cssi/SciSciGPT-SciSciNet huggingface dataset:
Disease characteristics, patterns of care, and survival in very elderly patients with diffuse large B-cell lymphoma

BACKGROUND Although the combination of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is considered standard therapy for diffuse large B-cell lymphoma (DLBCL), patterns of use and the impact of R-CHOP on survival in patients aged >80 years are less clear. METHODS The Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to characterize presentation, treatment, and survival patterns in patients with DLBCL who were diagnosed between 2002 and 2009. Chi-square tests compared characteristics and initial treatments among patients with DLBCL who were aged >80 years and ≤80 years. Multivariable logistic regression models examined factors associated with treatment selection in patients aged >80 years; standard and propensity score-adjusted multivariable Cox proportional hazards models examined relationships between treatment regimen, treatment duration, and survival. RESULTS Among 4635 patients with DLBCL, 1156 (25%) were aged >80 years. Patients aged >80 years were less likely to receive R-CHOP and more likely to be observed or receive the combination of rituximab, cyclophosphamide, vincristine, and prednisone (P 80 years. In propensity score-matched multivariable Cox proportional hazards models examining relationships between treatment regimen and survival, R-CHOP was the only regimen found to be associated with improved overall survival (hazard ratio, 0.45; 95% confidence interval, 0.33-0.62) and lymphoma-related survival (hazard ratio, 0.58; 95% confidence interval, 0.38-0.88). CONCLUSIONS Although patients with DLBCL who were aged >80 years were less likely to receive R-CHOP, this regimen conferred the longest survival and should be considered for this population. Further studies are needed to characterize the impact of treatment of DLBCL on quality of life among patients in this age group. Cancer 2015;121:1800–1808. © 2015 American Cancer Society.
Una especie nueva de Lentiella (Cestoda: Anoplocephalidae) de Proechimys (Rodentia: Echimyidae) en Bolivia

COMO PARTE DEL MONITOREO DE LA BIODIVERSIDAD DE BOLIVIA, VARIAS RATAS ESPINOSAS (PROECHIMYS SIMONSI THOMAS, 1900) FUERON EXAMINADAS EN BUSCA DE PARASITOS DURANTE EL VERANO BOREAL DEL ANO 2000. EN EL PRESENTE TRABAJO SE DESCRIBEEL CESTODO LENTIELLA LAMOTHEI N. SP. RECOLECTADO EN ESTOS HOSPEDEROS. ESTA ESPECIE PUEDE DISTINGUIRSE DE L. MACHADOIRUGO, 1964 POR TENER UNA MAYOR LONGITUD TOTAL PERO MENOR ANCHO MAXIMO, MAYOR NUMERO DE PROGLOTIDOS, BOLSA DEL CIRRO MAS PEQUENA, ESCOLEX DE MENOR DIAMETRO, Y UN MAYOR APARATO PIRIFORME EN LOS HUEVOS. ADEMAS, SE REVALIDA FORMALMENTE AL GENERO LENTIELLA RUGO, 1964, ANTERIORMENTE SINONIMIZADO CON MONOECOCESTUS BEDDARD, 1914.
On the accelerated failure time model for current status and interval censored data

AND TIANXI CAI This paper introduces a novel approach to making inference about the regression parameters in the accelerated failure time model for current status and interval censored data. The estimator is constructed by inverting a Wald-type test for testing a null proportional hazards model. A numerically efficient Markov chain Monte Carlo based resampling method is proposed for obtaining simultaneously the point estimator and a consistent estimator of its variance-covariance matrix. We illustrate our approach with interval censored datasets from two clinical studies. Extensive numerical studies are conducted to evaluate the finite-sample performance of the new estimators.
Recent Advances on the Total Syntheses of Communesin Alkaloids and Perophoramidine

The communesin alkaloids are a diverse family of Penicillium-derived alkaloids. Their caged-polycyclic structure and intriguing biological profiles have made these natural products attractive targets for total synthesis. Similarly, the ascidian-derived alkaloid, perophoramidine, is structurally related to the communesins and has also become a popular target for total synthesis. This review serves to summarize the many elegant approaches that have been developed to access the communesin alkaloids and perophoramidine. Likewise, strategies to access the communesin ring system are reviewed.
The demography of youth in developing countries and its economic implications

The number of young people is reaching unprecedented levels in most developing countries. In many countries, especially in East Asia and Latin America, youth populations are at or near their peak, and will decline in coming decades. In other countries, especially in Africa and South Asia, youth populations will continue growing for several decades. From an economic perspective, absolute numbers may be less important than the growth rate or relative size of youth cohorts. Growth rates and the ratio of youth to working-age population reached a peak in the 1970s or 1980s in most developing countries. The worst economic pressures of youth demography may have already occurred in many countries, although significant pressure will continue in Africa and South Asia.
Bradley–Terry Model

In a paired comparison experiment, several judges compare several objects. Each judge performs a number of paired comparisons, that is, considers a pair of the objects, and indicates which of the two is preferred. The Bradley–Terry model is a simple but powerful model in which each object is equipped with a measure of overall strength, and the chance that one object is preferred to another depends on only their relative strengths. The model is useful not only for preference data but also for competitions, for example, among sports teams. Keywords: Bradley–Terry model; paired comparisons; Luce's Choice Axiom; Thurstone model; logistic regression
Shift Equivalence and the Conley Index

