cssi/SciSciGPT-SciSciNet huggingface dataset:
An Analysis of Blocking Switches Using Error Control Codes

We study the relationship between the degree of blocking and the amount of resource speedup necessary for blocking switches to possess the capabilities of nonblocking switches. We construct an analogy between switch configurations and the codewords of certain error control codes for which we use space covering ideas to derive relations between speedup and number of switch configurations. To derive the necessary speedup for nonblocking, we use two sphere packing bounds: the Hamming bound and the Gilbert-Varshamov bound. To construct nonblocking switches with a given speedup we use maximum distance separable codes. We consider both multicast and point to point scenarios.
Control of substrate access to the active site in methane monooxygenase

Methanotrophs consume methane as their major carbon source and have an essential role in the global carbon cycle by limiting escape of this greenhouse gas to the atmosphere. These bacteria oxidize methane to methanol by soluble and particulate methane monooxygenases (MMOs). Soluble MMO contains three protein components, a 251-kilodalton hydroxylase (MMOH), a 38.6-kilodalton reductase (MMOR), and a 15.9-kilodalton regulatory protein (MMOB), required to couple electron consumption with substrate hydroxylation at the catalytic diiron centre of MMOH. Until now, the role of MMOB has remained ambiguous owing to a lack of atomic-level information about the MMOH-MMOB (hereafter termed H-B) complex. Here we remedy this deficiency by providing a crystal structure of H-B, which reveals the manner by which MMOB controls the conformation of residues in MMOH crucial for substrate access to the active site. MMOB docks at the α(2)β(2) interface of α(2)β(2)γ(2) MMOH, and triggers simultaneous conformational changes in the α-subunit that modulate oxygen and methane access as well as proton delivery to the diiron centre. Without such careful control by MMOB of these substrate routes to the diiron active site, the enzyme operates as an NADH oxidase rather than a monooxygenase. Biological catalysis involving small substrates is often accomplished in nature by large proteins and protein complexes. The structure presented in this work provides an elegant example of this principle.
Time in Eating and Food Preparation among Single Adults

We investigate factors affecting the duration of eating and food preparation among adults in single decision-maker households. Eating time is differentiated into primary and secondary eating time and further differentiated by location: at home vs. away from home. We construct a simple theoretical model, based on Becker’s household production approach, to motivate empirical equations for eating and food preparation time. Empirical analysis is performed using data from the 2006–2008 Eating and Health (EH) Module of the American Time Use Survey (ATUS). Higher food-at-home prices are found to be associated with more time in food preparation and primary eating at home. Higher fast food prices are associated with more time in food preparation and less time in primary eating at home. We conclude that food prices influence home production and time allocation decisions. We also find that low-income adults spend more time in food preparation and primary eating at home and are less likely to eat away from home than those with more income. The presence of children in the household is associated with more time in food preparation and less time in primary eating away from home. Public policies attempting to effect an increase in food preparation among low-income, single adult households with children may need to account for limited opportunities such households can have to acquire and prepare healthier foods when additional time is required.
Numerical Simulation for Under-Floor Air Distribution System With Swirl Diffusers

A finite volume renormalization group (RNG) k-e turbulent model was employed to simulate an under-floor air distribution (UFAD) system consisting of eight swirl diffusers. Mesh generation was conducted using PRO/E and GAMBIT. Computational fluid dynamics (CFD) results using FLUENT show both flow and thermal patterns for an instrumented laboratory room (Building Technology Laboratory-BTL) located at the University of Nevada Las Vegas. Simulation results are presented using symmetrical boundary settings for the BTL. Stratification heights and clear zones are discussed. The application of CFD simulation provides insightful analyses in UFAD design and placement.
Imaging system response linearization and shading correction

Shading correction of image sensors is a very important operation in visual inspection applications. The generation and application of shading cor-rection with and without imaging system response linearization is discussed and demonstrated. The linearization is achieved by subtracting the dark current image and by applying a look-up table operation. The content of the look-up table is obtained by fitting an analytical function to the measured system response. The linearization enables the shading correction to be a linear operation. The quality of the linearization and the shading correction is evaluated using statistical parameters of the processed images. The results show a substantial decrease in the standard deviation of the gray level distribution of uniform reference images.
MEASURE RIGIDITY AND p-ADIC LITTLEWOOD-TYPE PROBLEMS

The paper investigates various p-adic versions of Little- wood's conjecture, generalizing a set-up considered recently by de Mathan and Teulie. In many cases it is shown that the sets of exceptions to these conjectures have Hausdor dimension zero. The proof follows the mea- sure ridigity approach of Einsiedler, Katok and Lindenstrauss.
Electrogenerative chloro- and bromo-fluorination of olefins from aqueous media; the electrogenerative cell as a chemical reactor

