cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational solutions for omics data

High-throughput experimental technologies are generating increasingly massive and complex genomic data sets. The sheer enormity and heterogeneity of these data threaten to make the arising problems computationally infeasible. Fortunately, powerful algorithmic techniques lead to software that can answer important biomedical questions in practice. In this Review, we sample the algorithmic landscape, focusing on state-of-the-art techniques, the understanding of which will aid the bench biologist in analysing omics data. We spotlight specific examples that have facilitated and enriched analyses of sequence, transcriptomic and network data sets.
Diagnosis and management of sinusitis in children

Acute bacterial sinusitis is a common clinical problem. The usual predisposing events are either viral upper respiratory infection or allergic inflammation. Patients present with either persistent or severe respiratory symptoms. Subacute and chronic sinusitis are characterized by very protracted respiratory symptoms that include nasal discharge, cough, or both. A precise diagnosis of bacterial sinusitis is made when sinus aspiration is performed and yields pus and bacteria in high colony count. Images, either plain radiographs or computer tomographic scans, can be used to confirm the diagnosis of bacterial sinusitis in patients whose signs and symptoms suggest the diagnosis. Streptococcus pneumoniae, Haemophilus influenzae , and Moraxella catarrhalis are the usual pathogens retrieved from patients with acute, subacute, and recurrent acute sinusitis. These same pathogens cause acute exacerbations of chronic sinusitis. In patients with chronic persistent sinusitis, the role of bacterial agents is less clear. The prescription of antimicrobials is the backbone of the medical management of acute bacterial sinusitis. Clinical improvement is prompt in nearly all children treated with an appropriate agent.
Direct, intermolecular, enantioselective, iridium-catalyzed allylation of carbamates to form carbamate-protected, branched allylic amines.

The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylic amines with high regioselectivity and enantioselectivity is reported. This process occurs without base or with 0.5 equiv K3PO4 in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted allylic carbonates with BocNH2, FmocNH2, CbzNH2, TrocNH2, TeocNH2, and 2-oxazolidinone occur in good yields, with high selectivity for the branched isomer and high enantioselectivities (98% average ee).
Research on Attention Networks as a Model for the Integration of Psychological Science

As Titchener pointed out more than one hundred years ago, attention is at the center of the psychological enterprise. Attention research investigates how voluntary control and subjective experience arise from and regulate our behavior. In recent years, attention has been one of the fastest growing of all fields within cognitive psychology and cognitive neuroscience. This review examines attention as characterized by linking common neural networks with individual differences in their efficient utilization. The development of attentional networks is partly specified by genes, but is also open to specific experiences through the actions of caregivers and the culture. We believe that the connection between neural networks, genes, and socialization provides a common approach to all aspects of human cognition and emotion. Pursuit of this approach can provide a basis for psychology that unifies social, cultural, differential, experimental, and physiological areas, and allows normal development to serve as a baseline for understanding various forms of pathology. D.O. Hebb proposed this approach 50 years ago in his volume Organization of Behavior and continued with introductory textbooks that dealt with all of the topics of psychology in a common framework. Use of a common network approach to psychological science may allow a foundation for predicting and understanding human behavior in its varied forms.
Sintering and redispersion of supported metals: Perspectives from the literature of the past decade

Studies of the sintering of supported metals over the past decade have emphasized (1) the use of sophisticated spectroscopies and surface-science techniques in combination with industrially-relevant and model catalyst systems to better understand the mechanistic aspects and (2) the analysis of available kinetic data for sintering with more physically-meaingful models. The recent experimental work reveals the complexities of sintering and redispersion processes, which include for example, dissociation/emission of metal atoms from crystallites, diffusion of atoms and crystallites across support surfaces, wetting and spreading of crystallites in oxygen, rupture of films and nucleation of particles in H2, coalescence and/or bridging of two particles, capture of atoms by particles, epitaxy of metal clusters with support surfaces, restructuring and faceting of metal surfaces by different atmospheres and the formation of compounds such as surface aluminates in steam or O2. Sintering rate data obtained over the past four decades have been reanalyzed using the new General Power Law Expression (GPLE), which provides the capability of treating these data in a consistent, unifying fashion such that quantitative comparisons of effects of reaction conditions and catalyst properties are possible for the first time.
Excess Funds and Agency Problems: An Empirical Study of Incremental Cash Disbursements

This study investigates the excess funds hypothesis using samples of special dividends, regular dividend increases, and self-tender offers. All three types of firms tend to have funds in excess of industry norms before the events. The excess funds are largely nonrecurring for special dividend and self-tender offer firms and recurring for regular dividend increase firms. The analysis of the stock price reaction suggests that large incremental disbursements mitigate the agency problem associated with excess funds. In particular, the stock price reaction is positively related to excess funds for self-tender offers and large special dividends, but not Ž. for regular dividend increases which tend to be smaller or small special dividends.
Unstructured sequential testing in sensor networks

