cssi/SciSciGPT-SciSciNet huggingface dataset:
Collimating the ionizing radiation in AGN

Abstract The hard-edged ionization cone seen by the HST imaging of NGC 4151 and the line-of-sight gas observed in some Seyfert 1 galaxies present a strong challenge for the simplest version of the Unified Model of AGN, which predicts that bi-conically shaped EELR can be observed only in type 2 objects and the line-of-sight to type 1 nucleus must be clear. To accommodate these rather contradictory requirements we suggest a modification of the shadowing/obscuration scenario. In our model the collimation of the ionizing radiation is provided by a partially neutral atmosphere surrounding the physically thin, dense torus. This atmosphere provides a natural way of producing wide angle ionization cones and at the same time allows for a relatively clear view of the central regions for some angles outside the cone edges. The model has an observationally testable predictions. Recently discovered nuclear disks in some elliptical galaxies hosting AGN may provide a natural way of supplying the gas for both the torus and the atmosphere surrounding it.
Making Sense of Big Data with the Berkeley Data Analytics Stack

The Berkeley AMPLab is creating a new approach to data analytics. Launching in early 2011, the lab aims to seamlessly integrate the three main resources available for making sense of data at scale: Algorithms (machine learning and statistical techniques), Machines (in the form of scalable clusters and elastic cloud computing), and People (both individually as analysts and in crowds). The lab is realizing its ideas through the development of a freely-available Open Source software stack called BDAS: the Berkeley Data Analytics Stack. In the four years the lab has been in operation, we've released major components of BDAS. Several of these components have gained significant traction in industry and elsewhere: the Mesos cluster resource manager, the Spark in-memory computation framework, and the Shark query processing system. BDAS features prominently in many industry discussions of the future of the Big Data analytics ecosystem -- a rare degree of impact for an ongoing academic project. Given this initial success, the lab is continuing on its research path, moving "up the stack" to better integrate and support advanced analytics and to make people a full-fledged resource for making sense of data. In this talk, I'll first outline the motivation and insights behind our research approach and describe how we have organized to address the cross-disciplinary nature of Big Data challenges. I will then describe the current state of BDAS with an emphasis on our newest efforts, including some or all of: the GraphX graph processing system, the Velox and MLBase machine learning platforms, and the SampleClean framework for hybrid human/computer data cleaning. Finally I will present our current views of how all the pieces will fit together to form a system that can adaptively bring the right resources to bear on a given data-driven question to meet time, cost and quality requirements throughout the analytics lifecycle.
Postoperative radioactive iodine evaluation of total thyroidectomy for thyroid carcinoma: Reappraisal and therapeutic implications

The records of 430 patients who underwent total thyroidectomy with radioactive iodine (RAI) uptake studies performed postop-eratively were reviewed. Indications for the administration of an ablative dose of iodine 131 are given. The majority (85.4%) had no or low (less than 2%) evidence of focal uptake and therefore were not treated with ablative doses of iodine 131. RAI scanning is necessary postoperatively to determine the completeness of the surgical procedure and to detect residual or metastatic disease. Small foci of residual disease or occult distant metastases can be adequately treated with therapeutic doses of RAI. Nodal or distant metastases that become clinically evident following thyroidectomy are usually not successfully treated with RAI. © John Wiley & Sons, Inc.
Resonant ultrasound spectroscopy

Resonant ultrasound spectroscopy (RUS) involves the study of the mechanical resonances of solids. The resonant response of a particular object depends on its shape, elastic constants, crystallographic orientation, density, and dissipation. It is possible to obtain the complete elastic constant matrix of relatively low-symmetry materials from a RUS spectrum on a single small sample . The measurement and the computation of the RUS spectra of solids are reviewed. Several examples of the use of the technique are discussed.
Finding Large Clique Minors is Hard

We prove that it is NP-complete, given a graph G and a parameter h, to determine whether G contains a complete graph Kh as a minor.
The study of exotic nuclei

Abstract The quantum many body system of protons and neutrons that makes up the nucleus of atoms has been studied for nearly 100 years, yet there are many unexplored aspects. One of the frontiers is in the production and study of isotopes with exotic neutron to proton number ratios. A key technical development that allows the study of exotic nuclei is the capability to produce them as beams. Exotic nuclei are known to exhibit qualitatively new phenomena and provide a new testing ground for our understanding of quantum many-body science. This article outlines some of the new aspects of exotic nuclei, how they are produced, and how they are studied. A description is given of how one recognizes the signatures of exotic nuclei and how manifestations of changes in the standard structure of nuclei may be identified.
Without Oil, How Do Gulf Countries Move? Non-hydrocarbon Business Cycles