In this paper we introduce filtration pairs for isolated invariant sets of continuous maps. We prove the existence of filtration pairs and show that, up to shift equivalence, the induced map on the corresponding pointed space is an invariant of the isolated invariant set. Moreover, the maps defining the shift equivalence can be chosen canonically. Lastly, we define partially ordered Morse decompositions and prove the existence of Morse set filtrations for such decompositions.
Unsupervised feature learning through divergent discriminative feature accumulation

Unlike unsupervised approaches such as autoencoders that learn to reconstruct their inputs, this paper introduces an alternative approach to unsupervised feature learning called divergent discriminative feature accumulation (DDFA) that instead continually accumulates features that make novel discriminations among the training set. Thus DDFA features are inherently discriminative from the start even though they are trained without knowledge of the ultimate classification problem. Interestingly, DDFA also continues to add new features indefinitely (so it does not depend on a hidden layer size), is not based on minimizing error, and is inherently divergent instead of convergent, thereby providing a unique direction of research for unsupervised feature learning. In this paper the quality of its learned features is demonstrated on the MNIST dataset, where its performance confirms that indeed DDFA is a viable technique for learning useful features.
Cholesterol vehicle in experimental atherosclerosis

Summary The atherogenic effects of diets containing cholesterol suspended in heated or unheated olive and corn oils were compared. The diet containing heated corn oil was more atherogenic than that containing unheated corn oil, confirming our previously published findings. The increased atherogenicity of the heated corn oil diet could be correlated with an increase in its free fatty acid content. The two olive oil diets were of comparable atherogenicity, and heating did not elevate the free fatty acid content of the olive oil. These findings further suggest that one of the factors affecting atherogenicity of heated fats is their free fatty acid content.
Self-serving behavior in managers' discretionary information disclosure decisions

Abstract Research has shown that managers display self-serving behavior in a variety of discretionary information production decisions. We test whether such behavior is also manifest in discretionary information disclosure decisions — in particular, in the common stock return performance comparisons now required in corporate proxy statements. We find evidence that the industry and peer-company stock return benchmarks, and broader market indices, chosen by management for those comparisons are downward biased, thereby overstating relative reporting-firm performance. Cross-sectionally, the extent of the bias varies with key reporting-firm attributes, including firm performance and the character of firm ownership structure.
An Analysis of Stapp’s “A Bell-Type Theorem without Hidden Variables”

H.P. Stapp has proposed a number of demonstrations of a Bell-type theorem which dispensed with an assumption of hidden variables, but relied only upon locality together with an assumption that experimenters can choose freely which of several incompatible observables to measure. In recent papers his strategy has centered upon counterfactual conditionals. Stapp’s paper in American Journal of Physics, 2004, replies to objections raised against earlier expositions of this strategy and proposes a simplified demonstration. The new demonstration is criticized, several subtleties in the logic of counterfactuals are pointed out, and the proofs of J.S. Bell and his followers are advocated.
SU(3) glueballs on coarse, anisotropic lattices☆

Abstract Results from a calculation of the low-lying glueball spectrum of pure-gauge SU(3) are used as a test of the effectiveness of improved discretisation schemes in reducing finite spacing errors. Glueball masses are extracted from simulations on anisotropic lattices, where the temporal lattice spacing is much shorter than the spatial ones. This allows clearer resolution of the decay of glueball correlators.
Gravity-driven turbulence in galactic disks

High-resolution, two-dimensional hydrodynamical simulations with a large dynamic range are performed to study the turbulent nature of the interstellar medium (ISM) in galactic disks. The simulations are global, where the self-gravity of the ISM, realistic radiative cooling, and galactic rotation are taken into account. In the analysis undertaken here, feedback processes from the stellar energy source are omitted. We find that the velocity field of the disk in a nonlinear phase shows a steady power-law energy spectrum over 3 orders of magnitude in wavenumber. This implies that the random velocity field can be modeled as fully developed, stationary turbulence. Gravitational and thermal instabilities under the influence of galactic rotation contribute to the formation of the turbulent velocity field. The Toomre effective Q-value, in the nonlinear phase, covers a wide range, and gravitationally stable and unstable regions are distributed patchily in the disk. These results suggest that large-scale galactic rotation coupled with the self-gravity of the gas can be the ultimate energy sources that maintain the turbulence in the local ISM. Our models of turbulent rotating disks are consistent with the velocity dispersion of an extended H I disk in the dwarf galaxy NGC 2915, where there is no prominent active star formation. Numerical simulations show that the stellar bar in NGC 2915 enhances the velocity dispersion, and it also drives spiral arms, as observed in the H I disk.
The nullcone in the multi-vector representation of the symplectic group and related combinatorics

We study the nullcone in the multi-vector representation of the symplectic group with respect to a joint action of the general linear group and the symplectic group. By extracting an algebra over a distributive lattice structure from the coordinate ring of the nullcone, we describe a toric degeneration and standard monomial theory of the nullcone in terms of double tableaux and integral points in a convex polyhedral cone.
Tracer- and Pressure-Test Analysis for Characterization of Areally Heterogeneous Reservoirs