We consider the problem of quickly detecting a signal in a sensor network when the subset of sensors in which signal may be present is completely unknown. We formulate this problem as a sequential hypothesis testing problem with a simple null (signal is absent everywhere) and a composite alternative (signal is present somewhere). We introduce a novel class of scalable sequential tests which, for any subset of affected sensors, minimize the expected sample size for a decision asymptotically, that is as the error probabilities go to 0. Moreover, we propose sequential tests that require minimal transmission activity from the sensors to the fusion center, while preserving this asymptotic optimality property.
Effect of Protective Helmet Mass on Head/Neck Dynamics

The crash helmet which provides protection against injury due to direct head impact may actually contribute to injury in indirect head impact (e.g., hyperflexion or "whiplash") situations because of the added mass of the helmet on the head/neck system. It has been suggested that it may be possible to reduce this hyperflexion/hyperextension injury hazard while retaining the beneficial protection against direct impact through use of the helmet restraining collars, such as styrofoam or inflatable airbags. These claims are quantitatively and qualitatively examined and discussed in this paper. The UCIN HEAD/NECK computer stimulation model is used for the quantitative analysis. It is shown that the helmet can indeed contribute to the hyperflexion/hyperextension injury hazard and that the proposed restraining devices can potentially provide protection against this hazard.
Legal Innovation and the Control of Gang Behavior

This review considers one of the most prominent methods of combating gang activity in the second half of the last century, namely the deployment of legal strategies to prevent gang formation and intervene in existing gang structures. These include highly formalized strategies, such as the enactment of legislative decrees such as injunctions that limit the association of gang members in public space, as well as informal procedures in which communities create an indigenous and localized set of norms and juridical procedures to fight gang activity. Research on legal tactics and gang control in the past few decades has shown that the formative understanding of the city as a social ecology of distinct and separate communities, in which social institutions and residents are largely attuned to activity occurring within their boundaries, remains at the heart of social policy formulation with respect to youth delinquency. The review addresses these major legal innovations and the debates surrounding them.
Regularization of Case-Specific Parameters for Robustness and Efficiency

Regularization methods allow one to handle a variety of inferential problems where there are more covariates than cases. This allows one to consider a potentially enormous number of covariates for a problem. We exploit the power of these techniques, supersaturating models by augmenting the “natural” covariates in the problem with an additional indicator for each case in the data set. We attach a penalty term for these case-specific indicators which is designed to produce a desired effect. For regression methods with squared error loss, an $\ell_{1}$ penalty produces a regression which is robust to outliers and high leverage cases; for quantile regression methods, an $\ell_{2}$ penalty decreases the variance of the fit enough to overcome an increase in bias. The paradigm thus allows us to robustify procedures which lack robustness and to increase the efficiency of procedures which are robust. We provide a general framework for the inclusion of case-specific parameters in regularization problems, describing the impact on the effective loss for a variety of regression and classification problems. We outline a computational strategy by which existing software can be modified to solve the augmented regularization problem, providing conditions under which such modification will converge to the optimum solution. We illustrate the benefits of including case-specific parameters in the context of mean regression and quantile regression through analysis of NHANES and linguistic data sets.
Planar-adaptive routing: low-cost adaptive networks for multiprocessors

Network throughput can be increased by allowing multipath, adaptive routing. Adaptive routing allows more freedom in the paths taken by messages, spreading load over physical channels more evenly. The flexibility of adaptive routing introduces new possibilities of deadlock. Previous deadlock avoidance schemes in k-ary n-cubes require an exponential number of virtual channels. We describe a family of deadlock-free routing algorithms, called planar-adaptive routing algorithms, that require only a constant number of virtual channels, independent of networks size and dimension. Planar-adaptive routing algorithms reduce the complexity of deadlock prevention by reducing the number of choices at each routing step. In the fault-free case, planar-adaptive networks are guaranteed to be deadlock-free. In the presence of network faults, the planar-adaptive router can be extended with misrouting to produce a working network which remains provably deadlock free and is provably livelock free. In addition, planar-adaptive networks can simultaneously support both in-order and adaptive, out-of-order packet delivery.Planar-adaptive routing is of practical significance. It provides the simplest known support for deadlock-free adaptive routing in k-ary n-cubes of more than two dimensions (with k>2). Restricting adaptivity reduces the hardware complexity, improving router speed or allowing additional performance-enhancing network features. The structure of planar-adaptive routers is amenable to efficient implementation.Simulation studies show that planar-adaptive routers can increase the robustness of network throughput for nonuniform communication patterns. Planar-adaptive routers outperform deterministic routers with equal hardware resources. Further, adding virtual lanes to planar-adaptive routers increases this advantage. Comparisons with fully adaptive routers show that planar-adaptive routers, limited adaptive routers, can give superior performance. These results indicate the best way to allocate router resources to combine adaptivity and virtual lanes.Planar-adaptive routers are a special case of limited adaptivity routers. We define a class of adaptive routers with f degrees of routing freedom. This class, termed f-flat adaptive routers, allows a direct cost-performance tradeoff between implementation cost (speed and silicon area) and routing freedom (channel utilization). For a network of a particular dimension, the cost of adaptivity grows linearly with the routing freedom. However, the rate of growth is a much larger constant for high-dimensional networks. All of the properties proven for planar-adaptive routers, such as deadlock and livelock freedom, also apply to f-flat adaptive routers.
Polarity of GaN Grown on Sapphire by Molecular Beam Epitaxy with Different Buffer Layers

