cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal convection in ice-I shells of Titan and Enceladus

Abstract Cassini–Huygens observations have shown that Titan and Enceladus are geologically active icy satellites. Mitri and Showman [Mitri, G., Showman, A.P., 2005. Icarus 177, 447–460] and McKinnon [McKinnon, W.B., 2006. Icarus 183, 435–450] investigated the dynamics of an ice shell overlying a pure liquid-water ocean and showed that transitions from a conductive state to a convective state have major implications for the surface tectonics. We extend this analysis to the case of ice shells overlying ammonia-water oceans. We explore the thermal state of Titan and Enceladus ice-I shells, and also we investigate the consequences of the ice-I shell conductive–convective switch for the geology. We show that thermal convection can occur, under a range of conditions, in the ice-I shells of Titan and Enceladus. Because the Rayleigh number Ra scales with δ 3 / η b , where δ is the thickness of the ice shell and η b is the viscosity at the base of the ice-I shell, and because ammonia in the liquid layer (if any) strongly depresses the melting temperature of the water ice, Ra equals its critical value for two ice-I shell thicknesses: for relatively thin ice shell with warm, low-viscosity base (Onset I) and for thick ice shell with cold, high-viscosity base (Onset II). At Onset I, for a range of heat fluxes, two equilibrium states—corresponding to a thin, conductive shell and a thick, convective shell—exist for a given heat flux. Switches between these states can cause large, rapid changes in the ice-shell thickness. For Enceladus, we demonstrate that an Onset I transition can produce tectonic stress of ∼ 500 bars and fractures of several tens of km depth. At Onset II, in contrast, we demonstrate that zero equilibrium states exist for a range of heat fluxes. For a mean heat flux within this range, the satellite experiences oscillations in surface heat flux and satellite volume with periods of ∼ 50 – 800 Myr even when the interior heat production is constant or monotonically declining in time; these oscillations in the thermal state of the ice-I shell would cause repeated episodes of extensional and compressional tectonism.
DISCOVERY OF A HIGH PROPER MOTION L DWARF BINARY: 2MASS J15200224 4422419AB

We report the discovery of the wide L1.5+L4.5 binary 2MASS J15200224-4422419AB, identified during spectroscopic follow-up of high proper motion sources selected from the Two Micron All Sky Survey. This source was independently identified by Kendall et al. in the SuperCOSMOS Sky Survey. Resolved JHK photometry and low-resolution near-infrared spectroscopy demonstrate that this system is composed of two well-separated (1.174'' ± 0.016'') L dwarfs. Component classifications are derived using both spectral ratios and comparison to the near-infrared spectra of previously classified field L dwarfs. Physical association for the pair is deduced from the large common proper motion of the components (μ = 0.73'' ± 0.03'' yr-1) and their similar spectrophotometric distances (19 ± 2 pc). The projected separation of the binary, 22 ± 2 AU, is consistent with maximum separation/total system-mass trends for very low mass binaries. The 2MASS J1520-4422 system exhibits both large tangential (66 ± 7 km s-1) and radial velocities (-70 ± 18 km s-1), and its motion in the local standard of rest suggests that it is an old member of the Galactic disk population. This system joins a growing list of well-separated (>0.5''), very low mass binaries, and is an excellent target for resolved optical spectroscopy to constrain its age, as well as trace activity/rotation trends near the hydrogen-burning limit.
The Beta-MANOVA Ensemble with General Covariance

We consider adding arbitrary covariance to the β-Jacobi random matrix model. We recall that for β = 1 the Jacobi random matrix model may be thought of as the eigenvalues, λi, of YtY(XTX + YtY)-1 where X and Y are matrices whose elements are i.i.d. standard normals. Equivalently we can take the generalized cosine singular values of (Y, X), ci, and use . When β = 1 we add covariance by considering YtY(YtY + ΩXtXΩ)-1, for a positive definite diagonal matrix Ω. Equivalently, and preferably, we consider the generalized singular value decomposition (gsvd) of (Y, XΩ). We refer to Ω = I as the Jacobi case and the general Ω case as the MANOVA case. In this paper, we provide a matrix model for the general β-MANOVA ensemble. In particular, we provide an algorithm for the numerical sampling of eigenvalues or generalized cosine singular values. The β-MANOVA algorithm uses the β-Wishart algorithm of Forrester and Dubbs–Edelman–Koev–Venkataramana as a subroutine, perhaps making β-MANOVA the first "second-order" continuous-β random matrix algorithm. Our proofs make use of a conjecture of MacDonald (proven by Baker and Forrester), a theorem of Kaneko, and many identities from Forrester's Log-Gases and Random Matrices. We supply numerical evidence that our theorems are correct.
Evaluation of ionospheric densities using coincident OII 83.4 nm airglow and the Millstone Hill Radar

