cssi/SciSciGPT-SciSciNet huggingface dataset:
Which Broiler Part is the Best Part

Predominance of production and marketing contracts in the broiler industry suggests a traditional analysis of price relationships might no longer be appropriate. In this study, markets for broiler cuts are defined as spatial. Results of a vector autoregressive regression analysis of monthly USDA data from 1987 to 2000 verify the price relationship between white meat and whole broiler prices. Price shocks in the boneless skinless breast market have a greater effect than dark meat shocks, suggesting this market is most important in price transmission. These results will assist industry participants to form more effective marketing and pricing strategies, thus adding efficiency to the market.
Globular cluster ages.

Within the framework of a model cosmology, the ages of the globular clusters should provide upper limits to the value of Hubble’s constant. Should both the ages and H be known to high accuracy, we may ask if standard comsological models are adequate. This paper will summarize recent results obtained by many astronomers for the ages of the globular clusters, how large the uncertainties are thought to be, and will suggest some further work.
Measurements of complex permittivity of microwave substrates in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

A knowledge of the dielectric properties of microwave substrates at low temperatures is useful in the design of superconducting microwave circuits. In this paper, we report the results of a study of the complex permittivity of sapphire (Al2O3), magnesium oxide (MgO), silicon oxide (Si02), lanthanum aluminate (LaA1O3), and zirconium oxide (ZrO2), in the 20 to 300 K temperature range, at frequencies from 26.5 to 40.0 GHz. The values of the real and imaginary parts of the complex permittivity were obtained from the scattering parameters, which were measured using a HP-8510 automatic network analyzer. For these measurements, the samples were mounted on the cold head of a helium gas closed cycle refrigerator, in a specially designed vacuum chamber. An arrangement of wave guides, with mica windows, was used to connect the cooling system to the network analyzer. A decrease in the value of the real part of the complex permittivity of these substrates, with decreasing temperature, was observed. For MgO and Al2O3, the decrease from room temperature to 20 K was of 7 and 15 percent, respectively. For LaA1O3, it decreased by 14 percent, for ZrO2 by 15 percent, and for SiO2 by 2 percent, in the above mentioned temperature range.
Astrophysical Programs for High Angular Resolution Optical Interferometry

Optical interferometry will contribute to astrophysical programs for study of the solar system, stars, and galaxies. The earliest and richest applications are expected to be in stellar astronomy, where interferometry will touch almost every aspect of the subject. However, within a few decades, interferometric studies of the galaxy, the Magellanic clouds, the local group, active galactic nuclei, and quasars will provide critical and subtle information on the scale and the contents of the universe.
LINGUISTIC-MATHEMATICAL STATISTICS IN REBUS, LYRICS, JURIDICAL TEXTS, FANCIES AND PARADOXES

This is a collection of linguistic-mathematical approaches to Romanian rebus, poetical and juridical texts, and proposes fancies, recreational math problems, and paradoxes. We study the frequencies of letters, syllables, vowels in various poetry, grill definitions in rebus, and rebus rules. We also compare the scientific language, lyrical language, and puzzles' language, and compute the Shannon entropy and Onicescu informational energy.
Strand Algebras for DNA Computing

We present a process algebra for DNA computing, discussing compilation of other formal systems into the algebra, and compilation of the algebra into DNA structures.
Terrorist Events and Attitudes toward Immigrants: A Natural Experiment ⇤

Using a quasi-experimental research design, this study examines the effect of terrorist events on the perception of immigrants across 65 regions in nine European countries. It first elaborates a theoretical argument that explains the effect of events and points to economic conditions, the size of the immigrant population, and personal contact as mediating factors. This argument is evaluated using the fact that the terror attack in Bali on October 12, 2002, occurred during the fieldwork period of the European Social Survey. The findings from this natural experiment reveal considerable cross-national and regional variation in the effect of the event and its temporal duration. The analysis on the regional level supports the argument about contextual variations in the response to the event and a second analysis based on the 2004 Madrid bombing confirms the study’s conclusions. Implications of the findings for societal responses to terror attacks, the literature on attitudes toward immigrants, and survey resea...
Enabling conditions for second pillars of pension systems

This note adds to the existing literature by examining the enabling conditions for the creation of mandatory funded pension funds, and identifying additional factors that are important to consider in the early stages of the reform. The note stresses the importance of some factors that had already been identified in previous literature but not fully observed by reforming countries, including the strong and lasting commitment of the authorities with the reform, the fiscal commitment with the reform, and some basic financial infrastructure. The analysis is also extended to analyze the role of supervision in the early stages of the reform and the role of the government in fostering the development of the domestic capital market.
Multi-Task Learning with Group-Specific Feature Space Sharing