We report on polarity of GaN films grown on sapphire substrates by molecular beam epitaxy using different buffer layers and growth conditions. On high temperature AlN or GaN buffer layers, the GaN films typically show Ga or N-polarity, respectively. When low temperature (either AlN or GaN) buffer layers are employed, GaN films of both polarities can be grown, but these films have high density of inversion domains. Insertion of additional GaN/AlN quantum dot layers between the buffer layers and the GaN films provides strain relief and a significant improvement in the quality of the GaN epilayers.
Methanol oxidative dehydrogenation in a catalytic packed-bed membrane reactor: experiments and model

Abstract Methanol oxidative dehydrogenation to formaldehyde over a Fe–Mo oxide catalyst was studied experimentally in three reactor configurations: the conventional fixed-bed reactor (FBR) and the packed-bed membrane reactor (PBMR), with either methanol (PBMR-M) or oxygen (PBMR-O) as the permeating component. The kinetics of methanol and formaldehyde partial oxidation reactions were determined independently from FBR experiments. A steady state plug-flow PBMR model, utilizing these kinetics and no adjustable parameters, fit the experiments accurately. It is shown experimentally and in accordance with the model that for given overall feed conditions, the reactor performance for methanol conversion and formaldehyde yield is in the order PBMR-M
Constraining-unification and the programming language unicorn

Up to this point direct implementations of axiomatic or equational specifications have been limited because the implementation mechanisms used are incapable of capturing the full semantics of the specifications. The programming language Unicorn was designed and implemented with the intention of exploring the full potential of programming with equations. Unicorn introduces a new language mechanism, called constraining-unification. When coupled with semantic unification, constraining-unification closely models the semantics of equational specifications thereby allowing for the implementation of a wider class of specifications. Unlike the language mechanisms of rewrite-rule and logic programming, constraining-unification is free of order dependencies. The same results are produced regardless of the order in which the axioms are stated. The use of viewpoints contributes to the flexibility of the Unicorn language. Preconditions for partial operations can be specified without added machinery.
ISOPINOCAMPHEYLBROMOBORANE, A NEW PROMISING REAGENT FOR THE ASYMMETRIC HYDROBORATION OF PROCHIRAL ALKENES

Abstract A new promising in situ generated hydroborating agent, isopinocampheylbromoborane (IpcBHBr), achieves the asymmetric hydroboration of representative prochiral alkenes in pentane at lower temperatures, even at −78 °C, than has been possible with isopinocampheylborane (IpcBH 2 ) and isopinocampheylchloroborane·EE (IpcBHCl·EE) reagents, usually in higher enantioselectivities than previously achieved. This is first time that the asymmetric hydroboration of prochiral alkenes with an α-pinene-derived borane reagent (IpcBHBr) has been achieved at such low temperature, −78 °C, in a relatively short time, 4–6 h.
On the number of ranked species trees producing anomalous ranked gene trees

Analysis of probability distributions conditional on species trees has demonstrated the existence of anomalous ranked gene trees (ARGTs), ranked gene trees that are more probable than the ranked gene tree that accords with the ranked species tree. Here, to improve the characterization of ARGTs, we study enumerative and probabilistic properties of two classes of ranked labeled species trees, focusing on the presence or avoidance of certain subtree patterns associated with the production of ARGTs. We provide exact enumerations and asymptotic estimates for cardinalities of these sets of trees, showing that as the number of species increases without bound, the fraction of all ranked labeled species trees that are ARGT-producing approaches 1. This result extends beyond earlier existence results to provide a probabilistic claim about the frequency of ARGTs.
Parallax and Kinematics of PSR B0919+06 from VLBA Astrometry and Interstellar Scintillometry

