cssi/SciSciGPT-SciSciNet huggingface dataset:
Physical controls on the salinity of mid-ocean ridge hydrothermal vent fluids

Abstract Variations in the salinity of black smoker effluents (0.1–∼ 8 wt.% NaCl) relative to seawater (3.2 wt.% NaCl) are attributed to phase separation and segregation of the resulting brines and vapors. However, models of phase separation predict brines with substantially higher salinities than observed at vents and such brines are commonly observed in fluid inclusions from fossil hydrothermal systems. It has been postulated that the range of observed salinities is controlled by the density of upwelling fluids. Here we present models of hydrothermal circulation that predict the observed maximum salinity when an upper layer of high-permeability is included, and also reproduce black smoker temperatures when the upflow zone is surrounded by a low-permeability shell. Pressure gradients across the permeability boundary act as a density filter impeding the passage of high-salinity fluids, while the shell provides sufficient insulation to tap hot fluids to the surface. Our models fit the observations when the permeabilities of the upper layer differ from the permeability of the lower layer by factors of ∼ 10 and ∼ 100 in upflow and downflow regions, respectively, and when the permeability of the shell is one tenth that of the lower layer. The permeability structure we propose is consistent with observations in oceanic crust and inferences from ophiolites. While a previous study argues that black smoker temperatures are a consequence of the thermodynamic properties of seawater, our work suggests that very specific permeability configurations are required to match both the temperature and maximum salinity.
Diamond synthesis in a 50 kW inductively coupled atmospheric pressure plasma torch

Abstract Polycrystalline diamond coatings have been deposited on metal substrates using a 50 kW atmospheric pressure inductively coupled plasma torch. The argon-hydrogen-methane plasma generated has a free stream active area of 35 cm 2 and a temperature of approximately 4500 K. Growth rates are of the order of 10 μm/hour. The growth morphology is found to vary significantly with reactor processing conditions as well as gasdynamic effects near the substrate surface. In this work, we explore the effects of varying the parameters controlling both the surface kinetics (surface temperature and near surface flpofield) and gas phase chemistry (initial gas feed composition and plasma temperature). Stagnation point and flat plate boundary layer flows are investigated. Scanning electron microscopy indicates that well facetted crystals are obtained with growth along the 100 and 111 planes. Nearly continuous films are also formed and found to be of lower quality. Raman scattering data is used to compare the bonding structure to that obtained by other various deposition techniques.
Rh(II)-catalyzed intermolecular oxidative sulfamidation of aldehydes: a mild efficient synthesis of N-sulfonylcarboxamides.

Rh(II)-catalyzed oxidative coupling of aldehydes and sulfonamides has been developed to provide N-sulfonylcarboxamides in one step. A variety of sulfonamides were found to react with aromatic and aliphatic aldehydes to afford the desired products in good to excellent yields. Mechanistic data, including kinetic isotope effect experiments, suggest that the transformation proceeds through a concerted asynchronous nitrene insertion into an aldehydic hydrogen.
On the Hardy-Littlewood maximal function for the cube

It is shown that the Hardy-Littlewood maximal function associated to the cube in ℝ n obeys dimensional free bounds in L p for p > 1. Earlier work only covered the range p > $$\frac{3}{2}$$ .
Comment on “Self-organized criticality in living systems” by C. Adami

Abstract Following extensive numerical experiments, Adami [Phys. Lett. A 203 (1995) 29; Artificial Life 1 (1995) 429] has suggested that the evolution of competing computer programs in artificial life simulations shows signs of being a self-organized critical process. The primary evidence for this claim comes from the distribution of the lifetimes of species in the simulations, which appears to follow a power law. We argue that, for a number of reasons, it is unlikely that the system is in fact at a critical point and suggest an alternative explanation for the power-law lifetime distribution.
QCA is of questionable value for policy research

Qualitative Comparative Analysis (QCA) has been championed as a valuable tool for public policy research. Focusing on the field of policy evaluation, this research note assesses QCA by comparing re...
Nonlinear finite element shell formulation accounting for large membrane strains

Abstract A previously developed nonlinear finite element shell formulation is generalized to accomodate large membrane strains. The formulation is demonstrated on the bending and inflation of a circular plate and the axisymmetric stretching of an annular plate. Both problems are modeled with a Mooney-Rivlin material and involve large membrane strains.
Luminescence properties of a Fibonacci photonic quasicrystal

An active one-dimensional Fibonacci photonic quasi-crystal is realized via spin coating. Luminescence properties of an organic dye embedded in the quasi-crystal are studied experimentally and compared to theoretical simulations. The luminescence occurs via the pseudo-bandedge mode and follows the dispersion properties of the Fibonacci crystal. Time resolved luminescence measurement of the active structure shows faster spontaneous emission rate, indicating the effect of the large photon densities available at the bandedge due to the presence of critically localized states. The experimental results are in good agreement with the theoretical calculations for steady-state luminescence spectra.
Analytical Lower Bounds on the Critical Density in Continuum Percolation