When faced with learning a set of inter-related tasks from a limited amount of usable data, learning each task independently may lead to poor generalization performance. (MTL) exploits the latent relations between tasks and overcomes data scarcity limitations by co-learning all these tasks simultaneously to offer improved performance. We propose a novel Multi-Task Multiple Kernel Learning framework based on Support Vector Machines for binary classification tasks. By considering pair-wise task affinity in terms of similarity between a pair's respective feature spaces, the new framework, compared to other similar MTL approaches, offers a high degree of flexibility in determining how similar feature spaces should be, as well as which pairs of tasks should share a common feature space in order to benefit overall performance. The associated optimization problem is solved via a block coordinate descent, which employs a consensus-form Alternating Direction Method of Multipliers algorithm to optimize the Multiple Kernel Learning weights and, hence, to determine task affinities. Empirical evaluation on seven data sets exhibits a statistically significant improvement of our framework's results compared to the ones of several other Clustered Multi-Task Learning methods.
Learning to linearize under uncertainty

Training deep feature hierarchies to solve supervised learning tasks has achieved state of the art performance on many problems in computer vision. However, a principled way in which to train such hierarchies in the unsupervised setting has remained elusive. In this work we suggest a new architecture and loss for training deep feature hierarchies that linearize the transformations observed in unlabeled natural video sequences. This is done by training a generative model to predict video frames. We also address the problem of inherent uncertainty in prediction by introducing latent variables that are non-deterministic functions of the input into the network architecture.
Item Response Theory and Measuring Abilities

Ability measurement changed greatly at the end of the last century. Classical test theory (CTT) methods guided measurement for most of the last century. CTT methods are based on large sampling norms, fixed length tests, and ordinal level measurement scales. Here, a person's ability performance is based on relative standing among a population of individuals for a given test. However, a person's performance, or its change, relative to a person's performance on a particular item is not well incorporated. Ability measurement and test theory have evolved into newer methods. These newer approaches, known as item response theory (IRT) methods, are replacing CTT techniques. In IRT methods, person performance may be referenced to specific item parameters, as well as to relative standing in a population of persons. Persons can receive different tests measuring the same unidimensional trait, of varying lengths, and still be meaningfully compared, given that the tests are linked or equated. The scale of measurement for IRT is interval-level, so relative score levels and their change are weighted accordingly. In this chapter, both classical and item response theory approaches will be covered, and each method's strengths and weaknesses discussed. Keywords: ability measurement; classical test theory; item response theory; test theory
Newton-Okounkov polyhedra for character varieties and configuration spaces

We construct families of Newton-Okounkov bodies for the free group character varieties and configuration spaces of any connected reductive group. We use this construction to give a proof that these spaces are Cohen-Macaulay.
Hausdorff convergence and universal covers

We prove that if Y is the Gromov-Hausdorff limit of a sequence of compact manifolds, M n i , with a uniform lower bound on Ricci curvature and a uniform upper bound on diameter, then Y has a universal cover. We then show that, for i sufficiently large, the fundamental group of Mi has a surjective homeomorphism onto the group of deck transforms of Y . Finally, in the non-collapsed case where the Mi have an additional uniform lower bound on volume, we prove that the kernels of these surjective maps are finite with a uniform bound on their cardinality. A number of theorems are also proven concerning the limits of covering spaces and their deck transforms when the Mi are only assumed to be compact length spaces with a uniform upper bound on diameter.
An Introduction to spin foam models of quantum gravity and BF theory

In loop quantum gravity we now have a clear picture of the quantum geometry of space, thanks in part to the theory of spin networks. The concept of ‘spin foam’ is intended to serve as a similar picture for the quantum geometry of spacetime. In general, a spin network is a graph with edges labeled by represen- tations and vertices labeled by intertwining operators. Similarly, a spin foam is a 2-dimensional complex with faces labeled by representations and edges labeled by intertwining operators. In a ‘spin foam model’ we describe states as linear combina- tions of spin networks and compute transition amplitudes as sums over spin foams. This paper aims to provide a self-contained introduction to spin foam models of quantum gravity and a simpler field theory called BF theory.
Globalization and Investment in Human Capital

Workers are becoming increasingly concerned about the impact that globalization has on their domestic labor market. While existing research typically focuses on the effects on labor market outcomes such as wages and employment, we examine whether American workers respond to globalization by increasing their investment in human capital. Specifically, we measure the extent to which offshoring and immigration affect enrollment at institutions of higher education. The results indicate that both offshoring and immigration increase enrollment at community colleges, particularly among older students. We conclude that workers in the U.S. are responding to offshoring and immigration by acquiring the skills necessary to compete in a global economy.
The Secondary Stars in Short Period (Magnetic) Cataclysmic Variables

We review the recent knowledge base pertaining to causes for mass accretion variations (high/low states) in highly magnetic cataclysmic variables (i.e. polars). We then examine what theory has to say about the properties of the secondary stars (the mass donors) with respect to those CVs with very short orbital periods. Finally, we use recent observations of EF Eri in an extended low state to provide direct observational evidence which shows that this CV, as well as a few others, likely contain very low mass, sub-stellar secondary stars.
Tendon-healing in a bone tunnel: a biomechanical and histological study in the dog.

