cssi/SciSciGPT-SciSciNet huggingface dataset:
On the construction of particle distributions with specified single and pair densities

We discuss necessary conditions for the existence of a probability distribution on particle configurations in d-dimensions, i.e., a point process, compatible with a specified density ρ and radial distribution function g(r). In d = 1 we give necessary and sufficient criteria on ρg(r) for the existence of such a point process of renewal (Markov) type. We prove that these conditions are satisfied for the case g(r) = 0, r D, if and only if ρD ≤ e-1: the maximum density obtainable from diluting a Poisson process. We then describe briefly necessary and sufficient conditions, valid in every dimension, for ρg(r) to specify a determinantal point process for which all n-particle densities,ρn(r1,...,rn), are given explicitly as determinants. We give several examples.
Cosmic Concordance and Quintessence

We present a comprehensive study of the observational constraints on spatially flat cosmological models containing a mixture of matter and quintessence—a time-varying, spatially inhomogeneous component of the energy density of the universe with negative pressure. Our study also includes the limiting case of a cosmological constant. We classify the observational constraints by redshift: low-redshift constraints include the Hubble parameter, baryon fraction, cluster abundance, the age of the universe, bulk velocity and the shape of the mass power spectrum; intermediate-redshift constraints are due to probes of the redshift-luminosity distance based on Type Ia supernovae, gravitational lensing, the Lyα forest, and the evolution of large-scale structure; high-redshift constraints are based on measurements of the cosmic microwave background temperature anisotropy. Mindful of systematic errors, we adopt a conservative approach in applying these observational constraints. We determine that the range of quintessence models in which the ratio of the matter density to the critical density is 0.2 Ωm 0.5, and the effective, density-averaged equation of state is -1 ≤ w -0.2, is consistent with the most reliable, current low-redshift and microwave background observations at the 2 σ level. Factoring in the constraint due to the recent measurements of Type Ia supernovae, the range for the equation of state is reduced to -1 ≤ w -0.4, where this range represents models consistent with each observational constraint at the 2 σ level or better (concordance analysis). A combined maximum likelihood analysis suggests a smaller range, -1 ≤ w -0.6. We find that the best-fit and best-motivated quintessence models lie near Ωm ≈ 0.33, h ≈ 0.65, and spectral index ns = 1, with an effective equation of state w ≈ -0.65 for "tracker" quintessence and w = -1 for "creeper" quintessence.
Schur positivity and Schur log-concavity

We prove Okounkov's conjecture, a conjecture of Fomin-Fulton-Li-Poon, and a special case of Lascoux-Leclerc-Thibon's conjecture on Schur positivity and give several more general statements using a recent result of Rhoades and Skandera. We also give an intriguing log-concavity property of Schur functions.
Dynamic kinetic asymmetric cycloadditions of isocyanates to vinylaziridines.

The first examples of the use of racemic vinylaziridines in a Pd-catalyzed dynamic kinetic asymmetric transformation have been examined. Optimization studies of the Pd-catalyzed addition of vinylaziridines to isocyanates revealed that the chiral ligand between trans-1,2-diaminocyclohexane and 2-diphenylphosphino-1-naphthoic acid is superior to that involving 2-diphenylphosphino benzoic acid. Surprisingly, high ee's required the use of an acid whose pKa was about 4.7 ± 0.1 as a cocatalyst. Both acetic acid and hydroxybenzotriazole meet this requirement. Less electrophilic isocyanates (e.g., benzyl, p-methoxyphenyl) gave higher ee's than more electrophilic ones (phenyl or benzoyl). Both N-benzyl and N-arylaziridines react well to give good yields and ee's, whereas N-tosylaziridines gave lower ee's. A 1,1-disubstituted aziridine led to the formation of a tertiary C−N bond with ee's comparable to the formation of the secondary C−N bond. The products were easily reduced almost quantitatively to the sensitive i...
Mechanism and kinetics of the stepwise voltammetric reduction of pertechnetate in alkaline solution to Tc(VI, Tc(V) and Tc(IV)

Abstract The mechanism of the stepwise reduction of TcO−14 to Tc(VI), Tc(V) and Tc(IV) from pH 9.2 to pH 13.6 was studied by normal pulse polarography and dc polarography. In low ionic strength media normal pulse polarography yields TcO2−4 as the primary product. This species gains a proton by hydrolysis and reacts with water to form a 5- or 6-coordinate species which then is reduced to Tc(V) by an ECE/DISP1 mechanism. The rapid increase of the rate of the chemical reaction with increasing ionic strength is attributed to a specific ionic strength effect arising from intramolecular repulsion of charged ligands. Above pH 12 in high ionic strength media, Tc(V) is reduced to Tc(IV) in an unusual step whose rate increases with increasing pH. The rate is second order in Tc, suggesting a DISP 2 process or the formation of dimeric Tc(IV).
A New Stress Intensity Factor Solution for Cracks at an Offset Loaded Fastener Hole

