cssi/SciSciGPT-SciSciNet huggingface dataset:
Foreseeable thermal, mechanical, and materials engineering problems of fusion reactor power plants

Abstract The engineering problems that will be posed by full-scale fusion reactor power plants are illustrated by examining a representative conceptual design. The temperature extremes that must be accommodated run from 4 K in superconducting magnets to 108 K in the plasma. These temperature differences lead to difficult problems with differential thermal expansion, high heat fluxes, and stringent thermal insulation requirements. The magnetic fields that must be provided run from 25 to 100 kG, and these fields induce forces on elements of the structure of the order of 20 000 tons. The walls of the chamber containing the plasma must withstand intense radiation by 14 MeV neutrons and 1–50 keV ions. Unusual fluid flow and heat transfer problems include two-phase boiling flow of helium in the super-conducting magnets, and the magnetohydrodynamic effects on the flows of red hot lithium and boiling potassium in a high magnetic field. These and many other problems must be solved in such a way as to give a reliable, safe system at a reasonable capital cost, and this must be done with materials whose nuclear, physical, and fabrication properties and resistance to corrosion meet all of the requisite boundary conditions.
THERMAL FLIPPING OF INTERSTELLAR GRAINS

In interstellar dust grains, internal processes dissipate rotational kinetic energy. The dissipation is accompanied by thermal fluctuations, which transfer energy from the vibrational modes to rotation. Together, these processes are known as internal relaxation. For the past several years, internal relaxation has been thought to give rise to thermal flipping, with profound consequences for grain alignment theory. I show that thermal flipping is not possible in the limit that the inertia tensor does not vary with time.
Uncertainty Quantification and Certification Prediction of Low-Boom Supersonic Aircraft Configurations

The primary objective of this work was to develop and demonstrate a process for accurate and efficient uncertainty quantification and certification prediction of low-boom, supersonic, transport air...
Balanced actuator and sensor placement for flexible structures

Properties of flexible structures in modal and balanced coordinates are derived. From these properties the root-mean-square law of the Hankel singular values is obtained. It says that the squares of the Hankel singular values of a set of sensors and actuators is approximately a root-mean-square sum of the squares of the Hankel singular values for each individual sensor and actuator. This property allows us to evaluate each actuator and sensor in terms of the joint controllability and observability, and to serve as a tool of the actuator and/or sensor placement methodology.
Camphanylboronic acid, a chiral derivatizing agent for optical purity determination of diols

Abstract Camphanylboronic acid is a simple, effective chiral derivatizing agent for the optical purity determination of 1,2-diols. Esterification to the boronate esters, even with hindered diols proceeds in quantitative yield. Optical purity is determined by 13 C-NMR spectroscopy.
Cantor series constructions contrasting two notions of normality

Renyi (Mat Lapok 7:77–100, 1956) made a definition that gives a generalization of simple normality in the context of Q-Cantor series. In Mance http://arxiv.org/abs/0911.1485), a definition of Q-normality was given that generalizes the notion of normality in the context of Q-Cantor series. In this work, we examine both Q-normality and Q-distribution normality, treated in Lafer (Normal numbers with respect to Cantor series representation, 1974) and Salat (Czechoslovak Math J 18(93):476–488, 1968). Specifically, while the non-equivalence of these two notions is implicit in Lafer (Normal numbers with respect to Cantor series representation. Washington State University, 1974), in this paper, we give an explicit construction witnessing the nontrivial direction. That is, we construct a base Q as well as a real x that is Q-normal yet not Q-distribution normal. We next approach the topic of simultaneous normality by constructing an explicit example of a base Q as well as a real x that is both Q-normal and Q-distribution normal.
Self-Intersection Numbers of Curves on the Punctured Torus

On the punctured torus the number of essential self-intersections of a homotopy class of closed curves is bounded (sharply) by a quadratic function of its combinatorial length (the number of letters required for its minimal description in terms of the two generators of the fundamental group and their inverses). We show that if a homotopy class has combinatorial length L, then its number of essential self-intersections is bounded by (L − 2)2/4 if L is even, and (L − 1)(L − 3)/4 if L is odd. The classes attaining this bound can be explicitly described in terms of the generators; there are (L − 2)2 + 4 of them if L is even, and 2(L − 1)(L − 3) +8 if L is odd. Similar descriptions and counts are given for classes with self-intersection number equal to one less than the bound. Proofs use both combinatorial calculations and topological operations on representative curves. Computer-generated data are tabulated by counting for each nonnegative integer how many length-L classes have that selfintersection number, f...
Measurements of the Effects of Smoke on Active Circuits

