cssi/SciSciGPT-SciSciNet huggingface dataset:
X-ray and radio monitoring of GX 339-4 and CYG X-1

Previouswork by Motch et al. [1985, Space Sci. Rev. 40, 219] suggested that in the low/hard state of GX 339-4, the soft X-ray power-law extrapolated backward in energy agrees with the IR flux level. Corbel and Fender [2002, ApJ 573, L35—L39] later showed that the typical hard state radio power-law extrapolated forward in energy meets the backward extrapolated X-ray power-law at an IR spectral break, which was explicitly observed twice in GX 339-4. This has been cited as further evidence that jet synchrotron radiation might make a significant contribution to the observed X-rays in the hard state. We explore this hypothesis with a series of simultaneous radio/X-ray hard state observations of GX 339-4.We fit these spectra with a simple, but remarkably successful, doubly broken power-lawmodel that indeed requires a spectral break in the IR. For most of these observations, the break position as a function of X-ray flux agrees with the jet model predictions.We then examine the radio flux/X-ray flux correlation in Cyg X-1 through the use of 15 GHz radio data, obtained with the Ryle radio telescope, and Rossi X-ray Timing Explorer data, from the All Sky Monitor and pointed observations. We find evidence of ‘parallel tracks’ in the radio/X-ray correlation which are associated with ‘failed transitions’ to, or the beginning of a transition to, the soft state. We also find that for Cyg X-1 the radio flux is more fundamentally correlated with the hard, rather than the soft, X-ray flux.
Probabilistic Weyl Laws for Quantized Tori

For the Toeplitz quantization of complex-valued functions on a 2n-dimensional torus we prove that the expected number of eigenvalues of small random perturbations of a quantized observable satisfies a natural Weyl law (1.3). In numerical experiments the same Weyl law also holds for “false” eigenvalues created by pseudospectral effects.
Spin Analysis of Concentrated Traction Contacts

Spin, the result of a mismatch in contact radii on either side of the point of rolling, has a detrimental effect on traction contact performance. It occurs in concentrated contacts having conical or contoured rolling elements, such as those in traction drives or angular contact bearings, and is responsible for an increase in contact heating and power loss. The kinematics of spin producing contact geometries and the subsequent effect on traction and power loss are investigated. The influence of lubricant traction characteristics and contact geometries that minimize spin are also addressed.
Deglacial dust provenance changes in the Eastern Equatorial Pacific and implications for ITCZ movement

Abstract The provenance of eolian dust supplied to deep-sea sediments has the potential to offer insights into changes in past atmospheric circulation. Specifically, measuring temporal changes in dust provenance can shed light on changes in the mean position of the Intertropical Convergence Zone (ITCZ), a region acting as a barrier separating wind-blown material derived from northern versus southern hemisphere sources. Here we have analyzed Nd, Sr, and Pb isotope ratios in the operationally-defined detrital component extracted from deep-sea sediments in the eastern equatorial Pacific (EEP) along a meridional transect at 110°W from 3°S to 7°N (ODP Leg 138, sites 848–853). Sr isotope results show that barite Sr has a significant influence on 87Sr/86Sr isotope ratios of samples in the upwelling zone of the EEP. However, sites located >3° or more away from the equator (sites 852 and 853) are believed to not be affected by barite Sr and provide useful detrital Sr signals. 208Pb/206Pb and 207Pb/206Pb ratios in all cores fall into the Pb-isotope space of five potential dust sources (Asia, North and Central/South America, Sahara, and Australia), with no distinct isotopic fingerprinting of the dominant source(s). eNd values were most valuable for discerning detrital source provenance, and their values at all sites, ranging from −5.46 to −3.25, were more unradiogenic for sediments deposited during the last glacial than for those deposited during the Holocene. There are distinct latitudinal trends in the eNd values, with more radiogenic values further south and less radiogenic values further north, excluding site 848. This distinction holds true for both Holocene and last glacial periods. For the most southerly site, 848, we invoke, for the first time, a distinct southern hemisphere Australian source as being responsible for the unradiogenic Nd isotope ratios. Both average last glacial and Holocene eNd values show similar sharp gradients along the transect between 5.29°N and 2.77°N, suggesting little movement of the glacial ITCZ in the EEP. However, during the deglacial, this gradient is stronger and shifted further north between 5.29°N and 7.21°N, suggesting a more northerly, possibly stronger, deglacial ITCZ.
Numerical Simulation of Steady Supersonic Viscous Flow

A noniterative, implicit, space-marching, finite-difference algorithm is developed for the steady thin-layer Navier-Stokes equations in conservation-law-form. The numerical algorithm is applicable to steady supersonic viscous flow over bodies of arbitrary shape. In addition, the same code can be used to compute supersonic inviscid flow or three-dimensional boundary layers. Computed results from two-dimensional and three-dimensional versions of the numerical algorithm are in good agreement with those obtained from more costly time-marching techniques.
Computing hypermatrix spectra with the Poisson product formula

