cssi/SciSciGPT-SciSciNet huggingface dataset:
Chondrule Formation in Radiative Shock

Abstract Previous models of solid grain melting in solar nebula shocks have neglected gas cooling behind the shock front; i.e., they considered adiabatic shocks. The effect of gas cooling in the postshock region is studied in this article. It was found that shocked gas is cooled efficiently by dipole molecules and small dust particles, and this results in a sharp increase in gas density in the postshock region. Submillimeter and larger grains cross the region of cooling before being decelerated, and are heated by the drag (through the cooled and compressed postshock gas) more strongly than in an adiabatic shock. This effect opens the possibility of melting of millimeter-size dust aggregates (chondrule precursors) in that cooler region, even when the matter is transparent for the thermal radiation of the aggregates. The possibility of formation of chondrule precursors in the collapsing presolar cloud and of melting of the precursors in the radiative accretional shock during formation of the solar nebula is speculated. In such a shock, grains could be melted at heliocentric radii up to the inner part of asteroidal belt if the density of infalling gas were only few times larger than the average density of infalling gas corresponding to an accretion rate of 10 -5 M ⊙ year -1 ; the limiting radius for melting increases with density. Clumpy accretion and enhancement of density in the vicinity of the centrifugal radius of infalling gas provide the necessary densities of infalling gas. Enhancement of drag heating due to fast cooling of postshock gas is also significant for shocks of other origin in the solar nebula. At the central plane of a minimum-mass solar nebula, chondrule precursors could be melted in shocks with velocity ≥10 km sec -1 . The duration of the molten state and the cooling rate of a grain are determined by the grain's kinetic energy and the rate of its decay (not the time scale of radiational cooling for the grain!). Millimeter-size compact grams have temperatures ≥1600 K for 3 sec, and ≥700 K for ∼10 4 sec, times that are appropriate for chondrules. These time scales could be larger in faster shocks when grains have larger kinetic energy, Chondrule precursors could be formed as fluffy aggregates before and during the collapse of presolar cloud. Later they must increase their density. The possibility of increasing the density of the aggregates by means of mutual collisions or as a result of surface tension when they began to melt is discussed possibility of increasing the density of the aggregates by means of mutual collisions or as a result of surface tension when they began to melt is discussed.
Ages and Abundances of Red Sequence Galaxies as a Function of LINER Emission Line Strength

Although the spectrum of a prototypical early-type galaxy is assumed to lack emission lines, a substantial fraction (likely as high as 30%) of nearby red sequence galaxy spectra contain emission lines with line ratios characteristic of LINERs. We use spectra of ~6000 galaxies from the SDSS in a narrow redshift slice (0.06 < z < 0.08) to compare the stellar populations of red sequence galaxies with and without LINER-like emission. The spectra are binned by internal velocity dispersion (σ) and by emission properties to produce high-S/N stacked spectra. The recent stellar population models of R. Schiavon make it possible to measure ages, [Fe/H], and individual elemental abundance ratios [Mg/Fe], [C/Fe], [N/Fe], and [Ca/Fe] for each of the stacked spectra. We find that red sequence galaxies with strong LINER-like emission are systematically 2-3.5 Gyr (10%-40%) younger than their emission-free counterparts at the same σ. This suggests a connection between the mechanism powering the emission (whether AGN, post-AGB stars, shocks, or cooling flows) and more recent star formation in the galaxy. We find that mean stellar age and [Fe/H] increase with σ for all galaxies. Elemental abundance [Mg/Fe] increases modestly with σ in agreement with previous results, and [C/Fe] and [N/Fe] increase more strongly with σ than does [Mg/Fe]. [Ca/Fe] appears to be roughly solar for all galaxies. At fixed σ galaxies with fainter r-band luminosities have lower [Fe/H] and older ages but similar abundance ratios compared to brighter galaxies.
Bulge Predictions in Steady State Bar Rolling Processes

A new algorithm for free surface corrections in Eulerian finite element computations is presented and applied to a steady state bar rolling process to predict lateral spread. A variety of rolling geometries are examined, including differing height to width ratios and reductions. The bulge profiles, as well as the maximum and mean bulge amounts, are compared in detail with experiments.
Quantum Computation with Hot and Cold Ions: An Assessment of Proposed Schemes

We present a brief critical review of the proposals for quantum computation with trapped ions, with particular emphasis on the schemes for quantum computation which relax the stringent requirements for maintaining the ions in the quantum ground state of their collective oscillatory modes.
An Automation Algorithm for Harvesting Capital Market Information from the Web

Purpose – The purpose of this paper is to develop an algorithm to harvest user specified information on finance portals and compile it into machine‐readable datasets for quantitative analysis.Design/methodology/approach – The Visual Basic macro language in Microsoft Excel is applied to develop code that is not constrained by the single‐query function of Excel. The core of the algorithm is built around the splitting of the URL connector line and the placement of a continuously updating variable into which are looped as many tickers as there are in the input list. The output is then written to non‐overlapping cells.Findings – Numerical information placed on major finance websites can be harvested into structured machine‐readable datasets by applying this algorithm.Research limitations/implications – One significant change in Microsoft Excel 2007 is that the worksheet is expanded from 224 to 234 cells, or to be more specific, from 256 (IV) columns × 65,536 rows (28 × 216) to 16,384 (XFD) × 1,048,576 (214 × 2...
Selective networks and recognition automata

