cssi/SciSciGPT-SciSciNet huggingface dataset:
Palladium-Catalyzed Stereoretentive Olefination of Unactivated C(sp3)–H Bonds with Vinyl Iodides at Room Temperature: Synthesis of β-Vinyl α-Amino Acids

A method is reported for palladium-catalyzed N-quinolyl carboxamide-directed olefination of the unactivated C(sp(3))-H bonds of phthaloyl alanine with a broad range of vinyl iodides at room temperature. This reaction represents the first example of the stereoretentive installation of multisubstituted terminal and internal olefins onto unactivated C(sp(3))-H bonds. These methods enable access to a wide range of challenging β-vinyl α-amino acid products in a streamlined and controllable fashion, beginning from simple precursors.
Multiple laser beam combining and phasing using closed-loop control

One method for scaling lasers to higher power is to build several separate amplifier chains, and then coherently combine the individual beams together. To combine the beams the pathlengths must be matched to an integer number of waves, and the tip and tilt of each beam must be the same. Since optical tolerances are fractional micrometers, a sophisticated control system must be employed to actively measure tip/tilt and piston errors, and apply real time corrections. We have developed a test bed that allows us to develop the required control algorithms for two to four beams and then scale to a larger number.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Exploration of fractal nature of WO3 nanowire aggregates

Abstract The morphology of WO3 aggregates formed by irregular nanoparticles (D∼40 nm) and nanowires of different aspect ratios (2, 4, 6, and 10 μm nominal lengths) dispersed in commonly used polar solvents without dispersant agents is investigated using a small-angle light scattering technique and by means of fractal theory. Nanoparticles form compact spherical aggregates (Df∼2.6), whereas 2 μm nanowires with low aspect ratio (L/D∼10) follow a slow cluster–cluster aggregation mechanism with no discernable change in fractal dimension (Df=2.1) monitored in an extended period of 6 months, despite a notable growth in size (Rg=2.3–3.1 μm). For higher aspect ratio nanowires, scattered intensity profiles, which migrate towards the Porod regime, qualitatively obey the Lorenz–Mie theory predictions. The 10 μm nanowires with very high aspect ratio (L/D∼250) are observed to form stable dispersions in a time span of 6 days. Analytical methods based on spherical primary particle formulations predict Df=1.9, 1.7, and 1.4 for 4, 6, and 10 μm nanowires, respectively.
Revisiting Marshall's Third Law: Why Does Labor's Share Interact with the Elasticity of Substitution to Decrease the Elasticity of Labor Demand?

Abstract The third Marshall–Hicks–Allen rule of elasticity of derived demand purports to show that labor demand is less elastic when labor is a smaller share of total costs. As Hicks, Allen, and then Bronfenbrenner showed, this rule is not quite correct, and actually is complicated by an unexpected negative relationship involving labor's share of total costs and the elasticity of substitution. The standard intuitive explanation for the exception to the rule presented by Stigler and referenced in many textbooks describes a situation rather different than the one described in the rule. The author presents an example that illustrates the peculiar negative impact of labor's share operating via the elasticity of substitution and then explains why the unexpected relationship between labor's share of total cost, the elasticity of substitution, and the elasticity of labor demand holds.
Simulations for surface profile imaging

Abstract The feasibility of quantifying surface structures using the profile imaging technique in high-resolution electron microscopy has been considered using theoretical multi-slice simulations. The possibilities for observing surfaces with missing or additional atoms, or with reconstruction, have been investigated in detail, with reference to particular oxides (UO 2 , TbO 2 ) and compound semiconductors (CdTe, GaAs). The influence of such factors as incident beam misalignment, accelerating voltage, objective lens defocus and crystal thickness on the apparent surface relaxation were also considered, together with the possibility of eliminating any artefacts by using a focal series restoration.
The Berry phase and the pump flux in stochastic chemical kinetics

We study a classical two-state stochastic system in a sea of substrates and products (absorbing states), which can be interpreted as a single Michaelis-Menten catalyzing enzyme or as a channel on a cell surface. We introduce a novel general method and use it to derive the expression for the full counting statistics of transitions among the absorbing states. For the evolution of the system under a periodic perturbation of the kinetic rates, the latter contains a term with a purely geometrical (the Berry phase) interpretation. This term gives rise to a pump current between the absorbing states, which is due entirely to the stochastic nature of the system. We calculate the first two cumulants of this current, and we argue that it is observable experimentally.
Resolution lower bounds for perfect matching principles

