cssi/SciSciGPT-SciSciNet huggingface dataset:
Local monopsony and free riders

Abstract In an industry with upstream economies of scale in the distribution of differentiated products to retailers which have monopoly power within separate local market areas, the retailers have an incentive to exert monopsony power due to the divergence between average and marginal costs in the distribution of those inputs. The retailers increase their ability to exert monopsony power by forming coalitions (that is, chains) across local markets. Sufficiently large retail chains may force input price below the seller's average cost, thus ‘free riding’ on the level of product variety supported by other retailers. Vertical integration, cartels, or other cooperative behavior, however, can be means to control the level of product variety, and may increase both industry profits and economic welfare. Policy applications to the cable television, motion picture, and pharmaceutical industries are discussed.
An analysis of thrust-induced effects on the longitudinal aerodynamics of STOL fighter configurations

An analysis of the thrust-induced longitudinal aerodynamic characteristics of three fighter-type configurations is presented. A brief discussion of the take-off and landing requirements for the next generation fighter aircraft leads to the conclusion that advances in lift coefficient and thrust reversing will be required to allow short-field operation. Typical power-on longitudinal aerodynamic data for the three fighter configurations, indicating different approaches to meeting the high-lift coefficient requirement, are discussed. Thrust reversing is not addressed in this paper. The power-on data are analyzed to determine what power effects are present, that is, direct thrust, boundary-layer control, vortex flows, or supercirculation. The results of the analysis indicate, for the configurations studied, that induced effects are small compared to direct thrust and that boundary-layer control, rather than leading-edge vortex flows or supercirculation, is the only significant thrust-induced effect.
Magnetic Properties of Ordered and Disordered Spinel‐Phase Ferrimagnets

In spinel-phase ferrimagnets, disorder in the cation distribution between octahedral and tetrahedral sites can influence such fundamental magnetic properties as saturation magnetization, exchange coupling, and ferrimagnetic ordering temperatures. Given the sensitivity of magnetic properties to structure, it has been suggested that magnetic properties may be used as a probe of disorder in ferrimagnetic spinels. In this article, we review the fundamentals of the magnetic properties of spinel ferrites, including the interesting manifestation of noncollinear spin structures in Yafet-Kittel triangular spin configurations. This is followed by description of some experimental observations on the structure and magnetic properties of (MnxAl1-x)3O4 spinels and hausmannites, which exhibit Yafet-Kittel-type ordering in their spin structures.
The implications of electronic health records for personalized medicine.

The emerging concept of an electronic health record (EHR) targeted at a patient centric, cross-institutional and longitudinal information entity (possibly spanning the individuals lifetime) has great promise for personalized medicine. In fact, it is probably the only vehicle through which we may truly realize the personalization of medicine beyond population-based genetic profiles that are expected to become part of medication and treatment indications in the near future. The new EHR standards include mechanisms that integrate clinical data with genomic testing results obtained through applying research-type procedures, such as full DNA sequencing, to an individual patient. Although the most optimal process for the utilization of integrated clinical-genomic data in the EHR framework is still unclear, the new Health Level Seven (HL7) Clinical Genomics Draft Standard for Trial Use suggests using the ‘encapsulate & bubble-up’ approach, which includes two main phases: the encapsulation of raw genomic data and...
A Predictive approach for adaptive inferential control

Abstract To improve the regulatory performance of the adaptive inferential control system, a cautious on-line parameter estimation algorithm and an adaptive predictive model for unmeasured load disturbances are proposed. The cautious on-line parameter estimation algorithm is used to provide reliable model parameter values in the presence of frequent changes in unmeasured disturbances. Then, the future effects of load disturbances are predicted through the use of an autoregressive model based on the estimated load disturbances. Simulation results demonstrate that better regulatory performance can be obtained with a proper selection of the prediction horizon.
The effect of spiral structure on the measurements of the Oort constants

We perform test-particle simulations in a 2D, differentially rotating stellar disc, subjected to a two-armed steady state spiral density wave perturbation in order to estimate the influence of spiral structure on the local velocity field. By using Levenberg‐Marquardt least-squares fit we decompose the local velocity field (as a result of our simulations) into Fourier components to fourth order. Thus we obtain simulated measurements of the Oort constants, A, B, C and K. We get relations between the Fourier coefficients and some galactic parameters, such as the phase angle of the solar neighbourhood and the spiral pattern speed. We show that systematic errors due to the presence of spiral structure are likely to affect the measurements of the Oort constants (OC). Moderate strength spiral structure causes errors of order 5 km s −1 kpc −1 in A and B. We find variations of the Fourier coefficients with velocity dispersion, pattern speed and sample depth. For a sample at an average heliocentric distance of 0.8 kpc we can summarize our findings as follows: (i) if our location in the Galaxy is near corotation then we expect a vanishing value for C for all phase angles; (ii) for a hot disc, spiral structure induced errors for all OC vanish at, and just inward of the corotation radius; (iii) as one approaches the 4:1 Lindblad resonances |C| increases and so does its variation with galactic azimuth; (iv) for all simulations |C|, on average, is larger for lower stellar velocity dispersions, contrary to recent measurements.
A comparison of Gd-153 and Co-57 as transmission sources for simultaneous TCT and Tl-201 SPECT

