composite” particle exhibits gaussian diffusive behavior in the long-time limit, owing to the effectively stochastic nature of the overall transport phenomena induced by the interstate transition. The asymptotic results obtained are compared with numerical computations.
Recursion theory on the reals and continuous-time computation

Abstract We define a class of recursive functions on the reals analogous to the classical recursive functions on the natural numbers, corresponding to a conceptual analog computer that operates in continuous time. This class turns out to be surprisingly large, and includes many functions which are uncomputable in the traditional sense. We stratify this class of functions into a hierarchy, according to the number of uses of the zero-finding operator μ. At the lowest level are continuous functions that are differentially algebraic, and computable by Shannon's general purpose analog computer. At higher levels are increasingly discontinuous and complex functions. We relate this μ-hierarchy to the arithmetical and analytical hierarchies of classical recursion theory.
Radio and X-Ray Profiles in Supernova Remnants Undergoing Efficient Cosmic-Ray Production

The strong shocks in young supernova remnants (SNRs) should accelerate cosmic rays (CRs), and there is no doubt that relativistic electrons are produced in SNRs. However, direct and convincing evidence that SNRs produce CR nuclei has not yet been obtained and may, in fact, be long in coming if current γ-ray observatories do not see an unambiguous pion-decay feature. Nevertheless, the lack of an observed pion-decay feature does not necessarily mean that CR ions are not abundantly produced since ions do not radiate efficiently. If CR ions are produced efficiently by diffusive shock acceleration (DSA), their presence will modify the hydrodynamics of the SNR and produce morphological effects that can be clearly seen in radiation produced by electrons. We describe in some detail our CR-hydro model, which couples DSA with the remnant hydrodynamics, and the synchrotron emission expected for two distinct parameter sets representing Type Ia and Type II supernovae. Several morphological features emerge in radial profiles, including the forward shock precursor, which are observable with current X-ray observatories and should definitively show whether young SNRs produce CR ions efficiently or not. For the specific case of SN 1006 we conclude, as have others, that the extremely short X-ray scale heights observed near the outer shock argue convincingly for the efficient production of CR ions.
Supercritical fluid extraction and separation of uranium from other actinides.

Abstract The feasibility of separating U from nitric acid solutions of mixed actinides using tri-n-butylphosphate (TBP)-modified supercritical fluid carbon dioxide (sc-CO2) was investigated. The actinides U, Np, Pu, and Am were extracted into sc-CO2 modified with TBP from a range of nitric acid concentrations, in the absence of, or in the presence of, a number of traditional reducing and/or complexing agents to demonstrate the separation of these metals from U under sc-CO2 conditions. The separation of U from Pu using sc-CO2 was successful at nitric acid concentrations of less than 3 M in the presence of acetohydroxamic acid (AHA) or oxalic acid (OA) to mitigate Pu extraction, and the separation of U from Np was successful at nitric acid concentrations of less than 1 M in the presence of AHA, OA, or sodium nitrite to mitigate Np extraction. Americium was not well extracted under any condition studied.
Faint U-Band Dropouts in the WFPC2 Parallels of the Hubble Ultra Deep Field

We combine data from the extremely deep Hubble Space Telescope U (F300W) image, obtained using WFPC2 as part of the parallel observations of the Hubble Ultra Deep Field campaign, with BVi images from the Great Observatories Origins Deep Survey to identify a sample of Lyman break galaxies in the redshift range 2.0 z 3.5. We use recent stellar population synthesis models with a wide variety of ages, metallicities, redshifts, and dust content, and a detailed representation of the H I cosmic opacity as a function of redshift to model the colors of galaxies in our combination of WFPC2 and ACS filters. Using these models, we derive improved color selection criteria that provide a clean selection of relatively unobscured star-forming galaxies in this redshift range. Our WFPC2 F300W image is the deepest image ever obtained at that wavelength. The 10 σ limiting magnitude measured over 0.2 arcsec2 is 27.5 mag in the WFPC2 F300W image, about 0.5 mag deeper than the F300W image in the Hubble Deep Field (HDF)-North. This extra depth relative to the HDFs allows us to directly probe the luminosity function about 0.5 mag deeper than the depth accessible with the HDF data along an independent line of sight. Our sample of star-forming galaxies with 2.0 z 3.5 includes 125 objects, the majority of which show clumpy morphologies. We measure a star formation rate density of 0.18 M⊙ yr-1 Mpc-3, marginally higher than the value measured for the HDFs.
Integrated high-quality factor silicon-on-sapphire ring resonators for the mid-infrared

We demonstrate high-quality (Q) factor grating-coupled silicon-on-sapphire ring resonators, operating around 4.5 μm. Total Q-factors of 151,000 and intrinsic Q-factors of 278,000 are measured, enabling applications in nonlinear wavelength generation and other areas.
Household Debt and Income Distribution

