cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis, structure, and magnetic properties of the layered copper(II) oxide Na2Cu2TeO6.

A new quaternary layered transition-metal oxide, Na2Cu2TeO6, has been synthesized under air using stoichiometric (with respect to the cationic elements) mixtures of Na2CO3, CuO, and TeO2. Na2Cu2TeO6 crystallizes in the monoclinic space group C2/m with a = 5.7059(6) A, b = 8.6751(9) A, c = 5.9380(6) A, β = 113.740(2)°, V = 269.05(5) A3, and Z = 2, as determined by single-crystal X-ray diffraction. The structure is composed of [Cu2TeO6] layers with the Na atoms located in the octahedral voids between the layers. Na2Cu2TeO6 is a green nonmetallic compound, in agreement with the electronic structure calculation and electrical resistance measurement. The magnetic susceptibility shows Curie−Weiss behavior between 300 and 600 K with an effective moment of 1.85(2) μB/CuII and ϑc = −87(6) K. A broad maximum at 160 K is interpreted as arising from short-range one-dimensional antiferromagnetic correlations. With the aid of the technique of magnetic dimers, the short-range order was analyzed in terms of an alternatin...
Network control without CSI using rateless codes for downlink cellular systems

Wireless network scheduling and control techniques (e.g., opportunistic scheduling) rely heavily on access to Channel State Information (CSI). However, obtaining this information is costly in terms of bandwidth, time, and power, and could result in large overhead. Therefore, a critical question is how to optimally manage network resources in the absence of such information. To that end, we develop a cross-layer solution for downlink cellular systems with imperfect (and possibly no) CSI at the transmitter. We use rateless codes to resolve channel uncertainty. To keep the decoding complexity low, we explicitly incorporate time-average block-size constraints, and aim to maximize the system utility. The block-size of a rateless code is determined by both the network control decisions and the unknown CSI of many time slots. Therefore, unlike standard utility maximization problems, this problem can be viewed as a constrained partial observed Markov decision problem (CPOMDP), which is known to be hard due to the “curse of dimensionality.” However, by using a modified Lyapunov drift method, we develop a dynamic network control scheme, which yields a total network utility within O(1/Lav) of utility-optimal point achieved by infinite block-size channel codes, where Lav is the enforced value of the time-average block-size of rateless codes. This opens the door of being able to trade complexity/delay for performance gains in the absence of accurate CSI. Our simulation results show that the proposed scheme improves the network throughput by up to 68% over schemes that use fixed-rate codes.
CARTE: A thematic mapping program

Abstract CARTE is the graphics display program of the LBL Computer Mapping System, producing thematic maps on microfilm at one hundredth the cost of producing negatives by hand. The program matches a geographical area with statistical data to produce graphic output on 35 mm film in the form of cross-hatched maps for single-color printing or slides, or color separation frames for multi-color printing (either computer-generated dot screens or total mask frames for photographic screening). A versatile set of directives allows the user to design the map and a corresponding report, and to specify such features as automatic placement of area names, calculation of a smooth distribution for color coding, and boundary clipping to specified limits for sectioning a map.
A discontinuous Galerkin method for the Vlasov-Poisson system

A discontinuous Galerkin method for approximating the Vlasov-Poisson system of equations describing the time evolution of a collisionless plasma is proposed. The method is mass conservative and, in the case that piecewise constant functions are used as a basis, the method preserves the positivity of the electron distribution function and weakly enforces continuity of the electric field through mesh interfaces and boundary conditions. The performance of the method is investigated by computing several examples and error estimates of the approximation are stated. In particular, computed results are benchmarked against established theoretical results for linear advection and the phenomenon of linear Landau damping for both the Maxwell and Lorentz distributions. Moreover, two nonlinear problems are considered: nonlinear Landau damping and a version of the two-stream instability are computed. For the latter, fine scale details of the resulting long-time BGK-like state are presented. Conservation laws are examined and various comparisons to theory are made. The results obtained demonstrate that the discontinuous Galerkin method is a viable option for integrating the Vlasov-Poisson system.
THE ROLE OF PROTOTYPING LANGUAGES IN CASE

Prototyping languages form a new category in the computer language family. They are different from the commonly familiar computer languages because they are used to support a higher level of automation at early phases of software development as well as throughout the entire process. They are used to create mechanically processable and executable descriptions or models of proposed software systems. Prototyping languages are also used to firm up requirements via frequent modifications and demonstrations of the models in an iterative process of prototype evolution. The benefits of a prototyping language are fully realized when it is used with its computer-aided prototyping system (CAPS). In this paper, we describe the background, requirements, characteristics, computational features, and general principles for the design of prototyping languages. An example of a prototyping language design is used to illustrate these concepts.
Complex monopoles in the Georgi-Glashow-Chern-Simons model