Results are presented from a long-term astrometry program on PSR B0919+06 using the NRAO Very Long Baseline Array. With 10 observations (seven epochs) between 1994 and 2000, we measure a proper motion μα = 18.35 ± 0.06 mas yr-1, μδ = 86.56 ± 0.12 mas yr-1 and a parallax π = 0.83 ± 0.13 mas (68% confidence intervals). This yields a pulsar distance of 1.21 ± 0.19 kpc, making PSR B0919+06 the farthest pulsar for which a trigonometric parallax has been obtained, and the implied pulsar transverse speed is 505 ± 80 km s-1. Combining the distance estimate with interstellar scintillation data spanning 20 yr, we infer the existence of a patchy or clumpy scattering screen along the line of sight in addition to the distributed electron density predicted by models for the Galaxy and constrain the location of this scattering region to within ~250 pc of the Sun. Comparison with the lines of sight toward other pulsars in the same quadrant of the Galaxy permits refinement of our knowledge of the local interstellar medium in this direction.
Melts of garnet lherzolite: experiments, models and comparison to melts of pyroxenite and carbonated lherzolite

Phase equilibrium experiments on a compositionally modified olivine leucitite from the Tibetan plateau have been carried out from 2.2 to 2.8 GPa and 1,380–1,480 °C. The experiments-produced liquids multiply saturated with spinel and garnet lherzolite phase assemblages (olivine, orthopyroxene, clinopyroxene and spinel ± garnet) under nominally anhydrous conditions. These SiO2-undersaturated liquids and published experimental data are utilized to develop a predictive model for garnet lherzolite melting of compositionally variable mantle under anhydrous conditions over the pressure range of 1.9–6 GPa. The model estimates the major element compositions of garnet-saturated melts for a range of mantle lherzolite compositions and predicts the conditions of the spinel to garnet lherzolite phase transition for natural peridotite compositions at above-solidus temperatures and pressures. We compare our predicted garnet lherzolite melts to those of pyroxenite and carbonated lherzolite and develop criteria for distinguishing among melts of these different source types. We also use the model in conjunction with a published predictive model for plagioclase and spinel lherzolite to characterize the differences in major element composition for melts in the plagioclase, spinel and garnet facies and develop tests to distinguish between melts of these three lherzolite facies based on major elements. The model is applied to understand the source materials and conditions of melting for high-K lavas erupted in the Tibetan plateau, basanite–nephelinite lavas erupted early in the evolution of Kilauea volcano, Hawaii, as well as younger tholeiitic to alkali lavas from Kilauea.
Selective removal of fluorenylmethoxycarbonyl (fmoc) groups under mild conditions

Abstract N-Fluorenylmethoxycarbonyl groups may be removed by potassium fluoride/18-crown-6 in the presence of methyl, ethyl, tert-butyl, benzyl, and p-methoxybenzyl esters.
Puncture black hole initial data in the conformal thin-sandwich formalism

We revisit the construction of puncture black hole initial data in the conformal thin-sandwich (CTS) decomposition of Einstein's constraint equations. It has been shown previously that this approach cannot yield quasiequilibrium wormhole data, which connect two asymptotically flat spatial infinities. This argument does not apply to trumpet data, which connect the spatial infinity in one universe with the future timelike infinity of another. As a numerical demonstration, we present results for a single boosted trumpet-puncture black hole, constructed in the original version of the CTS formalism.
Low-temperature hall coefficient and conductivity in heavily doped silicon

Abstract The Hall coefficient and conductivity of fifteen heavily doped silicon samples have been measured. The Hall-coefficient measurements were generally made in the temperature region 15−300°K, while the conductivity measurements were taken in the region 3−30°K. The general behavior of the Hall coefficient and conductivity is similar to that in germanium and other semiconductors exhibiting impurity conduction. Two types of impurity conduction were observed: one believed to be non-band conduction and the other, band conduction. Investigation of the temperature region where the transition between normal band conduction and impurity conduction takes place shows a minimum in the impurity conduction resistivity vs. reciprocal temperature curve. Comparison of various samples shows that for a given impurity concentration, the lower impurity conductivity is found in the samples containing majority impurity atoms with the larger ionization energy. A possible model for impurity conduction is discussed.
A model of the solar cycle driven by the dynamo action of the global convection in the solar convection zone.

Extensive numerical studies of the dynamo equations due to the global convection are presented to simulate the solar cycle and to open the way to study general stellar magnetic cycles. The dynamo equations which represent the longitudinally-averaged magnetohydrodynamical action (mean magnetohydrodynamics) of the global convection under the influence of the rotation in the solar convection zone are considered here as an initial boundary-value problem. The latitudinal and radial structure of the dynamo action consisting of a generation action due to the differential rotation and a regeneration action due to the global convection is parameterized in accordance with the structure of the rotation and of the global convection. This is done especially in such a way as to represent the presence of the two cells of the regneration action in the radial direction in which the action has opposite signs, which is typical of the regeneration action of the global convection. The effects of the dynamics of the global convection (e.g., the effects of the stratification of the physical conditions in the solar convection zone) are presumed to be all included in those parameters used in the model and they are presumed not to alter the results drastically since these effects are only to change the structure of the regeneration action topologically. However, since the structure of the differential rotation is not known precisely, several typical cases of the differential rotation are examined. A nonlinear process is included by assuming that part of the magnetic field energy is dissipated away when magnetic-field strength exceeds some critical value, simulating the formation of active regions and subsequent dissipation.
Analysis of LWR model with fundamental diagram subject to uncertainties