Fluoride ion can be discharged in conjunction with chloride and bromide ions under electrogenerative conditions at catalytic porous platinum electrodes to give dihaloalkanes. The cell C2H4(g), Pt black|KF, KCl (aq, barrier electrolyte)|Pt black, Cl2(g) gave 2-chloroethanol, 1,2-dichloroethane and 1-chloro-2-fluoroethane (I); a similar cell gave 1-bromo-2-fluoroethane (II) and analogous products with a platinum or carbon black anode and fluoride-bromide electrolyte. While the yield of fluorinated compounds is low, they are prepared under very mild conditions. The electrogenerative cell can be operated to yield a variety of halogenated products in addition to (I) and (II).
Preparation of KTaO3 and KNbO3 Solid Solutions through Sol–Gel Processing

In this paper, potassium tantalate niobate solid-solution (KTN) powders and thin films are prepared from metallo organic compounds through sol-gel processing. The KTN precursors were chemically modified and then prehydrolyzed with various concentrations of water. The stability of the modified solutions and the effects of prehydrolysis on the crystallization are discussed. Powder gels were obtained by exposing the solution to the atmospheric water, hydrolyzing the solutions. Alternatively, thin films were deposited on fused silica, silicon, sapphire, MgO, and SrTiO[sub 3], using the spinning technique. The pyrolysis and crystallization of KTN powders and films were investigated by differential thermal analysis, thermogravimetric analysis, and X-ray diffraction. The effects of substrate and other processing parameters on the crystal structure of the KTN phases were also investigated. KTN powders crystallized into a perovskite phase regardless of the processing conditions. The crystal structure of the KTN thin films had a strong dependency on the crystal structure of the substrates, while other processing parameters played smaller roles. Pyrochlore KTN was the major phase that crystallized on fused silica and silicon, whereas oriented perovskite KTN was obtained on single-crystal MgO and SrTiO[sub 3].
Three-dimensional point cloud recognition via distributions of geometric distances

A geometric framework for the recognition of three-dimensional objects represented by point clouds is introduced in this paper. The proposed approach is based on comparing distributions of intrinsic measurements on the point cloud. In particular, intrinsic distances are exploited as signatures for representing the point clouds. The first signature we introduce is the histogram of pairwise diffusion distances between all points on the shape surface. These distances represent the probability of traveling from one point to another in a fixed number of random steps, the average intrinsic distances of all possible paths of a given number of steps between the two points. This signature is augmented by the histogram of the actual pairwise geodesic distances in the point cloud, the distribution of the ratio between these two distances, as well as the distribution of the number of times each point lies on the shortest paths between other points. These signatures are not only geometric but also invariant to bends. We further augment these signatures by the distribution of a curvature function and the distribution of a curvature weighted distance. These histograms are compared using the @g^2 or other common distance metrics for distributions. The presentation of the framework is accompanied by theoretical and geometric justification and state-of-the-art experimental results with the standard Princeton 3D shape benchmark, ISDB, and nonrigid 3D datasets. We also present a detailed analysis of the particular relevance of each one of the different proposed histogram-based signatures. Finally, we briefly discuss a more local approach where the histograms are computed for a number of overlapping patches from the object rather than the whole shape, thereby opening the door to partial shape comparisons.
Brane world scenarios and the cosmological constant

Abstract Brane world scenarios offer a way of ensuring that a Poincare invariant four-dimensional world can emerge, without fine tuning, as a solution to the equations of motion of an effective action. We discuss the different ways in which this happens, and point out that the underlying reason is that there is a contribution to the effective cosmological constant which is a constant of integration, that maybe adjusted to ensure a flat space solution. Basically this is an old idea revived in a new context and we speculate that there may be string scenarios that provide a concrete realization of it. Finally we discuss to what extent this is a solution to the cosmological constant problem.
Unveiling the Nuclear Structure at Small x Using Azimuthal Correlations in dA Collisions

We discuss azimuthal correlations in double inclusive hadron production in high energy $dA$ collisions at RHIC. We argue that the leading logarithmic approximation is inadequate for description of experimental data. Realistic shape of the azimuthal correlation function is obtain only if we keep terms that are finite in the rapidity difference between the produced hadrons. Likewise, transverse momentum dependence of parton distribution functions in both deuteron and nucleus must be retained. We observe depletion of the back-to-back correlations in central $dAu$ collisions in the forward direction consistent with the Color Glass Condensate predictions.
Motion and structure from orthographic projections

S. Ullman's classical (1979) results on motion/structure from orthographic views are revisited. Specifically, two results are presented: (1) two orthographic views allow an uncountably infinite number of solutions to motion/structure of a rigid body, and (2) a linear algorithm for solving motion/structure from four point correspondences over three views. >
The determinants of trading volume of high-yield corporate bonds☆

Abstract This paper examines the trading volume of a sample of high-yield corporate bonds reported on Nasdaq's Fixed Income Pricing System (FIPS). This analysis of volume allows us to better understand the liquidity of debt issues. We demonstrate that the `mandatory’ FIPS issues trade fairly actively. We also conduct tests of the determinants of trading volume and produce evidence that mandatory issues with higher volume tend to be larger, more recently issued, and the obligations of firms without publicly traded equity.
Asymmetric synthesis of amines by the Knochel-type MgCl2-enhanced addition of benzyl zinc reagents to N-tert-butanesulfinyl aldimines.

