cssi/SciSciGPT-SciSciNet huggingface dataset:
Support for maintaining object-oriented programs

It is explained how inheritance and dynamic binding make object-oriented programs difficult to maintain, and a concrete example of the problems that arise is given. It is shown that the difficulty lies in the fact that conventional tools are poorly suited for work with object-oriented languages, and it is argued that semantics-based tools are essential for effective maintenance of object-oriented programs. A system developed for working with C++ programs is described. It comprises a relational database system for information about programs and an interactive database interface integrated with a text editor. The authors describe the system architecture, detail the database relations, provide informal evidence on the system's effectiveness, and compare it to other research with similar goals. >
Regional dependence for continuous bivariate densities

When the region of support for a continuous bivariate density is not a Caresian product set, the joint distribution cannot be independent. This is closely to the effects caused by "stuctural zeroes" in two-way contingency tables. Nonrectangular regions of support for continuous densities are analogous to the incomplete twoiway tables. Quasi-independence is introduced to replace independence. A measure of association t quantify the degree of dependence due to region is defined. discussed, and applied to several examples receiveddate="Mar1986" reviseddate="Sep1986"
A note on circular trace formulae

We find a finite CMV matrix whose eigenvalues coincide with the Dirichlet data of a circular periodic problem. As a consequence, we obtain circular analogues of the classical trace formulae for periodic Jacobi matrices.
Elevated coherent motion thresholds in mild traumatic brain injury

Abstract Purpose Individuals with mild traumatic brain injury (mTBI) frequently complain of increased sensitivity to visual motion. Thus, the purpose of this study was to assess the coherent motion threshold (CMT) in subjects with mTBI and reported visual motion sensitivity. Methods Fourteen adult subjects with mTBI and symptoms of motion sensitivity were tested. They were compared with 40 age-matched asymptomatic visually normal individuals. CMT was assessed using a 2-alternative, forced choice paradigm. A symptom rating-scale questionnaire related to motion and light sensitivity, vertigo, and self-reported reading ability was also administered to the mTBI group. Results Mean CMTs were significantly elevated in the mTBI (8.81%) versus the normal subjects (6.53%). There was a trend for a progressive increase in mean CMT in mTBI with increased symptoms related to visual motion sensitivity and vertigo. However, there was no apparent relation to either light sensitivity or self-reported reading ability in mTBI. There was no significant age effect in either group. Conclusions The elevated CMT in mTBI suggests damage to the magnocellular pathway, such as extrastriate visual cortical area V5, visual area medial temporal, and the medial superior temporal cortex, which is involved directly in various aspects of motion processing. These findings are consistent with the subjects’ symptoms of motion sensitivity and vertigo in their natural environments.
A dynamical pairing between two rational maps

This is the publisher’s final pdf. The published article is copyrighted by American Mathematical Society and can be found at: http://www.ams.org/home/page.
A dynamic model for aircraft poststall departure

An aerodynamic model is developed for use with a numerical simulation of vehicle motion for the purpose of analyzing high-angle-of-attack behavior including poststall departure. The model consists of a nonlinear lifting line theory that includes unsteady wake effects due to a discrete, nonplanar vortex system. Each lifting surface is modeled with discrete vortex segments and their associated control points. The wing, horizontal, and vertical tail are treated in this manner. Application to a general-aviation-type vehicle indicates the effects of flight asymmetries and rate of stall penetration on poststall departure. In addition, forced oscillation wind tunnel tests in roll are simulated using this areodynamic model and are shown to agree quite well with actual tests for two different configurations.
Estimating the Relationship between Pest Management and Energy Prices, and the Implications for Environmental Damage

A practicing pest management consultant recently suggested that we need to broaden our research emphasis beyond integrated pest management and consider the total crop system. Instead of our more narrow focus, a more appropriate area of investigation would be the economics of integrated crop and pest management (ICPM) systems. Components of private crop management services may include pest, fertility, water, and soil management, as well as other input decisions. Yet, the key input is improved information to assist in decision making. We need to integrate the crop production and pest management decisions to determine the most efficient (profitable) way to produce output. Unfortunately, a major difficulty in the economic assessment of ICPM is the lack of appropriate biological data. Many of the linkages in crop production systems are not well understood or, if understood, reliable parameter estimates are not available. Thus, one of the "emerging issues" of the 1980s should be the development of better ICPM systems through both basic and applied research. This paper considers alternative pest management systems for corn production with rising energy prices. First, pest control practices are discussed. Second, historical data are used to estimate derived demand equations for insecticide and herbicide treatment. Third, the impact of rising energy prices on the future demand and supply of pest management systems and on the implied use of insecticides is considered. Pest Control Practices in Corn Production
SWIM: A Scheduler for Unsolicited Grant Service (UGS) in IEEE 802.16e Mobile WiMAX Networks

Most of the IEEE 802.16e Mobile WiMAX scheduling proposals for real-time traffic using Unsolicited Grant Service (UGS) focus on the throughput and guaranteed latency. The delay jitter and the effect of burst overhead have not yet been investigated. This paper introduces a new technique called Swapping Min- Max (SWIM) for UGS scheduling that not only meets the delay constraint with optimal throughput, but also minimizes the delay jitter and burst overhead.
Nonlinear composition dependence of the Fermi-surface dimensions in alpha-phase copper-germanium alloys

