cssi/SciSciGPT-SciSciNet huggingface dataset:
Improved post-transplant survival in the United States for patients with cholangiocarcinoma after 2000.

The incidence of cholangiocarcinoma (CCA) continues to rise. Orthotopic liver transplantation (OLT) can be used for selected patients with localized but unresectable hilar CCA. Although initial post-OLT survival rates were poor, outcomes after introduction of the Mayo Clinic protocol have been more promising and there has been increased interest in OLT for CCA nationally. The aim of this study is to determine post-transplant survival and prognostic factors for patients undergoing OLT for CCA. A retrospective analysis of all patients with CCA listed nationwide for OLT between October 1987 and May 2008 was performed using the Scientific Registry of Transplant Recipients database. Survival curves were generated using the Kaplan–Meier method and compared using log-rank test. Of 595 patients with CCA listed for OLT, 359 (60.3 %) underwent OLT. Median age at OLT was 49 years, 66 % were male and 91 % were Caucasian. The median follow-up time was 2 years. There has been an increasing number of liver transplants performed for CCA since 2000. The 1- and 5-year probability of survival was 85.8 and 51.4 %, respectively. On multivariate analysis, significant prognostic factors for decreased post-OLT survival included transplant before 2000 (HR 11.25, 95 % CI 1.28–98.7) and acute cellular rejection (HR 5.64, 95 % CI 1.14–27.8). Survival after transplant for CCA has improved over time, and OLT is being used more frequently in the treatment of CCA. Significant predictors of post-OLT survival include a history of acute rejection and date of transplant in relation to the publication of Mayo protocol results.
Cycle groups for Artin stacks

We construct an algebraic homology functor for Artin stacks of finite type over a field, and we develop intersection-theoretic properties.
Condensation of a strongly interacting parton plasma into a hadron gas in high energy nuclear collisions

Abstract We examine the effects of color screening on the transition of a parton plasma into a hadron gas at RHIC energies. It is found that as expected, color screening posed itself as a significant barrier for hadronization. Parton-hadron conversion would therefore be delayed and prolonged when compared to that occuring in a vacuum. Due to the on-going expansion, the resulting hadron densities are lowered. Parton equilibration is also shown to be seriously disrupted in the process.
Complex Fenchel-Nielsen coordinates with small imaginary parts

Kahn and Markovic \cite{KahnMark} proved that the fundamental group of each closed hyperbolic three manifold contains a closed surface subgroup. One of the main ingredients in their proof is a theorem which states that an assignment of nearly real, complex Fenchel-Nielsen coordinates to the cuffs of a pants decomposition of a closed surface $S$ induces a quasiFuchsian representation of the fundamental group of $S$. We give a new proof of this theorem with a slightly stronger conditions on the Fenchel-Nielsen coordinates and explain how to use the exponential mixing of the geodesic flow on a closed hyperbolic three manifold to prove that our theorem is sufficient for the applications in the work of Kahn and Markovic \cite{KahnMark}.
Wind-Tunnel Tests of an Aircraft Turret Model

The drag of a half-scale aircraft laser turret is investigated in a low-speed wind tunnel. Forces, moments, and pressures are recorded fortheturretand aft-mounted fairings and splitter plates. Oil traces and tufts indicatethat the e ow is characterized by dominant vortices shedding from the top of the turret and a large trailing wake of vorticity. Splitter plates are ineffective in reducing drag as a result of the strong e ow over the top of the turret. A small fairing reduces the baseline drag coefe cient by 49% but is unable to produce attached e ow near the turret. A large fairing eliminates nearly all separation regions and reduces the baseline drag coefe cient by 55%.
Statistical plant set estimation using Schroeder-phased multisinusoidal input design

Abstract In this paper, a frequency domain method is developed for plant set estimation. The estimation of a plant “set” rather than a point estimate is required to support many methods of modern robust control design. The approach here is based on using a Schroeder-phased multisinusoid input design which has the special property of placing input energy only at the discrete frequency points used in the computation. A detailed analysis of the statistical properties of the frequency domain estimator is given, leading to exact expressions for the probability distribution of the estimation error and many important properties. It is shown that for any nominal parametric plant estimate, one can use these results to construct an overbound on the additive uncertainty to any prescribed statistical confidence. The “soft” bound thus obtained can be used to replace “hard” bounds presently used in many robust control analysis and synthesis methods.
Phonon Mechanism of High-Tc Superconductivity

For a long time the majority view has been that phonons are irrelevant to the mechanism of high-temperature superconductivity. However, recent experimental results, including the neutron inelastic scattering measurements reviewed here, seriously challenge this view. We point out that the electron–phonon coupling in the cuprates can be substantially different from that in simple metals because of the covalency and strong electron correlation. In particular certain phonon branches induce substantial intersite charge transfer that can result in a negative electronic dielectric susceptibility. Such a strong electron–phonon coupling of certain modes could form the basis for the phonon mechanism of superconductivity in the cuprates.
Thermal X-Rays from Millisecond Pulsars: Constraining the Fundamental Properties of Neutron Stars