The MgCl2-enhanced addition of benzyl zinc reagents to N-tert-butanesulfinyl imines proceeds readily at room temperature to afford the N-tert-butanesulfinyl-protected amine products in good yields and diastereomeric ratios. This method is functional group tolerant in both the imine substrate and benzyl zinc coupling partner. Moreover, benzyl zinc reagent addition to the N-tert-butanesulfinyl imine 3o prepared from isopropylidene-protected glyceraldehyde proceeds in high yield and with exceptional selectivity to provide rapid entry to hydroxyethylamine-based aspartyl protease inhibitors.
Fuzzy learning enhanced speed control of an indirect field-oriented induction machine drive

Indirect field orientation (IFO) induction machine drives are increasingly employed in industrial drive systems, but the drive performance often degrades due to machine parameter variations. In this paper, a fuzzy model reference learning control technique is applied to an IFO induction machine drive, such that the machine can follow a reference model (an ideal field oriented machine) to achieve the desired speed performance. Experimental results are presented to verify the effectiveness of the proposed control scheme.
Rare Macroeconomic Disasters

The potential for rare macroeconomic disasters may explain an array of asset-pricing puzzles. Our empirical studies of these extreme events rely on long-term data now covering 28 countries for consumption and 40 for GDP. A baseline model calibrated with observed peak-to-trough disaster sizes accords with the average equity premium with a reasonable coefficient of relative risk aversion. High stock-price volatility can be explained by incorporating time-varying long-run growth rates and disaster probabilities. Business-cycle models with shocks to disaster probability have implications for the cyclical behavior of asset returns and corporate leverage, and international versions may explain the uncovered-interest-parity puzzle. Richer models of disaster dynamics allow for transitions between normalcy and disaster, bring in postcrisis recoveries, and use the full time series on consumption. Potential future research includes applications to long-term economic growth and environmental economics, and the use of...
High-power quantum cascade lasers (QCLs) grown by GasMBE

This paper is a brief summary of the technological development and state-of-the-art performance of quantum cascade lasers produced at the Centre for Quantum Devices. Laser design will be discussed, as well as experimental details of device fabrication. Recent work has focused on the development of high peak and average power QCLs emitting at room temperature and above. Scaling of the output is demonstrated by increasing the number of emitting regions in the waveguide core. At λ = 9 μm, over 7 W of peak power has been demonstrated at room temperature for a single diode, with an average power of 300 mW at 6% duty cycle. At shorter wavelengths, laser development includes the use of highly strain-balanced heterostructures in order to maintain a high conduction band offset and minimize leakage current. At λ = 6 μm, utilizing a high reflective coating and epilayer-down mounting of the laser, we have demonstrated 225 mW of average power from a single facet at room temperature. Lastly, these results are put in perspective of other reported results and possible future directions are discussed.
Control of Grain-Boundary Pinning in Al2O3/ZrO2 Composites with Ce3+/Ce4+ Doping

In this paper the control of the microstructure of Ce-doped Al{sub 2}O{sub 3}/ZrO{sub 2} composites by the valence change of cerium ion is demonstrated. Two distinctively different types of microstructure, large Al{sub 2}O{sub 3} grains with intragranular ZrO{sub 2} particles and small Al{sub 2}O{sub 3} grains with intergranular ZrO{sub 2} particles, can be obtained under identical presintering processing conditions. At doping levels greater than {approximately}3 mol % with respect to ZrO{sub 2}, Ce{sup 3+} raises the alumina grain-boundary to zirconia particle mobility ratio. This causes the breakaway of grain boundary from particles and the first type of microstructure. On the other hand, Ce{sup 4+} causes no breakaway and produces a normal intergranular ZrO{sub 2} distribution. The dramatic effect of Ce{sup 3+} on the relative mobility ratio is found to be associated with fluxing of the glassy boundary phase and is likewise observed for other large trivalent cation dopants. The ZrO{sub 2} second phase acts as a scavenger for these trivalent cations, provided their solubility limit in ZrO{sub 2} is not exceeded.
HIV/AIDS and social capital in a cross-section of countries

This paper attempts to quantify the impact of the HIV/AIDS epidemic on social capital with cross-country data. It estimates reduced-form regressions of the main determinants of social capital controlling for HIV prevalence, institutional quality, social distance, and economic indicators using data from the World Values Survey. The results obtained indicate that HIV prevalence affects social capital negatively. The empirical estimates suggest that a one standard deviation increase in HIV prevalence will lead to a 1 percent decline in trust, controlling for other determinants of social capital. If one moves from a country with a relatively low level of HIV prevalence such as Estonia, to a country with a high level such as Zimbabwe, one would observe an approximate 8 percent decline in social capital. These results are robust in a number of dimensions and highlight the empirical importance of an additional mechanism through which HIV/AIDS hinders the development process.
A Viscous Flow Study of Shock-Boundary Layer Interaction, Radial Transport, and Wake Development in a Transonic Compressor