Smoke has long been recognized as the most common source of fire damage to electrical equipment; however, most failures have been analysed after the fire was out and the smoke vented. The effects caused while the smoke is still in the air have not been explored. Such effects have implications for new digital equipment being installed in nuclear reactors. The US Nuclear Regulatory Commission is sponsoring work to determine the impact of smoke on digital instrumentation and control. As part of this programme, Sandia National Laboratories has tested simple active circuits to determine how smoke affects them. These tests included the study of three possible failure modes on a functional board: (1) circuit bridging, (2) corrosion (metal loss), and (3) induction of stray capacitance. The performance of nine different circuits was measured continuously on bare and conformally coated boards during smoke exposures lasting 1 h each and continued for 24 h after the exposure started, The circuit that was most affected by smoke (100% change in measured values) was the one most sensitive to circuit bridging. Its high impedance (50 M Omega) was shorted during the exposure, but in some cases recovered after the smoke was vented, The other two failure modes, corrosion and induced stray capacitance, caused little change in the function of the circuits. The smoke permanently increased resistance, of the circuit tested for corrosion, implying that the contacts were corroded. However, the change was very small (less than 2%). The stray-capacitance test circuit showed very little change after a smoke exposure in either the short or long term. The results of the tests suggest that conformal coatings and type of circuit are major considerations when designing digital circuitry to be used in critical control systems.
"The Use of the Census to Estimate Childhood Mortality: Comparisons fromthe 1900 and 1910 United States Census Public Use Samples"

In this article we present estimates of childhood mortality calculated by indirect methods for the whole United States...in conjunction with data from the 1900 and 1910 PUMS....The estimates are for the entire nation and relate to the period just prior to the censuses of 1900 and 1910....The present 1910 indirect mortality estimates are made for the total population as well as for the white black native-white and foreign-born white populations....The results reported in this article are presented entirely as probabilities of child death between birth and given ages {q(x)s} along with the implied expectations of life at birth and approximate dates to which the estimates applied. (EXCERPT)
THE HORMONE OF THE ADRENAL CORTEX

We have previously1 demonstrated that an extract which will definitely prolong the lives and ameliorate the symptoms of adrenal-ectomized cats can be made from the adrenal cortex.We have proposed t...
The Sensor Selection Problem for Bounded Uncertainty Sensing Models

We address the problem of selecting sensors so as to minimize the error in estimating the position of a target. We consider a generic sensor model where the measurements can be interpreted as polygonal, convex subsets of the plane. In our model, the measurements are merged by intersecting corresponding subsets, and the measurement uncertainty corresponds to the area of the intersection. This model applies to a large class of sensors, including cameras. We present an approximation algorithm which guarantees that the resulting error in estimation is within factor 2 of the least possible error. In establishing this result, we formally prove that a constant number of sensors suffice for a good estimate-an observation made by many researchers. We demonstrate the utility of this result in an experiment where 19 cameras are used to estimate the position of a target on a known plane. In the second part of this paper, we study relaxations of the problem formulation. We consider 1) a scenario where we are given a set of possible locations of the target (instead of a single estimate) and 2) relaxations of the sensing model. Note to Practitioners-This paper addresses a problem which arises in applications where many sensors are used to estimate the position of a target. For most sensing models, the estimates get better as the number of sensors increases. On the other hand, energy and communication constraints may render it impossible to use the measurements from all sensors. In this case, we face the sensor selection problem: how to select a "good" subset of sensors so as to obtain "good" estimates. We show that under a fairly restricted sensing model, a constant number of sensors are always competitive with respect to all sensors and present an algorithm for selecting such sensors. In obtaining this result, we assume that the sensor locations are known. In future research, we will investigate methods that are robust with respect to errors in sensor localization/calibration
A general bifunctional catalyst for the anti-Markovnikov hydration of terminal alkynes to aldehydes gives enzyme-like rate and selectivity enhancements.

A new, bifunctional catalyst for anti-Markovnikov hydration of terminal alkynes to aldehydes (6) allows practical room-temperature hydration of alkyl-substituted alkynes. Other outstanding features include near-quantitative aldehyde yields from both alkyl- and aryl-substituted alkynes and wide functional group tolerance. The uncatalyzed rate of alkyne hydration is measured for the first time, showing the enzyme-like rate and selectivity enhancements of aldehyde formation by 6. For aldehyde formation, an uncatalyzed rate 600 000 years. The catalyzed rate is up to 23.8 mol (mol 6)-1 h-1 and 10 000:1 ratio in favor of aldehyde. Changes in rate and selectivity induced by 6 are thus >2.4 × 1011 and 300 000, respectively.
Generation And Amplification Of Nanosecond Duration Multiline Hf Laser Pulses

High-power, fast-rising pulses of hydrogen fluoride laser energy suitable for laser-fusion target interaction experiments can in principle be generated by directing an electro-optically shuttered oscillator pulse through one or more electron-beam driven amplifiers. We have constructed and successfully tested a three-stage HF master oscillator-power amplifier (MOPA) configuration using SF6-C2H6 in which an E-0 generated 4-ns-FWHM pulse was amplified in an electron-beam-excited third stage and subsequently isolated with a Brewster angle splitter. Independent experiments in which a 100-ns-FWHM pilot pulse interacted with the power amplifier demonstrated for the first time complete extraction of the available laser energy. These two results provide strong evidence that with upgrading to H2-F2, it should be possible to obtain nanosecond duration pulses with power levels sufficient for meaningful laser fusion target coupling experiments.
Some reductions on Jacobian problem in two variables