We model the X-ray properties of millisecond pulsars (MSPs) by considering hot-spot emission from a weakly magnetized neutron star (NS) covered by a hydrogen atmosphere. We investigate the limitations of using the thermal X-ray pulse profiles of MSPs to constrain the mass-to-radius (M/R) ratio of the NS. The accuracy is strongly dependent on the viewing angle and magnetic inclination, but is ultimately limited only by photon statistics. We demonstrate that valuable information regarding NSs can be extracted, even from data of fairly limited photon statistics through modeling of archival observations of the nearby isolated PSRs J0030+0451 and J2124–3358. The X-ray emission from these pulsars is consistent with the presence of an atmosphere and a dipolar field configuration. For both MSPs, the favorable geometry allows us to place limits on the allowed M/R of NSs. Assuming 1.4 M☉, the stellar radius is constrained to be R > 9.4 km and R > 7.8 km (68% confidence) for PSRs J0030+0451 and J2124–3358, respectively. We explore the prospects of using future observatories such as Constellation-X and XEUS to conduct X-ray-timing searches for MSPs not detectable at radio wavelengths due to unfavorable viewing geometry. We are also able to place strong constraints on the magnetic field evolution model proposed by Ruderman. The pulse profiles indicate that the magnetic field of an MSP does not have a tendency to align itself with the spin axis or migrate toward one of the spin poles during the low-mass X-ray binary phase.
On Kontsevich's Hochschild cohomology conjecture

Generalizing a conjecture of Deligne, Kontsevich proposed that there should be a notion of Hochschild cohomology of algebras over the little cube operad (or its chain complex) which in a natural way generalizes Hochschild cohomology of associative algebras. He moreover conjectured that the Hochschild cohomology, in this new sense, of an algebra over the little k-cube operad is an algebra over the little (k + 1)-cube operad. In this paper, we precisely state and prove this conjecture.
Catalytic DNA (deoxyribozymes) for synthetic applications—current abilities and future prospects

The discovery of naturally occurring catalytic RNA (RNA enzymes, or ribozymes) in the 1980s immediately revised the view of RNA as a passive messenger that solely carries information from DNA to proteins. Because DNA and RNA differ only by the absence or presence of a 2′-hydroxyl group on each ribose ring of the polymer, the question of ‘catalytic DNA?’ arises. Although no natural DNA catalysts have been reported, since 1994 many artificial DNA enzymes, or ‘deoxyribozymes’, have been described. Deoxyribozymes offer insight into the mechanisms of natural and artificial ribozymes. DNA enzymes are also used as tools for in vitro and in vivo biochemistry, and they are key components of analytical sensors. This review focuses primarily on catalytic DNA for synthetic applications. Broadly defined, deoxyribozymes may have the greatest potential for catalyzing reactions in which the high selectivities of ‘enzymes’ are advantageous relative to traditional small-molecule catalysts. Although the scope of DNA-catalyzed synthesis is currently limited in most cases to oligonucleotide substrates, recent efforts have began to expand this frontier in promising new directions.
An Improved Synthesis of 8-Bromo-2′-deoxyguanosine

Abstract A new synthesis of 8-bromo-2′-deoxyguanosine, a key intermediate in the synthesis of the mutagenic DNA adduct 8-oxo-2′-deoxyguanosine is described. The advantages of this method are significantly improved yields and ease of isolation.
Earthquakes in the Holy Land: A Correction

IN an article on earthquakes in the Holy Land1 there is given a list of 207 shocks, of which there is record, between the years 1606 B.C. and A.D 1927. Among these are 27 dates from an Arabian authority, As-Soyuti, whose work appears in translation in the Journal of the Asiatic Society of Bengal. In transcribing these dates I failed to observe that they were stated as A.H., that is, Anno Hejira, instead of Anno Domini. They are, therefore, as quoted in my list something over six centuries too early. The corrected dates are as follows:
Low-Temperature Pseudomorphic Transformation of Ordered Hierarchical Macro-mesoporous SiO2/C Nanocomposite to SiC via Magnesiothermic Reduction

A magnesiothermic reduction synthesis approach is reported for direct conversion of SiO2/C composite nanostructures to corresponding SiC materials without losing their nanostructure morphologies. Crystalline SiC materials can be obtained by this approach at a temperature as low as 600 °C, only approximately half of that applied in the generally used carbothermal reduction and preceramic polymer pyrolysis methods. An ordered hierarchical macro-mesoporous SiC material was synthesized for the first time as a demonstration. This pseudomorphic transformation can be regarded as a general synthesis method for different kinds of SiC nanostructures, and it can also be readily extended to other metal carbide materials as well as TiC.
Specialized Legal Research Courses: The Next Generation of Advanced Legal Research

This article examines the current state of Advanced Legal Research (ALR) courses and the emergence of Specialized Legal Research (SLR) courses. It surveys the curriculum of all ABA-accredited law schools and provides updated statistics of ALR course offerings. It also identifies for the first time (1) the law schools currently offering SLR courses, (2) the most popular SLR course topics, and (3) the role of the law library in determining whether to implement a SLR course. The results of this survey will hopefully educate law schools about the trends and variety of legal research course offerings.
Combinatorial Model Categories Have Presentations