The LWR model is of interest since it is simple and can successfully reproduce some essential features of traffic flow, such as the formation and propagation of traffic disturbances. In this article, we investigate the LWR model from an uncertainty perspective. We attempt to analyse how reliable the LWR model prediction will be if the fundamental diagram (FD) in use is not accurately specified. To fulfil this end, we postulate a flux function (equivalently a FD) driven by a random free flow speed, which accommodates the uncertain feature observed in the speed–density data. We provide essential mathematical properties and solution schemes of the LWR model with the probabilistic FD. In case studies, the approach to evaluate the uncertainty of traffic disturbance propagation with this model is presented. We find that if FD in a LWR model cannot be perfectly specified, the uncertainty associated with the location of a traffic disturbance would increase over time. In contrast, the magnitude of the traffic dist...
HISTOGRAMMING ON A RECONFIGURABLE MESH COMPUTER

We develop efficient reconfigurable mesh (RMESH) algorithms to compute the histogram of an image and to perform histogram modification. The histogram of an N × N image is computed by an N × N RMESH in O(√Blog√B (N/√B) for B < N, O(√N) for B = N, and O(√B) for N < B ≤ N 2. B is the number of gray scale values. Histogram modification is done in O(√N) time by an N × N RMESH.
Synopsis diffusion for robust aggregation in sensor networks

Previous approaches for computing duplicate-sensitive aggregates in wireless sensor networks have used a tree topology, in order to conserve energy and to avoid double-counting sensor readings. However, a tree topology is not robust against node and communication failures, which are common in sensor networks. In this article, we present synopsis diffusion, a general framework for achieving significantly more accurate and reliable answers by combining energy-efficient multipath routing schemes with techniques that avoid double-counting. Synopsis diffusion avoids double-counting through the use of order- and duplicate-insensitive (ODI) synopses that compactly summarize intermediate results during in-network aggregation. We provide a surprisingly simple test that makes it easy to check the correctness of an ODI synopsis. We show that the properties of ODI synopses and synopsis diffusion create implicit acknowledgments of packet delivery. Such acknowledgments enable energy-efficient adaptation of message routes to dynamic message loss conditions, even in the presence of asymmetric links. Finally, we illustrate using extensive simulations the significant robustness, accuracy, and energy-efficiency improvements of synopsis diffusion over previous approaches.
More complicated questions about maxima and minima, and some closures of NP

Abstract Starting from NP -complete problems defined by questions of the kind ‘max…⩾ m ?’ and ‘min…⩽ m ?’ we consider problems defined by more complicated questions about these maxima and minima, as for example ‘max…= m ?’. ‘min…ϵ M ?’ and ‘is max… odd?’. This continues a work started by Papadimitriou and Yannakakis (1982). It is shown that these and other problems are complete in certain subclasses of the Boolean closure of NP and other classes in the interesting area below the class Δ p 2 of the polynomial-time hierarchy. Special methods are developed to prove such completeness results. For this it is necessary to establish some properties of the classes in question which might be interesting in their own right.
Impact of Manufacturing Variability on Combustor Liner Durability

This paper presents a probability-based systems-level approach for assessing the impact of manufacturing variability on combustor liner durability. Simplified models are used to link combustor life, liner temperature variability, and the effects of manufacturing variability. A probabilistic analysis is then applied to the simplified models to estimate the combustor life distribution. The typical combustor life was found to be approximately 20% less than the estimate life using deterministic methods for these combustors, and the probability that a randomly selected combustor will fail earlier than expected using deterministic methods is approximately 80%. The application of a sensitivity analysis to a surrogate model for the life identified the leading drivers of the minimum combustor life and the typical combustor life as the material property variability and the circumferential variability of turbulent mixing rates, respectively.
Asset trading volume in infinite-horizon economies with dynamically complete markets and heterogeneous agents: Comment

In a recent paper, Judd et al. [2003. Journal of Finance 58, 2203-2217] study asset trading in a version of the standard Lucas infinite horizon economy with heterogeneous agents. They report the surprising finding that (for generic economies in their class), in equilibrium, there is no trade in (long-lived) assets after the initial date. This note points out that the conclusions of Judd et al. [2003. Journal of Finance 58, 2203-2217] are artifacts of the assumption that asset dividends and individual endowments follow the same stationary finite state Markov process. Without this assumption-and even if asset dividends and aggregate endowments follow the same stationary process-there will necessarily be trade at many histories. © 2006 Elsevier Inc. All rights reserved.
Point source bubbler systems to suppress ice