Abstract We investigate the three-dimensional Georgi-Glashow model with a Chern-Simons term. We find that there exist complex monopole solutions of finite action. They dominate the path integral and disorder the Higgs vacuum, but electric charges are not confined. Subtleties in the gauge-fixing procedure in the path integral and issues related to Gribov copies are noted.
Crossed-listed foreign firms' earnings informativeness, earnings management and disclosures of corporate governance information under SOX

Abstract The passage of the Sarbanes–Oxley Act (SOX) marks the beginning of the mandatory disclosure of audit-committee composition and other corporate governance information for cross-listed foreign firms. We posit that the provisions of SOX improve the effectiveness of an independent audit committee and other corporate-governance functions in monitoring the earnings quality of cross-listed foreign firms, and we use cross-listed firms' earnings informativeness and earnings management to measure earnings quality. Our findings show earnings informativeness is significantly associated with audit-committee independence as well as with board independence in the post-SOX period. In contrast, we do not find a significant association between earnings informativeness and audit-committee independence in the pre-SOX period. Our findings also show a consistently negative association between earnings management and audit-committee independence after SOX, an association that is not found in the pre-SOX period. Similarly, a negative association between earnings informativeness and the CEO duality as the chair of the board is only found in the post-SOX period. Furthermore, our results show a positive (negative) association between earnings informativeness (earnings management) and an aggregate corporate-governance score as a measure of overall corporate-governance functions in both the pre- and post-SOX periods. Our findings on the change of magnitude in the relationship between earnings informativeness (earnings management) and corporate governance suggest that the SOX provisions improve the effectiveness of cross-listed foreign firms' corporate-governance functions in monitoring the quality of accounting earnings.
Lanthanum Tricyanide-Catalyzed Acyl Silane−Ketone Benzoin Additions

Lanthanum tricyanide efficiently catalyzes a benzoin-type coupling between acyl silanes and ketones. Yields range from moderate to excellent over a broad substrate scope encompassing aryl, alkyl, electron-rich, and sterically hindered ketones.
Abnormal Anodic Aluminum Oxide Formation in Confined Structures for Lateral Pore Arrays

We report on abnormal behavior in anodic oxidation of Al in mechanically confined structures for formation of horizontal nanoporous anodic alumina oxide (H-AAO). Instead of smooth pore walls, periodic dendrite inner pore structures form, the growth rate is suppressed to 5% of its value during bulk anodization under the same conditions, and a steady-state is never reached. These anomalies associated with H-AAO originate from suppressed volume expansion and a plastic flow of Al 2 O 3 confined by the Si0 2 hard mask. By determining new anodization conditions leading to zero volume expansion, dendritic H-AAO can be avoided and kinetic retardation minimized.
In-Pile Measurement of the Thermal Conductivity of Irradiated Metallic Fuel

Transient test data and posttest measurements from recent in-pile overpower transient experiments are used for an in situ determination of metallic fuel thermal conductivity. For test pins that undergo melting but remain intact, a technique is described that relates fuel thermal conductivity to peak pin power during the transient and a posttest measured melt radius. Conductivity estimates and their uncertainty are made for a database of four irradiated Integral Fast Reactor-type metal fuel pins of relatively low burnup (<3 at.%). In the assessment of results, averages and trends of measured fuel thermal conductivity are correlated to local burnup. Emphasis is placed on the changes of conductivity that take place with burnup-induced swelling and sodium logging. Measurements are used to validate simple empirically based analytical models that describe thermal conductivity of porous media and that are recommended for general thermal analyses of irradiated metallic fuel.
HEATING IN AN EXTENDED ACCRETION DISK CORONA ALONG THE Z-PATTERN IN CYG X-2

We observed at very high spectral resolution the prototype Z-source Cyg X-2 twice along its entire X-ray spectral variation pattern. In this preliminary analysis, we find an extended accretion disk corona (ADC) exhibiting Lyα emissions from various H-like ions, as well as emissions from He-like ions of Fe and Al, and Be-like ions of Fe. The brightest lines show a range of line broadening: H-like lines are very broad with Doppler velocities between 1100 and 2700 km s–1, while some others are narrower with widths of a few hundred km s–1. Line diagnostics allow us for the first time to determine coronal parameters. The line properties are consistent with a stationary, extended up to 1010 cm, dense (1 × 1015 cm–3), and hot (log ξ 3; T 106 K) ADC. We find ongoing heating of the corona along the Z-track and determine that heating luminosities change from about 0.4×L Edd on the horizontal to about 1.4 × L Edd on the flaring branch.
Cloud radiative effect on tropical troposphere to stratosphere transport represented in a large-scale model

