cssi/SciSciGPT-SciSciNet huggingface dataset:
Determination of complex microcalorimeter parameters with impedance measurements

Abstract The proper understanding and modeling of a microcalorimeter's response requires accurate knowledge of a handful of parameters, such as C, G, α . While a few of these parameters are directly determined from the IV characteristics, some others, notoriously the heat capacity (C) and α , appear in degenerate combinations in most measurable quantities. The consideration of a complex microcalorimeter leads to an added ambiguity in the determination of the parameters. In general, the dependence of the microcalorimeter's complex impedance on these various parameters varies with frequency. This dependence allows us to determine individual parameters by fitting the prediction of the microcalorimeter model to impedance data. In this paper we describe efforts at characterizing the Goddard X-ray microcalorimeters. With the parameters determined by this method, we compare the pulse shape and noise spectra predictions to data taken with the same devices.
Structural similarity and distance in learning

We propose a novel method of introducing structure into existing machine learning techniques by developing structure-based similarity and distance measures. To learn structural information, low-dimensional structure of the data is captured by solving a non-linear, low-rank representation problem. We show that this low-rank representation can be kernelized, has a closed-form solution, allows for separation of independent manifolds, and is robust to noise. From this representation, similarity between observations based on non-linear structure is computed and can be incorporated into existing feature transformations, dimensionality reduction techniques, and machine learning methods. Experimental results on both synthetic and real data sets show performance improvements for clustering, and anomaly detection through the use of structural similarity.
Dynamical Model of Elementary Particles Based on an Analogy with Superconductivity. II

Continuing the program developed in a previous paper, a "superconductive" solution describing the proton-neutron doublet is obtained from a nonlinear spinor field Lagrangian. We find the pions of finite mass as nucleon-antinucleon bound states by introducing a small bare mass into the Lagrangian which otherwise possesses a certain type of the ${\ensuremath{\gamma}}_{5}$ invariance. In addition, heavier mesons and two-nucleon bound states are obtained in the same approximation. On the basis of numerical mass relations, it is suggested that the bare nucleon field is similar to the electron-neutrino field, and further speculations are made concerning the complete description of the baryons and leptons.
Laser cooling of TeV muons

Abstract We show that Compton scattering can be used to cool TeV-scale muon beams, and we derive analytical expressions for the equilibrium transverse angular spread, longitudinal energy spread, and power requirements. We find that a factor of a few thousand reduction in emittance is possible for a 3 TeV muon collider.
X-Ray-Optical-Radio Observations of a Resolved Supernova Remnant in NGC 6822

The supernova remnant (SNR) Ho 12, in the center of the dwarf irregular galaxy NGC 6822, was previously observed at X-ray, optical, and radio wavelengths. By using archival Chandra and ground-based optical data, we found that the SNR is spatially resolved in X-rays and optical. In addition, we obtained a ~5'' resolution radio image of the SNR. These observations provide the highest spatial resolution imaging of an X-ray–optical–radio SNR in that galaxy to date. The multiwavelength morphology, X-ray spectrum and variability, and narrowband optical imagings are consistent with an SNR. The SNR is a shell-shaped object with a diameter of about 10'' (24 pc). The morphology of the SNR is consistent across the wavelengths, while the Chandra spectrum can be well fitted with a nonequilibrium ionization model with an electron temperature of 2.8 keV and a 0.3–7 keV luminosity of 1.6 × 1037 ergs s-1. The age of the SNR is estimated to be 1700–5800 yr.
Ownership and employment in Russian industry: 1992‐1995

What impact did privatization have on employment in Russian industry? Utilizes data collected from a panel of 6,205 civilian manufacturing firms in the Central, Volga, North Caucasus, Northern and Western Siberian regions of Russia to explore in more detail the relationship between changes in ownership and employment in Russian industry between 1992 and 1995. In particular investigates whether change in ownership structure is relatively more important than industry, region, or the competitive position of the firm in explaining variation in the employment response to changing output conditions during the initial stage of Russia’s transition from plan to market.
Characteristics of surface roughness associated with leading-edge ice accretion

Detailed size measurements of surface roughness associated with leading edge ice accretions are presented to provide information on characteristics of roughness and trends of roughness development with various icing parameters. Data was obtained from icing tests conducted in the Icing Research Tunnel (IRT) at NASA Lewis Research Center (LeRC) using a NACA 0012 airfoil. Measurements include diameters, heights, and spacing of roughness elements along with chordwise icing limits. Results confirm the existence of smooth and rough ice zones and that the boundary between the two zones (surface roughness transition region) moves upstream towards stagnation region with time. The height of roughness grows as the air temperature and the liquid water content increase, however, the airspeed has little effect on the roughness height. Results also show that the roughness in the surface roughness transition region grows during a very early stage of accretion but reaches a critical height and then remains fairly constant. Results also indicate that a uniformly distributed roughness model is only valid at a very initial stage of the ice accretion process.
Novel generation of conjugated alkynyl ketenes : efficient synthesis of β,γ-alkynyl lactones

Abstract New methodology for the synthesis of certain β,γ-alkynyl lactones is described based on the in situ generation of ω-hydroxy alkynyl ketenes from 1-tert-butoxy-1,3-diynes which are prepared by oxidative coupling of terminal alkynes with tert-butoxyacetylene.
Results of combined multispecialty endoscopic dacryocystorhinostomy.