A numerical study based on the 3D Reynolds-averaged Navier-Stokes equation has been conducted to investigate the detailed flow physics inside a transonic compressor. 3D shock structure, shock-boundary layer interaction, flow separation, radial mixing, and wake development are all investigated at design and off-design conditions. Experimental data based on laser anemometer measurements are used to assess the overall quality of the numerical solution. An additional experimental study to investigate end-wall flow with a hot-film was conducted, and these results are compared with the numerical results. Detailed comparison with experimental data indicates that the overall features of the 3D shock structure, the shock-boundary layer interaction, and the wake development are all calculated very well in the numerical solution. The numerical results are further analyzed to examine the radial mixing phenomena in the transonic compressor. A thin sheet of particles is injected in the numerical solution upstream of the compressor. The movement of particles is traced with a 3D plotting package. This numerical survey of tracer concentration reveals the fundamental mechanisms of radial transport in this transonic compressor.
Fast computer vision algorithms for reconfigurable meshes

A bus system that can change dynamically to suit computational needs is referred to as reconfigurable. The authors are interested in obtaining fast algorithms for a number of low-level vision tasks on a two-dimensional mesh augmented with a reconfigurable bus system (reconfigurable mesh). Specifically, for an n*n digitized image stored one pixel per processor they present O(loglogn) algorithms to compute low-level descriptors including perimeter, area, histogram, median row, center as well as several moments. >
Molecular gas in galactic nuclei

Dense molecular clouds are critical to the activity occurring in galactic nuclei. They are the active component from which starbursts arise and this dense interstellar gas may be the fuel for AGNs. In both the nearby infrared bright galaxies (e.g., M82, NGC 253, and IC342) and the ultraluminous IRAS galaxies, high resolution millimeter line mapping has shown extremely high gas surface densities in the central kpc. Often a significant fraction (> 25%) of the total molecular line emission from the galaxy arises from these central regions. New maps at resolutions down to 0.8″ of the ultraluminous IRAS galaxies reveal kinematic gradients parallel to the major axis of the CO intensity distribution, suggesting that the gas is situated in a central rotating disk. The most extreme central concentrations are seen in Arp 220 and Mrk 231 (Sey 1), which have now been mapped in both the 2.6 and 1.3 mm CO transitions. In both galaxies, the high observed CO brightness temperatures indicate large area filling factors with mean H2 densities exceeding 104cm~3. To produce the observed luminosities, the star formation rates must be ∼100 M⊙ yr−1 within the central 500 pc radius. Estimated time scales for both the dynamical evolution and the exhaustion of the observed central ISM are typically 2 × 108 years.
On the Existence of Universally Decodable Matrices

Universally decodable matrices (UDMs) can be used for coding purposes when transmitting over slow fading channels. These matrices are parameterized by positive integers L and N and a prime power q. The main result of this correspondence is that the simple condition L = q + 1 is both necessary and sufficient for (L, N, q)-VDMs to exist. The existence proof is constructive and yields a coding scheme that is equivalent to a class of codes that was proposed by Rosenbloom and Tsfasman. Our work resolves an open problem posed recently in the literature.
The Vortical Environment: The Fifth in the Emery-Trist Levels of Organizational Environments

The paper develops a conceptual scheme that has not been developed to extend the Emery-Trist levels of organizational environments to afifth level consistent with premises laid in their milestone paper (Emery & Trist, 1965). The mounting contemporary evidence that can be observed in the salience of maladaptive responses to turbulent environments is the second reason for undertaking this challenge. More specifically, it is argued that the prevalence of stalemate, polarization, and monothematic dogmatism, the second-order maladaptive responses to the turbulent environment, leads to a frozen or a clinched order of connectedness as well as that of unevenly dynamic turbulent conditions. This approach facilitates the articulation of a different causal texture of an organizational environment than the previous four levels (placid random, placid clustered, disturbed reactive, and turbulent).
Intrametropolitan Opportunity Structure and the Self-Employment of Asian and Latino Immigrants:

Using 2000 Census microdata for the Atlanta metropolitan area as a case study, this research investigates the effect of intrametropolitan opportunity structure and local area context, especially sp...
Uncertainty and unemployment: The effects of aggregate and sectoral channels

We explore the role of uncertainty shocks in explaining unemployment dynamics over the time period 1963–2014. The novelty of our approach is that we distinguish between aggregate and sectoral channels of uncertainty and compare their effects on the unemployment rate. Using S&P500 data we construct both an aggregate measure of time-series volatility in stock returns and a sectoral measure of cross-industry uncertainty in stock returns. We find that an increase in aggregate uncertainty leads to an immediate increase in unemployment, only lasting for three quarters. An increase in sectoral uncertainty leads to a longer-lasting increase in unemployment, with the peak impact occurring after two years. The combination of the two channels can account for the unemployment experience during periods such as the Great Recession when unemployment increased sharply at the outset and remained persistently high. The results are based on a standard macroeconomic vector autoregressive model and are shown to be robust to various checks, as well as to the use of other techniques such as a local projection method.
Velocity estimation by image-focusing analysis