[1] We test the utility of the OII 83.4 nm emission feature as a measure of ionospheric parameters. Observed with the Remote Atmospheric and Ionospheric Detection System (RAIDS) Extreme Ultraviolet Spectrograph on the International Space Station (ISS), limb profiles of 83.4 nm emissions are compared to predicted dayglow emission profiles from a theoretical model incorporating ground-based electron density profiles measured by the Millstone Hill radar and parameterized by a best-fit Chapman-α function. Observations and models are compared for periods of conjunction between Millstone Hill and the RAIDS fields-of-view. These RAIDS observations show distinct differences in topside morphology between two days, 15 January and 10 March 2010, closely matching the forward model morphology and demonstrating that 83.4 nm emission is sensitive to changes in the ionospheric density profile from the 340 km altitude of the ISS during solar minimum. We find no significant difference between 83.4 nm emission profiles modeled assuming a constant scale height Chapman-α best-fit to the ISR measurements and those assuming varying scale height.
IODIDE ACCELERATION IN THE PD-CATALYZED COUPLING OF AROMATIC 1,2-DITRIFLATES WITH ALKYNES : SYNTHESIS OF ENEDIYNES

Abstract Aryl enediynes have been synthesized in a one-pot procedure by a Pd-catalyzed coupling of terminal alkynes and ortho-aryl ditriflates. A variety of substrates have been examined.
Mainstreaming international governance: The environment, gender, and IO performance in the European Union

International organizations (IOs) have moved increasingly in recent years to adopt cross-cutting mandates that require the “mainstreaming” of particular issues, such as gender equality or environmental protection, across all IO policies. Successful IO performance with respect to such mandates, we hypothesize, is determined in large part by the use of hard or soft institutional measures to shape the incentives of sectoral officials whose cooperation is required for successful implementation. We test this hypothesis with respect to two such mandates—gender mainstreaming and environmental policy integration—in a single international organization, the European Union, demonstrating a strong causal link between the use of hard incentives and IO performance in these and related mandates.
Assignment of Absolute Stereochemistry and Total Synthesis of (−)-Spongidepsin

An enantioselective total synthesis of (−)-spongidepsin (2) and elucidation of the absolute stereochemistry of its four stereocenters are described. Spongidepsin (2), a 13-membered depsipeptide isolated from the Vanuatu marine sponge Spongia sp., has shown potent antitumor properties against a variety of NCI tumor cell lines. Our synthesis is convergent, and the absolute stereochemistry of four of the five chiral centers was assigned through synthesis.
Attitudes to ambiguity in one-shot normal-form games: An experimental study

Abstract Based on an experiment in the lab, we classify behavior in one-shot normal-form games along three important dimensions. The first dimension, which is of main interest, is about whether subjects are ambiguity-loving, ambiguity-neutral, or ambiguity-averse. The second dimension is about whether subjects are risk-loving, risk-neutral, or risk-averse. The third dimension is about whether subjects are naive or strategic. Our main result is that, in our main treatment, 32 / 46 / 22 percent of subjects are classified as ambiguity-loving/ambiguity-neutral/ambiguity-averse.
Pricing and Travelers' Decision To Use Frequent Flyer Miles: Evidence From the U.S. Airline Industry

Previous research on Frequent Flyer Programs (FFP) covered various topics, from analyzing the effect of international airline alliances on domestic travel demand to the effect of airport dominance and FFP on pricing. However, one important constraint in previous empirical research on FFP is the lack of a measure of these programs at a specific time-variant route and carrier level. In this chapter we use a novel way to measure the extent of FFP which allows us to analyze how these programs change from route to route, across carriers and over time. The dataset, that covers the quarters from 1993.1 to 2009.3, was constructed with data obtained from the Bureau of Transportation and Statistics and it has information on prices, proportion of frequent flyer tickets as well as various route and carrier variables. Using panel data techniques to control for unobservables along with the use of instrumental variables to control for potentially endogenous regressors, the results found are consistent with our economic model: travelers are more likely to redeem their frequent flyer miles in more expensive routes. Moreover, business travelers, who usually pay higher prices, were found to be less price sensitive than tourists when switching to buy with accumulated miles.
Distributed and/or grid-oriented approach to BTeV data analysis

The BTeV collaboration will record approximately 2 petabytes of raw data per year. It plans to analyze this data using the distributed resources of the collaboration as well as dedicated resources, primarily residing in the very large BTeV trigger farm, and resources accessible through the developing world-wide data grid. The data analysis system is being designed from the very start with this approach in mind. In particular, we plan a fully disk-based data storage system with multiple copies of the data distributed across the collaboration to provide redundancy and to optimize access. We will also position ourself to take maximum advantage of shared systems, as well as dedicated systems, at our collaborating institutions.
Public choice and the development of modern laboratory experimental methods in economics and political science

The paper is an account of the development of laboratory experimental methods in the early 1970s as influenced by the fields of Public Choice and Social Choice. Just a few key experiments conducted during a period when no experimental markets research was taking place, provide a bridge with the subsequent, rapid, growth of experimental economics. A new focus on public goods and externalities, as opposed to private goods traditionally used in economics experiments, required new representations of the commodity space and preference inducement methods. The importance of voting and collective decision making processes dictated the testing of equilibrium concepts from political science and cooperative game theory as opposed to the competitive equilibrium and Nash equilibria found in economics. The existence of many theories from multiple disciplines required new experimental designs and experimental tests. The Public Choice and Social Choice emphasis on comparing the performance of different types of collective decision processes induced early experiments related to institutional design and testing.
Cosmic-ray lifetime in the Galaxy - Experimental results and models

