cssi/SciSciGPT-SciSciNet huggingface dataset:
LONG-TERM PREDICTIVE AND CONSTRUCT VALIDITY OF TWO TRADITIONAL PREDICTORS OF LAW SCHOOL PERFORMANCE

The relative contribution of two traditional, widely used preadmission measures, undergraduate grade point average (UGPA) and the Law School Admission Test (LSAT), to predicting academic performance in each of the three years of law school was investigated in a heterogeneous sample of 23 law schools. The contribution of each measure was uneven across years, with the LSAT making its greatest contribution in early years and UGPA in later years. Differences between law school years with respect to the nature of instructional techniques and curricular emphases were considered in order to gain a better understanding of the construct validity of each measure as a predictor of performance in law school. The results were consistent with the test sponsor's interpretation of the LSAT as a measure of the ability to confront new situations and new problems such as those encountered in the first year of law school. They were also consistent with an interpretation of UGPA as a measure not only of academic competence but also of other qualities (such as persistence and motivation) that are needed over the long haul for the study of law. The author wishes to acknowledge the Law School Admission Council for its support of the project on which this paper is based. Thanks go to Franklin R. Evans for helpful suggestions in conducting the research; to Thomas F. Donlon, Kenneth M. Wilson, and three anonymous reviewers for thoughtful reviews of this paper; to Miriam Godshalk for helpful editorial suggestions; and to the admissions staff of the participating schools for providing the data. Special thanks go to Frieda Hardy and Marie Ormond for managing the data collection activities; to Christopher Constantini, Katherine Kornhauser, and Norma Norris for processing and analyzing the data; to Henry Braun for statistical consultation; and to Lorraine Simon for her careful attention to numerous administrative tasks and to the final preparation of this manuscript.
The spin-flavor dependence of nuclear forces from large-N QCD

Abstract We show that nuclear interactions are SU (4) symmetric at leading order in chiral perturbation theory in the large- N limit of QCD. The nucleons and delta resonances form a 20-dimensional representation of SU (4) and we show how Wigner's supermultiplet symmetry SU (4) sm , under which the nucleons transform as a 4-dimensional representation, follows as an accidental low energy symmetry. Exploiting SU (4) symmetry allows one to express the 18 independent leading N , Δ interaction operators invariant under SU (2) I × SU (2) J in terms of only two couplings. The three flavor analogue allows one to express the 28 leading octet, decuplet interactions in terms of only two couplings, which has implications for hypernuclei and strangeness in “neutron” stars.
Calibration of in-situ plasma instruments

Abstract Calibration of scientific instruments is an important task. Only by proper calibration and understanding of the instrument can we address the scientific questions. Unfortunately, in the field of space plasma physics calibration is not considered science and therefore, calibration techniques and results are often not reported in the space physics literature. This paper reviews how in-situ particle instruments for plasma measurements are calibrated in the laboratory and in flight. Absolute calibration traceable to a national measurements institute is very difficult to achieve. A calibration transfer standard is suggested to reduce relative differences of individual calibration facilities with each other. Instrument degradation is of particular concern for long-term studies, but there is no inflight calibration standard either. Cross calibration with other instruments on the same spacecraft is described. In order to speed up the calibration for multi-spacecraft missions, several methods ranging from artificial intelligence methods, numerical ray tracing to improved vacuum chamber pump speed are suggested. In summary, there is a need for further improvements in the area of instrument calibrations, especially in light of the up-coming multi-spacecraft missions or for long-term studies of solar cycle effects.
Club-guessing, stationary reflection, and coloring theorems

Abstract We obtain very strong coloring theorems at successors of singular cardinals from failures of certain instances of simultaneous reflection of stationary sets. In particular, the simplest of our results establishes that if μ is singular and μ + → [ μ + ] μ + 2 , then there is a regular cardinal θ μ such that any fewer than cf ( μ ) stationary subsets of S ≥ θ μ + must reflect simultaneously.
Evidence in Virgo for the Universal Dark Matter Halo

A model is constructed for the mass and dynamics of M87 and the Virgo Cluster. Existing surface photometry of the galaxy, mass estimates from X-ray observations of the hot intracluster gas, and the velocity dispersions of early-type Virgo galaxies are all used to constrain the run of dark matter density over 0 ≤ r 2 Mpc in the cluster. The "universal" halo advocated by Navarro, Frenk, & White, ρdm ∝ (r/rs)-1(1 + r/rs)-1, provides an excellent description of the combined data, as does a Hernquist profile with ρdm ∝ (r/rs)-1(1+r/rs)-3. These models are favored over isothermal spheres, and their central structure is preferred to density cusps either much stronger or much weaker than r-1. The galaxies and gas in the cluster trace its total mass distribution (ρgal ∝ ρgas ∝ ρdm), the galaxies' velocity ellipsoid is close to isotropic, and the gas temperature follows the virial temperature profile of the dark halo. The virial radius and mass and the intracluster gas fraction of Virgo are evaluated.
Boundedness on inhomogeneous Lipschitz spaces of fractional integrals singular integrals and hypersingular integrals associated to non-doubling measures