In this study we investigated the potential of Gd-153 and Co-57 as transmission sources. Since both of these sources have higher energy photopeaks higher than that of the predominant Tl-201 photons, they will result in contamination of the emission data. The amount of contamination and the ease of compensating for it are important factors in selecting an isotope for the transmission source. These factors were investigated and, based on these studies, we conclude that both isotopes result in a level of contamination that is significant in comparison to typical Tl-201 emission count levels. While Gd-153 results in approximately 50% more contamination of the emission data than Co-153, the object dependence of the contamination for both isotopes is such that contamination compensation will be difficult. In fact, compensation may be somewhat easier for Gd-153. As a result, selection of one of these isotopes may be based on other considerations such as cost and usability with other emission isotopes. >
The Myth of the Bureaucratic Paradigm: What Traditional Public Administration Really Stood For

For a decade, public administration and management literature has featured a riveting story: the transformation of the field's orientation from an old paradigm to a new one. While many doubt claims concerning a new paradigm—a New Public Management—few question that there was an old one. An ingrained and narrowly focused pattern of thought, a “bureaucratic paradigm,” is routinely attributed to public administration's traditional literature. A careful reading of that literature reveals, however, that the bureaucratic paradigm is, at best, a caricature and, at worst, a demonstrable distortion of traditional thought that exhibited far more respect for law, politics, citizens, and values than the new, customer-oriented managerialism and its variants. Public administration as a profession, having let lapse the moral and intellectual authority conferred by its own traditions, mounts an unduly weak challenge to the superficial thinking and easy answers of the many new paradigms of governance and public service. As a result, literature and discourse too often lack the recognition that reformers of institutions and civic philosophies must show how the capacity to effect public purposes and accountability to the polity will be enhanced in a manner that comports with our Constitution and our republican institutions.
Structured Training for Neural Network Transition-Based Parsing

We present structured perceptron training for neural network transition-based dependency parsing. We learn the neural network representation using a gold corpus augmented by a large number of automatically parsed sentences. Given this fixed network representation, we learn a final layer using the structured perceptron with beam-search decoding. On the Penn Treebank, our parser reaches 94.26% unlabeled and 92.41% labeled attachment accuracy, which to our knowledge is the best accuracy on Stanford Dependencies to date. We also provide indepth ablative analysis to determine which aspects of our model provide the largest gains in accuracy.
MAGNETIC RECONNECTION AS THE CAUSE OF COSMIC RAY EXCESS FROM THE HELIOSPHERIC TAIL

The observation of a broad excess of sub-TeV cosmic rays compatible with the direction of the heliospheric tail and the discovery of two significant localized excess regions of multi-TeV cosmic rays by the MILAGRO Collaboration, also from the same region of the sky, have raised questions on their origin. In particular, the coincidence of the most significant localized region with the direction of the heliospheric tail and the small angular scale of the observed anisotropy (~10°) is suggestive of a local origin and of a possible connection to the low-energy broad excess. Cosmic ray acceleration from magnetic reconnection in the magnetotail is proposed as a possible source of the energetic particles.
The diameter of the set of boundary slopes of a knot

Let K be a tame knot with irreducible exterior M.K/ in a closed, connected, orientable 3–manifold † such that 1.†/ is cyclic. If 1 is not a strict boundary slope, then the diameter of the set of strict boundary slopes of K , denoted dK , is a numerical invariant of K . We show that either (i) dK 2 or (ii) K is a generalized iterated torus knot. The proof combines results from Culler and Shalen [3] with a result about the effect of cabling on boundary slopes.
Dissipative, forced turbulence in two-dimensional magnetohydrodynamics

The equations of motion for turbulent two-dimensional magnetohydrodynamic flows are solved in the presence of finite viscosity and resistivity, for the case in which external forces (mechanical and/or magnetic) act on the fluid. The goal is to verify the existence of a magnetohydrodynamic dynamo effect which is represented mathematically by a substantial back-transfer of mean square vector potential to the longest allowed Fourier wavelengths. External forces consisting of a random part plus a fraction of the value at the previous time step are employed, after the manner of Lilly for the Navier-Stokes case. The regime explored is that for which the mechanical and magnetic Reynolds numbers are in the region of 100 to 1000. The conclusions are that mechanical forcing terms alone cannot lead to dynamo action, but that dynamo action can result from either magnetic forcing terms or from both mechanical and magnetic forcing terms simultaneously.
Strategy, stakeholders and managerial discretion

