cssi/SciSciGPT-SciSciNet huggingface dataset:
Coronal Sources, Elemental Fractionation, and Release Mechanisms of Heavy Ion Dropouts in the Solar Wind

The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) where are the source loops located in the large-scale corona?; (2) how does the interplay between coronal processes influence the end elemental abundances?; and (3) what are the most probable release mechanisms? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space.
Flux growth of a new cobalt‒zinc‒tin ternary phase Co7+xZn3−xSn8 and its relationship to CoSn

The intermetallic compound Co{sub 7+x}Zn{sub 3-x}Sn{sub 8} (-0.2 Co{sub 7+x}Zn{sub 3-x}Sn{sub 8} grows from reaction of cobalt in Zn/Sn eutectic flux. > Varying Co in reaction stoichiometry yields Cmcm subcell or Pnma supercell structure. > Co{sub 7+x}Zn{sub 3-x}Sn{sub 8} structural building blocksmore » similar to those in CoSn binary phase. > Co{sub 7+x}Zn{sub 3-x}Sn{sub 8} forms from reaction of CoSn in the Zn/Sn flux.« less
Probing the Balance of AGN and Star-Forming Activity in the Local Universe with ChaMP

The combination of the Sloan Digital Sky Survey (SDSS) and the Chandra Multiwavelength Project (ChaMP) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relation between X-ray nuclear emission, nebular line emission, black hole masses, and properties of the associated stellar populations. We provide X-ray spectral fits and valid uncertainties for all the galaxies with counts ranging from 2 to 1325 (mean 76, median 19). We present here novel constraints that both X-ray luminosity LX and X-ray spectral energy distribution bring to the galaxy evolutionary sequence H II → Seyfert/Transition Object → LINER → Passive suggested by optical data. In particular, we show that both LX and Γ, the slope of the power law that best fits the 0.5-8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z 0, or at low-luminosity active galactic nucleus (AGN) levels, there is an anticorrelation between Γ and L/L edd, opposite to the trend exhibited by high z AGN (quasars). The turning point in the Γ-L/L edd LLAGN + quasars relation occurs near Γ 1.5 and L/L edd 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that we have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anticorrelation we find between Γ and L/L edd may instead indicate that stronger accretion correlates with greater absorption. Therefore, the trend for softer spectra toward more luminous, high redshift, and strongly accreting (L/L edd 0.01) AGNs/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections.
Joule heating of the south polar terrain on Enceladus

[1] We report that Joule heating in Enceladus, resulting from the interaction of Enceladus with Saturn's magnetic field, may account for 150 kW to 52 MW of power through Enceladus. Electric currents passing through subsurface channels of low salinity and just a few kilometers in depth could supply a source of power to the south polar terrain, providing a small but previously unaccounted for contribution to the observed heat flux and plume activity. Studies of the electrical heating of Jupiter's moon Europa have concluded that electricity is a negligible heating source since no connection between the conductive subsurface and Alfven currents has been observed. Here we show that, contrary to results for the Jupiter system, electrical heating may be a source of internal energy for Enceladus, contributing to localized heating, production of water vapor, and the persistence of the “tiger stripes.” This contribution is of order 0.001–0.25% of the total observed heat flux, and thus, Joule heating cannot explain the total south polar terrain heat anomaly. The exclusion of salt ions during refreezing serves to enhance volumetric Joule heating and could extend the lifetime of liquid water fractures in the south polar terrain.
Encoding certainty in bump attractors

Persistent activity in neuronal populations has been shown to represent the spatial position of remembered stimuli. Networks that support bump attractors are often used to model such persistent activity. Such models usually exhibit translational symmetry. Thus activity bumps are neutrally stable, and perturbations in position do not decay away. We extend previous work on bump attractors by constructing model networks capable of encoding the certainty or salience of a stimulus stored in memory. Such networks support bumps that are not only neutrally stable to perturbations in position, but also perturbations in amplitude. Possible bump solutions then lie on a two-dimensional attractor, determined by a continuum of positions and amplitudes. Such an attractor requires precisely balancing the strength of recurrent synaptic connections. The amplitude of activity bumps represents certainty, and is determined by the initial input to the system. Moreover, bumps with larger amplitudes are more robust to noise, and over time provide a more faithful representation of the stored stimulus. In networks with separate excitatory and inhibitory populations, generating bumps with a continuum of possible amplitudes, requires tuning the strength of inhibition to precisely cancel background excitation.
Effect of Forming and Aging Atmospheres on E‐Glass Strength

E-glass fibers were drawn in various atmospheres. The specific surface area measured by water vapor adsorption was larger than the geometric area. Specific surface increases with the square root of drawing gas pressure. Exposure of glass fibers to ambient atmosphere decreases the strength and increases the area of macropores (rp> 100 A). The reciprocal strength of E-glass filaments aged at ambient humidity for various times is proportional to the square root of macro pore area. This relation is independent of the drawing atmosphere, at least for water and tetrafluoromethane.
Does prior use of acid suppressive therapy predict etiology or affect outcome in acute upper GI bleeding