We compute the spectrum of the ‘all ones’ hypermatrix using the Poisson product formula. This computation includes a complete description of the eigenvalues’ multiplicities, a seemingly elusive aspect of the spectral theory of tensors. We also give a distributional picture of the spectrum as a point-set in the complex plane. Finally, we use the technique to analyse the spectrum of ‘sunflower hypergraphs’, a class that has played a prominent role in extremal hypergraph theory.
Beyond the damping tail: Cross-correlating the kinetic Sunyaev-Zel'dovich effect with cosmic shear

Secondary anisotropies of the cosmic microwave background (CMB) have the potential to reveal intricate details about the history of our universe between the present and recombination epochs. However, because the CMB we observe is the projected sum of a multitude of effects, the interpretation of small-scale anisotropies by future high-resolution experiments will be marred by uncertainty and speculation without the handles provided by other observations. The recent controversy over the excess small-scale anisotropy detected by CBI and the BIMA array is a foretaste of potential challenges that will be faced when interpreting future experiments. In this paper we show that cross-correlating the CMB with an overlapping weak-lensing survey will isolate the elusive kinetic Sunyaev-Zel'dovich (kSZ) effect from secondary anisotropies generated at higher redshifts. We show that if upcoming high angular resolution CMB experiments, like Planck/ACT/SPT, cover the same area of sky as current and future weak-lensing surveys, like CFTHLS/SNAP/LSST, the cross-correlation of cosmic shear with the kSZ effect will be detected with high signal-to-noise ratio, increasing the potential science accessible to both sets of surveys. For example, if ACT and a CFHTLS-like survey were to overlap, this cross-correlation would be detected with a total signal-to-noise ratio greater than 220, reaching 1.8 per individual multipole around l ~ 5000. Furthermore, this cross-correlation probes the three-point coupling between the underlying dark matter and the momentum of the ionized baryons in the densest regions of the universe at intermediate redshifts. Similar to the thermal Sunyaev-Zel'dovich (tSZ) power spectrum, its strength is extremely sensitive to the power spectrum normalization parameter, σ8, scaling roughly as σ. It provides an effective mechanism to isolate any component of anisotropy due to patchy reionization and rule out primordial small-scale anisotropy.
Searches for Long-lived Particles at the Tevatron Collider

Several searches for long-lived particles have been performed using data from $p\bar p$ collisions from Run II at the Tevatron. In most cases, new analysis techniques have been developed to carry out each search and/or estimate the backgrounds. These searches expand the discovery potential of the CDF and D0 experiments to new physics that may have been missed by traditional search techniques. This review discusses searches for (1) neutral, long-lived particles decaying to muons, (2) massive, neutral, long-lived particles decaying to a photon and missing energy, (3) stopped gluinos, and (4) charged massive stable particles. It summarizes some of the theoretical and experimental motivations for such searches.
Model Averaging and Dimension Selection for the Singular Value Decomposition

Many multivariate data-analysis techniques for an m × n matrix Y are related to the model Y = M + E, where Y is an m × n matrix of full rank and M is an unobserved mean matrix of rank K < (m ∧ n). Typically the rank of M is estimated in a heuristic way and then the least-squares estimate of M is obtained via the singular value decomposition of Y, yielding an estimate that can have a very high variance. In this article we suggest a model-based alternative to the preceding approach by providing prior distributions and posterior estimation for the rank of M and the components of its singular value decomposition. In addition to providing more accurate inference, such an approach has the advantage of being extendable to more general data-analysis situations, such as inference in the presence of missing data and estimation in a generalized linear modeling framework.
Photolysis of glyoxal at 193, 248, 308 and 351 nm

Abstract The UV photochemistry of glyoxal in nitrogen has been investigated by employing excimer laser photolysis at 193, 248, 308 and 351 nm in combination with cavity ring-down spectroscopy. The HCO radical was a photofragmentation product with yields of 0.42 ± 0.21, 0.53 ± 0.24, 0.69 ± 0.29, and 1.5 ± 0.6 at 193, 248, 308 and 351 nm. The larger than unity HCO yield at 351 nm suggests the photolysis channel (CHO) 2 + hv (351 nm) → 2 HCO. The decrease in HCO yields at higher photolysis photon energies is attributed to the opening up of additional glyoxal photolysis pathways.
Materials and nanotechnology

This paper transcribes a talk given at Drexel University as part of the April 2002 Franklin Medal festivities. Nanomaterials are ubiquitous in occurrence in nature as well as technology. They present immense opportunities both for furthering fundamental understanding and for technological applications. They provide challenges for the infrastructure of science and of interdisciplinary research and education. Nanotechnology itself neither solves nor creates uniquely new societal problems, but interacts with existing societal trends, augmenting existing strengths and weaknesses by hastening technological change.
New approach to GUTs

We introduce a new string-inspired approach to the subject of grand unification which allows the GUT scale to be small, ≲200 TeV, so that it is within the reach of conceivable laboratory accelerated colliding beam devices. The key ingredient is a novel use of the heterotic string symmetry group physics ideas to render baryon number violating effects small enough to have escaped detection to date. This part of the approach involves new unknown parameters to be tested experimentally. A possible hint at the existence of these new parameters may already exist in the EW precision data comparisons with the SM expectations.
Environmental effects on the dynamics and control of an orbiting large flexible antenna system

