cssi/SciSciGPT-SciSciNet huggingface dataset:
Modulation of plasmaspheric hiss intensity by thermal plasma density structure

[1] Plasmaspheric hiss is an electromagnetic whistler-mode emission confined to high density regions such as the plasmasphere and plasmaspheric plumes. We present a dayside THEMIS event showing that the hiss emission intensity is strongly modulated by thermal plasma density variations. The calculated local growth rate is small (less than 5 dB/RE) and increases as the plasma density increases, which partly accounts for the modulation. Ray tracing shows that chorus rays, which eventually evolve into plasmaspheric hiss, are focused towards field lines of higher density and defocused away from field lines of lower density. We suggest that the observed modulation is caused by a combined effect of local cyclotron resonant amplification together with ray focusing during propagation.
Photographs of coronal streamers from a rocket on May 9, 1967.

A photograph of the white-light corona from a rocket on May 9, 1967 showed many streamers, all straight and nearly radial, extending across the field of view, 3 to 9R ⊙. At the North there were three spectacular streamers, making angles with the polar axis of 21° E, 20° W and 27° N. Projected inward, they were radial and passed through the probable positions of the principal plages on the back side.
Whither Civil Defense and Homeland Security in the Study of Public Policy? A Look at Research on the Policy, the Public, and the Process

Though the policy science movement was born with the purpose of counseling the Department of Defense on a plethora of security matters, modern research within the field of public policy has tended to neglect issues of defense and security focusing instead on a wide variety of domestic problems. This nearly exclusive focus on domestic issues remained largely intact until September 11, 2001, when the threat of terrorism propelled defense and security back onto the disciplinary research agenda. Though exceptionally slow to adjust, policy scholars are gradually coming to terms with this new reality and are beginning to focus on security and defense in a way that informs policymakers and advances policy theory. This research note is meant to introduce interested readers to this trend by exploring broad themes and exemplar works within the field over the last few years.
Rain driven by receding ice sheets as a cause of past climate change

[1] The Younger Dryas cold period, which interrupted the transition from the last ice age to modern conditions in Greenland, is one of the most dramatic incidents of abrupt climate change reconstructed from paleoclimate proxy records. Changes in the Atlantic Ocean overturning circulation in response to freshwater fluxes from melting ice are frequently invoked to explain this and other past climate changes. Here we propose an alternative mechanism in which the receding glacial ice sheets cause the atmospheric circulation to enter a regime with greater net precipitation in the North Atlantic region. This leads to a significant reduction in ocean overturning circulation, causing an increase in sea ice extent and hence colder temperatures. Positive feedbacks associated with sea ice amplify the cooling. We support the proposed mechanism with the results of a state-of-the-art global climate model. Our results suggest that the atmospheric precipitation response to receding glacial ice sheets could have contributed to the Younger Dryas cooling, as well as to other past climate changes involving the ocean overturning circulation.
Extremal optimization: methods derived from co-evolution

We describe a general-purpose method for finding high-quality solutions to hard optimization problems, inspired by self-organized critical models of co-evolution such as the Bak-Sneppen model. The method, called Extremal Optimization, successively eliminates extremely undesirable components of sub-optimal solutions, rather than "breeding" better components. In contrast to Genetic Algorithms which operate on an entire "gene-pool" of possible solutions, Extremal Optimization improves on a single candidate solution by treating each of its components as species co-evolving according to Darwinian principles. Unlike Simulated Annealing, its non-equilibrium approach effects an algorithm requiring few parameters to tune. With only one adjustable parameter, its performance proves competitive with, and often superior to, more elaborate stochastic optimization procedures. We demonstrate it here on two classic hard optimization problems: graph partitioning and the traveling salesman problem.
Who Bears the Cost of Russia's Military Draft?

The authors use data from a large nationally representative survey in Russia to analyze the distributional and welfare implications of draft avoidance as a common response to Russia's highly unpopular conscription system. They develop a simple theoretical model that describes household compliance decisions with respect to enlistment. The authors use several econometric techniques to estimate the effect of various household characteristics on the probability of serving in the army and the implications for household income. Their results indicate that the burden of conscription falls disproportionately on the poor. Poor, rural households, with a low level of education, are more likely to have sons who are enlisted than urban, wealthy, and better-educated families. The losses incurred by the poor are disproportionately large and exceed the statutory rates of personal income taxes.
Reproducibility of oligonucleotide arrays using small samples