For an arbitrary hypergraph H, let PM(H) be the propositional formula asserting that H contains a perfect matching. We show that every resolution refutation of PM(H) must have size exp(Ω(δ(H)/λ(H)r(H)(log n(H))(r(H) + log n(H)))), where n(H) is the number of vertices, δ(H) is the minimal degree of a vertex, r(H) is the maximal size of an edge, and λ(H) is the maximal number of edges incident to two different vertices.For ordinary graphs G our general bound considerably simplifies to exp(Ω(δ(G)/(log n(G))2)) (implying an exp(Ω(δ(G)1/3)) lower bound that depends on the minimal degree only). As a direct corollary, every resolution proof of the functional onto version of the pigeonhole principle onto - FPHPmn must have size exp(Ω(n/(log m)2)) (which becomes exp(ω(n1/3)) when the number of pigeons m is unbounded). This in turn immediately implies an exp(Ω(t/n3)) lower bound on the size of resolution proofs of the principle asserting that the circuit size of the Boolean function fn in n variables is greater than t. In particular, Resolution does not possess efficient proofs of NP ⊈ P/poly.These results relativize, in a natural way, to a more general principle M(U|H) asserting that H contains a matching covering all vertices in U ⊆ V(H).
The development of controls for pulse-to-pulse modulation at the brookhaven AGS complex☆

Abstract The AGS Complex includes, in addition to the AGS itself, a 200 MeV proton linac and 1.5 GeV proton Booster (also capable of accelerating 400 MeV/u heavy ions) which is currently under construction. Operation of this complex requires service to multiple users with different beam requirements. Booster commissioning with protons and heavy ions must run concurrently and in various combinations with programs on the linac and with physics and accelerator study programs on the AGS. A new timing system is being built which will distribute serially encoded events derived from real-time and magnetic-field clocks to each accelerator. The master timing of the supercycle will be managed centrally with encoded reset events determining the assigned user for each pulse. Operational aspects of the design of this system are described, together with the principal control-system modifications necessary to implement this mode of operation.
Theoretical principles of single-molecule electronics: A chemical and mesoscopic view

Exploring the use of individual molecules as active components in electronic devices has been at the forefront of nanoelectronics research in recent years. Compared to semiconductor microelectronics, modeling transport in single-molecule devices is much more difficult due to the necessity of including the effects of the device electronic structure and the interface to the external contacts at the microscopic level. Theoretical formulation of the problem therefore requires integrating the knowledge base in surface science, electronic structure theory, quantum transport, and device modeling into a single unified framework starting from the first principles. In this article, we introduce the theoretical framework for modeling single-molecule electronics and present a simple conceptual picture for interpreting the results of numerical computation. We model the device using a self-consistent matrix Green's function method that combines nonequilibrium Green's function theory of quantum transport with atomic-scale description of the device's electronic structure. We view the single-molecule device as “heterostructures” composed of chemically well-defined atomic groups, and analyze the device characteristics in terms of the charge and potential response of these atomic groups to perturbation induced by the metal–molecule coupling and the applied bias voltage. We demonstrate the power of this approach using as examples devices formed by attaching benzene-based molecules of different size and internal structure to the gold electrodes through sulfur end atoms. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
One- and two-photon physics with relativistic heavy ions

The physics of peripheral collisions with relativistic heavy ions (PCRHI) is reviewed. One- and two-photon processes are discussed.
Rapid intravenous infusion of 20 mL/kg saline alters the distribution of perfusion in healthy supine humans.

Abstract Rapid intravenous saline infusion, a model meant to replicate the initial changes leading to pulmonary interstitial edema, increases pulmonary arterial pressure in humans. We hypothesized that this would alter lung perfusion distribution. Six healthy subjects (29 ± 6 years) underwent magnetic resonance imaging to quantify perfusion using arterial spin labeling. Regional proton density was measured using a fast-gradient echo sequence, allowing blood delivered to the slice to be normalized for density and quantified in mL/min/g. Contributions from flow in large conduit vessels were minimized using a flow cutoff value (blood delivered >35% maximum in mL/min/cm3) in order to obtain an estimate of blood delivered to the capillary bed (perfusion). Images were acquired supine at baseline, after infusion of 20 mL/kg saline, and after a short upright recovery period for a single sagittal slice in the right lung during breath-holds at functional residual capacity. Thoracic fluid content measured by impedance cardiography was elevated post-infusion by up to 13% (p
Screening incentives and privacy protection in financial markets: a theoretical and empirical analysis

We study a model in which firms offer financial products to individuals, post prices for their products, and screen consumers who apply to purchase them. Any information obtained in the screening process may be traded to another firm selling related products. We show that firms' ability to sell consumer information can lead to lower prices, higher screening intensities, and increased social welfare. By exploiting variations in the adoption of local financial-privacy ordinances in five California Bay Area counties, we are able to provide simple estimates of the effects of stricter financial-privacy laws on mortgage denial rates during 2001�2006. Consistent with the model's predictions, denial rates for home-purchase loans and refinancing loans decreased in counties where opt-in privacy ordinances were adopted. Moreover, estimated foreclosure start rates during the financial crisis of 2007�2008 were higher in counties where the privacy ordinance was adopted.
Suzuki-Miyaura coupling of NHC-boranes: a new addition to the C-C coupling toolbox.