Our study evaluated tendon-to-bone healing in a dog model. Twenty adult mongrel dogs had a transplantation of the long digital extensor tendon into a 4.8-millimeter drill-hole in the proximal tibial metaphysis. Four dogs were killed at each of five time-periods (two, four, eight, twelve, and twenty-six weeks after the transplantation), and the histological and biomechanical characteristics of the tendon-bone interface were evaluated. Serial histological analysis revealed progressive reestablishment of collagen-fiber continuity between the bone and the tendon. A layer of cellular, fibrous tissue was noted between the tendon and the bone, along the length of the bone tunnel; this layer progressively matured and reorganized during the healing process. The collagen fibers that attached the tendon to the bone resembled Sharpey fibers. High-resolution radiographs showed remodeling of the trabecular bone that surrounded the tendon. At the two, four, and eight-week time-periods, all specimens had failed by pull-out of the tendon from the bone tunnel. The strength of the interface was noted to have significantly and progressively increased between the second and the twelfth week after the transplantation. At the twelve and twenty-six-week time-periods, all specimens had failed by pull-out of the tendon from the clamp or by mid-substance rupture of the tendon. The progressive increase in strength was correlated with the degree of bone ingrowth, mineralization, and maturation of the healing tissue, noted histologically.
GPS roadside integrated precision positioning system

A real-time integrated navigation system with 2-cm position accuracy was developed using commercial off-the shelf (COTS) equipment including inertial sensors and differential Global Positioning System (GPS) receivers, and was demonstrated for transportation applications with an emphasis on lane departure detection. A 900-MHz radiofrequency communications link transmits GPS base station range and carrier phase measurements to a GPS receiver on the vehicle. The GPS receiver calculates the vehicle position relative to the surveyed base location. The loosely coupled eight-state extended Kalman filter with 10-Hz navigation aids provides smoothed position information between 2-Hz GPS updates and provides graceful degradation in the presence of GPS blockages or communication dropouts. Currently, the navigation aids include anti-lock braking system wheel turns, electronic compass heading and pitch, and map vertical height. Data acquisition and Kalman filtering systems were developed to handle real-time processing and recording of all instrument data for further post-test system evaluation to determine the optimum configuration. An accurate rapid survey and map representation approach for measuring lane boundaries was validated using a vehicle, demonstrating inherit repeatability by the GPS positioning system. Real-time lane departure monitoring was developed. A video camera was installed to assist in accurate surveying and real-time system validation. This GPS-based positioning system is suitable for highway speeds during all weather conditions. It can be extended to other collision avoidance, drowsy driver awareness, advanced curve or intersection warnings, SOS, tracking, automated control, fast precision road mapping, and traffic management applications.
Inflated granularity: Spatial ''Big Data'' and geodemographics

Data analytics, particularly the current rhetoric around “Big Data”, tend to be presented as new and innovative, emerging ahistorically to revolutionize modern life. In this article, we situate one branch of Big Data analytics, spatial Big Data, through a historical predecessor, geodemographic analysis, to help develop a critical approach to current data analytics. Spatial Big Data promises an epistemic break in marketing, a leap from targeting geodemographic areas to targeting individuals. Yet it inherits characteristics and problems from geodemographics, including a justification through the market, and a process of commodification through the black-boxing of technology. As researchers develop sustained critiques of data analytics and its effects on everyday life, we must so with a grounding in the cultural and historical contexts from which data technologies emerged. This article and others (Barnes and Wilson, 2014) develop a historically situated, critical approach to spatial Big Data. This history illustrates connections to the critical issues of surveillance, redlining, and the production of consumer subjects and geographies. The shared histories and structural logics of spatial Big Data and geodemographics create the space for a continued critique of data analyses’ role in society.
The Spending Clause as a Positive Source of Environmental Protection: A Primer

The last third of the Twentieth Century witnessed a veritable explosion of environmental legislation. While some environmental statutes harken back a century, indeed long before the word “environmental” was conceived, most environmental legislation started emerging in the late 1960’s, highlighted by the enactment of the National Environmental Policy Act of 1970 (NEPA). The statutes may be widely known and of broad applicability, such as the Clean Air Act, Clean Water Act, Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), NEPA, and the Endangered Species Act, or of specific application, such as the Surface Mining Control and Reclamation Act (SMCRA), or of little public familiarity, such as the Ports and Waterways Safety Act of 1970. As the number of statutes approach the century mark, little thought has been given by Congress to the constitutional basis of the legislation. The underlying assumption is that the Commerce
The Information Content of Risk Factor Disclosures in Quarterly Reports