In the context of a finite measure metric space whose measure satisfies a growth condition, we prove “T1” type necessary and sufficient conditions for the boundedness of fractional integrals, singular integrals, and hypersingular integrals on inhomogeneous Lipschitz spaces. We also indicate how the results can be extended to the case of infinite measure. Finally we show applications to Real and Complex Analysis.
Laser velocimetry: the elusive third component

The historical development of techniques for measuring three velocity components using laser velocimetry is presented. The techniques are described and their relative merits presented. Many of the approaches currently in use based on the fringe laser velocimeter have yielded inaccurate measurements of turbulence intensity in the on-axis component. A possible explanation for these inaccuracies is presented along with simulation results.
Numerical Modeling of Gas Expansion from Microtubes

The expansion of argon jets from cylindrical microtubes is investigated using a three-dimensional unstructured direct simulation Monte Carlo (DSMC) method. The simulation results for a microtube with an aspect ratio (tube length to diameter) of 1.5 are shown to compare well with theoretical formulations of free-jet expansion. The DSMC simulations are performed in computational domains that feature both an internal microtube region and external jet expansion region. Microtubes with orifice diameters ranging between 100 μm and 100 nm are used in the simulations in order to investigate the effects of Knudsen number, aspect ratio, Reynolds number, and microtube scale on jet structure. The jet shape is shown to narrow with increasing Knudsen number, increasing aspect ratio and decreasing Reynolds number. The reduction in relative number density along the flow axis is shown to decrease with increasing Knudsen number and Reynolds number.
The Information Content of Business Combination Disclosure Level

ABSTRACT: This study explores causes and effects of business combinations disclosure level. Investigating the association between disclosure level on business combination and acquirers' future performance, I find that acquirers' future performance as measured by the change in ROA and by abnormal stock returns increases with abnormal levels of disclosure on business combinations. Investigating the determinants of business combination disclosure, I find that the disclosure level on business combinations decreases with abnormal levels of the purchase price allocated to goodwill. Both results provide evidence consistent with disclosure theory and suggest that acquirers tend to provide less forthcoming disclosure on less favorable acquisitions (“bad news”). I also provide evidence consistent with investors failing to immediately incorporate the information content of business combination disclosure level into their information set and evidence that investors are quicker to react to firms with negative abnormal...
The plank problem for symmetric bodies

Given a symmetric convex bodyC andn hyperplanes in an Euclidean space, there is a translate of a multiple ofC, at least\(\frac{1}{{n + 1}}\) times as large, insideC, whose interior does not meet any of the hyperplanes. The result generalizes Bang's solution of the plank problem of Tarski and has applications to Diophantine approximation.
[P2S10]4-: A novel polythiophosphate anion containing a tetrasulfide fragment

The novel polythiophosphate anion [P2S10]4- adopts two different conformations in the structure of Cs4P2S10; these consist of two PS4 tetrahedra connected via a disulfide, giving rise to a S42- fragment. Cs4P2S10 has been characterized by single-crystal X-ray diffraction, differential thermal analysis, Raman, optical diffuse reflectance, and 31P solid-state NMR spectroscopy. This new salt may be useful as a starting material for solid-state reactions or for developing the solution coordination chemistry of this potential ligand.
Nuclear physics from scratch

We report on applications of the ab initio, no-core shell model with the primary goal of achieving an accurate description of nuclear structure and reactions from the fundamental inter-nucleon interactions. We show that realistic two-nucleon interactions are inadequate to describe the low-lying structure of 10B, and that realistic three-nucleon interactions are essential. We report preliminary attempts to compute astrophysical S-factors
Inverse Problem in Cylindrical Electrical Networks

In this paper we study the inverse Dirichlet-to-Neumann problem for certain cylindrical electrical networks. We define and study a birational transformation acting on cylindrical electrical networks called the electrical $R$-matrix. We use this transformation to formulate a general conjectural solution to this inverse problem on the cylinder. This conjecture extends work of Curtis, Ingerman, and Morrow [Linear Algebra Appl., 283 (1998), pp. 115--150] and of de Verdiere, Gitler, and Vertigan [Comment. Math. Helv., 71 (1996), pp. 144--167] for circular planar electrical networks. We show that our conjectural solution holds for certain „purely cylindrical” networks. Here we apply the grove combinatorics introduced by Kenyon and Wilson [Trans. Amer. Math. Soc., 363 (2011), pp. 1325--1364].
Digital divide or digital opportunity in the Mississippi Delta region of the US

Abstract This study analyzes the interdependence of telecommunications manufacturing, services, and user industries in the Mississippi Delta region of the US to understand the social and economic prospects of poorer rural areas of the US as advanced technologies rapidly proliferate. An underlying assumption is that telecommunications industries should not be viewed only by the employment they directly support; they should also be analyzed in terms of their linkages to other industries and how those linkages influence the competitiveness and growth prospects of businesses and public institutions in the region by building a capable community of technology users. The absence of leading telecom manufacturing and service firms in rural Delta counties together with low levels of connectivity suggest that digital divide problems are very real for the region. The central economic development challenge should be to ensure that rural businesses, government, health care, education, and non-profit institutions gain access to an advanced telecommunications infrastructure and that they develop the capacity to leverage this access to enhance their performance and expand their reach.
Modeling of joints with clearance in flexible multibody systems