Does prior use of acid suppressive therapy predict etiology or affect outcome in acute upper GI bleeding?
Facets of access: a typology of information dissemination systems

In this poster, we describe a new way of conceptualizing relationships between systems for information dissemination throughout history, based on a set of basic attributes or facets. This poster illustrates one way in which these attribute-based relationships might be visualized, as a step toward illuminating novel perspectives on and comparisons between these phenomena.
Distributed modal identification and vibration control of continua : theory and applications

Conventional transducers and actuators are "discrete" in nature, i.e., they usually measure and control spatially discrete locations. These discrete devices become useless when they are placed at modal nodes or lines. In this paper, a generic "distributed" modal identification and vibration control theory for sensing and control of continua, e.g., shells, plates, cylinders, beams, etc., is proposed. The generic theory is derived for a thin shell coupled with two electroded piezoelectric layers. One piezoelectric layer serves as a distributed sensor and the other a distributed actuator. The sensor output, or a reference signal, is processed, amplified, and fed back into the distributed actuator. Due to the converse effect, the injected high voltage induces in-plane strains which result in counteracting moments used to suppress the shell oscillation. System dynamic equations and state equations are also derived. The theory shows that the distributed sensor can identify all vibration modes and the distributed actuators also control all modes. Simplification of the generic theory to other geometries is also demonstrated.
ALTERNATIVE MODELS OF STRUCTURAL CHANGE IN AGRICULTURE AND RELATED INDUSTRIES

Various models or explanations of structural change in agriculture are presented including the technology model, the human capital model, the financial model, the institutional (structure—conduct—performance) model, and the sociological (family firm) model. Each of these models provides useful insights into the forces that are resulting in changes in the size, specialization, resource ownership and financing, and sectoral linkages in agriculture.
Modeling Weather Impact on a Secondary Electrical Grid

Abstract Weather can cause problems for underground electrical grids by increasing the probability of serious “manhole events” such as fires and explosions. In this work, we compare a model that incorporates weather features associated with the dates of serious events into a single logistic regression, with a more complex approach that has three interdependent log linear models for weather, baseline manhole vulnerability, and vulnerability of manholes to weather. The latter approach more naturally incorporates the dependencies between the weather, structure properties, and structure vulnerability.
SUBSONIC FLOWS FOR THE FULL EULER EQUATIONS IN HALF PLANE

We study the subsonic flows governed by full Euler equations in the half plane bounded below by a piecewise smooth curve asymptotically approaching the x1-axis. Nonconstant conditions in the far field are prescribed to ensure the real Euler flows. The Euler system is reduced to a single elliptic equation for the stream function. The existence, uniqueness, and asymptotic behaviors of the solutions for the reduced equation are established by the Schauder fixed point argument and some delicate estimates. The existence of subsonic flows for the original Euler system is proved based on the results for the reduced equation, and their asymptotic behaviors in the far field are also obtained.
Treatment results of carcinoma in situ of the glottis: an analysis of 82 cases.

Objectives To evaluate the results of different treatment modalities for carcinoma in situ of the glottis, and to identify important prognostic factors for outcome. Design Review of 82 cases treated definitively for glottic carcinoma in situ between 1958 and 1998. The median follow-up for all patients was 112 months, and 90% had more than 2 years of follow-up. Setting Academic tertiary care referral centers. Intervention Fifteen patients were treated with vocal cord stripping (group 1), 13 with more extensive surgery (group 2) including endoscopic laser resection (11 patients) and hemilaryngectomy (2 patients), and 54 with radiotherapy (group 3). Thirty patients had anterior commissure involvement and 9 had bilateral vocal cord involvement. Radiotherapy was delivered via opposed lateral fields at 1.5 to 2.4 Gy per fraction per day (median fraction size, 2 Gy), 5 days per week. The median total dose was 64 Gy, and the median overall time was 47 days. Main Outcome Measures Initial locoregional control (LRC), ultimate LRC, and larynx preservation. Results The 10-year initial LRC rates were 56% for group 1, 71% for group 2, and 79% for group 3. Of those who failed, the median time to relapse was 11 months for group 1, 17 months for group 2, and 41 months for group 3. Univariate analysis showed that the difference in initial LRC rates between groups 1 and 3 was statistically significant ( P = .02), although it was not statistically significant on multivariate analysis ( P = .07). Anterior commissure involvement was an important prognostic factor for LRC on both univariate ( P = .03) and multivariate ( P = .04; hazard ratio, 1.6) analysis, and its influence appeared to be mainly confined to the surgically treated patients (groups 1 and 2). The 10-year larynx preservation rates were 92% for group 1, 70% for group 2, and 85% for group 3. Anterior commissure involvement was the only important prognostic factor for larynx preservation ( P = .01) on univariate analysis. All but 2 patients in whom treatment failed underwent successful salvage surgery. Voice quality was deemed good to excellent in 73% of the patients in group 1, 40% in group 2, and 68% in group 3. Conclusions Treatment of carcinoma in situ of the glottis with vocal cord stripping or more extensive surgery or radiotherapy provided excellent ultimate LRC and comparable larynx preservation rates. Anterior commissure involvement was associated with poorer initial LRC and larynx preservation, particularly in the surgically treated patients. The choice of initial treatment should be individualized, depending on patient age, reliability, and tumor extent. Pretreatment and posttreatment objective evaluation of voice quality should be helpful in determining the best therapy for these patients.
Numerical simulation of phase change material composite wallboard in a multi-layered building envelope

