cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurement of the muon anomaly to high and even higher precision

Our recent series of measurements at Brookhaven National Laboratory determined the muon anomalous magnetic moment α μ to a precision of 0.5 ppm. The final result—representing the average of five running periods using both positive and negative muons—is α μ ± = 11 659 208 ( 6 ) × 10 −10 . It lies 2.7 standard deviations above the standard model expectation, which is based on updates given at this Workshop. Importantly, only the e + e − annihilation and new KLOE radiative return data are used for the hadronic vacuum polarization input. Because the systematic limit has not been reached in the experiment, a new effort has been proposed and approved with the highest scientific priority at Brookhaven. The goal is an experimental uncertainty of 0.2 ppm, a 2.5-fold reduction in the overall experimental uncertainty. To do so will require a suite of upgrades and several qualitative changes in the philosophy of how the measurement is carried out. I discuss the old and new experiments with a particular emphasis on the technical matters that require change for the future.
DISCOVERY OF A CANDIDATE FOR THE COOLEST KNOWN BROWN DWARF

We have used multi-epoch images from the Infrared Array Camera on board the Spitzer Space Telescope to search for substellar companions to stars in the solar neighborhood based on common proper motions. Through this work, we have discovered a faint companion to the white dwarf WD 0806-661. The comoving source has a projected separation of 130'', corresponding to 2500 AU at the distance of the primary (19.2 pc). If it is physically associated, then its absolute magnitude at 4.5 μm is ~1 mag fainter than the faintest known T dwarfs, making it a strong candidate for the coolest known brown dwarf. The combination of M 4.5 and the age of the primary (1.5 Gyr) implies an effective temperature of ~300 K and a mass of ~7 M Jup according to theoretical evolutionary models. The white dwarf's progenitor likely had a mass of ~2 M ☉, and thus could have been born with a circumstellar disk that was sufficiently massive to produce a companion with this mass. Therefore, the companion could be either a brown dwarf that formed like a binary star or a giant planet that was born within a disk and has been dynamically scattered to a larger orbit.
Signal-to-noise Ratio of Heterodyne Lidar Systems in the Presence of Atmospheric Turbulence

A general expression for the signal-to-noise ratio of a heterodyne lidar system in the presence of atmospheric turbulence is derived which is valid both in the near- and far-field of the laser and remoted scattering source. We consider the situation where a laser transmitter directs an optical beam at some remote scattering region of interest. The backscattered light is collected by a receiving aperture and mixed with a suitable coherent local oscillator reference field. Both coaxial and bistatic lidar systems are considered. In both cases we are able to obtain algebraic expressions for the signal-to-noise ratio which are valid for an arbitrary propagation path through the atmosphere. Numerical results are presented for both a 3.7 and 10.6 micrometer lidar system. Additionally, we obtain the conditions under which atmospheric turbulence will limit severely the performance of heterodyne lidar systems.
SURGERY DESCRIPTIONS AND VOLUMES OF BERGE KNOTS I: LARGE VOLUME BERGE KNOTS

By obtaining surgery descriptions of knots which lie on the genus one fiber of the trefoil or figure eight knot, we show that these include hyperbolic knots with arbitrarily large volume. These knots admit lens space surgeries and form two families of Berge knots. By way of tangle descriptions we also obtain surgery descriptions for these knots on minimally twisted chain links.
Application of a variational method for generating adaptive grids

The application of variational methods for generating adaptive grids is not as straightforward as one is led to believe. Proper scaling, suitable weight functions and appropriate clustering on boundaries must be employed to obtain a satisfactory grid. This work, which is based on the framework developed by Brackbill and Saltzman, provides simple methods for determining scaling and investigates possible options for selecting the weight function and clustering points on the boundaries. The concepts developed here are applied to two two-dimensional problems: a model problem based on Burger's equation which contains two length scales and, transonic flow past airfoils using the Euler equations.
The demand for E85: Geographical location and retail capacity constraints

Abstract Consumption of high-ethanol gasoline blends must increase if United States renewable biofuel mandates are to rise above current levels as envisioned by the Renewable Fuel Standard. One such blend is E85 which contains no more than 85% ethanol and no less than 15% gasoline. We derive the demand for E85 based on a model of motorists' preferences for motor fuel blends and calibrate the demand for E85 using data on the location of flex vehicles and fuel stations that sell E85 in the United States. We also show how limits on the capacity of fuel stations to sell E85 affect demand and explore the potential future demand for E85 by increasing the number of fuel stations offering E85 and the number of flex vehicles. We show that the existing fleet of flex vehicles is sufficient to accommodate more than 15 billion gallons of ethanol without a large price discount on E85 only if the number of stations that sell E85 increases substantially. Provided with fast enough installation of new E85 pumps, this level of consumption would be sufficient to meet the mandates envisioned for conventional ethanol by 2015.
A renormalized index theorem for some complete asymptotically regular metrics: the Gauss - Bonnet theorem