We begin by elaborating on the building blocks for understanding the dynamic interrelationships between stakeholder theory, managerial discretion and stakeholder orientation. We then provide a sketch of the dynamic between managerial discretion and stakeholder orientation and their likely interaction. We conclude by considering some future research directions motivated by this dynamic.
Attitude Control of a Space Platform/Manipulator System Using Internal Motion

Attitude control of a space platform/manipulator system, using internal motion, is an example of a nonholonomic motion plan ning (NMP) problem arising from symmetry and conservation laws. Common to NMP problems are that an admissible con figuration space path is constrained to a given nonholonomic distribution. We formulate the dynamic equations of a system consisting of a 3-DOF PUMA-like manipulator attached to a space platform (e.g., a space station or a satellite) as an NMP problem and discuss the controllability of the system. Then we describe the application of a simple algorithm for obtaining approximate optimal solutions. We conclude with a descrip tion of simulation software implementing the algorithm and simulation results for two experiments.
The Conley index, gauge theory, and triangulations

This is an expository paper about Seiberg–Witten Floer stable homotopy types.We outline their construction, which is based on the Conley index and finite-dimensional approximation. We then describe several applications, including the disproof of the high-dimensional triangulation conjecture.
The Aggregate Effects of Health Insurance: Evidence from the Introduction of Medicare

This paper investigates the effects of market-wide changes in health insurance by examining the single largest change in health insurance coverage in American history: the introduction of Medicare in 1965. I estimate that the impact of Medicare on hospital spending is over six times larger than what the evidence from individual-level changes in health insurance would have predicted. This disproportionately larger effect may arise if market-wide changes in demand alter the incentives of hospitals to incur the fixed costs of entering the market or of adopting new practice styles. I present some evidence of these types of effects. A back of the envelope calculation based on the estimated impact of Medicare suggests that the overall spread of health insurance between 1950 and 1990 may be able to explain about half of the increase in real per capita health spending over this time period.
Relaxed commutant lifting: Existence of a unique solution

In this paper we present necessary and sufficient conditions for the existence of a unique solution to the relaxed commutant lifting problem. The obtained conditions are more complicated than those for the classical commutant lifting setting, and earlier obtained sufficient conditions turn out not to be necessary conditions. It is also shown that these conditions simplify in certain special cases.
Dilatancy Transition in a Granular Model

We introduce a model of granular matter and use a volume/strain ensemble to analyze infinitesimal shearing. Monte Carlo simulation suggests the model exhibits a second order phase transition associated with the onset of dilatancy.
Availability of Enriched Isotopic Material for Accelerator Targets

The electromagnetic isotope enrichment facility at the Oak Ridge National Laboratory provides a broad spectrum of highly enriched stable isotopes to the worldwide scientific community. The continued timely availability of these materials is of vital importance in many areas of basic research and, in particular, as source material for the fabrication of accelerator targets. A brief description of the facility and its capabilities and limitations is presented.
Computational Study of Small Molecule Binding for Both Tethered and Free Conditions

Using a calix[4]arene-benzene complex as a test system, we compare the potential of mean force for when the calix[4]arene is tethered versus free. When the complex is in vacuum, our results show that the difference between tethered and free is primarily due to the entropic contribution to the potential of mean force resulting in a significant binding free energy difference of 6.6 kJ/mol. By contrast, when the complex is in water, our results suggest that there is no appreciable difference between tethered and free. This study elucidates the roles of entropy and enthalpy for this small molecule system and emphasizes the point that tethering the receptor has the potential to dramatically impact the binding properties. These findings should be taken into consideration when using calixarene molecules in nanosensor design.
Ab initio linear response study of SrTiO3

Abstract The lattice instabilities of perovskite structure oxides are responsible for many of their interesting properties, such as temperature-dependent ferroelectric phase transitions. First-principles calculations using linear response theory provide an accurate means to determine the lattice dynamics throughout the entire Brillouin zone (BZ). Using the LAPW linear response method[1], we have previously carried out such a study on ferroelectric KNbO3 [2]. We present here the results of a similar investigation for cubic SrTiO3. While KNbO3 has only ferroelectric-type instabilities, SrTiO3 exhibits both ferroelectric (FE) and antiferrodistortive (AFD) instabilities. We correctly predict the known instability at the R-point in the Brillouin zone, which is responsible for the AFD phase transition to the tetragonal structure at about 105 K. Furthermore, the phase space of the ferroelectric instability is greatly reduced compared to KNbO3. Antiferrodistortive instabilities exist in one-dimensional cylindrica...
Multiple-bidding in auctions as bidders become confident of their private valuations.