Abstract Phase change materials (PCMs) have the capability to store/release massive latent heat when undergoing phase change. When impregnated or encapsulated into wallboard or concrete systems, PCMs can greatly enhance their thermal energy storage capacity and effective thermal mass. When used in the building envelope PCM wallboard has the potential to improve building operation by reducing the energy requirement for maintaining thermal comfort, downsizing the AC/heating equipment, and shifting the peak load from the electrical grid. In this work we numerically studied the potential of PCM on energy saving for residential homes. For that purpose we solved the one-dimensional, transient heat equation through the multi-layered building envelope using the Crank–Nicolson discretization scheme. A source term is incorporated to account for the thermal-physical properties of the composite PCM wallboard. Using this code we examined a PCM composite wallboard incorporated into the walls and roof of a typical residential building across various climate zones. The PCM performance was studied under all seasonal conditions using the latest typical meteorological year (TMY3) data for exterior boundary conditions. Our simulations show that PCM performance highly depends on the weather conditions, emphasizing the necessity to choose different PCMs at different climate zones. Comparisons were also made between different PCM wallboard locations. Our work shows that there exists an optimal location for PCM placement within building envelope dependent upon the resistance values between the PCM layer and the exterior boundary conditions. We further identified the energy savings potential by comparing the performance of the PCM wallboard against the performance of a building envelope without PCM. Our study shows that PCM composite wallboard can reduce the energy consumption in summer and winter and can shift the peak electricity load in the summer.
A survey of the geometry of hydrogen bonds in the crystal structures of barbiturates, purines and pyrimidines

Abstract A survey of 832 hydrogen bonds in 45 crystal structures of barbiturates and 214 crystal structures of purines and pyrimidines shows well-defined distributions of hydrogen-bond length characteristics of the donor/acceptor combinations. For the donor groups, the sequence of bond lengths is . For the acceptor groups it is . The , N(H)H---OC and bonds, of which there are forty or more of each type in this data set, have most probable lengths of 1.84, 1.87, 1.88, 1.99 A. The proportion of three-center bonds is 27%, which is comparable to that observed in the crystal structures of the carbohydrates, nucleosides and nucleotides. There is a small number, 1%, of four-center bonds.
Nonlocal sensitivity analysis, automatic derivative evaluation, and sequential nonlinear estimation

Abstract The present paper summarizes recent work by the authors on computational methods for nonlinear processes. Section 2 develops a complete set of ordinary differential equations for generating solutions to parameterized systems of nonlinear equations over parameter intervals of interest. Section 3 presents a simple finite algorithm for the systematic exact evaluation of higher-order partial derivatives. Section 4 obtains an exact sequential characterization for the solution to a general nonlinear least-squares estimation problem as the duration of the process increases and additional observations are made.
Stress-induced martensitic transformations in NiTi and NiTi–TiC composites investigated by neutron diffraction

Abstract Superelastic NiTi (51.0 at.% Ni) specimens reinforced with 0, 10 and 20 vol.% TiC particles were deformed under uniaxial compression while neutron diffraction spectra were collected. The experiments yielded in-situ measurements of the thermoelastic stress-induced transformation. The evolution of austenite/martensite phase fractions and of elastic strains in the reinforcing TiC particles and the austenite matrix were obtained by Rietveld refinement [1] during the loading cycle as the austenite transforms to martensite (and its subsequent back transformation during unloading). Phase fractions and strains are discussed in terms of load transfer in composites where the matrix undergoes a stress-induced phase transformation.
The Social Capital Paradigm: Bridging across Disciplines—An Overview

Social capital consists of the norms and networks that define groups and influence actions of people within groups. A degree of trust, an expectation of reciprocity, and exchange of information are expected to prevail in relations among members within a group if that group is to constitute social capital. As used here, a norm is an authoritative rule or standard; a network pertains to formal and informal interconnections within a group. These definitions follow Coleman and Woolcock and guide this overview.
Deregulating union democracy