In considering the $\ensuremath{\alpha}\ensuremath{-}{\mathrm{CU}}_{100\ensuremath{-}x}{\mathrm{Ge}}_{x}$ alloys on the basis of a realistic muffin-tin Hamiltonian, the most notable feature of the electronic spectra is found to be the appearance of an impurity band below the host conduction band. In accord with relevant experiments, a Fermi surface is predicted to grow at approximately half the rigid-band rate for $xl0.5$ at.% Ge and essentially at the rigid-band rate for $xg5$ at.% Ge. This effect is related to a transition in the nature of states associated with the impurity band; these states are localized atomic $s$-like states for $xl~0.5$ and become delocalized in concentrated alloys.
On the generality of certain predictions for quark mixing

Abstract The relations |V ub |/|V cb |= m u m c and |V td |/|V ts |= m d m s are significant successes of some specific models for quark masses. We show that these relations are more general, resulting from a much wider class of models. Consequences of these predictions for CP violating asymmetries in neutral B mesons decays are discussed.
Polarization of broad absorption line qsos I. a spectropolarimetric atlas

We present a spectropolarimetric survey of 36 broad absorption line quasi-stellar objects (BAL QSOs). The continuum, absorption trough, and emission-line polarization of BAL QSOs yield clues about their structure. We confirm that BAL QSOs are in general more highly polarized than non-BAL QSOs, consistent with a more equatorial viewing direction for the former than the latter. We have identified two new highly polarized QSOs in our sample (1232+1325 and 1333+2840). The polarization rises weakly to the blue in most objects, perhaps owing to scattering and absorption by dust particles. We find that a polarization increase in the BAL troughs is a general property of polarized BAL QSOs, indicating an excess of scattered light relative to direct light, and consistent with the unification of BAL QSOs and non-BAL QSOs. We have also discovered evidence of resonantly scattered photons in the red wing of the C IV broad emission lines of a few objects. In most cases, the broad emission lines have lower polarization and a different position angle than the continuum. The polarization characteristics of low-ionization BAL QSOs are similar to those of high-ionization BAL QSOs, suggesting a similar BAL wind geometry.
Luminosity Indicators in the Ultraviolet Spectra of Type Ia Supernovae

We present a complete sample of International Ultraviolet Explorer and Hubble Space Telescope ultraviolet (UV) spectra of Type Ia supernovae (SNe Ia) through 2004. We measure the equivalent width (EW) and blueshifted velocity of the minimum of the one strong UV feature, Fe II λ3250. We also quantify the slope of the near-UV spectra using a new parameter, the "UV ratio." We find that the velocity of the Fe II line does not correlate with light-curve shape, while the EW shows distinct behavior for the slow- and fast-declining objects. Using precise Cepheid and surface brightness fluctuation distance measurements of six objects with UV spectra observed near maximum light (a total of 12 spectra), we determine that the UV ratio at maximum light is highly correlated with SN Ia luminosity. A larger sample of UV spectra is necessary to determine the validity of these luminosity indicators and whether they can be combined with light-curve shape to improve measured SN Ia distances.
Tin(II) chloride catalyzed addition of diazo sulfones, diazo phosphine oxides, and diazo phosphonates to aldehydes.

Abstract Diazo sulfones, diazo phosphine oxides, and diazo phosphonates add to aldehydes in the presence of a catalytic amounts of tin(II) chloride to yield β-keto sulfones, β-keto phosphine oxides, and β-keto phosphonates, respectively. Reactions with primary aldehydes proceed in higher yields, 53–79%, than those of secondary aldehydes, 42–56%. Reactions with tertiary aldehydes, which are more sterically encumbered substrates, give only 5–36% yields.
The Structure of the Local Interstellar Medium. II. Observations of D I, C II, N I, O I, Al II, and Si II toward Stars within 100 Parsecs

Moderate- and high-resolution measurements (λ/Δλ 40,000) of interstellar resonance lines of D I, C II, N I, O I, Al II, and Si II (hereafter called light ions) are presented for all available observed targets located within 100 pc that also have high-resolution observations of interstellar Fe II or Mg II (heavy ions) lines. All spectra were obtained with the Goddard High Resolution Spectrograph or the Space Telescope Imaging Spectrograph instrument aboard the Hubble Space Telescope. Currently, there are 41 sight lines to targets within 100 pc with observations that include a heavy ion at high resolution and at least one light ion at moderate or high resolution. We present new measurements of light ions along 33 of these sight lines and collect from the literature results for the remaining sight lines that have already been analyzed. For all of the new observations we provide measurements of the central velocity, Doppler width parameter, and column density for each absorption component. We greatly increase the number of sight lines with useful local interstellar medium (LISM) absorption-line measurements of light ions by using knowledge of the kinematic structure along a line of sight obtained from high-resolution observations of intrinsically narrow absorption lines, such as Fe II and Mg II. We successfully fit the absorption lines with this technique, even with moderate-resolution spectra. Because high-resolution observations of heavy ions are critical for understanding the kinematic structure of local absorbers along the line of sight, we include 18 new measurements of Fe II and Mg II in an Appendix. We present a statistical analysis of the LISM absorption measurements, which provides an overview of some physical characteristics of warm clouds in the LISM, including temperature and turbulent velocity. This complete collection and reduction of all available LISM absorption measurements provides an important database for studying the structure of nearby warm clouds, including ionization, abundances, and depletions. Subsequent papers will present models for the morphology and physical properties of individual structures (clouds) in the LISM.
A Simple Fabry and Perot Interferometer