Complexes of triaryl- and trialkylboranes with N-heterocyclic carbenes (NHCs) participate in Suzuki−Miyaura cross-coupling reactions and provide coupled products in good yields under base-free conditions. The reaction can be applied to Csp2−Csp2 and Csp2−Csp3 carbon−carbon bond formation with triflates, iodides, bromides, and chlorides. These results enrich the utility of NHC−borane complexes, which can be added to the toolkit of Suzuki−Miyaura cross-couplings, along with boronic acids and organotrifluoroborates.
A note on the cone restriction conjecture in the cylindrically symmetric case

In this paper, we present two arguments showing that the classical linear adjoint cone restriction conjecture holds for the class of functions supported on the cone and invariant under spatial rotation in all dimensions. The first is based on a dyadic restriction estimate, while the second follows from a strengthening version of the Hausdorff-Young inequality and the Holder inequality in Lorentz spaces.
Segregation by friction

Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments are carried out by placing steel spheres on a horizontal plane enclosed by rectangular sidewalls, and subjecting them to horizontal shaking. Half the spheres are highly smooth; the remainder are identical to the first half, except that their surfaces have been roughened by chemical etching, giving them higher coefficients of friction. Segregation due to this difference in friction occurs, particularly when the grains have a relatively long mean free path. In the presence of an appropriately chosen small hill in the middle of the container, the grains can be made to completely segregate by friction type.
Financial liberalization and banking crises in emerging economies

Abstract Financial liberalization often leads to financial crises. This link has usually been attributed to poorly designed banking systems, an explanation that is largely static. In this paper we develop a dynamic explanation, by modelling the evolution of a newly-liberalized bank's opportunities and incentives to take on risk over time. The model reveals that even if a banking system is well-designed, in the sense of having good long-run properties, many countries will enjoy an initial period of rapid, low-risk growth and then enter a period with an elevated risk of banking crisis. This transition emerges because of the way in which the degree of foreign competition, the marginal product of capital, and the bank's own net worth simultaneously evolve.
An analysis of the quasicontinuum method

The aim of this paper is to present a streamlined and fully three-dimensional version of the quasicontinuum (QC) theory of Tadmor et al. (Philos. Mag. A 73 (1996) 1529; Langmuir 12 (1996) 4529) and to analyze its accuracy and convergence characteristics. Specifically, we assess the effect of the summation rules on accuracy; we determine the rate of convergence of the method in the presence of strong singularities, such as point loads; and we assess the effect of the refinement tolerance, which controls the rate at which new nodes are inserted in the model, on the development of dislocation microstructures.
Thermal Injury in the Pregnant Patient

Thermal injury sustained during pregnancy presents special management problems for both the gravid woman and her unborn child. Of 6,573 admissions to this burn center during the period of 1950 through 1982, 1,157 (17.6 per cent) were female and 448 (6.8 per cent) were of reproductive age. Thirty of this latter group (6.7 per cent) of burned patients were pregnant at the time of injury. These 30 patients ranged in age from 16 to 37 years old (an average of 22.7 years) and the burned portion of the total body surface area ranged from 6 to 92 per cent (an average of 39.7 per cent). A review of the clinical courses of these 30 patients suggests several observations and conclusions. Pregnancy does not alter the maternal outcome after thermal injury and maternal survival is usually accompanied by fetal survival in the absence of significant complications. If the injury of the gravid patient is lethal, the pregnancy will usually terminate spontaneously prior to her death. Obstetric support and aggressive fetal monitoring is recommended for all moderately and severely burned pregnant patients. Obstetric intervention may be considered in the ill patient with a near term fetus in whom significant complications (such as, hypotension, hypoxemia or sepsis) jeopardize the life of the fetus.
A Hybrid Analog-Digital Pseudo Random Noise Generator

Analog and hybrid analog-digital computers used for random-process and statistical studies require noise sources capable of generating random signals whose amplitude distribution, d-c unbalance, spectrum, and RMS level are specified within the computer accuracy limits. Noise samples must not be correlated for time delays exceeding one-ten-thousandth to one-thousandth of a computer run.
A magnetospheric critical velocity experiment: Particle results

In March of 1983, a barium injection sounding rocket experiment (The Star of Lima) was conducted to investigate Alfven's critical ionization velocity (CIV) hypothesis in space. Included in the instrumented payload was a particle detection experiment consisting of five retarding potential analyzers. Despite conditions that appeared to be optimal for the critical velocity effect, the particle data, in agreement with optical observations, indicates that a fractional ionization of only approximately .0005 was observed, indicating that the conditions required for the effect to occur are still not well understood. However many of the required phenomena associated with the CIV effect were observed; in particular a superthermal electron population was formed at the expense of ion drift kinetic energy in the presence of intense electrostatic waves near the lower hybrid frequency. The amount of ionization produced is plausibly consistent with the observed electron flux, but could also be accounted for by residual solar UV at the injection point. It is shown based on the data set that one obvious explanation for the low ionization efficiency, namely that the ionizing superthermal electrons may rapidly escape along field lines, can be ruled out.
Update on behavioral interventions for autism and developmental disabilities.