This paper is concerned with the modeling of joints with clearance within the framework of finite element based dynamic analysis of nonlinear, flexible multibody systems. For actual joints, clearance, lubrication and friction phenomena can significantly affect the dynamic response of the system. In this work, the effects of clearance and lubrication are studied for revolute and spherical joints. The formulation is developed within the framework of energy preserving and decaying time integration schemes that provide unconditional stability for nonlinear, flexible multibody systems. Numerical examples are presented that demonstrate the efficiency and accuracy of the proposed approach. The importance of modeling structural damping and limited driving power are discussed.
The Pains of Endometriosis

Endometriosis is a disease defined by the presence of endometrial tissue outside of the uterus. Severe pelvic pain is often associated with endometriosis, and this pain can be diminished with therapies that suppress estrogen production. Many women with endometriosis also suffer from other chronic pain conditions. Recent studies suggest that mechanisms underlying these pains and sensitivity to estrogen involve the growth into the ectopic endometrial tissue of a nerve supply, which could have a varied and widespread influence on the activity of neurons throughout the central nervous system.
Raman Scattering Study of the Crystallization and Phase Transformations of ZrO2

X-ray diffraction, electron diffraction, and Raman scattering measurements are presented for dehydrated amorphous ZrO2. Although the material lacks sufficient crystallinity to diffract X rays, electron diffraction patterns indicate a microcrystallinity with a grain size of 15 to 30 A. Raman spectra characteristic of the metastable tetragonal polymorph were obtained from these materials. Heating the amorphous materials induces recrystallization into first a metastable tetragonal phase and then the stable monoclinic phase.
Metall-Isotopie-Effekt bei Metall-Ligand-Schwingungen

Die Nutzung des Isotopie-Effekts unter Verwendung von Schwermetallisotopen ermoglicht nunmehr eine eindeutige Zuordnung der Metall-Ligand-Schwingungen in den IR- und Raman-Spektren von Komplexverbindungen. Die bisher mit dieser neuen Methode erhaltenen Ergebnisse sowie ihre derzeitigen Limitationen werden im vorliegenden Fortschrittsbericht beschrieben.
The Datum Flow Chain: A systematic approach to assembly design and modeling

Current CAD systems are ‘part-centric’ and do not capture the underlying logic of an assembly at an abstract level. We need to make CAD systems ‘assembly-centric’. To be able to lay out, analyze, outsource, assemble and debug complex assemblies, we need ways to capture their fundamental structure in a top-down design process, including the designer's strategy for constraining the parts kinematically and locating them accurately with respect to each other. We describe a concept called the ‘Datum Flow Chain’ to capture this logic. Most assembly problems occur due to ineffective datum logic or the choice of assembly procedures that are not consistent with the datum logic, if any, that was used to design the parts. The DFC relates the datum logic explicitly to the product's key characteristics, assembly sequences, and choice of mating features, and provides the information needed for tolerance analyses. Two types of assemblies are addressed: Type-1, where the assembly process puts parts together at their pre-fabricated mating features, and Type-2, where the assembly process can incorporate in-process adjustments to redistribute variation. Two types of assembly joints are defined: mates that pass dimensional constraint from part to part, and contacts that merely provide support. The scope of DFC in assembly planning is presented using several examples. Analysis tools to evaluate different DFCs and select the ones of interest are also presented.
How Economic Development and Family Planning Programs Combined to Reduce Indonesian Fertility

This paper examines the contributions of family planning programs, economic development, and women’s status to Indonesian fertility decline from 1982 to 1987. Methodologically we unify seemingly conflicting demographic and economic frameworks into a single “structural” proximate-cause model as well as controlling statistically for the targeted (nonrandom) placement of family planning program inputs. The results are consistent with both frameworks: 75% of the fertility decline resulted from increased contraceptive use, but was induced primarily through economic development and improved education and economic opportunities for females. Even so, the dramatic impact of the changes in demand-side factors (education and economic development) on contraceptive use was possible only because there already existed a highly responsive contraceptive supply delivery system.
Spray characteristics of a spill-return airblast atomizer

The spray characteristics of a spill-return airblast atomizer are examined using water as the working fluid. Measurements of mean drop size, drop size distribution, spray cone angle, and circumferential liquid distinction, are carried out over wide ranges of liquid injection pressures and atomizing air velocities. Generally, it is found that an increase in nozzle bypass ratio worsens the atomization quality and widens the spray cone angle. Increase in airblast air velocity may improve or impair atomization quality depending on whether it increases or decreases the relative velocity between the liquid and the surrounding air. Airblast air can also be used to modify the change in spray cone angle that normally accompanies a change in bypass ratio.
Detection of Extended Hot Water in the Outflow from NGC 2071