Solar radiation pressure on the vibrating antenna structure, temperature gradients induced by solar heating, and stabilizing gravity-gradient torques were considered when the linear regulator theory was used to obtain orientation and shape control of a hoop/column antenna system being considered for the land mobile satellite system. A finite element model of the antenna system which includes all six rigid modes and seven flexible modes was used. Results show that the environmental disturbances affect only the rigid modes of the structure. The effect of solar radiation pressure interacting with the vibrating system is smaller than the solar radiation pressure acting on the thermally deformed structure. To reduce control effect in order to maintain shape and orientation, thermal deformations must be minimized in the preliminary design of the system.
The progress of Mexican and white non-Hispanic immigrants in California and Texas, 1980 to 1990

Abstract This article compares assimilation rates of Mexican and white non-Hispanic immigrants in California and Texas in the 1980s, within and across entry cohorts. Using wage functions estimated with 1980 and 1990 Census data, wages are predicted for each immigrant entry cohort and for natives in each year, at a given experience and education level. Mexican immigrants who arrived in the 1970s experienced wage growth relative to comparable natives ranging from 7% to 21%, depending on state and gender; that of non-Hispanic white immigrants ranged from −1% to +6%. Both groups' relative wages grew faster in California than in Texas, and men's grew faster than women's. Across-cohort deterioration between the 1970s and 1980s entrants relative to natives averaged 10% for Mexicans and 4% for non-Hispanic whites.
Enantioselective N-Heterocyclic Carbene-Catalyzed β-Hydroxylation of Enals Using Nitroarenes: An Atom Transfer Reaction That Proceeds via Single Electron Transfer

A novel oxidative N-heterocyclic carbene-catalyzed reaction pathway has been discovered. Alkyl and aryl enals undergo β-hydroxylation via oxygen atom transfer from electron-deficient nitrobenzenes, followed by trapping of the resultant acyl azolium by the solvent. The proposed mechanism involves a single electron transfer event to initiate the reaction followed by radical recombination. This represents a profound mechanistic departure from the established two-electron disconnects in NHC catalysis.
Serotonergic aspects of acute extrapyramidal syndromes in nonhuman primates

Neuroleptic drug-induced acute extrapyramidal syndromes (EPS) are the major reasons why patients discontinue their antipsychotic medicines. Serotonin S2 antagonists prevent catalepsy in rodents but the effects in nonhuman primates have received only minimal study and deserve further evaluation as potential "non-neuroleptic neuroleptics" (antipsychotic effects free of acute EPS). Twenty Cebus monkeys (22 to 28 yrs. old) were tested with compounds that ranged from high to very low D2/S2 ratios. These were haloperidol, clopenthixol, tefludazine, and setoperone, all tested in the dosage range of .01 to .25 mg/kg and compared with saline i.m. once weekly in a random schedule. Dystonia was scored on four different symptoms by an experienced rater blind to drug dosage. All four active compounds produced clinically indistinguishable, dose related dystonia with very similar dose thresholds. In contrast to rodent studies these nonhuman primate investigations with drugs of widely differing D2/S2 antagonism ratios produced clinically similar EPS. Thus adding an S2 antagonism component to neuroleptics appears not to provide a unique approach to neuroleptic therapy which will be free of acute EPS.
FeAl-TiC and FeAl-WC composites-melt infiltration processing, microstructure and mechanical properties

Abstract TiC-based and WC-based cermets were processed with iron aluminide, an intermetallic, as a binder by pressureless melt infiltration to near full density (>97% TD). Phase equilibria calculations in the quaternary Fe–Al–Ti–C and Fe–Al–W–C systems at 1450°C were performed to determine the solubility of the carbide phases in liquid iron aluminide. This was done by using Thermocalc™ and the results show that molten Fe–40 at.% Al in equilibrium with Ti 0.512 C 0.488 and graphite, dissolves 4.9 at.% carbon and 64 at. ppm titanium. In the Fe–Al–W–C system, liquid Fe–40 at.% Al in equilibrium with graphite dissolves ≈5 at.% carbon and 1 at.% tungsten. Due to the low values for the solubility of the carbide phases in liquid iron aluminide, liquid phase sintering of mixed powders does not yield a dense, homogenous microstructure for carbide volume fractions greater than 0.70. Melt infiltration of molten FeAl into TiC and WC preforms serves as a successful approach to process cermets with carbide contents ranging from 70 to 90 vol.%, to greater than 97% TD. Also, the microstructures of cermets prepared by melt infiltration were very homogenous. Typical properties such as hardness, bend strength and fracture toughness are reported. SEM observations of fracture surfaces suggest the improved fracture toughness to result from the ductility of the intermetallic phase. Preliminary experiments for the evaluation of the oxidation resistance of iron aluminide bonded cermets indicate that they are more resistant than WC–Co cermets.
Exact Solutions to Diameter and Routing Problems in PEC Networks