AbstractObjective: To characterize the pre- and post-operative findings in patients undergoing endoscopic dacryocystorhinostomy (eDCR) performed jointly by ophthalmologists and otolaryngologists.Methods: Retrospective case series consisting of all the patients who underwent eDCR for nasolacrimal duct obstruction at New York Presbyterian Hospital/Weill Cornell Medical College between the 2009–2012 academic years. Patients were followed post-operatively for at least six months. The primary endpoint assessed in this study was symptom recurrence (epiphora).Results: A total of 20 patients (25 total cases) underwent eDCR within the study interval. Of the 25 cases, 7 (28.0%) represented reoperations due to recurrent symptoms. All 20 patients in the study exhibited sinus pathology, as determined during a pre-operative otolaryngology assessment. As a result, 16 of these patients (80.0%) underwent concurrent sinonasal surgery at the time of eDCR. The success rate in cases without prior DCR was 83.3% (15/18). Only 5...
Real-Time Computerized Fluoroscopic Cardiac Imaging

A computerized fluoroscopy system employing several time and energy subtraction algorithms has permitted good visualization of the cardiovascular system using peripheral intravenous iodine injections of about 1 cm3/kg. Image contrast im-provements of 8-16 over conventional fluoroscopy are common. Several canine and human imaging studies are described including visualization of myocardial infarc-tions as regions of anomalous image grey shade. The system employs a standard image intensified fluoroscopy system and a specially constructed real-time image processor. Quasimonoenergetic x-ray beams formed by filtration deliver typical doses of 400 mR/sec in adult human cardiac exams.© (1979) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
COSMOS: A Hybrid N-Body/Hydrodynamics Code for Cosmological Problems

We describe a new hybrid N-body/hydrodynamical code based on the particle-mesh (PM) method and the piecewise-parabolic method (PPM) for use in solving problems related to the evolution of large-scale structure, galaxy clusters, and individual galaxies. The code, named COSMOS, possesses several new features that distinguish it from other PM-PPM codes. In particular, to solve the Poisson equation we have written a new multigrid solver which can determine the gravitational potential of isolated matter distributions and which properly takes into account the finite-volume discretization required by PPM. All components of the code are constructed to work with a nonuniform mesh, preserving second-order spatial differences. The PPM code uses vacuum boundary conditions for isolated problems, preventing inflows when appropriate. The PM code uses a second-order variable-time-step time integration scheme. Radiative cooling and cosmological expansion terms are included. COSMOS has been implemented for parallel computers using the Parallel Virtual Machine (PVM) library, and it features a modular design which simplifies the addition of new physics and the configuration of the code for different types of problems. We discuss the equations solved by COSMOS and describe the algorithms used, with emphasis on these features. We also discuss the results of tests we have performed to establish that COSMOS works and to determine its range of validity.
Long-Range, Pattern-Dependent Contextual Effects in Early Human Visual Cortex

Summary The standard view of neurons in early visual cortex is that they behave like localized feature detectors [1–7]. Here we demonstrate that processing in early visual areas goes beyond feature detection by showing that neural responses are greater when a feature deviates from its context compared to when it does not deviate from its context. Using psychophysics, fMRI, and electroencephalography methodologies, we measured neural responses to an oriented Gabor ("target") embedded in various visual patterns as defined by the relative orientation of flanking stimuli. We first show using psychophysical contrast adaptation and fMRI that a target that differs from its context results in more neural activity compared to a target that is contained within an alternating sequence, suggesting that neurons in early visual cortex are sensitive to large-scale orientation patterns. Next, we use event-related potentials to show that orientation deviations affect the earliest sensory components of the target response. Finally, we use forced-choice classification of "noise" stimuli to show that we are more likely to "see" orientations that deviate from the context. Our results suggest that early visual cortex is sensitive to global patterns in images in a way that is markedly different from the predictions of standard models of cortical visual processing.
A Memory-Based Model of Bounded Rationality

In order to investigate the impact of limited memory on human behavior, I develop a model of memory grounded in psychological and biological research. I assume that people take their memories as accurate and use them to make inferences. The resulting model predicts both over- and underreaction but provides enough structure to predict when each effect dominates. I then use this framework to study the consumption decision. The results match empirical work on consumption predictability as well as differences in the marginal propensity to consume from different income streams. Most importantly, because it ties the extent of bias to a measurable aspect of the stochastic process being forecasted, the model makes testable empirical predictions.
Synthesis of a Broad Array of Highly Functionalized, Enantiomerically Pure Cyclohexanecarboxylic Acid Derivatives by Microbial Dihydroxylation of Benzoic Acid and Subsequent Oxidative and Rearrangement Reactions