Abstract We study the Gauss–Bonnet theorem as a renormalized index theorem for edge metrics. These metrics include the Poincare–Einstein metrics of the AdS/CFT correspondence and the asymptotically cylindrical metrics of the Atiyah–Patodi–Singer index theorem. We use renormalization to make sense of the curvature integral and the dimensions of the L 2 -cohomology spaces as well as to carry out the heat equation proof of the index theorem. For conformally compact metrics even mod x m , we show that the finite time supertrace of the heat kernel on conformally compact manifolds renormalizes independently of the choice of special boundary defining function.
A multi-scale model for correlation in B cell VDJ usage of zebrafish

The zebrafish (Danio rerio) is one of the model animals used for the study of immunology because the dynamics in the adaptive immune system of zebrafish are similar to that in higher animals. In this work, we built a multi-scale model to simulate the dynamics of B cells in the primary and secondary immune responses of zebrafish. We use this model to explain the reported correlation between VDJ usage of B cell repertoires in individual zebrafish. We use a delay ordinary differential equation (ODE) system to model the immune responses in the 6-month lifespan of a zebrafish. This mean field theory gives the number of high-affinity B cells as a function of time during an infection. The sequences of those B cells are then taken from a distribution calculated by a 'microscopic' random energy model. This generalized NK model shows that mature B cells specific to one antigen largely possess a single VDJ recombination. The model allows first-principle calculation of the probability, p, that two zebrafish responding to the same antigen will select the same VDJ recombination. This probability p increases with the B cell population size and the B cell selection intensity. The probability p decreases with the B cell hypermutation rate. The multi-scale model predicts correlations in the immune system of the zebrafish that are highly similar to that from experiment.
Patterns and determinants of intra-industry trade in Asia

Abstract Intra-industry trade (IIT) has gained in importance across Asia as a result of the rapid growth of Asian economies and their key role in the international fragmentation of production. This paper examines the level of IIT for 22 countries in East, Southeast, South, and Central Asia in 2003. IIT is measured as a multilateral trade-weighted index and is reported for ten different categories of goods in the primary and secondary sectors. In addition, the determinants of IIT are investigated using a Tobit regression model. The results indicate that ASEAN and the high-income countries in East Asia exhibit the highest levels of IIT, followed closely by China and India. R&D spending, openness, and a higher share of manufactured exports were found to promote IIT, while geographical distance and the difference in economic size had an adverse effect, especially for manufactured goods. The ASEAN free trade area was most prominently associated with IIT across all SITC categories. Central and South Asian regional trade agreements had a positive influence on IIT in primary products.
Experimental study of the kinetics of the reaction of acetic acid with hydroxyl radicals from 255 to 355 K.

The rate constant of the reaction of OH with acetic acid over the temperature range of 255−355 K was determined using our High-Pressure Flow System with laser-induced fluorescence detection of the OH radicals and FTIR spectrometry for acetic acid quantification. The rate constant displays a negative temperature dependence and can be described by the Arrhenius expression: k1(T) = (5.38 ± 0.28) × 10−14 exp(740 ± 51/T) cm3 molecule −1 s−1, with k1 = (6.77 ± 0.14) × 10−13 cm3 molecule −1 s−1 at 295 K. The negative temperature dependence suggests a pre-reactive complex formation between the OH radicals and the acetic acid monomer, and this result is consistent with previous reports. The use of FTIR spectrometry allows for separation of the acetic acid monomer and dimer in the spectrum and gives a measurement of the acetic acid monomer that is independent of the temperature measurement and free of reliance on an equilibrium constant expression that can introduce high uncertainty. The highly sensitive laser-indu...
Experiments and modeling of bubble column dehumidifier performance

Abstract Humidification–dehumidification is a promising technology for decentralized, small-scale desalination, but conventional dehumidifiers are expensive due to the large surface area required. Direct-contact dehumidification in bubble columns has been shown to significantly decrease dehumidifier size and cost. In this paper, the heat flux and parallel-flow effectiveness of a bubble column dehumidifier are investigated experimentally using significantly smaller cooling coils than in previous work. In addition, a model is developed which predicts the heat transfer rate with an average error of less than 3%. It is found that heat flux rises and effectiveness decreases with decreasing coil area. Increasing air flow rate and air temperature both lead to increased heat flux but decreased effectiveness. Neither bubble-on-coil impact nor column height are found to significantly affect heat flux or effectiveness. The conflicting findings of previous research on bubble-on-coil impact are explained by the other trends identified in this work. Modeling results for salt water temperature and tube diameter are presented. Additional heat transfer in the air gap above the column liquid is explored, but found to be minimal for well-designed columns with low temperature pinch. These findings will inform the design of bubble column dehumidifiers for high heat recovery and low capital cost.
An Improved Transient Method for the Synthesis of N-Benzoylated Nucleosides