We report the results of spectroscopic mapping observations carried out toward an ~1' × 1' region within the northern lobe of the outflow from NGC 2071 using the Infrared Spectrograph (IRS) of the Spitzer Space Telescope. These observations covered the 5.2-37 μm spectral region and have led to the detection of a number of ionic, atomic, and molecular lines, including fine-structure emission of Si+, Fe+, S++, S, the S(0)-S(7) pure rotational lines of H2, the R(3) and R(4) transitions of HD, and at least eleven transitions of H2O. In addition, the 6.2, 7.4, 7.6, 7.9, 8.6, and 11.3 μm PAH emission bands were also observed and several transitions of OH were tentatively detected. Most of the detected line transitions were strong enough to map, including, for the first time, three transitions of hot H2O. We find that (1) the water emission is extended; (2) the extended emission is aligned with the outflow; and (3) the spatial distribution of the water emission generally follows that observed for H2. Based on the measured line intensities, we derive an HD abundance relative to H2 of (1.1–1.8) × 10−5 and an H2O number density of 12-29 cm−3. The H2 density in the water-emitting region is not well constrained by our observations, but is likely between 3 × 104 and 106 cm−3, yielding an H2O abundance relative to H2 of between 2 × 10−5 and 6 × 10−4. Finally, we note a possible departure from the H2O ortho-to-para ratio of 3 : 1 expected for water formed in hot postshocked gas, suggesting that a significant fraction of the water vapor we detect may arise from H2O sputtered from cold dust grains.
First‐in‐Human Trial Participants: Not a Vulnerable Population, but Vulnerable Nonetheless

The 21st-century translational science campaign could lead to an increase in first-in-human (FIH) trials. As tests of investigational interventions move from the laboratory to human research, scientists, officials, and review committees should address ongoing concerns about the ethics of FIH trials. In this article, I describe three ethical considerations relevant to all FIH trials: (1) the requirement for adequate preclinical research; (2) study design safeguards; and (3) choice of subject population. I also examine specific ethical considerations relevant to the three subject populations (healthy volunteers, seriously ill patients lacking standard treatment options, and stable patients) involved in FIH research. I recommend a variety of actions that could increase subject protection and the value of the information generated in FIH trials.
Nanomaterial deposits formed by DC plasma spraying of liquid feedstocks

An experimental system consisting of an axial feed plasma gun, a variable-rate liquid delivery system, a liquid atomizer-feeder, and a substrate movement and control system was designed and assembled for preparing nanograined ceramic deposits. Sprayed deposits were produced with different spray and sol feed parameters and investigated in both the as-sprayed and heat-treated conditions. As-sprayed deposits were predominately hydroxide phases and were strongly adherent to the substrates. Postspray heat treatment at 873 K led to conversion of the alumina and zirconia deposits to γ-alumina and tetragonal zirconia phases, respectively. Subsequent heat treatment at 1273 K resulted in densification of the deposits and formation of high-temperature phases. A small increase in the grain size was observed with heat treatment, but the specimens still retained nanosized grains.
The strong Lefschetz property for coinvariant rings of finite reflection groups

Abstract In this paper we prove that a deformed tensor product of two Lefschetz algebras is a Lefschetz algebra. We then use this result in conjunction with some basic Schubert calculus to prove that the coinvariant ring of a finite reflection group has the strong Lefschetz property.
Substituent effects in dinuclear paddlewheel compounds: electrochemical and spectroscopic investigations

Abstract This review summarizes substituent effects in dinuclear compounds supported by diarylformamidinate (form) ligands, where aryl is phenyl substituted with various polar groups (X). These dinuclear compounds, M2(form)4(Lax)m with M as Mo, Ru, Rh, or Ni, Lax as either neutral or anionic axial ligand, and m=0–2, may undergo up to three (quasi)reversible one-electron, metal-centered redox processes. Linear correlations have been established between the electrode potentials (E1/2, Epc or Epa) and the substituent constants (σ) according to the following Hammett equation: ΔE=E(X)−E(H)=ρ(Σ σ), with the reaction constant ρ ranging from +60 to +100 mV. The existence of such relationships indicates that the energy levels of the frontier orbitals of dinuclear species are controlled precisely by the substituent within each series, and generally decrease with an increase in the electron withdrawing ability of the substituent. However, nearly identical UV–vis absorption spectra were observed within each homologous series, and one can infer a minimal substituent perturbation on the distribution of upper valence molecular orbitals. Axial ligation of organic π acids such as CO and phenylacetylide in both the diruthenium and dirhodium series also provides insight to the activation of these substrates by the dinuclear core, and the linear free energy relationship therein. A brief overview of other investigations of substituent effects in dinuclear compounds is provided also.
Annotating Sequence Data Using Genotator

In this postgenomic era, it is no longer necessary to argue the need for automated methods for sequence annotation. Many researchers have designed tools for analyzing DNA sequences, but running multiple tools and interpreting the results can be tedious and confusing. In the last few years, many analysis workbenches have been developed to help streamline the process of sequence annotation. Genotator, developed in 1996, is still a popular choice owing to its ease of use and its configurability. This article will review annotating sequence data using the Genotator.
Rabacus: A Python package for analytic cosmological radiative transfer calculations