[1] GFDL AM2 model simulations are analyzed to assess the simulated radiative effect of tropical tropopause layer (TTL) cirrus on tropical troposphere-to-stratosphere transport (TST). The strongest upward motion in the model's TTL is generally driven by dynamics instead of radiation, occurring in those TTL cloudy regions that overlap with optically thick clouds in the upper troposphere (UT). However, the occurrence frequency of such strong ascent is about one order of magnitude smaller than that of moderate ascent related to the radiative effect of TTL cirrus. The mean upward velocity of moderate ascent in the cloudy regions (∼−2.5— −3.5 hPa/day) is one order of magnitude larger than that induced by TTL clear-sky radiative heating (∼−0.18 hPa/day). This supports the hypothesis that cirrus radiative heating contributes substantially to the average tropical TST rates. The implication for future model-satellite comparisons is discussed.
Chemical ‘Jekyll and Hyde’s: Small-molecule inhibitors of developmental signaling pathways

Small molecules that perturb developmental signaling pathways can have devastating effects on embryonic patterning, as evidenced by the chemically induced onset of cyclopic lambs and children with severely shortened limbs during the 1950s. Recent studies, however, have revealed critical roles for these pathways in human disorders and diseases, spurring the re-examination of these compounds as new targeted therapies. In this tutorial review, we describe four case studies of teratogenic compounds, including inhibitors of the Hedgehog (Hh), Wnt, and bone morphogenetic protein (BMP) pathways. We discuss how these teratogens were discovered, their mechanisms of action, their utility as molecular probes, and their potential as therapeutic agents. We also consider current challenges in the field and possible directions for future research.
The structure of the internal wave Mach front generated by a point source moving in a stratified fluid

The height and velocity of an internal wave (IW) generated by a point fluid source moving horizontally in a stratified fluid is calculated at asymptotically large distances behind the source, in linear approximation. Particular emphasis is given to the region near the Mach front, defined by the off‐track angle θM =sin−1(cM/ V), where cM is the speed of the fastest IW and V is the source velocity. To elucidate the asymptotic IW profile in that regime, a novel uniform asymptotic expansion is developed which is valid on both sides of the Mach front. It is found that, for the fluid model employed, the asymptotic approximation for the IW height, as well as for all its derivatives, is continuous at that front, and that all these IW profiles are remarkably smooth and slowly varying functions of off‐track distance in that regime.
Using drill cutting separates to estimate the strength of narrow shear zones at SAFOD

[1] A technique is presented for estimating frictional strength of narrow shear zones based on hand selection of drillhole cuttings separates. Tests were conducted on cuttings from the SAFOD scientific drillhole near Parkfield, California. Since cuttings are mixed with adjacent material as they travel up the drillhole, these fault-derived separates give a better representation of the frictional properties of narrow features than measurements from the bulk material alone. Cuttings from two shear zones (one an active trace of the San Andreas fault) contain a significant weight percent of clay-rich grains that exhibit deformation-induced slickensides. In addition, cuttings from the active SAF trace contain around 1% serpentine. Coefficients of friction for clay-rich and serpentine grains were 0.3–0.5 and 0.4–0.45, respectively. These values are around 0.12 lower than the friction coefficient of the corresponding bulk cuttings, providing an improved estimate of the frictional strength of the San Andreas fault.
Low-Energy Excitations in an Incipient Antiferromagnet

Abstract We present fully self-consistent calculations in the fluctuation exchange approximation for the half-filled Hubbard model in two dimensions. A non-Fermi-liquid state evolves with decreasing temperature in this self-consistent model of coupled spin fluctuations and quasiparticles. The mean-field phase transition to long-range antiferromagnetic order is suppressed and we find no evidence of a phase transition to long-range magnetic order. We show that the real part of the self-energy at zero energy shows a positive slope and the imaginary part of the self-energy shows a local minimum. The scale of this structure is set by the zero-temperature gap in mean-field theory. The growth of spin fluctuations is reflected in the evolution of sharply peaked structure in the spin fluctuation propagator around zero energy and Q = (π, π). We present calculations for the Hubbard model in one dimension in a two-particle self-consistent parquet approximation. A second-moment sum rule suggests that vertex correction...
Outsourcing business services and the role of central administrative offices

Abstract In this paper, I study whether there is any evidence that the market scale surrounding a central administrative office (CAO) has any relation to a firm's cost-effectiveness in procuring business services. By linking plant-level data from the 1992 Annual Survey of Manufactures with CAO information from the Survey of Auxiliary Establishments, I examine manufacturing plants' practice of outsourcing services in relation to the size of the local service market surrounding the plant and that surrounding the plant's CAO. I found evidence which suggests that the greater the size of local market surrounding a CAO, the higher the plant's probability of relying on the CAO for outsourcing advertising, bookkeeping and accounting, and legal services.
On solving convex optimization problems with linear ascending constraints

In this paper, we propose two algorithms for solving convex optimization problems with linear ascending constraints. When the objective function is separable, we propose a dual method which terminates in a finite number of iterations. In particular, the worst case complexity of our dual method improves over the best-known result for this problem in Padakandla and Sundaresan (SIAM J Optim 20(3):1185–1204, 2009). We then propose a gradient projection method to solve a more general class of problems in which the objective function is not necessarily separable. Numerical experiments show that both our algorithms work well in test problems.
A semantic web approach to biological pathway data reasoning and integration