The results we have presented demonstrate that a network based on a selective principle can function in the absence of forced learning or an a priori program to give recognition, classification, generalization, and association. While Darwin II is not a model of any actual nervous system, it does set out to solve one of the same problems that evolution had to solve--the need to form categories in a bottom-up manner from information in the environment, without incorporating the assumptions of any particular observer. The key features of the model that make this possible are (1) Darwin II incorporates selective networks whose initial specificities enable them to respond without instruction to unfamiliar stimuli; (2) degeneracy provides multiple possibilities of response to any one stimulus, at the same time providing functional redundancy against component failure; (3) the output of Darwin II is a pattern of response, making use of the simultaneous responses of multiple degenerate groups to avoid the need for very high specificity and the combinatorial disaster that would imply; (4) reentry within individual networks vitiates the limitations described by Minsky and Papert for a class of perceptual automata lacking such connections; and (5) reentry between intercommunicating networks with different functions gives rise to new functions, such as association, that either one alone could not display. The two kinds of network are roughly analogous to the two kinds of category formation that people use: Darwin, corresponding to the exemplar description of categories, and Wallace, corresponding to the probabilistic matching description of categories. These principles lead to a new class of pattern-recognizing machine of which Darwin II is just an example. There are a number of obvious extensions to this work that we are pursuing. These include giving Darwin II the capability to deal with stimuli that are in motion, an ability that probably precedes the ability of biological organisms to deal with stationary stimuli, giving it the capability to deal with multiple stimulus objects through some form of attentional mechanism, and giving it a means to respond directly and to receive feedback from the world so that it can learn conventionally. Already, however, we have shown that a working pattern-recognition automaton can be built based on a selective principle. This development promises ultimately to show us how to build recognizing machines without programs and to provide a sound basis for the study of both natural and artificial intelligence.
9-Carboranylcarbene by indirection

9-Carboranylcarbene is formed by reaction of carbon atoms with o-carborane. The triplet state reacts with alkenes by hydrogen abstraction, not the more usual addition reaction.
An Infinite Presentation of the Torelli Group

In this paper, we construct an infinite presentation of the Torelli subgroup of the mapping class group of a surface whose generators consist of the set of all “separating twists”, all “bounding pair maps”, and all “commutators of simply intersecting pairs” and whose relations all come from a short list of topological configurations of these generators on the surface. Aside from a few obvious ones, all of these relations come from a set of embeddings of groups derived from surface groups into the Torelli group. In the process of analyzing these embeddings, we derive a novel presentation for the fundamental group of a closed surface whose generating set is the set of all simple closed curves.
Average-Case Performance Analysis Of Online Non-Clairvoyant Scheduling Of Parallel Tasks With Precedence Constraints

We evaluate the average-case performance of three approximation algorithms for online non-clairvoyant scheduling of parallel tasks with precedence constraints. We show that for a class of wide task graphs, when task sizes are uniformly distributed in the range [1₀C], the online non-clairvoyant scheduling algorithm LL-SIMPLE has an asymptotic average-case performance bound of M/(M-(3-(1 + 1/C)C+1)C-1), where M is the number of processors. For uniform probability distributions of task sizes, we present numerical and simulation data to demonstrate the accuracy of our general asymptotic average-case performance bound. We also report extensive experimental results on the average-case performance of online non-clairvoyant scheduling algorithms LL-GREEDY and LS. Algorithm LL-GREEDY has better performance than LL-SIMPLE using an improved algorithm to schedule independent tasks in the same level. Algorithm LS produces even better schedules due to a break of boundaries among levels.
Biomolecular specificity controlled nanomaterial synthesis.

Biomolecules capable of fabricating complex nanomaterials with required functions in nature have been exploited to artificially control nanomaterial synthesis in all aspects. This tutorial review provides an overview of recent efforts in biomimetic synthesis and the relevant mechanistic studies on biomolecular specificities toward material surfaces. It starts with a discussion of the state-of-the-art progress in colloidal nanocrystal synthesis, wherein the importance of the interfacial control over nanoscale building blocks discloses the potential of exploiting biomolecular recognition properties in nanostructure synthesis. Continued discussions will review the progress in biomimetic syntheses of different classes of nanoscale materials. In vitro biomimetic syntheses with both biomolecules isolated from organisms and material-specific peptide sequences selected from combinatorial molecular evolution processes will be demonstrated. The final part of the review presents the recent research efforts and advances in understanding biomolecule–inorganic material interactions. It is believed that with continued experimental efforts and fundamental understanding of biomolecule–material interactions scientists can one day harvest the ability to rationally design molecules to produce intricate material structures with a similar level of sophistication, precision, and superior functions as those found in nature.
Exemplary programming in RITA

