cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal throughput-outage trade-off in wireless one-hop caching networks

We consider a wireless device-to-device (D2D) network where the nodes have cached information from a library of possible files. Inspired by the current trend in the standardization of the D2D mode for 4th generation wireless networks, we restrict to one-hop communication: each node places a request to a file in the library, and downloads from some other node which has the requested file in its cache through a direct communication link, without going through a base station. We describe the physical layer communication through a simple “protocol-model”, based on interference avoidance (independent set scheduling). For this network we define the outage-throughput tradeoff problem and characterize the optimal scaling laws for various regimes where both the number of nodes and the files in the library grow to infinity.
Fluorous methods for synthesis and separation of organic molecules

Fluorous molecules partition out of an organic phase and into a fluorous (highly fluorinated) phase in a liquid-liquid extraction. New fluorous techniques allow simple yet substantive separations of organic reaction mixtures based on the presence or absence of a fluorous tag. Fluorous-tagged molecules can also be separated from nontagged molecules by solid phase extraction over fluorous reverse-phase silica gel. This technique is ideal for solution-phase parallel synthesis because it allows simple yet substantive separations of organic reaction mixtures.
TWIN BINARIES: STUDIES OF STABILITY, MASS TRANSFER, AND COALESCENCE

Motivated by suggestions that binaries with almost equal-mass components ("twins") play an important role in the formation of double neutron stars and may be rather abundant among binaries, we study the stability of synchronized close and contact binaries with identical components in circular orbits. In particular, we investigate the dependency of the innermost stable circular orbit on the core mass, and we study the coalescence of the binary that occurs at smaller separations. For twin binaries composed of convective main-sequence stars, subgiants, or giants with low mass cores (M_c ~0.15M), we find that stable contact configurations exist at all separations down to the Roche limit, when mass shedding through the outer Lagrangian points triggers a coalescence of the envelopes and leaves the cores orbiting in a central tight binary. In addition to the formation of binary neutron stars, we also discuss the implications of our results for the production of planetary nebulae with double degenerate central binaries.
Financing small business creation: The case of Chinese and Korean immigrant entrepreneurs

Abstract Conventional wisdom claims that entrepreneurship in the United States among Asian immigrants has been substantially promoted by the operation of rotating credit associations specifically and supportive social networks generally. The rotating credit association (RCA) typifies the process whereby supportive peer and community subgroups assist in the creation and operation of firms by providing social capital in the form of loans. One problem with the RCA as an example of social resources is that there is no solid evidence that it is a major source in financing immigrant-owned firms. This study utilizes data from the U.S. Bureau of the Census to analyze sources and amounts of start-up capital that financed small business creation for immigrant Koreans and Chinese. Data self-reported by over 2,000 Korean/Chinese who opened new firms during 1979–1987 are analyzed and compared with start-up statistics for nonminorities and Asian Americans who are not immigrants. The majority of start-up capital that financed small business formation came from family wealth (equity) and financial institution loans (debt). These financing patterns typified all groups. High levels of start-up capital typify Korean/Chinese immigrant-owned firms, reflecting their heavy reliance upon equity capital to finance small business creation. If no loan funds were forthcoming from friends, rotating credit associations, associates, family, and other secondary debt sources, the average Korean/Chinese start-up would nonetheless possess substantially more financial capital than its nonminority cohort. Looking solely at firms utilizing loan funds to finance business creation, Korean/Chinese borrowers had lower mean loan sizes and lower debt to equity ratios than the comparison group firms: the aggregate debt to equity ratios for nonminorities and Chinese/Korean immigrants were 2.75 and 1.18, respectively. Among the borrowing firms, financial institutions skim off the most attractive Korean/Chinese borrowers, mostly college graduates who invest substantial sums of equity capital into their start-ups. The nonbank borrowers—particularly those borrowing from friends—were most disadvantaged, relative to nonminority small business owners. Controlling for firm and owner characteristics statistically, the Korean/Chinese start-ups borrowing from friends and family were found to be penalized by over $25,000 in loan size, relative to nonminorities, whereas Asian nonimmigrant borrowers incurred no such penalty. Prevailing scholarly literature misinterprets the realities of how Korean and Chinese immigrant entrepreneurs finance entry into small businesses. These firms stand out for their particularly heavy reliance upon family wealth. Nontraditional debt capital sources are of secondary importance, and they are utilized more by the weaker start-ups.
Extracting Energy from a Black Hole through Its Disk.