This paper compares simulated well-to-well tracer and transient pressure tests in a quadrant of a repeated five-spot with spatial variations in permeability. Single-layer heterogeneous media with an autocorrelated and log-normal permeability distribution are generated with a stochastic moving-average method. finite-difference simulation of pressure behavior in these systems indicates that the geometric means of effective permeabilities around injection and production wells is a good approximation for the steady-state interwell permeability. A dimensionless permeability difference, defined in terms of these quantities, correlates with a heterogeneity index, defined as the product of permeability variance and a dimensionless correlation length scale. Tracer flow is simulated with a particle-tracking procedure. Simulations show that when the heterogeneity index is small, tracer response can be matched with solutions of the convection-dispersion equation with a constant dispersivity that is proportional to the heterogeneity index. For large values of this index, preferential flow paths are created that cause tracer-breakthrough curves to behave as though they result from flow in a layered system. A method is proposed to estimate the heterogeneity index from pressure-test data and thus to predict the nature of the tracer response qualitatively.
INLET GUIDE VANE WAKES INCLUDING ROTOR EFFECTS

Abstract Fundamental experiments are described directed at the investigation of forcing functions generated by an inlet guide vane (IGV) row, including interactions with the downstream rotor, for application to turbomachine forced response design systems. The experiments are performed in a high-speed research fan facility comprised of an IGV row upstream of a rotor. IGV-rotor axial spacing is variable, with the IGV row able to be indexed circumferentially, thereby allowing measurements to be made across several IGV wakes. With an IGV relative Mach number of 0·29, measurements include the IGV wake pressure and velocity fields for three IGV-rotor axial spacings. The decay characteristics of the IGV wakes are compared to the Majjigi and Gliebe empirical correlations. After Fourier decomposition, a vortical–potential gust splitting analysis is implemented to determine the vortical and potential harmonic wake gust forcing functions both upstream and downstream of the rotor. Higher harmonics of the vortical gust component of the IGV wakes are found to decay at a uniform rate due to viscous diffusion.
Short Duration Heat Transfer Studies at High Free-Stream Temperatures

This paper describes short duration heat transfer measurements on a flat plate and a gas turbine nozzle airfoil at high free-stream temperatures. A shock tube generated the high temperature and pressure air flow. Thin-film heat gages recorded the surface heat flux. The flat plate was tested both in the shock tube and in a shock tunnel placed aft of the tube. Shock tunnel tests on the nozzle airfoil measured the local heat transfer distribution. The flat plate free-stream temperatures varied from 830 °R (460 K) to 3190 °R (1770 K) for a Tw/TT,g temperature ratio of 0.17 to 0.64 at Mach numbers from 0.12 to 1.34. The nozzle measurements at a Tw/TT,g of 0.35 to 0.39 generally indicate that pressure (concave) surface heat transfer coefficients are high, whereas the suction (convex) surface shows much lower heat transfer coefficients than a turbulent flat plate correlation.Copyright © 1982 by ASME
Precision orbit computations for Starlette

The Starlette satellite, launched in February 1975 was designed to minimize the effects of nongravitational forces and to obtain the highest possible accuracy for laser range measurements. Analyses of the first four months of laser tracking data from nine stations have confirmed the stability of the orbit and the precision to which the satellite's position can be established. Initial orbit computations using the GSFC GEM - 7 gravity model produced rms fits of about 8 to 10 meters for arc lengths of 5 days. After tailoring a gravity model specifically to Starlette, the rms fits for the 5 day arcs were reduced significantly to the 1 to 2 meter level. An rms fit of 4.3 meters was obtained for a 90 day arc. Five day arcs overlapped by 2.5 days showed rms satellite position differences generally less than 2 meters. Prediction errors at the end of two months were less than 30 milliseconds.
Photocatalytic oxidation of multifunctional organic molecules. The effect of an intramolecular aryl thioether group on the semiconductor-mediated oxidation/dehydrogenation of a primary aliphatic alcohol

Abstract A remote thiophenyl group retards the TiO 2 -mediated photocatalytic oxidation of the alcohol group in 4-thiophenyl-l-butanol. Model studies implicate intramolecular bridging in the adsorbed cation radical and/or hole trapping by sulfur in the primary oxidative photoprocess at the photocatalyst-liquid interface.
Optical properties of self-assembled quantum wires for application in infra-red detection

Abstract We present theoretical studies of optical properties of Ga 1− x In x As self-assembled quantum-wires (QWRs) made of short-period superlattices with strain-induced lateral ordering. Valence-band anisotropy, band mixing, and effects due to local strain distribution at the atomistic level are all taken into account. Using realistic material parameters which are experimentally feasible, we perform simulations of the absorption spectra for both inter-subband and inter-band transitions (including the excitonic effect) of this material. It is shown that the self-assembled QWRs have favorable optical properties for application in infra-red detection with normal incidence. The wavelength of detection for inter-subband transitions ranges from 10 to 20 μm with the length of QWR period varying from 150 to 300 A, while the wavelength for inter-band absorption is in the mid-IR range (
Sporadic distal myopathy with early adult onset

