cssi/SciSciGPT-SciSciNet huggingface dataset:
I do declare: consensus in a logic language

The Paxos consensus protocol can be specified concisely, but is notoriously difficult to implement in practice. We recount our experience building Paxos in Overlog, a distributed declarative programming language. We found that the Paxos algorithm is easily translated to declarative logic, in large part because the primitives used in consensus protocol specifications map directly to simple Overlog constructs such as aggregation and selection. We discuss the programming idioms that appear frequently in our implementation, and the applicability of declarative programming to related application domains.
Dynamic Mechanical Analysis of Fly Ash Filled Polyurea Elastomer

In this work, the material properties of a series of fly ash/polyurea composites were studied. Dynamic mechanical analysis was conducted to study the effect of the fly ash volume fraction on the composite's mechanical properties, i.e., on the material's frequency- and temperature-dependent storage and loss moduli. It was found that the storage and loss moduli of the composite both increase as the fly ash volume fraction is increased. The storage and loss moduli of the composites relative to those of pure polyurea initially increase significantly with temperature and then slightly decrease or stay flat, attaining peak values around the glass transition region. The glass transition temperature (measured as the temperature at the maximum value of the loss modulus) shifted toward higher temperatures as the fly ash volume fraction increased. Additionally, we present the storage and loss moduli master curves for these materials obtained through application of the time-temperature superposition on measurements taken at a series of temperatures.
Reflective ghost imaging through turbulence

Recent work has indicated that ghost imaging may have applications in standoff sensing. However, most theoretical work has addressed transmission-based ghost imaging. To be a viable remote-sensing system, the ghost imager needs to image rough-surfaced targets in reflection through long, turbulent optical paths. We develop, within a Gaussian-state framework, expressions for the spatial resolution, image contrast, and signal-to-noise ratio of such a system. We consider rough-surfaced targets that create fully developed speckle in their returns and Kolmogorov-spectrum turbulence that is uniformly distributed along all propagation paths. We address both classical and nonclassical optical sources, as well as a computational ghost imager.
Exceptions to the Rules: Variances from Regulatory Standards

In the major areas of regulation, standards can be violated through an appeal process set up as a part of the statutes. This paper formulates a model of the variance appeal process, characterizes the (perfect Bayesian) equilibria of this procedure and studies the welfare properties of these equilibria. I consider two versions of the decision rule used by the appeal board and suggest institutionally feasible alterations in these rules which can improve equilibrium welfare. I also study how obstructionist interest groups can affect the welfare performance of the decision rules.
Npas4 Regulates a Transcriptional Program in CA3 Required for Contextual Memory Formation

The rapid encoding of contextual memory requires the CA3 region of the hippocampus, but the necessary genetic pathways remain unclear. We found that the activity-dependent transcription factor Npas4 regulates a transcriptional program in CA3 that is required for contextual memory formation. Npas4 was specifically expressed in CA3 after contextual learning. Global knockout or selective deletion of Npas4 in CA3 both resulted in impaired contextual memory, and restoration of Npas4 in CA3 was sufficient to reverse the deficit in global knockout mice. By recruiting RNA polymerase II to promoters and enhancers of target genes, Npas4 regulates a learning-specific transcriptional program in CA3 that includes many well-known activity-regulated genes, which suggests that Npas4 is a master regulator of activity-regulated gene programs and is central to memory formation.
Equality, Efficiency, and Market Fundamentals: The Dynamics of International Medical Care Reform.

Public opinion surveys uniformly show low support for medical-care systems in developed countries. The longstanding conflict between equal access to care and efficient service provision partly explains this dissatisfaction. But the trade-off is particularly acute in medical care, as new technologies developed over time have increased the cost of care and made the equity commitment even more expensive. Countries first dealt with rising costs by maintaining equal access and restricting total spending. Efficiency suffered, however. As a result, many countries are considering a move away from spending controls and toward incentive-based medical-care reform.
Early events of B-cell receptor signaling are not essential for the proliferation and viability of AIDS-related lymphoma

Early events of B-cell receptor signaling are not essential for the proliferation and viability of AIDS-related lymphoma
Some Macroeconomic Aspects of Global Population Aging

Across the demographic transition, declining mortality followed by declining fertility produces decades of rising support ratios as child dependency falls. These improving support ratios raise per capita consumption, other things equal, but eventually deteriorate as the population ages. Population aging and the forces leading to it can produce not only frightening declines in support ratios but also very substantial increases in productivity and per capita income by raising investment in physical and human capital. Longer life, lower fertility, and population aging all raise the demand for wealth needed to provide for old-age consumption. This leads to increased capital per worker even as aggregate saving rates fall. However, capital per worker may not rise if the increased demand for wealth is satisfied by increased familial or public pension transfers to the elderly. Thus, institutions and policies matter for the consequences of population aging. The accumulation of human capital also varies across the transition. Lower fertility and mortality are associated with higher human capital investment per child, also raising labor productivity. Together, the positive changes due to human and physical capital accumulation will likely outweigh the problems of declining support ratios. We draw on estimates and analyses from the National Transfer Accounts project to illustrate and quantify these points.
Predictors of language service availability in U.S. hospitals