When some magnetic field lines connect a Kerr black hole with a disk rotating around it, energy and angular momentum are transferred between them. If the black hole rotates faster than the disk, ca/GMH > 0.36 for a thin Keplerian disk, then energy and angular momentum are extracted from the black hole and transferred to the disk (MH is the mass and aMH is the angular momentum of the black hole). This way, the energy originating in the black hole may be radiated away by the disk. The total amount of energy that can be extracted from the black hole spun down from ca/GMH = 0.998 to ca/GMH = 0.36 by a thin Keplerian disk is ≈0.15MHc2. This is larger than ≈0.09MHc2, which can be extracted by the Blandford-Znajek mechanism.
Effect of shaft rotation on the incompressible flow in a labyrinth seal

A computational/experimental study was conducted concerning the incompressible flow in a labyrinth seal at low leakage rates over a wide range of seal rotation rates. The predictions were obtained using a finite-difference code that utilized a higher order differencing scheme (QUICK) to reduce the effects of false diffusion. Measured inlet boundary conditions for the axial and swirl velocity components as well as turbulence kinetic energy were employed. This yielded fair agreement between velocity predictions and hot-film anemometer measurements. The effects of seal rotation rate on the overall pressure drop are presented in terms of a loss coefficient. It was determined that when the rotation rate is increased beyond a certain point, a second recirculation zone (SRZ) forms inside the seal cavity. This dramatically alters the flowfield in the cavity and results in a substantial increase in the pressure drop across it. A flow map is presented indicating the approximate rotation rate required to produce this phenomenon at a given leakage rate. Unfortunately, for most practical applications, the SRZ will not form until an extremely high shaft speed is reached.
The speed of rational learning

A central result in the rational learning literature is that if the true measure is absolutely continuous with respect to the beliefs then, given enough data, the updated beliefs merge with the true distribution. In this paper, we show that, under absolute continuity, weak merging occurs fast (at the rate \(\)) with density one. Moreover, if weak merging occurs fast enough (at the rate 1/t) then absolute continuity holds. These rates are sharp. We also show that, under some conditions, if weak merging occurs at the rate \(\) then absolute continuity holds.
Transurethral Puncture of Ureterocele Associated With Single Collecting System in Neonates

Be&ground/Purpose: It is believed by some investigators that transurethral puncture (TUP) of single-system intravesical ureterocele (SSU) is the treatment of choice in totally asymptomatic patients who receive this diagnosis in utero, but its success depends on the incision technique and type of the uroterocele incised. Methods: Experience with 20 SSU in 17 asymptomatic newborns detected by prenatal ultrasound scan is reviewed. TUP of the SSU was performed as treatment of choice in 12 (60%) renal units (RU). Results: Decompression of the ureterocele was achieved in 100% of cases, and a vesicoureteral reflux was created in three (25%) RU. Surgery was performed in only 30% of patients who underwent TUP of the ureterocele. Our experience confirms that short (2 to 3 mm) TUP achieves decompression of the affected renal unit and that this procedure can be performed in neonates as outpatient procedure. In addition, it is often the only procedure to perform.
Cosmological perturbations at second order and recombination perturbed

We derive the full set of second-order equations governing the evolution of cosmological perturbations, including the effects of the first-order electron number density perturbations, δe. We provide a detailed analysis of the perturbations to the recombination history of the universe and show that a perturbed version of the Peebles effective 3-level atom is sufficient for obtaining the evolution of δe for comoving wavenumbers smaller than 1 Mpc−1. We calculate rigorously the perturbations to the Lyα escape probability and show that to a good approximation it is governed by the local baryon velocity divergence. For modes longer than the photon diffusion scale, we find that δe is enhanced during recombination by a factor of roughly 5 relative to other first-order quantities sourcing the CMB anisotropies at second order. Using these results, in a companion paper we calculate the CMB bispectrum generated during recombination.
New nonsingular forms of perturbed satellite equations of motion

Vector calculus is used to derive two new forms of the equations of motion of perturbed satellites. Both forms are given in terms of nonsingular orbital elements in extended vector space that eliminate the ambiguity in the variation of retrograde orbits. In the first form, the orbital eccentricity, true anomaly, argument of latitude, and orbital inclination are substituted by four fast variables whose unperturbed periods are essentially equal to the orbital period. In the second form, these four fast variables are transformed to four slow variables such that the eccentricity vector variation is independent of the out-of-plane acceleration. The transformation matrix between these new nonsingular elements and Cartesian coordinates is given and perturbing accelerations due to the Earth and a third body are developed. Applications of the perturbation methods of multiple scale and averagings to the developed equations of motion are demonstrated. T HE satellite equations of motion can be expressed in various forms. A simple Cartesian form1'2 is widely used in connection with numerical integration. More sophisticated forms based on the variation of parameters developed by Lagrange3 are particularly useful in connection with perturbation theories. Lagrange's equations can be transformed to canonical forms3'5 or nonsingular noncanonical forms.6'7 The independent variable is usually the time but in some cases, e.g., Earth's zonal harmonic perturbations, it is advantageous to use an independent variable other than time8'10 (e.g., true anomaly or a similar fast angle). The purpose of this paper is to develop two new forms of Lagrange's equations of motion [Eqs. (12) and (19)] in terms of nonsingular orbital elements whose variations are determined by the components (Fr,Fe,FH) of a perturbing acceleration in the Euler-Hill rotating frame depicted in Fig. 1. Section II develops the equations of motion in terms of the fast variables [Eq. (12)]. This form is particularly useful for the application of perturbation method of Lindested-Poincare' and the method of multiple scale.11'13 Section III derives the equations of motion in terms of slow variables [Eq. (19)] in a form suitable for the application of the method of averaging,14 Lie transform,15'16 and Lie series.17 Section IV summarizes the transformation between the Cartesian and the nonsingular orbital elements useful for the evaluation of the initial conditions. Section V develops the form of the perturbing acceleration of the Earth and a third body in terms of the obtained variables. Sections VI and VII demonstrate the application of the method of multiple scale and the methods of averaging to the obtained equations of motion. II. Equations of Motion in Terms of Fast Variables This section starts with the equations of motion in the Cartesian form and applies vector calculus to obtain the equations of motion in terms of a set of fast nonsingular orbital elements. Following Newton's law of gravitation, the equations of motion of a satellite can be written in the vectorial form r = v
A reductive coupling strategy towards ripostatin A