Recently, the diameter problem for packed exponential connections (PEC) networks was addressed by Cho-Chin Lin and V. K. Prasanna Proc. Symposium on Parallel and Distributed Processing, 1992, pp. 368?375], who presented asymptotically tight bounds for the diameter and showed asymptotically optimal routing algorithms. In this paper exact, solutions to the diameter and routing problems of PEC networks are derived, thereby strengthening the asymptotic bounds of Lin and Prasanna. For anN= 2nnode PEC network, withformula]an integer, it is shown that the diameter is given by the simple expressionformula]An exact expression for the diameter of PEC networks for generalNis also derived. Efficient algorithms for shortest-path routing between nodes in a PEC network are then developed. These algorithms use at mostO(log2N) time for computing the lengths of minimal routes between nodes. Finally, a simple modification to obtain symmetric PEC networks is suggested.
On the hardness of finding optimal multiple preset dictionaries

We show that the following simple compression problem is NP-hard: given a collection of documents, find the pair of Huffman dictionaries that minimizes the total compressed size of the collection, where the best dictionary from the pair is used to compress each document. We also show the NP-hardness of finding optimal multiple preset dictionaries for LZ'77-based compression schemes. Our reductions make use of the catalog segmentation problem, a natural partitioning problem. Our results justify heuristic attacks used in practice.
Isotopically sensitive branching and its effect on the observed intramolecular isotope effects in cytochrome P-450 catalyzed reactions: a new method for the estimation of intrinsic isotope effects

Two selectively deuterated n-octanes (octane-1-/sup 2/H/sub 3/ and octane-1,2,3-/sup 2/H/sub 7/) were synthesized and subjected to hydroxylation by phenobarbital-induced rat liver microsomes and purified cytochrome P-450b. The results of these experiments provide evidence which clarifies the interplay between a branched reaction pathway and the equilibration of an enzyme-substrate complex, in determining the magnitude of an observed isotope effect. An equation is derived that allows limits to placed on the intrinsic isotope effect. The equation is based on the observed isotope effect and the regioselectivity of a branch reaction pathway, catalyzed by an enzyme that forms two products via a single enzyme-substrate complex. The intrinsic isotope effect for the formation of 1-octanol was determined by this equation to lie between 9.5 and 9.8.
Generation of short pulses for laser fusion in an actively mode-locked Nd:YAG laser

Abstract Active mode-locking and Q -switching of the Nd:YAG laser has produced short, transform-limited pulses from 60 ps to 1 ns, with more than 0.4 mJ energy per short pulse over most of this range. Pulse-to-pulse stability is better than ±3%.
The Calibration of DC Voltage Standards at Nist

This document describes the procedures used at NIST to calibrate dc voltage standards in terms of the NIST volt. Three calibration services are offered by the Electricity Division: Regular Calibration Service (RCS) of client standard cells at NIST; the Volt Transfer Program (VTP) a process to determine the difference between the NIST volt and the volt as maintained by a group of standard cells in a client laboratory; and the calibration of client solid-state dc voltage standards at NIST. The operational procedures used to compare these voltage standards to NIST voltage standards and to maintain the NIST volt via the ac Josephson effect are discussed.
Development of the 2-MV Injector for HIF ☆

Abstract The 2-MV Injector consists of a 17-cm-diameter surface ionization source, an extraction diode, and an electrostatic quadrupole (ESQ) accelerator, with maximum current of 0.8 A of potassium beam at 2 MeV. Previous performance of the Injector produced a beam with adequate current and emittance but with a hollow profile at the end of the ESQ section. We have examined the profile of the beam as it leaves the diode. The measured nonuniform beam density distribution qualitatively agrees with EGUN simulation. Implications for emittance growth in the post acceleration and transport phase will be investigated.
A suggestion for the numerical solution of the steady Navier-Stokes equations.

The great difficulties connected with the numerical solution of the steady compressible Navier-Stokes equations can be avoided if the steady flow is considered as the asymptotic form of a time-dependent flow, thus profiting from the techniques available for the numerical solution of initial value problems. In practice, the numerical procedure can imitate the natural development of the final steady flow in a shock tube. It is observed, however, that the accuracy and the consistency of the transient flow computations is here of no concern; this part of the calculations is merely fulfilling the function of an iteration procedure. This gives a great freedom in the choice of the numerical schemes, which therefore can be adjusted to fit, in the best way, the stability requirements. As a simple example of this technique, calculations have been performed of the one-dimensional formation of a standing shock in a divergent duct with initially supersonic flow when a back pressure is applied. Stability of the calculations is assured through the use of a suitable, conditionally stable, difference scheme. The results of the calculations show indeed that stability can be obtained in practice, provided certain precautions are taken in the application of the back pressure, and that the resulting flow converges to the expected mixed supersonic-subsonic flow with a standing shock. However, for sufficiently low viscosity the steady solution exhibits a wavy character with no counterpart in nature. These waves are analytically shown to appear whenever the space interval becomes larger than half the shock thickness.
Automatic concurrency in SequenceL

Abstract This paper presents a programming language which we believe to be most appropriate for the automation of parallel data processing, especially data processing of concern to the oil industry and to the U.S. Federal Agencies involved in the analysis of satellite telemetry data. Focus is placed upon major language issues facing the development of the information power grid. The paper presents an example of the type of parallelism desired in the Grid. To implement this parallelism in such a language as Java we need to specify parallelism explicitly. We show that if we rewrite the same solution in the high level language SequenceL, then parallelism becomes implicit. SequenceL seems therefore to be a good candidate for a grid oriented language, because its abstraction relieves the problem solver of much of the burden normally required in development of parallel problem solutions.
Time Resolution Performance Studies of Contemporary High Speed Photomultipliers