This paper describes the development of a RITA agent for Exemplary Programming (EP). The EP agent learns new facts and stores them in a data base and can learn new procedures for data manipulation. Both the EP agent and the programs it creates are written as sets of IF-THEN rules (production systems) in RITA: the Rule-directed Interactive Transaction Agent system. The programs produced by the EP agent act as "personal computer agents" to perform a variety of tasks for the user. Program creation is a cooperative effort between the user and the EP agent: the user illustrates what he wants done by performing a series of operations on the computer, and the agent watches and asks the user pertinent questions during the demonstration. The resulting program then becomes the user's personal computer agent for performing the given task.
Moduli Spaces of Modules of Schur-Tame Algebras

In this paper, we first show that for an acyclic gentle algebra A, the irreducible components of any moduli space of A-modules are products of projective spaces. Next, we show that the nice geometry of the moduli spaces of modules of an algebra does not imply the tameness of the representation type of the algebra in question. Finally, we place these results in the general context of moduli spaces of modules of Schur-tame algebras. More specifically, we show that for an arbitrary Schur-tame algebra A and 𝜃-stable irreducible component C of a module variety of A-modules, the moduli space $\mathcal {M}(C)^{ss}_{\theta }$ is either a point or a rational projective curve.
Mode coupling mechanism for late-time Kerr tails

We consider the decay rate for scalar fields in Kerr spacetime. We consider pure initial (azimuthal) multipoles ${\ensuremath{\ell}}^{\ensuremath{'}}$ with respect to the class that includes Boyer-Lindquist coordinates, and focus attention on the decay rate of the multipole $\ensuremath{\ell}$. We use an iterative method proposed by Gleiser, Price, and Pullin, and identify the mode-coupling mechanism through the iterations in powers of the square of the Kerr black hole's specific angular momentum that gives rise to a decay rate formula recently proposed by Zengino\ifmmode \breve{g}\else \u{g}\fi{}lu, Khanna, and Burko. Modes $\ensuremath{\ell}$ may be excited through different channels, each leading to its own decay rate. The asymptotic decay rate of the mode $\ensuremath{\ell}$ is the slowest of the decay rate of the various channels. In some cases, more than one channel leads to the same decay rate, and then the amplitude of the mode is the sum of the amplitudes of the partial fields generated by the individual channels. We also show that one may identify the asymptotically dominant channel of mode excitations and obtain approximate results for the mode of interest by studying the dominant channel. The results of the dominant channel approximation approach the full-mode results at late times, and their difference approaches zero quadratically in inverse time.
A δ-lactone synthesis involving an intramolecular 1,4-addition of α-iodoacetates to enones

Abstract A cyclization of δ-(iodoacetoxy)-α,β-unsaturated ketones using iodotrimethylsilane involved a selective 1,4-addition of the acetate subunit to the enone and furnished δ-lactones in good yield.
Cometary impacts with the Sun: Physical and dynamical considerations

Michels et al. (1982) observed the apparent impacting of the sun by a comet, and Sekanina (1982) showed that the comet, 1979XI, was probably a member of the Kreutz group of sun-grazing comets, although its perihelion of 0.35 solar radii was much smaller than the 1.2-1.9 solar radii common for this comet class. The perihelion change cannot be explained by planetary, stellar, or nongravitational perturbations. The most plausible explanation is collision with another body, probably a comet, at large heliocentric distance. The probability of such an event is, however, extremely small. The sublimation of the comet's nucleus before impact is discussed, and it is suggested that its ultimate destruction probably resulted from the shock of entry into the denser regions of the solar atmosphere, just above the photosphere.
Evaluation of the Universal Newborn Hearing Screening and Intervention Program

During the last 20 years, the number of infants evaluated for permanent hearing loss at birth has increased dramatically with universal newborn hearing screening and intervention (UNHSI) programs operating in all US states and many territories. One of the most urgent challenges of UNHSI programs involves loss to follow-up among families whose infants screen positive for hearing loss. We surveyed 55 state and territorial UNHSI programs and conducted site visits with 8 state programs to evaluate progress in reaching program goals and to identify barriers to successful follow-up. We conclude that programs have made great strides in screening infants for hearing loss, but barriers to linking families of infants who do not pass the screening to further follow-up remain. We identified 4 areas in which there were barriers to follow-up (lack of service-system capacity, lack of provider knowledge, challenges to families in obtaining services, and information gaps), as well as successful strategies used by some states to address barriers within each of these areas. We also identified 5 key areas for future program improvements: (1) improving data systems to support surveillance and follow-up activities; (2) ensuring that all infants have a medical home; (3) building capacity beyond identified providers; (4) developing family support services; and (5) promoting the importance of early detection.
Bounded Rationality in Individual Decision Making

The main objectives of this paper are: (i) To give a pithy, opinionated summary of what has been learned about bounded rationality in individual decision making from experiments in economics and psychology (drawing on my 1995 Handbook of Experimental Economics chapter); and (ii) mention some promising new directions for research which would be included if that chapter were written today.
Efficient Access to the Core of the Strychnos, Aspidosperma and Iboga Alkaloids. A Short Synthesis of Norfluorocurarine