SYNOPSIS: I examine whether recently required risk factor update disclosures in quarterly reports provide investors with timely information regarding potential future negative economic events. Specifically, I examine whether risk factor updates in 10-Q filings are associated with negative abnormal returns at the time the updates are disclosed and whether quarterly updates are followed by negative earnings shocks. I find that firms presenting updates to their risk factor disclosures have significantly lower abnormal returns around the filing date of the 10-Q relative to firms without updates. I also find that firms with updates to their risk factors section have significantly lower future unexpected earnings and are more likely to experience future extreme negative earnings shocks. These findings suggest that the recent disclosure requirement mandated by the SEC was successful in generating timely disclosure of bad news. JEL Classifications: M41; M48; D80; G18. Data Availability: Please contact the author...
Cardiovascular disease in athletes

As a physician, coach, or trainer, we see athletes as healthy, physically fit, and able to tolerate extremes of physical endurance. It seems improbable that such athletes may have, on occasion, underlying life-threatening cardiovascular abnormalities. Regular physical activity promulgates cardiovascular fitness and lowers the risk of cardiac disease. However, under intense physical exertion and with a substrate of significant cardiac disease--whether congenital or acquired--athletes may succumb to sudden cardiac death. The deaths of high-profile athletes receive much attention through the national news media, but there are also deaths of other athletes. With repetitive, intense physical exercise, the heart undergoes functional and morphologic changes. Knowledge of those changes may help one identify cardiovascular abnormalities that can cause sudden death from the heart known as an "athlete's heart." This article will review cardiovascular diseases that may limit an athlete's participation in sports and that may put an athlete at risk for sudden cardiac death. It also reviews the extent and limitations of the cardiovascular preparticipation screening examination. Team physicians, coaches, and trainers must understand the process of evaluation of a symptomatic athlete that may indicate significant cardiac abnormalities. Finally, guidelines to determine eligibility of athletes with cardiovascular disease to return to sports will be reviewed.
A tomographic study of V691 CrA (X1822−371)

We present Doppler and modulation tomography of the low-mass X-ray binary V691 CrA with data obtained using the 6.5-m Magellan Baade telescope at the Las Campanas Observatory in 2010 and 2011. The disc and hotspot are observed in Hα and He ii (λ4686) in both years. A clear image of the disc is seen in He ii (λ5411) using the 2010 data. We present the first tomography of the absorption line He i (λ5876) and detect absorption near the L1 point of the donor star. We also present the first modulation tomography of the emission line Hα and detect emission from the secondary. The Hα double peaks are imbedded in a deep absorption trough confirming the presence of Balmer line absorbing material in the system. Our observations of Hα show absorption in a larger phase range than in Hβ which could be due to heating up of sprayed matter from the hotspot as it travels downstream. We also suggest possible occultation of the Hα absorbing spray by the disc bulge at certain phases.
Chemical and electronic structure of the SiO2/Si interface

The motivation for understanding the physics and chemistry of the SiO2/Si interface lies in the pivotal role it plays in current metal-oxide-semiconductor (MOS) technology. In this paper, we are concerned with the chemical structure of this interface and its relationship to both MOS device processing chemistry and, ultimately, the resultant electrical device properties. Emphasis is placed on the use of X-ray photoemission to probe the structure of the SiO2 near the SiO2/Si interface as well as the composition of the SiO2/Si chemical transition boundary itself. Complementary data from a wide range of other techniques such as 29Si NMR, ellipsometry, SEXAFS, and a variety of electrical probes are also considered. The topics discussed include the presence of a structurally-distinct region of SiO2 near the interface and its effect on the SiO2 band gap, the distribution and crystallographic dependence of suboxide states at the monolayer SiO2/Si transition boundary, the effect of electron irradiation on the SiO2 network structure, the influence of hydrogen on the SiO2 valence band discontinuity between SiO2 and Si, and the influence of processing chemistry on the chemical and electronic structure of the interface.
Determination of all rational preperiodic points for morphisms of PN

For a morphism $f:\P^N \to \P^N$, the points whose forward orbit by $f$ is finite are called preperiodic points for $f$. This article presents an algorithm to effectively determine all the rational preperiodic points for $f$ defined over a given number field $K$. This algorithm is implemented in the open-source software Sage for $\Q$. Additionally, the notion of a dynatomic zero-cycle is generalized to preperiodic points. Along with examining their basic properties, these generalized dynatomic cycles are shown to be effective.
Intramolecular [4 + 2] Cycloadditions of Iminoacetonitriles: A New Class of Azadienophiles for Hetero Diels−Alder Reactions