The separation of the cosmic-ray Be isotopes achieved by two satellite experiments is discussed. From the measured isotopic ratio between the radioactive Be-10 (half-life = 1,500,000 years) and the stable Be-9, it is deduced that the cosmic rays propagate through matter with an average density of 0.24 = or - 0.07 atoms/ cu cm. The implications of this result for the cosmic-ray age is reviewed in the context of two models of confinement and propagation: the homogeneous model, normally identified with confinement ot the galactic gaseous disk, and a diffusion model in which the cosmic rays extend into a galactic halo. A newly deduced cosmic-ray pathlength distribution, a self-consistent model of solar modulation, and a set of fragmentation cross sections are calculated. It is concluded that in a homogeneous model, the cosmic-ray age is 15 (+7, -4) million years, about a factor longer than early estimates based on the abundances of the light nuclei Li, Be, and B and a nominal interstellar density of 1 atom/ cu cm.
Compressibility of a two-dimensional hole gas in a tilted magnetic field

We have measured compressibility of a two-dimensional hole gas in p-GaAs/Al x Ga 1 - x As heterostructure, grown on a (100) surface, in the presence of a tilted magnetic field. It turns out that the parallel component of magnetic field affects neither the spin splitting nor the density of states. We conclude that (a) g factor in the parallel magnetic field is nearly zero in this system, and (b) the level of the disorder potential is not sensitive to the parallel component of the magnetic field.
Proteoglycan 4 expression protects against the development of osteoarthritis

Osteoarthritis (OA) is a common degenerative condition that afflicts more than 70% of the population between 55 and 77 years of age. Although its prevalence is rising globally with aging of the population, current therapy is limited to symptomatic relief and, in severe cases, joint replacement surgery. We report that intra-articular expression of proteoglycan 4 (Prg4) in mice protects against development of OA. Long-term Prg4 expression under the type II collagen promoter (Col2a1) does not adversely affect skeletal development but protects from developing signs of age-related OA. The protective effect is also shown in a model of posttraumatic OA created by cruciate ligament transection. Moreover, intra-articular injection of helper-dependent adenoviral vector expressing Prg4 protected against the development of posttraumatic OA when administered either before or after injury. Gene expression profiling of mouse articular cartilage and in vitro cell studies show that Prg4 expression inhibits the transcriptional programs that promote cartilage catabolism and hypertrophy through the up-regulation of hypoxia-inducible factor 3α. Analyses of available human OA data sets are consistent with the predictions of this model. Hence, our data provide insight into the mechanisms for OA development and offer a potential chondroprotective approach to its treatment.
Prediction of the Bulk Temperature in Spur Gears Based on Finite Element Temperature Analysis

The temperature distribution in spur gears operating in a state of thermal equilibrium is solved by using a finite element method. The effects of various dimensionless parameters on bulk temperature are shown. A table is provided which can be used to predict the bulk temperature on gear teeth, once the heat transfer coefficients and frictional heat input is estimated. Theoretical results for estimating heat transfer coefficients and frictional heat are also summarized. Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference in Kansas City, Missouri, October 3–5, 1977
One-pot synthesis of 2-aminoquinoline-based alkaloids from acetonitrile

α-Diaminoboryl carbanions, readily prepared from acetonitrile, stereoselectively convert 2-nitrobenzaldehydes into nitrophenyl (Z)-acrylonitriles. Subsequent reductive cyclization leads to a series of 2-aminoquinoline derivatives. The entire procedure is practically operated in a single flask.
Dynamic Role of Cross-Linking Proteins in Actin Rheology

We develop a computational model to compare the relative importance of unbinding and unfolding of actin cross-linking proteins (ACPs) in the dynamic properties of the actin cytoskeleton. We show that in the strain-stiffening regime with typical physiological and experimental strain rates, unbinding events are predominant with negligible unfolding. ACPs unbound by greater forces experience larger displacements, with a tendency to rebind to different filaments. At constant strain, stress relaxes to physiological levels by unbinding only—not unfolding—of ACPs, which is consistent with experiments. Also, rebinding of ACPs dampens full relaxation of stress. When the network is allowed to return to a stress-free state after shear deformation, plastic deformation is observed only with unbinding. These results suggest that despite the possibility of unfolding, unbinding of ACPs is the major determinant for the rheology of the actin network.
Performance analysis of token bus LAN in coordinating multiple robots

Using a local area network (LAN) to coordinate multiple industrial robots is considered in this paper. The LAN uses the standard Manufacturing Automation Protocol (MAP) to control the access of the communication bus. Since the MAP based LAN was not designed for real-time applications, performance evaluation of the LAN becomes an important issue. A new evaluation method is proposed in this paper. The method evaluates the efficiency of the LAN by a parameter called effective token passing ratio. This parameter is affected by the speed and the access protocol of the LAN as well as the task decomposition-and-allocation scheme for computing the coordination algorithms. Previous methods, however, only evaluate the speed and the access protocol of the LAN. As a result, the new method provides more options for improving the LAN based system. To guarantee real-time coordination of multiple robots, the lower bound of the effective token passing ratio is determined and the probability of successful coordination when the transmission errors are possible is also considered. >
ECONOMIC MODELING AND THE FALSE TRADEOFF BETWEEN ENVIRONMENTAL PROTECTION AND ECONOMIC GROWTH