Our previous work argued that the official U.S. poverty definition is flawed because it ignores interest paid on household debt. When it was developed in the early 1960s, this was not a problem because U.S. households had little consumer debt. Today, most households have considerable consumer debt and are paying high interest rates on that debt. This paper argues that what is true of poverty is likewise true of income inequality indices, such as the gini coefficient and the percentage of middle-class families. Interest payments on past debt reduce the income that households have to maintain a certain standard of living. A problem (such as a bout of unemployment, the expenses of having a new baby, or a health problem) leads to borrowing that tends to reduce household living standards in the long run. This phenomenon is not captured in standard measures of income equality. We then use the Survey of Consumer Finances to correct this problem, estimating income inequality both before and after subtracting inte...
Copper(II) Complexes of Binucleating Macrocyclic Bis(Disulfide) Tetramine Ligands

The few well-characterized examples of Cu(II)-disulfide bonding are those involving synthetic low molecular weight complexes. Suggestions in the chemical literature for the existence of disulfide-containing copper protein active sites have been limited to stellacyanin, a blue copper protein that is devoid of methionine residues and thus cannot have the customary axial thioether ligation. This possibility of disulfide ligation has been considered in detail and shown to be unlikely based upon a structural study of cucumber basic blue protein, which shares considerable sequence homologies with stellacyanin.1 Spectroscopic studies have led to suggestions that an amide croup substitutes for the usual methionine ligation,1 and a recent pulsed endor study2 of the high pH form of stellacyanin indicates that the active site unit is Cu(II)[N(His)2]S(Cys)N(deprotonated amide). Structurally characterized examples of Cu(II)-disulfide bonding are limited to three binuclear complexes3–5 and one polymeric complex6 that all feature Cu(H) ions weakly interacting with apical disulfide groups. The reported Cu(II)-S (disulfide) bond distances are 3.057(10) and 3.138(9)A,3 3.16(1) and 3.28(10)A,4 2.721(3)A,5 and 2.678(2)A.6 On the basis of an electronic absorption at 330 nm assigned as Cu(n)→disulfide CT, equatorial Cu(II)-disulfide bonding was proposed for the solution complex formed from CuCl2 and bis[2-(2-pyridylmethylamino)ethyl]disulfide.7 This ligand is pentadentate towards Ni(II). The equatorial Ni-(S)disulfide bond distance is 2.472(5)A, and the sixth coordination site of Ni(H) is occupied by a chloride ion.8
Greedy Algorithms Make Efficient Mechanisms

We study mechanisms that use greedy allocation rules and pay-your-bid pricing to allocate resources subject to a matroid constraint. We show that all such mechanisms obtain a constant fraction of the optimal welfare at any equilibrium of bidder behavior, via a smoothness argument. This unifies numerous recent results on the price of anarchy of simple auctions. Our results extend to polymatroid and matching constraints, and we discuss extensions to more general matroid intersections.
Admissibility criteria for propagating phase boundaries in a van der Waals fluid

Abstract : This paper gives admissibility criteria for weak solutions to the partial differential equations governing isothermal motion of a van der Waals fluid. The main issue is that an admissibility criterion based on viscosity alone is too restrictive - it rules out all slowly propagating phase boundaries. Instead a criterion based on viscosity and capillarity is proposed. The viscosity-capillarity condition is studied and shown to imply that the state on one side of a phase boundary specifies both the speed of the phase boundary and the state of the other side of the phase boundary (a result which is different from classical gas dynamics).
Aphasia with left occipitotemporal hypometabolism: A novel presentation of posterior cortical atrophy?

Alzheimer's disease is a common neurodegenerative disease often characterized by initial episodic memory loss. Atypical focal cortical presentations have been described, including the logopenic variant of primary progressive aphasia (lvPPA) which presents with language impairment, and posterior cortical atrophy (PCA) which presents with prominent visuospatial deficits. Both lvPPA and PCA are characterized by specific patterns of hypometabolism: left temporoparietal in lvPPA and bilateral parietoccipital in PCA. However, not every patient fits neatly into these categories. We retrospectively identified two patients with progressive aphasia and visuospatial deficits from a speech and language based disorders study. The patients were further characterized by MRI, fluorodeoxyglucose F18 and Pittsburgh Compound B (PiB) positron emission tomography. Two women, aged 62 and 69, presented with a history of a few years of progressive aphasia characterized by fluent output with normal grammar and syntax, anomia without loss of word meaning, and relatively spared repetition. They demonstrated striking deficits in visuospatial function for which they were lacking insight. Prominent hypometabolism was noted in the left occipitotemporal region and diffuse retention of PiB was noted. Posterior cortical atrophy may present focally with left occipitotemporal metabolism characterized clinically with a progressive fluent aphasia and prominent ventral visuospatial deficits with loss of insight.
Attainment of Gigavolt Potentials by Fluid Dynamic Suppression of the Stepped Leader—Its Significance for Thermonuclear Ignition