Synthetic studies on the antibiotic natural product ripostatin A have been carried out with the aim to construct the C9−C10 bond by a nickel(0)-catalyzed coupling reaction of an enyne and an epoxide, followed by rearrangement of the resulting dienylcyclopropane intermediate to afford the skipped 1,4,7-triene. A cyclopropyl enyne fragment corresponding to C1−C9 has been synthesized in high yield and demonstrated to be a competent substrate for the nickel(0)-catalyzed coupling with a model epoxide. Several synthetic approaches toward the C10−C26 epoxide have been pursued. The C13 stereocenter can be set by allylation and reductive decyanation of a cyanohydrin acetonide. A mild, fluoride-promoted decarboxylation enables construction of the C15−C16 bond by an aldol reaction. The product of this transformation is of the correct oxidation state and potentially three steps removed from the targeted epoxide fragment.
Recent Developments in Quasi-Newton Methods for Structural Analysis and Synthesis

Unlike the Newton-Raphson method, quasi-Newton methods by virture of the updates and step length control procedures are globally convergent and hence better suited for the solution of nonlinear problems of structural analysis and synthesis. Extension of quasi-Newton algorithms to large scale problems has led to the development of sparse update algorithms and to economical strategies for evaluating sparse Hessians. Ill-conditioning problems have led to the development of self-scaled variable metric and conjugate gradient algorithms, as well as the use of the singular perturbation theory. This paper emphasizes the effectiveness of such quasi-Newton algorithms for nonlinear structural analysis and synthesis.
Maximum likelihood bounded tree-width Markov networks

We study the problem of projecting a distribution onto (or finding a maximum likelihood distribution among) Markov networks of bounded tree-width. By casting it as the combinatorial optimization problem of finding a maximum weight hypertree, we prove that it is NP-hard to solve exactly and provide an approximation algorithm with a provable performance guarantee.
Metastability of yttrium oxides

Abstract Metastable yttrium oxide films are synthesized using reactive sputter deposition. The yttrium concentration of the as-deposited film is found to vary as a function of the sputter deposition rate. In addition to the synthesis of the cubic equilibrium phase Y 2 O 3 , oxide compounds can be formed with 40–80 at. % Y. The crystalline state of the as-deposited film is dependent on the substrate temperature. A metastable, orthorhombic yttrium-rich oxide is formed on room temperature substrates. Substrates of Ta 10 W are coated with several micrometers of yttrium oxide. The stability of these yttrium oxide coatings is investigated as they are subjected to an atmospheric pressure of oxygen at an elevated temperature of 1773 K. The coatings and substrates are examined for the stability of the crystalline structure, composition, cracking, adhesion and corrosion. An yttrium-rich oxide coating is found to offer the best corrosion protection to the Ta 10 W substrate.
Can transabdominal ultrasound be used as a screening test for short cervical length

Objective Universal transvaginal cervical length screening can be associated with a significant logistical burden. We hypothesized that there is a threshold cervical length measured by transabdominal ultrasound above which risk for short transvaginal cervical length is extremely low. Study Design This prospective cohort study evaluated a consecutive series of women offered universal transvaginal cervical length screening during anatomy ultrasound. Transabdominal measurement of the cervix—obtained before and after voiding for each patient—was performed before transvaginal ultrasound. The study was powered to detect a transabdominal cervical length cutoff with 95% sensitivity (95% confidence interval, 90–99%) for transvaginal cervical length of ≤25 mm. Results One thousand two hundred seventeen women were included in the analysis. Prevoid transabdominal cervical length ≤36 mm detects 96% of transvaginal cervical lengths ≤25 mm with 39% specificity. A prevoid transabdominal cervical length ≤35 mm detects 100% of transvaginal cervical lengths ≤20 mm with 41% specificity. Transabdominal images of the cervix could not be obtained in 6.2% of women prevoid and 17.9% of women postvoid. Conclusion Transabdominal cervical length screening successfully identifies women at very low risk for short transvaginal cervical length. Transabdominal screening may significantly reduce the burden of universal cervical length screening by allowing approximately 40% of women to avoid transvaginal ultrasound. To ensure high sensitivity of transabdominal screening, approximately 60% of patients will still require a transvaginal study.
Monotone Structure in Discrete-Event Systems