Iminoacetonitriles participate as reactive dienophiles in stereoselective intramolecular hetero Diels−Alder reactions which afford substituted quinolizidines. The cycloadduct with exo-oriented cyano group is obtained as the major or exclusive product of the reaction as a consequence of the α-amino nitrile anomeric effect The α-amino nitrile moieties incorporated in the cycloadducts constitute latent iminium ions, which upon exposure to mild protic or Lewis acids are unmasked, setting the stage for further useful synthetic transformations. For example, reductive decyanation with NaBH3CN excises the cyano group, while Bruylants reaction with Grignard reagents and acetylides lead to α-substituted amines. The substrates for these [4 + 2] cycloadditions are prepared from readily available alcohols via a Mitsunobu coupling reaction with the previously unknown, easily prepared reagent HN(Tf)CH2CN followed by cesium carbonate promoted elimination of trifluoromethanesulfinate.
The politics and economics of decentralization

Abstract This paper analyzes a simple general equilibrium model with local public goods subject to exclusion and crowding. In general, no competitive equilibrium exists for such models. However, in this paper we study a four-person example, satisfying assumptions formulated in a paper by McGuire [Group segregation and optimal jurisdictions, J. Political Econ. 82, 112–132 (1974)], in which a competitive equilibrium does exist. This example demonstrates that the model is capable of generating realistic implications regarding stratification of jurisdictions, the decision to subdivide or consolidate jurisdictions, reliance on exclusionary zoning, and the use of revenue sharing.
Probabilistic Method to Compute the Optimal Slip Load for a Mistuned Bladed Disk Assembly With Friction Dampers

In this paper, an analytical technique has been developed to compute the statistics of forced response of a mistuned bladed disk assembly with friction dampers. The method is based on the statistical linearization approach and predicts the probability distribution function of a blade's amplitude. The validity of this technique has been corroborated by comparison with the results from numerical simulations. Using this technique, the optimal value of the slip load at the friction joint has been computed to minimize the probability that a blade's amplitude will exceed a critical value
Migration of alkyl groups from zirconium to various haloboranes

Abstract The hydrozirconations of acyclic alkenes are known to yield the dicyclopentadienyl-1-aklyl-zirconium chlorides regioselectively and in high yields. These alkyl groups may readily be transmetallated to the haloboranes forming regioisomeric pure alkylboranes in good yields. In principle, this migration reaction combines the facile hydrozirconation and unique isomerization reactions of organozirconiums with the established chemistry of boron, expanding the utility of both metals for use in organic synthesis.
The Non-existence of the Labor Demand/Supply Diagram, and Other Theorems of Institutional Economics

The most famous and influential diagram in modern (neoclassical) labor economics is the model of wage determination by supply and demand. Using concepts and ideas from institutional economics, I argue that the theory of a perfectly competitive labor market is logically contradictory and, hence, the demand/supply diagram cannot exist on the plane of pure theory. Four other fundamental theorems concerning labor markets are also derived, as are implications about the theoretical foundation of the field of industrial relations and the economic evaluation of labor and employment policy.
The impact of work hour restrictions on surgical resident education.

Objective Resident work-hour restrictions were instituted in July 2003 based on ACGME mandates. The American Board of Surgery In-Training Examination (ABSITE), American Board of Surgery Qualifying Examination (ABSQE), and operative volume traditionally have been measures of surgical resident education and competency. The objective of this study was to determine the effect of reduced work hours on resident standardized test scores and operative volume at our institution. Design We reviewed ABSITE scores, ABSQE scores, and operative logs from 1997 to 2005 of all general surgery residents. Linear mixed-effects models were fitted for each component ABSITE score (total, basic science, and clinical management), and they were compared using a chi-squared likelihood ratio. Operative logs of graduating residents were compared before and after the work restrictions and were evaluated for association with ABSITE score. p-values less than 0.05 were considered significant. Results The program was compliant with ACGME mandates within 6 months of institution. ABSITE scores improved significantly after the restriction of work hours in both basic science (p = 0.003) and total score (p = 0.008). Clinical management scores were not affected. The number of major cases recorded by graduating residents did not change. A positive correlation was found between number of cases performed during residency and clinical management ABSITE scores (p = 0.045). ABSQE scores were not impacted by operative volume during residency. Conclusions ABSITE scores improved significantly after the restriction of resident work hours. Resident operative experience was not affected. An unexpected consequence of work-hour restrictions may be an improvement in surgical resident education.
Modification of organic interfaces: from molecular level measurements to injection characteristics

Ultra-violet and X-ray photoemission spectroscopy and current- voltage measurements were used to investigate the fundamental mechanisms responsible for the improvement of hole injection between modified indium-tin-oxide (ITO) surfaces and the hole- transport layer (HTL) of an organic light emitting diode. Two ITO surface modification techniques were investigated: oxygen- plasma treatment and deposition of an ultra-thin organic interlayer between the ITO and the HTL. We demonstrate that the improvement in injection is due to an increase in surface work function of ITO mediated by the presence of an oxygen radical in the first case, and to the presence of an intermediate energy level between the ITO Fermi level and the HTL highest occupied molecular orbital in the second.
Bank Competition and Credit Standards