Migration velocity can be estimated from seismic data by analyzing, focusing, and defocusing of residual-migrated images. The accuracy of these velocity estimates is limited by the inherent ambiguity between velocity and reflector curvature. However, velocity resolution improves when reflectors with different curvatures are present. Image focusing is measured by evaluating coherency across structural dips, in addition to coherency across aperture/azimuth angles. The inherent ambiguity between velocity and reflector curvature is directly tackled by introducing a curvature correction into the computation of the semblance functional that estimates image coherency. The resulting velocity estimator provides velocity estimates that are (1) unbiased by reflector curvature and (2) consistent with the velocity information that is routinely obtained by measuring coherency over aperture/azimuth angles. Applications to a 2D synthetic prestack data set and a 2D field prestack data set confirm that the proposed method provides consistent and unbiased velocity information. They also suggest that velocity estimates based on the new image-focusing semblance may be more robust and have higher resolution than estimates based on conventional semblance functionals. Applying the proposed method to zero-offset field data recorded in New York Harbor yields a velocity function that is consistent with available geologic information and clearly improves the focusing of the reflectors.
Immobilized metal complexes in porous hosts: catalytic oxidation of substituted phenols in CO2 media

Development of processes that utilize heterogeneous catalysis in environmentally beneficial media is of fundamental and practical importance. The oxidation of 2,6-di-tert-butylphenol (DTBP) to 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) and 3,5,3′,5′-tetra-tert-butyl-4,4′-diphenoquinone (TTBDQ) has been investigated to evaluate the factors necessary to achieve high product conversion and selectivity in various media. A series of porous materials with immobilized Co(II) complexes served as catalysts and their reactivities using O2 as the terminal oxidant were screened in neat acetonitrile, supercritical carbon dioxide (scCO2), and CO2-expanded acetonitrile. The highest conversions were found with the catalysts that had high affinity for dioxygen. Moreover, the greatest conversions (∼60%) were obtained when reactions were done in scCO2, which is attributed to improved mass transfer of O2 and substrates through the porous catalysts. Furthermore, the heterogeneous catalysts can be recycled with some loss of activity (∼30%) after three cycles; nonetheless these results suggest that the polymer hosts efficiently protect the immobilized catalytic sites from destructive bimolecular routes.
Management of irrigated agriculture to increase organic carbon storage in soils

Increasing the amount of C in soils may be one method to reduce the concentration of C02 in the atmosphere. We measured organic C stored in southern Idaho soils having long term cropping histories that supported native sagebrush vegetation (N SB), irrigated moldboard plowed crops (IMP), irrigated conservation -chisel- tilled crops (ICT) and irrigated pasture systems (1?). The C02 emitted as a result of fertilizer production, farm operations and CO; lost via dissolved carbonate in irrigation water, over a 30 year period, was included. Net organic C in ecosystems decreased in the order IP>ICT>NSB>IMP. In this study, if NSB were converted to IMP, 0.15 g C m“2 would be emitted to the atmosphere, but if converted to IP , 3.56 g C m'2 could be sequestered. If IMP land were converted to ICT, 0.95 g C m"2 could be i sequestered in soil and if converted to I? 3.71 g C 111'2 could be sequestered. There are 2.6)(108 ha of land worldwide presently irrigated. If irrigated agriculture were expanded 10% and the same amount of rainfed land were converted back to native grassland, an increase of 3.4x109 Mg C (5.9% of the total C emitted in the next 30 yr) could potentially be sequestered. The total projected release of CO2 is 5.7x10‘° Mg C worldwide during the next 30 years. Converting rainfed agriculture back to native vegetation while modestly increasing areas in f irrigated agriculture could have a signi?cant impact on C0; atmospheric concentrations while maintaining or increasing food production.
Controls on the size and occurrence of pools in coarse-grained forest rivers

Controls on pool formation are examined in gravel- and cobble-bed rivers in forest mountain drainage basins of northern California, southern Oregon, and southeastern Alaska. We demonstrate that the majority of pools at our study sites are formed by flow obstructions and that pool geometry and frequency largely depend on obstruction characteristics (size, type, and frequency). However, the effectiveness of obstructions to induce scour also depends on channel characteristics, such as channel gradient, width:depth ratio, relative submergence (ratio of flow depth to grain size), and the calibre and rate of bed material supply. Moreover, different reach-scale channel types impose different characteristic physical processes and boundary conditions that further control the occurrence of pools within a catchment. Our findings indicate that effective management of pools and associated aquatic habitat requires consideration of a variety of factors, each of which may be more or less important depending on channel type and location within a catchment. Consequently, strategies for managing pools that are based solely on single-factor, regional target values (e.g. a certain number of wood pieces or pools per stream length) are likely to be ineffective because they do not account for the variety of local and catchment controls on pool scour and, therefore, may be of limited value for proactive management of complex ecosystems. Copyright  2002 John Wiley & Sons, Ltd.
CONTRACTING, CAPTIVE SUPPLIES, AND PRICE BEHAVIOR