Let f=(f1,f2) be a regular sequence of affine curves in C2. Under some reduction conditions achieved by composing with some polynomial automorphisms of C2, we show that the intersection number of curves (fi) in C2 equals to the coefficient of the leading term xn−1 in g2, where n=degfi(i=1,2) and (g1,g2) is the unique solution of the equation yJ(f)=g1f1+g2f2 with deggi⩽n−1. So the well-known Jacobian problem is reduced to solving the equation above. Furthermore, by using the result above, we show that the Jacobian problem can also be reduced to a special family of polynomial maps.
Government Bond Market Seasonality, Diversification, and Cointegration: International Evidence

Using government bond market data for the United States, Canada, the United Kingdom, Germany, France, and Japan, I investigate several hypotheses. Market efficiency is investigated by testing for seasonality and cointegration. The seasonality results are mixed. In regression tests, a January effect is detected in several markets (United States, Germany, France, United Kingdom, and Canada) using local currencies. However, in a nonparametric test, the January effect is supported only for France. When U.S. dollar returns are used, regression results also reveal a January effect for several markets (United States, Germany, France, and United Kingdom). These results are not confirmed by a nonparametric test. Correlation analysis shows considerable diversification opportunities for short-term investors. Cointegration tests indicate that several of the markets share cointegrating vectors, increasing the possibilities of using other endogenous bond markets to better predict movements in a particular market.
Ten trends in managed care and their impact on the biopsychosocial model

Dr. Sharfstein's introduction: Managed care has had a profound impact on clinical practice. Clinicians find fourth and fifth parties are looking over thier shoulders to review their treatment plans for cost-efficiency. The biopsychosocial model of diagnosis and treatment is called into question as more stringent measures of medical necessity and appropriateness become the basis for reimbursement. In this column, Dr. Robert Schreter identifies ten trends in managed care and examines their impact on the biopsychosocial model.
Petri net models of concurrent Ada programs

Abstract In this paper we give a translation of a subset of the programming language Ada to Petri nets. The subset contains Ada rendezvous and dynamic task creation, but does not contain loops. The design of the translation algorithm was influenced by methods of denotational semantics which made the implementation of the algorithm particularly simple in the programming language ML. This approach makes possible proofs about the nature of the Petri net models. Properties of a concurrent Ada program can be studied by analyzing the Petri net model. It is possible to determine the possible interleavings of statements and do static deadlock detection. We are interested in applying the models of Ada programs to the problem of determining which program segments form the critical path in the time it takes an Ada program to execute.
New Results on Heavy Flavor Baryons

Heavy flavor baryons are attractive systems for testing effective theories for weak lifetime and decay systematics. Recently, new experimental results have mitigated one historic problem in the weak lifetime systematics and continued another. The charm baryon system continues to show new high mass, narrow states well isolated from one another. The spectroscopy of these states will challenge new advances in lattice gauge theoretic calculations of baryon structure. Double charm baryons still are seen only by SELEX, which showed a new $\Xi_{cc}^{++*}$ candidate. High-sensitivity searches by BELLE and BaBar show only featureless background.
Catalyst free one-pot synthesis of symmetrical diaryl tellurides with Te0/KOH

Abstract A highly efficient new protocol for C-Te bond formation leading to symmetrical diaryl tellurides has been developed. The synthesis employed aryl iodides and elemental tellurium as starting materials in the presence of KOH. It is a one-pot reaction without using any catalyst. Utilizing this new protocol, a variety of aryl and heteroaryl iodides are reacted with elemental tellurium to afford the corresponding diaryl tellurides in good to excellent yields.
Generator-produced alpha-emitters

This review briefly describes the nuclear characteristics and production parameters for 7.2-h {sup 211}At, 60.6-min {sup 212}Bi, 45.6-min {sup 213}Bi, 11-d {sup 233}Ra, and 20-h {sup 255}Fm. These a-emitting radioisotopes are the subject of current interest for a-particle-mediated radioimmunotherapy.
Neurological Paraneoplastic Syndromes

