cssi/SciSciGPT-SciSciNet huggingface dataset:
Measuring the Determinants of School Completion in Pakistan: Analysis of Censoring and Selection Bias.

Abstract This paper explores the demand for child schooling in Pakistan, using the Pakistan Integrated Household Survey (1991). There have been few such studies for Pakistan, a country with relatively low enrollment rates and education levels, high illiteracy, and a large disparity between male and female education. Additionally, this study focuses on two potential sources of bias in the estimation of the demand for schooling. First, studies that do not distinguish between currently enrolled children and those who have completed their schooling subject their estimates to a form of censoring bias. Second, studies that exclude children who have left the household from their samples may introduce sample selection bias if the decisions to leave home and to attend school are related. This study finds evidence of both “censoring” and “sample selection” bias in the demand for child schooling in Pakistan.
Enabling rapid development of parallel tree search applications

Virtual observatories will give astronomers easy access to anunprecedented amount of data. Extracting scientific knowledge from these data will increasingly demand both efficient algorithms as well as the power of parallel computers. Nearly all efficient analyses of large astronomical datasets use trees as their fundamental data structure. Writing efficient tree-based techniques, a task that is time-consuming even on single-processor computers, is exceedingly cumbersome on massively parallel platforms (MPPs). Most applications that run on MPPs are simulation codes, since the expense of developing them is offset by the fact that they will be used for many years by many researchers. In contrast, data analysis codes change far more rapidly, are often unique to individual researchers, and therefore accommodate little reuse. Consequently, the economics of the current high-performance computing development paradigm for MPPs does not favor data analysis applications. We have therefore built a library, called Ntropy, that provides a flexible, extensible, and easy-to-use way of developing tree-based data analysis algorithms for both serial and parallel platforms. Our experience has shown that not only does our library save development time, it can also deliver excellent serial performance and parallel scalability. Furthermore, Ntropy makes it easy for an astronomer with little or noparallel programming experience to quickly scale their application to a distributed multiprocessor environment. By minimizing development time for efficient and scalable data analysis, we enable wide-scale knowledge discovery on massive datasets.
Radical Induced Cyclopropane Fragmentation—H-Abstraction—Cyclization Cascade: Synthesis of Carbocyclic Systems Containing Bridgehead Methyl Groups

Abstract The intramolecular hydrogen abstraction by an alkyl radical has been exploited for the first time in a synthetically useful tandem sequence that gives rise to cis-fused bicyclic systems carrying bridgehead methyl groups, a structural feature found in numerous natural products. © 1997 Elsevier Science Ltd.
Synthesis of 2,3-disubstituted benzo[b]thiophenes via palladium-catalyzed coupling and electrophilic cyclization of terminal acetylenes.

2,3-Disubstituted benzo[b]thiophenes have been prepared in excellent yields via coupling of terminal acetylenes with commercially available o-iodothioanisole in the presence of a palladium catalyst and subsequent electrophilic cyclization of the resulting o-(1-alkynyl)thioanisole derivatives. I2, Br2, NBS, p-O2NC6H4SCl, and PhSeCl have been utilized as electrophiles. Aryl-, vinyl-, and alkyl-substituted terminal acetylenes undergo this coupling and cyclization to produce excellent yields of benzo[b]thiophenes. (Trimethylsilyl)acetylene also undergoes this coupling/cyclization process with I2, NBS, and the sulfur and selenium electrophiles to afford the corresponding 2-(trimethylsilyl)benzo[b]thiophenes. However, cyclization of the silyl-containing thioanisole using Br2 affords 2,3-dibromobenzo[b]thiophene.
Deterministic separation of cancer cells from blood at 10 mL/min

Circulating tumor cells (CTCs) and circulating clusters of cancer and stromal cells have been identified in the blood of patients with malignant cancer and can be used as a diagnostic for disease severity, assess the efficacy of different treatment strategies and possibly determine the eventual location of metastatic invasions for possible treatment. There is thus a critical need to isolate, propagate and characterize viable CTCs and clusters of cancer cells with their associated stroma cells. Here, we present a microfluidic device for mL/min flow rate, continuous-flow capture of viable CTCs from blood using deterministic lateral displacement (DLD) arrays. We show here that a DLD array device can isolate CTCs from blood with capture efficiency greater than 85% CTCs at volumetric flow rates of up to 10 mL/min with no effect on cell viability.
Electrostatic properties of PE and PTFE subjected to atmospheric pressure plasma treatment; correlation of experimental results with atomistic modeling