We have found that the 1,2-dihydroxylation of benzoic acid with Alcaligenes eutrophus strain B9, first reported in 1971 by Reiner and Hegeman, is readily adapted for the preparation of tens to hundreds of grams of (1S,2R)-1,2-dihydroxycyclohexa-3,5-diene-1-carboxylic acid of >95% ee. This unique substrate undergoes many specific oxidative and rearrangement processes. Among these are transformations of unanticipated chemical novelty and many products that have not been previously described.
The synthesis of the C-9 to C-21 sector of discodermolide: An efficient route to the C13–14 Z-trisubstituted alkene

Abstract The synthesis of the C-9 to C-21 sector of the immunosuppressive marine natural product discodermolide is described. The C-9 to C-15 subunit is synthesized in five steps from aldehyde 5 using the diene aldehyde cyclocondensation reaction. Diastereoselective alkylation of the previously synthesized C-16 to C-21 subunit by a suitably functionalized C-9 to C-15 synthon ( 3 ) leads to the C-9 to C-21 sector of discodermolide.
Productivity and Exporting Status of Manufacturing Firms: Evidence from Quantile Regressions

Past literature has established the relationship between productivity and exporting. This paper provides further understanding about this issue by examining the productivity effects of export status at different points of the conditional output distribution and by investigating the productivity effects of firms with different exporting status (i.e., new exporters versus continuous exporters). Plant-level data of Turkish manufacturing firms are analyzed using quantile regression techniques. The empirical results indicate that the productivity effect of exporting is present at all points along the conditional output distribution, and this effect increases as one moves from the lower tail to the upper tail of the distribution. Exporting firms that continuously exported throughout the time period have more pronounced productivity effects compared to firms in other categories (i.e., new exporting firms, exporting firms that exit, and exporting firms that switch exporting practices). These results have implications for firm behavior and for targeting policy prescriptions to augment manufacturing competitiveness.
Fast ion-driven Bernstein instabilities

Abstract A novel instability concept, namely, a two-streaming process in gyrospace, is investigated. This leads to a two-energy-stream cyclotron instability even without beams in real space, where fast ions drive electrostatic ion Bernstein waves unstable. The instability comes from the coupling of the fast and slow ion Bernstein branches due to a weak relativistic effect. When an unstable condition is satisfied, the growth rate of the cubic instability is proportional to (n f /n s ) 1 3 (γ f −1) 1 3 while the efficiency ∝ (n f /n s ) 1 3 (γ f −1) −2 3 . A quadratic instability dominates high harmonics at the lower-hybrid frequency regime and its growth rate has no γ f −1 dependence. The mechanism may play an important role in the interaction and dynamics of fast ions in magnetized plasmas.
An ab initio study of multiple phonon scattering resonances in silicon germanium alloys

We have computed phonon scattering rates and density of states in silicon germanium alloys using Green's function calculations and density functional theory. This method contrasts with the virtual crystal approximation (VCA) used in conjunction with Fermi's golden rule, which cannot capture resonance states occurring through the interaction of substitutional impurities with the host lattice. These resonances are demonstrated by density of states and scattering rate calculations in the dilute limit and show broadening as the concentration increases. Although these deviations become significant from the VCA at high frequencies, the relaxation times obtained for these phonon modes are small in both the full scattering theory and the VCA, resulting in their negligible contribution to thermal transport.
Neuropsychiatric Side Effects of FK506 vs. Cyclosporine A: First-Week Postoperative Findings

The authors studied 31 liver transplant patients to compare neuropsychiatric side effects of a newer immunosuppressant, FK506, to cyclosporine A (CYA). Patients were randomly assigned to either FK506 or CYA. At the 1-week postoperative stage, cognitive status was assessed with the Mini-Mental State Exam, Trailmaking Tests (TMT) A and B, Delirium Rating Scale, and a neuropsychiatric symptom checklist. No statistically significant differences were found on any outcome variable between these two drugs, though scores on the TMTs were impaired as compared with published norms. The FK506 patients had moderately impaired TMT scores, whereas the CYA patients had only mild impairment. The patients demonstrate good cognitive recovery at 1 week posttransplantation, with only mild evidence of cognitive impairment.
Forecasting an aggregate of cointegrated disaggregates

This study examines the problem of forecasting an aggregate of cointegrated disaggregates. It first establishes conditions under which forecasts of an aggregate variable obtained from a disaggregate VECM will be equal to those from an aggregate, univariate time series model, and develops a simple procedure for testing those conditions. The paper then uses Monte Carlo simulations to show, for a finite sample, that the proposed test has good size and power properties and that whether a model satisfies the aggregation conditions is closely related to out-of-sample forecast performance. The paper then shows that ignoring cointegration and specifying the disaggregate model as a VAR in differences can significantly affect analyses of aggregation, with the VAR-based test for aggregation possibly leading to faulty inference and the differenced VAR forecasts potentially understating the benefits of disaggregate information. Finally, analysis of an empirical problem confirms the basic results. Copyright © 2000 John Wiley & Sons, Ltd.
A unified framework for the Kondo problem and for an impurity in a Luttinger liquid