Low RNA yields from small tissue samples can limit the use of oligonucleotide microarrays (Affymetrix GeneChips®). Methods using less cRNA for hybridization or amplifying the cRNA have been reported to reduce the number of transcripts detected, but the effect on realistic experiments designed to detect biological differences has not been analyzed. We systematically explore the effects of using different starting amounts of RNA on the ability to detect differential gene expression. The standard Affymetrix protocol can be used starting with only 2 micrograms of total RNA, with results equivalent to the recommended 10 micrograms. Biological variability is much greater than the technical variability introduced by this change. A simple amplification protocol described here can be used for samples as small as 0.1 micrograms of total RNA. This amplification protocol allows detection of a substantial fraction of the significant differences found using the standard protocol, despite an increase in variability and the 5' truncation of the transcripts, which prevents detection of a subset of genes. Biological differences in a typical experiment are much greater than differences resulting from technical manipulations in labeling and hybridization. The standard protocol works well with 2 micrograms of RNA, and with minor modifications could allow the use of samples as small as 1 micrograms. For smaller amounts of starting material, down to 0.1 micrograms RNA, differential gene expression can still be detected using the single cycle amplification protocol. Comparisons of groups of four arrays detect many more significant differences than comparisons of three arrays.
SPIKY: a graphical user interface for monitoring spike train synchrony

Techniques for recording large-scale neuronal spiking activity are developing very fast. This leads to an increasing demand for algorithms capable of analyzing large amounts of experimental spike t...
Software for Sample Survey Data, Misuse of Standard Packages†

Many health science researchers conduct primary or secondary analyses with data from complex sample surveys but do not realize that specialized statistical software needs to be used. This article compares analyses of survey data conducted with survey software and with standard statistical software. The numerical example illustrates that the inappropriate use of standard statistical software for sample survey data can result in: (a) biased point estimates of population parameters, (b) underestimation of standard errors, (c) confidence intervals that are too wide, and (d) misleading tests of statistical significance. Weighted analyses with standard statistical software, with regular or normed weights, can yield correct point estimates of population parameters but still yield incorrect results for estimated standard errors and statistical tests. Data analysts are advised to use appropriate software for the analysis of survey data. Keywords: sample survey data; survey software; analysis of sample surveys; biased estimators; standard error estimation; weighted analyses
Syntaxin 4 Overexpression Ameliorates Effects of Aging and High-Fat Diet on Glucose Control and Extends Lifespan

Indirect evidence suggests that improved insulin sensitivity may contribute to improved lifespan of mice in which aging has been slowed by mutations, drugs, or dietary means, even in stocks of mice that do not show signs of late-life diabetes. Peripheral responses to insulin can be augmented by overexpression of Syntaxin 4 (Syn4), a plasma-membrane-localized SNARE protein. We show here that Syn4 transgenic (Tg) mice with high level expression of Syn4 had a significant extension of lifespan (33% increase in median) and showed increased peripheral insulin sensitivity, even at ages where controls exhibited age-related insulin resistance. Moreover, skeletal muscle GLUT4 and islet insulin granule exocytosis processes were fully protected in Syn4 Tg mice challenged with a high-fat diet. Hence, high-level expressing Syn4 Tg mice may exert better glycemic control, which slows multiple aspects of aging and extends lifespan, even in non-diabetic mice.
Self-Focusing and Continuum Generation in Gases

This book attests to the fact that continuum generation has become both technically and conceptually important. Discovered in 1970 (Alfano and Shapiro, 1970a, 1970b), continuum generation is a ubiquitous response of transparent materials (liquids, solids, and gases) to high-power, ultrashort-pulse radiation. This chapter highlights some of these aspects while presenting the sometimes unique characteristics of continuum generation in gases. In addition, we introduce some related results that reflect on the light-atom interaction at high intensities.
The pseudorandom sequence of arrays

Pseudorandom sequences, also known as maximal-length sequences, are generated by 1/D(z), where the denominator is a primitive polynomial of a given degree. The pseudorandom sequence of arrays (PRSA) is generated by N(z)/D(z), where for a fixed D(z) the numerator polynomial varies over an arbitrary set of linearly independent polynomials. Some properties of the PRSA are mentioned; these show that the PRSA is in many ways similar to pseudorandom sequences and that each member of the PRSA is in many ways similar to pseudorandom arrays. An immediate application is an autonomous binary image sequence generator. >
Timing, Sequencing, and Transitional Justice Impact: A Qualitative Comparative Analysis of Latin America

Transitional justice (TJ) scholars are increasingly concerned with measuring the impact of transitional justice initiatives. Scholars often assume that TJ mechanisms must be properly designed and ordered to achieve lasting effect, but the impact of TJ timing and sequencing has attracted relatively little theoretical or empirical attention. Focusing on Latin America, this article explores variation within the region as to when TJ occurs and the order in which mechanisms are implemented. We utilize qualitative comparative analysis (QCA) to assess the impact of TJ timing and sequencing on democratic development. We find little evidence for path dependency owing to the chronological order of mechanisms. We do find, however, that amnesties and trials approach a sufficient condition for democratic consolidation in Latin America; trials, however, come closest to being a necessary condition for successful democratic consolidation.
American politics, the presidency of the World Bank, and development policy