I argue that union democracy regulation is misguided for a number of reasons. First, the regulations do not do a good of reducing agency costs of union leadership because internal union elections are not salient to most union members who rationally do not make the investments in time and information to participate. Second, they are misguided because the franchise is limited to full-fledged union members. Employees, therefore, must expose themselves to the risk of union discipline in order to have any say in critical economic decisions concerning the terms of their collective representation. Finally, the rules artificially limit the supply of representation service providers to non-profit membership organizations whose structure conforms to federal requirements. I propose in place of existing regulations a legal regime that is indifferent to the form that bargaining agencies take. They can be for profit or nonprofit, oligarchies or democracies. The Landrum-Griffin Act model is only one option. What federal law should require is that employees in a bargaining unit have statutory rights, irrespective of membership, to cast secret ballots on whether (i) they want collective representation, (ii) who the collective representative shall be, (iii) dues structure, i.e., costs of representation, (iv) employer's last offer in bargaining, (v) strike authorization, (vi) contract ratification, and (vii) reauthorization or deauthorization of the bargaining agency. These "critical voting opportunities" should be made available irrespective of whether the employee is a union member and should be available without any prior showing of interest by represented employees. What the bargaining agent does with union dues and other income is its business, subject to the usual rules for enforcement of contracts and prohibition of fraud. Because the proposal envisions an "easy out" approach to deauthorization, consideration might also be given to an "easy in" approach to authorization of the bargaining agency without elections and on the basis of card signatures, although this is not necessary to the proposal. The government's job is to facilitate these elections by regularizing the format for ballots and perhaps using the Internet to give potential competitors information about upcoming election dates, etc. The proposal should promote a better functioning marketplace for representational services, and give employees a greater set of options in deciding whether to pursue (or retain) collective representation.
The Mimas ghost revisited - An analysis of the electron flux and electron microsignatures observed in the vicinity of Mimas at Saturn

An analysis of the electron absorption signature observed by the Cosmic Ray System (CRS) on Voyage 2 near the orbit of Mimas is presented. We find that these observations cannot be explained as the absorption signature of Mimas. Combing Pioneer 11 and Voyager 2 measurements of the electron flux at Mimas's orbit (L=3.1), we find an electron spectrum where most of the flux above approx 100 keV is concentrated near 1 to 3 MeV. The expected Mimas absorption signature is calculated from this spectrum neglecting radial diffusion. A lower limit on the diffusion coefficient for MeV electrons is obtained. With a diffusion coefficient this large, both the Voyager 2 and the Pioneer 11 small-scale electron absorption signature observations in Mimas's orbit are enigmatic. Thus we refer to the mechanism for producing these signatures as the Mimas ghost. A cloud of material in orbit with Mimas may account for the observed electron signature if the cloud is at least 1% opaque to electrons across a region extending over a few hundred kilometers.
Increasing the Efficiency of Spectrum Allocation

Over the past 80 years, the Federal Communications Commission has been responsible for the allocation of non-governmental use of the radio frequency spectrum. Over that time, here have been significant changes in spectrum use that have been driven by changes in demand and technology. The technical, regulatory, and business obstacles in past reallocations shed light on some of the FCC’s implementation decisions for its upcoming two-sided auction.
Bounded Generation of S-Arithmetic Subgroups of Isotropic Orthogonal Groups over Number Fields

Let f be a nondegenerate quadratic form in n ¾ 5 variables over a number field K and let S be a finite set of valuations of K containing all Archimedean ones. We prove that if the Witt index of f is ¾ 2 or it is 1 and S contains a non- Archimedean valuation, then the S-arithmetic subgroups of SOn( f ) have bounded generation. These groups provide a series of examples of boundedly generated Sarithmetic groups in isotropic, but not quasi-split, algebraic groups.
Chemotherapy-induced neutropenia and fever in patients receiving cisplatin-based chemotherapy for ovarian malignancy.

Fifty-six episodes of chemotherapy-induced neutropenia and fever occurred in forty-three patients receiving cisplatin-based combination chemotherapy for ovarian cancer. All patients were treated with broad-spectrum antibiotics including gentamicin. Twelve of fifty-six episodes were associated with positive cultures; in six patients a single organism was isolated, and the other six patients had polymicrobial infection. The mean duration of antibiotic therapy was 6.5 days. One patient died of sepsis. Fifty-five episodes had a successful outcome. There was no antibiotic-related morbidity. Based on this review we recommend broad-spectrum antibiotic therapy for chemotherapy-induced neutropenia with fever. The regimen of gentamicin plus ticarcillin and clavulanic acid (ceftazidime for penicillin-allergic patients) is effective as initial therapy. Additional agents (i.e., vancomycin) may be necessary in culture-positive patients based on sensitivity testing of bacterial isolates. Gentamicin can be safely administered to patients receiving cisplatin-based chemotherapy without compromising ability to continue cisplatin therapy in subsequent treatment cycles.
Nominal interest rates, consumption booms, and lack of credibility: A quantitative examination