We develop a unified theoretical framework for the anisotropic Kondo model and the boundary sine-Gordon model. They are both boundary integrable quantum field theories with a quantum-group spin at the boundary which takes values, respectively, in standard or cyclic representations of the quantum groupSU(2)q. This unification is powerful, and allows us to find new results for both models. For the anisotropic Kondo problem, we find exact expressions (in the presence of a magnetic field) for all the coefficients in the Anderson-Yuval perturbative expansion. Our expressions hold initially in the very anisotropic regime, but we show how to continue them beyond the Toulouse point all the way to the isotropic point using an analog of dimensional regularization. The analytic structure is transparent, involving only simple poles which we determine exactly, together with their residues. For the boundary sine-Gordon model, which describes an impurity in a Luttinger liquid, we find the nonequilibrium conductance for all values of the Luttinger coupling. This is an intricate computation because the voltage operator and the boundary scattering do not commute with each other.
Algorithms for an optimal A* search and linearizing the search in the stack decoder

Two algorithms are presented for accelerating the operation of a stack decoder. The first is a method for computing the true least upper bound so that an optimal admissible A* search can be performed. The second is a set of methods for linearizing the computation required by a stack decoder. The A* search has been implemented in a continuous speech recognizer simulator and has demonstrated a significant speedup. The linearizing algorithm has been partially implemented in the simulator and has also shown significant computational savings. >
On the mechanism of anomalous slip in bcc metals

Abstract The anomalous-slip behavior of bcc metals has been studied by TEM analyses of dislocation substructures developed in a [ 2 ¯ 9 20 ] -oriented Mo single crystal uniaxially compressed at room temperature to a total-strain of 0.4%. It is found that the initial dislocation lines in association with “grown-in” super-jogs can act as effective sources for the formation of both a0/2[1 1 1] (Schmid factor = 0.5) and a 0 / 2 [ 1 1 ¯ 1 ] (Schmid factor = 0.167) coplanar screw dislocation arrays in the ( 1 ¯ 0 1 ) primary slip plane. The interaction between the multiplied a0/2[1 1 1] dislocations and pre-existing a 0 / 2 [ 1 1 ¯ 1 ] dislocation segments, which block the motion of the a0/2[1 1 1] dislocations, renders the multiplication of a 0 / 2 [ 1 1 ¯ 1 ] dislocations and leads to the formation of a0/2[1 1 1] and a 0 / 2 [ 1 1 ¯ 1 ] dislocation arrays on the ( 1 ¯ 0 1 ) primary slip plane. The occurrence of { 0 1 ¯ 1 } anomalous slip is accordingly proposed to be resulting from the mutual trapping of a0/2[1 1 1] and a 0 / 2 [ 1 1 ¯ 1 ] coplanar dislocation arrays on the ( 1 ¯ 0 1 ) primary slip plane, which renders a cross-slip propagation of both a0/2[1 1 1] and a 0 / 2 [ 1 1 ¯ 1 ] screw dislocations from the ( 1 ¯ 0 1 ) plane onto the { 0 1 ¯ 1 } planes and thus activates the { 0 1 ¯ 1 } 〈1 1 1〉 slip systems.
The weak-type (1,1) of Fourier integral operators of order –(n–1)/2

Let T be a Fourier integral operator on Rn of order–(n–1)/2. Seeger, Sogge, and Stein showed (among other things) that T maps the Hardy space H1 to L1. In this note we show that T is also of weak-type (1, 1). The main ideas are a decomposition of T into non-degenerate and degenerate components, and a factorization of the non-degenerate portion.
Dynamics evolution of shock waves in laser–material interaction

In this work, the dynamics and internal structure of shock waves in picosecond laser–material interaction are explored at the atomistic level. The pressure of the shock wave, its propagation, and interaction zone thickness between the plume and ambience are evaluated to study the effect of the laser absorption depth, ambient pressure, and laser fluence. Sound agreement is observed between the MD simulation and theoretical prediction of shock wave propagation and mass velocity. Due to the strong constraint from the compressed ambient gas, it is observed that the ablated plume could stop moving forward and mix with the ambient gas, or move backward to the target surface, leading to surface redeposition. Under smaller laser absorption depth, lower ambient pressure, or higher laser fluence, the shock wave will propagate faster and have a thicker interaction zone between the target and ambient gas.
CALIBRATING AN INTERFEROMETRIC NULL

One of the biggest challenges associated with a nulling-interferometer-based approach to detecting extrasolar Earthlike planets comes from the extremely stringent requirements of path length, polarization, and amplitude matching in the interferometer. To the extent that the light from multiple apertures is not matched in these properties, light will leak through the nuller and confuse the search for a planetary signal. Here we explore the possibility of using the coherence properties of the starlight to separate contributions from the planet and nuller leakage. We find that straightforward modifications to the optical layout of a nulling interferometer will allow one to measure and correct for the leakage to a high degree of precision. This nulling calibration relaxes the field matching requirements substantially and should consequently simplify the instrument design.
Sustainability: The materials role