Stress intensity factors were obtained for radial and diametrical cracks at an offset (noncentered) loaded fastener hole. The new closed-form solution was derived by superposing and compounding several stress intensity factor solutions, including a new key stress intensity factor solution developed for cracks in a finite plate with in-plane bending loads. The accuracy of the new closed-form solutions was verified for various configurations against results found in the literature as well as finite element analysis results. Nomenclature = half crack length from tip-to-tip = length of crack i from the edge of the hole to the tip = distance between the edge and the center of the crack = edge distance of the hole = bearing to bypass stress ratio (
Simulations of collisionless shocks

A problem of critical importance to space and astrophysics is the existence and properties of high‐Mach‐number (HMN) shocks. In this letter we present the results of simulations of perpendicular shocks with Alfven Mach number 22. We show that the shock structure is a sensitive function of resistivity, becoming turbulent when the resistivity is too low. We discuss the problem of electron heating, and the extension of our results to higher Mach numbers.
Genetic Spatial Optimization of Active Elements on an Aeroelastic Delta Wing

This work outlines a cohesive approach for the design and implementation of a genetically optimized, active aeroelastic delta wing. Emphasis was placed on computational efficiency of model development and efficient means for optimizing sensor and actuator geometries. Reduced-order models of potential-flow aerodynamics were developed for facilitation of analysis and design of the aeroelastic system in the early design phase. Using these methods, models capturing 95% of the physics with 8% of the modeling effort can be realized to evaluate various active and passive design considerations. The aeroelastic delta wing model was employed in determining the most effective locations and sizes for transducers required to provide flutter control. The basic design presented is based upon an analytical model of the structure. A comparison of optimization strategies led to the use of a genetic algorithm to determine the optimal transducer locations, sizes, and orientations required to provide effective flutter control based upon an open-loop performance metric. The genetic algorithm and performance metric essentially provided loop shaping through the adaptive structure design. An experimental model was then developed based upon the optimal transducer designs. Wind tunnel tests were performed to demonstrate closed-loop performance for flutter control. Results from this study indicate that a single sensor/actuator pair can be designed to extend the flutter boundary and selectively couple to only those modes reauired to control the response.
Hadron structure functions in a chiral quark model

We present a consistent regularization procedure for calculating hadron structure functions in a bosonized chiral quark model. We find that the Pauli-Villars regularization scheme is most suitable. We also summarize the phenomenology of structure functions calculated in the valence quark approximation.
A simulation of a business firm

This paper describes a simulation model of a hypothetical business firm. The model was constructed to include not only the accounting and economic factors of costs, profits, sales, units produced, etc., but also psychological and behavioral concepts. Individuals in the firm have aspiration levels, feel pressure, and react in accordance with behavioral theory.The purpose of the model is to study the effects of informational and organizational factors upon the decisions of a business firm. We have had limited knowledge of such variables as: the effects of tardy information, the effects of different distributions of information within the firm, the effects of differing degrees of centralization or decentralization, etc. A comprehensive model, such as the one proposed, is necessary to answer such questions.Eight specific hypotheses involving changes in the organization and information system of the firm were formulated and tested using a factorial experimental design. The results of this experiment demonstrate the usefulness of this model as a research tool.
Assembly of bacterial ribosomes.

I have not mentioned the remarkable progress made mainly by Fellner and his co-workers (86) in the elucidation of the primary structure of rRNA9s and by Wittmann and his co-workers (87) in determining the structure of several ribosomal proteins. Such knowledge of primary structures is certainly the basis of complete understanding of the structure of the ribosome. With the current progress in technology, complete elucidation of the primary structure of all the ribosomal components is probably a matter of time. As indicated in this article, a rough approximation of the three-dimensional structure of ribosomes is likely to emerge soon. Although not mentioned in this article, studies of ribosomes from higher organisms are also progressing. We must, therefore, consider what further studies should be conducted and what kinds of questions we would like to solve. Some groups of investigators aim to elucidate the complete three-dimensional structure of ribosomes and to find out how these complex cell organelles function; they hope to determine the conformational changes of many of the component molecules within the ribosome structure in response to external macromolecules and cofactors engaged in protein synthesis. Such knowledge will also be important in enabling us to understand the regulation of translation of genetic messages. Other groups of investigators aim to elucidate the complex series of events which originate in the transcription of the more than 60 genes and culminate in the formation of the specific structure of the organelle. Complete reproduction in vitro of all the assembly events that occur in vivo should not be difficult to achieve in principle. It should then become possible to study in vitro any factor regulating the biogenesis of the organelle. Although we do not know whether such studies would reveal any new fundamental principle that governs the complex circuits of interconnected macromolecular interactions, the achievement of such a complete in vitro system would represent a necessary step in the comprehensive understanding of biogenesis of organelles, and eventually, of the more complex behavior and genesis of cells (89).
Optimal Design of Research Contests

Procurement of an innovation often requires substantial effort by potential suppliers. Motivating effort may be difficult if the level of effort and quality of the resulting innovation are unverifiable, if innovators cannot benefit directly by marketing their innovations, and if the buyer cannot extract up-front payments from suppliers. We study the use of contests to procure an innovation in such an environment. An auction in which two suppliers are invited to innovate and then bid their prizes is optimal in a large class of contests. If contestants are asymmetric, it is optimal to handicap the most efficient one.
Problems with the quenched approximation in the chiral limit