With the exception of the large series of adult-onset hereditary distal myopathy from Sweden, few cases of primary muscle disease with a definite distal predilection have been published. We report 3 sporadic cases of distal myopathy with the following features: (1) early adult onset (26 to 33 years); (2) slowly progressive weakness affecting first the distal leg muscles and later the arms; (3) marked elevation of creatine phosphokinase (more than 10 times the normal value); and (4) electromyographic and histological evidence of myopathy in distal muscles. The differential diagnosis is discussed and other reported cases are reviewed. The differences between hereditary cases reported by others and the sporadic cases reported here form the basis for a tentative subclassification of this syndrome.
Effects of price-responsive residential demand on retail and wholesale power market operations

This paper describes a computational platform for studying the effects of price-responsive residential demand for air-conditioning (A/C) on integrated retail and wholesale power market operations. The physical operations of the A/C system are represented by means of the physics-based equivalent thermal parameter model. Residential A/C energy usage levels are determined by means of a stochastic dynamic-programming optimization in which the daily comfort attained by the resident is optimally traded off against his daily energy costs, conditional on retail energy prices, environmental conditions, and A/C operational constraints. An example is provided to illustrate the dynamic feedback loop connecting residential A/C load, the energy prices determined at wholesale conditional on A/C load, and the retail energy prices offered to residential A/C consumers by wholesale energy buyers.
The separation and determination of plutonium in diverse biological samples

Abstract A greatly simplified separation scheme for plutonium in biological samples has been devised. It is based on the absorption of an anionic form of quadrivalent plutonium in a strong hydrochloric acid solution by a strong base anion-exchange resin. The greatest difficulty in obtaining complete recovery from some samples was in getting the sample completely dissolved. For the acid-insoluble portion of samples such as faecal ash, it was necessary to resort to carbonate and bisulphate fusions. Elution from the ion-exchange column was accomplished with sulphurous acid, and the final determination was made by liquid scintillation counting.
Independent-Gate Controlled Asymmetrical SRAM Cells in Double-Gate MOSFET Technology for Improved READ Stability

This paper presents novel asymmetrical SRAM cell topologies in double-gate technology. These cells utilize the independent-gate control to overcome the limitation of conventional device sizing for stability improvement in asymmetrical SRAM cells. We show that optimal READ stability, where the READ stability approaches the HOLD stability, can be achieved with the proposed scheme. Mixed-mode device/circuit simulations show that the proposed cell has 1.9X stability improvement over conventional SRAM and 1.5X stability improvement over asymmetrical SRAM with device sizing only.
Characterization of moving dust particles

A large depth-of-field Particle Image Velocimeter (PIV) has been developed at NASA GSFC to characterize dynamic dust environments on planetary surfaces. This instrument detects and senses lofted dust particles. To characterize a dynamic planetary dust environment, the instrument would have to operate for at least several minutes during an observation period, easily producing more than a terabyte of data per observation. Given current technology, this amount of data would be very difficult to store onboard a spacecraft and downlink to Earth. We have been developing an autonomous image analysis algorithm architecture for the PIV instrument to greatly reduce the amount of data that it has to store and downlink. The algorithm analyzes PIV images and reduces the image information down to only the particle measurement data we are interested in receiving on the ground - typically reducing the amount of data to be handled by more than two orders of magnitude. We give a general description of the PIV algorithms and describe in detail the algorithm for estimating the direction and velocity of the traveling particles, which was done by taking advantage of the optical properties of moving dust particles along with image processing techniques.
Baryon-strangeness correlations: a diagnostic of strongly interacting matter

The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the critical temperature severely limits the presence of q q ¯ bound states, thus supporting a picture of independent (quasi)quarks. Details may be found in [V. Koch, A. Majumder and J. Randrup, arXiv:nucl-th/0505052 , Phys. Rev. Lett. in print].
An Upper Bound for the Critical Boiling Heat Flux

The great value of boiling and condensation in process heat transfer is that they yield the highest known heat transfer coefficients. People who have to transfer a great deal of energy rapidly, under fairly low driving temperature differences, usually turn to these processes. The authors therefore constantly face the question. What is the upper limit on these heat fluxes - how far can they be driven.
A practical synthesis of flavones from methyl salicylate

Abstract A facile synthetic method has been developed for the conversion of methyl salicylate (5) into flavones 1a-i in high yields. Compound 5 on treatment with t-butyldimethylsilyl chloride (6) gave the O-silyl protected ester 7. Condensation of this ester 7 with the lithium anion generated from acetophenones 3a-i yielded the 1.3-diarylpropane-1,3-diones 8a-i, which on treatment with glacial acetic acid containing 0.5% H2SO4 for 3 h at 95-100 °C provided the desired flavones 1a-i in 83–94% yields.
Copper(I)-catalyzed addition of Grignard reagents to in situ-derived N-sulfonyl azoalkenes: an umpolung alkylation procedure applicable to the formation of up to three contiguous quaternary centers.