Abstract An analysis of a point source bubbler system used to induce local melting of an ice cover is presented. The analysis uses empirical results of bubbler plume experiments and impingement heat transfer results to determine the rate of melting at the underside of an ice cover. Through a simple energy budget analysis of the ice cover, the melting of the ice cover and resulting extent of open water are determined as a function of air temperatures, depth and air discharge of the source, and water temperature. The analysis leads to a numerical simulation and an example simulation is presented.
Supersymmetry in Singular Spaces and Domain Walls

We discuss some recent work on brane world construction and supersymmetry issues. We introduce a concept of bulk & brane supersymmetry in the framework of 5-dimensional supergravity which allows to formulate the rules for supersymmetry in singular spaces. The original fine-tuning of the Randall-Sundrum world brane which provides the flatness of the brane is shown to follow from bulk & brane supersymmetry on ${S_1\over Z_2}$ orbifold. Examples of RS-type domain walls are presented.
Shock-Free Solutions of the Compressible Euler Equations

We study the structure of shock-free solutions of the compressible Euler equations with large data. We describe conditions under which the rarefactive/ compressive character of solutions changes, and conditions under which the vacuum is formed asymptotically. We present several new examples of shock-free solutions, which demonstrate a large variety of behaviors.
On the dissociation equilibrium of H2 in very cool, helium-rich white dwarf atmospheres

We investigate the dissociation equilibrium of H2 in very cool, helium-rich white dwarf atmospheres. We present the nonideal chemical equilibrium solution for the dissociation of molecular hydrogen in a medium of dense helium. We find that at the photosphere of cool white dwarfs of Teff = 4000 K, the nonideality results in an increase of the mole fraction of molecular hydrogen by up to a factor of ~10 compared to the equilibrium value for the ideal gas. This increases the H2-He collision-induced absorption (CIA) opacity by an order of magnitude and will affect the determination of the abundance of hydrogen in very cool, helium-rich white dwarfs.
2,5-Di-t-butyl-4-fluorophenol

Abstract Treatment of 4-fluorophenol with excess t-butyl chloride and aluminum chloride results in the formation of 2,5-di-t-fluorobutylphenol.
Moment method analysis of linearly tapered slot antennas

An accurate Method of Moments (MoM) model is developed and implemented for the analysis of the linearly tapered slot antenna (LTSA). The model employs an unequal size reactangular sectioning for conducting parts of the antenna. Piecewise sinusoidal basis functions are used for the expansion of conductor current. The effect of the dielectric is incorporated in the model by using equivalent volume polarization current density and solving the equivalent problem in free space. The feed section of the antenna including the micro-stripline is handled rigorously in the MoM model by including slotline short-circuit and microstripline currents among the unknowns. Comparison with measurements is made to demonstrate the validity of the model for both the air case and the dielectric case. Numerical results for the effect of the dielectric permittivity are presented.
Naturally heavy scalars in supersymmetric grand unified theories

Abstract The supersymmetric flavor, CP and Polonyi problems are hints that the fundamental scale of the soft supersymmetry breaking parameters may be above a TeV, in apparent conflict with naturalness. We consider the possibility that multi-TeV scalar masses are generated by Planck- or unification-scale physics, and find the conditions under which the masses of scalars with large Yukawa couplings are driven, radiatively and asymptotically, to the weak scale through renormalization group evolution. Light third generation scalars then satisfy naturalness, while first and second generation scalars remain heavy to satisfy experimental constraints. We find that this mechanism is beautifully realized in the context of grand unified theories. In particular, the existence of right-handed neutrinos plays an important role in allowing remarkably simple scenarios. For example, for SO(10) boundary conditions with the squared masses of Higgs scalars double those of sleptons and squarks, we find that the entire scalar mass scale may be increased to 4 TeV at the unification scale without sacrificing naturalness.
Determination of thorium in the parts per million range in rocks

Abstract A procedure is presented for the determination of thorium in the concentration range of 0·2 to 10 parts per million ThO 2 in felsic or mafic rocks. Thorium is extracted by mesityl oxide and purified by iodate precipitation from nitric acid medium containing tartaric acid and hydrogen peroxide. The thorium is determined spectrophotometrically with thoron from meso-tartaric acid medium.
Anisotropic Elasticity and Multi-Material Singularities