Abstract We show that every combinatorial model category is Quillen equivalent to a localization of a diagram category (where “diagram category” means diagrams of simplicial sets). This says that every combinatorial model category can be built from a category of “generators” and a set of “relations.”
Design and Implementation of the Robotic Platform

The diversity of robotic research areas along with the complex requirements of hardware and software for robotic systems have always presented a challenge for system developers. Many past robot control platforms were complex, expensive, and not very user friendly. Even though several of the previous platforms were designed to provide an open architecture system, very few of the previous platforms have been reused. To address previous disadvantages, this paper describes the design and implementation of the Robotic Platform, an object-oriented development platform for robotic applications. The Robotic Platform includes hardware interfacing, servo control, trajectory generation, 3D simulation, a graphical user interface, and a math library. As opposed to distributed solutions, the Robotic Platform implements all these components in a homogenous architecture that utilizes a single hardware platform (a standard PC), a single programming language (C++), and a single operating system (the QNX Real-Time Platform) while guaranteeing deterministic real-time performance. This design leads to an open architecture that is less complex, easier to use, and easier to extend. Particularly, the area of multiple cooperating robots benefits from this kind of architecture, since the Robotic Platform achieves a high integration of its components and provides a simple and flexible means of communication. The architecture of the Robotic Platform builds on the following state-of-the-art technologies and general purpose components to further increase simplicity and reliability: (i) PC technology, (ii) the QNX Real-Time Platform, (iii) the Open Inventor library, (iv) object-oriented design, and (v) the QMotor control environment.
Starting Small and Commitment

Abstract I study a model of a long-term partnership with two-sided incomplete information. The partners jointly determine the stakes of their relationship and individually decide whether to cooperate with or betray each other over time. I characterize the extremal— interim incentive efficient —equilibria. In these equilibria, the partners generally “start small,” and the level of interaction grows over time. The types of players separate quickly. Further, cooperation between “good” types is viable regardless of how pessimistic the players are about each other initially. The quick nature of separation in an extremal equilibrium contrasts with the outcome selected by a strong renegotiation criterion (as studied in Watson (1999, J. Econ. Theory 85 , 52–90). Journal of Economic Literature Classification Numbers: C72, C73, D74.
Vibration ride comfort criteria

Results are presented for an experimental study directed to derive equal vibration discomfort curves, to determine the influence of vibration masking in order to account for the total discomfort of any random vibration, and to develop a scale of total vibration discomfort in the case of human response to whole-body vertical vibration. Discomfort is referred to as a subjective discomfort associated with the acceleration level of a particular frequency band. It is shown that passenger discomfort to whole-body vibration increases linearly with acceleration level for each frequency. Empirical data provide a mechanism for determining the degree of masking (or summation) of the discomfort of multiple frequency vibration. A scale for the prediction of passenger discomfort is developed.
A Lower Bound for Nodal Count on Discrete and Metric Graphs

We study the number of nodal domains (maximal connected regions on which a function has constant sign) of the eigenfunctions of Schrodinger operators on graphs. Under a certain genericity condition, we show that the number of nodal domains of the nth eigenfunction is bounded below by n − l, where l is the number of links that distinguish the graph from a tree.
Experimental Studies of Allene, Methylacetylene, and the Propargyl Radical: Bond Dissociation Energies, Gas-Phase Acidities, and Ion-Molecule Chemistry

Electron affinities and A&ld are combined in a thermochemical cycle to arrive at bond dissociation energies for allene, methylacetylene, and the propargyl radical: Do(CH2eC=CH-H) = 88.7 f 3 kcal mol-', Do(HCH2CECH) = 90.3 f 3 kcal mol-', Do(CH3CrC-H) = 130.2 f 3 kcal mol-', and Do(CHz=C=C-H) = 100 f 5 kcal mol-'. Electron affinity measurements were determined using negative ion photoelectron spectroscopy and yielded the following for the propargyl, I-propynyl, and propadienylidene radicals: EA(CH2=C=CH) = 0.918 f 0.008 eV, EA(CH3Cd) = 2.718 f 0.008 eV, and EA(CHz=C=C) = 1.794 f 0.008 eV. Gas-phase acidity measurements were made using proton transfer kinetics in a flowing afterglow/selected-ion flow tube and yielded the following for allene, methylacetylene, and the propargyl radical: AGacld(CH2=C=CH-H) = 372.8 f 3 kcal mol-', AGacld(H-CH2C'CH) = 374.7 f 3 kcal mol-', AGaCld(CH3C~C-H) = 373.4 f 2 kcal mol-', and AGacld(CH2=C=CH) = 364 f 5 kcal mol-'. AGac,d was converted to hHac,d by employing ASac,d: AHac,d(CH2%%H-H) = 381.1 f 3 kcal mol-', AZ-Zyld(H-CHzC*H) = 382.7 f 3 kcal mol-', AHacld(CH3CSH) = 381.1 f 3 kcal mol-', and &i!,,,d(CH2=C=CH) = 372 f 5 kcal mol-'. Evidence is provided for the isomerization of the allenyl anion (CH2%4H-) to the 1-propynyl anion ( C H F S ) in the proton transfer reactions of CH2=C=CHwith CH30H and CH3CH20H. This complexity limits the precision of experimental measurements. This study explores the intricacies of determining gas phase acidity values by proton transfer reactions for systems in which isomerization can occur.
Selmer companion curves