DURING a course of experiments with interferometers it was found that a very simple and inexpensive Fabry and Perot instrument could be constructed of plate glass which gives results almost as good as the costly interferometer. The construction of this apparatus for demonstration purposes will well repay the teacher and student. The sharp-coloured interference rings, obtained by using luminous gases in vacuum tubes as sources are extremely beautiful. The D lines from a sodium burner are easily separable. If the interference pattern, using a copper or iron arc, is focussed on a wide slit of a single-prism spectrometer, a section of the interference rings is seen in the various spectrum lines, illustrating the method of Fabry and Buisson, and Eversheim, for the determination of the new standard table of wave-lengths. The Zeeman effect can also be easily shown with this apparatus.
Pile-of-Plates Polarizers for the Infrared: Improvement in Analysis and Design

The history of the transmission-type pile-of-plates polarizer has been dominated by two equations which make different assumptions as to the fate of the unwanted, multiply-reflected rays. Both equations assume that the polarizer consists of parallel-sided plates mounted parallel to one another and inserted in the beam at Brewster’s angle. The present article shows that better results are obtained if the plates are slightly wedge-shaped, are mounted in “fanned” manner, and are mounted at an angle slightly exceeding Brewster’s angle. A performance better than that implied by either equation is achievable.
Stability of shell distributions

Abstract Stability criteria for parallel propagating plasma waves driven unstable by a nearly isotropic bump-in-energy “half-shell” beam of electrons along a magnetic field are investigated. Comparison with the drifting Maxwellian at equal densities reveals smaller growth rates for the half-shell and a shift in the unstable wavenumbers towards smaller phase velocities. The limit of complete isotropy is stable to the waves under consideration.
The vector probe in heavy-ion reactions

We review essential elements in using the JP = 1− channel as a probe for hot and dense matter as produced in (ultra-) relativistic collisions of heavy nuclei. The uniqueness of the vector channel resides in the fact that it directly couples to photons, both real and virtual (dileptons), enabling the study of thermal radiation and in-medium effects on both light (ρ, ω, ) and heavy (Ψ, ) vector mesons. We emphasize the importance of inter-relations between photons and dileptons, and characterize relevant energy/mass regimes through connections to QGP emission and chiral symmetry restoration. On the basis of a critical analysis of our current understanding of data from fixed-target energies, we identify open key questions to be addressed.
The RAPT Control Method for Nonlinear Systems

The Rapid Advancement Preview Tracking (RAPT) control method uses both a nonlinear system model and a linearized system model to provide a form of feedback/preview control for nonlinear systems. It uses measurements of the states to calculate the current preview control signal from a local linearization of the state equations, and then iteratively calculates a perturbation correction for that control using the nonlinear equations. The corrected control signal is then applied to the system, driving the end-effector to the next position along a specified trajectory. Computer simulations of tracking control for two-link planar manipulators indicate that this algorithm may be fast enough for real-time control.
Heavy ions in Jupiter's environment

The extended atmosphere of the Jupiter system consists of atoms and ions of heavy elements. This material originates on the satellite Io. Energy is lost from the thermal plasma in collisionally excited optical and ultraviolet emission. The juxtaposition of Earth and spacecraft measurements provide insight concerning the underlying processes of particle transport and energy supply.
Diastereoselective Synthesis of Seven-Membered Ring trans-Alkenes from Dienes and Aldehydes by Silylene Transfer

Silver-catalyzed silylene transfer to alkenes forms vinylsilacyclopropanes regioselectively. These allylic silanes undergo additions to aldehydes to form seven-membered-ring trans-alkenes with high diastereoselectivity. The high reactivity of the trans-alkenes is evidenced by their formal [1,3]-sigmatropic rearrangement reactions and the rapid additions of oxygen–hydrogen bonds across the carbon–carbon double bonds.
Synthesis and characterization of optically nonlinear and light emitting Lanthanide borates

Lanthanide borates, LnBO3 (Ln = La, Pr and Nd), were prepared via supercritical hydrothermal methods in sizes up to 3 × 0.5 × 0.5 mm and their crystallography and physical and optical properties studies. The materials are thermally stable up to at least 1000 °C and their crystal structure, although previously thought to be centric orthorhombic, is shown to be orthorhombic yet acentric as is confirmed by the observance of second harmonic generated light. Absorption and luminescence from the NdBO3 and PrBO3 is provided and discussed, as is the corroboration that these materials have bandgaps well above 5 eV. This works marks the lanthanide borates as candidate materials for deep-UV and nonlinear optical applications.
Concluding Remarks/Summary