Background: Hispanics comprise 17% of the total U.S. population, surpassing African-Americans as the largest minority group. Linguistically, almost 60 million people speak a language other than English. This language diversity can create barriers and additional burden and risk when seeking health services. Patients with Limited English Proficiency (LEP) for example, have been shown to experience a disproportionate risk of poor health outcomes, making the provision of Language Services (LS) in healthcare facilities critical. Research on the determinants of LS adoption has focused more on overall cultural competence and internal managerial decision-making than on measuring LS adoption as a process outcome influenced by contextual or external factors. The current investigation examines the relationship between state policy, service area factors, and hospital characteristics on hospital LS adoption. Methods: We employ a cross-sectional analysis of survey data from a national sample of hospitals in the American Hospital Association (AHA) database for 2011 (N= 4876) to analyze hospital characteristics and outcomes, augmented with additional population data from the American Community Survey (ACS) to estimate language diversity in the hospital service area. Additional data from the National Health Law Program (NHeLP) facilitated the state level Medicaid reimbursement factor. Results: Only 64% of hospitals offered LS. Hospitals that adopted LS were more likely to be not-for-profit, in areas with higher than average language diversity, larger, and urban. Hospitals in above average language diverse counties had more than 2-fold greater odds of adopting LS than less language diverse areas [Adjusted Odds Ratio (AOR): 2.26, P< 0.01]. Further, hospitals with a strategic orientation toward diversity had nearly 2-fold greater odds of adopting LS (AOR: 1.90, P< 0.001). Conclusion: Our findings support the importance of structural and contextual factors as they relate to healthcare delivery. Healthcare organizations must address the needs of the population they serve and align their efforts internally. Current financial incentives do not appear to influence adoption of LS, nor do Medicaid reimbursement funds, thus suggesting that further alignment of incentives. Organizational and system level factors have a place in disparities research and warrant further analysis; additional spatial methods could enhance our understanding of population factors critical to system-level health services research.
Casimir forces between beads on strings and membranes

Abstract We develop a general formalism to calculate the force between beads attached to a flat d -dimensional membrane due to the quantum fluctuations of the membrane. The interaction potential is derived as a function of d and the membrane energy density, tension, stiffness and temperature. We find that the induced interactions turn off when d exceeds a certain critical dimension. The potential is attractive in all cases where it is non-zero and at finite temperature falls off exponentially for large distances.
The stirred tank reactor polymer electrolyte membrane fuel cell

The design and operation of a differential polymer electrolyte membrane (PEM) fuel cell is described. The fuel cell design is based on coupled stirred tank reactors (STRs) coupled through a membrane; the gas phase in each reactor compartment is well mixed. The characteristic times for reactant flow, gas phase diffusion, and reaction were chosen so that the gas compositions at both the anode and cathode are uniform. The STR PEM fuel cell is one-dimensional; the only spatial gradients are transverse to the membrane. The cell is used to examine start-up, and dynamic responses to changes in load, temperature, and reactant flow rates. Multiple time scales in the system’s response are found to correspond to water absorption by the membrane, water transport through the membrane, and stress-related mechanical changes of the membrane. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1889 –1900, 2004
A total synthesis of racemic paulownin using a type II photocyclization reaction

The lignan paulownin was prepared in a seven-step route from piperonal. The key step was a type II photocyclization reaction wherein two of the four stereogenic centers were introduced
Titan’s global crater population: A new assessment

Abstract We report a revised crater population for Titan using Cassini RADAR data through January 2010 (flyby T65), and make a size-dependent correction for the incomplete coverage (∼33%) using a Monte-Carlo model. Qualitatively, Titan’s landscape is more heavily cratered than Earth, but much less than Mars or Ganymede: the area fraction covered by craters is in fact comparable with that of Venus. Quantitative efforts to interpret crater densities for Titan as surface age have been confounded by widely divergent crater production rates proposed in the literature. We elucidate the specific model assumptions that lead to these differences (assumed projectile density, scaling function for simple crater diameter, and complex crater size exponent) and suggest these are reasonable bounding models, with the Korycansky and Zahnle (2005) model representing a crater retention age of ∼1 Ga, and the Artemieva and Lunine (2005) model representing a crater retention age of ∼200 Ma. These estimates are consistent with models of Titan’s evolution that predict a thickening of its crust 0.3–1.2 Gyr ago.
The Whitham equations for optical communications: mathematical theory of NRZ