Purpose of reviewGiven the explosion in published behavioral interventions over the past several years, this review highlights the latest trends over the past year (2014) for children with complex learning and developmental needs.Recent findingsThere were virtually no rigorous intervention studies p
Convective Characteristics of the Madden-Julian Oscillation over the Central Indian Ocean Observed by Shipborne Radar during DYNAMO

AbstractThis study investigates the convective population and environmental conditions during three MJO events over the central Indian Ocean in late 2011 using measurements collected from the Research Vessel (R/V) Roger Revelle deployed in Dynamics of the MJO (DYNAMO). Radar-based rainfall estimates from the Revelle C-band radar are first placed in the context of larger-scale Tropical Rainfall Measuring Mission (TRMM) rainfall data to demonstrate that the reduced Revelle radar range captured the MJO convective evolution. Time series analysis and MJO phase-based composites of Revelle measurements both support the “recharge–discharge” MJO theory. Time series of echo-top heights indicate that convective deepening during the MJO onset occurs over a 12–16-day period. Composite statistics show evident recharging–discharging features in convection and the environment. Population of shallow/isolated convective cells, SST, CAPE, and the lower-tropospheric moisture increase (recharge) substantially approximately tw...
A graph theoretic approach to markets for indivisible goods

Abstract Many important markets, such as the labor market and the housing market, involve goods that are both indivisible and of budgetary significance. We introduce new graph theoretic objects ideally suited to analyzing such markets. We show that the minimum equilibrium price is characterized by a certain optimization problem on these graph theoretic objects.
Stator/rotor interaction in a transonic turbine

This paper presents calculations of a stator/rotor interaction in a highly loaded transonic first turbine stage. Of particular interest is the propagation and reflection of shocks which originate at the trailing edge of the upstream stator. These produce a 40% variation in the lift on the rotor, which would cause structural vibrations and increased losses. Also, the unsteady shocks would cause temporary boundary-layer separation near the leading edge of the suction surface. The numerical procedure solves the inviscid unsteady Euler equations, including quasi-three-dimensional terms. The use of a conservative treatment guarantees the correct treatment of the moving shocks. A simple technique is used to couple the calculations on the stator and rotor grids. A key feature of the paper is the use of "time-incline d" computational planes to allow the analysis of cases in which the ratio of stator and rotor pitches is not equal to unity or the ratio of two small integers.
A Highly Stereoselective Diels–Alder Cycloaddition of Enones with Chiral Cyclic 2-Amidodienes Derived from Allenamides

Lewis acid promoted Diels–Alder cycloadditions of a series of de novo chiral cyclic 2-amidodienes are described. These cyclic 2-amidodienes are derived from chiral α-allyl allenamides via a sequence of E-selective 1,3-H shift and 6π-electron pericyclic ring closure. With enones serving as effective dienophiles, these cycloadditions can be highly diastereoselective depending upon the chiral amide substituent, thereby representing a facile entry to optically enriched [2.2.2]bicyclic manifolds.
Algorithm-based checkpoint-free fault tolerance for parallel matrix computations on volatile resources

As the size of today's high performance computers increases from hundreds, to thousands, and even tens of thousands of processors, node failures in these computers are becoming frequent events. Although checkpoint/rollback-recovery is the typical technique to tolerate such failures, it often introduces a considerable overhead. Algorithm-based fault tolerance is a very cost-effective method to incorporate fault tolerance into matrix computations. However, previous algorithm-based fault tolerance methods for matrix computations are often derived using algorithms that are seldomly used in the practice of today's high performance matrix computations and have mostly focused on platforms where failed processors produce incorrect calculations. To fill this gap, this paper extends the existing algorithm-based fault tolerance to the volatile computing platform where the failed processor stops working and applies it to scalable high performance matrix computations with two dimensional block cyclic data distribution. We show the practicality of this technique by applying it to the ScaLAPACK/PBLAS matrix-matrix multiplication kernel. Experimental results demonstrate that the proposed approach is able to survive process failures with a very low performance overhead.
mP‐BaP3: A New Phase from an Old Binary System

A polyphosphide, mP-BaP3, with a unique two-dimensional phosphorus layer has been discovered and characterized. It crystallizes in the monoclinic space group P2₁/c with unit-cell parameters a=6.486(1), b=7.710(1), c=8.172(2) A; β=104.72(3)°; Z=4. Its phosphorus polyanion can be derived from the strong elongation of 2/3 of the P-P bonds present in the layers of black phosphorus. The unit-cell volume of the mP-BaP3 phase is 1.4% larger than the volume of another polymorph, mS-BaP3, reported more than 40 years ago. The latter phase features the presence of one-dimensional phosphorus chains separated by Ba atoms. The differences in the structures of the phosphorus fragments in both polymorphs of barium triphosphide result in large differences in both the thermal stability of these materials as well as in their properties as evidenced by DSC, (31)P solid-state MAS NMR, UV/Vis, and surface photovoltage spectroscopies, alongside quantum-chemical calculations.
Entry and Bidding in Common and Private Value Auctions with an Unknown Number of Rivals