These remarks summarize some of the discussion at the Now 2004; in addition some topics not touched on at the meeting are reviewed briefly.
Response of a Parametrically Excited System to a Nonstationary Excitation

The response of a single-degree-of-freedom system to a nonstationary excitation is investigated by using the method of multiple scales as well as analog- and digital-computer simulations. The unexcited system has one focus and two saddle points. The system can be used to model rolling of ships in head or follower seas. The method of multiple scales is used to derive equations governing the modulation of the amplitude and phase of the response. The modulation equations are used to find the stationary solutions and their stability. The response to nonstationary excitations is found by integrating the original governing equation as well as the modulation equations. There is good agreement between the results of both approaches. For some frequency and amplitude sweeps, the nonstationary response found from integrating the original governing equation exhibits behaviors that are analogous to symmetry-breaking bifurcations, period-doubling bi furcations, chaos, and unboundedness present in the stationary case. T...
Convenient synthetic equivalents of 2-lithiopyrrole and 2,5-dilithiopyrrole

Abstract Bromination of pyrrole by 1,3-dibromo-5,5-dimethylhydantoin, followed by direct reaction with BOC anhydride and DMAP, affords the stable N-BOC dervatives of 2-bromopyrrole and 2,5-dibromopyrrole. Lithium-halogen exchange of the latter with n-butyllithium generates the N-BOC derivatives of 2-lithiopyrrole, 2,5-dilithiopyrrole or 5-bromo-2-lithiopyrrole, which react with various electrophiles to give substituted N-BOC pyrroles in excellent yield.
Computer Modeling Of Optical Trackers

A computer code has been developed to predict the detector output from a translation-scanning optical tracker with realistic input scenes. The approach is based on Fourier transform techniques with some new manipulations being introduced in frequency space. The code has been validated by use of a laboratory tracker with complex extended targets and point sources.
Back from Oblivion: The Nature of 'Word' in Yona Wallach's Poetry

Yona Wallach (1944-1985) is both a major poet and an outstanding personality in the history of Hebrew literature. Challenged by the enigmatic nature of her poetry, literary critics tend to attribute its obscurities to the modernist and postmodernist milieu from which she emerged, deeming it essentially indecipherable. Presenting a close reading of two of Wallach's meta-poetic poems: "Precisely" (Bediyuk Nimrats), a four part poem from her 1969 collection Shenai Ganim (Two Gardens), and "Let the Words" (Ten la-Milim) that opens the 1985 collection Tsurot (Forms), this study exposes the traditional, essentially Romantic foundation of her work. It features Wallach's struggle with the enduring philosophical question pertaining to the origin of language and words' meaning while highlighting her deep-rooted faith in the inherently natural character of language and words' propensity to directly reveal the essence of things.
NLOS UV channel modeling using numerical integration and an approximate closed-form path loss model

In this paper we propose a simulation method using numerical integration, and develop a closed-form link loss model for physical layer channel characterization for non-line of sight (NLOS) ultraviolet (UV) communication systems. The impulse response of the channel is calculated by assuming both uniform and Gaussian profiles for transmitted beams and different geometries. The results are compared with previously published results. The accuracy of the integration approach is compared to the Monte Carlo simulation. Then the path loss using the simulation method and the suggested closed-form expression are presented for different link geometries. The accuracies are evaluated and compared to the results obtained using other methods.
Gravitational Microlensing and the Structure of the Inner Milky Way

We analyze the first-year MACHO collaboration observations of microlensing toward the Galactic center using a new direct likelihood technique that is sensitive to the distribution of the events on the sky. We consider the full set of 41 events and calculate the direct likelihood against a simply parameterized Galactic model consisting of either a Gaussian or exponential bar and a double exponential disk. Optical depth maps are calculated taking into account the contribution of both disk lenses and sources. We show that based on the presently available data, a slope in the optical depth has been clearly detected (3 σ) in Galactic latitude and that there are indications of a small slope in Galactic longitude. We discuss limits that can be set on the mass, angle, and axis ratio of the Galactic bulge. We show that based on microlensing considerations alone, MBulge > 1.5 × 1010 M☉ at the 90% confidence level and that the bulge inclination angle is less than 30° also at the 90% confidence level. The most likely bar mass is MBulge = 2.5 × 1010 M☉. Such a high mass would imply a low MACHO fraction for the halo. We consider disk parameters and show that there are two degeneracies between the effects of a disk and those of a bar on the optical depths. Finally, we discuss how to break these degeneracies and consider various strategies for future microlensing observations.
Observations of high‐speed plasma flow near the Earth's magnetopause: Evidence for reconnection?