Abstract The Jones' transient method for the synthesis of N-benzoylated nucleosides is improved by reducing the amounts of chlorotrimethylsilane (TMSCl) and benzoyl chloride to nearly equivalent quantities. The easy work-up and high yields of products are the major advantages of this approach. Jones' method is further simplified by omitting the addition of ammonium hydroxide. The utility of this modification for the preparation of some useful protected nucleosides is also presented.
Color-singlet technipions at the Tevatron

Abstract I discuss production and detection at the Tevatron p p collider of pairs of light ( M π T = 100–200GeV) color-singlet technipions that are expected in all nonminimal models of technicolor. Gluon fusion production rates can be as large as O (1 pb). Topcolor-assisted technicolor is required to prevent top quarks from decaying at t → π T + b . An intriguing consequence of this is that the decays π T + → τ + ν τ , c s and π T 0 → b b may also be suppressed so that π T + → W + γ and π T 0 → γγ are significant. These modes have spectactular signatures at the Tevatron.
Observations of 1–30 MeV gamma rays from the galactic center

Preliminary results are reported for gamma ray observations of the galactic center region made during a 15-hour balloon flight from Alice Springs, Australia on April 18, 1979. The observations were carried out with the UGR double-scatter gamma-ray telescope at energies of 1 to 30 MeV. The observations are compatible with a galactic source of approximately equal brightness along the region of system II galactic longitudes between 300 and 60 deg. The energy distribution joins smoothly to previous spark chamber results at energies above 30 MeV and to scintillator results below 1 MeV. It appears to be a combination of nuclear gamma ray lines superimposed on a power-law bremsstrahlung spectrum. The metastable C-12 line at 4.4 MeV appears to be present with a significance of about 16 standard deviations. The flux in the line is 0.0006 + or - 0.0003 photons/sq cm per sec per rad. The oxygen line at 6.1 MeV does not seem to appear significantly above background.
Concentration, incumbency, and interconnection: broadband development and the lessons of history

With recent investments in broadband network development, policymakers have devoted new attention and resources to the social, economic, and political questions surrounding broadband development. While progressive policy in this space necessarily depends on careful forward thinking, it would also benefit from more thoughtful forms of hindsight that bring the lessons of history to bear on the ongoing problems of network development. This paper re-thinks and re-grounds current broadband development efforts from the standpoint of three central challenges -- concentration, incumbency, and interconnection -- that have long shaped and limited policy efforts in the telecommunications and wider infrastructural industries. Long-term success of the sort envisioned under the National Broadband Plan and broadband stimulus programs will depend on new and better solutions to these problems.
Encapsulation of cationic ruthenium complexes into a chiral self-assembled cage.

A chiral supramolecular assembly encapsulates the two cationic ruthenium sandwich complexes [CpRu(η6-C6H6)]+ and [CpRu(p-cymene)]+. The host−guest complexes K11[CpRu(η6-C6H6) ⊂ Ga4L6] (2) and K11[CpRu(p-cymene) ⊂ Ga4L6] (3) were characterized by one- and two-dimensional NMR techniques as well as by electrospray mass spectrometry. Encapsulation of the prochiral complex [CpRu(p-cymene)]+ by the chiral host renders enantiotopic protons diastereotopic as evidenced by 1H NMR spectroscopy.
Fuel Cell/Gas Turbine Hybrid System Control for Daily Load Profile and Ambient Condition Variation

Fuel Cell/Gas Turbine (FC/GT) hybrid technology is promising, but introduces challenges in system operation and control. For base-load applications, changes in ambient conditions perturb the system and it becomes difficult to maintain constant power production by the FC/GT system. If the FC/GT hybrid system is load-following, then the problem becomes even more complex. In the current study, a dynamic model of a FC/GT power plant is developed with system controls. Two cases are evaluated: (1) system controls are developed to maintain constant power and process control within acceptable constraints and (2) the FC/GT power plant is set in power following mode connected in parallel to the grid for a daily load profile scenario. Changing ambient conditions are employed in the dynamic analysis for both cases. With appropriate attention to design of the system itself and the control logic, the challenges for dynamic system operation and control can be addressed. © 2010 by ASME.
One-Step Synthesis of Methyl Esters from Nitriles

Abstract Polyphosphate ester that contains methanol easily converts aromatic and alkyl nitriles in one step and in high yield to the corresponding methyl ester at 120° – 150°c.
The cosmological constant in Calabi–Yau 3-fold compactifications of the Horava–Witten theory