Percolation theory has become a useful tool for the analysis of large-scale wireless networks. We investigate the fundamental problem of characterizing the critical density lambdac (d) for d-dimensional Poisson random geometric graphs in continuum percolation theory. By using a probabilistic analysis which incorporates the clustering effect in random geometric graphs, we develop a new class of analytical lower bounds for the critical density lambdac (d) in d-dimensional Poisson random geometric graphs. The lower bounds are the tightest known to date. In particular, for the two-dimensional case, the analytical lower bound is improved to lambdac (2) ges 0.7698. For the three-dimensional case, we obtain lambdac (3) ges 0.4494.
Random interlacements on Galton-Watson Trees

We study the critical parameter $u^*$ of random interlacements on a Galton-Watson tree conditioned on the non-extinction event. We show that, for a given law of a Galton-Watson tree, the value of this parameter is a.s. constant and non-trivial. We also characterize this value as the solution of a certain equation.
Predicting technology transfer from data in research on technology development

Neither the average effectiveness nor the variations of technology in transfer applications can be adequately estimated directly from performance data in standard research studies designed to develop technology or to "prove" its suitability for markets. The characteristics of the adopter and the situation to which the technology is transferred affect the estimates of outcomes most likely to be observed. A statistical procedure – generalisability analysis – is presented that can be used with various development or qualifying research to estimate variance associated with various factors that might influence technology transfer. By combining these variance estimates with known characteristics of specific applications, adopters of technology can estimate likely effects and their variance when applying technology. The use of generalisability analysis to estimate components of variance in technology transfer is illustrated with data from a study involving the fabrication of temporary crowns in dentistry. A three-factorial, fully crossed, random effects model was tested with a range of user skill values and two values on a technology and situational factors (U × T × S). It is shown in this case that the user contributes the largest amount of expected variance in normal transfer applications, followed by the interaction between the user and technology, complex interactions and error, and technology. It is demonstrated how regressions analysis and confidence intervals partitioned by expected sources of variance can be used to estimate the most likely results of technology transfer to various application contexts based on data provided in technology development or qualification studies. General observations about the nature of technology transfer are also offered.
A new high resolution color flow system using an eigendecomposition-based adaptive filter for clutter rejection

We present a new signal processing strategy for high frequency color flow mapping in moving tissue environments. A new application of an eigendecomposition-based clutter rejection filter is presented with modifications to deal with high blood-to-clutter ratios (BCR). Additionally, a new method for correcting blood velocity estimates with an estimated tissue motion profile is detailed. The performance of the clutter filter and velocity estimation strategies is quantified using a new swept-scan signal model. In vivo color flow images are presented to illustrate the potential of the system for mapping blood flow in the microcirculation with external tissue motion.
Aza-Nazarov cyclization cascades.

Benzamides with tethered acetal groups undergo reactions in CF3SO3H to give ring-fused isoindolinones by a cyclization cascade. The reaction initially forms an N-acyliminium ion which then gives the isoindolinone by the aza-Nazarov reaction. An unusual variant also cyclizes at the allylic position.
Eulerian quasisymmetric functions and cyclic sieving

It is shown that a refined version of a q-analogue of the Eulerian numbers together with the action, by conjugation, of the subgroup of the symmetric group Sn generated by the n-cycle (1,2,?,n) on the set of permutations of fixed cycle type and fixed number of excedances provides an instance of the cyclic sieving phenomenon of Reiner, Stanton and White. The main tool is a class of symmetric functions recently introduced in work of two of the authors.
Synthesis of the Pentacyclic Skeleton of the Aspidosperma Alkaloids Using Rhodium Carbenoids as Reactive Intermediates.

A series of diazo amido keto esters prepared from N-alkenyl-substituted 3-carbalkoxy-2-piperidone derivatives was treated with rhodium(II) acetate. Attack of the amido carbonyl oxygen at the resultant rhodium carbenoid center produced a transient push−pull carbonyl ylide dipole which underwent an intramolecular dipolar cycloaddition reaction. A related annulation sequence was used to prepare the pentacyclic skeleton of the aspidosperma family of alkaloids. Synthesis of the required diazo imide was carried out from 3-carboxy-3-ethyl-2-piperidone and N-methyl-3-indoleacetic acid. Treatment of the diazo imide with rhodium(II) acetate afforded a transient 1,3-dipole which subsequently underwent cycloaddition across the indole π-bond. The resulting cycloadduct is the consequence of endo cycloaddition with respect to the dipole which is fully in accord with the lowest energy transition state. The cycloadduct was converted in three steps into desacetoxy-4-oxo-6,7-dihydrovindorosine. The stereochemistry of the fi...
Two-Loop Helicity Amplitudes for Gluon-Gluon Scattering in QCD and Supersymmetric Yang-Mills Theory