This paper describes the use of semantic web technology and Description Logic (DL) for facilitating the integration of molecular pathway data, which is illustrated by an Web Ontology Language (OWL)-based transformation of a more complex pathway structure (Reactome) into a simpler one (HPRD). The process starts by adding OWL axioms to BioPAX, a pathway interchange standard. The axioms are designed for mapping BioPAX-formatted Reactome interactions to ''molecular binding event'' interactions, which can be easily aligned with the HPRD data. Using an automated OWL reasoner, we find overlapping and non-overlapping molecular interactions between the two pathway datasets. The paper demonstrates the potential of semantic web and its enabling technologies in biological pathway data reasoning and integration.
Bayesian Dynamic Pricing Policies: Learning and Earning Under a Binary Prior Distribution

Motivated by applications in financial services, we consider a seller who offers prices sequentially to a stream of potential customers, observing either success or failure in each sales attempt. The parameters of the underlying demand model are initially unknown, so each price decision involves a trade-off between learning and earning. Attention is restricted to the simplest kind of model uncertainty, where one of two demand models is known to apply, and we focus initially on performance of the myopic Bayesian policy (MBP), variants of which are commonly used in practice. Because learning is passive under the MBP (that is, learning only takes place as a by-product of actions that have a different purpose), it can lead to incomplete learning and poor profit performance. However, under one additional assumption, a constrained variant of the myopic policy is shown to have the following strong theoretical virtue: the expected performance gap relative to a clairvoyant who knows the underlying demand model is bounded by a constant as the number of sales attempts becomes large. This paper was accepted by Gerard P. Cachon, stochastic models and simulation.
Channels of Redistribution: Inequality and Poverty in the Russian Transition

Among the many popular images of the Russian transition, none cast a more dramatic shadow than the apparently rapid transformation of an entire system from one characterised by low inequality and largely absent poverty to one marked by extremes of deprivation and prosperity. Once hailed as a salutary contrast to the extremes of well-being so characteristic of many economies at comparable levels of income, Russia now exhibits the tell-tale inequities that mark, for example, many Latin American economies. How accurate is this representation, both in its depiction of the situation pre-transition, let alone the consequences of recent changes? This paper is an attempt to answer these questions in as precise a manner as possible. The paper is organised as follows. Section 1 gives a brief description of the datasets — primarily the six rounds of a large household survey, the Russian Longitudinal Monitoring Survey (RLMS) - that we use in this paper. Section 2 sets out the initial conditions that obtained in the Former Soviet Union and Russia and the picture that emerges from use of official statistics. These are shown to be seriously misleading in a number of key respects. Section 3 deals with the channels of redistribution that are likely to be present in the transition and surveys the evidence available from both aggregate data and firm-level information. In Section 4 the key channels are formalised in a two sector model of transition in which the reallocation of labour and capital across state and private sectors is seen as the determining feature of transition. The model is primarily concerned with labour allocation and hence can provide the paths of inequality and poverty over the transition primarily associated with labour income. Some simulations are presented which provide a set of simple benchmarks for understanding the size of likely effects from both within-sector inequality as also through restructuring and closure probabilities for state firms and the relative productivity of both state and private sectors. Section 5 turns to the empirical findings that emerge from a detailed look at the household surveys, including the factors driving the changes in inequality. Section 6 looks at how stable the transitions over the income distribution have been and, in particular, takes a closer look at groups of stable winners and losers. Section 7 turns to the measurement of poverty and the results that emerge from the household survey regarding both expenditure and income measured poverty. We also look at the characteristics of the poor. Section 8 concludes.
Ceramics by the solution-sol-gel route

The use of solution mixing followed by gelation to make ultrahomogeneous glasses and ceramics of various oxide compositions for laboratory experimentation, with first organic and later principally colloidal inorganic, precursors was developed over 30 years ago. Major technologies that use the solution-sol-gel route have been developed to make nuclear fuel pellets, ceramic fibers, thin coatings, and abrasive grain. This article reviews the early history and summarizes present research in this field, particularly new processes aimed at achieving xerogel precursors of maximum heterogeneity with respect either to composition or to structure. Such nanocomposites provide major advantages in lowering sintering temperatures, refining microstructure, and controlling morphology and final phase composition.
Hydrothermal synthesis of selected phosphates and molybdates

Demonstration de l'utilite de la methode hydrothermale dans la croissance de monocristaux de plusieurs varietes de phosphates et molybdates; cette methode est utilisable pour des composes ne pouvant etre obtenus par une methode «seche» ou a des pressions normales
INITIAL STEREO ANALYSIS OF MRK 421 FROM THE VERITAS TELESCOPES