Abstract The use of an atmospheric pressure glow discharge (APGD) plasma was used at Kennedy Space Center (KSC) to increase the hydrophilicity of spaceport materials to enhance their surface charge dissipation and prevent possible electrostatic discharge (ESD) in spaceport operations. Significant decreases in charge decay times were observed after tribocharging the materials using the standard KSC tribocharging test. The polarity and amount of charge transferred was dependant upon the effective work function differences between the respective materials. In this study, PE and PTFE were exposed to a He+O 2 APGD. The pre and post-treatment surface chemistries were analyzed by X-ray photoelectron spectroscopy and contact angle measurements. Semi-empirical and ab initio calculations were performed to correlate the experimental results with some plausible molecular and electronic structure features of the oxidation process. For the PE, significant surface oxidation was observed, as indicated by XPS showing C–O, C O, and O–C O bonding, and a decrease in the surface contact angle from 98.9° to 61.2°. For the PTFE, no C–O bonding appeared and the surface contact angle increased indicating the APGD only succeeded in cleaning the PTFE surface without affecting the surface structure. The calculations using the Parametric Method 3 (PM3) and Density Function Theory (DFT) methods were performed on single and multiple oligomers to simulate a wide variety of oxidation scenarios. Calculated work function results suggest that regardless of oxidation mechanism, e.g. –OH, O or a combination thereof, the experimentally observed levels of surface oxidation are unlikely to lead to a significant change in the electronic structure of PE and that its increased hydrophilic properties are the primary reason for the observed changes in its electrostatic behavior. The calculations for PTFE argue strongly against significant oxidation of that material, as confirmed by the XPS results.
Assessing and managing medically fragile children: tracheostomy and ventilatory support.

Over the past decade, there has been an increase in premature births. Children born prematurely often present with complex medical conditions; some require a tracheostomy. Although many children wi...
Diffusive Acceleration at the Blunt Termination Shock

Voyager 1's recent and long-anticipated passage into the heliosheath contradicted the prediction that we would observe the source of anomalous cosmic rays accelerated by the termination shock. The observed energetic protons reveal a power-law spectrum below several MeV, but above several MeV the spectrum falls more sharply, and we observe the familiar bump caused by modulation of anomalous cosmic rays. This paper develops the theoretical framework to include the motions and drift of particles during diffusive shock acceleration at a three-dimensional (3-D) termination shock, including cross-field diffusion, and curvature and gradient drifts. Our model supports the concept of McComas and Schwadron that because of the termination shock's blunt structure with a strong nose-to-tail asymmetry, there should be a strong deficit of locally accelerated anomalous cosmic rays (ACRs) near the nose. With reasonable parameters for the scattering mean free path and the ratio of perpendicular to parallel diffusion, the model produces an energy spectrum that agrees well with the Voyager 1 observations near the termination shock. These parameters also lead to an acceleration time to 10 MeV of about 1 yr, which is comparable to previous estimates derived from the observed charge states of ACRs. Thus, we provide a theory for diffusive acceleration at the blunt termination shock. The predictions of this theory are consistent with Voyager 1's observations, showing a lack of ACRs accelerated near the nose of the termination shock and the ACR acceleration timescale derived from ACR charge states.
Efficient algorithms for inverting evolution

Evolution can be mathematically modelled by a stochastic process that operates on the DNA of species. Such models are based on the established theory that the DNA sequences, or genomes, of all extant species have been derived from the genome of the common ancestor of all species by a process of random mutation and natural selection.A stochastic model of evolution can be used to construct phylogenies, or evolutionary trees, for a set of species. Maximum Likelihood Estimation (MLE) methods seek the evolutionary tree which is most likely to have produced the DNA under consideration. While these methods are intellectually satisfying, they have not been widely accepted because of their computational intractability.In this paper, we address the intractability of MLE methods as follows: We introduce a metric on stochastic process models of evolution. We show that this metric is meaningful by proving that in order for any algorithm to distinguish between two stochastic models that are close according to this metric, it needs to be given many observations. We complement this result with a simple and efficient algorithm for inverting the stochastic process of evolution, that is, for building a tree from observations on two-state characters. (We will use the same techniques in a subsequent paper to solve the problem for multistate characters, and hence for building a tree from DNA sequence data.) The tree we build is provably close, in our metric, to the tree generating the data and gets closer as more observations become available.Though there have been many heuristics suggested for the problem of finding good approximations to the most likely tree, our algorithm is the first one with a guaranteed convergence rate, and further, this rate is within a polynomial of the lower-bound rate we establish. Ours is also the first polynomial-time algorithm that is proven to converge at all to the correct tree.
Mono- and Dibridged Isomers of Si2H3 and Si2H4: the True Ground State Global Minima. Theory and Experiment in Concert

Highly correlated ab initio coupled-cluster theories (e.g., CCSD(T), CCSDT) were applied on the ground electronic states of Si2H3 and Si2H4, with substantive basis sets. A total of 10 isomers, which include mono- and dibridged structures, were investigated. Scalar relativistic corrections and zero-point vibrational energy corrections were included to predict reliable energetics. For Si2H3, we predict an unanticipated monobridged H2Si−H−Si-like structure (Cs, 2A‘ ‘) to be the lowest energy isomer, in constrast to previous studies which concluded that either H3Si−Si (Cs, 2A‘ ‘) or near-planar H2Si−SiH (C1, 2A) is the global minimum. Our results confirm that the disilene isomer, H2Si−SiH2, is the lowest energy isomer for Si2H4 and that it has a trans-bent structure (C2h, 1Ag). In addition to the much studied silylsilylene, H3Si−SiH, we also find that a new monobridged isomer H2Si−H−SiH (C1, 1A, designated 2c) is a minimum on the potential energy surface and that it has comparable stability; both isomers are ...
Combined Geometrical And Optical Transforms For Invariant Processing

