cssi/SciSciGPT-SciSciNet huggingface dataset:
Building string field theory around non-conformal backgrounds☆

Abstract The main limitations of string field theory arise because its present formulation requires a background representing a classical solution, a background defined by a strictly conformally invariant theory. Here we sketch a construction for a gauge-invariant string field action around non-conformal backgrounds. The construction makes no reference to any conformal theory. Its two-dimensional field-theoretic aspect is based on a generalized BRST operator satisfying a set of Weyl descent equations. Its geometric aspect uses a complex of moduli spaces of two-dimensional Riemannian manifolds having ordinary punctures, and organized by the number of special punctures which goes from zero to infinity. In this complex there is a Batalin-Vilkovisky algebra that includes naturally the operator which adds one special puncture. We obtain a classical field equation that appears to relax the condition of conformal invariance usually taken to define classical string backgrounds.
A deterministic forcing scheme for direct numerical simulations of turbulence

Abstract Direct numerical simulations of statistically-stationary homogeneous isotropic turbulence require an artificial input of energy via a forcing scheme. Previous forcing methods based on a stochastic addition of energy have resulted in a poor representation of the energy-containing range of the energy spectrum function and significant temporal fluctuations of energy and other large-scale quantities. In this work a deterministic forcing scheme for direct numerical simulation is developed which uses wave number-dependent linear amplification of the lower-wave number modes, relaxing them over time toward a model energy spectrum function, which accurately represents grid turbulence. The scheme is shown to be robust and computationally efficient, resulting in velocity and scalar fields which quickly reach stationarity. It also has the significant advantages over stochastic forcing methods of not introducing additional statistical variability into the computations and allowing more physically realistic large-scale motions.
The devil is in the details: Compact structures in pulsar wind nebulae

Abstract The large-scale structure of pulsar wind nebulae (PWNe) tells us a considerable amount about their average magnetic fields, the total particle input from the pulsar winds, and the confining pressure at their outer boundaries. However, the details of the pulsar outflow, the sites of shocks and particle acceleration, the effects of instabilities in the magnetic field, and the interaction between the relativistic wind and the surrounding ejecta are contained in small-scale structures, where we observe jets and toroidal structures, time-varying emission from compact clumps, and filaments in both the inner and outer regions of the nebulae. Here, I review recent observational studies of compact structures in PWNe and present current scenarios (and questions) regarding their origin.
Two New X-Ray/Optical/Radio Supernova Remnants in M31

We compare a deep (37 ks) Chandra ACIS-S image of the M31 bulge to Local Group Survey narrowband optical data and Very Large Array (VLA) radio data of the same region. Our precisely registered images reveal two new optical shells with X-ray counterparts. These shells have sizes, [S ]/Hα flux ratios, and X-ray spectral properties typical of supernova remnants (SNRs) with ages of 9 and 17 kyr. Analysis of complementary VLA data reveals the radio counterparts, further confirming that they are SNRs. We discuss and compare the properties and morphologies of these SNRs at the different wavelengths.
Particle-confinement criteria for axisymmetric field-reversed magnetic configurations

Based on two constants of motion, H and Pθ, where H is the total energy of a particle and Pθ is its canonical angular momentum, particle confinement criteria are derived which impose constraints on H and Pθ. With no electric field at the ends of field-reversed magnetic configurations, confinement criteria for closed-field and absolute confinements are obtained explicitly, including both lower and upper bounds of Pθ/q, where q is the charge of the species considered, for a class of Hill's vortex field-reversed magnetic configurations. The commonly used criterion for the Hamiltonian, H < −ω0Pθ, where ω0 ≡ qB0/mc, is deduced from a more general form as a special case. In this special case, it is found necessary to impose a new criterion, , where Rw is the wall radius and B0 is the vacuum field, which reduces the confinement region in (H, Pθ) space. With the presence of electric fields at the ends of field-reversed magnetic configurations, confinement criteria are obtained for two interesting cases. In addition to lower and upper bounds of H, both lower and upper bounds of Pθ/q are found. For axially confined particles, the lower bound of Pθ/q reduces the confinement region in (H, Pθ) space and represents a new criterion. These results can be applied to calculations for field-reversed mirrors and field-reversed theta pinches.
Signal characteristics of tumors shown by high‐resolution endorectal coil magnetic resonance imaging may predict outcome among patients with cervical carcinoma treated with irradiation: A preliminary study