We present the two-loop helicity amplitudes for the scattering of two gluons into two gluons in QCD, which are relevant for next-to-next-to-leading order corrections to jet production at hadron colliders. We give the results in the 't Hooft-Veltman and four-dimensional helicity variants of dimensional regularization. Summing our expressions over helicities and colors, and converting to conventional dimensional regularization, gives results in complete agreement with those of Glover, Oleari and Tejeda-Yeomans. We also present the amplitudes for 2 ! 2 scattering in pure N = 1 supersymmetric Yang-Mills theory.
Numerical simulations of competition in quantities

Abstract We present a series of numerical simulation models built in Excel that can be used to explore the properties of various models of strategic competition in quantities and their economic implications. The resources incorporate both tabular and graphical data presentation formats and are built in such a way that they provide instant or ‘live’ feedback on the consequences of changes in the economic system. We discuss the theory behind the models, how they can be implemented as numerical simulations in Excel, and ways in which the simulations can be used to enhance student understanding of the material.
The Symmetrical Top in the Undulatory Mechanics

Schr\"odinger's method for determining the energy levels of an atomic system is applied to the case of the symmetrical top (moment of inertia about axis of symmetry $C$, the other one $A$). The energy values are found to be ${W}_{\mathrm{jn}}=\frac{{h}^{2}}{8{\ensuremath{\pi}}^{2}}\left[\frac{1}{A}j(j+1)+\left(\frac{1}{C}\ensuremath{-}\frac{1}{A}\right){n}^{2}\right]$ in agreement with the result obtained by Dennison from the matrix mechanics. The quantum numbers $j$ and $n$ must be integers restricted by $0\ensuremath{\leqq}j$, $|n|\ensuremath{\leqq}j$, while half-integral values are not permissible. The intensities of transitions are also calculated.
The Experimental Study of Asset Pricing Theory

1. Introduction. 2. Why We Need Experiments. 3. Risk Aversion In The Laboratory. 4. Creating Competitive Markets. 5. Static, Complete-Markets Asset Pricing Theory. 6. Dynamic Asset Pricing Theory. 7. Ambiguity Aversion. 8. Equilibration. 9. Information Amplification. 10. Loan and Insurance Markets. 11. Concluding Comments. References.
Down-regulation of 5-lipoxygenase activity and leukotriene production by prolonged exposure to lipopolysaccharide.

Eicosanoids are a diverse group of intercellular mediators derived from the enzymatic modification of arachidonic acid (AA1). The prostaglandins (PGs) and leukotrienes (LTs) are two major groups of eicosanoids. These mediators can evoke a diverse array of responses. In some cases, similar eicosanoids evoke opposing effects. For example, PGE2and prostacyclin (PGI2) promote smooth muscle relaxation, while PGD2, LTC4and thromboxane cause muscle contraction.
Multiscale relationships between fracture length, aperture, density and permeability

[1] Fractured rocks exhibit a hierarchical structure which renders their attributes scale-dependent. In particular available data indicate a tendency for fracture length scales to be distributed according to a power law, average fracture aperture to be given by a power of the fracture length scale, and fracture density as well as log permeability to behave as random fractals. To date, no consistent theoretical relationship has been developed between fracture type (as categorized, for example, by length scale and/or aperture) and corresponding fractal attributes (such as density and log permeability). We develop and explore multiscale relationships between these fracture categories and attributes on the basis of a theory recently proposed by the author, which allows linking them in a formal way.
The generation and suppression of synchrotron sidebands

Computer simulations of FEL lasing differ in the degree to which they approximate real experiments. One of the FEL codes used extensively at Los Alamos takes account of the features of each electron micropulse and follows the growth and saturation of the optical micropulse. With no additional adjustments, this code displays the development of sidebands and demonstrates their control when optical filters of various kinds are used. Other codes that do not include a description of the micropulse do not automatically display sidebands but need to have artificial noise of some kind added. This is not unexpected because sidebands are generated by an FEL instability; instabilities, in general, need some kind of initiating disturbance. In this paper we: identify the disturbance that triggers the instability in the pulse code; discuss a practical way to suppress the instability without using filters; compare these results with experiments; and discuss these findings. 22 refs., 9 figs.
Chemical and Physical Properties of Fructans

Summary Fructans are defined as compounds in which linkages between fructose residues constitute the majorityof linkages. This includes small oligomers and polymers with more than 10,000 residues. The structures and basic chemistry of fructose and glucose are reviewed, and conformational nomenclature for fructo-furanose is adapted from the study of furanose rings of ribose. The fructofuranose ring is a high-energy form, according to molecular mechanics calculations, and its preferred form is puckered with carbon 3 down. Crystal structures containing fructofuranose residues have, with one exception, variations of this form. Compounds and complexes of fructose are briefly mentioned. The analysis of di-fructose dian-hydride 1 by Lemieux and Nagarajan is discussed to indicate the importance of conformation to chemical behavior of compounds containing fructose; a computer model of dianhydride 1 supports their proposal. Computer models of inulin and linear levan are shown to be flexible, but the shapes of levans are restricted by the presence of the primary alcohol group on CI that is adjacent to the polymeric linkage.
Toward Nanoprocessor Thermodynamics