Abstract We describe rabacus , a Python package for calculating the transfer of hydrogen ionizing radiation in simplified geometries relevant to astronomy and cosmology. We present example solutions for three specific cases: (1) a semi-infinite slab gas distribution in a homogeneous isotropic background, (2) a spherically symmetric gas distribution with a point source at the center, and (3) a spherically symmetric gas distribution in a homogeneous isotropic background. All problems can accommodate arbitrary spectra and density profiles as input. The solutions include a treatment of both hydrogen and helium, a self-consistent calculation of equilibrium temperatures, and the transfer of recombination radiation. The core routines are written in Fortran 90 and then wrapped in Python leading to execution speeds thousands of times faster than equivalent routines written in pure Python. In addition, all variables have associated units for ease of analysis. The software is part of the Python Package Index and the source code is available on Bitbucket at https://bitbucket.org/galtay/rabacus . In addition, installation instructions and a detailed users guide are available at http://pythonhosted.org//rabacus .
STERIC CONTROL OF OXIDATION SELECTIVITY IN MACROCYCLIC PHOSPHINE OXIDE-DITHIOETHERS

Abstract Macrocyclic phosphine oxide-disulfoxides 1a - e and 2a - e were synthesized by oxidation of the corresponding dithioethers with CPBA. Four stereoisomers are possible, but a single stereoisomer was 02 isolated as the major product in each case. This paper describes the structural characterization of several trioxides as well as studies designed to determine the origin of oxidation selectivity.
The Knowlton-Graham Partition Problem

A set partition technique that is useful for identifying wires in cables can be recast in the language of 0?1 matrices, thereby resolving an open problem stated by R. L. Graham in Volume 1 of this journal. The proof involves a construction of 0?1 matrices having row and column sums without gaps.
Managing atypical squamous cells of undetermined significance (ASCUS): Human papillomavirus testing, ASCUS subtyping, or follow-up cytology?

Abstract OBJECTIVE: This study related morphologic subtype, human papillomavirus status, and a second cytologic examination to the follow-up biopsy-proven high-grade squamous intraepithelial lesion (HSIL; grade II or III cervical intraepithelial neoplasia) after a cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS). STUDY DESIGN: Seven hundred four liquid-based cervical cytology specimens were classified as normal, "ASCUS, favor reactive" (AFR), "ASCUS, not otherwise specified," "ASCUS, favor low-grade squamous intraepithelial lesion," "ASCUS, favor HSIL" (AFHS), low-grade squamous intraepithelial lesion, and HSIL. Human papillomavirus typing used polymerase chain reaction-restriction fragment length polymorphism analysis. A longitudinal review of the cytologic and histologic records of ASCUS cases with ≥1 follow-up test or biopsy ascertained the frequency of a follow-up diagnosis of biopsy-proven HSIL (grade II or III cervicalintraepithelial neoplasia). RESULTS: Three hundred eighty-six cases (208 ASCUS, 68 normal, 86 with low-grade squamous intraepithelial lesions, and 24 with HSIL) were evaluated. High-risk human papillomavirus (HRHPV positive) was lowest with normal cytology (13%), highest with HSIL (71%), and was present in 29.8% of ASCUS cases, ranging from 22.2% (AFR) to 75% (AFHS). Most ASCUS tests (64%) were followed by a negative cytologic or histologic examination. Overall, 3.8% and 11% of ASCUS and HRHPV-positive ASCUS had histologic outcomes of HSIL. AFHS had the highest (25%) and AFR had the lowest (1.1%) proportion of HSIL outcomes. Sensitivity, specificity, and positive predictive values of human papillomavirus testing for biopsy-proven HSIL were 87.5%, 72.5%, and 11.3%, respectively. CONCLUSION: HSIL and AFHS are distinguished by the highest frequency of HRHPV types and higher rates of HSIL outcome. The remaining categories of ASCUS are heterogeneous with respect to human papillomavirus type and HSIL risk, and the value of subclassification of these entities is dependent on the practice. A human papillomavirus detection system based on polymerase chain reaction-restriction fragment length polymorphism identifies a smaller percentage of high-risk human papillomaviruses than mixed probe-based methods, probably because of the more precise exclusion of cross-reacting low-risk human papillomavirus. Negative HRHPV findings by either system show a markedly reduced risk of an HSIL outcome. However, the relative advantage of human papillomavirus testing over follow-up cytology will be influenced by the frequency of negative follow-up cytologic examination and sensitivity of liquid-based preparations in a given practice. (Am J Obstet Gynecol 2002;186:396-403.)
A CHI wiggler ubitron amplifier experiment: wiggler characterization

Abstract A Ka-band (26–40 GHz) coaxial hybrid iron (CHI) wiggler ubitron amplifier experiment under construction at the Naval Research Laboratory is described. The principal goal of the experiment is to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Nonlinear simulations of the interaction are presented, along with the results of magnetic field measurements performed on a prototype version of the CHI wiggler.
The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy’s Central Black Hole: A Paradox of Youth