A bidder may increase his bid over the course of an auction when (1) he becomes more certain about his private valuation over time (as he has more time to consider using the item), and (2) there is a positive probability he is unable to return to the auction to submit a bid in a later period.
Completion Time Minimization and Robust Power Control in Wireless Packet Networks

A wireless packet network is considered in which each user transmits a stream of packets to its destination. The transmit power of each user interferes with the transmission of all other users. A convex cost function of the completion times of the user packets are minimized by optimally allocating the users' transmission power subject to their respective power constraints. It is shown that, at all ranges of SINR, completion time minimization can be formulated as a convex optimization problem and hence can be efficiently solved. When channel knowledge is imperfect, robust power control is considered based on the channel fading distribution subject to outage probability constraints. The problem is shown to be convex when the fading distribution is log-concave in exponentiated channel power gains; e.g., when each user is under independent Rayleigh, Nakagami, or log-normal fading.
X-Ray Emission from Extragalactic Jets

AbstractThis review focuses on the X-ray emission processes of extragalactic jets on scales resolvable by the subarcsec resolution of the Chandra X-ray Observatory. It is divided into four parts. The introductory section reviews the classical problems for jets, as well as those associated directly with the X-ray emission. Throughout this section, we deal with the dualisms of low-powered radio sources versus high-powered radio galaxies and quasars and of synchrotron models versus inverse Compton models; and the distinction between the relativistic plasma responsible for the received radiation and the medium responsible for the transport of energy down the jet. The second section collects the observational and inferred parameters for the currently detected X-ray jets and attempts to put their relative sizes and luminosities in perspective. In the third section we first give the relevant radio and optical jet characteristics, and then examine the details of the X-ray data and how they can be related to vario...
Robustly Optimal Monetary Policy with Near-Rational Expectations

The paper considers optimal monetary stabilization policy in a forward-look ing model, when the central bank recognizes that private sector expectations need not be precisely model-consistent, and wishes to choose a policy that will be as good as possible in the case of any beliefs that are close enough to model consistency. It is found that commitment continues to be important for optimal policy, that the optimal long-run inflation target is unaffected by the degree of potential distortion of beliefs, and that optimal policy is even more history dependent than if rational expectations are assumed. (JEL C62, D84, El 3, E31, E32, E52) An extensive literature has considered the optimal conduct of monetary policy under the assumption of rational (or model-consistent) expectations. This literature has found that it is quite important to take account of the effects of the systematic (and hence predictable) compo nent of monetary policy on expectations. For example, it is found quite generally that an optimal policy commitment differs from the policy that would be chosen through a sequential optimiza tion procedure with no advance commitment of future policy. It is also found quite generally that optimal policy is history-dependent?a function of past conditions that no longer affect the degree to which it would be possible to achieve stabilization aims from the present time onward.1 Both of these conclusions depend critically, however, on the idea that an advance commitment of future policy should change people's expectations at earlier dates. This may lead to the fear that analyses that assume rational expectations (RE) exaggerate the degree to which a policy authority can rely upon private sector expectations to be shaped by its policy commitments in precisely the way that it expects them to be. What if the relation between what a central bank plans to do and what the public will expect to happen is not quite so predictable? Might both the case for advance commitment of policy and the case for history-dependent policy be considerably weakened under a more skeptical view of the precision with which the public's expectations can be predicted? One way of relaxing the assumption of rational expectations is to model agents as forecasting using an econometric model, the coefficients of which they must estimate using data observed prior to some date; sampling error will then result in forecasts that depart somewhat from pre cise consistency with the analyst's model.2 However, selecting a monetary policy rule on the basis of its performance under a specific model of "learning" runs the risk of exaggerating the degree to which the policy analyst can predict, and hence exploit, the forecasting errors that result from a particular way of extrapolating from past observations. One might even conclude
Multiple-model adaptive estimation using a residual correlation Kalman filter bank

We propose a modified multiple model adaptive estimation (MMAE) algorithm that uses the time correlation of the Kalman filter residuals, in place of their scaled magnitude, to assign conditional probabilities for each of the modeled hypotheses. This modified algorithm, denoted the residual correlation Kalman filter bank (RCKFB), uses the magnitude of an estimate of the correlation of the residual with a slightly modified version of the usual MMAE hypothesis testing algorithm to assign the conditional probabilities to the various hypotheses that are modeled in the Kalman filter bank within the MMAE. This concept is used to detect flight control actuator failures, where the existence of a single frequency sinusoid (which is highly time correlated) in the residual of an elemental filter within an MMAE is indicative of that filter having the wrong actuator failure status hypothesis. This technique results in a delay in detecting the flight control actuator failure because several samples of the residual must be collected before the residual correlation can be estimated. However, it allows a significant reduction of the amplitude of the required system inputs for exciting the various system modes to enhance identifiability, to the point where they may possibly be subliminal, so as not to be objectionable to the pilot and passengers.
Further Validation of Age-Dependent FE Models of a Mid-Sized Male Thorax