Abstract Exchange rate-based stabilization programs in chronic-inflation countries have often been accompanied by an initial expansion of private consumption followed by a contraction. This consumption cycle has been attributed to lack of credibility, in the sense that the public views the reduction in the devaluation rate as temporary. This paper assesses the quantitative relevance of the ‘temporariness’ hypothesis by comparing the predictions of a simple model to the actual figures for seven major programs. The paper concludes that nominal interest rates must fall substantially for the ‘temporariness’ hypothesis to account for an important fraction of the observed consumption booms.
Hydrodynamics of Supernova Evolution in the Winds of Massive Stars

Core-Collapse supernovae arise from stars greater than 8 M ⊙. These stars lose a considerable amount of mass during their lifetime, which accumulates around the star forming wind-blown bubbles. Upon the death of the star in a spectacular explosion, the resulting SN shock wave will interact with this modified medium. We study the evolution of the shock wave, and investigate the properties of this interaction. We concentrate on the evolution of the SN shock wave in the medium around a 35 solar mass star. We discuss the hydrodynamics of the resulting interaction, the formation and growth of instabilities, and deviations from sphericity.
Electro-mechanical analysis of a dielectric EAP actuator

Dielectric Electro-Active Polymers (EAP's) can achieve substantial deformation (>300% strain) while, compared to their ionic counterparts, sustaining large forces. This makes them attractive for various actuation and sensing applications such as light weight and energy efficient valve and pumping systems.. This paper provides a systematic experimental investigation of the quasi-static and dynamic electro-mechanical properties of a commercially available dielectric EAP actuator in the frequency range up to 20Hz. In order to completely characterize the fully coupled behavior force vs. displacement measurements at various constant voltages and force vs. voltage measurements at various fixed displacements are conducted. The experiments are conducted with a particular focus on the hysteretic and ratedependent material behavior.
Master-equation approach to stochastic neurodynamics.

A master-equation approach to the stochastic neurodynamics proposed by Cowan [in Advances in Neural Information Processing Systems 3, edited by R. P. Lippman, J. E. Moody, and D. S. Touretzky (Morgan Kaufmann, San Mateo, 1991), p. 62] is investigated in this paper. We deal with a model neural network that is composed of two-state neurons obeying elementary stochastic transition rates. We show that such an approach yields concise expressions for multipoint moments and an equation of motion. We apply the formalism to a (1+1)-dimensional system. Exact and approximate expressions for various statistical parameters are obtained and compared with Monte Carlo simulations.
Para - Quinol Derivatives via Oxidative Cyclization of N-Acyl-4-Hydroxyphenethylamines

Abstract Oxidation of N-acyl-4-hydroxyphenethylamines by thallium(III) trifluoroacetate in trifluoroacetic acid affords spirocyclohexadienone dihydro-1,3-oxazines or derivatives of hexahydroidol-6-one.
New Ternary Phases in Some Alkaline‐Earth Rare‐Earth Sulfide Systems

New ternary alkaline-earth rare-earth sulfide phases of composition MLn2S7 where M = Ca or Sr and Ln = La, Nd, or Gd have been formed by open-system reactions in flowing H2S. The phases have been characterized by X-ray powder diffraction and electron microprobe analysis. These compounds form as low-melting (Tm approximately 1100°C) products when refractory compounds along the MS-Ln2S3 join are oxidized at high sulfur fugacities.
STREAMING INSTABILITIES IN PROTOPLANETARY DISKS

Interpenetrating streams of solids and gas in a Keplerian disk produce a local, linear instability. The two components mutually interact via aerodynamic drag, which generates radial drift and triggers unstable modes. The secular instability does not require self-gravity, yet it generates growing particle-density perturbations that could seed planetesimal formation. Growth rates are slower than dynamical but faster than radial drift timescales. Growth rates, like streaming velocities, are maximized for marginal coupling (stopping times comparable to dynamical times). Fastest growth occurs when the solid-to-gas density ratio is order unity and feedback is strongest. Curiously, growth is strongly suppressed when the densities are too nearly equal. The relation between background drift and wave properties is explained by analogy with Howard's semicircle theorem. The three-dimensional, two-fluid equations describe a sixth-order (in the complex frequency) dispersion relation. A terminal velocity approximation allows simplification to an approximate cubic dispersion relation. To describe the simplest manifestation of this instability, we ignore complicating (but possibly relevant) factors such as vertical stratification, dispersion of particle sizes, turbulence, and self-gravity. We consider applications to planetesimal formation and compare our work to other studies of particle-gas dynamics.
On Hilbert modular threefolds of discriminant 49