VERITAS (Very Energetic Radiation Imaging Telescope Array System), an array of ground-based gamma-ray telescopes in southern Arizona, USA, has been taking data in hardware stereo mode since March, 2006. The April–May 2006 dark run provided a large set of data from two telescopes on the known blazar Markarian (Mrk) 421. An initial analysis produced a light curve and preliminary cuts showing the two telescope array's angular resolution to be 0.19°. The remaining two VERITAS telescopes will be brought online by January, 2007.
International transmission of U.S. monetary policy shocks: Evidence from VAR's ☆

Abstract This paper documents data-oriented, detailed evidence on the international transmission of U.S. monetary policy shocks for the flexible exchange rate period using VAR models. First, U.S. expansionary monetary policy shocks lead to booms in the non-U.S., G-6 countries. In this transmission, changes in trade balance seem to play a minor role while a decrease in the world real interest rate seems important. Second, U.S. expansionary monetary policy shocks worsen the U.S. trade balance in about a year, but subsequently it improves. Overall, the basic versions of Mundell–Flemming–Dornbusch (MFD) and the sticky price (or sticky wage) intertemporal models do not seem to be consistent with the details of the transmission mechanism, and some extended versions seem to be necessary to fit the details.
Hot H2O Emission and Evidence for Turbulence in the Disk of a Young Star

Abstract : We report on the detection and analysis of hot rovibrational H2O emission from SVS 13, a young stellar object previously known to have strong CO overtone band head emission. Modeling of the high-resolution infrared spectrum shows that the H2O emission is characterized by temperatures of 1500 K, significantly lower than the temperatures that characterize the CO band head emission. The widths of the H2O lines are also found to be smaller than those of the CO lines. We construct a disk model of the emission that reproduces the CO and H2O spectrum. In this model, the H2O lines originate at somewhat larger disk radii ( 0.3 AU) than the CO overtone lines ( 0.1 AU). We find that the H2O abundance is about a factor of 10 lower than the calculated chemical equilibrium abundance. Large, approximately transonic, local line broadening is required to fit the profile of the CO band head. If this velocity dispersion is identified with turbulence, it is of significant interest regarding the transport of angular momentum in disks. Large local broadening is also required in modeling CO overtone emission from other young stellar objects, suggesting that large turbulent velocities may be characteristic of the upper atmospheres of the inner disks of young stars.
Lexicographic probability, conditional probability, and nonstandard probability

Abstract The relationship between Popper spaces (conditional probability spaces that satisfy some regularity conditions), lexicographic probability systems (LPS's), and nonstandard probability spaces (NPS's) is considered. If countable additivity is assumed, Popper spaces and a subclass of LPS's are equivalent; without the assumption of countable additivity, the equivalence no longer holds. If the state space is finite, LPS's are equivalent to NPS's. However, if the state space is infinite, NPS's are shown to be more general than LPS's.
High field magnetization of the spin fluctuation compounds UPt3, U0.1Pr0.9In3 and U1−xYxAl2

Abstract Measurements on M vs H up to 50 T in pulsed fields are reported for the spin fluctuation compounds UPt3 (where measurements up to 35 T already exist), U1−xYxAl2 and Pr0.9U0.1In3. The known metamagnetic transition at 20 T in UPt3 is observed; no further transition is observed in Upt3 up to 50 T. Although the compounds U0.9Y0.1Al2U0.7Y0Al2 and Pr0.1In, also show T4. In T spin fluctuation terms in their specific heat with specific heat γ values spanning the range 190–670 mJ per mole UK2, (where Upt, has γ=450 mJ per mole-K2), no metamagnetic transitions up to 50 are observed in these systems. Possible scaling relations between Bmetamag and various parameters are discussed.
Two temporal bone computed tomography measurements increase recognition of malformations and predict sensorineural hearing loss.

Objectives/Hypothesis: The objectives of this prospective study were to assess the reproducibility of the measurements of the cochlea and lateral semicircular canal (LSCC) and to determine if abnormal measurements predict sensorineural hearing loss (SNHL). Methods: Two readers independently measured the cochlear height on coronal section and the LSCC bony island width on axial section on 109 temporal bone computed tomography scans; audiologic data on these patients were collected independently from medical records. Inter- and intrareader variability was evaluated using intraclass correlation coefficients (ICCs) based on a random-effects model. The positive and negative predictive values of abnormal measurement for hearing loss were determined. Results: There was excellent inter- and intraobserver agreement for both measurements (ICC >80%). The average cochlear height was 5.1 mm (normal range, 4.4–5.9 mm) and average LSCC bony island width was 3.7 mm (normal range, 2.6–4.8 mm). Review of the original radiology reports demonstrated that both cochlear hypoplasia and LSSC dysplasia were overlooked in >50% of patients with both abnormal measurements and SNHL. Cochlear hypoplasia (<4.4 mm) had a positive predictive value of 100% for SNHL, whereas cochlear hyperplasia and bony island dysplasia were less predictive. Conclusion: The measurements of coronal cochlear height and axial LSCC bony width have excellent reproducibility and identify bony labyrinth abnormalities missed by visual inspection alone. In addition, cochlear hypoplasia is highly predictive of SNHL. To reliably identify inner ear malformations, measurement of the cochlear height and LSCC bony island width, in addition to the vestibular aqueduct, should be routinely performed on all temporal bone studies.
Sigma Limiting Effects on the Response of a Ceramic Matrix Beam