We have obtained the first detection of spectral absorption lines in one of the high-velocity stars in the vicinity of the Galaxy's central supermassive black hole. Both Brγ (2.1661 μm) and He I (2.1126 μm) are seen in absorption in S0-2 with equivalent widths (2.8 ± 0.3 and 1.7 ± 0.4 A) and an inferred stellar rotational velocity (220 ± 40 km s^(-1)) that are consistent with that of an O8-B0 dwarf, which suggests that it is a massive (~15 M_☉) young (less than 10 Myr) main-sequence star. This presents a major challenge to star formation theories, given the strong tidal forces that prevail over all distances reached by S0-2 in its current orbit (130-1900 AU) and the difficulty in migrating this star inward during its lifetime from farther out where tidal forces should no longer preclude star formation. The radial velocity measurements (v_z) = -510 ± 40 km s^(-1)) and our reported proper motions for S0-2 strongly constrain its orbit, providing a direct measure of the black hole mass of 4.1(±0.6) × 10^6 (Ro/8kpc)^3 M_☉. The Keplerian orbit parameters have uncertainties that are reduced by a factor of 2-3 compared to previously reported values and include, for the first time, an independent solution for the dynamical center; this location, while consistent with the nominal infrared position of Sgr A^*, is localized to a factor of 5 more precisely (±2 mas). Furthermore, the ambiguity in the inclination of the orbit is resolved with the addition of the radial velocity measurement, indicating that the star is behind the black hole at the time of closest approach and counterrevolving against the Galaxy. With further radial velocity measurements in the next few years, the orbit of S0-2 will provide the most robust estimate of the distance to the Galactic center.
Giant Radio Galaxies and Cosmic-Ray Acceleration

Giant radio galaxies (GRGs) are prime and unique laboratories for constraining the plasma processes that accelerate relativistic electrons within large intergalactic volumes. The evidence for short radiative loss times rules out certain scenarios for energy transport within their very large dimensions. This, combined with their high energy content, large ordered magnetic field structures, the absence of strong large-scale shocks, and very low upper limits on their internal thermal plasma densities, points to a direct and efficient conversion of force-free magnetic field to particle energy. This is underlined by the evidence in GRGs that their internal Alfven speeds are higher than the lobe expansion speeds. We discuss these constraints in the context of models in which the central black hole energy is initially extracted as electromagnetic Poynting flux that injects large amounts of magnetic flux into the lobes. Recent advances in the theory of collisionless magnetic reconnection make this a favored mechanism to explain the particle acceleration in these systems. The energy reservoir is likely to be force-free fields, which is independently consistent with recent models of initial electromagnetic energy transfer from the parent galaxy's supermassive black hole. Such a scenario has wide-ranging astrophysical consequences: it implies that space-distributed magnetic reconnection or some other highly efficient field-to-particle energy conversion process likely dominates in all extended extragalactic radio sources.
Rhenium(V)-Catalyzed Synthesis of 2-Deoxy-α-glycosides

A mild method for the synthesis of 2-deoxysugars from the coupling of glycals with a range of nucleophiles is described. The method employs 1 mol % of an air- and moisture-tolerant rhenium−oxo complex [ReOCl3(SMe2)(Ph3PO)] as a catalyst for the formation of O-, N-, and S-α-glycosides. The catalytic system tolerates a number of commonly employed protecting groups, including isopropylidene acetals, alkyl and silyl ethers, acetates, and benzoates. Furthermore, the high-oxidation-state complex selectively catalyzes the coupling with the glycal acceptor in preference to oxidation of the glycals, alcohols, and even thiols.
The Spatial Vectorcardiogram in Right Bundle Branch Block

The spatial vectorcardiograms of 24 subjects with electrocardiographic evidence of right bundle branch block are described. Correlation of the vectorcardiographic patterns observed, with clinical and roentgenologic data, suggests that the recognition of ventricular hypertrophy in the presence of such a conduction defect may be improved by this method of study.
New Time Signatures in Neutron Stars and Pulse-Height Variability in Crab

Accumulating evidence for new time scales other than the spin and orbital periods in several single and binary systems involving neutron stars are noted and the pulse height variability observed in Crab pulsar is discussed.
Insider ownership and signals: evidence from stock split announcement effects

This study examines whether investors regard the level of insider ownership of a firm as useful for evaluating stock split decisions. Results show that the abnormal returns at the announcement of stock splits are positively related to the level of insider ownership. The results prevail even after controlling for other relevant factors. Further analysis indicates the positive relation exists for small firms, but not for large firms. This indicates the market evaluates stock split decisions within the context of both insider ownership and information asymmetry.
Notes on D-branes in 2D type 0 string theory

In this paper we construct complete macroscopic operators in two dimensional type 0 string theory. They represent D-branes localized in the time direction. We give another equivalent description of them as deformed Fermi surfaces. We also discuss a continuous array of such D-branes and show that it can be described by a matrix model with a deformed potential. For appropriate values of parameters, we find that it has an additional new sector hidden inside its strongly coupled region.
THE YELLOW AND RED SUPERGIANTS OF M33