We say that two elliptic curves E1, E2 over a number field K are n-Selmer companions for a positive integer n if for every quadratic character χ of K, there is an isomorphism Seln(E χ 1 /K) ∼= Seln(E 2 /K) between the nSelmer groups of the quadratic twists E 1 , E χ 2 . We give sufficient conditions for two elliptic curves to be n-Selmer companions, and give a number of examples of non-isogenous pairs of companions.
OBSERVATIONAL SIGNATURES OF TILTED BLACK HOLE ACCRETION DISKS FROM SIMULATIONS

Geometrically thick accretion flows may be present in black hole X-ray binaries observed in the low/hard state and in low-luminosity active galactic nuclei. Unlike in geometrically thin disks, the angular momentum axis in these sources is not expected to align with the black hole spin axis. We compute images from three-dimensional general relativistic magnetohydrodynamic simulations of misaligned (tilted) accretion flows using relativistic radiative transfer and compare the estimated locations of the radiation edge with expectations from their aligned (untilted) counterparts. The radiation edge in the tilted simulations is independent of black hole spin for a tilt of 15°, in stark contrast to the results for untilted simulations, which agree with the monotonic dependence on spin expected from thin accretion disk theory. Synthetic emission line profiles from the tilted simulations depend strongly on the observer's azimuth and exhibit unique features such as broad "blue wings." Coupled with precession, the azimuthal variation could generate time fluctuations in observed emission lines, which would be a clear "signature" of a tilted accretion flow. Finally, we evaluate the possibility that the observed low- and high-frequency quasi-periodic oscillations (QPOs) from black hole binaries could be produced by misaligned accretion flows. Although low-frequency QPOs from precessing, tilted disks remains a viable option, we find little evidence for significant power in our light curves in the frequency range of high-frequency QPOs.
A man-machine approach toward solving the traveling salesman problem

The traveling salesman problem, (form a circuit through N points with no subloops in such a way as to minimize the length of the circuit), is a close kin to many board wiring problems. It has been attacked by many mathematical methods with only meager results. Only for special forms of the problem or for problems with relatively few points can it be solved exactly even using very large amounts of computer time. Heuristic procedures have been proposed and tested with only slightly better results. This paper will describe a computer-aided heuristic technique which uses only a modest amount of computer time in real time to solve large (100-200) point problems. This technique takes advantage of both the computer's and the human's problem solving abilities. The computer is not asked to solve the problem in a brute force way as is the case in many of today's heuristics but it is asked to organize the data for the human in a fashion that allows the human to solve the problem easily.The techniques employed in this paper require that the computer and the human cooperate to find the solution to the problem in reasonable amounts of both of their times. The computer initially uses a series of heuristics that produce groups of points and some partial connections of these points. The human is asked to connect the points within the groups and then connect the groups in a manner that produces a circuit and appears to the human to maximize the ratio of enclosed area to perimeter. The computer takes this solution and uses another set of heuristics to make improvements. The solution is displayed to the human and if he is satisfied the procedure stops; if not the former procedure is repeated until the human is satisfied that cost for finding a better solution exceeds his estimate of the best possible improvement that could be obtained by further work. The heuristic procedures seek to group points around information obtained from solving a series of mathematical programming problems (assignment problems) and some observed correlations between these problems and the traveling salesman problem.The results are very good. The man-machine interaction solution for all problems in the literature is within one per cent of the solution for a fraction of the computer time. The experience to date indicates that the technique can be taught to inexperienced persons and their results, after training, are similar to those of the authors'.
A parallel processor for evaluation studies

The Multi Associative Processor system is a multiple control unit parallel processor capable of executing a maximum of 8 single-instruction-stream, multiple-data-stream programs simultaneously. The architecture supports parallelism at two levels: the lower level is the tightly coupled parallelism typical of array processors, and the higher level is the more loosely coupled parallelism between independent processes. The architecture of the machine is described and an example program for the machine is given to illustrate many of the concepts of the architecture. Measurement and evaluation studies on the machine are also briefly discussed.
Physics of systematic frequency variations in hydrogen masers

The frequency stability of hydrogen masers for intervals longer than 10/sup 4/ s is currently limited by systematic processes. The physics of frequency-determining mechanisms internal to the maser that are susceptible to systematic variations, and the connections between these internal mechanisms and external environmental factors are discussed. From estimates of the magnitudes of systematic effects, it is found that the primary internal mechanisms limiting long-term maser frequency stability are cavity pulling, at the level of parts in 10/sup 15/ per day, and wall shift variations, at the level of parts in 10/sup 16/ to parts in 10/sup 15/ per day. Strategies for reducing systematic frequency variations are discussed. >
Religious Penalty in the U.S. News & World Report College Rankings.