In many procurement auctions bidders do not know how many rivals they face at the time that they incur the cost of preparing their bids. We show in a theoretical model that regardless of whether the procurement is characterized by private or by common values an increase in the potential number of bidders may lead to higher procurement costs. This raises potential policy questions of whether and how entry should be encouraged or limited in public procurement auctions. We use evidence from auctions of construction contracts to estimate the effect of an increase in the pool of potential bidders on entry and auction prices when entry and bidding decisions are made sequentially with no knowledge of the number or identity of the actual competitors.
Sample-Align-D: A high performance Multiple Sequence Alignment system using phylogenetic sampling and domain decomposition

Multiple sequence alignment (MSA) is one of the most computationally intensive tasks in Computational Biology. Existing best known solutions for multiple sequence alignment take several hours (in some cases days) of computation time to align, for example, 2000 homologous sequences of average length 300. Inspired by the Sample Sort approach in parallel processing, in this paper we propose a highly scalable multiprocessor solution for the MSA problem in phylogenetically diverse sequences. Our method employs an intelligent scheme to partition the set of sequences into smaller subsets using k- mer count based similarity index, referred to as k-mer rank. Each subset is then independently aligned in parallel using any sequential approach. Further fine tuning of the local alignments is achieved using constraints derived from a global ancestor of the entire set. The proposed sample-align-D algorithm has been implemented on a cluster of workstations using MPI message passing library. The accuracy of the proposed solution has been tested on standard benchmarks such as PREFAB. The accuracy of the alignment produced by our methods is comparable to that of well known sequential MSA techniques. We were able to align 2000 randomly selected sequences from the Methanosarcina acetivorans genome in less than 10 minutes using sample-align-D on a 16 node cluster, compared to over 23 hours on sequential MUSCLE system running on a single cluster node.
Random weighted projections, random quadratic forms and random eigenvectors

We present a concentration result concerning random weighted projections in high dimensional spaces. As applications, we prove 1 New concentration inequalities for random quadratic forms. 2 The infinity norm of most unit eigenvectors of a random ±1 matrix is of order Ologn/n. 3 An estimate on the threshold for the local semi-circle law which is tight up to a logn factor. © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 47, 792-821, 2015
Control of stress in protected silver mirrors prepared by plasma beam sputtering

Plasma beam sputtering was used to deposit dielectric-protected silver mirrors that exhibited excellent durability and controlled stress. The durability of the mirrors was strongly dependent upon the presence of a very thin chromium adhesion layer between the silver layer and the dielectric overcoat. The stress of the five-layer mirror was balanced by controlling the compressive stress in the top dielectric layer, offsetting the net tensile stress of the combination of layers below.
Impurity Alkali Diffusion in Sodium-Cesium Silicate Glasses

The tracer diffusion coefficient of 86Rh was measured as a function of Cs/Na ratio in (Na, CS)2O:3SiO2 glasses. A comparison of the compositional dependence of this impurity alkali diffusion with the self-diffusion coefficients of 22Na and 137Cs suggests that the alkali-ion pair concept in the weak-electrolyte model is not sufficient to explain the mixed-alkali effect.
Sovereign Debt Repurchases: No Cure for Overhang

Troubled debtor countries do not gain by repurchasing external bank debt at market discount, even if a buyback would stimulate investment by relieving debt overhang. The reason is that buybacks allow creditors to reap more than 100 percent of any efficiency gains that might result from increased investment. We show that open-market buybacks provide a benchmark for evaluating more complex negotiated buyback deals. By comparing any given deal with a hypothetical market buyback of the same size, one can derive upper and lower bounds on the gain to the country. We apply our model to the 1990 Mexican debt deal.
Symptom Burden: Multiple Symptoms and Their Impact as Patient-Reported Outcomes

Cancer and its treatment produce multiple symptoms that significantly distress patients and impair function. Symptoms caused by treatment may delay treatment or lead to premature treatment termination, and residual treatment-related symptoms often complicate posttreatment rehabilitation. When treatment is no longer possible, symptom control becomes the focus of cancer care. Patient ratings of symptom severity and impact are important patient-reported outcomes (PROs) in cancer clinical trials and comprise a subset of a larger domain of PROs generally referred to as health-related quality of life (HRQOL). Symptoms rarely occur in isolation; rather, there is now ample evidence that symptoms frequently occur in clusters. The impact of these multiple symptoms upon the patient can be described as "symptom burden," a concept that encompasses both the severity of the symptoms and the patient's perception of the impact of the symptoms. The distress caused by symptoms is a subject of much investigation, and several validated measures of the severity and impact of multiple symptoms are now available. Symptom measures are generally brief, thereby reducing respondent burden, and can be administered repeatedly during a trial to give a relatively fine-grained picture of the patient's status across time. In many instances, information on trial-related changes in symptom burden, or comparison of symptom burden between arms in a clinical trial, may provide sufficient self-report data for clinical trial consumers (patients, clinicians, and regulators) to make treatment choices or to evaluate new therapies, without measuring other HRQOL domains.
The Solo operating system: processes, monitors and classes