This paper investigates the empirical characteristics of business cycles and the extent of cyclical comovement in the Gulf Cooperation Council (GCC) countries, using nonhydrocarbon GDP (excluding crude oil and natural gas sectors) and constituents of aggregate demand during the period 1990~2010. Although hydrocarbons still account for an overwhelming share of export earnings and fiscal revenues in the GCC countries leading to a higher degree of business cycle synchronicity at an aggregate level, this is driven largely by external factors influencing the price of crude oil and natural gas. By applying the Christiano-Fitzgerald asymmetric band-pass filter and a mean corrected concordance index, the results show that low level of synchronization in nonhydrocarbon business cycles across the GCC economies and a decline in the degree of synchronicity in the 2000s if Kuwait is excluded from the sample. It is partly because of divergent fiscal policies. The GCC countries do not appear to efficiently coordinate policies, let alone forming an optimal currency area.
Organoaluminum promoted conversion of aldehydes to methyl ketones

Abstract The conversion of aromatic aldehydes to the corresponding methyl ketones has been accomplished with the use of the organo-aluminum aryloxide compound, AlMe2(BHT)(OEt2).
Subthreshold Oscillations Induced By Spinal Nerve Injury In Dissociated Muscle And Cutaneous Afferents Of Mouse DRG

Whole cell patch-clamp recordings were obtained from dissociated mouse lumbar dorsal root ganglion (DRG) neurons. Recordings were made from control neurons and neurons axotomized by transection of the corresponding spinal nerve 1-2 days prior to dissociation. Medium to large muscle and cutaneous afferent neurons were identified by retrograde transport of True Blue or Fluoro-Gold injected into the corresponding peripheral tissue. Action potentials were classified as non-inflected spikes (A(0)) and inflected spikes (A(inf)). High-frequency, low-amplitude subthreshold membrane potential oscillations were observed in 8% of control A(0) neurons, but their incidence increased to 31% in the nerve injury group. Fifty percent of axotomized muscle afferent A(0) cells displayed oscillations, while 26% of axotomized cutaneous afferents exhibited oscillations. Lower-frequency oscillations were also observed in a small fraction (4%) of A(inf) neurons on strong depolarization. Their numbers were increased after the nerve injury, but the difference was not statistically significant. The oscillations often triggered burst firing in distinct patterns of action potential activity. These results indicate that injury-induced membrane oscillations of DRG neurons, previously observed in whole DRG of rats, are present in dissociated DRG neurons of the adult mouse. Moreover, these observations indicate that both muscle and cutaneous afferents in the A(beta) size range give rise to injury-induced membrane oscillations, with muscle afferents being more prone to develop oscillations.
SPIMbot: an engaging, problem-based approach to teaching assembly language programming

This paper describes SPIMbot, an extension to James Larus's widely-used MIPS simulator SPIM, that allows virtual robots to be controlled by writing programs in the MIPS assembly language. SPIMbot was written to provide an engaging environment to motivate students to learn assembly language concepts. The SPIMbot tool allows the development of scenarios--in which students must program the robot to perform certain tasks--and provides the means to compete two robots against each other.In our sophomore/junior-level class, we structure the programming component as a collection of structured assignments that produce sub-components for the robot; these sub-components are then used in a final open-ended programming assignment to produce an entry for a SPIMbot tournament. In our experience, this has been an effective means of engaging students, with many students investing time to aggressively optimize their implementations. SPIMbot has been effectively used in large classes and its source code is freely available [8].
The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters

The angular power spectrum of the Sunyaev–Zel'dovich (SZ) effect is a powerful probe of cosmology. It is easier to detect than individual clusters in the field, is insensitive to observational selection effects and does not require a calibration between cluster mass and flux, reducing the systematic errors that dominate the cluster-counting constraints. It receives a dominant contribution from virialized cluster region between 20 and 40 per cent of the virial radius and is thus relatively insensitive to the poorly known gas physics in the cluster centre, such as cooling or (pre)heating. In this paper we derive a refined analytic prediction for the SZ angular power spectrum using the universal gas density and temperature profile and the dark matter halo mass function. The predicted power spectrum has no free parameters and fits all of the published hydrodynamic simulation results to better than a factor of 2 for 2000 < l < 10 000. We find that the angular power spectrum Cl scales as Cl∝σ78(Ωbh)2 and is almost independent of all of the other cosmological parameters. This differs from the local cluster abundance studies, which give a relation between σ8 and Ωm. We also compute the covariance matrix of Cl using the halo model and find a good agreement relative to the simulations. We argue that the best constraint from the SZ power spectrum comes from l∼ 3000, where the sampling variance is sufficiently small and the spectrum is dominated by massive clusters above 1014h−1 M⊙ for which cooling, heating and details of star formation are not very important. We estimate how well we can determine σ8(Ωbh)2/7 with sampling-variance-limited observations and find that for a several-square-degree survey with arcmin resolution one should be able to determine σ8 to within a few per cent, with the remaining uncertainty dominated by theoretical modelling. If the recent excess of the cosmic microwave background power on small scales reported by Cosmic Background Imager (CBI) and Berkeley Illinois Maryland Association (BIMA) experiments is due to the SZ effect, then we find σ8(Ωbh/0.035)0.29= 1.04 ± 0.12 at 95 per cent confidence level (statistical) and with a residual 10 per cent systematic (theoretical) uncertainty.
Cosmological constraints and SU(5) supergravity grand unification