Let $$K$$ be the totally real cubic field of discriminant $$49$$ , let $${\fancyscript{O}}$$ be its ring of integers, and let $$p\subset {\fancyscript{O}}$$ be the prime over $$7$$ . Let $$\Gamma (p)\subset \Gamma = SL_{2} ({\fancyscript{O}})$$ be the principal congruence subgroup of level $$p$$ . This paper investigates the geometry of the Hilbert modular threefold attached to $$\Gamma (p) $$ and some related varieties. In particular, we discover an octic in $$\mathbb{P }^3$$ with $$84$$ isolated singular points of type $$A_2$$ .
A Consequence of Necessary Conditions for Optimal Control Problems Involving Differential Equations with Delays

Necessary conditions are derived for an optimal control problem in which the states are governed by integral or integro-differential equations. The results are obtained by showing that corresponding necessary conditions hold for a sequence of optimal control problems in which the states are governed by differential equations involving delays, the solutions of which converge uniformly to the solution of the given problem.
Bisimilarity as a theory of functional programming

Abstract Morris-style contextual equivalence – invariance of termination under any context of ground type – is the usual notion of operational equivalence for deterministic functional languages such as PCF. Contextual equivalence is hard to establish directly. Instead, we define a labelled transition system for call-by-name PCF (and variants) and prove that CCS-style bisimilarity equals contextual equivalence. Using co-induction we establish equational laws. By considering variations of Milner’s ‘bisimulations up to ∼’ we obtain a second co-inductive characterisation of contextual equivalence in terms of reduction behaviour and production of values. Hence we use co-induction to establish contextual equivalence in a series of stream-processing examples. We show that Milner’s context lemma may be extended to our variants of PCF, but in fact our form of bisimilarity supports simpler co-inductive proofs. We sketch how these results extend to variants, including eager evaluation and the addition of sums, pairs and recursive types.
Cisplatin in children: hearing loss correlates with iris and skin pigmentation

Pigmentation is reported to affect cisplatin-induced ototoxicity in adult humans. The hearing loss is worse in people with brown irises, than in those with blue irises. We assessed the hypothesis that cisplatin-treated children with dark irises suffer more deterioration in auditory thresholds than do those with less pigmentation. For the 19 children whose data met the requirements of this observational retrospective study, we found a weak correlation (Spearman's r = 0.50; p < 0.05) of high frequency hearing loss (at 4000 Hz) and pigmentation. Blue or hazel-eyed children averaged 2.9 dB worsening at 4000 Hz, in contrast to 14.2 dB worsening for brown or black-eyed children. Pigmentation may account for some of the individual susceptibility to cisplatin ototoxicity. We suggest that iris colour be included in future reports of cisplatin-related hearing loss.
Field experiments in the developed world: an introduction

Field experiments represent a relatively new area in economics to understand the causal links from one variable to another. They have been used by academics to help answer interesting and policy-relevant questions in the developed world relating to educational attainment, tax avoidance, consumer finance, negative externalities, charitable giving, and labour market contracts. In this paper we bring together the key ideas behind the different variants of field experiments, how field experiments have been used to test theory, their limitations, and the new areas currently being opened up by field experiments.
Selective selenocatalytic allylic chlorination.

Ene-chlorination of olefins by N-chlorosuccinimide is catalyzed by phenylselenenyl chloride. This reaction demonstrates the catalytic conversion of C−H bonds into more reactive C−Cl bonds.
AnaDroid: Malware Analysis of Android with User-supplied Predicates

Abstract Today's mobile platforms provide only coarse-grained permissions to users with regard to how third-party applications use sensitive private data. Unfortunately, it is easy to disguise malware within the boundaries of legitimately-granted permissions. For instance, granting access to “contacts” and “internet” may be necessary for a text-messaging application to function, even though the user does not want contacts transmitted over the internet. To understand fine-grained application use of permissions, we need to statically analyze their behavior. Even then, malware detection faces three hurdles: (1) analyses may be prohibitively expensive, (2) automated analyses can only find behaviors that they are designed to find, and (3) the maliciousness of any given behavior is application-dependent and subject to human judgment. To remedy these issues, we propose semantic-based program analysis, with a human in the loop as an alternative approach to malware detection. In particular, our analysis allows analyst-crafted semantic predicates to search and filter analysis results. Human-oriented semantic-based program analysis can systematically, quickly and concisely characterize the behaviors of mobile applications. We describe a tool that provides analysts with a library of the semantic predicates and the ability to dynamically trade speed and precision. It also provides analysts the ability to statically inspect details of every suspicious state of (abstract) execution in order to make a ruling as to whether or not the behavior is truly malicious with respect to the intent of the application. In addition, permission and profiling reports are generated to aid analysts in identifying common malicious behaviors.
The X-Ray Binary GRS 1741.9–2853 in Outburst and Quiescence