Multi-material wedges associated with convergence of geometrical and material discontinuity lines generally show singular stress fields around the vertex of the wedge. In this paper, the eigenvalue problem for a multi-material wedge composed of several anisotropic elastic sectors is formulated in a completely generally manner, including the cases of degenerate and extra-degenerate material sectors, and various types of edge conditions for both open and closed wedges. General representation of the elasticity solution in a degenerate or extra-degenerate anisotropic sector requires higher-order eigenmodes (generalized eigenfunctions) in addition to zeroth-order eigenmodes. Such higher-order eigenmodes are obtained from appropriate analytical expressions of the zeroth-order eigenmode by using the derivative rule. The analysis is applied to one bisector wedge and one trisector wedge in a three-layer cracked composite model to obtain accurate elasticity solutions of the singular stress fields. These solutions were determined using the traction data generated on a circular collocation path by a conventional finite element analysis.
Treatment of idiopathic gastroparesis with injection of botulinum toxin into the pyloric sphincter muscle

Treatment of idiopathic gastroparesis with injection of botulinum toxin into the pyloric sphincter muscle
Household and market production of families in a late nineteenth century American city

Abstract Urban families in the late nineteenth century depended upon their children as their most important source of labor income apart from the male head of house-hold. This paper explores the determinants of the labor force participation of children over 10 years old within the context of the economic theory of household and market production, using microlevel data from 1880 Philadelphia. The father's income and unemployment, the presence of the mother or father, boarders, servants, older and younger siblings, parents' literacy, and ethnicity, among other variables, are used in a probit analysis of the labor force participation of children. The results validate the economic theory of household and market production demonstrating, in particular, substitution between mothers and their daughters and the role of comparative advantage in family decisions concerning the allocation of their members' time. Ethnic differences were only important for daughters.
"Electron Trigonometry", a new tool for electron optical design

In electron-optical devices of circular symmetry whose axis potential is a quadratic function of distance, we have found that a very general law can be formulated which we call the "triangle theorem of electron optics." It deals with three individual phase angles which are defined, respectively, for image-space, object-space and lens-volume. The "triangle theorem" states that in any image-forming system as above, the sum of these three phase angles is 180 degrees for a converging electron lens, and zero for a diverging electron lens. The "triangle theorem" permits the immediate determination of size and position of an electron image including real as well as virtual images. It is not restricted to thin lenses but applies to long electron lenses as well.
Electro-mechanical resonant magnetic field sensor

Abstract We describe a new type of magnetic field sensor, which is termed as an Electro-Mechanical Resonant Sensor (EMRS). The key part of this sensor is a small conductive elastic element with low damping rate and therefore, a high Q fundamental mode of frequency f 1 . An AC current is driven through the elastic element which, in the presence of a magnetic field, causes an AC force on the element. When the frequency of the AC current matches the resonant frequency of the element, maximum vibration of the element occurs and this can be measured precisely by optical means. We have built and tested a model sensor of this type by using for the elastic element, a length of copper wire of diameter 0.030 mm formed into a loop shape. The wire motion was measured using a light-emitting diode photo-transistor assembly. This sensor demonstrated a sensitivity better than 0.001 G for an applied magnetic field of ∼1 G and a good selectivity for the magnetic field direction. The sensitivity can be easily improved by a factor of ∼10–100 by a more sensitive measurement of the elastic element motion and by having the element in vacuum to reduce the drag force.
Favorable versus Unfavorable Recommendations: The Impact on Analyst Access to Management-Provided Information

This study examines recent regulatory and practitioner concerns that managers provide more (less) information to analysts with more (less) favorable stock recommendations. We examine the relative forecast accuracy of analysts before and after a recommendation issuance under the assumption that increases (decreases) in management-provided information will increase (decrease) analysts' relative forecast accuracy. We find that analysts issuing more favorable recommendations experience a greater increase in their relative forecast accuracy compared with analysts with less favorable recommendations. Additional tests on the change in frequency with which analysts issue forecasts independent of or in conjunction with other analysts after their recommendation change yield corroborating results. In addition, we find that the greater increase in relative accuracy for analysts with more favorable recommendations exists prior to the passage of Regulation FD but not after. The combined results are consistent with analysts receiving relatively more management-provided information following the issuance of more favorable recommendations.
SYNTHESES OF IMINOLYXITOLS VIA TANDEM REDUCTION-ALKENYLATION OF O'DONNELL'S SCHIFF BASES

Abstract The concise enantioselective synthesis of iminolyxitol glycosidase inhibitors starting from benzophenone imines of D-serine and L-alanine esters is very efficient. The reductive-alkenylation of the Schiff bases followed by substrate-directed dihydroxylation and amino dehydration gave the polyhydroxylated pyrrolidines in excellent overall yields (19.6% for 3 → 8 , 9.9% for 9 → 13 .)
Boundary-Layer-Ingesting Inlet Flow Control