The objective of this study was to further validate three previously-developed, age-dependent finite element models representing 35, 55, and 75 year old mid-sized males. The validation was based on comparisons with the following published tests involving post mortem human subjects: oblique thoracic and abdominal pendulum impact (4-10 m/s), oblique and lateral thoracic pendulum impact (2.5 m/s), and lateral thoracic pendulum impact (4.3 and 6.7 m/s). The responses of the models were compared to cadaveric response corridors and responses from specific cadavers similar in size and age. When compared to the cadaveric response corridors, the model responses were generally within those corridors. When compared to the responses of specific cadavers, the results were mixed. In some of the cases the model responses predicted the age-dependency of the cadaveric responses. In other cases, the model responses had the opposite trend of those of the cadavers. The comparisons of the model-predicted impact force, normalized chest compression, and viscous criterion to those of the cadavers were deemed acceptable. The model-predicted peak rib stress and strain for the different simulations were also reported and were compared to the injury outcome of the tests. Language: en
LOCAL VELOCITY MEASUREMENTS AND COMPUTATIONAL FLUID DYNAMICS (CFD) SIMULATIONS OF SWIRLING FLOW IN A CYLINDRICAL CYCLONE SEPARATOR

Local measurements and 3-D CFD simulations in GasLiquid cylindrical Cyclone (GLCC © ) separators are scarce. The main objective of this study is to conduct local measurements and 3-D CFD simulations to understand the swirling flow behavior in a cylindrical cyclone with one inclined tangential inlet. Axial and tangential velocities and turbulent intensities across the GLCC © diameter (ID=3.5″) were measured at 24 different axial locations (12.5″ to 35.4″ below the inlet) by using a Laser Doppler Velocimeter (LDV). The liquid flow rate was 72GPM, which corresponds to an average axial velocity of 0.732 m/s and Reynolds number of 66,900. Measurements are used to create color contour plots of axial and tangential velocity and turbulent kinetic energy. Color contour maps revealed details of the flow behavior. Additionally, 3-D CFD simulations with different turbulence models are conducted. Simulations results are compared to LDV measurements.
Endogenous Rationing, Price Dispersion and Collusion in Capacity Constrained Supergames ⁄

This paper examines the feasibility of collusion in capacity constrained duopoly supergames. In each period firms simultaneously set a price–quantity pair specifying the price for the period and the maximum quantity the firm is willing to sell at this price. Under price–quantity competition firms are able to ration their output below capacity. For a wide range of capacity pairs, the equilibrium path providing the smaller firm with its highest stationary perfect equilibrium payoff requires that it undercut its rival’s price and ration demand. Furthermore, for some capacities and discount factors supporting security level punishments, price shading and rationing arise everywhere on the set of stationary perfect equilibrium paths yielding (constrained) Pareto optimal payoffs. That is, price shading may not only be consistent with optimal collusion, it may be a requirement of optimal collusion.
How Are Derivatives Used? Evidence from the Mutual Fund Industry

We investigate investment managers' use of derivatives by comparing return distributions for equity mutual funds that use and do not use derivatives. In contrast to public perception, derivative users have risk exposure and return performance that are similar to nonusers. We also analyze changes in fund risk in response to prior fund performance. Changes in risk are substantially less severe for funds using derivatives, consistent with the explanation that managers use derivatives to reduce the impact of performance on risk. We provide new evidence regarding the implications of cash flows and managerial gaming for the relation between performance and risk.
A Multi-Resolution Hidden Markov Model Using Class-Specific Features

We apply the PDF projection theorem to generalize the hidden Markov model (HMM) to accommodate multiple simultaneous segmentations of the raw data and multiple feature extraction transformations. Different segment sizes and feature transformations are assigned to each state. The algorithm averages over all allowable segmentations by mapping the segmentations to a “proxy” HMM and using the forward procedure. A by-product of the algorithm is the set of a posteriori state probability estimates that serve as a description of the input data. These probabilities have simultaneously the temporal resolution of the smallest processing windows and the processing gain and frequency resolution of the largest processing windows. The method is demonstrated on the problem of precisely modeling the consonant “T” in order to detect the presence of a distinct “burst” component. We compare the algorithm against standard speech analysis methods using data from the TIMIT corpus.
A convex control model of dynamic system-optimal traffic assignment