It is proposed to levitate a conducting sphere in a high pressure Taylor flow and to charge it up to gigavolt potentials, either mechanically as in a Van de Graaff electrostatic generator, or inductively by a rising magnetic field. If the Taylor flow is sufficiently fast, it should overcome the electric pressure and breakdown by stepped leader formation, leading to the maximum attainable voltage by the Paschen law. Discharging the electro-statically stored energy can be done by controlled breakdown. With gigajoule energies stored and released in about 10−8 s, this implies and electric pulse power of the order 1017 W, opening the prospect of large driver energies for thermonuclear ignition.
Bogomol'nyi solitons and Hermitian symmetric spaces

Abstract We apply the coadjoint orbit method to construct relativistic nonlinear sigma models (NLSM) on the target space of coadjoint orbits coupled with the Chern-Simons (CS) gauge field and we study self-dual solitons. When the target space is given by a Hermitian symmetric space (HSS), we find that the system admits self-dual solitons whose energy is Bogomol'nyi bounded from below by a topological charge. The Bogomol'nyi potential on the Hermitian symmetric space is obtained in the case when the maximal torus subgroup is gauged, and the self-dual equation in the CP ( N − 1) case is explored. We also discuss the self-dual solitons in the case of noncompact SU (1, 1) and present a detailed analysis for the rotationally symmetric solutions.
The approach of Otto-Reznikoff revisited

In this article we consider a lattice system of unbounded continuous spins. Otto and Reznikoff used the two-scale approach to show that exponential decay of correlations yields a logarithmic Sobolev inequality (LSI) with uniform constant in the system size. We improve their statement by weakening the assumptions, for which a more detailed analysis based on two new ingredients is needed. The two new ingredients are a covariance estimate and a uniform moment estimate. We additionally provide a comparison principle for covariances showing that the correlations of a conditioned Gibbs measure are controlled by the correlations of the original Gibbs measure with ferromagnetic interaction. This comparison principle simplifies the verification of the hypotheses of the main result. As an application of the main result we show how sufficient algebraic decay of correlations yields the uniqueness of the infinite-volume Gibbs measure, generalizing a result of Yoshida from finite-range to infinite-range interaction.
A Remarkably Efficient Synthesis of Pure cis-Stilbenoid Hydrocarbons Using trans-Dibromoalkenes via Palladium Catalysis

A remarkably versatile synthesis of cis-stilbenoid hydrocarbons containing highly functionalized phenyl groups is developed via an efficient palladium-catalyzed coupling of aryl Grignard reagents with trans-1,2-dibromoalkenes (generally obtained via bromination of the corresponding dialkylacetylenes) in tetrahydrofuran.
Total factor productivity and the convergence hypothesis

Abstract We study the convergence, or lack thereof, of total factor productivity and real gross domestic product (GDP) per worker for a pooled (cross-section, time-series) sample of developed and developing countries, adding breadth and depth to the convergence debate. We first estimate total factor productivity from a parsimonious specification of the aggregate production function involving output per worker, capital per worker, and the labor force, both with and without the stock of human capital. Then we test for absolute and conditional convergence of total factor productivity and real GDP per worker, using cross-section and cross-section, time-series data. Fixed-effect estimates across countries convert the cross-section test of absolute convergence into a pooled test of conditional convergence, since it controls for country-specific effects. Our tests consider both β - and σ -convergence. Our findings support both absolute and conditional β -convergence of total factor productivity, but only conditional convergence of real GDP per worker. Further, σ -convergence tests must measure absolute convergence, since conditional convergence assumes that an equilibrium dispersion of total factor productivity or real GDP per worker exists. We find mixed evidence for absolute σ -convergence.
Shadowing Matching Errors for Wave-Front-Like Solutions☆

Abstract Consider a singularly perturbed system[formula]Assume that the system has a sequence of regular and internal layers occurring alternatively along the x direction. These “multiple wave” solutions can formally be constructed by matched asymptotic expansions. To obtain a genuine solution, we derive a Spatial Shadowing Lemma which assures the existence of an exact solution that is near the formal asymptotic series provided (1) the residual errors are small in all the layers, and (2) the matching errors are small along the lateral boundaries of the adjacent layers. The method should work on some other systems like eu t =−(− e 2 D xx ) m u +….
Initial Experience With Tadalafil in Pediatric Pulmonary Arterial Hypertension