This lecture series began in 1971 focused on the links between materials, energy, and the environment. The issue of sustainability had emerged, but only as an exploration of the possibility of materials depletion in the face of predicted population growth. Today, sustainability implies a global economic and social system that both satisfies human needs and does not despoil the earth. What has been our role in this increasingly important arena of human concern and what should it be?
AutoTutor and Family: A Review of 17 Years of Natural Language Tutoring

AutoTutor is a natural language tutoring system that has produced learning gains across multiple domains (e.g., computer literacy, physics, critical thinking). In this paper, we review the development, key research findings, and systems that have evolved from AutoTutor. First, the rationale for developing AutoTutor is outlined and the advantages of natural language tutoring are presented. Next, we review three central themes in AutoTutor’s development: human-inspired tutoring strategies, pedagogical agents, and technologies that support natural-language tutoring. Research on early versions of AutoTutor documented the impact on deep learning by co-constructed explanations, feedback, conversational scaffolding, and subject matter content. Systems that evolved from AutoTutor added additional components that have been evaluated with respect to learning and motivation. The latter findings include the effectiveness of deep reasoning questions for tutoring multiple domains, of adapting to the affect of low-knowledge learners, of content over surface features such as voices and persona of animated agents, and of alternative tutoring strategies such as collaborative lecturing and vicarious tutoring demonstrations. The paper also considers advances in pedagogical agent roles (such as trialogs) and in tutoring technologies, such semantic processing and tutoring delivery platforms. This paper summarizes and integrates significant findings produced by studies using AutoTutor and related systems.
Sidewall Effects on Heat Transfer Coefficient in a Narrow Impingement Channel

This paper examines the local and averaged effects of channel height in the presence of sidewalls on heat transfer coefficients, with special attention given to the sidewall behavior. High resolution local heat transfer coefficient distributions on target and sidewall surfaces were computed using temperature sensitive paint, recorded via a scientific-grade charge-coupled device camera, and compared with available literature. This is important, as many of the major correlations related to impingement channels are directly applicable to wide arrays of jets, for which the influence of the presence of sidewalls is minimal. Streamwise pressure distributions were recorded and used to explain heat transfer trends and to determine the thermal effectiveness of each channel. Results are presented for average jet-based Reynolds numbers between 17,000 and 45,000. All experiments were carried out on a large-scale single-row 15-hole impingement channel (with an X/D of 5, a Y/D of 4, and a Z/D of 1, 3 and 5). It was observed that available correlations accurately predict the target surface heat transfer coefficients when the influence of the sidewall is minimal, typically at larger channel heights and lower Reynolds numbers. Smaller channel heights tend to outperform larger channels, when considering thermal effectiveness and channel-averaged heat transfer rates, due to the increased heat transfer on the channel sidewalls.
Aza- and Carbo-[3 + 3] Annulations of Exo-Cyclic Vinylogous Amides and Urethanes. Synthesis of Tetrahydroindolizidines and An Unexpected Formation of Hexahydroquinolines.

[3+3] Annulations of exo-cyclic vinylogous amides and urethanes with vinyl iminium salts are described here. We observed an intriguing dichotomy in their reaction pathways. For pyrrolidine- and azepane-based vinylogous amides or urethanes, aza-[3+3] annulation would dominate to give tetrahydroindolizidines, whereas, unexpectedly, for piperidine-based vinylogous amides or urethanes, carbo-[3+3] annulation was the pathway, leading to hexahydroquinolines. The origin for such a contrast is likely associated with a switch in the initial reaction pathway between C-1,2-addition and C-1,4-addition.
Discovery of Par 1802 as a Low-Mass, Pre-Main-Sequence Eclipsing Binary in the Orion Star-Forming Region

We report the discovery of a pre-main-sequence (PMS), low-mass, double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We present our observations, including radial velocities derived from optical high-resolution spectroscopy, and present an orbit solution that permits the determination of precise empirical masses for both components of the system. We find that Par 1802 is composed of two equal-mass ( -->0.39 ± 0.03, -->0.40 ± 0.03 M☉) stars in a circular, 4.7 day orbit. There is strong evidence, such as the system exhibiting strong Li lines and a center-of-mass velocity consistent with cluster membership, that this system is a member of the Orion star-forming region and quite possibly the Orion Nebula Cluster, and therefore has an age of only a few million years. As there are currently only a few empirical mass and radius measurements for low-mass, PMS stars, this system presents an interesting test for the predictions of current theoretical models of PMS stellar evolution.
D6 + D0 and five-dimensional spinning black hole

We study the system of D6+D0 branes at sub-stringy scale. We show that the proper description of the system, for large background field associated with the D0-branes, is via spinning chargeless black holes in five dimensions. The repulsive force between the D6-branes and the D0-branes is understood through the centrifugal barrier. We discuss the implication on the stability of the D6 + D0 solution.
Condensation of propargylic alcohols with 1,3-dicarbonyl compounds and 4-hydroxycoumarins in ionic liquids (ILs)