An efficient anionic bicyclization of tryptamine-derived Zincke aldehydes forms the basis for a three-step route to the tetracyclic ABCE core of many Strychnos, Aspidosperma, and Iboga alkaloids. This powerful reaction is showcased in a five-step synthesis of the Strychnos alkaloid norfluorocurarine from tryptamine and pyridine.
Molecular Mechanisms of Failure in Polymer Nanocomposites

Molecular dynamics simulations of polymers reinforced with nanoscopic filler particles reveal the mechanisms by which nanofillers improve the toughness of the material. We find that the mobility of the nanofiller particle, rather than its surface area, controls its ability to dissipate energy. Our results show similarities between the toughening mechanisms observed in polymer nanocomposites and those postulated for biological structural materials such as spider silk and abalone adhesive.
Synthesis of 4,7-disubstituted spirobenzofuran-2(3H)-cyclohexanes

A general synthetic strategy was designed for the preparation of 7-substituted-4-methoxy- and 4-hydroxyspiro[benzofuran-2(3H)-cyclohexanes] 5 and 6 (Figure 1) using successive, regioselective hetero-atom-facilitated aromatic lithiation reactions and subsequent reaction with various electrophiles.
Conserved quantities in isotropic loop quantum cosmology

We develop an action principle for those models arising from isotropic loop quantum cosmology, and show that there is a natural conserved quantity Q for the discrete difference equation arising from the Hamiltonian constraint. This quantity Q relates the semi-classical limit of the wave function at large values of the spatial volume, but opposite triad orientations. Moreover, there is a similar quantity for generic difference equations of one parameter arising from a self-adjoint operator.
Sonoluminescence: nature’s smallest blackbody

The transduction of sound into light through the implosion of a bubble of gas leads to a flash of light whose duration is delineated in picoseconds. Combined measurements of spectral irradiance, Mie scattering, and flash width (as determined by time-correlated single-photon counting) suggest that sonoluminescence from hydrogen and noble-gas bubbles is radiation from a blackbody with temperatures ranging from 6000 KH2 to 20,000 K (He) and a surface of emission whose radius ranges from 0.1 μmHe to 0.4 μmXe. The state of matter that would admit photon–matter equilibrium under such conditions is a mystery.
Efficient and scalable compiler-directed energy optimization for realtime applications

With continuing shrinkage of technology feature sizes, the share of leakage in total energy consumption of digital systems continues to grow. Coordinated supply voltage and body bias throttling enables the compiler to better optimize the total energy consumption of the system in future technology nodes. We present a compilation technique that targets realtime applications running on embedded processors with combined dynamic voltage scaling (DVS) and adaptive body biasing (ABB) capabilities. Considering the delay and energy penalty of switching between operating modes of the processor, our compiler judiciously inserts mode-switch instructions in selected locations of the code and generates executable binary that is guaranteed to meet the deadline constraint. More importantly, our algorithm runs very fast and comes reasonably close to the theoretical limit of energy optimization using DVSpABB. At 65nm technology, we improve the energy dissipation of the generated code by an average of 33.20p under deadline constraints. While our technique's improvement in energy dissipation over conventional DVS is marginal (6.91p) at 130nm, the average improvement continues to grow to 13.19p, 22.97p, and 33.21p for 90nm, 65nm, and 45nm technology nodes, respectively. Compared to a recent ILP-based competitor, we improve the runtime by more than three orders of magnitude, while producing improved results.
Use of Arbitrary Quasi-Orthogonals for Calculating Flow Distribution in a Turbomachine

Arbitrary quasi-orthagonal method for calculating flow distribution in turbomachine suitable for computer programming
Accountabilities of presence: reframing location-based systems

How do mobility and presence feature as aspects of social life? Using a case study of paroled offenders tracked via Global Positioning System (GPS), we explore the ways that location-based technologies frame people's everyday experiences of space. In particular, we focus on how access and presence are negotiated outside of traditional conceptions of "privacy." We introduce the notion of accountabilities of presence and suggest that it is a more useful concept than "privacy" for understanding the relationship between presence and sociality.
A Simple Grand Unified Relation between Neutrino Mixing and Quark Mixing

It is proposed that all flavor mixing is caused by the mixing of the three quark and lepton families with vectorlike fermions in $ 5+\bar{5} $ multiplets of SU(5). This simple assumption implies that both V CKM and U M N S are generated by a single matrix. The entire 3 × 3 complex mass matrix of the neutrinos M v is then found to have a simple expression in terms of two complex parameters and an overall scale. Thus, all the presently unknown neutrino parameters are predicted. The best fits are for θ atm ≲ 40°. The leptonic Dirac CP phase is found to be somewhat greater than π.
New Results for an Asymmetric Rigid Body with Constant Body-Fixed Torques