One important element of the current policy debate on what measures should be taken to reduce greenhouse gas emissions is the controversy over the costs of reducing those emissions. “Top-down” macroeconomic and general equilibrium models give much higher estimates of the costs than “bottom-up” models based on microeconomic and engineering data. This paper investigates the causes of the divergence between the two modeling approaches. The conventional top-down models incorporate strong implicit assumptions about maximization, technical progress, and organizational efficiency that predetermine their results. However, these assumptions are questionable on both theoretical and empirical grounds. Economic assessment of policy alternatives would benefit. from analyses that take account of the actual characteristics of business firms and other organizations that emit greenhouse gases in the course of their activities.
Local Global Tradeoffs in Metric Embeddings

Suppose that every $k$ points in a $n$ point metric space $X$ are $D$-distortion embeddable into $\ell_1$. We give upper and lower bounds on the distortion required to embed the entire space $X$ into $\ell_1$. This is a natural mathematical question and is also motivated by the study of relaxations obtained by lift-and-project methods for graph partitioning problems. In this setting, we show that $X$ can be embedded into $\ell_1$ with distortion $O(D\times\log(n/k))$. Moreover, we give a lower bound showing that this result is tight if $D$ is bounded away from 1. For $D=1+\delta$ we give a lower bound of $\Omega(\log(n/k)/\log(1/\delta))$; and for $D=1$, we give a lower bound of $\Omega(\log n/(\log k+\log\log n))$. Our bounds significantly improve on the results of Arora et al. who initiated a study of these questions.
Generating uniaxial vibration with an electrodynamic shaker and external air bearing

Abstract Electrodynamic shakers are widely used in experimental investigations of vibrated fluids and granular materials. However, they are plagued by undesirable internal resonances that can significantly impact the quality of vibration. In this work, we measure the performance of a typical shaker and characterize the influence that a payload has on its performance. We present the details of an improved vibration system based on a concept developed by Goldman (2002) [1] which consists of a typical electrodynamic shaker with an external linear air bearing to more effectively constrain the vibration to a single axis. The principal components and design criteria for such a system are discussed. Measurements characterizing the performance of the system demonstrate considerable improvement over the unmodified test shaker. In particular, the maximum inhomogeneity of the vertical vibration amplitude is reduced from approximately 10 percent to 0.1 percent; moreover, transverse vibrations were effectively eliminated.
Nonequilibrium Viscous Shock-Layer Heat Transfer with Arbitrary Surface Catalycity

An approximate yet accurate analysis of aerodynamic heating at a highly cooled stagnation region, which embraces the entire high-altitude hypersonic flight regime where nonequilibrium dissociation/recombination in the shock layer and finite surface catalysis effects are both important, is given. Closed-form relationships are given for the relative nonequilibrium effects that are convenient for cost-effective engineering studies of high-altitude hypervelocity vehicle heating.
A note on the strong formulation of stochastic control problems with model uncertainty

We consider a Markovian stochastic control problem with model uncertainty. The controller (intelligent player) observes only the state, and, therefore, uses feedback (closed-loop) strategies. The adverse player (nature) who does not have a direct interest in the payoff, chooses open-loop controls that parametrize Knightian uncertainty. This creates a two-step optimization problem (like half of a game) over feedback strategies and open-loop controls. The main result is to show that, under some assumptions, this provides the same value as the (half of) the zero-sum symmetric game where the adverse player also plays feedback strategies and actively tries to minimize the payoff. The value function is independent of the filtration accessible to the adverse player. Aside from the modeling issue, the present note is a technical companion to a previous work.
A feedback microprocessor for hadron colliders

Abstract A feedback microprocessor has been built for the TEVATRON. It was constructed to be applicable to hadron colliders in general. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor software includes a finite state machine. Each state corresponds to a specific TEVATRON operation and has a state-specific TEVATRON model. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime corrections. We also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. In this paper we will describe this device and its use to control the TEVATRON tunes as well as other possible applications.
The role of conformational diffusion in ion channel gating

Abstract We consider an exactly tractable model of the Kramers type for the voltage-dependent gating dynamics of single ion channels. It is assumed that the gating dynamics is caused by the thermally activated transitions in a bistable potential. Moreover, the closed state of the channel is highly degenerate and embraces the whole manifold of closed substates. Opening of the ion channel is energetically prohibited from most of the closed substates and requires a special conformation where the voltage sensor can move along an activation pathway and trigger the transition into the open conformation. When the corresponding activation barrier towards the channel's opening is removed by the applied voltage, the statistics of non-conducting time intervals become strongly influenced by the conformational diffusion. For the corresponding supra-threshold voltages, our model explains the origin of the power law distribution of the closed time intervals. The exponential-linear dependence of the opening rate on voltage, often used as an experimental fit, is also reproduced by our model.
New allylstannanes for the connective construction of monoprotected vicinal diols