Cancer arising outside of the nervous system (systemic cancer) often causes neurological disability without spreading to the nervous system [1] (Table 1). Such indirect or paraneoplastic effects of systemic cancer on the nervous system include vascular disorders (hemorrhages and/or infarction), infections, metabolic and nutritional disorders, as well as several disorders called by Brain and Norris [2] “remote effects of cancer on the nervous system”. For the neurologist, the term paraneoplastic syndrome and remote effects of cancer are synonymous and can be defined as “neurological disorders pathogenetically related to a systemic cancer but not ascribable to nervous system metastases or to destruction of vital systemic organs by the tumor or by treatment of the tumor”. Paraneoplastic syndromes affect any portion of the nervous system; they either mainly involve a single cell type, such as the Purkinje cell in paraneoplastic cerebellar degeneration (PCD), or the cholinergic synapse, in the Lambert-Eaton myasthenic syndrome (LEMS), or they may involve multiple areas of the nervous system simultaneously, as in neuromyopathy or encephalomyelitis associated with cancer (Table 2). Neurological disorders that are clinically and pathologically identical to paraneoplastic syndromes also occur in the absence of cancer but at substantially decreased incidence [3]. For example, LEMS is rare in the general population but affects about 3% of patients with small cell lung cancer [4]. About 60% of patients with LEMS have small cell lung cancer [5]. Nevertheless, 30–40% of patients with LEMS will have neither identifiable cancer nor develop that disease within several years following the diagnosis and treatment of LEMS. Table 3 gives our estimates of the likelihood that a given neurological syndrome is paraneoplastic in origin.
Snowmobiling: characteristics of owners, patterns of use and injuries†☆

Abstract Snowmobilers injured in northern Vermont during the 1971–1972 and 1972–1973 seasons were compared with uninjured snowmobilers from the same communities. Lack of familiarity with the machine or the environment was an important factor in injury events. Among injured adults there was overrepresentation of persons who had been drinking, who have higher horsepower machines which they use at faster speeds, who drive greater highway mileage, and who have an excess of previous snowmobile injuries, highway crashes, and traffic citations. The vehicle itself appeared to contribute to the occurrence or severity of injury in at least half of the events, and there is urgent need to improve upon the stability, lighting, energy attenuation capacity, and other features of the snowmobile. Gross inadequacies of emergency care were identified, including use of alcohol after injury, delay in seeking care and general absence of first aid, including only rare splinting for fractures. Finally, when the injured arrived at the hospital some of them were lectured and berated because their injuries had involved a form of recreation not to the liking of a few members of the hospital staff.
On the convergence and singularities of the J-Flow with applications to the Mabuchi energy

The J-flow of S. K. Donaldson and X. X. Chen is a parabolic flow on Kahler manifolds with two Kahler metrics. It is the gradient flow of the J-functional that appears in Chen's formula for the Mabuchi energy. We find a positivity condition in terms of the two metrics that is both necessary and sufficient for the convergence of the J-flow to a critical metric. We use this result to show that on manifolds with ample canonical bundle, the Mabuchi energy is proper on all Kahler classes in an open neighborhood of the canonical class defined by a positivity condition. This improves previous results of Chen and of the second author. We discuss the implications of this for the problem of the existence of constant-scalar-curvature Kahler metrics. We also study the singularities of the J-flow and, under certain conditions (which always hold for dimension 2) derive some estimates away from a subvariety. We discuss the conjectural remark of Donaldson that if the J-flow does not converge on a Kahler surface, then it should blow up over some curves of negative self-intersection. © 2007 Wiley Periodicals, Inc.
Seeing Dark Energy

This talk is largely based on the work now published in (Riess et al. in Astrophys. J. 659:98, 2007).
Theory of Idealized Two-Dimensional Ballute in Newtonian Hypersonic Flow

A differential equation governing the geometry of a two-dimensional ballute in hypersonic flow and its constraining boundary conditions are derived under idealized assumptions. By solving these equations, the shape of the ballute is determined over a range of conditions. Lift, drag, pitching moment, and the allowed limit of center-of-gravity location for stability (meta-center) are then calculated using Newtonian hypersonic approximation. It is shown that the meta-center occurs near the forward end because of compliance of the ballute membrane to the shock layer pressures, especially at low free-stream densities. In order for the vehicle employing the ballute to be stable at all densities, the center of gravity must be within approximately the forward 20 percent of overall length of the vehicle. However, typical flight trajectories of an aeroassisted orbital transfer vehicle employing the ballute for aerobraking show that the vehicle may be able to complete its atmospheric flight without tumbling provided that the center of gravity is located within the forward 43 percent of the vehicle length because of the relatively short duration of flight through the destabilizing low-density regime.
Using the internet for news and perceptions of news organization bias

Purpose – The purpose of this paper is to reveal perceptions of news organization bias among people who use the internet.Design/methodology/approach – Data for this study were drawn from the Pew Research Center June 2005 News Interest Index. Respondents were asked if news organizations were politically biased in their reporting. Another question asked respondents if news organizations had a liberal or conservative bias. The final question asked respondents to judge news organization bias on political and social issues.Findings – In two of the three perceptions of internet user/non‐user ratings of ideological bias in news organizations, internet news users surveyed rate news organizations as more biased than non‐users. However, when asked to ascertain either liberal or conservative bias in news organizations, non‐internet news users were more likely to claim that news organizations were biased.Research limitations/implications – More valid measures of the dimension of liberal and conservative bias could he...
G29.7-0.3 ― another supernova remnant with an identity crisis