We present a model of optical communication system for high-bit-rate data transmission in the nonreturn-to-zero (NRZ) format over transoceanic distance. The system operates in a small group velocity dispersion regime, and the model equation is given by the well-known Whitham equations describing the slow modulation of multiphase wavetrains of the (defocusing) nonlinear Schrodinger (NLS) equation. The model equation is of hyperbolic type, and NRZ pulse with certain initial phase modulation develops a shock. We then show how one can obtain a global solution by choosing an appropriate Riemann surface on which the Whitham equation is defined. We also discuss the effect of third order dispersion by using an integrable hierarchy of the NLS equation, and we give a condition to avoid a shock formation.
Compact scattered spaces in forcing extensions

We consider the cardinal sequences of compact scattered spaces in models where CH is false. We describe a number of models where the continuum is aleph_2 in which no such space can have aleph_2 countable levels.
Personality profiles of male and female data processing personnel

The study of personality is concerned with both the total individual and with individual differences. Personality is important to the understanding of behavior within organizations because there are few, if any, aspects of human functioning that are not to some degree reflective of individual personality.
Vasculitis in children

This article provides a general overview of vasculitis, situations in which the diagnosis should be considered, diagnostic methods, and therapeutic considerations. Details and treatments unique to specific vasculitides are also reviewed.
Containerless polymeric microsphere production for biomedical applications

A containerless method that produces highly uniform microspheres (> 50 microns in diameter) from many materials has been developed for biomedical applications. A piezoelectrically vibrated drop generator forms uniform (monodisperse) monomer droplets that are either electrostatically levitated and polymerized using UV irradiation, or free radical polymerized. Spheres of 2-hydroxyethyl methacrylate (HEMA) polymer have been produced with diameters of 155 microns ±1.57%.
Synthesis of Deoxytabtoxinine-β-Lactam

Abstract Deoxytabtoxinine-β-lactam (12) was synthesized in 6 steps from 3. β-Lactam 12 does not inhibit glutamine synthetase indicating that the hydroxyl group of tabtoxinine-β-lactam (2) is necessary for inhibition of glutamine synthetase.
Keck Interferometer Observations of Classical and Weak-line T Tauri Stars

We present observations of the T Tauri stars BP Tau, DG Tau, DI Tau, GM Aur, LkCa 15, RW Aur, and V830 Tau, using long baseline infrared interferometry at K band (2.2 μm) from the Keck Interferometer. The target sources have a range of mass accretion rates and excess near-infrared emission. The interferometer is most sensitive to extended emission on characteristic size scales of 1-5 mas. All sources show evidence for resolved K-band emission on these scales, although a few of the sources are marginally consistent with being unresolved. We calculate the infrared excess based on fitting stellar photosphere models to the optical photometry and estimate the physical size of the emission region using simple geometric models for the sources with a significant infrared excess. Assuming that the K-band-resolved emission traces the inner edge of the dust disk, we compare the measured characteristic sizes to predicted dust sublimation radii and find that the models require a range of dust sublimation temperatures and possibly optical depths within the inner rim to match the measured radii.
Distribution of the First Particle in Discrete Orthogonal Polynomial Ensembles

We show that the distribution function of the first particle in a discrete orthogonal polynomial ensemble can be obtained through a certain recurrence procedure, if the (difference or q-) log-derivative of the weight function is rational. In a number of classical special cases the recurrence procedure is equivalent to the difference and q-Painleve equations of [10, 17]. Our approach is based on the formalism of discrete integrable operators and discrete Riemann–Hilbert problems developed in [3, 4].
Heating measurements on Space Shuttle orbiter models with differentially deflected elevons

The phase change paint technique was used to make heat transfer measurements on the windward wing/elevons area of Space Shuttle Orbiter models with differentially deflected elevons. Outboard elevons were deflected windward at angles from 0 to 20 deg. The inboard elevons were deflected leeward. The models were tested in air at Mach 6 and 10 with two flow conditions and three angles of attack for both Mach numbers. Heat transfer coefficient contour maps of the wing/elevon area were obtained for all test conditions. The maximum heat transfer coefficient on the outboard elevon and on certain areas of the wing that were obtained when the elevons were deflected are compared to values obtained when the elevons were undeflected.
Effect of Unheated Starting Lengths on Film Cooling Experiments

The effect of an unheated starting length upstream of a row of film cooling holes was studied experimentally to determine its effect on heat transfer coefficients downstream of the holes. Cases with a single row of cylindrical film cooling holes inclined at 35 deg to the surface of a flat plate were considered at blowing ratios of 0.25, 0.5, 1.0, and 1.5. For each case, experiments were conducted to determine the film-cooling effectiveness and the Stanton number distributions in cases with the surface upstream of the holes heated and unheated. Measurements were made using an infrared camera, thermocouples, and hot and cold-wire anemometry. Ratios were computed of the Stanton number with film cooling (St f ) to corresponding Stanton numbers in cases without film cooling (St o ), but the same surface heating conditions. Contours of these ratios were qualitatively the same regardless of the upstream heating conditions, but the ratios were larger for the cases with a heating starting length. Differences were most pronounced just downstream of the holes and for the lower blowing rate cases. Even 12 diameters downstream of the holes, the Stanton number ratios were 10-15% higher with a heated starting length. At higher blowing rates the differences between the heated and unheated starting length cases were not significant. The differences in Stanton number distributions are related to jet flow structures, which vary with blowing rate.
Order Imbalance on Ex-Dividend Days