Some Basic Concepts. Antimatroid Structure: Monotonicity. Lattice Structure: Convexity and Concavity. Links to Other Models. Monotone Optimal Control. Subadditivity and Stability. Association and Optimal Coupling. Perturbation Analysis. Index.
Prediction of an axisymmetric combusting flow

A numerical model for turbulent, recirculating combusting flow is developed and applied to a research combustor. The model is based on the time-averaged Navier-Stokes equations with k-epsilon turbulence closure and the compositional fluctuations at each point are given probabilistically in terms of the mixture fraction. The probability density function is derived from transport equations for its first two moments along with an assumption regarding its shape. The resulting equations are solved using a standard line relaxation algorithm. It is found that the predictions of the model are in good agreement with data from an axisymmetric, bluff-body stabilized research combustor, while the major discrepancies are similar to those found in isothermal flow comparisons. The peculiar features of this flow which contribute to the errors are examined. The agreement between the theory and data deteriorates as the central jet velocity is increased which indicates an enhanced role for unsteady effects.
Penicillin skin testing in pregnant women with a history of penicillin allergy and group B streptococcus colonization.

Background The safety and utility of penicillin skin testing (PST) in pregnant women with a history of penicillin allergy and group B streptococcus (GBS) colonization have not been studied. Objectives To document the safety and utility of PST in pregnant women with a history of penicillin allergy and GBS colonization. Methods Pregnant GBS culture–positive women with a history compatible with an IgE-mediated or unknown reaction to a penicillin-class antibiotic were recruited for PST. If PST results were negative, penicillin-class antibiotics were recommended for GBS prophylaxis. Adverse reactions associated with PST or antibiotic use from the time of PST through delivery and 6 months post partum were reported. Results In 56 enrolled patients, there were only 2 mild adverse reactions (4%) associated with PST and 3 positive PST results (5%). Of the 53 PST-negative patients, 47 (89%) received at least 1 course of penicillin. There were 2 delayed-onset rashes associated with the use of intrapartum penicillins and 1 immediate-onset rash with intrapartum vancomycin therapy in a PST-positive woman. There were 7 reactions (6%) associated with 122 antibiotic courses administered. Conclusions Penicillin skin testing can be performed safely in pregnant women and, if the results are negative, allows penicillins to be used safely at delivery for GBS prophylaxis.
Design of nanophotonic circuits for autonomous subsystem quantum error correction

We reapply our approach to designing nanophotonic quantum memories in order to formulate an optical network that autonomously protects a single logical qubit against arbitrary single-qubit errors. Emulating the nine-qubit Bacon–Shor subsystem code, the network replaces the traditionally discrete syndrome measurement and correction steps by continuous, time-independent optical interactions and coherent feedback of unitarily processed optical fields.
Dihydrobenzofuran derivatives via the anodic cycloaddition reaction of p-methoxyphenols and vinyl sulfides

Abstract The anodic oxidation of p-methoxyphenols in the presence of vinyl sulfides gives high yields of dihydrobenzofurans arising via a formal 1,3-cycloaddition reaction of the vinyl sulfide and the anodically generated phenoxonium ion.
Fivefold confinement time increase in the Madison Symmetric Torus using inductive poloidal current drive

Current profile control is employed in the Madison Symmetric Torus [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)] reversed field pinch to reduce the magnetic fluctuations responsible for anomalous transport. An inductive poloidal electric-field pulse is applied in the sense to flatten the parallel current profile, reducing the dynamo fluctuation amplitude required to sustain the equilibrium. This technique demonstrates a substantial reduction in fluctuation amplitude (as much as 50%), and improvement in energy confinement (from 1 to 5 ms); a record low fluctuation (0.8%) and record high temperature (615 eV) for this device were observed simultaneously during current drive experiments. Plasma beta increases by 50% and the Ohmic input power is three times lower. Particle confinement improves and plasma impurity contamination is reduced. The results of the transient current drive experiments provide motivation for continuing development of steady-state current profile control strategies for the reversed field pinch.
Expanding your accounting classroom with digital video technology