High sigma events were studied in the narrowband random response of a cantilevered beam excited by an electrodynamic shaker. The effects of truncating the input signal to the shaker with a Blackglas beam are discussed. Tests were conducted with the shaker option of the shaker controller sigma limiting turned off, sigma limited to 2.5, and sigma limited to 3.5. Large data files were recorded and analyzed. The results were compared with similar previous tests with an aluminum alloy beam. The sigma values calculated varied considerably with the record lengths. When a fatigue failure was assumed, the cumulative fatigue damage was computed as a function of the sigma value of the response peak probability density function. Very little damage was found for the high sigma peaks compared to the damage that occurred with the many smaller peaks.
The Role of the Achiral Template in Enantioselective Transformations. Radical Conjugate Additions to α-Methacrylates Followed by Hydrogen Atom Transfer

We have evaluated various achiral templates (1a−g, 10, and 16) in conjunction with chiral Lewis acids in the conjugate addition of nucleophilic radicals to α-methacrylates followed by enantioselective H-atom transfer. Of these, a novel naphthosultam template (10) gave high enantioselectivity in the H-atom-transfer reactions with ee's up to 90%. A chiral Lewis acid derived from MgBr2 and bisoxazoline (2) gave the highest selectivity in the enantioselective hydrogen-atom-transfer reactions. Non-C2 symmetric oxazolines (20−25) have also been examined as ligands, and of these, compound 25 gave optimal results (87% yield and 80% ee). Insights into rotamer control in α-substituted acrylates and the critical role of the tetrahedral sulfone moiety in realizing high selectivity are discussed.
Primordial nucleosynthesis in the new cosmology

Abstract Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies independently predict the universal baryon density. Comparing their predictions will provide a fundamental test on cosmology. Using BBN and the CMB together, we will be able to constrain particle physics, and predict the primordial, light element abundances. These future analyses hinge on new experimental and observational data. New experimental data on nuclear cross sections will help reduce theoretical uncertainties in BBN's predictions. New observations of light element abundances will further sharpen BBN's probe of the baryon density. Observations from the MAP and PLANCK satellites will measure the fluctuations in the CMB to unprecedented accuracy, allowing the precise determination of the baryon density. When combined, this data will present us with the opportunity to perform precision cosmology.
Changepoints in stochastic ordering

This article studies the problem of testing and locating changepoints in stochas¬tic ordering. We propose a sequential process to detect the changepoints from two multinomial distributions. We also obtain the maximum likelihood estimators of two multinomial probability vectors under the assumption that the cumulative distribu¬tions have a changepoint. Asymptotically unbiased Akaike's information criterion is used to estimate the changepoints of two discrete probability distributions. Finally. we demonstrate our procedure by studying a data set pertaining to average daily insulin dose from the Boston Collaborative Drug Surveillance Program and locate the changepoints in stochastic ordering.
Serum zinc levels in lung cancer patients.

Serum zinc concentrations were determined in 26 extensive squamous cell lung cancer patients and were tested for correlations with survival, response to therapy, nutritional status indices, and various host defense characteristics. Subnormal serum zinc levels were found in 24 of the 26 patients. The mean serum zinc concentration was 43.2/micrograms 100 ml +/- 3.6 S.E.M. (normal = 80-100 micrograms/100 ml). A significant (P = 0.007) survival advantage was demonstrated for those patients with pretreatment zinc concentrations greater than 45 micrograms%, but serum zinc levels did not correlate with response to chemotherapy (also significantly affecting survival). Decreased serum zinc concentrations were significantly associated with decreased neutrophil migration measured by the skin window technique and with decreased triceps skin fold thickness but not with any of the other host defense and nutritional induces measured. These data suggest that further studies are indicated to examine the role of serum zinc concentration as a possible sensitive prognostic characteristic and to determine if zinc administration may be of therapeutic benefit in cancer patients.
Social Networks and the Convergence of Population Attributes: A Generalization

Analysis of social interactions has recently become an important area of economic research, and the focus of researchers in this area has increasingly shifted toward dynamic models. In one recent contribution, Brueckner and Smirnov (2006) analyze the evolution of population attributes in an exceedingly simple model where an agent’s attributes at time t are equal to the average attribute value among his acquaintances. The pattern of acquaintances in the population is determined by the social network, and Brueckner and Smirnov (BS) explore the effect of network characteristics on the convergence of population attributes over time. They show that some simple sufficient conditions on the network structure ensure convergence to a “melting-pot” equilibrium, where attributes are uniform across agents. The present paper provides a generalization of BS’s analysis, allowing for a more general form of the rule governing the evolution of population attributes. The analysis shows that BS’s previous conclusions continue to hold under this generalization, while also providing a result that can be applied more generally to other models.
Some Properties of Subsets of Hyperbolic Groups