In this article we test an alternative to the tax-based explanation for why prices decline on ex-dividend days by an amount less than the dividend. We examine whether there is order imbalance on cum- and ex-dividend days. We find that on ex-dividend days, there are more buys than sells in the number of orders, but not in the number of shares ordered, and the imbalance in the number of orders is limited to small orders. We find that the difference between the dividend amount and the ex-dividend-day price drop is significantly related to the magnitude of the buy-sell order imbalance. We find no order imbalance on cum-dividend days in either the number of orders or the number of shares ordered.
Corporate Taxes and Financing Methods for Taxable Acquisitions

We examine the influence of corporate taxes on U.S. firms' financing methods for taxable acquisitions of 100 percent of a target corporation's stock. We conduct tests of acquirer firms' use of debt or internal funds as the funding source for these acquisitions over the period 1987-97. Our results provide the first empirical evidence that U.S. firms' use of debt to fund acquisitions significantly declines as foreign tax credit limitations reduce the marginal tax benefits received from borrowing. This finding is consistent with earlier speculation that U.S. foreign tax credit provisions could materially affect the capital costs of U.S. companies in debt-financed acquisitions. We also find that these firms are generally high-tax-rate corporations whose financing choices are not significantly influenced by whether they acquire target-firm tax loss carryovers. Our findings contribute to the accounting literature on the influence of taxes on the structure and financing of corporate acquisitions.
Charles Darwin and Human Evolution

No field of biology has been more deeply influenced by Darwin’s notion of evolution than has the science of human origins. Yet while Charles Darwin himself was happy to speculate in the abstract upon the qualities of hypothetical human ancestors, he remained curiously reluctant to engage directly with its tangible fossil record. There appear to have been several reasons for this, including Darwin’s desire to avoid confrontation; the scandal-ridden nature of antiquarianism in the mid-nineteenth century; Darwin’s own abiding qualms about the reliability of the fossil record; and his close colleague Thomas Henry Huxley’s dismissal of the Neanderthal skeleton, the most distinctive hominid fossil known at the time, as merely representing a “barbaric” variety of Homo sapiens. There can be no doubt that human evolution and its implications had been very much on Darwin’s mind in the years leading up to the publication of On the origin of species; but in the end he seems to have made a conscious decision to stay clear of this social and intellectual minefield. Even his vast treatise on The descent of man is more plausibly read as an anti-polygenist, anti-slavery tract, and as an exegesis of sexual selection, than as a serious examination of the actual tangible evidence for the origins of humankind. Nonetheless, while staying safely in the realm of abstract speculation, in this great work Darwin managed to establish many of the themes that still dominate paleoanthropology today, including human descent from a single species of ape-like progenitor, the primacy of upright locomotion in human evolution, the birth of our family in the continent of Africa, and, for better or for worse, “the necessary acquirement of each mental power and capacity by gradation”, the founding mantra of today’s evolutionary psychology.
Photochemistry of methane–water ices

Abstract We report a study on the broadband ultraviolet photolysis of methane–water ice mixtures, at low methane concentrations and temperatures relevant to the icy satellites of the outer Solar System. The photochemistry of these mixtures is dominated by the action of hydroxyl radicals on methane and the resulting products. This implies that, given sufficient exposure time, the methane will eventually be completely oxidized to carbon dioxide. The presence of methane inhibits the formation of hydrogen peroxide by serving as a trap for hydroxyl radicals. The distribution of photochemical products is broadly similar to that previously conducted using ion and electron sources, with some differences possibly attributable to the difference in radiation source. The results are applicable to a variety of icy bodies in the Solar System. On Enceladus, where methane mixed with water is measured in the plumes, methane in the surface ices is subject to oxidation and will eventually be converted to CO 2 . The C H stretch feature detected in the VIMS spectra of the Enceladus surface ice suggests that methane is currently being supplied to the surface ice, likely from re-condensation of the plume gas.
Hard thermal loops in a moving plasma and a magnetic mass term

Abstract We consider the generating functional for the hard thermal loops of Quantum Chromodynamics for a moving quark-gluon plasma. We show that there is a different but closely related term which gives magnetic screening and can be used as a magnetic mass term in perturbative calculations.
Extending WWW for synchronous collaboration

Abstract The World-Wide-Web (WWW), in conjunction with such tools as Mosaic, is an extremely effective mechanism for individuals to share distributed information. However, access to this information is unidirectional, asynchronous, and limited by a client/server model in which only predefined data are provided. We describe augmenting WWW to support bidirectional, synchronous collaboration between data producers and their consumers. This is accomplished by exploiting WWW's ease of access and use, and by incorporating a peer-to-peer model that provides real-time collaboration services.
Event-by-event jet quenching and higher Fourier moments of hard probes