This article offers an explanation for the substantial variation of credit standards and price competition among banks over the business cycle. As the economic outlook improves, the average default probabilities of borrowers decline. This affects the profitability of screening and causes bank screening intensity to display an inverse U-shape as a function of economic prospects. Low screening activity in expansions creates intense price competition among lenders and loans are extended to lower-quality borrowers. As the economic outlook worsens, price competition diminishes, and credit standards tighten significantly. Deposit insurance may contribute to the countercyclical variation of credit standards. Copyright 2004, Oxford University Press.
A nursing perspective on the interrelationships between theory, research and practice

This paper is concerned with the interrelationships between the three concepts of theory, research and practice. In the course of discussing the interrelationships between these concepts, research is identified as the link between theory and practice on both a formal (explicit) and informal (tacit) level. The role of formal and informal research in the development of nursing expertise is also given some consideration.
An Economical and Efficient Foundation Connection for Concrete Filled Steel Tube Piers and Columns

Concrete filled steel tubes (CFT) are economical and result in rapid construction. The steel tube serves as formwork and reinforcement to the concrete fill, and the fill increases the compressive strength and stiffness of the tube. The fill delays and restrains local buckling, and enhances ductility and resistance if composite action is achieved. Circular CFT provides better performance because the circular tube provides greater confinement of the concrete and composite interaction between the two materials. However, circular CFT is more difficult to connect to other structural elements, and recent research has provided a simple and economical connection to connect circular CFT piers or columns to reinforced concrete foundations, beams and pier caps. The connection does not require any reinforcement or dowels connecting the tube to the footing. A second variation of this connection permits sequencing of steel and concrete construction trades and connecting to precast concrete elements. A series of experiments have been completed to evaluate the inelastic seismic performance and establish design criteria for the connection. This work shows that the connection can develop the full capacity of the composite column, and provide great ductility and inelastic deformation capacity under seismic loading.
The long range gravitational potential energy between strings

Abstract We calculate the gravitational potential energy between infinitely long parallel strings with tensions τ 1 and τ 2 . Classically, it vanishes, but at one loop, we find that the long range gravitational potential energy per unit length is U / L =24 G N 2 τ 1 τ 2 /(5 πa 2 )+⋯, where a is the separation between the strings, G N is Newton's constant, and we set ℏ= c =1. The ellipses represent terms suppressed by more powers of G N τ i . Typically, massless bulk fields give rise at one loop to a long range potential between p -branes in space–times of dimension p +2+1. The contribution to this potential from bulk scalars is computed for arbitrary p (strings correspond to p =1) and in the case of three-branes its possible relevance for cosmological quintessence is commented on.
Synthesis of protected guanidinium linked dinucleoside incorporable into an oligonucleotide using solid phase DNA methodology

The synthesis of novel fully protected guanidinium linked dinucleoside for incorporation into oligonucleotide using solid-phase DNA synthesis methodology was developed. The three different protecting groups selected allow different deprotection conditions.
Principles of scaling in a uniaxial medium

Solution to Maxwell’s equations is given for source currents in an unbounded magneto-ionic medium for which the dielectric tensor is uniaxial, that is, diagonal with two elements equal. Three-dimensional Fourier transforms technique is used because it gives the field solutions in a form which shows that the uniaxial fields may be obtained by a scaling of certain quantities. These quantities are related to fields in free space due to an equivalent source current. The choice of the quantities to be scaled and their respective equivalent source currents depend on how the uniaxial field solution is arranged. For example, two methods of scaling are given for the case of the source current perpendicular to the magnetostatic field. The problems of an electric dipole parallel and perpendicular to the magnetostatic field are given as examples of such scaling.
Metal-Catalyzed [2+2+1] Cycloadditions of 1,3-Dienes, Allenes, and CO

Step economy is a preeminent goal of synthesis. [1] It influences the length, efficiency, cost, time, separation, and environmental impact of a synthesis. Step economy is favored by the use of single, serial, or multicomponent reactions that proceed in one operation with a great increase in target revelant complexity. The design or discovery of such reactions is thus critical to extending the practical reach of organic synthesis. Toward this end, we have directed effort at the identification of new metal-catalyzed reactions, especially those which are forbidden or difficult to achieve in the absence of a catalyst. This program has thus far produced several new two-, three-, and four-component reactions, including [4+4], [2] [4+2], [3] [5+2], [4] [6+2], [5] [5+2+1], [6] [2+2+1], [7] [4+2+1], [7a] and [5+1+2+1] [8] cycloadditions. Herein, we report the first examples of the [2+2+1] cycloaddition reaction of diene– allenes and CO and preliminary examples of acceleration of this process by Bronsted acids.
A Convenient Synthesis of Hindered N-Aryl Substituted Cyclic Amines

Abstract An efficient and high yielding synthesis of N-substituted pyrrolidines and piperidines is described.
Order parameter suppression in double layer quantum Hall ferromagnets