Abstract The predictions of SU(5) supergravity models with radiative breaking constrained by experimental proton decay bounds are discussed. It is shown that cosmological constraints further restrict the parameter space but can be satisfied for a wide range of parameters. It is also shown that no serious fine tuning problems (either at M SUSY or M GUT ) exist.
Frequency Response of Multiconductor Transmission Lines Illuminated by an Electromagnetic Field

A well-known result [1], [2] for the response of a two-wire transmission line illuminated by a nonuniform electromagnetic field is extended to multiconductor lines. A simple matrix equation for the currents induced in arbitrary termination networks is obtained. Air Development Center.
Adaptive Regulation of Amplitude Limited Robot Manipulators With Uncertain Kinematics and Dynamics

Common assumptions in most of the previous robot controllers are that the robot kinematics and manipulator Jacobian are perfectly known and that the robot actuators are able to generate the necessary level of torque inputs. In this note, an amplitude-limited torque input controller is developed for revolute robot manipulators with uncertainty in the kinematic and dynamic models. The adaptive controller yields semiglobal asymptotic regulation of the task-space setpoint error. The advantages of the proposed controller include the ability to actively compensate for unknown parametric effects in the dynamic and kinematic model and the ability to ensure actuator constraints are not breached by calculating the maximum required torque a priori
A Probabilistic Approach to Conjugacy Classes in the Finite Symplectic and Orthogonal Groups

Abstract Markov chains are used to give a purely probabilistic way of understanding the conjugacy classes of the finite symplectic and orthogonal groups in odd characteristic. As a corollary of these methods, one obtains a probabilistic proof of Steinberg's count of unipotent matrices and generalizations of formulas of Rudvalis and Shinoda.
Theoretical study of thieno[3,4‐d]thiepin and furo[3,4‐d]thiepin as dienes in the diels‐alder reaction

Theoretical study of thiophene and furan c-fused rings with unsaturated seven membered rings with oxygen or sulfur as dienes for Diels-Alder reactions was conducted with the semiempirical Austin Model 1 (AMI). Four approaches were considered: frontier orbital theory, resonance stability of the dienophiles determined through heat of hydrogenation, progress of the reaction through bond orders, and the estimation of the reaction barriers. It was determined that the most unreactive species with the highest resonance stability are sulfur heterocyclic compounds, while furan derivatives are the most reactive. Using o-quinonoid episulfide as an intermediate was rejected because the estimated activation energy for its formation is too high. The possibility of a three bond formation in the transition state of thieno[3,4-d]thiepin reaction with ethylene was considered and rejected on the basis of AMI estimated activation energy. The S-methylated derivatives of thieno[3,4-d]thiepin were predicted to react with less reactive dienophiles like ethylene under moderate reaction conditions. If thieno[3,4-d]thiepin is not activated through S-methylation then a reactive dienophile and drastic reaction conditions are predicted to be necessary to force the cycloaddition reaction. The obtained results are in agreement with experimental evidence.
Brain serotonin and pituitary-adrenal function.

Publisher Summary This chapter describes the serotonin (5-HT) and pituitary-adrenal function. The effects of altering 5-HT synthesis on the diurnal rhythm of plasma corticosterone and on the pituitary adrenal response to stress were studied in rats and man. The hypothesis is proposed that 5-HT mediates the corticosteroid negative feedback mechanism that regulates corticotrophin (ACTH) secretion and that the primary site of this feedback is extra hypothalamic. In contrast, pretreatment with I-tryptophan, 5-HTP alone or 5-HTP and MK 486 reduced slightly the stress response in intact rats and 5-HTP with MK 486 reduced 24 h urinary 17-hydroxycorticosteroids (17-OHCS) excretion in humans. On the other hand corticosterone administration or stress increased the activity of tryptophan hydroxylase in the midbrain and the conversion of tryptophan to 5-HT. In addition, there appears to be a correlation between the daily rhythm of 5-HT content in the limbic system and that of circulating corticosterone. It is reported that treatment with parachlorophenylalanine (PCPA) abolished the diurnal variation of plasma corticosterone at an intermediate level in the rat, affect the metabolism or action of 5-HT abolished the daily rise in plasma 17-OHCS in the cat but did not block the response to stress.
Exploratory photochemistry of iodinated aromatic azides

Abstract In contrast to the photolysis of p-toluyl azide, photolysis of ortho - or meta -iodo substituted p-toluyl azide in the presence of nucleophilic trapping agents produced the corresponding triplet nitrene which led to the simple aniline products and not to the dehydroazepine-nucleophile adducts.
Hydroboration reactions mediated by bis(mesityl)niobium: Beware of the trojan horse

Bis(mesityl)niobium (1) promotes hydroborations of alkenes by catecholborane but via an indirect mechanism.
Implementation Challenges in Translating Pivotal Response Training into Community Settings

Implementing evidence-based practices (EBPs) for children with autism is challenging for teachers because these practices are often complex, requiring significant training and resources that are not available in most school settings. This brief investigation was designed to identify areas of strength and difficulty for teachers implementing one such EBP, pivotal response training (PRT). Observational data were gathered from 41 teachers participating in two separate investigations involving PRT. Despite differences in training procedures, teachers demonstrated similarities in areas of strength (clear opportunities/instruction and child choice) and difficulty (turn taking and multiple cues). These findings suggest next steps toward systematic adaptation of PRT for classroom use. The research may serve as a model for the process of adapting EBPs for practice settings.
Design of price mechanisms for network resource allocation via price of anarchy