Abstract Brane world scenarios offer a way of setting the cosmological constant to zero after supersymmetry breaking provided there is a sufficient number of adjustable integration constants/parameters. In the case of the Horava–Witten theory compactified on a Calabi–Yau three-fold, we argue that it is difficult to find enough freedom to get a zero (or small) cosmological constant after supersymmetry breaking.
ON THE MEASUREMENT OF ELEMENTAL ABUNDANCE RATIOS IN INNER GALAXY H II REGIONS

Although abundance gradients in the Milky Way Galaxy certainly exist, details remain uncertain, particularly in the inner Galaxy, where stars and H II regions in the Galactic plane are obscured optically. In this paper we revisit two previously studied, inner Galaxy H II regions: G333.6-0.2 and W43. We observed three new positions in G333.6-0.2 with the Kuiper Airborne Observatory and reobserved the central position with the Infrared Space Observatory's Long Wavelength Spectrometer in far-infrared lines of S++, N++, N+, and O++. We also added the N+ lines at 122 and 205 microns to the suite of lines measured in W43 by Simpson et al.. The measured electron densities range from approx. 40 to over 4000 per cu cm in a single HII region, indicating that abundance analyses must consider density variations, since the critical densities of the observed lines range from 40 to 9000 per cu cm. We propose a method to handle density variations and make new estimates of the S/H and N/H abundance ratios. We find that our sulfur abundance estimates for G333.6-0.2 and W43 agree with the S/H abundance ratios expected for the gradient previously reported by Simpson et al., with the S/H values revised to be smaller owing to changes in collisional excitation cross sections. The estimated N/H, S/H, and N/S ratios are the most reliable because of their small corrections for unseen ionization states (< or approx. 10%). The estimated N/S ratios for the two sources are smaller than what would be calculated from the N/H and S/H ratios in our previous paper. If all low excitation H II regions had similar changes to their N/S ratios as a result of adding measurements of N+ to previous measurements of N++, there would be no or only a very small gradient in N/S. This is interesting because nitrogen is considered to be a secondary element and sulfur is a primary element in galactic chemical evolution calculations. We compute models of the two H II regions to estimate corrections for the other unseen ionization states. We find, with large uncertainties, that oxygen does not, have a high abundance, with the result that the N/O ratio is as high (approx. 0.35) as previously reported. The reasons for the uncertainty in the ionization corrections for oxygen are both the non-uniqueness of the H II region models and the sensitivity of these models to different input atomic data and stellar atmosphere models. We discuss these predictions and conclude that only a few of the latest models adequately reproduce H II region observations, including the well-known, relatively-large observed Ne++/O++ ratios in low- and moderate-excitation H II regions.
Reduction of the Hall–Paige conjecture to sporadic simple groups

Abstract A complete mapping of a group G is a permutation ϕ : G → G such that g ↦ g ϕ ( g ) is also a permutation. Complete mappings of G are equivalent to transversals of the Cayley table of G, considered as a Latin square. In 1953, Hall and Paige proved that a finite group admits a complete mapping only if its Sylow-2 subgroup is trivial or noncyclic. They conjectured that this condition is also sufficient. We prove that it is sufficient to check the conjecture for the 26 sporadic simple groups and the Tits group.
Fiber motion analysis by two-pulse holography

Double-pulse in-line Fraunhofer holography has been applied to the development of an aerosol spectrometer. The device, which has been applied to asbestos (crocidolite) dust, yields estimates of position, velocity, size, shape, and tumbling rate.
Cascadic Multilevel Algorithms for Symmetric Saddle Point Systems

Abstract In this paper, we introduce a multilevel algorithm for approximating variational formulations of symmetric saddle point systems. The algorithm is based on availability of families of stable finite element pairs and on the availability of fast and accurate solvers for symmetric positive definite systems . On each fixed level an efficient solver such as the gradient or the conjugate gradient algorithm for inverting a Schur complement is implemented. The level change criterion follows the cascade principle and requires that the iteration error be close to the expected discretization error. We prove new estimates that relate the iteration error and the residual for the constraint equation. The new estimates are the key ingredients in imposing an efficient level change criterion. The first iteration on each new level uses information about the best approximation of the discrete solution from the previous level. The theoretical results and experiments show that the algorithms achieve optimal or close to optimal approximation rates by performing a non-increasing number of iterations on each level. Even though numerical results supporting the efficiency of the algorithms are presented for the Stokes system, the algorithms can be applied to a large class of boundary value problems, including first order systems that can be reformulated at the continuous level as symmetric saddle point problems, such as the Maxwell equations.
Supernova Remnants in Molecular Clouds