Abstract The preparation of allylstannanes 1a–c , all of which bear an oxygen substituent at the allylic terminus, is described. These reagents react with alpha- and beta-alkoxyaldehydes in the presence of MgBr2 as Lewis acid to give SE′, products with diastereofacial selectivity consistent with “chelation control”; a syn disposition of substituents about the newly formed bond is highly favored in all cases.
A Highly Stereoselective Addition of Lithiated Ynamides to Ellman–Davis Chiral N-tert-Butanesulfinyl Imines

A highly diastereoselective addition of lithiated ynamides to Ellman–Davis chiral imines is described. While additions of N-sulfonyl ynamides are highly stereoselective even without Lewis acids, the use of BF3–OEt2 completely reversed the stereoselectivity. In addition, oxazolidinone-substituted ynamides behaved differently and functioned better with BF3–OEt2, and the chirality of the oxazolidinone ring exerts no impact on the selectivity.
Dynamic Traffic Assignment under Uncertainty: A Distributional Robust Chance-Constrained Approach

This paper provides a chance-constrained programming approach for transportation planning and operations under uncertainty. The major contribution of this paper is to approximate a joint chance-constrained Cell Transmission Model based System Optimum Dynamic Traffic Assignment with only partial distributional information about uncertainty as a linear program which is computationally efficient. Numerical experiments have been conducted to show the performance of the proposed approach compared with other two workable approaches based on a cumulative distribution function and a sampling method. This new approach can be used as a pragmatic tool for system optimum dynamic traffic control and management.
Preheated, combustion-driven gasdynamic lasers

The effect of preheated nitrogen on the available laser specific energy is examined for two classes of combustion-driven gasdynamic lasers (GDLs). The analysis combines a nonequilibrium model of the relevant GDL processes with a simplified nondissociating combustion model handling a variety of candidate GDL fuels. For a more comprehensive evaluation of the capabilities of preheating, an optimization routine is added to the combined laser/combustion models. The effectiveness of preheating to enhance laser specific energy is demonstrated, although preheating may impose unacceptable hardware requirements. The application of numerical optimization techniques appears to offer a means to improve laser design.
The first asymmetric synthesis of (2S)- and (2R)-amino-3,3-dimethoxypropanoic acid

The first asymmetric synthesis of (2S)-, and (2R)-amino-3,3-dimethoxypropanoic acid (α-formylglycine dimethylacetal) has been achieved in two steps and 91% overall yield. The key step involved the quenching of a chiral glycine titanium enolate with trimethyl orthoformate.
Dyson’s Constants in the Asymptotics of the Determinants of Wiener-Hopf-Hankel Operators with the Sine Kernel

Let \(K_\alpha^\pm \) stand for the integral operators with the sine kernels \(\frac{\sin(x-y)}{\pi(x-y)} \pm \frac{\sin(x+y)}{\pi(x+y)}\) acting on L2[0,α]. Dyson conjectured that the asymptotics of the Fredholm determinants of \(I-K_\alpha^\pm\) are given by $$ \log\det(I-K_{\alpha}^\pm) = -\frac{\alpha^2}{4}\mp \frac{\alpha}{2}-\frac{\log\alpha}{8}+\frac{\log 2}{24}\pm \frac{\log 2}{4} +\frac{3}{2} \zeta'(-1)+o(1),$$ as α→∞. In this paper we are going to give a proof of these two asymptotic formulas.
THE MAN OF PILTDOWN

THE story of the Piltdown discovery is already more or less familiar to readers of this journal.1 But the recent gathering and publishing of additional data2 on the subject should not be allowed to pass unnoticed. This is especially true not only because of the far-reaching significance of the discovery, but also because British scientists have been known to be at odds concerning the reconstruction of the skull in question. It will be recalled that Dr Smith Woodward regarded the Piltdown specimen as the type of a new genus of the family Hominidae, to which he gave the name Eoanthropus dawsoni, and which was defined primarily by the characters of the mandible. Of the mandible only the right ramus with first and second molar teeth in situ was at first discovered. The condyle and symphysis were both lacking, but the fragment was of sufficient size to enable Dr Smith Woodward to reconstruct the symphysis with a fair degree of accuracy. It was the reconstruction of the cranium about which differences of opinion arose between Dr Smith Woodward and Professor Elliot Smith on the one hand and Professor Arthur Keith on the other. Of the brain case nine fragments, parts of the frontal, parietal occipital, and temporal, were found. From these Dr Smith Woodward reconstructed a skull with a capacity of about o1076 cc. On the other hand a reconstruction by Professor Keith gave to the skull a brain capacity of 1500oo cc., in other words that of a welldeveloped modern European skull. After further study Dr Smith
Comparison of Bayesian Model Selection Criteria and Conditional Kolmogorov Test as Applied to Spot Asset Pricing Models