Abstract Double-layer quantum Hall systems at Landau level filling factor ν =1 have a broken symmetry ground state with spontaneous interlayer phase coherence and a gap between symmetric and antisymmetric subbands in the absence of interlayer tunneling. We examine the influence of quantum fluctuations on the spectral function of the symmetric Green's function, probed in optical absorption experiments. We find that as the maximum layer separation at which the ν =1 quantum Hall effect occurs is approached, absorption in the lowest Landau level grows in strength. Detailed line shapes for this absorption are evaluated and related to features in the system's collective excitation spectrum.
A hypothesis of origin for podiform chromite deposits

Abstract Podiform chromite deposits are lenticular, chromite-rich autoliths in deformed dunites and harzburgites of ophiolite complexes. The ophiolite association is assumed to be created along accreting plate boundaries in the oceanic lithosphere. It is suggested that podiform chromite deposits form as magmatic cumulates in elongate magma pockets along the accreting plate boundaries. Chemical variations exhibited by chromites in podiform deposits (high Cr and/or Al contents, great Cr:Al variation, low Ti concentrations, limited Fe:Mg variation) are caused by fractional crystallization of primitive magmas buffered by residual, mafic silicates. Nodular textures, which characterize podiform chromite deposits, may result from snowballing of chromite crystals in a turbulent zone of magma segregation. After formation, the chromite cumulates sink as podiform autoliths into the under-lying, residual harzburgites and dunites.
Simulating CCDs for the Chandra Advanced CCD Imaging Spectrometer

Abstract We have implemented a Monte Carlo algorithm to model and predict the response of various kinds of CCDs to X-ray photons and minimally ionizing particles and have applied this model to the CCDs in the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer. This algorithm draws on empirical results and predicts the response of all basic types of X-ray CCD devices. It relies on new solutions of the diffusion equation, including recombination, to predict the radial charge cloud distribution in field-free regions of CCDs. By adjusting the size of the charge clouds, we can reproduce the event grade distribution seen in calibration data. Using a model of the channel stops developed here and an insightful treatment of the insulating layer under the gate structure developed at MIT, we are able to reproduce all notable features in ACIS calibration spectra. The simulator is used to reproduce ground and flight calibration data from ACIS, thus confirming its fidelity. It can then be used for a variety of calibration tasks, such as generating spectral response matrices for spectral fitting of astrophysical sources, quantum efficiency estimation, and modeling of photon pile-up.
Flavor asymmetry of light quarks in the nucleon sea

Abstract A surprisingly large asymmetry between the up and down sea quark distributions in the nucleon has been observed in recent deep inelastic scattering and Drell-Yan experiments. This result strongly suggests that the mesonic degrees of freedom play an important role in the description of the parton distributions of the hadronic sea. In this article, we review the current status of our knowledge of the flavor structure of the nucleon sea. The implications of various theoretical models as well as possible future measurements are also discussed.
Building a solid foundation for intranet security

Abstract The acceleration of change in the telecommunications network environment is presenting a serious challenge to the protection of information. Intranets — internal use of World Wide Web technology — are compelling because use of familiar Internet standards for access also reduces costs. Undoubtedly, one of the major issues for intranets is information security, defined as the protection of information from accidental or intentional loss of availability, integrity, or confidentiality. Organizations providing internal data to external users, such as customers, vendors, consultants, and partners, face further hazards. The Web is designed to be open to everyone so that information can be easily disseminated throughout the world. Security on intra- nets requires control — individual identification and authentication of users along with specific authorization for access to resources. The romance with technology is proceeding at such a rapid pace that there seems to be little time for analysis of control ...
The Effects of Environmental Regulation on Technology Diffusion: The Case of Chlorine Manufacturing

We use a hazard model to estimate the effect of environmental regulation on the diffusion of membrane cell production technology in the chlorine manufacturing industry. We estimate the effect of regulation on both the adoption of the membrane technology at existing plants and on the exit of existing plants using older technologies. We find that environmental regulation did affect the diffusion of the cleaner technology in the chlorine industry. However, it did so not by encouraging the adoption of membrane cells by existing facilities, but by reducing the demand for chlorine and hence encouraging the shutdown of facilities using the environmentally inferior options.(This abstract was borrowed from another version of this item.)
Emotional response inhibition in bipolar disorder: A functional magnetic resonance imaging study of trait- and state-related abnormalities