Theoretical and simulation results clarify the role of procurement contracting in determining spot price levels and volatility. A generic model determines market share across quality. Actual supply is specified as price dependent and stochastic. Simulation examines the sensitivity of price level and volatility to extent of forward contracting, risk aversion, and ability to adjust spot market demand (recontracting). The results show that as forward contracting increases mean spot price decreases and variance increases. This effect increases as risk aversion decreases and as extent of recontracting adjustment in spot demand decreases.
One-step synthesis of 2-arylbenzothiazole (‘BTA’) and -benzoxazole precursors for in vivo imaging of β-amyloid plaques

Abstract We report the simple and efficient synthesis of 2-arylbenzothiazoles (‘BTA’) and 2-arylbenzoxazoles by direct coupling of benzothiazoles or benzoxazoles with aryl bromides. This method permits direct one-step access to precursors of radiolabeled BTA-1 and BTA-2 and their 6-methoxy analogues, used for in vivo imaging of β-amyloid plaques with positron emission tomography (PET).
First Example of the Intermolecular Palladium-Catalyzed Asymmetric Allylic Alkylation of Hydroxyacrylates: Synthesis of All-Carbon α-Aryl Quaternary Aldehydes

A set of acyclic all-carbon α-aryl quaternary aldehydes was synthesized by intermolecular palladium-catalyzed asymmetric allylic alkylation (Pd-AAA). Hydroxyacrylates were used as unprecedented nucleophilic counterparts instead of widely used ketone substrates. This produced a very rare all-carbon quaternary aldehyde. Chiral ligand (R,R)-L3 was found to be optimal in this Pd-AAA reaction and provided good to excellent yields (75–99 %) and enantioselectivities (75–94 %) with a range of analogs.
Addition of Allenylzinc Reagents, Prepared in Situ from Nonracemic Propargylic Mesylates, to Aldehydes. A New Synthesis of Highly Enantioenriched Homopropargylic Alcohols

Enantioenriched propargylic mesylates are converted to chiral allenylzinc reagents via transient allenylpalladium species by treatment with a Pd(0)-phosphine catalyst in the presence of excess Et2Zn. These zinc reagents undergo SE2‘ additions to various aldehydes to yield mainly the anti homopropargylic alcohol adducts of high ee. The reaction is most efficient in THF with Pd(OAc)2·PPh3 as the catalyst precursor. As little as 2.5 mol % of this precursor is effective.
Collective thermoregulation in bee clusters

Swarming is an essential part of honeybee behaviour, wherein thousands of bees cling onto each other to form a dense cluster that may be exposed to the environment for several days. This cluster has the ability to maintain its core temperature actively without a central controller. We suggest that the swarm cluster is akin to an active porous structure whose functional requirement is to adjust to outside conditions by varying its porosity to control its core temperature. Using a continuum model that takes the form of a set of advection–diffusion equations for heat transfer in a mobile porous medium, we show that the equalization of an effective ‘behavioural pressure’, which propagates information about the ambient temperature through variations in density, leads to effective thermoregulation. Our model extends and generalizes previous models by focusing the question of mechanism on the form and role of the behavioural pressure, and allows us to explain the vertical asymmetry of the cluster (as a consequence of buoyancy-driven flows), the ability of the cluster to overpack at low ambient temperatures without breaking up at high ambient temperatures, and the relative insensitivity to large variations in the ambient temperature. Our theory also makes testable hypotheses for the response of the cluster to external temperature inhomogeneities and suggests strategies for biomimetic thermoregulation.
From BCS to the LHC

Reflections on spontaneous symmetry breaking, and the connection between condensed matter physics and particle physics, as given in a talk at a symposium at the University of Illinois in Urbana, celebrating the 50th anniversary of the theory of superconductivity.
Scleral-fixated capsular tension rings and segments for ectopia lentis in children.

Purpose To report the short-term outcomes and complications of implantation of scleral-fixated capsular tension rings and/or capsular tension segments with intraocular lenses (IOL) in pediatric patients with ectopia lentis. Design Retrospective, observational case series. Methods Thirteen consecutive pediatric patients (19 eyes) underwent placement of in-the-bag IOL with either a Cionni modified capsular tension ring or a capsular tension segment in conjunction with a conventional capsular tension ring between January 1, 2009 and March 30, 2013 by 3 anterior segment surgeons at a single academic center. The scleral fixation suture was 9-0 polypropylene in 16 eyes and CV-8 Gore-Tex (expanded polytetrafluoroethylene) in 3 eyes. Outcome measures included change in corrected distance visual acuity (CDVA) and complications. Results The mean age was 10.2 years ± 4.8 (SD) and the median follow-up, 23.4 months. A Cionni modified capsular tension ring was implanted in 5 eyes and a capsular tension segment with an unsutured capsular tension ring was implanted in 12 eyes. In 2 eyes, capsular tension segment alone was placed. The mean CDVA at the final follow-up (0.10 ± 0.11 logMAR, 18 eyes) was significantly better than preoperatively (0.58 ± 0.26 logMAR, 15 eyes) ( P Conclusions Implantation of in-the-bag IOL with either a Cionni modified capsular tension ring or a capsular tension segment in conjunction with a conventional capsular tension ring appears to be a safe and effective technique for visual rehabilitation in pediatric ectopia lentis.
Who Is a Journalist and Why Does it Matter? Disentangling the Legal and Ethical Arguments