Space variant image processing using combined geometrical transformations and optical transforms is discussed, whereby the flexibility of an optical processor is enhanced. Use of computer generated hologram masks to effect the geometric transforms is emphasized.© (1977) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Hilbert–Schmidt Hankel Operators with Anti-holomorphic Symbols on Complex Ellipsoids

On a complex ellipsoid in \({\mathbb{C}^n}\) , we show that there is no nonzero Hankel operator with an anti-holomorphic symbol that is Hilbert–Schmidt.
The structure of the scaffold nucleoporin Nup120 reveals a new and unexpected domain architecture

Nucleocytoplasmic transport is mediated by nuclear pore complexes (NPCs), enormous protein assemblies residing in circular openings in the nuclear envelope. The NPC is modular, with transient and stable components. The stable core is essentially built from two multiprotein complexes, the Y-shaped heptameric Nup84 complex and the Nic96 complex, arranged around an eightfold axis. We present the crystal structure of Nup120(1-757), one of the two short arms of the Y-shaped Nup84 complex. The protein adopts a compact oval shape built around a novel bipartite alpha-helical domain intimately integrated with a beta-propeller domain. The domain arrangement is substantially different from the Nup85*Seh1 complex, which forms the other short arm of the Y. With the data presented here, we establish that all three branches of the Y-shaped Nup84 complex are tightly connected by helical interactions and that the beta-propellers likely form interaction site(s) to neighboring complexes.
General qubit errors cannot be corrected

Error correction in the standard meaning of the term implies the ability to correct all small analog errors and some large errors. Examining assumptions at the basis of the recently proposed quantum error-correcting codes, it is pointed out that these codes can correct only a subset of errors, and are unable to correct small phase errors which can have disastrous consequences for a quantum computation. This shortcomings will restrict their usefulness in real applications.
What can we learn from revisions to the Greenbook forecasts

Abstract Although there have been many evaluations of the Federal Reserve’s Greenbook forecasts, we analyze them in a different dimension. We examine the revisions of these forecasts in the context of fixed event predictions to determine how new information is incorporated in the forecasting process. This analysis permits us to determine if there was an inefficient use of information in the sense that the forecast revision has predictive power for the forecast error. Research on forecast smoothing suggests that we might find a positive relationship between the forecast error and the forecast revision. Although we do find for some variables and horizons the Fed’s forecast errors are predictable from its forecast revisions, there is no evidence of forecast smoothing. Instead the revisions sometimes have a negative relationship with the forecast error, suggesting in these cases that the Fed may be over-responsive to new information.
Theoretical Insights into Photoinduced Charge Transfer and Catalysis at Oxide Interfaces

Review: emphasis on processes that are essential in terms of photovoltaic and photocatlytic cells; 655 refs.
Thermal activation rates in the chirally asymmetric Gross-Neveu model.

Abstract We address the problem of how to incorporate quantum effects into the calculation of finite-temperature decay rates for a metastable state of a quantum field theory. To do this, we consider the Gross-Neveu model with an explicit chiral symmetry breaking term, which allows for a metastable state. This theory can be shown to have a “critical bubble” which is a solution to the exact equations of motions (i.e. to all orders in perturbation theory, including all higher derivative, quantum and thermal corrections). This configuration mediates the thermal activation of the metastable vacuum to the true ground state, with a decay rate Γ ∞ exp(− F c / T ), where F c is the free energy of the critical bubble. We then compare this exact calculation to various approximations that have been used in previous work. We find that these approximations all overestimate the activation rate. Furthermore, we study the effect of finite baryon number upon the bubble profile and the activation barriers. We find that beyond a critical baryon number the activation barriers disappear altogether.
Characteristic Length and Dynamic Time Scale Associated with Aircraft Pitching Motion

The 5 % -static-margin requirement once used by the military has been removed in favor of dynamic requirements. However, static margin is still commonly used as a preliminary guideline for establishing adequate pitch stability in piloted airplanes. Here, a dynamic margin is defined to be the distance that the airplane's stick-fixed maneuver point lies aft of the center of gravity, expressed as a fraction of the pitch radius of gyration. A proposed minimum-dynamic-margin constraint is shown to agree with the short-period-frequency requirements used in recent military specifications to an accuracy of about 2%.For some airplanes, this stability constraint is shown to differ from the 5 % -minimum-static-margin guideline by more than 400%. Two worked examples are presented, which demonstrate the significance of the proposed dynamic-margin constraint.
Parity-induced Selmer growth for symplectic, ordinary families