Massive (8 M☉) stars may end their lives in the molecular clouds in which they were born. O-type stars probably have sufficient photoionizing radiation and wind power to clear a region more than 15 pc in radius of molecular material. Early B stars (B1-B3 on the main sequence, or 8-12 M☉ stars) are not capable of this and may interact directly with molecular gas when they explode. Molecular clouds are known to be clumpy, with dense molecular clumps occupying only a few percent of the volume. A supernova remnant then evolves primarily in the interclump medium, which has a density nH=5-25 H atoms cm-3. The remnant becomes radiative at a radius of ~6 pc, forming a shell that is magnetically supported. The structure of the shell can be described by a self-similar solution. When this shell interacts with the dense clumps, the molecular shock fronts are driven by a considerable overpressure compared to the pressure in the rest of the remnant. The expected range of clump sizes leads to a complex velocity distribution, with the possibility of molecular gas accelerated to a high velocity. Observations of the remnants W44 and IC 443 can be understood in this model. W44 has a shell expanding at ~150 km s-1 into a medium with density 4-5 cm-3. The shock emission expected in such a model is consistent with the observed Hα surface brightness and the [O I] 63 μm line luminosity. The clump interaction is seen in OH maser emission, which shows a magnetic field strength that is consistent with that expected in the model. IC 443 appears to be expanding at a lower velocity, 100 km s-1, into an interclump medium with a higher density, ~15 cm-3. The interaction of the radiative shell with molecular clumps can produce the molecular emission that is observed from IC 443. Both remnants are shell sources of radio synchrotron emission, which can be attributed to relativistic electrons in the cool radiative shell. If ambient cosmic-ray electrons are further accelerated by the shock front and by the postshock compression, the radio fluxes and the flat spectral indices of W44 and IC 443 can be explained. The energetic electrons are in a high-density shell and their bremsstrahlung emission can approximately produce the γ-ray fluxes observed by EGRET. Molecular clouds have a significant uniform magnetic field component so that heat conduction is likely to be important in the hot interior and can explain the isothermal X-ray emission observed from the remnants.
Palladium-Catalyzed Coupling of Ammonia with Aryl Chlorides, Bromides, Iodides, and Sulfonates: A General Method for the Preparation of Primary Arylamines

We report that the complex generated from Pd[P(o-tol)3]2 and the alkylbisphosphine CyPF-t-Bu is a highly active and selective catalyst for the coupling of ammonia with aryl chlorides, bromides, iodides, and sulfonates. The couplings of ammonia with this catalyst conducted with a solution of ammonia in dioxane form primary arylamines from a variety of aryl electrophiles in high yields. Catalyst loadings as low as 0.1 mol % were sufficient for reactions of many aryl chlorides and bromides. In the presence of this catalyst, aryl sulfonates also coupled with ammonia for the first time in high yields. A comparison of reactions in the presence of this catalyst versus those in the presence of existing copper and palladium systems revealed a complementary, if not broader, substrate scope. The utility of this method to generate amides, imides, and carbamates is illustrated by a one-pot synthesis of a small library of these carbonyl compounds from aryl bromides and chlorides, ammonia, and acid chlorides or anhydrid...
Some applications of the overlap formalism

The massless vector Schwinger model with N f = 1, 2, 3, 4 number of flavors is studied on the lattice using the overlap formalism. A full Monte Carlo simulation yields values for the bilinear fermion condensate that are in agreement with the exact solution of the continuum Schwinger model with an added Thirring interaction.
Mechanism of action of steroid hormones.

Abstract Despite the diversity in the target sites and physiological actions of the steroids, an impressive body of evidence has been assembled in support of a unitary theory of the mechanism of action of these hormones in vertebrates. The steroids set in motion a train of events, as follows: (a) penetration into the target cell, (b) stereospecific binding to high affinity receptors, (c) temperature-sensitive activation of the steroid-receptor complex, (d) attachment of the active complex to chromatin, (e) induction of RNA and protein synthesis, and (f) physiological expression of the induced protein. Although the overall sequence is well-defined, our knowledge of the molecular processes involved in each of these steps is still quite incomplete. Two of the major efforts now underway to elucidate these molecular processes involve, (a) purification and characterization, in terms of structure-function relations, of the putative receptors, and (b) studies on the nature of the interaction between steroid-receptor complexes and the genome. It is now apparent that steroids induce de novo synthesis of both messenger RNA (mRNA) and ribosomal RNA (rRNA); the role of the former in directing the synthesis of specific proteins is reasonably clear but that of the latter remains to be elucidated. The mechanism of induction is also under scrutiny since the observed increases in mRNA synthesis could arise in a variety of ways, e.g. negative or positive regulation of chromatin template (gene) activity, changes in processing of heterogeneous RNA to mRNA, effects on RNA polymerase or ribonuclease activities. Although steroidal regulation of RNA and protein synthesis is a dominant pathway, the possibility of direct actions on membranes or regulatory enzymes in some circumstances can not be excluded at the present time.
Developing verified programs with dafny