Abstract We investigate the effect of event-by-event fluctuations of the fireball created in high energy nuclear collisions on hard probe observables. We show that spatial inhomogeneities lead to changes in the nuclear suppression factor of high momentum hadrons which can be absorbed in the quenching strength q ˆ . This can increase the theoretical uncertainty on extracted values of q ˆ by up to 50%. We also investigate effects on azimuthal asymmetries v 2 and dihadron correlation functions. The latter show a promising residual signal of event-by-event quenching that might allow us to estimate the size of spatial inhomogeneities in the fireball from experimental data.
Orbifold cohomology of torus quotients

We introduce the inertial cohomology ring NHT*,◊(Y) of a stably almost complex manifold carrying an action of a torus T. We show that in the case where Y has a locally free action by T, the inertial cohomology ring is isomorphic to the Chen-Ruan orbifold cohomology ring HCR*(Y/T) (as defined in [CR]) of the quotient orbifold Y/T. For Y a compact Hamiltonian T-space, we extend to orbifold cohomology two techniques that are standard in ordinary cohomology. We show that NHT*,◊(Y) has a natural ring surjection onto HCR*(Y//T), where Y//T is the symplectic reduction of Y by T at a regular value of the moment map. We extend to NHT*,◊(Y) the graphical Goresky-Kottwitz-MacPherson (GKM) calculus (as detailed in, e.g., [HHH]) and the kernel computations of [TW] and [G1], [G2]. We detail this technology in two examples: toric orbifolds and weight varieties, which are symplectic reductions of flag manifolds. The Chen-Ruan ring has been computed for toric orbifolds, with Q-coefficients, in [BCS]; we reproduce their results over Q for all symplectic toric orbifolds obtained by reduction by a connected torus (though with different computational methods) and extend them to Z-coefficients in certain cases, including weighted projective spaces
Evidence on the Dark Side of Internal Capital Markets

This article documents differences between the (?-sensitivity of investment of stand-alone firms and unrelated segments of conglomerate firms. Unrelated segments exhibit lower o-sensitivity of investment than stand-alone firms. This fact is driven by unrelated segments of conglomerate firms that tend to invest less than stand-alone firms in high-s industries. This finding is robust to matching on industry, year, size, age, and profitability. The differences are more pronounced in conglomerates in which top management has small ownership stakes, suggesting that agency problems explain the investment behavior
A Model of Financial Fragility

Abstract This article presents a dynamic, stochastic game-theoretic model with two essential features. First, agents hold diversified portfolios that link their financial positions to those of other agents. Second, shocks to fundamentals at the initial date cause some portfolio losses. Agents who incur losses reallocate their portfolios, thereby breaking some linkages. In the Pareto-efficient symmetric equilibrium studied, two related types of financial crisis can occur in response. One occurs gradually as losses spread, breaking more links. The other type occurs instantaneously when forward-looking agents preemptively shift to safer portfolios to avoid future losses from contagion. An economy is more fragile the earlier its last remaining link breaks from such a crisis. Journal of Economic Literature Classification Numbers: C7, E00, E3, E44, G1.
Ogallala: Water for a Dry Land

"A sane, scholarly model for addressing local enviro-crises."-Booklist. "This work will give the reader the basis for planning the future of the Ogallala."-Journal of Sustainable Agriculture. This book illustrates that the aquifer is more than a local resource or a regional treasure, and it illuminates the necessity for new management of the aquifer to prevent a return to subsistence conditions on the plains.
The REIT Modernization Act of 1999

This article examines two effects of the passage of the REIT Modernization Act (RMA) of 1999: its impacts on REIT shareholder wealth and changes in REIT systematic risk in the period following its passage. The results indicate a modest positive wealth effect associated with the legislative events leading to its enactment. Our estimates of the wealth gain probably underestimate the true wealth gain because of the partially anticipated nature of the legislative process. We also document a significant decline in the systematic risk of REITs subsequent to the passage of the RMA. The evidence suggests that this decline is not attributable to a provision of the RMA that allows REITs to establish taxable subsidiaries.
NICMOS Photometry of the Unusual Dwarf Planet Haumea and its Satellites

We present here Hubble Space Telescope NICMOS F110W and F160W observations of Haumea, and its two satellites Hi'iaka and Namaka. From the measured (F110W-F160W) colors of –1.208 ± 0.004, –1.48 ± 0.06, and –1.4 ± 0.2 mag for each object, respectively, we infer that the 1.6 μm water-ice absorption feature depths on Hi'iaka and Namaka are at least as deep as that of Haumea. The light curve of Haumea is detected in both filters, and we find that the infrared color is bluer by ~2%-3% at the phase of the red spot. These observations suggest that the satellites of Haumea were formed from the collision that produced the Haumea collisional family.
The asymptotic inadmissibility of the spatial sign covariance matrix for elliptically symmetric distributions