We study the design of price mechanisms for communication network problems in which a user’s utility depends on the amount of flow she sends through the network, and the congestion on each link depends on the total traffic flows over it. The price mechanisms are characterized by a set of axioms that have been adopted in the cost-sharing games, and we search for the price mechanisms that provide the minimum price of anarchy. We show that, given the non-decreasing and concave utilities of users and the convex quadratic congestion costs in each link, if the price mechanism cannot depend on utility functions, the best achievable price of anarchy is $${{4(3-2 \sqrt{2}) \approx 31.4 \% }}$$. Thus, the popular marginal cost pricing with price of anarchy less than 1/3 ≈ 33.3% is nearly optimal. We also investigate the scenario in which the price mechanisms can be made contingent on the users’ preference profile while such information is available.
Strategic buyers, horizontal mergers and synergies: An experimental investigation

Abstract This paper reports an experiment designed to evaluate interrelationships between strategic buyers, market power and merger-induced synergies. The experiment consists of 40 posted-offer quadropolies. Treatments include the use of simulated or human buyers, seller consolidations and merger-induced fixed cost and unit cost synergies. In the simulated-buyer markets we observe behavior generally consistent with comparative static predictions: prices rise post-merger, and unit (but not fixed) cost synergies may exert some price-moderating effect. The addition of powerful buyers changes results markedly. Although prices are lower in the human buyer markets, outcomes are more variable and predicted comparative static effects are no longer observed.
CONTROLS ON RESERVOIR QUALITY IN TIGHT SANDSTONES OF THE TRAVIS PEAK FORMATION, EAST TEXAS.

Most sandstone in the gas-bearing Travis Peak formation has undergone compaction and extensive cementation during its burial history, resulting in low porosity and permeability. Diagenetically induced permeability variations are superimposed on original permeability variations produced by depositional processes. Sandstones range from fluvial-channel to shallow-marine, bay and tidal-flat deposits. Three types of sandstone that differ in their original permeability distribution and lateral continuity are distinguished. Travis Peak sandstones have undergone a complex series of diagenetic modifications. Precipitation of authigenic quartz, ankerite, dolomite, illite, and chlorite, and the introduction of reservoir bitumen, were the most important causes of occlusion of primary porosity and reduction of permeability. Porosimeter-measured porosity is the best predictor of permeability, and there is a statistically significant inverse correlation between total volume of cement and permeability. Permeability decreases with depth in the Travis Peak, suggesting that the diagenetic processes that caused extensive cementation and resultant low permeability throughout most of the formation did not operate as completely on sediments deposited near the top of the formation.
The production of O(1D) from dissociative recombination of O2

The results of large scale ab initio calculations of the rates for production of O(1D) by dissociative combination of O2(+) are presented for electron temperatures in the range 100 to 3000 K. A 1-delta-u state is the dominant dissociative route from v = 0 and a 3-sigma-u(-) state is the most important route from v = 1 and v = 2. The calculated total rate for O(1D) production from v = 0 is 2.21(+0.21, -0.24) x 10(-7) x (T sub e/300) exp -.46 near room temperature. The v = 1 and v = 2 rates are about 17 percent and 47 percent smaller respectively, than the v = 0 rate at 300 K.
Interference Channels With Rate-Limited Feedback

We consider the two-user interference channel with rate-limited feedback. Related prior works focus on the case where feedback links have infinite capacity, while no research has been done for the rate-limited feedback problem. Several new challenges arise due to the capacity limitations of the feedback links, both in deriving inner bounds and outer bounds. We study this problem under three different interference models: the El Gamal-Costa deterministic model, the linear deterministic model, and the Gaussian model. For the first two models, we develop an achievable scheme that employs three techniques: Han-Kobayashi message splitting, quantize-and-binning, and decode-and-forward. We also derive new outer bounds for all three models and we show the optimality of our scheme under the linear deterministic model. In the Gaussian case, we propose a transmission strategy that incorporates lattice codes, inspired by the ideas developed in the first two models. For symmetric channel gains, we prove that the gap between the achievable sum rate of the proposed scheme and our new outer bounds is bounded by a constant number of bits, independent of the channel gains.
The energy distributions of magnetic variables: The effects of inhomogeneous accretion columns

Previous shock models for the AM Herculis-type magnetic variables have assumed homogeneous accretion columns, with constant infall densities out to a characteristic column radius. The resulting energy distributions are strongly peaked in the visible to ultraviolet and are in disagreement with observations. We report the preliminary results of calculations with more general radial functions of the infall density. Exponential and gaussian profiles yield continua similar to those of the standard model. More tapered, power-law profiles produce continua which are flatter and in better agreement with observations. Comparisons are made to data for AM Her and E2003+225.
A multigroup diffusion solver using pseudo transient continuation for a radiation-hydrodynamic code with patch-based AMR