Dafny is a programming language and program verifier. The language includes specification constructs and the verifier checks that the program lives up to its specifications. These tutorial notes give some Dafny programs used as examples in the tutorial.
Neural changes in control implementation of a continuous task

It is commonly agreed that control implementation, being a resource-consuming endeavor, is not exerted continuously or in simple tasks. However, most research in the field was done using tasks that varied the need for control on a trial-by-trial basis (e.g., Stroop, flanker) in a discrete manner. In this case, the anterior cingulate cortex (ACC) was found to monitor the need for control, whereas regions in the prefrontal cortex (PFC) were found to be involved in control implementation. Whether or not the same control mechanism would be used in continuous tasks was an open question. In our study, we found that in a continuous task, the same neural substrate subserves control monitoring (ACC) but that the neural substrate of control implementation changes over time. Early in the task, regions in the PFC were involved in control implementation, whereas later the control was taken over by subcortical structures, specifically the caudate. Our results suggest that humans possess a flexible control mechanism, with a specific structure dedicated to monitoring the need for control and with multiple structures involved in control implementation.
Continuous newton method and its modification

The Continuous Newton method CNM and its modification MCNM are studied. MCNM permits one to replace the inversion of the derivative operator at every step of iterations by its inversion only at the initial approximation point. Then the extended system of the differential equations in Hilbert space, introduced in this paper, permits the realization of the iterative process with the simultaneous calculation of the inverse derivative operator. For CNM and MCNM the theorems establishing convergence with exponential rate are proved. The convergence theorem for MCNM is proved under almost the same conditions as for CNM.
A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data

Wavelets are scalable, oscillatory functions that deviate from zero only within a limited spatial regime and have average value zero, and thus may be used to simultaneously characterize the shape, location, and strength of astronomical sources. But in addition to their use as source characterizers, wavelet functions are rapidly gaining currency within the source detection field. Wavelet-based source detection involves the correlation of scaled wavelet functions with binned, two-dimensional image data. If the chosen wavelet function exhibits the property of vanishing moments, significantly nonzero correlation coefficients will be observed only where there are high-order variations in the data; e.g., they will be observed in the vicinity of sources. Source pixels are identified by comparing each correlation coefficient with its probability sampling distribution, which is a function of the (estimated or a priori known) background amplitude. In this paper, we describe the mission-independent, wavelet-based source detection algorithm "WAVDETECT," part of the freely available Chandra Interactive Analysis of Observations (CIAO) software package. Our algorithm uses the Marr, or "Mexican Hat" wavelet function, but may be adapted for use with other wavelet functions. Aspects of our algorithm include: (1) the computation of local, exposure-corrected normalized (i.e., flat-fielded) background maps; (2) the correction for exposure variations within the field of view (due to, e.g., telescope support ribs or the edge of the field); (3) its applicability within the low-counts regime, as it does not require a minimum number of background counts per pixel for the accurate computation of source detection thresholds; (4) the generation of a source list in a manner that does not depend upon a detailed knowledge of the point spread function (PSF) shape; and (5) error analysis. These features make our algorithm considerably more general than previous methods developed for the analysis of X-ray image data, especially in the low count regime. We demonstrate the robustness of WAVDETECT by applying it to an image from an idealized detector with a spatially invariant Gaussian PSF and an exposure map similar to that of the Einstein IPC; to Pleiades Cluster data collected by the ROSAT PSPC; and to simulated Chandra ACIS-I image of the Lockman Hole region.
Siegel zeros of Eisenstein series

If E(z,s) is the nonholomorphic Eisenstein series on the upper half plane, then for all y sufficiently large, E(z,s) has a "Siegel zero." That is E(z,\beta)=0 for a real number \beta just to the left of one. We give a generalization of this result to Eisenstein series formed with real valued automorphic forms on a finite central covering of the adele points of a connected reductive algebraic group over a global field.
Corrosion of Silicon-Based Ceramics in Combustion Environments

The processes of passive oxidation, deposit-induced corrosion, active oxidation, scale/substance interactions, and scale volatility are presently studied in the case of high-purity SiC and Si3N4 in pure oxygen, giving attention to such secondary elements in the ceramics as water and CO2 oxidants, combustion environment impurities, and thermal cycling. Deposit-induced corrosion is discussed for the cases of NaSO4 as well as vanadate and oxide-slag deposits; issues associated with the active-to-passive oxidation transition are noted.
The future of urology.