Yellow and red supergiants are evolved massive stars whose numbers and locations on the Hertzsprung-Russell (H-R) diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative number of yellow supergiants (YSGs) observed as a function of mass and those predicted by evolutionary models, while a disagreement between the predicted and observed locations of red supergiants (RSGs) on the H-R diagram was only recently resolved. Here, we extend these studies by examining the YSG and RSG populations of M33. Unfortunately, identifying these stars is difficult as this portion of the color-magnitude diagram is heavily contaminated by foreground dwarfs. We identify the RSGs through a combination of radial velocities and a two-color surface gravity discriminant, and after re-characterizing the rotation curve of M33 with our newly selected RSGs, we identify the YSGs through a combination of radial velocities and the strength of the O I λ7774 triplet. We examine ~1300 spectra in total and identify 121 YSGs (a sample that is unbiased in luminosity above log (L/L ☉) ~ 4.8) and 189 RSGs. After placing these objects on the H-R diagram, we find that the latest generation of Geneva evolutionary tracks shows excellent agreement with the observed locations of our RSGs and YSGs, the observed relative number of YSGs with mass, and the observed RSG upper mass limit. These models therefore represent a drastic improvement over previous generations.
Computer applications of lasers.

The applicability of lasers to the logic, memory, input-output, and data transmission linkages portions of computers are analyzed qualitatively. The more promising potential applications are considered to lie in the memory, interconnection, and input-output areas, and the least promising in the fast logic area. Coherent optical data preprocessing is cited as an example of an already clearly useful laser application.
Using decision diagrams to compactly represent the state space for explicit model checking

The enormous number of states reachable during explicit model checking is the main bottleneck for scalability. This paper presents approaches of using decision diagrams to represent very large state space compactly and efficiently. This is possible for asynchronous systems as two system states connected by a transition often share many same local portions. Using decision diagrams can significantly reduce memory demand by not using memory to store the redundant information among different states. This paper considers multi-value decision diagrams for this purpose. Additionally, a technique to reduce the runtime overhead of using these diagrams is also described. Experimental results and comparison with the state compression method as implemented in the model checker SPIN show that the approaches presented in this paper are memory efficient for storing large state space with acceptable runtime overhead.
Enantioselective Claisen rearrangements: development of a first generation asymmetric acyl-Claisen reaction.

The development of an enantioselective catalytic Claisen rearrangement remains an important yet elusive goal in chemical synthesis. With this objective in mind, we recently reported the acyl-Claisen rearrangement, a Lewis acid-catalyzed variant of the Bellus reaction that utilizes acid chlorides and allylic amines in the stereoselective synthesis of ɑ,β-disubstituted-y,δ-unsaturated carbonyls (eq 1).
SOI technology for the GHz era

Silicon-on-insulator (SOI) CMOS offers a 20–35% performance gain over bulk CMOS. High-performance microprocessors using SOI CMOS have been commercially available since 1998. As the technology moves to the 0.13-µm generation, SOI is being used by more companies, and its application is spreading to lower-end microprocessors and SRAMs. In this paper, after giving a short history of SOI in IBM, we describe the reasons for performance improvement with SOI, and its scalability to the 0.1-µm generation and beyond. Some of the recent applications of SOI in high-end microprocessors and its upcoming uses in low-power, radio-frequency (rf) CMOS, embedded DRAM (EDRAM), and the integration of vertical SiGe bipolar devices on SOI are described. As we move to the 0.1-µm generation and beyond, SOI is expected to be the technology of choice for system-on-a-chip applications which require high-performance CMOS, low-power, embedded memory, and bipolar devices.
Structure and dynamics of dipolar fluids under strong shear

Molecular dynamical simulation has been carried out to investigate the structure and dynamics of a dipolar fluid under strong shear. Dipolar fluid consists of polarizable particles, which have an induced dipole moment in the applied field direction. Shear stress is perpendicular to the field direction. When shear stress is small, the flow has a flowing-chain structure. If shear stress increases to pass a critical value, flowing-chain structure changes to flowing layer structure. Each layer is parallel to the flow direction and shear direction. Within one layer, particles form strings in the flow direction.
Reversible gel formation of triblock copolymers studied by molecular dynamics simulation

Molecular dynamics simulations have been employed to study the forma- tion of a physical (thermoreversible) gel by amphiphilic A-B-A triblock copolymers in aqueous solution. To mimic the structure of the hydrogel-forming polypeptides employed in experiments (W.A. Petka et al., Science 281, 389 (1998)), the end blocks of the polymer chains are modeled as hydrophobic rods representing the a-helical part of the polypeptides, whereas the central B block is hydrophilic and semiflexible. We have determined structural properties, such as the hydrophobic cluster-size distribu- tion function, the geometric percolation point, and pair correlation functions, and related them to the dynamic properties of the system. Upon a decrease in the tem- perature, a network structure is formed in which bundles of end blocks act as network junctions. Both at short and medium distances, increased ordering is observed, as characterized by the pair correlation function. Micelle formation and the correspond- ing onset of geometric percolation induce a strong change in dynamic quantities (e.g., in the diffusion constant and the viscosity) and cause the system to deviate from the Stokes-Einstein relation. The dynamic properties show a temperature dependence that is strongly reminiscent of the behavior of glass-forming liquids. The appearance of a plateau in the stress autocorrelation function suggests that the system starts to exhibit a solid-like response to applied stress once the network structure has been formed, although the actual sol-gel transition occurs only at a considerably lower tem- perature. � C 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 959-969, 2005
The Determinants of Disciplinary System Effectiveness: A Line-Management Perspective