In the quenched approximation, loops of the light singlet meson (the [eta][prime]) give rise to a type of chiral logarithm absent in full QCD. These logarithms are singular in the chiral limit, throwing doubt upon the utility of the quenched approximation. In previous work, I summed a class of diagrams, leading to non-analytic power dependencies such as [l angle][anti [psi]][psi][r angle] [proportional to] m[sub q][sup [minus][delta]]/(1+[delta]) I suggested, however, that these peculiar results could be redefined away. Here I give an alternative derivation of the results, based on the renormalization group, and argue that they cannot be redefined away. I discuss the evidence (or lack thereof) for such effects in numerical data.
Fairness, stewardship and sustainable development

Abstract The welfare economic concept of fairness offers an attractive, axiomatic foundation for the popular notion of stewardship. Fairness emphasizes the ex ante equal standing of all persons, across and within generations. This highlights the inextracability of poverty alleviation and environmental sustainability, especially in the agrarian tropics where biodiversity loss, deforestation and desertification are growing global concerns.
Chromosome transfer in mature oocytes.

Objective To demonstrate step-by-step micromanipulation procedures required for transfer of spindle-chromosomal complexes between mature oocytes. Design Video presentation of reproductive biology study. Setting In vitro fertilization and embryo manipulation laboratory. Animal(s) Rhesus ( Macaca mulatta ) primates. Intervention(s) Transplantation of the genetic material between mammalian oocytes offers many opportunities to study various aspects of nuclear-cytoplasmic interactions during oogenesis, fertilization and embryo development. We demonstrate the feasibility of isolation and transfer of chromosomes between mature metaphase II (MII) primate oocyte. After fertilization, manipulated oocytes were capable of producing healthy offspring or embryonic stem cells. Main Outcome Measure(s) In this video, we show micromanipulation procedures required for isolation and transfer of spindle-chromosomal complexes between rhesus MII oocytes. In brief, the spindle is visualized using a polarized microscope and extracted into a membrane enclosed karyoplast. Karyoplasts are then reintroduced into an enucleated recipient oocyte (cytoplast, derived from an another female) by karyoplast-cytoplast membrane fusion. Result(s) Newly reconstructed oocytes consist of nuclear genetic material from one female and cytoplasmic components, including mitochondria and mitochondrial DNA from another. Conclusion(s) This video demonstrates the protocol developed for primate oocytes that successfully allowed of isolation and transfer of chromosomes between mature metaphase II (MII) oocytes. Potential clinical applications include mitochondrial gene replacement therapy to prevent transmission of mtDNA mutations and treatment of infertility caused by cytoplasmic defects in oocytes. Video is available at http://fertstertforum.com/2012974tachibana/.
Scaling of a Slope: The Erosion of Tilted Landscapes

We formulate a stochastic equation to model the erosion of a surface with fixed inclination. Because the inclination imposes a preferred direction for material transport, the problem is intrinsically anisotropic. At zeroth order, the anisotropy manifests itself in a linear equation that predicts that the prefactor of the surface height-height correlations depends on direction. The first higher order nonlinear contribution from the anisotropy is studied by applying the dynamic renormalization group. Assuming an inhomogeneous distribution of soil substrate that is modeled by a source of static noise, we estimate the scaling exponents at first order in an £-expansion. These exponents also depend on direction. We compare these predictions with empirical measurements made from real landscapes and find good agreement. We propose that our anisotropic theory applies principally to small scales and that a previously proposed isotropic theory applies principally to larger scales. Lastly, by considering our model as a transport equation for a driven diffusive system, we construct scaling arguments for the size distribution of erosion "events" or "avalanches." We derive a relationship between the exponents characterizing the surface anisotropy and the avalanche size distribution, and indicate how this result may be used to interpret previous findings of power-law size distributions in real submarine avalanches.
Multiple perspectives on clinical decision support: a qualitative study of fifteen clinical and vendor organizations

Background: Computerized clinical decision support (CDS) can help hospitals to improve healthcare. However, CDS can be problematic. The purpose of this study was to discover how the views of clinical stakeholders, CDS content vendors, and EHR vendors are alike or different with respect to challenges in the development, management, and use of CDS. Methods: We conducted ethnographic fieldwork using a Rapid Assessment Process within ten clinical and five health information technology (HIT) vendor organizations. Using an inductive analytical approach, we generated themes from the clinical, content vendor, and electronic health record vendor perspectives and compared them. Results: The groups share views on the importance of appropriate manpower, careful knowledge management, CDS that fits user workflow, the need for communication among the groups, and for mutual strategizing about the future of CDS. However, views of usability, training, metrics, interoperability, product use, and legal issues differed. Recommendations for improvement include increased collaboration to address legal, manpower, and CDS sharing issues. Conclusions: The three groups share thinking about many aspects of CDS, but views differ in a number of important respects as well. Until these three groups can reach a mutual understanding of the views of the other stakeholders, and work together, CDS will not reach its potential.
Institutionalizing Ethics in Institutional Voids: Building Positive Ethical Strength to Serve Women Microfinance Borrowers in Negative Contexts