Since its debut in 1983, the U.S. News & World Report College Guide has become the premier ‘consumer report’ of higher education. We find that peer assessment, which is the largest component of the U.S. News & World Report ranking function, contains a penalty for religiously affiliated schools that is independent of the other U.S. News & World Report variables and several proxies for quality. Possible explanations of the religious penalty include taste‐based discrimination, perceived differences in the quality of the curriculum, and strategic voting by college administrators.
Structural-acoustic design at high frequency using the energy finite element method

Energy flow analysis methods, particularly as implemented using the finite element method, are useful as design techniques for high frequency structural-acoustic applications. In this paper, the derivation of energy flow analysis techniques are summarized. Particular attention is given to the specification of joint models for situations where there is a discontinuity in either geometric properties or material properties. The finite element formulation of this approach is also summarized. A case study is included to illustrate the utility of the method as a design technique.
On constrained instantons

Abstract A simple method is presented for doing systematic constrained instanton calculations in models such as φ4 or Higgs theories where the presence of a mass term prevents the existence of a classical solution. As an application, instanton estimates of the large-order behavior of the perturbation series in massive φ44 theory are derived. (These estimates agree with those of Frishman and Yankielowicz.)
Infrared-to-Ultraviolet Wavelength-dependent Variations Within the Pulse Profile Peaks of the Crab Nebula Pulsar

We present evidence of wavelength-dependent variations within the infrared, optical, and ultraviolet pulse profile peaks of the Crab Nebula pulsar. The leading and trailing edge half-width half-maxima of the peaks display clear differences in their wavelength dependences. In addition, phase-resolved infrared-to-ultraviolet color spectra show significant variations from the leading to trailing edges of the peaks. The color variations between the leading and trailing edges remain significant over phase differences smaller than 0.0054, corresponding to timescales of <180 μs. These results are not predicted by any current models of the pulsar emission mechanism and offer new challenges for the development of such models.
Nash equilibria in stabilizing systems

Abstract The objective of this paper is three-fold. First, we specify what it means for a fixed point of a stabilizing distributed system to be a Nash equilibrium. Second, we present methods that can be used to verify whether or not a given fixed point of a given stabilizing distributed system is a Nash equilibrium. Third, we argue that in a stabilizing distributed system, whose fixed points are all Nash equilibria, no process has an incentive to perturb its local state, after the system reaches one fixed point, in order to force the system to reach another fixed point where the perturbing process achieves a better gain. If the fixed points of a stabilizing distributed system are all Nash equilibria, then we refer to the system as perturbation-proof. Otherwise, we refer to the system as perturbation-prone. We identify four natural classes of perturbation-(proof/prone) systems. We present system examples for three of these classes of systems, and show that the fourth class is empty.
Magnetic recording head design

An analysis of the process of magnetic recording of digital data is presented from which qualitative magnetic head design concepts are developed and their usefulness demonstrated, both in the evaluation of magnetic head structures and in design for high-density storage.
Risk Management: Lessons from Six Continents

Globally, the need to construct new pipelines is increasing dramatically, both on shore and off shore. So too are the risks that are faced in attempting to meet project and stakeholder goals. Not meeting such goals has even greater consequences as a result. Project execution from potential identification of its need through execution and in-service use to decommissioning requires project management processes and tools at all stages of this timeline. Today, global project management standards are being developed, promulgated, taught, and applied. The reason is obvious. Project management is an essential function that is the single greatest means of assuring that a project is successful in meeting all objectives from cost to functionality. It also is the single greatest means of assuring that a party with a role in the project execution (developer, owner-employer, engineer-constructor, contractor-subcontractor, vendor, operator-user, etc.) achieves its commercial, professional, and related goals. Project ma...
In pursuit of comparable concepts and data about collective action

Empirical research must overcome two major obstacles: conceptual inconsistency and the scarcity of comparable data. These problems are particularly severe for interdisciplinary research on topics such as the study of collective action. There is no agreement on the appropriate unit of analysis (who should act collectively), measures of successful collective action, ways to distinguish among forms of collective action, or how best to measure independent variables. These disagreements limit the inferences that can be drawn from empirical research. We discuss the implications for scientific advancement in this area of research and present the strategies developed by the International Forestry Resources and Institutions research programme to overcome each of these problems. 2004 Elsevier Ltd. All rights reserved.
ONE-INSTANTON PREDICTIONS FOR NON-HYPERELLIPTIC CURVES DERIVED FROM M-THEORY

Abstract One-instanton predictions are obtained from certain non-hyperelliptic Seiberg-Witten curves derived from M-theory for N = 2 supersymmetric gauge theories. We consider SU( N 1 ) × SU( N 2 ) gauge theory with a hypermultiplet in the bifundamental representation together with hypermultiplets in the defining representations of SU( N 1 ) and SU( N 2 ). We also consider SU( N ) gauge theory with a hypermultiplet in the symmetric or antisymmetric representation, together with hypermultiplets in the defining representation. The systematic perturbation expansion about a hyperelliptic curve together with the judicious use of an involution map for the curve of the product groups provide the principal tools of the calculations.
How Important is Technical Writing? — A Survey of the Opinions of Successful Engineers