Propargylic alcohols are activated toward 1,3-diketones by Lewis or Bronsted acidic ionic liquids (ILs) without an added catalyst, but significantly better conversions are achieved with metallic triflates [in particular Sc(OTf)3 and Ln(OTf)3] and bismuth nitrate in imidazolium ILs. The scope of this condensation reaction was investigated with a variety of propargylic alcohols and a host of acyclic and cyclic dicarbonyl compounds. Concomitant cycloisomerization leading to tetrasubstituted furans was observed with the propargylic alcohols 1b and 1c in reaction with 1,3-diketone 2b and the β-ketoester 2c. With propargylic alcohol 1c, propargylation, cycloisomerization, or dienone formation were observed, depending on the structure of the 1,3-dicarbonyl compound. The [BMIM][PF6]/Bi(NO3)3·5H2O system proved efficient for propargylation, vinylation, and alkylation of 4-hydroxycoumarins. The recycling and reuse of the IL are added advantages of this method.
A general approach for high yield fabrication of CMOS-compatible all-semiconducting carbon nanotube field effect transistors

We report strategies to achieve both high assembly yield of carbon nanotubes at selected positions of the circuit via dielectrophoresis (DEP) and field effect transistor (FET) yield using an aqueous solution of semiconducting-enriched single-walled carbon nanotubes (s-SWNTs). When the DEP parameters were optimized for the assembly of individual s-SWNTs, 97% of the devices showed FET behavior with a maximum mobility of 210 cm2 V−1 s−1, on–off current ratio ∼ 106 and on-conductance up to 3 µS, but with an assembly yield of only 33%. As the DEP parameters were optimized so that one to five s-SWNTs are connected per electrode pair, the assembly yield was almost 90%, with ∼90% of these assembled devices demonstrating FET behavior. Further optimization gave an assembly yield of 100% with up to 10 SWNTs per site, but with a reduced FET yield of 59%. Improved FET performance including higher current on–off ratio and high switching speed were obtained by integrating a local Al2O3 gate to the device. Our 90% FET with 90% assembly yield is the highest reported so far for carbon nanotube devices. Our study provides a pathway which could become a general approach for the high yield fabrication of complementary metal oxide semiconductor (CMOS)-compatible carbon nanotube FETs.
Potential energy surfaces for CH bond cleavage reactions

Ab initio, multi-reference, configuration interaction calculations are reported for the reactions, CH 4 ↔ CH 3 + H (4) CH 3 F ↔ CH 2 F+H (5) CH 2 F 2 ↔ CHF 2 +H (6) CHF 3 ↔ CF 3 +H (7) two equivalent, barrier-less paths are found for the CH 3 + H recombination, two inequivalent, barrier-less paths are found for the CH 2 F + H and CHF 2 + H recombinations (depending on which side of the radical the hydrogen atom approaches) and only one barrier-less path is found for the CF 3 + H recombination. The minimum energy path for H atom approaching CF 3 from the concave side is predicted to have a barrier of 27 kcal/mol. Both the minimum energy path energies and the transitional frequencies as a function of R CH for all four reactions are predicted to be quite similar.
New base‐labile amino‐protective groups for peptide synthesis

Modification of the methyl group in 2-(methylsulphonyl)ethanol gave alcohols which could be used to introduce amino-protective groups of the urethane type, which are labile in alkaline media. The cleavage involves β-elimination. Exchange of the methyl group by a phenyl group bearing a function with a negative inductive effect (NO2 or MeSO2) afforded protecting groups with a higher sensitivity to base. The recommended function is a disulphone: 2-[4-(methylsulphonyl)phenylsulphonyl]ethanol. The function has a somewhat better stability than the Fmoc group, resists catalytic hydrogenolysis, is highly stable in acidic medium and its elimination product does not polymerize spontaneously. The suggested designation of the new protective group is Mpc.
Electronic structure of silicon superlattices

Abstract Utilizing a new complex-band-structure technique, the electronic structure of model Si-Si1−xGex and MOS superlattices have been obtained over a wide range of layer thickness d (11 ≤ d ≤ 110 A). For d ≥ 44 A, it is found that these systems exhibit a direct fundamental band gap. Further calculations of band-edge effective masses and impurity scattering rates suggest the possibility of a band-structure-driven enhancement in electron mobility over bulk silicon.
A novel synthesis of 1-aryl-3-piperidone derivatives.