The World Bank's president has been an American by tradition. Yet little work has explored the consequences for this connection in influencing visions of development in the organization across time. This paper uses evidence from archives, congressional hearing records, and memoirs and histories of World Bank presidents to investigate United States-World Bank relations and development policy during four presidencies--Eugene Meyer, Eugene Black, Robert McNamara, and James Wolfensohn. The author argues that at times the political arrangements had the effect of pushing the Bank toward greater institutional independence from the United States, particularly when partisanship in American politics rose and new United States presidential administrations came into office with the World Bank president's term holding over from before. At other times, United States-World Bank connections pulled the Bank into foreign policy issues in the United States that the Bank might not otherwise have addressed when advocates pressed their case on Capitol Hill.
Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to α,β-Unsaturated Cyclic Electrophiles

This account describes our laboratory’s efforts in the development of a palladium-catalyzed asymmetric conjugate addition of arylboronic acids to cyclic conjugate acceptors. Specifically, we highlight the study of this transformation in the following areas: (a) construction of all-carbon quaternary stereocenters, (b) elucidation of the reaction mechanism, (c) addition to heterocyclic acceptors to generate tertiary stereocenters, and (d) application in the synthesis of natural products.
Institutional and policy analysis of river basin management: the Murray Darling River Basin, Austrialia

The authors describe and analyze management in the Murray-Darling basin of Australia, long regarded as a model for integrated river basin management. This interior basin of over 1 million km2 in semi-arid southeastern Australia is defined by the catchment areas of the Murray and Darling Rivers and their tributaries. Water management issues include allocation, quality, and dryland salinity. Because of Australia's federal governmental structure, institutional development has been more a matter of integrating state and local endeavors than decentralization of national authority. The Australian national government has little constitutional power over water resources. The five states in the basin make policy regarding water rights, discharge permits, fees, and the construction and operation of physical structures. River management began on the Murray River in the 1920s under the terms of a tri-state agreement. As the scope of management widened to the entire basin, more states were added and the national government supported the creation of new arrangements for integrated water resource management, with some provision for stakeholder participation. The dynamics of state-national authority over water policy, and the emergence in recent years of numerous local-level catchment organization, contribute to some uncertainty about the future course of basin management in this internationally renowned site.
An infinite-time relaxation theorem for differential inclusions

The fundamental relaxation result for Lipschitz differential inclusions is the Filippov-Wažewski Relaxation Theorem, which provides approximations of trajectories of a relaxed inclusion on finite intervals. A complementary result is presented, which provides approximations on infinite intervals, but does not guarantee that the approximation and the reference trajectory satisfy the same initial condition.
A Subsampled Double Bootstrap for Massive Data

ABSTRACTThe bootstrap is a popular and powerful method for assessing precision of estimators and inferential methods. However, for massive datasets that are increasingly prevalent, the bootstrap becomes prohibitively costly in computation and its feasibility is questionable even with modern parallel computing platforms. Recently, Kleiner and co-authors proposed a method called BLB (bag of little bootstraps) for massive data, which is more computationally scalable with little sacrifice of statistical accuracy. Building on BLB and the idea of fast double bootstrap, we propose a new resampling method, the subsampled double bootstrap, for both independent data and time series data. We establish consistency of the subsampled double bootstrap under mild conditions for both independent and dependent cases. Methodologically, the subsampled double bootstrap is superior to BLB in terms of running time, more sample coverage, and automatic implementation with less tuning parameters for a given time budget. Its advant...
Pharmaceutical patents and prices : a preliminary empirical assessment using data from India

The enforcement of stringent intellectual property rights in the pharmaceutical sector of developing countries generates considerable controversy, due to both the extensive research investment and the public policy importance of this sector. This paper explores the likely effects of enforcing product patents on prices and utilization of drugs in the Central Nervous System market in India. The Central Nervous System segment is the second largest therapeutic category in terms of retail sales in the world and is one of the fastest growing segments in India. Using information on product patents granted by the government and panel data on pharmaceutical prices and utilization from 2003-2008, the paper finds limited evidence of overall price increase following the introduction of product patents. However, there appear to be heterogeneous effects on prices by the type of product patent granted on drugs, implying the need for a careful examination of the product patent portfolio.
Coulomb Oscillations in Antidots in the Integer and Fractional Quantum Hall Regimes

We report measurements of resistance oscillations in micron-scale antidots in both the integer and fractional quantum Hall regimes. In the integer regime, we conclude that oscillations are of the Coulomb type from the scaling of magnetic field period with the number of edges bound to the antidot. Based on both gate-voltage and field periods, we find at filling factor $\ensuremath{\nu}=2$ a tunneling charge of $e$ and two charged edges. Generalizing this picture to the fractional regime, we find (again, based on field and gate-voltage periods) at $\ensuremath{\nu}=2/3$ a tunneling charge of $(2/3)e$ and a single charged edge.
Design of a Compact Biaxial Tensile Stage for Fabrication and Tuning of Complex Micro- and Nano-scale Wrinkle Patterns