The time resolution capabilities of prototype microchannel plate and static crossedfield photomultipliers have been investigated. Measurements were made of electron transit time, rise time, time response, single photoelectron time spread and multiphotoelectron time spread for LEP HR350 proximity focused high gain curved microchannel plate and VPM-154A/1.6L static crossed-field photomultipliers. The experimental data have been compared with results obtained with conventionally designed RCA 8850 and C31024 high speed photomultipliers. Descriptions are given of both the measuring techniques and the measuring systems.
An Assessment of the Fe XVIII and Fe XIX Line Ratios from the Chandra Grating Observations of Capella

Observations of Fe XVIII and Fe XIX X-ray, extreme-UV, and far-UV line emission, formed at the peak of Capella's (α Aurigae's) emission measure distribution and ubiquitous in spectra of many cool stars and galaxies, provide a unique opportunity to test the robustness of Fe XVIII and Fe XIX spectral models. The Astrophysical Plasma Emission Code (APEC) is used to identify over 35 lines from these two ions alone, and to compare model predictions with spectra obtained with the Chandra Low Energy Transmission Grating and High Energy Transmission Grating Spectrometers, the Far Ultraviolet Spectroscopic Explorer (FUSE), and the Extreme Ultraviolet Explorer. Some flux discrepancies larger than a factor of 2 are found between observations of Fe XVIII and Fe XIX lines and predictions by APEC and other models in common use. In particular, the X-ray resonance lines for both ions are stronger than predicted by all models relative to the EUV resonance lines. The multiwavelength observations demonstrate the importance of including dielectronic recombination and proton-impact excitation, and of using accurate wavelengths in spectral codes. These ions provide important diagnostic tools for 107 K plasmas currently observed with Chandra, XMM-Newton, and FUSE.
Examining the concept of convenient collection: an application to extended producer responsibility and product stewardship frameworks.

Abstract Increasingly, Extended Producer Responsibility (EPR) and Product Stewardship (PS) frameworks are being adopted as a preferred policy approach to promote cost-effective diversion and recovery of post-consumer solid waste. Because the application of EPR/PS generally requires the creation of a separate and often parallel collection and/or management system, key to increasing the amount of waste recovered is to maximize the convenience of the collection system to maximize consumer participation. Convenient collection is often mandated in EPR/PS laws, however it is not defined. Convenience is a subjective construct rendering it extremely difficult to define. However, based on a dissection of post-consumer collection efforts under a generic EPR/PS system, this paper identifies and examines five categories of convenience – knowledge requirements, proximity to a collection site, opportunity to drop-off materials, the draw of the collection site, and the ease of the process—and the various factors of convenience within each of these categories. By using a simplified multiple criteria decision analysis, this paper proposes a performance matrix of criteria of convenience. Stakeholders can use this matrix to assist in the design, assessment, and/or implementation of a convenient post-consumer collection system under an EPR/PS framework.
Chiral Yukawa models in the planar limit

Abstract We consider the most general renormalizable chiral Yukawa model with SU(3)color replaced by SU(Nc), SU(2)L replaced by SU(Nw) and U(1)Y replaced by U(1)Nw−1 in the limit Nc → ∞, Nw → ∞ with the ϱ= N w N c ≠0 , ∞ held fixed. Since for Nw⩾3 only one renormalizable Yukawa coupling per family exists and there is no mixing between families the limit is appropriate for the description of the effects of a heavy top quark when all the other fermions are taken to be massless. A rough estimate of the triviality bound on the Yukawa coupling is equivalent to mt⩽1 TeV.
Detection of O i and SI II Far-Infrared Fine-Structure Emission from alpha Orionis

We have detected forbidden O I 63 micron and forbidden Si II 35 micron emission from the oxygen-rich, M2 lab supergiant, Alpha Orionis (Betelgeuse). The forbidden O I line flux is 2.4 +/- 0.2 x 10 exp -18 W/sq cm, and the forbidden Si II line flux is 0.9 +/- 0.4 x 10 exp -18 W/sq cm. These fluxes are consistent with the thermal model of Rodgers and Glassgold (1991), which indicates that the emission arises in dense, warm gas in Alpha Ori's inner envelope and implies that nearly all of the available O and Si is in atomic form. This is the first reported detection of FIR, fine-structure emission from the inner or transition region of a circumstellar envelope, where molecules and dust are expected to form.
Syntheses of methylene-bridged benzopyrenes, carcinogenic components of automobile exhaust residue

Abstract Syntheses of the methylene-bridged derivatives of benzo[a]pyrene and benzo[e]pyrene ( 1 and 2 ) are described. The latter was obtained by a route involving in the key step tandem cyclization of a diacid derivative of pyrene. Although analogous preparation of 1 failed, it was obtained successfully by a synthetic route based on cyclopenta[def]phenanthrene.
The warlord as arbitrageur

This article seeks to generate a more precise understanding of the emergence and perpetuation of warlords. First, it offers a simple, intuitive, and empirically grounded conceptual definition of warlordism. Second, it argues that the primary factor contributing to the success of warlords is the ability to take advantage of price differentials for political, economic, and cultural goods across terrains—in a word, to arbitrage. Third, it illustrates this model with a case study of Khun Sa (1934–2007), the self-proclaimed Shan freedom-fighter and “king” of Burma’s heroin trade. Finally, it suggests that the international community rethink its commitment to the norm of sovereignty in order to combat the proliferation of such non-state violence-wielders.
The economic effects of constitutions: do budget institutions make forms of government more alike?