Background The purpose of this study was to evaluate the role of high-resolution magnetic resonance imaging with the endorectal coil (eMRI) in the management of cervical carcinoma treated with definitive irradiation. Methods Eighteen patients with invasive cervical carcinoma (International Federation of Gynecology and Obstetrics Stages Ib-IIIb) consented to evaluation with eMRI on a 1.5 tesla system with high resolution (400 x 400 microM). Images were read to provide staging information and to grade the signal characteristics of the individual tumors as low (dark), intermediate, or high (bright) relative to surrounding isointense fat. Patients were treated with standard megavoltage irradiation (prescribed dose, 80-85 Gray); shaped antero-posterior/postero-anterior or 4-field box techniques, plus brachytherapy, were used. Results In 39% of patients, tumors were determined to be in a higher stage by eMRI because of proximal vaginal involvement (n = 4) or the combination of proximal vaginal involvement and parametrial extension (n = 3). Features predictive of improved local control and survival without evidence of disease included stage, hemoglobin levels > or = 11, complete response to external irradiation, and bright signal characteristics. Compared with those who had dark and/or intermediate tumors, patients who had tumors with bright signal characteristics tended to present with earlier stage disease, were less likely to have anemia, and were more likely to have complete response to external irradiation. Conclusions Prognostic information for clinical staging of cervical carcinoma was contributed by eMRI. The technique was more likely to suggest proximal vaginal involvement by a tumor than was examination under anesthesia. Signal characteristics of tumors may provide valuable predictive information that is supplementary to conventional discriminants of outcome that follow definitive irradiation. Such information could allow physicians to tailor treatment (e.g., by the addition of radiation sensitizers) at an earlier point in disease management.
Scalar mediated FCNC at the first muon collider

Abstract In the most general two-Higgs doublet model (generally referred to as Model III), tree level scalar-mediated flavor changing neutral couplings exist. It has been noted that the most natural value for such a coupling is of the order of the geometric mean of the Yukawa couplings of the two fermions. Bounds on those couplings that involve the second and third generations, from τ,B,D and μ physics, are very weak and are not sensitive to this “natural” value. In this paper, it is pointed out that the process μ+μ−→μτ, at a muon collider tuned to the scalar resonance, will easily reach this sensitivity if the scalar mass is below 140 GeV. Hundreds of events are expected for an integrated luminosity of an inverse femtobarn, and there appears to be no background. Failure to observe this process, if the scalar is below 140 GeV, would effectively rule out Model III.
Preparation of Diamines of Adamantane and Diamantane from the Diazides

Abstract A novel synthetic method for preparing diaminodiamondoids from diazidodiamondoids starting from the hydrocarbons is described.
Protocol analysis as a task for artificial intelligence

Abstract We are attempting to automate protocol analysis, which is a form of data analysis in psychology for inferring the information processes used by a human from his verbal behavior while solving a problem. The paper discusses protocol analysis as a task in artificial intelligence. The discussion is based on (but broader than) our current program, PAS-I, which creates a description of a subject's changing knowledge state from his verbal behavior.
Global Kinematics for Manipulator Planning and Control

This paper reviews one method of global kinematic analysis, based on a manifold mapping reformulation of manipulator kinematics, which is suitable for both non-redundant and redundant serial chain manipulators. Two applications of this approach are considered: the relationship between changing pose and singularities for non-redundant manipulators and the homotopy class of redundant manipulator self-motions. The first relationship has important implications for non-redundant manipulator regrasping operations. Variations in redundant manipulator self-motion homotopy can have an important effect on motion and redundancy resolution planning, since they can lead to algorithmic singularities and unexpected loss of manipulator capabilities.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Particle characteristics from the spectra of polar mesospheric clouds

[1] Spectrographic imagers on the Midcourse Space Experiment (MSX) satellite have obtained the first spectra of polar mesospheric clouds (PMCs) from the far ultraviolet to the visible (164–585 nm). Several hundred PMC spectra were extracted over a 3 week period during the summer of 1999. To improve statistics, the spectra were normalized and averaged within 32 groups of clouds having common latitudes and scattering angles. The subsequent spectra, from three spectrographic imagers, produced a PMC signal that fell into the noise at wavelengths short of 200 nm and showed Earth albedo effects longward of ∼315 nm. The spectra between these limiting wavelengths were subjected to a least squares analysis to determine characteristics of the scattering particles assuming a lognormal distribution of Mie scatterers made of ice. Averaged over all PMCs, the distribution mode (size) was 65.2 ± 2.2 nm and the distribution dispersion (width) was 1.15 ± 0.04. Over the period of observation, neither the mode nor the dispersion exhibited systematic variations in time or latitude, although less intense clouds at lower latitudes may have been undersampled.
New Perspectives on Adoption Revelation.

†The Editor gratefully acknowledges the kind permission of the Author and the Editor of Adoption and Fostering to reproduce this paper. Professor Brodzinsky's paper first appeared in 1984 in Vol.8, No. 2 of Adoption and Fostering, the Quarterly Journal of British Agencies for Adoption and Fostering.
Systems analysis as a technique for solving social problems—a realistic overview

Abstract Drawing on case materials from completed and ongoing systems analyses, this paper presents an empirical assessment of the current and growing trend toward the utilization of this and related quantitative techniques, such as cost/benefit measures and program budgeting, in social planning. The first section is devoted to examination of the bases for and assumptions underlying the general acceptance and ubiquitous application of the systems approach; the second deals with the concepts of systems analysis and related techniques; and the third with that technique throught which systems management capability is transferred from the private to the public sector. The final section contains a critical appraisal of systems techniques as currently applied to social problems.
Pyroelectric Heat-Transfer Sensors for Hypersonic Impulse Facilities