This study examines whether microfinance institutions (MFIs) that serve women borrowers at the base of the economic pyramid are likely to adopt a written code of positive organizational ethics (POE). Using econometric analysis of operational and economic data of a sample of MFIs from across the world, we find that two contextual factors—poverty level and lack of women’s empowerment—moderate the influence of an MFI’s percentage of women borrowers on the probability of the MFI having a POE code. MFIs that serve more women borrowers are more likely to adopt a POE code, especially in negative contexts (where women borrowers face poverty and disempowerment and are therefore susceptible to abuse). This study provides evidence that MFIs can build positive ethical strength in negative contexts.
Oxidation and hydrolysis of tris-tert-butylgallium

Abstract The oxidation of GaBu3t with oxygen leads to the formation of [Bu3tGa(μ-OOBut)]2 (1). The thermolysis of 1 yields the alkoxide complex [Bu2tGa(μ-OBut)]2 (2), which may also be prepared directly from GaBu3t and ButOH. The reaction of [ButGaCl(μ-Cl)]2 (3) with oxygen does not result in its oxidation, but may be used in its purification due to the oxidation of the GaBu3t impurities. The hydrolysis of GaBu3t in thf solution, in which it exists as the solvated complex 4, results in the formation of the monomeric hydroxide complex Bu2tGa(OH)(thf) (5). In contrast, the use of non-coordinating solvents results in the trimeric hydroxide [Bu2tGa(μ-OH)]3 (6). Compound 6 is also isolated from the reaction of Bu2tGaCl(thf) (7) with KOH in refluxing thf. The solid state pyrolysis of 6 gives the polymeric oxide [ButGa(O)]x (8). All the compounds have been characterized by NMR, IR and mass spectroscopy, while the structures of 1, 2 and 3 have been confirmed by X-ray crystallography. Compound 1 crystallizes in the monoclinic space group C2/m with a = 16.375(2), b = 11.323(2), c = 8.895(2) A and β = 116.710(12)°, Z = 2, R = 0.042 and Rw, = 0.038. Compound 2 crystallizes in the orthorhombic space group Pbca with a = 15.0072(17), b = 9.8399(8), c = 18.3840(15) A, Z = 4, R = 0.037 and Rw = 0.041. Compound 3 crystallizes in the monoclinic space group P21/c with a = 6.816(4), b = 6.743(5), c = 17.062(10)A and β = 95.87(4)°, Z = 2, R = 0.042, Rw = 0.049.
Exploring the unique reactivity of diazoesters: an efficient approach to chiral β-amino acids.

The development of a highly stereospecific process for the C–O to C–N exchange with retention of configuration is described. This transformation enables access to optically enriched β-amido-α-diazoesters. These products are transformed to β-amino acids not readily accessible using known methods.
Interference Problems for Nongeostationary Satellites

The interference problems faced by nongeostationary satellites may be of major significance. A general discussion indicates the scope of the problems and describes several configurations of importance. Computer programs are described, which are employed by NASA/JPL and the U.S. Air Force Satellite Control Facility to provide interference-free scheduling of commands and data transmission. Satellite system mission planners are not concerned with the precise prediction of interference episodes, but rather with the expected total amount of interference, the mean and maximum duration of events, and the mean spacing between episodes. The procedures in the theory of probability developed by the author which permit calculation of such quantities are described and applied to several real cases. It may be anticipated that the problems will become steadily worse in the future as more and more data transmissions attempt to occupy the same frequency band.
Multidomain spectral solutions of high-speed flows over blunt cones

A shock-fitted multidomain spectral collocation method is used to solve steady inviscid supersonic flows over two blunt, axisymmetric cones. The calculations are compared to a conical flow solution and to experimental data
Profit Possibilities in Currency Markets: Arbitrage, Hedging, and Speculation

This paper reviews and extends the existing literature on covered arbitrage, delineates the conditions for profitable arbitrage with the hedging instruments of forward and options contracts in the foreign exchange markets, and defines the maximum possible profits out of a given market environment. Next, the simple rules on speculation are articulated with and without transaction costs, and then we show how speculation can be covered with options and forwards. Finally, speculation is integrated with arbitrage and hedging, and further compounding of profit possibilities is illustrated.
Interpretation of the lunar gravitational field

Abstract The most significant inference from the gravitational field is that the isostatic compensation of the highlands requires a thorough fractionation of at least one-third of the Moon's mass. The Apollo samples and other recent data make creation of the mascons by surface transfer processes much less plausible, leave their creation by infalling denser bodies speculative, and make more acceptable to disciples of William of Occam their creation by processes internal to the Moon. A Moon which experienced drastic fractionation of its outer parts and then a billion years later has volcanism is certainly one which would have a thermal history where the outer parts cooled relative to the inner. The interpretation of magnetometry near and on the Moon is still sufficiently unsure that broad variations in the gravitational field could be caused by convection in the Moon's core. The orientation of the maria toward the Earth might be caused by tidal effects when the Moon was a few Earth radii from the Earth, but the mechanism of such effects depends upon how the Moon's orbit was modified by infalling bodies from outside the Earth-Moon system.
Multi-Component Extracellular Matrices Based on Peptide Self-Assembly