Wrinkling of thin films is a strain-driven process that enables scalable and low-cost fabrication of periodic micro- and nano-scale patterns. In the past, single-period sinusoidal wrinkles have been applied for thin-film metrology and microfluidics applications. However, real-world adoption of this process beyond these specific applications is limited by the inability to predictively fabricate a variety of complex functional patterns. This is primarily due to the inability of current tools and techniques to provide the means for applying large, accurate, and nonequal biaxial strains. For example, the existing biaxial tensile stages are inappropriate because they are too large to fit within the vacuum chambers that are required for thin-film deposition/growth during wrinkling. Herein, we have designed a compact biaxial tensile stage that enables (i) applying large and accurate strains to elastomeric films and (ii) in situ visualization of wrinkle formation. This stage enables one to stretch a 37.5 mm long film by 33.5% with a strain resolution of 0.027% and maintains a registration accuracy of 7 μm over repeated registrations of the stage to a custom-assembled vision system. Herein, we also demonstrate the utility of the stage in (i) studying the wrinkling process and (ii) fabricating complex wrinkled patterns that are inaccessible via other techniques. Specifically, we demonstrate that (i) spatial nonuniformity in the patterns is limited to 6.5%, (ii) one-dimensional (1D) single-period wrinkles of nominal period 2.3 μm transition into the period-doubled mode when the compressive strain due to prestretch release of plasma-oxidized polydimethylsiloxane (PDMS) film exceeds ∼18%, and (iii) asymmetric two-dimensional (2D) wrinkles can be fabricated by tuning the strain state and/or the actuation path, i.e., the strain history. Thus, this tensile stage opens up the design space for fabricating and tuning complex wrinkled patterns and enables extracting empirical process knowledge via in situ visualization of wrinkle formation.
Online Support Service Quality, Online Learning Acceptance, and Student Satisfaction.

Abstract This paper examines potential differences between Korean and American students in terms of their perception levels regarding online education support service quality, online learning acceptance, and satisfaction. Eight hundred and seventy-two samples, which were collected from students in online classes in the United States and Korea, were analyzed using factor analysis, structural equation model techniques, independent sample t-test, and logistic regression. The following results were obtained from this analysis: 1) There were significant differences between the perceptions of Korean and US students with regard to online education support service quality. In this context, Korean students held a significantly higher perception of online support service quality. 2) Perception of online support service quality was a significant predictor of online learning acceptance and satisfaction for both Korean and American students. It appears that a majority of the students in the two countries, irrespective of the differences in their perceptions of online support service quality, believe that the acceptance of online classes would benefit them.
Acyl CoA:cholesterol acyltransferase (ACAT) inhibitors: heterocyclic bioisosteres for the urea group in DuP 128

Abstract A series of compounds bearing two heterocyclic substituents were evaluated for inhibition of the ACAT enzyme. One heterocyclic group was chosen to mimic the urea group in our clinical candidate, DuP 128. Of the several groups examined, aminobenzoxazoles proved to be the most potent in terms of inhibition of ACAT in J774 macrophage cells.
A Tandem Approach to Photoactivated Olefin Metathesis: Combining a Photoacid Generator with an Acid Activated Catalyst

Combining an acid activated precatalyst with a photoacid generator (PAG) in the presence of ultraviolet light resulted in a highly efficient catalyst for olefin metathesis. The tandem system of precatalyst and PAG was capable of both ring closing metathesis (RCM) and ring opening metathesis polymerization (ROMP) in good to excellent conversion. Mechanistic investigations revealed that the catalytically active species is very similar to that of other well-known Ru-based catalysts.
Ranked-set sample nonparametric quantile confidence intervals

A nonparametric exact quantile interval is developed for ranked-set samples. The proposed interval provides higher coverage probability and shorter expected length than its simple random sample analog. In order to achieve the desired confidence level a distribution-free confidence interval that interpolates the adjacent order statistics is constructed.
Analysis of PWM Frequency Control to Improve the Lifetime of PWM Inverter

Studies show that the power cycling mean time to failure (MTTF) of the insulated-gate bipolar transistor (IGBT) bond wire in an adjustable speed drive may be very short under some very common conditions. This paper proposes a switching frequency reduction method based on the junction temperature variation (ΔTj) of an inverter IGBT. It has the following advantages. First, it reduces the pulsewidth-modulation frequency under low-speed higher torque condition. Second, the inverter is started more smoothly and safely under higher command switching frequency and high-torque condition. Third, the overall MTTF of the inverter IGBT can be improved. The theory analysis, simulation, and experimental result are provided to show these advantages.
Capillary electrophoresis with constant potential amperometric detection using a nickel microelectrode for detection of carbohydrates