ABSTRACT We present some results about quasiconvex subgroups of infinite index and their products. After that we extend the standard notion of a subgroup commensurator to an arbitrary subset of a group and generalize some of the previously known results.
OLTP through the looking glass, and what we found there

Online Transaction Processing (OLTP) databases include a suite of features - disk-resident B-trees and heap files, locking-based concurrency control, support for multi-threading - that were optimized for computer technology of the late 1970's. Advances in modern processors, memories, and networks mean that today's computers are vastly different from those of 30 years ago, such that many OLTP databases will now fit in main memory, and most OLTP transactions can be processed in milliseconds or less. Yet database architecture has changed little.Based on this observation, we look at some interesting variants of conventional database systems that one might build that exploit recent hardware trends, and speculate on their performance through a detailed instruction-level breakdown of the major components involved in a transaction processing database system (Shore) running a subset of TPC-C. Rather than simply profiling Shore, we progressively modified it so that after every feature removal or optimization, we had a (faster) working system that fully ran our workload. Overall, we identify overheads and optimizations that explain a total difference of about a factor of 20x in raw performance. We also show that there is no single "high pole in the tent" in modern (memory resident) database systems, but that substantial time is spent in logging, latching, locking, B-tree, and buffer management operations.
Repackaging cashflows and the creation of value: The case of primes and scores

Abstract This paper examines whether primes and scores sell at a premium to the underlying stock and also evaluates the efficiency of the market. The paper differentiates between open and closed trusts. Trusts are “closed” when increases, but not decreases, in supply are precluded. Higher premiums were expected, and found, for many closed trusts. When-issued trading may have contributed to premiums paid for open trusts. Two bounds tests were applied to examine market efficiency. Discounts in excess of transactions costs were precluded by the trust's structure. Therefore, the distribution of discounts was used to estimate transactions costs in the upper bound. One test used the outer tails of the distribution in the estimation procedure; the second incorporated information from the entire distribution. Bounds were exceeded with both tests although arbitrage opportunities did not exist.
Liquid crystal films as on-demand, variable thickness (50–5000 nm) targets for intense lasers

We have developed a new type of target for intense laser-matter experiments that offers significant advantages over those currently in use. The targets consist of a liquid crystal film freely suspended within a metal frame. They can be formed rapidly on-demand with thicknesses ranging from nanometers to micrometers, where the particular value is determined by the liquid crystal temperature and initial volume as well as by the frame geometry. The liquid crystal used for this work, 8CB (4′-octyl-4-cyanobiphenyl), has a vapor pressure below 10−6 Torr, so films made at atmospheric pressure maintain their initial thickness after pumping to high vacuum. Additionally, the volume per film is such that each target costs significantly less than one cent to produce. The mechanism of film formation and relevant physics of liquid crystals are described, as well as ion acceleration data from the first shots on liquid crystal film targets at the Ohio State University Scarlet laser facility.
The relation between variance and information rent in auctions

Abstract This paper examines the conventional wisdom, expressed in McAfee and McMillan's (1987) widely cited survey paper on auctions, that links increased variance of bidder values to increased information rent. We find that although the conventional wisdom does indeed hold in their (1986) model of a linear contract auction, this relationship is an artifact of that particular model and cannot be generalized. Using Samuelson's (1987) model, which is similar but allows for unobservable costs, we show that increased variance does not always imply increased information rent. Finally, we give the appropriate measure of dispersion (different from variance) that provides the link between the bidder value distribution and information rent.
Localization algebras and deformations of Koszul algebras

We show that the center of a flat graded deformation of a standard Koszul algebra A behaves in many ways like the torus-equivariant cohomology ring of an algebraic variety with finite fixed point set. In particular, the center of A acts by characters on the deformed standard modules, providing a “localization map”. We construct a universal graded deformation of A and show that the spectrum of its center is supported on a certain arrangement of hyperplanes which is orthogonal to the arrangement coming from the algebra Koszul dual to A. This is an algebraic version of a duality discovered by Goresky and MacPherson between the equivariant cohomology rings of partial flag varieties and Springer fibers; we recover and generalize their result by showing that the center of the universal deformation for the ring governing a block of parabolic category \({\mathcal{O}}\) for \({\mathfrak{gl}_n}\) is isomorphic to the equivariant cohomology of a Spaltenstein variety. We also identify the center of the deformed version of the “category \({\mathcal{O}}\)” of a hyperplane arrangement (defined by the authors in a previous paper) with the equivariant cohomology of a hypertoric variety.
A new paradigm for two-dimensional spin liquids