Extracellular matrices (ECMs) are challenging design targets for materials synthesis because they serve multiple biological roles, and they are composed of multiple molecular constituents. In addition, their composition and activities are dynamic and variable between tissues, and they are difficult to study mechanistically in physiological contexts. Nevertheless, the design of synthetic ECMs is a central consideration in applications such as regenerative medicine and 3D cell culture. In order to produce synthetic matrices having both multi-component construction and high levels of compositional definition, strategies based on molecular self-assembly are receiving increasing interest. These approaches are described in this tutorial review and compared with the structures and processes in native ECMs that serve as their inspiration.
A cycloaddition approach to breynolide

Abstract A novel approach to the functionalized hydrobenzothiophene subunit of the sesquiterpene breynolide (3) has been developed. The sequence features the Diels-Alder reaction of the vinyl sulfones 12 and 13 with the Danishefsky diene 9 to give the cycloadducts 14 and 16 as the major products. Reduction of the sulfone moieties of 14 and 16 gave the sulfides 20 and 21, respectively. Subsequent dipolar cycloaddition of 20 and 21 with a functionalized nitrile oxide gave the corresponding adducts 24 and 25, which possess functionality suitable for elaboration into breynolide (3).
A Bioeconomic Model of the Pacific Whiting

The Pacific whiting (Merluccius productus) is a highly migratory fish occupying the continental shelf and slope off the west coast of North America. The species spawns in January off southern California and northern Mexico. During spring and summer the older and larger fish will migrate as far north as central Vancouver Island. Recruitment is highlys variable, with strong year classes often supporting the commercial fishery during several years of low recruitment. The level of recruitment appears to be independent of the size of the spawning population.
High-Temperature Measurements of Q-Factor in Rotated X-Cut Quartz Resonators

The Q-factors of piezoelectric resonators fabricated from natural and synthetic quartz with a 34° rotated X-cut orientation have been measured at temperatures up to 325°C. The synthetic material, which was purified by electrolysis, retains a high enough Q to be suitable for high-temperature pressure-transducer applications, whereas the natural quartz is excessively lossy above ~200°C application. The present results are compared to results obtained previously at AT-cut resonators.
Ultra-relativistic geometrical shock dynamics and vorticity

Geometrical shock dynamics, also called CCW theory, yields approximate equations for shock propagation in which only the conditions at the shock appear explicitly; the post-shock flow is presumed approximately uniform and enters implicitly via a Riemann invariant. The non-relativistic theory, formulated by G. B. Whitham and others, matches many experimental results surprisingly well. Motivated by astrophysical applications, we adapt the theory to ultra-relativistic shocks advancing into an ideal fluid whose pressure is negligible ahead of the shock, but is one third of its proper energy density behind the shock. Exact results are recovered for some self-similar cylindrical and spherical shocks with power-law pre-shock density profiles. Comparison is made with numerical solutions of the full hydrodynamic equations. We review relativistic vorticity and circulation. In an ultra-relativistic ideal fluid, circulation can be defined so that it changes only at shocks, notwithstanding entropy gradients in smooth parts of the flow.
Economic Reform, Structural Adjustment and Female Labor Force Participation in Buenos Aires, Argentina

Abstract Female labor force participation (LFP) has recently increased in the Metropolitan Area of Buenos Aires in a remarkable way. This increase has been a result neither of improvements in the conditions of labor supply nor due to the diversification of the structure of occupational opportunities available for women. Using cross-sectional and panel data I show that most of the growth in female LFP can be explained as a response to increasing unemployment and job instability associated with the implementation of structural adjustment policies since 1991. I argue that more women have decided to look for work as a way to reduce households’ economic uncertainty.
Molecular Hydrogen in Infrared Cirrus

We combine data from our recent FUSE survey of interstellar molecular hydrogen absorption toward 50 high-latitude AGNs with COBE-corrected IRAS 100 ?m emission maps to study the correlation of infrared cirrus with H2. A plot of the H2 column density versus IR cirrus intensity shows the same transition in molecular fraction, f, as seen with total hydrogen column density, NH. This transition is usually attributed to H2 self-shielding, and it suggests that many diffuse cirrus clouds contain H2 in significant fractions, f ? 1%-30%. These clouds cover ~50% of the northern sky at b > 30?, at temperature-corrected 100 ?m intensities D ? 1.5 MJy sr-1. The sheetlike cirrus clouds, with hydrogen densities nH ? 30 cm-3, may be compressed by dynamical processes at the disk-halo interface, and they are conducive to H2 formation on grain surfaces. Exploiting the correlation between N and 100 ?m intensity, we estimate that cirrus clouds at b > 30? contain ~3000 M? in H2. Extrapolated over the inner Milky Way, the cirrus may contain 107 M? of H2 and 108 M? in total gas mass. If elevated to 100 pc, their gravitational potential energy is ~1053 ergs.
Application of Turbulence Model Equations to Axisymmetric Wakes