This study examines how characteristics of an organization and its disciplinary system affect line-management perceptions of disciplinary system effectiveness. Using responses from 418 organizations, we found a curvilinear relationship between disciplinary system restrictiveness and perceptions of disciplinary system effectiveness. Results also indicate that monitoring costs, investment in training, grievance systems, unionization, and pressure to perform are significantly related to perceptions of disciplinary system effectiveness.
A Probabilistic Micromechanical Code for Predicting Fatigue Life Variability: Model Development and Application

This paper summarizes the development of a probabilistic micromechanical code for treating fatigue life variability resulting from material variations. Dubbed MICROFAVA (micromechanical fatigue variability), the code is based on a set of physics-based fatigue models that predict fatigue crack initiation life, fatigue crack growth life, fatigue limit, fatigue crack growth threshold, crack size at initiation, and fracture toughness. Using microstructure information as material input, the code is capable of predicting the average behavior and the confidence limits of the crack initiation and crack growth lives of structural alloys under LCF or HCF loading. This paper presents a summary of the development of the code and highlights applications of the model to predicting the effects of microstructure on the fatigue crack growth response and life variability of the α+β Ti-alloy Ti-6Al-4V.
Case study of the failure of two 13.8KV control & metering transformers that caused significant equipment damage

The degradation and failure of cast-coil epoxy windings within 13.8kV control power transformers and metering potential transformers has been shown to be dangerous to both equipment and personnel, even though best industrial design practices were followed. Accident scenes will be examined for two events at a U.S. Department of Energy laboratory. Failure modes will be explained and current design practices discussed with changes suggested to prevent a recurrence and to minimize future risk. New maintenance philosophies utilizing partial discharge testing of the transformers as a prediction of end-of-life will be examined.
Reaction between nitric oxide and ozone in solid nitrogen

Nitrogen dioxide, NO2, is produced when nitric oxide, NO, and ozone, O3, are suspended in a nitrogen matrix at 11-20 K. The NO2 is formed with first-order kinetics, a 12 K rate constant of (1.4 + or - 0.2) x 0.00001/sec, and an apparent activation energy of 106 + or - 10 cal/mol. Isotopic labeling, variation of concentrations, and cold shield experiments show that the growth of NO2 is due to reaction between ozone molecules and NO monomers, and that the reaction is neither infrared-induced nor does it seem to be a heavy atom tunneling process. Reaction is attributed to nearest-neighbor NO.O3 pairs probably held in a specific orientational relationship that affects the kinetic behavior. When the temperature is raised, more such reactive pairs are generated, presumably by local diffusion. Possible mechanisms are discussed.
Effective Thermal Conductivity of a Thin, Randomly Oriented Composite Material

The thermal conductivity of a randomly oriented composite material is modeled using a probabilistic approach in order to determine if a size effect exists for the thermal conductivity at small composite thicknesses. The numerical scheme employs a random number generator to position the filler elements, which have a relatively high thermal conductivity, within a matrix having a relatively low thermal conductivity. The results indicate that, below some threshold thickness, the composite thermal conductivity increases with decreasing thickness, while above the threshold the thermal conductivity is independent of thickness. The threshold thickness increases for increasing filler fraction and increasing k{sub f}/k{sub m}, the ratio between the filler and matrix thermal conductivities.
Hearing pseudoconvexity with the Kohn Laplacian

A bounded domain in Open image in new window with connected Lipschitz boundary is pseudoconvex if the bottom of the essential spectrum of the Kohn Laplacian on the space of (0,q)-forms, 1≤q≤n−1, with L2-coefficients is positive.
Polarimetric Imaging of the Massive Black Hole at the Galactic Center

The radio source Sagittarius A* in the Galactic center emits a polarized spectrum at millimeter and submillimeter wavelengths that is strongly suggestive of relativistic disk accretion onto a massive black hole. We use the well-constrained mass of Sgr A* and a magnetohydrodynamic model of the accretion flow to match both the total flux and polarization from this object. Our results demonstrate explicitly that the shift in the position angle of the polarization vector, seen at wavelengths near the peak of the millimeter to submillimeter emission from this source, is a signal of relativistic accretion flow in a strong gravitational field. We provide maps of the polarized emission to illustrate how the images of polarized intensity from the vicinity of the black hole would appear in upcoming observations with very long baseline radio interferometers (VLBIs). Our results suggest that near-term VLBI observations will be able to directly image the polarized Keplerian portion of the flow near the horizon of the black hole.