Abstract In the past, many activities of accounting professors were restricted or confined by their classroom walls. Bringing in guest speakers, taking students on field trips and teaching students off-campus (either locally or globally) were extraordinary efforts that required significant organization. Today, numerous technological advancements in communication infrastructure, equipment and online tools greatly facilitate such initiatives. Outside experts can now visit the classroom, students can explore or collaborate in distant places and professors can extend the geographical reach of their lessons simply via the means of digital video technology. Based on our 2010 Conference on Teaching and Learning in Accounting (CTLA) Master Class, we share our experiences in exploring the use of digital video in teaching accounting and explain how numerous accounting professors are taking advantage of the capabilities afforded by digital video technologies. Online video clips, student video projects, and online video lecture recordings hold great promise for accounting education. We have created a website that complements and demonstrates the teaching ideas presented in this article and that facilitates video integration into accounting courses. We discuss the pedagogical benefits of using video, including those from general education and accounting literature. The article concludes with suggestions for how accounting faculty can keep current with video technology, areas for future accounting research and a call to action for accounting educators. Our work with digital video technology has led to the 2011 American Accounting Association (AAA) Innovation in Accounting Education Award as well as the 2010 Canadian Academic Accounting Association (CAAA) Howard Teall Innovation in Accounting Education Award.
Organizational Characteristics, Perceived Work Stress, and Depression in Emergency Medicine Residents

Abstract A structural equation analysis of data collected from 484 members of the Emergency Medicine Residents Association was used to test a model in which peer support and work-group cohesiveness predicted role ambiguity. Role ambiguity was then specified as a predictor of work-related stress. Stress was hypothesized to affect depression and work satisfaction. The analysis confirmed the direct relationship between stress and depression and indicated that support from peers and the work group reduces stress. This impact is influenced by the amount of role ambiguity perceived by residents. Peer support, role ambiguity, and stress explain 52% of the variance in depression reported by residents. Residents are more satisfied with their work when their peers are supportive and when levels of occupational stress and role ambiguity are not high. The model accounted for 47% of the variance in reported work satisfaction. The results suggest that role ambiguity leads to perceptions of stress. This perceived stress...
Probing the CORE of the Haldane conjecture

The Contractor Renormalization group method (CORE), originally developed for application to lattice gauge theories, is very well adapted to the study of spin systems and systems with fermions. As a warmup exercise for studying Hubbard models this method is applied to spin-1/2 and spin-1 anti-ferromagnets in one space dimension in order to see if it is able to explain the physics of the Haldane conjecture. The method not only provides support for Haldane's conjecture but provides insight int the physics of a more general class of spin-1 systems with Hamiltonians of the form H = {summation}{sub j} {rvec s}(j) {center_dot} {rvec s}(j + 1) - {beta}({rvec s}(j) {center_dot} {rvec s}(j+1)){sup 2} about which, until now, little was known.
Synthesis, Characterization, and Bonding of Heteroatomic Clusters: Na13Cd20E7 (E = Pb, Sn), a Further Example of a Structure Containing Empty Icosahedra without an Element of Group 13

The compounds Na13Cd20E7 (E = Pb, Sn) were made in nearly 100% yield by quenching the melts of appropriate mixtures of elements sealed in niobium containers. They crystallize in the cubic space group Im3, Z = 4, with a = 15.992(2) and 15.790(4) A for E = Pb and Sn, respectively. The Cd/E part of the structure is a framework of heavily fused monocapped truncated trigonal prisms. Twelve-bonded icosahedra are nested in cavities of the framework. This is the second example of a structure containing empty icosahedra made without the participation of an element of the boron group. The sodium cations occupy the space between the clusters and inside the 13-atom polyhedra.
Monocular UHECR spectra as measured by HiRes

Abstract We have measured the spectrum of UHE cosmic rays in monocular mode using separately both detectors the High Resolution Fly's Eye experiment. We describe the two detectors and the basic methods of analysis, and we present our measured spectra. We compare these spectra with that produced by an astrophysical source model with galactic and uniformly distributed extra-galactic sources. We also compare our spectra to the spectra produced by the AGASA experiment.
Modal Analysis of Jointed Structures

Abstract Structural systems are often composed of multiple components joined together at localized interfaces. Compared to a corresponding monolithic system these interfaces are designed to have little influence on the load carrying capability of the system, and the resulting change in the overall system mass and stiffness is minimal. Hence, under nominal operating conditions the mode shapes and frequencies of the dominant structural modes are relatively insensitive to the presence of the interfaces. However, the energy dissipation in such systems is strongly dependent on the joints. The microslip that occurs at each interface couples together the structural modes of the system and introduces nonlinear damping into the system, effectively altering the observed damping of the structural modes, which can then significantly alter the amplitude of the response at the resonant modal frequencies. This work develops equations of motion for a jointed structure in terms of the structural modal coordinates and implements a reduced-order description of the microslip that occurs at the interface between components. The interface is incorporated into the modal description of the system through an existing decomposition of a series-series Iwan interface model and a continuum approximation for microslip of an elastic rod. The developed framework is illustrated on several examples, including a discrete three degree-of-freedom system as well as the longitudinal deformation of a continuum beam.
MODELLING SPACE WITH AN ATOM OF QUANTUM GEOMETRY