The second-order invariant modeling technique for turbulent flows as developed by Donaldson is applied to axisymmetric wakes. All empirical model parameters are chosen from data on jets and shear layers leaving the wake completely determined as a function of initial conditions. Model predictions for the mean velocity distribution and the distributions of the four components of the second-order stress tensor are verified by comparison with the experimental observations of Chevray for a wake with significant mean momentum and Naudascher for the wake behind a self-propelled body. Nomenclature a, b = model constants defined in Eq. (12) D = diameter of the generating body M = normalized momentum defect in the wake, see Eq. (15) p = pressure q = square root of twice the turbulent kinetic energy per unit mass r = radial coordinate r* = radius at which 1/2 reaches one half its maximum
Projected U.S. Demographics and Social Security

Abstract Without policy reforms, the aging of the U.S. population is likely to increase the burden of the currently unfunded Social Security and Medicare systems. In this paper we build an applied general equilibrium model and incorporate the population projections made by the Social Security Administration (SSA) to evaluate the macroeconomic and welfare implications of alternative fiscal responses to the retirement of the baby-boomers. Our calculations suggest that it will be costly to maintain the benefits at the levels now promised because the increases in distortionary taxes required to finance those benefits will reduce private saving and labor supply. We also find that the “accounting calculations” made by the SSA underestimate the required fiscal adjustments. Finally, our results confirm that policies with similar long-run characteristics have very different transitional implications for the distribution of welfare across generations. Journal of Economic Literature Classification Numbers: D52, D58, E21, E62.
Chronic femoral artery occlusion augments exercise pressor reflex in decerebrated rats

In decerebrated rats, we determined the pressor and cardioaccelerator reflex responses to static contraction of hindlimb muscles whose femoral arteries were either occluded 72 h before contraction,...
Concerning the reaction of (η5-1-methoxycarbonylpentadienyl)(tricarbonyl)iron(+1) with malonate anion: a structural correction

The title reaction was originally reported to afford the E,Z-η4-diene complex. Reexamination of the spectral data and decomplexation of the ligand indicates that the product is a σ-π-allyl complex.
Hopping expansion as a tool for handling dual variables in lattice models

Abstract The hopping expansion of 8-vertex models in their Grassmann representation is studied. We use the functional similarity of the Ising model in this expansion with the hopping expansion of 2-D Wilson fermions to show that the lattice fermions are equivalent to the Self-avoiding Loop Model at bending rigidity .
Capillary wave scattering from a surfactant domain

The study of capillary wave scattering by a circular region with different interfacial properties from the rest of an otherwise homogeneous interface is motivated by experiments on wave attenuation at a monolayer‐covered air–water interface where domains of one surface phase are dispersed in a second surface phase. Here the scattering function is calculated for an incident wave of frequency ω (wavevector k0) scattering from an isolated circular domain of radius a with surface tension σ1 which is imbedded in an otherwise infinite interface of surface tension σ0. The underlying fluid is treated as irrotational and the three‐dimensional flow problem coupling the heterogeneous surface to the underlying liquid is reduced to a set of dual integral equations, which are solved numerically. With this solution the scattering amplitudes and the total scattering cross sections are calculated as a function of the surface tension ratio σ0/σ1 and incident wavenumber k0a. The analogous problem of a discontinuous change i...
Photochemical Transformation of Aqueous C60 Clusters in Sunlight

C60 is emerging in a variety of potential applications; however, its environmental fate remains largely unknown. Photochemical transformation may be an important fate process of C60 in the aquatic environment due to its strong light absorption within the solar spectrum. In this study, the photochemical transformation of aqueous C60 clusters (nC60) in sunlight (West Lafayette, IN, 86° 55′ W, 40° 26′ N) and in lamp light (300−400 nm wavelengths) was investigated. When exposed to light, the brown to yellow color of nC60 was lost gradually, and the cluster size decreased as the irradiation time increased. TOC analysis on the water phase of centrifuged samples indicated that water soluble products formed and that with continued light exposure, these intermediates eventually mineralized, volatilized, or were converted to other products not quantified by TOC after centrifugation and filtration. In sunlight at ∼1 mg/L C60, the decay rate of C60 in small clusters (diameter = 150 nm) was greater than for C60 in lar...
Gaugomaly mediation revisited

Most generic models of hidden sector supersymmetry breaking do not feature singlets, and gauginos obtain masses from anomaly mediated supersymmetry breaking. If one desires a natural model, then the dominant contribution to scalar masses should be of the same order, i.e. also from AMSB. However, pure AMSB models suffer from the tachyonic slepton problem. Moreover, there is a large splitting between the gluino and the wino LSP masses resulting in tight exclusion limits from typical superpartner searches. We introduce messenger fields into this framework to obtain a hybrid theory of gauge and anomaly mediation, solving both problems simultaneously. Specifically, we find any number of vector-like messenger fields (allowed by GUT unification) compress the predicted gaugino spectrum when their masses come from the Giudice-Masiero mechanism. This more compressed spectrum is less constrained by LHC searches and allows for lighter gluinos. In addition to the model, we present gaugino pole mass equations that differ from (and correct) the original literature.
Multiplex CARS temperature measurements in a coal-fired MHD environment