This paper describes the implementation of the Solo operating system written in Concurrent Pascal. It explains the overall structure and details of the system in which concurrent processes communicate by means of a hierarchy of monitors and classes. The concurrent program is a sequence of nearly independent components of less than one page of text each. The system has been operating since May 1975.
Measured vehicular antenna performance

Power gain radiation patterns of mobile antennas mounted in six different locations on a test vehicle were measured with and without typical lights and sirens mounted on the roof. The measurements were performed at frequencies representing the frequency bands of 25 to 50, 150 to 174, 400 to 512, and 806 to 866 MHz. In addition, special antennas consisting of three disguised antennas operating at discrete frequencies of 40.27, 162.475, and 416.975 MHz and one slot antenna operating at 413 MHz were also measured. Plots of power gain radiation patterns are given for the mobile antennas mounted in six different locations on the test vehicle and for the special antennas. Results showing the effects of poor grounding characteristics are also included. Recommended locations for mounting the mobile antennas are given for specific frequency bands.
Analysis of spectral regrowth of weakly nonlinear power amplifiers

Power amplifiers (PAs) are important components in a wireless communications system. Linearity and efficiency are two desirable but conflicting requirements of a PA. All PAs exhibit varying degrees of nonlinearity which causes spectral regrowth and adjacent channel interference. Based on the behavior model of the PA and statistics of the input, it is possible to infer spectral regrowth in the output. Existing analytical results on spectral regrowth assume that the input is Gaussian, which is unrealistic for many digital communications signals. We derive a closed form expression between the covariance function (and hence the power spectrum) of the output and statistics of the input, based on a polynomial behavior model of the PA, without assuming that the input is Gaussian. Such analytical results are useful in finding optimal operating conditions of the PA so that maximum efficiency is achieved without violating the out-of-band emission requirement.
Feature selection in simple neurons: How coding depends on spiking dynamics

The relationship between a neuron's complex inputs and its spiking output defines the neuron's coding strategy. This is frequently and effectively modeled phenomenologically by one or more linear filters that extract the components of the stimulus that are relevant for triggering spikes and a nonlinear function that relates stimulus to firing probability. In many sensory systems, these two components of the coding strategy are found to adapt to changes in the statistics of the inputs in such a way as to improve information transmission. Here, we show for two simple neuron models how feature selectivity as captured by the spike-triggered average depends on both the parameters of the model and the statistical characteristics of the input.
Relativistic Klystron amplifiers driven by modulated intense relativistic electron beams

An overview is provided for the novel relativistic klystron amplifiers which are under active study at the Naval Research Laboratory. These amplifiers are driven by an annular intense relativistic electron beam (500-kV, 10-kA range), which is modulated by an external RF source (1.3-GHz, 100-kW range). Experiments, theory, simulation, and simple models are presented to illustrate the unusual properties of such devices which result from the intense space charge of the beam. Chief among them are electrostatic insulation against vacuum breakdown at high power levels, efficient current modulation, short bunching length, and amplitude and phase stability of the output signal. Many of these unexpected features were revealed in two separate experiments: one with a lower current beam (5 kA, 2-cm beam radius), and the other one with a higher current beam (16 kA, 6.6-cm beam radius). Three gigawatts of RF power at 1.3 GHz were generated with the large diameter beam at an efficiency of 35% with 37-dB gain. These experiments are reviewed, along with a combination of particle simulation results and analytic models which facilitate the interpretation. Special attention is paid to the unfamiliar features of these amplifiers, and the critical problems which must be solved before such amplifiers can fulfil their potential in a wide range of applications are addressed. >
A Repair Framework for Scalar MDS Codes

Several works have developed vector-linear maximum-distance separable (MDS) storage codes that minimize the total communication cost required to repair a single coded symbol after an erasure, referred to as repair bandwidth (BW). Vector codes allow communicating fewer sub-symbols per node, instead of the entire content. This allows non trivial savings in repair BW. In sharp contrast, classic codes, like Reed-Solomon (RS), used in current storage systems, are deemed to suffer from naive repair, i.e. downloading the entire stored message to repair one failed node. This mainly happens because they are scalar-linear. In this work, we present a simple framework that treats scalar codes as vector-linear. In some cases, this allows significant savings in repair BW. We show that vectorized scalar codes exhibit properties that simplify the design of repair schemes. Our framework can be seen as a finite field analogue of real interference alignment. Using our simplified framework, we design a scheme that we call clique-repair which provably identifies the best linear repair strategy for any scalar 2-parity MDS code, under some conditions on the sub-field chosen for vectorization. We specify optimal repair schemes for specific (5,3)- and (6,4)-Reed-Solomon (RS) codes. Further, we present a repair strategy for the RS code currently deployed in the Facebook Analytics Hadoop cluster that leads to 20% of repair BW savings over naive repair which is the repair scheme currently used for this code.
Near-Infrared Spectroscopy of Molecular Filaments in the Reflection Nebula NGC 7023