Carbohydrates were separated by capillary electrophoresis (CE) and detected electrochemically using a nickel microelectrode which was operated at a constant applied potential (∼0.6 V vs. Ag/AgCI). A simple capillary electrode holder design facilitated alignment between the separation capillary and the working microelectrode without the use of micro-positioning equipment. The separations were performed under alkaline conditions (pH > 11), matching the high pH requirements for amperometric detection at the nickel electrode. The analytical procedure developed showed detection limits for the carbohydrates studied in the micromolar range, showing a linear response in the range tested (micromolar to millimolar). The procedure was used to identify sugars in two real samples (i.e., urine and in a common beverage). The potential use of the system for the determination of amino acids was also demonstrated.
Installation Alignment Of A Multi-Beam Icf Target Illumination System

Target illumination systems for inertial confinement fusion (ICF) experiments require precise alignment of a multitude of mirrors, usually spherically arranged around the ICF target. The mechanical support structure for these mirrors generally consists of a large space frame with many voids. This makes direct alignment or boresighting impossible, since alignment instruments and references cannot be placed at the coordinate centers representing the mirror arrays or focal points. Nevertheless, the structural members must be accurately aligned during the assembly phase, to provide the focusing precision required by the completed illumination system. This paper describes the techniques used to assemble and align the Antares Laser space frame, where a total of 48 mirrors fold and focus 24 laser beams onto the ICF target, with in a 7.3 meter space frame. The alignment procedures described use optical tooling and test techniques supplemented by surveying instruments and auxiliary devices, as required by the unique geometry of the space frame.
Long-term Effects of Subliminal Priming on Academic Performance

This research examines the temporal range of subliminal priming effects on complex behavior. In Experiments 1 and 2, participants were subliminally primed with words either related or unrelated to intelligence before completing a practice exam, administered 1 to 4 days before an actual course midterm. Results revealed that the intelligence primes increased performance on the midterm compared to neutral primes. Experiment 1 demonstrated that being told that the priming task was designed to help exam performance moderated the effect of the intelligence primes. In Experiment 2, practice test performance mediated the effect of the primes on midterm performance. These experiments demonstrated that subliminal priming may have long-term effects on real-world behavior, and demonstrates one means by which long-term priming effects may occur.
Use of Stabilized ZrO2 to Measure O2 Permeation

The rate of permeation of CaO-stabilized ZrO2 (CSZ) by O2 gas was measured from 640° to 1200°C with the CSZ tubing used simultaneously as the sample and the O2 pressure detector. The apparent permeation rate depended significantly on the O2 pressure at the low-pressure side. The rate measured by this method was orders of magnitude smaller than that measured under steady-state conditions, except when the O2 partial pressure was high (>10−4 atm), in which case the agreement was good. The difference between steady-state permeability and non-steady-state permeability is related to the deviation in stoichiometry in a sample or detector. The transient response (measured under variable pressure difference) may be very different from steady-state permeation (measured under constant differential pressures across the membranes). To apply CSZ to typical O2 gas permeability measurements, the O2 pressure must be kept above ∼ 10−3.5 atm. In this range, the permeability of CSZ may be regarded as a temperature-dependent material property which is governed by the electron-hole mobility. At lower O2 pressures the permeation rate is a more complex function of the pressure difference and level.
The opacity of the universe and the strong equivalence principle

Abstract A possible explanation of why the advanced (i.e. acausal) solutions of Maxwell's equations are not observed in nature is by way of absorption by an opaque universe. As Davies has shown, the ever expanding, general relativistic cosmological models fail to provide the needed absorption. This is perhaps not surprising. In fact, the absorption mechanism calling for an interplay between local physics and cosmology, is usually developed adopting the strong equivalence principle, SEP, which precludes such interplay. We show that complete absorption of electromagnetic radiation by ionized intergalactic plasma is obtained provided a violation of the SEP, of the order of the Hubble's constant, is allowed to occur. The same degree of violation was previously found to be compatible with a large body of observational data.
Visual Tracking of a Maneuvering Target

This paper presents an acceleration-command generation and its implementation for an aerial vehicle in the problem of visual target tracking, when the target is free to make any maneuver with arbitrary but otherwise bounded acceleration. The acceleration command is generated by an adaptive disturbance rejection control algorithm that uses only visual information about the target, obtained by a monocular camera mounted on the aerial vehicle. This information consists of the maximal image size in pixels and the pixel coordinates of the image centroid in the image plane. The acceleration command is translated into forward velocity and attitude angle commands, which are afterward used to obtain actual control surface deflections for the aerial vehicle. Simulations of a full nonlinear model verify the theoretical statements.
A Renaissance in Noble Gas Chemistry.