The α-alkylation of N-sulfonyl hydrazones via in situ-derived azoalkenes provides an umpolung approach to ketone α-alkylation that has considerable potential with regard to catalysis and the direct incorporation of functionality not amenable to the use of enolate chemistry. Herein, we describe the first Cu(I)-catalyzed addition of Grignard reagents to in situ-derived N-sulfonyl azoalkenes. This method is remarkable in its ability to deliver highly sterically hindered compounds that would be difficult or impossible to synthesize via traditional enolate chemistry, including those having up to three contiguous quaternary centers.
Statistics of cycles: how loopy is your network?

We study the distribution of cycles of length h in large networks (of size N 1) and find it to be an excellent ergodic estimator, even in the extreme inhomogeneous case of scale-free networks. The distribution is sharply peaked around a characteristic cycle length, h ~ Nα. Our results suggest that h and the exponent α might usefully characterize broad families of networks. In addition to an exact counting of cycles in hierarchical nets, we present a Monte Carlo sampling algorithm for approximately locating h and reliably determining α. Our empirical results indicate that for small random scale-free nets of degree exponent λ, α = 1/(λ − 1), and α grows as the nets become larger.
Direct Calculation of the Turbulent Dissipation Efficiency in Anelastic Convection

The current understanding of the turbulent dissipation in stellar convective zones is based on the assumption that the turbulence follows Kolmogorov scaling. This assumption is valid for some cases in which the time frequency of the external shear is high (e.g., solar p modes). However, for many cases of astrophysical interest (e.g., binary orbits, stellar pulsations, etc.), the timescales of interest lie outside the regime of applicability of Kolmogorov scaling. We present direct calculations of the dissipation efficiency of the turbulent convective flow in this regime, using simulations of anelastic convection with external forcing. We show that the effects of the turbulent flow are well represented by an effective viscosity coefficient, we provide the values of the effective viscosity as a function of the perturbation frequency and compare our results to the perturbative method for finding the effective viscosity of Penev et al. that can be applied to actual simulations of the surface convective zones of stars.
Logarithms of iteration matrices, and proof of a conjecture by Shadrin and Zvonkine

A proof of a conjecture by Shadrin and Zvonkine, relating the entries of a matrix arising in the study of Hurwitz numbers to a certain sequence of rational numbers, is given. The main tools used are iteration matrices of formal power series and their (matrix) logarithms.
Thermal Instabilities in the Plasma Edge

A body of theory for the prediction of thermal instabilities in the plasma edge and application to interpretation of experimental phenomena are summarized. The evidence suggests that thermal instabilities are involved in the formation of “divertor MARFEs” and MARFEs in the edge plasma, in confinement degradation over the course of a discharge, and in radiative collapse leading to disruptions.
Semantic Instance Labeling Leveraging Hierarchical Segmentation

Most of the approaches for indoor RGBD semantic labeling focus on using pixels or super pixels to train a classifier. In this paper, we implement a higher level segmentation using a hierarchy of super pixels to obtain a better segmentation for training our classifier. By focusing on meaningful segments that conform more directly to objects, regardless of size, we train a random forest of decision trees as a classifier using simple features such as the 3D size, LAB color histogram, width, height, and shape as specified by a histogram of surface normal's. We test our method on the NYU V2 depth dataset, a challenging dataset of cluttered indoor environments. Our experiments using the NYU V2 depth dataset show that our method achieves state of the art results on both a general semantic labeling introduced by the dataset (floor, structure, furniture, and objects) and a more object specific semantic labeling. We show that training a classifier on a segmentation from a hierarchy of super pixels yields better results than training directly on super pixels, patches, or pixels as in previous work.
Active Nitrogen and the Auroral Spectrum

IN my letter in a recent number of NATUREI described an afterglow in nitrogen in which the first negative bands of N2 were present, and in which the excitation of the first positive bands was different from that hitherto observed in nitrogen afterglows. At the time the letter was written, no photograph of the afterglow intense enough to print had been obtained. Fig. 1 shows a photograph of the spectrum of the afterglow which has been obtained since then, and it is to be noted that with the exception of the green auroral line, the afterglow spectrum is remarkably like the auroral spectrum. In my first letter it was stated that the second positive bands were completely missing from the afterglow, and that was true of the plate which was described in that letter, but a trace of the second positive group can be very easily seen on the present plate and they have been obtained with considerable intensity on a plate taken on a small quartz Hilger spectrograph. The arrows on Fig. 1 point to first positive band sequences which originate on V = 16, 17, 18, etc., and it is seen that these sequences are present on the afterglow plates also.
Invited talk: what's the future for proof-carrying code?