Abstract In this paper, a dynamic system-optimal traffic assignment model is formulated as a convex control problem for a congested general network with many origins and many destinations. Analytical and computational difficulties caused by the nonconvexity of the previous models are eliminated. The modeling of arc traffic dynamics is improved to prohibit instantaneous flow propagation on each arc even though the concave exit functions are still employed to represent the physical process of traffic congestion. An economic interpretation of the optimality conditions is given as a dynamic assignment principle which requires equilibration of actual marginal costs on all the paths that are used. A numerical example is also presented.
A concise route to the core pentasaccharide of N-linked glycoproteins

A concise preparation of the common pentasaccharide core of the N-linked glycoproteins is described. The reducing end glycal is functionalized at the level of chitobiose, which is then β-mannosylated using Crich's direct coupling protocol. Deprotection of the branching mannose residue, and di-α-mannosylation complete the synthesis.
Variational Gaussian Process

Abstract: Representations offered by deep generative models are fundamentally tied to their inference method from data. Variational inference methods require a rich family of approximating distributions. We construct the variational Gaussian process (VGP), a Bayesian nonparametric model which adapts its shape to match complex posterior distributions. The VGP generates approximate posterior samples by generating latent inputs and warping them through random non-linear mappings; the distribution over random mappings is learned during inference, enabling the transformed outputs to adapt to varying complexity. We prove a universal approximation theorem for the VGP, demonstrating its representative power for learning any model. For inference we present a variational objective inspired by autoencoders and perform black box inference over a wide class of models. The VGP achieves new state-of-the-art results for unsupervised learning, inferring models such as the deep latent Gaussian model and the recently proposed DRAW.
Generation of 3-Pyridyl Biaryl Systems via Palladium-Catalyzed Suzuki Cross-Couplings of Aryl Halides with 3-Pyridylboroxin

The synthesis of 3-pyridyl biaryl systems can be readily achieved by means of palladium-catalyzed Suzuki cross-coupling reactions between aryl halides and 3-pyridylboroxin. A series of cross-couplings were conducted in order to investigate the scope and limitations of this protocol.
Cobalt−Phosphite-Catalyzed Asymmetric Pauson−Khand Reaction

A complex formed from dicobalt octacarbonyl and a chiral aryl bisphosphite served as a catalyst for the intramolecular asymmetric Pauson-Khand reaction. Bicyclic cyclopentenones were obtained in up to 75% enantiomeric excess. For a terminal 1,6-enyne, the incremental enantiomeric excess was found to increase from 4 to 26% over the course of the reaction. The scope of this process was examined for a variety of 1,6- and 1,7-enynes, and a moderate degree of enantioselectivity was maintained only in the case of aryl-substituted 1,6-enynes.
Implementing trustworthy services using replicated state machines

A thread of research has emerged to investigate the interactions of replication with threshold cryptography for use in environments that satisfy weak assumptions. The result is a new paradigm known as distributed trust, and this chapter attempts to survey that landscape.
Method for Ensuring Accurate AC Waveforms With Programmable Josephson Voltage Standards

The amplitudes of stepwise-approximated sine waves generated by programmable Josephson voltage standards (PJVS) are not intrinsically accurate because the transitions between the quantized voltages depend on numerous conditions. We have developed a method that ensures that the total rms output voltages of arbitrary ac waveforms synthesized by the PJVS are accurately referenced to the quantized Josephson voltages. This is accomplished by digitizing the output waveform, utilizing the quantized voltages to correct digitizer gain, noise, and nonlinearity, and then utilizing measurements of the bandwidth, rise time, and harmonic content to precisely tune the PJVS bias parameters. Our goal is to develop an AC standard source that can directly synthesize voltages with the accuracy expected of a quantum-based standard without the use of a thermal voltage converter.
Supply chain contracting for vertically differentiated products

Abstract We study a supply chain where the supplier sells a family of vertically differentiated products with varying quality levels through a network of distributors to end consumers who have heterogeneous valuations for quality. With traditional wholesale pricing, it has been shown that the supplier does not share the same incentives as the distributors to sell higher quality products and as a result their economics are not well aligned. To analyze this problem, we consider the simplistic case in which the product family consists of two products with high and low quality. After arguing for the two kinds of distortions caused by the firm׳s status-quo wholesale pricing, we show that some of the earlier contracts studied for one product can be designed to achieve supply chain coordination for this setting with two vertically differentiated products; similarly, we propose a completely new (bundling) contract that is easy to communicate within the supply chain and show that an existing contract (ASP) currently in use in the industry does not necessarily align the incentives and achieve coordination. Because manufacturers generally have a network of distributors, we then extend our results to the case of Cournot competition. We first characterize the emerging equilibrium and then analyze a similar set of coordinating mechanisms. We show that the efficiency of the wholesale pricing contract improves as the number of competitors increases which means competition eliminates not just the well-known double marginalization, but also the vertical double marginalization-a distortion and source of inefficiency specific to this environment.
Synthesis of 2,3-disubstituted benzo[b]furans by the palladium-catalyzed coupling of o-iodoanisoles and terminal alkynes, followed by electrophilic cyclization