We present a scheme to solve the nonlinear multigroup radiation diffusion (MGD) equations. The method is incorporated into a massively parallel, multidimensional, Eulerian radiation-hydrodynamic code with Adaptive Mesh Refinement (AMR). The patch-based AMR algorithm refines in both space and time creating a hierarchy of levels, coarsest to finest. The physics modules are time-advanced using operator splitting. On each level, separate "level-solve" packages advance the modules. Our multigroup level-solve adapts an implicit procedure which leads to a two-step iterative scheme that alternates between elliptic solves for each group with intra-cell group coupling. For robustness, we introduce pseudo transient continuation (Ψtc). We analyze the magnitude of the Ψtc parameter to ensure positivity of the resulting linear system, diagonal dominance and convergence of the two-step scheme. For AMR, a level defines a subdomain for refinement. For diffusive processes such as MGD, the refined level uses Dirichlet boundary data at the coarse-fine interface and the data is derived from the coarse level solution. After advancing on the fine level, an additional procedure, the sync-solve (SS), is required in order to enforce conservation. The MGD SS reduces to an elliptic solve on a combined grid for a system of G equations, where G is the number of groups. We adapt the "partial temperature" scheme for the SS; hence, we reuse the infrastructure developed for scalar equations. Results are presented. We consider a multigroup test problem with a known analytic solution. We demonstrate utility of Ψtc by running with increasingly larger timesteps. Lastly, we simulate the sudden release of energy Y inside an Al sphere (r=15cm) suspended in air at STP. For Y=11kT, we find that gray radiation diffusion and MGD produce similar results. However, if Y=1MT, the two packages yield different results. Our large Y simulation contradicts a long-standing theory and demonstrates the inadequacy of gray diffusion.
Direct Stereospecific Amination of Alkyl and Aryl Pinacol Boronates

The direct amination of alkyl and aryl pinacol boronates is accomplished with lithiated methoxyamine. This reaction directly provides aliphatic and aromatic amines, stereospecifically, and without preactivation of the boronate substrate.
The cost of annoying ads

Display advertisements vary in the extent to which they annoy users. While publishers know the payment they receive to run annoying ads, little is known about the cost such ads incur due to user abandonment. We conducted two experiments to analyze ad features that relate to annoyingness and to put a monetary value on the cost of annoying ads. The first experiment asked users to rate and comment on a large number of ads taken from the Web. This allowed us to establish sets of annoying and innocuous ads for use in the second experiment, in which users were given the opportunity to categorize emails for a per-message wage and quit at any time. Participants were randomly assigned to one of three different pay rates and also randomly assigned to categorize the emails in the presence of no ads, annoying ads, or innocuous ads. Since each email categorization constituted an impression, this design, inspired by Toomim et al. (2011), allowed us to determine how much more one must pay a person to generate the same number of impressions in the presence of annoying ads compared to no ads or innocuous ads.
Enantioselective hydroacylation of N-vinylindole-2-carboxaldehydes

We report catalytic, enantioselective intramolecular hydroacylation of N-vinylindole-2-carboxaldehydes. These hydroacylation reactions occur in the presence of a readily accessible rhodium catalyst and form chiral, non-racemic 2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-ones in high yields with excellent enantioselectivities.
A methodology for the automation of medium or small manufacturing companies

Abstract Many products are produced by discrete manufacturing plants in lots of 100 items or fewer. Currently, most small and medium-sized manufacturing companies are far from computer-integrated automation. New computer-integrated manufacturing systems with their associated hardwares require tremendous initial investments that are beyond the means of most small and medium-sized companies. In this paper we investigate how these companies can upgrade and automate their existing facilities at a minimal and viable cost. In Section 2 we discuss main references (books and trade journals) that contain detailed information on software packages for automation. In Section 3 we discuss the criteria for selecting software packages. In Section 4 we discuss how to use the obtained information to create a data base of different alternatives. In Section 5 we outline different areas of manufacturing. For illustrations, we discuss manufacturing planning, intelligent systems, and computer areas. In Section 6 we discuss a new method for the selection of the best alternative using the data base. The method is a simple interactive paired comparison method based on a computer package developed on a personal computer.
An uncertainty principle on compact manifolds

Breitenberger’s uncertainty principle on the torus $$\mathbb {T}$$ and its higher-dimensional analogue on $$\mathbb {S}^{d-1}$$ are well understood. We describe an entire family of uncertainty principles on compact manifolds $$(M,g)$$ , which includes the classical Heisenberg–Weyl uncertainty principle (for $$M=B(0,1) \subset \mathbb {R}^d$$ the unit ball with the flat metric) and the Goh–Goodman uncertainty principle (for $$M=\mathbb {S}^{d-1}$$ with the canonical metric) as special cases. This raises a new geometric problem related to small-curvature low-distortion embeddings: given a function $$f:M \rightarrow \mathbb {R}$$ , which uncertainty principle in our family yields the best result? We give a (far from optimal) answer for the torus, discuss disconnected manifolds and state a variety of other open problems.
Pyridynes and indolynes as building blocks for functionalized heterocycles and natural products