The results obtained in recent tests conducted to compare the performance of pyroelectric heat-transfer sensors to that of thin-skin thermocouple heat-transfer sensors are presented. These results show that under conditions of clean flow and low heating rates there is excellent agreement between the two types of sensors. In a severe environment such as small particles in the flow and high heating rates, the results agree less closely. Techniques to reduce the difference between the heat-transfer rates indicated by the sensors when operating in a severe environment are presented. Installation and calibration procedures for the pyroelectric sensors are discussed. A relative performance comparison of the pyroelectric, thin-skin thermocouple, and platinum resistance thermometer heat-transfer sensors shows that the pyroelectric sensor is superior to the others in sensitivity, minimum size, and ease of data reduction and that it is comparable in durability, accuracy, and vibration susceptibility. The comparison shows the limitations of the pyroelectric sensors include a need for a dynamic calibration, limited operating temperature range, and short test times.
Progress towards a theory of jet-flap thrust recovery

Abstract : A combination of analysis and testing has been utilized to develop a theory of jet flap thrust recovery at the low speeds and large deflection angles characteristic of V/STOL lift systems. The contribution of jet drag to the reduction in recovery has been computed with a viscid/inviscid interaction analysis. The results of this computation are compared to wake survey and airfoil surface pressure measurements made with a two-dimensional jet flapped airfoil model. The thrust recovery is nearly complete for small values of the jet deflection angle, but for larger angles, the recovery decreases as the thrust coefficient increases. It is concluded that the loss of recovery is due to the jet drag for values of the thrust coefficient less than unity; for larger values, the loss is increased by flow separation from the airfoil. (Author)
Graphene oxide as an electrophile for carbon nucleophiles

The covalent, surface functionalization of graphene oxide with the malononitrile anion has been demonstrated. Once installed, these surface-bound “molecular lynchpins” can be chemically modified to increase the solubility of the graphene derivative in either organic or aqueous environments.
Stationary Navier–Stokes equations with critically singular external forces: Existence and stability results

Abstract We show the unique existence of solutions to stationary Navier–Stokes equations with small singular external forces belonging to a critical space. To the best of our knowledge, this is the largest critical space that is available up until now for this kind of existence. This result can be viewed as the stationary counterpart of the existence result obtained by H. Koch and D. Tataru for the free non-stationary Navier–Stokes equations with initial data in BMO − 1 . The stability of the stationary solutions in such spaces is also obtained by a series of sharp estimates for resolvents of a singularly perturbed operator and the corresponding semigroup.
An "anti-Baldwin" 3-exo-dig cyclization: preparation of vinylidene cyclopropanes from electron-poor alkenes.

Stabilized carbanions undergo an uncommon 3-exodig cyclization onto propargyl halides through an SN2′ substitution. Propargyl iodides as electrophiles are necessary to achieve good yields (36−95%) for most substrates, although the usefulness of chlorides and bromides is documented. A variety of monocyclic and bicyclic vinylidene cyclopropanes can be prepared. These products are not available by standard carbene methodology.
An evaluation tool for measuring authoring system performance

A MODEL FOR PRODUCING OBJECTIVE and precise measurements of the power and performance of authoring systems is described. An animation task is given as an example of the model’s potential as a tool for evaluating authoring systems along the dimensions of functionality, flexibility, and productivity.
Solution of the Moving Mass Problem Using Complex Eigenfunction Expansions

A new solution technique is developed for solving the moving mass problem for nonconservative, linear, distributed parameter systems using complex eigenfunction expansions. Traditional Galerkin analysis of this problem using complex eigenfunctions fails in the limit of large numbers of trial functions because complex eigenfunctions are not linearly independent. This linear dependence problem is circumvented by applying a modal constraint on the velocity of the distributed parameter system (Renshaw, A. A., 1997, J. Appl. Mech., 64, pp. 238-240). This constraint is valid for all complete sets of eigenfunctions but must be applied with care for finite dimensional approximations of concentrated loads such as found in the moving mass problem. Numerical results indicate that the proposed method is competitive with Galerkin's method with real trial functions in terms of accuracy and rate of convergence.
Urea-catalyzed N-H insertion-arylation reactions of nitrodiazoesters.