Abstract Let p be an odd prime, and let K / K 0 be a quadratic extension of number fields. Denote by K ± the maximal Z p -power extensions of K that are Galois over K 0 , with K + abelian over K 0 and K − dihedral over K 0 . In this paper we show that for a Galois representation over K 0 satisfying certain hypotheses, if it has odd Selmer rank over K then for one of K ± its Selmer rank over L is bounded below by [ L : K ] for L ranging over the finite subextensions of K in K ± . Our method of proof generalizes a method of Mazur and Rubin, building upon results of Nekovař, and applies to abelian varieties of arbitrary dimension, (self-dual twists of) modular forms of even weight, and (twisted) Hida families.
MNCs and micro-entrepreneurship in emerging economies: The case of Avon in the Amazon

Abstract This article examines the activities of multinational corporations (MNCs) in the direct sales industry through an ethnographic case study of micro-entrepreneurship in the Brazilian Amazon. In large emerging economies, intra-country heterogeneity poses challenges for MNCs. Because national trends often obscure regional variations, the case study highlights the realities of the rural Amazon, and the specific challenges and potential for MNCs. Findings from the case study support three propositions. The development of direct sales networks in remote areas facilitates: (1) additional entrepreneurship, and encourages a progression from necessity to opportunity entrepreneurship; (2) social change in gender norms, including higher level of female empowerment and decision-making within families and communities; and (3) a reconciliation of local and global values on beauty and fashion for customers, leading to stronger brand relationships. By leveraging micro-entrepreneurship, MNCs can compete with local firms, even in rural areas lacking basic infrastructure, to the benefit of communities and individuals.
Investment and Monetary Policy: Learning and Determinacy of Equilibrium

We explore determinacy and expectational stability (learnability) of rational expectations equilibrium (REE) in New Keynesian (NK) models that include capital. Using a consistent calibration across three different models—labor-only, firm-specific capital, or an economy-wide rental market for capital, we provide a clear picture of when REE is determinate and learnable and when it is not under a variety of monetary policy rules. Our findings make a case for greater optimism concerning the use of such rules in NK models with capital. While Bullard and Mitra’s (2002, 2007) findings for the labor-only NK model do not always extend to models with capital, we show that determinate and learnable REE can be achieved in NK models with capital if there is (i) plausible capital adjustment costs, (ii) some weight given to output in the policy rule, and/or (iii) a policy of interest rate smoothing.
Breaking of the overall permutation symmetry in nonlinear optical susceptibilities of one-dimensional periodic dimerized Hückel model

Based on one-dimensional single-electron infinite periodic models of trans-polyacetylene, we show analytically that the overall permutation symmetry of nonlinear optical susceptibilities is, although preserved in bound-state molecular systems, no longer generally held in periodic systems. The overall permutation symmetry breakdown provides a natural explanation of the widely observed large deviations of Kleinman symmetry in off-resonant regions of periodic systems. Finally, physical conditions to experimentally test the overall permutation symmetry breakdown are discussed.
Non prefix-free codes for constrained sequences

In this paper we consider the use of variable length non prefix-free codes for coding constrained sequences of symbols. We suppose to have a Markov source where some state transitions are impossible, i.e. the stochastic matrix associated with the Markov chain has some null entries. We show that classic Kraft inequality is not a necessary condition, in general, for unique decodability under the above hypothesis and we propose a relaxed necessary inequality condition. This allows, in some cases, the use of non prefix-free codes that can give very good performance, both in terms of compression and computational efficiency. Some considerations are made on the relation between the proposed approach and other existing coding paradigms
INTERNATIONAL INTEGRATION AND GROWTH: A SURVEY AND EMPIRICAL INVESTIGATION

Endogenous growth theory suggests that increased international interactions can lead to increased growth. Growth may be stimulated through a variety of means: trade and/or direct investment may act as a means of technology diffusion; increased imports may reduce competitive distortions in the domestic economy; reduced barriers to trade may cre­ ate a larger market and hence a higher return to innovation, encouraging higher investment in RD reduced barriers to trade may lead to rationalization of the RD results are mixed. Notably, empirical work has typically focused on a single avenue of international integration - trade, FDI, or regional integration - rather than taking a comprehensive ap­ proach. The problem with a piecemeal approach is that variables measuring international interactions are highly correlated, not only with each other but with other regressors com­ monly included in growth equations. Thus focusing on one form of international integration while omitting the other forms is likely to result in a biased estimate of the impact of the variable of interest. After surveying the theoretical and empirical work, we attempt a comprehensive as­ sessment of different forms of international integration on growth. In particular, we consider the impact of trade, of inward foreign direct investment, of preferential treatment of less developed countries, and of membership in trade blocs. Our results confirm that general openness and foreign direct investment into a country do lead to increased growth; that special treatment by the European Union of former colonies statistically insignificantly in­ creases growth; that membership in a trade bloc facilitates growth; and that the size of the trade bloc to which a country belongs and the variation in income in the trade bloc also encourage more rapid growth among member countries. We also find that omission any of these international sources of growth biases the coefficients estimated on included regressors.
The Impact of Pollution on Stellar Evolution Models