This article concerns a survey made by the author to determine the importance of technical writing to prominent engineers. Specific items discussed are the place of technical writing in the engineering curriculum and what should be included in a technical writing course. The results of a lengthy questionnaire are given, with some individual comments.
An analysis of the tradeoff between tax deferred earnings in iras and preferential capital gains

Abstract This paper extends prior research in evaluating the decision of whether to invest in a mutual fund either outright or through one of the three available IRAs: the deductible IRA, the Roth IRA, and the nondeductible IRA. We provide mathematical models for after-tax accumulations for each of the investments that are a function of return, the percentage of the return currently taxable to the investor, the time horizon of the investment, the capital gain tax rate, and the ordinary income tax rate. The Roth IRA and the deductible IRA always dominate investments in the nondeductible IRA or through outright investment. However, in comparing the nondeductible IRA and outright investments, the outcome is dependent on the investment goals of the mutual fund and whether it generates substantial dividend distributions or capital gain distributions. Mutual funds with small dividend and capital gain distributions may accumulate larger amounts if held outright while mutual funds that pay substantial dividends or make substantial capital gain distributions accumulate larger after-tax amounts when invested in a nondeductible IRA.
Single Crystal X-Ray Structure of [Galvinoxyl]X-[Hydrogalvinoxyl]1−X (X = 0.85 ± 0.02) At 20 and 203 K

Abstract Galvinpxyl undergoes a first order phase transition at 85 K with a concomitant transition from a ferromagnetic-coupled to essentially diamagnetic susceptibility. Attempts to obtain the single crystal x-ray structure below 85 K have failed due to disintegration of the crystals. Solid solutions of galvinoxyl/hydrogalvinoxyl, however, suppress the phase transition. The structures of [galvinoxyl]x-[hydrpgalvinoxyl]1−X (x = 0.85 ± 0.02) at 20 ± 5 and 203 ±2 K are described. The motif and atomic coordinates are essentially identical to those previously reported for the room temperature structure.
Intercalation of Multiple Carbon Atoms between the Carbonyls of α-Diketones

The reaction of open-chain or cyclic α-diketones with specific ω-alkenyl organometallics leads readily under the proper conditions to 1,2-diols bonded to terminal olefinic chains. With 1-phenyl-1,2-propanedione, biacetyl, and cyclohexane-1,2-dione, allylindation in aqueous THF proceeds readily at both adjacent carbonyls. For cyclododecane-1,2-dione, recourse must be made to allylmagnesium bromide for completing the second-stage condensation. Grignard reagents have also served well as reactants for biacetyl monoadducts. In contrast, monoallylated camphorquinone is reluctant to couple to Grignard reagents and reacts only when Barbier-type alkyllithium reactions are applied. The ring closing metatheses of these products have been examined. Where six-membered ring formation operates, cyclization can be performed directly on diols. When larger rings are involved, the diols will react only if structural preorganization capable of facilitating mutual approach of the two double bonds is at play. For this purpose,...
The association of aniridia and Wilms' tumor: methods of surveillance and diagnosis.

The association between aniridia and Wilms' tumor (WT) is well known. The availability of data on a large number of WT patients entered on the first and second National Wilms' Tumor Studies provided the opportunity to review which examinations had been most effective in detecting the presence of WT in patients being followed with aniridia. The records of 1287 patients were available and 13 or 1% had known aniridia. The details of the prediagnostic studies were available in 9/13 patients. Those nine patients had been examined regularly by IVP at intervals of 3–12 months prior to the discovery of the WT, but in only one was the unsuspected WT detected by these means. In the remaining eight patients, the tumor was discovered by palpation in six and suspected because of hematuria in two. It is concluded that repeated IVP's are not a satisfactory method to diagnose a WT at an early stage and newer radiodiagnostic studies, such as ultrasonography, will probably prove more effective.
Design, fabrication, and testing of a gradient-index binocular objective

A two-element axial gradient-index binocular objective has been designed and fabricated by the ion exchange technique. A prototype system has been assembled and tested.
Chemotherapy-induced peripheral neuropathy

Recent advances in the development and administration of chemotherapy for malignant diseases have led to prolonged survival of patients and the promise of a return to normal lives. This progress comes with a price, however, and the nervous system is frequently the target of therapy-induced toxicity. Unlike more immediate toxicities that affect the gastrointestinal tract and bone marrow, chemotherapy-induced neurotoxicity is frequently delayed in onset and may progress over time. In the peripheral nervous system, the major brunt of the toxic attack is directed against the peripheral nerve, targeting the neuronal cell body, the axonal transport system, the myelin sheath, and glial support structures, resulting in chemotherapy-induced peripheral neuropathy.
Photometric Selection of QSO Candidates from GALEX Sources