The power of hydrogen-bond donor catalysis has been harnessed to elicit and control carbene-like reactivity from nitrodiazoesters. Specifically, select ureas have been identified as effective catalysts for N–H insertion and multicomponent coupling reactions of nitrodiazoesters, anilines, and aromatic nucleophiles, thereby preparing a variety of α-aryl glycines in high yield. Experimental and computational studies designed to probe the plausible reaction pathways suggest that difluoroboronate ureas are particularly well-suited to catalyze reactions of nitrodiazoesters with a range of anilines through a polar reaction pathway. Urea-facilitated loss of nitrite followed by addition of a nucleophile conceivably generates the observed aryl glycine products.
Trade and Turnover: Theory and Evidence

Is the pattern of trade correlated with cross-sector differences in job turnover? Theoretically, external shocks feed through to changes in domestic employment and cross-sector differences in turnover give rise to compensating wage differentials, which feed through to output prices. Using two different datasets on turnover, we find strong evidence that normalized US net exports by sector are negatively correlated with job destruction and worker separation rates. Weaker evidence suggests a positive correlation between normalized net exports and job acquisition. Using sector-specific job destruction data for both Canada and the US, we find confirmation of the theoretical prediction that normalized net exports to Canada are negatively related to the ratio of the US job destruction rate to the Canadian job destruction rate.
Deformation of elastic particles in viscous shear flow

In this paper, the dynamics of two dimensional elastic particles in a Newtonian viscous shear flow is studied numerically. To describe the elastic deformation, an evolution equation for the Eulerian Almansi strain tensor is derived. A constitutive equation is thus constructed for an incompressible ''Neo-Hookean'' elastic solid where the extra stress tensor is assumed to be linearly proportional to the Almansi strain tensor. The displacement field does not appear in this formulation. A monolithic finite element solver which uses Arbitrary Lagrangian-Eulerian moving mesh technique is then implemented to solve the velocity, pressure and stress in both fluid and solid phase simultaneously. It is found that the deformation of the particle in the shear flow is governed by two non-dimensional parameters: Reynolds number (Re) and Capillary number (Ca, which is defined as the ratio of the viscous force to the elastic force). In the Stokes flow regime and when Ca is small (Ca<0.65), the particle deforms into an elliptic shape while the material points inside the particle experience a tank-treading like motion with a steady velocity field. The deformation of the elastic particle is observed to vary linearly with Ca, which agrees with theoretical results from a perturbation analysis. Interactions between two particles in a viscous shear flow are also explored. It is observed that after the initial complicated interactions, both particles reach an equilibrium elliptic shape which is consistent with that of a single particle.
The Strong Perfect Graph Theorem

A graph G is perfect if for every induced subgraph H, the chromatic number of H equals the size of the largest complete subgraph of H, and G is Berge if no induced subgraph of G is an odd cycle of length at least five or the complement of one. The ?strong perfect graph conjecture? (Berge, 1961) asserts that a graph is perfect if and only if it is Berge. A stronger conjecture was made recently by Conforti, Cornu?ejols and Vuiskovi?c ? that every Berge graph either falls into one of a few basic classes, or admits one of a few kinds of separation (designed so that a minimum counterexample to Berge?s conjecture cannot have either of these properties). In this paper we prove both of these conjectures.
Mod p classification of Shimura F-crystals

Let k be an algebraically closed field of positive characteristic p. We first classify the D -truncations mod p of Shimura F -crystals over k and then we study stratifications defined by inner isomorphism classes of these D -truncations. This generalizes previous works of Kraft, Ekedahl, Oort, Moonen, and Wedhorn. As a main tool we introduce and study Bruhat F -decompositions; they generalize the combined form of Steinberg theorem and of classical Bruhat decompositions for reductive groups over k (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Scintillating fiber ribbon-tungsten calorimeter

Abstract We describe an ultra-high density scintillating fiber and tungsten calorimeter used as an active beam-dump for electrons. Data showing the calorimeter response to electrons with momenta between 50 and 350 GeV/ c are presented.
The end of the age problem, and the case for a cosmological constant revisited.

The case for an open universe versus a flat universe with nonzero cosmological constant is reanalyzed, following new globular cluster dating results that now suggest a dramatically reduced lower limit on the age of the universe, which, for example, allow age consistency for a flat matter-dominated universe with a Hubble constant H0 ≤ 67 km s-1 Mpc-1. I incorporate not only the new age data but also updates on baryon abundance constraints and large-scale structure arguments. For the first time, the allowed parameter space for the density of nonrelativistic matter appears larger for an open universe than for a flat universe with cosmological constant, while a flat universe with zero cosmological constant remains strongly disfavored, in spite of the fact that it is now more consistent with the new age constraint. I argue that fundamental theoretical arguments favor a nonzero cosmological constant over an open universe. However, if either case is confirmed, the challenges posed for fundamental physics will be great.
Direct aerobic α,β-dehydrogenation of aldehydes and ketones with a Pd(TFA)2/4,5-diazafluorenone catalyst

The direct α,β-dehydrogenation of aldehydes and ketones represents an efficient alternative to stepwise methods to prepare enal and enone products. Here, we describe a new Pd(TFA)2/4,5-diazafluorenone dehydrogenation catalyst that overcomes key limitations of previous catalyst systems. The scope includes successful reactivity with pharmaceutically important cyclopentanone and flavanone substrates, as well as acyclic ketones. Preliminary mechanistic studies compare the reactivity of this catalyst to previously reported dehydrogenation catalysts and reveal that cleavage of the α-C–H bond of the ketone is the turnover-limiting step of the catalytic mechanism.
Experiment on entrepreneurial discovery: an attempt to demonstrate the conjecture of Hayek and Kirzner