Within the context of loop quantum gravity there are several operators which measure geometry quantities. This work examines two of these operators, volume and angle, to study quantum geometry at a single spin network vertex—'an atom of geometry'. Several aspects of the angle operator are examined in detail including minimum angles, level spacing and the distribution of angles. The high spin limit of the volume operator is also studied for monochromatic vertices. The results show that demands of the correct scaling relations between area and volume and requirements of the expected behaviour of angles in three-dimensional flat space require high-valence vertices with total spins of approximately 1020.
Money-Demand Variability: A Demand-Systems Approach

This article tests the Fourier flexible form on quarterly U.S. monetary data. The data have been prescreened for consistency with the general axiom of revealed preference, and subindexes are formed using the Divisia approach. In this article, the global Fourier model fits well, although there is a potential problem of overfitting and certain data points exhibit behavior inconsistent with the model. The elasticities are variable over time, particularly around business-cycle troughs. It appears that financial asset demand surfaces are highly nonlinear and the many unsuccessful existing attempts to estimate money demand may not have worked well for this reason.
Monte Carlo sampling of negative-temperature plasma states.

A Monte Carlo procedure is used to generate N-particle configurations compatible with two-temperature canonical equilibria in two dimensions, with particular attention to nonlinear plasma gyrokinetics. An unusual feature of the problem is the importance of a nontrivial probability density function ${\mathcal{P}}_{0}(\ensuremath{\varphi}),$ the probability of realizing a set \ensuremath{\varphi} of Fourier amplitudes associated with an ensemble of uniformly distributed, independent particles. This quantity arises because the equilibrium distribution is specified in terms of \ensuremath{\varphi}, whereas the sampling procedure naturally produces particle states \ensuremath{\Gamma}; \ensuremath{\varphi} and \ensuremath{\Gamma} are related via a gyrokinetic Poisson equation, highly nonlinear in its dependence on \ensuremath{\Gamma}. Expansion and asymptotic methods are used to calculate ${\mathcal{P}}_{0}(\ensuremath{\varphi})$ analytically; excellent agreement is found between the large-N asymptotic result and a direct numerical calculation. The algorithm is tested by successfully generating a variety of states of both positive and negative temperature, including ones in which either the longest- or shortest-wavelength modes are excited to relatively large amplitudes.
The Duration-Photon Energy Relation of Gamma-Ray Bursts and Its Interpretations

Fenimore et al. have recently presented a very tight correlation between the spectral and the temporal structure in gamma-ray bursts (GRBs). In particular, they discovered that the durations of the constituent subpulses which make up the time profile of a given GRB have a well-defined power-law dependence of index 0.45 on the energy E of the observed photons. In this paper we present two simple models which can account in a straightforward fashion for the observed correlation. These models involve (1) the impulsive injection of a population of relativistic electrons and their subsequent cooling by synchrotron radiation, and (2) The impulsive injection of monoenergetic high-energy photons in a medium of Thompson depth τT ~ 5 and their subsequent downgrading in energy due to electron scattering. We present arguments for distinguishing between these two models from the existing data.
Synthesis of 2′,3′-Dideoxypurinenucleosides via the Palladium Catalyzed Reduction of 9-(2,5-Di-O-acetyl-3-bromo-3-deoxy-β-d-xylofuranosyl)purine Derivatives †

Abstract Practical method to produce 2′,3′-dideoxypurinenucleosides from 9-(2,5-di-O-acetyl-3-bromo-3-deoxy-β-D-xylofuranosyl)purines (1) was developed. High ratio of 2′,3′-dideoxynucleoside to 3′-deoxyribonucleoside was obtained by selecting the reaction conditions (solvent, pH and/or base), or changing 2′-acyloxy leaving group. The reaction mechanism was studied by deuteration experiments of 1a and 1-(3,5-di-O-acety1-2-bromo-2-deoxy-β-D-ribofuranosyl)thymine (12). †Dedicated to Dr. Yoshihisa Mizuno on the occasion of his 75th birthday.
Computational studies of room temperature ionic liquid–water mixtures

Room temperature ionic liquids (IL) have been used in numerous applications in chemistry. Addition of water alters many of their properties making it possible to custom design solvents for specific applications. Along with experiments, computational studies using various approaches have provided key insights into the structure and dynamics of IL systems, as well as aggregate formation and phase behavior of the IL/water mixtures. These systems provide computational challenges since ILs and IL/water mixtures are viscous liquids with intrinsically slow processes and structural organization over surprisingly large length scales, which push the limits of applicability of the available techniques. Recent developments in the studies of IL/water mixtures using computational methodologies are reviewed and the future prospects for the field are briefly discussed.
Bach-flat asymptotically locally Euclidean metrics

We obtain a volume growth and curvature decay result for various classes of complete, noncompact Riemannian metrics in dimension 4; in particular our method applies to anti-self-dual or Kahler metrics with zero scalar curvature, and metrics with harmonic curvature. Similar results were obtained for Einstein metrics in [And89], [BKN89], [Tia90], but our analysis differs from the Einstein case in that (1) we consider more generally a fourth order system in the metric, and (2) we do not assume any pointwise Ricci curvature bound.
The Reason of the Law