According to an influential theoretical argument, presidential systems tend to present smaller governments relative to parliamentary countries because the separation between those who decide the size of the fiscal purse and those who allocate it creates incentives for lower public expenditures. In practice, however, presidential and parliamentary countries come in many forms. In particular, variation in procedural rules that assign budget prerogatives across the popular branches of government may affect the underlying incentives that differentiate these types of regimes in terms of fiscal outcomes. More specifically, we argue that more hierarchical rules that concentrate budgetary power in the executive relative to the legislature do not only reduce the extent of the common pool problem but also limit the degree of separation of powers, which may have a countervailing effect. Consequently, the effect of the form of government on public expenditures is conditional on specific procedural rules. We test this hypothesis on a broad cross-section of countries and find that presidentialism has a negative impact on government size only when executive discretion in the budget process is low (that is, in a context of separation of powers). However, the negative effect of presidentialism on expenditures vanishes when the executive’s discretion over the budget process is higher. This result, in addition to highlighting that not all budget institutions have the same effect on incentives and outcomes, points out how important it is to go beyond broad characterizations of political institutions for explaining policy outcomes, and more generally, for moving forward the research agenda in constitutional political economy.
Crystal structure of the kinesin motor domain reveals a structural similarity to myosin.

KINESIN is the founding member of a superfamily of microtubule-based motor proteins that perform force-generating tasks such as organelle transport and chromosome segregation1,2. It has two identical ∼960-amino-acid chains containing an ammo-terminal globular motor domain, a central α-helical region that enables dimer formation through a coiled-coil, and a carboxy-terminal tail domain that binds light chains and possibly an organelle receptor1. The kinesin motor domain of ∼340 amino acids, which can produce movement in vitro3, is much smaller than that of myosin (∼850 amino acids) and dynein (1,000 amino acids), and is the smallest known molecular motor. Here, we report the crystal structure of the human kinesin motor domain with bound ADP determined to 1.8-A resolution by X-ray crystallography. The motor consists primarily of a single α/β arrowhead-shaped domain with dimensions of 70×45×45 A. Unexpectedly, it has a striking structural similarity to the core of the catalytic domain of the actin-based motor myosin. Although kinesin and myosin have virtually no amino-acid sequence identity, and exhibit distinct enzymatic4–6 and motile7–10 properties, our results suggest that these two classes of mechanochemical enzymes evolved from a common ancestor and share a similar force-generating strategy.
Nanoscale Encapsulation : The Structure of Cations in Hydrophobic Microporous Aluminosilicates

Hydrophobic microporous aluminosilicates created by the modification of zeolites and clays are currently being investigated as storage media for hazardous cations. Addition of an organic monolayer to the surface of an aluminosilicate after introduction of an ion into the zeolite or clay reduces the interaction of water with the material. The resultant systems are approximately 20 times more resistant to leaching of the stored ion than the unmodified ion-exchanged materials. XAS spectra demonstrate that byproducts from the organic modifier can complex with the encapsulated cation. This complexation can result in a decreased affinity of the cation for the aluminosilicate matrix. Changing the organic modifier eliminates this problem. XAS spectra also indicate that the reactivity and subsequent speciation of the encapsulated ion alters upon application of the hydrophobic layer.
TYPE IIb SUPERNOVAE WITH COMPACT AND EXTENDED PROGENITORS

The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova that has a more compact progenitor with a lower density, probably fast, wind. Distinguishing features of the compact category are weak optical emission from the shock heated envelope at early times, nonexistent or very weak H emission in the late nebular phase, rapidly evolving radio emission, rapid expansion of the radio shell, and expected nonthermal as opposed to thermal X-ray emission. Type IIb supernovae that have one or more of these features include SNe 1996cb, 2001ig, 2003bg, 2008ax, and 2008bo. All of these with sufficient radio data (the last four) show evidence for presupernova wind variability. We estimate a progenitor envelope radius ~1 × 1011 cm for SN 2008ax, a value consistent with a compact Wolf-Rayet progenitor. Supernovae in the SN 1993J extended category include SN 2001gd and probably the Cas A supernova. We suggest that the compact Type IIb events be designated Type cIIb and the extended ones Type eIIb. The H envelope mass dividing these categories is ~0.1 M ☉.
Analysis of an Early Intervention Tibial Component for Medial Osteoarthritis