A hierarchical methodology for the determination of fundamental lower bounds on energy dissipation in nanoprocessors is described. The methodology aims to bridge computational description of nanoprocessors at the instruction-set-architecture level to their physical description at the level of dynamical laws and entropic inequalities. The ultimate objective is hierarchical sets of energy dissipation bounds for nanoprocessors that have the character and predictive force of thermodynamic laws and can be used to understand and evaluate the ultimate performance limits and resource requirements of future nanocomputing systems. The methodology is applied to a simple processor to demonstrate instruction- and architecture-level dissipation analyses.
Kinematical & Chemical Characteristics of the Thin and Thick Disks

I discuss how the chemical abundance distributions, kinematics and age distributions of stars in the thin and thick disks of the Galaxy can be used to decipher the merger history of the Milky Way, a typical large galaxy. The observational evidence points to a rather quiescent past merging history, unusual in the context of the ‘consensus’ cold-dark-matter cosmology favoured from observations of structure on scales larger than individual galaxies.
High Energy Neutrinos From Quasars

We review and clarify the assumptions of our basic model for neutrino production in the cores of quasars, as well as those modifications to the model made subsequently by other workers. We also present a revised estimate of the neutrino background flux and spectrum obtained using more recent empirical studies of quasars and their evolution. We compare our results with other theoretical calculations and experimental upper limits on the AGN neutrino background flux. We also estimate possible neutrino fluxes from the jets of blazars detected recently by the EGRET experiment on the Compton Gamma Ray Observatory. We discuss the theoretical implications of these estimates.
Rayleigh adjustment of narrow barriers in protoplanetary discs

Sharp density features in protoplanetary discs, for instance at the edge of a magnetically dead zone, have recently been proposed as effective barriers to slow down or even stop the problematically fast migration of planetary cores into their central star. Density features on a radial scale approaching the disc vertical scaleheight might not exist, however, since they could be Rayleigh (or more generally Solberg-Hoiland) unstable. Stability must be checked explicitly in one-dimensional viscous accretion disc models because these instabilities are artificially eliminated in the process of reducing the full set of axisymmetric equations. The disc thermodynamics, via the entropy stratification, and its vertical structure also influence stability when sharp density features are present. We propose the concept of Rayleigh adjustment for viscous disc models: any density feature that violates Rayleigh stability (or its generalization) should be diffused radially by hydrodynamical turbulence on a dynamical time-scale, approaching marginal stability in a quasi-continuous manner.
Wave drag due to lift for transonic airplanes

Liftdominated pointed aircraft configurations are considered in the transonic range. To make the approximations more transparent, twodimensionally cambered untwisted lifting wings of zero thickness...
ROC and the bounds on tail probabilities via theorems of Dubins and F. Riesz

For independent X and Y in the inequality P(X ≤ Y + μ), we give sharp lower bounds for unimodal distributions having finite variance, and sharp upper bounds assuming symmetric densities bounded by a finite constant. The lower bounds depend on a result of Dubins about extreme points and the upper bounds depend on a symmetric rearrangement theorem of F. Riesz. The inequality was motivated by medical imaging: find bounds on the area under the Receiver Operating Characteristic curve (ROC).
Solvent-dependent oxidative coupling of 1-aryl-1,3-dicarbonyls and styrene

This report describes the scope and mechanism of the solvent-dependent, chemoselective oxidative coupling of 1-aryl-1,3-dicarbonyls with styrene using Ce(IV) reagents. Dihydrofuran derivatives are obtained when reactions are performed in methanol whereas α-tetralones can be selectively synthesized in acetonitrile and methylene chloride. Mechanistic studies are consistent with the rate of solvent-assisted deprotonation of a radical cation intermediate playing an integral role in the selective formation of products.
Developing a summary measure of medical status

Health status surveys and assessments typically obtain detailed information on specific physical health conditions. While such specific details are important, it is frequently also valuable to have a summarized evaluation of medical conditions which can be used to compare subjects, or for statistical analyses. Using data from the Duke Established Populations for Epidemiologic Studies of the Elderly survey, we indicate how to obtain a weighted sum of chronic medical conditions. Like the sum of the same conditions, it explains variance in selected measures of health service use and health status, in some instances making a contribution beyond that of the summed measure. It is a significantly better predictor of mortality within six years.
Impact of geoengineering schemes on the global hydrological cycle