An approach is introduced for incorporating the concept of stellar pollution into stellar evolution models. The approach involves enhancing the metal content of the surface layers of stellar models. In addition, the surface layers of stars in the mass range of 0.5-2.0 M☉ are mixed to an artificial depth motivated by observations of lithium abundance. The behavior of polluted stellar evolution models is explored assuming the pollution occurs after the star has left the fully convective pre-main-sequence phase. Stellar models polluted with a few Earth masses (M⊕) of iron are significantly hotter than stars of the same mass with an equivalent bulk metallicity. Polluted stellar evolution models can successfully reproduce the metal-rich, parent star τ Bootis and suggest a slightly lower mass than standard evolution models. Finally, the possibility that stars in the Hyades open cluster have accreted an average of 0.5 M⊕ of iron is explored. The results indicate that it is not possible to rule out stellar pollution on this scale from the scatter of Hyades stars on a color-magnitude diagram. The small amount of scatter in the observational data set does rule out pollution on the order of ~1.5 M⊕ of iron. Pollution effects at the low level of 0.5 M⊕ of iron do not produce substantial changes in a star's evolution.
Direct Acceleration of Pickup Ions at the Solar Wind Termination Shock: The Production of Anomalous Cosmic Rays

We have modeled the injection and acceleration of pickup ions at the solar wind termination shock and investigated the parameters needed to produce the observed Anomalous Cosmic Ray (ACR) fluxes. A non-linear Monte Carlo technique was employed, which in effect solves the Boltzmann equation and is not restricted to near-isotropic particle distribution functions. This technique models the injection of thermal and pickup ions, the acceleration of these ions, and the determination of the shock structure under the influence of the accelerated ions. The essential effects of injection are treated in a mostly self-consistent manner, including effects from shock obliquity, cross- field diffusion, and pitch-angle scattering. Using recent determinations of pickup ion densities, we are able to match the absolute flux of hydrogen in the ACRs by assuming that pickup ion scattering mean free paths, at the termination shock, are much less than an AU and that modestly strong cross-field diffusion occurs. Simultaneously, we match the flux ratios He(+)/H(+) or O(+)/H(+) to within a factor approx. 5. If the conditions of strong scattering apply, no pre-termination-shock injection phase is required and the injection and acceleration of pickup ions at the termination shock is totally analogous to the injection and acceleration of ions at highly oblique interplanetary shocks recently observed by the Ulysses spacecraft. The fact that ACR fluxes can be modeled with standard shock assumptions suggests that the much-discussed "injection problem" for highly oblique shocks stems from incomplete (either mathematical or computer) modeling of these shocks rather than from any actual difficulty shocks may have in injecting and accelerating thermal or quasi-thermal particles.
Some Measured Temperature Characteristics in a Two-Dimensional Heated Jet of Air

The mean and conditional temperature and velocity profiles and their correlations were measured in a heated jet of air. The conditional measurements were “zone” averaged measurements, taken only in the fully turbulent region of the flow field by using an electronic sampling technique. The zone averaged measurements were taken of the velocity, temperature, shear stress, and the velocity-temperature correlation at three axial stations: x/D = 35, 45, and 50. The jet Reynolds number (based on the jet slot width) was held constant at 1.43 × 104 , with a jet exit temperature excess of θ = 35°C. The conditioned profiles show a large variation from the mean measurements in the fully turbulent region of the jet. The zone averaged measurements approach the mean only as the jet center line and jet interface is approached.
Structural Response of Composite Sandwich Panels Impacted With and Without Compression Loading

The results of an experimental study of the impact damage characteristics and residual strength of composite sandwich panels impacted with and without a compression loading are presented. Results of impact damage screening tests conducted to identify the impact-energy levels at which damage initiates and barely visible impact damage occurs in the impacted facesheet are discussed. Parametric effects studied in these tests include the impactor diameter and dropped-weight vs airgun-launched impactors. Residual strength results of panels tested in compression after impact are presented and compared with results of panels that are subjected to a compressive preload prior to being impacted.
Color-flavor locking and chiral symmetry breaking in high density QCD

Abstract We propose a symmetry breaking scheme for QCD with three massless quarks at high baryon density wherein the color and flavor SU(3) color × SU(3) L × SU(3) R symmetries are broken down to the diagonal subgroup SU(3) color+ L + R by the formation of a condensate of quark Cooper pairs. We discuss general properties that follow from this hypothesis, including the existence of gaps for quark and gluon excitations, the existence of Nambu-Goldstone bosons which are excitations of the diquark condensate, and the existence of a modified electromagnetic gauge interaction which is unbroken and which assigns integral charge to the elementary excitations. We present mean-field results for a Hamiltonian in which the interaction between quarks is modeled by that induced by single-gluon exchange. We find gaps of order 10–100 MeV for plausible values of the coupling. We discuss the effects of non-zero temperature, non-zero quark masses and instanton-induced interactions on our results.
The New International Economic Order and the New Regime for Fisheries Management