This paper gives an overview of a research study conducted in support of the small-scale demonstration of an active flow control system for a boundary-layer-ingesting (BLI) inlet. The effectiveness of active flow control in reducing engine inlet circumferential distortion was assessed using a 2.5% scale model of a 35% boundary-layer-ingesting flush-mounted, offset, diffusing inlet. This experiment was conducted in the NASA Langley 0.3-meter Transonic Cryogenic Tunnel at flight Mach numbers with a model inlet specifically designed for this type of testing. High mass flow actuators controlled the flow through distributed control jets providing the active flow control. A vortex generator point design configuration was also tested for comparison purposes and to provide a means to examine a hybrid vortex generator and control jets configuration. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion and pressure recovery were determined by 40 total pressure measurements on 8 rake arms each separated by 45 degrees and were located at the aerodynamic interface plane. The test matrix was limited to a maximum free-stream Mach number of 0.85 with scaled mass flows through the inlet for that condition. The data show that the flow control jets alone can reduce circumferential distortion (DPCPavg) from 0.055 to about 0.015 using about 2.5% of inlet mass flow. The vortex generators also reduced the circumferential distortion from 0.055 to 0.010 near the inlet mass flow design point. Lower inlet mass flow settings with the vortex generator configuration produced higher distortion levels that were reduced to acceptable levels using a hybrid vortex generator/control jets configuration that required less than 1% of the inlet mass flow.
Macroeconomic issues for Latin America

Abstract Recent macroeconomic issues in Latin America are reviewed, with an emphasis on theory. Topics covered include multiple equilibria from hysteresis or increasing returns, exchange rate management and the output and asset market effects of devaluation, speculation, interest rate management and financial reform, government behavior, income distribution and growth, inertial inflation and heterodox policy shocks, and disequilibrium theories.
Event-related potential evidence for multiple causes of the revelation effect

Abstract Asking people to discover the identity of a recognition test probe immediately before making a recognition judgment increases the probability of an old judgment. To inform theories of this “revelation effect,” event-related potentials (ERPs) were recorded for revealed and intact test items across two experiments. In Experiment 1, we used a revelation effect paradigm where half of the test probes were presented as anagrams (i.e., a related task) and the other items were presented intact. The pattern of ERP results from this experiment suggested that revealing an item decreases initial familiarity levels and caused the revealed items to elicit similar levels of activity. In Experiment 2, half of the probes were preceded by an addition task (i.e., an unrelated task). The pattern of ERP effects in this study were distinct from those observed in Experiment 1. More specifically, revealed item ERPs were more negative than intact ERPs at frontal electrodes and more positive at parietal electrodes early in the interval. Later in the epoch, revealed item ERPs were more negative than intact items. These data suggest that related tasks decrease familiarity and alter the signal-to-noise ratio of old and new items, whereas unrelated tasks affect processing in a different way (perhaps by changing decision processes) that also results in the revelation effect. The implications for current theories of the revelation effect are discussed.
Square-root variable-metric methods for minimization

Variable-metric methods are presented which do not need an accurate one-dimensional search and eliminate roundoff error problems which can occur in updating the metric for large-dimension systems. The methods are based on updating the square root of the metric, so that a positive-definite metric always results. The disadvantage of intentionally relaxing the accuracy of the one-dimensional search is that the number of iterations (and hence, gradient evaluations) increases. For problems involving a large number of variables, the square-root method is presented in a triangular form to reduce the amount of computation. Also, for usual optimization problems, the square-root procedure can be carried out entirely in terms of the metric, eliminating storage and computer time associated with computations of the square root of the metric.
Dynamic Bifurcations: Hysteresis, Scaling Laws and Feedback Control

We review some properties of dynamical systems with slowly varying parameters, when a parameter is moved through a bifurcation point of the static system. Bifurcations with a single zero eigenvalue may create hysteresis cycles, whose area scales in a nontrivial way with the adiabatic parameter. Hopf bifurcations lead to the delayed appearance of oscillations. Feedback control theory motivates the study of a bifurcation with double zero eigenvalue, in which this delay is suppressed.
On the estimation technique to reveal government distributional weights

This paper provides a critique of techiniques for estimating distributional weights using the revealed preference (imputational) approach. Stochastic versus deterministic methods are contrasted and a preference for the stochastic methodology is indicated. It argues that Probit is the most appropriate technique. This allows both decision-marker error (an inability to make full interpersonal income comparisons, as suggested by Basu) and the imputer's error (an inability to observe all components in the utiliy function, as suggested by McFadden) to be incorporated in the estimation equation. The implications of using Probit are discussed in the context of UK railway closure decisions.
On liftable and weakly liftable modules

Abstract Let T be a Noetherian ring and f a nonzerodivisor on T . We study concrete necessary and sufficient conditions for a module over R = T / ( f ) to be weakly liftable to T , in the sense of Auslander, Ding, and Solberg. We focus on cyclic modules and obtain various positive and negative results on the lifting and weak lifting problems. For a module over T we define the loci for certain properties: liftable, weakly liftable, having finite projective dimension and study their relationships.