The rapidly rising CO2 level in the atmosphere has led to proposals of climate stabilization by ‘‘geoengineering’’ schemes that would mitigate climate change by intentionally reducing solar radiation incident on Earth’s surface. In this article we address the impact of these climate stabilization schemes on the global hydrological cycle. By using equilibrium climate simulations, we show that insolation reductions sufficient to offset global-scale temperature increases lead to a decrease in global mean precipitation. This occurs because solar forcing is more effective in driving changes in global mean evaporation than is CO2 forcing of a similar magnitude. In the model used here, the hydrological sensitivity, defined as the percentage change in global mean precipitation per degree warming, is 2.4% K 1 for solar forcing, but only 1.5% K 1 for CO2 forcing. Although other models and the climate system itself may differ quantitatively from this result, the conclusion can be understood based on simple considerations of the surface energy budget and thus is likely to be robust. For the same surface temperature change, insolation changes result in relatively larger changes in net radiative fluxes at the surface; these are compensated by larger changes in the sum of latent and sensible heat fluxes. Hence, the hydrological cycle is more sensitive to temperature adjustment by changes in insolation than by changes in greenhouse gases. This implies that an alteration in solar forcing might offset temperature changes or hydrological changes from greenhouse warming, but could not cancel both at once. climate change global hydrology radiative forcing mitigation
A carrier sense multiple access protocol for local networks

Abstract A consequence of bursty traffic in computer communications is that among a large population of network users, at any one time only a small number of them have data to send (ready users). In this environment, the performance of an access protocol for a broadcast network depends mainly upon how quickly one of the ready users can be identified and given sole access to the shared channel. The relative merits of the access protocols of polling, probing and carrier sense multiple access (CSMA) with respect to this channel assignment delay in local networks are considered. A central controller is needed for polling and probing while CSMA employs distributed control. A specific CSMA protocol is defined which requires that “collisions” in the channel be detected and that the users involved in a collision abort their transmissions quickly. In addition, it is assumed that the contention algorithm is adaptive and gives rise to a stable channel. An analytic model is developed. Our main result is the moment generating function of the distributed queue size (number of ready users). Mean value formulas for message delay and channel assignment delay are also derived. These results on queue size and delay are the major contribution of this paper, since they are not available in prior CSMA models in close analytical form. Numerical results are given to illustrate the performance of the CSMA protocol. When the channel utilization is light to moderate, the mean channel assignment delay of the CSMA protocol is significantly less than that of both polling and probing; consequently, the mean message delay is much smaller. It is also shown that when queueing of messages is permitted at individual users, the maximum channel throughput of CSMA approaches unity in the limit of very long queues. Finally, simulation results of several adaptive control algorithms are presented. The accuracy of our analytic formulas was carefully studied and found to be very good in all cases considered.
Growth and properties of near‐UV light emitting diodes based on InN/GaN quantum wells

Near-ultraviolet light emitting diodes (LEDs), based on one monolayer thick InN/GaN multiple quantum wells, were grown by radio-frequency plasma-assisted molecular beam epitaxy. The active region was grown at 685 °C, a temperature where the growth of thick InN layers is not possible. High resolution transmission electron microscopy revealed that the InN well layers were grown pseudomorphically in between the GaN barriers and were characterized by well defined interfaces and uniform thickness. The LED structures exhibited electroluminescence emission at 384 nm, with a FWHM of about 14 nm. The peak emission wavelength was independent of the injection current, indicating the absence of quantum confined Stark effect in these structures. Output optical power of 0.84 mW was measured at 200 mA in a bare die configuration. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Exploiting parallelism for the performance enhancement of non-numeric applications

In this paper we examine the design of computer architectures that use parallelism to enhance the performance of non-numeric applications. In particular we examine how the technology of mass-storage devices has affected the design of computer architectures for non-numeric processing.
A galaxy halo model of large-scale structure

We present a new, galaxy halo model of large-scale structure, in which the galaxies entering a given sample are the fundamental objects. Haloes attach to galaxies, in contrast to the standard halo model, in which galaxies attach to haloes. The galaxy halo model pertains mainly to the relationships between the power spectra of galaxies and mass, and their cross-power spectrum. With surprisingly little input, an intuition-aiding approximation to the galaxy-matter cross-correlation coefficient R(k) emerges in terms of the halo mass dispersion. This approximation seems valid to mildly non-linear scales (k ≤ 3 h Mpc -1 ), allowing the measurement of the bias and the matter power spectrum from measurements of the galaxy and galaxy-matter power spectra (or correlation functions). This is especially relevant given the recent advances in precision in measurements of the galaxy-matter correlation function from weak gravitational lensing. The galaxy halo model also addresses the issue of interpreting the galaxy-matter correlation function as an average halo density profile, and provides a simple description of galaxy bias as a function of scale.
The Use of Solid Etalon Devices as Narrow Band Interference Filters

The fabrication of Fabry-Perot Etalon Filters with spacer elements of solid fused silica is described. Typically spacer thicknesses of 120pm are used to provide filters with .05nm to .07nm FWHM at 656.3nm centre wavelength. More complex devices having two coherently coupled cavities are described. The effect of optical system parameters on the spectral performance of the solid etalon filters is discussed and suitable operating parameters are suggested. The performance of solid etalon filters is compared with the birefringent filters of the Lyot type.
Seismic evidence for an extensive gas-bearing layer at shallow depth, offshore from Prudhoe Bay, Alaska