The asymptotic efficiency of the spatial sign covariance matrix relative to affine equivariant estimators of scatter is studied. In particular, the spatial sign covariance matrix is shown to be asymptotically inadmissible, i.e., the asymptotic covariance matrix of the consistency-corrected spatial sign covariance matrix is uniformly larger than that of its affine equivariant counterpart, namely Tyler’s scatter matrix. Although the spatial sign covariance matrix has often been recommended when one is interested in principal components analysis, its inefficiency is shown to be most severe in situations where principal components are of greatest interest. Simulation shows that the inefficiency of the spatial sign covariance matrix also holds for small sample sizes, and that the asymptotic relative efficiency is a good approximation to the finite-sample efficiency for relatively modest sample sizes.
Electron paramagnetic resonance spectroscopy of free radicals in corneal tissue following excimer laser irradiation

Background and Objective Free radicals, detected previously in corneal tissue following 193 nm laser irradiation, may be important agents in the laser/tissue interaction. Electron paramagnetic resonance spectroscopy (EPR) has been used to examine such radical formation in detail. Study Design/Materials and Methods Bovine corneal strips were frozen in liquid nitrogen, irradiated with excimer laser pulses, and assayed by EPR. Exposure conditions were varied to study radical formation dependence on laser intensity and repetition. Results were measured against a quantifiable standard to calculate radical quantum yield. Results Either weak or intense laser fluences produced comparable tissue EPR signals. Radicals accumulated in frozen tissue for at least 10 initial ablation pulses. Radical quantum yield in cornea was 0.15%. Conclusion Corneal radical formation is largely a photochemical process driven by the 193 nm laser radiation. Reactive radical species are produced in substantial numbers and likely have a significant clinical role. © 1996 Wiley-Liss, Inc.
Community detection thresholds and the weak Ramanujan property

Decelle et al. [1] conjectured the existence of a sharp threshold on model parameters for community detection in sparse random graphs drawn from the stochastic block model. Mossel, Neeman and Sly [2] established the negative part of the conjecture, proving impossibility of non-trivial reconstruction below the threshold. In this work we solve the positive part of the conjecture. To that end we introduce a modified adjacency matrix B which counts self-avoiding paths of a given length e between pairs of nodes. We then prove that for logarithmic length e, the leading eigenvectors of this modified matrix provide a non-trivial reconstruction of the underlying structure, thereby settling the conjecture. A key step in the proof consists in establishing a weak Ramanujan property of the constructed matrix B. Namely, the spectrum of B consists in two leading eigenvalues ρ(B), λ2 and n -- 2 eigenvalues of a lower order O(ne √ρ(B) for all e 0, ρ(B) denoting B's spectral radius.
Microdebrider removal of tracheal papilloma via tracheostomy in the child with an obliterated larynx

In children, recurrent respiratory papillomatosis is the most common benign neoplasm of the airway. The disease frequently involves the larynx and may spread to extralaryngeal sites. Use of a microdebrider has been suggested as a safe and low-cost technique which reduces operating time, compared with laser removal of laryngeal lesions. We describe a technique for using a microdebrider to remove tracheal papillomas when the larynx is obliterated with the disease.
Nickel-Catalyzed Suzuki–Miyaura Couplings in Green Solvents

The nickel-catalyzed Suzuki–Miyaura coupling of aryl halides and phenol-derived substrates with aryl boronic acids using green solvents, such as 2-Me-THF and tert-amyl alcohol, is reported. This methodology employs the commercially available and air-stable precatalyst, NiCl2(PCy3)2, and gives biaryl products in synthetically useful to excellent yields. Using this protocol, bis(heterocyclic) frameworks can be assembled efficiently.
Astrometric Microlensing Constraints on a Massive Body in the Outer Solar System with Gaia

A body in solar orbit beyond the Kuiper Belt exhibits an annual parallax that exceeds its apparent proper motion by up to many orders of magnitude. Apparent motion of this body along the parallactic ellipse will deflect the angular position of background stars due to astrometric microlensing ("induced parallax"). By synoptically sampling the astrometric position of background stars over the entire sky, constraints on the existence (and basic properties) of a massive nearby body may be inferred. With a simple simulation, we estimate the signal-to-noise ratio for detecting such a body—as a function of mass, heliocentric distance, and ecliptic latitude—using the anticipated sensitivity and temporal cadences from Gaia (launch date 2011). A Jupiter-mass (MJ) object at 2000 AU is detectable by Gaia over the whole sky above 5 σ, with even stronger constraints if it lies near the ecliptic plane. Hypotheses for the mass (~3MJ), distance (~20,000 AU), and location of the proposed perturber ("Planet X"), which gives rise to long-period comets, may be testable.
A New Optimality Criterion Method for Large Scale Structures.