Friedrich Hayek conjectured that the free enterprise system is most effective in making discoveries. Israel Kirzner refines the conjecture as follows: the availability of profit opportunities tends to evoke entrepreneurial discovery. We hoped to demonstrate the conjecture in an outdoor experiment. We asked subjects to transfer water from one bucket to another. There were two methods of doing so, an obvious method and a nonobvious and much superior method. We varied the payment schedules to see if higher potential rewards would more readily evoke discovery of the superior method. The hoped-for demonstration was not achieved. The investigation holds several lessons for those who would attempt to demonstrate the entrepreneurship conjecture. Investigators must make the opportunity discoverable but not obvious, operationalize motivation (not merely vary monetary rewards), and separate entrepreneurial discovery from other types of discovery (such as that had by deliberate problem solving).
A bio-optical approach to estimating chlorophyll-a concentration from hyperspectral remote sensing

Eagle Creek Reservoir is one of three central Indiana reservoirs supplying drinking water for the residents of Indianapolis. The occurrence of blue-green algae blooms resulting from high nutrient input has been a major public concern so that estimation of chlorophyll-a concentration of this reservoir is significantly important for assessing the reservoir's water quality. Empirical and semi-empirical methods were used in our previous studies for estimating CHL. Due to limitations to empirical and semi-empirical methods, a bio-optical model is tested in this study. Field campaigns were carried out in Eagle Creek Reservoir in central Indiana, and water samples analyzed for water quality parameter concentrations and their inherent optical properties (IOPs). A bio-optical model parameterized with these derived IOPs is used to estimate CHL concentration through a matrix inversion of hyperspectral data, and its performance is compared with those for empirical and semi-empirical models. The result demonstrates that the bio-optical model results in a higher correlation than empirical and semi-empirical models do.
Split-Phase Control: Achieving Complete Soft-Charging Operation of a Dickson Switched-Capacitor Converter

Switched-capacitor (SC) converters are gaining popularity due to their high power density and suitability for on-chip integration. Soft-charging and resonant techniques can be used to eliminate the current transient during the switching instances, and improve the power density and efficiency of SC converters. In this paper, we propose a split-phase control scheme that enables the Dickson converter to achieve complete soft-charging (or resonant) operation, which is not possible using the conventional two-phase control. An analytical method is extended to help in the analysis and design of split-phase controlled Dickson converters. The proposed technique and analysis are verified by both simulation and experimental results. An 8-to-1 step-down Dickson converter with an input voltage of 150 V and rated power of 36 W is built using GaN FETs. The converter prototype demonstrated a five fold reduction in the output impedance (which corresponds to conduction power loss) compared to a conventional Dickson converter, as a result of the split-phase controlled soft-charging operation.
Ring expansion of an α-bromoalkynol camphor by means of iodine and Koser's reagent

Abstract The bromoethynyl adduct of camphor was treated with equimolar amounts of iodine and Koser's reagent (HTIB) to afford in good yield and in good stereospecificity a (Z)-bromoiodoenone, a synthon for enantiospecific syntheses.
Comets in the near-Earth object population

Abstract Because the lifespan of near-Earth objects (NEOs) is shorter than the age of the Solar System, these objects originate elsewhere. Their most likely sources are the main asteroid belt and comets. Through physical observations we seek to identify potential dormant or extinct comets among “asteroids” catalogued as NEOs and thereby determine the fraction of “comet candidates” within the total NEO population. Both discovery statistics and dynamical models indicate that candidate cometary objects in near-Earth space are predominantly found among those having a jovian Tisserand parameter T j 3 . Therefore, we seek to identify comet candidates among asteroid-like NEOs using three criteria: T j 3 , spectral parameters (C, D, T, or P taxonomic types), and/or low ( T j 3 , consisting of visible spectra, near-infrared spectra, and/or albedo measurements obtained using the NASA Infrared Telescope Facility, the Kitt Peak National Observatory 4 m, and the Magellan Observatory 6.5-m. Four of our “asteroid” targets have been subsequently confirmed as low activity comets. Thus our sample includes spectra of the nuclei of Comets 2002 EX12 = 169P (NEAT), 2001 WF2 = 182P (LONEOS), 2003 WY25 = D/1891 W1 (Blanplain), and Halley Family Comet 2006 HR30 = P/2006 HR30 (Siding Spring). From the available literature, we tabulate physical properties for 55 NEOs having T j 3 , and after accounting for possible bias effects, we estimate that 54 ± 10 % of NEOs in T j 3 orbits have “comet-like” spectra or albedos. Bias corrected discovery statistics [Stuart, J.S., Binzel, R.P., 2004. Icarus 170, 295–311] estimate 30 ± 5 % of the entire NEO population resides in orbits having T j 3 . Combining these two factors suggests that 16 ± 5 % of the total discovered “asteroid-like” NEO population has “comet-like” dynamical and physical properties. Outer main-belt asteroids typically have similar taxonomic and albedo properties as our “comet candidates.” Using the model of Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.M., Levison, H., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399–433] to evaluate source region probabilities, we conclude that 8 ± 5 % of the total asteroid-like NEO population have the requisite orbital properties, physical properties, and dynamical likelihood to have originated as comets from the outer Solar System.
Many-electron effects in electron-impact ionization of multiply charged ions