New radio and X-ray observations of the galactic supernova remnant G29.7-0.3 show that it is composed of two spectrally distinct components: a steep-spectrum, incomplete shell 3 arcmin in extent enclosing a flat-spectrum, X-ray emitting region 30 arcsec across. Thus, G29.7-0.3 joins the ranks of supernova remnants which exhibit a combination of Crab-like and shell remnant attributes. The Crab-like core has the highest ratio of X-ray radio luminosity of all the Crab-like remnants observed to date, suggesting that it is an extremely young object.
A solution for automatic unit control

Sales activity tapes, as well as receiving tapes produced in the receiving departments of the several stores, are to be processed against an inventory tape, and a daily selling report produced. These tapes are to be sorted into order; in this particular case, they will be sorted according to store, department, class, manufacturer, style, color, size, etc. Since it has been indicated that the inventory consists of some 200,000 items, several tapes actually would be required for the master files, perhaps organized on the basis of stores and departments.
Transients from initial conditions in cosmological simulations

We study the impact of setting initial conditions in numerical simulations using the standard procedure based on the Zel'dovich approximation (ZA). As it is well known from the perturbation theory, ZA initial conditions have incorrect second- and higher-order growth and therefore excite long-lived transients in the evolution of the statistical properties of density and velocity fields. We also study the improvement brought by using more accurate initial conditions based on second-order Lagrangian perturbation theory (2LPT). We show that 2LPT initial conditions reduce transients significantly and thus are much more appropriate for numerical simulations devoted to precision cosmology. Using controlled numerical experiments with ZA and 2LPT initial conditions, we show that simulations started at redshift z i = 49 using the ZA underestimate the power spectrum in the non-linear regime by about 2,4 and 8 per cent at z = 0, 1, and 3, respectively, whereas the mass function of dark matter haloes is underestimated by 5 per cent at m = 10 15 M ⊙ h -1 (z = 0) and 10 per cent at m = 2 × 10 14 M ⊙ h - (z = 1). The clustering of haloes is also affected to the few per cent level at z = 0. These systematics effects are typically larger than statistical uncertainties in recent mass function and power spectrum fitting formulae extracted from numerical simulations. At large scales, the measured transients in higher-order correlations can be understood from first principle calculations based on perturbation theory.
Augmented biracks and their homology

We introduce augmented biracks and define a (co)homology theory associated to augmented biracks. The new homology theory extends the previously studied Yang–Baxter homology with a combinatorial formulation for the boundary map and specializes to N-reduced rack homology when the birack is a rack. We introduce augmented birack 2-cocycle invariants of classical and virtual knots and links and provide examples.
Applying extra-resource analysis to load balancing

Previously, extra-resource analysis has been used to argue that certain on-line algorithms are good choices for solving specific problems because these algorithms perform well with respect to the optimal off-line algorithm when given extra resources. We now introduce a new application for extra-resource analysis: deriving a qualitative divergence between off-line and on-line algorithms. We do this for the load-balancing problem, the problem of assigning a list of jobs on m identical machines to minimize the makespan, the maximum load on any machine. We analyze the worst-case performance of on-line and off-line approximation algorithms relative to performance of the optimal off-line algorithm when the approximation algorithms have k extra machines. Our main result are the following: The Longest-Processing-Time (ℒ) algorithm will produce a schedule with makespan no larger than that of the optimal off-line algorithm if ℒ has at least (4m−1) /3 machines while the optimal off-line algorithm has m machines. In contrast, no on-line algorithm can guarantee the same with any number of extra machines. Copyright © 2000 John Wiley & Sons, Ltd.
Diffusion of tungsten in chromium: Experiments and atomistic modeling

Abstract The solute diffusion of tungsten at low concentrations in chromium has been investigated both by experiments and computational methods. From finite-source diffusion experiments measured with an Electron Probe Micro Analyzer at temperatures from 1526 to 1676 K, it was found that the diffusivity of tungsten in chromium follows the Arrhenius relationship D = D 0 exp - Q RT , where the activation energy was found to be Q = 386 ± 33 kJ/mol. Diffusion of tungsten in chromium was investigated computationally with both the activation–relaxation technique (ART) and molecular dynamics (MD) using a hybrid potential. From ART, the effective diffusion activation energy was determined to be Q = 315 ± 20 kJ/mol based on a multi-frequency model for a monovacancy mechanism. From MD, the square displacement of tungsten was analyzed at temperatures between 1200 and 1700 K, and the diffusion activation energy was determined to be Q = 310 ± 18 kJ/mol. In spite of possible complications arising due to experimental compositions away from the dilute limit, the agreement between experiments and simulations falls within the calculated uncertainties, supporting a monovacancy mechanism for diffusion of tungsten in chromium.
Use of computer-assisted rescreening as an ancillary tool to subclassify AGUS cervical smears.