UROLOGY IS currently defined as the surgical specialty that treats diseases of the adrenals , urinary system in women, and urinary and genital systems in men. Presently, of more than 550,000 physicians in the United States, 8,400 state the practice of urology is their livelihood. The American Urological Association was founded in 1902. The Board of Urology was founded in 1934 and has since certified 9,948 applicants. Urology is currently divided into eight sections in the United States for organizational purposes, and each section contributes to the annual national meeting. Areas in which urologists currently work include the treatment of congenital anomalies, neoplasia, inflammatory disorders, renovascular problems and hypertension, infertility, incontinence, surgical adrenal disease, stone disease in the urinary tract , impotence, and urinary diversion for bladder substitution. The average urologist spends about 42 % of his time in the operating room and the rest in travel, office work, outpatient care, and hospital rounds. Presently, 97 % of urologists are in private practice. Three percent are full-time academicians and one tenth of 1 % state that they are full-time academic , full-time research employed. Recent events have occurred to further decrease the operating room time for the average urologist. Chemotherapy for testis tumors, pioneered by Einhorn of Indiana and Samuels of M.D. Anderson, along with extracorporeal shockwave lithotripsy, have resulted in a decrease of about 22 % in major surgery performed by urologists . Millions will be spent in the next few years seeking alternatives to the most common major operation in the field of urology, the transurethral resection of the prostate. Under continuing investigation will be a-
Earnings-based bonus plans and earnings management by business-unit managers

Abstract This study tests the bonus-maximization hypothesis that managers make discretionary accrual decisions to maximize their short-term bonuses. By using the management and financial reporting database of a large conglomerate, we extend previous investigations in two ways. First, the analysis is conducted using business unit-level data, which reduces the aggregation problem that is likely to arise using firm-level data. Second, managers in this setting are paid bonuses based solely on business unit earnings. The potentially confounding effects of long-term performance and stock-based incentive compensation are thus absent. These innovations yield robust evidence consistent with Healy (1985) .
The Effect of Asymmetrically Held Information and Market Power in Agricultural Markets

Division of Agricultural Sciences U~IVERSITY OF'CALIFORNIA ~rking Paper No. 264 THE EFFECT OF ASYMMETRICALLY HELD INFORMATION AND MARKET POWER IN AGRICULTURAL MARKETS Jeffrey M. Perloff and Gordon C. Rausser California Agricultural Experiment Station Giannini Foundation of Agricultural Economics
PRTAD: A database for protein residue torsion angle distributions

PRTAD is a dedicated database and structural bioinformatics system for protein analysis and modelling. The database is developed to host and analyse the statistical data for protein residue level 'virtual' bond and torsion angles obtained from their distributions in databases of known protein structures such as in the PDB Data Bank. PRTAD is capable of generating, caching, and displaying the statistical distributions of the angles of various types. The collected information can be used to extract geometric restraints or define statistical potentials for protein structure determination. PRTAD is supported with a friendly designed web interface so that users can easily specify the angle types, and retrieve, visualise, or download the distributions of the angles as they desire.
Nickel-catalyzed cross-coupling of potassium aryl- and heteroaryltrifluoroborates with unactivated alkyl halides.

A method for the cross-coupling of alkyl electrophiles with various potassium aryl- and heteroaryltrifluoroborates has been developed. Nearly stoichiometric amounts of organoboron species could be employed to cross-couple a large variety of challenging heteroaryl nucleophiles. Several functional groups were tolerated on both the electrophilic and the nucleophilic partners. Chemoselective reactivity of C(sp3)−Br bonds in the presence of C(sp2)−Br bonds was achieved.
Synthesis of arabinofuranosides via low-temperature activation of thioglycosides

Abstract The synthesis of oligosaccharides containing arabinofuranose residues is reported. Coupling of thioglycoside donors 4 , 6 , or 7 and with acceptors 8 – 17 using N -iodosuccinimide and silver triflate activation provided glycosides with varying degrees of stereocontrol.
Output Fluctuations at the Plant Level

This paper examines the short-run dynamics of manufacturing costs by detailing how plants in the U. S. automobile industry change output. Weekly data show a variety of margins on which firms adjust production. These margins, which are distinct from the usual factor demand choices, differ in their lumpiness, their adjustment costs, and their variable costs. The existence of these margins explains several empirical puzzles of output fluctuations. Using a theory of the short-run dynamic cost function, we are able to infer some of the characteristics of the underlying cost function from the dynamic behavior of the different margins.
The Modigliani-Miller Propositions After Thirty Years