We present a catalog of 36,120 QSO candidates from the Galaxy Evolution Explorer (GALEX) Release Two (GR2) UV catalog and the USNO-A2.0 optical catalog. The selection criteria are established using known quasars from the Sloan Digital Sky Survey (SDSS). The SDSS sample is then used to assign individual probabilities to our GALEX USNO candidates. The mean probability is ~50% and would rise to ~65% if better morphological information than that from USNO were available to eliminate galaxies. The sample is ~40% complete for i ≤ 19.1. Candidates are cross identified in 2MASS, FIRST, SDSS, and the XMM-Newton Slewing Survey (XMMSL1), whenever such counterparts exist. The present catalog covers the 8000 deg2 of GR2 lying above = 25°, but can be extended to all 24,000 deg2 that satisfy this criterion as new GALEX data become available.
Submillimeter Wave Astronomy Satellite Mapping Observations of Water Vapor around Sagittarius B2

Observations of the 110-101 556.936 GHz transition of ortho-water with the Submillimeter Wave Astronomy Satellite have revealed the presence of widespread emission and absorption by water vapor around the strong submillimeter continuum source Sagittarius B2. An incompletely sampled spectral line map of a region of size 26' × 19' around Sgr B2 reveals three noteworthy features. First, absorption by foreground water vapor is detectable at local standard of rest (LSR) velocities in the range -100 to 0 km s-1 at almost every observed position. Second, spatially extended emission by water is detectable at LSR velocities in the range 80-120 km s-1 at almost every observed position. This emission is attributable to the 180 pc molecular ring identified from previous observations of CO. The typical peak antenna temperature of 0.075 K for this component implies a typical water abundance of (1.2-8) × 10-6 relative to H2. Third, strong absorption by water is observed within 5' of Sgr B2 at LSR velocities in the range 60-82 km s-1. An analysis of this absorption yields a HO abundance ~(2-4) × 10-7 relative to H2 if the absorbing water vapor is located within the core of Sgr B2 itself, or, alternatively, a water column density of ~(2.5-4) × 1016 cm-2 if the water absorption originates in the warm, foreground layer of gas proposed previously as the origin of ammonia absorption observed toward Sgr B2.
Do Relationships Matter? Evidence from Loan Officer Turnover

We show that the cost of employee turnover in firms that rely on decentralized knowledge and personal relationships depends on the firms' planning horizons and the departing employees' incentives to transfer information. Using exogenous shocks to the relationship between borrowers and loan officers, we document that borrowers whose loan officers are on leave are less likely to receive new loans from the bank, are more likely to apply for credit from other banks, and are more likely to miss payments or go into default. These costs are smaller when turnover is expected, as in the case of maternity leave, or when loan officers have incentives to transfer information, as in the case of voluntary resignations. This paper was accepted by Wei Jiang, finance.
Demand System Estimation in the Absence of Price Data: an Application of Stone-Lewbel Price Indices

This article evaluates the feasibility of estimating a system of demand equations in the absence of price information using the approach developed by Lewbel (1989). Stone-Lewbel (SL) price indices for commodity groups are constructed using information on the budget shares and the Consumer Price Indices (CPIs) of the goods comprising the commodity groups, which allows for household-level prices to be recovered. This study evaluates how susceptible are elasticities and marginal effects estimates from traditional parametric demand systems to the CPI used in the construction of the SL prices. To do this, three alternative regional CPIs are considered for the construction of the SL prices: monthly, quarterly and a constant (unity) price index. Elasticities and marginal effect estimates are computed for eight food commodity groups using the Exact Affine Stone Index (EASI) model as the parametric demand system and data from the United States Consumer Expenditure Survey. The estimates proved to be robust to the a...
Quantum noise and excess noise in optical homodyne and heterodyne receivers

A parallel development of the semiclassical and quantum statistics of multispatiotemporal mode direct, homodyne, and heterodyne detection using an ideal (except for its subunity quantum efficiency) photon detector is presented. Particular emphasis is placed on the latter two coherent detection Configurations. The primary intent is to delineate the semiclassical theory's regime of validity and to show, within this regime of validity, how the quantum theory's signal quantum noise, local oscillator quantum noise, the quantum noise incurred because of subunity detector quantum efficiency, plus (for heterodyning only) image band quantum noise produce the quantitative equivalent of the semiclassical theory's local oscillator shot noise. The effects of classical fluctuations on the local oscillator, and the recently suggested dual-detector arrangement for suppressing these fluctuations, are treated. It is Shown that previous studies of this arrangement have neglected a potentially significant noise contribution.
Interpreting New Data on Large-Scale Bulk Flows

We study the implications of a recent estimate of the bulk flow of a sample of galaxies containing Type Ia supernovae (SN Ia's) by Riess, Press, & Kirshner. We find that their results are quite consistent with power spectra from several currently popular models of structure formation, but that the sample is as yet too sparse to put significant constraints on the power spectrum. We compare this new result with that of Lauer & Postman, with which there is apparent disagreement. We find that for the power spectra we consider, the difference in window functions between the two samples used for the measurements results in a low level of expected correlation between the estimated bulk flows. We calculate a χ2 for the two measurements taken together and find that their lack of agreement tends to disfavor spectra with excessive power on large scales, but not at a level sufficient to rule them out. A sample consisting of other SN Ia's found in the Asiago catalog is used to study how the sensitivity of the method used by Riess, Press, & Kirshner will improve with increasing sample size. We conclude that the Local Group motion should be able to be determined with a sample of ~100 SN Ia light-curve shapes.
Southwestern Internal Medicine Conference: Medical Management of Nephrolithiasis-A New, Simplified Approach for General Practice