Motivated by the geometry of the materials Na2Ti2As2O and Na2Ti2Sb2O, we study a square-lattice Heisenberg antiferromagnet, with spins located at the bond centers. The largest exchange constant J couples neighboring spins in a given row or column. This leads to a mesh of isolated spin chains running along the X and Y axes. A weaker exchange constant J′ couples the nearest-neighbor spins on the lattice. Classically, J′ fails to fix the relative spin orientation for different chains and hence the ground state is highly degenerate. Quantum order by disorder effect is studied by spin-wave theory and numerical methods. It is shown that a four-sublattice order is favored by quantum fluctuations. However, several arguments are presented that suggest that the ground state of the system remains disordered, thus providing us with a paradigm for a two-dimensional spin liquid.
Definitions, measurements, and classifications of stimuli, situations, and environments

A review is presented of issues relevant to the definition, measurement, and classification of stimuli, situations, and environments. Problems such as the lack of adequate definitions of concepts, error and bias in measurement procedures, confusion between measurement of a concept and measurement of its behavioral effects, and the lack of agreement among alternative measures are emphasized. It is suggested that concepts be defined in terms of objective characteristics while allowing for the study of the transactional relationship between organism and environment. The work of the ethologists in defining stimuli while studying their relationship to different organismic states and situational contexts is emphasized in this regard. Following Brunswik, it is also suggested that wherever possible there be a representative sampling of variables in natural settings.
Can Streamlined Multicriteria Decision Analysis Be Used to Implement Shared Decision Making for Colorectal Cancer Screening

Background. Current US colorectal cancer screening guidelines that call for shared decision making regarding the choice among several recommended screening options are difficult to implement. Multicriteria decision analysis (MCDA) is an established method well suited for supporting shared decision making. Our study goal was to determine whether a streamlined form of MCDA using rank-order–based judgments can accurately assess patients’ colorectal cancer screening priorities. Methods. We converted priorities for 4 decision criteria and 3 subcriteria regarding colorectal cancer screening obtained from 484 average-risk patients using the analytic hierarchy process (AHP) in a prior study into rank-order–based priorities using rank order centroids. We compared the 2 sets of priorities using Spearman rank correlation and nonparametric Bland–Altman limits of agreement analysis. We assessed the differential impact of using the rank-order–based versus the AHP-based priorities on the results of a full MCDA comparing...
How to beat Capablanca

We consider the chess problem of checkmating a king with a king and a rook on an mxn board at a specific starting position. We analyze the fastest way to checkmate.
Pseudoretraction of the eyelid in thyroid-associated orbitopathy.

• Two patients with previously stable thyroid-associated orbitopathy presented with the fairly sudden onset of apparent upper eyelid retraction in their nondominant eye, accompanied by asymmetry of the eyebrows, with elevation on the side without the eyelid retraction. No other signs of worsening of the orbitopathy were present, and instillation of 2.5% phenylephrine hydrochloride in the contralateral, dominant eye relieved the eyelid retraction and normalized the eyebrow position. At surgery, both patients were found to have levator aponeurogenic ptosis in the eyelid that appeared to be "normal." This occurrence is explained by Hering's law and should be considered in planning surgery to reestablish palpebral fissure symmetry in such patients.
Quantum Chemical Models (Nobel Lecture).

The solving of chemical problems to which the answer is unknown or in dispute is the important objective of each theoretical model. How far quantum chemistry has come in this respect is described here for the ab initio concept, which is known to just about every chemist under the name GAUSSIAN. The major advantage of this method is that it can be used to define a way in which one can obtain more accurate results. The target of calculating binding energies and similar values with precisions of 1 kcal mol-1 is not far away for small molecules containing up to fifty electrons.
An Efficient Procedure for Visualizing the Sound Field Radiated by Vehicles during Standardized Passby Tests

Abstract Throughout the world, motor vehicles are required to conform to statutory passby noise requirements. These standards usually entail the measurement of the peak A-weighted sound level while the vehicle accelerates past a stationary microphone. This pass-or-fail test is of little diagnostic value when a vehicle exceeds the statutory level. In the work presented here it is shown that a stationary array of microphones may be used to visualize the location of the noise sources on a vehicle executing a standard passby test. By locating the positions of the sources that dominate the received sideline levels, noise control efforts may be directed appropriately and efficiently. In the present work, a delay-and-sum beamformer approach was used to detect noise source locations. Algorithms have been included to correct the apparent source frequency shifts that result from the source motion. The restoration and de-Dopplerization procedure is based on using a polynomial representation of the source velocity (inferred in the first instance from a radar signal). Forward and backward propagation procedures are compared in terms of computational expense. In addition, a spherical spreading correction factor is described, along with a maximum likelihood procedure for obtaining an optimal array weighting dependent on the relative distance between the microphones and the focus point. The new weighting factor is compared with a more “intuitive” weighting factor and it will be shown that the new approach can reduce the sidelobe levels by comparison with the more intuitive approach. Experimental results presented here were based on the use of a 16 element, sparse array. It will be shown that this array could be used to identify the location and directivity of tire noise sources and of other sources on accelerating vehicles.