Multiplex coherent anti-Stokes Raman spectra (CARS) of nitrogen were recorded in an environment that simulates the postmagnet gas stream of a coal-fired MHD generator. The presence of coal fly ash and potassium seed created a weakly ionized, highly luminous medium with a high number density of relatively large (1–50-μm) diam particles. Maximum temperatures of 2500 K were measured with a spatial resolution of 5 mm. The precision optical alignment necessary for folded BOXCARS phase-matching was maintained for the long distances (>10 m) necessary to route the laser beams from the CARS instrument to the combustion facility. The increased luminosity caused by injection of potassium seed did not impede the recovery of good quality spectra. The coal fly ash particles precipitated laser-induced breakdown, which, in turn, led to the generation of a coherent interference with N2 spectra. Techniques to overcome this problem are discussed. A nonlinear least-squares fitting computer program was used to examine systematically the error in inferred temperatures caused by uncertainties in the parameters used in the Kataoka-Teets algorithm employed to reduce the data. The accuracy of the temperature measurements is estimated to be ±3%.
The Energy Return on Investment for Algal Biocrude: Results for a Research Production Facility

This study is an experimental determination of the energy return on investment (EROI) for algal biocrude production at a research facility at the University of Texas at Austin (UT). During the period of this assessment, algae were grown at several cultivation scales and processed using centrifugation for harvesting, electromechanical cell lysing, and a microporous hollow fiber membrane contactor for lipid separation. The separated algal lipids represent a biocrude product that could be refined into fuel and the post-extraction biomass could be converted to methane. To determine the EROI, a second-order analysis was conducted, which includes direct and indirect energy flows, but does not include energy expenses associated with capital investments. The EROI for the production process evaluated here was significantly less than 1, however, the majority of the energy consumption resulted from non-optimized growth conditions. While the experimental results do not represent an expected typical case EROI for algal fuels, the approach and end-to-end experimental determination of the different inputs and outputs provides a useful outline of the important parameters to consider in such an analysis. The Experimental Case results are the first known experimental energy balance for an integrated algal biocrude production facility, and as such, are expected to be helpful for setting research and development priorities. In addition to the Experimental Case (based on direct measurements), three analytical cases were considered in this work: (1) a Reduced (Inputs) Case, (2) a Highly Productive Case, and (3) a Literature Model. The Reduced (Inputs) Case and the Highly Productive Case speculate the energy use for a similar system in an improved, commercial-scale production setting. The Literature Model is populated with relevant data that have previously been reported in the literature. For the Experimental Case, Reduced Case, Highly Productive Case, and Literature Model, the estimated second-order EROI was 9.2 × 10−4, 0.074, 0.22, and 0.35, respectively. These results were dominated by growth inputs (96%, 89%, 87%, and 61% of the total energy requirement, respectively). Furthermore, the EROI was adjusted using quality factors that were calculated according to the price of each input, yielding a quality-adjusted EROI that parallels a partial financial return on investment analysis. For the Experimental Case, the Reduced Case, and the Highly Productive Case, the quality-adjusted EROI was 9.2 × 10−5, 0.013, and 0.36, respectively.
Atomizer: A dynamic atomicity checker for multithreaded programs

Ensuring the correctness of multithreaded programs is difficult, due to the potential for unexpected interactions between concurrent threads. Much previous work has focused on detecting race conditions, but the absence of race conditions does not by itself prevent undesired interactions between threads. A more fundamental noninterference property is atomicity. A method is atomic if its execution is not affected by and does not interfere with concurrently-executing threads. Atomic methods can be understood according to their sequential semantics, which significantly simplifies both formal and informal correctness arguments. This paper presents a dynamic analysis for detecting atomicity violations. This analysis combines ideas from both Lipton's theory of reduction and earlier dynamic race detectors. Experience with a prototype checker for multithreaded Java code demonstrates that this approach is effective for detecting errors due to unintended interactions between threads. In particular, our atomicity checker detects errors that would be missed by standard race detectors. Our experimental results also indicate that the majority of methods in our benchmarks are atomic, indicating that atomicity is a standard methodology in multithreaded programming.
Kinematic orbits and the structure of the internal space for systems of five or more bodies

The internal space for a molecule, atom, or other n -body system can be conveniently parametrized by 3n -9 kinematic angles and three kinematic invariants. For a fixed set of kinematic invariants, the kinematic angles parametrize a subspace, called a kinematic orbit, of the n -body internal space. Building on an earlier analysis of the three- and four-body problems, we derive the form of these kinematic orbits (that is, their topology) for the general n -body problem. The case n = 5 is studied in detail, along with the previously studied cases n = 3,4.
Some methods for structural analysis