Considerable progress has been made regarding pathophysiology, diagnosis, and medical prevention of recurrent renal stone formation. The medical approach is not applied widely because of the availability of extracorporeal shockwave lithotripsy and the complexity of medical diagnostic and treatment modalities. In this review, a simplified program for the medical management of stones is described. From analysis of stone risk factors in 24-hour urine specimens, uncomplicated calcium stone disease is separated from other stone diseases. The uncomplicated calcium stone disease, comprising the illness in the majority of patients with recurrent renal calculi, is characterized by normocalcemia, normouricemia, calcium stones, and the absence of urinary tract infection, bowel disease, or marked hyperoxaluria. Uncomplicated calcium stone disease is separated into a hypercalciuric group and a normocalciuric group. In the simplified treatment program, the hypercalciuric group would be offered thiazide plus potassium citrate, whereas the normocalciuric group would receive potassium citrate alone.
LPCVD Silicon Dioxide Sacrificial Layer Etching for Surface Micromachining

The key step in producing a movable microstructure is the controllable sacrificial layer etching process. For the current study, a 1 fum silicon-rich silicon nitride structural layer was deposited on a 2 fum phosphosilicate glass (PSG) sacrificial layer that had been deposited on a single-crystal silicon wafer. Silicon nitride, unlike the more common polycrystalline silicon (poly-Si) structural material, is transparent and, therefore, allows the observation of an etch front in the underlying PSG sacrificial layer. The PSG is an amorphous silicon dioxide, with phosphorus added as a controlled impurity, that can be selectively etched in hydrofluoric acid. Several experiments have been performed with four HF concentrations using these test structures. Diffusion limited etching is observed at long etching times for each concentration. Additional experimental work has been done to determine appropriate kinetic expressions for the PSG/HF reactions. The sacrificial layer etching process has been modeled as a chemical reaction/diffusion system. Constants for the kinetic expression have been found from independent experimental work. This Deal-Grove type model assumes isothermal conditions, constant density solution, onedimensional etching, and the equality of the diffusion and reaction fluxes. The model calculates the HF surface concentration and the length of PSG underetched as a function of time. It fits the data well but requires the use of an unphysical diffusion coefficient. An extension of the Deal-Grove model to nonfirst order kinetics allows for a reasonable estimate of the reactant/product mixture diffusivity in water to be used when fitting the model to experimental data.
Segment-specific organization of leg motoneurones is transformed in bithorax mutants of Drosophila

In Drosophila, genes controlling segmentation in the thorax and abdomen are clustered in one region of the genome known as the bithorax complex. Studies of the genetics of this complex suggest that loss of activity of a gene causes transformation of a particular segment to a more anterior one, mesothorax representing the ultimate transformation. This transformation is well described for the epidermis, but it is not clear whether other segmentally arranged tissues are also transformed. The segmental ganglia are fused in Drosophila into a single compact mass termed the thoracic ganglion but the segmental organization of the nervous system is still apparent. There are discrete regions of neuropil, termed neuromeres, corresponding to the three thoracic segments: pro thorax, mesothorax and meta-thorax. A small terminal neuromere corresponds to the abdominal segments. Evidence is presented here that the leg motoneurones of each of the three thoracic segments are arranged in a segment-specific pattern in the thoracic ganglion. In mutant flies which have the metathoracic cuticle transformed to mesothoracic, the arrangement of the metathoracic leg motoneurones can be altered to resemble that of the mesothoracic leg motoneurones.
A comparison between two paradigms of intelligent systems: an example

Almost all intelligent computer systems of the past decade could be characterized by the General Problem Solver (GPS) paradigm. This paradigm states that the intelligent system activity consists of two distinct elements considered as separate modules. The first module is the generalist, the general problem solver while the second module could be considered as its data base, consisting of facts about the universe of discourse.Current research indicates that to bridge the gap between simple display of inference making ability and an actual complex world situation requires a shift in philosophical approach. A new approach which promises to overcome the major drawbacks of the old paradigm could be characterized as the Plan-Debug paradigm. Similar to the old paradigm it could also be characterized as consisting of two modules, the plan making module and the debugging module. Conceptually this paradigm states that in order to execute any task or solve a problem we need to start with a plan of action regardless how imperfect. Once we get stuck, we consult a specialist with a lot of knowledge about the particular situation.
Simulation of local computer networks — a case study

Abstract This paper is a report on the modeling technique employed in simulating several local networks that use Network Systems Corporation Hyper Channel products. The technique involves incremental modeling based on systematic model construction and validation. Three levels of incrementation were used, with each level systematically constructed and validated according to the HyperNet protocol corresponding to it. The detailed tasks of model construction and validation for each level of model are discussed in this paper.