The rotational motion of an asymmetric rigid body under the ine uence of constant body-e xed torque is investigated. A set of nondimensional equations of motion is introduced for the stability analysis of equilibrium points. In particular, three-dimensional phase space trajectories are developed for two different cases: 1 ) constant torque along the major or minor axis and 2 ) constant torque along the intermediate axis. For both cases, some new analytical as well as simulation results are presented in terms of equilibrium manifolds, separatrix surfaces, periodic or nonperiodic solutions, and extrema of the periodic solutions.
Diassociativity in Conjugacy Closed Loops

Abstract Let Q be a conjugacy closed loop, and N(Q) its nucleus. Then Z(N(Q)) contains all associators of elements of Q. If in addition Q is diassociative (i.e., an extra loop), then all these associators have order 2. If Q is power-associative and |Q| is finite and relatively prime to 6, then Q is a group. If Q is a finite non-associative extra loop, then 16 ∣ |Q|.
Current Experimental Basis for Modeling Ice Accretions on Swept Wings

This work presents a review of the experimental basis for modeling ice accretions on swept wings. Experimental work related to ice accretion physics on swept wings conducted between 1954 and 2004 is reviewed. Proposed models or explanations of scallop formations are singled out and discussed. Special emphasis is placed on reviewing the work done to determine the basic macroscopic mechanisms of scallop formation. The role of feather growth and its connection to scallop growth is discussed. Conceptual steps in modeling scallop formations are presented. Research elements needed for modeling are discussed.
Gauge principles for multi-superparticles

Abstract We formulate new gauge principles for n supersymmetric particles in a worldline formalism with N supersymmetries. The models provide realizations of the more general supersymmetries that are encountered in sectors of S-theory or Matrix theory, with a superalgebra of the form Q α A ,Q β B =δ AB γ αβ μ 1 ⋯μ n (p μ 1 1 ⋯p μ n n ). Due to the local gauge and kappa symmetries the n superparticle momenta p iμ and N supercharges Q α A are constrained by p i · p j =0 and γ · p i Q A =0. The constraints have solutions only in a space with n timelike dimensions and SO d+n−2,n spacetime symmetry. The cases SO(9,1), SO(10,2) and SO(10,3), with one, two and three timelike dimensions respectively, are of special interest. In each case, due to the constraints, the classical motion and quantum theory of each superparticle are equivalent to the physics with a single time-like dimension in an effective 10D superspace with SO 9,1 Lorentz symmetry.
Tracking and pointing maneuvers with slew-excited deformation shaping

It is shown in this paper how it is possible to shape the slew-excited structural response of a deformable vehicle undergoing agile attitude maneuvers, so that the required fully corrected slew torque profiles can be computed on-line in closed form, and with the same bandwidth as required for the rigid body case. This is accomplished by simultaneously applying maneuver-dependent structural force controls of progressively smaller amplitudes, at the cost of progressively higher signal processing complexity of slew torque and structural force command generation.
Can a pseudo-symmetry solve the cosmological constant problem?

Abstract A general no-go theorem dampens hope that the cosmological constant problem can be solved by a local symmetry mechanism. The possibility is considered here that this no-go theorem can be avoided by a pseudo-symmetry. A simple macroscopic effective field theory is constructed which admits an enhanced pseudo-symmetry in the absence of a cosmological term. It is pointed out that this pseudo-symmetry is an exact classical invariance of superstrings. The conjecture that this pseudo-symmetry survives in the quantum theory has several interesting consequences.
NEW MULTICATEGORY BOOSTING ALGORITHMS BASED ON MULTICATEGORY FISHER-CONSISTENT LOSSES

Fisher-consistent loss functions play a fundamental role in the construction of successful binary margin-based classifiers. In this paper we establish the Fisher-consistency condition for multicategory classification problems. Our approach uses the margin vector concept which can be regarded as a multicategory generalization of the binary margin. We characterize a wide class of smooth convex loss functions that are Fisher-consistent for multicategory classification. We then consider using the margin-vector-based loss functions to derive multicategory boosting algorithms. In particular, we derive two new multicategory boosting algorithms by using the exponential and logistic regression losses.
Locating Supreme Court Opinions in Doctrine Space

We develop a scaling model to estimate U.S. Supreme Court opinion locations and justice ideal points along a common spatial dimension using data derived from the citations between opinions. Citations from new opinions to precedent opinions usually apply and endorse the doctrine of the precedent opinion; however, sometimes they implicitly or explicitly dispute the precedent opinion. We collect original datasets classifying citations from search and seizure and freedom of religion opinions written between 1953 and 2006 into these different types and develop a model relating the similarity of the doctrine embodied in the citing and cited opinions to the relative probability of these different types of citations. The resulting spatial estimates of opinion location are used to evaluate theories of Supreme Court bargaining and opinion writing. We find empirical support for theoretical models that predict the majority opinion will fall at the ideal point of the median member of the majority coalition. Given the centrality of theories of judicial policymaking to various substantive problems in political science, the method of scaling opinions developed in this article can facilitate a range of future research.
Atmospheric tar balls from biomass burning in Mexico