Heterocyclic arynes, or hetarynes, have been studied for over 100 years. However, challenges associated with observing these reactive species, as well as developing synthetically useful methods for their generation and trapping, have limited their use. This review provides a brief historical perspective on the field of hetarynes, in addition to a discussion of pyridyne and indolyne methodologies. Moreover, this review highlights the use of pyridynes, indolynes, and related strained intermediates in natural product synthesis.
Synthesis of (±)-7-episordidin

Abstract The stereoselective synthesis of (±)-7-episordidin, an aggregation pheromone from the male banana weevil, Cosmopolites sordidus Germar, is reported. The key step of this work is a regioselective rhodium(II)-catalyzed diazocarbonyl C H insertion reaction that simultaneously generates three of the natural product's four stereocenters. The work reported herein also represents a formal synthesis of sordidin.
Design of Long Pulse/Steady State Negative Hydrogen Ion Sources for Fusion Applications

As part of the program to develop a high energy neutral beam injector based on neutralization of negative ions, several types of negative hydrogen (or deuterium) ion sources for long pulse or steady state operation are being studied at Brookhaven National Laboratory. By using parameters of ion sources when operating in a pulsed mode and without cooling (pulse length < 0.1 s), requirements have been determined for a long pulse (several seconds) or steady state operating mode and two sources have been designed and fabricated. First of the two is a Penning source, designed for a steady state operation with a cathode power density of 1 kW/cm2. For the range of cathode power densities between 0.2 kW/cm2 and 1 kW/cm2, nucleated boiling has to be used for heat removal; below 0.2 kW/cm2 water flow cooling suffices. Although this source should deliver 0.3-0.5 A of H- ions in a steady state operation and at full power, the other source, which has a magnetron geometry, is more promising. The latter incorporates twd new features compared to first designs, geometrical focusing of fast, primary negative hydrogen ions from the cathode into the extraction slit, and a wider discharge gap in the back of the source. These two changes have resulted in an improvement of the power and gas efficiencies by a factor of 3 to 4 and in a reduction of the cathode power density by an order of magnitude.
Experimentally Determined Rotor Power Losses in Homopolar and Heteropolar Magnetic Bearings

The identification of parameters that dictate the magnitude of rotor power losses in radial magnetic bearings is very important for many applications. Low loss performance of magnetic bearings in aerospace equipment such as jet engines and flywheel energy storage systems is especially critical. Two basic magnetic bearing designs are employed in industrial practice today: the homopolar design, where the flux paths are of a mixed radial/axial orientation, and the heteropolar design, where the flux paths are primarily radial in nature. The stator geometry and flux path of a specific bearing can have a significant effect on the rotor losses. This paper describes the detailed measurement of rotor losses for experimentally comparable homopolar and heteropolar designs. The two test bearing configurations are identical except for geometric features that determine the direction of the flux path. Both test bearing designs have the same air gap length, tip clearance ratio, surface area under the poles, and bias flux levels. An experimental test apparatus was used where run down tests were performed on a test rotor with both bearing designs to measure power losses. Numerous test runs where made for each bearing configuration by running multiple levels of flux density. The components of the overall measured power loss, due to hysteresis, eddy currents, and windage, were determined based on theoretical expressions for power loss. It was found that the homopolar bearing had significantly lower power losses than the heteropolar bearing.
Determining the adenoma detection rate and adenomas per colonoscopy by photography alone: Proof-of-concept study

Background and study aims: The adenoma detection rate (ADR) and adenomas detected per colonoscopy (APC) are measures of the quality of mucosal inspection during colonoscopy. In a resect and discard policy, pathologic assessment for calculation of ADR and APC would not be available. The aim of this study was to determine whether ADR and APC calculation based on photography alone is adequate compared with the pathology-based gold standard. Patients and methods: A prospective, observational, proof-of-concept study was performed in an academic endoscopy unit. High definition photographs of consecutive polyps were taken, and pathology was estimated by the colonoscopist. Among 121 consecutive patients aged ≥ 50 years who underwent colonoscopy, 268 polyps were removed from 97 patients. Photographs of consecutive polyps were reviewed by a second endoscopist. Results: The resect and discard policy applied to lesions that were ≤ 5 mm in size. When only photographs of lesions that were ultimately proven to be adenomas were included, the reviewer assessed ADR and APC to be lower than that determined by pathology (absolute reductions of 6.6 % and 0.17, and relative reductions of 12.6 % and 13.1 % in ADR and APC, respectively). When all photographs were included for calculation of ADR and APC, the reviewer determined the ADR to be 3.3 % lower (absolute reduction) and the APC to be the same as the rates determined by pathology. Conclusions: In a simulated resect and discard strategy, a high-level detector can document adequate ADR and APC by photography alone.
Selectivity in quaternion algebras

Abstract We prove an integral version of the classical Albert–Brauer–Hasse–Noether theorem regarding quaternion algebras over number fields. Let K be a number field with ring of integers O K , and let A be a quaternion algebra over K satisfying the Eichler condition. Let Ω be a commutative, quadratic O K -order and let R ⊂ A be an order of full rank. Assume that there exists an embedding of Ω into R . We describe a number of criteria which imply that every order in the genus of R admits an embedding of Ω. In the case that the relative discriminant ideal of Ω is coprime to the level of R and the level of R is coprime to the discriminant of A , we give necessary and sufficient conditions for an order in the genus of R to admit an embedding of Ω. We explicitly parameterize the isomorphism classes of orders in the genus of R which admit an embedding of Ω. In particular, we show that the proportion of the genus of R admitting an embedding of Ω is either 0, 1/2 or 1. Analogous statements are proven for optimal embeddings.
Life Years Lost Associated with Obesity-Related Diseases for U.S. Non-Smoking Adults.