This study aimed to investigate the safety, tolerability, and effects of tadalafil on children with pulmonary arterial hypertension (PAH) after transition from sildenafil or after tadalafil received as initial therapy. A total of 33 pediatric patients with PAH were retrospectively evaluated. Of the 33 patients, 29 were switched from sildenafil to tadalafil. The main reason for the change from sildenafil was once-daily dosing. The average dose of sildenafil was 3.4 ± 1.1 mg/kg/day, and that of tadalafil was 1.0 ± 0.4 mg/kg/day. For 14 of the 29 patients undergoing repeat catheterization, statistically significant improvements were observed after transition from sildenafil to tadalafil in terms of mean pulmonary arterial pressure (53.2 ± 18.3 vs. 47.4 ± 13.7 mmHg; p < 0.05) and pulmonary vascular resistance index (12.2 ± 7.0 vs 10.6 ± 7.2 Units/m2; p < 0.05). Clinical improvement was noted for four patients treated with tadalafil as initial therapy. The side effect profiles were similar for the patients who had transitioned from sildenafil to tadalafil including headache, nausea, myalgia, nasal congestion, flushing, and allergic reaction. Two patients discontinued tadalafil due to migraine or allergic reaction. One patient receiving sildenafil had no breakthrough syncope after transition to tadalafil. Tadalafil can be safely used for pediatric patients with PAH and may prevent disease progression.
Bayesian Compressed Regression

As an alternative to variable selection or shrinkage in high-dimensional regression, we propose to randomly compress the predictors prior to analysis. This dramatically reduces storage and computational bottlenecks, performing well when the predictors can be projected to a low-dimensional linear subspace with minimal loss of information about the response. As opposed to existing Bayesian dimensionality reduction approaches, the exact posterior distribution conditional on the compressed data is available analytically, speeding up computation by many orders of magnitude while also bypassing robustness issues due to convergence and mixing problems with MCMC. Model averaging is used to reduce sensitivity to the random projection matrix, while accommodating uncertainty in the subspace dimension. Strong theoretical support is provided for the approach by showing near parametric convergence rates for the predictive density in the large p small n asymptotic paradigm. Practical performance relative to competitors ...
Designing online auctions with past performance information

We investigate the value of past performance information in the context of keyword advertising auctions, where advertisers differ both in valuation-per-click and in the numbers of clicks they can generate (their performance). We focus on weighted unit-price-contract (UPC) auctions, in which bidders bid unit prices and pay accordingly if they win, and their bids are weighted by factors based on their own past performance. We characterize the efficient and the revenue-maximizing weighting factors and apply our framework to study Yahoo!'s and Google's auction designs, each of which can be viewed as a special case of weighted UPC auctions.
Preparation of bis-cyclopentene ring systems via reaction of bis[phenyl(iodonium)] diyne triflates with soft nucleophiles

Abstract The synthesis and characterization of substituted bis-cyclopentene ring systems derived from the interaction of nucleophiles and bis[phenyl(iodonium)] diyne triflate salts is described.
Quantitative temperature imaging in gas-phase turbulent thermal convection by laser-induced fluorescence of acetone

In this paper, an acetone planar laser-induced fluorescence (PLIF) technique for nonintrusive temperature imaging is demonstrated in gas-phase (Pr = 0.72) turbulent Rayleigh–Benard convection at Rayleigh number Ra = 1.3×105. The PLIF technique provides quantitative spatially correlated temperature data without the flow intrusion or time lag associated with physical probes, and without the significant path averaging that plagues most optical heat-transfer diagnostic tools, such as the Mach–Zehnder interferometer, thus making PLIF an attractive choice for quantitative thermal imaging in easily perturbed, complex three-dimensional flow fields. The "instantaneous" (20-ns integration time) thermal images presented have a spatial resolution of 176×176×500 µm and a single-pulse temperature measurement precision of ± 2.5 K, or 2.5% of the total temperature difference. These images represent a two-dimensional slice through a complex three-dimensional flow, allowing for thermal structure of the turbulence to be quantified. Statistics such as the horizontally averaged temperature profile, root-mean square (rms) temperature fluctuation, two-point spatial correlations, and conditionally averaged plume structures are computed from an ensemble of 100 temperature images. The profiles of the mean temperature and rms temperature fluctuation are in good agreement with previously published data, and the results obtained from the two-point spatial correlations and conditionally averaged temperature fields show the importance of large-scale coherent structures in this turbulent flow.
Evaluating the partition function for systems with long range interactions

Abstract We express the partition function for an equilibrium system of interacting particles in the canonical ensemble as a functional integration over the particles' density field. We outline a method to evaluate the partition function by expanding around a saddle point. The saddle point is shown to be the solution of the equivalent mean-field theory. Leading corrections to the mean-field theory takes the form of a Gaussian integral.
SPY: a program to monitor OS/360

It is generally agreed that one of the major problems facing the manufacturers of large scale computer systems today is the problem of measuring the performance of a computer in conjunction with the operating system which drives it. This problem is under consideration for operating systems currently in the design and implementation stages through studies on: (i) the establishment of reasonable criteria under which performance can be measured; (ii) means of actually making the measurements; and (iii) ways of using the information obtained to optimize the performance of the system under the established criteria for a particular user's environment.
High Technology Health Care