Background Impaired response inhibition and poor impulse control are hallmarks of the manic phase of bipolar disorder but are also present during depressive and, to a lesser degree, euthymic periods. The neural mechanisms underlying these impairments are poorly understood, including how mechanisms are related to bipolar trait or state effects. Methods One-hundred four unmedicated participants with bipolar mania (BM) ( n = 30), bipolar depression (BD) ( n = 30), bipolar euthymia (BE) ( n = 14), and healthy control subjects ( n = 30) underwent functional magnetic resonance imaging during emotional and nonemotional go/no-go tasks. The go/no-go task requires participants to press a button for go stimuli, while inhibiting the response to no-go trials. In separate blocks, participants inhibited the response to happy faces, sad faces, or letters. Results The BE group had higher insula activity during happy face inhibition and greater activity in left inferior frontal gyrus during sad face inhibition, demonstrating bipolar trait effects. Relative to the BE group, BD and BM groups demonstrated lower insula activity during inhibition of happy faces, though the depressed sample had lower activity than manic patients. The BD and BM groups had a greater response to inhibiting sad faces in emotion processing and regulation regions, including putamen, insula, and lateral prefrontal cortex. The manic group also had higher activity in insula and putamen during neutral letter inhibition. Conclusions These results suggest distinct trait- and state-related neural abnormalities during response inhibition in bipolar disorder, with implications for future research and treatment.
Constraints and Hamiltonian in light front quantized field theory

A self-consistent Hamiltonian formulation of scalar theory on the null plane is constructed and quantized following the Dirac procedure. The theory contains alsoconstraint equations which would lead, if solved, to a non-local Hamiltonian. In contrast to the equal-time formulation we obtain a different description of the spontaneous symmetry breaking in the continuum and the symmetry generators are found to annihilate the light-front vacuum. Two examples are given where the procedure cannot be applied self-consistently. The corresponding theories are known to be ill-defined from the equal-time quantization.
Free trade taxation and protectionist taxation

The goal of this paper is to seek new insight regarding international tax policy by recasting it in parallel with the theory of international trade. This is accomplished by defining a free trade taxation regime as one that is consistent with an efficient worldwide allocation of capital, and evaluating within this perspective various aspects of tax policy, such as value-added taxes, integration, income shifting, and the choice of worldwide or territorial system of taxes.
Indirect Interaction between Adatoms on a Tight-Binding Solid

The indirect interaction between adatom pairs on the (100) surface of a simple-cubic tight-binding solid is investigated within a molecular-orbital approach. A general scheme for calculating the surface-density-of-states change and the interaction energy of one and two single-level adatoms is presented, and contact (and a correction) is made with Grimley's formulation. The method permits binding above surface atoms, at bridge sites, or at centered positions, and yields interaction energy as a function of band filling, adatom energy level, and a general hopping potential $V$ between an adatom and the nearest surface atom(s). Calculations have been carried out for $\frac{V}{{W}_{b}}$ in the range 1/12-1/2, the upper limit giving split-off states (${W}_{b}\ensuremath{\equiv}\mathrm{bandwidth}$). The single-atom interaction shows little dependence on binding type, in all three cases being most attractive when the Fermi energy equals the noninteracting adatom level, with a strongly $V$-dependent strength. For the pair interaction, one finds a strength at nearest-neighbor separation of about an order of magnitude smaller than the absorption energy of a single adatom. This interaction has an exponentiallike dropoff and sign alternations as one moves along the $〈10〉$ direction. Under reasonable conditions, the nearest-neighbor interaction is often repulsive while the next nearest, third nearest, or fourth nearest is attractive, suggesting the patterns $c(2\ifmmode\times\else\texttimes\fi{}2)$, (2 \ifmmode\times\else\texttimes\fi{} 2), and $c(4\ifmmode\times\else\texttimes\fi{}2)$, respectively, which are frequently observed in the adsorption of simple gases on the (100) surfaces of transition metals. On the basis of two-dimensional Ising-model calculations including second-neighbor interactions, one can estimate the strength of $V$ from the observed disordering temperature of the adatom lattice; the result is similar to that obtained from estimates based on the heat of adsorption.
Capacity of a Class of Deterministic Relay Channels

The capacity of a class of deterministic relay channels with the transmitter input X, the receiver output Y, the relay output Y1 = f(X,Y), and a separate communication link from the relay to the receiver with capacity R0, is shown to be C(R0) =max min{I(X;Y) + R0, I(X;Y,Y1)}. p(x) Thus every bit from the relay is worth exactly one bit to the receiver. Two alternative coding schemes are presented that achieve this capacity. The first scheme, "hash-and-forward", is based on a variation of the usual random binning on the relay outputs, while the second scheme uses the usual "compress-and- forward". In fact, these two schemes can be combined to give a class of optimal coding schemes. As a corollary, this relay capacity result confirms a conjecture by Ahlswede and Han on the capacity of a channel with rate-limited state information at the decoder in the special case when the channel state is recoverable from the channel input and output.
Conceiving and marketing NASA’s Great Observatories

In early 1984, the astronomical community’s plans to launch a series of powerful telescopes able to study celestial sources at almost any wavelength were in trouble. The President of the United States had just declared his priority for a Space Station that was bound to be expensive, and Congress could not understand why yet another set of space observatories was needed when others were already being funded. To realize their aims, astronomers would have to advocate their needs much more effectively than in the past.