[1] Atmospheric tar balls (TBs) are spherical, organic aerosol particles that occur in smoke from biomass burning (BB). They absorb sunlight and thereby cause warming of the atmosphere. This study reports a transmission electron microscope (TEM) study of TBs from BB smoke samples collected within minutes to hours from emission in a tropical area of Mexico. Their spherical shapes as seen in both scanning electron microscope images and with electron tomography indicate that they were solid when collected. They consist of C and minor O, S, K, and N. The hygroscopic growth factor for our relatively fresh TBs is 1.09 ± 0.04 at a relative humidity of 100%. In samples 1.6 km from the fire, an average of ∼1 and 14%, respectively, of particles with aerodynamic diameter from 50 to 300 nm consisted of TBs. For the latter, more aged samples, the total volume was roughly double that of soot, and their total calculated light absorption at a wavelength of 550 nm was between 74 and 96% that of soot, with the exact amount depending on the size, shape, and coating of the soot. In general, the TBs that we analyzed were similar to those from North America, southern Africa, and Europe in terms of size, external mixing, relative freedom of inclusions, and composition. This and previous studies show that TBs result from a range of biomass fuels. Their distribution from various regions across the globe, combined with their optical properties, suggests they have important effects on regional and perhaps global climate.
Relativistic formulation of reaction theory

A relativistic formulation of reaction theory for nuclei with a dynamics given by a unitary representation of the Poincare group is developed. Relativistic dynamics is introduced by starting from a relativistic theory of free particles to which rotationally invariant interactions are added to the invariant mass operator. Poincare invariance is realized by requiring that simultaneous eigenstates of the mass and spin transform as irreducible representations of the Poincare group. A relativistic formulation of scattering theory is presented and approximations emphasizing dominant degrees of freedom that preserve unitarity, exact Poincare invariance and exchange symmetry are discussed. A Poincare invariant formulation of a (d,p) reaction as a three-body problem is given as an explicit example.
Restoration of Gamma Globulin Production in Agammaglobulinemic Chickens

Chickens irradiated and bursectomized in the newly hatched period consistently develop agammaglobulinemia and form no circulating antibodies; if the birds are treated immediately after operations by intra-abdominal injection of unirradiated autologous bursa cells, immunoglobulin production, lymphoid germinal centers, and plasma cells are restored; however, the birds fail to produce antibody to specific antigenic challenge.
The K and L Absorption and Emission Spectra of Tungsten

Both the absorption and emission spectra were photographed simultaneously on the same plate, using a special float-operated mechanism to turn the crystal very slowly so as to obtain the faint lines between ${\ensuremath{\beta}}_{2}$ and ${\ensuremath{\beta}}_{5}$. The absorption wave-lengths were found to be: L${\mathrm{A}}_{1}$, 1.2122A; L${\mathrm{A}}_{2}$, 1.0716A; L${\mathrm{A}}_{3}$, 1.0217A; KA,.17802A. Table I gives the emission wave-lengths of 28 L emission lines including the four new lines ${\ensuremath{\beta}}_{15}$ (1.2432), ${\ensuremath{\beta}}_{16}$ (1.2166), ${\ensuremath{\gamma}}_{12}$ (1.0748) and n (1.0699), and of the $\mathrm{K}{\ensuremath{\beta}}_{3}$ line (.18525) which is the line found by DeBroglie. Comparison with the Bohr theory. The agreement of the emission frequencies computed from the energy levels with the measured wave-lengths is better than 1/10 per cent, except for ${\ensuremath{\beta}}_{15}$ and ${\ensuremath{\beta}}_{16}$. The lines ${\ensuremath{\beta}}_{10}$, ${\ensuremath{\beta}}_{9}$, ${\ensuremath{\gamma}}_{12}$, and ${\ensuremath{\gamma}}_{11}$, however, correspond to transitions between energy levels which are not predicted by the selection principle, and lines ${\ensuremath{\beta}}_{8}$ and n are not in agreement with the accepted energy levels. While Ln may be due to an impurity, ${\ensuremath{\beta}}_{8}$ is probably a tungsten line.
Foreshock sequences and short-term earthquake predictability on East Pacific Rise transform faults

East Pacific Rise transform faults are characterized by high slip rates (more than ten centimetres a year), predominately aseismic slip and maximum earthquake magnitudes of about 6.5. Using recordings from a hydroacoustic array deployed by the National Oceanic and Atmospheric Administration, we show here that East Pacific Rise transform faults also have a low number of aftershocks and high foreshock rates compared to continental strike-slip faults. The high ratio of foreshocks to aftershocks implies that such transform-fault seismicity cannot be explained by seismic triggering models in which there is no fundamental distinction between foreshocks, mainshocks and aftershocks. The foreshock sequences on East Pacific Rise transform faults can be used to predict (retrospectively) earthquakes of magnitude 5.4 or greater, in narrow spatial and temporal windows and with a high probability gain. The predictability of such transform earthquakes is consistent with a model in which slow slip transients trigger earthquakes, enrich their low-frequency radiation and accommodate much of the aseismic plate motion.
Strategic Formation of Credit Networks