The objectives of this paper are to predict life years lost associated with obesity-related diseases (ORDs) for U.S. non-smoking adults, and to examine the relationship between those ORDs and mortality. Data from the National Health Interview Survey, 1997–2000, were used. We employed mixed proportional hazard models to estimate the association between those ORDs and mortality and used simulations to project life years lost associated with the ORDs. We found that obesity-attributable comorbidities are associated with large decreases in life years and increases in mortality rates. The life years lost associated with ORDs is more marked for younger adults than older adults, for blacks than whites, for males than females, and for the more obese than the less obese. Using U.S. non-smoking adults aged 40 to 49 years as an example to illustrate percentage of the life years lost associated with ORDs, we found that the mean life years lost associated with ORDs for U.S. non-smoking black males aged 40 to 49 years with a body mass index above 40 kg/m2 was 5.43 years, which translates to a 7.5% reduction in total life years. White males of the same age range and same degree of obesity lost 5.23 life years on average – a 6.8% reduction in total life years, followed by black females (5.04 years, a 6.5% reduction in life years), and white females (4.7 years, a 5.8% reduction in life years). Overall, ORDs increased chances of dying and lessened life years by 0.2 to 11.7 years depending on gender, race, BMI classification, and age.
Global neutral polar wind model

[1] The neutral polar wind shows a highly dynamic structure that depends on the characteristics of convection and precipitation. The ions in the polar wind are highly dependent on convection electric fields at high latitudes, and their outflow dynamics are modified by the heat input of precipitating electrons in the auroral zone. A new three-dimensional model of the neutral polar wind has been developed which takes into account the convecting ion polar wind and heating due to precipitating electrons in the auroral zone, along with charge exchange between the ion polar wind and the background thermal and geocoronal neutral atoms. The results show that over the polar caps the neutral polar wind particles exhibit extremely large fluxes in both the horizontal and vertical directions, and to a fixed observer it would appear that the neutral polar wind particles are moving in all directions. The results also show that the heating that occurs during geomagnetic storms leads to a significant coupling between the ionosphere and magnetosphere via both ion and neutral particles.
Oxidation Behavior of Hot-Pressed Si3N4

The high-temperature chemical stability of hot-pressed Si3N4 was studied between 600° and 1450°C. Reactions were followed by X-ray diffraction and scanning electron microscopy. In air, this material begins to oxidize at 700° to 750°C; a distinct amorphous siO2 surface layer results after 24 h at 750°C-Concomitant formation of cristobalite occurs, depending on exposure time, and is enhanced as temperature is Increased. Magnesium and calcium magnesium silicates form above 1000°C. The data suggest that impurities, e.g. Mg, Ca, and Fe, greatly lower the oxidation resistance of Si3N4 in air.
Scanning tunneling microscopy of processes at liquid-solid interfaces

Images of a graphite surface before and after electroplating with gold were obtained without ever removing the sample from the electroplating solution. Images of a metal surface in salt water were obtained every 5 s as the surface corroded away. Together these images suggest a bright future for in situ investigations of processes with scanning tunneling microscopy.
Chemically produced XeF(B) electronic excited state

Ultraviolet (UV) emission has been observed in the reactions of XeF/sub 2/+F/sub 2/+SiH/sub 4/ and XeF/sub 2/+F/sub 2/+F+B/sub 2/H/sub 6/. The emission spectra have been identified with the B/sup 2/ Sigma to X/sup 2/ Sigma transition of XeF. The emission intensity has also been examined as functions of the XeF/sub 2/, F/sub 2/, SiH/sub 4/, and Ar concentrations. Possible mechanisms of XeF(B) production are discussed. >
Selective formation of non-conjugated olefins by samarium(II)-mediated elimination/isomerization of allylic benzoates

Aromatic allylic benzoates can be selectively transformed to the corresponding benzoate eliminated olefin by the action of samarium diiodide. Depending on the substrate and the elimination conditions, high selectivity for the non-conjugated alkene product can be achieved.
Modeling Of Induction-Linac Based Free-Electron Laser Amplifiers