Abstract High-resolution seismic reflection data, recorded offshore from Prudhoe Bay, Alaska, were processed digitally to determine the reflectivity structure of the uppermost layers of the seafloor. A prominent reflector, found at 27 m below the mud line (water depths 7–9 m), has a negative reflection coefficient greater than 0.5. The large acoustic impedance contrast, coupled with a report of gas encountered at a corresponding depth in a nearby drillhole, shows that the reflector is the upper boundary of a zone containing gas. The gas exists in sandy gravel capped by stiff, silty clay. Analysis of unprocessed conventional high-resolution records from the region indicates that the gas-bearing layer may extend over an area of at least 50 km2 at a depth of 20–35 m below the mud line. Similar-appearing reflectors (Reimnitz, 1972), previously unexplained, occur in patches over wide regions of the shelf where offshore oil development is beginning at a rapid pace. This suggests the exercise of caution with respect to possible hazards from shallow gas pockets.
What Makes Annuitization More Appealing

We conduct and analyze two large surveys of hypothetical annuitization choices. We find that allowing individuals to annuitize a fraction of their wealth increases annuitization relative to a situation where annuitization is an “all or nothing” decision. Very few respondents choose declining real payout streams over flat or increasing real payout streams of equivalent expected present value. Highlighting the effects of inflation increases demand for cost of living adjustments. Frames that highlight flexibility, control, and investment significantly reduce annuitization. A majority of respondents prefer to receive an extra “bonus” payment during one month of the year that is funded by slightly lower payments in the remaining months. Concerns about later-life income, spending flexibility, and counterparty risk are the most important self-reported motives that influence the annuitization decision.
Nonlinear Comparison of High-order and Optimized Finite-difference Schemes

The effect of reducing the formal order of accuracy of a finite-difference scheme in order to optimize its high-frequency performance is investigated using the I-D nonlinear unsteady inviscid Burgers'equation. It is found that the benefits of optimization do carry over into nonlinear applications. Both explicit and compact schemes are compared to Tam and Webb's explicit 7-point Dispersion Relation Preserving scheme as well as a Spectral-like compact scheme derived following Lele's work. Results are given for the absolute and L2 errors as a function of time.
Circadian Rhythm has no Effect on Mortality in Coronary Artery Bypass Surgery

Background: The circadian variation that affects atherosclerosis has not been studied in the surgical patient. The circadian variation in mortality dependent on the time of surgery was examined in patients undergoing coronary artery bypass graft (CABG) surgery. Methods: A 4-year retrospective review of all CABG patients (n = 3140) from 1999 to 2002 was undertaken. The patients were divided into elective, urgent, and emergency cases. The cases were subdivided according to the start time of the operation as morning (7 AM to 2 PM = AM), afternoon (2 PM to 8 PM = AF), and night (8 PM to 7 AM = NT). The outcome was mortality within 30 days and compared for three different time frames: (1) AM versus AF (2) AM versus NT (3) AF versus NT for each prioritized group. Risk factors and number of anastamoses were compared for each group. Sigma Statistical package and Z-test for two group comparison were used for analysis. t-Test was used to compare age and ejection fraction. Results: No statistically significant difference in mortality was observed for the elective and urgent groups for each of the time periods compared. The emergency cases had significantly increased deaths in the AM and NT compared to the AF (p < 0.01 and p < 0.05, respectively). There was no statistically significant difference with respect to age, gender, number of anastamoses performed, ejection fraction, and preoperative risk factors between groups. Conclusions: The mortality for nonemergent CABG is independent of the timing of surgery. Circadian variation does not influence the outcome in cardiac surgical patients.
Strings on AdS wormholes

We consider the behavior of open strings on anti-de Sitter wormholes in Gauss-Bonnet theory, which are the Gauss-Bonnet gravity duals of a pair of field theories. A string with both endpoints on the same side of the wormhole describes two charges within the same field theory, which exhibit Coulomb interaction for small separation. On the other hand, a string extending through the wormhole describes two charges which live in different field theories, and they exhibit a springlike confining potential. A transition occurs when there is a pair of charges present within each field theory: for small separation each pair of charges exhibits Coulomb interaction, while for large separation the charges in the different field theories pair up and exhibit confinement. Two steadily-moving charges in different field theories can occupy the same location provided that their speed is less than a critical speed, which also plays the role of a subluminal speed limit. However, for some wormhole backgrounds, charges moving at the critical speed cannot occupy the same location and energy is transferred from the leading charge to the lagging one. We also show that strings on anti-de Sitter wormholes in supergravity theories without higher-derivative curvature terms can exhibit these properties as well.
Non-Commutative Calabi-Yau Manifolds