Credit networks are an abstraction for modeling trust among agents in a network. Agents who do not directly trust each other can transact through exchange of IOUs (obligations) along a chain of trust in the network. Credit networks are robust to intrusion, can enable transactions between strangers in exchange economies, and have the liquidity to support a high rate of transactions. We study the formation of such networks when agents strategically decide how much credit to extend each other. We find strong positive network formation results for the simplest theoretical model. When each agent trusts a fixed set of other agents and transacts directly only with those it trusts, all pure-strategy Nash equilibria are social optima. However, when we allow transactions over longer paths, the price of anarchy may be unbounded. On the positive side, when agents have a shared belief about the trustworthiness of each agent, simple greedy dynamics quickly converge to a star-shaped network, which is a social optimum. Similar star-like structures are found in equilibria of heuristic strategies found via simulation studies. In addition, we simulate environments where agents may have varying information about each others’ trustworthiness based on their distance in a social network. Empirical game analysis of these scenarios suggests that star structures arise only when defaults are relatively rare, and otherwise, credit tends to be issued over short social distances conforming to the locality of information. Overall, we find that networks formed by self-interested agents achieve a high fraction of available value, as long as this potential value is large enough to enable any network to form.
Exchange rate regimes and international market segmentation: Evidence from pricing effects of international listings

This study analyzes stock price reactions to listings of foreign stocks in the U.S. before and after the dismantling of the fixed exchange rate system resulting from the Smithsonian agreement of 1971. Listings during the fixed exchange rate regime had significantly greater abnormal returns than those during the floating exchange rate regime. The results are consistent with the notion that a switch to the floating exchange rate system enhanced integration in the international capital markets. A similar conclusion is drawn from the results obtained in testing the law of one price which is observed to hold immediately following the listings during the floating exchange rate regime. Our findings suggest that government controls are a source of segmentation in international markets, and their removal leads to a more integrated market. No evidence was found to suggest that non-Canadian markets are less integrated with the U.S. market than is the Canadian market with the U.S. market, nor was any differential price reaction observed between listings on NYSE/AMEX and OTC markets. However, the difference in price reaction between listings of sponsored and non-sponsored American Depository Receipts was positive and significant.
The status of strange meson spectroscopy

Abstract The present status of strange meson spectroscopy is reviewed with emphasis on the results obtained with the LASS spectrometer at SLAC. The systematics of the level structure are discussed with respect to quark model expectations, and the impact of the proposed KAON Factory on the future of the subject considered.
An optimization model for location of subsidized housing in metropolitan areas

Abstract This paper presents an optimization model for evaluation of alternative spatial configurations of rent-subsidized housing in a large metropolitan area as well as associated monetary and nonmonetary impacts. Groups affected by these configurations include residents of subsidized housing, owners of nearby single-family housing, employers and society at large. Since impacts of subsidized housing are very localized, the first stage of the model creates potential location patterns for many small geographic areas. The second stage of the model uses local benefits to derive a location scheme for the metropolitan area which balances net social benefit with equity considerations of the geographical impact of subsidized housing. We apply this methodology to a small region in metropolitan Chicago and demonstrate alternative location schemes.
Mechanisms of Interannual Variations of the Meridional Overturning Circulation of the North Atlantic Ocean

The authors investigate the nature of the interannual variability of the meridional overturning circulation (MOC) of the North Atlantic Ocean using an Estimating the Circulation and Climate of the Ocean (ECCO) assimilation product for the period of 1993-2003. The time series of the first empirical orthogonal function of the MOC is found to be correlated with the North Atlantic Oscillation (NAO) index, while the associated circulation anomalies correspond to cells extending over the full ocean depth. Model sensitivity experiments suggest that the wind is responsible for most of this interannual variability, at least south of 40(deg)N. A dynamical decomposition of the meridional streamfunction allows a further look into the mechanisms. In particular, the contributions associated with 1) the Ekman flow and its depth-independent compensation, 2) the vertical shear flow, and 3) the barotropic gyre flowing over zonally varying topography are examined. Ekman processes are found to dominate the shorter time scales (1.5-3 yr), while for longer time scales (3-10 yr) the MOC variations associated with vertical shear flow are of greater importance. The latter is primarily caused by heaving of the pycnocline in the western subtropics associated with the stronger wind forcing. Finally, how these changes in the MOC affect the meridional heat transport (MHT) is examined. It is found that overall, Ekman processes explain a larger part of interannual variability (3-10 yr) for MHT (57%) than for the MOC (33%).
Synthesis and characterization of the new 22-π aromatic furan-containing macrocycle, “ozaphyrin”