We describe the modeling of an induction-linac based free-electron laser (IFEL) amplifier for producing multimegawatt levels of microwave power. We have used the Lawrence Livermore National Laboratory (LLNL) free-electron laser simulation code, FRED, and the simulation code for sideband calculations, GINGER for this study. For IFEL amplifiers in the frequency range of interest (200 to 600 GHz), we have devised a wiggler design strategy which incorporates a tapering algorithm that is suitable for free-electron laser (FEL) systems with moderate space-charge effects and that minimizes spontaneous noise growth at frequencies below the fundamental, while enhancing the growth of the signal at the fundamental. In addition, engineering design considerations of the waveguide wall loading and electron beam fill factor in the waveguide set limits on the waveguide dimensions, the wiggler magnet gap spacing, the wiggler period, and the minimum magnetic field strength in the tapered region of the wiggler. As an example, we shall describe an FEL amplifier designed to produce an average power of about 10 MW at a frequency of 280 GHz to be used for electron cyclotron resonance heating of tokamak fusion devices. 17 refs., 4 figs.
Approximate Methods for Calculation of Intrinsic Total-Absorption-and Double-Escape-Peak Efficiencies for Ge(Li) Detectors

Approximate methods are presented for calculation of intrinsic total-absorption-and double-escape-peak efficiencies of Ge(Li) detectors. These methods utilize "average" characteristics of gamma-ray photon interactions with matter, and, while developed in this paper for specific application to the Ge(Li) detector efficiency problem, should be applicable to any gamma-ray detector or absorptive medium. The technique for total-absorption-peak efficiency determination includes the use of an "average-photon energy-degradation curve" and of the Dirac chord method for calculation of collision probabilities. The average-photon energy-degradation curve is obtained from differential Compton collision cross sections and detector material total-crosssection characteristics; it is independent of detector size and shape. The Dirac chord method is then used to determine the probability of further collisions for photons "generated" within the detector volume. In the model these probabilities are functions only of a characteristic detector dimension, s?, where s is the average chord length and ? is the total linear attenuation coefficient. Double-escape-peak efficiencies are determined through the calculation of the average probability of occurrence of the following three phenomena: (1) pair production, (2) electron-positron absorption, and (3) annihilation-photon double escape. Complete working curves and expressions are included to enable convenient utilization of these techniques. Example results are compared with efficiency determinations made experimentally and by Monte Carlo calculations.
On almost everywhere convergence of strong arithmetic means of Fourier series

This article establishes a real-variable argument for Zygmund's theorem on almost everywhere convergence of strong arithmetic means of partial sums of Fourier series on $\mathbb{T}$, up to passing to a subsequence. Our approach extends to, among other cases, functions that are defined on $\mathbb{T}^d$, which allows us to establish an analogue of Zygmund's theorem in higher dimensions.
QCD phases at high density and instantons

At this workshop one probably does not need to explain why we study QCD at large density: it is, after all, a traditional domain of nuclear physics. However, as a part of the spiraling development related in general with the transitions into quark-gluon plasma (QGP) the non-perturbative QCD, studies of high density direction are rather new. Since the main perturbative phenomena (such as screening and plasma oscillations) in dense quark matter has been worked out (see e.g. [1]) the field was essentially dormant for 2 decades.
Building on Cram’s Legacy: Stimulated Gating in Hemicarcerands

CONSPECTUS: Donald Cram's pioneering Nobel Prize-winning work on host-guest molecules led eventually to his creation of the field of container molecules. Cram defined two types of container molecules: carcerands and hemicarcerands. Host-guest complexes of carcerands, called carceplexes, are formed during their synthesis; once a carceplex is formed, the trapped guest cannot exit without breaking covalent bonds. Cram defined a quantity called constrictive binding, arising from the mechanical force that prevents guest escape. The constrictive binding in carceplexes is high. In contrast, hemicarcerands have low constrictive binding and are able to release the incarcerated guests at elevated temperatures without breaking covalent bonds. We have designed molecules that can switch from carcerand to hemicarcerand through a change in structure that we call gating. The original discovery of gating in container molecules involved our computational studies of a Cram hemicarceplex that was observed to release a guest upon heating. We found that the side portals of this hemicarceplex have multiple thermally accessible conformations. An eight-membered ring that is part of a portal changes from a "chair" to a "boat" structure, leading to the enlargement of the side portal and the release of the guest. This type of gating is analogous to phenomena often observed with peptide loops in enzymes. We refer to this phenomenon as thermally controlled gating. We have also designed and synthesized redox and photochemically controlled gated hemicarceplexes. Gates are built onto host molecules so that the opening or closing of such gates is stimulated by reducing or oxidizing conditions, or by ultraviolet irradiation. In both cases, the appropriate stimuli can produce a carceplex (closed gates) or hemicarceplex (open gates). A hemicarceplex with closed gates behaves like a carceplex, due to its very high constrictive binding energy. When the gates are opened, constrictive binding is dramatically lowered, and guest entrance and exit become facile. This stimulated switching between open and closed states controls access of the guest to the binding site. The experimental and computational investigations of gated hemicarcerands and several potential applications of gated hemicarceplexes are described in this Account.
DYNAMICS OF COMPLEX TRUSS-TYPE SPACE STRUCTURES

A laboratory test was conducted to validate experimentally and to help establish the limits of the MBCT approach. The results show that the MBCT method is a vital alternate technique for ground testing large flexible structures. A three-dimensional MAST-type truss structure has been successfully simulated