The 200-mile exclusive economic zone for fisheries management is criticized by some as being inconsistent with demands for a New International Economic Order. This paper examines the implications of the new fisheries regime for the developing countries. While the regime is no panacea, it will improve the allocation of resources and the bargaining leverage of developing countries. Their long run success in achieving nutritional, employment and commercial benefits will depend upon availability of infrastructure and venture capital for processing and marketing of the catch, sea-orientation among the people and the pattern of economic concentration within.
Selective synthesis and equilibration of methylamines on sodium mordenite

Abstract Sodium mordenite catalyzes the sequential reactions of methanol and ammonia to give methylamine and dimethylamine, but little trimethylamine. The kinetics of this selective reaction are compared to the nonselective reaction catalyzed by Bronsted acids. Selective adsorption, not shape selectivity, is the critical factor in determining the catalyst's selectivity.
Plasmadynamic effects in thermochemical nonequilibrium aerobrake flows

The paper discusses modifications to the governing equations of thermochemical nonequilibrium flow to include plasmadynamic effects. The magnetic field about a 1.1-m nose-radius aerobrake entering the earth's atmosphere at 80-km altitude and traveling 12 km/s is computed. The result of coupling the additional terms into the Langley Aerothermodynamics Upwind Relaxation Algorithm indicate that plasmadynamic effects are negligible for this two-temperature Mars-return aerobraking simulation. By examining the magnitude of the ohmic heating and observing a decrease in this heating when coupling terms are included in the two-temperature solution, it is argued that a three-temperature solution should not produce any different conclusions for aerobraking into the earth's atmosphere.
Elevation of the Erythrocyte Sedimentation Rate Precedes Exacerbation of Bleomycin-Induced Pulmonary Toxicity: Report of Two Cases and Review of Literature

Bleomycin is included in a number of potentially curative chemotherapy regimens. It is associated with distinct forms of pulmonary toxicity, with interstitial pneumonitis the most common. Early detection of pulmonary toxicity is not always predictable by monitoring serial chest radiographs and pulmonary function tests. Even newer serum markers are not useful indicators of bleomycin-induced pulmonary damage. Two patients developed bleomycin pulmonary toxicity, in both of whom increases in erythrocyte sedimentation rate (ESR) preceded clinical deterioration and radiographic changes. The ESR may have potential significance as a monitoring test in patients receiving bleomycin.
A tight distance-dependent estimator for screening three-center Coulomb integrals over Gaussian basis functions

A new estimator for three-center two-particle Coulomb integrals is presented. Our estimator is exact for some classes of integrals and is much more efficient than the standard Schwartz counterpart due to the proper account of distance decay. Although it is not a rigorous upper bound, the maximum degree of underestimation can be controlled by two adjustable parameters. We also give numerical evidence of the excellent tightness of the estimator. The use of the estimator will lead to increased efficiency in reduced-scaling one- and many-body electronic structure theories.
Neutralino relic density in minimal supergravity with co-annihilations

We evaluate the relic density of neutralinos in the minimal supergravity (mSUGRA) model. All 2?2 neutralino annihilation diagrams, as well as all processes involving sleptons, charginos, neutralinos and third generation squarks are included. Relativistic thermal averaging of the velocity times cross sections is performed. We find that co-annihilation effects are only important on the edges of the model parameter space, where some amount of fine-tuning is necessary to obtain a reasonable relic density. Alternatively, at high tan ?, annihilation through very broad Higgs resonances gives rise to an acceptable neutralino relic density over broad regions of parameter space where little or no fine-tuning is needed. Finally, we compare our results against the reach of various e+e? and hadron colliders for supersymmetric matter.
Performance expectations for future moderate resolution visible and infrared space instruments based on AIRS and MODIS in-flight experience

Lessons learned from the Atmospheric Infrared Sounder (AIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) projects highlight areas where further technology development is needed to address future land, ocean and atmospheric measurement needs. Although not established as requirements at this time, it is anticipated that scientists will expect improvements in the areas of spatial, spectral, radiometric, polarimetric, temporal and calibration performance for future instruments. This paper addresses each of these performance areas and provides lessons learned from MODIS and AIRS. We also present expectations in performance of a Medium Earth Orbit (MEO) Infrared Imaging Spectrometer based on information from the NASA Instrument Incubator Program and industry reports. Tradeoffs are presented vs orbit altitude (LEO, MEO and GEO) and provide a "systems" perspective to future measurement concepts.
Non-Standard Physics and Nucleon Strangeness in Low-Energy PV Electron Scattering