We compare Bayesian and sample theory model specification criteria. For the Bayesian criteria we use the deviance information criterion and the cumulative density of the mean squared errors of forecast. For the sample theory criterion we use the conditional Kolmogorov test. We use Markov chain Monte Carlo methods to obtain the Bayesian criteria and bootstrap sampling to obtain the conditional Kolmogorov test. Two non nested models we consider are the CIR and Vasicek models for spot asset prices. Monte Carlo experiments show that the DIC performs better than the cumulative density of the mean squared errors of forecast and the CKT. According to the DIC and the mean squared errors of forecast, the CIR model explains the daily data on uncollateralized Japanese call rate from January 1, 1990 to April 18, 1996; but according to the CKT, neither the CIR nor Vasicek models explains the daily data.
Additive Self Helicity as a Kink Mode Threshold

In this paper, we propose that additive self-helicity, introduced by Longcope and Malanushenko, plays a role in the kink instability for complex equilibria, similar to twist helicity for thin flux tubes. We support this hypothesis by a calculation of additive self-helicity of a twisted flux tube from the simulation of Fan and Gibson. As more twist gets introduced, the additive self-helicity increases, and the kink instability of the tube coincides with the drop of additive self-helicity, after the latter reaches the value of H{sub A} /{phi}{sup 2} {approx} 1.5 (where {phi} is the flux of the tube and H{sub A} is the additive self-helicity). We compare the additive self-helicity to twist for a thin subportion of the tube to illustrate that H{sub A} /{phi}{sup 2} is equal to the twist number, studied by Berger and Field, when the thin flux tube approximation is applicable. We suggest that the quantity H{sub A} /{phi}{sup 2} could be treated as a generalization of a twist number, when the thin flux tube approximation is not applicable. A threshold on a generalized twist number might prove extremely useful studying complex equilibria, just as the twist number itself has proven useful studying idealized thin flux tubes. more » We explicitly describe a numerical method for calculating additive self-helicity, which includes an algorithm for identifying a domain occupied by a flux bundle and a method of calculating potential magnetic field confined to this domain. We also describe a numerical method to calculate twist of a thin flux tube, using a frame parallelly transported along the axis of the tube. « less
Finite number of states, de Sitter space and quantum groups at roots of unity

This paper explores the use of a deformation by a root of unity as a tool to build models with a finite number of states for applications to quantum gravity. The initial motivation for this work was cosmological breaking of supersymmetry. We explain why the project was unsuccessful. What is left are some observations on supersymmetry for q-bosons, an analogy between black holes in de Sitter and properties of quantum groups, and an observation on a noncommutative quantum mechanics model with two degrees of freedom, depending on one parameter. When this parameter is positive, the spectrum has a finite number of states; when it is negative or zero, the spectrum has an infinite number of states. This exhibits a desirable feature of quantum physics in de Sitter space, albeit in a very simple, non-gravitational context.
Embedding shuffle networks in hypercubes

Abstract We consider the problem of embedding perfect shuffle and shuffle exchange networks in hypercubes. We prove that perfect embedding is possible for perfect shuffle with 2k nodes only when k is a power of 2, and we give an efficient algorithm for embedding perfect shuffle networks with 2k nodes when k is a power of 2. We also discuss a scheme for embedding shuffle exchange networks with 2k nodes, k being a power of 2, and give its extensions to the general case.
On fast algorithms for two servers

Abstract We consider 2-server algorithms with time complexity O(1) per each request. We show that the previously known algorithm BALANCE2 has competitiveness constant not better than 6, and we present another algorithm whose competitiveness constant is 4.
How to leak on key updates

In the continual memory leakage model, security against attackers who can repeatedly obtain leakage is achieved by periodically updating the secret key. This is an appealing model which captures a wide class of side-channel attacks, but all previous constructions in this model provide only a very minimal amount of leakage tolerance during secret key updates. Since key updates may happen frequently, improving security guarantees against attackers who obtain leakage during these updates is an important problem. In this work, we present the first cryptographic primitives which are secure against a super-logarithmic amount of leakage during secret key updates. We present signature and public key encryption schemes in the standard model which can tolerate a constant fraction of the secret key to be leaked between updates as well as a constant fraction of the secret key and update randomness to be leaked during updates. Our signature scheme also allows us to leak a constant fraction of the entire secret state during signing. Before this work, it was unknown how to tolerate super-logarithmic leakage during updates even in the random oracle model. We rely on subgroup decision assumptions in composite order bilinear groups.
WhittleSearch: Interactive Image Search with Relative Attribute Feedback

We propose a novel mode of feedback for image search, where a user describes which properties of exemplar images should be adjusted in order to more closely match his/her mental model of the image sought. For example, perusing image results for a query "black shoes", the user might state, "Show me shoe images like these, but sportier." Offline, our approach first learns a set of ranking functions, each of which predicts the relative strength of a nameable attribute in an image (e.g., sportiness). At query time, the system presents the user with a set of exemplar images, and the user relates them to his/her target image with comparative statements. Using a series of such constraints in the multi-dimensional attribute space, our method iteratively updates its relevance function and re-ranks the database of images. To determine which exemplar images receive feedback from the user, we present two variants of the approach: one where the feedback is user-initiated and another where the feedback is actively system-initiated. In either case, our approach allows a user to efficiently "whittle away" irrelevant portions of the visual feature space, using semantic language to precisely communicate her preferences to the system. We demonstrate our technique for refining image search for people, products, and scenes, and we show that it outperforms traditional binary relevance feedback in terms of search speed and accuracy. In addition, the ordinal nature of relative attributes helps make our active approach efficient--both computationally for the machine when selecting the reference images, and for the user by requiring less user interaction than conventional passive and active methods.
Real-analytic, volume-preserving actions of lattices on 4-manifolds