Proof-carrying code (PCC) was introduced by George Necula and Peter Lee in 1996. The principle is simple: we can eliminate the need to trust code by forcing the producer to give us a formal, machine-checkable proof that the code won't exhibit some "bad behavior" when executed. Thus, instead of having to perform a complicated (and thus un-trustworthy) analysis to determine whether or not code is bad, we can instead use a simple (and thus trustworthy) proof checker.The attraction to systems people was that the PCC framework placed no inherent limits on good code. As long as you could manufacture a proof that the code wasn't bad, then the code would be accepted. So, at least in principle, you wouldn't have to pay a performance penalty for safety. Over the past eight years, many researchers have worked to make PCC a reality. But I would argue that we are still very far from reaping the benefits that the framework promises. Good progress has been made in some areas, but there are a number of hard problems that remain. The hardest conceptual questions are (a) "What policies should we enforce?" and (b) "How does the code producer generate a proof?
The role of asymmetric information among investors in the foreign exchange market

This paper posits asymmetric information as the missing link between the currency demands of investors and changes in the exchange rate. A theoretical model demonstrates that changes in the exchange rate and currency demand are positively correlated for well-informed investors and negatively correlated for less well-informed investors, results consistent with stylized facts from the empirical literature. These theoretical findings are supported empirically using a new data set from the Israeli foreign exchange market. The empirical analysis indicates that a one million dollar larger purchase than sales by well-informed financial investors induces an increase of 0.060 per cent in the Israeli Sheqel/Dollar exchange rate over a one month period. A similar net flow from less well-informed investors results in a 0.046 per cent decrease in the exchange rate. Copyright © 2008 John Wiley & Sons, Ltd.
STRONGLY GRADED HEREDITARY ORDERS

Let R be a Dedekind domain with global quotient field K. The purpose of this note is to provide a characterization of when a strongly graded R-order with semiprime 1-component is hereditary. This generalizes earlier work by the first author and G. Janusz in (J. Haefner and G. Janusz, Hereditary crossed products, Trans. Amer. Math. Soc. 352 (2000), 3381–3410). *This work was supported in part by a Baylor University Research Grant.
WATER, O2, AND ICE IN MOLECULAR CLOUDS

We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external far-ultraviolet (FUV; 6 eV <hν < 13.6 eV) flux G 0 (scaling factor in multiples of the local interstellar field). Extending previous photodissociation region (PDR) models, we include the freezing of species, simple grain surface chemistry, and desorption (including FUV photodesorption) of ices. We also treat the opaque cloud interior with time-dependent chemistry. Here, under certain conditions, gas-phase elemental oxygen freezes out as water ice and the elemental C/O abundance ratio can exceed unity, leading to complex carbon chemistry. Gas-phase H2O and O2 peak in abundance at intermediate depth into the cloud, roughly AV ~ 3-8 from the surface, the depth proportional to ln(G 0/n). Closer to the surface, molecules are photodissociated. Deeper into the cloud, molecules freeze to grain surfaces. At intermediate depths, PDRs are attenuated by dust extinction, but photodesorption prevents total freeze-out. For G 0 < 500, abundances of H2O and O2 peak at values ~10–7, producing columns ~1015 cm–2, independent of G 0 and n. The peak abundances depend primarily on the product of the photodesorption yield of water ice and the grain surface area per H nucleus. At higher values of G 0, thermal desorption of O atoms from grains slightly enhances the gas-phase H2O peak abundance and column, whereas the gas-phase O2 peak abundance rises to ~10–5 and the column to ~2 × 1016 cm–2. We present simple analytical equations for the abundances as a function of depth, which clarify the dependence on parameters. The models are applied to observations of H2O, O2, and water ice in a number of sources, including B68, NGC 2024, and ρ Oph.
Rhodium(III)-catalyzed synthesis of phthalides by cascade addition and cyclization of benzimidates with aldehydes

We herein report the Rh(III)-catalyzed C–H bond activation and addition of benzimidates to aldehydes to afford biologically important phthalides in a single step. The imidate is a novel and unexplored directing group that not only enables C–H bond activation and addition to aldehydes, but also serves to capture the reversibly formed alcohol intermediate. The reaction shows broad scope with a high level of functional group compatibility and is applicable to both aromatic and aliphatic aldehydes.
Disorder in DNA-Linked Gold Nanoparticle Assemblies

We report experimental observations on the effect of disorder on the phase behavior of DNA-linked nanoparticle assemblies. Variation in DNA linker lengths results in different melting temperatures of the DNA-linked nanoparticle assemblies. We observed an unusual trend of a nonmonotonic ``zigzag'' pattern in the melting temperature as a function of DNA linker length. Linker DNA resulting in unequal DNA duplex lengths introduces disorder and lowers the melting temperature of the nanoparticle system. Comparison with free DNA thermodynamics shows that such an anomalous zigzag pattern does not exist for free DNA duplex melting, which suggests that the disorder introduced by unequal DNA duplex lengths results in this unusual collective behavior of DNA-linked nanoparticle assemblies.
Use of metal complexation in the synthesis of medium-ring acetylenic lactones

Abstract The hexacarbonyldicobalt complexes of several appropriately designed acetylenic lactone precursors have been prepared, and lactones containing Co2(CO)6-complexed triple bonds in seven-, ten-, and eleven-membered rings obtained. The latter were best obtained through a retro-Dieckmann fragmentation of 2-(hydroxybutynyl) derivatives of 1,3-clohexanedione. Attempts to extend this reaction to cyclohexanones bearing other anion-stabilizing groups in the 2-position or to 1,3-cyclopentanediones were unsuccessful. Decomplexation afforded the metal-free 11-ring lactone, characterized crystallographically. Treatment of this system with basic reagents led to dimerization. In the case of the smaller rings, cyclization of the complexed acetylenic hydroxyacids under Mukaiyama conditions (2-chloro-N-methylpyridinium iodide, CH2Cl2, reflux) succeeded in modest yields.
Minority carrier diffusion length and edge surface‐recombination velocity in InP