We present near-infrared spectroscopy of Nuorescent molecular hydrogen emission from molecu- (H 2 ) lar -laments in the reNection nebula NGC 7023. We derive the relative column densities of H 2 rotational-vibrational states from the measured line emission and compare these results with several model photodissociation regions covering a range of densities, incident UV -elds, and excitation mecha- nisms. Our best--t models for one -lament suggest, but do not require, either a combination of di†erent densities, suggesting clumps of 106 cm~3 in a1 0 4 E105 cm~3 -lament, or a combination of Nuorescent excitation and thermally excited gas, perhaps due to a shock from a bipolar outNow. We derive densities and UV -elds for these molecular -laments that are in agreement with previous determinations. Subject headings: infrared: ISM: lines and bands E ISM: individual (NGC 7023) E ISM: molecules E ISM: structure E reNection nebulae
Detecting cold dark-matter candidates.

The growing synergy between astrophysics, particle physics, and low background experiments strengthens the possibility of detecting astrophysical non-baryonic matter. The idea of direct detection is that an incident, massive weakly interacting particle could collide with a nucleus and transfer an energy that could be measured. The present low levels of background achieved by the PNL/USC Ge detector represent a new technology which yields interesting bounds on galactic cold dark matter and on light bosons emitted from the Sun. Further improvements require the development of cryogenic detectors, e.g. superheated superconducting colloid (SSCD) and crystal bolometers. We report two tests designed to study the practicality of a superheated superconducting colloid detector using a SQUID readout system. Furthermore, we show that in case of particles with spin interactions, one should consider detectors based on compounds of boron, lithium and fluorine.
Learning from Los Angeles: Transport, Urban Form, and Air Quality

Los Angeles is well known around the world as an automobile-oriented low density community, yet recent transportation policies have emphasized greater capital investment in rail transportation than in highways, and recent policies have attempted to discourage automobile usage through transportation demand management. While these policies have accomplished small shifts toward public transport and somewhat lower dependence upon singly occupied automobilies for work commuting, the financial costs of these policy changes has been very large in relation to their benefits. Proper pricing of transportation alternatives, more creative use of new and emerging transportation technologies, and the provision of many more opportunities for simpler private sector transport services, would all appear to be more promising as cost-effective approaches to coping with congestion in Los Angeles than the current regional transportation policies.
Azimuthal anisotropy of charged and identified high pT hadrons in Au+Au collisions at RHIC

We report new results on v{sub 2}(p{sub T}) for Au+Au collisions at {radical}(S{sub NN}) = 200 GeV for charged hadrons, pions, kaons,(anti)protons, K{sub s}{sup 0}, and Lambda. The analysis is extended to p{sub T} = 12 GeV/c for charged hadrons and p{sub T} = 4 GeV/c for identified particles. A comparison of the azimuthal anisotropy of charged hadrons measured at sqrt {radical}(s{sub NN}) = 130 and 200 GeV is presented. The p{sub T}-dependence of baryon versus meson elliptic flow is discussed.
Tidal alignments as a contaminant of the galaxy bispectrum

If the orientations of galaxies are correlated with large-scale structure, then anisotropic selection effects such as preferential selection of face-on disc galaxies can contaminate large-scale structure observables. Here we consider the effect on the galaxy bispectrum, which has attracted interest as a way to break the degeneracy between galaxy bias and the amplitude of matter fluctuations σ_8. We consider two models of intrinsic galaxy alignments: one where the probability distribution for the galaxy’s orientation contains a term linear in the local tidal field, appropriate for elliptical galaxies; and one with a term quadratic in the local tidal field, which may be applicable to disc galaxies. We compute the correction to the redshift space bispectrum in the quasi-linear regime, and then focus on its effects on parameter constraints from the transverse bispectrum, i.e. using triangles (k_1, k_2, k_3) in the plane of the sky. We show that in the linear alignment model, intrinsic alignments result in an error in the galaxy bias parameters, but do not affect the inferred value of σ8. In contrast, the quadratic alignment model results in a systematic error in both the bias parameters and σ8. However, the quadratic alignment effect has a unique configuration dependence that should enable it to be removed in upcoming surveys.
Testing Subgame Perfection Apart From Fairness in Ultimatum Games

We present an experiment designed to separate the two commonplace explanations for behavior in ultimatum games—subjects’ concern for fairness versus the failure of subgame perfection as an equilibrium re…nement. We employ a tournament structure of the bargaining interaction to eliminate the potential for fairness to in‡uence behavior. Comparing the results
Stereoselective Preparation of (E)- and (Z)-α-Fluorostilbenes via Palladium-Catalyzed Cross-Coupling Reaction of High E/Z Ratio and (Z)-1-Bromo-1-fluoroalkenes