This issue of the Journal of Economic Perspectives appears on the 30th anniversary of the Modigliani-Miller propositions in "The Cost of Capital, Corporation Finance and the Theory of Investment," published in the American Economic Review, June 1958. The editors have invited me, if not to celebrate, at least to mark the event with a retrospective look at what we set out to do on that occasion and an appraisal of where the propositions stand today after three decades of intense scrutiny and often bitter controversy. Some of these controversies can be now be regarded as settled. Our Proposition I, holding the value of a firm to be independent of its capital structure (that is, its debt/equity ratio) is accepted as an implication of equilibrium in perfect capital markets. The validity of our then-novel arbitrage proof of that proposition is also no longer disputed, and essentially similar arbitrage proofs are now common throughout finance. Propositions analogous to, and often even called, M and M propositions, have spread beyond corporation finance to the fields of money and banking, fiscal policy and international finance.
The interaction of an incident shock wave with liquid fuel drops

Liquid hydrocarbon fuel drop interaction with incident shock wave in oxidizing and inert atmospheres, investigating aerodynamic shattering and combustion
Recent developments in no-core shell-model calculations

We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this approach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions, this might not be necessary. If this is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states, is given in the concluding part of the review.
Multiple Uncertainties in Time-Variant Cosmological Particle Data

Though the mediums for visualization are limited, the potential dimensions of a dataset are not. In many areas of scientific study, understanding the correlations between those dimensions and their uncertainties is pivotal to mining useful information from a dataset. Obtaining this insight can necessitate visualizing the many relationships among temporal, spatial, and other dimensionalities of data and its uncertainties. We utilize multiple views for interactive dataset exploration and selection of important features, and we apply those techniques to the unique challenges of cosmological particle datasets. We show how interactivity and incorporation of multiple visualization techniques help overcome the problem of limited visualization dimensions and allow many types of uncertainty to be seen in correlation with other variables.
Imaging Transgene Expression for Gene Therapy

Imaging transgene activity is of great interest to the development and implementation of genetically based therapies. Gene transfer in human cells and in humans is performed using either viral or nonviral vectors. Vectors are the vehicles used to transduce cells that are either cultured and destined to be transfused or implanted in patients (ex vivo gene transfer) or cells residing in the body (in vivo gene transfer). To illustrate the principles involved in imaging transgene expression, focus was given to the herpes simplex virus thymidine kinase gene (HSV1-tk) and the HSV1-tk ganciclovir “drug sensitivity” cancer treatment protocol. The imaging paradigm is based on an enzymatic radiotracer assay in which the market substrate, radiolabeled 2′-fluoro-1-β-D-arabinofuranosyl-5-iodo-uracil (FIAU), is selectively phosphorylated by HSV1-thymidine kinase and “trapped” in transduced cells. Information is presented that shows that the images of FIAU-derived radioactivity obtained using quantitative autoradiograph...
Global warming policy, energy, and the Chinese economy

Abstract China is the world's largest user of coal and therefore a major generator of greenhouse gases. This paper addresses the issue of whether the country can reconfigure its energy structure without hindering its future economic development. We construct a dynamic linear programming model of the Chinese economy and use it to simulate five alternative strategies to stabilize CO2 emissions at 20% of projected year 2000 baseline levels. Our results, under more optimistic assumptions, indicate this goal can be achieved with no growth penalty. However, if major technological changes relating to energy conservation and coal displacement, as well as vastly increasing availabilities of clean fuels, are not forthcoming, China could suffer a significant decline in its rate of economic growth.
Hodge decomposition of Alexander invariants.

Multivariable Alexander invariants of algebraic links calculated in terms of algebro-geometric invariants (polytopes and ideals of quasiadjunction). The relations with log-canonical divisors, the multiplier ideals and a semicontinuity property of polytopes of quasiadjunction are discussed.
Asymptotic freedom in a string model of high temperature QCD

Abstract Recently we have shown that a phase transition occurs in the leading and sub-leading approximation of the large N limit in rigid strings coupled to long range Kalb-Ramond interactions. The disordered phase is essentially the Nambu-Goto-Polyakov string theory while the ordered phase is a new theory. In this letter we compute the free energy per unit length of the interacting rigid string at finite temperature. We show that the mass of the winding states solves that of QCD strings in the limit of high temperature. We obtain a precise identification of the QCD coupling constant and those of the interacting rigid string. The relation we obtain is Ng qcd 2 = (4π2( d−2 )/3)21/3κ where κ = Dtα πμ c is the ratio of the extrinsic curvature coupling constant t, the Kalb-Ramond coupling constant α, and the critical string tension μc. The running beta function of κ reproduces correctly the asymptotic behaviour of QCD.
Physics of the pseudogap phase of high Tc cuprates, or, RVB meets umklapp

Abstract It is argued that the dominant feature of the phase diagram of the high T c cuprates is the crossover to the pseudogap phase in the energy (temperature) region E ( T ∗ ). We argue that this scale is determined by the effective anti-ferromagnetic interaction which we calculate to be J eff = J superexchange − xt where x is the hole percentage and t the hopping integral.