Contributions from physics beyond the Standard Model, strange quarks in the nucleon, and nuclear structure effects to the left-right asymmetry measured in parity-violating (PV) electron scattering from 12C and the proton are discussed. It is shown how lack of knowledge of the distribution of strange quarks in the nucleon, as well as theoretical uncertainties associated with higher-order dispersion amplitudes and nuclear isospin-mixing, enter the extraction of new limits on the electroweak parameters S and T from these PV observables. It is found that a series of elastic PV electron scattering measurements using 4He could significantly constrain the s-quark electric form factor if other theoretical issues are resolved. Such contraints would reduce the associated form factor uncertainty in the carbon and proton asymmetries below a level needed to permit extraction of interesting low-energy constraints on S and T from these observables. For comparison, the much smaller scale of s-quar
Application of Chiral Mixed Phosphorus/Sulfur Ligands to Enantioselective Rhodium-Catalyzed Dehydroamino Acid Hydrogenation and Ketone Hydrosilylation Processes

Chiral mixed phosphorus/sulfur ligands 1−3 have been shown to be effective in enantioselective Rh-catalyzed dehydroamino acid hydrogenation and ketone hydrosilylation reactions (eqs 1, 2). After assaying the influence of the substituents at sulfur, the substituents on the ligand backbone, the relative stereochemistry within the ligand backbone, and the substituents at phosphorus, ligands 2c (R = 3,5-dimethylphenyl) and 3 were found to be optimal in the Rh-catalyzed hydrogenation of a variety of α-acylaminoacrylates in high enantioselectivity (89−97% ee). A similar optimization of the catalyst for the Rh-catalyzed hydrosilylation of ketones showed that ligand 3 afforded the highest enantioselectivities for a wide variety of aryl alkyl and dialkyl ketones (up to 99% ee). A model for asymmetric induction in the hydrogenation reaction is discussed in the context of existing models, based on the absolute stereochemistry of the products and the X-ray crystal structures of catalyst precursors and intermediates.
Increasing Market Share as a Rationale for Corporate Acquisitions

This study examines the relative importance of market share in acquisitions because anecdotal evidence and economic theory suggest that merging firms benefit from larger market share. Firms might focus on market share to improve shareholder value through improved efficiency, which benefits consumers. Alternatively, higher market share could generate greater market power, which adversely affects consumers. I find that market share of merging firms increases by more than 30%, relative to the pre-acquisition level, and the increase is even larger after I account for industry changes. Abnormal returns are positively correlated with changes in market share around acquisitions, but not with changes in industry concentration, which suggests stock market's expectation of future benefits from efficiency rather than market power. More directly, I find that merging firms’ long-run profitability increases with market share, and the increase in profitability primarily results from better asset management.
Hebrew language usage: determinants and effects on earnings among immigrants in Israel.

This paper uses the 1983 Census of Israel to analyze Hebrew speaking skills and the effects of Hebrew fluency on the earnings of adult male immigrants. Hebrew fluency increases with a longer duration in Israel, the presence of children in the household, marrying after immigration, living in an area in which a smaller proportion speak one‘s mother tongue, a younger age at migration, a higher level of schooling and varies by country of birth. Earnings increase monotonically with the use of Hebrew. Speaking English as a second language is associated with higher earnings, even when country of origin is held constant.
Intramolecular cyclization of aromatic imines: an approach to tetrahydrochromano[4,3-b]quinolines

Abstract A synthesis of polysubstituted tetrahydrochromano[4,3- b ]quinolines is described. These compounds have been prepared by the reaction of anilines with derivatives of salicylic aldehyde containing electron-rich olefin substituents. In the described acid-mediated intramolecular [4+2] cycloaddition reaction, the targeted products are isolated as a 1:1 mixture of diastereomers in excellent yields and purities.
Precision measurements of the 7Be(p,γ)8B reaction with radioactive beams and the 8B solar neutrino flux

Abstract The 7Be(p,γ)8B reaction is one of the major source of uncertainties in estimating the 8B solar neutrino flux and is critical for undertsanding the Solar Neutrino Problem and neutrinos. The main source of uncertainty is the existence of conflicting data with different absolute normalization. Attempts to measure this reaction rate with 7Be beams are under way by the UConn-LLN collaboration, and we discuss a newly emerging method to extract this cross section from the Coulomb dissociation of the radioactive beam of 8B. We discuss some of the issues relevant for this study including the question of the E2 contribution to the Coulomb dissociation process which was measured to be small. The Coulomb dissociation appears to provide a viable alternative method for measuring the 7Be(p,γ)8B reaction rate, with a weighted average of the RIKEN1, RIKEN2 and GSI1 published results of S17(0) = 19.4 ± 1.3 eV-b.
EAZY: A Fast, Public Photometric Redshift Code

We describe a new program for determining photometric redshifts, dubbed EAZY. The program is optimized for cases where spectroscopic redshifts are not available, or are only available for a biased subset of the galaxies. The code combines features from various existing codes: it can fit linear combinations of templates, it includes optional flux- and redshift-based priors, and its user interface is modeled on the popular HYPERZ code. A novel feature is that the default template set, as well as the default functional forms of the priors, are not based on (usually highly biased) spectroscopic samples, but on semianalytical models. Furthermore, template mismatch is addressed by a novel rest-frame template error function. This function gives different wavelength regions different weights, and ensures that the formal redshift uncertainties are realistic. We introduce a redshift quality parameter, -->Qz, which provides a robust estimate of the reliability of the photometric redshift estimate. Despite the fact that EAZY is not trained on spectroscopic samples, the code (with default parameters) performs very well on existing public data sets. For K-selected samples in CDF-South and other deep fields, we find a 1 ? scatter in -->? z/(1 + z) of 0.034, and we provide updated photometric redshift catalogs for the FIRES, MUSYC, and FIREWORKS surveys.
Global Biogeochemical Changes at Both Ends of the Proterozoic: Insights from Phosphorites