A highly stereoselective method to prepare both (E)- and (Z)-α-fluorostilbenes is described. 1-Bromo-1-fluoroalkenes (E/Z ≈ 1:1), a readily available starting material, isomerizes to high E/Z ratios by storage at −20 °C or by photolysis at 254 nm. Stille coupling between these high E/Z 1-bromo-1-fluoroalkenes and aryl stannanes gave (Z)-α-fluorostilbenes in high stereoselectivity. (Z)-1-Bromo-1-fluoroalkenes, which were kinetically separated from 1-bromo-1-fluoroalkenes (E/Z ≈ 1:1), can participate in Suzuki coupling reactions to give (E)-α-fluorostilbenes stereoselectively.
Evolutionary Perspectives on Religion

Recent work in biology, cognitive psychology, and archaeology has renewed evolutionary perspectives on the role of natural selection in the emergence and recurrent forms of religious thought and behavior, i.e., mental representations of supernatural agents, as well as artifacts, ritual practices, moral systems, ethnic markers, and specific experiences associated with these representations. One perspective, inspired from behavioral ecology, attempts to measure the fitness effects of religious practices. Another set of models, representative of evolutionary psychology, explain religious thought and behavior as the output of cognitive systems (e.g., animacy detection, social cognition, precautionary reasoning) that are not exclusive to the religious domain. In both perpectives, the question remains open, whether religious thought and behavior constitute an adaptation or a by-product of adaptive cognitive function.
Nonlinear Pricing Kernels, Kurtosis Preference, and Evidence from the Cross Section of Equity Returns

This paper investigates nonlinear pricing kernels in which the risk factor is endogenously determined and preferences restrict the definition of the pricing kernel. These kernels potentially generate the empirical performance of nonlinear and multifactor models, while maintaining empirical power and avoiding ad hoc specifications of factors or functional form. Our test results indicate that preferencerestricted nonlinear pricing kernels are both admissible for the cross section of returns and are able to significantly improve upon linear single- and multifactor kernels. Further, the nonlinearities in the pricing kernel drive out the importance of the factors in the linear multi-factor model.
Tax Avoidance: Does Tax-Specific Industry Expertise Make a Difference?

ABSTRACT : This study investigates whether the tax-specific industry expertise of the external audit firm influences its clients' level of tax avoidance. Our results suggest that clients purchasing...
Design of patchy particles using ternary self-assembled monolayers

Binary and ternary self-assembled monolayers (SAMs) adsorbed on gold nanoparticles (NPs) have been previously studied for their propensity to form novel and unexpected patterns. The patterns found were shown to arise from a competition between immiscibilty of unlike surfactants and entropic gains due to length or other architectural differences between them. We investigate patterns self-assembled from quaternary monolayers on spherical nanoparticles. We perform simulations to study the effect of NP radius, degree of immiscibility between surfactants, length differences, and stoichiometry of the SAM on the formation of patterns. We report patterns analogous to binary and ternary cases, as well as some novel patterns specific to quaternary SAMs.
Services, industry evolution, and the competitive strategies of product firms

Services of different types have become increasingly important for product firms. While these firms mainly focus on products, managers and researchers lack a comprehensive framework to understand when to make significant investments in particular kinds of services. We identify three categories of product-related services from a product firm—smoothing and adapting services, which complement products, and substitution services, which enable customers to pay for the use of a product without buying the product itself. We develop propositions about the relative level of these different kinds of services vis-a-vis industry evolution, as well as suggest how these services affect industry structure. We draw upon various literatures, though we conclude that the relationship between products and services is more complex and richer than any one literature suggests.
Broadband impedance of azimuthally symmetric devices in RHIC

The interaction between the beam and its environment leads to beam instabilities, and is characterized by coupling impedance. The longitudinal coupling impedance of some RHIC devices with azimuthal symmetry such as bellows, pipe transition, gate valve and collimator have been calculated numerically using the time domain code TBCI. The objective is to keep the broadband impedance below a threshold so that it satisfies the microwave stability criteria; and make sure there is no contribution to narrowband impedance from any of these structures. >
Making Gradient Descent Optimal for Strongly Convex Stochastic Optimization

Stochastic gradient descent (SGD) is a simple and popular method to solve stochastic optimization problems which arise in machine learning. For strongly convex problems, its convergence rate was known to be O(log(T)/T), by running SGD for T iterations and returning the average point. However, recent results showed that using a different algorithm, one can get an optimal O(1/T) rate. This might lead one to believe that standard SGD is suboptimal, and maybe should even be replaced as a method of choice. In this paper, we investigate the optimality of SGD in a stochastic setting. We show that for smooth problems, the algorithm attains the optimal O(1/T) rate. However, for non-smooth problems, the convergence rate with averaging might really be Ω(log(T)/T), and this is not just an artifact of the analysis. On the flip side, we show that a simple modification of the averaging step suffices to recover the O(1/T) rate, and no other change of the algorithm is necessary. We also present experimental results which support our findings, and point out open problems.