In an attempt to confirm the evidence for reconnection reported by Paschmann et al. (1979), we have examined three-dimensional plasma velocity distributions sampled near the magnetopause by using the LEPEDEA plasma instrument. During the magnetopause crossing of September 8, 1978, we observe high-speed plasma flow in the magnetospheric boundary layer that is suggestive of the accelerated flow predicted by reconnection models. However, our low-energy plasma observations reveal an apparent inconsistency with the tangential stress balance condition, and there is no clear evidence available from the plasma measurements for a local, normal flow component υn. Simultaneous measurements of ⩾45-keV energetic electrons show pancake-shaped pitch angle distributions and intensity variations that suggest a closed field line regime, whereas the high-speed plasma flow is predicted to occur on open field lines for the reconnection hypothesis. Allowing for finite gyroradius effects, the energetic particles show no signature of traversing from a closed to an open field line regime upon entering the boundary layer which contains high-speed ion flow. Since the energetic particle angular distributions indicate that the high-speed plasma flow occurs partly or entirely on closed field lines, we suggest that the simplest hypothesis is to place the entire boundary layer observed during this crossing on closed field lines. We find that several detailed features of the available measurements can be explained readily in this way. Our ISEE observations appear to be most consistent with impulsive injection of magnetosheath plasma across the magnetopause in a process that involves both MHD and plasma kinetic instabilities.
Chronological inversion method for the Dirac matrix in hybrid Monte Carlo

Abstract In hybrid Monte Carlo simulations for full QCD, the gauge fields evolve smoothly as a function of molecular dynamics time. Here we investigate improved methods of estimating the trial or starting solutions for the Dirac matrix inversion as superpositions of a chronological sequence of solutions in the recent past. By taking as the trial solution the vector which minimizes the residual in the linear space spanned by the past solutions, the number of conjugate gradient iterations per unit MD time is decreased by at least a factor of 2. Extensions of this basic approach to precondition the conjugate gradient iterations are also discussed.
Optimization of ZEP7000 writing and development conditions

Advanced reticule specifications for 150nm generation devices require large-scale improvements to resolution and critical dimension (CD) control. Resolution can be obtained by the adoption of electron-beam (e-beam) exposure and plasma etching with zero bias processes. However, CD control can not be achieved without a writing and development strategy optimization. This paper describes the optimization of the key parameters (exposure and development) needed to reach CD uniformity below 20nm necessary for 150nm generation devices. The three factors (exposure dose, spot size and development time) were investigated by design of experiment (DOE). ZEP 7000 is an e-beam dry-etchable resist which requires higher dose than PBS and EBR-9 HS-31 usual e-beam resists. Therefore the exposure was made on a MEBES 4500 system combined with multipass gray (MPG) writing strategy. A puddle development was done on a STEAG ASE500 tool. CD measurements have been done after development on LEICA IPRO system using reflective light in order to eliminate the error induced by etching. The DOE results have been interpreted separately on the X and Y axis. The results of the DOE have been verified by measuring the edge resist slope with a scanning electron microscope (SEM) and by measuring chrome CD uniformity after dry etching and stripping.
Remarks on solid state amorphizing transformations

Abstract Amorphous solids can now be produced through a variety of laboratory synthesis techniques as well as through many naturally occurring processes. In general, we might classify the methods of synthesis of amorphous solids as follows: (a) rapid solidification of melts or vapors; (b) atomic disordering of crystalline lattices; (c) solid state reactions between pure elements; (d) solid state transformations from metastable crystalline states; and (e) deposition from electrolytes. We give a short summary of the historical development of methods (a) — (d) (method (e) is clearly outside the focus of this conference), and we discuss the basic physical principles behind the methods.
Mesoscopic model for the fluctuating hydrodynamics of binary and ternary mixtures

A recently introduced particle-based model for fluid dynamics with continuous velocities is generalized to model immiscible binary mixtures. Excluded-volume interactions between the two components are modeled by stochastic multiparticle collisions which depend on the local velocities and densities. Momentum and energy are conserved locally, and entropically driven phase separation occurs for high collision rates. An explicit expression for the equation of state is derived, and the concentration dependence of the bulk free energy is shown to be the same as that of the Widom-Rowlinson model. Analytic results for the phase diagram are in excellent agreement with simulation data. Results for the interfacial tension obtained from the analysis of the capillary wave spectrum of a two-dimensional droplet agree with measurements based on the Laplace's equation. The introduction of "amphiphilic" dimers makes it possible to model the phase behavior and dynamics of ternary surfactant mixtures.
COLLISIONAL CASCADES IN PLANETESIMAL DISKS. II. EMBEDDED PLANETS