High technology medicine often harms more people than it saves. The resources that are spent in too many of our high technology procedures could be far more effectively used to save far more lives in other parts of the system. High technology health care is thus a blessing and a curse. It is a blessing if it is used correctly, but tragically it is too often a curse, stealing resources desperately needed elsewhere.
Current Algebra, Baryons, and Quark Confinement

It is shown that ordinary baryons can be understood as solitons in current algebra effective lagrangians. The formation of color flux tubes can also be seen in current algebra, under certain conditions.
Effects of flexibility on the stability of flying aircraft

Traditionally, flying aircraft have been treated within the confines of flight dynamics, which is concerned, for the most part, with rigid aircraft. On the other hand, flexible aircraft fall in the domain of aeroelasticity. In reality all aircraft possess some measure of flexibility and carry out rigid body maneuvers, so that the question arises as to whether rigid body motions and flexibility in combination can affect adversely the stability of flying aircraft. This paper addresses this question by solving the eigenvalue problem for the following three cases: (i) the flight dynamics of a flexible aircraft regarded as rigid and whose perturbations about the flight path are controlled by feedback control, (ii) the aeroelasticity of a corresponding flexible aircraft prevented from undergoing rigid body translations and rotations, and (iii) the control of the actual flexible aircraft using the control gains derived in the first case by regarding the aircraft as rigid. This investigation demonstrates that it is not always safe to treat separately rigid body and flexibility effects in a flying flexible aircraft.
Fe K Emission and Absorption in the XMM-EPIC Spectrum of the Seyfert Galaxy IC 4329a

We present a re-analysis of the XMM-Newton long-look of the X-ray bright Seyfert galaxy IC 4329a. The Fe K bandpass is dominated by two peaks, consistent with emission from neutral or near-neutral Fe Ka and KP. A relativistic diskline model whereby both peaks are the result of one doubly-peaked diskline profile is found to be a poor description of the data. Models using two relativistic disklines are found to describe the emission profile well. A low-inclination, moderately-relativistic dual-diskline model is possible if the contribution from narrow components, due to distant material, is small or absent. A high-inclination, moderately relativistic profile for each peak is possible if there are roughly equal contributions from both the broad and narrow components. Upper limits on Fe XXV and Fe XXVI emission and absorption at the systemic velocity of IC 4329a are obtained. We also present the results of RXTE monitoring of this source obtained so far; the combined XMM-Newton and RXTE data sets allow us to explore the time-resolved spectral behavior of this source on time scales ranging from hours to 2 years. We find no strong evidence for variability of the Fe Ka emission line on any time scale probed, likely due to the minimal level of continuum variability. We detect a narrow absorption line, at a energy of 7.68 keV in the rest frame of the source; its significance has been confirmed using Monte Carlo simulations. This feature is most likely due to absorption from Fe XXVI blueshifted to approximately 0.1c relative to the systemic velocity, making IC 4329a the lowest-redshift AGN known with a high-velocity, highly-ionized outflow component. As is often the case with similar outflows seen in high-luminosity quasars, the estimated mass outflow rate is larger than the inflow accretion rate, signaling that the outflow represents a substantial portion of the total energy budget of the AGN. The outflow could arise from a radiatively-driven disk wind, or it may be in the form of a discrete, transient blob of ejected material.
Thermal conductivities of individual tin dioxide nanobelts

We have measured the thermal conductivities of a 53-nm-thick and a 64-nm-thick tin dioxide (SnO2) nanobelt using a microfabricated device in the temperature range of 80–350 K. The thermal conductivities of the nanobelts were found to be significantly lower than the bulk values, and agree with our calculation results using a full dispersion transmission function approach. Comparison between measurements and calculation suggests that phonon–boundary scattering is the primary effect determining the thermal conductivities.
Inverse Kinematics of General 6R and 5R,P Serial Manipulators

In this paper we present a solution to the inverse kinematics problems for serial manipulators of general geometry. The method is presented in detail as it applies to a 6R manipulator of general geometry. The equations used are derived using power products and dialytic elimination. In doing this, all variables except one, a tangent half angle of a joint variable, can be eliminated. The result is a 16 by 16 matrix in which all terms are linear in the suppressed variable. The unique design of this matrix allows the suppressed variable to be solved as an eigenvalue problem. Substituting these values of the suppressed variable back into the equations, all other joint variables can be found using linear equations. The result is the 16 solutions expected for the 6R case. The same technique is also applicable to manipulators with prismatic joints. We present the solution technique for all six possible 5R,P manipulators through numerical examples. The primary distinction between the technique presented in this paper and the recently published Raghavan and Roth (1990) solution is that they removed two spurious imaginary roots of multiplicity four from a 24th order polynomial to obtain a 16th order polynomial for 6R and 5R,P cases. In our formulation, the 16th degree polynomial can be derived directly without having to remove any spurious imaginary roots. Another distinction is that the solution procedure can be reduced to an eigenvalue problem. This results in significant gains in computation time.
Blood amino acids and the distribution of alanine and aspartate amino transferases in fed and fasted murres (Uria aalge)