A substantial percentage of women with a diagnosis of atypical glandular cells of undetermined significance (AGUS) on cervical smears harbor a significant squamous or glandular, preneoplastic or neoplastic lesion on subsequent follow-up. Attempts to subclassify AGUS smears by conventional methods have had mixed results. To determine whether subclassification of AGUS cervical smears using computer-assisted rescreening based on the neural network would improve correlation with subsequent histologic follow-up, 91 cervical smears, conventionally diagnosed as AGUS without concomitant squamous lesions, were subjected to analysis by a computer-assisted automated screening system. Computer-generated images were evaluated by a cytotechnologist without the knowledge of the histologic outcomes. Prior to manual review, each case was classified as either within normal limits, no review required; or abnormal, review required. Based on the degree of abnormality, the latter category was further subclassified into either low probability or high probability of abnormality. The results of the computer-assisted reclassification were then compared with the histologic follow-up of all patients. Thirty-three cases (38.8%) had a significant lesion on histologic follow-up. The lesions included 4 CIN I, 7 CIN II/III, 12 endocervical adenocarcinomas (ACA), and 10 endometrial ACA. Based on computer-generated images, 65% of the smears that were triaged as high probability of abnormality, 11.5% that were triaged as low probability of abnormality, and 10.5% that were triaged as within normal limits had a significant lesion on subsequent follow-up. We conclude that computer-assisted rescreening aids in the triage of AGUS smears and that computer-assisted rescreening based on the neural network or other algorithms may be a useful ancillary tool for subclassifying AGUS cervical smears.
Do Market Returns Influence Risk Tolerance? Evidence from Panel Data

This study used the 1992–2006 waves of the Health and Retirement Study (HRS) to investigate changes in risk tolerance levels over time in response to stock market returns. Findings indicate that risk tolerance tends to increase when market returns increase and decrease when market returns decrease. Individuals who change their risk tolerance in this manner are likely to invest in stocks when prices are high and sell when prices are low. Researchers, employers, financial educators and practitioners should help investors overcome the bias of overweighting recent news of market performance.
Advances in the chemistry of β-lactam and its medicinal applications

β-Lactam or azetidin-2-one is an important structural motif of the penicillin, cephalosporin, carbapenem and carbecephem classes of antibiotics.1 Naturally occurring as well as synthetic monobactams, such as nocardicins and tabtoxin, are also known for their unique antibacterial activities.2–4 Besides their importance as the key structural component of β-lactam antibiotics, β-lactams have been attracting considerable interest in organic synthesis as versatile synthetic intermediates and chiral synthons.5–13 In addition, the β-lactam scaffold has found new pharmaceutical applications other than its use as antibiotics, such as LHRH antagonists,14 cholesterol-absorption inhibitors,15 and anticancer agents.16–19 The ring strain of the β-lactam skeleton facilitates ring-opening reactions,8,20,21,22 and this unique property has been exploited for the synthesis of a variety of medicinally active compounds. For the last couple of decades, a large number of β-lactam-based synthetic methods, collectively termed as “β-lactam-synthon method”, has been developed. This method has provided highly efficient routes to a variety of non-protein amino acids, oligopeptides, peptidomimetics and nitrogen-heterocycles, as well as biologically active natural and unnatural products of medicinal interest, such as indolizidine alkaloids, paclitaxel, docetaxel, taxoids, cyptophycins, lankacidins, etc.5,7–13 In this report, we present an overview of the evolution of the methods for the synthesis of enantiopure β-lactams, and the applications of the “β-lactam synthon method” for the synthesis of biologically active compounds of medicinal interest. Examples of the use of the rigid β-lactam scaffold for drug design and discovery are also described.
Morita Equivalence of $C^*$-Crossed Products by Inverse Semigroup Actions and Partial Actions

Morita equivalence of twisted inverse semigroup actions and discrete twisted partial actions are introduced. Morita equivalent actions have Morita equivalent crossed products.
Searching for planets in the Hyades. III. The quest for short-period planets

We have been using the Keck I High Resolution Spectrograph to search for planetary companions in the Hyades cluster. We selected four stars from this sample that showed significant radial velocity variability on short timescales to search for short-period planetary companions. The radial velocities of these four stars were monitored regularly with the Hobby-Eberly Telescope for approximately 2 months, while sparse data were also taken over ~4 months: we also obtained near-simultaneous photometric observations with one of the automatic photoelectric telescopes at Fairborn Observatory. For three of the stars, we detect photometric variability with the same period present in the radial velocity (vr) measurements, compatible with the expected rotation rates for Hyades members. The fourth star continues to show vr variations and minimal photometric variability but with no significant periodicity. This study shows that for the three stars with periodic behavior, a significant portion of the vr fluctuations are likely due primarily to magnetic activity modulated by stellar rotation rather than planetary companions. Using simple models for the vr perturbations arising from spot and plage, we demonstrate that both are likely to contribute to the observed vr variations. Thus, simultaneous monitoring of photometric (photospheric) and spectroscopic (chromospheric) variations is essential for identifying the cause of Doppler-shifted absorption lines in more active stars.
Additions of Allyl, Allenyl, and Propargylstannanes to Aldehydes and Imines