A novel method to construct the 1-aryl-3-piperidone scaffold is described here. Starting from 3,5-dichloroaniline, a seven-step synthesis, without the use of protecting groups, generates the desired 3-piperidone ring in an overall yield of 30% through a key Morita–Baylis–Hillman reaction and ring-closing metathesis, providing easy access to diverse and useful heterocycles.
CLASSICAL MECHANICS OF DIPOLAR ASYMMETRIC TOP MOLECULES IN COLLINEAR STATIC ELECTRIC AND NONRESONANT LINEARLY POLARIZED LASER FIELDS: ENERGY-MOMENTUM DIAGRAMS, BIFURCATIONS AND ACCESSIBLE CONFIGURATION SPACE

We study classical energy-momentum (E-m) diagrams for rotational motion of dipolar asymmetric top molecules in strong external fields. Static electric fields, nonresonant linearly polarized laser fields, and collinear combinations of the two are investigated. We treat specifically the molecules iodobenzene (a nearly prolate asymmetric top), pyridazine (nearly oblate asymmetric top), and iodopentafluorobenzene (intermediate case). The location of relative equilibria in the E-m plane and associated bifurcations are determined by straightforward calculation, with analytical results given where possible. In cases where analytical solutions cannot be obtained, we resort to numerical solutions, while keeping a geometrical picture of the nature of the solutions to the fore. The classification we obtain of the topology of classically allowed rotor configuration space regions in the E-m diagram is of potential use in characterization of energy eigenstates of the corresponding quantum mechanical problem.
Privacy integrated queries: an extensible platform for privacy-preserving data analysis

Privacy Integrated Queries (PINQ) is an extensible data analysis platform designed to provide unconditional privacy guarantees for the records of the underlying data sets. PINQ provides analysts with access to records through an SQL-like declarative language (LINQ) amidst otherwise arbitrary C# code. At the same time, the design of PINQ's analysis language and its careful implementation provide formal guarantees of differential privacy for any and all uses of the platform. PINQ's guarantees require no trust placed in the expertise or diligence of the analysts, broadening the scope for design and deployment of privacy-preserving data analyses, especially by privacy nonexperts.
Spectinomycin versus tetracycline for the treatment of gonorrhea

Abstract Spectinomycin and tetracycline are alternative drugs to penicillin in the treatment of gonorrhea. To compare the efficacy of these agents and their propensity to select resistant gonococci, we treated 4043 patients randomly with either 2 or 4 g of spectinomycin once or 9 g of oral tetracycline for four days. Minimum cure rate for anogenital gonorrhea was 94 per cent with either drug. Oropharyngeal infection responded poorly to spectinomycin in men, with failure of therapy in six of 11. Postgonococcal urethritis in men was less common after tetracycline than after spectinomycin (P<0.005). Spectinomycin failure was not related to drug resistance. Tetracycline failure correlated with resistance (P<0.0002); one fifth of the isolates resistant to 1.0 μg per milliliter of tetracycline were not eradicated. For several reasons, including the appearance of β-lactamase-producing gonococci, it is no longer clear that penicillin G is the "drug of choice" for gonorrhea. Spectinomycin and tetracycline are equa...
Migration effects of Olympic siting: A pooled time series cross-sectional analysis of host regions

There has been considerable opposition to the 2002 Winter Olympics, to be held in the Salt Lake City metro area. This opposition stems primarily from fears of increased population growth due to the international attention. Proponents maintain that the Games will enhance the quality and quantity of jobs in the local economy, mitigating any undesirable impacts. This paper analyzes the experiences of past North American Olympic host regions, rather than the single case of Salt Lake City, to determine whether concerns are substantiated. Findings show that most population growth effects relate to the announcement of the Olympics rather than the actual hosting of the event. While the Olympics are likely to attract jobs to the host region, the nature of this employment growth and its effect on per-capita income are questionable.
The Impact of Strategic Management Accounting and Cost Structure on ABC Systems in Hotels

ABSTRACT The purpose of this paper is to examine the extent to which potential factors affect the adoption of ABC systems. An empirical survey was conducted on a sample of 85 leading hotel enterprises in Greece. Results show that the adoption of ABC systems is positively associated with the extent of use of strategic management accounting techniques and with cost structure. No association was found between the adoption of ABC systems and the importance of cost data, level of price competition, and size.
Channel-adaptive sensing strategy for Cognitive Radio ad hoc networks

In Cognitive Radio (CR) ad hoc networks, secondary users (SU) attempt to utilize valuable spectral resources without causing significant interference to licensed primary users (PU). While there is a large body of research on spectrum opportunity detection, exploitation, and adaptive transmission in CR, most existing approaches focus only on avoiding PU activity when making sensing decisions. Since the myopic sensing strategy results in congestion and poor throughput, several collision-avoidance sensing approaches were investigated in the literature. However, they provide limited improvement. A channel-aware myopic sensing strategy that adapts the reward to the fading channel state information (CSI) of the SU link is proposed. This CSI varies over the CR spectrum and from one SU pair to another due to multipath and shadow fading, thus randomizing sensing decisions and increasing the network throughput. The proposed joint CSI adaptation at the medium access control (MAC) and physical layers provides large throughput gain over randomized sensing strategies and/or conventional adaptive transmission methods. The performance of the proposed CSI-aided sensing strategy is validated for practical network scenarios and demonstrated to be robust to CSI mismatch, sensing errors, and spatial channel correlation.
MARKET STRUCTURE, CHANGING INCENTIVES, AND UNDERWRITER CERTIFICATION