A scanning electron microscope was used to obtain the electron‐beam‐induced current (EBIC) profiles in InP specimens containing a Schottky barrier perpendicular to the scanned (edge) surface. An independent technique was used to measure the edge surface‐recombination velocity (Vs). These values were used in a fit of the experimental EBIC data with a theoretical expression for normalized EBIC [C. Donolato, Solid State Electron. 25, 1077 (1982)] to obtain the electron (minority carrier) diffusion length (Ln).
Photoreduction of Au(III) to form Au(0) nanoparticles using ferritin as a photocatalyst

Gold metal nanoparticles have applications in bio sensing technology, nano-tube formation, and cancer therapy. We report attempts to synthesize gold nanoparticles within the ferritin cavity (8 nm) or to use ferritin as a scaffold for coating gold on the outside surface (12 nm). The intrinsic iron oxide core of ferritin is a semi-conductor and light can excite electrons to a conduction band producing a powerful reductant when a sacrificial electron donor fills the electron hole. We present a method using ferritin to photo chemically reduce Au(III) to metallic gold nanoparticles. During initial studies we observed that the choice of buffers influenced the products that formed as evidenced by a red product formed in TRIS and a purple produce formed in MOPS. Gold nanoparticles formed in MOPS buffer in the absence of illumination have diameters of 15-30 nm whereas illumination in TRIS buffer produced 5-10 nm gold nanoparticles. Increases in temperature cause the gold nanoparticles to form more rapidly. Chemical reduction and photochemical reduction methods have very different reaction profiles with photochemical reduction possessing a lag phase prior to the formation of gold nanoparticles.
Entry, Exit, Embodied Technology, and Business Cycles

Abstract This paper studies the entry and exit of U.S. manufacturing plants over the business cycle and compares the results with those from a vintage capital model augmented to reproduce observed features of the plant life cycle. Looking at the entry and exit of plants provides new evidence supporting the hypothesis that shocks to embodied technological change are a significant source of economic fluctuations. In the U.S. economy, the entry rate covaries positively with output and total factor productivity growth, and the exit rate leads all three of these. A vintage capital model in which all technological progress is embodied in new plants reproduces these patterns. In the model economy, a persistent improvement to embodied technology induces obsolete plants to cease production, causing exit to rise. Later, as entering plants embodying the new technology become operational, both output and productivity increase.Journal of Economic LiteratureClassification Numbers: L16, E22.
Blow-up solutions on a sphere for the 3D quintic NLS in the energy space

We prove that if u(t) is a log-log blow-up solution, of the type studied by Merle and Raphael, to the L2 critical focusing NLS equation i∂tu+Δu+|u|4∕du=0 with initial data u0∈H1(ℝd) in the cases d=1,2, then u(t) remains bounded in H1 away from the blow-up point. This is obtained without assuming that the initial data u0 has any regularity beyond H1(ℝd). As an application of the d=1 result, we construct an open subset of initial data in the radial energy space Hrad1(ℝ3) with corresponding solutions that blow up on a sphere at positive radius for the 3D quintic (Ḣ1-critical) focusing NLS equation i∂tu+Δu+|u|4u=0. This improves the results of Raphael and Szeftel [2009], where an open subset in Hrad3(ℝ3) is obtained. The method of proof can be summarized as follows: On the whole space, high frequencies above the blow-up scale are controlled by the bilinear Strichartz estimates. On the other hand, outside the blow-up core, low frequencies are controlled by finite speed of propagation.
Patchy reconnection in a Y-type current sheet

We study the evolution of the magnetic field in a Y-type current sheet subject to a brief, localized magnetic reconnection event. The reconnection produces up- and down-flowing reconnected flux tubes which rapidly decelerate when they hit the Y-lines and underlying magnetic arcade loops at the ends of the current sheet. This localized reconnection outflow followed by a rapid deceleration reproduces the observed behavior of post-CME downflowing coronal voids. These simulations support the hypothesis that these observed coronal downflows are the retraction of magnetic fields reconnected in localized patches in the high corona.
THE LOCAL LEO COLD CLOUD AND NEW LIMITS ON A LOCAL HOT BUBBLE