The contemporary debate about “who is a journalist” is occurring in two distinct domains: law and professional ethics. Although the debate in these domains is focused on separate problems, participants treat the central question as essentially the same. This article suggests that the debates in law and professional ethics have to be resolved independently and that debate within those domains needs to be more nuanced. In law, it must vary depending on whether the context involves constitutional law, statutory law, or the distribution of informal privileges by government officials. In professional ethics, the debate should not be oriented around a single definitional threshold but should identify tiers that take account of different communicators' unique goals, tactics, and values.
The mechanical design of a humanoid robot with flexible skin sensor for use in psychiatric therapy

In this paper, a humanoid robot is presented for ultimate use in the rehabilitation of children with mental disorders, such as autism. Creating affordable and efficient humanoids could assist the therapy in psychiatric disability by offering multimodal communication between the humanoid and humans. Yet, the humanoid development needs a seamless integration of artificial muscles, sensors, controllers and structures. We have designed a human-like robot that has 15 DOF, 580 mm tall and 925 mm arm span using a rapid prototyping system. The robot has a human-like appearance and movement. Flexible sensors around the arm and hands for safe human-robot interactions, and a two-wheel mobile platform for maneuverability are incorporated in the design. The robot has facial features for illustrating human-friendly behavior. The mechanical design of the robot and the characterization of the flexible sensors are presented. Comprehensive study on the upper body design, mobile base, actuators selection, electronics, and performance evaluation are included in this paper.
Optimum solar-sail interplanetary trajectories

A description is given of the optimization of solar-sail interplanetary trajectories. The optimization procedure is based on the calculus of variations. Attention is given to aspects of thrust optimization, optimization criteria, a terrestrial planet rendezvous, the Venus and Mars rendezvous, the Mercury rendezvous, and an asteroid roundtrip mission. The investigation shows that a solar-sail spacecraft represents a viable option for the exploration of the solar system in the future.
"Narco" emotions: affect and desensitization in social media during the mexican drug war

Social media platforms have emerged as prominent information sharing ecosystems in the context of a variety of recent crises, ranging from mass emergencies, to wars and political conflicts. We study affective responses in social media and how they might indicate desensitization to violence experienced in communities embroiled in an armed conflict. Specifically, we examine three established affect measures: negative affect, activation, and dominance as observed on Twitter in relation to a number of statistics on protracted violence in four major cities afflicted by the Mexican Drug War. During a two year period (Aug 2010 - Dec 2012), while violence was on the rise in these regions, our findings show a decline in negative emotional expression as well as a rise in emotional arousal and dominance in Twitter posts: aspects known to be psychological markers of desensitization. We discuss the implications of our work for behavioral health, facilitating rehabilitation efforts in communities enmeshed in an acute and persistent urban warfare, and the impact on civic engagement.
Vector boson pair production at the LHC

We present phenomenological results for vector boson pair production at the LHC, obtained using the parton-level next-to-leading order program MCFM. We include the implementation of a new process in the code, pp → γγ, and important updates to existing processes. We incorporate fragmentation contributions in order to allow for the experimental isolation of photons in γγ, Wγ, and Zγ production and also account for gluon-gluon initial state contributions for all relevant processes. We present results for a variety of phenomenological scenarios, at the current operating energy of √ s = 7 TeV and for the ultimate machine goal, √ s = 14 TeV. We investigate the impact of our predictions on several important distributions that enter into searches for new physics at the LHC.
Quantum sine-Gordon equation as the massive Thirring model

The sine-Gordon equation is the theory of a massless scalar field in one space and one time dimension with interaction density proportional to $cos\ensuremath{\beta}\ensuremath{\phi}$, where $\ensuremath{\beta}$ is a real parameter. I show that if ${\ensuremath{\beta}}^{2}$ exceeds $8\ensuremath{\pi}$, the energy density of the theory is unbounded below; if ${\ensuremath{\beta}}^{2}$ equals $4\ensuremath{\pi}$, the theory is equivalent to the zero-charge sector of the theory of a free massive Fermi field; for other values of $\ensuremath{\beta}$, the theory is equivalent to the zero-charge sector of the massive Thirring model. The sine-Gordon soliton is identified with the fundamental fermion of the Thirring model.
Lower bounds for sparse recovery