Abstract We discuss aspects of the algebraic geometry of compact non-commutative Calabi–Yau manifolds. In this setting, it is appropriate to consider local holomorphic algebras which can be glued together into a compact Calabi–Yau algebra. We consider two examples: a toroidal orbifold T 6 / Z 2 × Z 2 , and an orbifold of the quintic in CP 4 , each with discrete torsion. The non-commutative geometry tools are enough to describe various properties of the orbifolds. First, one describes correctly the fractionation of branes at singularities. Secondly, for the first example we show that one can recover explicitly a large slice of the moduli space of complex structures which deform the orbifold. For this example we also show that we get the correct counting of complex structure deformations at the orbifold point by using traces of non-commutative differential forms (cyclic homology).
Evaluation of test methods designed to obtain the undrained shear strength of muds

Abstract One parameter needed for the stability analysis of seafloor mud‐covered slopes is the undrained shear strength, cu, of the mud. A literature review dealing with mudslides shows that six methods exist to measure the cu of muds either in the laboratory or in the field. These methods are: 1) the vane shear test, 2) the cylinder‐strength meter test, 3) the sphere‐strength meter test, 4) the cone penetrometer test, 5) the pullout test using a cylinder, and 6) the use of the vertical profile of a mudslide in the direction of movement. The present study reports a laboratory investigation of the undrained shear strength of artificially prepared muds using the six methods in order to evaluate their accuracy. It was found that for mud samples with low clay content (less than 45% by weight), the cylinder‐strength meter test, the mudslide profile test, the cone penetrometer test, and the pullout test gave similar results for cu and therefore compare well. However, the sphere and vane shear tests gave values ...
Universal cokriging under intrinsic coregionalization

Under the intrinsic coregionalization model if both primary and secondary measurements are available at all sample locations, the conventional geostatistical wisdom is that cokriging provides exactly the same solution as univariate kriging on the primary process alone. However, recent eamples have been given where nonzero secondary cokriging weights have accurred under this spatial dependence structure. This note identifies the conditions under which secondary information is useful under the assumption of intrinsic coregionalization. An illustration is given using a dataset of plutonium and americium concentrations collected from a region of the Nevada Test Site.
Solid Phase Synthesis and Application of Labeled Peptide Derivatives: Probes of Receptor-Opioid Peptide Interactions

Solid phase synthetic methodology has been developed in our laboratory to incorporate an affinity label (a reactive functionality such as isothiocyanate or bromoacetamide) into peptides (Leelasvatanakij and Aldrich J Peptide Res 56, 80, 2000), and we have used this synthetic strategy to prepare affinity label derivatives of a variety of opioid peptides. To date side reactions have been detected only in two cases, both involving intramolecular cyclization. We have identified several peptide-based affinity labels for δ opioid receptors that exhibit wash-resistant inhibition of binding to these receptors and are valuable pharmacological tools to study opioid receptors. Even in cases where the peptide derivatives do not bind covalently to their target receptor, studying their binding has revealed subtle differences in receptor interactions with particular opioid peptide residues, especially Phe residues in the N-terminal “message” sequences. Solid phase synthetic methodology for the incorporation of other labels (e.g. biotin) into the C-terminus of peptides has also been developed in our laboratory (Kumar and Aldrich Org Lett 5, 613, 2003). These two synthetic approaches have been combined to prepare peptides containing multiple labels that can be used as tools to study peptide ligand-receptor interactions. These solid phase synthetic methodologies are versatile strategies that are applicable to the preparation of labeled peptides for a variety of targets in addition to opioid receptors.
ECONOMIES OF SCALE IN MUTUAL FUND ADMINISTRATION

Since many mutual fund expenses are fixed costs, asset growth should reduce the ratio of fund expenses to average net assets. A translog cost function is estimated for a sample of 2,610 funds to evaluate the existence and extent of economies of scale in mutual fund administration. The elasticity of fund expenses with respect to fund assets is significantly less than one, indicating there are economies of scale in mutual fund administration. Average costs diminish over the full range of fund assets; however, the rapid decrease in average costs is exhausted by about $3.5 billion in fund assets.
Single Motherhood, Employment, or Social Assistance: Why Are U.S. Women Poorer Than Women in Other Affluent Nations?

U.S. women have higher poverty rates than women in other affluent nations. In this paper I attempt to explain this disparity by examining the effect of single motherhood, employment, and social assistance on women's poverty. With cross-national comparisons of quantitative data, I find that the relatively high rate of single motherhood among U.S. women is not a main cause of their high poverty rates. Compared to their counterparts in other Western nations, U.S. women, mothers and single mothers are among the most likely to earn poverty wages. In addition, U.S. social assistance programs are the least effective in reducing poverty. I conclude with the policy implications of my findings, focusing on strategies to ameliorate the high poverty rates of U.S. women and mothers.
Robust adaptive dynamic programming for optimal nonlinear control design