Abstract Solutions based on fundamental aspects of beam theory are used for establishing some new methods in the structural analysis of continuous beams and frames. New slope - deflection equations are given which represent an improvement over the conventional slope - deflection method. A method using end moments and deflections as primary quantities is presented as an alternative procedure to the slope - deflection method. This alternative method is referred to as the moment - or curvature - deflection method. The method and some results based on the alternative procedure are compared with the slope - deflection method through illustrative examples. A third procedure of using Fourier series in conjunction with the Stokes' transformation is discussed. The Stokes' transformation procedure suggests that the choice of end curvatures and deflections as primary quantities used in the moment - deflection method is more natural than choosing the end slopes and deflections.
Scattering Theory for Conformally Compact Metrics with Variable Curvature at Infinity

Abstract We develop the scattering theory of a general conformally compact metric by treating the Laplacian as a degenerate elliptic operator (with non-constant indicial roots) on a compact manifold with boundary. Variability of the roots implies that the resolvent admits only a partial meromorphic continuation, and the bulk of the paper is devoted to studying the structure of the resolvent, Poisson, and scattering kernels for frequencies outside the region of meromorphy. For low frequencies the scattering matrix is shown to be a pseudodifferential operator with frequency dependent domain. In particular, generalized eigenfunctions exhibit L 2 decay in directions where the asymptotic curvature is sufficiently negative. We explicitly construct the resolvent kernel for generic frequency in this part of the continuous spectrum.
String theory duals of Lifshitz–Chern–Simons gauge theories

We propose candidate gravity duals for a class of non-Abelian z = 2 Lifshitz Chern–Simons (LCS) gauge theories studied by Mulligan, Kachru and Nayak. These are nonrelativistic gauge theories in 2+1 dimensions in which parity and time-reversal symmetries are explicitly broken by the presence of a Chern–Simons term. We show that these field theories can be realized as deformations of DLCQ super Yang–Mills theory. Using the holographic dictionary, we identify the bulk fields of type IIB supergravity that are dual to these deformations. The geometries describing the groundstates of the non-Abelian LCS gauge theories realized here exhibit a mass gap.
House Prices and the Structure of Local Government: An Application of Spatial Statistics

When two internally homogeneous communities decide to jointly provide a public service, residents of each community lose some control over the public service provision. The loss of control over public schooling provision contributes to a $2,929 or 3.5 percent drop in constant-quality house value. Increased heterogeneity of the consolidated district is responsible for almost all the drop; the increased number of service recipients alone is responsible for almost none of the drop. The spatial hedonic, corrected for sample selection bias, also suggests economies of scale gains from school district consolidation must be worth at least $3,369—4 percent of house value.
Dielectrophoretic Microweaving: Biofabrication of Aligned Bacterial Nanocellulose for Regenerative Medicine

The use of natural and synthetic polymers as scaffolding material for regenerative medicine is far from clinical translation for most tissue applications. This is due primarily to lack of manufacturing control over mechanical properties and 3D architecture which promote cell attachment and proliferation. Cellulose, a natural polymer produced by the majority of plants, can be assembled into nanofibrils by bacteria. The advantage of bacterial cellulose is that it has unique biocompatibility, mechanical integrity, hydroexpansivity, and is stable under a wide range of conditions [1]. It is thus ideal as a scaffolding material on which to seed cells for regenerative medicine applications. The bacteria Acetobacter Xylinum produces nanoscale cellulose ribbons at an average rate of 2μm/min [2].Copyright © 2009 by ASME
Debromination of 4-Bromo-3-arylsydnones with Sodium Sulfite

Abstract 4-Bromo-3-arylsydnones 1 are denominated to the corresponding 3-arylsydnones 2 in good to excellent yield using sodium sulfite in methanol/water. In contrast to previously employed reagents, the reduction is successful in the presence of electron-donating, electron- withdrawing and bulky groups.
Quantum mechanics on a noncommutative brane in M(atrix) theory

Abstract We consider the quantum mechanics of a particle on a noncommutative two-sphere with the coordinates obeying an SU(2)-algebra. The momentum operator can be constructed in terms of an SU(2)×SU(2)-extension and the Heisenberg algebra recovered in the smooth manifold limit. Similar considerations apply to the more general SU(n) case.
Rapid Entry into the Cryptophycin Core via an Acyl-β-lactam Macrolactonization: Total Synthesis of Cryptophycin-24

An efficient, concise approach to the macrolide core of the cryptophycins, potent antimitotic agents, has been achieved. The reaction sequence features a novel macrolactonization utilizing a reactive acyl-β-lactam intermediate that incorporates the β-amino acid moiety within the 16-membered macrolide core. This highly modular approach, which allows for multiple alterations throughout the structure, was successfully applied to the total synthesis of cryptophycin-24.
Animals in War: Commemoration, Patriotism, Death

Patriotism poses a threat, not just to democracy but also to life itself. It finds expression in a new species of civic memorial dedicated to animals. In wartime, the animal world, including dogs, ...