Abstract 1. 1. The subcellular distribution of alanine and aspartate amino transferases in the liver of fed and fasted and kidney of fasted common murres ( Una aalge ) was determined. 2. 2. Alanine amino transferase was distributed approximately equally between mitochondria and cytosol in the liver and kidney of fed and fasted murres. 3. 3. Aspartate amino transferase was distributed approximately equally between mitochondria and cytosol in the liver of fasted murres but was approximately three-quarters cytosolic in fasted kidney. 4. 4. The concentration of amino acids in blood from fed and fasted murres was similar to that previously reported for other avian species. The pattern of changes in blood amino acids caused by fasting was different from that previously reported for other avian species.
The New Genetics in Child Psychiatry

In this issue of the Journal (and also in half of the issue to follow in September), we present a selection of 14 papers that cover advances in the field of child psychiatric genetics over the past 10 years. The August issue of the Journal will highlight both old and new paradigms for studying the genetics of childhood psychiatric disorders. These papers focus on candidate genes, gene-by-environment (GxE) interaction, endophenotypes, genome-wide association studies (GWAS), submicroscopic insertions and deletions, epigenetics, and genetic neuroimaging. In turn, the September issue will present papers on the advances in ADHD genetics research, ranging from twin and molecular genetic approaches, two GWAS studies, a meta-analysis of all prior ADHD GWAS studies, and a study of GxE interaction, all of which demonstrate just how far genetics research has come in child psychiatry. Some of the articles are reviews; others highlight new research. In this special edition-and-a-half, we hope that the general reader will come to better understand the importance, limitations, and possibilities of genetic research for child psychiatry.
Walking on a graph with a magnifying glass: stratified sampling via weighted random walks

Our objective is to sample the node set of a large unknown graph via crawling, to accurately estimate a given metric of interest. We design a random walk on an appropriately defined weighted graph that achieves high efficiency by preferentially crawling those nodes and edges that convey greater information regarding the target metric. Our approach begins by employing the theory of stratification to find optimal node weights, for a given estimation problem, under an independence sampler. While optimal under independence sampling, these weights may be impractical under graph crawling due to constraints arising from the structure of the graph. Therefore, the edge weights for our random walk should be chosen so as to lead to an equilibrium distribution that strikes a balance between approximating the optimal weights under an independence sampler and achieving fast convergence. We propose a heuristic approach (stratified weighted random walk, or S-WRW) that achieves this goal, while using only limited information about the graph structure and the node properties. We evaluate our technique in simulation, and experimentally, by collecting a sample of Facebook college users. We show that S-WRW requires 13-15 times fewer samples than the simple re-weighted random walk (RW) to achieve the same estimation accuracy for a range of metrics.
Deformations of holomorphic Lagrangian fibrations

Let X --E P' be a 2n-dimensional projective holomorphic sym plectic manifold admitting a Lagrangian fibration over Pn. Matsushita proved that the fibration can be deformed in a codimension one family in the moduli space Def(X) of deformations of X. We extend his result by proving that if the Lagrangian fibration admits a section, then there is a codimension two family of deformations which also preserve the section.
Palladium- (and nickel-) catalyzed vinylation of aryl halides

Functionalized styrenes are extremely useful building blocks for organic synthesis and for functional polymers. One of the most general syntheses of styrenes involves the combination of an aryl halide with a vinyl organometallic reagent under catalysis by palladium or nickel complexes. This Feature Article provides the first comprehensive summary of the vinylation methods currently available along with a critical comparison of the efficiency, cost and scope of the methods.
Double stereodifferentiation in the lewis acid promoted crotylation of (S)-2-Alkoxypropanal with chiral β-Alkyl (E)-Crotylsilanes

Abstract The sense and level of 1,2-asymmetric induction have been evaluated in the Lewis acid promoted addition of ( E )crotylsilanes ( S )-1 and ( R )-2 to ( S )-2-alkoxypropanal 3 and 7. These aldehydes are substituted at the α-position with benzyloxy (OBn) to reinforce chelation and tert-butyldiphenylsilyloxy (TBDPSO) groups to prevent chelation with bidentate Lewis acids. The nature of the Lewis acid and the chirality of the silane reagent were found to playa pivotal role in the direction and levels of carbonyl diastcreoface selectivity.
Impact‐induced hydrothermal activity on early Mars