Natural products that contain stereocenters such as those having polyacetate and polypropionate structures are of considerable interest. Current technology for constructing these chiral molecules consists of strategies broadly defined as “acyclic stereocontrol.” The most efficient tools for this strategy include modern aldol reactions and the reaction of carbonyl compounds with allylmetal reagents. In order to achieve highly efficient syntheses of natural products rich with stereochemistry, highly stereoselective transformations are required. One solution is the use of allylstannane reagents. Their advantages include ease of handling, relative stability, and selective reactivity. The addition of allystannanes to aldehydes combines the process of CC bond formation with the stereoselective production of one or two new stereocenters. The configuration of these centers is predictable based on reaction conditions. Oxygen substitution also contributes to the versatility of these reagents. Recently developed chiral allenystannanes and the use of InCl3 as a transmetallation agent have greatly enhanced the practical utility of these reagents. This chapter is limited mainly to carbonyl and imine addition reactions, most of which create one or two new stereocenters. Keywords: allylstannanes; allenylstannanes; propargylstannanes; thermal reactions; promoted reactions; Lewis acid; transmetallation; achiral aldehydes; chiral aldehydes; indium trichloride; scope; limitations; natural products; addition reactions; stannane reagents; boranes; tin chlorides; method comparisons; imines; palladium catalyst; synthesis applications; oxygen substitution
High Resolution Aerospace Applications Using the NASA Columbia Supercomputer

This paper focuses on the parallel performance of two high-performance aerodynamic simulation packages on the newly installed NASA Columbia supercomputer. These packages include both a high-fidelity, unstructured, Reynolds-averaged Navier-Stokes solver, and a fully-automated inviscid flow package for cut-cell Cartesian grids. The complementary combination of these two simulation codes enables high-fidelity characterization of aerospace vehicle design performance over the entire flight envelope through extensive parametric analysis and detailed simulation of critical regions of the flight envelope. Both packages are industrial-level codes designed for complex geometry and incorporate customized multigrid solution algorithms. The performance of these codes on Columbia is examined using both MPI and OpenMP and using both the NUMAlink and InfiniBand interconnect fabrics. Numerical results demonstrate good scalability on up to 2016 CPUs using the NUMAlink4 interconnect, with measured computational rates in the vicinity of 3 TFLOP/s, while InfiniBand showed some performance degradation at high CPU counts, particularly with multigrid. Nonetheless, the results are encouraging enough to indicate that larger test cases using combined MPI/OpenMP communication should scale well on even more processors.
Dividend Initiations and Asymmetric Information: A Hazard Model

This paper investigates the dynamics of dividend policy using a hazard model. Specifically, the paper examines dividend initiations for a sample of firms that went public between 1990 and 1997. These dividend initiations are examined in the context of an alternative explanation based on the pecking order theory. The results indicate that the probability or the hazard rate of a dividend initiation is negatively related to both the level of asymmetric information and growth opportunities and positively related to the level of cash flow. These results are consistent with a pecking order explanation but inconsistent with a signaling explanation.
Mixed variable optimization using Taguchi's orthogonal arrays

Taguchi's orthogonal arrays for robust design are used in this paper in a nontraditional way to solve a mixed continuous-discrete structural optimization problem. The factors of an orthogonal array correspond to the members of a structure and the levels of each factor correspond to the material choices of each member. Based on the number of factors to be studied and the number of levels of each factor, an appropriate orthogonal array is selected for each specific problem. The number of rows of the orthogonal array correspond to the number of experiments (i.e. continuous sizing optimizations) to be conducted. The response of these experiments, which are the weight of the optimal designs corresponding to different material settings, are then used to calculate the mean effect of each factor level. Some possible optimal material settings can then be determined. Three examples are presented in this paper. Analysis using Taguchi's orthogonal arrays was able to isolate several near optimal or optimal designs. The accuracy and efficiency of the proposed method compared to more traditional solution methodologies are also discussed.
Surface impedance of several magnetic superconductors

Abstract Spin fluctuations play an important role in determining the surface impedance, Z s , in magnetic superconductors. The suppression of spin fluctuations in Er 0.5 Ho 0.5 Rh 4 B 4 gives rise to an abrupt change of Z s at the reentrant superconduction critical temperature T c2 . However, gradual changes of Z s for SmRh 4 B 4 and ErRh 4 B 4 due to spin fluctuations were observed in superconducting state.
Study of Two Axisymmetric Inlets Designed for Mach 3.5