Abstract We prove that if Γ is a lattice of Q -rank at least 7 in a simple linear Lie group, then any real-analytic, volume-preserving action of Γ on a closed 4-manifold of nonzero Euler characteristic factors through a finite group action. To cite this article: B. Farb, P.B. Shalen, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 1011–1014.
Motivation for Hodge cycles

Given two smooth projective varieties X and Y, X is defined to motivate Y if the motive of Y is contained in the tensor category generated by X. Some techniques are given for checking this condition. It is shown that in a number of cases moduli spaces of sheaves over curves or surfaces are motivated by the underlying curve or surface. This is used to check the Hodge and related conjectures for some of these examples.
Some minimization problems in the class of convex functions with prescribed determinant

We consider minimizers of linear functionals of the type L ( u ) = ∫ ∂ Ω u d σ − ∫ Ω u d x in the class of convex functions u with prescribed determinant detD2u=f. We obtain compactness properties for such minimizers and discuss their regularity in two dimensions.
Structure and mixing properties of combusting monopropellant sprays

The spray combustion properties of a hydroxylammonium nitrate (HAN)-based monopropellant (LGP 1845) were studied both theoretically and experimentally. Drop size, liquid mass flow rate, and liquid mass flux distributions were measured for pressure-atomized sprays in the atomization breakup regime, burning within a combustion gas environment at pressures of 4.5-5.0 MPa. Two separated-flow models were evaluated using the new measurements: a deterministic separated-flow model where drop-turbulence interactions were ignored, and a stochastic separated-flow model where drop-turbulence interactions were considered using random-walk computations for drop motion. When based on burning rates found from earlier single-drop experiments, both models were in reasonably good agreement with the measurements. Separated-flow effects are quite important for these sprays, with the length of the liquid-containing region being relatively independent of injector diameter and extending roughly 300 mm from the injector exit for injector exit velocities of roughly 70 m/s and injector diameters of 0.3 and 0.6 mm.
Rational Drug Design and Synthesis of a Highly Selective Nonpeptide δ-Opioid Agonist, (4aS * , 12aR * )-4a-(3-Hydroxyphenyl)-2-methyl-1, 2, 3, 4, 4a, 5, 12, 12a-octahydropyrido[3, 4-b]acridine (TAN-67)

We designed highly selective non-peptide agonists for the δ-opioid receptor. On the basis of the "message-address" concept in this field and the accessory site hypothesis, a novel class of hetericycle-fused octahydroisoquinoline derivatives were synthesized. One of these compounds (4aS*, 12aR*)-4a-(3-hydroxyphenyl)-2-methyl-1, 2, 3, 4, 4a, 5, 12, 12a-octahydropyrido[3, 4-b]acridine, TAN-67 (2)] showed high selectivity for the δ-opioid receptor (Ki=1.12 nM) in guinea-pig cerebrum with a 2070-fold lower affinity for the μ-opioid receptor and a 1600-fold lower affinity for the К-opioid receptor. TAN-67 was a potent δ-opioid receptor agonist with an IC50 value of 6.61 nM in the mouse vas deferens assay that was reversed by naltrindole (NTI) (Ke=0.21). Moreover, TAN-67 was shown to have antinociceptive activity following subcutaneous administration in the mouse acetic acid abdominal constriction assay that was antagonized by NTI (δ1-and δ2-antagonist) and 7-benzylidinenaltrexone (δ1-antagonist), but not by naltriben (δ2-antagonist). This systemically applicable non-peptide agonist will be useful for elucidating the pharmacological properties of the δ-opioid receptor.
Periodic resolutions and self-injective algebras of finite type

Abstract We say that an algebra A is periodic if it has a periodic projective resolution as an ( A , A ) -bimodule. We show that any self-injective algebra of finite representation type is periodic. To prove this, we first apply the theory of smash products to show that for a finite Galois covering B → A , B is periodic if and only if A is. In addition, when A has finite representation type, we build upon results of Buchweitz to show that periodicity passes between A and its stable Auslander algebra. Finally, we use Asashiba’s classification of the derived equivalence classes of self-injective algebras of finite type to compute bounds for the periods of these algebras, and give an application to stable Calabi–Yau dimensions.
Sustained Comoving Acceleration of Overdense Plasmas by Colliding Laser Pulses

We review recent PIC simulation results which show that double-sided irradiation of a thin over-dense plasma slab by ultra-intense laser pulses from both sides can lead to sustained comoving acceleration of surface electrons to energies much higher than the conventional ponderomotive limit. The acceleration stops only when the electrons drift transversely out of the laser beam. We show latest 2.5D results of parameter studies based on finite laser spot size and discuss future laser experiments that can be used to test these results.
Atoms in the p -localization of Stable Homotopy Category