Moral premises are required in sound reasoning to the conclusion that a community does or does not (more or less) attain the rule of law. Those moral premises include, for example, the principle that judges should act with comity toward executive agencies. A failure in that moral requirement of comity is a failure to attain the rule of law. Because the ideal of the rule of law necessarily has a moral content, there is a necessary connection between law and morality- albeit a modest connection that is compatible with deep moral defects in the law
Chaotic Evolution of the Solar System

The evolution of the entire planetary system has been numerically integrated for a time span of nearly 100 million years. This calculation confirms that the evolution of the solar system as a whole is chaotic, with a time scale of exponential divergence of about 4 million years. Additional numerical experiments indicate that the Jovian planet subsystem is chaotic, although some small variations in the model can yield quasiperiodic motion. The motion of Pluto is independently and robustly chaotic.
Detecting dangerous queries: a new approach for chosen ciphertext security

We present a new approach for creating chosen ciphertext secure encryption. The focal point of our work is a new abstraction that we call Detectable Chosen Ciphertext Security (DCCA). Intuitively, this notion is meant to capture systems that are not necessarily chosen ciphertext attack (CCA) secure, but where we can detect whether a certain query CT can be useful for decrypting (or distinguishing) a challenge ciphertext CT*. We show how to build chosen ciphertext secure systems from DCCA security. We motivate our techniques by describing multiple examples of DCCA systems including creating them from 1-bit CCA secure encryption -- capturing the recent Myers-shelat result (FOCS 2009). Our work identifies DCCA as a new target for building CCA secure systems.
Androgen Receptors in Human Thymocytes

On the basis of a variety of evidence androgenic hormones are thought to exert modulatory effects on immune function. Because specific actions of these hormones are exerted through receptor-mediated mechanisms, we have examined the human thymus gland for the presence of specific high-affinity androgen receptors. Cytosolic extracts of whole human thymus were found to contain 6.5 (+/- 2.6) fmol of specific [3H]methyltrienolone binding per mg protein. The receptor sedimented at 8s on sucrose density gradient centrifugation analysis. Thymic fibroblast lines derived from these glands did not express sufficient receptor content to account for the findings in whole thymus cytosolic extracts. Purified thymocyte preparations (greater than 99.3% pure as assessed by flow cytometry with monoclonal anti-thymocyte marker OKT11) contained 3.34 (+/- 1.2) fmol receptor per mg cytosolic protein. Mature peripheral blood lymphocytes, human T cells obtained from thoracic duct drainage, and the human T cell line Jurkat were not found to contain these receptors. These studies demonstrate for the first time that a high affinity androgen receptor is present in maturing human thymocytes. A functional role for these receptors is suggested by dihydrotestosterone-mediated decreases in interleukin 2-like activity produced by cultured human thymocytes.
A note on S(t) and the zeros of the Riemann zeta-function

LetS(t) denote the argument of the Riemann zeta-function at the point 1 +it. Assuming the Riemann Hypothesis, we sharpen the constant in the best currently known bounds for S(t) and for the change of S(t) in intervals. We then deduce estimates for the largest multiplicity of a zero of the zeta-function and for the largest gap between the zeros.
A Method for Bayesian Monotonic Multiple Regression

. When applicable, an assumed monotonicity property of the regression function w.r.t. covariates has a strong stabilizing effect on the estimates. Because of this, other parametric or structural assumptions may not be needed at all. Although monotonic regression in one dimension is well studied, the question remains whether one can find computationally feasible generalizations to multiple dimensions. Here, we propose a non-parametric monotonic regression model for one or more covariates and a Bayesian estimation procedure. The monotonic construction is based on marked point processes, where the random point locations and the associated marks (function levels) together form piecewise constant realizations of the regression surfaces. The actual inference is based on model-averaged results over the realizations. The monotonicity of the construction is enforced by partial ordering constraints, which allows it to asymptotically, with increasing density of support points, approximate the family of all monotonic bounded continuous functions.
Imperfect Knowledge, Inflation Expectations, and Monetary Policy

This paper investigates the role that imperfect knowledge about the structure of the economy plays in the formation of expectations, macroeconomic dynamics, and the ecient formulation of monetary policy. Economic agents rely on an adaptive learning technology to form expectations and continuously update their beliefs regarding the dynamic structure of the economy based on incoming data. The process of perpetual learning introduces an additional layer of dynamic interactions between monetary policy and economic outcomes. We nd that policies that would be ecient under rational expectations can perform poorly when knowledge is imperfect. In particular, policies that fail to maintain tight control over inflation are prone to episodes in which the public’s expectations of inflation become uncoupled from the policy objective and stagflation results, in a pattern similar to that experienced in the United States during the 1970s. More generally, we show that policy should respond more aggressively to inflation under imperfect knowledge than under perfect knowledge.
American Dreaming: Critical Perspectives on a Media Training Program for Emerging Democracies