Abstract : In spite of the predictions of stable noble-gas compounds since at least 1902, unsuccessful attempts at their synthesis gave rise to the widely held opinion that noble-gases are not only noble but also inert . Thus, dogma-like statements to this effect could be found in practically every chemistry textbook and discouraged or a long time, experimentalists to work in this area. It was not until 1962 that this dogma was shattered when Bartlett in Canada and Hoppe in Germany independently discovered with XePtF6 and XeF2, respectively, the first stable noble-gas compounds. These discoveries triggered an explosion of worldwide frenzy in this area and within a short span of time many new xenon, radon and krypton compounds were prepared and characterized. About 30 years and many publications later, new results in this area had slowed down to a trickle and in the minds of most chemists the chapter on noble-gas chemistry had been completed. A recent burst of startling discoveries, however, shows that noble-gas chemistry is still full of surprises and may signal the beginning of a renaissance in this field.
The automatic transcription of machine shorthand

The recognition of digitalized speech signals is an important data processing problem, still completely unsolved. In fact, speech is the basic input to many data processing problems, and before any processing can take place, the speech signals must first be transformed into digital form, recognized, and identified. Typical applications include: the processing of court testimony, the recording of data in medical practice, the handling of business correspondence, and the monitoring of radio broadcasts.
Frame selection performance limits for statistical image reconstruction of adaptive optics compensated images

Adaptive optics systems have been used to compensate for the degrading effects of atmospheric turbulence in images collected with large astronomical telescopes. Postdetection processing techniques are also employed to further improve adaptive optics compensated images. Typically, many short-exposure images are collected, recentered to compensate for tilt, and then averaged to overcome randomness in the images and improve signal-to-noise ratio (SNR). Experience shows that some short-exposure images in a data set are better than others. The frame selection postdetection processing technique uses an image quality metric to discard low-quality frames and improve image spectrum SNR. We address key issues pertaining to frame selection performance limits. Noise trade-offs are used to investigate minimum object brightness for successful application of the frame selection technique. Limits imposed by noise effects result in a minimum object brightness of apparent visual magnitude +8 for point sources and +4 for a +2-m length representative extended object imaged with a 1-m-diam telescope with no central obscuration. Effective average point spread functions for the point source and the representative extended object after frame selection processing under equivalent seeing conditions are almost identical. Thus, deconvolution could be applied to these images obtained via frame selection.
Inequivalence of first- and second-order formulations in D=2 gravity models

The usual equivalence between the Palalini and metric (or affinity and vielbein) formulations of Einstein theory fails in two spacetime dimensions for its “Kaluza-Klein” reduced (as well as for its standard) version. Among the differences is the necessary vanishing of the cosmological constant in the first-order forms. The purely affine Eddington formulation of Einstein theory also fails here.
A Model of Commodity Differentiation with Indivisibilities and Production

This paper presents an existence theorem in a general equilibrium model of a production economy with commodity differentiation and indivisibilities. The model is motivated by the existence of markets with indivisible commodities, such as the markets for automobiles and computers. As is standard in the literature, the space of commodity characteristics is described by a compact metric space and a commodity vector is described by an integer-valued Borel measure on the space of commodity characteristics. An atomless measure space of producers and consumers is assumed to overcome the problem of non-convexity of the production and consumption sets induced by indivisibilities.
Three-point functions of N=4 super-Yang–Mills from light cone string field theory in pp-wave

Abstract In this Letter we calculate three-string interaction from light cone string field theory in pp-wave. We find exact agreements with the free planar three point functions of non-chiral BMN operators of N =4 super-Yang–Mills. The three string interaction vertex involving the Neumann matrices was derived in a recent paper hep-th/0204146 . We explicitly calculate the bosonic Neumann matrices in the limit of large μp + α ′. Using the Neumann matrices we are able to compute the cubic interactions of three string modes in a pp-wave background.
Computational neuroanatomy and gene expression: Optimal sets of marker genes for brain regions

The three-dimensional data-driven Anatomic Gene Expression Atlas of the adult mouse brain consists of numerized in situ hybridization data for thousands of genes, co-registered to the Allen Reference Atlas. We propose quantitative criteria to rank genes as markers of a brain region, based on the localization of the gene expression and on its functional fitting to the shape of the region. These criteria lead to natural generalizations to sets of genes. We find sets of genes weighted with coefficients of both signs with almost perfect localization in all major regions of the left hemisphere of the brain, except the pallidum. Generalization of the fitting criterion with positivity constraint provides a lesser improvement of the markers, but requires sparser sets of genes.
Immigration Justice: Beyond Liberal Egalitarian and Communitarian Perspectives