The new 22-π, aromatic “pentaplanar” macrocycle, ozaphyrin (6), has been synthesized by a McMurry coupling of 5,5′-diformyl-4,4′-dipropyl-2,2′-bipyrrole (1) with 2,5-bis(5-formyl-4-propyl-2-pyrrolyl)furan (5). This synthetic pathway to ozaphyrin and its characterization by 1H nmr spectroscopy, uv-visible spectroscopy, cyclic voltammetry, and X-ray crystallography are described. The structure consists of layers of planar, staggered macrocycles stacked perpendicular to the α-axis. Ozaphyrin crystallizes with four formula units in the monoclinic space group C52h-P21/n in a cell of dimensions a = 10.481(7) A, b = 17.353(17) A, c = 18.726(12) A, and β = 102.84(5)° (108 K). The structure has been refined on F2 (5171 unique reflections, 411 variables) to Rw(Fo2) = 0.165. The conventional agreement index R(F) is 0.074 for the 3289 reflections have Fo2>2o(Fo2).
Distributed decision fusion using empirical estimation

The problem of optimal data fusion in multiple detection systems is studied in the case where training examples are available, but no a priori information is available about the probability distributions of errors committed by the individual detectors. Earlier solutions to this problem require some knowledge of the error distributions of the detectors, for example, either in a parametric form or in a closed analytical form. Here we show that, given a sufficiently large training sample, an optimal fusion rule can be implemented with an arbitrary level of confidence. We first consider the classical cases of Bayesian rule and Neyman-Pearson test for a system of independent detectors. Then we show a general result that any test function with a suitable Lipschitz property can be implemented with arbitrary precision, based on a training sample whose size is a function of the Lipschitz constant, number of parameters, and empirical measures. The general case subsumes the cases of nonindependent and correlated detectors.
Operational characteristics of microfabricated electric motors

Abstract We report on the operational characteristics of LOCOS-based microfabricated radial-gap electric motors through lifetime tests, transient measurements, modeling, and parameter extraction. We have found that the reduction of static friction (stiction) in the bearings by the incorporation of a silicon nitride film permits these micromotors to spin in normal air ambients. Frictional drag from the bearing, which results from the electric-based side-pull of the rotor, is found to be the dominant rotor-retarding force and to lead to motor wearout after approximately 10 000 rotor revolutions. Furthermore, the frictional coefficient of the nitride-on-polysilicon micromotor bearing is determined to be 0.36 ± 0.04.
Effects of bailouts, taxes, and risk-aversion on the enterprise

Abstract The paper analyzes a model in which the firm's output is stochastic and in which the manager receives subsidies if his operating profit is negative and is taxed in the converse case. The amount of the subsidy may depend on the amount of managerial labor expended on securing favorable treatment by the Center. Expected-profit maximization yields the result that input use is at least as great as that in the standard competitive case if the subsidy rate exceeds the tax rate. In various special cases, however, the solution under bailouts may coincide with the standard competitive case. The comparative statics of the model are analyzed and the results are extended to (1) the balanced budget case, in which the Center's expected tax receipts are equal to the expected subsidies it disburses and (2) the case in which the manager is riskaverse.
Effects of hypothermia on ionic movement in the guinea pig cochlea.

Abstract Anesthetized and immobilized guinea pigs were subjected to hypothermia. During cooling, the cochlea: microphonics and endocochlear potential decreased and K+ concentrations in both endolymph and perilymph were not significantly affected. The rate constant for K+ turnover to endolymph was determined by uptake of 43K into the endolymph when the perilymphatic space was perfused with artificial perilymph containing 43K. The rate constant for K+ decreased significantly in hypothermic guinea pigs when compared with that in normal guinea pigs. The K+ conductance of the endolymph-perilymph barrier, estimated from the rate constant, showed a marked decrease in hypothermic guinea pigs and was comparable with the K conductance, calculated from the rate of change of the endolymph K+ concentration relative to the K+ electrochemical potential difference, recorded during permanent anoxia. These results suggest that hypothermia not only suppresses the active K+ transport system but also decreases the K+ permeability of the endolymph-perilymph barrier.
Allan V. Cox: AGU President 1978”1980

When Allan V. Cox was presented AGU's John Adam Fleming Medal in 1969, John Verhoogen described Cox's work as “characterized by painstaking care, proper attention to and use of statistics, and great insight.” Those same thoughts were echoed on February 3, 1987, during the memorial service for Cox, who died in a bicycling accident on January 27. The Stanford Memorial Church was crowded with colleagues, students, and friends. The Fleming Medal was presented to Cox in recognition of his studies on the fluctuation of the geomagnetic field. These studies helped to confirm theories of continental drift and seafloor spreading. The medal is awarded annually by AGU for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, and related sciences. In addition to the Fleming Medal, Cox received the Antarctic Service Medal in 1970, the Vetlesen Prize in 1971, and the Arthur L. Day Prize of the National Academy of Sciences in 1984. He was a Fellow of AGU and a member of the National Academy of Sciences.
Towards a modular approach for heparin synthesis

Trisaccharide 23 and sulfated disaccharide 28 have been prepared by a strategy whereby the glucuronic acid moieties were introduced at a late stage of a synthetic sequence by selective oxidation of primary hydroxy groups with TEMPO and NaOCl. During the oxidation step, the primary hydroxy groups of glucosamine moieties were efficiently protected as TBDPS ethers. The oxidation procedure and removal of the TBDPS groups proved to be compatible with the presence of sulfate esters.