We use a multiannulus planetesimal accretion code to investigate the growth of icy planets in the outer regions of a planetesimal disk. In a quiescent minimum-mass solar nebula, icy planets grow to sizes of 1000–3000 km on a timescale tP ≈ (15–20)[a/(30 AU)]3 Myr, where a is the distance from the central star. Planets form faster in more massive nebulae. Newly formed planets stir up leftover planetesimals along their orbits and produce a collisional cascade in which icy planetesimals are slowly ground to dust. The dusty debris of planet formation has physical characteristics similar to those observed in β Pic and HR 4796A and other debris disks. The computed dust masses are Md(r 1 mm) ~ 1026(M0/MMMSN) g and Md(1 mm r 1 m) ~ 1027(M0/MMMSN) g, where r is the radius of a particle, M0 is the initial mass in solids, and MMMSN is the mass in solids of a minimum-mass solar nebula at 30–150 AU. The luminosity of the dusty disk relative to the stellar luminosity is LD/L0 ~ Lmax(t/t0)-m, where Lmax ~ 10-3(M0/MMMSN), t0 ≈ 10–1000 Myr, and m ≈ 1–2. Our calculations produce bright rings and dark gaps with sizes Δa/a ≈ 0.1. Bright rings occur where planets 1000 km and larger have recently formed. Dark gaps are regions where planets have cleared out dust, or shadows where planets have yet to form. Planets can also grow in a planetesimal disk perturbed by the close passage of a star. Stellar flybys initiate collisional cascades, which produce copious amounts of dust. The dust luminosity following a modest perturbation is 3–4 times larger than the maximum dust luminosity of a quiescent planet-forming disk. In 10 Myr or less, large perturbations remove almost all of the planetesimals from a disk. After a modest flyby, collisional damping reduces planetesimal velocities and allows planets to grow from the remaining planetesimals. Planet formation timescales are then 2–4 times longer than timescales for undisturbed disks; dust luminosities are 2–4 times smaller.
Positron implantation profiles in elemental and multilayer systems

Abstract The different Monte Carlo schemes for modeling positron and electron implantation in solids have been briefly reviewed. The main results (mean depth, backscattered fraction, profile shapes) of the different Monte Carlo schemes are compared with experimental data and with each other. Qualitatively, the results of the different Monte Carlo schemes are the same, the most significant difference is in the value of the mean implantation depth. The scaled profiles (for positron implantation in any material) generated by the different Monte Carlo schemes can be superimposed on a universal curve which can be appropriately parameterized. The shapes of the scaled profiles, and the mean depth parameters A and n, are found to be material-dependent.
Monte Carlo processes for including Chandra instrument response uncertainties in parameter estimation studies

Instrument response uncertainties are almost universally ignored in current astrophysical X-ray data analyses. Yet modern X-ray observatories, such as Chandra and XMM-Newton, frequently acquire data for which photon counting statistics are not the dominant source of error. Including allowance for performance uncertainties is, however, technically challenging in terms of both understanding and specifying the uncertainties themselves, and in employing them in data analysis. Here we describe Monte Carlo methods developed to include instrument performance uncertainties in typical model parameter estimation studies. These methods are used to estimate the limiting accuracy of Chandra for understanding typical X-ray source model parameters. The present study indicates that, for ACIS-S3 observations, the limiting accuracy is reached for ~ 104 counts.
The Contribution of Faculae and Network to Long-Term Changes in the Total Solar Irradiance

A new database of individual solar features has been compiled from the full-disk photometric Ca II K images taken at the San Fernando Observatory (SFO) during solar cycle 22. The distribution of facular region sizes differs at different phases of the solar cycle; the area coverage of large active regions is reduced by a factor of about 20 at solar minimum compared to solar maximum, while the smaller regions cover about half as much area at minimum as at maximum. The irradiance contribution of large features is about 10 times greater at maximum than at minimum, while that of small features is about twice as large. We have used this data set to model the fraction of variation in the total solar irradiance S that is due to solar features of various sizes. The data show that large-scale bright solar features, i.e., faculae, dominate the ~0.1% change in S between solar maximum and solar minimum. Using a variety of data sets, we conclude that large active regions produce about 80% of the total change.
Modeling and Optimization of Hybrid Solar Thermoelectric Systems with Thermosyphons

Abstract We present the modeling and optimization of a new hybrid solar thermoelectric (HSTE) system which uses a thermosyphon to passively transfer heat to a bottoming cycle for various applications. A parabolic trough mirror concentrates solar energy onto a selective surface coated thermoelectric to produce electrical power. Meanwhile, a thermosyphon adjacent to the back side of the thermoelectric maintains the temperature of the cold junction and carries the remaining thermal energy to a bottoming cycle. Bismuth telluride, lead telluride, and silicon germanium thermoelectrics were studied with copper–water, stainless steel–mercury, and nickel–liquid potassium thermosyphon-working fluid combinations. An energy-based model of the HSTE system with a thermal resistance network was developed to determine overall performance. In addition, the HSTE system efficiency was investigated for temperatures of 300–1200 K, solar concentrations of 1–100 suns, and different thermosyphon and thermoelectric materials with a geometry resembling an evacuated tube solar collector. Optimizations of the HSTE show ideal system efficiencies as high as 52.6% can be achieved at solar concentrations of 100 suns and bottoming cycle temperatures of 776 K. For solar concentrations less than 4 suns, systems with thermosyphon wall thermal conductivities as low as 1.2 W/mK have comparable efficiencies to that of high conductivity material thermosyphons, i.e. copper, which suggests that lower cost materials including glass can be used. This work provides guidelines for the design, as well as the optimization and selection of thermoelectric and thermosyphon components for future high performance HSTE systems.
A trigonal-prismatic hexanuclear technetium(II) bromide cluster: solid-state synthesis and crystallographic and electronic structure.