Immigration law resides within a complex web of interconnected political, cultural, and economic realities. Politically the world is organized around nation states, which exercise the legal authority to control their borders. Multiple factors push people into emigrating from their country of origin or pull people toward immigrating to particular countries. Given historic migration patterns and the fluidity of national borders, cultures transcend these boundaries, creating demand for transnational mobility. The global economy coupled with disparate economic opportunities between nations spurs immigration. War, civil unrest, and natural disasters also contribute to the international movement of peoples. In this article, I explore the foundations of a socially just immigration regime. Part one provides an overview of the push–pull factors influencing the decision of individuals and families to migrate. Part two places these decisions within the context of United States immigration law, exploring both the sta...
Palladium-catalyzed aerobic oxidative dehydrogenation of cyclohexenes to substituted arene derivatives

A palladium(II) catalyst system has been identified for aerobic dehydrogenation of substituted cyclohexenes to the corresponding arene derivatives. Use of sodium anthraquinone-2-sulfonate (AMS) as a cocatalyst enhances the product yields. A wide range of functional groups are tolerated in the reactions, and the scope and limitations of the method are described. The catalytic dehydrogenation of cyclohexenes is showcased in an efficient route to a phthalimide-based TRPA1 activity modulator.
The arterial medial cell, smooth muscle or multifunctional mesenchyme?

Summary Accumulating evidence indicates that there is really only one cell type in the artery media and that it is a multifunctional cell in the sense that it fabricates or directs the fabrication of elastic fibers, collagen fibers, mucopolysaccharides and myosin. In the arteries of man and experimental animals with atherosclerosis this cell, in situ , frequently is found to contain lipid which on fluorescent microscopy has the antigenic specificity of low-density lipoproteins. During the development of fatty plaques this cell type probably both proliferates and migrates to contribute to the thickened intima. It seems possible that much of the fibroplasia in the thickened intima may be the result of relatively increased collagen formation by these cells at the expense of elastic fiber formation or myosin formation. Similar diversion of synthetic processes may account for the increased acid mucopolysaccharides seen in some atheromatous lesions. It is possible that this cell sometimes circulates and colonizes in order to produce the atheroma which have been observed occasionally on prosthetic implants in arterial lumina.
Gold(I)-catalyzed intramolecular hydroamination of unactivated C==C bonds with alkyl ammonium salts.

A mixture of (5)AuCl {5 = PCy2[2-(2,6-C6H3(OMe)2)C6H4]} and AgOTf catalyzes the intramolecular hydroamination of unactivated CC bonds with primary and secondary ammonium salts.
Micellar catalysis of Suzuki-Miyaura cross-couplings with heteroaromatics in water.

Pd-catalyzed couplings involving several heteroaromatic halides (bromides and chlorides) as well as boronic acids can be done under exceedingly mild conditions (between rt and 40 °C) in pure water using commercially available Pd catalysts and PTS, a nanomicelle-forming amphiphile.
HIGH RATE NEUTRINO DETECTORS FOR NEUTRINO FACTORIES.

Abstract Three types of high-rate neutrino detectors for neutrino interaction physics at neutrino factories are discussed. High-performance general-purpose detectors might collect event samples of the order of a billion events or more. This could greatly improve on the existing analyses of neutrino interactions and also lead to new and important analysis topics including, for example, precise determinations of the CKM matrix elements |Vub| and |Vcb|. The potential of such general-purpose detectors is illustrated with reference to a previously discussed detector (B.J. King, Neutrino physics at a Muon Colliders, Proceedings of the Workshop on Physics at the First Muon Collider and Front End of a Muon Collider, Fermilab, November 6–9, 1997) that is structured around a novel and compact vertexing and tracking neutrino target comprising a stack of CCD pixel devices. Design ideas and prospects are also discussed for two types of specialized detectors: (i) polarized targets filled with polarized solid protium–deuterium (HD), for unique and powerful studies of the nucleon's spin structure, and (ii) fully active liquid tracking targets with masses of several tonnes for precise determinations of the weak mixing angle, sin 2 θ W , from the total cross-section for neutrino–electron scattering. All three detector types pose severe technical challenges but their utilization could add significantly to the physics motivation for neutrino factories.
Future neutrino oscillation facilities: physics priorities and open issues

The recent discovery that neutrinos have masses opens a wide new field of experimentation. Accelerator-made neutrinos are essential in this program. Ideas for future facilities include Superbeam, Beta-beam, or Neutrino Factory, each associated with one or several options for detector systems. We now begin a “scoping study” aimed at determining a set of key R&D projects enabling the community to propose an ambitious accelerator neutrino program at the turn of this decade. As an introduction to this study, a set of physics priorities, a summary of the perceived virtues and shortcomings of the various options, and a number of open questions are presented.
Stereoselective synthesis of 3-hydroxy-2-sulfonyltetrahydrofurans from β-(triethylsilyloxy)aldehydes and p-tolylsulfonyldiazomethane