Results from wind-tunnel tests of two large-scale models of axisymmetric mixed-compression inlet systems designed for Mach number 3.5 are compared. One inlet incorporated a 'traveling'-bleed system in an effort to achieve maximum transonic engine airflow supply. The other inlet required only a 'fixed'-bleed system, but had 21 percent less transonic airflow supply. The inlet with fixed bleed appears more attractive, if auxiliary airflow systems are used to increase the transonic airflow supply, because it can be 45 percent shorter and would be considerably lighter than the traveling-bleed inlet. In addition, the fixed-bleed inlet offers more operating-control margin at supersonic Mach numbers when the inlet is started. Further, its off-design performance is higher because separation of the flow in the subsonic diffuser can be avoided - something that apparently cannot be done with a traveling-bleed inlet without reducing the transonic airflow supply. Finally, it appears that the management and efficiency of bleed airflow for the fixed-bleed inlet can be improved using analytical methods verified by the tests.
Refractive Errors Associated With Hemangiomas of the Eyelids and Orbit in Infancy

Asymmetrical refractive errors, both astigmatic and myopic, were associated with infantile hemangiomas of the eyelids and orbit in 46% of 37 patients who had large lesions and upper eyelid involvement predisposing to the ammetropia. The axis of the astigmatic error related to the location of the eyelid hemangioma and correlated closely with keratometric measurements of corneal astigmatism. The refractive errors tended to be stable despite eventual resolution of the hemangiomas. Efforts to combat strabismic and refractive amblyopia were rewarding in many patients. A history of complete eyelid occlusion during part of the first year of life was associated with dense amblyopia and eccentric fixation in some patients, but in other patients this history was compatible with the eventual development of useful vision. Absence of an asymmetrical refractive error in patients with eyelid and orbital hemangiomas rendered the prognosis for vision good in involved eyes.
Introduction of full-length APC modulates cyclooxygenase-2 expression in HT-29 human colorectal carcinoma cells at the translational level

Mutation of the adenomatous polyposis coli (APC) gene is associated with the earliest stages of colorectal tumorigenesis and appears to be responsible for the hereditary condition familial adenomatous polyposis (FAP). Evidence indicates that cyclooxygenase-2 (COX-2) is induced and at elevated levels in human colorectal cancers and in the polyps of mouse FAP models. We have used HT-29 cells, a human colorectal carcinoma cell line with a mutant carboxy-truncated APC gene, in which intact APC gene has been introduced under the control of an inducible promoter. These HT-29-APC cells provide a suitable model system to examine how COX-2 expression becomes dysregulated after loss of APC function. Induction of full-length APC causes the HT-29-APC cells to undergo apoptosis. However, differentiation, as measured by alkaline phosphatase activity, is not induced upon expression of full-length APC. Full-length APC protein has been shown to bind the intracellular protein beta-catenin and, as a result, the Lef/Tcf transcription factors are down-regulated. Analysis of APC immunoprecipitates demonstrate a time-dependent increase of beta-catenin interacting with full-length APC. Thus, the Lef/Tcf signaling pathway is intact at this point in these cells. Furthermore, upon expression of full-length APC, COX-2 protein expression is down-regulated while COX-2 mRNA levels remain the same. These data indicate that APC plays a role, either directly or indirectly, in the translational regulation of COX-2. Treatment of the HT-29-APC cells with sodium butyrate, an inducer of apoptosis, does not alter COX-2 protein expression. Thus, COX-2 down-regulation appears to be APC specific and not just due to apoptotic induction. APC appears to uniquely regulate COX-2 expression. The mechanism by which COX-2 protein expression is down-regulated in the HT-29-APC cells is under investigation.
Static behavior and the effects of thermal cycling in hybrid laminates

The influence of hybridization with stacking sequence variation on static stiffness, strength, ultimate strain and residual properties after thermal cycling of graphite/Kevlar 49/ epoxy and graphite/S-glass/epoxy angle-ply laminates was investigated. Tensile stress-strain curves to failure and uniaxial tensile properties were determined for all laminates. Theoretical predictions of modulus, Poisson's ratio and ultimate strain were made, based on linear lamination theory, constituent ply properties and measured strength. Reasonably good agreement was found. Stacking sequence variation showed no significant systematic influence on the measured results. Specimens containing only two 0-degree Kevlar or S-glass plies behaved linearly to failure. Specimens containing four 0-degree Kevlar or S-glass plies displayed characteristic non-linearity. One group of laminates was subjected to a tensile load and to 100 thermal cycles between room temperature and 280°F, and another group to a tensile load and 100 thermal cycles between room temperature and −100°F. All surviving specimens were tested statically to failure to determine residual properties which were compared with the properties of uncycled specimens. Specimens containing two Kevlar or two S-glass plies behaved linearly to failure. Residual moduli in these specimens were lower than for uncycled specimens but residual strengths and ultimate strains were higher. Specimens with four Kevlar or four S-glass plies showed some nonlinear behavior. No significant differences were found between residual and uncycled values for modulus and strength.