The compound Na{[Tc6Br12]2Br} has been obtained from the decomposition of TcBr4 under vacuum in a Pyrex ampule at 450 °C. The stoichiometry of the compound has been confirmed by energy-dispersive X-ray spectroscopy and its structure determined by single-crystal X-ray diffraction. The compound contains a trigonal-prismatic hexanuclear [Tc6Br12] cluster. The cluster is composed of two triangular Tc3Br6 units linked by multiple Tc-Tc bonds. In the Tc3Br6 unit, the average Tc-Tc distance [2.6845(5) A] is characteristic of Tc-Tc single bonds, while the average Tc-Tc distance between the two triangular units [2.1735(5) A] is characteristic of Tc≡Tc triple bonds. The electronic structure of the [Tc6Br12] cluster was studied by first-principles calculations, which confirm the presence of single and triple Tc-Tc bonds in the cluster.
Mixed valency in Yb7Co4InGe12: A novel intermetallic compound stabilized in liquid indium

The quaternary compounds RE7Co4InGe12 (RE = Dy, Ho, Yb) were obtained from In flux reactions as thin silver needles. RE7Co4InGe12 crystallizes in the tetragonal P4/m space group under a new structure type which is characterized by columnar units forming three different types of channels with the RE atoms situated within these channels. Investigation of the Yb analog with magnetic susceptibility measurements, X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES) revealed that Yb7Co4InGe12 is a mixed-valence compound and that the relative Yb3+/Yb2+ ratio is slightly temperature-dependent. Additionally, resistivity measurements for Yb7Co4InGe12 exhibited negative magnetoresistance at low temperatures.
Managing Care in the New Era of "Systems-Think": The Implications for Managed Care Organizational Liability and Patient Safety

Three major trends in American health policy are intersecting in a fascinating way. First, managed care has grown to become the most dominant form of health-care delivery, leading to reductions in health-care costs as insurers are able to influence health-care providers with financial incentives. Second, the present growth of managed care has slowed, almost to a standstill, largely on account of consumers questioning what effects these financial incentives are having on the care of patients — questioning that has been expressed in particular through lawsuits against managed care companies. Third, we are experiencing a renewed interest in the existence of medical error and how it may be reduced as a result of the Institute of Medicine’s (IOM) report, To Err Is Human: Building a Safer Health System. The most important aspect of this renaissance in error reduction has been its emphasis on health care as a system that can be made better through system-oriented change. The most frustrating aspect is that the IOM did not endorse change in malpractice liability, which consistently puts the impetus for reducing medical error on the individual provider rather than the system as a whole.
Asymptotically exact inference in conditional moment inequality models

This paper derives the rate of convergence and asymptotic distribution for a class of Kolmogorov–Smirnov style test statistics for conditional moment inequality models for parameters on the boundary of the identified set under general conditions. Using these results, I propose tests that are more powerful than existing approaches for choosing critical values for this test statistic. I quantify the power improvement by showing that the new tests can detect alternatives that converge to points on the identified set at a faster rate than those detected by existing approaches. A Monte Carlo study confirms that the tests and the asymptotic approximations they use perform well in finite samples. In an application to a regression of prescription drug expenditures on income with interval data from the Health and Retirement Study, confidence regions based on the new tests are substantially tighter than those based on existing methods.
Cusp latitude and the optimal solar wind coupling function

[1] Previous work has established that the linear correlation of the low-altitude particle cusp latitude with the southward component of the IMF is about 0.70. Several possibly better candidate functions for determining the coupling between the magnetosphere and the solar wind have been advanced, but none have been evaluated in terms of the cusp, which is a site of direct solar wind–magnetosphere interaction. On the basis of 11 years of DMSP satellite particle data from 1984–1994 (with verification from the subsequent 11 years, 1995–2005), we find that the best solar wind–magnetosphere coupling function involves electric field dimensions, such as the half wave rectifier (vBs) and the Kan-Lee electric field (EKL = vBTsin2(θc/2), where θc is the IMF clock angle). Both the half wave rectifier (r = 0.77) and the Kan-Lee (r = 0.78) functions have a linear correlation with cusp latitude which is noticeably better than the Bz function used in previous work, and also better than the ɛ parameter (ɛ = vB2sin4(θc/2)). However, the best correlation is with a function whose clock angle dependence is intermediate between the pure half wave rectifier (which implies no merging for Bz > 0) and the Kan-Lee function. Namely, EWAV = vBTsin4(θc/2) correlates with cusp latitude at the r = 0.81 level. This latter clock angle dependence has been previously suggested at various times by J. R. Wygant, by S.-I. Akasofu, and by V. M. Vasyliunas. The improved result holds for both the equatorward and poleward edge of the cusp, and regardless of how the IMF is propagated. Earlier work on cross polar cap potentials and on nightside auroral luminosity also favored the EWAV function, which in combination with our findings suggests a widely applicable result. Dayside merging is thus clearly not purely component driven, as the half wave rectifier formula implies. These results also suggest, albeit less convincingly, that merging shuts down for increasingly northward IMF more rapidly than the Kan-Lee electric field implies.
Trauma, stress, grief, loss, and separation among older adults in prison: the protective role of coping resources on physical and mental well-being