Abstract A new method for the stereoselective syntheses of 2-sulfonyltetrahydrofurans from β-(triethylsilyloxy)aldehydes and p -tolylsulfonyldiazomethane in the presence of BF 3 ·OEt 2 as Lewis acid is reported. The versatility of the sulfonyl functional group allows further functionalization alpha to the sulfonyl group. For example, treatment of 2-sulfonlytetrahydrofuran 2b with BF 3 ·OEt 2 and allyl silane afforded alkylative desulfonylation product in 85% yield.
Measurement of overall solids mass flux in a gas–solid Circulating Fluidized Bed

It is important to know the overall solids flux and solids Cycle Time Distribution (CTD) to properly characterize Circulating Fluidized Bed (CFB) systems. Although conceptually simple, estimating the solids mass flux in these closed loop systems, either via experiments or by using a model, is a non-trivial problem. In the present work, a non-invasive in situ technique is applied, which is sensitive, and can be used on a large-scale circulating flow systems. The technique is based on estimating the solids velocity and volume fraction distribution in a section (downcomer) of the CFB loop. Solids velocity is obtained by tracking a single radioactive particle as tracer, using a two detector setup, and the volume fraction distribution is obtained by γ-ray densitometry measurements. In the downcomer section of a 2-in.-diameter column, the solids flow was found to be close to a moving packed bed condition, with minimal random fluctuations in the solids volume fraction. Hence, only a negligible error is incurred by using the cross-sectionally averaged solids velocity and holdup values for the estimation of the solids mass flow. A calibration curve was established for the overall solids mass flux as a function of superficial gas velocity, and the mass flux values compared with those obtained from a timing and weighing method were within 4%.
Inertial range scaling in rotations of long rods in turbulence.

We derive a scaling relationship for the mean square rotation rate of rods with lengths in the inertial range in turbulence: $⟨{\stackrel{.}{p}}_{i}{\stackrel{.}{p}}_{i}⟩\ensuremath{\propto}{l}^{\ensuremath{-}4/3}$. We present experimental measurements of the rotational statistics of neutrally buoyant rods with lengths $2.8ll/\ensuremath{\eta}l72.9$, and find that the measurements approach the predicted scaling. The approach to inertial range scaling is shown to be more complex than anticipated with an overshoot and approach to the scaling from above. For all rod lengths, the correlation time of the Lagrangian autocorrelation of the rotation rate scales as the turnover time of the eddies of the size of the rod. Measuring rotational dynamics of single long rods provides a new way to access the spatial structure of the flow at different length scales.
High resolution measurements of density structures in the Jovian plasma sheet

A recent effort to determine the plasma density by using the low-frequency cutoff of trapped continuum radiation in the vicinity of the Jovian plasma sheet has revealed the existence of sharply defined density structures in the plasma sheet. These structures typically have a plasma density which is relatively constant, but of order 50% greater or less than that of the surrounding plasma. The transitions from low to high density occur on time scales of about ten seconds, which correspond to spatial dimensions of the order of a few ion Larmor radii. Voyager requires time intervals of less than a minute to more than five minutes to traverse the structures themselves, corresponding to size scales from a fraction of a Jovian radius to more than a Jovian radius. The existence of such structures in the Jovian magnetosphere raises obvious questions as to their three-dimensional nature as well as their origin. We suggest that the structures might represent flux tubes of varying plasma content, but on the basis of single-point measurements, we do not have the observations necessary to describe the three-dimensional form of the structures. A Fourier transform of the density variations yields a featureless spectrum which displays an inverse frequency dependence. This spectrum is consistent with the square wave-like form of the density variations observed. The observations of flux tubes in the middle magnetosphere of widely varying plasma content may be the result of a centrifugally-driven plasma transport mechanism acting inwards of the point of observation. We conclude that the structures observed are not consistent with an eddy-diffusion model.
Critical groups of covering, voltage and signed graphs

Graph coverings are known to induce surjections of their critical groups. Here we describe the kernels of these morphisms in terms of data parametrizing the covering. Regular coverings are parametrized by voltage graphs, and the above kernel can be identified with a naturally defined voltage graph critical group. For double covers, the voltage graph is a signed graph, and the theory takes a particularly pleasant form, leading also to a theory of double covers of signed graphs.
Spatial Parallelism of a 3D Finite Difference Velocity-Stress Elastic Wave Propagation Code

In a three-dimensional isotropic elastic earth, the wave equation solution consists of three velocity components and six stresses. We discretize the partial derivatives using second order in time and fourth order in space staggered finite difference operators. The parallel implementation uses the message passing interface library for platform portability and a spatial decomposition for efficiency. Most of the communication in the code consists of passing subdomain face information to neighboring processors. When the parallel communication is balanced against computation by allocating subdomains of reasonable size, we observe excellent scaled speedup. Allocating subdomains of size $25 \times 25 \times 25$ on each node, we achieve efficiencies of 94\% on 128 processors of an Intel\linebreak Paragon.