An optimality criterion method, which exploits the concept of one most critical constraint, is reported. The method eliminates the need to calculate a large set of Lagrange multipliers for the active constraints, and also eliminates the need for a decision as to whether or not a particular constraint should be considered active. The method can treat multiple load conditions and stress and displacement constraints. Application of the method to a number of truss and frame structures demonstrates the efficiency and accuracy of the method.
The manual use of automatic records

Summary---Records that are to be processed automatically necessarily must be stored in media accessible to a machine and in codes suitable for machine interpretation. Consequently, such records may be not readily accessible to the unaided human clerk. Steps that may be taken to provide adequate facilities for the occasional manual interrogation and processing of automatic records are suggested and examined.
Oscillations-Induced Transitions and Their Application in Control of Dynamical Systems

Studies of the use of oscillations for control purposes continue to reveal new practically important properties unique to the oscillatory open and closed loop control laws. The goal of this paper is to enlarge the available set of analytical tools for such studies by introducing a method of analysis of the qualitative changes in the behavior of dynamical systems caused by the zero means parametric excitations. After summarizing and slightly refining a technique developed previously for the finite dimensional nonlinear systems, one considers an extension of this technique to a class of distributed parameter systems governed by semilinear parabolic equations
Nonlinear filtering of convex sets of probability distributions

A solution is provided to the problem of computing a convex set of conditional probability distributions that characterize the state of a nonlinear dynamic system as it evolves in time. The estimator uses the Galerkin approximation to solve Kolmogorov's equation for the diffusion of a continuous-time nonlinear system with discrete-time measurement updates. Filtering of the state is accomplished for a convex set of distributions simultaneously, and closed-form representations of the resulting sets of means and covariances are generated.
Controlling cyclizations of 2-pyrrolecarboxamidoacetals. Facile solvation of β-amido aldehydes and revised structure of synthetic homolongamide

Abstract Pyrrole N–C and C–C bond-forming cyclizations are described with 2-pyrrolecarboxamidoacetals 1 – 3 under standard acetal deprotection conditions ( p TsOH/H 2 O) and with methanesulfonic acid. Under the former, N–C cyclization provided fused bi- and tricyclic systems bearing five- or six-membered rings, while the latter produced six- and seven-membered C–C cyclized products. Furthermore, an alternative structure for homolongamide 10 is proposed and is based on the facile solvation of β-amido aldehyde 7 .
Preparation and dienophilicity of 3-methyl-4,5-benzofurandione

Abstract The o-quinone 3-methyl-4,5-benzofurandione, 1 , was prepared in 94% overall yield from p-henzoquinone and 1-morpholino-propene. The cycloaddition chemistry of 1 with several dienes was examined and found to proceed in good to excellent yields.
Scanning Tunneling Microscopy and Atomic Force Microscopy in Organic Chemistry

When Kekule awoke from dreams of snakes biting their own tails, he didn't have the benefit of a scanning tunneling microscope (STM) image to confirm that his vision of benzene as a cyclic molecule was accurate. References to STM in the chemical literature increase steadily, although the technique was perhaps oversold in its early days of the 1980s, with such promises as DNA sequencing and tailored bi-molecular chemical reactions (literally, two molecules). Publications alternate between attempting to explain the process by which images of traditional insulators are obtained and simply presenting the end images themselves as stunning views of atoms and molecules. While imaging mechanisms are still being debated, these instruments' ability to “see” single molecules has been established, albeit at the fringes of our expectations. For example, whereas STM studies at present might not be able to answer the question of why adsorption of CO doubles the density of platinum atoms on the surface of a single crystal of the metal, the images go far in illustrating that this is a process which platinum undergoes. As with any emerging analytical tool, these scanning, very localized microscopic methods are undergoing the growing pains of irreproducible results and mis-marketed artifacts. Nonetheless, we assemble here, primarily for the uninitiated, a collection of careful and credible studies to mark the progress of scanning tunneling microscopy and atomic force microscopy into chemistry, and to encourage a healthy blend of idealism and skepticism toward future work.
Reply to comments

The main theme in most of the contributions to the symposium on Making Sense of Marx is methodological individualism. In the first part of my reply I consider the objections raised to this, in my opinion, trivially true doctrine. Against Taylor I argue that social relations, seen in abstraction from their relata, have no causal efficacy. Against Wood I argue that my defence of methodological individualism and my criticism of functional explanation are less closely related than he makes them out to be. Against Slaughter I argue that he holds two inconsistent views on the importance of individual desires and beliefs in social explanation. Against Meikle I argue that his view that entities are ‘real natures’ with a normal path of development needs to be restated in terms of dynamically stable processes. In the second part of the reply I deal with the individual contributions one by one. The replies to the ‘fundamentalist Marxists’ Slaughter and Meikle are relatively brief, because of the dismissive, unschola...
The M-algebra

Abstract We construct a new extension of the Poincare superalgebra in eleven dimensions which contains super one-, two- and five-form charges. The latter two are associated with the supermembrane and the superfivebrane of M-theory. Using the Maurer-Cartan equations of this algebra, we construct closed super seven-forms in a number of ways. The pull-back of the corresponding super six-forms are candidate superfivebrane Wess-Zumino terms, which are manifestly supersymmetric, and contain coordinates associated with the new charges.
Four-dimensional quantitative structure-activity relationship analysis of a series of interphenylene 7-oxabicycloheptane oxazole thromboxane A2 receptor antagonists.