[reaction: see text] 2,3-Disubstituted benzo[b]furans are readily prepared under very mild reaction conditions by the palladium/copper-catalyzed cross-coupling of various o-iodoanisoles and terminal alkynes, followed by electrophilic cyclization with I2, PhSeCl, or p-O2NC6H4SCl. Aryl- and vinylic-substituted alkynes undergo electrophilic cyclization in excellent yields. Biologically important furopyridines can be prepared by this approach in high yields.
A Study of Pair Encodings: Predicate Encryption in Prime Order Groups

Pair encodings and predicate encodings, recently introduced by Attrapadung [2] and Wee [36] respectively, greatly simplify the process of designing and analyzing predicate and attribute-based encryption schemes. However, they are still somewhat limited in that they are restricted to composite order groups, and the information theoretic properties are not sufficient to argue about many of the schemes. Here we focus on pair encodings, as the more general of the two. We first study the structure of these objects, then propose a new relaxed but still information theoretic security property. Next we show a generic construction for predicate encryption in prime order groups from our new property; it results in either semi-adaptive or full security depending on the encoding, and gives security under SXDH or DLIN. Finally, we demonstrate the range of our new property by using it to design the first semi-adaptively secure CP-ABE scheme with constant size ciphertexts.
The comparative function of 'llh in 2 Sam 21 and the philistine war tales

En 2 Sam 21:22 hay diversos elementos linguisticos con dificultades gramaticales. La investigacion de estas peculiaridades hizo evidente una rara funcion comparativa del pronombre demostrativo plural 'llh . Es decir, que esta funcion comparativa, junto con la repeticion de una sintaxis particular y la simetria de elementos linguisticos y tematicos demostrarian relaciones confusas, aunque decididas, entre las tres ubicaciones de los relatos de las guerras filisteas en 2 Sam 5, 21 y 23. Sin embargo, este tipo de relaciones se contradicen con el modo en el que suele interpretarse el material 2 Sam 21–24, que las considera como un hecho “accidental” y como parte de un desenlace de confusion. Por su parte, la funcion del pronombre 'llh en 2 Sam 21: 22 tambien provee una herramienta literaria critica para que el autor pueda contrastar la victoria de los protectores de la linea davidica con la derrota de aquellos enemigos que se le opusieron. Esta herramienta, tambien, permite ampliar uno de los temas fundamentales de la tradicion de Samuel, como es la declinacion de la Casa de Saul y el concurrente ascenso de la Casa de David
How Important Are Banks for Development? National Banks in the United States, 1870–1900

Abstract Do banks matter for growth, and if so, how? This paper examines the effects of national banks in the United States from 1870 to 1900. I use the discontinuity in entry caused by a large minimum size requirement to identify the effects of banking. For the counties on the margin between getting a bank and not, gaining a bank increased production per person by 10%. National banks in rural areas improved agriculture over manufacturing, moving counties toward geographic comparative advantage. Since these banks made few long-term loans, the evidence suggests that the provision of working capital and liquidity matters for growth.
Synthetic Control Estimation Beyond Case Studies: Does the Minimum Wage Reduce Employment?

Panel data are often used in empirical work to account for additivexed time and unit effects. More recently, the synthetic control estimator relaxes the assumption of additivexed effects for case studies, using pre-treatment outcomes to create a weighted average of other units which best approximate the treated unit. The synthetic control estimator is currently limited to case studies in which the treatment variable can be represented by a single indicator variable. Applying this estimator more generally, such as applications with multiple treatment variables or a continuous treatment variable, is problematic. This paper generalizes the case study synthetic control estimator to permit estimation of the effect of multiple treatment vari- ables, which can be discrete or continuous. The estimator jointly estimates the impact of the treatment variables and creates a synthetic control for each unit. Additivexed effect models are a special case of this estimator. Because the number of units in panel data and synthetic control applications is often small, I discuss an inference procedure forxed N. The estimation technique generates correlations across clusters so the inference procedure will also account for this dependence. Simulations show that the estimator works well even when additivexed effect models do not. I estimate the impact of the minimum wage on the employment rate of teenagers. I estimate an elasticity of -0.44, substantially larger than estimates generated using additivexed effect models, and reject the null hypothesis that there is no effect.
A Spatial Framework for Understanding Population Structure and Admixture

Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We use genome-wide polymorphism data to build “geogenetic maps,” which, when applied to stationary populations, produces a map of the geographic positions of the populations, but with distances distorted to reflect historical rates of gene flow. In the underlying model, allele frequency covariance is a decreasing function of geogenetic distance, and nonlocal gene flow such as admixture can be identified as anomalously strong covariance over long distances. This admixture is explicitly co-estimated and depicted as arrows, from the source of admixture to the recipient, on the geogenetic map. We demonstrate the utility of this method on a circum-Tibetan sampling of the greenish warbler (Phylloscopus trochiloides), in which we find evidence for gene flow between the adjacent, terminal populations of the ring species. We also analyze a global sampling of human populations, for which we largely recover the geography of the sampling, with support for significant histories of admixture in many samples. This new tool for understanding and visualizing patterns of population structure is implemented in a Bayesian framework in the program SpaceMix.
Eyeblink Conditioning in Schizophrenia: A Critical Review

There is accruing evidence of cerebellar abnormalities in schizophrenia. The theory of cognitive dysmetria considers cerebellar dysfunction a key component of schizophrenia. Delay eyeblink conditioning (EBC), a cerebellar-dependent translational probe, is a behavioral index of cerebellar integrity. The circuitry underlying EBC has been well characterized by non-human animal research, revealing the cerebellum as the essential circuitry for the associative learning instantiated by this task. However, there have been persistent inconsistencies in EBC findings in schizophrenia. This article thoroughly reviews published studies investigating EBC in schizophrenia, with an emphasis on possible effects of antipsychotic medication and stimulus and analysis parameters on reports of EBC performance in schizophrenia. Results indicate a consistent finding of impaired EBC performance in schizophrenia, as measured by decreased rates of conditioning, and that medication or study design confounds do not account for this impairment. Results are discussed within the context of theoretical and neurochemical models of schizophrenia.
Intellectual Property Rights and Crop-Improving R&D under Adaptive Destruction

This paper studies how the strength of intellectual property rights (IPRs) affects investments in biological innovations when the value of an innovation is stochastically reduced to zero because of the evolution of pest resistance. We frame the problem as a research and development (R&D) investment game in a duopoly model of sequential innovation. We characterize the incentives to invest in R&D under two competing IPR regimes, which differ in their treatment of the follow-on innovations that become necessary because of pest adaptation. Depending on the magnitude of the R&D cost, ex ante firms might prefer an intellectual property regime with or without a “research exemption” provision. The study of the welfare function that also accounts for benefit spillovers to consumers—which is possible analytically under some parametric conditions, and numerically otherwise—shows that the ranking of the two IPR regimes depends critically on the extent of the R&D cost.
Aerobic Linear Allylic C-H Amination: Overcoming Benzoquinone Inhibition.

An efficient aerobic linear allylic C–H amination reaction is reported under palladium(II)/bis-sulfoxide/Bronsted base catalysis. The reaction operates under preparative, operationally simple conditions (1 equiv of olefin, 1 atm O2 or air) with reduced Pd(II)/bis-sulfoxide catalyst loadings while providing higher turnovers and product yields than systems employing stoichiometric benzoquinone (BQ) as the terminal oxidant. Pd(II)/BQ π-acidic interactions have been invoked in various catalytic processes and are often considered beneficial in promoting reductive functionalizations. When such electrophilic activation for functionalization is not needed, however, BQ at high concentrations may compete with crucial ligand (bis-sulfoxide) binding and inhibit catalysis. Kinetic studies reveal an inverse relationship between the reaction rate and the concentration of BQ, suggesting that BQ is acting as a ligand for Pd(II) which results in an inhibitory effect on catalysis.
Silicon Nanoelectronics: The Road Less Travelled

The study of nanometer-scale devices has attracted a great deal of attention in the past few years. A number of discoveries have heightened scientific interest in this area. There is also a great deal of interest from the technological point of view. This interest arises on both the primary (new device concepts) and the secondary (impact on existing devices) levels. Except in isolated instances, the unique potential of silicon-based materials has not been exploited to study mesoscopic phenomena. We will examine the key breakthroughs in mesoscopic physics and exploratory silicon technology that may provide extraordinary opportunities to investigate nanometer-scale electronic devices.
White Matter Injury Susceptibility via Fiber Strain Evaluation Using Whole-Brain Tractography.

Abstract Microscale brain injury studies suggest axonal elongation as a potential mechanism for diffuse axonal injury (DAI). Recent studies have begun to incorporate white matter (WM) structural anisotropy in injury analysis, with initial evidence suggesting improved injury prediction performance. In this study, we further develop a tractography-based approach to analyze fiber strains along the entire lengths of fibers from voxel- or anatomically constrained whole-brain tractography. This technique potentially extends previous element- or voxel-based methods that instead utilize WM fiber orientations averaged from typically coarse elements or voxels. Perhaps more importantly, incorporating tractography-based axonal structural information enables assessment of the overall injury risks to functionally important neural pathways and the anatomical regions they connect, which is not possible with previous methods. A DAI susceptibility index was also established to quantify voxel-wise WM local structural integr...