We present a multi-wavelength study of the local Leo cold cloud (LLCC), a very nearby, very cold cloud in the interstellar medium (ISM). Through stellar absorption studies we find that the LLCC is between 11.3 pc and 24.3 pc away, making it the closest known cold neutral medium cloud and well within the boundaries of the local cavity. Observations of the cloud in the 21 cm H I line reveal that the LLCC is very cold, with temperatures ranging from 15 K to 30 K, and is best fit with a model composed of two colliding components. The cloud has associated 100 μm thermal dust emission, pointing to a somewhat low dust-to-gas ratio of 48 ×10–22 MJy sr–1 cm2. We find that the LLCC is too far away to be generated by the collision among the nearby complex of local interstellar clouds but that the small relative velocities indicate that the LLCC is somehow related to these clouds. We use the LLCC to conduct a shadowing experiment in 1/4 keV X-rays, allowing us to differentiate between different possible origins for the observed soft X-ray background (SXRB). We find that a local hot bubble model alone cannot account for the low-latitude SXRB, but that isotropic emission from solar wind charge exchange (SWCX) does reproduce our data. In a combined local hot bubble and SWCX scenario, we rule out emission from a local hot bubble with an 1/4 keV emissivity greater than 1.1 Snowdens pc–1 at 3σ, four times lower than previous estimates. This result dramatically changes our perspective on our local ISM.
Carbon nanotube computer: transforming scientific discoveries into working systems

Carbon Nanotube Field Effect Transistors (CNFETs) are excellent candidates for building highly energy-efficient future electronic systems. Unfortunately, carbon nanotubes (CNTs) are subject to substantial inherent imperfections that pose major obstacles to the design of robust and very large-scale CNFET digital systems: It is nearly impossible to guarantee perfect alignment and positioning of all CNTs. This limitation introduces stray conducting paths, resulting in incorrect circuit functionality.CNTs can be metallic or semiconducting depending on chirality. Metallic CNTs cause shorts resulting in excessive leakage and incorrect circuit functionality.A combination of design and processing techniques overcomes these challenges by creating robust CNFET digital circuits that are immune to these inherent imperfections. This imperfection-immune design paradigm enables the first experimental demonstration of the carbon nanotube computer, and, more generally, arbitrary digital systems that can be built using CNFETs. Monolithically-integrated three-dimensional CNFET circuits will also be discussed.This research was performed at Stanford University in collaboration with Prof. H.-S. Philip Wong and several graduate students.
The gastrointestinal motility laboratory.

Abnormalities of gastrointestinal (GI) motor function contribute directly or indirectly to a number of common clinical problems and account for significant health care–related expenditure. Proper evaluation of patients who have suspected GI motility disorders is important to ensure a correct diagnosis and to embark on an appropriate plan of treatment. The GI motility laboratory serves as an important area for patient evaluation in gastroenterology and is an essential element in any comprehensive digestive disease program. This article addresses important concepts in setting up and running an efficient and practical GI motility laboratory.
Comparison of two and three spatial dimensional solutions of the wave equation at ocean‐basin scales in the presence of internal waves

Numerical solutions are given for a parabolic approximation to the acoustic wave equation at 75 Hz in two and three spatial dimensions to determine if azimuthal coupling of the field significantly affects horizontal coherence. Coupling is a small effect at 4000 km in the presence of internal gravity waves. This implies that accurate solutions are possible using computations from uncoupled vertical slices through the field. The shape of horizontal coherence is inconsistent with shapes given by two theories. Estimates of horizontal coherence at 4000 km and 25, 50, and 75 Hz are 10, 2, and 1 km respectively. [Work supported by the ONR.]
Nuclear A-dependence near the saturation boundary

The A-dependence of the saturation momentum and the scaling behavior of the scattering of a small dipole on a nuclear target are studied in the McLerran–Venugopalan model, in fixed coupling BFKL dynamics and in running coupling BFKL dynamics. In each case, we find scaling not too far from the saturation boundary, although for fixed coupling evolution the scaling function for large A is not the same as for an elementary dipole. We find that Qs2 is proportional to A1/3 in the McLerran–Venugopalan model and in fixed coupling evolution, however, we find an almost total lack of A-dependence in Qs2 in the case of running coupling evolution.
Giant varices in portal hypertension: CT findings

Two cases of giant varices in portal hypertension are presented. Dynamic computed tomography (CT) was useful in establishing that the masses were in fact dilated veins.
Superconducting linacs — some recent developments☆

Abstract The paper is a review of superconducting linacs that are of interest for heavy-ion acceleration. Most of the paper is concerned with energy boosters for projectiles from tandem electrostatic accelerators, the only application for which superconducting linacs are now used for heavy-ion acceleration. There is also a brief discussion of the concept of a superconducting injector linac being developed as a replacement of the tandem in a multi-stage acceleration system. Throughout, the emphasis is on the technology of the superconducting linac, including some attention to the relationships between resonator design parameters and accelerator performance characteristics.
Credibility may require discretion, not rules

Abstract We reexamine the common argument that rules produce greater credibility than discretion. Rules limit the actions of agents, restricting observations of the agents’ preferences or types. In a second-best world, where rules cannot be everlasting, a regime of discretion in some periods may produce superior credibility and dominate a regime of rules.
Vortex transport and voltage noise in disordered superconductors

Abstract We study, by means of three-dimensional Monte Carlo simulations, the current–voltage (I–V) characteristics and the voltage noise spectrum at low temperatures of driven magnetic flux lines interacting with randomly placed point or columnar defects, as well as with periodically arranged linear pinning centers. Near the depinning current Jc, the voltage noise spectrum S(ω) universally follows a 1/ωα power law. For currents J>Jc, distinct peaks appear in S(ω) which are considerably more pronounced for extended as compared to point defects, and reflect the spatial distribution of the correlated pinning centers.