Tibial component loosening is an important failure mode in unicompartmental knee arthroplasty (UKA) which may be due to the 6-8 mm of bone resection required. To address component loosening and fixation, a new early intervention (EI) design is proposed which reverses the traditional material scheme between femoral and tibial components. The EI design consists of a plastic inlay for the distal femur and a thin metal plate for the proximal tibia. With this reversed materials scheme, the EI design requires minimal tibial bone resection compared with traditional UKA. This study investigated, by means of finite element (FE) simulations, the advantages of a thin metal tibial component compared with traditional UKA tibial components, such as an all-plastic inlay or a metal-backed onlay. We hypothesized that an EI tibial component would produce comparable stress, strain, and strain energy density (SED) characteristics to an intact knee and more favorable values than UKA components, due primarily to the preservation of dense cancellous bone near the surface. Indeed, FE results showed that stresses in the supporting bone for an EI design were close to intact, while stresses, strains, and strain energy densities were reduced compared with an all-plastic UKA component. Analyzed parameters were similar for an EI and a metal-backed onlay, but the EI component had the advantage of minimal resection of the stiffest bone.
Gradient Estimates for the Perfect and Insulated Conductivity Problems with Multiple Inclusions

In this paper, we study the perfect and the insulated conductivity problems with multiple inclusions imbedded in a bounded domain in ℝ n , n ≥ 2. For these two extreme cases of the conductivity problems, the gradients of their solutions may blow up as two inclusions approach each other. We establish the gradient estimates for the perfect conductivity problems and an upper bound of the gradients for the insulated conductivity problems in terms of the distances between any two closely spaced inclusions.
Vortex stretching and reconnection in a compressible fluid

Vortex stretching in a compressible fluid is considered. Two-dimensional (2D) and axisymmetric cases are considered separately. The flows associated with the vortices are perpendicular to the plane of the uniform straining flows. Externally-imposed density build-up near the axis leads to enhanced compactness of the vortices — “dressed" vortices (in analogy to “dressed" charged particles in a dielectric system). The compressible vortex flow solutions in the 2D as well as axisymmetric cases identify a length scale relevant for the compressible case which leads to the Kadomtsev-Petviashvili spectrum for compressible turbulence. Vortex reconnection process in a compressible fluid is shown to be possible even in the inviscid case — compressibility leads to defreezing of vortex lines in the fluid.
Turán Problems and Shadows III: Expansions of Graphs

The expansion G + of a graph G is the 3-uniform hypergraph obtained from G by enlarging each edge of G with a new vertex disjoint from V (G) such that distinct edges are enlarged by distinct vertices. Let ex3(n, F ) denote the maximum number of edges in a 3-uniform hypergraph with n vertices not containing any copy of a 3-uniform hypergraph F. The study of ex3(n, G + ) includes some well-researched problems, including the case that F consists of k disjoint edges, G is a triangle, G is a path or cycle, and G is a tree. In this paper we initiate a broader study of the behavior of ex3(n, G+). Specifically, we show ex3(n, K + )=Θ (n 3−3/s) whenever t> (s − 1)! and s ≥ 3. One of the main open problems is to determine for which graphs G the quantity ex3(n, G + ) is quadratic in n. We show that this occurs when G is any bipartite graph with Turan number o(n ϕ ) where ϕ = 1+ √ 5 2 , and in particular this shows ex3(n, G + )= O(n 2 )w henG is the three-dimensional cube graph.
Thrift Asset-Class Returns and the Efficient Diversification of Thrift Institution Portfolios

We estimate quarterly return series from March 1984 through December 1989 for ten classes of thrift assets using the statistical cost accounting methodology of Hester and Zoellner (1966). We then use these return series to estimate mean-variance efficient frontiers for all thrifts, for thrifts that were well-capitalized two years earlier, and for thrifts that were insolvent two years earlier. Our results show that neither the asset restrictions existing before nor those in effect after passage of the Financial Institutions Reform, Recovery and Enforcement Act of 1989 would have prevented thrifts from reaching most of the portfolios along the efficient frontier. The actual portfolio chosen by well capitalized thrifts is close to the estimated efficient frontier, while the actual portfolio chosen by insolvent thrifts is located far from the frontier in the high-risk end of investment space. These findings, coupled with the high proportion of nontraditional assets in the actual portfolio chosen by insolvent thrifts, support the hypothesis that moral hazard induced thrifts to take on investments that were excessively risky from the deposit insurer's point of view.
Is the Compensation Model for Real Estate Brokers Obsolete

This study examines the traditional compensation model for real estate brokers under which both the listing and buyer brokers are paid by the seller based on a percentage of the property sales price. We argue that this model has not evolved to reflect contemporary legal agency relationships and technology-driven information availability. It therefore creates substantial transactional inefficiencies for buyers and sellers at both the matching and bargaining stages of a transaction. While there is evidence that market forces are pushing for a change in the status quo, there is also evidence that the brokerage industry is resisting this change by pursuing anti-competitive policies and laws. We explore the economics of the current and alternative compensation structures and suggest policy implications regarding anti-competitive behavior in the brokerage industry.
Mapping the bid behavior of conference referees

Abstract The peer-review process, in its present form, has been repeatedly criticized. Of the many critiques ranging from publication delays to referee bias, this paper will focus specifically on the issue of how submitted manuscripts are distributed to qualified referees. Unqualified referees, without the proper knowledge of a manuscript’s domain, may reject a perfectly valid study or potentially more damaging, unknowingly accept a faulty or fraudulent result. In this paper, referee competence is analyzed with respect to referee bid data collected from the 2005 Joint Conference on Digital Libraries (JCDL). The analysis of the referee bid behavior provides a validation of the intuition that referees are bidding on conference submissions with regards to the subject domain of the submission. Unfortunately, this relationship is not strong and therefore suggests that there may potentially exists other factors beyond subject domain that may be influencing referees to bid for particular submissions.
Commensuration and interlayer coherence in twisted bilayer graphene