[1] We report on numerical modeling results of postimpact cooling of craters with diameters of 30, 100, and 180 km in an early Martian environment, with and without the presence of water. The effects of several variables, such as ground permeability and the presence of a crater lake, were tested. Host rock permeability is the main factor affecting fluid circulation and lifetimes of hydrothermal systems, and several permeability cases were examined for each crater. The absence of a crater lake decreases the amount of circulating water and increases the system lifetime; however, it does not dramatically change the character of the system as long as the ground remains saturated. It was noted that vertical heat transport by water increases the temperature of localized near-surface regions and can prolong system lifetime, which is defined by maximum near-surface temperature. However, for very high permeabilities this effect is negated by the overall rapid cooling of the system. System lifetimes, which are defined by near-surface temperatures and averaged for all permeability cases examined, were 67,000 years for the 30-km crater, 290,000 years for the 100-km crater, and 380,000 for the 180-km crater. Also, an approximation of the thermal evolution of a Hellas-sized basin suggests potential for hydrothermal activity for ∼10 Myr after the impact. These lifetimes provide ample time for colonization of impact-induced hydrothermal systems by thermophilic organisms, provided they existed on early Mars. The habitable volume reaches a maximum of 6,000 km 3 8,500 years after the impact in the 180-km crater model.
Foliations by Stable Spheres with Constant Mean Curvature for Isolated Systems with General Asymptotics

We prove the existence and uniqueness of constant mean curvature foliations for initial data sets which are asymptotically flat satisfying the Regge–Teitelboim condition near infinity. It is known that the (Hamiltonian) center of mass is well-defined for manifolds satisfying this condition. We also show that the foliation is asymptotically concentric, and its geometric center is the center of mass. The construction of the foliation generalizes the results of Huisken–Yau, Ye, and Metzger, where strongly asymptotically flat manifolds and their small perturbations were studied.
Sequential Analysis Techniques for Correlation Studies in Particle Astronomy

Searches for statistically significant correlations between arrival directions of ultra-high-energy cosmic rays and classes of astrophysical objects are common in astroparticle physics. We present a method to test potential correlation signals of a priori unknown strength and evaluate their statistical significance sequentially, i.e., after each incoming new event in a running experiment. The method can be applied to data taken after the test has concluded, allowing for further monitoring of the signal significance. It adheres to the likelihood principle and rigorously accounts for our ignorance of the signal strength.
The Roelcke compactification of groups of homeomorphisms

Abstract Let X be a zero-dimensional compact space such that all non-empty clopen subsets of X are homeomorphic to each other, and let Aut X be the group of all self-homeomorphisms of X , equipped with the compact-open topology. We prove that the Roelcke compactification of Aut X can be identified with the semigroup of all closed relations on X whose domain and range are equal to X . We use this to prove that the group Aut X is topologically simple and minimal.
World trade as the adjustment mechanism of agriculture to climate change

This paper evaluates the role of trade as a mechanism of economic adjustment to the impacts of climate change on agriculture. The study uses a model of the world economy able to reflect changes in comparative advantage; the model is used to test the hypotheses that trade can assure that, first, satisfying global agricultural demand will not be jeopardized, and, second, general access to food will not decrease. The hypotheses are tested for three alternative scenarios of climate change; under each scenario, regions adjust to the climatic assumptions by changing the land areas devoted to agriculture and the mix of agricultural goods produced, two of the major mechanisms of agricultural adaptation. We find that trade makes it possible to satisfy the world demand for agricultural goods under the changed physical conditions. However, access to food decreases in some regions of the world. Other patterns also emerge that indicate areas of concern in relying on trade as a mechanism for the adjustment of agriculture to likely future changes in climate.
Comlex Syntax: building a computational lexicon

We describe the design of Comlex Syntax, a computational lexicon providing detailed syntactic information for approximately 38,000 English headwords. We consider the types of errors which arise in creating such a lexicon, and how such errors can be measured and controlled.
Distinguishing between SUSY and Littlest Higgs Model using trileptons at the LHC

Littlest Higgs model with T‐parity and Minimal Supersymmtric standard Model (MSSM) with R‐parity both give similar signatures in collider experiment with a huge amount of missing energy depending upon mass of the lightest T‐odd/R‐odd particle. In this talk, I will discuss possibility of distinguishing the two models at the LHC in hadronically quiet signal where masses of R‐odd particles are identical to masses of T‐odd particles.
The MPS II Drift Chamber System

A description of this highly integrated drift chamber system is presented. This high resolution and deadtimeless apparatus achieves excellent performance without channel-by-channel parameter corrections. This approach is suited for very large drift chamber systems since it contains an average of less than one active component per channel. In addition to a description of the system, results from beam tests, and actual use in an experiment are discussed.
Mean field solution of the Ising model on a Barabási–Albert network

Abstract The mean field solution of the Ising model on a Barabasi–Albert scale-free network with ferromagnetic coupling between linked spins is presented. The critical temperature T c for the ferromagnetic to paramagnetic phase transition (Curie temperature) is infinite and the effective critical temperature for a finite size system increases as the logarithm of the system size in agreement with recent numerical results of Aleksiejuk, Holyst and Stauffer.
Molien function for duality

The Molien function counts the number of independent group invariants of a representation. For chiral superfields, it is invariant under duality by construction. We illustrate how it calculates the spectrum of supersymmetric gauge theories.
Organizational Learning and Capital Productivity in Semiconductor Manufacturing