This paper studies the robust optimal control design for uncertain nonlinear systems from a perspective of robust adaptive dynamic programming (robust-ADP). The objective is to fill up a gap in the past literature of ADP where dynamic uncertainties, or unmodeled dynamics, are not addressed. A key strategy is to integrate tools from modern nonlinear control theory, such as the robust redesign and the backstepping techniques as well as the nonlinear small-gain theorem, with the theory of ADP. The proposed robust-ADP methodology can be viewed as a natural extension of ADP to uncertain nonlinear systems. A practical learning algorithm is developed in this paper, and has been applied to analyze a sensorimotor control problem.
Guidelines for Improving the Standard Fire Resistance Test Specifications

The current approach of evaluating fire resistance is mainly through standard fire tests. The specifications for standard fire tests have a number of drawbacks and require only a limited amount of data to be collected during tests, and this is hindering the development of calculation methodologies for evaluating fire resistance. This paper discusses the various drawbacks in the current specifications for undertaking fire resistance tests. The improvements needed to make the standard fire resistance tests more effective and the collected test data more useful are outlined. Strategies for implementing the proposed recommendations (improvements) in test standards are illustrated with examples. Finally, the applicability of the proposed recommendations is illustrated by undertaking fire resistance tests on a midsized column and a midsized beam under improved test specifications. Data collected from these fire resistance tests is used to calibrate finite element based computer models, thus demonstrating the effectiveness of collecting additional test data.
Can monetizing trade lower welfare? An example

Abstract In decentralized trade individuals self-insure against consumption risk via costly diversification of skills. Although money acts as consumption insurance, it may lead to a moral hazard problem. If the problem is severe, monetizing trade can lower welfare relative to barter.
New models of gauge mediated dynamical supersymmetry breaking

Abstract We propose a simple class of nonrenormalizable models of gauge mediated dynamical supersymmetry breaking. The models do not have gauge singlet fields. The Standard Model gauge group is embedded in the global symmetry of the SUSY breaking sector. At the renormalizable level the models possess a set of classical flat directions. Only one of those flat directions is unlifted by quantum effects, and requires nonrenormalizable term to stabilize the potential for the corresponding modulus. Large vacuum expectation value of this modulus at the minimum of the potential generates mass terms for the messenger fields. There are no light messengers, thus this class of models evades difficulties encountered in earlier constructions using nonrenormalizable models.
The Efficiency of Human Capital Allocations in Developing Countries

Abstract For a set of 14 developing countries I evaluate whether differences in wage gaps between sectors – estimated from individual-level wage data – have meaningful effects on aggregate productivity. Under the most generous assumptions regarding the homogeneity of human capital, my analysis shows that eliminating wedges between wages in different sectors leads to gains in output of less than 5% for most countries. These estimated gains of reallocation represent an upper bound as some of the observed differences in wages are due to unmeasured human capital. Under reasonable assumptions on the amount of unmeasured human capital the gains from reallocation fall well below 3%. Compared to similar estimates made using data from the U.S., developing countries would gain more from a reallocation of human capital, but the differences are too small to account for a meaningful portion of the gap in income per capita with the United States.
Broadly Neutralizing Influenza Hemagglutinin Stem-Specific Antibody CR8020 Targets Residues that Are Prone to Escape due to Host Selection Pressure

Broadly neutralizing antibodies (bNAb) that target a conserved region of a viral antigen hold significant therapeutic promise. CR8020 is a bNAb that targets the stem region of influenza A virus (IAV) hemagglutinin (HA). CR8020 is currently being evaluated for prophylactic use against group 2 IAVs in phase II studies. Structural and computational analyses reported here indicate that CR8020 targets HA residues that are prone to antigenic drift and host selection pressure. Critically, CR8020 escape mutation is seen in certain H7N9 viruses from recent outbreaks. Furthermore, the ability of the bNAb Fc region to effectively engage activating Fcγ receptors (FCγR) is essential for antibody efficacy. In this regard, our data indicate that the membrane could sterically hinder the formation of HA-CR8020-FcγRIIa/HA-IgG-FcγRIIIa ternary complexes. Altogether, our analyses suggest that epitope mutability and accessibility to immune complex assembly are important attributes to consider when evaluating bNAb candidates for clinical development.
Failure of nontopological boundary conditions in gauge theories

Abstract In quantum gauge theory, when a particular direction xa is compactified to a circle, the energy of the vacuum Veff becomes dependent on a constant value AμaC of the gauge potential. The parameter C is a periodic variable, and the vacuum energy typically has a local minimum at C = 0. Circular topology implies, of course, periodic boundary conditions in xa. When the boundary conditions around the circle are changed to, say, Dirichlet ones, the variable C becomes noncompact, and it turns out that the vacuum energy has no global minimum. We interpret this to mean that quantum gauge theories with Dirichlet or similar boundary conditions on actual boundaries are not well defined.
Review: Adding dexamethasone to standard therapy reduces short-term relapse for acute migraine in the emergency department

Source Citation Singh A, Alter HJ, Zaia B. Does the addition of dexamethasone to standard therapy for acute migraine headache decrease the incidence of recurrent headache for patients treated in th...