The low-energy electronic spectra of rotationally faulted graphene bilayers are studied using a long-wavelength theory applicable to general commensurate fault angles. Lattice commensuration requires low-energy electronic coherence across a fault and pre-empts massless Dirac behavior near the neutrality point. Sublattice exchange symmetry distinguishes two families of commensurate faults that have distinct low-energy spectra which can be interpreted as energy-renormalized forms of the spectra for the limiting Bernal and $AA$ stacked structures. Sublattice-symmetric faults are generically fully gapped systems due to a pseudospin-orbit coupling appearing in their effective low-energy Hamiltonians.
Satellite wide-area-network for telemedicine

Communications for telemedicine requires substantial bandwidths to provide timely transmission of large data sets. To provide rural America with modern telemedicine requires very high bandwidth resources that may take decades to appear. Satellites provide the natural choice for communication between the rural primary care centers and the tertiary care hospital. However, there are problems if TCP, as required for Internet access, is to be the protocol of choice. Analysis of multistation satellite access clearly argues for distributed non-random methods and, hence, for appropriate handling of TCP data streams.
Pulse Bifurcations in Stochastic Neural Fields

We study the effects of additive noise on traveling pulse solutions in spatially extended neural fields with linear adaptation. Neural fields are evolution equations with an integral term characterizing synaptic interactions between neurons at different spatial locations of the network. We introduce an auxiliary variable to model the effects of local negative feedback and consider random fluctuations by modeling the system as a set of spatially extended Langevin equations whose noise term is a $Q$-Wiener process. Due to the translation invariance of the network, neural fields can support a continuum of spatially localized bump solutions that can be destabilized by increasing the strength of the adaptation, giving rise to traveling pulse solutions. Near this criticality, we derive a stochastic amplitude equation describing the dynamics of these bifurcating pulses when the noise and the deterministic instability are of comparable magnitude. Away from this bifurcation, we investigate the effects of additive ...
Growth Effects of Income and Consumption Taxes: Positive and Normative Analysis

The effects of income and consumption taxation are examined in the context of models in which the growth process is driven by the accumulation of human and physical capital. The different channels through which these taxes affect economic growth are discussed, and it is shown that in general the taxation of factor incomes (human and physical capital) is growth-reducing. The effects of consumption taxation on growth depend crucially on the elasticity of labor supply, and therefore on the specification of the leisure activity. The paper also derives implications for the optimal intertemporal choice of tax instruments.
The Dynamic Transfer Function for a Cavitating Inducer

Knowledge of the dynamic performance of pumps is essential for the prediction of transient behavior and instabilities in hydraulic systems; the necessary information is in the form of a transfer function which relates the instantaneous or fluctuating pressure and mass flow rate at inlet to the same quantities in the discharge from the pump. The presence of cavitation within the pump can have a major effect on this transfer function since dynamical changes in the volume of cavitation contribute to the difference in the instantaneous inlet and discharge mass flow rates. The present paper utilizes results from free streamline cascade theory to evaluate the elements in the transfer function for a cavitating inducer and shows that the numerical results are consistent with the characteristics observed in some dynamic tests on rocket engine turbopumps.
Synthesis and x-ray structure of a potent superpositional analog of the enantiomeric forms of fluoxetine

Abstract 4-Phenyl-4-(p-trifluoromethylphenoxy)piperidine (1), a molecule which approximates a sueprimposition of the enantiomers of fluoxetine (2a and 2b), has been synthesized and found to be somewhat more active than 2a or 2b as an inhibitor of serotonin uptake.
Rocket measurement of nitric oxide in the upper atmosphere

Abstract A scanning ultraviolet spectrometer was flown from Wallops Island, Va. on NASA Aerobee 4.85 on November 17, 1963 at 1:15 p.m. EST to an altitude of 185 km. The 0.5 m spectrometer scanned from 1500 to 3200 A with a resolution of 8.6 A. The rocket's attitude-control-system aimed the spectrometer at the zenith during the ascent and at the horizon during the descent. Spectra of the ultraviolet dayglow were obtained in the zenith direction in the altitude range from 76 to 114 km, and also (with greatly increased intensity) during the horizon scan. The most prominent features of these spectra were the gamma bands of nitric oxide. The most intense bands observed were the (2-0) at 2053 A, the (1-0) at 2155 A, the (1-1) at 2246 A, the (0-0) at 2269 A, the (0-1) at 2370 A and the (0-2) at 2479 A. The distribution of nitric oxide in the upper atmosphere between 76 and 125 km is determined by the analysis of the intensity variation of these bands with height. The column density at 76 km is 2.5 × 10 14 molecules cm −2 decreasing to 1.5 × 10 13 molecules cm −2 at 125 km. The volume density at 76 km is 6.2 × 10 7 molecules cm −3 , at 95 km 6.0 × 10 7 molecules cm −2 , and at 125 km 6.0 × 10 6 molecules cm −3 .