This paper presents an empirical study, which leads to a theoretical framework that links organizational learning and capital productivity. The approach described in this paper helps fab managers make fundamental strategic decisions concerning capital investment and point of entry by engaging in scenario planning. Three strategic options for semiconductor manufacturing are analyzed in detail-leading-edge manufacturer, fast follower, and slow follower. The study concludes that profitability and capital productivity can be in conflict with each other. Leading-edge manufacturers can make large profits, if they ramp up to volume production in a timely manner, but their return on investment and thus their capital productivity are relatively low. Generally, manufacturers that do not run state-of-the-art processes are less profitable than those that do, but their return on investment and thus their capital productivity is comparatively high. Fast followers, which import part of their manufacturing process and ramp to volume production rapidly but with a delay, neither break even nor recover their investment.
Point-Form Electrodynamics and the Construction of Conserved Current Operators

A general procedure for constructing conserved electromagnetic current operators in the presence of hadronic interactions is given. The four-momentum operator in point-form relativistic quantum mechanics is written as the sum of hadronic, photon, and electromagnetic four-momentum operators, where the electromagnetic four-momentum operator is generated from a vertex operator, in which a conserved current operator is contracted with the four-vector potential operator. The current operator is the sum of free, dynamically determined and model-dependent operators. The dynamically determined current operator is formed from a free current operator and the interacting hadronic four-momentum operator, in such a way that the sum of free and dynamically determined current operators is conserved with respect to the hadronic interactions. The model-dependent operator is a many-body current operator, formed as the commutator of an antisymmetric operator with the hadronic four-momentum operator. It is shown that such an operator is also conserved with respect to the hadronic interactions and also does not renormalize the charge.
Real-time deferrable load control: handling the uncertainties of renewable generation

Real-time demand response is potential to handle the uncertainties of renewable generation. It is expected that a large number of deferrable loads, including electric vehicles and smart appliances, will participate in demand response in the future. In this paper, we propose a decentralized algorithm that reduces the tracking error between demand and generation, by shifting the power consumption of deferrable loads to match the generation in real-time. At each time step within the control window, the algorithm minimizes the expected tracking error to go with updated predictions on demand and generation. It is proved that the root mean square tracking error vanishes as control window expands, even in the presence of prediction errors.
Testing for Nodal Dependence in Relational Data Matrices

Relational data are often represented as a square matrix, the entries of which record the relationships between pairs of objects. Many statistical methods for the analysis of such data assume some degree of similarity or dependence between objects in terms of the way they relate to each other. However, formal tests for such dependence have not been developed. We provide a test for such dependence using the framework of the matrix normal model, a type of multivariate normal distribution parameterized in terms of row- and column-specific covariance matrices. We develop a likelihood ratio test (LRT) for row and column dependence based on the observation of a single relational data matrix. We obtain a reference distribution for the LRT statistic, thereby providing an exact test for the presence of row or column correlations in a square relational data matrix. Additionally, we provide extensions of the test to accommodate common features of such data, such as undefined diagonal entries, a nonzero mean, multipl...
A Precautionary Tale of Uncertain Tail Fattening

Suppose that there is a probability density function for how bad things might get, but that the overall rate at which this probability density function slims down to approach zero in the tail is uncertain. The paper shows how a basic precautionary principle of tail fattening could then apply. The worse is the contemplated damage, the more should a decision maker consider the bad tail to be among the relatively fatter-tailed possibilities. A rough numerical example is applied to the uncertain tail distribution of climate sensitivity.
Mirror And Grating Surface Figure Requirements For Grazing Incidence Synchrotron Radiation Beamlines: Power Loading Effects

At present, grazing incidence mirrors are used almost exclusively as the first optical element in VUV and soft x-ray synchrotron radiation beamlines. The performance of these mirrors is determined by thermal and mechanical stress-induced figure errors as well as by figure errors remaining from the grinding and polishing process. With the advent of VUV and soft x-ray undulators and wigglers has come a new set of thermal stress problems related to both the magnitude and the spatial distribution of power from these devices. In many cases the power load on the entrance slits and gratings in these beamlines is no longer negligible. The dependence of thermally induced front-end mirror figure errors on various storage ring and insertion device parameters (especially those at the National Synchrotron Light Source) and the effects of these figure errors on two classes of soft x-ray beamlines are presented.
1,2-Halogen Migration in Haloallenyl Ketones: Regiodivergent Synthesis of Halofurans

Selective 1,2-iodine, bromine, and chlorine migration in haloallenyl ketones in the presence of Au catalyst has been demonstrated. It was found that, depending on the nature of the Au catalyst used, either selective bromine migration or hydrogen shift occurs, leading to the formation of 3- or 2-bromofurans, respectively. Halirenium intermediate was proposed for the unusual 1,2-halogen migration. This cascade transformation allows for mild and efficient synthesis of various types of 3-halofurans.