Abstract Many-electron phenomena critically influence the ionization of multiply charged ions by electron impact. In general, inner-shell electrons play an increasingly important role in the electron-impact ionization process as the ionic or nuclear charge increase along an ionic sequence. A few specific examples are given to illustrate the signature and relative contributions of a number of indirect ionization mechanisms to the total ionization cross sections.
Saturation of the polar cap potential: Inference from Alfven wing arguments

[1] The cross polar cap potential varies roughly linearly with the solar wind electric field for nominal conditions but asymptotes to a constant value of order 200 kV for large electric field. When the impedance of the solar wind across open polar cap field lines dominates the impedance of the ionosphere, Alfven waves incident from the solar wind are partially reflected, reducing the signal in the polar cap. Thus, the ratio of the cross polar cap potential to the potential imposed by the solar wind is 2ΣA/(ΣP + ΣA), where ΣA is the Alfven conductance of the solar wind (= (ρsw/μo)1/2/Bsw) to within a density-dependent factor on average of order 1, ΣP is the Pedersen conductance of the ionosphere, and ρsw (Bsw) is the density (magnetic field magnitude) of the solar wind. For small Bsw, the response is proportional to Bsw. For large Bsw, the cross polar cap potential depends only on the solar wind dynamic pressure (with small viscous and density-dependent corrections). Quantitative estimates require knowledge of ΣP and the dependence of the potential imposed by the solar wind on its measured properties; standard assumptions yield saturation levels consistent with observations made during 13 storm intervals. Previous explanations of saturation have invoked changing reconnection efficiency, specific characteristics of the Region 1 current system, or the effect of the bow shock on the reconnecting plasma. Although our relation is mathematically similar to some previously proposed, our arguments place no constraints on reconnection efficiency or on magnetospheric geometry.
Vitamin D status is related to intramyocellular lipid in older adults.

Vitamin D and intramyocellular lipid (IMCL) both affect muscle function, but the relationship between vitamin D status and IMCL has not been established. To assess the relationship between vitamin D [measured as 25-hydroxy-vitamin-D (25(OH)D)] and IMCL, 20 community-dwelling adults between the ages of 65 and 85 were recruited. Serum 25(OH)D, and gastrocnemius IMCL and extramyocellular lipid (EMCL) were measured with magnetic resonance spectroscopy and fat ratio segmentation. A lifestyle questionnaire assessed physical activity. Muscle strength (1-repetition maximum) and physical function tests (timed up and go, timed sit to stand, four square step test, and gait speed) were also performed. Mean 25(OH)D was 37.9 ± 13.1 ng/mL with a range of 19–68 ng/mL. Soleus and gastrocnemius IMCL to water ratio was 1.04 ± 0.43 and 0.53 ± 0.22, respectively, but only gastrocnemius IMCL was correlated with 25(OH)D (R2 = 0.39; p = 0.02). This relationship was independent of body mass index (p > 0.14), physical activity level (p > 0.08), and sex (p > 0.13). 25(OH)D did not correlate with EMCL (R2 = 0.007; p = 0.78). The four square step test was the only performance or strength test correlated with 25(OH)D (R2 = 0.26; p = 0.023). Muscle strength and physical function measures were not correlated with IMCL or EMCL. These data suggest that vitamin D status may influence gastrocnemius IMCL content independent of body mass and physical activity. Future studies should consider exploring whether vitamin D has an independent role in affecting muscle lipid metabolism and function.
Synthesis of 1,4-diketones by the coupling reaction of trimethylsilyl enol ethers with lead tetraacetate

Abstract Synthesis of 1,4-diketones in good yields was achieved by the coupling reaction of the trimethylsilyl enol ethers of acetophenone, thiophene or furan with lead tetraacetate in dry dichloromethane and tetrahydrofuran at −78°C.
Does age structure forecast economic growth

Abstract Increases in the proportion of the working age population can yield a “demographic dividend” that enhances the rate of economic growth. We estimate the parameters of an economic growth model using a cross section of countries over the period 1960 to 1980, and investigate whether the inclusion of age structure improves the model's forecasts for the period 1980 to 2000. We find that including the age structure improves the forecast, although there is evidence of parameter instability between periods with an unexplained growth slowdown in the second period. We use the model to generate growth forecasts for the period 2000 to 2020.
The Hot Interstellar Medium in Normal Elliptical Galaxies. III. The Thermal Structure of the Gas