Recent evidence suggests that older adults in prison experience a high level of adverse life experiences that can be categorized as trauma, stress, grief and loss. However, there is a dearth of research that examines how older adults' use of physical, cognitive, emotional, social, and spiritual coping resources influence their physical and mental well-being. The current study uses a cross-sectional correlational design and a sample of 667 adults aged 50 and older in a northeastern state prison system. Data were collected using a mailed survey that included the Life Stressors Checklist-Revised, the Coping Resources Inventory, and Health-Related Quality of Life Survey to measure the variables of central interest. The majority (70%) of the sample reported some type of traumatic and stressful life experiences that included childhood and/or adult exposure to violence, unexpected and expected loss of a loved one, family separation, or being diagnosed with a serious physical or mental illness. Path analysis resu...
Synthetic α-(aminomethyl)-γ-butyrolactones and their anti-pancreatic cancer activities

Aminated α-methylene-γ-butyrolactones, which are readily synthesized with facile control of the diastereoisomerism, provide an economical and commercially-viable alternative to the use of aminated natural products. These aminoloactones, which exhibit excellent activity against three pancreatic cancer cell lines when measured at 10 μM-Panc-1, MIA PaCa-2, and BxPC-3-and are comparable to or better than parthenolide and dimethylaminoparthenolide (DMAPT, LC-1). It has also been shown that there is an effect on the biological activity depending on the identity of the amine.
Wind energy statistics for large arrays of wind turbines (New England and Central U.S. Regions)

Abstract The performance characteristics have been simulated for large dispersed arrays of 500–1500 kW wind turbines producing power and feeding it directly into the New England or Central U.S. utility distribution grids. These studies, based on design power performance curves, indicate that in good wind environments the 500 kW generators can average (on an annual basis) up to 240 kW mean power output, and the 1500 kW generators can average up to 350 kW mean power output. Higher mean power output (averaging up to 470 kW) is indicated, however from a hypothetical 1125 kW rated power unit designed to operate at wind speeds near those observed throughout the study area, rather than the higher design operating wind speed of the 1500 kW unit. The beneficial effect of operating large disperse arrays of wind turbines is that available power output can be increased—if winds are not blowing over one part of the array, chances are they will over some other part of the array. These studies indicate that wind power availability levels of 200 kW per 1125 kW generator were 77–93 per cent, depending on season. Reasonably steady high wind power in winter and high afternoon peak wind power in summer (corresponding to peak air conditioning load) means that significant peak load displacement can be achieved without the use of storage.
Remark about scalar curvature and Riemannian submersions

We consider modified scalar curvature functions for Riemannian manifolds equipped with smooth measures. Given a Riemannian submersion whose fiber transport is measure-preserving up to constants, we show that the modified scalar curvature of the base is bounded below in terms of the scalar curvatures of the total space and fibers. We give an application concerning scalar curvatures of smooth limit spaces arising in bounded curvature collapses.
The severity of pedestrian crashes: an analysis using Google Street View imagery

Data derived from visual inspection of Google Street View imagery associated with a variety of pedestrian and road infrastructure features are analyzed with a database of pedestrian casualties. These features include the presence of sidewalks, buffers between the road and the sidewalk, street lighting, number of travel lanes and the presence of medians, traffic controls at intersections, and posted speed limits. The analysis focuses on how these features affect the severity of a pedestrian casualty once it has occurred. Other controls used in the analysis include the age of the victim, ambient lighting conditions, and whether the vehicle driver was intoxicated. Results suggest that severity of pedestrian casualties is associated with the lack of sidewalks and buffers, high-speed roads, roads with six or more lanes and a median, and lack of traffic lighting when it is dark. Speed is a critical factor in determining the severity of crash outcomes, and most road characteristics affect crash outcomes to the extent that they moderate or facilitate high speeds. Casualties are more severe when it is dark than when it is daylight. Older pedestrians tend to have more severe casualties. A key contribution of this work is the use of Google Street View imagery; however, a limitation is that the analysis cannot examine the probability of a pedestrian casualty. Implications for road safety are consistent with national efforts to make streets safer via Complete Streets policies.
Vertex operator algebras associated to modified regular representations of affine Lie algebras

Let G be a simply-connected complex Lie group with simple Lie algebra and let be its affine Lie algebra. We use intertwining operators and Knizhnik�Zamolodchikov equations to construct a family of -graded vertex operator algebras (VOAs) associated to . These vertex operator algebras contain the algebra of regular functions on G as the conformal weight 0 subspaces and are -modules of dual levels in the sense that , where h is the dual Coxeter number of . This family of VOAs was previously studied by Arkhipov�Gaitsgory and Gorbounov�Malikov�Schechtman from different points of view. We show that when k is irrational, the vertex envelope of the vertex algebroid associated to G and the level k is isomorphic to the vertex operator algebra we constructed above. The case of rational levels is also discussed