We study p-localizations, where p is an odd prime, of the full subcategories $$ {\mathcal{S}}^n $$ of stable homotopy category formed by CW-complexes with cells in n successive dimensions. Using the technique of triangulated categories and matrix problems, we classify the atoms (indecomposable objects) in $$ {\mathcal{S}}_p^n $$ for n ≤ 4(p − 1) and show that, for n > 4(p − 1), this classification is wild in a sense of the representation theory.
Modeling the performance of water- and liquid-gallium-cooled X-ray optical components — a comparison with experiment

Abstract Thermal and structural analyses of a water- or liquid-gallium-cooled silicon crystal X-ray monochromator subjected to high heat loads have been carried out using a finite-element method. Rocking curves were produced from the computed strain distributions in the crystal and compared with experimentally measured rocking curves. Good agreement between the general width and shape of the calculated and measured rocking curve profiles was obtained. This agreement provides a foundation for extending our modeling to the prediction of X-ray optical component performance with more-complex cooling schemes. Such elaborate cooling techniques may be required for the increased power load that will be produced by insertion devices in the next generation of low-emittance storage ring sources, such as the Advanced Photon Source (APS) to be constructed at Argonne National Laboratory.
Retention of palladium and phosphine ligands using nanoporous polydicyclopentadiene thimbles.

Thimbles composed of polydicyclopentadiene retained Pd and phosphines used in Buchwald–Hartwig and Sonogashira coupling reactions but allowed the products to permeate. The products were isolated in high yields on the exteriors of the thimbles with no detectable contamination from phosphine and with Pd loadings as low as < 5.5 ppm.
Construction of cyclopentanol derivatives via three-component coupling of silyl glyoxylates, acetylides, and nitroalkenes.

The three-component coupling of Mg acetylides, silyl glyoxylates, and nitroalkenes results in a highly diastereoselective Kuwajima–Reich/vinylogous Michael cascade that provides tetrasubstituted si...
Characterizing users' visual analytic activity for insight provenance

Insight provenance - a historical record of the process and rationale by which an insight is derived - is an essential requirement in many visual analytics applications. Although work in this area has relied on either manually recorded provenance (for example, user notes) or automaticalily recorded event-based insight provenance (for example, clicks, drags and key-presses), both approaches have fundamental limitations. Our aim is to develop a new approach that combines the benefits of both approaches while avoiding their deficiencies. Toward this goal, we characterize users' visual analytic activity at multiple levels of granularity. Moreover, we identify a critical level of abstraction, Actions, that can be used to represent visual analytic activity, with a set of general but semantically meaningful behavior types. In turn, the action types can be used as the semantic building blocks for insight provenance. We present a catalog of common actions identified through observations of several different visual analytic systems. In addition, we define a taxonomy to categorize actions into three major classes based on their semantic intent. The concept of actions has been integrated into our lab's prototype visual analytic system, HARVEST, as the basis for its insight provenance capabilities.
Should children with acute asthma exacerbation receive inhaled anticholinergics

ATA SOURCES n this updated review, the authors dded to an initial search ofMEDLINE 1966 to April 2000), EMBASE (1980 o April 2000) and CINAHL (1982 to pril 2000), by including “all years” of he Cochrane Airways Group egister of Trials (searched April 18, 012). In addition, they searched the eference lists of relevant reviews and ontacted both the manufacturer of pratropiumbromide and researchers n the field of pediatric asthma.
The value of fiscal discipline for oil-exporting countries

Abstract The value of fiscal discipline is assessed by analyzing the role of fiscal policy as a transmission mechanism of oil price shocks in oil-exporting small open economies. Fiscal policy is an important propagation channel. Taking policy as given by the data, the model can successfully explain the responses of key macroeconomic variables, but it is unable to explain these responses under counterfactual fiscal frameworks. Interestingly, fiscal policy also seems capable of regulating the size of pass-through. Furthermore, fiscal policies that insulate the economy from oil price shocks seem to be welfare improving over procyclical ones.
Double-diffusive counterbuoyant boundary layer in laminar natural convection

Double-diffusive counterbuoyant boundary layers may possess the classical self-similar structure only within two distinct and disconnected subdomains of the physical parameter space. In the outer-dominated subdomain, it is the more diffusive (and hence, outermost) of the buoyancy mechanisms which controls the primary direction of flow and the direction of boundar-layer growth, and the converse is true for inner-dominated flows. Between the inner-dominated and outer-dominated domains there lies a still-unexplored domain of nonsimilar flows. Along the similar/nonsimilar borders there are marginal zones of nonuniqueness in which a multiplicity of self-similar solutions may exist. The self-similar subdomains are investigated by several numerical methods (shooting, finite differences, and Picard's method) and by the method of matched asymptotic expansions (at high Prandtl number and/or high Lewis number) in order to demonstrate the above-outlined qualitative features and to map out the borderlines of incipient counterflow.