This is the third paper in a series analyzing X-ray emission from the hot interstellar medium in a sample of 54 normal elliptical galaxies observed by Chandra. We focus on a subset of 36 galaxies with sufficient signal to compute radial temperature profiles. We distinguish four qualitatively different types of profile: positive gradient (outwardly rising), negative gradients (falling), quasi-isothermal (flat), and hybrid (falling at small radii and rising at larger radii). We measure the mean logarithmic temperature gradients in two radial regions: from 0 to 2 J-band effective radii RJ (excluding the central point source), and from 2 to 4 RJ. We find the outer gradient to be uncorrelated with intrinsic host galaxy properties, but strongly influenced by the environment: galaxies in low-density environments tend to show negative outer gradients, while those in high-density environments show positive outer gradients, suggesting the influence of circumgalactic hot gas. The inner temperature gradient, however, is largely unaffected by the environment, but strongly correlated with intrinsic host galaxy characteristics: negative inner gradients are more common for smaller, optically faint, low radio luminosity galaxies, whereas positive gradients are found in bright galaxies with stronger radio sources. There is no evidence for bimodality in the distribution of inner or outer gradients. We propose three scenarios to explain the inner temperature gradients: (1) weak AGNs heat the ISM locally, while higher luminosity AGNs heat the system globally through jets inflating cavities at larger radii; (2) the onset of negative inner gradients indicates a declining importance of AGN heating relative to other sources, such as compressional heating or supernovae; or (3) the variety of temperature profiles are snapshots of different stages of a time-dependent flow, cyclically reversing the temperature gradient over time.
SERT II - Thruster system ground testing

SERT 2 thrustor system performance over expected mission parameters, noting operational lifetime excess over mission requirements
Acute Changes in Sleep Duration on Eating Behaviors and Appetite-Regulating Hormones in Overweight/Obese Adults

There is considerable interest in the role of sleep in weight regulation, yet few studies have examined this relationship in overweight/obese (OW/OB) adults. Using a within-subject, counterbalanced design, 12 OW/OB women were studied in lab with two nights of short (5 hr time in bed [TIB]) and two nights of long (9 hr TIB) sleep. Hunger, consumption at a buffet, and fasting hormone levels were obtained. Significant polysomnographic differences occurred between conditions in total sleep time and sleep architecture (ps < .001). Percent energy from protein at the buffet increased following short sleep. No differences were observed for total energy intake or measured hormones. Further research is needed to determine how lengthening sleep impacts weight regulation in OW/OB adults.
An expert simulator for allocating the quality assurance effort in software development

Increasingly software quality assurance (QA) is being recognized as a critical factor in the successful development of software systems. However, because the utilization of QA tools and techniques adds significantly to the cost of developing software, the cost-effectiveness of QA has been a significant concern to the software quality manager. As of yet this concern has not been adequately addressed in the literature.The objective of this research effort is to develop an expert/simulator to support the QA effort allocation decision. The expert system module derives QA effort allocation schemes, feeds them into the simulation model for testing, and uses the feedback from the simulation results to improve upon the efficiency of the QA effort distribution.In a case study involv ing a NASA software project, the model accurately replicated the project's dynamic behavior. The expertlsimulator was then capable of deriving a more cost effective QA policy that achieved a 26% reduction in total project cost.
Global dynamics of the smallest chemical reaction system with Hopf bifurcation

The global behavior of solutions is described for the smallest chemical reaction system that exhibits a Hopf bifurcation, discovered in [12]. This three-dimensional system is a competitive system and a monotone cyclic feedback system. The Poincare–Bendixson theory extends to such systems [2,3,6,8] and a Bendixson criterion exists to rule out periodic orbits [4].
The Extragalactic Lens VLBI Imaging Survey (ELVIS). I. A Search for the Central Image in the Gravitational Lens PMN J1838–3427

The Extragalactic Lens VLBI Imaging Survey (ELVIS) searches for central images of lensed radio quasars, in order to measure the central density profiles of distant galaxies. Here we present sensitive multiepoch Very Long Baseline Array (VLBA) observations of PMN J1838-3427 at 8 GHz, with a 1 σ noise level of 38 μJy beam-1. Based on the absence of a central image of the background source at this level, we explore the possibilities for the central matter distribution in the lens galaxy. A power-law density profile, ρ ∝ r-γ, must have γ > 1.93. Thus, the density profile is close to an isothermal profile (γ = 2) or steeper. The upper limit on any constant-density core in an otherwise isothermal profile is 5 pc. We also derive the constraints on models in which the density profile is isothermal on kiloparsec scales, but is allowed to have a different power law in the central ~100 pc. If the lens galaxy harbors a supermassive black hole, the galaxy profile is allowed to be shallower, but for the expected black hole mass, the galaxy profile must still be close to isothermal or steeper.
Molecular Mechanisms of Bone Metastasis and Associated Muscle Weakness