Since the end of the Cold War, the International Media Training Center has brought dozens of Eastern European journalists to study in non-degree programs at U.S. universities. This study is a cultural critique of one such program. The analysis is based on in-depth interviews, participant observation, and articles from university newsletters. The trainees reveal that support from mentors is often insufficient, and some participants face significant hostility after returning to their native countries. The fast-paced media environments in those countries have not forgiven their yearlong absence: organizational power has been redistributed, connections have been weakened, and new colleagues have aggressively taken over one's old turf. The findings suggest that training a few journalists from disparate media outlets is unlikely to have much effect on media professionalism in emerging democracies, unless the trainees are guaranteed an opportunity to become trainers. URN: urn:nbn:de:0114-fqs100376
Two-parameter heavy-traffic limits for infinite-server queues

In order to obtain Markov heavy-traffic approximations for infinite-server queues with general non-exponential service-time distributions and general arrival processes, possibly with time-varying arrival rates, we establish heavy-traffic limits for two-parameter stochastic processes. We consider the random variables Q e (t,y) and Q r (t,y) representing the number of customers in the system at time t that have elapsed service times less than or equal to time y, or residual service times strictly greater than y. We also consider W r (t,y) representing the total amount of work in service time remaining to be done at time t+y for customers in the system at time t. The two-parameter stochastic-process limits in the space D([0,?),D) of D-valued functions in D draw on, and extend, previous heavy-traffic limits by Glynn and Whitt (Adv. Appl. Probab. 23, 188---209, 1991), where the case of discrete service-time distributions was treated, and Krichagina and Puhalskii (Queueing Syst. 25, 235---280, 1997), where it was shown that the variability of service times is captured by the Kiefer process with second argument set equal to the service-time c.d.f.
Squarks below the Z

Abstract We investigate the possibility that the difference between the measurements of α 3 ( M z ) from the hadronic branching ratio of the Z 0 and the world average of other measurements is due to the decay of the Z 0 into quark, anti-squark, and gluino. Consequences for supersymmetry breaking models are discussed.
(Anti-)de Sitter black hole thermodynamics and the generalized uncertainty principle

We extend the derivation of the Hawking temperature of a Schwarzschild black hole via the Heisenberg uncertainty principle to the de Sitter and anti-de Sitter spacetimes. The thermodynamics of the Schwarzschild-(anti-)de Sitter black holes is obtained from the generalized uncertainty principle of string theory and non-commutative geometry. This may explain why the thermodynamics of (anti-)de Sitter-like black holes admits a holographic description in terms of a dual quantum conformal field theory, whereas the thermodynamics of Schwarzschild-like black holes does not.
An equivalence of two constructions of permutation-twisted modules for lattice vertex operator algebras

Abstract The problem of constructing twisted modules for a vertex operator algebra and an automorphism has been solved in particular in two contexts. One of these two constructions is that initiated by the third author in the case of a lattice vertex operator algebra and an automorphism arising from an arbitrary lattice isometry. This construction, from a physical point of view, is related to the space–time geometry associated with the lattice in the sense of string theory. The other construction is due to the first author, jointly with C. Dong and G. Mason, in the case of a multifold tensor product of a given vertex operator algebra with itself and a permutation automorphism of the tensor factors. The latter construction is based on a certain change of variables in the worldsheet geometry in the sense of string theory. In the case of a lattice that is the orthogonal direct sum of copies of a given lattice, these two very different constructions can both be carried out, and must produce isomorphic twisted modules, by a theorem of the first author jointly with Dong and Mason. In this paper, we explicitly construct an isomorphism, thereby providing, from both mathematical and physical points of view, a direct link between space–time geometry and worldsheet geometry in this setting.
A Theoretical Model and Empirical Results Linking Website Interactivity and Usability Satisfaction

Usability is a key component of websites that are commercially successful. Interactivity has been inconclusively linked to website usability. This study strengthens the theoretical understanding of how interactivity affects usability by measuring user satisfaction — a subconstruct of usability — across bookstore and e-card websites. We build on theoretical models from Liu and Shrum [17] and Khalifa and Liu [15]. Users were asked to perform tasks of varying levels of interactivity at bookstore and e-card websites. Measures were obtained for the users expectations of, desires for, and satisfaction with the websites. Results indicate that interactivity is successfully able to increase website satisfaction. Finally, implications for practitioners, limitations of the study, and directions for future research are addressed.
Nonfarm income diversification and household livelihood strategies in rural Africa: concepts, dynamics, and policy implications

Abstract Asset, activity and income diversification lie at the heart of livelihood strategies in rural Africa. This paper introduces a special issue on the topic “Income Diversification and Livelihoods in Rural Africa: Cause and Consequence of Change.” We concentrate on core conceptual issues that bedevil the literature on rural income diversification and the policy implications of the empirical evidence presented in this special issue.