Abstract The distribution of major phosphate deposits in the Precambrian sedimentary rock record is restricted to periods that witnessed global biogeochemical changes, but the cause of this distribution is unclear. The oldest known phosphogenic event occurred around 2.0 Ga and was followed, after more than 1.3 billion years, by an even larger phosphogenic event in the Neoproterozoic. Phosphorites (phosphate-rich sedimentary rocks that contain more than 15% P2O5) preserve a unique record of seawater chemistry, biological activity, and oceanographic changes. In an attempt to emphasize the potentially crucial significance of phosphorites in the evolution of Proterozoic biogeochemical cycles, this contribution provides a review of some important Paleoproterozoic phosphate deposits and of models proposed for their origin. A new model is then presented for the spatial and temporal modes of occurrence of phosphorites along with possible connections to global changes at both ends of the Proterozoic. Central to th...
NEUTRINO SPECTRA FROM ACCRETION DISKS: NEUTRINO GENERAL RELATIVISTIC EFFECTS AND THE CONSEQUENCES FOR NUCLEOSYNTHESIS

Black hole (BH) accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the BH influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from BH accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome.
Ginzburg-Landau equations for the extended saddle-point model

Ginzburg-Landau-type equations are derived describing the model of tetragonal high-temperature superconducting cuprates based on the dominant role of extended saddle-point singularities in the electron spectrum and the assumption that the interaction between electrons consists of a strong long-range phonon-mediated attraction and a weak short-range repulsion. The connection between ${\mathrm{CuO}}_{2}$ layers is assumed to be established by resonant tunneling. As an example, the temperature dependence of the upper critical field along the $c$ axis is calculated, which appears to have a positive curvature, as observed in many experiments. This is explained by the fact that with departure from ${T}_{c}$ the connection between different singular points becomes increasingly less important, and the electrons become more one-dimensional. Other explanations are briefly discussed.
Patterns of UN documentation

Abstract This lecture outlines the structure and functions of the main organs of the United Nations and describes their documentation, emphasizing how the documentation flows from the operations of the organs. In addition to a detailed description of the official records, the author explains how to read and compose document symbols. She also discusses the use of the primary indexes to UN materials, particularly UNDEX , and Indexes to Proceedings and the Indexes to Resolutions .
A synthesis of ammonium 3-deoxy-(d)-manno-2-octulosonate (ammonium kdo) from (d)-mannose via cobaloxime-mediated radical alkyl-alkenyl cross coupling

Abstract We report a synthesis of the ammonium salt of the 8-carbon monosaccharide 3-deoxy-(d)- manno -2-octulosonic acid (KDO) starting from (d)-mannose. The key C-C bond construction in our synthetic strategy is a novel alkyl cobaloxime mediated radical alkyl-alkenyl cross coupling of α-ethoxyacrylonitrile with an alkyl cobaloxime derivative of D-mannose. KMnO 4 unmasking of the latent functionality in the α-ethoxyacrylonitrile moiety provides the α-hydroxyester moiety necessary for completion of the KDO synthesis.
Volatility in an era of reduced uncertainty: Lessons from Pax Britannica

Abstract Although it has been well established that financial volatility is related to news and macroeconomic shocks, less emphasis has been placed on the importance of underlying economic and political stability. In this paper we study the behavior of consol returns since 1729 and identify a greater-than-50% decline in volatility from the end of the Napoleonic Wars in 1815 until the First World War. News events and macroeconomic variables cannot account for this extended period of reduced volatility. Underlying political stability under Pax Britannica seems to be a more likely explanation.
Dynamically triangulated random surfaces

Abstract Dynamically triangulated random surfaces are studied. In view of the cellular automata description of quantum gravity, the covariant formulation is achieved by varying the adjaciency matrix. Computer simulations are discussed.
Managing the Internet Payment Platform project

This case examines issues in the assessment and adoption of Internet technologies in a federal US government context, and describes in detail a pilot project to determine the feasibility of adopting an application service provider solution to support procurement by multiple federal agencies using a variety of different legacy transaction systems. The pilot test of the Internet Payment Platform (IPP) by the eMoney group of the United States Treasury's Financial Management Service involved three federal agencies and subsets of their suppliers. Participants saw many benefits from their use of the IPP, but agreed that for full-scale operation it needed to be modified to better fit the government procurement context. The project manager is weighing the pros and cons of conducting another pilot test using the same commercial software as before, or obtaining and customizing a new commercial package, or building a new system from scratch.