We report Chandra and XMM-Newton observations of the transient neutron star low-mass X-ray binary GRS 1741.9-2853. Chandra detected the source in outburst on 2000 October 26 at an X-ray luminosity of ~1036 ergs s-1 (2-8 keV; 8 kpc), and in quiescence on 2001 July 18 at ~1032 ergs s-1. The latter observation is the first detection of GRS 1741.9-2853 in quiescence. We obtain an accurate position for the source of 17h45m233, -28°54'497 (J2000), with an uncertainty of 07. GRS 1741.9-2853 was not detected significantly in three other Chandra observations, nor in three XMM-Newton observations, indicating that the luminosity of the source in quiescence varies by at least a factor of 5 from (<0.9-5.0) × 1032 ergs s-1 (2-8 keV). A weak X-ray burst with a peak luminosity of 5 × 1036 ergs s-1 above the persistent level was observed with Chandra during the outburst on 2000 October 26. The energy of this burst, 1038 ergs, is unexpectedly low and may suggest that the accreted material is confined to the polar caps of the neutron star. A search of the literature reveals that GRS 1741.9-2853 was observed in outburst with ASCA in the fall of 1996 as well, when the BeppoSAX WFC detected the three previous X-ray bursts from this source. The lack of X-ray bursts from GRS 1741.9-2853 at other epochs suggests that it produces bursts only during transient outbursts when the accretion rate onto the surface of the neutron star is about 10-10 M☉ yr-1. A similar situation may hold for other low-luminosity bursters recently identified from WFC data.
Variations of trough positions and precipitation patterns in the mediterranean area

Recent variations of circulation and climate can be studied by investigating even rather short periods of time as far as they display different modes or anomalies which may also act on larger timescales as more persistent ones. Thus a period of 10 years (September 1966 to August 1976) which could be covered by daily sets of 500hPa airflow data in the Atlantic-European region and of precipitation data at 101 Mediterranean stations was chosen to examine the variable distribution patterns of upper troughs in the Mediterranean area and their corresponding patterns of precipitation anomalies. After the outline of trough axis distribution to eight successive longitudinal bands and of the different percentages of trough precipitation at various trough axis positions for the whole period of 10 years a subdivision into individual years was made to show some of the operative deviations both of the upper trough distribution and of the corresponding precipitation pattern in relation to the overall mean situation. Together with some circulation indices (zonal index, geopotential anomaly, measure of (he relative vorticity, specifications about the Westerlies' main branch) which have been calculated for the crucial upstream region of the North Atlantic, some basic tendencies concerning different circulation patterns and their consequences for the Mediterranean region could be outlined. Considering within-type changes and the variations of further cyclonic elements this might serve for estimating climatological effects on larger time-scales of more persistent anomalies of circulation.
Construction and testing of the mirror fusion test facility magnets

This paper describes the construction and testing of the Mirror Fusion Test Facility superconducting magnet set. Construction of the first Yin Yang magnet was started in 1978. And although this particular magnet was later modified, the final construction of these magnets was not completed until 1985. When completed these 42 magnets weighed over 1200 tonnes and had a maximum stored energy of approximately 1200 MJ at full field. Together with power supplies, controls and liquid nitrogen radiation shields the cost of the fabrication of this system was over $100M. General Dynamics/Convair Division was responsible for the system design and the fabrication of 20 of the magnets. This contract was the largest single procurement action at the Lawrence Livermore National Laboratory. During the PACE acceptance tests, the 26 major magnets were operated at full field for more than 24 hours while other MFTF subsystems were tested. From all of the data, the magnets operated to the performance specifications. For physics operation in the future, additional helium and nitrogen leak checking and repair will be necessary. In this report we will discuss the operation and testing of the MFTF Magnet System, the world's largest superconducting magnet set built to date. The topics covered include a schedule of the major events, summary of the fabrication work, summary of the installation work, summary of testing and test results, and lessons learned.
Charles Mason and Jeremiah Dixon

DURING recent years, I have published articles1 on Charles Mason and Jeremiah Dixon, attempting to present their survey of the Maryland-Pennsylvania boundary (1763–1768), as a chapter of contemporary science and technology in Great Britain. The work is being continued and extended, and the American Philosophical Society has made a grant of funds to secure copies of source material dealing with the careers of the two men.
Enantioselective Carbonyl Reverse Prenylation from the Alcohol or Aldehyde Oxidation Level Employing 1,1-Dimethylallene as the Prenyl Donor