We consider the following k-sparse recovery problem: design an m x n matrix A, such that for any signal x, given Ax we can efficiently recover x satisfying ||x -- x||i ≤ C mink-sparse x' ||x - x'||1. It is known that there exist matrices A with this property that have only O(k log(n/k)) rows.In this paper we show that this bound is tight. Our bound holds even for the more general randomized version of the problem, where A is a random variable, and the recovery algorithm is required to work for any fixed x with constant probability (over A).
The Origins and Consequences of Consensus Decision Making: A Test of the Social Consensus Model

This study developed and tested the Social Consensus Model of group decision making. According to the model, group members who are extraverted, agreeable, conscientious, non-neurotic, and open to experience are likely to generate a relatively high rate of supportive communication, in turn leading to the group's voluntary adoption of the consensus decision rule. The model also holds that when group members voluntarily employ the consensus decision rule, they are likely to be satisfied with their decision, view the decision as representative of their own and other members' views, and perceive the decision-making process to be fair. In a laboratory simulation involving 50 zero-history groups of undergraduates, we found that group members' average scores on the extraversion, agreeableness, and openness personality factors all correlated positively with the rate at which they generated supportive communication, and that the rate of supportive communication correlated positively with the percentage of members w...
PRE- AND POST-TRIAL EQUALITY IN CRIMINAL JUSTICE IN THE CONTEXT OF THE SEPARATION OF POWERS

The previous Westminster criminal justice system entailed a different kind of separation of powers insofar as it concerns the role of state prosecutors. In the Westminster system prosecutors are part of the executive branch, whereas they were a split-off from the judiciary in constitutional states and function like a de facto second organ of the third branch of state power. Currently executive interference in state prosecutions often leads to pre-trial inequality. A further difficulty arises from the unconsidered manner in which the former royal prerogative of pardoning was retained in the Constitution of the Republic of South Africa, 1996. It used to be a royal veto of judicial sentences in the constitutional monarchy of the former Westminster model. Although the corresponding veto of parliamentary legislation by the head of state did not survive into modern times, the pardoning power has not been discontinued. Section 84(2)(j) thus causes an irreconcilable conflict with section 165(5) of the Constitution which guarantees the legally binding force of judicial decisions. It undermines the rule of law and leads to post-trial inequality in the execution of sentences. The parole system, which dates back to 1959, likewise allows the executive to overrule judicial sentences and is in conflict with section 165(5). The perpetuation of the status quo in criminal justice is in effect leading to a re-Westminstering of the constitutional state.
H∞ synthesis of nonlinear feedback systems in a volterra representation

Presented in this paper is a procedure for selecting the H∞ performance weights for a class of nonlinear feedback systems modeled by a truncated Volterra series. The performance weight selection addresses the trade-offs between closed-loop performance and closed-loop stability. The class of feedback systems considered are regulating systems subject to step disturbances. The methodology is based on two recent results concerning closed loop stability for this class of nonlinear feedback systems. These stability conditions can be formulated as an H∞ problem where the performance weights are systematically identified. This synthesis procedure is applied to the idle speed control of a Ford 4.6L V-8 fuel injection engine. Through this application, the design trade-off between closed-loop performance and stability is illustrated.
Market coverage and the nature of product differentiation: a note

In this note, we analyze the equilibrium outcomes of pricing games with product differentiation in relation with the extent of market coverage. It is a received idea in the IO literature that the horizontal and vertical models of product differentiation are almost formally equivalent. We show that this idea turns out to be wrong when the full market coverage assumption is relaxed. We then argue that there exist two fundamentally different classes of address-models of differentiation, although their difference is not perfectly captured by the standard horizontal/vertical typology.
Can We Trust Shoestring Evaluations

Many more impact evaluations could be done, and at lower unit cost, if evaluators could avoid the need for baseline data using objective socio-economic surveys and rely instead on retrospective subjective questions on how outcomes have changed, asked post-intervention. But would the results be reliable? This paper tests a rapid-appraisal, “shoestring” method using subjective recall for welfare changes. The recall data were collected at the end of a full-scale evaluation of a large World Bank supported poor-area development program in China. Qualitative recalls on how living standards have changed are found to provide only weak and biased signals of the changes in consumption as measured from contemporaneous surveys. Importantly, the shoestring method was unable to correct for the selective placement of the program favoring poor villages. The results of this case study are not encouraging for future applications of the shoestring method, although similar tests are needed in other settings.
Time optimal linear schedules for algorithms with uniform dependencies

The authors address the problem of identifying optimal linear schedules for uniform dependence algorithms so that their execution time is minimized. Procedures are proposed to solve this problem based on the mathematical solution of a nonlinear optimization problem. The complexity of these procedures is independent of the size of the algorithm. Actually, the complexity is exponential in the dimension of the index set of the algorithm, and for all practical purposes, very small due to the limited dimension of the index set of algorithms of practical interest. A particular class of algorithms for which the proposed solution is greatly simplified is considered, and the corresponding simpler organization procedure is provided. >