Bone is a preferred site for breast cancer metastasis and leads to pathologic bone loss due to increased osteoclast-induced bone resorption. The homing of tumor cells to the bone depends on the support of the bone microenvironment in which the tumor cells prime the premetastatic niche. The colonization and growth of tumor cells then depend on adaptations in the invading tumor cells to take advantage of normal physiologic responses by mimicking bone marrow cells. This concerted effort by tumor cells leads to uncoupled bone remodeling in which the balance of osteoclast-driven bone resorption and osteoblast-driven bone deposition is lost. Breast cancer bone metastases often lead to osteolytic lesions due to hyperactive bone resorption. Release of growth factors from bone matrix during resorption then feeds a "vicious cycle" of bone destruction leading to many skeletal-related events. In addition to activity in bone, some of the factors released during bone resorption are also known to be involved in skeletal muscle regeneration and contraction. In this review, we discuss the mechanisms that lead to osteolytic breast cancer bone metastases and the potential for cancer-induced bone-muscle cross-talk leading to skeletal muscle weakness.
Volatility Timing in Mutual Funds: Evidence from Daily Returns

I use daily mutual fund returns to shed new light on the question of whether or not mutual fund managers are successful market timers. Previous studies find that funds are unable to time the market return. I study the funds' ability to time market volatility. I show that volatility timing is an important factor in the returns of mutual funds and has led to higher risk-adjusted returns. The returns of surviving funds are especially sensitive to market volatility; those of nonsurvivors are not. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Prescribed subintegral extensions of local Noetherian domains

Abstract We show how subintegral extensions of certain local Noetherian domains S can be constructed with specified invariants including reduction number, Hilbert function, multiplicity and local cohomology. The construction behaves analytically like Nagata idealization but rather than a ring extension of S , it produces a subring R of S such that R ⊆ S is subintegral.
Hessian Equations with Elementary Symmetric Functions

We consider the Dirichlet problem for two types of degenerate elliptic Hessian equations. New results about solvability of the equations in the C 1,1 space are provided.
Interactions of Genotype and Glutenin Subunit Composition on Breadmaking Quality of Durum 1AS•1AL-1DL Translocation Lines

ABSTRACT Dual-purpose durum (Triticum turgidum L. subsp. durum) wheat, having both good pasta and breadmaking quality, would be an advantage in the market. In this study, we evaluated the effects of genotype and varying HMW and LMW glutenin subunit composition on durum breadmaking quality. Genotypes included five near-isogenic backgrounds that also differed by variability at the Glu-D1d (HMW subunits 1Dx5+1Dy10), Glu-B1 (presence or absence of subunit 1By8), and Glu-B3 (LMWI or LMWII pattern) loci. Quality tests were conducted on genotypes grown at five North Dakota locations. Genotype had a stronger influence on free asparagine content than glutenin subunit composition. Genotypes carrying Glu-D1d had higher glutenin content than lines that did not carry Glu-D1d. Among Rugby translocation genotypes, lines carrying LMWI had higher gliadin content and better loaf volume than genotypes carrying LMWII. Absence of 1By8 produced major reductions in loaf volume in nontranslocation lines regardless of whether LMW...
Experimental and simulation studies of alignment marks

The roles of alignment mark structure, geometry, film materials and scanned illumination image on dark-field alignment signal quality are investigated through simulation interpreted experiments. The illumination of the alignment system consists of a low numerical aperture 1.0 micrometers image of a slit at 488.0 and 514.5 nm which is scanned across the alignment mark. The light scattered into a dark-band protected cone is collected. The structures consist of 0.5 to 1.2 micrometers wide features including trenches in silicon coated with 1.34 micrometers of photoresist, and trenches in nitride coated silicon with 1.00 micrometers of photoresist. For simulation, the illumination image is calculated using SAMPLE and input to a massively parallel finite-difference time-domain scattering analysis program called TEMPEST at various lateral shifts to simulate scanning. The diffracted orders output from TEMPEST are used to calculate total diffracted energy in various angular bands and to view dark field instantaneous images. Studied of depth, width, thin-film stack and coating thickness are used to identify key phenomena such as the role of interference between reflection from the alignment mark and substrate surfaces. Simulations are used to interpret the experimental observations and provide guidelines for topography control, and illumination and collection optics. The alignment signal is shown to be a strong function of trench depth, and only a weak function of trench width. An order of magnitude signal strength reduction occurs when the effective optical depth of the trench is a multiple of (lambda) resist/2 compared to the surrounding area.
The first true inorganic fullerenes

Boron nitride and materials of composition MX2, where M is molybdenum or tungsten and X is sulphur or selenium, can form fullerene-like structures such as nested polyhedra or nanotubes1,2,3. However, the analogy to the carbon fullerene family4 falls short because no small preferred structure akin to C60(ref. 5) has been found. We have discovered nano-octahedra of MoS2of discrete sizes in soots that we prepared by laser ablation of pressed MoS2targets. These nano-octahedra are much larger than C60structures, having edge lengths of about 4.0 and 5.0 nanometres, and may represent the first ‘inorganic fullerenes’.