Enantioselective transfer hydrogenation of 1,1-dimethylallene 1a in the presence of aromatic, α,β-unsaturated, or aliphatic aldehydes 2a−i mediated by 2-propanol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, m-nitrobenzoic acid, and (S)-SEGPHOS delivers reverse-prenylation products 4a−i in good to excellent isolated yields (65−96%) and enantioselectivities (87−93% ee). In the absence of 2-propanol, enantioselective carbonyl reverse prenylation is achieved directly from the alcohol oxidation level to furnish an equivalent set of adducts 4a−i in good to excellent isolated yields (68−94%) and enantioselectivities (86−91% ee). Competition and isotopic labeling experiments suggest rapid alcohol−aldehyde redox equilibration in advance of carbonyl addition along with capture of the kinetically formed π-allyl complex at a higher rate than reversible β-hydride elimination−hydrometalation. This protocol represents an alternative to the use of allylmetal reagents in enantioselective...
Dynamics of geometrically-exact sandwich beams/1-D plates: computational aspects

A Galerkin projection of the complete equations of motion of geometrically-exact sandwich beams applicable to 1-D plates is presented here. The beam can take any arbitrary initial position in the 2-D space. Each layer of the beam can have different material constants with no restriction on the mass distribution and layer thickness; further, each layer can take on different length, thus allowing the modeling of multilayer structures with ply drop-offs. Finite rotation and shear deformation are accommodated for in each layer. The deformed cross section of the beam is continuous, piecewise linear. The continuity of displacement across the interlayer boundaries is exactly enforced. Extensive numerical examples including sandwich beams with three identical layers, sandwich structures with ply drop-off, free flying and spin-up maneuver of sandwich beams are presented to illustrate the applicability and versatility of the proposed formulation.
Quantum chemistry by quantum monte carlo: Beyond ground-state energy calculations

We present recent advances with the quantum Monte Carlo (QMC) method in its application to molecular systems. The QMC method is a procedure for solving the Schroedinger equation statistically, by the simulation of an appropriate random process. The formal similarity of the Schroedinger equation with a diffusion equation allows one to calculate quantum mechanical expectation values as Monte Carlo averages over an ensemble of random walks. We have previously obtained highly accurate correlation energies for a number of molecules, as well as the singlet-triplet splitting in methylene and the barrier height for the H + H/sub 2/ exchange reaction. Recently we have begun a program of extending the QMC approach to the calculation of analytic derivatives of the energy. A brief description of the approach is presented here, together with some preliminary results. In addition, we are now computing expectation values of properties other than the energy. We summarize how standard QMC must be modified, and present some results for H/sub 2/ and N/sub 2/. Finally, we describe preliminary work toward the goal of obtaining accurate molecular excited states through QMC. 24 refs., 5 tabs.
Making It Happen: Beyond Theories of the Firm to Theories of Firm Design

Current theories of the firm provide no explanation for entrepreneurial success except in terms of firm success. Even when the focus is on the entrepreneur, s/he is entirely cast as a bundle of tra...
The Witch Woman: A Recurring Motif in Recent Fantasy Writing for Young Readers

In these books and others (see Related Reading), we find a richly varied portrayal of the wise/witch woman. Sometimes these women work alone, as inThe Earth Witch. Sometimes they work with a single apprentice, as in The Ghost Drum. At other times they live in community, as inSnow-Eyes. Sometimes their work is primarily beneficent, as inSnow-Eyes. Sometimes it is primarily evil, as inThe Earth Witch. And at other times it is a mixture, depending on what evokes the magic, as inThe Ghost Drum. Often these women possess simple herb lore; all three books feature main characters with this ability. Sometimes the abilities are more complex. They may be complex physical abilities. For example, Chingis inThe Ghost Drum can reinhabit and bring to a semblance of life a dead body. Sometimes the complex abilities are mental. Bronwen inThe Earth Witch is able to make Owen forget his friends and family, desiring only to be with her. An interesting feature of these powerful women is that their abilities are always limited in some way. InThe Ghost Drum, Chingis cannot write the spells of the drum. Bronwen inThe Earth Witch cannot prevent herself from growing old. And inSnow-Eyes, the servitors cannot call the rains unless they act together. In these fantasies and others published recently, we find an impressive array of abilities, making the witch/wise woman one of the most interesting characters in this genre.
Reconstructing High-Order Surfaces for Meshing

We consider the problem of reconstructing a high-order surface from a given surface mesh. This problem is important for many meshing operations, such as generating high-order finite elements, mesh refinement, mesh smoothing and mesh adaptation. We introduce two methods, called Weighted Averaging of Local Fittings (WALF) and Continuous Moving Frames (CMF). These methods are both based on weighted least squares polynomial fittings and guarantee C 0 continuity. Unlike existing methods for reconstructing surfaces, our methods are applicable to surface meshes composed of triangles and/or quadrilaterals, can achieve third and even higher order accuracy, and have integrated treatments for sharp features. We present the theoretical framework of our methods, experimental comparisons against other methods, and its applications in a number of meshing operations.