A series of 39 (a training set of 29 and a test set of 10) interphenylene 7-oxabicyclo[2.2.1]heptane oxazole thromboxane A2 (TXA2) receptor antagonists were studied using four-dimensional quantitative structure−activity relationship (4D-QSAR) analysis. Two thousand conformations of each analogue were sampled to generate a conformational energy profile (CEP) from a molecular dynamic simulation (MDS) of 100 000 trajectory states. Each conformation was placed in a grid cell lattice for each of six trial alignments. Cubic grid cell sizes of 1 and 2 A were considered. The frequency of occupation of each grid cell was computed for each of seven types of pharmcacophoric group classes of atoms of each compound. These grid cell occupancy descriptors (GCODs) were then used as independent variables in constructing three-dimensional (3D)-QSAR models after data reduction. The types of data reduction included doing no reducing, reduction based on individual GCOD correlation with activity, and reduction from minimum var...
Market presence, contestability, and the terms-of-trade effects of regional integration

Abstract This paper examines the impact of market presence and contestability on the price behavior of US exporters in Brazil’s market when MERCOSUR and MFN trade liberalization take place. Using detailed panel data on trade and tariff rates, we find that both the preferred supplier’s market presence and threat of entry lower (raise) the US price reaction to MFN (preferential) trade liberalization, with similar quantitative effects. Thus, presence in, or threat of entry into, partners’ markets implies lower optimal MFN tariffs, and regional agreements can have pro-competitive effects in contestable markets. We also examine the ‘symmetry’ hypothesis between the effect of tariffs and exchange rates.
The performance evaluation of a new neural network-based traffic management scheme for a satellite communication network ☆

Abstract This paper presents the first attempt to incorporate the map configuration task with the routing task in the traffic management scheme of a satellite communication network. The map configuration task, which is automated by a self-organization scheme modified from Kohonen's model, consists of three stages. The first stage is the pattern recognition task, which selects an exemplar map that best meets the current network requirement. The second stage consists of analyzing the discrepancy between the chosen exemplar map and the state of the network, and adaptively modifying the chosen exemplar map to conform closely to the network requirement (input data pattern) by self-organization. Based on certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. The routing task is implemented by a state-dependent routing algorithm which arranges the incoming call to some proper path to make the network more efficient, and lowers the call block rate. The new scheme inheriting merits of both the map configuration and routing tasks provides the best compromised performance in terms of block rates at various load conditions as compared to status quo approaches — schemes with either only the map configuration task or only the routing task.
Existence results for some damped second-order Volterra integro-differential equations

Abstract In this paper we make a subtle use of operator theory techniques and the well-known Schauder fixed-point principle to establish the existence of pseudo-almost automorphic solutions to some second-order damped integro-differential equations with pseudo-almost automorphic coefficients. In order to illustrate our main results, we will study the existence of pseudo-almost automorphic solutions to a structurally damped plate-like boundary value problem.
Large optical gain from four-wave mixing instabilities in semiconductor quantum wells

Based on a microscopic many-particle theory, we predict large optical gain in the probe and background-free four-wave mixing directions caused by excitonic instabilities in semiconductor quantum wells. For a single quantum well with radiative-decay limited dephasing in a typical pump-probe setup we discuss the microscopic driving mechanisms and polarization and frequency dependence of these instabilities.
2,3-Pyridyne Formation by Fluoride-Induced Desilylation-Elimination

Abstract The formation of 2,3-pyridyne by a desilylation-elimination sequence employing anhydrous CsF is reported.
Analysis of star pair latitudes

Star pair latitude observations forming the basis for the pole positions reported by the International Polar Motion Service (IPMS) are processed to produce a mean pole position. However, the time series of raw observations contains high frequency information which is lost in the calculation of the mean pole. Analysis of 2931 star pair observations reveals a possible large excitation at one cycle per solar day. The average power level in the frequency band of the tesseral tides is seen to be high, although the peaks do not occur at the expected tidal frequencies.
Simulating the scratch standards for optical surfaces: theory.

I show how to simulate the scattering generated by a scratch on the surface of high-quality optics and their elements. This is accomplished by first describing how the present cosmetic scratch standards tend to be used in the optics industry. Second, I derive from first principles, using the scalar model for electromagnetic radiation, the first-order scattering coefficients for the far-field radiation due to a particular scratch pattern. There are approximations made to get these coefficients. The results allow construction of a set of secondary scratch standards. These are a pattern of rectangular grooves that can be made precisely reproducible during the manufacturing phase. Appropriate selection from this set can provide the same range of scattering power and character as is present in the current scratch standards, which are not easily reproducible. Because the method for construction of these new secondary standards is nonrandom, to guarantee the reproducible construction between these standards it is necessary to restrict the observation range 5– 10° from the direct beam.