Early studies find that higher quality underwriters are associated with lower underpricing; however, more recent evidence suggests the opposite relation. By controlling for influences associated with the changing market structure of the underwriter industry, I provide a potential explanation for this conflict, that is, that higher quality underwriters do certify initial public offerings, resulting in lower underpricing. However, effects associated with increasing market shares tend to offset certification benefits, particularly for issues underwritten by the largest investment banks.
Contradiction, convergence and the knowledge economy: the confluence of academic and commercial biotechnology

Effortstounderstandthestructureoftheemergingknowledgeeconomyhavepaid particular attention to the shifting boundary between academic and commercial (for-profit) research, especially in life sciences. Yet, empirical studies have tended to adopt a segmented approach, focusing on either industry or the academy, thus obscuring the increasingly interwoven nature of these two domains. In this paper, we explore the changing organizational logics that govern both academic and corporate science, using interview data gathered from two important clusters of the biotechnology industry: Route 128 in Massachusetts and the San Francisco Bay area. These data, while provisional, lead us to suggest that cultural traffic between university and commercial science has increased, blurring the boundary between them and generating a new and often contradictory knowledge regime,the product ofa growingconfluence oforganizational logics that had previously been distinct. The emergence of this regime, which conforms to Stark’s (2001) notion of ‘heterarchy’, holds important implications for prevailing theories of university‐industry relations and of organizational change as well.
Paraxial ray optics cloaking

Despite much interest and progress in optical spatial cloaking, a three-dimensional (3D), transmitting, continuously multidirectional cloak in the visible regime has not yet been demonstrated. Here we experimentally demonstrate such a cloak using ray optics, albeit with some edge effects. Our device requires no new materials, uses isotropic off-the-shelf optics, scales easily to cloak arbitrarily large objects, and is as broadband as the choice of optical material, all of which have been challenges for current cloaking schemes. In addition, we provide a concise formalism that quantifies and produces perfect optical cloaks in the small-angle (`paraxial') limit.
Optometry/Ophthalmology: the Future

SUMMARY 1 The most serious problem for the future of optometry and ophthalmology is surplus manpower. It is imperative that the two groups immediately join in future eye-manpower studies before we face an insoluble problem. 2 It is important that moderate leadership of optometry and ophthalmology put more time and effort into reducing the conflict between our two professions. The present actions by optometry and ophthalmology in legislative hearings are producing nothing but harm and a lack of credibility for optometry and ophthalmology. In general we are looked upon as ‘money grabbers’. 3 It is important that greater efforts be made in the area of joint education between optometry and ophthalmology in order to obtain not only better patient care but also to develop a better understanding of our roles in the eye-healthcare field. To obtain this, ophthalmology should provide leadership in developing programmes for optometrists. However, it is equally important that optometry ask ophthalmology to assist in formulating joint programmes. 4 It is important that we expand MD-OD or OD-MD committees that meet on a regular basis in order to discuss inter professional problems and to present a joint front in areas of common interests where unified action will be of benefit to the public, optometrists and ophthalmologists. 5 It is desirable to form more group practices of optometrists and ophthalmologists in order to provide better services at lower costs. The increasing costs of instruments, salaries, rent, etc., are making solo practice in metropolitan areas too expensive to provide services at a reasonable cost. 6 If optometry and ophthalmology fail to form closer relationships, the future is not good for either group, because the third party who pays the bills and the public will take advantage of our inability to respond rapidly to social problems and health-care costs. 7 It is important that optometry and ophthalmology review their individual attempts to obtain consumer attention, because the present actions result in consumer confusion. Despite both optometry's and ophthalmology's efforts to ‘educate the public’, a majority of consumers think of eye doctors and not the difference between the skills and practices of optometrists and ophthalmologists. Many consumers interpret these educational efforts of the public by both optometry and ophthalmology as serving the self-interest of each group and increasing eye-health-care costs. (The Carel C. Koch Award Lecture, 1977 reprinted by kind permission of the American Journal of Optometry and Physiological Optics 55, 1.)
The inference problem for template dependencies

A template dependency is a formalized integrity constraint on a relational database, stating that whenever tuples exist in the database that agree on certain attributes, an additional tuple must also be present that agrees with the others in a specified way. It is here shown that the inference problem for template dependencies is undecidable, that is, there can be no algorithm for determining whether a given dependency is a logical consequence of a given finite set of dependencies. The undecidability result holds whether or not databases are considered to be necessarily finite.
Wireless peer-to-peer scheduling in mobile networks

This paper considers peer-to-peer scheduling for a network with multiple wireless devices. A subset of the devices are mobile users that desire specific files. Each user may already have certain popular files in its cache. The remaining devices are access points that typically have access to a larger set of files. Users can download packets of their requested file from an access point or from a nearby user. Our prior work optimizes peer scheduling in a general setting, but the resulting delay can be large when applied to mobile networks. This paper focuses on the mobile case, and develops a new algorithm that reduces delay by opportunistically grabbing packets from current neighbors. However, it treats a simpler model where each user desires a single file with infinite length. An algorithm that provably optimizes throughput utility while incentivizing participation is developed for this case. The algorithm extends as a simple heuristic in more general cases with finite file sizes and random active and idle periods.